Data mediation towards semantic web service ...

Int. J. Web Science, Vol. 1, No. 3, 2012

Data mediation towards semantic web service interoperability Karima Mecheri* LRI Laboratory, Badji Mokhtar University, BP 12, 23000, Annaba, Algeria E-mail: [email protected] *Corresponding author

Mahmoud Boufaida LIRE Laboratory, Mentouri University, Route Ain El Bey, Constantine 25017, Algeria E-mail: [email protected]

Labiba Souici-Meslati LRI Laboratory, Badji Mokhtar University, BP 12, 23000, Annaba, Algeria E-mail: [email protected] Abstract: The interoperability of heterogeneous information systems via semantic web services keeps a real challenge. We propose a service oriented architecture for developing the interoperability mechanism in the information systems of companies. The core of this architecture is a web services semantic mediation infrastructure using a semantic model and the SAWSDL language for resolving mismatches. In the setting of this paper, we present our global approach then retail the data mediation and the semantic model which is based on the ontologies and the notion of context. Keywords: SOA; web services; SWS; information systems; semantic interoperability; data mediation, context; semantic model; ontologies; semantic annotation; SAWSDL. Reference to this paper should be made as follows: Mecheri, K., Boufaida, M. and Souici-Meslati, L. (2012) ‘Data mediation towards semantic web service interoperability’, Int. J. Web Science, Vol. 1, No. 3, pp.163–179. Biographical notes: Karima Mecheri is currently an Assistant Professor in the Computer Science Department of Badji Mokhtar University, Annaba, Algeria. She is affiliated to LRI Laboratory. She received her Magister degree in 2009 in the interoperability and service oriented architecture domain. She is preparing her PhD thesis in the field of semantic web services and interoperability of information systems.

Copyright © 2012 Inderscience Enterprises Ltd.

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K. Mecheri et al. Mahmoud Boufaïda is a Full Professor in the Computer Science Department of the University of Constantine, Algeria. He heads the research group Information Systems and Knowledge Bases. He has published several papers in international conferences and journals. He has managed and initiated multiple national and international level projects including interoperability of information systems and integration of applications in organisations. He has been programme committee member of several conferences. His research interests include cooperative information systems, web databases and software engineering. Labiba Souici-Meslati is an Associate Professor in the Computer Science Department of Badji Mokhtar University, Annaba, Algeria. She is affiliated to LRI Laboratory. She has published several papers in international conferences and journals. Her research interests include machine learning, pattern recognition, computational intelligence and application of artificial intelligence techniques in software engineering. This paper is a revised and expanded version of a paper entitled ‘A semantic web service oriented architecture for the information systems interoperability’ presented at Third Edition of the International Conference on Web and Information Technologies (ICWIT’2010), Marrakech, Morocco, 16–19 June 2010.

1

Introduction

The evolution of internet and the development of a globalise economy are at the origin of deep modifications in the information system architectures of the organisations. The new orientation of the enterprises is toward the use of the service oriented architectures (for SOA) (Bonnet, 2005) that bring a real more value in terms of loosely coupling and better flexibility. Also, it permits the conservation of legacy systems and the exhibition of the applications through internet (extranet or intranet) by new technologies that permit to develop the interoperability mechanism. In order to obtain a better migration of the information systems toward SOA, we adopt a methodology based on the model driven architecture (for MDA) (Blanc, 2005) because of its numerous advantages as reuse, interoperability of the models, independence of the platforms and automatic generation of code from the model. The main implementation of SOA is based on the web services (Monfort and Goudeau, 2004). SOA, MDA and web services encourage the interoperability of the information systems at the technical and syntactical level. However, the semantic interoperability is an aspect very necessary and important in the process of this mechanism. For this, we propose in this paper, an architecture that permits the interoperability mechanisms of the information systems via the semantic web services. The core of this architecture is a web service semantic mediation infrastructure. In the setting of this paper, we are going to present our global approach and to retail the mediation of the data exchanged between web services. Section 2 presents a study of related works. Section 3 provides the global approach, and the three next sections illustrate the conceptual architecture, the mechanisms of annotation and the web service mediation architecture. The Section 7 presents the

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validation of our approach. Finally, Section 8 gives a conclusion of the presented wok and some perspectives.

2

Related works

To make interoperate web services Mrissa (2007) distinguishes the following types of integration approaches: adapter-based approaches, community-based approaches, extended description-based approaches, and web service-based approaches (Mecheri and Souici-Meslati, 2010). Composition consists in combining web service functionalities into a business process (complex WS). Composition languages are, for example, BPEL4WS (WS-BPEL), BPML…etc. There are two execution methods of composition: orchestration and choreography (Mecheri and Souici-Meslati, 2010). The mediation is an aspect of composition for resolving the conflicts caused by the heterogeneities that can appear between web services, to assure their interoperability. In the literature, several classifications of mediation between web services exist. Mrissa (2007) proposes three mediation levels: •

Web services integration level: Has for goal to solve all heterogeneities between the web services, notably heterogeneities between the properties not described in the WSDL documents (non-functional), as the properties concerning the categorisation, the quality of services, the sequences of exchange, ...etc.

•

Interface adaptation level: has for goal to solve heterogeneities between the functional properties described in the WSDL documents, as functionalities offered by the web service, the protocols and the encoding used (RPC, literal document).

•

Data mediation level: Has for goal to solve the data heterogeneities of the data exchanged between web services. This level is a sub level of the interface adaptation, that herself is a sub level of the web services integration.

Besides this, Cabral and Domingue (2005), propose three other levels: data mediation, functionality mediation and business process mediation. At this levels, most approaches use descriptions enriched with the semantic information to solve the conflicts of significance used in the ontologies. To describe the web services semantically one approach is able: – either to use some languages as OWL-S (Martin et al., 2004), WSMO (Arroyo and Stollberg, 2004), – either to annotate the existing languages like semantic service markup (SESMA) (Peer, 2005), WSDL-S (Nagarajan, 2006), SAWSDL (Hausberger, 2009), and the annotation of the UDDI registers (Tektonidis et al., 2005) or ebXML (Dogac et al., 2004). We have classified some works through a comparative table (see Table 1) using some criteria concerning the semantic description approach and language, the integration approach, the functions taken into account (publication, discovery, invocation....), the mediation level and the composition method (Mecheri and Souici-Meslati, 2010). The semantic service oriented architecture WSMX of Haller et al. (2005), is an environment of web services execution based on the web services modelling ontology (WSMO). This architecture permits the dynamic discovery, the invocation and the

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composition of the semantic web services, it is used by the providers to register and to offer their services, and by the customers to discover dynamically and to invoke the selected services. WSMX assures the interoperability of the business to business (B2B) systems, it is presented as a web service. The IRS-III architecture (Cabral and Domingue, 2005) is a framework permitting the publication, the configuration and the execution of the heterogeneous web services. It is also based on the WSMO and contains the following components: server, publisher and customer who communicate through the SOAP protocol. IRS-III implements the data, the objective and the process mediations. The IRS-III architecture is used by Gugliotta et al. (2005) as a basis infrastructure for the semantic interoperability within an e-governmental portal architecture. Izza (2006) proposes a service oriented architecture for integrating industrial information systems applications. This architecture is named ontology driven service oriented architecture (ODSOIA), it is an intra-enterprise solution that enlarges the enterprise service bus (ESB) with two architectural layers in addition to the service oriented layer: the semantic and the integration layers. Izza uses the OWL-S+ to describe the web services semantically. For the mediation, there are three categories of services: data mediation service, functional mediation service and process mediation service. In these different mediations, several types of ontologies and mappings are used. Mrissa (2007) proposes a context oriented semantic mediation architecture for the composition of web services. It is an architecture containing a provider layer, a composition layer and a description layer. It is about a data mediation achieved by a mediator web service inserted between the sender web service and the receiver web service during the composition execution. These services are previously semantically described using the WSDL extensibility elements and a domain ontology to which are associated the contextual ontologies. Kourtesis and Paraskakis (2008) presented the implementation of the FUSION semantic registry, a semantically-enhanced service registry that builds on the UDDI specification and augments its service publication and discovery. The authors combine the use of SAWSDL for creating semantically annotated descriptions of service interfaces and the use of OWL-DL for modelling service capabilities and for performing matchmaking via DL reasoning. Bouras et al. (2010) proposed a semantically-enriched approach for dynamic data mediation in EAI scenarios, focusing on the resolution of message level heterogeneities between collaborative enterprise services, facilitating automated data mediation during execution by providing formal transformations of the output and input messages to a common reference business data model, that is, the enterprise interoperability ontology (ENIO). As discussed in (Mecheri and Souici-Meslati, 2010), the annotation approaches are advantageous because they are compatible with the existing languages and they are relatively simple and bring more flexibility. Concerning web service integration, we notice that service oriented approaches and extended description-based approaches are more interesting than the others since they benefit from advantages of the web services using existing languages and norms. Most works limit the mediation to the semantic correspondence establishment between terms of ontologies, which supposes that the web services adopt the data representation of a common ontology.


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We use the semantic annotations of WSDL (SAWSDL) (Hausberger, 2009) and we propose a semantic model that exploits ontology (Gruber, 1993) and context (Mrissa, 2007) notions and that serves as a reference to the SAWSDL. Table 1

Criteria reference

Comparative table of existing works Semantic Semantic descriptio description n approach language

Web service integration approach

WS functions

Mediation level

Composition method

Haller et al. (2005) (WSMX)

Semantic description language

WSMO

WS-based

Registration Process Choreography discovery functions data invocation mediation

Gugliotta et al. (2005) (IRS_III)

Semantic description language

WSMO

WS-based

Publication Process goal configuration data mediation execution

Semantic OWL_S+ Izza (2006) description (ODSOIA) language

Mrissa (2007)

Annotation WSDL_S of existing and languages context

WS-based

WS and extended description-based

Choreography orchestration

publication Process Orchestration discovery functions data mediation execution mediation

Data

Orchestration

Kourtesis and Paraskakis (2008)

Annotation SAWSDL WS and extended Publication Matchmaking of existing description-based discovery (categorisation languages matchmaking and data)

______

Bouras et al. (2010)

Annotation SAWSDL Extended of existing description-based languages

______

3

mediation

Data

Overview of the proposed approach

Our global approach for the information systems interoperability is based on the semantic web services and can be summarised as follows: •

Construction of service oriented architecture: To permit the information systems interoperability mechanisms, we keep the SOA because of their multiple advantages. However, their main limit is the lack of efficient development methodologies. As a matter of fact, we adapt a methodology of migration of the information systems toward an architecture oriented services based on MDA (Blanc, 2005), from where, different types of services are cleared of which the business services that, will be exposed to the tierce organisations with the help of the main standards of the web services.

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•

Construction of a conceptual architecture describing the service oriented architecture: The standards used by the web services support the interoperability to the technical level. However, the semantic heterogeneities between the web services are complex and return their interoperability difficult because of the non-takes in account of the semantic by the pile of web services standards. Of this fact, we propose a conceptual architecture permitting to capture the semantics of the web services. This architecture is based on the notion of local, domain and contextual ontologies.

•

Annotation of the service oriented architecture: This stage consists in the proposition of a methodology to enrich the web service semantics being based on the SAWSDL one of the recent standards of the World Wide Web consortium W3C (Hausberger, 2009) and taking the ontology’s conceptual architecture as a reference to annotate the web service descriptions.

•

Semantic web service oriented architecture for the interoperability of the information systems: At this level our architecture appears, it contains the previous elements and permits the publication, the discovery the invocation and the execution of the heterogeneous web services with the help of the mediation to solve the conflicts that can exist between the web services and to permit their interoperability. This architecture is based on layers (Figure 1).

Figure 1 Different layers for the semantic interoperability of the information systems (see online version for colours)

The web services semantic heterogeneities concern their non-functional, and functional properties including the exchanged data. In this paper, we focus on the resolution of the mismatches due to the data heterogeneities. The following three sections are dedicated to the description of the steps defining our approach.

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Construction of the conceptual architecture

Initially, the semantic heterogeneities of the mismatches between web services can only be solved by a semantic description of these last. The best method to capture the semantics consists in the use of ontologies. Our conceptual architecture is built according to the three levels of mediation. It is inspired from a semantic model and is composed of three sub-models (Figure 2):


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Figure 2 Semantic sub-models

•

Non-functional properties semantic sub-model (NSSM): Describes the semantics of the non-functional properties of the services web as the properties concerning the categorisation, the quality of services, the sequences of exchange.

•

Functional properties semantic sub-model (FSSM): Describes the semantics of the functional properties as functionalities offered by the web service, the protocols and the encoding (RPC, literal document).

•

Data semantic sub-model (DSSM): Describes the semantics of the data exchanged between two web services.

These sub models will be used respectively in the mediation of the non-functional properties, the mediation of the functional properties and the mediation of the data. In this paper, we retail the semantic sub model of the data.

4.1 Data semantic sub-model The DSSM will be the reference model to annotate the data exchanged between web services. The DSSM and the semantic annotations will be used for the semantic mediation of the data exchanged to solve the mismatches that can exist. Our model exploits the context notion and semantic object introduced by Mrissa (2007). Context: “The context of a data includes all the internal or external elements, related to the data or even completely outside, that is necessary to the correct interpretation of the data” Mrissa (2007). Semantic object: A semantic object S is defined as a 4-tuple: S = (c, v, t, C) where c

a concept that defines the ontologic family to which data belongs, that is the abstract class of which the data is an instance

t

a type that defines the kind of content of the data (simple/complex XML schema)

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v

a value, that is the data herself, it is an instance of the type of the data

C

context, that brings some precisions on the interpretation of the data.

The context (C) is himself composed of semantic objects named modifiers. These last have the capacity to modify the significance of the unique semantic object to which they are associated. A formal description of a context C is: C = {( c1 , v1 , t1 , C1 ) , …, ( cn , vn , t n , C n )} , nЄ IN

for n > 0

where (ci, vi, ti, Ci), 1 ≤ i ≤ n, are the modifiers that describes the different semantic properties of S. It permits to form recursive descriptions and to represent the context of the semantic objects with arborescent structures composed of modifiers. These last can be static or dynamic. •

Static modifier: Is independent of the other modifiers. It possesses an explicit value that brings an information as for the interpretation of the semantic object.

•

Dynamic modifier: Is dependent of one or several other modifiers. It possesses a value that can be deducted, by a function or a set of logical rules of the values taken by other modifiers belonging to the same context.

Example: S = < ns: Price, 10,000, xsd: double, Context >. The context can be formed of the following modifiers: Static modifiers: Scale factor Country

1 or 1,000 Algeria/Japan

Dynamic modifiers: Currency

DA/JPY

Format of date

dd/mm/yyyy or yyyy/mm/dd

The value of the modifier currency is deducted from the value of the modifier country belonging to the same context. The logical rule permitting this deduction can be described like follows: “IF country = Japan, THEN currency = JPY”.

Our semantic model consists of three types of ontologies: of the local ontologies, an domain ontology and, of the contextual ontologies. •

The data local ontologies (DLO): Describing the local semantics of the data to provider’s level. Every provider describes the semantics of his own web services, what permits a reliability of the annotations of the web service description and the integration of the existing services without the recourse to a supplementary service description. The use of the SAWSDL returns this solution compatible with the


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WSDL this permits the interoperability with the existing architectures and the adherence of new providers. •

Data domain ontology (DDO): That constitutes an agreement concerning the names of the semantic concepts used to permit the interoperability. Therefore, each provider must adhere to this ontology.

•

Data contextual ontologies (DCO) which are associated to the concepts of the domain ontology: A contextual ontology permits to describe the context of a domain ontology concept. Thus, to every domain ontology concept we associate a contextual ontology, what permits to clarify the semantic heterogeneities and to solve the conflicts bound to the users contexts at the time of the updating of the contextual ontologies. These last provide the vocabularies that permit to specify the different structural and semantic representations of the modifiers. We propose to specify the names and values of the static modifiers in the local ontology, because this last transports every provider’s local context. After having integrated the domain ontology, the provider must update the contextual ontologies associated to his local semantics. It permits to establish the correspondences with the representations of the other providers.

4.2 Ontology conception approach Since our DSSM model concerns the data, we adopt for the design of the local ontologies the method that consists in translating the model of data in an ontology. Indeed, a model class UML can be transformed in an ontology for the semantic web with the help of the Protege tool (Protégé website). With regard to the domain ontology that constitutes an agreement on the sense of the terms and the contextual ontologies, their development is also based on the conceptual model, and respects the following stages: •

to define its domain and its range

•

to study the possibility to use existing ontologies

•

to enumerate the important terms in the ontology as well as their properties

•

to define the classes (concepts) and their hierarchy

•

to define the properties of the classes (attributes), and their facets (types of values, possible values, number of values.); and for the contextual ontologies

•

to study for every concept (class) of the domain ontology, the possibility of the need of a contextual ontology, while enumerating the concepts that constitute the context (static modifiers, and dynamic modifiers)

•

the static modifiers and their values exist in the local ontologies.

The ontologies proposed in this work are classically built from the conceptual model of the data. They all are described with the help of the OWL (Schreiber and Dean, 2004) that offers important possibilities of description as the relations of equivalence, identity and difference between two resources, of the properties of transitivity and so on.

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Figure 3 Web service description annotations of the example (see online version for colours)

DCO Price

DDO

Currency

Scale factor

Date

Country

Date format

…

Price

Country = Japan

DLOS

Scale factor = 1,000

Source web service XML schema /xs : sequences>

5

…

Facteur multiplicateur =1

Price

DLOT

Country = Algérie

Target web service XML schema Sawsdl: lowringSchemaMapping = ’http:///MK/AOSS/mapping/OLD2prix.xslt’>/xs: sequences>

Semantic annotation mechanisms

The semantic enrichment of the web services descriptions by the reference model is necessary to enables the semantic mediation and therefore the semantic interoperability to the data level of the web services. We annotate the XSD elements of (the value and her type) a WSDL with the SAWSDL attributes, to associate them with a concept ‘c’ of the local ontology that describes the concept, its static modifiers and their values. For the dynamic modifiers their values are inferred with the help of logical rules. So, we get the semantic object S. •

SAWSDL (Hausberger, 2009): The semantic annotations web service description language one of the recent standards of the World Wide Web consortium W3C,


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defines how to add semantic annotations to the different components of a WSDL2.0 document (Chinnici et al., 2006) [and also supports the WSDL1.1 (Christensen et al., 2001)], as the input/output messages, the interfaces and the operations. To accomplish the semantic annotation, SAWSDL defines extension attributes that can be applied to the WSDL elements as well as the XML schema elements. These attributes are: •

Model reference: SAWSDL defines this extension attribute to annotate the different parts of the description document, wsdl: interface, wsdl: operation, wsdl: fault, xs: element, xs: complexType, xs: simpleType and xs: attribute.

•

Lifting schema mapping and lowering schema mapping: SAWSDL introduces schema mapping annotation to address post discovery issues in using a web service. The mapping referenced by the first attribute defines how an XML instance document conforming to the element or type defined in schema, is transformed to data that conforms to some semantic model. The mapping referenced by the second attribute defines how data in a semantic model is transformed to XML instance data.

As shows the Figure 3, some SAWSDL attributes are added to the source and target web service descriptions, it is about the XML schemas. These annotations (in bold) make reference to the XML data mapping definitions of and toward the DLO in which we find the static modifiers and their values joined to the concerned (price) concept.

6

Web service mediation architecture

In the setting of this paper we are interested in the mediation of the data exchanged between web services. At the time of the data exchange between two web services the conflicts can appear because of the semantic heterogeneities. In this context, the semantic mediation is necessary to guarantee the coherence of exchanged data and permits the web services interoperability. Figure 4 Conceptual architecture of the proposed mediation (see online version for colours)

DDO OWL Contextual ontologies DLOs OWL

WSDLs enriched

Source WS

DLOt OWL

Mediator web service

WSDLT enriched

Target WS

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6.1 Conceptual architecture of mediation As our approach is service oriented, the data mediation is managed by a mediator web service integrated between the source web service and the target web one (Figure 4).

6.2 Mediation process Our architecture exploits the DSSM reference and the SAWSDL annotations of the descriptions to solve the semantic mismatches at the time of the data exchange. Our process of mediation consists of the following levels (Figure 5): a

Abstraction level: Permits to translate an annotated source/target data XML (type definition or element) in one or several concepts belonging to the semantic model DSSM (source/target OLD).

b

Semantic level: It concerns concept correspondences used by the web service: – context identification of every semantic object of the two web services from the local and contextual ontologies, – and the data conversion. It is about the semantic-semantic transformations.

c

Concretisation level: Permits to transform the resulting ontologic concepts belonging to the target semantic level to the target XML data format of the concerned service.

6.3 Mediator web service The semantic mediation of the data exchanged is assured by a web service that uses the ontologies, the annotated descriptions, and the syntactic mapping definitions, and makes call to an inference engine and a knowledge base to execute the mediation according to the following stages (Figure 6): Figure 5 Data mediation processes

Semantic description: -Domain ontology (OWL). -Contextual ontologies (OWL)

Semantic description: source local ontology (OWL) a Annotated syntaxic Description of source web service (.XSD)

b

Semantic description: target local ontology (OWL)

a

c

Annotated syntaxic description of target web service (.XSD)


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Figure 6 Description of mediator web service (see online version for colours)

Web service interface

Wsdl annotation reader

Syntactic mapping definition

Inference engine

Mediator

OLD DDO DLO

DCO

Knowledge base

•

Abstraction level: The mediator web service downloads the files wsdl of the source WS and target WS, and call the mapping definitions relative to the lifting schema mapping annotations to execute the transformations syntactic-semantics, of the XML schemas toward the local ontologies.

•

Semantic level: Contains several operations: a Making correspondences of the concepts used by the two local ontologies with the help of the domain ontology. b Establishment by the mediator web a temporary data contextual ontology (TDCO) for each of the source and target web services, from the contextual ontology associated to the domain ontology concept. The values of the static modifiers are identified from the local ontologies (Figure 7). c Deduction of the dynamic modifiers values with the help of rules to complete the temporary data contextual ontologies (TDCO). d Value conversions using the conversion functions.

•

Concretisation level: With the help of the attribute low ring schema mapping that references the mapping definitions of the semantic data toward XML data.

6.4 Conversion functions and mappings According to the principle of our data mediation several transformation types are defined to know: •

The syntactic-semantic translations, that the annotations SAWSDL ‘liftingSchemaMapping’ associating a type or element of the XML schema to a mapping toward the semantic model, defining how a process of the XML document is transformed toward one or several concepts of the semantic model. We use SPARQL (Prud’hommeaux and Seaborne, 2006) and XSLT (Kay, 2005).

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•

The semantic-syntactic translations, that use the annotations SAWSDL ‘loweringSchemaMapping’ associating a concept of the semantic model to a mapping toward a data of the XML document, defining how a semantic concept is transformed in a XML data. We also use the XSLT (Kay, 2005).

•

The semantic-semantic translations, in addition to the classic mappings we use the conversion functions of modifiers, types and concepts. These functions are stocked as rules.

Figure 7 TDCO and conversions (see online version for colours)

TDCO S

Conversions

TDCOT

Currency = JPY Currency = DA Scale factor = 1,000

Country = Japan

Country = Algerie

Scale factor = 1

Date = 2009/01/12

Date = 12/01/2009 Date format = aaaa/mm/jj

7

Date format = jj/mm/aaaa

Approach validation

We have demonstrated the use of our approach in a real-world case study (Mecheri et al., 2010). The main objective of our research work is to make inter-operate the information system applications of the SETA (Technical studies Society of Annaba) between them and with those of its environment. It is about intra-enterprise and inter-enterprises interoperability. The SETA is an economic and autonomous public company, whose head office is fixed in Annaba (East of Algeria). It is organised as departments and antennas distributed on the East of the national territory. The activity of the enterprise is essentially characterised by the control, the expertise, the geometric studies and structural conception of the roads, railways, airports and so on. The SETA develops multiple relations with outside organisms as the analysis laboratories, national and international suppliers, the banks, and so on. To achieve these benefits the enterprise and its customer pass a contract. The information system applications are, among others, the following: calculation of the unit selling prices, contract management, invoicing and recovery.


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To make inter-operate these applications, we have followed the stages of our approach based on the semantic web services and that can be summarised like follows (Mecheri et al., 2010): •

construction of an architecture oriented services implemented by the standards of the web services

•

construction of a conceptual architecture describing the architecture oriented services and based on the notion of ontologies and context (for example the data local ontology DLO is presented in Figure 8)

•

annotation of the web service descriptions with the help of the SAWSDL, and taking the ontologies of the conceptual architecture as reference for this annotation (see Figure 3)

•

construction of the infrastructure for the semantic data mediation of the web services.

Figure 8 Excerpt of the data local ontology (DLO) of the SETA with the concepts inside the grey zones representing the static modifiers (context) of the concept ‘price’ (see online version for colours) Contrat

Travaux

Type analyse

Client

Devis 1 Facture

Laboratoire

Analysis

Attachment

Analysis name

Analysis ID

Detail realisation

Price

Taux = 13%

8

TVA include = true

Facteur multiplicateu r=1

Pays = Algérie

Conclusions and perspectives

We presented a global approach based on four steps: the construction of service oriented architecture, the construction of a semantic model, the annotation of the service oriented architecture with the help of the semantic model and the semantic web service oriented architecture for developing the interoperability mechanism of the information systems. The core of this architecture is a web service semantic mediation infrastructure. In the setting of this paper, we retail the data mediation which uses the DSSM as reference to semantic annotation for WSDL document. The semantic model is composed of three types of ontologies, of the local ontologies, of the contextual ontologies associated to the domain ontology. Our approach has been validated on a real-world case study (Mecheri et al., 2010).

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In a future work, we plan to introduce the notion of context to the sub-models of functional and non-functional properties in order to establish the semantic mediation to the functional level and non-functional one.

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