http://www.bibsonomy.org/burst/group/eswc2008BibSonomy BuRST Feed for /group/eswc20082009-01-06T15:42:43+01:00http://www.bibsonomy.org/bibtex/26b1ee8e572600c6d2efc47c9f58817ee/eswc2008eswc20082008-05-28T14:50:07+02:00services wsdl sawsdl semantic web ontology integration description semantic-web-services-1 owl service universal annotations language discovery uddi <span style="color:#555555;">Dimitrios <a href="http://www.bibsonomy.org/author/Kourtesis">Kourtesis</a> and Iraklis <a href="http://www.bibsonomy.org/author/Paraskakis">Paraskakis</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:07 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSCombining SAWSDL, OWL-DL and UDDI for Semantically Enhanced Web Service Discovery2008services wsdl sawsdl semantic web ontology integration description semantic-web-services-1 owl service universal annotations language discovery uddi UDDI registries are included as a standard offering within the product suite of any major SOA vendor, serving as the foundation for establishing design-time and run-time SOA governance. Despite the success of the UDDI specification and its rapid uptake by the industry, the capabilities of its offered service discovery facilities are rather limited. The lack of machine-understandable semantics in the technical specifications and classification schemes used for retrieving services, prevent UDDI registries from supporting fully automated and thus truly effective service discovery. This paper presents the implementation of a semantically-enhanced registry that builds on the UDDI specification and augments its service publication and discovery facilities to overcome the aforementioned limitations. The proposed solution combines 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.http://www.bibsonomy.org/bibtex/24351fdf2185be4ce88dae92d12848dae/eswc2008eswc20082008-05-28T14:50:06+02:00provenance search datasets sitemaps crawling foundational-issues-storage-and-retrieval <span style="color:#555555;">Richard <a href="http://www.bibsonomy.org/author/Cyganiak">Cyganiak</a> and Renaud <a href="http://www.bibsonomy.org/author/Delbru">Delbru</a> and Holger <a href="http://www.bibsonomy.org/author/Stenzhorn">Stenzhorn</a> and Giovanni <a href="http://www.bibsonomy.org/author/Tummarello">Tummarello</a> and Stefan <a href="http://www.bibsonomy.org/author/Decker">Decker</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:06 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSExposing Large Datasets with Semantic Sitemaps2008provenance search datasets sitemaps crawling foundational-issues-storage-and-retrieval Increasing amounts of RDF data are available on the Web for consumption by Semantic Web browsers and indexing by Semantic Web search engines. Current Semantic Web publishing practices, however, do not directly support efficient discovery and high-performance retrieval by clients and search engines. We propose an extension to the Sitemaps protocol which provides a simple and effective solution: Data publishers create Semantic Sitemaps to announce and describe their data so that clients can choose the most appropriate access method. We show how this protocol enables an extended notion of authoritative information across different access methods.http://www.bibsonomy.org/bibtex/2771947296490ffa6cd01ada59cb6c1ec/eswc2008eswc20082008-05-28T14:50:06+02:00methods alignment distance end-to-end cultural semantic retrieval ontology-alignment ontology heritage evaluation <span style="color:#555555;">Laura <a href="http://www.bibsonomy.org/author/Hollink">Hollink</a> and Mark van <a href="http://www.bibsonomy.org/author/Assem">Assem</a> and Antoine <a href="http://www.bibsonomy.org/author/Isaac">Isaac</a> and Shenghui <a href="http://www.bibsonomy.org/author/Wang">Wang</a> and Guus <a href="http://www.bibsonomy.org/author/Schreiber">Schreiber</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:06 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSTwo Variations on Ontology Alignment Evaluation: Methodological Issues2008methods alignment distance end-to-end cultural semantic retrieval ontology-alignment ontology heritage evaluation Evaluation of ontology alignments is in practice done in two ways: (1) assessing individual correspondences and (2) comparing the alignment to a reference alignment. However, this type of evaluation does not guarantee that an application which uses the alignment will perform well. In this paper, we contribute to the current ontology alignment evaluation practices by proposing two alternative evaluation methods that take into account some characteristics of a usage scenario without doing a full-fledged end-to-end evaluation. We compare different evaluation approaches in three case studies, focussing on methodological issues. Each case study considers an alignment between a different pair of ontologies, ranging from rich and well-structured to small and poorly structured. This enables us to conclude on the use of different evaluation approaches in different settings.http://www.bibsonomy.org/bibtex/22a2a25f0c3ca04f9657805a465179975/eswc2008eswc20082008-05-28T14:50:06+02:00subgraph result graph estimation query-processing-2 summaries cardinality <span style="color:#555555;">Angela <a href="http://www.bibsonomy.org/author/Maduko">Maduko</a> and Kemafor <a href="http://www.bibsonomy.org/author/Anyanwu">Anyanwu</a> and Amit <a href="http://www.bibsonomy.org/author/Sheth">Sheth</a> and Paul <a href="http://www.bibsonomy.org/author/Schliekelman">Schliekelman</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:06 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSGraph Summaries for Subgraph Frequency Estimation2008subgraph result graph estimation query-processing-2 summaries cardinality Graphs are increasingly used to model data in many disciplines. Structure search which matches a query graph against a data graph, is a common information retrieval paradigm for graph structured data. A crucial factor in optimizing such searches is the ability to estimate the frequency of substructures within a query graph. In this work, we present and evaluate two techniques for estimating the frequency of subgraphs from a summary of the data graph. In the first technique, we assume that edge occurrences on edge sequences are position independent and summarize only the most informative dependencies. In the second technique, we prune small subgraphs based on a valuation scheme that blends information about their importance and estimation power. In both techniques, we assume conditional independence to estimate the frequencies of larger subgraphs. We validate the effectiveness of our techniques using experiments on real and synthetic datasetshttp://www.bibsonomy.org/bibtex/20702addea22ce6b1b90eccffef1b9397/eswc2008eswc20082008-05-28T14:50:05+02:00information patterns desktop semantic theory workflow speech personal email social applications-1 act management <span style="color:#555555;">Simon <a href="http://www.bibsonomy.org/author/Scerri">Scerri</a> and Siegfried <a href="http://www.bibsonomy.org/author/Handschuh">Handschuh</a> and Stefan <a href="http://www.bibsonomy.org/author/Decker">Decker</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:05 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSSemantic Email as a communication medium for the Social Semantic Desktop2008information patterns desktop semantic theory workflow speech personal email social applications-1 act management In this paper, we introduce a formal email workflow model based on traditional email, which enables the user to define and execute ad-hoc workflows in an intuitive way. This model paves the way for semantic annotation of implicit, well-defined workflows, thus making them explicit and exposing the missing information in a machine processable way. Grounding this work within the Social Semantic Desktop [1] via appropriate ontologies means that this information can be exploited for the benefit of the user. This will have a direct impact on their personal information management - given email is not just a major channel of data exchange between desktops, but it also serves as a virtual working environment where people collaborate. Thus the presented workflow model will have a concrete manifestation in the creation, organization and exchange of semantic desktop data.http://www.bibsonomy.org/bibtex/2e672f158fc594179cd9fd36f8a135de4/eswc2008eswc20082008-05-28T14:50:05+02:00xmpp agents-application-ontologies rdf messaging agent instant sparql <span style="color:#555555;">Sebastian <a href="http://www.bibsonomy.org/author/Dietzold">Dietzold</a> and J&#246;rg <a href="http://www.bibsonomy.org/author/Unbehauen">Unbehauen</a> and S&#246;ren <a href="http://www.bibsonomy.org/author/Auer">Auer</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:05 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSxOperator - Interconnecting the Semantic Web and Instant Messaging Networks2008xmpp agents-application-ontologies rdf messaging agent instant sparql Instant Messaging is in addition to Web and Email the most popular service on the Internet. With xOperator we present a strategy and implementation which deeply integrates Instant Messaging networks with the Semantic Web. The xOperator concept is based on the idea of creating an overlay network of collaborative information agents on top of social IM networks. It can be queried using a controlled and easily extensible language based on AIML templates. Such a deep integration of semantic technologies and Instant Messaging bears a number of advantages and benefits for users when compared to the separated use of Semantic Web technologies and IM, the most important ones being context awareness as well as provenance and trust. We showcase how the xOperator approach naturally facilitates contacts and calendar management as well as access to large scale heterogeneous information sources.http://www.bibsonomy.org/bibtex/2537f0259c3f88cd0ff7507c2de0feb42/eswc2008eswc20082008-05-28T14:50:05+02:00process agents-application-ontologies analysis ontology management business <span style="color:#555555;">Carlos <a href="http://www.bibsonomy.org/author/Pedrinaci">Pedrinaci</a> and John <a href="http://www.bibsonomy.org/author/Domingue">Domingue</a> and Ana Karla Alves de <a href="http://www.bibsonomy.org/author/Medeiros">Medeiros</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:05 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSA Core Ontology for Business Process Analysis2008process agents-application-ontologies analysis ontology management business Business Process Management (BPM) aims at supporting the whole life-cycle necessary to deploy and maintain business processes in organisations. An important step of the BPM life-cycle is the analysis of the processes deployed in companies. However, the degree of automation currently achieved cannot support the level of adaptation required by businesses. Initial steps have been performed towards including some sort of automated reasoning within Business Process Analysis (BPA) but this is typically limited to using taxonomies. We present a core ontology aimed at enhancing the state of the art in BPA. The ontology builds upon a Time Ontology and is structured around the process, resource, and object perspectives as typically adopted when analysing business processes. The ontology has been extended and validated by means of an Events Ontology and an Events Analysis Ontology aimed at capturing the audit trails generated by Process-Aware Information Systems and deriving additional knowledge.http://www.bibsonomy.org/bibtex/2c637e37e6eb5932d4550f10f0e84c7a2/eswc2008eswc20082008-05-28T14:50:04+02:00computational reasoning ontologies complexity description formal-languages-2 logics <span style="color:#555555;">Riccardo <a href="http://www.bibsonomy.org/author/Rosati">Rosati</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:04 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSFinite model reasoning in DL-Lite2008computational reasoning ontologies complexity description formal-languages-2 logics The semantics of OWL-DL and its subclasses are based on the classical semantics of first-order logic, in which the interpretation domain may be an infinite set. This constitutes a serious expressive limitation for such ontology languages, since, in many real application scenarios for the Semantic Web, the domain of interest is actually finite, although the exact cardinality of the domain is unknown. Hence, in these cases the formal semantics of the OWL-DL ontology does not coincide with its intended semantics. In this paper we start filling this gap, by considering the subclasses of OWL-DL which correspond to the logics of the DL-Lite family, and studying reasoning over finite models in such logics. In particular, we mainly consider two reasoning problems: deciding satisfiability of an ontology, and answering unions of conjunctive queries (UCQs) over an ontology. We first consider the description logic DL-Lite_R and show that, for the two above mentioned problems, finite model reasoning coincides with classical reasoning, i.e., reasoning over arbitrary, unrestricted models. Then, we analyze the description logics DL-Lite_F and DL_Lite_A. Differently from DL-Lite_R, in such logics finite model reasoning does not coincide with classical reasoning. To solve satisfiability and query answering over finite models in these logics, we define techniques which reduce polynomially both the above reasoning problems over finite models to the corresponding problem over arbitrary models. Thus, for all the DL-Lite languages considered, the good computational properties of satisfiability and query answering under the classical semantics also hold under the finite model semantics. Moreover, we have effectively and easily implemented the above techniques, extending the DL-Lite reasoner QuOnto with support for finite model reasoning.http://www.bibsonomy.org/bibtex/2cd8b469b8da63e07df36d51c92fc8868/eswc2008eswc20082008-05-28T14:50:03+02:00ontologies localization semantic-web-services-2 multilingual ontology <span style="color:#555555;">Mauricio <a href="http://www.bibsonomy.org/author/Espinoza">Espinoza</a> and Asunci&#243;n <a href="http://www.bibsonomy.org/author/Gómez-Pérez">G&#243;mez-P&#233;rez</a> and Eduardo <a href="http://www.bibsonomy.org/author/Mena">Mena</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:03 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSEnriching an Ontology with Multilingual Information2008ontologies localization semantic-web-services-2 multilingual ontology Typically ontologies are described in a determined natural language. Organizations working in a multilingual environment demand multilingual ontologies. To solve this problem we propose LabelTranslator, a NeOn plug-in that automatically localize ontologies. Ontology localization consists in adapting an ontology to a concrete language and culture community. LabelTranslator takes as input an ontology whose labels are described in a source natural language and obtains the most probable translation of each ontology label in a target natural language. Our main contribution is the automatization of this process which reduces human efforts to localize manually the ontology. First, our system uses a translation service which obtains automatic translations of each ontology label (name of an ontology term) in English, German, or Spanish by consulting different linguistic resources such as lexical databases, bilingual dictionaries, and terminologies. Second, a ranking method is used to sort each ontology label according to similarity with its lexical and structural context. The experiments performed in order to evaluate the quality of translation show that our approach is a good approximation to enrich an ontology with multilingual information.http://www.bibsonomy.org/bibtex/27d5bef571852a9d6c49d409d25ba7f5f/eswc2008eswc20082008-05-28T14:50:03+02:00services wsmo-lite service semantic web modelling ontology <span style="color:#555555;">Tomas <a href="http://www.bibsonomy.org/author/Vitvar">Vitvar</a> and Jacek <a href="http://www.bibsonomy.org/author/Kopecky">Kopecky</a> and Jana <a href="http://www.bibsonomy.org/author/Viskova">Viskova</a> and Dieter <a href="http://www.bibsonomy.org/author/Fensel">Fensel</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:03 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSWSMO-Lite Annotations for Web Services2008services wsmo-lite service semantic web modelling ontology Current efforts in Semantic Web Services do not sufficiently address the industrial developments of SOA technology in regards to bottom-up modeling of services, that is, building incremental layers on top of existing service descriptions. An important step in this direction has been made in the W3C by the SAWSDL WG proposing a framework for annotating WSDL services with arbitrary semantic descriptions. We build on the SAWSDL layer and define WSMO-Lite service ontology, narrowing down the use of SAWSDL as an annotation mechanism for WSMO-Lite. Ultimately, our goal is to allow incremental steps on top of existing service descriptions, enhancing existing SOA capabilities with intelligent and automated integration.http://www.bibsonomy.org/bibtex/22f250404994a287160f00ef1e8a631ac/eswc2008eswc20082008-05-28T14:50:02+02:00concept similarity semantic learning drift conceptual novelty setection clustering <span style="color:#555555;">Nicola <a href="http://www.bibsonomy.org/author/Fanizzi">Fanizzi</a> and Claudia <a href="http://www.bibsonomy.org/author/d&#039;Amato">d'Amato</a> and Floriana <a href="http://www.bibsonomy.org/author/Esposito">Esposito</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:02 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSConceptual Clustering and its Application to Concept Drift and Novelty Detection2008concept similarity semantic learning drift conceptual novelty setection clustering We present a method based on clustering techniques to detect concept drift or novelty in a knowledge based expressed in Description Logics. The method exploits an effective and language-independent semi-distance measure defined for the space of individuals, that is based on a finite number of dimensions corresponding to a committee of discriminating features (represented by concept descriptions). A maximally discriminating group of features can be obtained with the randomized optimization methods described in the paper. An experimentation with some ontologies proves the feasibility of our method and its effectiveness in terms of clustering validity indices. Then, with a supervised learning phase, each cluster can be assigned with a refined or newly constructed intensional definition expressed in the adopted language. We propose a method for exploiting the clustering results for concept drift and novelty detectionhttp://www.bibsonomy.org/bibtex/2a87c0da670998e2977d26a48b072870c/eswc2008eswc20082008-05-28T14:50:02+02:00safety formal-languages-1 conservative reuse modularity locality ontology extensions <span style="color:#555555;">Ernesto <a href="http://www.bibsonomy.org/author/Jimenez-Ruiz">Jimenez-Ruiz</a> and Bernardo Cuenca <a href="http://www.bibsonomy.org/author/Grau">Grau</a> and Ulrike <a href="http://www.bibsonomy.org/author/Sattler">Sattler</a> and Thomas <a href="http://www.bibsonomy.org/author/Schneider">Schneider</a> and Rafael <a href="http://www.bibsonomy.org/author/Berlanga-Llavori">Berlanga-Llavori</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:02 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSSafe and Economic re-use of ontologies: a logic-based methodology and tool support2008safety formal-languages-1 conservative reuse modularity locality ontology extensions Driven by application requirements and using well-understood theoretical results, we describe a novel methodology and a tool for modular ontology design. We support the user in the safe use of imported symbols and in the economic import of the relevant part of the imported ontology. Both features are supported in a well-understood way: safety guarantees that the semantics of imported concepts is not changed, and economic import guarantees that no difference can be observed between importing the whole ontology and importing the relevant part.http://www.bibsonomy.org/bibtex/2d972de0a0bd5ae9067c390046fc34c7d/eswc2008eswc20082008-05-28T14:50:02+02:00vectors expansion query-processing-2 query semantic interoperability interpretation <span style="color:#555555;">Anthony <a href="http://www.bibsonomy.org/author/Ventresque">Ventresque</a> and Sylvie <a href="http://www.bibsonomy.org/author/Cazalens">Cazalens</a> and Philippe <a href="http://www.bibsonomy.org/author/Lamarre">Lamarre</a> and Patrick <a href="http://www.bibsonomy.org/author/Valduriez">Valduriez</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:02 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSImproving interoperability using query interpretation in semantic vector spaces2008vectors expansion query-processing-2 query semantic interoperability interpretation In semantic web applications where query initiators and information providers do not necessarily share the same ontology, semantic interoperability typically relies on ontology matching or schema mappings. Information exchange is then not only enabled by the established correspondences (the ``shared'' parts of the ontologies) but, in some sense, limited to them. Then, an important question which has not received attention is how the ``unshared'' parts can also contribute to and improve information exchange. In this paper, we address this question by considering a system where documents and queries are represented by semantic vectors. We propose a specific query expansion step at the query initiator's side and a query interpretation step at the document provider's. Through these steps, unshared concepts contribute to evaluate the relevance of documents wrt. a given query. Our experiments show an important improvement of retrieval relevance when concepts of documents and queries are not shared. Even if the concepts of the initial query are not shared by the document provider, our method still ensures 90% of the precision and recall obtained when the concepts are shared.http://www.bibsonomy.org/bibtex/20aedaf7d891b39d35f46baf40901c299/eswc2008eswc20082008-05-28T14:50:01+02:00inductive measure query description unswering learning ontology logic uncertainty population similalrity <span style="color:#555555;">Claudia <a href="http://www.bibsonomy.org/author/d&#039;Amato">d'Amato</a> and Nicola <a href="http://www.bibsonomy.org/author/Fanizzi">Fanizzi</a> and Floriana <a href="http://www.bibsonomy.org/author/Esposito">Esposito</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:01 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSQuery Answering and Ontology Population: an Inductive Approach2008inductive measure query description unswering learning ontology logic uncertainty population similalrity In the context of Semantic Web, deductive reasoning is used for making explicit the implicit knowledge of a knowledge base (KB). Anyway, purely logic-based approaches can fail when data comes from distributed sources, where contradictions usually turn out. Inductive instance-based learning methods can be effectively used in such a case, since they are well known to be efficient and fault tolerant. In this paper we propose an inductive method for improving the concept retrieval and for the performing the ontology population in a (semi-)automatic way. By casting concept retrieval to a classification problem with the goal of assessing the individual memberships w.r.t. the query concepts, we propose an extension of the \emph{k-Nearest Neighbor} algorithm for Description Logic KBs. It is based on the exploitation of an \emph{entropy}-based dissimilarity measure. The procedure retrieves individuals belonging to query concepts, by analogy with other training instances, on the grounds of the classification of the nearest ones w.r.t.\ the dissimilarity measure. We experimentally show that the behavior of the classifier is comparable with the one of a standard reasoner. Moreover we show that new knowledge (not logically derivable) is induced. It can be suggested to the knowledge engineer for validation, during the ontology population task.http://www.bibsonomy.org/bibtex/21a97459b80d2cac3fd8b935452fe0418/eswc2008eswc20082008-05-28T14:50:01+02:00distance measure rdf learning clustering <span style="color:#555555;">Gunnar <a href="http://www.bibsonomy.org/author/Grimnes">Grimnes</a> and Peter <a href="http://www.bibsonomy.org/author/Edwards">Edwards</a> and Alun <a href="http://www.bibsonomy.org/author/Preece">Preece</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:01 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSDistance Based clustering of Semantic Web Resources2008distance measure rdf learning clustering The original Semantic Web vision was explicit in the need for intelligent autonomous agents that would represent users and help them navigate the Semantic Web. We argue that an essential feature for such agents is the capability to analyse data and learn. In this paper we outline the challenges and issues surrounding the application of clustering algorithms to Semantic Web data. We present several ways to extract instances from a large RDF graph and computing the distance between these. We evaluate our approaches on three different data-sets, one representing a typical relational database to RDF conversion, one based on data from a ontologically rich Semantic Web enabled application, and one consisting of a crawl of FOAF documents; applying both supervised and unsupervised evaluation metrics. Our evaluation did not support choosing a single combination of instance extraction method and similarity metric as superior in all cases, and as expected the behaviour depends greatly on the data being clustered. Instead, we attempt to identify characteristics of data that make particular methods more suitable.http://www.bibsonomy.org/bibtex/227eff85c634f0afa66d22980c36ff478/eswc2008eswc20082008-05-28T14:50:01+02:00naming identity system entity uri reference foundational-issues-storage-and-retrieval <span style="color:#555555;">Paolo <a href="http://www.bibsonomy.org/author/Bouquet">Bouquet</a> and Heiko <a href="http://www.bibsonomy.org/author/Stoermer">Stoermer</a> and Barbara <a href="http://www.bibsonomy.org/author/Bazzanella">Bazzanella</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:01 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSAn Entity Naming System for the Semantic Web2008naming identity system entity uri reference foundational-issues-storage-and-retrieval Today, as a result of many independent initiatives, research projects and commercial initiatives, relatively large and important content repositories are available which actually are (or can be easily tranformed into) local ``semantic webs'', namely graphs of resources connected through properties which are defined in some schema or vocabulary. The data published as part of the LinkedData initiative are examples of content already insemantic web format (RDF/OWL); however, any social network, digital library metadata collection, commercial catalog and in principle any relational database could be easily (and mostly syntactically) transformed into a local semantic web. So what is missing enabling factor which can support the automatic and smooth integration of these local ``semantic webs'' into something like the envisaged global Semantic Web? In this paper, we argue that the missing factor is a service which, in analogy with what the DNS did for the Web, can make the addressing mechanism of the Semantic Web global. The addressing mechanism of the WWW was made global by building it on top of the pre-existing DNS service; the addressing mechanism of the Semantic Web cannot go global, as no such pre-existing infrastructure is available, and therefore no fast and easy (semantic) integration is readily available. In this paper, we first introduce and describe what we consider to be the cornerstone of such an infrastructure, a service called Entity Naming System (ENS) which is designed to resolve a local URI or even an arbitrary description of a resource (not only, and not mainly, information resources) into a global identifier for that resource. Then we discuss the main issues and challenges associated with the design and implementation of a scalable and sustainable ENS. Third, we report the results of an experiment which we made on integrating the metadata of several Web and Semantic Web conference with or without a ENS. Finally, we present two simple examples of how existing applications can use the ENS for creating semantically integrated knowledge for the Semantic Web.http://www.bibsonomy.org/bibtex/2fc7f36c61174d07ed9bdb4608c250284/eswc2008eswc20082008-05-28T14:50:00+02:00query-processing-2 query integration distributed data semantic mediator processing web sparql <span style="color:#555555;">Andreas <a href="http://www.bibsonomy.org/author/Langegger">Langegger</a> and Wolfram <a href="http://www.bibsonomy.org/author/Wöß">W&#246;&#223;</a> and Martin <a href="http://www.bibsonomy.org/author/Blöchl">Bl&#246;chl</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:00 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSA Semantic Web Middleware for Virtual Data Integration on the Web2008query-processing-2 query integration distributed data semantic mediator processing web sparql In this contribution a system is presented, which provides access to distributed data sources using Semantic Web technology. While it was primarily designed for data sharing and scientific collaboration, it is regarded as a base technology useful for many other Semantic Web applications. The proposed system allows to retrieve data using SPARQL queries, data sources can register and abandon freely, and all RDF Schema or OWL vocabularies can be used to describe their data, as long as they are accessible on the Web. Data heterogeneity is addressed by RDF-wrappers like D2R-Server placed on top of local information systems. A query does not directly refer to actual endpoints, instead it contains graph patterns adhering to a virtual data set. A mediator finally pulls and joins RDF data from different endpoints providing a transparent on-the-fly view to the end-user. The SPARQL protocol has been defined to enable systematic data access to remote endpoints. However, remote SPARQL queries require the explicit notion of endpoint URIs. The presented system allows users to execute queries without the need to specify target endpoints. Additionally, it is possible to execute join and union operations across different remote endpoints. The optimization of such distributed operations is a key factor concerning the performance of the overall system. Therefore, proven concepts from database research can be applied.http://www.bibsonomy.org/bibtex/2e18420bd48a40bb0cf79265cb071c2b6/eswc2008eswc20082008-05-28T14:50:00+02:00services contracting choreography service semantic-web-services-2 semantic web wsmo <span style="color:#555555;">Dumitru <a href="http://www.bibsonomy.org/author/Roman">Roman</a> and Michael <a href="http://www.bibsonomy.org/author/Kifer">Kifer</a> and Dieter <a href="http://www.bibsonomy.org/author/Fensel">Fensel</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:00 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSWSMO Choreography: From Abstract State Machines to Concurrent Transaction Logic2008services contracting choreography service semantic-web-services-2 semantic web wsmo Several approaches to semantic Web services, including OWL-S, SWSF, and WSMO, have been proposed in the literature with the aim to enable automation of various tasks related to Web services, such as discovery, contracting, enactment, monitoring, and mediation. The ability to specify processes and to reason about them is central to these initiatives. In this paper we analyze the WSMO choreography model, which is based on Abstract State Machines (ASMs), and propose a methodology for generating WSMO choreography from visual specifications. We point out the limitations of the current WSMO model and propose a faithful extension that is based on Concurrent Transaction Logic (CTR). The advantage of a CTR-based model is that it uniformly captures a number of aspects that previously required separate mechanisms or were not captured at all. These include process specification, contracting for services, service enactment, and reasoning.http://www.bibsonomy.org/bibtex/27e0e8278793cb68e516ee4a564445bd9/eswc2008eswc20082008-05-28T14:50:00+02:00open authoring federation data semantic web applications-1 claim linked <span style="color:#555555;">Tudor <a href="http://www.bibsonomy.org/author/Groza">Groza</a> and Siegfried <a href="http://www.bibsonomy.org/author/Handschuh">Handschuh</a> and Knud <a href="http://www.bibsonomy.org/author/Möller">M&#246;ller</a> and Stefan <a href="http://www.bibsonomy.org/author/Decker">Decker</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:00 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSKonneX-SALT: First Steps towards a Semantic Claim Federation Infrastructure2008open authoring federation data semantic web applications-1 claim linked Dissemination, an important phase of scientific research, can be seen as a communication process between scientists. They expose and support their findings, while discussing claims stated in related scientific publications. However, due to the increasing number of publications, finding a starting point for such a discussion represents a real challenge. At same time, browsing can also be difficult since the communication spans across multiple publications on the open web. In this paper we propose a semantic claim federation infrastructure, named KonneX-SALT, as a solution for both issues mentioned above: (i) finding claims in scientific publications, and (ii) building the argumentation discourse network (ADN) for each claim and providing support for browsing it (in our case, by making use of transclusion). In addition, we join the web of "linked open data", by linking the metadata managed by KonneX-SALT with some of the known repositories of scientific publications.http://www.bibsonomy.org/bibtex/2e89c1407d23363623b309b221e2ca1e9/eswc2008eswc20082008-05-28T14:50:00+02:00document spreading search desktop semantic retrieval activation <span style="color:#555555;">Kinga <a href="http://www.bibsonomy.org/author/Schumacher">Schumacher</a> and Michael <a href="http://www.bibsonomy.org/author/Sintek">Sintek</a> and Leo <a href="http://www.bibsonomy.org/author/Sauermann">Sauermann</a> </span><em>Proceedings of the 5th European Semantic Web Conference, </em><em>Berlin, Heidelberg, </em><em>Springer Verlag, </em><em>June2008. </em>Wed May 28 14:50:00 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSCombining Meta Data and Document Search with Spreading Activation for Semantic Desktop Search2008document spreading search desktop semantic retrieval activation The Semantic Desktop is a means to support users in Personal Information Management (PIM). It provides an excellent test bed for Semantic Web technology: resources (e. g., persons, projects, messages, documents) are distributed amongst multiple systems, ontologies are used to link and annotate them. Finding information is a core element in PIM. For the end user, the search interface has to be intuitive to use, natural language queries provide a simple mean to express requests. State of the art semantic search engines focus on metadata search or on semantic document retrieval. We combine both approaches to search the Semantic Desktop exploiting all available information, where we build on semantic teleporting and spreading activation. This combination is able to answer queries with instances, subgraphs of the knowledge base, and with relevant documents. We evaluated our approach on ESWC 2007 data in comparison with Google site search.