i Hc Quc Gia Thnh Ph H Ch Minh Trng i Hc Cng Ngh Thng Tin Tng Quan V Ontology K Thut Lp Trnh Trnh Tr Tu Nhn To Lp: CNTN02 GVHD: TS. Nguyn Tun ng SVTH: Nguyn Hu Nht MSSV: 07520437

Mc Lc 1. Tng quan v Ontology ........................................................... ................................2 2. Thnh phn ca mt Ontology ....................... .........................................................2 2.1 Cc c th ............ ................................................................................ .............3 2.2 Cc lp ......................................................... .....................................................3 2.3 Cc thuc tnh ............ ................................................................................ .......4 2.4 Cc mi quan h ......................................................... ......................................4 3. Phn loi Ontology ...................... ...........................................................................4 4. Phng php xy dng Ontology ............................................................ ...............5 4.1 Xc nh min quan tm v phm vi ca Ontology ......................... ..............6 4.2 Xem xt vic k tha cc Ontology c sn ................................ ......................6 4.3 Lit k cc thut ng quan trng trong Ontology ................ ............................7 4.4 Xy dng cc lp v cu trc lp phn cp ................. ..............................7 4.5 nh ngha cc thuc tnh v quan h cho lp ............ ................................8 4.6 nh ngha cc rng buc v thuc tnh v quan h ca l ..................8 4.7 To cc thc th cho lp ......................................... .........................................9 5. Ngn ng Ontology .................... ............................................................................9 5. 1 RDF .......................................................................... .........................................9 5.2 RDFS ............................ ................................................................................ ...10 5.3 OWL .................................................................. ..............................................14 5.4 DAML+OIL .................. ................................................................................ .....16 6. Cng c pht trin Ontology ................................................. ................................16 6.1 Protg ..................................... .......................................................................16 6.2 Ch imaera ......................................................................... ................................18 6.3 KAON .................................... ...........................................................................18 7. Ti liu tham kho .................................................................. ...............................20 1

1. Tng quan v Ontology: Thut ng Ontology xut hin t rt sm. Trong cun sch Siu hnh (Metaphysics) ca m gy l mt nhnh ca trit hc, lin quan n s tn ti v bn cht cc s vt trong thc t Ontology xoay quanh vic phn loi cc s vt da trn cc c im mang tnh bn cht ca n trit hc c tm dch l bn th hc, nhm ch khoa hc m t cc loi thc th trong th ngnh khoa hc my tnh v khoa hc thng tin, Ontology mang ngha l cc loi vt v quan mt h thng hay ng cnh cn quan tm. Cc loi vt ny cn c gi l khi nim, thut ng huyn mn no . Ontology cng c th hiu l mt ngn ng hay mt tp cc quy tc c dng Ontology nh ngha mt tp cc t vng mang tnh ph bin trong lnh vc chuyn mn no v th c hiu bi c con ngi ln my tnh. Mt cch khi qut, c th hiu Ontology l "mt ca mt min hay lnh vc nht nh. N cung cp mt b t vng chung bao gm cc khi nim, ngha v cc khi nim v cc thuc tnh ny. Ngoi b t vng, Ontology cn cung cp cc rn nh cc gi nh c s v ngha mong mun ca b t vng, n c s dng trong mt lnh v khc. Ontology c s dng trong tr tu nhn to, cng ngh Web ng ngha (Semantic Web), hut phn mm, tin hc y sinh v kin trc thng tin nh l mt hnh thc biu din tri thc h. Vic to ra cc lnh vc v Ontology cng l c s nh ngha v s dng ca c cu m cture framework). 2. Thnh phn ca mt Ontology: Cc thnh phn thng gp ca Ontology bao gm:

Cc c th(individuals): cc thc th hoc cc i tng (cc i tng c bn hoc cp n khi nim, cc loi i tng, hoc cc loi khc. Cc thuc tnh(attributes): cc kha cnh, s m cc i tng (v cc lp) c th c. Cc quan h(relations): cch thc m cc lp v c hc nng(function terms): cu trc phc tp c hnh thnh t cc mi quan h nht nh c t rong mt bo co(statement). Cc s hn ch(restrictions): nhng m t chnh thc c tuyn mt s khng nh c chp nhn u vo. Cc quy tc(rules): tuyn b c hnh thc nh m c th c rt ra t mt s khng nh trong tng hnh thc ring. Cc tin (axioms): cc hnh thc hp l vi nhau bao gm cc l thuyt tng th m ontology m t trong lnh vc ca 2

Cc s kin(events): s thay i cc thuc tnh hoc cc mi quan h. Sau y chng ta s tm nht ca mt Ontology.

2.1 Cc c th (Individuals): Cc c th l cc thnh phn c bn, nn tng ca mt ontology. Cc c th trong mt ontology n ngi, ng vt, ci bn cng nh cc c th tru tng nh cc thnh vin hay cc t. Mt mt trong nhng l do chnh ca mt ontology l cung cp mt ng ngha ca vic phn lp hc s l mt phn ca ontology. 2.2 Cc lp (Classes): Cc lp l cc nhm, tp hp cc i tng tru tng. Chng c th cha cc c th, cc lp

Ngi (person), cc lp ca tt c mi ngi, hay i tng tru tng c th c m t bi le), cc lp ca tt c cc phng tin xe c, hay i tng tru tng c th c m t bi tt c cc xe t, hoc i tng tru tng c th c m t bi cc tiu ch c mt y i tng tru tng c th c m t bi cc tiu ch c mt lp hc. vt (Thing)

Cc ontology bin i tu thuc vo cu trc v ni dung ca n: Mt lp c th cha cc lp c mi th), c th l lp ch cha nhng c th ring l, Mt lp c th xp gp vo hoc b to ra mt cu trc c th bc cc lp, thng l vi mt lp thng dng nht trn nh xe hi nh hnh sau: Hnh M hnh phn lp xe hi. 3

Nu quy tc phn vng m bo rng mt xe duy nht khng th c hai lp, cc phn vng ny y tc phn vng m bo rng mi i tng c th trong siu lp l mt th hin ca t nht phn vng ton b.

2.3 Cc thuc tnh (Attributes): Cc i tng trong ontology c th c m t thng qua vic khai bo cc thuc tnh ca ch uc tnh . Cc thuc tnh c s dng lu tr cc thng tin m i tng c th c. V , s CMND Gi tr ca mt thuc tnh c th l mt kiu d liu phc tp.

2.4 Cc mi quan h (Relationships): Mi quan h (cn gi l quan h) gia cc i tng trong ontology nh r nh th no cc mi quan h loi ring bit (hay lp) m quy nh c th trong chiu hng cc i tng ny logy. Ch yu sc mnh ca ontology n t kh nng m t cc mi quan h. Cng vi nhau, tp ong mt lnh vc no . Cc thit lp ca cc loi quan h c s dng(cc lp ca cc quan ngn ng trong ontology c th hin. Mt kiu quan h quan trng l kiu quan h xp g n h ny m t cc i tng no l cc thnh vin ca cc lp no ca cc i tng. Ontolog h. V d: loi quan h dnh cho cc quan h gia cc lp loi quan h dnh cho cc quan h gia cc c quan h gia mt c th v mt lp loi quan h dnh cho cc quan h gia mt i tng n h dnh cho cc quan h gia cc b su tp Loi quan h i khi l mt lnh c trng v sau c dng lu tr cc loi c trng ca cc loi quan h c bao gm trong mt ontology, sau ontology nh ngha ring ngn

3. Phn loi Ontology: T khi bt u nghin cu v Ontology trong Khoa hc my tnh, Ontology c quan tm vi h thng c s tri thc bn trong, v n cng a ra nhiu dng Ontology m t kh nng khc c s tri thc. S phn loi Ontology c th c to ra theo ch 4 Hnh Phn loi Onlotogy.

ca s khi nim ha.Trong kha cnh ny, phn ct li nht c tng kt theo hnh bn cnh. ntology lp cao, nhm din t nhng khi nim tng quan v tru tng c th c chia s qua trit hc m t nhng khi nim lp cao cho mi vt v s tn ti ca chng, nh i tng v g v tri thc nhn thc thng thng v hin tng nh thi gian, khng gian, cc tin trnh g s dng trc tip trong cc ng dng, m thng qua cc Ontology khc. Domain Ontology v : cc loi Ontology ny ly tri thc t trong nhng lnh vc xc nh, nh trong y khoa, a v ring bit nh s chn hoc s cu hnh. V mt tng th Ontology loi ny thu hp hn gy. S khi nim ha trong mt Domain Ontology l gi cc tc v c lp, khi nhng nim tr t khng c tnh cht r rt vi chi tit c th n mt lnh vc. S pht trin ca Domain hc, di truyn, a l, du lch, thng tin mi trng. Cn Task Ontology c pht minh cho och lm vic, gim st trong mt lnh vc khoa hc, c s tri thc my tnh dy hc, s theo tr bnh ... Application Ontology: cng thu hp v phm vi, Application Ontology cung cp t vng xc nh c yu cu m t s ban hnh cc tc v chc chn trong mt ng cnh n ask Ontology v m t vai tr ca chng trong mt tc c th. Chng ta c th thy h thng p qua s trnh by trn: Ontology lp thp hn k tha v chuyn mn ha cc khi nim v m tology lp thp c th hn v phm vi ng dng thu hp hn, cn Ontology lp cao c kh nn k tha v s dng li.

4. Phng thc xy dng Ontology: C nhiu phng php khc nhau xy dng mt Ontology, nhng nhn chung cc phng php u rc lp phn cp v nh ngha cc thuc tnh cho lp. Trong thc t, vic pht trin mt Ont cng vic khng n gin, ph thuc rt nhiu vo cng c s dng, tnh cht, quy m, s th phc tp trong . Nhng kh khn ny i hi cng vic xy dng Ontology phi l mt qu tr h ch v pht trin dn sn phm ch khng phi l mt quy trnh khung vi cc cng on tch ogy cng cn phi tnh n kh nng m rng lnh vc quan tm trong tng lai, kh nng k th nh tnhlinh ng Ontology c kh nng m t tt nht cc quan h phc tp trong th gii dng Ontology thng qua cc cng on sau y: Xc nh min quan tm v phm vi ca tology c sn. Lit k cc thut ng quan trng trong Ontology. Xy dng cc lp v cu trc 5

nh ngha cc thuc tnh v quan h cho lp. nh ngha cc rng buc v thuc tnh v quan

4.1 Xc nh lnh vc quan tm v phm vi ca Ontology: Thng thng, cc yu cu i vi mt h thng Ontology l m t lnh vc quan tm nhm phc hng mc ch chuyn bit. Cng vic c t xc nh, phn tch, nhn din chnh xc yu c logy cn m t lnh vc no? Ontology phc v cho mc ch chuyn bit g? C s tri thc tro hng cu hi g? Ontology nhm vc v i tng no? Ai l ngi s xy dng, qun tr Ontolo

Nhn chung, cu tr li cho cc cu hi dng ny c th s thng xuyn thay i trong sut q ht l khi c s thay i v mc ch hoc cn b sung tnh nng trong vic s dng c s tri cc cu hi trn ti mi bc lp s gip gii hn phm vi ca m hnh cn m t v d tr c d, nu d tr kh nng xy ra s khc bit v ngn ng gia ngi pht trin v ngi s dn ng)qua li cc thut ng gia cc ngn ng khc nhau. Hoc gi s Ontology cn xy dng c ch dng dch ti liu t ng th cng cn thit phi c k thut xc nh t ng ngha... Sau tr li nhng cu hi trn, ngi thit k s tr li cc cu hi mang tnh nh gi, qua xy dng. Cc cu hi dng ny thng da trn c s tri thc ca Ontology v c gi l c stion): Ontology c thng tin tr li cho cc cu hi c quan tm trn c s p ng c mc , yu cu no ca ngi s dng? Cc rng buc v quan h phc tp tro

4.2 Xem xt vic k tha cc Ontology c sn: y l mt cng on thng hay s dng gim thiu cng sc xy dng mt Ontology. Bng c c th thm hoc bt cc lp, quan h gia cc lp, thc th... tinh chnh ty theo mc gy c sn cng rt quan trng khi cn s tng tc gia cc ng dng khc nhau, cc ng dng n h... ca nhau thun tin trong vic trao i hoc thng nht thng tin. Vn xy dng cc h thng c sn lin quan n mt bi ton rt phc tp l trn (merging)cc Ontology. V c nh ngha trong cc Ontology ny c th ging nhau trong khi chng c dng m t th xy ra trng hp ngc li, khi tn cc khi nim khc nhau nhng cng m t mt s vt, thuc tnh c sn vo mt h thng mi. Tuy nhin, hu ht cc Ontology s dng trong ngnh k v Web ng ngha ni ring u 6

c xy dng trn cc h thng xy dng v qun tr Ontology. Tn mt s cng c nh: Sesame , OntoEdit, OidEd... Hin nay, a s cc phn mm ny u h tr chc nng t ng trn cc O dng vi nhau. Mc d vy, mc no , ngi xy dng cng cn phi kim tra li mt cch t . Hin c rt nhiu Ontology c chia s trn Web ni ting nh: UNSPSC (www.unspsc.org)do c in ca Lin Hip Quc hp tc vi t chc Dun & Bradstreet nhm cung cp cc thut ng ca c Ontology trong lnh vc thng mi khc nh: RosettaNet (www.rosettanet.org), DMOZ (www.dmoz. rg), eClassOwl... Open Biological, BioPax trong lnh vc sinh vt hc, UMLS trong lnh vc m g ng ngha, GO (Gene Ontology), WordNet (i hc Princeton)...

4.3 Lit k cc thut ng quan trng trong Ontology: y l bc rt hu ch, lm tin cho hai bc tip theo l xy dng cu trc lp phn cp vic lit k tt c cc thut ng xut hin trong min quan tm (c th ng ngha hoc chn thuc tnh... Thng thng, cc thut ng l danh t s tr thnh cc lp, tnh t s tr th lp.

4.4 Xy dng cc lp v cu trc lp phn cp: y l mt trong hai bc quan trng nht ca cng vic xy dng mt Ontology. Nhim v ca b g lit k trong bc trn, sau xy dng cu trc lp phn cp theo quan h lp cha-lp cng cao. V tr u tin thuc v lp gc, tip theo l cc lp trung gian, v cui cng l i c na v ch c biu hin bng cc thc th. Hnh - Cu trc lp phn cp

Quan h gia thc th ca lp con vi lp cha l quan h is-a, ngha l mt thc th ca l nhiu hng tip cn khc nhau cho vn xy dng cu trc lp phn cp. C th k ra ba h 7

Hng xy dng t trn xung (top-down): bt u bng cc lp c mc tng qut cao nht, s (bottom-up): ngc vi hng xy dng cu trc lp phn cp t trn xung, hng ny bt u g qut ha n khi c lp gc. Cch kt hp (combination): cch ny kt hp c hai hng x rong lnh vc quan tm, sau tng qut ha v c th ha cho n khi c cu trc mong mu

4.5 nh ngha cc thuc tnh v quan h cho lp: Bn thn cc lp nhn c bc trn ch mi l nhng thut ng phn bit vi nhau bng tn i thc. Mun nh vy, cc thuc tnh ca lp cn c nh ngha. Thuc tnh ca lp l cc t ca lp v c dng phn bit vi cc lp khc. Thuc tnh c chia lm nhiu loi k loi: thuc tnh bn trong (intrinsic property)v thuc tnh bn ngoi (extrinsic property). tnh bn trong m t cc tnh cht ni ti bn trong s vt, v d: cht, lng, cu to... T hn biu hin ca s vt, v d: mu sc, hnh dng... V mt gi tr, cc thuc tnh cng property)v thuc tnh phc (complex property). Thuc tnh n l cc gi tr n v d: chu h cha hoc tham kho n mt i tng khc.

Mt ch quan trng na trong bc ny l vic mt lp s k tha ton b cc thuc tnh ca uc tnh c nh ngha cc lp thuc mc cao hn hay cha. Thuc tnh ch nn c n in cc lp cao hn.

4.6 nh ngha cc thuc tnh v quan h cho lp: Cc rng buc gii hn gi tr m mt thuc tnh c th nhn. Hai rng buc quan trng nht lity)v kiu (type). Rng buc s yu t quy nh s gi tr m mt thuc tnh c th nhn. H r (single)v a tr (multiple). Nhng mt s phn mm cn cho php nh ngha chnh xc kho h hai l v kiu. V c bn, cc kiu m mt thuc tnh c th nhn l: chui, s, boolean, h c lin quan n hai khi nim gi l: min (domain)v khong (range). Khi nim min c tnh thuc v. Trong khi , khong chnh l lp (hay cc lp)lm kiu cho gi tr thuc tnh rong hnh sau c thuc tnh loi thc n thuc kiu thc th (c cy, cn trng...). Lc n Hnh Rng buc. 8

thc n l ng vt, sinh vt... Cn khong ca n chnh l lp c, cy...

4.7 To cc thc th cho lp: y l bc cui cng khp li mt vng lp xy dng Ontology. Cng vic chnh lc ny l to uc tnh. Nhn chung, cc thc th s to nn ni dung ca mt c s tri thc.

5. Ngn ng Ontology: Ngn ng Ontology (Ontology languages)l ngn ng hnh thc c s dng xy dng Ontology thc trong mt lnh vc c th v thng bao gm cc quy tc suy lun cung cp cho vic x l gn ng Ontology thng l ngn ng khai bo, v hu ht l nhng s tng hp ca ngn ng c tc (First-Order Logic)hoc da trn Logic m t (Description Logic). C rt nhiu ngn ng O k v a ra tun theo s tiu chun ha, ta s tm hiu mt s ngn ng Ontology thng dng ngha v biu din tri thc hin nay. 5.1 RDF (Resource Description Framework): 5.1.1 Tng qu n RDF: RDF l nn tng cho vic biu din d liu trong lnh vc Web ng ngha. Thng tin bi DF l mt pht biu (statement) dng cu trc b ba gm ba thnh phn c bn l: subject, pr Trong : V d: Subject ch i tng ang c m t ng vai tr l ch th. Predica n h. Object l gi tr thuc tnh hay i tng ca ch th nu. Object c th l mt gi cng c th l mt ti nguyn.

Hnh - Object c th l ti nguyn hoc gi tr nguyn thy, nhng subject v predicate th b yn.

y l pht biu m t mt ch th person-1 c kiu thuc tnh name vi gi tr l An. Pht b . C th lit k mt s u im ca vic lu tr d liu RDF so vi d liu truyn thng l: thm bt chnh sa. Cu trc b ba gip cho thng tin d truy xut bi cc h thng suy lun vy m nhng b x l RDF c th suy lun ra nhng thng tin mi khng c trong h d liu. C s ng nht... 5.1.2 Chia s d liu RDF: 9

M hnh RDF th hin c nhiu u im trong vic biu din thng tin. Chnh v vy cn phi DF trn internet. l RDF/XML syntax do W3C a ra nm 1999. y l mt ngn ng da trn X quy tc v t vng h tr cho biu din thng tin RDF. RDF/XML syntax: RDF/XML c th gy v n c th c nhiu cch khi cng biu din mt pht biu, v mt phn l do URI (Uniform R nh danh cho mt ti nguyn th tng i di v kh c, kh vit. Tuy nhin vn ny namespace: vic s dng namespace gip cho ti liu RDF ngn gn v d c hn i vi ngi l http://www.semantic.vn/2009/01/rdf-syntax-ns#. Nu ta gn n cho mt namespace, v d nh : rdf, th t nay v sau ta ch vic dng rdf: phone thay cho http://www.semantic.vn/2009/01 rdf-syntax-ns#phone. nh danh mt ch th: Chng ta dng c php sau biu din mt b ba ,object}, v d: {person-1, name, An} {person-1, phone, 0909213456} V biu din v d trn t g ti liu RDF : Thuc tnh rdf : about dng ch nh resource, cn #person-1 cho ta bit rng person-1 c khai bo trong cng ti liu ny ( g ta khng ch ra person-1 c khai bo u). Nu person-1 khng c khai bo th chn g namespace i din cho URI . Chng ta dng thuc tnh rdf :ID gn nh danh cho mt iption rdf :ID= person-1> y, ti nguyn http://www.semantic.vn/2009/ 01/rdf-syntax-ns#person-1 c nh danh bi person-1. Thuc tnh ID gip cho chng ta s son-1 m khng phi dng li URI ca n di dng m phc tp. 5.2 RDFS (RDF-Schema): RDF-Sche Ontology c bn. N c pht trin tng trn ca RDF cho nn bn thn RDF-Schema cng chn ng thm cc tp t vng h tr cho vic xy dng cc Ontology c d dng. Nh chng ta c th hin dng b ba theo ng m hnh RDF ch thng tin vn cha th hin g v mt n thnh nn ng ngha cho thng tin, l c s xy dng cc cng c tm kim 10

ng ngha. RDFS v RDF c mi lin h tng i gn gi nn i lc ta gi ngn ng ny l RD Hnh So snh gia RDF v RDFS

Trong hnh v chng ta thy, tng RDF ch biu din c thng tin dng b ba. n tng R hn nh Quan Thanh Tho c kiu l Lecturer v Lecturer l lp con ca Academic Staff 5.2.1 uc tnh trong RDF/RDFS: RDF/RDFS nh ngha 13 lp c bn: rdfs :Resource (Ch nh y l Class (Dng khi to mt lp) rdfs :Literal (Lp cc gi tr nguyn thy: chui, s nguyn dfs :Container rdfs :ContainerMembershipProperty rdf :Property (Cho bit ti nguyn th uc lp ny l mt thuc tnh - property) rdf :Statement (Cho bit ti nguyn thuc lp ny l tement) rdf :Bag rdf :Seq rdf :Alt rdf :list (Lp danh sch RDF) rdf :Container V mt s thuc tnh : rdf :type (Xc nh kiu cho mt ti nguyn) rdfs :subClassOf (Cho bit l lp bPropertyOf (Thuc tnh con ca thuc tnh) 11

rdfs:domain (Ch nh vng) rdfs :range (Ch nh tm vc) rdfs:label (Gn nhn cho mt ti n ment (Ch thch) rdf :member (Thnh vin ca mt lp cha - container) rdf :first (Phn t mt danh sch RDF) rdf :rest (Danh sch cc phn t cn li) rdfs :seeAlso (Cc thng tin b s :isDefinedBy (c nh ngha bi) rdf :value (Gn mt gi tr no cho ch th) rdf :sub ) rdf :predicate (Thuc tnh ca mt pht biu) rdf :object (Gi tr thuc tnh ca mt pht thuc tnh c lit k trn y, RDF/RDFS mnh xy dng cc Ontology. Tuy nhin bn th v mt suy lun, cng nh cha c rng buc v kiu v s yu t... m cc ngn ng th h sa phn OWL). Cc lp v thuc tnh thng dng trong RDF/RDFS ch yu l: Resource, Class, Pro , label, subClassOf, subPropertyOf, domain, v range. Trong domain l min ti nguyn s d huc tnh , cn range l phm vi gi tr c th gn cho thuc tnh . V d ta c lp thu Child l lp Person, cn range l lp s nguyn dng chng hn(s con t 1 tr ln). 5.2.2 V RDFS: Chng ta s dng c php c bn sau biu din cho mt pht biu: {subject, predicate iu hn mt thuc tnh cho mt ch th th: {subject, {predicate1, object1} {predicate2, obje } Nu c nt trng th biu din nh sau: {subject, predicate, {predicate-of-bnode,object-ofde} } Mt ti nguyn bt u bi du # chng hn #resource_1 th c ngha l ti nguyn ta ang xy dng ontology. Sau ny mun s dng ti nguyn th ta dng #resource _1 ch k n cho phc tp, kh nhn. 12

By gi chng ta s i vo xy dng mt Ontology n gin, Ontology ny s xy dng tm gn s trn: {rdfs:Class {rdf:ID,"StaffMember"} {rdf:resource, http://www.semantic.vn/2009 /01/rdf-schema#StaffMember"} } {rdfs:Class {rdf:about,"AcademicStaff"} {rdfs:sub ClassOf, "# StaffMember"} } {rdfs:Class {rdf:about,"Lecturer"} {rdfs:subClassOf, #AcademicStaff} } {rdfs:Class {rdf:ID,"Course"} {rdf:resource, http://www.semant ic.vn/2009/01/rdf-schema#Course"} } {rdf:Property { rdf:ID,"phone"} {rdfs:domain , #staffMember} {rdfs:range ,"http://www.semantic.vn/ 2009/01/rdf-schema#Literal "} } {rdf:Property { rdf:ID,"ID"} {rdfs:domain, #staffMember} {rdfs:range ,"http ://www.semantic.vn/ 2009/01/rdf-schema#Literal"} } 13

{rdf:Property { rdf:ID,"involve"} {rdfs:domain, #Course} {rdfs:range ,#AcademicS taff} } {rdf:Property { rdf:ID,"isTaughtBy"} {rdfs:domain, #Course} {rdfs:range ,#AcademicStaff} {rdf:subPropertyOf, involve} } T Ontology c xy dng nh trn ta c th cc ti nguyn nh sau: Staff Member Academic Staff Lecturer Course Nhn s ta thy c hai l StaffMember v Course. Cc lp AcademicStaff v Lecturer ch l tha k t StaffMember. 5 (Ontology Web Language): OWL l ngn ng ontology kh mnh, n ra i sau RDFS nn bit k th ca ngn ng ny ng thi b sung thm nhiu yu t gip khc phc c nhng hn ch ca RD hng tin v kh nng phn loi, rng buc kiu cng nh s yu t tng i mnh. Ta hy tm g u im ca OWL so vi RDFS. Classes owl:AllDifferent owl:Class owl:DataRange owl:DataTy peProperty owl:DeprecatedProperty owl:DeprecatedClass owl:FunctionalProperty Pro perties owl:allValuesFrom owl:backwardCompatibleWith owl:cardinality owl:complem entOf owl:distinctMembers owl:differentFrom owl:disjointWith owl:TransitivePrope rty owl:inverseOf owl:maxCardinality owl:minCardinality owl:oneOf owl:onProperty owl:priorVersion owl:sameAs owl:InverseFunctionalProperty owl:equivalentClass 14

owl:Nothing owl:ObjectProperty owl:someValuesFrom owl:Ontology owl:Restriction o wl:SymmetricProperty owl:equivalentProperty owl:hasValue owl:imports owl:incompatiblewith owl:interse ctionOf owl:sameIndividualAs owl:subClassOf owl:unionOf owl:versionInfo

Trong OWL c thm mt s thuc tnh h tr suy lun v rng buc. H tr suy lun: Tnh c thuc tnh contain v gn cho n thuc tnh owl:transitivePropertive th thuc tnh contai cu. Gi s ta c thng tin A contain B v B contain C, th h thng s t suy lun ra mt th ontain C, v y l biu din thuc tnh contain trong OWL: {owl:TransitiveProperty {rdf:ID," tain"} } Tnh cht o ngc: Nu A c thuc tnh hasParent l B, th suy ra B c thuc tn :OjectProperty {Rdf:ID, hasChild} {owl:inverseOf, #hasParent} } H tr rng buc: Rng : Gi s ta c lp Human, tha k t hai lp ny l Man v Woman. Ta mun mt i tng th an v ngc li. {owl :Class {rdf :about, #Man} {owl :disjointWith, #Woman} } Rng buc s Ta mun mt ngi th ch c mt cha v mt m. Tc thuc tnh hasParent lun c gn s y :onProperty, #hasParent} {owl :cardinality, 2} 15

} Trn y l mt vi v d m trong RDFS khng th lm c. R rng OWL c nhiu u im h minh v c phn loi tt. Vi nhng c im , OWL ngy nay tr thnh ngn ng ontology cc h thng Semantic Web. 5.4 DAML + OIL (DARPA Agent Markup Language + Ontology Inf erence Layer): DAML + OIL l kt qu t hai d n nghin cu c lp vi nhau l DAML v OIL ch v kiu d liu trong cc ngn ng Ontology trc l RDF, RDFS. DAML + OIL (gi tt l cc ti nguyn trn Web, c h tr suy lun. Ngn ng ny c xy dng c k tha t cc chu s im ng ch ca ngn ng ny l: Cho php gii hn cc kiu d liu c nh ng , mt thuc tnh c th nhn gi tr trn nhiu khong khc nhau, to nn tnh uyn chuyn tr ngha thuc tnh unique xc nh cc i tng. Cho php m t cc quan h nh hon i v

DAML sau tip tc tr thnh nn tng cho mt ngn ng Ontology khc l OWL. DAML v c bn r tn mt s t thut ng, c php c sa i), tuy nhin kh nng m t cc rng buc km L t hn 20.000 Website trn Internet vo nm 2002.

6. Cng c pht trin Ontology: V l thuyt, ngi xy dng v pht trin Ontology c th khng cn cc cng c h tr, c t nhin, s khng kh thi khi Ontology c kch thc ln v cu trc phc tp. Thm vo , vi khng ch i hi vic to cu trc lp phn cp, nh ngha cc thuc tnh, rng buc... m uan trn n. C rt nhiu bi ton lin quan n mt h thng Ontology nh: T ht hin li. Kim tra tnh ng n v y . nh x qua li gia cc Ontology. Suy lun tr tology. Xa, sa v tinh chnh cc thnh phn bn trong Ontology. Tch bit Ontology vi ngn L, OWL...).

Nhng kh khn trn khin cc cng c tr thnh mt thnh phn khng th thiu, quyt nh rt nhiu cng c c kh nng h tr ngi thit k gii quyt nhng bi ton lin quan. C t ntolingua , Chimaera , OntoEdit , OidEd , Apollo , RDFedt , WebODE , KAON , ICOM , DOE , WebOnto... Chng ta s tm hiu mt s cng c ph bin nht.

6.1 Protg: Protg l b phn mm m ngun m Java ni ting. Protg c nghin cu v pht trin t n H. Stanford nhm qun l cc thng 16

tin trong lnh vc sinh y hc. y l d n c nhn c s quan tm v ti tr t rt nhi th c tm thy ti website: http://smi-protege.stanford.edu/repos/protege/owl/trunk/src/ed /stanford/smi/. Cc u im ca Protg l: H tr y ba phin bn ca ngn n s dng m hnh hng i tng ca ngn ng Java, Protg t ra rt hiu qu trong vic m h thit k trc quan c tnh tng tc cao. Ngi s dng c th nh ngha cc thnh phn ca php biu din trc quan Ontology di dng cc s . Cho php xy dng Ontology t nhiu ng mt bn tm ca Ontology. Nu c li pht sinh trong qu trnh thao tc th Ontology c s t c th chuyn qua li gia hai bn Ontology ny bng chc nng Revert to a Previous Version v Current Version. Cung cp chc nng tm kim li, kim tra tnh nht qun v y ca Ontol chc nng Run Ontology Test v Check Consistency. Cho php cc lp v thuc tnh ca Ontology g trong mt Namespace khc m ch cn s dng cc URL tham kho. s dng, chn chc nn space. H tr suy lun trc tip trn Ontology da trn Interface chun DL Implementation Gro IG). H tr sinh m t ng. Protg cho php chuyn Ontology thnh m ngun RDF/XML, OWL, DI Java Interfaces, Java Schema Classes... Cc m ny c th c nhng trc tip vo ng dng v trn Ontology khi cn. Cung cp y chun giao tip cho cc Plug-in.

Tuy nhin, Protg cng th hin mt s hn ch nh khng cho php truy vn tng phn mt c hiu qu cc c s tri thc c kch thc ln, hoc cha h tr kt ni trc tip vi mt s Hnh Giao din Protg 3.4 17

6.2 Chimaera: Chimaera cng l mt ng dng khc c pht trin bi i hc Stanford, vi mc ch ban u gy v chun on li, phn tch tnh nht qun gia cc Ontology phn tn. C th tm cc th a ch: http://www.ksl.stanford.edu/software/chimaera/. Mt s im ng ch ca Chimaera l ng dng chy trn nn Web, h tr thao tc vi hn 15 nh dng Ontology bao gm: ANSI K rotg, CLASSIC, iXOL, OKBC... Ring hai chun RDF v DAML s c h tr trong thi gian ti hp sn chc nng chnh sa Ontology, c bit c thm chc nng ko th v phm tt nh s rnh duyt. Tuy nhin, so vi cc ng dng GUI trn Windows/UNIX th vn cn nhiu hn ch. C phn tch, h tr ngi dng chun on v kim tra cc Ontology. Vic kim tra ny bao gm k th tham kho n mt lp hoc quan h cha c nh ngha trong c s tri thc), kim tra chu trnh (cc lp tham kho ln nhau theo mt chu trnh)... Kt qu s c th hin di d era ang c gng tch hp thm lp ngn ng di dng lut cho php ngi dng c t cc Hnh Chimaera h tr hu ht cc nh dng Ontology

6.3 KAON: KAON l mt h thng qun l Ontology m ngun m nhm cho cc ng dng thng mi. N l mt mt Ontology, v n cung cp mt nn tng (framework)cho vic xy dng cc ng dng Ontology cp ng dng cho hai cp ngi dng (user-level): OiModeler v KAON PORTAL, tt c mun KAON vic pht trin phn mm. OiModeler l mt chng trnh tinh chnh Ontology v h tr cho vi tology. KAON PORTAL cung cp mt nn tng n gin cho vic truy cp v tm kim ca Ontology eb. KAON ch yu l mt nn tng cho s pht trin cc ng dng Ontology c s. N c cc M 18

Ngoi vi (front-end): phn ln c trnh by bi hai ng dng: OI-modeler v KAON Portal. L e of KAON): l hai APIs cho RDF v ngn ng Ontology KAON. Th vin (libraries): cung cp ca KAON. Nhp/xut vi nh dng RDFS. Khng h tr quan st ha. Kim tra tnh thay i ORTAL. H tr a ngi dng. Khng h tr vic trn cc Ontology. Vic suy lun lun hiu qu FS vi cc quan h i xng, b sung v nghch o. Cc c tnh ca KAON: Hnh Giao din ca cng c KAON 19

7. Ti liu tham kho: Wikipedia: http://en.wikipedia.org/wiki/Ontology_(information_science) http://en .wikipedia.org/wiki/Ontology_components http://en.wikipedia.org/wiki/Ontology_en gineering http://en.wikipedia.org/wiki/Ontology_language Blog v Forum: http://my. opera.com/Alibobo/blog/index.dml/tag/WEB%20SEMANTIC http://ngo2uochung.blogspot. com/2009/04/quy-trinh-xay-dung-ontology.html http://www.aiti-aptech.edu.vn/forum s/showthread.php?t=1934&goto=nextnewest Ti liu, gio trnh, tiu lun, lun vn: GII T IC WEB & ONTOLOGY - V Hong Nguyn, Hong L Qun Thng 5/2009. Knowledge Representation Ontologies - Logic, Ontologies and Semantic Web Languages - FZI Research Center for Information Technologies, University of Karlsruhe, Germany & Institute AIFB, University of Karlsruhe, Germany. Survey about Ontology Development Tools for O ntology-based Knowledge Management - Seongwook Youn, Anchit Arora, Preetham Chan drasekhar, Paavany Jayanty, Ashish Mestry and Shikha Sethi - University of South ern California. Building Ontology from Knowledge Base Systems - Faten Kharbat, Z arqa Private University - Haya El-Ghalayini, Petra University, Jordan. A softwar e engineering approach to ontology building - Antonio De Nicola, Michele Missiko ff, Roberto Navigli. Slide: Ontologies in the Semantic Web TS. Hong Hu Hnh, H Khoa H Hu. Slide: OWL W3Cs Web Ontology Language - TS. Hong Hu Hnh, H Khoa Hc Hu. 20