Fit Cdio Slide Chcstt Tuan1

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Các hệ cơ sở tri thức Tuần 1: Giới thiệu về các hệ cơ sở tri thức Lê Hoàng Thái

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Transcript of Fit Cdio Slide Chcstt Tuan1

  • Cc h c s tri thc

    Tun 1: Gii thiu v cc h c s tri thc

    L Hong Thi

  • Gii thiu v cc h c s tri thc

    Gii thiu tng quan

    Th no l Qun l tri thc

    Tng quan v mt h c s tri thc

  • Qun l tri thc

    L Hong Thi

  • Qun l tri thc l g

    L qu trnh tm kim, lu gi v s dng cc kin thu thp t cc chuyn gia trong mt t chc ng dng thc t

    Qun l tri thc bao gm cc giai on: khi to, thu nhn, lu tr, phc hi, ph cp tri thc. ng thi, tin ti p dng n sao cho vn m bo s tn ti ca c cu t chc hin ti.

    Qun l tri thc l s kt hp hi ha gia khoa hc, ngh thut v s may ri.

  • Nhng yu t an xen ca QLTT

  • D liu, thng tin v tri thc

    D liu: Nhng s kin, hin tng thuc v bn cht ca t nhin (cha c t chc, cha c x l ); hoc l mt tp hp ri rc cc yu t phn nh mt s vic no .

    Thng tin: c hnh thnh t nhng thu np, kt hp qua li ca d liu sao cho vic ra quyt nh i vi vn cn gii quyt d dng hn.

    Tri thc: l nhng l gii ca thng tin da trn mc quan trng nhn thc c t n. Thng tin tr thnh tri thc vi nhng cu hi nh: Mc lin quan ca thng tin ny cho quyt nh cui

    cng ca ti khi gii quyt vn ?.

  • T x l d liu n cc h CSTT

  • Phn loi tri thc

    Tri thc nng (Shallow (readily recalled)) v Tri thc su (yu cu nhiu nm kinh nghim - deep)

    Tri thc R rng (cc lut Explicit) v tri thc ngm (ghi nhn trong ngh tacit)

    Tri thc th tc (tp hp cc k nng suy din Procedural) khc vi Tri thc t lun (c kh nng t phn on da vo cc tnh tit thu nhn- episodical) vv.

  • Tri thc r v Tri thc Ngm Tri thc ngm(Tacit): Tri thc c ghi nhn trong suy

    ngh ca con ngi thng qua kinh nghim v cng vic. N thng rt kh din t, hnh thc ha v chia s.

    Tri thc r (Explicit): Chuyn n mt kiu tri thc, n c th m ha, lu tr v vn chuyn bng cc k thut cng ngh thng tin sn c (nh sch, ti liu, bo co, b nh vv)

    Tri thc ngm(Tacit) v tri thc r(Explicit) tng c din t bi hai thut ng khc nhau knowinghow: bit nh th no v knowing-that: bit ci g

    Hiu c tri thc v bin i n thnh mt dng tri thc d hiu hn c th trao i, s dng v lu gi n l bn cht ca loi ngi.

  • Tri thc r v Tri thc Ngm

  • T Tri thc th tc n Tri thc t lun

    Tri thc th tc (Procedural Knowledge) Tri thc din t nhng thng tin cn thit thc hin c nhim v yu cu, (nhng thng tin ny chnh l tp hp cc suy din t nhin thc hin nhim v yu cu). Tri thc dng ny s c s dng lp i lp li nhiu ln.

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    Tri thc khi nim (Declarative Knowledge) Cc thng tin kiu b mt thng c sn trong nhng k c ngn hn v d dng din t. N rt hu ch trong cc giai on nm gi tri thc ban u nhng thng thiu ht trong cc giai on sau.

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    Tri thc m t- mng ng ngha (Semantic Knowledge) Tri thc c t chc mt cch trt t (c th bc) cc khi nim cc s kin v mi lin h gia cc s kin.

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    Tri thc t lun (Episodic Knowledge) Tri thc c t chc bi cc nhn t khng gian v thi gian, khng ph thuc vo cc khi nim hoc mi lin h gia chng; thng tin thu nhn c t cc kin ca cc chuyn gia s c khoanh vng da theo tm quan trong ca n. Tri thc ny c bin son, su tp v c tnh logic rt cao. N khng d g trch chn hay bt gi.

    Tri thc nng(Shallow Knowledge)

    Tri thc su (Deep Knowledge)

  • Ti sao phi qun l Tri thc? Chia s, phn b tri thc, mt cng ty s to ra

    li nhun bi ln t tri thc m cc nhn vin hc c.

    To nn mt nhy tt hn i vi t duy ca con ngi.

    Phn ng mau l i vi cc c hi kinh doanh mi

    m bo s hp tc thnh cng v ginh c s tin cy i vi nh cung cp, cc i l,khch hng cng nh nhng ngi y thc khc.

    Rt ngn thi gian o to.

  • Chng minh tnh kh thi ca qun l tri thc

    Tri thc hin ti liu c b mt khng?

    H thng xut cn thit cho nhng a ch ng dng no?

    Cc chuyn gia c sn sng v vui lng khng?

    Cc chuyn gia c m bo ch dn r rng cc bc cn thit gii quyt bi ton?

    H thng c phi l v ch trong ngi nh ca bn?

  • Nhng yu t xy ra trong qun l tri thc

    S i mi tr thnh im trng tm.

    Tnh tng qut ca h thng c th lm thay i phm vi ca t chc.

    Gim quy m v ti xy dng li s dn n s gim thiu v s lng cc nhn vin.

    Mng v lin kt truyn thng s thc y vic chia s tri thc mt cch d dng v nhanh trng.

    Vic gia tng u th ca tri thc ng vai tr lm nn tng cho vic ci tin hiu qu sn xut v tha hng hiu lc ca nhng tri thc c ca cc chuyn gia trc vv...

  • Mt vi thch thc

    Gii thch Qun l tri thc l g v lm th no n c th em li nhun cho mt t chc. Ni cch khc, QLTT phi c iu khin bi cc mc tiu kinh doanh.

    Phi nh gi c tri thc trng tm ca t chc, t nhn vin, t cc b phn, t s phn chia, vv(tri thc c tr nhiu ni).

    Tch tr, lu gi tri thc.

    Hc cch lm th no c th nm gi, x l v tip nhn cc tri thc t nhng gii php thng thng sn c, m n khng sn sng cho mt h QLTT (nh gi v phc tp lin quan n h QLTT) .

    Tip tc nghin cu h QLLTT ci tin v m rng kh nng hin ti ca n.

    Lm th no chia s vi tri thc ngm(tacit)

  • Cc h thng QLTT

    Cc h c s tri thc(KBS) c gng nm gi v dng li tri thc cn thit (nhng tri thc nm bn trong con ngi, vt dng do con ngi lm ra, hay t chc ang tn ti) ci tin tri thc kinh doanh hay t chc trong thc t.

    H thng khai thc tri thc (KDS) c gng khm ph tri thc hu ch mi t mt vng d liu ln.

    Cc h thng chia s tri thc (KSS) c gng h tr cc x l thng qua nhng tri thc r rng v tim n c lin kt vi cc c th khc, s dng nhng phng php truyn thng (cc nhm tranh lun) cng nh nhng k thut thng tin sau cng (nhm nghin cu online, chat room, vv).

  • Cc h c s tri thc (Knowledge base systems-

    KBS)

    L Hong Thi

  • Tc t thng minh(Rational agents)

    Environ

    ment Agent

    percepts

    actions

    ?

    Sensors

    Effectors

    How to design this?

  • H c s tri thc (KBS)

    H chuyn gia (Expert system). L h thng c th thc hin mt cng vic ch nh vi kh

    nng tng t nh chuyn gia con ngi.

    H c s tri thc (Knowledge based system). L mt mi trng cho php chng ta np min tri thc ca

    mt h chuyn gia.

    User World

    Inte

    rfac

    e

    Rea

    son

    ing

    mec

    han

    ism

    Kn

    ow

    led

    ge

    bas

    e

    Kn

    ow

    led

    ge

    acq

    uis

    itio

    n

    mec

    han

    ism

  • Cc h thng QLTT

    C s tri thc (Knowledge base) Nhng m t hnh thc cc s kin v cc lut v min gii

    php ca bi ton.

    Tp hp cc cu trc d liu chnh tc

    Nhng thng tin cn thit h tr cho c ch lp lun/suy din.

    u im ca c s tri thc? Tnh vnh cu: bo qun c nhng tri thc quan trng

    Tnh kin nh: Cc gii php khng thay i.

    Nhc im ca c s tri thc? Khng c kh nng chia s: ch c th s dng cho mt nhim

    v xc nh

    Khng ging con ngi: khng mm do, khng thch nghi, khng sng to

  • Cc giai on x l tri thc

    Biu din tri thc (Knowledge representation)

    Biu din hnh thc min gi tr tri thc

    Cc lut sn xut (Production rules), mng ng ngha(semantic network), khung(frame), logic hnh thc (formal logic).

    S dng tri thc

    C ch suy din (Reasoning mechanism)

    Suy din tin, suy din li, qui np, lp lun theo gi thuyt, lp lun tng t vv

    Vic s dng tri thc chu s nh hng trc tip ca cch biu din tri thc.

    Thu nhn hoc tinh chnh tri thc (Knowledge acquisition or refinement).

    Thu nhn hoc tinh chnh tri thc (Knowledge acquisition or refinement)?

    Phng vn cc chuyn gia

    Qui tc c chai(Bottleneck): Lm th no qun l c mt khi lng tri thc khng l?

    My hc

  • ng dng ca h CSTT

    X l iu khin

    Ti chnh (Vd. Ph chun cc khon vay ngn hng, cc yu cu bo him, cp php cho th tn dng)

    Chn on li (vi d: HP - ch to cht bn dn, NASA- tu con thoi trong khng gian )

    t cu hnh cho h thng my tnh (DEC, IBM)

    Thit k (Xerox- Thit k cc h thng in n bo)

    Lp dy chuyn sn xut (Carlton v United Breweries)

    Khai thc du (Schlumberger, BP)

  • Mt vi h CSTT ang hot ng

    DECs XCON configured complex computer systems. It reportedly did the work of > 300 human experts, with

    fewer mistakes

    American Express uses one to automate checking for fraud and misuses of its no-limit credit card. This has to

    be done in few secs while the customer waits, and the

    cost of an error can be high

    PROSPECTOR is a geological expert system (KBS) to help find valuable mineral deposits

    PIERS, an expert system (KBS) used to diagnose blood samples in St. Vincent Hospital, Sydney

    DENDRAL, an expert system (KBS) that examines the spectroscopic analysis of an unknown chemical

    compound and predicts its molecular structure

  • Lp trnh truyn thng

    Sau khi m ha, tri thc kh nhn bit v cng kh trao i.

    Khi mt lng tri thc ln c m ha, cc chng trnh s rt kh qun l tri thc.

    phc tp lm cho chng ta khng c kh nng b xung thm tr tu thc t hin ti vo mt chng trnh truyn thng.

  • H C S Tri Thc

    Chng trnh= Tri thc + B suy din

    Tri thc l r rng

    Quyt nh then cht cho vic thit k mt h c s tri thc l:

    Lm th no biu din c tri thc v

    Kiu lp lun no (my suy din) s c s dng.

  • Vy khi no cn thit xy dng H C S Tri Thc?

    Bi ton phi c nh ngha tt.

    Khng tn ti mt thut gii hiu qu bit cho vic gii quyt bi ton.

    Min gi tr tri thc cn thit gii quyt bi ton l xc nh (c gii hn).

    C tn ti cc li gii heuristics tng xng.

    Nhim v thc hin s thu c hiu qu cao (li nhun ng k).

    Tn ti: : Hng suy din

    S nhit tnh

    Chuyn gia

    Mt ai c thi gian d phng.

    Cng ty h tr cho d n.

  • BTVN#1: Tm hiu H chuyn

    gia y t MYCIN