A semantic web service-based architecture for the interoperability of e-government services

of 9
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Information Report



Views: 17 | Pages: 9

Extension: PDF | Download: 0

A semantic web service-based architecture for the interoperability of e-government services
  Open Research Online The Open University’s repository of research publicationsand other research outputs A semantic web service-based architecture for the in-teroperability of e-government services Conference Item How to cite: Roberto, V.; Rowlatt, M.; Davies, R.; Gugliotta, A.; Cabral, L. and Domingue, J. (2005). A semanticweb service-based architecture for the interoperability of e-government services. In: Web Information SystemsModeling Workshop (WISM 2005) / 5th International Conference on Web Engineering (ICWE 2005), 25 Jul2005, Sydney, Australia.For guidance on citations see FAQs.c  2005 The AuthorsVersion: Version of RecordCopyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copy-right owners. For more information on Open Research Online’s data policy on reuse of materials please consultthe policies page. oro.open.ac.uk  A Semantic Web Service-based Architecturefor the Interoperability of E-government Services Alessio Gugliotta ∗† , Liliana Cabral † , John Domingue † , Vito Roberto ∗ , Mary Rowlatt ‡ and Rob Davies ‡∗ Department of Computer Science, University of Udine,via delle Scienze 206, 33100 Udine, Italy,E-Mail: { gugliott, roberto } @dimi.uniud.it,http://www.dimi.uniud.it † Knowledge Media Institute, The Open University,Walton Hall, Milton Keynes, MK7 6AA, UK,E-Mail: {  j.b.domingue, l.s.cabral } @open.ac.uk,http://kmi.open.ac.uk  ‡ Strategic Information Manager, Essex County CouncilPO Box 11, County Hall Chelmsford Essex, CM1 1LXE-Mail: maryr@essexcc.gov.uk  ‡ MDR Partners11 Sanders Drive Colchester, Essex, UK CO3 3SEE-Mail: rob.davies@mdrpartners.com  Abstract —We propose a semantically-enhanced architecture toaddress the issues of interoperability and service integration ine-government web information systems. An architecture for a lifeevent portal based on Semantic Web Services (SWS) is described.The architecture includes loosely-coupled modules organized inthree distinct layers: User Interaction, Middleware and WebServices. The Middleware provides the semantic infrastructurefor ontologies and SWS. In particular a conceptual model forintegrating domain knowledge (Life Event Ontology), applicationknowledge (E-government Ontology) and service description(Service Ontology) is defined. The model has been applied toa use case scenario in e-government and the results of a systemprototype have been reported to demonstrate some relevantfeatures of the proposed approach. I. I NTRODUCTION The current trend in e-government applications calls for joined-up services that are effective, simple to use, shapedaround and responding to the needs of the citizen, and notmerely arranged for the provider’s convenience. In this way,the users need have no knowledge of – nor direct interactionwith – the government entities involved. The latter need tobe interoperable and allow for data and information to beexchanged and processed seamlessly across government.  Interoperability  is a key issue in the development of cur-rent e-government services. A recent working paper by theCommission of European Communities [14] emphasised itsrole, not only as a technical issue concerned with linking upcomputer networks, but also as a fundamental requirementto share and re-use knowledge between networks, and re-organise administrative processes to better support the servicesthemselves.Still in ref.[14], three levels of interoperability were indi-viduated:  technical ,  semantic  and  organizational.  The first onerefers to the topics of connecting systems, defining standardprotocols and data formats; the second one concerns theexchange of information in an understandable way, whetherwithin and between administrations, either locally or acrossCountries and with the enterprise sector; the third one refersto enabling processes to co-operate, by re-writing rules forhow Public Administrations (PAs) work internally, interactwith their customers, use ICTs.On practical grounds, the  integration  of services is a basicrequirement of PA portals, with the aim of gathering andtransforming processes – needed for a particular citizen’s lifeevent – into one single service and the corresponding back-office practices. A promising solution is offered by the  one-stop government portals  [23], [17].The present paper addresses the issues of semantic inter-operability and service integration, by adopting knowledgemanagement techniques. In particular, ontologies are em-ployed [2],[1] in support of the following activities: systematicand standard description of information resources: documents,processes and their relations; support to the automation of services, systems and infrastructures involving PAs; supply of added-value services, like selected information retrieval andpersonalization of contents.Moreover, technological solutions adopted for integrationpurposes are the Web Services (WS) [10] [3] and SemanticWeb Services (SWS) [12], which enable the standardizeddescription, retrieval, invocation and combined use of pre-existing applications.We describe the architecture of a one-stop governmentportal based on a SWS infrastructure, which we are realizingas an experimental testbed. The portal provides commonservices from government organizations without affecting theautonomy of the latter, with flexible solutions to enhance andinclude additional functionalities. We use the IRS-III [15]  framework that supports the creation and management of SWSaccording to the WSMO [25] ontology.Advantages of the proposed solution are: providing asingle access point to government services via web; pro-viding citizen-oriented services by means of the life eventmetaphor; providing the tools for collecting information fromautonomous Public Administrations (PAs), keeping their inter-nal processes and legacy systems intact.The project involves the development of a domain ontologythat represents the semantic structure of life events underlyingthe service supply.The paper is organized as follows: in Section III we in-troduce the system architecture; in Sections V and IV wedescribe the middleware layer; in the next we present typicalsystem operations and a case study implemented using thearchitecture. The final section contains our conclusions.II. R ELATED  W ORKS  A. Web Information Systems in E-Government  Many e-government projects are being developed and var-ious approaches have been proposed for the design and thedevelopment of an architecture to deliver e-government ser-vices to citizens.The  eGOV   project [6] proposes an architecture to enable‘one-stop government’; in order to describe services a markuplanguage (GovML) has been developed [11]; GovML definesa set of metadata to describe public administration servicesand life events.The  FASME   project [9] focuses supporting citizen mobilityacross European countries by the integration of administrativeprocess. In order to satisfy this objective a smart card is pro-vided to citizen for the storage of all personal information anddocuments; services are delivered through dedicated kiosks.The  EU-PUBLI.com  project [8] defines a Unitary EuropeanNetwork Architecture; it proposes a middleware solution toconnect heterogeneous systems of different public administra-tion and to enable a service-based cooperation between publicadministrations.The  eGovSM   project [17] supports the automation of admin-istrative process involving several administration and allowingthe reuse of data. The eGovSM is formalized using a set of XML Schema models in order to support the realization of aninteroperable system.Unlike our approach, no one of such projects takes intoaccount the use of SWS technology as the base for developinga government portal nor the use of ontologies for describinglife events, services and e-government knowledge.  B. Semantic Technologies in E-Government  The e-government scenario is a obvious and promisingapplication field for ontologies, since legislative knowledgeis by nature formal to a big extent and it is definition sharedby many stakeholders. In fact there are other e-governmentprojects where the semantic technologies are involved.The  ONTOGOV   project [19] is developing a platform thatwill facilitate the consistent composition, reconfiguration andevolution of e-government services.The  e-POWER  project [7] has employed knowledge model-ing techniques for inferences like consistency check, harmon-isation or consistency enforcement in legislation.The  SmartGov  project [21] developed a knowledge basedplatform for assisting public sector employees to generate on-line transaction services.The  ICTE-PAN   project [13] developed a methodology formodeling PA operations and tools to transform these modelsinto design specification for government portals.Such projects have demonstrated the feasibility of semantictechnologies in e-government, but they did not explore thepossibility of using a Semantic Web Services infrastructurefor the interoperability and integration of different publicadministration services.III. T HE PROPOSED E - GOVERNMENT PORTALARCHITECTURE We define here the basic structure of a generic e-governmentone-stop portal based on a SWS infrastructure. This architec-ture extends the one defined in [16], where the concept andthe architecture of an  active life event portal  were illustrated.The core component of such portal is a knowledge-basedsystem: a program based on inference mechanisms to solve aproblem by employing the relevant knowledge, whose primarygoals are: identifying a life event applicable to the user’srequirements; identifying the services needed to solve a givenevent and matching the user request; identifying an instanceof each service in the list. In our approach, the role of knowledge-based system is played by a semantically-enhancedarchitecture. It is composed of the loosely-coupled modulesoutlined in Figure 1.The modules are organized in three layers: User Interaction : supports the user to identify a life event;collects information for service execution.  Middleware : allows the semantic description, publishing andupdating of life events in order to provide citizens with anup-to-date and personalized list of available services; allowsthe description, identification, instantiation and invocation of services. Service Layer  : responsible of the execution of services for alife event. Each PA supplies services through the WS technol-ogy; each one is connected to the back-office and semanticallydescribed via the IRS-III module of the Middleware layer.The core of the architecture is the Middleware, thesemantically-enhanced layer responsible of the interoperabilityand service integration. The main issues addressed in theMiddleware layer are [12]:  Infrastructure for semantic interoperability : enables theautomated interpretation and paves a common ground forservices. The ontologies : knowledge models for defining the conceptsof the e-government domain and the semantic structure of thelife events involved in the service supply.  Fig. 1. The semantically-enhanced infrastructure of a portal. Both issues will be detailed in the forthcoming sections.IV. T HE INFRASTRUCTURE FOR SEMANTICINTEROPERABILITY We use a Semantic Web Services infrastructure for thesemantic interoperability of e-government portal services. Ourapproach uses  IRS-III  , that it is a framework allowing the pub-lication, configuration, execution of multiple, heterogeneousweb services, compliant with WSMO. Architecture of IRS-III includes the following components: Server, Publisher andClient, which communicate through a SOAP-based protocol.Publishing with IRS-III entails associating a specific webservice to a WSMO description. IRS-III contains platforms tosupport the publishing of web services as well as standaloneJava and Lisp code. Web applications accessible via HTTPGET methods are handled internally by the IRS-III server. TheIRS-III Client supports a goal-centric invocation mechanism.The user simply asks for a goal to be solved; the IRS-III brokerlocates the appropriate semantic description, and then invokesthe deployed service.The  Web Service Modeling Ontology (WSMO)  [25] is aformal ontology for describing the various aspects of servicesin order to enable the automation of Web Service discovery,composition, mediation and invocation. Its main componentsare Ontologies, Goals, Web Services and Mediators.  Goals represent the objectives that users would like to achieve viathe WSs. The WSMO definition of goal describes the stateof the desired information space and the desired state of theworld after the execution of a given WS. A goal can importexisting concepts and relations defined elsewhere, by eitherextending or simply re-using them as appropriate.  Web Service descriptions describe the functional behavior of an actual WS.The description also outlines how Web Services communicate(choreography) and how they are composed (orchestration).  Mediators  define mappings between components: for instance,a goal can be related to one or more web services throughmediators. They facilitate the clear-cut separation of differentinteroperability mechanisms.  Ontologies  provide the basic gluefor semantic interoperability and are used by the three othercomponents.V. T HE  C ONCEPTUAL  M ODEL Both PAs and citizens can benefit from a standard con-ceptual model for describing public services and life events.PAs will have a shared description structure, thus productionand management of government information would be eased,while interoperability with other agencies would be fostered.Ontologies can also be used to capture the view point of thecitizens, in application making it easier for them to navigatethrough different services and administrations.Ontologies state an agreement to use the vocabulary abouta certain domain in a coherent and consistent manner [20]. Inparticular, ontologies are the tools for formalizing knowledgeand encoding higher-level data models, such as life events,procedures and services.We use OCML (Operational Conceptual Modeling Lan-guage) [18] for describing a conceptual model for thee-government portal based on three ontologies: the E-Government Domain Ontology, the Life Event Domain On-tology, and the Service Ontology.  In the design of the ontologies above, we followed adeductive approach based on existing upper and specializedontologies, with the assistance of domain experts. In particularwe used the Description & Situations (D&S) [5] – a moduleof the DOLCE ontology [4]. D&S is a theory to describecontext elements – non-physical situations, plans, beliefs,...–as entities: it features a philosophically concise axiomatization.The  E-Government Domain Ontology  encodes concepts inthe PA domain: organizational, legal, economic, business,information technology and end-user concepts. Starting fromthe D&S ontology we have built a domain ontology where allthe PA concepts refer to (subclass of) D&S main concepts. Theformal descriptions of the PA-related concepts are the buildingblocks for the descriptions of the two other ontologies. Partof this ontology has been reported in Figure 2.The  Life Event Domain Ontology  defines a hierarchy of topics – a life event can branch into sub-life events – anddescribes them in terms of: norms that define it; informationobjects that describe it; parameters; involved agents (actor,applicant and provider); involved objects; involved procedures;results (effects) of the life event. Moreover, for each Life Eventis possible to associate one or more Goals – a concept of theWSMO ontology (Section IV) – and Entitlements – Servicesor Benefits. We reported in Figure 3 the UML diagram of theLife Event model. All the classes describing life events – e.g.someone-move-in, getting-married, getting-divorced, moving-house, etc.– are subclasses of the life event class model.The  Service ontology  contains the SWS definitions. Theycorrespond to instances of the Goal, Web Service and Mediatorclasses used in the IRS-III module (Section IV), following theWSMO definitions (Section IV). The following OCML codedefines the  notify-change-of-address-goal  and the descriptionof the  county-council-provider-notify-change-of-address  capa-bility: (def-class notify-change-of-address-goal (GOAL) ?goal((has-input-role :value has-new-address:value has-old-address:value has-client-name:value has-client-id:value has-source-provider:value has-target-provider)(has-output-role :value has-confirmation)(has-new-address :type string)(has-old-address :type string)(has-client-name :type string)(has-client-id :type integer)(has-source-provider :type service-provider)(has-target-provider :type service-provider)(has-confirmation :type string)))(def-class county-council-provider-notify-change-of-address-ws-capability(capability) ?capability((used-mediator :value notify-change-of-address-mediatorhas-assumption :value(kappa (?psm)(and (unit-of-organization(role-value ?psm ’has-target-provider)?agency)(county-council-organization ?agency))))) VI. E-G OVERNMENT  P ORTAL  I MPLEMENTATION By using the infrastructure described previously, theapplication (portal) developer will use tools for describing,publishing and invoking services. Figure 4 shows somesnapshots for the prototype scenario explained in next section. Publishing new services  A developers creates a new WS forsupplying a service through the portal. He provides a Goaldescription which represents the objectives that citizens wouldlike to achieve via WS – and associates it to a Life Event. Thedeveloper might also refer to an already existing Goal insteadof defining a new one. Then, the developer semanticallydescribes its WS and associates it to the Goal. Dedicatedinterfaces and the IRS-III module are used for describingGoals and Web Services. Descriptions are maintained in theService Ontology. Finally, through the publisher interfaceof the IRS-III module, the developer publishes the SWS,associating the semantic description to the developed WS. Invoking a Goal  A request presented by the user through theportal interface is satisfied by goal achievement. The request isprocessed by the Life Event Manager module, which discoversall the related, allowing the user to select the appropriateLife Event (e.g. Notify change of address). Information aredescribed through the E-Government Domain Ontology, whilethe Goals are described via the Service Ontology. When theuser invokes one of the goals, the Life Event Manager callsthe IRS-III module, which retrieves the semantic descriptionof the goal. Then, it creates an instance with specific dataitems; identifies and invokes the web services addressing theuser needs by means of their semantic description. Finally, theweb service is executed by the PA information system and theresult is presented to the user.  A. Prototype Scenario: Change of Circumstance We illustrate the implementation of our e-government portalthrough an application scenario.The prototype is a portal for the Essex County Councilbased on the infrastructure reported in Section III. In thisscenario the end users are the caseworkers of the CommunityCare department which are helping the citizen to report his/herchange of circumstance to the different agencies involved inthat process. This way the citizen only has to inform onceabout his/her change, and the government agency (CommunityCare unit) automatically notifies all the agencies involved.Community Care service scenario in which, for instance, adisabled  Mother Moves In  to her daughter’s home; the changeof circumstance provokes a change in which services andbenefits – health, housing, etc. – the citizens are eligible to;multiple service-providing agencies need to be informed andinteract.The aim is that a citizen only has to notify his/her changeof circumstance to one single local authority; then, all changes(Post Office, Treasury, National Health Service, etc.) will beautomatically notified.For instance, the mother notifies a case worker at Com-munity Care department her moving. The case workers havea coordination role, which are frequently centred on trackingchanges of the living address of the client.
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks

We need your sign to support Project to invent "SMART AND CONTROLLABLE REFLECTIVE BALLOONS" to cover the Sun and Save Our Earth.

More details...

Sign Now!

We are very appreciated for your Prompt Action!