Spatial Databases: Lecture 6 DT211-4 DT228-4 Semester 2 2010 Pat Browne Web Mapping .
Sample Exam Questions for Intro to AI - Computing at ... Exam topics DT228-3.pdf · development...
Transcript of Sample Exam Questions for Intro to AI - Computing at ... Exam topics DT228-3.pdf · development...
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Sample Exam Questions for Intro to AI
Q (a) Describe the architecture of a rule-based expert system.
(b) Explain why the use of an expert system shell can dramatically reduce the
development time of an expert system.
(c) With the aid of a simple example, outline the Prolog inference mechanism, making
reference to unification and backtracking.
Q (a) Describe the architecture of a rule-based expert system.
(b) What is meant by the terms data driven and goal driven? Mention an AI language that
uses one of these approaches along with an illustrative example.
(c) In data driven rule based systems, when many rules can be fired at the same times,
outline three strategies that an inference engine might use in choosing which rule to
fire.
(d) Explain why the use of an expert system shell can dramatically reduce the
development time of an expert system.
Q (a) Outline three sources of uncertain knowledge.
Express the first 4 of the rules in part (c) in Prolog.
Give three reasons why Bayesian reasoning is difficult to use in an expert system.
Also, briefly describe three advantages in using certainty factors as opposed to
Bayesian reasoning. Briefly mention two well-known historical expert systems, one of
which used Bayesian reasoning and the other certainty factors.
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(c) Given the forecasting rules below, show how they would fire to forecast tomorrow’s
weather when provided with the following information: there is rain today and the
rainfall is low with a certainty factor of 0.8, and also it is cold with a certainty factor
of 0.9. This formula may be useful:
cf(cf1, cf2) = cf1 + cf2 × (1 – cf1) Rule: 1
if today is rain then tomorrow is rain {cf 0.5}
Rule: 2
if today is dry then tomorrow is dry {cf 0.5}
Rule: 3 if today is rain and rainfall is low then tomorrow is dry {cf 0.6}
Rule: 4
if today is rain and rainfall is low and temperature is cold then tomorrow is dry {cf 0.7}
Rule: 5
if today is dry and temperature is warm then tomorrow is rain {cf 0.65}
Rule: 6
if today is dry and temperature is warm and sky is overcast then tomorrow is rain {cf 0.55}
Q (a) Using a Prolog functor as the appropriate data structure for recording information on a
car such as value, registration number, year of purchase, mileage and make; declare
three example cars.
(b) Write a rule to display value and mileage information on all ford cars in the database
using the type of data in part(a).
(c) Given facts like: parent(tom, mary).
parent(tom, jim).
parent(jim, sue).
Write a predicate which could infer that tom is an ancestor of sue.
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(d) What happens when the following query is presented to a Prolog interpreter?
a(X,b(2,abc),[1,2,3,4]) = a(person(tom,24),b(_,Y),[_,Z|T]).
What happens if = is replaced with == ?
(e) Given the Fibonacci sequence: 0,1,1,2,3,5,8,13,21,34,…
Write a Prolog predicate fib(N, Y) to calculate any term of the sequence.
Q (a) Below is a simplified diagram of neuron connections in a brain. Provide a simple
description of each of the terms in the diagram.
(b) What is a perceptron? Draw a diagram for a single-layer two-input perceptron.
Explain what is meant by linear separability. How many categories can it classify
inputs into? Mention any issues involved in using a perceptron to compute logical
AND, OR and XOR.
(c) Draw a multilayer perceptron diagram that would be appropriate for an XOR gate.
Name and draw the activation function which is suitable for a multilayer perceptron.
Comment briefly on its learning algorithm.
(d) Illustrate the single perceptron training algorithm by computing the weight
adjustments for the first two epochs in the table below.
Perceptron Training for logical OR
Threshold 𝜃 = 0.2 , learning rate 𝛼 = 0.1.
Soma Soma
Synapse
Synapse
Dendrites
Axon
Synapse
Dendrites
Axon
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Epoch Inputs Desired output
Yd
Weights
Weighted sum
Actual Output
Y
Error
e
Weight adjustments
x1 x2 w1 w2 X Δw1 Δw2
1 0 0 0 0.3 -0.1
0 1 1
1 0 1
1 1 1 2 0 0 0
0 1 1
1 0 1
1 1 1 3 0 0 0
Q (a) Using a diagram and some comments, describe how an artificial neuron operates as a
simple computing element. Mention two different activation functions in your answer.
(b) In a multilayer perceptron, describe what is meant by feedforward and
backpropagation. Outline how feedforward might be implemented in a language like
Java (no code required).
(c) Describe how a multilayer perceptron could be trained and afterwards used when
presented with a large training data set.
(d) llustrate how a perceptron that acts as an OR gate is trained by computing the weight
adjustments for the first two epochs in the table below.
Perceptron Training for logical OR
Threshold 𝜃 = 0.2 , learning rate 𝛼 = 0.1.
Epoch Inputs Desired output
Yd
Weights Actual Output
Y
Error
e
Weight adjustments
x1 x2 w1 w2 Δw1 Δw2
1 0 0 0 0.3 -0.1
0 1 1
1 0 1
1 1 1 2 0 0 0
0 1 1
1 0 1
1 1 1 3 0 0 0
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Q (a) Explain breifly each of the following in the context of machine learning:
supervised learning
classification
regression
clustering.
(b) Mention four approaches to machine learning and briefly decribe two of them.
(c) In the context of supervised learning, suppose a 200 record data set was presented to a
learning algorithm, suggest how the set might be divided into 3 groups for training,
validation and testing and what is meant by these terms.
(d) In diagram 1 below there are 20 squares and 40 triangles. Diagram 2 show the same
distribution plus an extra input whose shape is unknown and a neighbourhood of the
input which has 3 squares and 1 triangle. Using the data from the diagrams, illustrate
how Naïve Bayes Classification works in deciding whether the input can be classified
as a square or triangle.
The Bayes formula is
𝑃(𝐻|𝐸) = 𝑃(𝐻)𝑃(𝐸|𝐻) 𝑃(𝐸)⁄
Diagram 1
Diagram 2
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Q (a) In early AI research general problem solving methods were investigated which made
the assumption that many problem domains could be characterised as a finite “state
space” in which the problem solver could “operate” by moving from one state to
another, making an allowed move.
Discuss this from the perspective of the farmer-wolf-goat-cabbage (fwgc) problem
and include in your answer the state space graph for this problem.
(couold be missionaries-cannoibals MC)
(b) Show how a fwgc (MC) state could be represented in Prolog and write some code for
generating allowed moves.
(c) Write a Prolog predicate solve/3 which could be used to find a solution path for the
fwgc or any other similar problem.
(d) Explain how an 8-puzzle state could represented in Prolog and use your scheme to
represent the following state.
(e) Could the code from part (c) be used to solve the 8-puzzle and if so would there be
any major limitation were it to be applied to the 8-puzzle? If such a limitation exists in
solve/3, describe a way (code not necessary) of overcoming it.
(a) In the early days of AI a research group in attempting to describe the semantics
underlying language invented a notation called Conceptual Dependency (CD).
Describe with the aid of simple examples what the following CD action primitive
represent.
atrans
ptrans
mtrans
propel
Mention two criticsim of Conceptual dependency.
(b) Dear CD diagram for “to hit” and then a more specific one for “Mary punched John”.
In what way if any would the CD of “Mary hit John with her fist” differ from this.
(c) Descrrbe what is meant by a Script in Procedural Knowledge Representation and
provide an example.
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