Using Semantic Web Services to Integrate Data and Processes from Different Web Portals Marília T. de Mello1 Mara Abel2 Francisco García-Sánchez3 Instituto de Informática – Instituto de Informática – Departamento de Ingeniería de Universidade Federal do Rio Universidade Federal do Rio la Información y las Grande do Sul (UFRGS) Grande do Sul (UFRGS) Comunicaciones – Porto Alegre - RS – Brazil Porto Alegre - RS – Brazil Universidad de Murcia mtmello@inf.ufrgs.br marabel@inf.ufrgs.br Murcia - Spain frgarcia@um.es Abstract power of the Web Service technology lies in the fact that it establishes a common platform for integrating Integration and exchange of information across the distributed computing applications, in intranets as well as Internet is a universally recognized need, in a wide variety the Internet at large [4]. of domains. New promising application fields such as The major difficulty when integrating different data Semantic Web Services can improve the integration sources is the semantic heterogeneity of information process in the Web, dealing with the major difficulty of sources. Besides being widely distributed across de the semantic heterogeneity in the resources, by means of Internet, and being found in a variety of storage formats, domain ontologies. In this research, we propose an different information sources can use the same object to integration system, combining domain ontologies and represent different concepts, or different objects to Semantic Web Services, to provide an integrated access to represent the same concept. In order to solve this problem, the information provided by different Web portals in two applications make use of domain ontologies, which application domains: biomedicine and geology. Semantic provide a common model of the concepts that are relevant Web Services were designed to encapsulate Web portals and their allowable relations. The idea of this project is to in both domains, allowing the system to accomplish the go beyond this scope and use Semantic Web Services, integration in each domain, separately. which make use of ontologies. The aim of Semantic Web Services is to provide 1. Introduction solutions to the challenges associated with automated discovery, dynamic composition, enactment, and other Strong efforts are being applied by the Artificial tasks associated with managing and using service-based Intelligence community dedicated to explore potential systems. Several researches explore the use of Web approaches to improve the process of data discovery and Services for information integration, like [17, 19]. integration. That happens mainly because Web users However, only a few studies make use of Semantic Web demand integrated access to all information resources Services. One of this is the Project DIP (Data, available through the Internet. New promising application Information, and Process Integration with Semantic Web fields such as the Semantic Web and Semantic Web Services), which intends to provide an environment in Services are being recognized as the adequate support for which different Web Services can cooperate with each integrating data sources and services in the Web. other and be found out automatically. Nowadays, it is possible to find independent and Moreover, according to [2], current integration heterogeneous data resources, accessible through the proposals do not allow users to take advantage of the Internet, covering information related to any kind of services offered by Web portals. This happens because domain. Information resources include not only data on traditional integration techniques are focused just on data the Web but also Web portals which offer services to the integration, ignoring the services provided by the portals. users, such as search engines, providing integrated access The present research intends to achieve the integration to dynamic content from a variety of sources. However, of data and processes (search engine services), which are only a few Web portals offer their information in the form offered through different Web portals. The portals offer a of Web Services (such as the portal of Amazon.com). The 1 http://dip.semanticweb.org/ International Workshop on Intelligent Web Based Tools (IWBT-07) in conjunction with 19th IEEE ICTAI-07 9 variety of functionalities and also permit accessing many Currently, a Web Service is a software system data related to a specific domain. The approach is to identified by a URI, whose public interfaces and bindings encapsulate these data sources through Web Services that are defined and described using XML [3]. A Web Service are semantically annotated based on a global domain can be accessed via the Internet, through its exposed ontology, which is specific to each application domain. interface, where its definition and functions can be found A system based on Semantic Web Services and on out by other software systems, in a controlled manner [4]. global domain ontologies was designed to encapsulate the These systems may then interact with the Web Service offer of web site services and to allow an integrated access using XML-based messages over Internet protocols. to that information. Once the Web Services are developed Basically the Web Service interface is presented in WSDL and semantically annotated, the system is able to access (Web Service Description Language), which describes their functionalities in an automatic way. The main goal is how other applications can interact with that Web Service, to offer an integrated access to the different functionalities through SOAP (Simple Object Access Protocol) provided by Web portals in specific domains. messages. Those messages are mostly transported using The remainder of this paper is organized as follows. http, with XML format, together with a set of other Web An overview of Web Services, the Semantic Web, and conventions. Semantic Web Services is given in Section 2. Section 3 A Web Service interaction involves two or more presents the proposal of the integration system, giving an software agents (clients and providers) exchanging overview of the complete project. Section 4 describes the information in the form of messages. First, the provider case study realized, using two application domains: registers the service it is offering, using WSDL. The biomedicine and geology. The design of a general registry is based on the UDDI specification (Universal integration application based on Semantic Web Services is Description Discovery and Integration), which defines described in section 5. Conclusions are pointed out in data structures and APIs for publishing (describing) and section 6. discovering Web Services [4]. Once the service is registered, a client can query the registry to search for the 2. Semantic Web Services Revision services it is interested in. After receiving a response, the client may invoke the service it wants, using SOAP. The Semantic Web is a promising evolution of today’s WSDL is the W3C recommended language for Web, providing ways to make the automation process describing the service interface, in an XML notation. It effective and easy. One of its fundamental components enables specification of data types, operation signatures, will be the markup of Web Services to make them port types, message format and transport protocol details, computer-interpretable, use-apparent, and agent-ready network addresses of different ports, and grouping of [13]. In this section, the main concepts related to Semantic different ports into a Web Service [16]. However, WSDL Web Services are presented. First, Web Services are does not enable specification of various constraints on defined, as well as its goals. Then, a general view of the operations and ports in a Web Service. The operations are Semantic Web is given. Thirdly, the concept of Semantic defined in terms of input and output messages. Web Services is introduced. Finally, a special attention is Currently, there are only few specifications available given to OWL-S, an approach to the development of for Web Services that are able to provide some kind of Semantic Web Service frameworks. formal definition to what the syntactic descriptions of their functionalities might mean. Besides OWL-S [12] 2.1. Web Services used in the present research, another important specification is SAWSDL [10], which allows description Web Services are well-defined and reusable software of additional semantics of WSDL components. The lack components that perform specific encapsulated tasks via of machine readable semantics requires human standardized Web-oriented mechanisms [8]. They can be intervention for automated service discovery and discovered, invoked, and the composition of several composition within open systems, thus hampering their services can be choreographed, using well defined usage in complex business contexts [8]. workflow modeling frameworks. Web Services were intended to bring a new level of 2.2. Semantic Web integration to the computing industry and its networked communities [9]. Service-based applications should be The Semantic Web provides a common framework able to interoperate despite being developed in different that allows data to be shared and reused across programming languages, at different times, by different application, enterprise, and community boundaries [18]. It people, with designs based on different assumptions. They is a collaborative effort led by W3C with participation provide a standard means of interoperating between from a large number of researches and industrial partners. different software applications, running on a variety of It is based on the Resource Description Framework platforms [3]. (RDF). International Workshop on Intelligent Web Based Tools (IWBT-07) in conjunction with 19th IEEE ICTAI-07 10 The Semantic Web is an extension of the current Web interface for its execution; and the prerequisites and where information has well-defined meaning [18]. The consequences of its use [13]. Semantic Web project intends to create a universal way of A Semantic Web Service is defined through a service exchanging information, providing knowledge to the ontology, which enables machine interpretability of its contents of Web documents so that it can be understood capabilities as well as integration with a domain by computers. Its goal is to transform the Web into a knowledge. The service ontology aggregates all concept medium through which data can be shared, understood, models related to the description of a Semantic Web and processed by automated tools. Service, and constitutes the Knowledge-level of the A large proportion of today’s data on the Web are information describing and supporting the usage of the “understandable” only to humans or custom-developed service [8]. applications. The Semantic Web will bring structure to the According to [8], three main approaches have been meaningful content of web pages, creating an environment driving the development of Semantic Web Service where software agents roaming from page to page can frameworks: IRS-II, WSMF and OWL-S. IRS-II (Internet readily carry out sophisticated tasks for users [6]. In order Reasoning Service) is a knowledge-based approach to to make it possible, there is the need to enrich the Web SWS, which evolved from research on reusable with ontologies, which capture the domain knowledge. knowledge components. WSMF (Web Service Modeling Technologies from the Semantic Web can make Framework) is a business-oriented approach to fully crucial contributions to Web Service frameworks [9]. enable e-commerce by applying Semantic Web Semantic Web Services take up on this idea, introducing technology to Web Services. OWL-S, in its turn, is an ontologies to describe, on the one hand, the concepts in agent-oriented approach, providing fundamentally an the services domains, and, on the other hand, ontology for describing Web Service capabilities. The characteristics of the services themselves and their following section describes the OWL-S approach in more relationships to the domain ontologies. These semantically detail. rich descriptions enable automated machine reasoning over service and domain descriptions, thus supporting 2.4. The OWL-S approach automation of service discovery, composition, and execution, besides reducing manual configuration and OWL-S is an OWL ontology with three interrelated programming efforts. subontologies, known as the service profile, service model (process model), and service grounding [12], as shown in 2.3. Semantic Web Services Figure 1. A service profile is the description of the offerings and requirements of a service. A service model At present, the use of Web Services requires human describes how a service works. The service grounding involvement (information has to be browsed and forms specifies details of how an agent can access a service. It need to be filled in). The existing technologies for Web will specify a communication protocol and port numbers Services only provide descriptions at the syntactic level, to be used while contacting a service. making it difficult for requesters and providers to interpret or represent nontrivial statements such as the meaning of inputs and outputs or applicable constraints [8]. Service The Semantic Web vision, as applied to Web Services, aims at automating the discovery, invocation, composition describedBy presents and monitoring of Web Services by providing machine- supports interpretable descriptions of services [5]. A prerequisite to this, however, is the emergence and evolution of the Semantic Web, which provides the infrastructure for the ServiceModel ServiceGrounding ServiceProfile semantic interoperability of Web Services. Semantic annotations are the base for the automatic Figure 1. Service ontology processing of Web pages. In order to achieve automation, Web Services will be augmented with rich formal OWL-S provides the major Semantic Web Service descriptions of their capabilities, such that they can be description language for specifying the functions utilized by applications or other services without human (preconditions and effects) of an operation and semantic assistance or highly constrained agreements on interfaces types for each of the inputs and outputs of the service. It and protocols [8]. The semantic description of a Web offers to extend the capability of OWL to form the Service should provide specific information such as: data required ontology for Web Services, making them and metadata associated with a service together with machine understandable while supporting automated Web specifications of its properties and capabilities; the Service composition and interoperability. International Workshop on Intelligent Web Based Tools (IWBT-07) in conjunction with 19th IEEE ICTAI-07 11 A service profile in OWL-S is described through the terminology for genetic oncology conceived, as part of the properties: input, output, precondition and effect. It project, to support integrated consultation over data and provides the following information: a human-readable information contained in the biological, medical and description of the service and its provider; a specification information areas. The knowledge model in the geological of the functionalities provided by the service; and field is represented by the existing ontology of the additional information, such as expected response time PetroGrapher project [1], which was refined in order to and geographic constraints [5]. become more specific to the present application. This Service models are based on the key concept of a ontology represents the vocabulary applied by geologists process, which describes a service in terms of inputs, in order to make the description of rock samples during outputs, preconditions, effects, and its composition of the analysis for petroleum reservoir evaluation. component subprocesses. A powerful feature of OWL-S is The main goal of this project is having a system, based the ability to model composite processes [9]. A composite on global domain ontologies and on Semantic Web process is constructed from subprocesses. The control Services, that encapsulates the offer of different Web flow of a composite process is defined using control portal services and allows an integrated access to the constructs, such as If-Then-Else, Sequence, and Repeat- functionalities provided by them. We apply this system to Until. both domains in order to evaluate the capability of The (OWL-S/WSDL) grounding uses OWL classes as information integration in a domain-independent way. In the abstract types of message parts declared in WSDL. order to provide those functionalities, a complete system The central function of the OWL-S grounding is to show architecture was designed, making use of all the how the inputs and outputs of an atomic process are techniques described in the previous section. The realized as messages in transmittable format [3]. An integration system comprises all the components OWL-S atomic process corresponds to a WSDL illustrated in Figure 2. operation. The OWL-S description relates to a WSDL file The user interface allows users to express their query through the grounding. using an ontology guided tool (based on the global Since the OWL-S service ontology is public and does domain ontology), which assists them in expressing their not prescribe a framework implementation, it has been goals. The domain ontology is loaded through the used as the starting point of individual efforts towards Protégé-OWL API, and its main concepts are used to form Semantic Web Services [8]. a simple menu where the user can choose the type (class) of the object they are looking for. 3. Proposal Through the query component, the system searches and selects the most appropriate Web Services by Whenever users need to look up information related to accessing their semantic description. This is done by a given domain, they have to access one or more Web matching the term from the domain ontology with the portals, making queries in each one, until they find the semantic description of the services capabilities. The answer they are looking for. However, people want to matching is done by using the criteria proposed by save time, improving the quality of their work. Therefore, Paolucci et al. [15], but here only exact matches are an integrated access to the portals of interest would considered (where both terms denote exact the same facilitate the user’s task, providing them with a unique concept or the term from the request is a subclass of the tool, where they can access all the available definitions concept specified in the service being offered). The query with just one query. component returns a list with the services that attend the In this work, we propose the development of a domain user’s need. independent integration system to provide users with an The invoker, in its turn, uses the grounding of the Web integrated access to data and processes, offered by Web Services, which is part of the semantic description, to portals that may attend their goals. Two application invoke each service selected by the query component. It domains will be used as case studies in this project: the returns the result of each service execution to the core biomedicine and the geological domain, each one component. providing its own domain ontology. The domain The main component is the core of the system, which ontologies will help users expressing their needs and will acts as an intermediate application among the other provide information integration by means of Semantic components. Once the results are returned by the invoker, Web Services. they are integrated and given to the user by the core of the The biomedical domain is supported by the ‘Oncogen’ system. ontology [14], which is an ontology of biological International Workshop on Intelligent Web Based Tools (IWBT-07) in conjunction with 19th IEEE ICTAI-07 12 Figure 2. Integration system architecture 4. Case Study as data sources for biomedicine and two were used for geology. The selected sources are described as follows. As the present study aims at providing a global The Gene Ontology project provides a controlled domain independent solution to the problem of Web vocabulary to describe gene and gene product attributes in portals integration, the biomedicine and the geological any organism. The PubMed database, available via the domains will be used as case studies, each one providing NCBI Entrez information retrieval system, is a free search its own domain ontology. engine developed by the National Center for The development of the complete integration system Biotechnology Information (NCBI) at the National starts with the design of Semantic Web Services to Library of Medicine (NLM). MPact - the Representation encapsulate different Web portals in each domain. The of Interaction Data at MIPS (The Munich Information idea is to select a few web portals from the ones that Center for Protein Sequences) provides a common access provide information about genes, proteins, and their point to interaction resources at MIPS [11], which relations, in the biomedicine domain; and about minerals provides resources related to genome information. MPact and rocks, in the geological domain. Next step is to design provides the user with intuitive query forms to quickly a Web Service to each web portal, offering access to its retrieve the interactions of interest. The Swiss-Prot information. However, to make use of a Web Service, a Protein Knowledgebase is a curated protein sequence software agent needs a computer-interpretable description database which strives to provide a high level of of the service and the means to access it. In order to make annotation, a minimal level of redundancy and high level it possible, the developed Web Services must be of integration with other databases. semantically described, based on a domain ontology, so Schlumberger Oilfield Glossary6 is an instant that the automation can be achieved. reference that offers accurate definitions for major oilfield activities, reviewed by technical experts. The 4.1. Data Sources Geologynet7, through two of its online geology databases: the Mineral and the Rock databases. They have a search People who work in research fields, such as interface providing access to a collection of rock and biomedicine and geology, need the source of information to be available whenever they need a specific definition. Therefore, we analyzed Web portals in both domains, 2 http://www.geneontology.org/ choosing the ones that provide search mechanisms or 3 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed glossaries with definitions and descriptions of interest. 4 http://mips.gsf.de/genre/proj/mpact/ From the Web portals that were analyzed, four were used 5 http://www.expasy.ch/cgi-bin/sprot-search-ful 6 http://www.glossary.oilfield.slb.com/default.cfm 7 http://geologynet.com/indexa.htm International Workshop on Intelligent Web Based Tools (IWBT-07) in conjunction with 19th IEEE ICTAI-07 13 mineral databases that can be used for education and terminology, encoding this definition, then solving the reference. data heterogeneity problem. Each input and output from the operations provided by the portals must be validated 4.2. Domain Ontology against a domain ontology type. This way, the system not only recognizes the parameters as strings, integers, or any A domain ontology is a type of formal specification of other basic type, but also as concepts related to the a shared conceptualization [7] conceived to capture ontology classes, having an associated meaning. The knowledge of one particular domain, providing detailed domain ontology will help users express their needs and description of the domain concepts and their relations. achieve information integration by means of Semantic The use of ontologies enables the sharing of common Web Services. concepts, the specialization of these concepts and vocabulary for reuse across multiple applications, the 4.3. Semantic Web Services Design mapping of concepts between different ontologies, and the composition of new concepts from multiple ontologies A Web Service must be developed to each data source [13]. in order to expose the functionalities provided by the The ontology used in the biomedicine domain, called selected Web portals. The implemented services are Oncogen, is a domain ontology for genetic oncology – simple Web Services because they do not rely upon other genes implied in the development of cancer. It is an Web Services nor require further interaction with the user. ontology of biological terminology, which provides a Each Web Service is designed as a common class in model of biological concepts that can be used to form a an object oriented programming language. Then, a WSDL semantic framework for data storage, retrieval and file is generated from the designed class, allowing the analysis tasks. Oncogen was implemented in OWL, specification of the syntax of input and output messages, through the Protégé ontology editor. as well as other necessary details to the service invocation The ontology applied in the geological domain is a [12]. The service that provides global access to the refinement of an existing domain ontology, which is part PubMed database (for example) consists of two methods of the PetroGrapher project. It is modeled as a partonomy (or operations): getProtein and getGene, which return the of terms and was translated to OWL, using the Protégé description of a protein and a gene, respectively, given its ontology editor. This ontology represents the vocabulary name. An extract of the WSDL file that describes the in the sedimentary petrography area. capabilities of the PubMed service is shown in Figure 3. The domain ontology provides the best way of helping communities in agreeing on a standard definition of PubMed Service + + + + + + + + + + + Figure 3. PubMed service WSDL file However, the WSDL description by itself does not without human assistance, because the WSDL provide enough information to support the decision of specification language provide no means of including which service better suits the client necessities. No representations of the semantics of the defined operations software system can read and utilize the WSDL interface and associated messages elements [12]. International Workshop on Intelligent Web Based Tools (IWBT-07) in conjunction with 19th IEEE ICTAI-07 14 The WSDL’s lack of semantic description associated description were generated automatically, based on the to the meaning of inputs and outputs makes it impossible inputs and outputs defined in the WSDL file that was to develop software clients that can, without human generated from the service class. Afterwards, this simple assistance, dynamically find and successfully invoke a description was enriched by the semantic part, which is service [12]. Therefore, after developing the Web the association of the parameters with the domain Services, their semantic description must be done to make ontology classes, together with the definition of it possible to access them in an automatic way. preconditions and effects. A piece of the OWL-S The semantic annotation was done in a semi- semantic description of the PubMed service is presented automated way, through the OWL-S language (based on in Figure 4. the domain ontology, which is written in OWL) using the The objective of Semantic Web Services is to support OWL-S Editor – as a Protégé plug-in. This tool offers a clients that can find and correctly utilize newly discovered development environment where the domain ontologies service without additional programming. The semantic are well integrated with the service descriptions. description allows the automatic access to the services by The OWL-S Editor allows the generation of a software agents. “skeletal” OWL-S description based on a preexisting WSDL file. Using this feature, parts of the OWL-S getGene Get gene description from a given gene name or ID + + + Figure 4. A portion of the OWL-S file for the PubMed service showing the operation ‘GetGene’ and its parameters 4.4. Results 5. Development process of an integration application based on Semantic Web Services Having the repositories with semantic descriptions related to both domains, and all the developed The development process of an integration application components of the application integrated, the system is be based on Semantic Web Services must begin with the able to perform the integration of the sources, based on collection and formalization of the essential information those repositories, in each domain separately. The that should be integrated in the given domain. Based on answers to the queries are validated against the that analysis, the data design is done in two tasks: Web information in the Web portals. Besides returning the portals analysis and selection, and the domain ontology expected results, it is important to notice that only the specification (or the reuse of an existing one). Next step is services of interest are invoked. That is, when a user to encapsulate each selected Web portal with a Web makes a query, the system does not invoke and execute all Service, followed by the semantic description of the the services in the domain to return the expected answer. designed Web Services, based on the domain ontology. Instead, it queries the semantic descriptions, building a The tasks described above are specific to each list with the services that must be invoked, which are only application domain, which means that they must be the ones that provide the answer to the user query. performed every time a new domain is chosen. After International Workshop on Intelligent Web Based Tools (IWBT-07) in conjunction with 19th IEEE ICTAI-07 15 having the semantic repositories, the components of the [3] Alesso, H.P., and C.F. Smith, Developing Semantic Web integration system must be developed and integrated. Services, A K Peters Ltd, Canada, 2005. The system development comprises the architecture design, the implementation, besides the testing and [4] Alonso, G. et al. Web Services: Concepts, Architectures and Applications, Springer Verlag, 2004. evaluation of the application as a whole. The complete system must encapsulate all the service offers from the [5] Antoniou, G., and F. Van Harmelen, A Semantic Web different Web portals, allowing an integrated access to Primer, The MIT Press. London, England, 2004. that information, and answering the user’s query. [6] Berners-Lee, T., J. Hendler, and O. Lassila, “The Semantic 6. Conclusions Web”, In Scientific American, 2001. [7] Borst, W.N. Construction of engineering ontologies, Web Services, as well as Semantic Web Services, are University of Twente, PhD Thesis, 1997. applications where Artificial Intelligence techniques can be used effectively [5]. Semantic Web Services is a new [8] Cabral, L. et al. “Approaches to Semantic Web Services: an research paradigm that, by making use of domain Overview and Comparisons”, In The Semantic Web: Research ontologies, establishes a common platform for integrating and Applications - ESWS 2004, Lecture Notes in Computer distributed computing applications. Moreover, they Science, 3053, Springer-Verlag, 2004, pp. 225-239. provide means to automate service discovery, composition, invocation, and monitoring in the Web [9] Elenius, D. et al. “The OWL-S Editor – A Development Tool environment. for Semantic Web Services”, In Proceedings of the Second European Semantic Web Conference, 2005. The use of domain ontologies, through the OWL-S tool, made it possible to give richer meaning to inputs and [10] Farrell, J., and H. Lausen. “Semantic Annotations for outputs through class hierarchies, properties and property WSDL and XML Schema”, W3C Recommendation, 2007, restrictions. The chosen Web portals in each domain http://www.w3.org/TR/sawsdl. could be encapsulated by Web Services, which, in their turn, could be semantically annotated using OWL-S, [11] Güldener, U. et al. “MPact: the MIPS protein interaction providing a consistent basis to automate the integration resource on yeast”, Nucl: Acids Res, 2006, pp. D436-D441. process. The major contribution of the present work is the [12] Martin, A. et al. “Bringing Semantics to Web Services: The OWL-S Approach”, In First International Workshop on provision of an integration system architecture with basic Semantic Web Services and Web Process Composition main components, which could be used in more than one (SWSWPC 2004), 2004. application domain. The system was able to provide integration both in the biomedical and in the geological [13] McIlraith, S., T.C. Son, and H. Zeng, “Semantic Web domain. The central components in the system perform Services”, In IEEE Intelligent Systems, 2001, 16(2), pp. 46-53. the integration according to the application domain specified and linked to the system by the domain [14] Muñoz-Garcia, A. et al. Oncogen Ontology, KLT Report, ontology, and the semantic descriptions. Universidad de Murcia, Spain, 2006. As future work, we plan to search and select a few [15] Paolucci, M. et al. “Semantic Matching of Web Services more web portals to improve the testing set. Besides that, Capabilities”, In Proceedings of the First International Semantic we plan on extending the case study, adding more Web Conference, LNCS 2342, Springer-Verlag, 2002, pp. 333- application domains, in order to turn the system into a 347. domain independent solution to the problem of integrating web portals functionalities through Semantic Web [16] Tosic, V., K. Patel, and B. Pagurek, “WSOL – Web Service Services. Offerings Language”, In CAiSE 2002 - WES 2002. Lecture Notes in Computer Science, 2512, Springer-Verlag, 2002, pp. 57-67. 7. References [17] Vinoski, S. “Integration with Web Services”, In Internet [1] Abel, M., L.A.L. Silva, et al. “PetroGrapher: Managing Computing. IEEE, 2003, pp. 75-77. petrographic data and knowledge using an intelligent database application”, In Expert Systems with Applications 26(1 [18] W3C “Semantic Web”, 2003. http://www.w3.org/2001/sw. SPECISS), 2004, pp. 9-18. [19] Zhu, F. et al. “Dynamic Data Integration Using Web [2] Acuña, C.J. et al. “Toward Web Portals Integration through Services”, In Proceedings of International Conference on Web Semantic Web Services”, In International Conference on Next Services. IEEE, 6-9 July, 2004, pp. 262-269. Generation Web Services Practices – NWeSP’05, 22-26 Aug, 2005, 6 pp. International Workshop on Intelligent Web Based Tools (IWBT-07) in conjunction with 19th IEEE ICTAI-07 16