An Evidence Clustering DSmT Approximate Reasoning Method

14
An Evidence Clustering DSmT Approximate Reasoning Method Based on Convex Functions Analysis GUO Qiang 1 , HE You 1 , GUAN Xin 2 , DENG Li 3 , PAN Lina 4 , JIAN Tao 1 (1. Research Institute of Information Fusion , Naval Aeronautical and Astronautical University ,Yantai Shandong 264001,China; 2. Electronics and Information Department, Naval Aeronautical And Astronautical University ,Yantai Shandong 264001,China; 3. Department of Armament Science and Technology, Naval Aeronautical and Astronautical University ,Yantai Shandong 264001,China; 4. Department of Basic Science, Naval Aeronautical and Astronautical University ,Yantai Shandong 264001,China) Corresponding author: GUO Qiang, Tel numbers: +8615098689289, E-mail address: [email protected]. Abstract With the increasing number of focal elements in frame of discernment, computational complexity of DSmT(Dezert-Smarandache Theory) increases exponentially, which blocks the wide application and development of DSmT. To solve this problem, a new evidence clustering DSmT approximate reasoning method is proposed in this paper based on convex functions analysis. The computational complexity of the method in this paper increases linearly instead of exponentially with the increasing number of focal elements in discernment framework. First, the method clusters the belief masses of focal elements in each evidence. Then, the first step results are obtained by the proposed DSmT approximate convex functions formula. Finally, the method gets the approximate fusion results by normalization method. The results of simulation show that the approximate fusion results of the method in this paper has higher Euclidean similarity with the exact fusion results of DSmT+PCR5, and need less computational complexity than the existing approximate methods. Especially, in the case of large data and complex fusion problems, the method in this paper can get highly accurate results and need low computation complexity. Keywords: Evidence clustering; Approximate reasoning; Information fusion; Convex functions analysis; Dezert-Smarandache Theory 1. Introduction 1 As a novel key technologe with vigorous development, information fusion can integrat multiple-source incomplete information and reduce uncertainty of information which always has the contradiction and redundancy. Information fusion can improve rapid correct decision capacity of intelligent systems and has been successfully used in the military and economy fields, thus great attention has been paid to its development and application by scholars in recent years 1-6 . As information evironment becomes more and more complex, greater demands for efficient fusion of highly conflict evidence are being placed on information fusion. DSmT is a new effective method for the fusion problem of uncertain, imprecise and highly conflict evidence, jointly proposed by French scientist Dr. Jean Dezert and American mathematician Florentin 6 . DSmT can be considered as an extension of the classical Dempster-Shafer. *Manuscript Click here to view linked References

description

With the increasing number of focal elements in frame of discernment, computational complexity ofDSmT(Dezert-Smarandache Theory) increases exponentially, which blocks the wide application and development of DSmT. To solve this problem, a new evidence clustering DSmT approximate reasoning method is proposed in this paper based on convex functions analysis. The computational complexity of the method in this paper increases linearly instead of exponentially with the increasing number of focal elements in discernment framework. First, the method clusters the belief masses of focal elements in each evidence. Then, the first step results are obtained by the proposed DSmT approximate convex functions formula.

Transcript of An Evidence Clustering DSmT Approximate Reasoning Method

Page 1: An Evidence Clustering DSmT Approximate Reasoning Method

An Evidence Clustering DSmT Approximate Reasoning

Method Based on Convex Functions Analysis

GUO Qiang1 HE You

1 GUAN Xin

2 DENG Li

3 PAN Lina

4 JIAN Tao

1

(1 Research Institute of Information Fusion Naval Aeronautical and Astronautical University Yantai Shandong 264001China

2 Electronics and Information Department Naval Aeronautical And Astronautical University Yantai Shandong 264001China

3 Department of Armament Science and Technology Naval Aeronautical and Astronautical University Yantai Shandong

264001China

4 Department of Basic Science Naval Aeronautical and Astronautical University Yantai Shandong 264001China)

Corresponding author GUO Qiang

Tel numbers +8615098689289

E-mail address gq19860209163com

Abstract

With the increasing number of focal elements in frame of discernment computational complexity of

DSmT(Dezert-Smarandache Theory) increases exponentially which blocks the wide application and development of

DSmT To solve this problem a new evidence clustering DSmT approximate reasoning method is proposed in this

paper based on convex functions analysis The computational complexity of the method in this paper increases

linearly instead of exponentially with the increasing number of focal elements in discernment framework First the

method clusters the belief masses of focal elements in each evidence Then the first step results are obtained by the

proposed DSmT approximate convex functions formula Finally the method gets the approximate fusion results by

normalization method The results of simulation show that the approximate fusion results of the method in this paper

has higher Euclidean similarity with the exact fusion results of DSmT+PCR5 and need less computational

complexity than the existing approximate methods Especially in the case of large data and complex fusion

problems the method in this paper can get highly accurate results and need low computation complexity

Keywords Evidence clustering Approximate reasoning Information fusion Convex functions analysis

Dezert-Smarandache Theory

1 Introduction1

As a novel key technologe with vigorous development information fusion can integrat multiple-source incomplete

information and reduce uncertainty of information which always has the contradiction and redundancy Information

fusion can improve rapid correct decision capacity of intelligent systems and has been successfully used in the

military and economy fields thus great attention has been paid to its development and application by scholars in

recent years1-6

As information evironment becomes more and more complex greater demands for efficient fusion of

highly conflict evidence are being placed on information fusion DSmT is a new effective method for the fusion

problem of uncertain imprecise and highly conflict evidence jointly proposed by French scientist Dr Jean Dezert

and American mathematician Florentin6 DSmT can be considered as an extension of the classical Dempster-Shafer

ManuscriptClick here to view linked References

middot

DSmT is able to solve complex static or dynamic fusion problems beyond the limits of the DST framework specially

when conflicts between sources become large and when the refinement of the frame of the problem under

consideration denoted becomes inaccessible because of the vague relative and imprecise nature of elements of

6-8

Recently DSmT has been applied to many fields such as image processing Robotrsquos Map Reconstruction

Target Type Tracking Sonar imagery and Radar targets classification and so on69-12

The bottleneck problem to block

the wide application and development of DSmT is that with the increment of focal element number in frame of

discernment computational complexity increases exponentially

In order to solve this problem many scholars presents approximate reasoning method of evidence combination in

D-S framework13-15

But these methods almost can not satisfy the small amount of computational complexity and less

loss of information requirements at the same time Dr Li Xinde and other scholars proposed a fast approximate

reasoning method in hierarchical DSmT16-18

However when processing highly conflict evidence by the method the

belief assignments of correct main focal elements transfer to the other focal elements which leads to low Euclidean

similarity of the results in this case

Aiming at reducing the computational complexity of DSmT and obtaining accurate results in any case a new

evidence clustering DSmT approximate reasoning method is proposed in this paper In section 2 information fusion

method of DSmT+PCR5 is introduced briefly In section 3 Mathematical analysis of DSmc+PCR5 formula is

conducted which discovers every conflict mass product satisfies the properties of convex function obtains the

approximate convex function formula of DSmT+PCR5 and analyses approximate convex function formula errors

Then a new approximate reasoning DSmT method is proposed by analysis of approximate convex function formula

errors in section 4 In section 5 analysis of computation complexity of DSmT+PCR5 and the method in this paper is

carried out The results of simulation show that the results of the method proposed in this paper have higher

Euclidean similarity with the exact fusion results of DSmT+PCR5 and lower computational complexity than

existing DSmT approximate method18

in section 6

2 Information fusion method of DSmT+PCR5

Instead of applying a direct transfer of partial conflicts onto partial uncertainties as with DSmH the idea behind

the Proportional Conflict Redistribution(PCR) rule19

is to transfer (total or partial) conflicting masses to non-empty

sets involved in the conflicts proportionally with respect to the masses assigned to them by sources as follows6

1 calculation the conjunctive rule of the belief masses of sources

2 calculation the total or partial conflicting masses

3 redistribution of the (total or partial) conflicting masses to the non-empty sets involved in the conflicts

proportionally with respect to their masses assigned by the sources

The way the conflicting mass is redistributed yields actually several versions of PCR rules PCR5 is the most

mathematically exact redistribution method of conflicting mass This rule redistributes the partial conflicting mass to

the elements involved in the partial conflict considering the conjunctive normal form of the partial conflict It does a

better redistribution of the conflicting mass than Dempsterrsquos rule since PCR5 goes backwards on the tracks of the

conjunctive rule and redistributes the conflicting mass only to the sets involved in the conflict and proportionally to

their masses put in the conflict

The PCR5 formula for the combination of two sources (s = 2) is given by6

middot

PCR5[ ] 0 m X G X

2 2

1 2 2 1PCR5 12

1 2 2 1

( ) ( ) ( ) ( )[ ] ( ) [ ]

( ) ( ) ( ) ( )Y G XX Y

m X m Y m X m Ym X m X

m X m Y m X m Y

(1)

where all sets involved in formulas are in canonical form and where G corresponds to classical power set 2 if

Shaferrsquos model is used or to a constrained hyper-power set D if any other hybrid DSm model is used insteador to

the super-power set S if the minimal refinement ref of is used 12 ( ) ( )m X m X corresponds to the

conjunctive consensus on X between the 2S sources and where all denominators are different from zero If a

denominator is zero that fraction is discarded

3 Mathematical analysis of DSmc+PCR5 formula

As shown in formula (1) 2 2

1 2 2 1

1 2 2 1

( ) ( ) ( ) ( )[ ]

( ) ( ) ( ) ( )Y G XX Y

m X m Y m X m Y

m X m Y m X m Y

has symmetry

Due to the symmetry analyse one item2

1 2

1 2

( ) ( )

( ) ( )

m X m Y

m X m Y

Let 1 2( ) ( )m X a m Y b

get 2 2

21 2

1 2

( ) ( ) 1[1 ( )]

( ) ( )

m X m Y a ba a

m X m Y a b a b

then

2

21 21 2

1 2 1 2

( ) ( ) 1 1 1[ ] [ ( )]

( ) ( )n

Y G X nX Y

m X m Ya n a b b b Y

m X m Y a b a b a b

(2)

Let 1

( )f xa x

due to ( )f x is continuous function on [01] has second order derivatives on (01) and ( ) 0f x on (01)

( )f x is a convex function

So 1 2

1 2

1( ( ) ( ) ( )) ( )n

n

x x xf x f x f x f

n n

the equality holds iff 1 2 nx x x

The approximate convex function formula is given by

1 2 1 2

1 1 1

( ) n n

n

a x a x a x a x x x n

(3)

Let 1 2 i nx x x x carry out analysis of convex function formula errors

1 1 2

2 1 2 1 2

1 1[ ]

( )

1 1 1 1[ ] [ ]

( ) ( )

n

n n n

a x a x x x n

a x a x x x n a x a x x x n

(4)

analysis of the i item in equality(4)

Let 1 2 0( ) nx x x n x then 1 2 0

1 1 1 1

( ) i n ia x a x x x n a x a x

By taylor expansion theorem

2 30

0 0 0 0 0 0

0

( )1 1 ( )( )( ) ( ) ( ) ( ) ( )

2 3i i i i i

i

f x ff x x x x x x x x x x x

a x a x

or

Then equality (4) is transformed to

0 1 0 2 0 1 0

1 2 1 2

12 2 2 20

1 0 2 0 1 0 0

1

1 1 1( )[( ) ( ) ( )]

( )

( )[( ) ( ) ( ) ] ( )

2

n

n n

n

n i

i

nf x x x x x x x

a x a x a x a x x x n

f xx x x x x x o x x

middot

0 1 0 2 0 1 0( )[( ) ( ) ( )] 0nf x x x x x x x then

2 20

0 0

1 11 2 1 2

( )1 1 1( ) ( )

( ) 2

n n

i i

i in n

f xnx x o x x

a x a x a x a x x x n

2 3 3 3 4 4 40 1 2

0 1 0 2 0 0 1 0 2 0 0

1

( ) ( )( ) ( )( ) [( ) ( ) ( ) ] ( ) ( ) ( )

3 4 4 4

nn

i n n

i

f x ff fo x x x x x x x x x x x x x x

Analysis of ( ) 23 mf x m

11 1

( )

m m

mf x ma x a x

then

2 11

1 10 0

0 0 0 0

0 0

2

1

0 0

0 0

( ) ( ) 1 1 1 1( ) ( ) ( ) ( )

( 1) ( 2) ( 1)

1 1 1 1( ) 1

( 2) ( 1)

m mm m

m m m m

m

m

f x f xx x x x x x x x

m m m a x m a x

x x x xm a x m a x

If 0x x 0 0 0x x x x x a

then 1

10 0

0 0

( ) ( )( ) ( )

( 1)

m m

m mf x f xx x x x

m m

If 0 02 2m x x x a x 0

0

1 1( ) 0

( 1)x x

m a x

So if 02 12 ix a x i n 1

10 0

0 0

( ) ( )( ) ( ) 2

( 1)

m m

m m

i i

f x f xx x x x m

m m

Namely 2 30 0 0

0 0 0

( ) ( ) ( )( ) ( ) ( )

2 3

m

m

i i i

f x f x f xx x x x x x

m

Neglect the fourth order item errors and more order item errors

For the third order item is odd number item for each 12 ix i n 3

30

0

( )( )

3i

f xx x can be positive and

negative Then the sum of he third order items is much smaller than the sum of the second order itmes if

02 12 ix a x i n Neglect the third order item and more order item errors if 02 12 ix a x i n

So

2

02 1

0 0311 2 1 2 1 0

( )1 1 1

( ) 2( ) 2 2( )

n

ini

i i

in n

x xn M

x x x a xa x a x a x a x x x n a x

Then

2

02 2 2 2 21 2 1 0 11 2

0 311 2 1 2 1 0

( )( ) ( )

( ) ( ) ( )( ) 2 2( )

n

inn n i

i

in n

x xx x x x f xx x

a a a x x aa x a x a x a x x x n a x

From the above analysis the errors are related to 2

0

1

( )n

i

i

x x

and 2

3

02( )

a

a x

By the properties of 2

3

02( )

a

a x if the mean point 0x increases

2

3

02( )

a

a x decreases quickly accordingly

When the cluster set ix is not particularly divergent 2

0

1

( )n

i

i

x x

is much smaller than divergent cluster So get

the conclsion that if the distribution of the cluster set ix is concentrated and the mean point 0x is large the erros

can be smaller

middot

Based on the above analysis for reducing approximate errors and remaining lower computing complex an

evidence clustering method is proposed as follows

1) Force the mass assignments of focal elements in the evidece to two sets by the standard of 2

n

2) If 2

ixn

ix is forced to one set denoted by L

ix and the sum of mass assignments for L

ix is denoted

by LS the number of points in L

ix is denoted by Ln otherwise

ix is forced to the other set denoted by

S

ix

3) If S

i ix x pick the focal element ix with the maximal value

maxix If max

2(1 )L

i

L

Sx

n n

ix is forced to

one set L

ix

4) Go on the step 3) untill max

2(1 )L

i

L

Sx

n n

the sum of mass assignments for S

ix is denoted by SS

After the above cluster steps in the evidence the mass assignments of focal elements are forced to 2 sets denoted

by L

ix and S

ix Compaerd to L

ix the distribution of S

ix may be more concentrated And Compaerd to

S

ix the main point of L

ix is large So carry out the above evidence clustering method in front of the

approximate convex function formula can make errors of approximate results much smaller

Let 1 2 1 2( ) ( ) nm X a m Y b b b the approximate convex function formula of DSmT+PCR5 is given by

221 2

1 2 1 2

( ) ( )[ ] [ ( )]

( ) ( ) ( ) Y G X nX Y

m X m Y na n a

m X m Y a b b b n

(5)

Finally analysis of relationship between the approximate computation item and its errors item

2

21 2

1 2

1 2 1 2

2

1 22 2 1

3

1 2 1 2

1 22 21 2

1 2

( ) ( ) 1 1 1[ ] [ ( )]

( ) ( )

( ( ) )

[ ( )]( ) 2( ( ) )

( (

[ ]( )

n

Y G X nX Y

n

i n

i

n n

i

n

n

m X m Ya n a b b b Y

m X m Y a b a b a b

x b b b nn

a n a aa b b b n a b b b n

x b b bb b b

a aa b b b n

2

1

3

1 2

) )

2( ( ) )

n

n

i

n

n

a b b b n

After evidence clustering method the influnce of numerator 1 2 nb b b to the approximate computation

item and the influnce of numerator 2

1 2

1

( ( ) )n

i n

i

x b b b n

to errors item is much smaller than the influnce

of their denominators So the approximate computation item 2 1 2

1 2

[ ]( )

n

n

b b ba

a b b b n

is mainly

proportional to the error item

2

1 22 1

3

1 2

( ( ) )

2( ( ) )

n

i n

i

n

x b b b n

aa b b b n

By the properies of convex function all the error

items of focal elements lt0 Based on the above analysis normalization method of the first-step approximate

middot

results is applied in this paper for errors redisturibution to get the final approximate results

4 An evidence clustering DSmT approximate reasoning method

Based on the Mathematical analysis of DSmT+PCR5 formula in 3 An evidence clustering DSmT approximate

reasoning method is proposed as follows

Defination1 Assuming the existence of a cluster set c the definition of the total number of c is

( ) Num c number c the sum of each point in c is ( ) Sum c c and the mean point of c is

( )

cMean c

number c

1) Carry out clustering evidence method proposed in 3 Force mass assignments of focal elements in each

evidence to two cluster sets Giving an example of two evidence denoted by 12 i ix x y y i n Then

force each evidence to two cluster sets respectively denoted by L L S S L S

i ix x x x x x x

L L S S L S

i i iy y y y y y y

2) First-step approximate fusion results are calculated by the approximate convex formula as follows

2 2 2 2

2 2

CONVEX

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

( ) (

( )

L S L S

L Li i i i i i i i i i

i i i i i iL S L S

i i i i i i i i i i

L

i i i i

i i L

i i

i

x Sum y y x Sum y y Sum x x y Sum xx y y y x x

x Mean y y x Mean y y Mean x x y Mean x

x Sum y x Sum yx y

x Mean ym

2 2

2 2 2

) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

S L S

L Si i i i i i

i i i iS L S

i i i i i i i i

L S L

i i i i i i i

i i L S L

i i i i i i i

y y Sum x x y Sum xy y x x

x Mean y y y Mean x x y Mean x

x Sum y x Sum y y y Sum x yx y

x Mean y x Mean y y y Mean x

2

2 2 2 2

( )

( )

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

S

S Si i i

i i i iS

i i i

L S L S

S Li i i i i i i i i i

i i i i i iL S L S

i i i i i i i i i i

Sum x xy y x x

y Mean x x

x Sum y y x Sum y y Sum x y Sum x xx y y y x x

x Mean y y x Mean y y Mean x y Mean x x

(6)

3) Normalization method of the first-step approximate results is given by

CONVEX

GH

CONVEX

1

(1 ( ))i j

i

nA x y

iA Gi

mm m A

m

(7)

5 Analysis of computation complexity

If there are 2 evidence sources assume that all singleton focal elements and multiple focal elements have mass

assignments in hyper-power sets of 2 evidence denoted by

1 2 [1 ]n i j k l g hG i f k l g h n n denote the number of singleton

focal elements c denote the number of multiple focal elements First analyse the computation comlplexity of

the processing procedure of 2 evidence sources fusion by DSmT+PCR5 Then analyse the computation

comlplexity of the same problem by the method in this paper Computation comlplexity comparison of two

methods can be obtained by the analysis

Assume that the computation comlplexity of one time multiplication is denoted by K the computation

comlplexity of one time addition is denoted by the computation comlplexity of one time division is denoted

by and the computation comlplexity of one time subtraction is denoted by B The computation comlplexity

middot

of the processing procedure of 2 evidence sources fusion by DSmT+PCR5 is denoted by DSmT[ ]o n Then

DSmT+PCR5[ ] [ (4 2 4 )( 1)]( ) (2 2 4 )

(4 4 3)( ) (2 2 2)( ) (4 4 4)( ) (2 2 4 )

o n c K K n c n c x K y

n c n c K n c n c n c n c x K y

(8)

x denote the number of multiple focal elements in the results y denote the number of the same multiple

focal elements generated in the procedure of mass assignments combination product The computation

comlplexity of the same problem by the method in this paper is denoted by GH[ ]o n c Then

GH[ ] 2( ) ( ) 2( )[2(3 ) ] (2 2 4 )

2( ) 13( ) [4( ) 1] (5 4 ) (2 2 4 )

o n c n c B n c K n c K n x K y

n c B n c K n c n c x K y

(9)

Computation comlplexity comparison of two methods obtained from equality (8) and equality (9) shows that

the computation comlplexity comparison of DSmT is almost propotion to 2( )n c and the computation

comlplexity comparison of the method in this paper is almost propotion to ( )n c Conclusions are drawn that he

computation comlplexity comparison of the method in this paper is much lower than DSmT with increasing

number of focal element numbers in hyper-power space

6 Simulation experiments

For comparison of the approximate method proposed in this paper with the other methods an Euclidean

similarity function20

is introduced in this paper as follows

2

1 2 1 2

1

1[ ] 1 [ [ ] [ ]]

2

G

E i i

i

N m m m X m X

(10)

61 Simple cases of cluster sets in each evidence

Example 1 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b the processing of the method is given

as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

1 2 3 5 6 7 4 1 2 3 4 5 7 6 a a a a a a a a b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

middot

2 2 22

1 2 3 5 6 7 1 2 3 4 5 7 1 61 4CONVEX1 1 1

1 2 3 5 6 7 1 4 1 2 3 4 5 7 1 6

2

2 1 3 5 6 7

CONVEX2 2 2 2

2 1 3 5

( ) ( )

( ) ( )

( )

(

b Sum a a a a a a Sum b b b b b a bb am a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a am a b

b Mean a a a a

2 22

2 1 3 4 5 7 2 62 4

2 2 2

6 7 2 4 2 1 3 4 5 7 2 6

2 2 2

3 1 2 5 6 7 3 4 3 1 2 4 5 7

CONVEX3 3 3 2 2 2

3 1 2 5 6 7 3 4 3

( )

) ( )

( ) ( )

( ) (

a Sum b b b b b a bb a

a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum b b b b bm a b

b Mean a a a a a b a a Mean b

2

3 6

2

1 2 4 5 7 3 6

2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

CONVEX4 4 4 2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

2

5 1 2 3 6

CONVEX5 5 5

)

( ) ( )

( ) ( )

(

a b

b b b b a b

b Sum a a a a a a a Sum b b b b b a bm a b

b Mean a a a a a a a Mean b b b b b a b

b Sum a a a am a b

2 2 2

7 5 4 5 1 2 3 4 7 5 6

2 2 2 2

5 1 2 3 6 7 5 4 5 1 2 3 4 7 5 6

2 2 2

6 1 2 3 5 7 6 4 6 1

CONVEX6 6 6 2 2

6 1 2 3 5 7 6 4

) ( )

( ) ( )

( ) (

( )

a b a a Sum b b b b b a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum bm a b

b Mean a a a a a b a

2 3 4 5 7

2

6 1 2 3 4 5 7

2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

CONVEX7 7 7 2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

)

( )

( ) ( )

( ) ( )

b b b b b

a Mean b b b b b b

b Sum a a a a a b a a Sum b b b b b a bm a b

b Mean a a a a a b a a Mean b b b b b a b

Get CONVEX 01588005580027303108019260310800273m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 01465005150025202869017780286900252m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 01435004880023702922017510292900237m

The results of the method18

XDL 01536006050025302980016700273800217m

Calculate the Euclidean similarity between results GHm obtained by the method in this paper and the results

DSmT+PCR5m of DSmT+PCR5 The Euclidean similarity GH 09932E

In the same way the Euclidean similarity between the results XDLm of the method18

and the results DSmT+PCR5m

of DSmT+PCR5 is denoted by XDL 09812E

From the above results of this example the results obtained by the method proposed in this paper have higher

Euclidean similarity with DSmT+PCR5 than the existing approximate DSmT method18

The Euclidean Similarity

which remains over 99 shows that the method proposed in this paper has high accuracy and has practical

meaning

Example 2 If there are the same 2 evidence sources in example 1 the hyper-power sets are denoted by

1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b The mass assignments in the second

evidence source are unchanged denoted by 020050050201503005b and the mass assignments in

the first evidence change whose sequnce of the mass belief of each focal element moves one position backward at

one time to procedure 6 new evidence such as

middot

1 2 3

4 5 6

0101005030202005 0050101005030202 0200501010050302

0202005010100503 0302020050101005 005030202005

a a a

a a a

0101

Each new evidence and the evidence b are calculated to obtain the fusion results by DSmT+PCR5 and the

approximate fusion results by the method in this paper and the method18

Then Euclidean similarity of the

approximate results of different methods with the results of DSmT+PCR5 is obtained by formula(10) and the average

computing time of each method is also taken record as tabel 1 (In this paper all the simulation experiments are

implemented by Matlab simulation in the hardware condition of Pentimu(R) Dual-Core CPU E5300 26GHz

259GHz memory 199GB)

Table 1 Euclidean similarity and average computing time coparison of the methods

Euclidean similarity with results of DSmT+PCR5

average

computing

time 1 2 3 4 5 6

The method in

this paper 09939 09911 09955 09938 09965 09960 00028s

The method18

09583 09791 09588 09530 09443 09347 00105s

As shown in table 1 under simple cases of cluster sets in each evidence the accuracy of the method in this

paper all remains over 99 and much higher than the method18

Average computing time of the method in this

paper is also lower than the existing approximate method18

At the same time the accuracy of the method in this

paper in different evidence cases changes little which proves that the method has higher performance stability

62 Complex cases of cluster sets in each evidence

Example 3 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

03035005005004006002001002001004005

02005004021015025005001001001001001

a

b

the method processing is given as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

3 4 5 6 7 8 9 10 11 12 1 2 2 3 7 8 9 10 11 12 1 4 5 6 a a a a a a a a a a a a a b b b b b b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

CONVEX 030690255900247013090083401662001770001900041000190011000153m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 030090250900242012830081801630001740001900041000190010800150m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 030190252400235012820081101635001690001800039000180010400146m

The results of the method18

XDL 037100183400276012690082801651000030000000001000010000200002m

Calculate the Euclidean similarity between the results GHm and DSmT+PCR5m The Euclidean Similarity

GH 09984E and computing time is 00035s

In the same way the Euclidean similarity between the results XDLm and DSmT+PCR5m is denoted by

middot

XDL 09287E and computing time is 00185s

As shown in the above experiment results in this example the results obtained by the method proposed in this

paper have higher Euclidean Similarity and lower computation complexity than the existing DSmT approximate

method18

The Euclidean Similarity which remains over 99 shows that the method proposed in this paper has

higher accuracy and has practical meaning

Example 4 If there are the same 2 evidence sources in example 3 the hyper-power sets are denoted by

1 2 12 1or 2kG k The mass assignments in the second evidence source are unchanged denoted

by 02005004021015025005001001001001001b and the mass assignments in the first source

change whose sequnce of the mass belief of each focal element moves one position backward at one time to

procedure 11 new evidence

Each new evidence and the second evidence b are calculated to get the fusion results of DSmT+PCR5 and the

approximate results by the method in this paper and the method18

Then Euclidean similarity of the approximate

results of different methods with the results of DSmT+PCR5 and the average computing time of each method are

taken record as tabel 2

Table 2 Euclidean similarity and average computing time coparison of the methods

As shown in table 2 under complex cases of cluster sets in each evidence the accuracy of the method in this

paper also remains over 99 and much higher than the method18

Average computing time of the method in this

paper is lower than the method18

At the same time the accuracy of the method in this paper in different evidence

cases changes little which proves that the method has higher performance stability

63 cases of highly conflict evidence sources

Example 5 In order to verify information fusion of highly conflict evidence sources can be effective solved by the

method in this paper Assume there are two highly conflict evidence sources with the hyper-power set denoted by

D a b c d The mass assignements of two evidenece sources are shown in tabel 3

Table 3 The mass assignements of highly conflict evidenece sources

Conflict evidenece sources a b c d

1S x 1 x

2S y 1 y

Let 001 [002098]x y The fusion results are obtained by different methods when x y is increasing

from 002 to 098 by 001 step at the same time Euclidean similarity of the method18

with DSmT+PCR5 is shown

in figure1 Euclidean similarity of the method in this paper with DSmT+PCR5 is shown in figure2

Euclidean similarity with results of DSmT+PCR5

Average

computing

time 1 2 3 4 5 6 7 8 9 10 11

The method in

this paper

09987 09983 09982 09979 09981 09985 09985 09983 09984 09983 09983 00038

The

method18

08795 09330 09514 09484 08112 08636 08253 08342 08331 08189 08483 00186

middot

Fig 1 Euclidean similarity of the method18

with DSmT+PCR5 Fig 2 Euclidean similarity of the method in this paper with DSmT+PCR5

The average Euclidean Similarity of the method in this paper is 09873 and the average Euclidean Similarity of

the method18

is 08513 Itrsquos shown that the method in this paper can effiectively solve information fusion problem

of highly conflict evidence sources

64 convergence analysis

Example 6 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

01001002025015005010101005005002

05035002002001001001001001001001004

a

b

First fusion results of two evidence a and b

are obtained by different fusion methods Then fuse the prior fusion results with b repeatedly Through the

experiment results each time analyze different methodrsquos convergence

Table 3 The mass assignements of highly conflict evidenece sources

As shown in tabel 3 the convergence of three methods is similar The results of each method can converge to the

main focal elements afer 3 times of evidence fusion However the results of the method in this paper have higher

Euclidean similarity with DSmT+PCR5 and lose less information than the method18

each time

65 monte carlo simulations in the case of non-empty multiple focal elements

If there are 2 evidence sources assume that singleton focal elements and multiple focal elements have mass

Fusion results

1 DSmT+PCR5 042870260000058011630053900109002970029700297001090010900136

The method18

040670099400212018880079800385000270002700027000100001000019

The method in this paper 042850261000060011510053500110002960029600296001100011000141

2 DSmT+PCR5 058290332400031003880012000017000530005300053000170001700099

The method18

056870168600036006420020200127000000000000000000000000000000

The method in this paper 057050345900031003710011600018000520005200052000180001800109

3 DSmT+PCR5 064390334200018000840001600006000080000800008000060000600060

The method18

061710196800009001090002700021000000000000000000000000000000

The method in this paper 061180365500021000780001500006000080000800008000060000600069

4 DSmT+PCR5 067260318100012000170000400004000040000400004000040000400040

The method18

061520204700008000180000400003000000000000000000000000000000

The method in this paper 062640362600015000170000400004000040000400004000040000400048

middot

assignments in hyper-power sets denoted by 1 2 20 1 5 10 20 P Carry out 1000 times monte

carlo simulation experiments First assign random mass value to every focal elements of hyper-power sets in each

evidence each time Then the fusion results of 2 evidence are obtained by DSmT+PCR5 and the method in this

paper seperately Thirdly calculate the Euclidean similarity of the method in this paper with DSmT+PCR5 and

computing time in each monte carlo experiment The monto carlo simulation results are shown in figure 3 figure 4

and table 4

Fig 3 Computing time comparison of the method in this paper with DSmT+PCR5 Fig 4 Euclidean similarity of the method in this paper with

DSmT+PCR5

Table 4 fusion results comparison in the case of increasing focal elements number

Average Euclidean

Similarity

Max Euclidean

Similarity

Min Euclidean

Similarity

Average computing

time(ms)

Max computing

time(ms)

Min computing

time(ms)

DSmT+PCR5 19 31 19

The method in

this paper 09849 09956 09693 084911 14 083593

As shown in figure3 figure4 and tabel 4 in the case of non-empty multiple focal elements the average Euclidean

similarity of the method in this paper can reach 9849 and Euclidean similarity changes little with different

evidence Computing time of the method in this paper almost reduce halfly than DSmT+PCR5

66 monte carlo simulations in the case of increasing focal elements number

Example 7 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 10 1or 2kG k Increase 10 focal elements each time until 500 to

the hyper-power sets and assign random mass value to every focal elements of hyper-power sets in each evidence

each time Carry out 1000 times monto carlo simulation in each hyper-power set calculate the average Euclidean

similarity of the method in this paper with DSmT+PCR5 as shown in figure 5 Compare the average computing

time of the method in this paper with DSmT+PCR5 in each hyper-power sets is shown in figure 6

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 2: An Evidence Clustering DSmT Approximate Reasoning Method

middot

DSmT is able to solve complex static or dynamic fusion problems beyond the limits of the DST framework specially

when conflicts between sources become large and when the refinement of the frame of the problem under

consideration denoted becomes inaccessible because of the vague relative and imprecise nature of elements of

6-8

Recently DSmT has been applied to many fields such as image processing Robotrsquos Map Reconstruction

Target Type Tracking Sonar imagery and Radar targets classification and so on69-12

The bottleneck problem to block

the wide application and development of DSmT is that with the increment of focal element number in frame of

discernment computational complexity increases exponentially

In order to solve this problem many scholars presents approximate reasoning method of evidence combination in

D-S framework13-15

But these methods almost can not satisfy the small amount of computational complexity and less

loss of information requirements at the same time Dr Li Xinde and other scholars proposed a fast approximate

reasoning method in hierarchical DSmT16-18

However when processing highly conflict evidence by the method the

belief assignments of correct main focal elements transfer to the other focal elements which leads to low Euclidean

similarity of the results in this case

Aiming at reducing the computational complexity of DSmT and obtaining accurate results in any case a new

evidence clustering DSmT approximate reasoning method is proposed in this paper In section 2 information fusion

method of DSmT+PCR5 is introduced briefly In section 3 Mathematical analysis of DSmc+PCR5 formula is

conducted which discovers every conflict mass product satisfies the properties of convex function obtains the

approximate convex function formula of DSmT+PCR5 and analyses approximate convex function formula errors

Then a new approximate reasoning DSmT method is proposed by analysis of approximate convex function formula

errors in section 4 In section 5 analysis of computation complexity of DSmT+PCR5 and the method in this paper is

carried out The results of simulation show that the results of the method proposed in this paper have higher

Euclidean similarity with the exact fusion results of DSmT+PCR5 and lower computational complexity than

existing DSmT approximate method18

in section 6

2 Information fusion method of DSmT+PCR5

Instead of applying a direct transfer of partial conflicts onto partial uncertainties as with DSmH the idea behind

the Proportional Conflict Redistribution(PCR) rule19

is to transfer (total or partial) conflicting masses to non-empty

sets involved in the conflicts proportionally with respect to the masses assigned to them by sources as follows6

1 calculation the conjunctive rule of the belief masses of sources

2 calculation the total or partial conflicting masses

3 redistribution of the (total or partial) conflicting masses to the non-empty sets involved in the conflicts

proportionally with respect to their masses assigned by the sources

The way the conflicting mass is redistributed yields actually several versions of PCR rules PCR5 is the most

mathematically exact redistribution method of conflicting mass This rule redistributes the partial conflicting mass to

the elements involved in the partial conflict considering the conjunctive normal form of the partial conflict It does a

better redistribution of the conflicting mass than Dempsterrsquos rule since PCR5 goes backwards on the tracks of the

conjunctive rule and redistributes the conflicting mass only to the sets involved in the conflict and proportionally to

their masses put in the conflict

The PCR5 formula for the combination of two sources (s = 2) is given by6

middot

PCR5[ ] 0 m X G X

2 2

1 2 2 1PCR5 12

1 2 2 1

( ) ( ) ( ) ( )[ ] ( ) [ ]

( ) ( ) ( ) ( )Y G XX Y

m X m Y m X m Ym X m X

m X m Y m X m Y

(1)

where all sets involved in formulas are in canonical form and where G corresponds to classical power set 2 if

Shaferrsquos model is used or to a constrained hyper-power set D if any other hybrid DSm model is used insteador to

the super-power set S if the minimal refinement ref of is used 12 ( ) ( )m X m X corresponds to the

conjunctive consensus on X between the 2S sources and where all denominators are different from zero If a

denominator is zero that fraction is discarded

3 Mathematical analysis of DSmc+PCR5 formula

As shown in formula (1) 2 2

1 2 2 1

1 2 2 1

( ) ( ) ( ) ( )[ ]

( ) ( ) ( ) ( )Y G XX Y

m X m Y m X m Y

m X m Y m X m Y

has symmetry

Due to the symmetry analyse one item2

1 2

1 2

( ) ( )

( ) ( )

m X m Y

m X m Y

Let 1 2( ) ( )m X a m Y b

get 2 2

21 2

1 2

( ) ( ) 1[1 ( )]

( ) ( )

m X m Y a ba a

m X m Y a b a b

then

2

21 21 2

1 2 1 2

( ) ( ) 1 1 1[ ] [ ( )]

( ) ( )n

Y G X nX Y

m X m Ya n a b b b Y

m X m Y a b a b a b

(2)

Let 1

( )f xa x

due to ( )f x is continuous function on [01] has second order derivatives on (01) and ( ) 0f x on (01)

( )f x is a convex function

So 1 2

1 2

1( ( ) ( ) ( )) ( )n

n

x x xf x f x f x f

n n

the equality holds iff 1 2 nx x x

The approximate convex function formula is given by

1 2 1 2

1 1 1

( ) n n

n

a x a x a x a x x x n

(3)

Let 1 2 i nx x x x carry out analysis of convex function formula errors

1 1 2

2 1 2 1 2

1 1[ ]

( )

1 1 1 1[ ] [ ]

( ) ( )

n

n n n

a x a x x x n

a x a x x x n a x a x x x n

(4)

analysis of the i item in equality(4)

Let 1 2 0( ) nx x x n x then 1 2 0

1 1 1 1

( ) i n ia x a x x x n a x a x

By taylor expansion theorem

2 30

0 0 0 0 0 0

0

( )1 1 ( )( )( ) ( ) ( ) ( ) ( )

2 3i i i i i

i

f x ff x x x x x x x x x x x

a x a x

or

Then equality (4) is transformed to

0 1 0 2 0 1 0

1 2 1 2

12 2 2 20

1 0 2 0 1 0 0

1

1 1 1( )[( ) ( ) ( )]

( )

( )[( ) ( ) ( ) ] ( )

2

n

n n

n

n i

i

nf x x x x x x x

a x a x a x a x x x n

f xx x x x x x o x x

middot

0 1 0 2 0 1 0( )[( ) ( ) ( )] 0nf x x x x x x x then

2 20

0 0

1 11 2 1 2

( )1 1 1( ) ( )

( ) 2

n n

i i

i in n

f xnx x o x x

a x a x a x a x x x n

2 3 3 3 4 4 40 1 2

0 1 0 2 0 0 1 0 2 0 0

1

( ) ( )( ) ( )( ) [( ) ( ) ( ) ] ( ) ( ) ( )

3 4 4 4

nn

i n n

i

f x ff fo x x x x x x x x x x x x x x

Analysis of ( ) 23 mf x m

11 1

( )

m m

mf x ma x a x

then

2 11

1 10 0

0 0 0 0

0 0

2

1

0 0

0 0

( ) ( ) 1 1 1 1( ) ( ) ( ) ( )

( 1) ( 2) ( 1)

1 1 1 1( ) 1

( 2) ( 1)

m mm m

m m m m

m

m

f x f xx x x x x x x x

m m m a x m a x

x x x xm a x m a x

If 0x x 0 0 0x x x x x a

then 1

10 0

0 0

( ) ( )( ) ( )

( 1)

m m

m mf x f xx x x x

m m

If 0 02 2m x x x a x 0

0

1 1( ) 0

( 1)x x

m a x

So if 02 12 ix a x i n 1

10 0

0 0

( ) ( )( ) ( ) 2

( 1)

m m

m m

i i

f x f xx x x x m

m m

Namely 2 30 0 0

0 0 0

( ) ( ) ( )( ) ( ) ( )

2 3

m

m

i i i

f x f x f xx x x x x x

m

Neglect the fourth order item errors and more order item errors

For the third order item is odd number item for each 12 ix i n 3

30

0

( )( )

3i

f xx x can be positive and

negative Then the sum of he third order items is much smaller than the sum of the second order itmes if

02 12 ix a x i n Neglect the third order item and more order item errors if 02 12 ix a x i n

So

2

02 1

0 0311 2 1 2 1 0

( )1 1 1

( ) 2( ) 2 2( )

n

ini

i i

in n

x xn M

x x x a xa x a x a x a x x x n a x

Then

2

02 2 2 2 21 2 1 0 11 2

0 311 2 1 2 1 0

( )( ) ( )

( ) ( ) ( )( ) 2 2( )

n

inn n i

i

in n

x xx x x x f xx x

a a a x x aa x a x a x a x x x n a x

From the above analysis the errors are related to 2

0

1

( )n

i

i

x x

and 2

3

02( )

a

a x

By the properties of 2

3

02( )

a

a x if the mean point 0x increases

2

3

02( )

a

a x decreases quickly accordingly

When the cluster set ix is not particularly divergent 2

0

1

( )n

i

i

x x

is much smaller than divergent cluster So get

the conclsion that if the distribution of the cluster set ix is concentrated and the mean point 0x is large the erros

can be smaller

middot

Based on the above analysis for reducing approximate errors and remaining lower computing complex an

evidence clustering method is proposed as follows

1) Force the mass assignments of focal elements in the evidece to two sets by the standard of 2

n

2) If 2

ixn

ix is forced to one set denoted by L

ix and the sum of mass assignments for L

ix is denoted

by LS the number of points in L

ix is denoted by Ln otherwise

ix is forced to the other set denoted by

S

ix

3) If S

i ix x pick the focal element ix with the maximal value

maxix If max

2(1 )L

i

L

Sx

n n

ix is forced to

one set L

ix

4) Go on the step 3) untill max

2(1 )L

i

L

Sx

n n

the sum of mass assignments for S

ix is denoted by SS

After the above cluster steps in the evidence the mass assignments of focal elements are forced to 2 sets denoted

by L

ix and S

ix Compaerd to L

ix the distribution of S

ix may be more concentrated And Compaerd to

S

ix the main point of L

ix is large So carry out the above evidence clustering method in front of the

approximate convex function formula can make errors of approximate results much smaller

Let 1 2 1 2( ) ( ) nm X a m Y b b b the approximate convex function formula of DSmT+PCR5 is given by

221 2

1 2 1 2

( ) ( )[ ] [ ( )]

( ) ( ) ( ) Y G X nX Y

m X m Y na n a

m X m Y a b b b n

(5)

Finally analysis of relationship between the approximate computation item and its errors item

2

21 2

1 2

1 2 1 2

2

1 22 2 1

3

1 2 1 2

1 22 21 2

1 2

( ) ( ) 1 1 1[ ] [ ( )]

( ) ( )

( ( ) )

[ ( )]( ) 2( ( ) )

( (

[ ]( )

n

Y G X nX Y

n

i n

i

n n

i

n

n

m X m Ya n a b b b Y

m X m Y a b a b a b

x b b b nn

a n a aa b b b n a b b b n

x b b bb b b

a aa b b b n

2

1

3

1 2

) )

2( ( ) )

n

n

i

n

n

a b b b n

After evidence clustering method the influnce of numerator 1 2 nb b b to the approximate computation

item and the influnce of numerator 2

1 2

1

( ( ) )n

i n

i

x b b b n

to errors item is much smaller than the influnce

of their denominators So the approximate computation item 2 1 2

1 2

[ ]( )

n

n

b b ba

a b b b n

is mainly

proportional to the error item

2

1 22 1

3

1 2

( ( ) )

2( ( ) )

n

i n

i

n

x b b b n

aa b b b n

By the properies of convex function all the error

items of focal elements lt0 Based on the above analysis normalization method of the first-step approximate

middot

results is applied in this paper for errors redisturibution to get the final approximate results

4 An evidence clustering DSmT approximate reasoning method

Based on the Mathematical analysis of DSmT+PCR5 formula in 3 An evidence clustering DSmT approximate

reasoning method is proposed as follows

Defination1 Assuming the existence of a cluster set c the definition of the total number of c is

( ) Num c number c the sum of each point in c is ( ) Sum c c and the mean point of c is

( )

cMean c

number c

1) Carry out clustering evidence method proposed in 3 Force mass assignments of focal elements in each

evidence to two cluster sets Giving an example of two evidence denoted by 12 i ix x y y i n Then

force each evidence to two cluster sets respectively denoted by L L S S L S

i ix x x x x x x

L L S S L S

i i iy y y y y y y

2) First-step approximate fusion results are calculated by the approximate convex formula as follows

2 2 2 2

2 2

CONVEX

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

( ) (

( )

L S L S

L Li i i i i i i i i i

i i i i i iL S L S

i i i i i i i i i i

L

i i i i

i i L

i i

i

x Sum y y x Sum y y Sum x x y Sum xx y y y x x

x Mean y y x Mean y y Mean x x y Mean x

x Sum y x Sum yx y

x Mean ym

2 2

2 2 2

) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

S L S

L Si i i i i i

i i i iS L S

i i i i i i i i

L S L

i i i i i i i

i i L S L

i i i i i i i

y y Sum x x y Sum xy y x x

x Mean y y y Mean x x y Mean x

x Sum y x Sum y y y Sum x yx y

x Mean y x Mean y y y Mean x

2

2 2 2 2

( )

( )

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

S

S Si i i

i i i iS

i i i

L S L S

S Li i i i i i i i i i

i i i i i iL S L S

i i i i i i i i i i

Sum x xy y x x

y Mean x x

x Sum y y x Sum y y Sum x y Sum x xx y y y x x

x Mean y y x Mean y y Mean x y Mean x x

(6)

3) Normalization method of the first-step approximate results is given by

CONVEX

GH

CONVEX

1

(1 ( ))i j

i

nA x y

iA Gi

mm m A

m

(7)

5 Analysis of computation complexity

If there are 2 evidence sources assume that all singleton focal elements and multiple focal elements have mass

assignments in hyper-power sets of 2 evidence denoted by

1 2 [1 ]n i j k l g hG i f k l g h n n denote the number of singleton

focal elements c denote the number of multiple focal elements First analyse the computation comlplexity of

the processing procedure of 2 evidence sources fusion by DSmT+PCR5 Then analyse the computation

comlplexity of the same problem by the method in this paper Computation comlplexity comparison of two

methods can be obtained by the analysis

Assume that the computation comlplexity of one time multiplication is denoted by K the computation

comlplexity of one time addition is denoted by the computation comlplexity of one time division is denoted

by and the computation comlplexity of one time subtraction is denoted by B The computation comlplexity

middot

of the processing procedure of 2 evidence sources fusion by DSmT+PCR5 is denoted by DSmT[ ]o n Then

DSmT+PCR5[ ] [ (4 2 4 )( 1)]( ) (2 2 4 )

(4 4 3)( ) (2 2 2)( ) (4 4 4)( ) (2 2 4 )

o n c K K n c n c x K y

n c n c K n c n c n c n c x K y

(8)

x denote the number of multiple focal elements in the results y denote the number of the same multiple

focal elements generated in the procedure of mass assignments combination product The computation

comlplexity of the same problem by the method in this paper is denoted by GH[ ]o n c Then

GH[ ] 2( ) ( ) 2( )[2(3 ) ] (2 2 4 )

2( ) 13( ) [4( ) 1] (5 4 ) (2 2 4 )

o n c n c B n c K n c K n x K y

n c B n c K n c n c x K y

(9)

Computation comlplexity comparison of two methods obtained from equality (8) and equality (9) shows that

the computation comlplexity comparison of DSmT is almost propotion to 2( )n c and the computation

comlplexity comparison of the method in this paper is almost propotion to ( )n c Conclusions are drawn that he

computation comlplexity comparison of the method in this paper is much lower than DSmT with increasing

number of focal element numbers in hyper-power space

6 Simulation experiments

For comparison of the approximate method proposed in this paper with the other methods an Euclidean

similarity function20

is introduced in this paper as follows

2

1 2 1 2

1

1[ ] 1 [ [ ] [ ]]

2

G

E i i

i

N m m m X m X

(10)

61 Simple cases of cluster sets in each evidence

Example 1 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b the processing of the method is given

as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

1 2 3 5 6 7 4 1 2 3 4 5 7 6 a a a a a a a a b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

middot

2 2 22

1 2 3 5 6 7 1 2 3 4 5 7 1 61 4CONVEX1 1 1

1 2 3 5 6 7 1 4 1 2 3 4 5 7 1 6

2

2 1 3 5 6 7

CONVEX2 2 2 2

2 1 3 5

( ) ( )

( ) ( )

( )

(

b Sum a a a a a a Sum b b b b b a bb am a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a am a b

b Mean a a a a

2 22

2 1 3 4 5 7 2 62 4

2 2 2

6 7 2 4 2 1 3 4 5 7 2 6

2 2 2

3 1 2 5 6 7 3 4 3 1 2 4 5 7

CONVEX3 3 3 2 2 2

3 1 2 5 6 7 3 4 3

( )

) ( )

( ) ( )

( ) (

a Sum b b b b b a bb a

a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum b b b b bm a b

b Mean a a a a a b a a Mean b

2

3 6

2

1 2 4 5 7 3 6

2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

CONVEX4 4 4 2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

2

5 1 2 3 6

CONVEX5 5 5

)

( ) ( )

( ) ( )

(

a b

b b b b a b

b Sum a a a a a a a Sum b b b b b a bm a b

b Mean a a a a a a a Mean b b b b b a b

b Sum a a a am a b

2 2 2

7 5 4 5 1 2 3 4 7 5 6

2 2 2 2

5 1 2 3 6 7 5 4 5 1 2 3 4 7 5 6

2 2 2

6 1 2 3 5 7 6 4 6 1

CONVEX6 6 6 2 2

6 1 2 3 5 7 6 4

) ( )

( ) ( )

( ) (

( )

a b a a Sum b b b b b a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum bm a b

b Mean a a a a a b a

2 3 4 5 7

2

6 1 2 3 4 5 7

2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

CONVEX7 7 7 2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

)

( )

( ) ( )

( ) ( )

b b b b b

a Mean b b b b b b

b Sum a a a a a b a a Sum b b b b b a bm a b

b Mean a a a a a b a a Mean b b b b b a b

Get CONVEX 01588005580027303108019260310800273m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 01465005150025202869017780286900252m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 01435004880023702922017510292900237m

The results of the method18

XDL 01536006050025302980016700273800217m

Calculate the Euclidean similarity between results GHm obtained by the method in this paper and the results

DSmT+PCR5m of DSmT+PCR5 The Euclidean similarity GH 09932E

In the same way the Euclidean similarity between the results XDLm of the method18

and the results DSmT+PCR5m

of DSmT+PCR5 is denoted by XDL 09812E

From the above results of this example the results obtained by the method proposed in this paper have higher

Euclidean similarity with DSmT+PCR5 than the existing approximate DSmT method18

The Euclidean Similarity

which remains over 99 shows that the method proposed in this paper has high accuracy and has practical

meaning

Example 2 If there are the same 2 evidence sources in example 1 the hyper-power sets are denoted by

1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b The mass assignments in the second

evidence source are unchanged denoted by 020050050201503005b and the mass assignments in

the first evidence change whose sequnce of the mass belief of each focal element moves one position backward at

one time to procedure 6 new evidence such as

middot

1 2 3

4 5 6

0101005030202005 0050101005030202 0200501010050302

0202005010100503 0302020050101005 005030202005

a a a

a a a

0101

Each new evidence and the evidence b are calculated to obtain the fusion results by DSmT+PCR5 and the

approximate fusion results by the method in this paper and the method18

Then Euclidean similarity of the

approximate results of different methods with the results of DSmT+PCR5 is obtained by formula(10) and the average

computing time of each method is also taken record as tabel 1 (In this paper all the simulation experiments are

implemented by Matlab simulation in the hardware condition of Pentimu(R) Dual-Core CPU E5300 26GHz

259GHz memory 199GB)

Table 1 Euclidean similarity and average computing time coparison of the methods

Euclidean similarity with results of DSmT+PCR5

average

computing

time 1 2 3 4 5 6

The method in

this paper 09939 09911 09955 09938 09965 09960 00028s

The method18

09583 09791 09588 09530 09443 09347 00105s

As shown in table 1 under simple cases of cluster sets in each evidence the accuracy of the method in this

paper all remains over 99 and much higher than the method18

Average computing time of the method in this

paper is also lower than the existing approximate method18

At the same time the accuracy of the method in this

paper in different evidence cases changes little which proves that the method has higher performance stability

62 Complex cases of cluster sets in each evidence

Example 3 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

03035005005004006002001002001004005

02005004021015025005001001001001001

a

b

the method processing is given as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

3 4 5 6 7 8 9 10 11 12 1 2 2 3 7 8 9 10 11 12 1 4 5 6 a a a a a a a a a a a a a b b b b b b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

CONVEX 030690255900247013090083401662001770001900041000190011000153m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 030090250900242012830081801630001740001900041000190010800150m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 030190252400235012820081101635001690001800039000180010400146m

The results of the method18

XDL 037100183400276012690082801651000030000000001000010000200002m

Calculate the Euclidean similarity between the results GHm and DSmT+PCR5m The Euclidean Similarity

GH 09984E and computing time is 00035s

In the same way the Euclidean similarity between the results XDLm and DSmT+PCR5m is denoted by

middot

XDL 09287E and computing time is 00185s

As shown in the above experiment results in this example the results obtained by the method proposed in this

paper have higher Euclidean Similarity and lower computation complexity than the existing DSmT approximate

method18

The Euclidean Similarity which remains over 99 shows that the method proposed in this paper has

higher accuracy and has practical meaning

Example 4 If there are the same 2 evidence sources in example 3 the hyper-power sets are denoted by

1 2 12 1or 2kG k The mass assignments in the second evidence source are unchanged denoted

by 02005004021015025005001001001001001b and the mass assignments in the first source

change whose sequnce of the mass belief of each focal element moves one position backward at one time to

procedure 11 new evidence

Each new evidence and the second evidence b are calculated to get the fusion results of DSmT+PCR5 and the

approximate results by the method in this paper and the method18

Then Euclidean similarity of the approximate

results of different methods with the results of DSmT+PCR5 and the average computing time of each method are

taken record as tabel 2

Table 2 Euclidean similarity and average computing time coparison of the methods

As shown in table 2 under complex cases of cluster sets in each evidence the accuracy of the method in this

paper also remains over 99 and much higher than the method18

Average computing time of the method in this

paper is lower than the method18

At the same time the accuracy of the method in this paper in different evidence

cases changes little which proves that the method has higher performance stability

63 cases of highly conflict evidence sources

Example 5 In order to verify information fusion of highly conflict evidence sources can be effective solved by the

method in this paper Assume there are two highly conflict evidence sources with the hyper-power set denoted by

D a b c d The mass assignements of two evidenece sources are shown in tabel 3

Table 3 The mass assignements of highly conflict evidenece sources

Conflict evidenece sources a b c d

1S x 1 x

2S y 1 y

Let 001 [002098]x y The fusion results are obtained by different methods when x y is increasing

from 002 to 098 by 001 step at the same time Euclidean similarity of the method18

with DSmT+PCR5 is shown

in figure1 Euclidean similarity of the method in this paper with DSmT+PCR5 is shown in figure2

Euclidean similarity with results of DSmT+PCR5

Average

computing

time 1 2 3 4 5 6 7 8 9 10 11

The method in

this paper

09987 09983 09982 09979 09981 09985 09985 09983 09984 09983 09983 00038

The

method18

08795 09330 09514 09484 08112 08636 08253 08342 08331 08189 08483 00186

middot

Fig 1 Euclidean similarity of the method18

with DSmT+PCR5 Fig 2 Euclidean similarity of the method in this paper with DSmT+PCR5

The average Euclidean Similarity of the method in this paper is 09873 and the average Euclidean Similarity of

the method18

is 08513 Itrsquos shown that the method in this paper can effiectively solve information fusion problem

of highly conflict evidence sources

64 convergence analysis

Example 6 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

01001002025015005010101005005002

05035002002001001001001001001001004

a

b

First fusion results of two evidence a and b

are obtained by different fusion methods Then fuse the prior fusion results with b repeatedly Through the

experiment results each time analyze different methodrsquos convergence

Table 3 The mass assignements of highly conflict evidenece sources

As shown in tabel 3 the convergence of three methods is similar The results of each method can converge to the

main focal elements afer 3 times of evidence fusion However the results of the method in this paper have higher

Euclidean similarity with DSmT+PCR5 and lose less information than the method18

each time

65 monte carlo simulations in the case of non-empty multiple focal elements

If there are 2 evidence sources assume that singleton focal elements and multiple focal elements have mass

Fusion results

1 DSmT+PCR5 042870260000058011630053900109002970029700297001090010900136

The method18

040670099400212018880079800385000270002700027000100001000019

The method in this paper 042850261000060011510053500110002960029600296001100011000141

2 DSmT+PCR5 058290332400031003880012000017000530005300053000170001700099

The method18

056870168600036006420020200127000000000000000000000000000000

The method in this paper 057050345900031003710011600018000520005200052000180001800109

3 DSmT+PCR5 064390334200018000840001600006000080000800008000060000600060

The method18

061710196800009001090002700021000000000000000000000000000000

The method in this paper 061180365500021000780001500006000080000800008000060000600069

4 DSmT+PCR5 067260318100012000170000400004000040000400004000040000400040

The method18

061520204700008000180000400003000000000000000000000000000000

The method in this paper 062640362600015000170000400004000040000400004000040000400048

middot

assignments in hyper-power sets denoted by 1 2 20 1 5 10 20 P Carry out 1000 times monte

carlo simulation experiments First assign random mass value to every focal elements of hyper-power sets in each

evidence each time Then the fusion results of 2 evidence are obtained by DSmT+PCR5 and the method in this

paper seperately Thirdly calculate the Euclidean similarity of the method in this paper with DSmT+PCR5 and

computing time in each monte carlo experiment The monto carlo simulation results are shown in figure 3 figure 4

and table 4

Fig 3 Computing time comparison of the method in this paper with DSmT+PCR5 Fig 4 Euclidean similarity of the method in this paper with

DSmT+PCR5

Table 4 fusion results comparison in the case of increasing focal elements number

Average Euclidean

Similarity

Max Euclidean

Similarity

Min Euclidean

Similarity

Average computing

time(ms)

Max computing

time(ms)

Min computing

time(ms)

DSmT+PCR5 19 31 19

The method in

this paper 09849 09956 09693 084911 14 083593

As shown in figure3 figure4 and tabel 4 in the case of non-empty multiple focal elements the average Euclidean

similarity of the method in this paper can reach 9849 and Euclidean similarity changes little with different

evidence Computing time of the method in this paper almost reduce halfly than DSmT+PCR5

66 monte carlo simulations in the case of increasing focal elements number

Example 7 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 10 1or 2kG k Increase 10 focal elements each time until 500 to

the hyper-power sets and assign random mass value to every focal elements of hyper-power sets in each evidence

each time Carry out 1000 times monto carlo simulation in each hyper-power set calculate the average Euclidean

similarity of the method in this paper with DSmT+PCR5 as shown in figure 5 Compare the average computing

time of the method in this paper with DSmT+PCR5 in each hyper-power sets is shown in figure 6

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 3: An Evidence Clustering DSmT Approximate Reasoning Method

middot

PCR5[ ] 0 m X G X

2 2

1 2 2 1PCR5 12

1 2 2 1

( ) ( ) ( ) ( )[ ] ( ) [ ]

( ) ( ) ( ) ( )Y G XX Y

m X m Y m X m Ym X m X

m X m Y m X m Y

(1)

where all sets involved in formulas are in canonical form and where G corresponds to classical power set 2 if

Shaferrsquos model is used or to a constrained hyper-power set D if any other hybrid DSm model is used insteador to

the super-power set S if the minimal refinement ref of is used 12 ( ) ( )m X m X corresponds to the

conjunctive consensus on X between the 2S sources and where all denominators are different from zero If a

denominator is zero that fraction is discarded

3 Mathematical analysis of DSmc+PCR5 formula

As shown in formula (1) 2 2

1 2 2 1

1 2 2 1

( ) ( ) ( ) ( )[ ]

( ) ( ) ( ) ( )Y G XX Y

m X m Y m X m Y

m X m Y m X m Y

has symmetry

Due to the symmetry analyse one item2

1 2

1 2

( ) ( )

( ) ( )

m X m Y

m X m Y

Let 1 2( ) ( )m X a m Y b

get 2 2

21 2

1 2

( ) ( ) 1[1 ( )]

( ) ( )

m X m Y a ba a

m X m Y a b a b

then

2

21 21 2

1 2 1 2

( ) ( ) 1 1 1[ ] [ ( )]

( ) ( )n

Y G X nX Y

m X m Ya n a b b b Y

m X m Y a b a b a b

(2)

Let 1

( )f xa x

due to ( )f x is continuous function on [01] has second order derivatives on (01) and ( ) 0f x on (01)

( )f x is a convex function

So 1 2

1 2

1( ( ) ( ) ( )) ( )n

n

x x xf x f x f x f

n n

the equality holds iff 1 2 nx x x

The approximate convex function formula is given by

1 2 1 2

1 1 1

( ) n n

n

a x a x a x a x x x n

(3)

Let 1 2 i nx x x x carry out analysis of convex function formula errors

1 1 2

2 1 2 1 2

1 1[ ]

( )

1 1 1 1[ ] [ ]

( ) ( )

n

n n n

a x a x x x n

a x a x x x n a x a x x x n

(4)

analysis of the i item in equality(4)

Let 1 2 0( ) nx x x n x then 1 2 0

1 1 1 1

( ) i n ia x a x x x n a x a x

By taylor expansion theorem

2 30

0 0 0 0 0 0

0

( )1 1 ( )( )( ) ( ) ( ) ( ) ( )

2 3i i i i i

i

f x ff x x x x x x x x x x x

a x a x

or

Then equality (4) is transformed to

0 1 0 2 0 1 0

1 2 1 2

12 2 2 20

1 0 2 0 1 0 0

1

1 1 1( )[( ) ( ) ( )]

( )

( )[( ) ( ) ( ) ] ( )

2

n

n n

n

n i

i

nf x x x x x x x

a x a x a x a x x x n

f xx x x x x x o x x

middot

0 1 0 2 0 1 0( )[( ) ( ) ( )] 0nf x x x x x x x then

2 20

0 0

1 11 2 1 2

( )1 1 1( ) ( )

( ) 2

n n

i i

i in n

f xnx x o x x

a x a x a x a x x x n

2 3 3 3 4 4 40 1 2

0 1 0 2 0 0 1 0 2 0 0

1

( ) ( )( ) ( )( ) [( ) ( ) ( ) ] ( ) ( ) ( )

3 4 4 4

nn

i n n

i

f x ff fo x x x x x x x x x x x x x x

Analysis of ( ) 23 mf x m

11 1

( )

m m

mf x ma x a x

then

2 11

1 10 0

0 0 0 0

0 0

2

1

0 0

0 0

( ) ( ) 1 1 1 1( ) ( ) ( ) ( )

( 1) ( 2) ( 1)

1 1 1 1( ) 1

( 2) ( 1)

m mm m

m m m m

m

m

f x f xx x x x x x x x

m m m a x m a x

x x x xm a x m a x

If 0x x 0 0 0x x x x x a

then 1

10 0

0 0

( ) ( )( ) ( )

( 1)

m m

m mf x f xx x x x

m m

If 0 02 2m x x x a x 0

0

1 1( ) 0

( 1)x x

m a x

So if 02 12 ix a x i n 1

10 0

0 0

( ) ( )( ) ( ) 2

( 1)

m m

m m

i i

f x f xx x x x m

m m

Namely 2 30 0 0

0 0 0

( ) ( ) ( )( ) ( ) ( )

2 3

m

m

i i i

f x f x f xx x x x x x

m

Neglect the fourth order item errors and more order item errors

For the third order item is odd number item for each 12 ix i n 3

30

0

( )( )

3i

f xx x can be positive and

negative Then the sum of he third order items is much smaller than the sum of the second order itmes if

02 12 ix a x i n Neglect the third order item and more order item errors if 02 12 ix a x i n

So

2

02 1

0 0311 2 1 2 1 0

( )1 1 1

( ) 2( ) 2 2( )

n

ini

i i

in n

x xn M

x x x a xa x a x a x a x x x n a x

Then

2

02 2 2 2 21 2 1 0 11 2

0 311 2 1 2 1 0

( )( ) ( )

( ) ( ) ( )( ) 2 2( )

n

inn n i

i

in n

x xx x x x f xx x

a a a x x aa x a x a x a x x x n a x

From the above analysis the errors are related to 2

0

1

( )n

i

i

x x

and 2

3

02( )

a

a x

By the properties of 2

3

02( )

a

a x if the mean point 0x increases

2

3

02( )

a

a x decreases quickly accordingly

When the cluster set ix is not particularly divergent 2

0

1

( )n

i

i

x x

is much smaller than divergent cluster So get

the conclsion that if the distribution of the cluster set ix is concentrated and the mean point 0x is large the erros

can be smaller

middot

Based on the above analysis for reducing approximate errors and remaining lower computing complex an

evidence clustering method is proposed as follows

1) Force the mass assignments of focal elements in the evidece to two sets by the standard of 2

n

2) If 2

ixn

ix is forced to one set denoted by L

ix and the sum of mass assignments for L

ix is denoted

by LS the number of points in L

ix is denoted by Ln otherwise

ix is forced to the other set denoted by

S

ix

3) If S

i ix x pick the focal element ix with the maximal value

maxix If max

2(1 )L

i

L

Sx

n n

ix is forced to

one set L

ix

4) Go on the step 3) untill max

2(1 )L

i

L

Sx

n n

the sum of mass assignments for S

ix is denoted by SS

After the above cluster steps in the evidence the mass assignments of focal elements are forced to 2 sets denoted

by L

ix and S

ix Compaerd to L

ix the distribution of S

ix may be more concentrated And Compaerd to

S

ix the main point of L

ix is large So carry out the above evidence clustering method in front of the

approximate convex function formula can make errors of approximate results much smaller

Let 1 2 1 2( ) ( ) nm X a m Y b b b the approximate convex function formula of DSmT+PCR5 is given by

221 2

1 2 1 2

( ) ( )[ ] [ ( )]

( ) ( ) ( ) Y G X nX Y

m X m Y na n a

m X m Y a b b b n

(5)

Finally analysis of relationship between the approximate computation item and its errors item

2

21 2

1 2

1 2 1 2

2

1 22 2 1

3

1 2 1 2

1 22 21 2

1 2

( ) ( ) 1 1 1[ ] [ ( )]

( ) ( )

( ( ) )

[ ( )]( ) 2( ( ) )

( (

[ ]( )

n

Y G X nX Y

n

i n

i

n n

i

n

n

m X m Ya n a b b b Y

m X m Y a b a b a b

x b b b nn

a n a aa b b b n a b b b n

x b b bb b b

a aa b b b n

2

1

3

1 2

) )

2( ( ) )

n

n

i

n

n

a b b b n

After evidence clustering method the influnce of numerator 1 2 nb b b to the approximate computation

item and the influnce of numerator 2

1 2

1

( ( ) )n

i n

i

x b b b n

to errors item is much smaller than the influnce

of their denominators So the approximate computation item 2 1 2

1 2

[ ]( )

n

n

b b ba

a b b b n

is mainly

proportional to the error item

2

1 22 1

3

1 2

( ( ) )

2( ( ) )

n

i n

i

n

x b b b n

aa b b b n

By the properies of convex function all the error

items of focal elements lt0 Based on the above analysis normalization method of the first-step approximate

middot

results is applied in this paper for errors redisturibution to get the final approximate results

4 An evidence clustering DSmT approximate reasoning method

Based on the Mathematical analysis of DSmT+PCR5 formula in 3 An evidence clustering DSmT approximate

reasoning method is proposed as follows

Defination1 Assuming the existence of a cluster set c the definition of the total number of c is

( ) Num c number c the sum of each point in c is ( ) Sum c c and the mean point of c is

( )

cMean c

number c

1) Carry out clustering evidence method proposed in 3 Force mass assignments of focal elements in each

evidence to two cluster sets Giving an example of two evidence denoted by 12 i ix x y y i n Then

force each evidence to two cluster sets respectively denoted by L L S S L S

i ix x x x x x x

L L S S L S

i i iy y y y y y y

2) First-step approximate fusion results are calculated by the approximate convex formula as follows

2 2 2 2

2 2

CONVEX

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

( ) (

( )

L S L S

L Li i i i i i i i i i

i i i i i iL S L S

i i i i i i i i i i

L

i i i i

i i L

i i

i

x Sum y y x Sum y y Sum x x y Sum xx y y y x x

x Mean y y x Mean y y Mean x x y Mean x

x Sum y x Sum yx y

x Mean ym

2 2

2 2 2

) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

S L S

L Si i i i i i

i i i iS L S

i i i i i i i i

L S L

i i i i i i i

i i L S L

i i i i i i i

y y Sum x x y Sum xy y x x

x Mean y y y Mean x x y Mean x

x Sum y x Sum y y y Sum x yx y

x Mean y x Mean y y y Mean x

2

2 2 2 2

( )

( )

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

S

S Si i i

i i i iS

i i i

L S L S

S Li i i i i i i i i i

i i i i i iL S L S

i i i i i i i i i i

Sum x xy y x x

y Mean x x

x Sum y y x Sum y y Sum x y Sum x xx y y y x x

x Mean y y x Mean y y Mean x y Mean x x

(6)

3) Normalization method of the first-step approximate results is given by

CONVEX

GH

CONVEX

1

(1 ( ))i j

i

nA x y

iA Gi

mm m A

m

(7)

5 Analysis of computation complexity

If there are 2 evidence sources assume that all singleton focal elements and multiple focal elements have mass

assignments in hyper-power sets of 2 evidence denoted by

1 2 [1 ]n i j k l g hG i f k l g h n n denote the number of singleton

focal elements c denote the number of multiple focal elements First analyse the computation comlplexity of

the processing procedure of 2 evidence sources fusion by DSmT+PCR5 Then analyse the computation

comlplexity of the same problem by the method in this paper Computation comlplexity comparison of two

methods can be obtained by the analysis

Assume that the computation comlplexity of one time multiplication is denoted by K the computation

comlplexity of one time addition is denoted by the computation comlplexity of one time division is denoted

by and the computation comlplexity of one time subtraction is denoted by B The computation comlplexity

middot

of the processing procedure of 2 evidence sources fusion by DSmT+PCR5 is denoted by DSmT[ ]o n Then

DSmT+PCR5[ ] [ (4 2 4 )( 1)]( ) (2 2 4 )

(4 4 3)( ) (2 2 2)( ) (4 4 4)( ) (2 2 4 )

o n c K K n c n c x K y

n c n c K n c n c n c n c x K y

(8)

x denote the number of multiple focal elements in the results y denote the number of the same multiple

focal elements generated in the procedure of mass assignments combination product The computation

comlplexity of the same problem by the method in this paper is denoted by GH[ ]o n c Then

GH[ ] 2( ) ( ) 2( )[2(3 ) ] (2 2 4 )

2( ) 13( ) [4( ) 1] (5 4 ) (2 2 4 )

o n c n c B n c K n c K n x K y

n c B n c K n c n c x K y

(9)

Computation comlplexity comparison of two methods obtained from equality (8) and equality (9) shows that

the computation comlplexity comparison of DSmT is almost propotion to 2( )n c and the computation

comlplexity comparison of the method in this paper is almost propotion to ( )n c Conclusions are drawn that he

computation comlplexity comparison of the method in this paper is much lower than DSmT with increasing

number of focal element numbers in hyper-power space

6 Simulation experiments

For comparison of the approximate method proposed in this paper with the other methods an Euclidean

similarity function20

is introduced in this paper as follows

2

1 2 1 2

1

1[ ] 1 [ [ ] [ ]]

2

G

E i i

i

N m m m X m X

(10)

61 Simple cases of cluster sets in each evidence

Example 1 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b the processing of the method is given

as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

1 2 3 5 6 7 4 1 2 3 4 5 7 6 a a a a a a a a b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

middot

2 2 22

1 2 3 5 6 7 1 2 3 4 5 7 1 61 4CONVEX1 1 1

1 2 3 5 6 7 1 4 1 2 3 4 5 7 1 6

2

2 1 3 5 6 7

CONVEX2 2 2 2

2 1 3 5

( ) ( )

( ) ( )

( )

(

b Sum a a a a a a Sum b b b b b a bb am a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a am a b

b Mean a a a a

2 22

2 1 3 4 5 7 2 62 4

2 2 2

6 7 2 4 2 1 3 4 5 7 2 6

2 2 2

3 1 2 5 6 7 3 4 3 1 2 4 5 7

CONVEX3 3 3 2 2 2

3 1 2 5 6 7 3 4 3

( )

) ( )

( ) ( )

( ) (

a Sum b b b b b a bb a

a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum b b b b bm a b

b Mean a a a a a b a a Mean b

2

3 6

2

1 2 4 5 7 3 6

2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

CONVEX4 4 4 2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

2

5 1 2 3 6

CONVEX5 5 5

)

( ) ( )

( ) ( )

(

a b

b b b b a b

b Sum a a a a a a a Sum b b b b b a bm a b

b Mean a a a a a a a Mean b b b b b a b

b Sum a a a am a b

2 2 2

7 5 4 5 1 2 3 4 7 5 6

2 2 2 2

5 1 2 3 6 7 5 4 5 1 2 3 4 7 5 6

2 2 2

6 1 2 3 5 7 6 4 6 1

CONVEX6 6 6 2 2

6 1 2 3 5 7 6 4

) ( )

( ) ( )

( ) (

( )

a b a a Sum b b b b b a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum bm a b

b Mean a a a a a b a

2 3 4 5 7

2

6 1 2 3 4 5 7

2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

CONVEX7 7 7 2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

)

( )

( ) ( )

( ) ( )

b b b b b

a Mean b b b b b b

b Sum a a a a a b a a Sum b b b b b a bm a b

b Mean a a a a a b a a Mean b b b b b a b

Get CONVEX 01588005580027303108019260310800273m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 01465005150025202869017780286900252m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 01435004880023702922017510292900237m

The results of the method18

XDL 01536006050025302980016700273800217m

Calculate the Euclidean similarity between results GHm obtained by the method in this paper and the results

DSmT+PCR5m of DSmT+PCR5 The Euclidean similarity GH 09932E

In the same way the Euclidean similarity between the results XDLm of the method18

and the results DSmT+PCR5m

of DSmT+PCR5 is denoted by XDL 09812E

From the above results of this example the results obtained by the method proposed in this paper have higher

Euclidean similarity with DSmT+PCR5 than the existing approximate DSmT method18

The Euclidean Similarity

which remains over 99 shows that the method proposed in this paper has high accuracy and has practical

meaning

Example 2 If there are the same 2 evidence sources in example 1 the hyper-power sets are denoted by

1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b The mass assignments in the second

evidence source are unchanged denoted by 020050050201503005b and the mass assignments in

the first evidence change whose sequnce of the mass belief of each focal element moves one position backward at

one time to procedure 6 new evidence such as

middot

1 2 3

4 5 6

0101005030202005 0050101005030202 0200501010050302

0202005010100503 0302020050101005 005030202005

a a a

a a a

0101

Each new evidence and the evidence b are calculated to obtain the fusion results by DSmT+PCR5 and the

approximate fusion results by the method in this paper and the method18

Then Euclidean similarity of the

approximate results of different methods with the results of DSmT+PCR5 is obtained by formula(10) and the average

computing time of each method is also taken record as tabel 1 (In this paper all the simulation experiments are

implemented by Matlab simulation in the hardware condition of Pentimu(R) Dual-Core CPU E5300 26GHz

259GHz memory 199GB)

Table 1 Euclidean similarity and average computing time coparison of the methods

Euclidean similarity with results of DSmT+PCR5

average

computing

time 1 2 3 4 5 6

The method in

this paper 09939 09911 09955 09938 09965 09960 00028s

The method18

09583 09791 09588 09530 09443 09347 00105s

As shown in table 1 under simple cases of cluster sets in each evidence the accuracy of the method in this

paper all remains over 99 and much higher than the method18

Average computing time of the method in this

paper is also lower than the existing approximate method18

At the same time the accuracy of the method in this

paper in different evidence cases changes little which proves that the method has higher performance stability

62 Complex cases of cluster sets in each evidence

Example 3 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

03035005005004006002001002001004005

02005004021015025005001001001001001

a

b

the method processing is given as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

3 4 5 6 7 8 9 10 11 12 1 2 2 3 7 8 9 10 11 12 1 4 5 6 a a a a a a a a a a a a a b b b b b b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

CONVEX 030690255900247013090083401662001770001900041000190011000153m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 030090250900242012830081801630001740001900041000190010800150m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 030190252400235012820081101635001690001800039000180010400146m

The results of the method18

XDL 037100183400276012690082801651000030000000001000010000200002m

Calculate the Euclidean similarity between the results GHm and DSmT+PCR5m The Euclidean Similarity

GH 09984E and computing time is 00035s

In the same way the Euclidean similarity between the results XDLm and DSmT+PCR5m is denoted by

middot

XDL 09287E and computing time is 00185s

As shown in the above experiment results in this example the results obtained by the method proposed in this

paper have higher Euclidean Similarity and lower computation complexity than the existing DSmT approximate

method18

The Euclidean Similarity which remains over 99 shows that the method proposed in this paper has

higher accuracy and has practical meaning

Example 4 If there are the same 2 evidence sources in example 3 the hyper-power sets are denoted by

1 2 12 1or 2kG k The mass assignments in the second evidence source are unchanged denoted

by 02005004021015025005001001001001001b and the mass assignments in the first source

change whose sequnce of the mass belief of each focal element moves one position backward at one time to

procedure 11 new evidence

Each new evidence and the second evidence b are calculated to get the fusion results of DSmT+PCR5 and the

approximate results by the method in this paper and the method18

Then Euclidean similarity of the approximate

results of different methods with the results of DSmT+PCR5 and the average computing time of each method are

taken record as tabel 2

Table 2 Euclidean similarity and average computing time coparison of the methods

As shown in table 2 under complex cases of cluster sets in each evidence the accuracy of the method in this

paper also remains over 99 and much higher than the method18

Average computing time of the method in this

paper is lower than the method18

At the same time the accuracy of the method in this paper in different evidence

cases changes little which proves that the method has higher performance stability

63 cases of highly conflict evidence sources

Example 5 In order to verify information fusion of highly conflict evidence sources can be effective solved by the

method in this paper Assume there are two highly conflict evidence sources with the hyper-power set denoted by

D a b c d The mass assignements of two evidenece sources are shown in tabel 3

Table 3 The mass assignements of highly conflict evidenece sources

Conflict evidenece sources a b c d

1S x 1 x

2S y 1 y

Let 001 [002098]x y The fusion results are obtained by different methods when x y is increasing

from 002 to 098 by 001 step at the same time Euclidean similarity of the method18

with DSmT+PCR5 is shown

in figure1 Euclidean similarity of the method in this paper with DSmT+PCR5 is shown in figure2

Euclidean similarity with results of DSmT+PCR5

Average

computing

time 1 2 3 4 5 6 7 8 9 10 11

The method in

this paper

09987 09983 09982 09979 09981 09985 09985 09983 09984 09983 09983 00038

The

method18

08795 09330 09514 09484 08112 08636 08253 08342 08331 08189 08483 00186

middot

Fig 1 Euclidean similarity of the method18

with DSmT+PCR5 Fig 2 Euclidean similarity of the method in this paper with DSmT+PCR5

The average Euclidean Similarity of the method in this paper is 09873 and the average Euclidean Similarity of

the method18

is 08513 Itrsquos shown that the method in this paper can effiectively solve information fusion problem

of highly conflict evidence sources

64 convergence analysis

Example 6 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

01001002025015005010101005005002

05035002002001001001001001001001004

a

b

First fusion results of two evidence a and b

are obtained by different fusion methods Then fuse the prior fusion results with b repeatedly Through the

experiment results each time analyze different methodrsquos convergence

Table 3 The mass assignements of highly conflict evidenece sources

As shown in tabel 3 the convergence of three methods is similar The results of each method can converge to the

main focal elements afer 3 times of evidence fusion However the results of the method in this paper have higher

Euclidean similarity with DSmT+PCR5 and lose less information than the method18

each time

65 monte carlo simulations in the case of non-empty multiple focal elements

If there are 2 evidence sources assume that singleton focal elements and multiple focal elements have mass

Fusion results

1 DSmT+PCR5 042870260000058011630053900109002970029700297001090010900136

The method18

040670099400212018880079800385000270002700027000100001000019

The method in this paper 042850261000060011510053500110002960029600296001100011000141

2 DSmT+PCR5 058290332400031003880012000017000530005300053000170001700099

The method18

056870168600036006420020200127000000000000000000000000000000

The method in this paper 057050345900031003710011600018000520005200052000180001800109

3 DSmT+PCR5 064390334200018000840001600006000080000800008000060000600060

The method18

061710196800009001090002700021000000000000000000000000000000

The method in this paper 061180365500021000780001500006000080000800008000060000600069

4 DSmT+PCR5 067260318100012000170000400004000040000400004000040000400040

The method18

061520204700008000180000400003000000000000000000000000000000

The method in this paper 062640362600015000170000400004000040000400004000040000400048

middot

assignments in hyper-power sets denoted by 1 2 20 1 5 10 20 P Carry out 1000 times monte

carlo simulation experiments First assign random mass value to every focal elements of hyper-power sets in each

evidence each time Then the fusion results of 2 evidence are obtained by DSmT+PCR5 and the method in this

paper seperately Thirdly calculate the Euclidean similarity of the method in this paper with DSmT+PCR5 and

computing time in each monte carlo experiment The monto carlo simulation results are shown in figure 3 figure 4

and table 4

Fig 3 Computing time comparison of the method in this paper with DSmT+PCR5 Fig 4 Euclidean similarity of the method in this paper with

DSmT+PCR5

Table 4 fusion results comparison in the case of increasing focal elements number

Average Euclidean

Similarity

Max Euclidean

Similarity

Min Euclidean

Similarity

Average computing

time(ms)

Max computing

time(ms)

Min computing

time(ms)

DSmT+PCR5 19 31 19

The method in

this paper 09849 09956 09693 084911 14 083593

As shown in figure3 figure4 and tabel 4 in the case of non-empty multiple focal elements the average Euclidean

similarity of the method in this paper can reach 9849 and Euclidean similarity changes little with different

evidence Computing time of the method in this paper almost reduce halfly than DSmT+PCR5

66 monte carlo simulations in the case of increasing focal elements number

Example 7 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 10 1or 2kG k Increase 10 focal elements each time until 500 to

the hyper-power sets and assign random mass value to every focal elements of hyper-power sets in each evidence

each time Carry out 1000 times monto carlo simulation in each hyper-power set calculate the average Euclidean

similarity of the method in this paper with DSmT+PCR5 as shown in figure 5 Compare the average computing

time of the method in this paper with DSmT+PCR5 in each hyper-power sets is shown in figure 6

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 4: An Evidence Clustering DSmT Approximate Reasoning Method

middot

0 1 0 2 0 1 0( )[( ) ( ) ( )] 0nf x x x x x x x then

2 20

0 0

1 11 2 1 2

( )1 1 1( ) ( )

( ) 2

n n

i i

i in n

f xnx x o x x

a x a x a x a x x x n

2 3 3 3 4 4 40 1 2

0 1 0 2 0 0 1 0 2 0 0

1

( ) ( )( ) ( )( ) [( ) ( ) ( ) ] ( ) ( ) ( )

3 4 4 4

nn

i n n

i

f x ff fo x x x x x x x x x x x x x x

Analysis of ( ) 23 mf x m

11 1

( )

m m

mf x ma x a x

then

2 11

1 10 0

0 0 0 0

0 0

2

1

0 0

0 0

( ) ( ) 1 1 1 1( ) ( ) ( ) ( )

( 1) ( 2) ( 1)

1 1 1 1( ) 1

( 2) ( 1)

m mm m

m m m m

m

m

f x f xx x x x x x x x

m m m a x m a x

x x x xm a x m a x

If 0x x 0 0 0x x x x x a

then 1

10 0

0 0

( ) ( )( ) ( )

( 1)

m m

m mf x f xx x x x

m m

If 0 02 2m x x x a x 0

0

1 1( ) 0

( 1)x x

m a x

So if 02 12 ix a x i n 1

10 0

0 0

( ) ( )( ) ( ) 2

( 1)

m m

m m

i i

f x f xx x x x m

m m

Namely 2 30 0 0

0 0 0

( ) ( ) ( )( ) ( ) ( )

2 3

m

m

i i i

f x f x f xx x x x x x

m

Neglect the fourth order item errors and more order item errors

For the third order item is odd number item for each 12 ix i n 3

30

0

( )( )

3i

f xx x can be positive and

negative Then the sum of he third order items is much smaller than the sum of the second order itmes if

02 12 ix a x i n Neglect the third order item and more order item errors if 02 12 ix a x i n

So

2

02 1

0 0311 2 1 2 1 0

( )1 1 1

( ) 2( ) 2 2( )

n

ini

i i

in n

x xn M

x x x a xa x a x a x a x x x n a x

Then

2

02 2 2 2 21 2 1 0 11 2

0 311 2 1 2 1 0

( )( ) ( )

( ) ( ) ( )( ) 2 2( )

n

inn n i

i

in n

x xx x x x f xx x

a a a x x aa x a x a x a x x x n a x

From the above analysis the errors are related to 2

0

1

( )n

i

i

x x

and 2

3

02( )

a

a x

By the properties of 2

3

02( )

a

a x if the mean point 0x increases

2

3

02( )

a

a x decreases quickly accordingly

When the cluster set ix is not particularly divergent 2

0

1

( )n

i

i

x x

is much smaller than divergent cluster So get

the conclsion that if the distribution of the cluster set ix is concentrated and the mean point 0x is large the erros

can be smaller

middot

Based on the above analysis for reducing approximate errors and remaining lower computing complex an

evidence clustering method is proposed as follows

1) Force the mass assignments of focal elements in the evidece to two sets by the standard of 2

n

2) If 2

ixn

ix is forced to one set denoted by L

ix and the sum of mass assignments for L

ix is denoted

by LS the number of points in L

ix is denoted by Ln otherwise

ix is forced to the other set denoted by

S

ix

3) If S

i ix x pick the focal element ix with the maximal value

maxix If max

2(1 )L

i

L

Sx

n n

ix is forced to

one set L

ix

4) Go on the step 3) untill max

2(1 )L

i

L

Sx

n n

the sum of mass assignments for S

ix is denoted by SS

After the above cluster steps in the evidence the mass assignments of focal elements are forced to 2 sets denoted

by L

ix and S

ix Compaerd to L

ix the distribution of S

ix may be more concentrated And Compaerd to

S

ix the main point of L

ix is large So carry out the above evidence clustering method in front of the

approximate convex function formula can make errors of approximate results much smaller

Let 1 2 1 2( ) ( ) nm X a m Y b b b the approximate convex function formula of DSmT+PCR5 is given by

221 2

1 2 1 2

( ) ( )[ ] [ ( )]

( ) ( ) ( ) Y G X nX Y

m X m Y na n a

m X m Y a b b b n

(5)

Finally analysis of relationship between the approximate computation item and its errors item

2

21 2

1 2

1 2 1 2

2

1 22 2 1

3

1 2 1 2

1 22 21 2

1 2

( ) ( ) 1 1 1[ ] [ ( )]

( ) ( )

( ( ) )

[ ( )]( ) 2( ( ) )

( (

[ ]( )

n

Y G X nX Y

n

i n

i

n n

i

n

n

m X m Ya n a b b b Y

m X m Y a b a b a b

x b b b nn

a n a aa b b b n a b b b n

x b b bb b b

a aa b b b n

2

1

3

1 2

) )

2( ( ) )

n

n

i

n

n

a b b b n

After evidence clustering method the influnce of numerator 1 2 nb b b to the approximate computation

item and the influnce of numerator 2

1 2

1

( ( ) )n

i n

i

x b b b n

to errors item is much smaller than the influnce

of their denominators So the approximate computation item 2 1 2

1 2

[ ]( )

n

n

b b ba

a b b b n

is mainly

proportional to the error item

2

1 22 1

3

1 2

( ( ) )

2( ( ) )

n

i n

i

n

x b b b n

aa b b b n

By the properies of convex function all the error

items of focal elements lt0 Based on the above analysis normalization method of the first-step approximate

middot

results is applied in this paper for errors redisturibution to get the final approximate results

4 An evidence clustering DSmT approximate reasoning method

Based on the Mathematical analysis of DSmT+PCR5 formula in 3 An evidence clustering DSmT approximate

reasoning method is proposed as follows

Defination1 Assuming the existence of a cluster set c the definition of the total number of c is

( ) Num c number c the sum of each point in c is ( ) Sum c c and the mean point of c is

( )

cMean c

number c

1) Carry out clustering evidence method proposed in 3 Force mass assignments of focal elements in each

evidence to two cluster sets Giving an example of two evidence denoted by 12 i ix x y y i n Then

force each evidence to two cluster sets respectively denoted by L L S S L S

i ix x x x x x x

L L S S L S

i i iy y y y y y y

2) First-step approximate fusion results are calculated by the approximate convex formula as follows

2 2 2 2

2 2

CONVEX

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

( ) (

( )

L S L S

L Li i i i i i i i i i

i i i i i iL S L S

i i i i i i i i i i

L

i i i i

i i L

i i

i

x Sum y y x Sum y y Sum x x y Sum xx y y y x x

x Mean y y x Mean y y Mean x x y Mean x

x Sum y x Sum yx y

x Mean ym

2 2

2 2 2

) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

S L S

L Si i i i i i

i i i iS L S

i i i i i i i i

L S L

i i i i i i i

i i L S L

i i i i i i i

y y Sum x x y Sum xy y x x

x Mean y y y Mean x x y Mean x

x Sum y x Sum y y y Sum x yx y

x Mean y x Mean y y y Mean x

2

2 2 2 2

( )

( )

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

S

S Si i i

i i i iS

i i i

L S L S

S Li i i i i i i i i i

i i i i i iL S L S

i i i i i i i i i i

Sum x xy y x x

y Mean x x

x Sum y y x Sum y y Sum x y Sum x xx y y y x x

x Mean y y x Mean y y Mean x y Mean x x

(6)

3) Normalization method of the first-step approximate results is given by

CONVEX

GH

CONVEX

1

(1 ( ))i j

i

nA x y

iA Gi

mm m A

m

(7)

5 Analysis of computation complexity

If there are 2 evidence sources assume that all singleton focal elements and multiple focal elements have mass

assignments in hyper-power sets of 2 evidence denoted by

1 2 [1 ]n i j k l g hG i f k l g h n n denote the number of singleton

focal elements c denote the number of multiple focal elements First analyse the computation comlplexity of

the processing procedure of 2 evidence sources fusion by DSmT+PCR5 Then analyse the computation

comlplexity of the same problem by the method in this paper Computation comlplexity comparison of two

methods can be obtained by the analysis

Assume that the computation comlplexity of one time multiplication is denoted by K the computation

comlplexity of one time addition is denoted by the computation comlplexity of one time division is denoted

by and the computation comlplexity of one time subtraction is denoted by B The computation comlplexity

middot

of the processing procedure of 2 evidence sources fusion by DSmT+PCR5 is denoted by DSmT[ ]o n Then

DSmT+PCR5[ ] [ (4 2 4 )( 1)]( ) (2 2 4 )

(4 4 3)( ) (2 2 2)( ) (4 4 4)( ) (2 2 4 )

o n c K K n c n c x K y

n c n c K n c n c n c n c x K y

(8)

x denote the number of multiple focal elements in the results y denote the number of the same multiple

focal elements generated in the procedure of mass assignments combination product The computation

comlplexity of the same problem by the method in this paper is denoted by GH[ ]o n c Then

GH[ ] 2( ) ( ) 2( )[2(3 ) ] (2 2 4 )

2( ) 13( ) [4( ) 1] (5 4 ) (2 2 4 )

o n c n c B n c K n c K n x K y

n c B n c K n c n c x K y

(9)

Computation comlplexity comparison of two methods obtained from equality (8) and equality (9) shows that

the computation comlplexity comparison of DSmT is almost propotion to 2( )n c and the computation

comlplexity comparison of the method in this paper is almost propotion to ( )n c Conclusions are drawn that he

computation comlplexity comparison of the method in this paper is much lower than DSmT with increasing

number of focal element numbers in hyper-power space

6 Simulation experiments

For comparison of the approximate method proposed in this paper with the other methods an Euclidean

similarity function20

is introduced in this paper as follows

2

1 2 1 2

1

1[ ] 1 [ [ ] [ ]]

2

G

E i i

i

N m m m X m X

(10)

61 Simple cases of cluster sets in each evidence

Example 1 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b the processing of the method is given

as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

1 2 3 5 6 7 4 1 2 3 4 5 7 6 a a a a a a a a b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

middot

2 2 22

1 2 3 5 6 7 1 2 3 4 5 7 1 61 4CONVEX1 1 1

1 2 3 5 6 7 1 4 1 2 3 4 5 7 1 6

2

2 1 3 5 6 7

CONVEX2 2 2 2

2 1 3 5

( ) ( )

( ) ( )

( )

(

b Sum a a a a a a Sum b b b b b a bb am a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a am a b

b Mean a a a a

2 22

2 1 3 4 5 7 2 62 4

2 2 2

6 7 2 4 2 1 3 4 5 7 2 6

2 2 2

3 1 2 5 6 7 3 4 3 1 2 4 5 7

CONVEX3 3 3 2 2 2

3 1 2 5 6 7 3 4 3

( )

) ( )

( ) ( )

( ) (

a Sum b b b b b a bb a

a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum b b b b bm a b

b Mean a a a a a b a a Mean b

2

3 6

2

1 2 4 5 7 3 6

2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

CONVEX4 4 4 2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

2

5 1 2 3 6

CONVEX5 5 5

)

( ) ( )

( ) ( )

(

a b

b b b b a b

b Sum a a a a a a a Sum b b b b b a bm a b

b Mean a a a a a a a Mean b b b b b a b

b Sum a a a am a b

2 2 2

7 5 4 5 1 2 3 4 7 5 6

2 2 2 2

5 1 2 3 6 7 5 4 5 1 2 3 4 7 5 6

2 2 2

6 1 2 3 5 7 6 4 6 1

CONVEX6 6 6 2 2

6 1 2 3 5 7 6 4

) ( )

( ) ( )

( ) (

( )

a b a a Sum b b b b b a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum bm a b

b Mean a a a a a b a

2 3 4 5 7

2

6 1 2 3 4 5 7

2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

CONVEX7 7 7 2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

)

( )

( ) ( )

( ) ( )

b b b b b

a Mean b b b b b b

b Sum a a a a a b a a Sum b b b b b a bm a b

b Mean a a a a a b a a Mean b b b b b a b

Get CONVEX 01588005580027303108019260310800273m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 01465005150025202869017780286900252m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 01435004880023702922017510292900237m

The results of the method18

XDL 01536006050025302980016700273800217m

Calculate the Euclidean similarity between results GHm obtained by the method in this paper and the results

DSmT+PCR5m of DSmT+PCR5 The Euclidean similarity GH 09932E

In the same way the Euclidean similarity between the results XDLm of the method18

and the results DSmT+PCR5m

of DSmT+PCR5 is denoted by XDL 09812E

From the above results of this example the results obtained by the method proposed in this paper have higher

Euclidean similarity with DSmT+PCR5 than the existing approximate DSmT method18

The Euclidean Similarity

which remains over 99 shows that the method proposed in this paper has high accuracy and has practical

meaning

Example 2 If there are the same 2 evidence sources in example 1 the hyper-power sets are denoted by

1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b The mass assignments in the second

evidence source are unchanged denoted by 020050050201503005b and the mass assignments in

the first evidence change whose sequnce of the mass belief of each focal element moves one position backward at

one time to procedure 6 new evidence such as

middot

1 2 3

4 5 6

0101005030202005 0050101005030202 0200501010050302

0202005010100503 0302020050101005 005030202005

a a a

a a a

0101

Each new evidence and the evidence b are calculated to obtain the fusion results by DSmT+PCR5 and the

approximate fusion results by the method in this paper and the method18

Then Euclidean similarity of the

approximate results of different methods with the results of DSmT+PCR5 is obtained by formula(10) and the average

computing time of each method is also taken record as tabel 1 (In this paper all the simulation experiments are

implemented by Matlab simulation in the hardware condition of Pentimu(R) Dual-Core CPU E5300 26GHz

259GHz memory 199GB)

Table 1 Euclidean similarity and average computing time coparison of the methods

Euclidean similarity with results of DSmT+PCR5

average

computing

time 1 2 3 4 5 6

The method in

this paper 09939 09911 09955 09938 09965 09960 00028s

The method18

09583 09791 09588 09530 09443 09347 00105s

As shown in table 1 under simple cases of cluster sets in each evidence the accuracy of the method in this

paper all remains over 99 and much higher than the method18

Average computing time of the method in this

paper is also lower than the existing approximate method18

At the same time the accuracy of the method in this

paper in different evidence cases changes little which proves that the method has higher performance stability

62 Complex cases of cluster sets in each evidence

Example 3 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

03035005005004006002001002001004005

02005004021015025005001001001001001

a

b

the method processing is given as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

3 4 5 6 7 8 9 10 11 12 1 2 2 3 7 8 9 10 11 12 1 4 5 6 a a a a a a a a a a a a a b b b b b b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

CONVEX 030690255900247013090083401662001770001900041000190011000153m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 030090250900242012830081801630001740001900041000190010800150m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 030190252400235012820081101635001690001800039000180010400146m

The results of the method18

XDL 037100183400276012690082801651000030000000001000010000200002m

Calculate the Euclidean similarity between the results GHm and DSmT+PCR5m The Euclidean Similarity

GH 09984E and computing time is 00035s

In the same way the Euclidean similarity between the results XDLm and DSmT+PCR5m is denoted by

middot

XDL 09287E and computing time is 00185s

As shown in the above experiment results in this example the results obtained by the method proposed in this

paper have higher Euclidean Similarity and lower computation complexity than the existing DSmT approximate

method18

The Euclidean Similarity which remains over 99 shows that the method proposed in this paper has

higher accuracy and has practical meaning

Example 4 If there are the same 2 evidence sources in example 3 the hyper-power sets are denoted by

1 2 12 1or 2kG k The mass assignments in the second evidence source are unchanged denoted

by 02005004021015025005001001001001001b and the mass assignments in the first source

change whose sequnce of the mass belief of each focal element moves one position backward at one time to

procedure 11 new evidence

Each new evidence and the second evidence b are calculated to get the fusion results of DSmT+PCR5 and the

approximate results by the method in this paper and the method18

Then Euclidean similarity of the approximate

results of different methods with the results of DSmT+PCR5 and the average computing time of each method are

taken record as tabel 2

Table 2 Euclidean similarity and average computing time coparison of the methods

As shown in table 2 under complex cases of cluster sets in each evidence the accuracy of the method in this

paper also remains over 99 and much higher than the method18

Average computing time of the method in this

paper is lower than the method18

At the same time the accuracy of the method in this paper in different evidence

cases changes little which proves that the method has higher performance stability

63 cases of highly conflict evidence sources

Example 5 In order to verify information fusion of highly conflict evidence sources can be effective solved by the

method in this paper Assume there are two highly conflict evidence sources with the hyper-power set denoted by

D a b c d The mass assignements of two evidenece sources are shown in tabel 3

Table 3 The mass assignements of highly conflict evidenece sources

Conflict evidenece sources a b c d

1S x 1 x

2S y 1 y

Let 001 [002098]x y The fusion results are obtained by different methods when x y is increasing

from 002 to 098 by 001 step at the same time Euclidean similarity of the method18

with DSmT+PCR5 is shown

in figure1 Euclidean similarity of the method in this paper with DSmT+PCR5 is shown in figure2

Euclidean similarity with results of DSmT+PCR5

Average

computing

time 1 2 3 4 5 6 7 8 9 10 11

The method in

this paper

09987 09983 09982 09979 09981 09985 09985 09983 09984 09983 09983 00038

The

method18

08795 09330 09514 09484 08112 08636 08253 08342 08331 08189 08483 00186

middot

Fig 1 Euclidean similarity of the method18

with DSmT+PCR5 Fig 2 Euclidean similarity of the method in this paper with DSmT+PCR5

The average Euclidean Similarity of the method in this paper is 09873 and the average Euclidean Similarity of

the method18

is 08513 Itrsquos shown that the method in this paper can effiectively solve information fusion problem

of highly conflict evidence sources

64 convergence analysis

Example 6 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

01001002025015005010101005005002

05035002002001001001001001001001004

a

b

First fusion results of two evidence a and b

are obtained by different fusion methods Then fuse the prior fusion results with b repeatedly Through the

experiment results each time analyze different methodrsquos convergence

Table 3 The mass assignements of highly conflict evidenece sources

As shown in tabel 3 the convergence of three methods is similar The results of each method can converge to the

main focal elements afer 3 times of evidence fusion However the results of the method in this paper have higher

Euclidean similarity with DSmT+PCR5 and lose less information than the method18

each time

65 monte carlo simulations in the case of non-empty multiple focal elements

If there are 2 evidence sources assume that singleton focal elements and multiple focal elements have mass

Fusion results

1 DSmT+PCR5 042870260000058011630053900109002970029700297001090010900136

The method18

040670099400212018880079800385000270002700027000100001000019

The method in this paper 042850261000060011510053500110002960029600296001100011000141

2 DSmT+PCR5 058290332400031003880012000017000530005300053000170001700099

The method18

056870168600036006420020200127000000000000000000000000000000

The method in this paper 057050345900031003710011600018000520005200052000180001800109

3 DSmT+PCR5 064390334200018000840001600006000080000800008000060000600060

The method18

061710196800009001090002700021000000000000000000000000000000

The method in this paper 061180365500021000780001500006000080000800008000060000600069

4 DSmT+PCR5 067260318100012000170000400004000040000400004000040000400040

The method18

061520204700008000180000400003000000000000000000000000000000

The method in this paper 062640362600015000170000400004000040000400004000040000400048

middot

assignments in hyper-power sets denoted by 1 2 20 1 5 10 20 P Carry out 1000 times monte

carlo simulation experiments First assign random mass value to every focal elements of hyper-power sets in each

evidence each time Then the fusion results of 2 evidence are obtained by DSmT+PCR5 and the method in this

paper seperately Thirdly calculate the Euclidean similarity of the method in this paper with DSmT+PCR5 and

computing time in each monte carlo experiment The monto carlo simulation results are shown in figure 3 figure 4

and table 4

Fig 3 Computing time comparison of the method in this paper with DSmT+PCR5 Fig 4 Euclidean similarity of the method in this paper with

DSmT+PCR5

Table 4 fusion results comparison in the case of increasing focal elements number

Average Euclidean

Similarity

Max Euclidean

Similarity

Min Euclidean

Similarity

Average computing

time(ms)

Max computing

time(ms)

Min computing

time(ms)

DSmT+PCR5 19 31 19

The method in

this paper 09849 09956 09693 084911 14 083593

As shown in figure3 figure4 and tabel 4 in the case of non-empty multiple focal elements the average Euclidean

similarity of the method in this paper can reach 9849 and Euclidean similarity changes little with different

evidence Computing time of the method in this paper almost reduce halfly than DSmT+PCR5

66 monte carlo simulations in the case of increasing focal elements number

Example 7 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 10 1or 2kG k Increase 10 focal elements each time until 500 to

the hyper-power sets and assign random mass value to every focal elements of hyper-power sets in each evidence

each time Carry out 1000 times monto carlo simulation in each hyper-power set calculate the average Euclidean

similarity of the method in this paper with DSmT+PCR5 as shown in figure 5 Compare the average computing

time of the method in this paper with DSmT+PCR5 in each hyper-power sets is shown in figure 6

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 5: An Evidence Clustering DSmT Approximate Reasoning Method

middot

Based on the above analysis for reducing approximate errors and remaining lower computing complex an

evidence clustering method is proposed as follows

1) Force the mass assignments of focal elements in the evidece to two sets by the standard of 2

n

2) If 2

ixn

ix is forced to one set denoted by L

ix and the sum of mass assignments for L

ix is denoted

by LS the number of points in L

ix is denoted by Ln otherwise

ix is forced to the other set denoted by

S

ix

3) If S

i ix x pick the focal element ix with the maximal value

maxix If max

2(1 )L

i

L

Sx

n n

ix is forced to

one set L

ix

4) Go on the step 3) untill max

2(1 )L

i

L

Sx

n n

the sum of mass assignments for S

ix is denoted by SS

After the above cluster steps in the evidence the mass assignments of focal elements are forced to 2 sets denoted

by L

ix and S

ix Compaerd to L

ix the distribution of S

ix may be more concentrated And Compaerd to

S

ix the main point of L

ix is large So carry out the above evidence clustering method in front of the

approximate convex function formula can make errors of approximate results much smaller

Let 1 2 1 2( ) ( ) nm X a m Y b b b the approximate convex function formula of DSmT+PCR5 is given by

221 2

1 2 1 2

( ) ( )[ ] [ ( )]

( ) ( ) ( ) Y G X nX Y

m X m Y na n a

m X m Y a b b b n

(5)

Finally analysis of relationship between the approximate computation item and its errors item

2

21 2

1 2

1 2 1 2

2

1 22 2 1

3

1 2 1 2

1 22 21 2

1 2

( ) ( ) 1 1 1[ ] [ ( )]

( ) ( )

( ( ) )

[ ( )]( ) 2( ( ) )

( (

[ ]( )

n

Y G X nX Y

n

i n

i

n n

i

n

n

m X m Ya n a b b b Y

m X m Y a b a b a b

x b b b nn

a n a aa b b b n a b b b n

x b b bb b b

a aa b b b n

2

1

3

1 2

) )

2( ( ) )

n

n

i

n

n

a b b b n

After evidence clustering method the influnce of numerator 1 2 nb b b to the approximate computation

item and the influnce of numerator 2

1 2

1

( ( ) )n

i n

i

x b b b n

to errors item is much smaller than the influnce

of their denominators So the approximate computation item 2 1 2

1 2

[ ]( )

n

n

b b ba

a b b b n

is mainly

proportional to the error item

2

1 22 1

3

1 2

( ( ) )

2( ( ) )

n

i n

i

n

x b b b n

aa b b b n

By the properies of convex function all the error

items of focal elements lt0 Based on the above analysis normalization method of the first-step approximate

middot

results is applied in this paper for errors redisturibution to get the final approximate results

4 An evidence clustering DSmT approximate reasoning method

Based on the Mathematical analysis of DSmT+PCR5 formula in 3 An evidence clustering DSmT approximate

reasoning method is proposed as follows

Defination1 Assuming the existence of a cluster set c the definition of the total number of c is

( ) Num c number c the sum of each point in c is ( ) Sum c c and the mean point of c is

( )

cMean c

number c

1) Carry out clustering evidence method proposed in 3 Force mass assignments of focal elements in each

evidence to two cluster sets Giving an example of two evidence denoted by 12 i ix x y y i n Then

force each evidence to two cluster sets respectively denoted by L L S S L S

i ix x x x x x x

L L S S L S

i i iy y y y y y y

2) First-step approximate fusion results are calculated by the approximate convex formula as follows

2 2 2 2

2 2

CONVEX

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

( ) (

( )

L S L S

L Li i i i i i i i i i

i i i i i iL S L S

i i i i i i i i i i

L

i i i i

i i L

i i

i

x Sum y y x Sum y y Sum x x y Sum xx y y y x x

x Mean y y x Mean y y Mean x x y Mean x

x Sum y x Sum yx y

x Mean ym

2 2

2 2 2

) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

S L S

L Si i i i i i

i i i iS L S

i i i i i i i i

L S L

i i i i i i i

i i L S L

i i i i i i i

y y Sum x x y Sum xy y x x

x Mean y y y Mean x x y Mean x

x Sum y x Sum y y y Sum x yx y

x Mean y x Mean y y y Mean x

2

2 2 2 2

( )

( )

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

S

S Si i i

i i i iS

i i i

L S L S

S Li i i i i i i i i i

i i i i i iL S L S

i i i i i i i i i i

Sum x xy y x x

y Mean x x

x Sum y y x Sum y y Sum x y Sum x xx y y y x x

x Mean y y x Mean y y Mean x y Mean x x

(6)

3) Normalization method of the first-step approximate results is given by

CONVEX

GH

CONVEX

1

(1 ( ))i j

i

nA x y

iA Gi

mm m A

m

(7)

5 Analysis of computation complexity

If there are 2 evidence sources assume that all singleton focal elements and multiple focal elements have mass

assignments in hyper-power sets of 2 evidence denoted by

1 2 [1 ]n i j k l g hG i f k l g h n n denote the number of singleton

focal elements c denote the number of multiple focal elements First analyse the computation comlplexity of

the processing procedure of 2 evidence sources fusion by DSmT+PCR5 Then analyse the computation

comlplexity of the same problem by the method in this paper Computation comlplexity comparison of two

methods can be obtained by the analysis

Assume that the computation comlplexity of one time multiplication is denoted by K the computation

comlplexity of one time addition is denoted by the computation comlplexity of one time division is denoted

by and the computation comlplexity of one time subtraction is denoted by B The computation comlplexity

middot

of the processing procedure of 2 evidence sources fusion by DSmT+PCR5 is denoted by DSmT[ ]o n Then

DSmT+PCR5[ ] [ (4 2 4 )( 1)]( ) (2 2 4 )

(4 4 3)( ) (2 2 2)( ) (4 4 4)( ) (2 2 4 )

o n c K K n c n c x K y

n c n c K n c n c n c n c x K y

(8)

x denote the number of multiple focal elements in the results y denote the number of the same multiple

focal elements generated in the procedure of mass assignments combination product The computation

comlplexity of the same problem by the method in this paper is denoted by GH[ ]o n c Then

GH[ ] 2( ) ( ) 2( )[2(3 ) ] (2 2 4 )

2( ) 13( ) [4( ) 1] (5 4 ) (2 2 4 )

o n c n c B n c K n c K n x K y

n c B n c K n c n c x K y

(9)

Computation comlplexity comparison of two methods obtained from equality (8) and equality (9) shows that

the computation comlplexity comparison of DSmT is almost propotion to 2( )n c and the computation

comlplexity comparison of the method in this paper is almost propotion to ( )n c Conclusions are drawn that he

computation comlplexity comparison of the method in this paper is much lower than DSmT with increasing

number of focal element numbers in hyper-power space

6 Simulation experiments

For comparison of the approximate method proposed in this paper with the other methods an Euclidean

similarity function20

is introduced in this paper as follows

2

1 2 1 2

1

1[ ] 1 [ [ ] [ ]]

2

G

E i i

i

N m m m X m X

(10)

61 Simple cases of cluster sets in each evidence

Example 1 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b the processing of the method is given

as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

1 2 3 5 6 7 4 1 2 3 4 5 7 6 a a a a a a a a b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

middot

2 2 22

1 2 3 5 6 7 1 2 3 4 5 7 1 61 4CONVEX1 1 1

1 2 3 5 6 7 1 4 1 2 3 4 5 7 1 6

2

2 1 3 5 6 7

CONVEX2 2 2 2

2 1 3 5

( ) ( )

( ) ( )

( )

(

b Sum a a a a a a Sum b b b b b a bb am a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a am a b

b Mean a a a a

2 22

2 1 3 4 5 7 2 62 4

2 2 2

6 7 2 4 2 1 3 4 5 7 2 6

2 2 2

3 1 2 5 6 7 3 4 3 1 2 4 5 7

CONVEX3 3 3 2 2 2

3 1 2 5 6 7 3 4 3

( )

) ( )

( ) ( )

( ) (

a Sum b b b b b a bb a

a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum b b b b bm a b

b Mean a a a a a b a a Mean b

2

3 6

2

1 2 4 5 7 3 6

2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

CONVEX4 4 4 2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

2

5 1 2 3 6

CONVEX5 5 5

)

( ) ( )

( ) ( )

(

a b

b b b b a b

b Sum a a a a a a a Sum b b b b b a bm a b

b Mean a a a a a a a Mean b b b b b a b

b Sum a a a am a b

2 2 2

7 5 4 5 1 2 3 4 7 5 6

2 2 2 2

5 1 2 3 6 7 5 4 5 1 2 3 4 7 5 6

2 2 2

6 1 2 3 5 7 6 4 6 1

CONVEX6 6 6 2 2

6 1 2 3 5 7 6 4

) ( )

( ) ( )

( ) (

( )

a b a a Sum b b b b b a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum bm a b

b Mean a a a a a b a

2 3 4 5 7

2

6 1 2 3 4 5 7

2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

CONVEX7 7 7 2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

)

( )

( ) ( )

( ) ( )

b b b b b

a Mean b b b b b b

b Sum a a a a a b a a Sum b b b b b a bm a b

b Mean a a a a a b a a Mean b b b b b a b

Get CONVEX 01588005580027303108019260310800273m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 01465005150025202869017780286900252m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 01435004880023702922017510292900237m

The results of the method18

XDL 01536006050025302980016700273800217m

Calculate the Euclidean similarity between results GHm obtained by the method in this paper and the results

DSmT+PCR5m of DSmT+PCR5 The Euclidean similarity GH 09932E

In the same way the Euclidean similarity between the results XDLm of the method18

and the results DSmT+PCR5m

of DSmT+PCR5 is denoted by XDL 09812E

From the above results of this example the results obtained by the method proposed in this paper have higher

Euclidean similarity with DSmT+PCR5 than the existing approximate DSmT method18

The Euclidean Similarity

which remains over 99 shows that the method proposed in this paper has high accuracy and has practical

meaning

Example 2 If there are the same 2 evidence sources in example 1 the hyper-power sets are denoted by

1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b The mass assignments in the second

evidence source are unchanged denoted by 020050050201503005b and the mass assignments in

the first evidence change whose sequnce of the mass belief of each focal element moves one position backward at

one time to procedure 6 new evidence such as

middot

1 2 3

4 5 6

0101005030202005 0050101005030202 0200501010050302

0202005010100503 0302020050101005 005030202005

a a a

a a a

0101

Each new evidence and the evidence b are calculated to obtain the fusion results by DSmT+PCR5 and the

approximate fusion results by the method in this paper and the method18

Then Euclidean similarity of the

approximate results of different methods with the results of DSmT+PCR5 is obtained by formula(10) and the average

computing time of each method is also taken record as tabel 1 (In this paper all the simulation experiments are

implemented by Matlab simulation in the hardware condition of Pentimu(R) Dual-Core CPU E5300 26GHz

259GHz memory 199GB)

Table 1 Euclidean similarity and average computing time coparison of the methods

Euclidean similarity with results of DSmT+PCR5

average

computing

time 1 2 3 4 5 6

The method in

this paper 09939 09911 09955 09938 09965 09960 00028s

The method18

09583 09791 09588 09530 09443 09347 00105s

As shown in table 1 under simple cases of cluster sets in each evidence the accuracy of the method in this

paper all remains over 99 and much higher than the method18

Average computing time of the method in this

paper is also lower than the existing approximate method18

At the same time the accuracy of the method in this

paper in different evidence cases changes little which proves that the method has higher performance stability

62 Complex cases of cluster sets in each evidence

Example 3 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

03035005005004006002001002001004005

02005004021015025005001001001001001

a

b

the method processing is given as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

3 4 5 6 7 8 9 10 11 12 1 2 2 3 7 8 9 10 11 12 1 4 5 6 a a a a a a a a a a a a a b b b b b b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

CONVEX 030690255900247013090083401662001770001900041000190011000153m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 030090250900242012830081801630001740001900041000190010800150m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 030190252400235012820081101635001690001800039000180010400146m

The results of the method18

XDL 037100183400276012690082801651000030000000001000010000200002m

Calculate the Euclidean similarity between the results GHm and DSmT+PCR5m The Euclidean Similarity

GH 09984E and computing time is 00035s

In the same way the Euclidean similarity between the results XDLm and DSmT+PCR5m is denoted by

middot

XDL 09287E and computing time is 00185s

As shown in the above experiment results in this example the results obtained by the method proposed in this

paper have higher Euclidean Similarity and lower computation complexity than the existing DSmT approximate

method18

The Euclidean Similarity which remains over 99 shows that the method proposed in this paper has

higher accuracy and has practical meaning

Example 4 If there are the same 2 evidence sources in example 3 the hyper-power sets are denoted by

1 2 12 1or 2kG k The mass assignments in the second evidence source are unchanged denoted

by 02005004021015025005001001001001001b and the mass assignments in the first source

change whose sequnce of the mass belief of each focal element moves one position backward at one time to

procedure 11 new evidence

Each new evidence and the second evidence b are calculated to get the fusion results of DSmT+PCR5 and the

approximate results by the method in this paper and the method18

Then Euclidean similarity of the approximate

results of different methods with the results of DSmT+PCR5 and the average computing time of each method are

taken record as tabel 2

Table 2 Euclidean similarity and average computing time coparison of the methods

As shown in table 2 under complex cases of cluster sets in each evidence the accuracy of the method in this

paper also remains over 99 and much higher than the method18

Average computing time of the method in this

paper is lower than the method18

At the same time the accuracy of the method in this paper in different evidence

cases changes little which proves that the method has higher performance stability

63 cases of highly conflict evidence sources

Example 5 In order to verify information fusion of highly conflict evidence sources can be effective solved by the

method in this paper Assume there are two highly conflict evidence sources with the hyper-power set denoted by

D a b c d The mass assignements of two evidenece sources are shown in tabel 3

Table 3 The mass assignements of highly conflict evidenece sources

Conflict evidenece sources a b c d

1S x 1 x

2S y 1 y

Let 001 [002098]x y The fusion results are obtained by different methods when x y is increasing

from 002 to 098 by 001 step at the same time Euclidean similarity of the method18

with DSmT+PCR5 is shown

in figure1 Euclidean similarity of the method in this paper with DSmT+PCR5 is shown in figure2

Euclidean similarity with results of DSmT+PCR5

Average

computing

time 1 2 3 4 5 6 7 8 9 10 11

The method in

this paper

09987 09983 09982 09979 09981 09985 09985 09983 09984 09983 09983 00038

The

method18

08795 09330 09514 09484 08112 08636 08253 08342 08331 08189 08483 00186

middot

Fig 1 Euclidean similarity of the method18

with DSmT+PCR5 Fig 2 Euclidean similarity of the method in this paper with DSmT+PCR5

The average Euclidean Similarity of the method in this paper is 09873 and the average Euclidean Similarity of

the method18

is 08513 Itrsquos shown that the method in this paper can effiectively solve information fusion problem

of highly conflict evidence sources

64 convergence analysis

Example 6 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

01001002025015005010101005005002

05035002002001001001001001001001004

a

b

First fusion results of two evidence a and b

are obtained by different fusion methods Then fuse the prior fusion results with b repeatedly Through the

experiment results each time analyze different methodrsquos convergence

Table 3 The mass assignements of highly conflict evidenece sources

As shown in tabel 3 the convergence of three methods is similar The results of each method can converge to the

main focal elements afer 3 times of evidence fusion However the results of the method in this paper have higher

Euclidean similarity with DSmT+PCR5 and lose less information than the method18

each time

65 monte carlo simulations in the case of non-empty multiple focal elements

If there are 2 evidence sources assume that singleton focal elements and multiple focal elements have mass

Fusion results

1 DSmT+PCR5 042870260000058011630053900109002970029700297001090010900136

The method18

040670099400212018880079800385000270002700027000100001000019

The method in this paper 042850261000060011510053500110002960029600296001100011000141

2 DSmT+PCR5 058290332400031003880012000017000530005300053000170001700099

The method18

056870168600036006420020200127000000000000000000000000000000

The method in this paper 057050345900031003710011600018000520005200052000180001800109

3 DSmT+PCR5 064390334200018000840001600006000080000800008000060000600060

The method18

061710196800009001090002700021000000000000000000000000000000

The method in this paper 061180365500021000780001500006000080000800008000060000600069

4 DSmT+PCR5 067260318100012000170000400004000040000400004000040000400040

The method18

061520204700008000180000400003000000000000000000000000000000

The method in this paper 062640362600015000170000400004000040000400004000040000400048

middot

assignments in hyper-power sets denoted by 1 2 20 1 5 10 20 P Carry out 1000 times monte

carlo simulation experiments First assign random mass value to every focal elements of hyper-power sets in each

evidence each time Then the fusion results of 2 evidence are obtained by DSmT+PCR5 and the method in this

paper seperately Thirdly calculate the Euclidean similarity of the method in this paper with DSmT+PCR5 and

computing time in each monte carlo experiment The monto carlo simulation results are shown in figure 3 figure 4

and table 4

Fig 3 Computing time comparison of the method in this paper with DSmT+PCR5 Fig 4 Euclidean similarity of the method in this paper with

DSmT+PCR5

Table 4 fusion results comparison in the case of increasing focal elements number

Average Euclidean

Similarity

Max Euclidean

Similarity

Min Euclidean

Similarity

Average computing

time(ms)

Max computing

time(ms)

Min computing

time(ms)

DSmT+PCR5 19 31 19

The method in

this paper 09849 09956 09693 084911 14 083593

As shown in figure3 figure4 and tabel 4 in the case of non-empty multiple focal elements the average Euclidean

similarity of the method in this paper can reach 9849 and Euclidean similarity changes little with different

evidence Computing time of the method in this paper almost reduce halfly than DSmT+PCR5

66 monte carlo simulations in the case of increasing focal elements number

Example 7 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 10 1or 2kG k Increase 10 focal elements each time until 500 to

the hyper-power sets and assign random mass value to every focal elements of hyper-power sets in each evidence

each time Carry out 1000 times monto carlo simulation in each hyper-power set calculate the average Euclidean

similarity of the method in this paper with DSmT+PCR5 as shown in figure 5 Compare the average computing

time of the method in this paper with DSmT+PCR5 in each hyper-power sets is shown in figure 6

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 6: An Evidence Clustering DSmT Approximate Reasoning Method

middot

results is applied in this paper for errors redisturibution to get the final approximate results

4 An evidence clustering DSmT approximate reasoning method

Based on the Mathematical analysis of DSmT+PCR5 formula in 3 An evidence clustering DSmT approximate

reasoning method is proposed as follows

Defination1 Assuming the existence of a cluster set c the definition of the total number of c is

( ) Num c number c the sum of each point in c is ( ) Sum c c and the mean point of c is

( )

cMean c

number c

1) Carry out clustering evidence method proposed in 3 Force mass assignments of focal elements in each

evidence to two cluster sets Giving an example of two evidence denoted by 12 i ix x y y i n Then

force each evidence to two cluster sets respectively denoted by L L S S L S

i ix x x x x x x

L L S S L S

i i iy y y y y y y

2) First-step approximate fusion results are calculated by the approximate convex formula as follows

2 2 2 2

2 2

CONVEX

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

( ) (

( )

L S L S

L Li i i i i i i i i i

i i i i i iL S L S

i i i i i i i i i i

L

i i i i

i i L

i i

i

x Sum y y x Sum y y Sum x x y Sum xx y y y x x

x Mean y y x Mean y y Mean x x y Mean x

x Sum y x Sum yx y

x Mean ym

2 2

2 2 2

) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

S L S

L Si i i i i i

i i i iS L S

i i i i i i i i

L S L

i i i i i i i

i i L S L

i i i i i i i

y y Sum x x y Sum xy y x x

x Mean y y y Mean x x y Mean x

x Sum y x Sum y y y Sum x yx y

x Mean y x Mean y y y Mean x

2

2 2 2 2

( )

( )

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

S

S Si i i

i i i iS

i i i

L S L S

S Li i i i i i i i i i

i i i i i iL S L S

i i i i i i i i i i

Sum x xy y x x

y Mean x x

x Sum y y x Sum y y Sum x y Sum x xx y y y x x

x Mean y y x Mean y y Mean x y Mean x x

(6)

3) Normalization method of the first-step approximate results is given by

CONVEX

GH

CONVEX

1

(1 ( ))i j

i

nA x y

iA Gi

mm m A

m

(7)

5 Analysis of computation complexity

If there are 2 evidence sources assume that all singleton focal elements and multiple focal elements have mass

assignments in hyper-power sets of 2 evidence denoted by

1 2 [1 ]n i j k l g hG i f k l g h n n denote the number of singleton

focal elements c denote the number of multiple focal elements First analyse the computation comlplexity of

the processing procedure of 2 evidence sources fusion by DSmT+PCR5 Then analyse the computation

comlplexity of the same problem by the method in this paper Computation comlplexity comparison of two

methods can be obtained by the analysis

Assume that the computation comlplexity of one time multiplication is denoted by K the computation

comlplexity of one time addition is denoted by the computation comlplexity of one time division is denoted

by and the computation comlplexity of one time subtraction is denoted by B The computation comlplexity

middot

of the processing procedure of 2 evidence sources fusion by DSmT+PCR5 is denoted by DSmT[ ]o n Then

DSmT+PCR5[ ] [ (4 2 4 )( 1)]( ) (2 2 4 )

(4 4 3)( ) (2 2 2)( ) (4 4 4)( ) (2 2 4 )

o n c K K n c n c x K y

n c n c K n c n c n c n c x K y

(8)

x denote the number of multiple focal elements in the results y denote the number of the same multiple

focal elements generated in the procedure of mass assignments combination product The computation

comlplexity of the same problem by the method in this paper is denoted by GH[ ]o n c Then

GH[ ] 2( ) ( ) 2( )[2(3 ) ] (2 2 4 )

2( ) 13( ) [4( ) 1] (5 4 ) (2 2 4 )

o n c n c B n c K n c K n x K y

n c B n c K n c n c x K y

(9)

Computation comlplexity comparison of two methods obtained from equality (8) and equality (9) shows that

the computation comlplexity comparison of DSmT is almost propotion to 2( )n c and the computation

comlplexity comparison of the method in this paper is almost propotion to ( )n c Conclusions are drawn that he

computation comlplexity comparison of the method in this paper is much lower than DSmT with increasing

number of focal element numbers in hyper-power space

6 Simulation experiments

For comparison of the approximate method proposed in this paper with the other methods an Euclidean

similarity function20

is introduced in this paper as follows

2

1 2 1 2

1

1[ ] 1 [ [ ] [ ]]

2

G

E i i

i

N m m m X m X

(10)

61 Simple cases of cluster sets in each evidence

Example 1 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b the processing of the method is given

as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

1 2 3 5 6 7 4 1 2 3 4 5 7 6 a a a a a a a a b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

middot

2 2 22

1 2 3 5 6 7 1 2 3 4 5 7 1 61 4CONVEX1 1 1

1 2 3 5 6 7 1 4 1 2 3 4 5 7 1 6

2

2 1 3 5 6 7

CONVEX2 2 2 2

2 1 3 5

( ) ( )

( ) ( )

( )

(

b Sum a a a a a a Sum b b b b b a bb am a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a am a b

b Mean a a a a

2 22

2 1 3 4 5 7 2 62 4

2 2 2

6 7 2 4 2 1 3 4 5 7 2 6

2 2 2

3 1 2 5 6 7 3 4 3 1 2 4 5 7

CONVEX3 3 3 2 2 2

3 1 2 5 6 7 3 4 3

( )

) ( )

( ) ( )

( ) (

a Sum b b b b b a bb a

a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum b b b b bm a b

b Mean a a a a a b a a Mean b

2

3 6

2

1 2 4 5 7 3 6

2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

CONVEX4 4 4 2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

2

5 1 2 3 6

CONVEX5 5 5

)

( ) ( )

( ) ( )

(

a b

b b b b a b

b Sum a a a a a a a Sum b b b b b a bm a b

b Mean a a a a a a a Mean b b b b b a b

b Sum a a a am a b

2 2 2

7 5 4 5 1 2 3 4 7 5 6

2 2 2 2

5 1 2 3 6 7 5 4 5 1 2 3 4 7 5 6

2 2 2

6 1 2 3 5 7 6 4 6 1

CONVEX6 6 6 2 2

6 1 2 3 5 7 6 4

) ( )

( ) ( )

( ) (

( )

a b a a Sum b b b b b a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum bm a b

b Mean a a a a a b a

2 3 4 5 7

2

6 1 2 3 4 5 7

2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

CONVEX7 7 7 2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

)

( )

( ) ( )

( ) ( )

b b b b b

a Mean b b b b b b

b Sum a a a a a b a a Sum b b b b b a bm a b

b Mean a a a a a b a a Mean b b b b b a b

Get CONVEX 01588005580027303108019260310800273m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 01465005150025202869017780286900252m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 01435004880023702922017510292900237m

The results of the method18

XDL 01536006050025302980016700273800217m

Calculate the Euclidean similarity between results GHm obtained by the method in this paper and the results

DSmT+PCR5m of DSmT+PCR5 The Euclidean similarity GH 09932E

In the same way the Euclidean similarity between the results XDLm of the method18

and the results DSmT+PCR5m

of DSmT+PCR5 is denoted by XDL 09812E

From the above results of this example the results obtained by the method proposed in this paper have higher

Euclidean similarity with DSmT+PCR5 than the existing approximate DSmT method18

The Euclidean Similarity

which remains over 99 shows that the method proposed in this paper has high accuracy and has practical

meaning

Example 2 If there are the same 2 evidence sources in example 1 the hyper-power sets are denoted by

1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b The mass assignments in the second

evidence source are unchanged denoted by 020050050201503005b and the mass assignments in

the first evidence change whose sequnce of the mass belief of each focal element moves one position backward at

one time to procedure 6 new evidence such as

middot

1 2 3

4 5 6

0101005030202005 0050101005030202 0200501010050302

0202005010100503 0302020050101005 005030202005

a a a

a a a

0101

Each new evidence and the evidence b are calculated to obtain the fusion results by DSmT+PCR5 and the

approximate fusion results by the method in this paper and the method18

Then Euclidean similarity of the

approximate results of different methods with the results of DSmT+PCR5 is obtained by formula(10) and the average

computing time of each method is also taken record as tabel 1 (In this paper all the simulation experiments are

implemented by Matlab simulation in the hardware condition of Pentimu(R) Dual-Core CPU E5300 26GHz

259GHz memory 199GB)

Table 1 Euclidean similarity and average computing time coparison of the methods

Euclidean similarity with results of DSmT+PCR5

average

computing

time 1 2 3 4 5 6

The method in

this paper 09939 09911 09955 09938 09965 09960 00028s

The method18

09583 09791 09588 09530 09443 09347 00105s

As shown in table 1 under simple cases of cluster sets in each evidence the accuracy of the method in this

paper all remains over 99 and much higher than the method18

Average computing time of the method in this

paper is also lower than the existing approximate method18

At the same time the accuracy of the method in this

paper in different evidence cases changes little which proves that the method has higher performance stability

62 Complex cases of cluster sets in each evidence

Example 3 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

03035005005004006002001002001004005

02005004021015025005001001001001001

a

b

the method processing is given as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

3 4 5 6 7 8 9 10 11 12 1 2 2 3 7 8 9 10 11 12 1 4 5 6 a a a a a a a a a a a a a b b b b b b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

CONVEX 030690255900247013090083401662001770001900041000190011000153m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 030090250900242012830081801630001740001900041000190010800150m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 030190252400235012820081101635001690001800039000180010400146m

The results of the method18

XDL 037100183400276012690082801651000030000000001000010000200002m

Calculate the Euclidean similarity between the results GHm and DSmT+PCR5m The Euclidean Similarity

GH 09984E and computing time is 00035s

In the same way the Euclidean similarity between the results XDLm and DSmT+PCR5m is denoted by

middot

XDL 09287E and computing time is 00185s

As shown in the above experiment results in this example the results obtained by the method proposed in this

paper have higher Euclidean Similarity and lower computation complexity than the existing DSmT approximate

method18

The Euclidean Similarity which remains over 99 shows that the method proposed in this paper has

higher accuracy and has practical meaning

Example 4 If there are the same 2 evidence sources in example 3 the hyper-power sets are denoted by

1 2 12 1or 2kG k The mass assignments in the second evidence source are unchanged denoted

by 02005004021015025005001001001001001b and the mass assignments in the first source

change whose sequnce of the mass belief of each focal element moves one position backward at one time to

procedure 11 new evidence

Each new evidence and the second evidence b are calculated to get the fusion results of DSmT+PCR5 and the

approximate results by the method in this paper and the method18

Then Euclidean similarity of the approximate

results of different methods with the results of DSmT+PCR5 and the average computing time of each method are

taken record as tabel 2

Table 2 Euclidean similarity and average computing time coparison of the methods

As shown in table 2 under complex cases of cluster sets in each evidence the accuracy of the method in this

paper also remains over 99 and much higher than the method18

Average computing time of the method in this

paper is lower than the method18

At the same time the accuracy of the method in this paper in different evidence

cases changes little which proves that the method has higher performance stability

63 cases of highly conflict evidence sources

Example 5 In order to verify information fusion of highly conflict evidence sources can be effective solved by the

method in this paper Assume there are two highly conflict evidence sources with the hyper-power set denoted by

D a b c d The mass assignements of two evidenece sources are shown in tabel 3

Table 3 The mass assignements of highly conflict evidenece sources

Conflict evidenece sources a b c d

1S x 1 x

2S y 1 y

Let 001 [002098]x y The fusion results are obtained by different methods when x y is increasing

from 002 to 098 by 001 step at the same time Euclidean similarity of the method18

with DSmT+PCR5 is shown

in figure1 Euclidean similarity of the method in this paper with DSmT+PCR5 is shown in figure2

Euclidean similarity with results of DSmT+PCR5

Average

computing

time 1 2 3 4 5 6 7 8 9 10 11

The method in

this paper

09987 09983 09982 09979 09981 09985 09985 09983 09984 09983 09983 00038

The

method18

08795 09330 09514 09484 08112 08636 08253 08342 08331 08189 08483 00186

middot

Fig 1 Euclidean similarity of the method18

with DSmT+PCR5 Fig 2 Euclidean similarity of the method in this paper with DSmT+PCR5

The average Euclidean Similarity of the method in this paper is 09873 and the average Euclidean Similarity of

the method18

is 08513 Itrsquos shown that the method in this paper can effiectively solve information fusion problem

of highly conflict evidence sources

64 convergence analysis

Example 6 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

01001002025015005010101005005002

05035002002001001001001001001001004

a

b

First fusion results of two evidence a and b

are obtained by different fusion methods Then fuse the prior fusion results with b repeatedly Through the

experiment results each time analyze different methodrsquos convergence

Table 3 The mass assignements of highly conflict evidenece sources

As shown in tabel 3 the convergence of three methods is similar The results of each method can converge to the

main focal elements afer 3 times of evidence fusion However the results of the method in this paper have higher

Euclidean similarity with DSmT+PCR5 and lose less information than the method18

each time

65 monte carlo simulations in the case of non-empty multiple focal elements

If there are 2 evidence sources assume that singleton focal elements and multiple focal elements have mass

Fusion results

1 DSmT+PCR5 042870260000058011630053900109002970029700297001090010900136

The method18

040670099400212018880079800385000270002700027000100001000019

The method in this paper 042850261000060011510053500110002960029600296001100011000141

2 DSmT+PCR5 058290332400031003880012000017000530005300053000170001700099

The method18

056870168600036006420020200127000000000000000000000000000000

The method in this paper 057050345900031003710011600018000520005200052000180001800109

3 DSmT+PCR5 064390334200018000840001600006000080000800008000060000600060

The method18

061710196800009001090002700021000000000000000000000000000000

The method in this paper 061180365500021000780001500006000080000800008000060000600069

4 DSmT+PCR5 067260318100012000170000400004000040000400004000040000400040

The method18

061520204700008000180000400003000000000000000000000000000000

The method in this paper 062640362600015000170000400004000040000400004000040000400048

middot

assignments in hyper-power sets denoted by 1 2 20 1 5 10 20 P Carry out 1000 times monte

carlo simulation experiments First assign random mass value to every focal elements of hyper-power sets in each

evidence each time Then the fusion results of 2 evidence are obtained by DSmT+PCR5 and the method in this

paper seperately Thirdly calculate the Euclidean similarity of the method in this paper with DSmT+PCR5 and

computing time in each monte carlo experiment The monto carlo simulation results are shown in figure 3 figure 4

and table 4

Fig 3 Computing time comparison of the method in this paper with DSmT+PCR5 Fig 4 Euclidean similarity of the method in this paper with

DSmT+PCR5

Table 4 fusion results comparison in the case of increasing focal elements number

Average Euclidean

Similarity

Max Euclidean

Similarity

Min Euclidean

Similarity

Average computing

time(ms)

Max computing

time(ms)

Min computing

time(ms)

DSmT+PCR5 19 31 19

The method in

this paper 09849 09956 09693 084911 14 083593

As shown in figure3 figure4 and tabel 4 in the case of non-empty multiple focal elements the average Euclidean

similarity of the method in this paper can reach 9849 and Euclidean similarity changes little with different

evidence Computing time of the method in this paper almost reduce halfly than DSmT+PCR5

66 monte carlo simulations in the case of increasing focal elements number

Example 7 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 10 1or 2kG k Increase 10 focal elements each time until 500 to

the hyper-power sets and assign random mass value to every focal elements of hyper-power sets in each evidence

each time Carry out 1000 times monto carlo simulation in each hyper-power set calculate the average Euclidean

similarity of the method in this paper with DSmT+PCR5 as shown in figure 5 Compare the average computing

time of the method in this paper with DSmT+PCR5 in each hyper-power sets is shown in figure 6

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 7: An Evidence Clustering DSmT Approximate Reasoning Method

middot

of the processing procedure of 2 evidence sources fusion by DSmT+PCR5 is denoted by DSmT[ ]o n Then

DSmT+PCR5[ ] [ (4 2 4 )( 1)]( ) (2 2 4 )

(4 4 3)( ) (2 2 2)( ) (4 4 4)( ) (2 2 4 )

o n c K K n c n c x K y

n c n c K n c n c n c n c x K y

(8)

x denote the number of multiple focal elements in the results y denote the number of the same multiple

focal elements generated in the procedure of mass assignments combination product The computation

comlplexity of the same problem by the method in this paper is denoted by GH[ ]o n c Then

GH[ ] 2( ) ( ) 2( )[2(3 ) ] (2 2 4 )

2( ) 13( ) [4( ) 1] (5 4 ) (2 2 4 )

o n c n c B n c K n c K n x K y

n c B n c K n c n c x K y

(9)

Computation comlplexity comparison of two methods obtained from equality (8) and equality (9) shows that

the computation comlplexity comparison of DSmT is almost propotion to 2( )n c and the computation

comlplexity comparison of the method in this paper is almost propotion to ( )n c Conclusions are drawn that he

computation comlplexity comparison of the method in this paper is much lower than DSmT with increasing

number of focal element numbers in hyper-power space

6 Simulation experiments

For comparison of the approximate method proposed in this paper with the other methods an Euclidean

similarity function20

is introduced in this paper as follows

2

1 2 1 2

1

1[ ] 1 [ [ ] [ ]]

2

G

E i i

i

N m m m X m X

(10)

61 Simple cases of cluster sets in each evidence

Example 1 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b the processing of the method is given

as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

1 2 3 5 6 7 4 1 2 3 4 5 7 6 a a a a a a a a b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

middot

2 2 22

1 2 3 5 6 7 1 2 3 4 5 7 1 61 4CONVEX1 1 1

1 2 3 5 6 7 1 4 1 2 3 4 5 7 1 6

2

2 1 3 5 6 7

CONVEX2 2 2 2

2 1 3 5

( ) ( )

( ) ( )

( )

(

b Sum a a a a a a Sum b b b b b a bb am a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a am a b

b Mean a a a a

2 22

2 1 3 4 5 7 2 62 4

2 2 2

6 7 2 4 2 1 3 4 5 7 2 6

2 2 2

3 1 2 5 6 7 3 4 3 1 2 4 5 7

CONVEX3 3 3 2 2 2

3 1 2 5 6 7 3 4 3

( )

) ( )

( ) ( )

( ) (

a Sum b b b b b a bb a

a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum b b b b bm a b

b Mean a a a a a b a a Mean b

2

3 6

2

1 2 4 5 7 3 6

2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

CONVEX4 4 4 2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

2

5 1 2 3 6

CONVEX5 5 5

)

( ) ( )

( ) ( )

(

a b

b b b b a b

b Sum a a a a a a a Sum b b b b b a bm a b

b Mean a a a a a a a Mean b b b b b a b

b Sum a a a am a b

2 2 2

7 5 4 5 1 2 3 4 7 5 6

2 2 2 2

5 1 2 3 6 7 5 4 5 1 2 3 4 7 5 6

2 2 2

6 1 2 3 5 7 6 4 6 1

CONVEX6 6 6 2 2

6 1 2 3 5 7 6 4

) ( )

( ) ( )

( ) (

( )

a b a a Sum b b b b b a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum bm a b

b Mean a a a a a b a

2 3 4 5 7

2

6 1 2 3 4 5 7

2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

CONVEX7 7 7 2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

)

( )

( ) ( )

( ) ( )

b b b b b

a Mean b b b b b b

b Sum a a a a a b a a Sum b b b b b a bm a b

b Mean a a a a a b a a Mean b b b b b a b

Get CONVEX 01588005580027303108019260310800273m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 01465005150025202869017780286900252m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 01435004880023702922017510292900237m

The results of the method18

XDL 01536006050025302980016700273800217m

Calculate the Euclidean similarity between results GHm obtained by the method in this paper and the results

DSmT+PCR5m of DSmT+PCR5 The Euclidean similarity GH 09932E

In the same way the Euclidean similarity between the results XDLm of the method18

and the results DSmT+PCR5m

of DSmT+PCR5 is denoted by XDL 09812E

From the above results of this example the results obtained by the method proposed in this paper have higher

Euclidean similarity with DSmT+PCR5 than the existing approximate DSmT method18

The Euclidean Similarity

which remains over 99 shows that the method proposed in this paper has high accuracy and has practical

meaning

Example 2 If there are the same 2 evidence sources in example 1 the hyper-power sets are denoted by

1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b The mass assignments in the second

evidence source are unchanged denoted by 020050050201503005b and the mass assignments in

the first evidence change whose sequnce of the mass belief of each focal element moves one position backward at

one time to procedure 6 new evidence such as

middot

1 2 3

4 5 6

0101005030202005 0050101005030202 0200501010050302

0202005010100503 0302020050101005 005030202005

a a a

a a a

0101

Each new evidence and the evidence b are calculated to obtain the fusion results by DSmT+PCR5 and the

approximate fusion results by the method in this paper and the method18

Then Euclidean similarity of the

approximate results of different methods with the results of DSmT+PCR5 is obtained by formula(10) and the average

computing time of each method is also taken record as tabel 1 (In this paper all the simulation experiments are

implemented by Matlab simulation in the hardware condition of Pentimu(R) Dual-Core CPU E5300 26GHz

259GHz memory 199GB)

Table 1 Euclidean similarity and average computing time coparison of the methods

Euclidean similarity with results of DSmT+PCR5

average

computing

time 1 2 3 4 5 6

The method in

this paper 09939 09911 09955 09938 09965 09960 00028s

The method18

09583 09791 09588 09530 09443 09347 00105s

As shown in table 1 under simple cases of cluster sets in each evidence the accuracy of the method in this

paper all remains over 99 and much higher than the method18

Average computing time of the method in this

paper is also lower than the existing approximate method18

At the same time the accuracy of the method in this

paper in different evidence cases changes little which proves that the method has higher performance stability

62 Complex cases of cluster sets in each evidence

Example 3 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

03035005005004006002001002001004005

02005004021015025005001001001001001

a

b

the method processing is given as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

3 4 5 6 7 8 9 10 11 12 1 2 2 3 7 8 9 10 11 12 1 4 5 6 a a a a a a a a a a a a a b b b b b b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

CONVEX 030690255900247013090083401662001770001900041000190011000153m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 030090250900242012830081801630001740001900041000190010800150m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 030190252400235012820081101635001690001800039000180010400146m

The results of the method18

XDL 037100183400276012690082801651000030000000001000010000200002m

Calculate the Euclidean similarity between the results GHm and DSmT+PCR5m The Euclidean Similarity

GH 09984E and computing time is 00035s

In the same way the Euclidean similarity between the results XDLm and DSmT+PCR5m is denoted by

middot

XDL 09287E and computing time is 00185s

As shown in the above experiment results in this example the results obtained by the method proposed in this

paper have higher Euclidean Similarity and lower computation complexity than the existing DSmT approximate

method18

The Euclidean Similarity which remains over 99 shows that the method proposed in this paper has

higher accuracy and has practical meaning

Example 4 If there are the same 2 evidence sources in example 3 the hyper-power sets are denoted by

1 2 12 1or 2kG k The mass assignments in the second evidence source are unchanged denoted

by 02005004021015025005001001001001001b and the mass assignments in the first source

change whose sequnce of the mass belief of each focal element moves one position backward at one time to

procedure 11 new evidence

Each new evidence and the second evidence b are calculated to get the fusion results of DSmT+PCR5 and the

approximate results by the method in this paper and the method18

Then Euclidean similarity of the approximate

results of different methods with the results of DSmT+PCR5 and the average computing time of each method are

taken record as tabel 2

Table 2 Euclidean similarity and average computing time coparison of the methods

As shown in table 2 under complex cases of cluster sets in each evidence the accuracy of the method in this

paper also remains over 99 and much higher than the method18

Average computing time of the method in this

paper is lower than the method18

At the same time the accuracy of the method in this paper in different evidence

cases changes little which proves that the method has higher performance stability

63 cases of highly conflict evidence sources

Example 5 In order to verify information fusion of highly conflict evidence sources can be effective solved by the

method in this paper Assume there are two highly conflict evidence sources with the hyper-power set denoted by

D a b c d The mass assignements of two evidenece sources are shown in tabel 3

Table 3 The mass assignements of highly conflict evidenece sources

Conflict evidenece sources a b c d

1S x 1 x

2S y 1 y

Let 001 [002098]x y The fusion results are obtained by different methods when x y is increasing

from 002 to 098 by 001 step at the same time Euclidean similarity of the method18

with DSmT+PCR5 is shown

in figure1 Euclidean similarity of the method in this paper with DSmT+PCR5 is shown in figure2

Euclidean similarity with results of DSmT+PCR5

Average

computing

time 1 2 3 4 5 6 7 8 9 10 11

The method in

this paper

09987 09983 09982 09979 09981 09985 09985 09983 09984 09983 09983 00038

The

method18

08795 09330 09514 09484 08112 08636 08253 08342 08331 08189 08483 00186

middot

Fig 1 Euclidean similarity of the method18

with DSmT+PCR5 Fig 2 Euclidean similarity of the method in this paper with DSmT+PCR5

The average Euclidean Similarity of the method in this paper is 09873 and the average Euclidean Similarity of

the method18

is 08513 Itrsquos shown that the method in this paper can effiectively solve information fusion problem

of highly conflict evidence sources

64 convergence analysis

Example 6 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

01001002025015005010101005005002

05035002002001001001001001001001004

a

b

First fusion results of two evidence a and b

are obtained by different fusion methods Then fuse the prior fusion results with b repeatedly Through the

experiment results each time analyze different methodrsquos convergence

Table 3 The mass assignements of highly conflict evidenece sources

As shown in tabel 3 the convergence of three methods is similar The results of each method can converge to the

main focal elements afer 3 times of evidence fusion However the results of the method in this paper have higher

Euclidean similarity with DSmT+PCR5 and lose less information than the method18

each time

65 monte carlo simulations in the case of non-empty multiple focal elements

If there are 2 evidence sources assume that singleton focal elements and multiple focal elements have mass

Fusion results

1 DSmT+PCR5 042870260000058011630053900109002970029700297001090010900136

The method18

040670099400212018880079800385000270002700027000100001000019

The method in this paper 042850261000060011510053500110002960029600296001100011000141

2 DSmT+PCR5 058290332400031003880012000017000530005300053000170001700099

The method18

056870168600036006420020200127000000000000000000000000000000

The method in this paper 057050345900031003710011600018000520005200052000180001800109

3 DSmT+PCR5 064390334200018000840001600006000080000800008000060000600060

The method18

061710196800009001090002700021000000000000000000000000000000

The method in this paper 061180365500021000780001500006000080000800008000060000600069

4 DSmT+PCR5 067260318100012000170000400004000040000400004000040000400040

The method18

061520204700008000180000400003000000000000000000000000000000

The method in this paper 062640362600015000170000400004000040000400004000040000400048

middot

assignments in hyper-power sets denoted by 1 2 20 1 5 10 20 P Carry out 1000 times monte

carlo simulation experiments First assign random mass value to every focal elements of hyper-power sets in each

evidence each time Then the fusion results of 2 evidence are obtained by DSmT+PCR5 and the method in this

paper seperately Thirdly calculate the Euclidean similarity of the method in this paper with DSmT+PCR5 and

computing time in each monte carlo experiment The monto carlo simulation results are shown in figure 3 figure 4

and table 4

Fig 3 Computing time comparison of the method in this paper with DSmT+PCR5 Fig 4 Euclidean similarity of the method in this paper with

DSmT+PCR5

Table 4 fusion results comparison in the case of increasing focal elements number

Average Euclidean

Similarity

Max Euclidean

Similarity

Min Euclidean

Similarity

Average computing

time(ms)

Max computing

time(ms)

Min computing

time(ms)

DSmT+PCR5 19 31 19

The method in

this paper 09849 09956 09693 084911 14 083593

As shown in figure3 figure4 and tabel 4 in the case of non-empty multiple focal elements the average Euclidean

similarity of the method in this paper can reach 9849 and Euclidean similarity changes little with different

evidence Computing time of the method in this paper almost reduce halfly than DSmT+PCR5

66 monte carlo simulations in the case of increasing focal elements number

Example 7 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 10 1or 2kG k Increase 10 focal elements each time until 500 to

the hyper-power sets and assign random mass value to every focal elements of hyper-power sets in each evidence

each time Carry out 1000 times monto carlo simulation in each hyper-power set calculate the average Euclidean

similarity of the method in this paper with DSmT+PCR5 as shown in figure 5 Compare the average computing

time of the method in this paper with DSmT+PCR5 in each hyper-power sets is shown in figure 6

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 8: An Evidence Clustering DSmT Approximate Reasoning Method

middot

2 2 22

1 2 3 5 6 7 1 2 3 4 5 7 1 61 4CONVEX1 1 1

1 2 3 5 6 7 1 4 1 2 3 4 5 7 1 6

2

2 1 3 5 6 7

CONVEX2 2 2 2

2 1 3 5

( ) ( )

( ) ( )

( )

(

b Sum a a a a a a Sum b b b b b a bb am a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a am a b

b Mean a a a a

2 22

2 1 3 4 5 7 2 62 4

2 2 2

6 7 2 4 2 1 3 4 5 7 2 6

2 2 2

3 1 2 5 6 7 3 4 3 1 2 4 5 7

CONVEX3 3 3 2 2 2

3 1 2 5 6 7 3 4 3

( )

) ( )

( ) ( )

( ) (

a Sum b b b b b a bb a

a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum b b b b bm a b

b Mean a a a a a b a a Mean b

2

3 6

2

1 2 4 5 7 3 6

2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

CONVEX4 4 4 2 2 2

4 1 2 3 5 6 7 4 1 2 3 5 7 4 6

2

5 1 2 3 6

CONVEX5 5 5

)

( ) ( )

( ) ( )

(

a b

b b b b a b

b Sum a a a a a a a Sum b b b b b a bm a b

b Mean a a a a a a a Mean b b b b b a b

b Sum a a a am a b

2 2 2

7 5 4 5 1 2 3 4 7 5 6

2 2 2 2

5 1 2 3 6 7 5 4 5 1 2 3 4 7 5 6

2 2 2

6 1 2 3 5 7 6 4 6 1

CONVEX6 6 6 2 2

6 1 2 3 5 7 6 4

) ( )

( ) ( )

( ) (

( )

a b a a Sum b b b b b a b

b Mean a a a a a b a a Mean b b b b b a b

b Sum a a a a a b a a Sum bm a b

b Mean a a a a a b a

2 3 4 5 7

2

6 1 2 3 4 5 7

2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

CONVEX7 7 7 2 2 2 2

7 1 2 3 5 6 7 4 7 1 2 3 4 5 7 6

)

( )

( ) ( )

( ) ( )

b b b b b

a Mean b b b b b b

b Sum a a a a a b a a Sum b b b b b a bm a b

b Mean a a a a a b a a Mean b b b b b a b

Get CONVEX 01588005580027303108019260310800273m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 01465005150025202869017780286900252m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 01435004880023702922017510292900237m

The results of the method18

XDL 01536006050025302980016700273800217m

Calculate the Euclidean similarity between results GHm obtained by the method in this paper and the results

DSmT+PCR5m of DSmT+PCR5 The Euclidean similarity GH 09932E

In the same way the Euclidean similarity between the results XDLm of the method18

and the results DSmT+PCR5m

of DSmT+PCR5 is denoted by XDL 09812E

From the above results of this example the results obtained by the method proposed in this paper have higher

Euclidean similarity with DSmT+PCR5 than the existing approximate DSmT method18

The Euclidean Similarity

which remains over 99 shows that the method proposed in this paper has high accuracy and has practical

meaning

Example 2 If there are the same 2 evidence sources in example 1 the hyper-power sets are denoted by

1 2 7 1or 2kG k The mass assignments in each evidence are

0101005030202005 020050050201503005a b The mass assignments in the second

evidence source are unchanged denoted by 020050050201503005b and the mass assignments in

the first evidence change whose sequnce of the mass belief of each focal element moves one position backward at

one time to procedure 6 new evidence such as

middot

1 2 3

4 5 6

0101005030202005 0050101005030202 0200501010050302

0202005010100503 0302020050101005 005030202005

a a a

a a a

0101

Each new evidence and the evidence b are calculated to obtain the fusion results by DSmT+PCR5 and the

approximate fusion results by the method in this paper and the method18

Then Euclidean similarity of the

approximate results of different methods with the results of DSmT+PCR5 is obtained by formula(10) and the average

computing time of each method is also taken record as tabel 1 (In this paper all the simulation experiments are

implemented by Matlab simulation in the hardware condition of Pentimu(R) Dual-Core CPU E5300 26GHz

259GHz memory 199GB)

Table 1 Euclidean similarity and average computing time coparison of the methods

Euclidean similarity with results of DSmT+PCR5

average

computing

time 1 2 3 4 5 6

The method in

this paper 09939 09911 09955 09938 09965 09960 00028s

The method18

09583 09791 09588 09530 09443 09347 00105s

As shown in table 1 under simple cases of cluster sets in each evidence the accuracy of the method in this

paper all remains over 99 and much higher than the method18

Average computing time of the method in this

paper is also lower than the existing approximate method18

At the same time the accuracy of the method in this

paper in different evidence cases changes little which proves that the method has higher performance stability

62 Complex cases of cluster sets in each evidence

Example 3 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

03035005005004006002001002001004005

02005004021015025005001001001001001

a

b

the method processing is given as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

3 4 5 6 7 8 9 10 11 12 1 2 2 3 7 8 9 10 11 12 1 4 5 6 a a a a a a a a a a a a a b b b b b b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

CONVEX 030690255900247013090083401662001770001900041000190011000153m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 030090250900242012830081801630001740001900041000190010800150m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 030190252400235012820081101635001690001800039000180010400146m

The results of the method18

XDL 037100183400276012690082801651000030000000001000010000200002m

Calculate the Euclidean similarity between the results GHm and DSmT+PCR5m The Euclidean Similarity

GH 09984E and computing time is 00035s

In the same way the Euclidean similarity between the results XDLm and DSmT+PCR5m is denoted by

middot

XDL 09287E and computing time is 00185s

As shown in the above experiment results in this example the results obtained by the method proposed in this

paper have higher Euclidean Similarity and lower computation complexity than the existing DSmT approximate

method18

The Euclidean Similarity which remains over 99 shows that the method proposed in this paper has

higher accuracy and has practical meaning

Example 4 If there are the same 2 evidence sources in example 3 the hyper-power sets are denoted by

1 2 12 1or 2kG k The mass assignments in the second evidence source are unchanged denoted

by 02005004021015025005001001001001001b and the mass assignments in the first source

change whose sequnce of the mass belief of each focal element moves one position backward at one time to

procedure 11 new evidence

Each new evidence and the second evidence b are calculated to get the fusion results of DSmT+PCR5 and the

approximate results by the method in this paper and the method18

Then Euclidean similarity of the approximate

results of different methods with the results of DSmT+PCR5 and the average computing time of each method are

taken record as tabel 2

Table 2 Euclidean similarity and average computing time coparison of the methods

As shown in table 2 under complex cases of cluster sets in each evidence the accuracy of the method in this

paper also remains over 99 and much higher than the method18

Average computing time of the method in this

paper is lower than the method18

At the same time the accuracy of the method in this paper in different evidence

cases changes little which proves that the method has higher performance stability

63 cases of highly conflict evidence sources

Example 5 In order to verify information fusion of highly conflict evidence sources can be effective solved by the

method in this paper Assume there are two highly conflict evidence sources with the hyper-power set denoted by

D a b c d The mass assignements of two evidenece sources are shown in tabel 3

Table 3 The mass assignements of highly conflict evidenece sources

Conflict evidenece sources a b c d

1S x 1 x

2S y 1 y

Let 001 [002098]x y The fusion results are obtained by different methods when x y is increasing

from 002 to 098 by 001 step at the same time Euclidean similarity of the method18

with DSmT+PCR5 is shown

in figure1 Euclidean similarity of the method in this paper with DSmT+PCR5 is shown in figure2

Euclidean similarity with results of DSmT+PCR5

Average

computing

time 1 2 3 4 5 6 7 8 9 10 11

The method in

this paper

09987 09983 09982 09979 09981 09985 09985 09983 09984 09983 09983 00038

The

method18

08795 09330 09514 09484 08112 08636 08253 08342 08331 08189 08483 00186

middot

Fig 1 Euclidean similarity of the method18

with DSmT+PCR5 Fig 2 Euclidean similarity of the method in this paper with DSmT+PCR5

The average Euclidean Similarity of the method in this paper is 09873 and the average Euclidean Similarity of

the method18

is 08513 Itrsquos shown that the method in this paper can effiectively solve information fusion problem

of highly conflict evidence sources

64 convergence analysis

Example 6 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

01001002025015005010101005005002

05035002002001001001001001001001004

a

b

First fusion results of two evidence a and b

are obtained by different fusion methods Then fuse the prior fusion results with b repeatedly Through the

experiment results each time analyze different methodrsquos convergence

Table 3 The mass assignements of highly conflict evidenece sources

As shown in tabel 3 the convergence of three methods is similar The results of each method can converge to the

main focal elements afer 3 times of evidence fusion However the results of the method in this paper have higher

Euclidean similarity with DSmT+PCR5 and lose less information than the method18

each time

65 monte carlo simulations in the case of non-empty multiple focal elements

If there are 2 evidence sources assume that singleton focal elements and multiple focal elements have mass

Fusion results

1 DSmT+PCR5 042870260000058011630053900109002970029700297001090010900136

The method18

040670099400212018880079800385000270002700027000100001000019

The method in this paper 042850261000060011510053500110002960029600296001100011000141

2 DSmT+PCR5 058290332400031003880012000017000530005300053000170001700099

The method18

056870168600036006420020200127000000000000000000000000000000

The method in this paper 057050345900031003710011600018000520005200052000180001800109

3 DSmT+PCR5 064390334200018000840001600006000080000800008000060000600060

The method18

061710196800009001090002700021000000000000000000000000000000

The method in this paper 061180365500021000780001500006000080000800008000060000600069

4 DSmT+PCR5 067260318100012000170000400004000040000400004000040000400040

The method18

061520204700008000180000400003000000000000000000000000000000

The method in this paper 062640362600015000170000400004000040000400004000040000400048

middot

assignments in hyper-power sets denoted by 1 2 20 1 5 10 20 P Carry out 1000 times monte

carlo simulation experiments First assign random mass value to every focal elements of hyper-power sets in each

evidence each time Then the fusion results of 2 evidence are obtained by DSmT+PCR5 and the method in this

paper seperately Thirdly calculate the Euclidean similarity of the method in this paper with DSmT+PCR5 and

computing time in each monte carlo experiment The monto carlo simulation results are shown in figure 3 figure 4

and table 4

Fig 3 Computing time comparison of the method in this paper with DSmT+PCR5 Fig 4 Euclidean similarity of the method in this paper with

DSmT+PCR5

Table 4 fusion results comparison in the case of increasing focal elements number

Average Euclidean

Similarity

Max Euclidean

Similarity

Min Euclidean

Similarity

Average computing

time(ms)

Max computing

time(ms)

Min computing

time(ms)

DSmT+PCR5 19 31 19

The method in

this paper 09849 09956 09693 084911 14 083593

As shown in figure3 figure4 and tabel 4 in the case of non-empty multiple focal elements the average Euclidean

similarity of the method in this paper can reach 9849 and Euclidean similarity changes little with different

evidence Computing time of the method in this paper almost reduce halfly than DSmT+PCR5

66 monte carlo simulations in the case of increasing focal elements number

Example 7 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 10 1or 2kG k Increase 10 focal elements each time until 500 to

the hyper-power sets and assign random mass value to every focal elements of hyper-power sets in each evidence

each time Carry out 1000 times monto carlo simulation in each hyper-power set calculate the average Euclidean

similarity of the method in this paper with DSmT+PCR5 as shown in figure 5 Compare the average computing

time of the method in this paper with DSmT+PCR5 in each hyper-power sets is shown in figure 6

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 9: An Evidence Clustering DSmT Approximate Reasoning Method

middot

1 2 3

4 5 6

0101005030202005 0050101005030202 0200501010050302

0202005010100503 0302020050101005 005030202005

a a a

a a a

0101

Each new evidence and the evidence b are calculated to obtain the fusion results by DSmT+PCR5 and the

approximate fusion results by the method in this paper and the method18

Then Euclidean similarity of the

approximate results of different methods with the results of DSmT+PCR5 is obtained by formula(10) and the average

computing time of each method is also taken record as tabel 1 (In this paper all the simulation experiments are

implemented by Matlab simulation in the hardware condition of Pentimu(R) Dual-Core CPU E5300 26GHz

259GHz memory 199GB)

Table 1 Euclidean similarity and average computing time coparison of the methods

Euclidean similarity with results of DSmT+PCR5

average

computing

time 1 2 3 4 5 6

The method in

this paper 09939 09911 09955 09938 09965 09960 00028s

The method18

09583 09791 09588 09530 09443 09347 00105s

As shown in table 1 under simple cases of cluster sets in each evidence the accuracy of the method in this

paper all remains over 99 and much higher than the method18

Average computing time of the method in this

paper is also lower than the existing approximate method18

At the same time the accuracy of the method in this

paper in different evidence cases changes little which proves that the method has higher performance stability

62 Complex cases of cluster sets in each evidence

Example 3 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

03035005005004006002001002001004005

02005004021015025005001001001001001

a

b

the method processing is given as follows

1) Force mass assignments of focal elements in each evidence to two cluster sets denoted by

3 4 5 6 7 8 9 10 11 12 1 2 2 3 7 8 9 10 11 12 1 4 5 6 a a a a a a a a a a a a a b b b b b b b b b b b b b

2) First-step approximate fusion results are calculated by formula(6)

CONVEX 030690255900247013090083401662001770001900041000190011000153m

3) Get the final approximate results by normalization method of the first-step approximate results

GH 030090250900242012830081801630001740001900041000190010800150m

4) The results of DSmc+PCR5 and the method18

are also calculated for the parison with the method in this

paper

The results of DSmT+PCR5

DSmT+PCR5 030190252400235012820081101635001690001800039000180010400146m

The results of the method18

XDL 037100183400276012690082801651000030000000001000010000200002m

Calculate the Euclidean similarity between the results GHm and DSmT+PCR5m The Euclidean Similarity

GH 09984E and computing time is 00035s

In the same way the Euclidean similarity between the results XDLm and DSmT+PCR5m is denoted by

middot

XDL 09287E and computing time is 00185s

As shown in the above experiment results in this example the results obtained by the method proposed in this

paper have higher Euclidean Similarity and lower computation complexity than the existing DSmT approximate

method18

The Euclidean Similarity which remains over 99 shows that the method proposed in this paper has

higher accuracy and has practical meaning

Example 4 If there are the same 2 evidence sources in example 3 the hyper-power sets are denoted by

1 2 12 1or 2kG k The mass assignments in the second evidence source are unchanged denoted

by 02005004021015025005001001001001001b and the mass assignments in the first source

change whose sequnce of the mass belief of each focal element moves one position backward at one time to

procedure 11 new evidence

Each new evidence and the second evidence b are calculated to get the fusion results of DSmT+PCR5 and the

approximate results by the method in this paper and the method18

Then Euclidean similarity of the approximate

results of different methods with the results of DSmT+PCR5 and the average computing time of each method are

taken record as tabel 2

Table 2 Euclidean similarity and average computing time coparison of the methods

As shown in table 2 under complex cases of cluster sets in each evidence the accuracy of the method in this

paper also remains over 99 and much higher than the method18

Average computing time of the method in this

paper is lower than the method18

At the same time the accuracy of the method in this paper in different evidence

cases changes little which proves that the method has higher performance stability

63 cases of highly conflict evidence sources

Example 5 In order to verify information fusion of highly conflict evidence sources can be effective solved by the

method in this paper Assume there are two highly conflict evidence sources with the hyper-power set denoted by

D a b c d The mass assignements of two evidenece sources are shown in tabel 3

Table 3 The mass assignements of highly conflict evidenece sources

Conflict evidenece sources a b c d

1S x 1 x

2S y 1 y

Let 001 [002098]x y The fusion results are obtained by different methods when x y is increasing

from 002 to 098 by 001 step at the same time Euclidean similarity of the method18

with DSmT+PCR5 is shown

in figure1 Euclidean similarity of the method in this paper with DSmT+PCR5 is shown in figure2

Euclidean similarity with results of DSmT+PCR5

Average

computing

time 1 2 3 4 5 6 7 8 9 10 11

The method in

this paper

09987 09983 09982 09979 09981 09985 09985 09983 09984 09983 09983 00038

The

method18

08795 09330 09514 09484 08112 08636 08253 08342 08331 08189 08483 00186

middot

Fig 1 Euclidean similarity of the method18

with DSmT+PCR5 Fig 2 Euclidean similarity of the method in this paper with DSmT+PCR5

The average Euclidean Similarity of the method in this paper is 09873 and the average Euclidean Similarity of

the method18

is 08513 Itrsquos shown that the method in this paper can effiectively solve information fusion problem

of highly conflict evidence sources

64 convergence analysis

Example 6 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

01001002025015005010101005005002

05035002002001001001001001001001004

a

b

First fusion results of two evidence a and b

are obtained by different fusion methods Then fuse the prior fusion results with b repeatedly Through the

experiment results each time analyze different methodrsquos convergence

Table 3 The mass assignements of highly conflict evidenece sources

As shown in tabel 3 the convergence of three methods is similar The results of each method can converge to the

main focal elements afer 3 times of evidence fusion However the results of the method in this paper have higher

Euclidean similarity with DSmT+PCR5 and lose less information than the method18

each time

65 monte carlo simulations in the case of non-empty multiple focal elements

If there are 2 evidence sources assume that singleton focal elements and multiple focal elements have mass

Fusion results

1 DSmT+PCR5 042870260000058011630053900109002970029700297001090010900136

The method18

040670099400212018880079800385000270002700027000100001000019

The method in this paper 042850261000060011510053500110002960029600296001100011000141

2 DSmT+PCR5 058290332400031003880012000017000530005300053000170001700099

The method18

056870168600036006420020200127000000000000000000000000000000

The method in this paper 057050345900031003710011600018000520005200052000180001800109

3 DSmT+PCR5 064390334200018000840001600006000080000800008000060000600060

The method18

061710196800009001090002700021000000000000000000000000000000

The method in this paper 061180365500021000780001500006000080000800008000060000600069

4 DSmT+PCR5 067260318100012000170000400004000040000400004000040000400040

The method18

061520204700008000180000400003000000000000000000000000000000

The method in this paper 062640362600015000170000400004000040000400004000040000400048

middot

assignments in hyper-power sets denoted by 1 2 20 1 5 10 20 P Carry out 1000 times monte

carlo simulation experiments First assign random mass value to every focal elements of hyper-power sets in each

evidence each time Then the fusion results of 2 evidence are obtained by DSmT+PCR5 and the method in this

paper seperately Thirdly calculate the Euclidean similarity of the method in this paper with DSmT+PCR5 and

computing time in each monte carlo experiment The monto carlo simulation results are shown in figure 3 figure 4

and table 4

Fig 3 Computing time comparison of the method in this paper with DSmT+PCR5 Fig 4 Euclidean similarity of the method in this paper with

DSmT+PCR5

Table 4 fusion results comparison in the case of increasing focal elements number

Average Euclidean

Similarity

Max Euclidean

Similarity

Min Euclidean

Similarity

Average computing

time(ms)

Max computing

time(ms)

Min computing

time(ms)

DSmT+PCR5 19 31 19

The method in

this paper 09849 09956 09693 084911 14 083593

As shown in figure3 figure4 and tabel 4 in the case of non-empty multiple focal elements the average Euclidean

similarity of the method in this paper can reach 9849 and Euclidean similarity changes little with different

evidence Computing time of the method in this paper almost reduce halfly than DSmT+PCR5

66 monte carlo simulations in the case of increasing focal elements number

Example 7 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 10 1or 2kG k Increase 10 focal elements each time until 500 to

the hyper-power sets and assign random mass value to every focal elements of hyper-power sets in each evidence

each time Carry out 1000 times monto carlo simulation in each hyper-power set calculate the average Euclidean

similarity of the method in this paper with DSmT+PCR5 as shown in figure 5 Compare the average computing

time of the method in this paper with DSmT+PCR5 in each hyper-power sets is shown in figure 6

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 10: An Evidence Clustering DSmT Approximate Reasoning Method

middot

XDL 09287E and computing time is 00185s

As shown in the above experiment results in this example the results obtained by the method proposed in this

paper have higher Euclidean Similarity and lower computation complexity than the existing DSmT approximate

method18

The Euclidean Similarity which remains over 99 shows that the method proposed in this paper has

higher accuracy and has practical meaning

Example 4 If there are the same 2 evidence sources in example 3 the hyper-power sets are denoted by

1 2 12 1or 2kG k The mass assignments in the second evidence source are unchanged denoted

by 02005004021015025005001001001001001b and the mass assignments in the first source

change whose sequnce of the mass belief of each focal element moves one position backward at one time to

procedure 11 new evidence

Each new evidence and the second evidence b are calculated to get the fusion results of DSmT+PCR5 and the

approximate results by the method in this paper and the method18

Then Euclidean similarity of the approximate

results of different methods with the results of DSmT+PCR5 and the average computing time of each method are

taken record as tabel 2

Table 2 Euclidean similarity and average computing time coparison of the methods

As shown in table 2 under complex cases of cluster sets in each evidence the accuracy of the method in this

paper also remains over 99 and much higher than the method18

Average computing time of the method in this

paper is lower than the method18

At the same time the accuracy of the method in this paper in different evidence

cases changes little which proves that the method has higher performance stability

63 cases of highly conflict evidence sources

Example 5 In order to verify information fusion of highly conflict evidence sources can be effective solved by the

method in this paper Assume there are two highly conflict evidence sources with the hyper-power set denoted by

D a b c d The mass assignements of two evidenece sources are shown in tabel 3

Table 3 The mass assignements of highly conflict evidenece sources

Conflict evidenece sources a b c d

1S x 1 x

2S y 1 y

Let 001 [002098]x y The fusion results are obtained by different methods when x y is increasing

from 002 to 098 by 001 step at the same time Euclidean similarity of the method18

with DSmT+PCR5 is shown

in figure1 Euclidean similarity of the method in this paper with DSmT+PCR5 is shown in figure2

Euclidean similarity with results of DSmT+PCR5

Average

computing

time 1 2 3 4 5 6 7 8 9 10 11

The method in

this paper

09987 09983 09982 09979 09981 09985 09985 09983 09984 09983 09983 00038

The

method18

08795 09330 09514 09484 08112 08636 08253 08342 08331 08189 08483 00186

middot

Fig 1 Euclidean similarity of the method18

with DSmT+PCR5 Fig 2 Euclidean similarity of the method in this paper with DSmT+PCR5

The average Euclidean Similarity of the method in this paper is 09873 and the average Euclidean Similarity of

the method18

is 08513 Itrsquos shown that the method in this paper can effiectively solve information fusion problem

of highly conflict evidence sources

64 convergence analysis

Example 6 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

01001002025015005010101005005002

05035002002001001001001001001001004

a

b

First fusion results of two evidence a and b

are obtained by different fusion methods Then fuse the prior fusion results with b repeatedly Through the

experiment results each time analyze different methodrsquos convergence

Table 3 The mass assignements of highly conflict evidenece sources

As shown in tabel 3 the convergence of three methods is similar The results of each method can converge to the

main focal elements afer 3 times of evidence fusion However the results of the method in this paper have higher

Euclidean similarity with DSmT+PCR5 and lose less information than the method18

each time

65 monte carlo simulations in the case of non-empty multiple focal elements

If there are 2 evidence sources assume that singleton focal elements and multiple focal elements have mass

Fusion results

1 DSmT+PCR5 042870260000058011630053900109002970029700297001090010900136

The method18

040670099400212018880079800385000270002700027000100001000019

The method in this paper 042850261000060011510053500110002960029600296001100011000141

2 DSmT+PCR5 058290332400031003880012000017000530005300053000170001700099

The method18

056870168600036006420020200127000000000000000000000000000000

The method in this paper 057050345900031003710011600018000520005200052000180001800109

3 DSmT+PCR5 064390334200018000840001600006000080000800008000060000600060

The method18

061710196800009001090002700021000000000000000000000000000000

The method in this paper 061180365500021000780001500006000080000800008000060000600069

4 DSmT+PCR5 067260318100012000170000400004000040000400004000040000400040

The method18

061520204700008000180000400003000000000000000000000000000000

The method in this paper 062640362600015000170000400004000040000400004000040000400048

middot

assignments in hyper-power sets denoted by 1 2 20 1 5 10 20 P Carry out 1000 times monte

carlo simulation experiments First assign random mass value to every focal elements of hyper-power sets in each

evidence each time Then the fusion results of 2 evidence are obtained by DSmT+PCR5 and the method in this

paper seperately Thirdly calculate the Euclidean similarity of the method in this paper with DSmT+PCR5 and

computing time in each monte carlo experiment The monto carlo simulation results are shown in figure 3 figure 4

and table 4

Fig 3 Computing time comparison of the method in this paper with DSmT+PCR5 Fig 4 Euclidean similarity of the method in this paper with

DSmT+PCR5

Table 4 fusion results comparison in the case of increasing focal elements number

Average Euclidean

Similarity

Max Euclidean

Similarity

Min Euclidean

Similarity

Average computing

time(ms)

Max computing

time(ms)

Min computing

time(ms)

DSmT+PCR5 19 31 19

The method in

this paper 09849 09956 09693 084911 14 083593

As shown in figure3 figure4 and tabel 4 in the case of non-empty multiple focal elements the average Euclidean

similarity of the method in this paper can reach 9849 and Euclidean similarity changes little with different

evidence Computing time of the method in this paper almost reduce halfly than DSmT+PCR5

66 monte carlo simulations in the case of increasing focal elements number

Example 7 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 10 1or 2kG k Increase 10 focal elements each time until 500 to

the hyper-power sets and assign random mass value to every focal elements of hyper-power sets in each evidence

each time Carry out 1000 times monto carlo simulation in each hyper-power set calculate the average Euclidean

similarity of the method in this paper with DSmT+PCR5 as shown in figure 5 Compare the average computing

time of the method in this paper with DSmT+PCR5 in each hyper-power sets is shown in figure 6

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 11: An Evidence Clustering DSmT Approximate Reasoning Method

middot

Fig 1 Euclidean similarity of the method18

with DSmT+PCR5 Fig 2 Euclidean similarity of the method in this paper with DSmT+PCR5

The average Euclidean Similarity of the method in this paper is 09873 and the average Euclidean Similarity of

the method18

is 08513 Itrsquos shown that the method in this paper can effiectively solve information fusion problem

of highly conflict evidence sources

64 convergence analysis

Example 6 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 12 1or 2kG k The mass assignments in each evidence are

01001002025015005010101005005002

05035002002001001001001001001001004

a

b

First fusion results of two evidence a and b

are obtained by different fusion methods Then fuse the prior fusion results with b repeatedly Through the

experiment results each time analyze different methodrsquos convergence

Table 3 The mass assignements of highly conflict evidenece sources

As shown in tabel 3 the convergence of three methods is similar The results of each method can converge to the

main focal elements afer 3 times of evidence fusion However the results of the method in this paper have higher

Euclidean similarity with DSmT+PCR5 and lose less information than the method18

each time

65 monte carlo simulations in the case of non-empty multiple focal elements

If there are 2 evidence sources assume that singleton focal elements and multiple focal elements have mass

Fusion results

1 DSmT+PCR5 042870260000058011630053900109002970029700297001090010900136

The method18

040670099400212018880079800385000270002700027000100001000019

The method in this paper 042850261000060011510053500110002960029600296001100011000141

2 DSmT+PCR5 058290332400031003880012000017000530005300053000170001700099

The method18

056870168600036006420020200127000000000000000000000000000000

The method in this paper 057050345900031003710011600018000520005200052000180001800109

3 DSmT+PCR5 064390334200018000840001600006000080000800008000060000600060

The method18

061710196800009001090002700021000000000000000000000000000000

The method in this paper 061180365500021000780001500006000080000800008000060000600069

4 DSmT+PCR5 067260318100012000170000400004000040000400004000040000400040

The method18

061520204700008000180000400003000000000000000000000000000000

The method in this paper 062640362600015000170000400004000040000400004000040000400048

middot

assignments in hyper-power sets denoted by 1 2 20 1 5 10 20 P Carry out 1000 times monte

carlo simulation experiments First assign random mass value to every focal elements of hyper-power sets in each

evidence each time Then the fusion results of 2 evidence are obtained by DSmT+PCR5 and the method in this

paper seperately Thirdly calculate the Euclidean similarity of the method in this paper with DSmT+PCR5 and

computing time in each monte carlo experiment The monto carlo simulation results are shown in figure 3 figure 4

and table 4

Fig 3 Computing time comparison of the method in this paper with DSmT+PCR5 Fig 4 Euclidean similarity of the method in this paper with

DSmT+PCR5

Table 4 fusion results comparison in the case of increasing focal elements number

Average Euclidean

Similarity

Max Euclidean

Similarity

Min Euclidean

Similarity

Average computing

time(ms)

Max computing

time(ms)

Min computing

time(ms)

DSmT+PCR5 19 31 19

The method in

this paper 09849 09956 09693 084911 14 083593

As shown in figure3 figure4 and tabel 4 in the case of non-empty multiple focal elements the average Euclidean

similarity of the method in this paper can reach 9849 and Euclidean similarity changes little with different

evidence Computing time of the method in this paper almost reduce halfly than DSmT+PCR5

66 monte carlo simulations in the case of increasing focal elements number

Example 7 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 10 1or 2kG k Increase 10 focal elements each time until 500 to

the hyper-power sets and assign random mass value to every focal elements of hyper-power sets in each evidence

each time Carry out 1000 times monto carlo simulation in each hyper-power set calculate the average Euclidean

similarity of the method in this paper with DSmT+PCR5 as shown in figure 5 Compare the average computing

time of the method in this paper with DSmT+PCR5 in each hyper-power sets is shown in figure 6

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 12: An Evidence Clustering DSmT Approximate Reasoning Method

middot

assignments in hyper-power sets denoted by 1 2 20 1 5 10 20 P Carry out 1000 times monte

carlo simulation experiments First assign random mass value to every focal elements of hyper-power sets in each

evidence each time Then the fusion results of 2 evidence are obtained by DSmT+PCR5 and the method in this

paper seperately Thirdly calculate the Euclidean similarity of the method in this paper with DSmT+PCR5 and

computing time in each monte carlo experiment The monto carlo simulation results are shown in figure 3 figure 4

and table 4

Fig 3 Computing time comparison of the method in this paper with DSmT+PCR5 Fig 4 Euclidean similarity of the method in this paper with

DSmT+PCR5

Table 4 fusion results comparison in the case of increasing focal elements number

Average Euclidean

Similarity

Max Euclidean

Similarity

Min Euclidean

Similarity

Average computing

time(ms)

Max computing

time(ms)

Min computing

time(ms)

DSmT+PCR5 19 31 19

The method in

this paper 09849 09956 09693 084911 14 083593

As shown in figure3 figure4 and tabel 4 in the case of non-empty multiple focal elements the average Euclidean

similarity of the method in this paper can reach 9849 and Euclidean similarity changes little with different

evidence Computing time of the method in this paper almost reduce halfly than DSmT+PCR5

66 monte carlo simulations in the case of increasing focal elements number

Example 7 If there are 2 evidence sources assume that only singleton focal elements have mass assignments in

hyper-power sets denoted by 1 2 10 1or 2kG k Increase 10 focal elements each time until 500 to

the hyper-power sets and assign random mass value to every focal elements of hyper-power sets in each evidence

each time Carry out 1000 times monto carlo simulation in each hyper-power set calculate the average Euclidean

similarity of the method in this paper with DSmT+PCR5 as shown in figure 5 Compare the average computing

time of the method in this paper with DSmT+PCR5 in each hyper-power sets is shown in figure 6

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 13: An Evidence Clustering DSmT Approximate Reasoning Method

middot

Fig 5 Euclidean similarity of the method in this paper with DSmT+PCR5 Fig 6 computing time comparison of the method in this paper with

DSmT+PCR5 The fusion results comparison in the case of increasing focal elements number is shown in table 4 (As the

increasing number of focal elements the mass assignment of average cluster center is decreasing sharply For

reducing computation complexity neglect the influnce of the different classification of clusters and apply the

standard of 2

n as one step cluster method n denote the focal elements number of hyper-power sets)

Table 5 Fusion results comparison in the case of increasing focal elements number

The focal elements number of hyper-power sets is increasing from 10 to 510

Average computing

time of DSmT+PCR5

(s)

00008 00032 00073 00132 00208 00297 00406 00530 00670 00829 01017 01219

01405 01636 01867 02133 02431 02685 03009 03319 03698 04013 04427 04816

05212 05588 06011 06462 06959 07413 07909 08425 08962 09505 10082 10659

11263 11882 12516 13166 13828 14509 15225 15926 16660 17409 18174 18946

19765 20574 21397

Average computing time of the method in

this paper (s)

00003 00006 00010 00013 00017 00020 00024 00028 00032 00036 00040 00044

00048 00053 00057 00062 00067 00071 00076 00081 00087 00092 00098 00103 00108 00114 00118 00124 00130 00136 00142 00148 00154 00160 00167 00173

00180 00186 00193 00200 00207 00214 00222 00229 00236 00244 00251 00259

00265 00275 00282

Average Euclidean

similarity with results

of DSmT+PCR5

09774 09826 09871 09881 09895 09907 09917 09922 09922 09927 09931 09933

09939 09940 09938 09945 09945 09946 09947 09947 09950 09953 09949 09954

09955 09955 09955 09956 09959 09958 09961 09959 09961 09960 09959 09961

09962 09964 09961 09964 09964 09964 09964 09965 09966 09966 09966 09968

09966 09968 09967

As shown in figure 5 figure 6 and table 5

1) In the case of increasing focal elements number computing time of the method in this paper decreases

significantly and the computation complexity of the method almost appears linear growth instead of exponential

growth which proves that the method in this paper has a high application in the case of complex fusion problems

2) The accuracy of the method in this paper is increasing with the growth of focal elements number of

hyper-power sets as the errors item becomes much smaller The minimum average Euclidean Similarity is 09974 in

the case of the minimum number of hyper-power sets When number of hyper-power sets increases over 50 the

average Euclidean similarity exeeds 99 which proves that the method in this paper can effectively support correct

and quick decision in the case of large data

4 Conclusions

A new evidence clustering DSmT approximate reasoning method is proposed by analysis of convex function errors

in this paper The method reduces computation complexity of DSmT+PCR5 signanificantly which blocks the wide

application and development of DSmT and remains high accuracy Simulation results show that in different cases the

method in this paper can process evidence fusion problems effectively and efficiently especially in the case of large

data and complex fusion problems the method can get highly accurate results and need low computation complexity

Acknowledgement

The authors are grateful to Prof Li Xinde for discussions They also thank the anonymous reviewers for their

critical and constructive review of the manuscript This study was co-supported by the National Natural Science

Foundations of China (Nos 61102166 and 61471379) and Program for New Century Excellent Tallents in University

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025

Page 14: An Evidence Clustering DSmT Approximate Reasoning Method

middot

(Nos NCET-11-0872)

References

1 Alan J Terry Munir Zaman John Illingworth Sensor fusion by a novel algorithm for time delay estimation[J]

Digital Signal Processing 2012 22(3) 439-452

2 Yilmaz Kalkan Buyurman Baykal Multiple target localization amp data association for frequency-only widely

separated MIMO radar[J] Digital Signal Processing 2014 2551-61

3 Donka Angelova Lyudmila Mihaylova Joint target tracking and classification with particle filtering and mixture

Kalman filtering using kinematic radar information[J] Digital Signal Processing 2006 16(2) 180-204

4 Lauro Snidaro Ingrid Visentini Karna Bryan Fusing uncertain knowledge and evidence for maritime situational

awareness via Markov Logic Networks[J] Information Fusion 2015 21 159-172

5 Yi Yang Deqiang Han Chongzhao Han Discounted combination of unreliable evidence using degree of

disagreement [J] International Journal of Approximate reasoning 2013 54(8) 1197-1216

6 Smarandache F Dezert J Advances and Applications of DSmT for Information Fusion[M] American Research

Press Rehoboth USA Vol1 Vol2 Vol3 200420062009

7 Li X Dezert J Smarandache F Dai X Combination of qualitative information based on 2-Tuple modelings in

DSmT[J] Journal of Computer Science and Technology 2009 24(4)786-798

8 Li X Dai X Dezert J Smarandache F Fusion of imprecise qualitative information[J] Applied Intelligence

2010 33(3)340- 351

9 Li XHuang XDezert Jet al A successful application of DSmT in sonar grid map building and comparison

with DST-based approach[J] International Journal of Innovative Computing Information and Control 2007

3(3)539-551

10 Richa Singh Mayank Vatsa Afzel Noore Integrated multilevel image fusion and match score fusion of visible

and infrared face images for robust face recognition[J] Pattern Recognition 2008 41(3) 880-893

11 Francis Faux Franck Luthon Theory of evidence for face detection and tracking[J] International Journal of

Approximate reasoning 2012 53(5) 728-746

12 Li Xinde Huang Xinhan Dai Xianzhong Meng Zhengda Study on environment perception of mobile robots

using DSmT-based fusion machine Journal of Huazhong University of Science an Technology 200912(37)

64-67[Chinese]

13 Bergsten U Schubert J Dempeters rule for evidence ordered in a complete directed acyclic graph[J]

International Journal of Approximate Reasoning 1993 9(1)37-73

14 Tessem B Approximations for efficient computation in the theory of evidence[J] Artificial Intelligence 1993

61315-329

15 Denoeux T Yaghlane A B Approximating the combination of belief functions using the fast mobiue Transform

in a coarsened frame International Journal of Approximate reasoning 20023177-101

16 Li Xinde Dezert J Huang Xinhan Meng Zhengda Wu Xuejian A Fast Approximate Reasoning Method in

Hierarchical DSmT(A) Acta Electronic Sinica 2010 112566-2572[Chinese]

17 Li Xinde Yang Weidong Wu Xuejian Dezert J A Fast Approximate Reasoning Method in Hierarchical

DSmT(B)[J] Acta Electronic Sinica 2011 3(A)31-36[Chinese]

18 Li Xinde Wu Xuejian Sun Jiaming Meng Zhengda An approximate reasoning method in dezert-smarandache

theory[J] Journal of electronics (China) 2009 26(6)738-745

19 F Smarandache J Dezert Information Fusion Based on New Proportional Conflict Redistribution Rules[C]

Proceedings of fusion 2005 Conf Philadelphia July 26-29 2005

20 Li X Dezert J Smarandache F Huang X Evidence supporting measure of similarity for reducing the

complexity in information fusion[J] Information Sciences 2010 DOI101016jins201010025