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Showing papers on "Web service published in 2004"


Book
05 Oct 2004
TL;DR: This book focuses on executable processes and comes back to abstract processes in Chapter 4, which can be used to replace sets of rules usually expressed in natural language, which is often ambiguous.
Abstract: processes are rarely used. The most common scenario is to use them as a template to define executable processes. Abstract processes can be used to replace sets of rules usually expressed in natural language, which is often ambiguous. In this book, we will first focus on executable processes and come back to abstract processes in Chapter 4. 21 This material is copyright and is licensed for the sole use by Encarnacion Bellido on 20th February 2006 Via Alemania, 10, bajos, , Palma de Mallorca, Baleares, 07006

3,772 citations


Journal ArticleDOI
TL;DR: This paper presents a middleware platform which addresses the issue of selecting Web services for the purpose of their composition in a way that maximizes user satisfaction expressed as utility functions over QoS attributes, while satisfying the constraints set by the user and by the structure of the composite service.
Abstract: The paradigmatic shift from a Web of manual interactions to a Web of programmatic interactions driven by Web services is creating unprecedented opportunities for the formation of online business-to-business (B2B) collaborations. In particular, the creation of value-added services by composition of existing ones is gaining a significant momentum. Since many available Web services provide overlapping or identical functionality, albeit with different quality of service (QoS), a choice needs to be made to determine which services are to participate in a given composite service. This paper presents a middleware platform which addresses the issue of selecting Web services for the purpose of their composition in a way that maximizes user satisfaction expressed as utility functions over QoS attributes, while satisfying the constraints set by the user and by the structure of the composite service. Two selection approaches are described and compared: one based on local (task-level) selection of services and the other based on global allocation of tasks to services using integer programming.

2,872 citations


Journal ArticleDOI
TL;DR: The Taverna project has developed a tool for the composition and enactment of bioinformatics workflows for the life sciences community that is written in a new language called Scufl, where by each step within a workflow represents one atomic task.
Abstract: Motivation:In silico experiments in bioinformatics involve the co-ordinated use of computational tools and information repositories. A growing number of these resources are being made available with programmatic access in the form of Web services. Bioinformatics scientists will need to orchestrate these Web services in workflows as part of their analyses. Results: The Taverna project has developed a tool for the composition and enactment of bioinformatics workflows for the life sciences community. The tool includes a workbench application which provides a graphical user interface for the composition of workflows. These workflows are written in a new language called the simple conceptual unified flow language (Scufl), where by each step within a workflow represents one atomic task. Two examples are used to illustrate the ease by which in silico experiments can be represented as Scufl workflows using the workbench application. Availability: The Taverna workflow system is available as open source and can be downloaded with example Scufl workflows from http://taverna.sourceforge.net

1,709 citations


Book ChapterDOI
06 Jul 2004
TL;DR: An overview of recent research efforts of automatic Web service composition both from the workflow and AI planning research community is given.
Abstract: In today’s Web, Web services are created and updated on the fly. It’s already beyond the human ability to analysis them and generate the composition plan manually. A number of approaches have been proposed to tackle that problem. Most of them are inspired by the researches in cross-enterprise workflow and AI planning. This paper gives an overview of recent research efforts of automatic Web service composition both from the workflow and AI planning research community.

1,216 citations


Proceedings ArticleDOI
Daniel E. Rose1, Danny Levinson1
17 May 2004
TL;DR: A framework for understanding the underlying goals of user searches is described and the experience in using the framework to manually classify queries from a web search engine is illustrated.
Abstract: Previous work on understanding user web search behavior has focused on how people search and what they are searching for, but not why they are searching. In this paper, we describe a framework for understanding the underlying goals of user searches, and our experience in using the framework to manually classify queries from a web search engine. Our analysis suggests that so-called navigational" searches are less prevalent than generally believed while a previously unexplored "resource-seeking" goal may account for a large fraction of web searches. We also illustrate how this knowledge of user search goals might be used to improve future web search engines.

1,062 citations


Proceedings ArticleDOI
19 May 2004
TL;DR: This paper presented an open, fair and dynamic QoS computation model for web services selection through implementation of and experimentation with a QoS registry in a hypothetical phone service provisioning market place application.
Abstract: The emerging Service-Oriented Computing (SOC) paradigm promises to enable businesses and organizations to collaborate in an unprecedented way by means of standard web services. To support rapid and dynamic composition of services in this paradigm, web services that meet requesters' functional requirements must be able to be located and bounded dynamically from a large and constantly changing number of service providers based on their Quality of Service (QoS). In order to enable quality-driven web service selection, we need an open, fair, dynamic and secure framework to evaluate the QoS of a vast number of web services. The fair computation and enforcing of QoS of web services should have minimal overhead but yet able to achieve sufficient trust by both service requesters and providers. In this paper, we presented our open, fair and dynamic QoS computation model for web services selection through implementation of and experimentation with a QoS registry in a hypothetical phone service provisioning market place application.

969 citations


Journal ArticleDOI
TL;DR: IntAct provides an open source database and toolkit for the storage, presentation and analysis of protein interactions, and allows exploring interaction networks in the context of the GO annotations of the interacting proteins.
Abstract: IntAct provides an open source database and toolkit for the storage, presentation and analysis of protein interactions. The web interface provides both textual and graphical representations of protein interactions, and allows exploring interaction networks in the context of the GO annotations of the interacting proteins. A web service allows direct computational access to retrieve interaction networks in XML format. IntAct currently contains approximately 2200 binary and complex interactions imported from the literature and curated in collaboration with the Swiss-Prot team, making intensive use of controlled vocabularies to ensure data consistency. All IntAct software, data and controlled vocabularies are available at http://www.ebi.ac.uk/intact.

965 citations


01 Jan 2004
TL;DR: This document describes Web Services Agreement Specification (WS-Agreement), a Web Services protocol for establishing agreement between two parties, such as between a service provider and consumer, using an extensible XML language for specifying the nature of the agreement, and agreement templates to facilitate discovery of compatible agreement parties.
Abstract: This document describes Web Services Agreement Specification (WS-Agreement), a Web Services protocol for establishing agreement between two parties, such as between a service provider and consumer, using an extensible XML language for specifying the nature of the agreement, and agreement templates to facilitate discovery of compatible agreement parties. The specification consists of three parts which may be used in a composable manner: a schema for specifying an agreement, a schema for specifying an agreement template, and a set of port types and operations for managing agreement life-cycle, including creation, expiration, and monitoring of agreement states. GFD-R-P.107 March 14, 2007 Grid Resource Allocation Agreement Protocol (GRAAP) WG graap-wg@ogf.org 2 Table of

959 citations


Book ChapterDOI
06 Jul 2004
TL;DR: This paper shows how to use OWL-S in conjunction with Web service standards, and explains and illustrates the value added by the semantics expressed in OWl-S.
Abstract: Service interface description languages such as WSDL, and related standards, are evolving rapidly to provide a foundation for interoperation between Web services. At the same time, Semantic Web service technologies, such as the Ontology Web Language for Services (OWL-S), are developing the means by which services can be given richer semantic specifications. Richer semantics can enable fuller, more flexible automation of service provision and use, and support the construction of more powerful tools and methodologies. Both sets of technologies can benefit from complementary uses and cross-fertilization of ideas. This paper shows how to use OWL-S in conjunction with Web service standards, and explains and illustrates the value added by the semantics expressed in OWL-S.

896 citations


Book ChapterDOI
Xin Dong1, Alon Halevy1, Jayant Madhavan1, Ema Nemes1, Jun Zhang1 
31 Aug 2004
TL;DR: Woogle supports similarity search for web services, such as finding similar web-service operations and finding operations that compose with a given one, and novel techniques to support these types of searches are described.
Abstract: Web services are loosely coupled software components, published, located, and invoked across the web. The growing number of web services available within an organization and on the Web raises a new and challenging search problem: locating desired web services. Traditional keyword search is insufficient in this context: the specific types of queries users require are not captured, the very small text fragments in web services are unsuitable for keyword search, and the underlying structure and semantics of the web services are not exploited. We describe the algorithms underlying the Woogle search engine for web services. Woogle supports similarity search for web services, such as finding similar web-service operations and finding operations that compose with a given one. We describe novel techniques to support these types of searches, and an experimental study on a collection of over 1500 web-service operations that shows the high recall and precision of our algorithms.

828 citations


Journal ArticleDOI
TL;DR: A sound and complete algorithm is provided to translate OWL-S service descriptions to a SHOP2 domain and it is proved the correctness of the algorithm by showing the correspondence to the situation calculus semantics of OWl-S.

Journal ArticleDOI
TL;DR: In this article, the authors present a predictive QoS model that makes it possible to compute the quality of service (QoS) for workflows automatically based on atomic task QoS attributes.

Proceedings ArticleDOI
17 May 2004
TL;DR: Experimental results show that search systems that adapt to each user's preferences can be achieved by constructing user profiles based on modified collaborative filtering with detailed analysis of user's browsing history in one day.
Abstract: Web search engines help users find useful information on the World Wide Web (WWW). However, when the same query is submitted by different users, typical search engines return the same result regardless of who submitted the query. Generally, each user has different information needs for his/her query. Therefore, the search result should be adapted to users with different information needs. In this paper, we first propose several approaches to adapting search results according to each user's need for relevant information without any user effort, and then verify the effectiveness of our proposed approaches. Experimental results show that search systems that adapt to each user's preferences can be achieved by constructing user profiles based on modified collaborative filtering with detailed analysis of user's browsing history in one day.

Journal ArticleDOI
TL;DR: Four key issues for Web service composition are described, which offer developers reuse possibilities and users seamless access to a variety of complex services.
Abstract: Web service composition lets developers create applications on top of service-oriented computing's native description, discovery, and communication capabilities. Such applications are rapidly deployable and offer developers reuse possibilities and users seamless access to a variety of complex services. There are many existing approaches to service composition, ranging from abstract methods to those aiming to be industry standards. The authors describe four key issues for Web service composition.

Proceedings ArticleDOI
17 May 2004
TL;DR: It is shown that a large class of composite web services with unbounded input queues can be completely verified using a finite state model checker such as SPIN, and a set of sufficient conditions that guarantee synchronizability and that can be checked statically are given.
Abstract: This paper presents a set of tools and techniques for analyzing interactions of composite web services which are specified in BPEL and communicate through asynchronous XML messages. We model the interactions of composite web services as conversations, the global sequence of messages exchanged by the web services. As opposed to earlier work, our tool-set handles rich data manipulation via XPath expressions. This allows us to verify designs at a more detailed level and check properties about message content. We present a framework where BPEL specifications of web services are translated to an intermediate representation, followed by the translation of the intermediate representation to a verification language. As an intermediate representation we use guarded automata augmented with unbounded queues for incoming messages, where the guards are expressed as XPath expressions. As the target verification language we use Promela, input language of the model checker SPIN. Since SPIN model checker is a finite-state verification tool we can only achieve partial verification by fixing the sizes of the input queues in the translation. We propose the concept of synchronizability to address this problem. We show that if a composite web service is synchronizable, then its conversation set remains same when asynchronous communication is replaced with synchronous communication. We give a set of sufficient conditions that guarantee synchronizability and that can be checked statically. Based on our synchronizability results, we show that a large class of composite web services with unbounded input queues can be completely verified using a finite state model checker such as SPIN.

Proceedings ArticleDOI
17 May 2004
TL;DR: A lattice-based static analysis algorithm derived from type systems and typestate is created, and its soundness is addressed, thus securing Web applications in the absence of user intervention and reducing potential runtime overhead by 98.4%.
Abstract: Security remains a major roadblock to universal acceptance of the Web for many kinds of transactions, especially since the recent sharp increase in remotely exploitable vulnerabilities have been attributed to Web application bugs. Many verification tools are discovering previously unknown vulnerabilities in legacy C programs, raising hopes that the same success can be achieved with Web applications. In this paper, we describe a sound and holistic approach to ensuring Web application security. Viewing Web application vulnerabilities as a secure information flow problem, we created a lattice-based static analysis algorithm derived from type systems and typestate, and addressed its soundness. During the analysis, sections of code considered vulnerable are instrumented with runtime guards, thus securing Web applications in the absence of user intervention. With sufficient annotations, runtime overhead can be reduced to zero. We also created a tool named.WebSSARI (Web application Security by Static Analysis and Runtime Inspection) to test our algorithm, and used it to verify 230 open-source Web application projects on SourceForge.net, which were selected to represent projects of different maturity, popularity, and scale. 69 contained vulnerabilities. After notifying the developers, 38 acknowledged our findings and stated their plans to provide patches. Our statistics also show that static analysis reduced potential runtime overhead by 98.4%.

Book ChapterDOI
07 Nov 2004
TL;DR: The experience in applying KAoS services to ensure policy compliance for Semantic Web Services workflow composition and enactment is described and how this work has uncovered requirements for increasing the expressivity of policy beyond what can be done with description logic is described.
Abstract: In this paper we describe our experience in applying KAoS services to ensure policy compliance for Semantic Web Services workflow composition and enactment. We are developing these capabilities within the context of two applications: Coalition Search and Rescue (CoSAR-TS) and Semantic Firewall (SFW). We describe how this work has uncovered requirements for increasing the expressivity of policy beyond what can be done with description logic (e.g., role-value-maps), and how we are extending our representation and reasoning mechanisms in a carefully controlled manner to that end. Since KAoS employs OWL for policy representation, it fits naturally with the use of OWL-S workflow descriptions generated by the AIAI I-X planning system in the CoSAR-TS application. The advanced reasoning mechanisms of KAoS are based on the JTP inference engine and enable the analysis of classes and instances of processes from a policy perspective. As the result of analysis, KAoS concludes whether a particular workflow step is allowed by policy and whether the performance of this step would incur additional policy-generated obligations. Issues in the representation of processes within OWL-S are described. Besides what is done during workflow composition, aspects of policy compliance can be checked at runtime when a workflow is enacted. We illustrate these capabilities through two application examples. Finally, we outline plans for future work.


Book
16 Apr 2004
TL;DR: This guide will help you dramatically reduce the risk, complexity, and cost of integrating the many new concepts and technologies introduced by the SOA platform.
Abstract: Web services is the integration technology preferred by organizations implementing service-oriented architectures. I would recommend that anybody involved in application development obtain a working knowledge of these technologies, and I'm pleased to recommend Erl's book as a great place to begin.-Tom Glover, Senior Program Manager, Web Services Standards, IBM Software Group, and Chairman of the Web Services Interoperability Organization (WS-I).An excellent guide to building and integrating XML and Web services, providing pragmatic recommendations for applying these technologies effectively. The author tackles numerous integration challenges, identifying common mistakes and providing guidance needed to get it right the first time. A valuable resource for understanding and realizing the benefits of service-oriented architecture in the enterprise.-David Keogh, Program Manager, Visual Studio Enterprise Tools, Microsoft.Leading-edge IT organizations are currently exploring second generation web service technologies, but introductory material beyond technical specifications is sparse. Erl explains many of these emerging technologies in simple terms, elucidating the difficult concepts with appropriate examples, and demonstrates how they contribute to service-oriented architectures. I highly recommend this book to enterprise architects for their shelves.-Kevin P. Davis, Ph. D., Software Architect.Service-oriented integration with less cost and less riski? i? The emergence of key second-generation Web services standards has positioned service-oriented architecture (SOA) as the foremost platform for contemporary business automation solutions. The integration of SOA principles and technology is empowering organizations to build applications with unprecedented levels of flexibility, agility, and sophistication (while also allowing them to leverage existing legacy environments).This guide will help you dramatically reduce the risk, complexity, and cost of integrating the many new concepts and technologies introduced by the SOA platform. It brings together the first comprehensive collection of field-proven strategies, guidelines, and best practices for making the transition toward the service-oriented enterprise.Writing for architects, analysts, managers, and developers, Thomas Erl offers expert advice for making strategic decisions about both immediate and long-term integration issues. Erl addresses a broad spectrum of integration challenges, covering technical and design issues, as well as strategic planning. Covers crucial second-generation (WS-*) Web services standards: BPEL4WS, WS-Security, WS-Coordination, WS-Transaction, WS-Policy, WS-ReliableMessaging, and WS-Attachments Includes hundreds of individual integration strategies and more than 60 best practices for both XML and Web services technologies Includes a complete tutorial on service-oriented design principles for business and technical modeling Explores design issues related to a wide variety of service-oriented integration architectures that integrate XML and Web services into legacy and EAI environments Provides a clear roadmap for planning a long-term migration toward a standardized service-oriented enterpriseService-oriented architecture is no longer an exclusive discipline practiced only by expensive consultants. With this book's help, you can plan, architect, and implement your own service-oriented environments-efficiently and cost-effectively.About the Web SitesErl's Service-Oriented Architecture books are supported by two Web sites. http://www.soabooks.com provides a variety of content resources and http://www.soaspecs.com supplies a descriptive portal to referenced specifications.

Journal ArticleDOI
TL;DR: This article addresses dynamic service selection via an agent framework coupled with a QoS ontology with the aim of enabling participants to collaborate to determine each other's service quality and trustworthiness.
Abstract: Current Web services standards lack the means for expressing a service's nonfunctional attributes - namely, its quality of service. QoS can be objective (encompassing reliability, availability, and request-to-response time) or subjective (focusing on user experience). QoS attributes are key to dynamically selecting the services that best meet user needs. This article addresses dynamic service selection via an agent framework coupled with a QoS ontology. With this approach, participants can collaborate to determine each other's service quality and trustworthiness.

Proceedings ArticleDOI
17 May 2004
TL;DR: MWSAF (METEOR-S Web Service Annotation Framework), a framework for semi-automatically marking up Web service descriptions with ontologies, which has developed algorithms to match and annotate WSDL files with relevant ontologies.
Abstract: The World Wide Web is emerging not only as an infrastructure for data, but also for a broader variety of resources that are increasingly being made available as Web services. Relevant current standards like UDDI, WSDL, and SOAP are in their fledgling years and form the basis of making Web services a workable and broadly adopted technology. However, realizing the fuller scope of the promise of Web services and associated service oriented architecture will requite further technological advances in the areas of service interoperation, service discovery, service composition, and process orchestration. Semantics, especially as supported by the use of ontologies, and related Semantic Web technologies, are likely to provide better qualitative and scalable solutions to these requirements. Just as semantic annotation of data in the Semantic Web is the first critical step to better search, integration and analytics over heterogeneous data, semantic annotation of Web services is an equally critical first step to achieving the above promise. Our approach is to work with existing Web services technologies and combine them with ideas from the Semantic Web to create a better framework for Web service discovery and composition. In this paper we present MWSAF (METEOR-S Web Service Annotation Framework), a framework for semi-automatically marking up Web service descriptions with ontologies. We have developed algorithms to match and annotate WSDL files with relevant ontologies. We use domain ontologies to categorize Web services into domains. An empirical study of our approach is presented to help evaluate its performance.

Book ChapterDOI
01 Jan 2004
TL;DR: This chapter introduces web services and explains their role in Microsoft’s vision of the programmable web and removes some of the confusion surrounding technical terms like WSDL, SOAP, and UDDI.
Abstract: Microsoft has promoted ASP.NET’s new web services more than almost any other part of the.NET Framework. But despite their efforts, confusion is still widespread about what a web service is and, more importantly, what it’s meant to accomplish. This chapter introduces web services and explains their role in Microsoft’s vision of the programmable web. Along the way, you’ll learn about the open standards plumbing that allows web services to work and removes some of the confusion surrounding technical terms like WSDL (Web Service Description Language), SOAP, and UDDI (universal description, discovery, and integration).

Proceedings ArticleDOI
15 Sep 2004
TL;DR: This work presents a constraint driven Web service composition tool in METEOR-S, which allows the process designers to bind Web services to an abstract process, based on business and process constraints and generate an executable process.
Abstract: Creating Web processes using Web service technology gives us the opportunity for selecting new services, which best suit our need at the moment. Doing this automatically requires us to quantify our criteria for selection. In addition, there are challenging issues of correctness and optimality. We present a constraint driven Web service composition tool in METEOR-S, which allows the process designers to bind Web services to an abstract process, based on business and process constraints and generate an executable process. Our approach is to reduce much of the service composition problem to a constraint satisfaction problem. It uses a multiphase approach for constraint analysis. This work was done as part of the METEORS framework, which aims to support the complete lifecycle of semantic Web processes.

Book ChapterDOI
01 Jan 2004
TL;DR: The goal of a UDDI directory is to ensure that enterprises and individuals can quickly, easily, and dynamically locate and make use of services—particularly Web services—that are of interest to them.
Abstract: Universal Description, Discovery, and Integration (UDDI) is a standardized process to publish and discover information of Web services (as well as other services) programmatically or via a graphical user interface that would typically be Web based. The aim of UDDI is to provide a standard, uniform service, which is readily accessible by applications via a programmatic interface or by people via a graphical user interface (GUI). A UDDI directory—referred to as a registry—is meant to be platform independent and can be readily accessible via a Web browser-based GUI or by applications via published application programming interfaces (APIs). The goal of a UDDI directory is to ensure that enterprises and individuals can quickly, easily, and dynamically locate and make use of services—particularly Web services—that are of interest to them. As with all things related to or inspired by Web services, the UDDI is highly Extensible Markup Language (XML)-centric. The core information model used by the UDDI—irrespective of the kind of service being described—is based on an XML schema.

Journal ArticleDOI
TL;DR: A novel technique to learn user profiles from users' search histories is proposed, which are then used to improve retrieval effectiveness in Web search.
Abstract: Current Web search engines are built to serve all users, independent of the special needs of any individual user. Personalization of Web search is to carry out retrieval for each user incorporating his/her interests. We propose a novel technique to learn user profiles from users' search histories. The user profiles are then used to improve retrieval effectiveness in Web search. A user profile and a general profile are learned from the user's search history and a category hierarchy, respectively. These two profiles are combined to map a user query into a set of categories which represent the user's search intention and serve as a context to disambiguate the words in the user's query. Web search is conducted based on both the user query and the set of categories. Several profile learning and category mapping algorithms and a fusion algorithm are provided and evaluated. Experimental results indicate that our technique to personalize Web search is both effective and efficient.

Journal ArticleDOI
TL;DR: This paper describes the design and implementation of a service matchmaking prototype that uses a DAML -S based ontology and a description logic reasoner to compare ontology-based service descriptions to represent the semantics of service descriptions.
Abstract: The semantic Web can make e-commerce interactions more flexible and automated by standardizing ontologies, message content, and message protocols. This paper investigates how semantic and Web Services technologies can be used to support service advertisement and discovery in e-commerce. In particular, it describes the design and implementation of a service matchmaking prototype that uses a DAML -S based ontology and a description logic reasoner to compare ontology-based service descriptions. By representing the semantics of service descriptions, the matchmaker enables the behavior of an intelligent agent to approach more closely that of a human user trying to locate suitable Web services. The performance of this prototype implementation was tested in a realistic agent-based e-commerce scenario.


Book ChapterDOI
07 Nov 2004
TL;DR: A planning technique for the automated composition of web services described in OWLS process models, which can deal effectively with nondeterminism, partial observability, and complex goals is proposed and implemented in a planner.
Abstract: Different planning techniques have been applied to the problem of automated composition of web services. However, in realistic cases, this planning problem is far from trivial: the planner needs to deal with the nondeterministic behavior of web services, the partial observability of their internal status, and with complex goals expressing temporal conditions and preference requirements. We propose a planning technique for the automated composition of web services described in OWLS process models, which can deal effectively with nondeterminism, partial observability, and complex goals. The technique allows for the synthesis of plans that encode compositions of web services with the usual programming constructs, like conditionals and iterations. The generated plans can thus be translated into executable processes, e.g., BPEL4WS programs. We implement our solution in a planner and do some preliminary experimental evaluations that show the potentialities of our approach, and the gain in performance of automating the composition at the semantic level w.r.t. the automated composition at the level of executable processes.

Proceedings ArticleDOI
20 Sep 2004
TL;DR: A mechanism is introduced that determines theQoS of a Web service composition by aggregating the QoS dimensions of the individual services by building upon abstract composition patterns derived from Van der Aalst's et al. comprehensive collection of workflow patterns.
Abstract: Contributions in the field of Web services have identified that (a) finding matches between semantic descriptions of advertised and requested services and (b) nonfunctional characteristics - the quality of service (QoS) - are the most crucial criteria for composition of Web services. A mechanism is introduced that determines the QoS of a Web service composition by aggregating the QoS dimensions of the individual services. This allows to verify whether a set of services selected for composition satisfies the QoS requirements for the whole composition. The aggregation performed builds upon abstract composition patterns, which represent basic structural elements of a composition, like sequence, loop, or parallel execution. This work focusses on workflow management environments. We define composition patterns that are derived from Van der Aalst's et al. comprehensive collection of workflow patterns. The resulting aggregation schema supports the same structural elements as found in workflows. Furthermore, the aggregation of several QoS dimensions is discussed.

Proceedings ArticleDOI
17 May 2004
TL;DR: PANKOW (Pattern-based Annotation through Knowledge on theWeb), a method which employs an unsupervised, pattern-based approach to categorize instances with regard to an ontology, is proposed.
Abstract: The success of the Semantic Web depends on the availability of ontologies as well as on the proliferation of web pages annotated with metadata conforming to these ontologies. Thus, a crucial question is where to acquire these metadata from. In this paper wepropose PANKOW (Pattern-based Annotation through Knowledge on theWeb), a method which employs an unsupervised, pattern-based approach to categorize instances with regard to an ontology. The approach is evaluated against the manual annotations of two human subjects. The approach is implemented in OntoMat, an annotation tool for the Semantic Web and shows very promising results.