NGHIN CU CSDL XML, ONTOLOGY

B GIO DC V O TO

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BO CO MN HCCC H C S D LIU NNG CAO ti:

NGHIN CU CSDL XML, ONTOLOGY GVHD: P.GS-TSKH TN HNH

NHM: V Minh Qun

Nguyn Vn Ha

Nguyn Anh Tun

TP. HCM, thng 10/2013MC LC1PHN I. L THUYT

1A. XML.

11. XML l g?

11.1 Lch s:

11.2 Cc c trng ca XML:

12. Nhng ng gp v c im c th ca XML?

12.1. XML c dng to cu trc d liu:

22.2. XML c mt s im ging vi HTML:

22.3. XML l mt vn bn, nhng khng ging nhng loi vn bn thng thng:

22.4. XML c mt tp hp cc k thut km theo:

32.5. XHTML l s kt hp gia XML v HTML:

32.6. XML c tnh module:

32.7. XML l c s ca RDF v Semantic Web

42.8. XML c s dng min ph, c platform c lp v c h tr rt tt:

43. So snh gia XML v HTML:

54. Cu trc ca XML:

75. ng dng ca XML:

76. Bin dch v chy ti liu XML:

87. DTD (Document Type Definition):

88. Xpath:

149. XSL:

28B. ONTOLOGY:

281. Gii thiu v Ontology:

282. Vi tr ca Ontology:

283. Xy dng Ontology:

294. Cc thnh phn ca ontology:

305. Ngn ng Ontology:

305.1. RDFS (RDF-Shema):

315.2. OWL (Ontology Web Language):

336. Cng c xy dng v qun tr Ontology:

336.1 Quy trnh pht trin Ontology:

356.2 Cng c pht trin ontology:

38PHN II. NG DNG

39TI LIU THAM KHO

PHN I. L THUYTA. XML.

1. XML l g?

1.1 Lch s:XML l vit tt cho ch eXtensible Markup Language (ngn ng nh du. Trong ngnh n lot, ch th cho th sp ch v cch in mt bi v, tc gi hay ch bt thng v cc vng trn trong bn tho v ch thch bng mt ngn ng nh du tng t nh tc k. Ngn ng y c gi l Markup Language.

XML l mt ngn ng nh du tng i mi v n l mt phn nh hn ca v n t mt ngn ng nh du tn l Standard Generalized Markup Language (SGML). Ngn ng HTML cng da vo SGML, tht ra n l mt p dng ca SGML.

V SGML rt rc ri, v HTML c nhiu gii hn nn nm 1996 t chc W3C thit k XML. XML version 1.0 c nh ngha trong h s February 1998 W3C Recommendation, ging nh mt Internet Request for Comments (RFC), l mt "tiu chun". T HTML n XMLS dng k thut XML khng ch c tp on Microsoft m ngay c hng Sun, IBM, Oracles u h tr XML v dng n trong cc ng dng.1.2 Cc c trng ca XML:

XML: Extensible Markup Language l ngn ng tng qut dng lu tr d liu thng qua cc th c ngha.

XML: c nh ngha bi t chc mng ton cu World Wide Web Consortium (W3C).

L ngn ng nh du c lp vi phn mm, phn cng.

Cho php cc my tnh truyn cc cu trc d liu gia h thng khng ng nht.

2. Nhng ng gp v c im c th ca XML?2.1. XML c dng to cu trc d liu:Chng hn nh bng cng tc, s a ch, cc tham s cu hnh, giao dch ti chnh v v k thut. XML l mt h thng cc lut (c th coi l nhng hng dn hay quy c) dng cho vic thit k cc format cho vn bn gip to cu trc cho d liu. XML khng phi l ngn ng lp trnh v ngi dng cng khng cn phi l mt lp trnh vin c th hc v s dng n thnh tho. XML gip cho ngi dng d dng to d liu, c d liu v lm cho cu trc d liu tr nn r rng d hiu. XML cng gip trnh c nhng by thng thng trong thit k ngn ng: n c th m rng, c platform hon ton c lp v h tr tnh quc t ha v ni a ha. XML h tr hon ton Unicode.

2.2. XML c mt s im ging vi HTML:Tng t HTML, XML cng s dng cc tags (cc t c t trong ngoc vi '') v dng thuc tnh (vi mu name="value"). Trong khi HTML c bit ch ti tng tag v attribute c ngha g, v phn vn bn gia cc tag s hin th nh th no trong trnh duyt th XML s dng cc tag ch phn nh ranh gii gia cc mu d liu, v coi vic c v x l d liu hon ton l nhim v ca ng dng. Ni cch khc, nu thy "" trong mt file XML, ng cho rng l k hiu ca mt on. Ty thuc vo vn cnh, n c th l gi (price), mt tham s (a parameter), mt ngi (a person), hay mt ci g bt u bng ch ci 'p' trong ting Anh.

2.3. XML l mt vn bn, nhng khng ging nhng loi vn bn thng thng:Cc chng trnh dng to bng cng tc, s a ch, v cc d liu c cu trc ha thng thng lu d liu trn a, s dng khun dng text hay nh phn. Mt thun li ca khun dng vn bn l cho php xem d liu m khng cn phi c chng trnh to ra d liu ; ni cch khc,ngi dng c th c n vi bt k b son tho vn bn no m h thch. Cc khun dng vn bn cng cho php tm li d dng hn trong cc ng dng. Tuy nhin XML li c im khng bng HTML, cc lut dng trong file XML rt hn ch. Ch cn qun mt tag, hay mt thuc tnh khng i km vi ni dung (quots) s lm cho ton b file XML ngng hot ng, trong khi HTML nhng li ny c th c b qua. Bn ghi XML chnh thc khng cho php cc ng dng tm hiu n ln th 2 nguyn nhn gy li file XML; nu file b li ng dng ngng hot ng ngay lp tc v bo li.

2.4. XML c mt tp hp cc k thut km theo:XML 1.0 l mt bn ghi nh ngha v "tags" v "thuc tnh". Trn XML 1.0, "the XML family" l mt b cc module cung cp cc dch v hu dng hon thnh nhng nhim v yu cu c tnh cht thng xuyn v quan trng. Xlink c coi nh mt phng thc chun a cc lin kt siu vn bn vo file XML. XPointer and XFragments l nhng c php pht trin cc phn trong vn bn XML . XPointer c i ch ging URL, nhng thay v tp trung vo vn bn trn mng, n li tp trung vo tng on d liu trong file XML. CSS, the style sheet language, c th p dng c i vi XML ging nh HTML. XSL l mt loi ngn ng rt tin b dng cho style sheets. N da trn XSLT, mt loi ngn ng chuyn i s dng trong vic sp xp li, Thm vo v xo i mt s tag v thuc tnh. DOM l mt b cc chc nng chun dng cho thao tc file XML (v HTML) t mt ngn ng lp trnh. XML Schemas 1 v 2 gip cc nh thit k nh ngha chnh xc cu trc nh dng trn ca chnh h. Ngoi ra cn c mt s module v cng c khc hay vn ang c pht trin.

2.5. XHTML l s kt hp gia XML v HTML:XML c mt ng dng rt quan trng l khun dng vn bn: XHTML ca W3C, y l th h tip sau ca HTML. XHTML c nhiu im chung vi HTML. Tuy nhin, trong c php cng c mt s thay i ph hp vi cc lut trong XML. Mt vn bn c to ra vi XML s mang cu trc ca XML v b hn ch mt s phng din. (V d, XHTML cho php "", nhng li khng cho ""); n cng b sung thm ngha cho c php (XHTML qui nh "" l "on vn (paragraph)", ch khng phi "gi (price)", "ngi (person)", hay bt c mt ci g khc).

2.6. XML c tnh module:XML cho php bn to ra mt khun dng vn bn mi bng cch kt hp hay s dng li cc khun dng c sn. Do 2 khun dng c pht trin c lp nn c th xut hin nhng c tnh v thuc tnh trng nhau. V vy phi thn trng khi kt hp nhng khun dng ny vi nhau (ngha l "" c th l "paragraph" trong khun dng ny nhng li l "person" trong khun dng kia. trnh nhm ln khi kt hp cc khun dng vi nhau, XML cung cp c ch namespace. XSL v RDF l nhng v d in hnh ca nh dng XML c s dng namespace. XML Schema to iu kin d dng kt hp 2 gin to ra ci th 3 c cu trc vn bn kt hp.

2.7. XML l c s ca RDF v Semantic Web

Khung miu t ti nguyn ca W3C (RDF) l mt khun dng vn bn XML h tr m t ti nguyn v cc ng dng metadata, v d nh danh sch bn nhc, b su tm nh , su tm th mc. RDF cho php bn nhn din ngi trong album nh web s dng thng tin t danh sch lin lc c nhn; sau chng trnh nhn gi th s t ng gi message n nhng ngi ny thng bo cho h bit nh ca h ang trn mng. Cng nh cc vn bn tch hp HTML, h thng menu, v ng dng forms dng bt u cc Web gc, ng dng tch hp RDF v cc tc nhn trong Semantic Web. Cng ging nh con ngi cn c s thng nht v ngha nhng t h s dng trong giao tip, cc my vi tnh cn c c ch thng nht v ngha cc thut ng truyn t thng tin mt cch hiu qu. nh ngha chnh thc cc thut ng trong mt vi lnh vc (mua bn hay sn xut) gi l bn th hc rt cn thit trong Web Semantic. RDF, bn th hc, v vic th hin ngha, v vy cc my tnh c th gip con ngi tin hnh cng vic ca mnh l ton b ni dung hot ng ca Semantic Web.

2.8. XML c s dng min ph, c platform c lp v c h tr rt tt:Khi la chn XML lm c s thc hin mt d n, bn c th tip cn vi rt nhiu cc cng c pht trin. La chn XML c i cht ging vi chn SQL cho c s d liu: bn vn phi xy dng c s d liu cho mnh v cc chng trnh ring cng nh phi c nhng qui tc thao tc n. C rt nhiu cng c c sn v bn cng c th d dng nhn c s gip ca nhiu ngi. V XML khng cn phi mua bn quyn mi s dng c nn bn c th to cho mnh mt phn mm ring m khng phi tr mt khon chi ph no ht.3. So snh gia XML v HTML:Phn bit gia HTML Sitemap v XML Sitemap? Khi ni v sitemap (s website), chng ta thng nhc n hai loi chnh: HTML (Hyper Text Makeup Language) sitemap v XML (EXtensible Makeup Language) sitemap. Tuy chc nng c bn u ls cu trc website, nhng v i tng v k thut th li hon ton khc nhau.

C HTML v XML u da trn chun ngn ng dng tng qut SGML

XMLHTML

Content Markup LanguagePresenttation Markup Language

Cho php ngi dng nh ngha cc phn tCc phn t c nh ngha sn

Kim tra tnh hp lHu nh khng bt li

Cho php trao i d liu gia cc ng dngCh c thit k trnh din

Cn phi c nh ngha mt cch cht chKhng bt buc

Cc phn t cn phi ngCc phn t rng khng cn phi ng

4. Cu trc ca XML:Mt ti liu XML gm: nh ngha cc phn t, cc thuc tnh, kiu d liu,vv...

Cha cc d liu, cc phn t cha d liu nh text, hnh nh, media,vv...

Tp tin XML c phn m rng .XML

V d: greeting.xml

Gii thch:

u im ca XML:

D dng x l, chuyn ti v trao i d liu.

M t d liu v cch d liu mun th hin thng qua th nh.

T chc d liu c cu trc v phn cp.

5. ng dng ca XML: CML Ngn ng nh dng ha hc.

MathML Ngn ng nh dng ton hc.

XHTML: M rng v nh ngha li HTML. WML (Wireless Markup Language)6. Bin dch v chy ti liu XML:B phn tch (XML Parser) Tch d liu thnh tng mu nh v khin chng c th truy xut c bi m lnh ca chng trnh. Mt s trnh phn tch kim lun c chc nng kim tra khun dng hoc tnh hp l ca ti liu XML. Cc b phn tch thng dng XML for Java (XML4J): L th vin phn tch ti liu XML c pht trin bi IBM AlphaWorks. Microsoft XML Parser: c km theo sn chng trnh duyt Internet Explorer 5 tr ln.B kim tra (XML Validator) Dng kim tra ti liu XML vit c ng khun dng v hp l hay khng? Cc b kim tra thng dng XML Write: L trnh son tho v kim tra tnh hp l ca ti liu. Altova XMLSpy 2010 : L trnh bin tp v l mi trng pht trin XML bn chy nht th trng cho cc tc v to mu, bin tp, chuyn i cng nh d li cc cng ngh da trn nn tng XML.7. DTD (Document Type Definition):DTD l mt b nhng qui tc c php cho nhn. N cho bn bit nhng nhn no bn c th s dng trong mt ti liu, chng nn c xp theo th t no, nhng nhn no c th xut hin bn trong cc nhn khc, nhng nhn no c cc thuc tnh,...Mt DTD c th l mt b phn ca mt ti liu XML, nhng thng n l mt ti liu ring bit hoc mt loi cc ti liu.

]>

Tove

Jani

Reminder

Don't forget me this weekend

Tove

Jani

Reminder

Don't forget me this weekend!

8. Xpath:Chng ta thy cu trc v c php ca XML tng i n gin. XML cho ta mt cch chun trao i tin tc gia cc computers. Bc tip theo l tm hiu cch no mt chng trnh ch bin (process) mt ti liu XML

D nhin ch bin mt XML chng trnh ng dng phi c cch i li bn trong ti liu ly ra values ca cc Elements hay Attributes. Do ngi ta thit k ra ngn ng XML Path language, m ta gi tt l XPath. XPath ng mt vai tr quan trng trong cng tc trao i d liu gia cc computers hay gia cc chng trnh ng dng v n cho php ta la chn hay sng lc ra nhng tin tc no mnh mun trao i hay hin th.

Nu khi lm vic vi c s d liu ta dng SQL statement Select .. from TableXYZ WHERE ... trch ra mt s records t mt table, th khi lm vic vi XML, mt table d liu nho nh, XPath cho ta nhng expressions v criteria (iu kin) ging ging nh clause WHERE trong SQL.

XPath l mt chun process XML, cng ging nh SQL l mt chun lm vic vi c s d liu. Tin phung trong vic trin khai cc chng trnh p dng XPath l cng tc ca cc cng ty phn mm ln nh Microsoft, Oracle, Sun, IBM, v.v. S d ta cn c mt chun XPath l v n c p dng trong nhiu hon cnh, nn cn phi c mt l thuyt r rng, chnh xc.

L thuyt v XPath hi kh khan nhng n c p dng trong mi k thut ca gia nh XML. Cho nn bn hy kin nhn nm vng nhng iu cn bn v n khi no gp ch ngi ta dng XPath th mnh nhn din v hiu c. So vi v thut, th XPath trong XML ging nh Tn php v cch th. Tp luyn Tn php th mi chn, tp th th nhm chn, nhng khng c hai th th ra chiu khng c cng lc, cha nh thua ri.

XPath cho ta c php din t cch i li trong XML. Ta coi mt ti liu XML nh c i din bng mt tree (cy) c nhiu nodes. Mi Element hay Attribute l mt node. minh ha nim ny, bn hy quan st ti liu t hng (order) XML sau:

2002-03-26 John Costello Chair 6 Desk 1

Ta c th biu din XML trn bng mt Tree nh di y, trong node Element mu nu, node Attribute mu xanh:

Ch nh Location Path Bn c th dng XPath expression ch nh Location Path (li i n v tr) n node no hay trch ra (tr v) mt hay nhiu nodes tha ng iu kin yu cu. XPath expression c th l tuyt i, tc l ly node gc lm chun hay tng i, tc l khi u t node va mi c chn. Node y c gi l context node (node vai chnh trong tnh hung).

C hai cch vit din t XPath Location, vit nguyn v vit tt. Trong c hai cch ta u dng du slash (/) ni n Document Element, tc l node gc. Ta c th i li trong cc node ca Tree ging ging nh cc node ca Windows System Directory m ta thy trong Panel bn tri ca Window Explorer. Ta cng s dng nhng k hiu nh slash /, mt chm . v hai chm .. ca Windows System File Folder cho cch vit tt trong XPath Location i xung cc nodes con, chu, ch nh context node, hay i ngc ln cc nodes t tin.

Location Path tuyt i Chng ta hy tm vi location paths trong ci Tree ca ti liu XML v t hng ni trn. Mun chn ci node ca Element Order (n cng l Root Element) bng c php nguyn, ta s dng XPath expression sau y:

/child::Order Dch ra c php tt, expression ny tr nn:

/Order i ra nhnh ca Tree, ta s tm c node Customer bng cch dng XPath expression sau:

/child::Order/child::Customer Sau y l XPath expression vit tt tng ng:

/Order/Customer Nu bn mun ly ra mt node Attribute, bn phi ni r iu ny bng cch dng t cha kha (keyword) attribute trong cch vit nguyn hay dng character @ trong c php tt. Do ly Attribute OrderNo ca Element Order, ta s dng XPath expression sau:

/child::Order/attribute::OrderNo C php tt cho Attribute OrderNo l:

/Order/@OrderNo trch ra cc nodes con chu, tc l cc nodes nhnh xa hn, ta dng keyword descendant trong c php nguyn hay mt double slash (//) trong c php tt. Th d, ly ra cc nodes Product trong ti liu, bn c th dng expression location path sau:

/child::Order/descendant::Product C php tt tng ng l:

/Order//Product Bn cng c th dng wildcards (l bi Joker) ni n nhng nodes m tn ca chng khng thnh vn . Th d, du asterisk (*) wildcard ch nh bt c node tn no. Location path sau y chn tt c cc nodes con ca Element Order:

/child::Order/child::* C php tt tng ng l:

/Order/* Location Path tng i Nhiu khi XPath location paths l tng i vi context node, trong trng hp y location path din t cch ly ra mt node hay mt s (set of) nodes tng i vi context node. Th d nh, nu Element Item th nht trong order l context node, th location path tng i trch ra Element con Quantity l:

child::Quantity Trong c php tt, location path tng i l:

Quantity Tng t nh vy, ly ra Attribute ProductID ca Element con Product, ci location path tng i l:

child::Product/attribute::ProductID Expression y dch ra c php tt l:

Product/@ProductID i ngc ln pha trn ca Tree, ta dng keyword parent (cha). Dng tt tng ng ca keyword ny l hai du chm (..). Th d nu context node l Element OrderDate, th Attribute OrderNo c th c ly ra t Element Order bng cch dng location path tng i sau:

parent::Order/attribute::OrderNo l c php ny ch tr v mt tr s khi node cha tn Order. Nu mun ly ra Attribute OrderNo t node cha khng cn bit n tn g bn phi dng expression sau:

parent::*/attribute::OrderNo Vit theo kiu tt n gin hn v bn khng cn phi cung cp tn ca node cha. Bn c th ni n node cha bng cch dng hai du chm (..) nh sau:

../@OrderNo Ngoi ra, bn c th ni n chnh context node bng cch dng hoc keyword self hoc mt du chm (.). iu ny rt tin trong vi trng hp, nht l khi bn mun bit current context node l node no. Dng iu kin trong Location Path Bn c th gii hn s nodes ly v bng cch gn thm iu kin sng lc vo location path. Ci iu kin gii hn mt hay nhiu nodes c thp vo expression bn trong mt cp ngoc vung ([]). Th d, ly ra mi Element Product c Attribute UnitPrice ln hn 70, bn c th dng XPath expression sau y:

/child::Order/child::Item/child::Product[attribute::UnitPrice>70] Trong c php tt, n l:

/Order/Item/Product[@UnitPrice>70] Trong expression ca iu kin bn cng c th dng Xpath tng i , do trong expression iu kin bn c th dng bt c node no trong th bc. Th d sau y ly v nhng nodes Item c Element con Product vi Attibute ProductID tr s bng 1:

/child::Order/child::Item[child::Product/attribute::ProductID=1] Dch ra c php tt, ta c:

/Order/Item[Product/@ProductID=1] 9. XSL:X ML l cch tuyt diu cho ta sp xp d liu trao i chng gia cc t chc v gia cc chng trnh ng dng. Tuy nhin, chng chng th chy, ta s khm ph s a din ca c s d liu khp ni. V ngay c c chun XML ri, ta vn cn mt cng c hiu lc trnh by d liu trong nhiu kiu khc nhau thch hp cho p dng ch bin mt ni khc.

XSL - eXtensible Style Sheet (nhng trang din t dng iu) l mt ngn ng chun gip ta bin i (transform) mt ti liu XML ra format khc, nh HTML, Wireless (v tuyn in) Markup Language (WML), v ngay c mt XML khc. Lc nguyn thy, XSL c thit k sanh ra nhiu HTML trong nhng dng khc nhau ty theo Style sheet. Tc l XSL thm dng iu cho XML, v chnh bn cht ca XML ch l mt cu trc ca nhng mnh d liu.

Th d ta c hai Style sheet versions cho mt XML, mt ci dng to ra HTML cho trang Web thng thng trn computer, cn ci kia to ra trang Web dng cho Mobile Phone hay Pocket PC, nhng dng c c mn nh nh. C hai trang Web u cha cng mt s d liu, c th trn mn nh nh th gii hn nhng d liu quan trng thi, nhng cch trnh by c th rt khc nhau.

Tuy nhin, sau khng lu, ngi ta thy XML c th c XSL bin i ra bt c Output Format no, ngay c chnh XML. C mt version mi, rt hay ca XSL va ra i. N c gi l XSL Transformations (XSLT).

Chng ta s ln lt hc cc c php thng dng ca XSL. Tuy khng nhiu, nhng n gip bn c mt nim cn bn v k thut ny bn c th bt u dng XSL style sheets bin ch d liu trong ti liu XML

Nn nh l ging nh XPath, XSL v XSLT ch l nhng tiu chun n nh nhng g ta i hi mt chng trnh p dng c thc hin h tr chng cn phi c. Tuy nhin, ai trin khai chng trnh , v bng ngn ng lp trnh no cng c. Th d nh Microsoft cho ta MSXML version 3 dng XSL v XSLT. Nhng trang XSL Style Sheet Nhng trang XSL nh ngha nhng style sheets (trang dng iu) ta c th p dng vo nhng ti liu XML. Mt style sheet cha nhng ch dn (instructions) bo mt XML parser lm cch no pht sinh (generate) ra mt ti liu trnh duyt kt qu cho nhng d liu trong mt ti liu XML.

Bn thn XSL style sheet cng l mt XML well-formed nhng n cha nhng lnh (commands) XSL v nhng cu HTML text dng y nguyn cho output.

XML parser nhn din c cc lnh trong mt XSL, bn phi khai bo (declare) mt namespace trong root element, thng thng vi mt prefix xsl. Mt Style sheet thng thng cha mt trong hai namespaces: ci namespace XSL nguyn thy (http://www.w3.org/TR/WD-xsl) hay ci namespace mi XSLT

(http://www.w3.org/1999/XSL/Transform). Microsoft XML parser (MSXML) t version 3.0 tr ln u h tr c hai namespaces.

Xin lu l Internet Explorer version 5.x dng MSXML 2.5, nn khng h tr namespace XSLT. Mun khc phc tr ngi y, hoc l bn ci t Internet Explorer version 6, hoc l bn ci MSXML3 trong Replace mode bng cch dng cng c tn Xmlinst.exe thm chc nng h tr namespace XSLT trong IE v5.x.

Ci Root Element trong mt ti liu XSL document thng thng l mt Element stylesheet. N cha mt hay nhiu Element Template c matched (cp i v ging nhau) vi d liu trong ti liu XML, th d nh ti liu t hng (order) di y:

2002-03-26 John Costello Chair 6 Desk 1

V chnh XSL style sheet cng l mt ti liu XML, nn n phi tun theo mi lut v mt XML well-formed. Sau y l mt XSL style sheet n gin c th c p dng vo ti liu order:

Northwind Home Page Customer Order Style sheet ny da trn namespace XSLT v cha vn vn mt template (bng km in) c p dng vo Root (biu hiu bng du slash / l tr s ca Attribute match) ca ti lu XML v mi Element bn trong ca n.

Mt template tht th gm c mt lot Tags HTML s hin ra trong h s kt qu, nhng trong trng hp ny ci Template khng lm chuyn g hu ch; n ch output (cho ra) mt ti liu HTML y nguyn nh nm trong XSL v khng c cha d liu g t h s input XML. merge (ha ng) cc d liu trong XML vo XSL template, bn cn phi dng mt t lnh (commands) XSL. Lnh value-of XSL nh ngha mt s lnh ch bin (processing commands) trch d liu ra t mt ti liu XML v ha n vo mt h s kt qu. Ci lnh cn bn v hu dng nht trong s ny l lnh value-of. Lnh value-of chn tr s (value) ca mt Element hay Attribute no trong XML v ha n vi h s output.

Lnh value-of c dng mt XML Element trong XSL. N dng mt Attribute tn select c value l mt XPath Location Path trch ra mt Node. Kt qu l value ca (value-of) Node y. Do , kh hn ln trc, by gi ta c th trnh by d liu ca XML vi lnh value-of nh sau:

Northwind Home Page Customer Order Order No: Date: Customer: Ci Style sheet k ny trch ra Attribute OrderNo v tr s ca cc Elements OrderDate v Customer t Element Order bng cch dng mt XPath location path. Lu l cc XPath expressions y th tng i vi context node ch nh trong match parameter ca Element template (trong trng hp ny l Root Element, biu hiu bng du slash / ).

p dng Style sheet ny vo h s t hng (order) XML ta s c HTML sau y:

Northwind Home Page Customer Order Order No: 1047 Date: 2002-03-26 Customer: John Costello Lnh for-each Trong mt ti liu XML, c th c nhiu Elements mang cng mt tn ni n mt danh sch nhng th tong t. Th d trong ti liu t hng c hai Element Item din t hai mn hng c t.

Hu ht ngn ng lp trnh cho ta phng tin p dng cng mt cch ch bin cho mi mn trong nhm. Nh trong Visual Basic ta c FOR loop hay DO loop iterate qua tng mn trong b. Trong XSL cng th, bn c th dng lnh for-each i ln lt qua tng Element trong nhm, bng cch dng Attribute select ch nh nhng nodes m bn mun lm vic.

Th d ta c th lm cho ci Style sheet hay hn bng cch lit k cc Item trong Order thnh mt table:

Northwind Home Page Customer Order Order No: Date: Customer: ProductID Product Name Price Quantity Ordered

Ln ny trong Style sheet, ta bo parser i qua tng Element Item ly ra Attributes ProductID v UnitPrice ca Element Product , v values ca Elements Product v Quantity, ri cho vo table.

Lu y cc XPath expressions tng i dng ci Node ch nh trong lnh for-each lm context node. Trong trng hp ny n l Node Item. Cui ca for-each loop l closing Tag ca Element for-each () . Style sheet trn ny khi p dng vo ti liu t hng s cho ra HTML sau y: Northwind Home Page Customer Order Order No: 1047 Date: 2002-03-26 Customer: John Costello ProductID Product Name Price Quantity Ordered 1 Chair 70 6 2 Desk 250 1 Phn BODY ca HTML trn hin th nh sau:

Customer Order

Order No: 1047

Date: 2002-03-26

Customer: John Costello

ProductID Product Name Price Quantity Ordered

1 Chair 70 6

2 Desk 250 1

Lnh Attribute i khi ta mun to ra thm mt Attribute trong h s output vi mt tr s ly t ti liu XML input. Th d nh tng ng vi mi tn ca mt Product, bn mun to ra mt hyperlink chuyn (pass) ci ProductID qua mt trang Web khc, ni s hin th chi tit v mt hng ny.

to ra mt hyperlink trong mt h s HTML, bn cn to ra mt Element A (Anchor) vi mt Attribute href. Bn c th dng lnh Attribute ca XSL thc hin chuyn y nh minh ha trong Style sheet di y:

Northwind Home Page

Customer Order

Order No:

Date:

Customer:

ProductID

Product Name

Price

Quantity Ordered

Products.asp?ProductID=

p dng Style sheet ny vo ti liu t hng XML, bn s c h s HTML sau:

Northwind Home Page Customer Order Order No: 1047 Date: 2002-03-26 Customer: John Costello ProductID Product Name Price Quantity Ordered 1 Chair 70 6 2 Desk 250 1 Phn BODY ca HTML trn hin th nh sau:

Customer Order

Order No: 1047

Date: 2002-03-26

Customer: John Costello

ProductID Product Name Price Quantity Ordered

1 Chair 70 6

2 Desk 250 1

Bn c th Mouse cursor ln ch Chair hay ch Desk thy tn hyperlink ca chng hin th trong status bar ca browser.

Cc lnh v iu kin Ging nh trong ngn ng lp trnh thng thng ta c cc instructions v iu kin nh IF, SELECT CASE, ELSE .v.v.. la chn, trong XSL ta c cc lnh v iu kin nh xsl:if, xsl:choose, xsl:when, v xsl:otherwise. Khi expression ca Element xsl:if, xsl:when, hay xsl:otherwise c tr s true, th ci Template nm bn trong n s c to ra (instantiated).

Thng thng, nu cng vic th tnh n gin ta dng xsl:if. Nu n hi rc ri v ty theo trng hp ta phi lm nhng cng tc khc nhau th ta dng choose/when/otherwise.

Tr s ca Attribute test ca xsl:if v xsl:when l mt expression tnh. Expression ny c th l mt so snh hay mt expression loi XPath. Kt qu vic tnh ny s l true nu n tr v mt trong cc tr s sau y:

Mt b node c t nht mt node

Mt con s khc zero

Mt mnh (fragment) Tree

Mt text string khng phi l trng rng (non-empty)

minh ha cch dng cc lnh XSL v iu kin ta s dng h s ngun tn catalog.xml sau y:

Ralls, Kim Midnight Rain Fantasy 5.95 2000-12-16 A former architect battles corporate zombies, an evil sorceress, and her own childhood to become queen of the world. Thurman, Paula Splish Splash Romance 4.95 2000-11-02 A deep sea diver finds true love twenty thousand leagues beneath the sea.

Knorr, Stefan Creepy Crawlies Horror 4.95 2000-12-06 An anthology of horror stories about roaches, centipedes, scorpions and other insects. Kress, Peter Paradox Lost Science Fiction 6.95 2000-11-02 After an inadvertant trip through a Heisenberg Uncertainty Device, James Salway discovers the problems of being quantum. O'Brien, Tim Microsoft .NET: The Programming Bible Computer 36.95 2000-12-09 Microsoft's .NET initiative is explored in detail in this deep programmer's reference. Di y l mt th d dng xsl:if:

cyan Trong th d trn, Attribute bgcolor ch c to ra vi tr s cyan khi price ca book ln hn 6. Mc ch ca ta l dng mu xanh da tri nht lm nn cho sch no c gi (price) cao hn 6.

Di y l mt th d dng xsl:choose: background-color: pink background-color: lightblue background-color: lightgreen Trong th d trn Attribute style ca Cascading Style Sheet s c nhng tr s cho background-color khc nhau ty theo loi sch. Nu l Romance th pink, Fantasy th lightblue, cn nu khng phi l Romance hay Fantasy (tc l xsl:otherwise) th lightgreen. Mu ny s c dng lm nn cho mc (title) ca sch. l cp Tags , c dng gi cc xsl:when, v xsl:otherwise bn trong.

Cch p dng Style Sheet vo ti liu XML Trc khi tip tc hc thm cc lnh khc ca XSL Style Sheet, ta cn hiu v bit cch p dng mt Style Sheet vo mt ti liu XML.

p dng mt Style Sheet l mt chc nng ca mt XML parser nh MSXML ca Internet Explorer. Bn c th bo mt XML parser p dng mt Style Sheet vo mt XML bng cch hoc l ch cn nht mt processing instruction vo u h s XML, hoc l vit mt vi dng code.

Dng XML parser hin th Nu ta lu tr XSL Style Sheet ca h s t hng trong mt file tn Order.xsl th ta c th thm mt hng processing instruction xml-stylesheet vo u h s t hng XML nh sau:

2002-03-26 John Costello Chair 6 Desk 1

Khi mt XML parser c h s XML ny, ci processing instruction xml-stylesheet bo parser p dng h s style sheet Order.xsl transform XML.

Attribute type cho bit loi style sheet c p dng, hoc l XSL style sheet hoc l cascading style sheet (CSS), mt loi style sheet dng ch nh mu v kiu ch. y n l XSL style sheet trong dng text.

Attribute href cho bit tn ca file dng lm Style Sheet, path ca tn file y c th l tng i hay tuyt i.

Nu ta dng mt chng trnh trnh duyt nh Internet Explorer 5.5 hay 6.0 n s t ng load Style Sheet thm dng iu cho ti liu XML.

B. ONTOLOGY:1. Gii thiu v Ontology:Trong khoa hc my tnh, mt ontology l mt m hnh d liu biu din mt lnh vc v c s dng suy lun v cc i tng trong lnh vc v mi quan h gia chng. Ontology cung cp mt b t vng chung bao gm cc khi nim, cc thuc tnh quan trng v cc nh ngha v cc khi nim v cc thuc tnh ny. Ngoi b t vng, ontology cn cung cp cc rng buc, i khi cc rng buc ny c coi nh cc gi nh c s v ngha mong mun ca b t vng, n c s dng trong mt min m c th c giao tip gia ngi v cc h thng ng dng phn tn hn tp khc.

2. Vi tr ca Ontology:Th nht, ontology cung cp mt tng tch hp d liu t nhiu ngun khc nhau vo trong mt m hnh ng ngha thng nht. Cc d liu c kt hp vi nhau c th c s dng suy din ra cc thng tin mong mun, cc thng tin ny khng c nh ngha trc tip trong tng ngun d liu ring l trc .

Th hai, mi quan h gia cc thnh phn source code vi nhau v source code vi ti liu l thnh phn khng th thiu trong vic bo tr phn mm. S dng ontology cho php h thng c th t chc v lu tr cc thng tin ny t so khp cc d liu v cc mi quan h phc v cho cng tc bo tr.

Th ba, ontology cho php suy din ra nhng tri thc mi t cc tri thc c s, cho php lin kt cc i tng theo cc mi quan h gin tip nhau.

Th t, d liu m ontology s dng c th c t nhiu ni khc nhau, iu ny ph hp vi m hnh chia s d liu gia cc thnh vin ca b phn bo tr.

3. Xy dng Ontology:Ngn ng ontology cho php ngi s dng vit r rng, cc khi nim hnh thc ca m hnh min. Cc yu cu chnh:

Cu trc r rng: y l iu kin cn cho my c th x l thng tin.

Ng ngha hnh thc miu t ngha tri thc mt cch chnh xc: ngha ca ng ngha hnh thc tn ti trong mt thi gian di trong min ton logic. Vic s dng ng ngha hnh thc cho php con ngi suy din tri thc. Vi tri thc trong ontology chng ta c th suy din v:

Thnh vin ca lp: Nu x l mt th hin ca lp C v C l lp con ca lp D th chng ta c x l th hin ca lp D

Cc lp tng ng: Nu lp A tng ng vi lp B v lp B tng ng vi lp C, th lp A cng tng ng vi lp C.

Tnh nht qun: Gi s chng ta khai bo x l th hin ca lp A v A l lp con ca B C, A l lp con ca lp D, Lp B v lp D khng c quan h vi nhau (disjoint). Th chng ta khng nht qun bi v A nn l rng nhng li c th hin l x. y l mt du hiu ca mt li trong ontology.

Phn loi : nu chng ta khai bo cc cp thuc tnh gi tr bit l iu kin cho thnh vin trong mt lp A, th nu mt c th x tha mn cc iu kin, chng ta c th kt lun x phi l mt th hin ca A.

Ng ngha l iu kin tin quyt cho vic h tr suy din: H tr suy din rt quan trng bi v n cho php kim tra tnh nht qun ca ontology v tri thc, kim tra cc quan h tha gia cc lp, t ng phn loi cc th hin trong lp.

Ng ngha hnh thc v h tr suy din thng c cung cp bi vic nh x mt ngn ng ontology n hnh thc logic v s dng suy din t ng bi cc hnh thc lun tn ti. OWL c nh x logic miu t v s dng cc suy din ang tn ti nh FaCT v RACER. Cc logic m t l tp con ca logic v t nhm h tr suy din hiu qu.

4. Cc thnh phn ca ontology:Ontology c s dng nh l mt biu mu trnh by tri thc v th gii hay mt phn ca n. Ontology thng miu t:

C th: Cc i tng c bn, nn tng.

Lp: Cc tp hp, hay kiu ca cc i tng.

Thuc tnh: Thuc tnh, tnh nng, c im, tnh cch, hay cc thng s m cc i tng c v c th em ra chia s.

Mi lin h: cch m cc i tng c th lin h ti mt i tng khc.

B t vng ontology c xy dng trn c s tng RDF v RDFS, cung cp kh nng biu din ng ngha mm do cho ti nguyn Web v c kh nng h tr lp lun.

C th (Individuals) Th hin

C th l thnh phn c bn ca mt ontology. Cc c th trong mt ontology c th bao gm cc i tng ri rc nh xe, con cop.. , cng nh cc i tng tru tng nh con s v t.Lp (Classes) - Khi nim

Lp l nhng nhm, b hoc tp hp cc i tng. Mt lp c th gp nhiu lp hoc c gp vo lp khc. Mt lp gp vo lp khc c gi l lp con ca lp gp. iu quan trng ca quan h xp gp l tnh k tha.

Thuc tnh (Properties)

Cc i tng trong ontology c th c m t thng qua vic khai bo cc thuc tnh ca chng. Mi mt thuc tnh u c tn v gi tr ca thuc tnh . Cc thuc tnh c s dng lu tr cc thng tin m i tng c th c. V d, i vi mt c nhn c th c cc thuc tnh: H_tn, ngy_sinh, qu_qun, s_cmndGi tr ca mt thuc tnh c th c cc kiu d liu phc tp.

Mi quan h (Relation)

Quan h gia cc i tng trong mt ontology cho bit cc i tng lin h vi i tng khc nh th no. Sc mnh ca ontolgy nm kh nng din t quan h. Tp hp cc quan h cng nhau m t ng ngha ca domain. Tp cc dng quan h c s dng v cy phn loi th bc ca chng th hin sc mnh din t ca ngn ng dng biu din ontology.

Ontology thng phn bit cc nhm quan h khc nhau. Vd:

Quan h gia cc lp

Quan h gia cc thc th

Quan h gia mt thc th v mt lp

Quan h gia mt i tng n v mt tp hp

Quan h gia cc tp hp.

5. Ngn ng Ontology:5.1. RDFS (RDF-Shema):RDF v RDFS cho php biu din mt vi tri thc ontology. M hnh c bn ca RDF/RDFS lin quan n t chc b t vng trong vic phn cp: cc quan h lp con, thuc tnh con, cc rng buc domain v range, cc th hin ca lp. Tuy nhin mt s cc c im b thiu. V d nh:

Tch ri cc lp: Thnh thong chng ta mun ch ra cc lp tch ri nhau. V d lp Male v lp Female l tch ri, nhng trong RDFS chng ta ch c th quan h lp con, v d: Female l lp con ca lp Person

Phm vi gi tr ca thuc tnh: rdfs:range nh ngha di gi tr ca thuc tnh p dng cho tt c cc lp. V vy trong RDF Schema chng ta khng th khai bo cc rng buc vi di gi tr ch p dng vi mt vi lp nht nh. V d, trong RDFS chng ta khng th nh ngha b ch n c, trong khi cc loi ng vt khc cng c th n c. Kt hp cc lp vi nhau: i khi chng ta mun xy dng mt lp mi c to ra t vic kt hp cc lp khc s dng hp hoc giao hoc b. V d chng ta c th nh ngha lp Person bng vic hp hai lp phn bit l Male v Female. RDF Schema khng cho php chng ta nh ngha nh vy. Cc rng buc v lc lng: Chng ta mun cc rng buc bao nhiu gi tr thuc tnh phn bit c th c hoc bt buc. V d: Chng ta thch ni rng mt ngi c ng hai cha m, hoc mt kha hc c dy bi t nht mt ging vin. Kiu rng buc ny khng th biu din trong RDF Schema c Cc c im c th ca thuc tnh: N hu ch khi ni mt thuc tnh l bc cu (v d Ln hn), hoc duy nht (l m ca), hoc nghch o ca thuc tnh khc (nh thuc tnh l m ca, v thuc tnh l con ca)V nhng hn ch ny m chng ta cn mt ngn ng ontology giu c hn (cch biu din phong ph ) RDF Schema. Trong thit k mt ngn ng nn ch n s cn bng gia sc mnh biu din v h tr suy din hiu qu. Nn ngn ng ontology cho web (OWL Ontology Web Language) ra i. OWL a ra tiu chun cho ontology s dng trong web. Mc ch chnh ca OWL l s cung cp cc chun to ra mt nn tng qun l ti nguyn, chia s cng nh ti s dng d liu trn Web

5.2. OWL (Ontology Web Language):OWL (The Web Ontology Language) l mt ngn ng gn nh XML dng m t cc h c s tri thc. OWL l mt ngn ng nh du dng xut bn v chia s d liu trn Internet thng qua nhng m hnh d liu gi l ontology. Ontology m t mt lnh vc (domain) v din t nhng i tng trong lnh vc cng nhng mi quan h gia cc i tng ny. OWL l phn m rng v t vng ca RDF v c k tha t ngn ng DAML+OIL Web ontology mt d n c h tr bi W3C. OWL biu din ngha ca cc thut ng trong cc t vng v mi lin h gia cc thut ng ny m bo ph hp vi qu trnh x l bi cc phn mm.

OWL c xem nh l mt k thut trng yu ci t cho Semantic Web trong tng lai. OWL c thit k c bit cung cp mt cch thc thng dng trong vic x l ni dung thng tin ca Web. Ngn ng ny c k vng rng s cho php cc h thng my tnh c th c c thay th cho con ngi. V OWL c vit bi XML, cc thng tin OWL c th d dng trao i gia cc kiu h thng my tnh khc nhau, s dng cc h iu hnh v cc ngn ng ng dng khc nhau. Mc ch chnh ca OWL l s cung cp cc chun to ra mt nn tng qun l ti sn, tch hp mc doanh nghip v chia s cng nh ti s dng d liu trn Web. OWL c pht trin bi n c nhiu tin li biu din ngha v ng ngha hn so vi XML, RDF v RDFS, v v OWL ra i sau cc ngn ng ny, n c kh nng biu din cc ni dung m my c th biu din c trn Web.

Cc phin bn ca OWL: Hin nay c ba loi OWL : OWL Lite, OWL DL (description logic), v OWL Full.

OWL Lite: h tr cho nhng ngi dng ch yu cn s phn lp theo th bc v cc rng buc n gin. V d: Trong khi n h tr cc rng buc v tp hp, n ch cho php tp hp gi tr ca 0 hay 1. iu ny cho php cung cp cc cng c h tr OWL Lite d dng hn so vi cc bn khc.

OWL DL (OWL Description Logic): h tr cho nhng ngi dng cn s din cm ti a trong khi cn duy tr tnh tnh ton ton vn (tt c cc kt lun phi c m bo tnh ton) v tnh quyt nh (tt c cc tnh ton s kt thc trong khong thi gian hn ch). OWL DL bao gm tt c cc cu trc ca ngn ng OWL, nhng chng ch c th c s dng vi nhng hn ch no (V d: Trong khi mt lp c th l mt lp con ca rt nhiu lp, mt lp khng th l mt th hin ca mt lp khc). OWL DL cng c ch nh theo s tng ng vi logic m t, mt lnh vc nghin cu trong logic to nn s thit lp chnh thc ca OWL.

OWL Full mun cp ti nhng ngi dng cn s din cm ti a v s t do ca RDF m khng cn m bo s tnh ton ca cc biu thc. V d, trong OWL Full, mt lp c th c xem xt ng thi nh l mt tp ca cc c th v nh l mt c th trong chnh bn thn n. OWL Full cho php mt ontology gia c thm nghi ca cc t vng c nh ngha trc (RDF hoc OWL).

Cc phin bn ny tch bit v cc tin ch khc nhau, OWL Lite l phin bn d hiu nht v phc tp nht l OWL Full.

Mi lin h gia cc ngn ng con ca OWL:

Mi ontology hp l da trn OWL Lite u l ontology hp l trn OWL DL

Mi ontology hp l da trn OWL DL u l ontology hp l trn OWL Full

Mi kt lun hp l da trn OWL Lite u l kt lun hp l trn OWL DL

Mi kt lun hp l da trn OWL DL u l kt lun hp l trn OWL Full

6. Cng c xy dng v qun tr Ontology:6.1 Quy trnh pht trin Ontology:Trong nhng nm gn y, mt lot cc phng php lun khc nhau c thit k tr gip cho vic tin hnh pht trin cc nhim v c bo co trong ti liu tr tu nhn to. Cc phng php truyn thng gm Cyc (Lenat & Guha 1990), Uschold v King (Uschold $ King 1995), Gruninger v Fox (Gruninger $ Fox 1995), Kactus (Kactus 1996),v Methontology (Fernandez-Lopez, Gomes-Perez & Juritso 1997). Cc phng php lun cung cp cc ch dn chung v c cu trc. Nu lm theo c th tng quy trnh pht trin v ci tin cht lng cho kt qu cui cng. Theo nh nh gi phng php lun Methontology l phng php lun thit k ontology ph bin nht (c h tr mi trng WebODE).

Quy trnh pht trin Ontology l mt quy trnh gm nhiu bc, tuy nhin vn cha c mt phng php chun ha no pht trin cc ontology. Quy trnh pht trin gm 7 bc do Stanford Center for Biomedical Informatics Research a ra (y l nhm pht trin phn mm Protg trnh din v son tho Ontology).

Bc 1: Xc nh lnh vc v phm vi ca Ontology

Trong giai on ny cn xc nh mc ch ca vic xy dng ontology l g? Phc v i tng no? Ontology sp xy dng cn c c im g, lin quan n lnh vc, phm vi no. Qu trnh khai thc, qun l v bo tr ontology c thc hin ra sao?

Bc 2: Xem xt vic s dng li cc ontology c sn

Cu trc ca mt Ontology bao gm 3 tng: tng tru tng (Abstract), tng min xc nh (Domain) v tng m rng (Extension). Trong tng tru tng c tnh ti s dng rt cao, tng min xc nh c th ti s dng trong mt lnh vc nht nh. Cng ng Ontology cng ang ln mnh v c rt nhiu Ontology c to ra, vi tm huyt ca nhiu chuyn gia. Do trc khi bt u xy dng ontology, cn xt n kh nng s dng li cc ontology c. Nu c th s dng li mt phn cc ontology c, chi ph b ra cho qu trnh xy dng ontology s gim i rt nhiu.

Bc 3: Lit k cc thut ng quan trng

Ontology c xy dng trn c s cc khi nim trong mt lnh vc c th, v vy khi xy dng ontology cn bt u t cc thut ng chuyn ngnh xy dng thnh cc lp trong ontology tng ng. Tt nhin khng phi thut ng no cng a vo ontology, v cha chc nh v c cho thut ng . Do cn phi lit k cc thut ng, xc nh ng ngha cho cc thut ng , cng nh cn nhc v phm vi ca ontology. Vic lit k cc thut ng cn cho thy c phn no tng quan v cc khi nim trong lnh vc , gip cho cc bc tip theo c thun li.

Bc 4: Xc nh cc lp v phn cp ca cc lp

Cng vic xc nh cc lp khng ch n gin l tin hnh tm hiu v ng ngha ca cc thut ng c c c cc m t cho thut ng , m cn phi nh v cho cc lp mi, loi b ra khi ontology nu nm ngoi phm vi ca ontology hay hp nht vi cc lp c nu c nhiu thut ng c ng ngha nh nhau (ng ngha, hay a ngn ng). Ngoi ra khng phi thut ng no cng mang tnh cht nh mt lp.

Mt cng vic cn phi tin hnh song song vi vic xc nh cc lp l xc nh phn cp ca cc lp . Vic ny gip nh v cc lp d dng hn.

C mt s phng php tip cn trong vic xc nh phn cp ca cc lp:

Phng php t trn xung (top-down): bt u vi nh ngha ca cc lp tng qut nht trong lnh vc v sau chuyn bit ha cc khi nim . V d: Trong Ontology v qun l nhn s, ta bt u vi lp Ngi, sau chuyn bit ha lp Ngi bng cch to ra cc lp con ca lp Ngi nh : K s, Cng nhn, Bc s, Lp K s cng c th chuyn bit ha bng cch to ra cc lp con nh K s CNTT, K s in, K s c kh,

Phng php t di ln (bottom-up): bt u vi nh ngha ca cc lp c th nht, nh cc l trong cy phn cp. Sau gp cc lp li thnh cc khi tng qut hn. V d: ta bt u vi vic nh ngha cc lp nh: nhn vin l tn, nhn vin v sinh, nhn vin k thut. Sau to ra mt lp chung hn cho cc lp l lp nhn vin.

Phng php kt hp: kt hp gia phng php t trn xung v t di ln: bt u t nh ngha cc lp d thy trc v sau tng qut ha v chuyn bit ha cc lp mt cch thch hp. V d ta bt u vi lp nhn vin trc, l thut ng hay gp nht trong qun l nhn s. Sau chng ta c th chuyn bit ha thnh cc lp con: nhn vin l tn, nhn vin v sinh, hoc tng qut ha ln thnh lp Ngi.

Bc 5: Xc nh cc thuc tnh

xc nh thuc tnh cho cc lp, ta quay tr li danh sch cc thut ng lit k c. Hu ht cc thut ng cn li (sau khi xc nh lp) l thuc tnh ca cc lp . Vi mi thuc tnh tm c, ta phi xc nh xem n m t cho lp no. Cc thuc tnh s tr thnh thuc tnh ca cc lp xc nh. V d lp Ngi c cc thuc tnh sau: H, Tn, Ngy sinh, Gii tnh, Ngh nghip, a ch, in thoi,Bc 6: Xc nh rng buc ca cc thuc tnh

Cc thuc tnh c th c nhiu kha cnh khc nhau: nh kiu gi tr, cc gi tr cho php, s cc thuc tnh (lc lng), v cc c trng khc m gi tr ca thuc tnh c th nhn. V d: Nm sinh ca mt nhn vin ch c duy nht v l s nguyn, c th nhn gi tr t 1948 n 1990. Cn phi xc nh cc rng buc cho mt thuc tnh cng cht ch cng tt, trnh trng hp nhp d liu sai, dn n v ca cc ng dng s dng Ontology ny.

Bc 7: To cc th hin / thc th

Bc cui cng l to ra cc th hin ca cc lp trong s phn cp. Vic to th hin cho mt lp l qu trnh in cc thng tin vo cc thuc tnh ca lp .

6.2 Cng c pht trin ontology:Mt s cng c pht trin v hiu chnh c gi tr trong vic lm gim phc tp v thi gian dng cho nhim v xy dng ontology. Cc cng c nh Kaon, OileEd v Protg cung cp cc giao din nhm gip ngi s dng thc hin cc hot ng chnh yu trong trong qu trnh pht trin mt ontology. Vic la chn mt cng c hiu chnh ph hp nht c nhiu kh khn v mi kiu ontology c cc yu cu v kinh ph, thi gian, ti nguyn khc nhau. gip cho vic gii quyt vng mc ny, Singh & Murshed (2005) a ra cc tiu chun nh gi cng c to ontology. Tiu chun bao gm tnh nng, kh nng s dng li, lu tr d liu, mc phc tp, quan h, tnh lu bn, an ton, chc chn, kh nng hc, tnh kh dng, hiu lc, v tnh r rng. Protg v OntoEditFree c pht trin bi Singh & Murshed s dng cc tiu chun ny.

Mt s cng c hiu chnh ontology ph bin:

Cc cng c pht trin Ontology

Protg h tr OWL, l cng c c s dng rng ri v lu nht hin nay. N cho php ngi s dng nh ngha v chnh sa cc lp ontology, cc thuc tnh v quan h v cc th hin s dng cu trc cy. Cc ontology c th c a ra theo cc nh dng RDF(S), XML Schema. Platform protg cung cp hai cch chnh m hnh ha ontology thng qua Protg - Frame v Protg OWL, ngoi ra c th c nhiu plugin. Chng ta c th quan st mt cch trc quan thng qua OWL Viz, n cho php quan st ontology di dng ha v a file nh JPEG. Ngoi ra cn h tr truy vn SPARQL.PHN II. NG DNG Cc chc nng chnh ca ng dng bao gm: To c s d liu XML. Truy xut c s d liu XML. Cp nht c s d liu XML. Truy vn c s d liu XML.TI LIU THAM KHO[1]. Nguyn Xun Huy, H suy dn, H Ni, 2013[2]. Nguyn Xun Huy, Cc ph thuc logic trong c s d liu, H Ni, 2006

[3]. Hong Vn Kim, Phc, Vn Nhn, Gio trnh Cc h c s tri thc, NXB i hc Quc gia Tp.HCM, 2012

[4]. Phan Huy Khnh, Bi ging cng ngh tri thc, Nng, 2011

[5]. Phan Huy Khnh, Gio trnh H chuyn gia, Nng, 2009

[6]. Trung Tun, Tr tu nhn to, NXB Gio dc, 1997

[7]. Nguyn nh Thun, Bi ging Tr tu nhn to, Nha trang, 2007