courssemantic web services

8/12/2019 CoursSemantic Web Services

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The Semantic WebServices

Dr. Ahlem Ben HassineEcole Nationale des Sciences de lInformatique

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$utline

The World Wide Web%ar&u' (an)ua)esH*'erTe+t %ar&u' (an)ua)e ,HT%(-e tensible %ar&u' (an)ua)e , %(-

Web ServicesSim'le $b/ect Access 0rotocol ,S$A0-Web Service Descri'tion (an)ua)e ,WSD(-1niversal Descri'tion2 Discover* and Inte)ration ,1DDI-

Semantic Web Services

3esource Descri'tion 4rame5or& ,3D4-Web $ntolo)* (an)ua)e ,$W(-%achine Intelli)enceWeb $ntolo)* (an)ua)e for Services ,$W(#S-

Web Services 6om'osition 0roblem


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In "78 2 3AND 6or'oration ,s'onsored b* 1S air force- be)an research todevelo' robust2 distributed communication net5or& for militar* commandand control ,event of nuclear attac&-.

In "7892 three different net5or& to'olo)ies 5ere 'ro'osed: centralized 2decentralized and distributed .

In "7872 ARPANET 5as created intended to 'romote the sharin) ofsu'er#com'uters amon) scientific and militar* researchers in the 1S ,9nodes-.

In "7;72 the first 1SENET ne5s)rou's 5as established. 1sers from allover the 5ord /oined these discussion )rou's to tal& about the net2 'olitics

and man* other to'ics.A30ANET continued to )ro5 in si


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In "77"2 Tim Berners#(ee2 5or&ed at the Euro'ean 0article 0h*sics(aborator* of the Euro'ean $r)ani


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Different a''lications required manual inte)ration2 not desi)ned to5or& to)ether and even not able to run on the same $S.

In "7872 6harles oldfarb2 Ed5ard %osher2 and 3a*mond (orie ofIB% develo'ed the Generalized Markup Lan ua e , %(- as as*stem to build 'o5erful 'ortable interchan)eable le)al documents.

%( is based on the )eneric codin) ideas: the se'aration of theformattin) of a document from its content.

The structure of each t*'e of document 5as strictl* defined in a file

called a !ocument T"pe !e#inition ,DTD-.DTD a mar&u' declarations that define a document t*'e for S %(#famil* ,S %(2 %(2 HT%(-2

The World Wide Web History of the Supporting Software


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In "7;!2 soft5are and 'rotocols 5ere introduced to facilitate email and file transfers A30ANET becomes a distributed s*stem of C many-to-many connection in a robust2fault tolerant manner.

Within *ears the* develo'ed a parser for validatin) a document2

B* "7=82 the final te+t of the $tandard Generalized Markup Lan ua e ,S %(-2

ne+t iteration on %( 5as issued as an IS$ standard.Electronic document F content and mar&u'

An S %( document consists of several 'arts:S %( Declaration G D$6T 0EJ2 5hich DTD )overns the current document2

Document T*'e Definition2 5hich defines the s*nta+ of the mar&u' constructs2

A s'ecification to describe semantics to be ascribe to the mar&u' im'oses s*nta+ thatcannot be e+'ressed 5ithin the DTD.

Document instances: content and mar&u'2 each instance contains reference to the DTD to beused to inter'ret it.



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DTD created for a boo& entitled CSam'le Boo&Sam'le Boo&

B* Anon*mous6ha'ter ". Hello6ha'ter . oodb*eG D$T 0E Boo& KG E(E%ENT Boo& ,Title2 6ha'ter L-JG E(E%ENT Boo& Author 6DATA M3E 1I3EDJ

G E(E%ENT Title ,M06DATA-JG E(E%ENT 6ha'ter ,M06DATA-JG ATT(IST 6ha'ter id ID M3E 1I3EDJOJ



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S %( )ave birth to the Internets 'rimar* communication toolsincludin): H*'erTe+t %ar&u' (an)ua)e2 e tensible H*'erTe+t%ar&u' (an)ua)e2 and e tensible %ar&u' (an)ua)e.

S %( 6a'abilities:

A 'o5erful technolo)* 'o5erful document definition.

S %( (imitations:

Too com'le+ for Web data and a''lications2

The Web needs more abstract and more semantic a''roach.


GML $GML %&TML

%ML

&TML


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HT%( is merel* one S %( document t*'e2 the 'rimar* lan)ua)efor formattin) Web 'a)es.

%( is a sim'lified version of the S %(2 used to define other

mar&u' lan)ua)es.In "77 2 %arc Andreesen and a )rou' of student 'ro)rammers at the

N6SA2 develo'ed a )ra'hical bro5ser for the World Wide Webcalled %osaic.

In "77;2 $ra (assila and 3al'h S5ic&2 established the foundationfor 3D4 ,3esource Descri'tion 4rame5or&- to deal 5ith aCmeanin) model rather than a content data model. The )oal 5as toadd semantic on the to' of %(.



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Since "77 2 efforts 5ere devoted to build a 'o5erful technolo)* toe+'ress semantics. 3D4 Schema2 an ob/ect#oriented t*'e s*stem as aminimal ontolo)* modelin) lan)ua)e.

3D4 and 3D4S still lac& sufficient e+'ressive 'o5er.

$ntolo)* becomes a ne5 research area 5ith the develo'ment ofSH$E ,Sim'le HT%( $ntolo)* E+tension-2 DA30A A)ent%ar&u' (an)ua)e ,DA%(-2 DA%(#$NT2

4rom "77; to "7772 $I( ,$ntolo)* Inference (a*er-2 andDA%(L$I( 5ere an on)oin) 5or& in Amsterdam.

In !! 2 the W 6 be)an final unification of the dis'arate ontolo)*efforts into a standardi


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The mar&u' lan)ua)es '*ramid

The World Wide Web Markup Languages

%ML ' $tructured !ocuments

%ML ' $c(ema

Resource !escription )rame*ork + R!)

R!) $c(ema

Web ,ntolo "

Lan ua e + ,WL


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Invented b* Berners#(ee a sim'le DTD based u'on S %( that 5ould allo5users to create sim'le h*'erte+t#lin&ed documents.%ost used document t*'e on the Web.HT%( defines dis'la* directives for documents on the World Wide Web.Directives are enclosed in brac&ets and affect the te+t in bet5een Ta)s.

Gta)J P G@ta)J indicates the be)innin) and the end of a ta)#'air res'ectivel*.The first and last ta) in a document to tell a Web bro5ser 5here a HT%( in *ourdocument be)ins and ends2 are GHT%(J G@HT%(JHT%( document includes t5o 'arts:

GHEADJ G@HEADJ ta)s contain all of the documents header information ,title2author2 etc.-2

GB$D J G@B$D J ta)s contain all the information to be dis'la*ed in the bro5ser5indo5.

The World Wide Web Markup Languages, H ML


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Sam'les of im'lemented meta ta)s:G%ETA NA%EFCauthor 6$NTENTFCthe authors name JG%ETA NA%EFCdescri'tion 6$NTENTFCA brief descri'tion of theWeb file J

G%ETA NA%EFC&e*5ords 6$NTENTFC&e*5ords relevant to thedocument JG(IN> 3E(FClin&Qt*'e H3E4FC13( T 0EFCt*'e of document J

Ho5ever meta ta)s are of lo5 values i)nored b* man* search

en)ine2 e.). oo)le )enerates automaticall* its o5n descri'tion ofthe Web 'a)e.HT%( is too sim'listic. It does not su''ort the structure andsemantics needed for com'le+ a''lications.

The World Wide Web Markup Languages, H ML


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%( offers some of the S %(s 'o5er 5hile avoidin) lan)ua)es com'le+it* enables Web authors to 'roduce full* customi


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%( Declaration is an announcement to the %( 'rocessor that thisdocument is mar&ed u' in %(.

Sam'le of 5ell#formed %( declaration:GR+ml version F C".! encodin)FCiso#== 7#" standaloneFC*es RJ

DTD is used to validate the %( document. It includes s'ecific informationabout the sequence2 frequenc*2 and hierarch* of the %( documentselements2 attributes2 and character data.

G D$6T 0E 3ootElem S STE% E+ternalDTD3ef KInternalDTDDeclOJ%( Schema , SD- ne5 technolo)* desi)ned to re'lace DTDs 5ith

more 'o5erful and intuitive a''roach.G+sd:schema +mlns:+sdFChtt':@@555.5 .or)@ !!"@ %(Schema JG@+sd:schemaJ

The World Wide Web Markup Languages, !ML


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Elements are the buildin) bloc&s of a document. Elements can becontainers 5ith a mi+ture of te+t and other elements.GB$$>6ATA($ J

GB$$>JP

G@B$$>JG@B$$>6ATA($ J

Attributes s'ecifies 'ro'erties of the element and consists ofname@value 'air.

GB$$> TitleFCSemantic Web Services J P G@B$$>J

Entities#S'ecial S*mbols must be entered differentl* than other te+tcharacters2 e.). )t for J2 quot for C.6omments be)in 5ith the combination of characters CG ## and ends5ith C##J .



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%( S*nta+ 3ulesTa) name are case sensitive2A closin) ta) for ever* o'enin) ta)2A nested ta) 'air cannot overla' another ta)2Attributes values must a''ear 5ithin quotes2

Ever* document must have a root element.%( famil* of lan)ua)es ,su''ort lan)ua)es-

%( ?alidation (an)ua)es: DTD2 %( Schema2%( Interfacin)@(ocation (an)ua)es: D$%2 SA 2 0ATH2 0$INTE32 and(IN>2

%( Dis'la* (an)ua)es: S(2 S(T2 S(#4$%( Web Services (an)ua)es: S$A02 WSD(2 1DDI

%( needs more abstract and semantic lan)ua)e for com'le+ tas&s.



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Billions of diverse documents online The 0roblemsR3etrievin) documents2E+tractin) relevant data from retrieved documents26ombinin) information from different sources to achieve a 'articular )oal.

What is missin) in the current WWWRautomated interactionscommonness bet5een different distributed a''lication technolo)ies

What is needed in tomorro5s WebRautomated interactions

a''lication level interactionsdistributed com'utin) 'latform

Ans*er : 5eb services

Web Services Introduction


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CA Web service is a software application identified b* a "#I 2 5hoseinterfaces and binding ,"- are ca'able of bein) defined, described anddisco$ered b* %( artefacts and su''orts direct interactions 5ith othersoft5are a''lications usin) !ML based messages via Internet-based

protocols% . , W-C de#inition -,"- An association bet5een an Interface2 a concrete 'rotocol and a data

format.,b.ective : to streamline almost an* business that needs to communicate5ith other business2 li&e su''liers2 ban&s2 and shi''in) com'anies.

What is reall* needed for a Web service to be 5idel* successful are Te+t# based Internet 'rotocols usable on an* 'latform ,U EE of Sun and .NET of5indo5s- or from an* lan)ua)e.



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To ma&e a Web service 5or&2 5e need:A 5a* to discover a service 'rovider on the Web2A 5a* to discover 5hat services are available on a 'articular site2A 5a* to describe ho5 to inference 5ith the service2

A 5a* to e+ecute the functions 'rovided b* the service2

A standard messa)in) format2A 5a* to re'resent the data in the e+chan)e.

Web Service 0artners$ervice Provider : creates the Web service2 then de'lo*s it in some Web servicere)istries.$ervice !irector" : 'rovides A''lication 0ro)rammin) Interfaces ,A0Is- for

'ublishin)2 findin)2 and bindin) services.$ervice Re/uester : accesses to the Web service re)istries to see& for desired servicethen connect to the su''lier to invo&e it.



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Web Service Standards:$imple ,b.ect Access Protocol ,S$A0- : result of several attem'ts atan %( 'rotocol for inter#'rocess communication. B* !!! S$A05as )ainin) 5ider acce'tanceWeb $ervice !escription Lan ua e ,WSD(- : result of mer)eds'ecification efforts done b* IB% and %icrosoft in !!! to

'ro)rammaticall* describe ho5 to connect to a Web service.0niversal !escription !iscover" Inte ration ,1DDI- : a 5a* toadvertise and locate Web services. In Se'tember !!! 1DDI ".! 5asannounced.

W$)L : Web Services 4lo5 (an)ua)e ,ne5: B0E(9WS-: for 5ebservices com'osition

$erviceProvider

$erviceRe/uestor

$ervice!irector"

)ind

W$!L1 0!!IPublis(

W$!L1 0!!I

2ind$,AP

Web Services&eb Ser$ice's echnologies


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S$A0 describes commands and 'arameters that can be 'assed bet5een bro5sers and Web services. It consists of three 'arts:

An envelope : a frame5or& for describin) 5hat is in a messa)e and ho5to 'rocess it2A set o# encodin rules : for e+'ressin) instances of a''lication#

defined data t*'es2A convention for re'resentin) remote 'rocedure calls and res'onses.

$,AP messa e 3%ML !ocument4

$,AP Envelope

$,AP &eader

&eader In#ormation

$,AP 2od" 3call and response4

)ault Element

Web Services&eb Ser$ice's echnologies, S()*


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Basic S$A0 messa)e Structure:

GR+ml version FC".! RJGsoa': Envelo'e

mlns: soa'F htt':@@555.5 .or)@ !!"@" @soa'#envelo'eSoa': encodin)St*leFChtt':@@555.5 .or)@ !!"@" @soa'#encodin) J

Gsoa': HeaderJG@soa' HeaderJGsoa': Bod*J

Gsoa': 4aultJG@soa': 4aultJG@soa': Bod*J

G@soa': Envelo'eJ

Web Services&eb Ser$ice's echnologies, S()*
http://www.w3.org/2001/12/soap-envelopehttp://www.w3.org/2001/12/soap-envelope


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Web Services&eb Ser$ice's echnologies, &S+L

WSD( is a s'ecification that defines ho5 to describe Web services in acommon %( )rammar. It 'rovides a 5a* for service 'roviders todescribe the format of requests to their s*stems re)ardless of theunderl*in) 'rotocol2 'latform or encodin).WSD( describes four critical 'ieces of data:6oncernin) abstract descri'tion:

Interface information ,describin) all 'ublicl* available functions-2Data t*'e information ,for messa)e requests@res'onses-2

6oncernin) concrete descri'tion:

Bindin) information ,5hich trans'ort 'rotocol 5ill be used-2Address information ,to locate the s'ecified service-.

WSD( 'rovides:A common lan)ua)e for describin) services2 andA 'latform to inte)rate those services.


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Web Services&eb Ser$ice's echnologies, &S+L Structure

!e#inition : 3oot WSD( element. It defines the name of WS2 the%ulti'le names'aces2 and the follo5in) service elements.T"pes : all data t*'es used bet5een client and server ,+sd datat*'es as default choice-2Messa e : 5hat messa)es 5ill be transmitted ,sin)le ms) requestor sin)le ms) res'onse2 name of the ms) and ms) 'art elements-.Port t"pe : 5hat o'erations ,functions- 5ill be su''orted. A 'ortt*'e element combines multi'le ms) elements to form a com'leteone#5a* or round#tri' o'eration.

2indin : Ho5 the ms)s 5ill be transmitted on the 5ireR WhatS$A0 s'ecific detailsR Describes the concrete s'ecifics of ho5the service 5ill be im'lemented on the 5ire.$ervice : 5here the service is located the address of invo&in)the s'ecified service ,13( for invo&in) the S$A0 service-.


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Web Services&eb Ser$ice's echnologies, &S+L

ConcreteDescription

AbstractDescription


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A com'leter PGmessa)e nameFC)etTerm3equest J

G'art nameF Cterm t*'eFC+s:strin) @JG@messa)eJ

Gmessa)e nameFC)etTerm3es'onse JG'art nameFCvalue t*'eFC+s:strin) @J

G@messa)eJG'ortT*'e nameFC)lossar*Terms J

Go'eration nameFC)etTerm JGin'ut messa)eFC)etTerm3equest @JGout'ut mess)aeFC)etTerm3es'onse @J

G@o'erationJG@'ortT*'eJ

Web Services&eb Ser$ice's echnologies, &S+L #e uest-#esponse (p


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,b.ective : to facilitate and mainl* automate 'ublishin)2 findin)2and bindin) businesses services.1DDI is a shared 'ublic re)istr* im'lementation based on a set of

'ublic s'ecifications.S'ecification for re)istr* also defines a S$A0#based Web servicefor locatin) WSD(#formatted 'rotocol descri'tions of Web services.A business can re)ister three t*'es of information into a 1DDI:

W(ite pa es : basic contact information and identifiers about acom'an* ,business name2 address2 contact information2 etc- toallo5 others to discover the WS based u'on the business identification.5ello* pa es : information that describes a Web service usin) differentcate)ori


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Availabilit" : li&e the Web2 Web services are not "!!V available.

Matc(in Re/uirements : an* service runs into s'eciali


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Tas& of combinin) and lin&in) e+istin) Web services to create ne5 5eb 'rocesses.

WH R ,e.).. 6onference boo&in) scenario-

Adds value to the collection of services2 b* orchestratin) them accordin) to

the requirement of the 'roblemT*'es of 6om'osition

Static 6om'osition # services to be com'osed are decided at desi)n time

D*namic 6om'osition # services to be com'osed are decided at run#time

?ertical 6om'osition # find the best combination of subtas&s ,Web services- tofulfill a )lobal one ,request- in other 5ords find the best 5or&flo5.

Hori


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Semantics based discover* of 5eb servicesWSD(2 1DDI do not su''ort descri'tion and 'ublishin) services

based on ca'abilities

'resent discover* is based on &e* 5ord search ,e.).. CTic&et Service -. Not efficient.solution: $ntolo)* based descri'tion and discover* of 5eb servicesachieves semantic mar& u' to 5eb services and 'rovides semanticintero'erabilit*

D*namic com'ositionHori


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Data are available 5ithin several HT%( Web 'a)es but:The* are difficult to use on a lar)e scale2cannot be easil* 'rocessed b* machines2cannot be directl* e+'loited b* information retrieval techniques2

no )lobal schema for these data2e.).2 data available on consumer 'roducts2 air 'lanes schedules2 etc.

Web is restricted to manual &e*5ord searches2 e.). if 5e 5ant to bu* a 'roduct over the internet2 5e must sit at a com'uter and search for most 'o'ular online stores containin) a''ro'riate cate)ories of 'roducts.

%( is richer than HT%(2 it allo5s ever*one to create their o5nta)s2 and to add arbitrar* structure to their documents but it sa*snothin) about 5hat the structure means .

Semantic Web Introduction


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(es annotationsconsistent en:Le rendu des informations(par

exemple, la taille de police etcouleur)H*'erliens vers descontenus(e contenu sXmantiqueest accessible YlZhomme mais 'as,facilement- Y desordinateurs P


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What a human can see:WWW !! The eleventh international 5orld 5ide 5eb conferenceSheraton 5ai&i&i hotel Honolulu2 ha5aii2 1SA ;#"" ma* !!" location da*s learn interact

3e)istered 'artici'ants comin) from australia2 canada2 chile denmar&2 france2)erman*2 )hana2 hon) &on)2 india2 ireland2 ital*2 /a'an2 malta2 ne5


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What a machine can see:

[\ M]\ VV\ ]\ ] [] ] ]

[ V Z

\ [\]V \Z ]\\ ^ M]C , - [ V V _ \ V\]\ LV\ M]\ VV\ M]\ VV\ M]\ VV\

M]\ VV\ M]\ VV\ \ M]\ VV\ L [ V V _ \ V\]\ L Z [ V ^ 2 #C 2 \ V . `] L


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,b.ective : to 'rovide a machine#readable intelli)ence that 5ouldcome from h*'erlin&ed vocabularies that Web authors 5ould use toe+'licitl* define their 5ords and conce'ts to allo5 soft5area)ents to anal*


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Semantic Web is constructed over:3esource Descri'tion 4rame5or& ,3D4-2 andWeb $ntolo)* (an)ua)e ,$W(-.

These lan)ua)es are develo'ed b* the W 6 ,u'on %(- 5ith

'artici'ation from academic researchers and industrial 'artners.Main ob.ective : to allo5 more effective discover*2 automation2inte)ration2 and reuse across different a''lications.4or the Semantic Web to function2 com'uters , System )gents - musthave access to a structured collections of information and sets ofinference rules , &eb-based .nowledge #epresentation - that the*can use to conduct automated reasonin) , .nowledge )c uisition -.


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The conce't for %achine Intelli)ence ,%I- is fundamental to thesemantic Web.%I F %achine (earnin) L 6om'utational Intelli)ence L Soft#6om'utin) L Artificial Intelli)ence.

Sub#branches of %I related to the Semantic Web:>no5led)e Acquisition and 3e'resentation2A)ent S*stems2$ntolo)*

>no5led)e acquisition is the e+traction of &no5led)e from varioussources.>no5led)e re'resentation is the e+'ression of &no5led)e incom'uter#tractable form that is used to hel' soft5are#a)ents

'erform.



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>no5led)e re'resentation lan)ua)es 'ermit the re'resentation andmani'ulation of &no5led)e to deduce ne5 facts the* must have a5ell#defined s*nta+ and semantic s*stem2 5hile su''ortin)inference.>no5led)e#based s*stems contain &no5led)e2 data and information.

!ata : an item of dada is a fundamental element of an a''lication.In#ormation : is an e+'licit association bet5een data thin)s.7no*led e : is a rule2 is an e+'licit functional association from a set ofinformation thin)s to a resultant information thin).

Three 5ell#established techniques have been used for &no5led)ere'resentation and inference:

4rames and semantic net5or&s2(o)ic based#a''roaches2

3ule based s*stems.



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CThe Semantic Web is an e+tension of the current Web in 5hichinformation is )iven well-defined meaning 2 better enablin) com'uters and

'eo'le to 5or& in coo'eration .## Tim Berners#(ee2 Uames Hendler2 $ra (assila2 The semantic Web2 Scientific

)merican 2 %ai !!".

Semantic Web +efinition

Current WWW

Set of documents2 Based on HT%(2 >e*5ords search s*stem2 Human understandable.

$emantic Web

Set of &no5led)e2 Based on %( and 3D4,S-2 6once'ts search s*stem2 %achine understandable.


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Semantic Web&eb Semantic technologies pyramid


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%( ta)s add meanin) to documents meanin) is onl*meanin)ful to human.E.). Gboo&J

GtitleJ Web Semantic G@titleJ

G@boo&JCThe boo& has the title Web Semantic Sub/ect 0redicate $b/ect3D4 constructs its o5n )rammatical re'resentation usin) the tri'le

,sub/ect2 'redicate2 ob/ect-.

Sub/ect2 0redicate and $b/ect are each identified b* an 13I

conce'ts are not /ust 5ords but tied to a unique definition ,13I-.

Semantic Web #esource +escription /ramework 0#+/1

Sub/ect $b/ect0redicate


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3D4 Tri'les form 5ebs of information about related thin)s result: a directed )ra'h 5hose nodes and arcs are all labeled 5ithqualified 13I.Traditional >3 s*stems are centrali


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$ra (assila and 3al'h S5ic&2 established the foundation for 3D4 in"77;.The first 3D4 Schema 5as released in !!! and co#edited b* DanBric&le* and 3.?. uha in !!!.3D4 model@s*nta+ s'ecification and 3D4S s'ecification are builtu'on %( and %(S.3D4S describes ho5 to use 3D4 to build 3D4 vocabularies.3D4 model is based on statements about resources ,an*thin) 5ith a13I-.

The basic 3D4 model 'roduces a triple 2 5here a resource ,thesub/ect- is lin&ed throu)h an arc labeled 5ith a property ,the 'redicate- to a $alue ,the ob/ect-.


3esource ?alue0ro'ert*


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3D4s Statement structure:Sub/ect: the resource that the statement describes. It can be an*thin) inthe data model ,document2 user2 'roduct2 etc.-. 3D4 resource isuniquel* identified b* a 13I.0redicate: the 'ro'ert* ,cit*2 title2 color2 etc- of the sub/ect ,'erson2

'lace2 thin)-. A 3D4 0redicate is uniquel* identified b* a 13I.$b/ect: the value ,Ne5 or&2 CWeb Semantic 2 red2 etc.- for the

'ro'ert* ,cit*2 tiltle2 color2 etc.- of the sub/ect ,'erson2 'lace2 thin)-.This value can be an* valid 3D4 data t*'es ,su''orted %( datat*'es-.

3D4s four im'ortant facts to be a5are of:Each 3D4 tri'le is made of sub/ect2 'redicate and ob/ect.Each 3D4 tri'le is a com'lete and unique fact.Each 3D4 tri'le is a #tu'le ,13I 3ef or bnode2 13I 3ef2 13I 3ef2

bnode or literal-.Each 3D4 tri'le can be /oined to other 3D4 tri'les ,but still retain itsmeanin)-.



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3D4 %odel advanta)es:An* data model can be reduced to a common stora)e format based ona tri'le.

3D4 can a))re)ate dis'arate data models ,all can be treated the same-

information can be combined from man* resources and 'rocessedas if it came from a sin)le one.

3D4s four im'ortant facts to be a5are of:Each 3D4 tri'le is made of sub/ect2 'redicate and ob/ect.

Each 3D4 tri'le is a com'lete and unique fact.Each 3D4 tri'le is a #tu'le ,13I 3ef or bnode2 13I 3ef2 13I 3ef2

bnode or literal-.

Each 3D4 tri'le can be /oined to other 3D4 tri'les ,but still retain itsmeanin)-.



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3ecordin) the 3D4 data in a )ra'h is not efficient for storin) orretrievin) data Seriali


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Assume 5e have the sim'le facts as follo5s:The name of this 13I , mailto:alesso 5eb#iq.com - is 0eter Alesso.The t*'e of this 13I , mailto:alesso 5eb#iq.com - is a 'erson.The author of this 13I , mailto:alesso 5eb#iq.com - isisbn:! !"; =;8;.The id of this 13I ,isbn:! !"; =;8;- is a boo&.The title of this 13I ,isbn:! !"; =;8;- is CWeb Semantic .

The mer)ed 3D4 )ra'h 3esult:

Semantic Web #esource +escription /ramework Schema 0#+/S1

mailto:alesso 5eb#iq.com

isbn:! !"; =;8;

'erson

0eter Alesso

boo&

Web Semantic

t*'e

name

t*'e

title

Author of
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


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3D4S 'rovides a 'o5erful model to describe meanin) of information.The 'ur'ose of 3D4 Schema is to 'rovide %( vocabular* to 5hich 5ecan e+'ress classes and their ,subclass- relationshi's2 as 5ell as to define

'ro'erties and associate them 5ith classes. 3D4S facilitates inferences and enhances searchin).3D4S uses the 3D4@ %( desi)n 'attern to define classes and

'ro'erties:E.). GR+ml versionFC".! RJ G6lass rdf:IDFC resource

+mlns:rdfF htt':@@555.5 .or)@"777@! @ #rdf#s*nta+#nsM +mlnsFCuri J G'ro'ert* rdf:resourceFCP @J G'ro'ert*J value G@'ro'ert*J P G@6lassJ

Grdfs:6lass rdf:IDFCSet" AND Set JGrdfs:sub6lass$f rdf:resourceFCMSet" @JGrdfs:sub6lass$f rdf:resourceFCMSet @J

G@rdfs:6lassJ

http://www.w3.org/1999/02/22-rdf-syntax-nshttp://www.w3.org/1999/02/22-rdf-syntax-ns


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3D4 and 3D4S classes and 'ro'erties:6lass name

rdfs:resource ,the class resource-rdfs:6lass ,the conce't of class-rdf:Ba) ,an unordered 6ollection-rdf:Seq ,an ordered 6ollection-P

0ro'ert* namerdf:t*'e ,indicates t*'e of a class-rdfs:sub6lass$f ,indicates membershi' of a class-rdf:sub/ect ,the sub/ect of an 3D4 statement-rdf:value ,identifies the 'rinci'le value usuall* a strin) of a

'ro'ert* 5hen the 'ro'ert* value is a structured resource-rdf:ob/ect ,the ob/ect of an 3D4 statement-

P



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3D4 'rovides a s*nta+ convention for re'resentin) thesemantics of data in a standardi


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3D4 and 3D4S lac& e+'ressive 'o5er:

The* cannot define 'ro'erties of 'ro'erties2 e.). the property parentis the negation of the property child2

The* can not define equivalence2 com'le+ conce't definition2 and

cardinalit* restriction.The* cannot define restriction over class of 'ro'ert*2 e.). a mother isa women that ha$e one child .

The* can not define dis/ointness of classes of 'ro'erties2 e.). the

class women and men are both sub-classes of human, but an ob3ectcannot be an instance of both together .

The* can not define Boolean combination2 e.). a anadian person isa person li$ing in canada or being born in anada2

Semantic Web #+/0S1 Limitations


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Semantic Web&4 5ision 0 im 6erners Lee1


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Intelli)ent s*stems are based on >N$W(ED E &no5led)e needs to beca'tured2 'rocessed2 reused and communicated.$ntolo)ies su''ort all these tas&s.$ntolo)* F e+'licit s'ecification of a conce'tuali


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3ecentl* ta&en b* AI researchers2 5ho use it to desi)nate the buildin) bloc&s out of 5hich models of the 5orld are made2 i2e2 in M)S, anontology becomes the basic le$el of a knowledge representation scheme foran agent 0hiloso'hical ontolo)* : C5hat are the features common to all bein)s .$ntolo)* intended as theor* of distinctions:

Amon) the entities of the 5orld ,'h*sical ob/ect2 events2 re)ions2 etc.-Amon) the meta#level cate)ories used to model the 5orld ,conce't2

'ro'ert*2 qualit*2 etc.-

Independently of the state of the world The definitions of an ontolo)* can be classified into three )rou's:

a term in 'hiloso'h* meanin) Ctheor* of e+istenceAn e+'licit s'ecification of conce'tuali


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An e+'licit s'ecification of conce'tuali


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$'erations on ontolo)ies%er)e ^ e+istin) ones%a''in)Ali)nment : ma''in) both direction3efinement 'artial orderin) of onolo)iesInte)ration to allo5 intero'erabilit*Inheritence conce'ts relations2 restrictions or a+ioms

De'endin) on the sco'e of the ontolo)*2 ma* be classified as follo5s1''er )eneric to'#level ontolo)* describin) )eneral &no5led)e2 time2 s'ace

Domain ontolo)*# describin) a domain2 medical domainTas& ontolo)* suitable for a s'ecific tas&2 such that assemblin) 'arts to)ether A''lication ontolo)* develo''ed for a s'ecific a''lication2 assemblin)

'ersonnal com'uter

Develo''in) ne5 ont reuse of e+istin) ones as much as 'ossible

Semantic Web(ntology


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To com'are information across t5o databases 5e have to &no55hich terms are bein) used to mean the same thin) 5e need tohave a 5a* to discover common meanin)s.Solution is 'rovided b* the Semantic Web in the form of acollection of information called $ntolo)ies .

Artificial Intelli)ence and Web researchers use the term ontolo)* fora document that defines the relations amon) terms.A t*'ical ontolo)* for the Web includes a ta+onom* L set ofinference rules.

,ntolo " < =ta6onom"1 in#erence rules> andTa6onom" < =?classes@1 ?relations@>

The ta+onom* defines classes of ob/ects and relations amon) them2e.).2 an address ma* be defined as a t*'e of location2 and cit* codesma* be defined to a''l* onl* to locations2 and so on.

Semantic Web(ntology


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6lasses2 subclasses and relations amon) entities are im'ortant tools a lar)e number of relations amon) entities can be e+'ressed b*assi)nin) 'ro'erties to classes and allo5in) subclasses to inheritsuch 'ro'erties.The real 'o5er of Semantic Web 5ill be reali


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Since "77 efforts have been made to im'rove 3D4 and 3D4S:Sim'le HT%( $ntolo)* E+tensions ,SH$E-2 initiated b* Uames A.Hendler of the universit* of %ar*landDA30A A)ent %ar&u' (an)ua)e ,DA%(-2 initiated b* %ichaelDean. DA30A develo'ed DA%( as a technolo)* 5ith intelli)ence

throu)h the behavior of a)ents ,to d*namicall* identif* andcom'rehend sources of information- DA%( allo5 a)ents to interactautonomousl*. .DA%(#$NT2 e+tension of DA%( 5ith the addition of 5ell#definedsemantics.

$ntolo)* Inference (a*er ,$I(-2 develo'ed in 'arallel 5ith DA%( b*Dr. Ian Harroc&s at the 1niversit* of %anchester. $I( 5as develo'edto 'roduce a 5ell#defined lan)ua)e for inte)ratin) ontolo)ies 5ithWeb standards %(@ %(S and 3D4@3D4S. $I( is a Web#basedre'resentation and inference la*er for ontolo)ies.DA%(L$I(2 the unification of various ontolo)* efforts ,b* !!!-.

Semantic Web&eb (ntology Language 0(&L1


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B* !! 2 $W( is a vocabular* e+tension of 3D4 and is derivedfrom DA%(#$I(. It is currentl* evolvin) into the semantic mar&u'lan)ua)e for 'ublishin) and sharin) ontolo)ies on the World WideWeb.


$W(

3D4@3D4S

%( @ DTD@ %(S

Semantics

S*nta+


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$W( facilitates )reater machine readabilit* of Web content than%(2 3D42 and 3D4S it 'rovides additional vocabularies.An ontolo)* defines the terms used to describe and re'resentconce'ts and mainl* the relationshi's bet5een the conce'ts.An ontolo)* ma* define &no5led)e such:

A 'a'erbac& is a t*'e of boo&2A boo& is a 5ritten document2Documents have 5riters2Writers are humans2Humans read 'a'erbac&s.

$W( versions:$W( (ite su''orts a classification hierarch* and sim'le constraints.$W( D( , descripti$e logic - su''orts ma+imum e+'ressiveness 5hileretainin) com'utational com'leteness.$W( 4ull su''orts ma+imum e+'ressiveness but 5ith no

com'utational )uarantee.



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>e* 'roblem in achievin) intero'erabilit* over the Web is theterminolo " ap : recognizing when two pieces of data described indifferent terminology and talking about the same thing .$W( ma* be used to brid)e the C terminolo " ap ;The basic of an $W( document:

6lasses23elationshi's bet5een classes20ro'erties of classes26onstraints on relationshi's bet5een classes and 'ro'erties of classes.

As a result2 an $W( documents identifies the follo5in) information:

6lass hierarch* ,defines class@subclasses relationshi's-2S*non*m ,identifies equivalent classes and equivalent 'ro'erties-26lass Association ,ma's one or more class to one or more classesthrou)h the use of 'ro'erties-20ro'ert* metadata26lass definition ,s'ecifies com'osition of classes-



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Difference bet5een $W( and 3D4S RBoth have same 'ur'ose to pro$ide an !ML $ocabulary to defineclasses, their properties and their relationships among classes .3D4S enable us to e+'ress ver* rudimentar* relationshi's and haslimited inferencin) ca'abilit*.$W( enable us to e+'ress much richer relationshi's2 *ieldin) a muchenhanced inferencin) ca'abilit*.

3D4S vocabular* can be used 5ith $W( ,but $W( is quite lar)er-.$W( (ite lan)ua)e constructs:

3D4 Schema features ,6lass2 rdf:'ro'ert*2 rdfs:domain2rdfs:sub6lass$f2 etc.-2 ,In-Equalit* ,equivalent6lass2equivalent0ro'ert*2 allDifferent2 etc.-2 0ro'ert* t*'e restriction,all?alues4rom2 some?alue4rom-2 0ro'ert* characteristics ,P-26lassIntersection ,intersection $f-

$W( D( and 41(( additional constructs:6lass A+ioms ,one of2 dis/ointWith2 etc.-2 Boolean combinations of

class e+'ressions ,union$f2 intersection$f2 etc.-.



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$W( (ite:Does not allo5 1NI$N26ardinalit* rather than ! and "2 e.). a person ha$ing at least 8 kids .Does not define a class b* enumeration2 e.). North )merica is defined

b* the set of entities anada, "S), Me7i ue 2Does not define classes dis/oint ness2Does not allo5 ran)es over rdfs:sub6lass$f

$W( D(: more e+'ressive2 com'leteness and decidabilit*.D( (o)ic Descri'tion2A class cannot be an instance of another class2%a/orit* of 3D4,S- vocabular* are not valid2All classes should be defined.

$W( 4ull: more e+'ressive2 no )uaranteeAll 5hat is 'ermitted b* 3D4S and $W( D( is also 'ermitted b* $W(4ull.



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$W( vocabular* for D( 6onstructsintersection$f2union$f2com'lement$f2one of2min6ardinalit*2Etc.

$W( vocabular* for D( A+iomssub6lass$f2sub0ro'ert*$f2equivalent6lass2transitive0ro'ert*2Etc.



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Semantic Web %ar&u' (an)ua)es such as $W(2 $W(#S enable thecreation of arbitrar* domain $ntolo)ies that su''ort theunambi)uous descri'tion of Web content.$W(#S could ma&e Web services com'uter#inter'retable in order to

'erform the follo5in) tas&s:!iscover" : loo&in) for Web service2Invocation : invocation of service b* a soft5are a)ent or anotherservice2Interoperation : brea&in) do5n intero'erabilit* barriers and allo5in)automatic insertion of messa)e 'arameters translations2Composition : ne5 services throu)h automatic selection2 com'ositionand intero'eration of e+istin) services2Beri#ication : verif* service 'ro'erties2E6ecution monitorin : trac&in) the e+ecution of com'osite tas&s and

identif*in) failure cases of different e+ecution traces.

4rom Semantic &eb to Semantic &eb Ser$ices&eb (ntology Language for Ser$ices 0(&L-S1

b


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$W(#S uses $W( to define a set of classes and 'ro'erties s'ecificto the descri'tion of ser$ices .6lass Service is at the to' of the $W(#S $ntolo)*.The $ntolo)* of services 'rovides three essential t*'es of

&no5led)e about a service:The class Service presents a $ervicePro#ile : CWhat does the service 'rovide for and require of a)entsRThe class Service is described6y $erviceModel : CHo5 does it 5or&The class Service su''orts a $erviceGroundin : CHo5 to access the

service$W(#S ontolo)*#based Web services are built u'on S$A0 andWSD( technolo)ies and can be invo&ed b* other services on theWeb.

Semantic Web Services&eb (ntology Language for Ser$ices 0(&L-S1

S i W b S i


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1''er $ntolo)* of services

Semantic Web Services&eb (ntology Language for Ser$ices 0(&L-S1

'rovides

'resentsdescribedb*

su''orts

3esource

Service

Service roundin)Service0rofile Service%odel

S i W b S i


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It 'rovides hi)h#level information about a service and its 'rovider that can be used b* an a)ent to determine if the service meets its rou)h needs2 andif it satisfies constraints such as securit*2 localit*2 and qualit* requirements.It includes:

a human readable descri'tion : serviceName2 intended0ur'ose2te+tDescri'tion2 role2 'rovidedB*2 requestedB*.A s'ecification of functionalities :

0arameterDescri'tion 'arameterNamerestrictedToP

6onditionalDescri'tionconditionalNameP

Io'ein'utsout'uts

'arameterseffects

Semantic Web Services&eb (ntology Language for Ser$ices 0(&L-S1, Ser$ice *rofile

S i W b S i


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4unctional attributes: )eo)ra'hic3adius ,)eo)ra'hic sco'e of theservice-2 de)reeof ualit*2 serviceT*'e ,ontolo)* of service t*'e suchas B B2 B 62 etc.-2 etc.

Service 'rofile can be e+'ressed b* t5o functions:

he information transformation : includes the in'ut and out'ut 'ro'erties of the 'rofile2 e.). a boo& sellin) service could require the bu*ers credit#card number and information on the boo&.

he state change : 'roduced b* the e+ecution of the service results fromthe 'recondition and effect 'ro'erties of the 'rofile2 e.). 'reconditioncredit#card actuall* e+ists and is not overdra5n. The effect is thetransfer of the boo& to the address of the bu*er.

Semantic Web Services&eb (ntology Language for Ser$ices 0(&L-S1, Ser$ice *rofile

S i W b S i


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Semantic Web Services&eb (ntology Language for Ser$ices 0(&L-S1, Ser$ice Model

Service%odel

0rocess%odel

0rocess$ntolo)* 0rocess6ontrol

$ntolo)*

6om'osite0rocess

S ti W b S i


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The main com'onents of a 0rocess%odel are the:0rocess $ntolo)*.0rocess 6ontrol $ntolo)*.

Process ,ntolo " describes a services in terms of io'e andcom'onent sub'rocesses.In the 0rocess $ntolo)*2 $W(#S defines three t*'es of

'rocesses:Atomic ,directl* invo&able-2

Sim'le ,sin)le ste'2 but not directl* invo&able2 used as element ofabstraction-26om'osite ,decom'osable into other 'rocesses usin) $W(#S controlconstructs2 e.).Sequence2 S'lit2 6hoice2 3e'eat#1ntil2 etc.-

Process Control ,ntolo " : to monitor e+ecution of a 'rocess.

Semantic Web Services&eb (ntology Language for Ser$ices 0(&L-S1, Ser$ice Model

b


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The t5o 'revious services ,Service0rofile and Service%odel- deal5ith an abstract level of re'resentation.$ervice Groundin deals 5ith concrete level of s'ecification.It s'ecifies the details of ho5 to access the service2 includin)

'rotocol and messa)e formats2 seriali