ĐỀ CƯƠNG PT HT HƯỚNG AGENT

7/31/2019 CNG PT HT HNG AGENT

1/25

CNG PT HT HNG AGENT

Cu 1:Gii thiu ngn gn v 5 xu hng pht trin trong lch s tnh ton ni chungdn n s ra i ca cng ngh agent.

5 xu hng pht trin trong lch s tnh ton dn n s ra i ca CN agent

- Ubiqiulity c tnh c mt khp ni

- Interconnection kt hp

- Inteligence Thng minh

- Delegation- i din/thay th

- Human oritentation hng con ngiCu 2 Agent l g?Cc c trng c bn ca Agent. Phn bit tnh phn ng v tnhch ng ca agent.

nh ngha agent- agent l mt h tnh ton hon chnh hay chung trnh uc t trong mt mi trungnht nh, c kh nng hot ng mt cch t ch v mm do trong mi trung nhmt uc mc ch thit k

- Mt agent thng minh l mt h thng my tnh c kh nng hot ng linh hot v t

ch trong mi trung. Linh hoat ngha l: Phn ng, ch ng, mang tnh x hi.Cc c trng c bn ca agent- tnh t ch

- kh nng phn ng

- tnh ch ng

- kh nng x hi

- ngoi ra agent cn c mt s c trng khc nh: Tnh thch nghi v t hc hi; Bnvng trong qu trnh hot ng, Hot ng hung ch, Giao tip v cng tc, Linh hot,Tnh di ng.

Phn bit tnh phn ng v tnh ch ng ca Agent- Tnh phn ng: l kh nng agent c th nhn bit uc mi trung ( qua b phncm nhn no ) v da qua nhn bit , agent p ng kp thi nhng thay i xy ratrog mi trung. Tnh phn ng th hin r nht cc agent hot ng trn cc mi trng


2/25

c tnh thay i nh Internet, mi trung mng phn tn, mi trung vt l,Phn ng cami agent i vi 1 mi trung bn ngoi u hung ti vic thc hin mc tiu ( ch)ca agent .

- Tnh ch ng: khi c s thay i ca mi trng, agent khng ch phn ng mt

cch n gin m cn xc nh mt chui cc hnh ng cn thc hin, bn thn miagent s ch ng trong vic khi ng v thcj hin chui hnh ng ny

Cu 3: c tnh x hi ca agent l g?

Cc agent khng ch hung ti ch ring ca mnh m cn c kh nng tung tc vi ccagent khc trong h thng hung ti ch chung ca h thng. Cc hot ng tung tcny rt a dng bao gm: phi hp, thung lng, cnh tranh.

Cu 4: So snh agent v i tng? Agent v h chuyn gia

So snh agent v i tng- Xt theo quan im h thng, c th xem mi agent cng l mt i tng nhng mctru tng cao hn.

- S khc bit gia Agent v i tng th hin:

Agent Object- Agent c tnh t ch: cc agent c th t quyt nh hnh ng ca mnh m khng hnhng theo yu cu ca agent khc.

- Agent c tnh hng ch: mi agent c mt ch ring v ch ca cc agent trong mth thng c th thng nht hay khng tng thch vi nhau. Do agent thng phithng lng vi nhau mt qu trnh tng tc.

- Agent thng minh, c cc hnh vi linh hot da trn cc c trng nh kh nng phnng, kh nng x hi.

- Agent hot ng: mi agent c mt hoc nhiu lung iu khin (thread) ring.

- C kh nng lin h vi cc agent khc tm kim thng tin cng nh nh s h tr haythng lng.

- Agent s dng ngn ng thng ip chung trao i thng tin vi cc agent khc.


3/25

- Object thng b ng hay ni cch khc object l cc thnh phn tnh v s tng tcgia chng ch thng qua cc thng ip. Object ch thc s hot ng khi nhn c ligi hm t cc i tng khc.- i tng khng c mc ch ring, chng cng chia s mc ch chung ca c h thng.

- Object khng c kh nng phn ng v tnh x hi.

- Trong hng i tng cng c iu khin theo lung (thread) nhng khng yu cu mii tng l c mt thread ring m ngc li c nhiu i tng chung mt thread.

- Tng tc thng qua s kch hot ln nhau khng c s lan ta, khi nhn c yu cu,ch thc hin yu cu trong kh nng ca mnh.

- Object tng tc vi nhau qua cc thng ip v cc thng ip ca object ch gii hntrong nhng class c lp.

2.Agent v h chuyn gia

agent ES( h chuyn gia)- Agent c t trong mi trng- Agent th hnh ng

- Agent c cc c trng ring nh: t ch, phn ng, ch ng v tnh x hi

- H chuyn gia ( Expert system) :l mt h thng tp trung gii quyt mt vn xc nhda trn tri thc ca chuyn gia v vn hoc ua ra li khuyn.- ES is disembodied, rather than being situated

- ES khng tng tc vi mi trng no v khng bt buc phi tng tc vi cc agentkhc

- ES khng c hnh vi phn ng, ch ng, tnh x hi( hp tc, phi hp, cnh tranh)

Cu 5: Phn bit h thng a agent dng Purely Reactive v Perception.


4/25

1. Purely Reactive agents:

- Mt s agent quyt nh lm g m khng cn quan tm n lch s. Quyt nh lm gca chng hon ton da vo hin ti, khng tham chin n trng thi qu kh.

- Chng ta gi nhng agent ny l purely reactive:Action: S A

Trong : S: mi trng . S = {s1,s2,L}

A: tp hnh ng . A={a1,a2,L}

V d: My iu nhit l mt purely reactive agent.

Action(e) = off nu e = nhit ok

on trng hp cn li

action(e) = off if e = temperature ok

on otherwise

e: trng thi (e E)

2. Perception: (Nhn thc)

Hnh ng ring ca agent:

- S tch ri ca mt chc nng Agent quyt nh thnh cc h thng con nhn thc(perception) v hnh ng (Active).

- Hm see l kh nng ca agent quan st chnh n trong mi trng, ni m cc hmaction m t quyt nh ca agent.

- u ra (output) ca hm see l mt percept (kt qu tri gic)

see: E Per

- Hm see l hm nh x t cc trng thi ca mi trng ti percept v u ra ca actionlc ny l mt hm

action: Per* A

ci m nh x chui cm nhn a ra hnh ng. (Per* chuyn gi tr cm nhn vo tphnh ng)


5/25

Per* tp gi tr cm nhn.

- Hai trng thi mi trng khc nhau c nh x ti cng mt kt qu tri gic (percept).

Cu 6: Phn bit cc dng kin trc agentTr li:

Cc dng kin trc Agent:

Kin trc suy din ( Deliberative Logic Based Architectures):- Da trn Symbolic AI : y l kin trc m qu trnh ra quyt nh c thc hin nhsuy din Logic.

- Cc phng php ra quyt nh : Logical Reasoning, Pattern matching, Symbolic

manipulation.- Miu t c trng ca th gii:

+ Mc ch cn t ti.

+ Tp miu t hnh ng -> tm mt chui action t ti mc ch.

+ S dng thut ton n gin

+ To k hoch khng hiu qu.

- M hnh kin trc:

* Nhng hn ch ca kin thc suy din:

- Vn Transduction : tn nhiu thi gian chuyn i tt c nhng thng tin cn thitthnh Symbolic Representation, c bit nu mi trng thay i rt nhanh.

- Vn Representation: Lm th no World model uc biu din mt cch tngtrng v lm th no Agent c th suy din kp thi vi s thay i thng tin

- Cho nhng kt qu hu hnh: nhng kt qu sau cng c th l v dng.

(c th c phn kin trc BDI hoc khng)


6/25

Kin trc BDI ( Belief- Desire Intention: Suy lun thng minh)

- Kin trc da trn qu trnh suy lun thng minh (Practical reasoning) trong qu trnh

ra quyt nh c tin hnh tng bc, cc hnh ng c thc hin xut pht t yucu ca hm mc tiu ra.

- Beliefs : biu din tp cc thng tin v Agent bit v mi trng hin ti ca n ( v cth mt vi trng thi trong).

- Desires: ci xc nh ng c ca n v d ci n ang khm ph.

-Intentions: biu din nhng quyt nh phi hnh ng nh th no hon ton t tidesires ca n.

- M hnh kin trc (BDI)+ Beliefs = hiu bit ca Agent

+ Desires = nhng mc ch ca Agent

+Intentions=nhng mc ch cn hon thnh(tp con ca Desires).

* Extended : goals, plans.

Kin trc phn x ( Reactive)- L kin trc m qu trnh ra quyt nh c ci t mt cch trc tip, tc l s c mtnh x trc tip t tnh hung ti hnh ng.

- S suy din phc tp c th dn n khng li gii hay p ng v mt thi gian.

- Cho php (brooks):

+ Nhng kin trc thng minh c to ra khng cn Symbolic (AI) Representation.

+ Behavior thng minh c th c to ra khng cn Explicit abstract symbolic reasioning(AI).

+ Tnh thng minh l thuc tnh ni bt trong h thng phc tp.

+ Behavior thng minh l kt qu vic tng tc vi mi trng.

- S kin trc:


7/25

- c th ca Agent phn x: Tnh phn x l mt m hnh phn x c s ca hnh ng(behavior based model of activity) m hnh thao tc tng trng c s dng trongs .

- u im: n gin, kinh t, kim sot c kh nng tnh ton, kh nng chu li cao.

- Nhc im:

+ Nu Agent khng s dng m hnh ging nh m hnh ca mi trng trong n hotng th chng phi c y nhng thng tin cn thit bn trong c th thc hin ccAction thch hp.

+ Hu ht cc Agent u ra quyt nh da trn cc thng tin mang tnh cc b ca ringmnh.

+ Cc agent u khng c kh nng hc t nhng kinh nghim gp phi cng nh nng

cao kh nng ca h thng k c hot ng trong mt thi gian di. Kin trc lai Hybrid :- Kt hp tnh phn x v tnh suy din.

- Subsystem to ra nhng k hoch v quyt nh s dng Symbolic reasoning v phn ngli s kin nhanh chng m khng cn nhng reasoning phc tp.

- M hnh kin trc: (Trang bn)

M hnh kin trc Hybrid:

- M hnh kin trc xy dng theo kin trc lp : Ngang v dc

+ u nhc im phn lp chiu ngang :

- n gin. Nu mt Agent c n cch c x khc nhau th s ci t m hnh ny.

- Tuy nhin lun c s tranh ginh trong vic ra quyt nh, bo m s tg thch tathng a vo mt hm iu khin trung tm quyt nh xem lp no ang iu khinhot ng ca Agent.

- C s tng tc gia cc Action khi thc hin.

- y l mt vn kh v khi hot ng c th gy hin tng tht c chai trong qu trnhra quyt nh.

+ u nhc im ca phn lp dc:

- S phc tp trong tng tc gia cc lp gim.


8/25

- Lung iu khin phi i qua ton b cc lp v th nu 1 lp no hot ngkhng n nh s nh hng n ton b h thng.

Cu 7: Chin lc u th (dominant strategies) v cn bng NASH trong tng tca agent l g?

1. Chin lc u th (dominant strategies)

- Cho rng mi agent c th c 2 hnh ng C (cooperate) v D (defect)

- a ra mt chin lc c th no (c C v D) ca agent I, s c mt s cc outcome

c th.- Ni S1 chim u th hn S2 nu mi outcome c th c bi i khi thc hin S1 u uth hn mi outcome c th c b i khi thc hin bi S2.

- Mt rational agent s khng ng vai tr mt chin lc u th (tc l s khng l mtu th ti u hot ng tt nht ti thi im hin ti).

- V th, trong khi quyt nh lm g, chng ta cn loi b cc chin lc chim u th.

- Khng may rng, khng phi lc no cng c duy nht mt chin lc chim u th.

2. Cn bng NASH:

- Ni rng, hai chin lc S1 v S2 c cn bng Nash nu gi thit rng: agent i thc hinS1, agent j khng th thc hin S2 tt hn v gi thit rng agent j thc hin S2, agent ikhng th thc hin S1 tt hn.

Note: Khng agent no c ng c (hnh ng) i ra khi cn bng Nash:

Lu : Khng phi mi tng tc u c cn bng Nash

Mt vi tng tc c th c nhiu hn mt cn bng Nash.

V d 1:

Trong mt tr chi gm 2 i th cng chn mt s bt k t 0 10. Ngi nochn s ln hn s thua v phi tr tin cho ngi kia. Tr chi ny ch c mt cn bngduy nht: c 2 cng chn s 0. Bt k s la chn no khc (m khng cn bit s lachn ca i th kia) cng c th lm i th thua cuc. Khi thay i lut chi, mi i


9/25

th s c hng s tin bng mt con s m c hai cng chn, nu chn trng nhau thkhng ai c tin, ta s c 11 cn bng Nash.

V d 2:

Vi vn Th tri buc tin thoi lng nan ca ngi t nhnSong ny minh ha s mu thun gia hnh vi c nhn, c nng lc suy on v

li ch ca vic hp tc. Vn mu cht l mi khi i th u c gng ti a ha li chca mnh m khng quan tm n li ch ca nhng ngi khc, tc l i th c tnh chk. Song t nhn c mt cn bng Nash khi c hai i th u khng tn trng giaoc. Tuy nhin c 2 u sai r rng khng bng c hai cng hp tc. Chin lc hp tckhng bn v mt i th c th lm tt hn bng cch khng tn trng giao c trong khii th ca anh ta vn hp tc.

Cu 8: Gii thiu ngn gn v cc m hnh tng tc kiu u gi v chin lc u th ca

agent trong cc kiu u gi .- Mt cuc u gi din ra gia mt agent c xem (ng vai tr) l ngi bn u giv mt s t hp ca cc agent c bit n nh nhng ngi tr gi (trong cuc ugi).

- Vi nhng ngi bn u gi th mc ch ca cuc u gi l (phn pht) hng ha(sn phm) cho mt trong s nhng ngi tr gi.

- Trong hu ht vic u gi, ngi bn u gi thng mong mun mt ga cao nht (tia ha li ch cho mnh); nhng ngi tr gi li mong mun gi tr thp nht.

Cc tham s ca mt cuc u gi:

1. Hng ha c th c:

- Gi tr ring

- Gi tr chung

- Gi tr tng quan

2. Quyt nh ca ngi thng cuc (trong cuc u gi) c th:

- Gi th nht

- Gi th hai

3. Tr gi (u gi) c th:


10/25

- Open cry

- u gi kn (sealed bid)

4. S u gi (S tr gi) c th:

- One shot

- Tng dn

- Gim dn

C 4 hnh thc u gi:

- English auctions (u gi kiu Anh)

- Dutch auctions (u gi H Lan)- First-Price Sealed Bid (u gi kn nhng ch mua vi gi u tin)

- Vickrey auctions (u gi Vickrey)

* English Auctions (First-Price Open-Cry)

- Mi ngi u gi t do nng mc gi ln. Khi khng c ngi tr gi cao hn na thcuc u gi kt thc v ngi u gi (tr gi) cao nht s dnh c vt u gi.

- Chin lc u th cho agent l lun tr gi nh hn gi cao nht hin ti v dng li khit c gi th ring.

* Dutch Auctions (u gi H Lan)

- Dutch auctions l mt v d ca cc cuc u gi m gim dn (open-cry descendingauctions)

+ Ngi bn u gi bt u a ra hng ha (sn phm) mc gi o cao

+ Ngi bn u gi gim dn mc gi c a ra ti khi mt s agent tr gi bng gic a ra hin ti.

+ Sau hng ha (sn phm) c phn pht cho agent m (agent) a ra gi hp l.

Chin lc cho agent: u gi H Lan c chin lc bng u gi kn nhng chmua vi gi u tin.

* First-Price Swaled-Bid Auctions (Tr gi kn nhng ch mua vi gi th nht)


11/25

- L u gi kiu one-shot

+ Ch c mt vng duy nht.

+ Ngi u gi chp nhn u gi kn hng ha (sn phm)+ Hng ha c phn pht cho agent m tr gi cao nht

+ Ngi thng cuc phi tr gi cao nht

- Trong cuc u gi ny th khng c mt s tr gi no c mt chin lc u th

Chin lc tt nht l: Tr gi thp hn gi tr thc.

* Vickrey Auctions

- u gi l:

Gi th hai Tr gi kn nhng chu gi kn mua vi gi th hai.

Hng ha c cp cho agent tr gi cao nht: mc gi ca ln u gi caonht th hai.

Chin lc chim u th cho agent trong u gi Vickrey l: tr gi bng vi githc ca bn.

Cu 9: Thng lng t ng l g? Gii thiu ngn gn v m hnh thng lngsong phng.

Thng lng t ng l g?- Thng lng l mt tin trnh c to ra bi hai hay nhiu bn tham gia, mi bntham gia tin hnh ngh cc yu cu v tr li cc yu cu cho i tc nhm i n mttho thun chung tho mn tt c cc bn .

- Thng lng t ng l mt qu trnh thng lng, trong , ngi mua v ngibn c thay th bng cc agent. Vic tm kim, mua bn v tho thun gia ngi muav ngi bn c thc hin t ng bi cc agent.

M hnh thng lng song phngThng lng song phng l dng thng lng ch c mt bn mua v mt bn bntham gia vo qu trnh giao dch. Thng lng c th lin quan n nhiu thuc tnh cahng ha nh gi bn, cht lng

Trong thng lng song phng ngi ta chia ra 3 cch tip cn:


12/25

Cch tip cn da trn l thuyt tr chi

Cch tip cn da trn Heuristic

Cch tip cn da trn lp lun

M hnh thng lng song phng

Chin lc thng lng cho agent bn

Trong m hnh thng lng song phng, agent bn c nhim v qun l vic giao dichng thi vi nhiu khch hng ca mnh. Mt agent bn c trang bi mt tp cc tri thcsau:

+ Tp O=(O1, O2,, Om} cc n v hng ha c th cung cp, mi n v hng ha Oic m t thng qua n thuc tnh {o1,o2,on} v c mt gi tr li ch gi nu bn

c n v hng ha +Mt tp R={r1,r2,,rm} cc rng buc i vi ngi mua ca cc n v hng ha. Tpny c min gi tr kiu boolean

+Mt tp C={c1,c2,..cn} cc hnh thc khuyn mi cho cc n v hng ha, tp ny cngc gi tr kiu boolean

+Mt tp B={B1,B2,..Bk) cc khch hang ang thng lng vi agent bn

Khi , hot ng thng lng ca agent bn nh sau:

Qu trnh trn c th din ra nhiu ln vi mt or nhiu agent mua khc nhau

Chin lc thng lng cho agent mua:

Trong m hnh thng lng song phuong, mi agent mua i din cho mt khch hng,sthng lng vi mt i tc duy nht v do mi agent mua c trag b cc tri thcsau:

+Tp A={A1,A2,..,An} cc thuc tnh hng ha.Mi thuc tnh Ai c u tin ui tngng

+Mi thuc tnh Ai c mt gi tr gi l ngng nhng b ca thuc tnh

+ Mt gi tr ngng chp nhn c trng cho kh nng chp nhn ca ngi dng

+Mt tp D cc cp thuc tnh v cc gi tr ca cc thuc tnh gi i cho bn agent bn

Qu trnh thng lng ca agent mua din ra nh sau:


13/25

Cu 10: Ngn ng truyn thng a agent l g? Th no l l thuyt li ni hnhng (Speech-act theory).

Ngn ng truyn thng a agent

Cc agent trao i vi nhau thng qua cc thng ip. Khc vi cc h hng i tngtrong h a agent khng ch biu din cc li gi hm n gin m cn phi biu dinthng tin v tri thc cn trao i gia cc agent. Cc thng ip ny c biu din theocc ngn ng truyn thng agent (ACL agent communication language) nhm:

- nh ngha khun dng cc thng ip trao i gia cc agent trong h thng

- Thit lp mt giao thc trao i gia cc agent, gm: nh ngha cc kiu thng ipgi v nhn, cc m hnh trao i thng ip gia cc agent

Cc ngn ng truyn thng u da trn l thuyt hnh ng li ni

L thuyt hnh ng li niMi speech act c 3 phng din:

- Locution (kiu ni/cch ni): nh ngha 1 cu trc li ni

- Illocution (hnh vi ngn ng thc hin bi ngi ni)

- Perlocution ( sc thuyt phc, li cun ca li ni): kt qu ca li pht biu

Mt hnh ng li ni ( speech act) y khng ch nh ngha cu trc li ni m cnxc nh hnh ng lin quan n li ni .

V d: John ni vi Mary : Lm n, ng ca li

- Hnh ng ny bao gm kiu din t( t ng) ca chnh JohnLocution

- Mc ch ca thng ip ny nh mooth yu cu or mnh lnhIllocution

- Nu s vic din ra sun s,( li ni c sc thuyt phc) th ca s cngPerlocution

Nhng mc ch ca thng ip thng khng c xc nh d dng

V d: Ti lnh

- Speech act y c th xem l 1 khng nh, 1 yu cu cho mn chic o len ornhu cu tng nhit phng


14/25

- i vi cc giao tip gia cc agent cn m bo rng khng c s nhp nhng vloi thng ip truyn i.

C 5 kiu speech act:

- Representtatives ( M t/din t/ thng bo)Vd: Tri ag ma ( speech act mag tnh cht thng bo v mt hin tng t nhin)

- Directives (ra lnh): yu cu ngi nghe lm g

Vd: Hy pha tr

- Commisive ( ha hn)

- Expressive ( li ni mag tnh cht biu cm)

- Declarations ( tuyn b)

L thuyt li ni hnh ng s dng thut ng performative xc inh hnh vi ngnng bi ngi ni trong cc pht biu in hnh

Nhn chung mt speech act gm 2 thnh phn:

- ng t performative

V d: yu cu, thng bo, ha hn.

- Ni dung (content) ca speech act

Chng hn:

- Nu performative = reaquest (yu cu)

Content =the door is closed

Speech act = please close the door

- Nu performative =inform (thng bo)

Content =the door is close

Speech act = the door is closed

- Nu performative =inquire (Hi han/iu tra/thm d)


15/25

Content = the door is closed

Speech act = is the door closed?

Tm li: L thuyt hnh ng li ni gip xc nh loi thng ip bng cch s dng cc

khi nin ca hnh vi ngn ng thc hin bi ngi ni m bc l ngha ca cc hnh vigiao tip ca chnh n hng ti ch chung ca h thng

Tuy nhin cc thng ip cha trong cc giao thc c th c nhiu hn 1 ngha

- C th khng c phn hi n gin

- Hoc c th yu cu s phn tch v tr gip ca cc agent khc

Cu 11: Ontology l gi? Vai tr ca Ontolofy trong tng tc a agent?

1. Ontology l g?Ontology l mt thut ng ca trit hc, c s dng rng ri trong lnh vc tr tu nhnto v c nhiu nh ngha khc nhau v Ontology trong nh ngha ca T.Gruber lc chp nhn rng ri nht. Theo T. Gruber, Ontology l mt c t hnh thc v khinhim. Cc yu cu cho biu din Ontology l:

- Cc khi nim c dng trong Ontology v cc rng buc gia cc khi nim cnh ngha mt cch r rng.

- Ontology phi l dng thng tin sao cho my c th hiu c.

- Thng tin biu din trong Ontology phi c tnh ph qut ngha l thng tin khng chcho mt thnh phn m cn c chp nhn bi mt nhm cc thnh phn khc nhau.

C th ni , Ontology xc nh tp cc thut ng dng m t v biu din cc khi nimda trn mi quan h qua li gia cc khi nim . Cc khi nim trong Ontology gipcho vic dng chung v chia s tri thc gia 2 min tri thc khc.

Trong h agent, Ontology biu din thng tin v tri thc v min quan tm ca cc agentnhm h tr tng tc. Mi Ontology l mt cu trc phn lp cc khi nim, thut ng,mi quan h gia khi nim, thut ng . Thng qua Ontology cc agent s hiu c nidung cc thng tin p truyn thng m n nhn c trong qu trnh tng tc.

2. Vai tr ca Ontology trong tng tc gia cc agent:

Ontology c xem nhu mt khun mu chung biu din ng ngha thng tin trongmt min xc nh thng qua mt tp khi nim, cc mi quan h v mt tp cc lut c


16/25

s dng rng buc cc khi nim v mi quan h cn thit. Ontology c s dng chocc mc ch sau:

- H tr truyn thng tin gia con ngi; gia con ngi vi my tnh v gia cc h thngmy tnh c lp vi nhau.

- Cho php cc h thng s dng li min tri thc.

- Lm cho min tri thc tr nn r rng hn.

- Phn tch hay kt hp cc min tri thc nh cc php ton.

Trong trng hp s dng Ontology h tr truyn thng gia cc agent phn mm thcc Ontology s biu din cc khi nim v cc thut ng c s dng trong qu trnhtng tc gia cc agent cng vi cc mi quan h cng nh cc lut rng buc gia cckhi nim, thut ng . thc hin truyn thng gi cc agent, mi mt agent trong h

thng phi bit cc thng tin:- Kh nng v dch v ca cc agent khc.

- Ontology nh ngha cc khi nim trao i.

- Ngn ng truyn thng agent m cc agent dng biu din thng ip.

Nh vy, cc agent trong h thng phi dng chung mt ngn ng truyn thng biudin cc thng ip v trong mi thng ip phi c Ontology tng ng m agent githng ip s dng

Cu 12: Cc phung php biu din Ontology?

C hai cch tip cn biu din Ontology:

- Cch tip cn biu din Ontology theo kiu hnh thc: Theo cch tip cn ny, Ontologys uc biu din da trn th t ta c th xy dng uc cu trc i s vi ccphp ton trn ontology

- Cch tip cn biu din ontology theo kiu khng hnh thc: Theo cch ny ontology suc biu din v s dng cho pht trin cc h thng theo mt ngn ng no uc xydng cho mc ch ring. ( v d : OIL, RDF,DAML,..) hoc s dng trc tip ngn nglp trnh ( nh Java)

Cu 13: Phung php xy dng ontology tng qut

Cc pha trong qu trnh xy dng ontology tng qut gm:


17/25

c tPha ny nhm xc nh mc ch v phm vi ca ontology. Mc ch l tr li cho cu hi Ti sao ontology uc xy dng?. Cn phm vi ca Ontolo gy tr li cho cu hiOntology hng ti ci g, i tung s dng ontology l ngui dng hay trnh ng dng?

Hnh thnh khi nimBuc ny tin hnh tp hp cc khi nim cn c trong Ontology v mi khi nim ucm t trong mt m hnh khi nim. M hnh khi nim ny phi m bo tha mn v ttc cc c t v mc ch v phm vi ca Ontology trong buc truc.

Hnh thc haBuc ny nhm hnh thc ha cc khi nim trong ontology. Buc ny uc thc hinthng qua vic chuyn m hnh khi nim trong buc truc vo mt m hnh hnh thc

Ci t

Mi thnh phn trong m hnh ontology hnh thc c trong buc truc s uc ci ttheo mt ngn ng biu din ontology no

Bo trMi thnh phn s uc cp nht v sa i to nn ontology hon chnh

Ngoi cc pha trn, trong vng i pht trin ca ontology tng qut cn c cc hot ngtn ti song song trong ton b qu trnh pht trin ca ontology. Cc hot ng ny baogm:

Thu thp tri thcnh giVit ti liuS dng l

Cu 14:Phn loi cc m hnh tung tc a agent

Da vo mc ch ca cc bn tham gia tung tc, c th chia cc hnh thc tung tcthnh hai loi chnh: Hp tc v cnh tranh

- hp tc: hai bn cng thc hin mt cng vic chung( cng tc) hoc cng vic cabn ny l buc tin cho bn kia ( phi hp). Hnh thc tung tc ny thung xut hinkhi cc agent c chung mc ch, nhim v hoc cng thc hin mt tin trnh phc tpnht nh.

- Canh tranh: hai bn cnh tranh nhau v thng tin, hoc quyn li ( thung lng)hoc hon ton tri nguc nhau v li ch ( i u)

Nh vy, c th c cc loi hnh tung tc sau:


18/25

Cu 15: Gii thiu ngn gn cc m hnh tung tc s dng agent trung gian

1. M hnh tung tc vi Agent trung tmTrong m hnh ny, nhim v ca cc agent trung tm l ch ng lin lc vi cc agent

khc c d liu hay tri thc cn thit trong h thng. Cc dch v m agent trung tm cth cung cp l:

- T ng xc nh cc dch v thng tin

- Xc nh vai tr ca cc agent trong h thng

- T thu thp va to ra thng tin t cc agent cung cp sau gi tr li cho cc agentyu cu

thc hin cc nhim v trn cc agent trung tm s dng m hnh thng tin ton cc bg

cch thu thp v tch hp cc thng tin cn thit gii quyt cc yu cu c th chuyncho cc agent ph hp trong h thng gii quyt.. Nh vy agent trung tm ng vai trl agent trc tip qun l cc agent khc li va t tm ra thng tin cn thit gii quytv gi tr li kt qu cho cc agent yu cu. Hiu qu hot ng ca h thng ph thucvo kh nng ca agent ny.

2. m hnh tung tc vi agent i uTrong m hnh ny, Midagent( agent trung gian) ng vai tr Agent iu phi ( BrockerAgent). Cng vic m Agent iu phi thc hin l mt phn cng vic ca agent trungtm v uc biu din nh sau:

Nh vy trong m hnh tng tc ny, bt k mt lin lc gia agent yu cu v agent cungcp du phi thng qua agent iu phi.

3. M hnh tng tc vi agent mi giiTrong m hnh ny, Midagent ng vai tr nh mt agent mi gii m nhim v chnh can l to ra c ch lin lc trc tip gia Agent yu cu v Agent cung cp nh hnh minhha

Khi mun tham gia vo h thng, mi agent ng k dich v mi gii vi agent mi gii vtr thnh nh cung cp dich v( agent cung cp). agent mi gii s cp nht vo c s trithc ca n tn v kh nng dch v ca agent cung cp. Trong 1 tng tc c th, khi cmt agent yu cu mt dch v th n s gi yu cu n agent mi gii, agent mi giixem xt v gi cho agent cung cp tn v a ch ca agent cung cp. qu trnh tng tcsau s din ra trc tip gia agent yu cu v agent cung cp

Cu 16: Gii thiu v so snh KQML v FIPA-ACL

KQML (Knowledge Query and Manipulation Language)


19/25

KQML nh ngha ba mc l mc ni dung, mc thng ip v mc truyn thng. Mithng ip KQML nh ngha mt hnh ng thoi, ng ngha i km hnh ng thoi ,giao thc v mt tp cc thuc tnh. Cu trc chung ca mt thng ip KQML nh sau

(performative-name

: sender A

: receiver B

: content X

: language L

: ontology N

: reply-with W: in-reply-to P)

Mi mt thng ip KQML tng ng vi mt dng tng tc trong trng performative-name. C ti 25 dng tng tc (performative) c nh ngha bao gm ask-one,advertise, broadcast, insert ng thi, KQML cho php m rng v nh ngha thm ccdng tng tc khc khi cn thit.

Trng content m t ni dung ca thng ip. Ni dung ny c th rt phc tp tu thucvo nhu cu trao i thng tin ca hai agent trong phin lin lc . Agent nhn s hiuc ni dung trong trng content bng cch tham chiu vo trng ontology ca thngip m n nhn c. KQML cng nh ngha cc giao thc truyn thng bao gm c tht cc thng ip, cc perormative. V d mt giao thc truyn thng c nh nghatrong KQML nh Hnh 2.1:

FIPA-ACL (Foudation for Intelligent Physical Agent)

- L mt chun ca ACL

- C cu trc tng t nh KQML

+ performative: c 20 dng performative trong FIPA

- FIPA-ACL cng da trn l thuyt hnh ng li ni . FIPA-ACL s dng XMLtheo dng nh sau [10]:


20/25

- Inform v Request l hai performative c bn trong FIPA-ACL.

- ngha ca Inform v Request c xc nh 2 phn:

+ Pre-condition ( iu kin tin quyt): nhng g phi ng s tht cc speech act thnhcng

+rational effect (nh hng mang tnh l lun): nhng g ngi gi thng ip hy vngmang li

So vi KQML, FIPA-ACl linh ng hn v c th d dng thm vo cc cc dng tngtc mi. Tuy nhin , FIPA-ACL khng nh ngha cc performative theo kiu s dng ccthnh phn trung gian nh trong KQML. l cc performative nh broker hay advertise.

Cu 17 So snh cc cch tip cn pht trin phn mm hng agent

1. Cch tip cn theo Agent v cng ngh agent:

- Xut pht t nhn nh:

+ Agent c nhng c trng ring nh tnh t ch, ch ng, khi nim phn ng. Cc ctrng ny l hon ton khc object v to cho agent kh nng tng tc ch ng v khnng suy lun m object khng c. khng th m hnh ha agent bng cc phng phplun dnh cho hng i tng.

+ Agent hot ng nh mt x hi vi cc lut chi phi ring nn c th xem agent t cckha cnh x hi v s dng cc khi nim tru tng mc x hi m hnh ha ccagent trong h thng.

- Cc khi nim tr tng mc x hi theo cch tip cn ny: agent, nhm (group), t chc(organization)

- Vi cch tip cn ny, qu trnh pht trin h thng c phn chia thnh 2 pha:


21/25

+ pha phn tch ng m hnh t chc (organization model)

+ pha thit k ng m hnh agent (agent model)

Phng php lun tiu biu theo hng tip cn ny: GaiA, SODA, AALAADIN2. Cch tip cn pht trin t phng hng i tng:

- Cch tip cn ny xem mi agent cng l mt i tng nhng mc tru tng caohn. Cng c s dng v biu din i tng v phn tch thng k h thng hng itng UML hon ton c th m rng biu din cc c trng ca agent.

- Cch tip cn ny tp trung vo cc cng vic sau:

+ pht trin cc cng c da trn nn tng sn c ca hng i tng p dng cho h

a agent. V d: m rng UML AUML.+ B sung cc bc, pha mang tnh c trng ca agent v cng ngh nh ch (goal), vaitr (role) v Ontology.

- Phng php lun tiu biu:

+ MASE (Multiagent System Engenerring)

+ MASSIVE

+ KGR

3. Cch tip cn da trn cng ngh tri thc:

- Phng php lun ny tp trung vo cc qu trnh thu thp tri thc (Knowledgeacquisition), m hnh tri thc (Knowledge modelling) v lp lun c s dng bi ccthnh phn agent trong h thng phn mm.

- Phng php lun tiu biu: CoMoMAS, MAS_comonKADS.

Cu 18: gii thiu ngn gn cc bc trong MaSE

Gm 8 bc bao gm 2 pha, pha phn tch v pha thit k.

- Pha phn tch: bc 15

- Pha thit k: bc 58


22/25

C th:

Bc 1: Xc nh cc ch.

Bc 2: Xy dng use caseBc 3: Xy dng Ontology

Bc 4: Xy dng s role

Bc 5: Xc nh cc lp agent

Bc 6: xy dng cc phin hi thoi

Vic chi tit ho cc phin hi thoi l ni dung ca bc 6

Bc 7: Hon thin cc agent

chi tit ho kin trc bn trong ca cc lp agent l ni dung ca bc 7.

Hai bc tip theo ny c th c tin hnh song song.

Bc 8: Trin khai h thng.

Cu 19: Goal l gi? Cc bc xc nh v phn tch goal trong MaSE

* Khi nim

- ch (goal) l mt khi nim ch mc ch m h thng cn t c.

+ Cc goal s phi thc hin c mt hoc nhiu agent

+ ch s c phn r thnh cc ch con, cc ch con tip tc c phn r v cc ch mc thp hn ny s khng c coi l ch m ch c xem xt a vo cc bcsau ca ta phn tch.

* Cc bc xc nh

- xy dng cy ch cn xc nh:

+ Tp hp cc ch


23/25

+ Xy dng cy phn tch cp ch

* Tp hp ch:

- Bc ny thc hin trch cc yu cu chc nng c trong ti liu c t h thng, mi yucu chc nng c m t bng mt ch.

Cc yu cu chc nng c xc nh bng cch tr li cu hi H thng phi lm cig?

- ch u tin xc nh mt cch trc quan thng qua vic xc nh mc tiu cn t cca h thng

- Cc ch tip theo c xc nh thng qua ch trc bng cch tr li cu hi Munt c ch X th cn phi c ci g? Qu trnh ny c gi l qu trnh phn r, t cc

ch ban u s tr thnh cc ch con. Qu trnh dng li khi cc chc nng con sinh rakhng phi l nhim v mc h thng (khng ng vai tr ch cu h thng).

* T chc cy ch:

- Mt s phn cp ch l mt th c hng v khng c chu trnh (dng ta hnhcy). Trong :

+ Cc nh biu din cc ch, c tn trng ch m n biu din.

+ Cc mi tn ch ra quan h ch cha-con v quan h vi cc ch khc.

- C 2 trng hp xy ra:

+ Nu xc nh c ch tng th ca h thng th t n gc ca cy ch.

+ Nu ch tng th khng xc nh c trc tip t yu cu th phi kt hp cc ch mc cao nht li thnh mt ch tng th cho h thng. Cc ch cn li c th phn cthnh cc quan h cha-con hoc ngang hng bng cch lp cc th tc sau:

Bc 1: Cc ch c phn r t cc ch khc trong cc bc con trc phi l ch convi ch cha tng ng.

Bc 2: Nu cc ch khng c phn r t bt k mt ch no, xc nh quan hcha-con, th tr li cu hi chng c thc hin mt phn nhim v cho mt ch nokhng?. Nu c, n s tr thnh ch con ca ch m n h tr. Nu khng, phi xem xtli rng ch c cn thit cho h thng hay khng. Nu khng cn thit th n s b loib v ngc li nu cn thit n s to mt nhnh mi ngay t nt gc ca cy ch.

Cu 20: Phng php nh x goal sang role trong MaSE


24/25

Tr li:

- Input: - Goal hierarchy diagram ( cy phn cp ch)

- Product: - Agent roles- Concurrent Tasks (Tc v ng thi)

- Mc tiu ca bc ny l chuyn tp cc ch (goal) ca h thng vo tp cc role cngvi cc nhim v ca n: Thng thng vic nh x t ch sang role l tng ng 1-1,ngha l mi role thc hin mt ch.

- Tuy nhin, trong mt s trng hp, mt role c th tng ng vi nhiu ch khi ccch ny c quan h cht ch hoc gn ging nhau.

- Cc giao tip vi bn ngoi s c xy dng thnh mt role ring bit v hot ngtng t nh mt tng tc t mt ngun ti nguyn bn ngoi vi phn cn li ca hthng. Cc thnh phn c coi l ngun ti nguyn bn ngoi bao gm: c s d liu, ccfile, h thng b sung v con ngi. Sau khi xc nh cc role ph hp ca h thng, phixc nh c tp cc giao thc giao tip ban u gia cc role ny.

- S role ban u s c chi tit ha bng cch gn task cho cc role. Task l mnhim v c th, chi tit m cc role phi thc hin nhm t c ch m n c trchnhim phi thc hin.

Mi task c th giao tip vi cc task khc m nhim ch ca chng.- Cc role c th hot ng vi 2 loi tng tc:

1. Tng tc trong: cc tng tc gia cc task trong cng mt role.

2. Tng tc ngoi: cc tng tc gia cc task ca cc role khc nhau.

- Thng thng, mi ch nn cho tng ng mt task, bi v mun t c mt ch, tht nht mt task cn phi hon thnh.

Cu 21: Phng php xc nh lp agent trong MaSE.

- Input:

+ Agent roles

+Tasks( cc tc v)

- Product:


25/25

Documents

ĐỀ CƯƠNG PT HT HƯỚNG AGENT