The Semantic Web - ISWC 2008 -- 7th International Semantic Web Conference, ISWC 2008, Karlsruhe, Germany, October 26-30, 2008. Proceedings

Doctoral Consortium Paper

1. Contracting and Copyright Issues for Composite Semantic Services , Christian Baumann , 895-900 , [OpenAccess] , [Publisher]
   In business webs within the Internet of Services arbitrary services shall be composed to new composite services and therewith creating tradeable goods. A composite service can be part of another composite service and so on. Since business partners can meet just for one transaction not having regular business which justifies frame contracts, ad-hoc automated contracting needs to be established. In addition services have an intangible character and therefore are prone to illegal reproduction. Thus intellectual property rights have to be considered. Our research approach is to assess the applicability of copyright law for semantic web services and develop a concept for automated contracting. Methodologies to be used are in the field of ontology modeling and reasoning.
2. End-User Assisted Ontology Evolution in Uncertain Domains , Thomas Scharrenbach , 920-925 , [OpenAccess] , [Publisher]
   Statical ontology learning from large text corpora is a well understood task while evolving ontologies dynamically from user-input has rarely been adressed so far. Evolution of ontologies has to deal with vague or incomplete information. Accordingly, the formalism used for knowledge representation must be able to deal with this kind of information. Classical logical approaches such as description logics are particularly poor in adressing uncertainty. Ontology evolution may benefit from exploring probabilistic or fuzzy approaches to knowledge representation. In this thesis an approach to evolve and update ontologies is developed which uses explicit and implicit user-input and extends probabilistic approaches to ontology engineering.
3. Interactive Exploration of Heterogeneous Cultural Heritage Collections , Michiel Hildebrand , 914-919 , [OpenAccess] , [Publisher]
   In this research we investigate to what extent explicit semantics can be used to support end users with the exploration of a large heterogeneous collection. In particular we consider cultural heritage, a knowledge-rich domain in which collections are typically described by multiple thesauri. We focus on three types of end user functionality. First, searching for terms within multiple thesauri to support manual annotation. Second, keyword search, as it has become the de-facto standard to access data on the web. Third, faceted browsing as it has become a popular method to interactively explore (image) collections. For these three tasks we question the role of explicit semantics in the search algorithm, the result organization and visualization and how to evaluate the added value of for end users. We investigate these questions by the implementation and evaluation of three prototype systems on top of large and real wold data collections.
4. Learning Methods in Multi-grained Query Answering , Philipp Sorg , 926-931 , [OpenAccess] , [Publisher]
   This PhD proposal is about the development of new methods for information access. Two new approaches are proposed: Multi-Grained Query Answering that bridges the gap between Information Retrieval and Question Answering and Learning-Enhanced Query Answering that enables the improvement of retrieval performance based on the experience of previous queries and answers.
5. Parallel Computation Techniques for Ontology Reasoning , Jürgen Bock , 901-906 , [OpenAccess] , [Publisher]
   As current reasoning techniques are not designed for massive parallelisation, usage of parallel computation techniques in reasoning establishes a major research problem. I will propose two possibilities of applying parallel computation techniques to ontology reasoning: parallel processing of independent ontological modules, and tailoring the reasoning algorithms to parallel architectures.
6. Semantic Enrichment of Folksonomy Tagspaces , Sofia Angeletou , 889-894 , [OpenAccess] , [Publisher]
   The usability and the strong social dimension of the Web2.0 applications has encouraged users to create, annotate and share their content thus leading to a rich and content-intensive Web. Despite that, the Web2.0 content lacks the explicit semantics that would allow it to be used in large-scale intelligent applications. At the same time the advances in Semantic Web technologies imply a promising potential for intelligent applications capable to integrate distributed content and knowledge from various heterogeneous resources. We present FLOR a tool that performs semantic enrichment of folksonomy tagspaces by exploiting online ontologies, thesauri and other knowledge sources.
7. Towards Semantic Mapping for Casual Web Users , Colm Conroy , 907-913 , [OpenAccess] , [Publisher]
   As yet there has been very little uptake of the semantic web within the mainstream internet environment. In contrast 'Web 2.0' has seen an explosion in uptake due to (among others) rich user experience, user participation and collective intelligence. We intend to make use of user-driven methodologies that exist within ‘Web 2.0’ to enhance semantic mapping. This paper is an extended abstract on PhD work that will identify interactions that will be acceptable, efficient and effective for casual web users to achieve semantic mappings gradually and over time between information models of interest to the user.

Research Track Paper

1. A Kernel Revision Operator for Terminologies - Algorithms and Evaluation , Guilin Qi,Peter Haase,Zhisheng Huang,Qiu JI,Jeff Z. Pan and Johanna Völker , 419-434 , [OpenAccess] , [Publisher]
   In this paper, we propose a general operator for revising terminologies in description logic-based ontologies. Our revision operator is based on a reformulation of the kernel contraction operator in belief revision. We first define our revision operator for terminologies in terms of MIPS (minimal incoherence-preserving sub-terminologies), and we show that it satisfies some desirable logical properties. Second, two algorithms are developed to instantiate the revision operator. Since these two algorithms are computationally too hard in general, we propose a third algorithm as a more efficient alternative. We implement the algorithms and provide evaluation results on their efficiency and effectiveness.
2. Algebras of Ontology Alignment Relations , Jerome Euzenat , 387-402 , [OpenAccess] , [Publisher]
   Correspondences in ontology alignments relate two ontology entities with a relation. Typical relations are equivalence or subsumption. However, different systems may need different kinds of relations. We propose to use the concepts of algebra of relations in order to express the relations between ontology entities in a general way. We show the benefits in doing so in expressing disjunctive relations, merging alignments in different ways, amalgamating alignments with relation sets of different granularity, and composing alignments.
3. An Experimental Comparison of RDF Data Management Approaches in a SPARQL Benchmark Scenario , Michael Schmidt,Thomas Hornung,Norbert Küchlin,Georg Lausen and Christoph Pinkel , 82-97 , [OpenAccess] , [Publisher]
   Efficient RDF data management is one of the cornerstones in realizing the Semantic Web vision. In the past, different RDF storage strategies have been proposed, ranging from simple triple stores to more advanced techniques like clustering or vertical partitioning on the predicates. We present an experimental comparison of existing storage strategies on top of the SP^2Bench SPARQL performance benchmark suite and put the results into context by comparing them to a purely relational model of the benchmark scenario. We observe that (1) in terms of performance and scalability, a simple triple store built on top of a column-store DBMS is competitive to the vertically partitioned approach when choosing a physical (predicate, subject, object) sort order, (2) in our scenario with real-world queries, none of the approaches scales to documents containing tens of millions of RDF triples, and (3) none of the approaches yet can compete with a purely relational model. We conclude that future research is necessary to further bring forward RDF data management.
4. An Interface-based Ontology Modularization Framework for Knowledge Encapsulation , Faezeh Ensan and Weichang Du , 517-532 , [OpenAccess] , [Publisher]
   In this paper, we present a framework for developing ontologies in a modular manner, which is based on the notions of interfaces and knowledge encapsulation. Within the context of this framework, an ontology can be defined and developed as a set of ontology modules that can access the knowledge bases of the others through their well-defined interfaces. An important implication of the proposed framework is that ontology modules can be developed completely independent of each others’ signature and language. Such modules are free to only utilize the required knowledge segments of the others. We describe the interface-based modular ontology formalism, which theoretically supports this framework and present its valuable features compared to the exiting modular ontology formalisms. We also describe the real-world design and implementation of the framework for creating modular ontologies by extending OWL-DL, Swoop interfaces and reasoner.
5. Anytime Query Answering in RDF through Evolutionary Algorithms , Eyal Oren,Christophe Guéret and Stefan Schlobach , 98-113 , [OpenAccess] , [Publisher]
   We present a technique for answering queries over RDF data through an evolutionary search algorithm, using fingerprinting and bloomfilters for rapid approximate evaluation of generated solutions. Our evolutionary approach has several advantages compared to traditional database-style query answering. First, the result quality increases monotonically and converges with each evolution, offering ``anytime'' behaviour with arbitrary trade-off between computation time and query results; in addition, the level of approximation can be tuned by varying the size of the bloomfilters. Secondly, through bloomfilter compression we can fit large graphs in main memory, reducing the need for disk I/O during query evaluation. Finally, since the individuals evolve independently, parallel execution is straightforward. We present an initial prototype that evaluates basic SPARQL queries over arbitrary RDF graphs and show initial results over large datasets.
6. Bringing the IPTC News Architecture into the Semantic Web , Raphael Troncy , 483-498 , [OpenAccess] , [Publisher]
   For easing the exchange of news, the International Press Telecommunication Council (IPTC) has developed the NewsML Architecture (NAR), an XML-based model that is specialized into a number of languages such as NewsML G2 and EventsML G2. As part of this architecture, specific controlled vocabularies, such as the IPTC News Codes, are used to categorize news items together with other industry-standard thesauri. While news is still mainly in the form of text-based stories, these are often illustrated with graphics, images and videos. Media-specific metadata formats, such as EXIF, DIG35 and XMP, are used to describe the media. The use of different metadata formats in a single production process leads to interoperability problems within the news production chain itself. It also excludes linking to existing web knowledge resources and impedes the construction of uniform end-user interfaces for searching and browsing news content. In order to allow these different metadata standards to interoperate within a single information environment, we design an OWL ontology for the IPTC News Architecture, linked with other multimedia metadata standards. We convert the IPTC NewsCodes into a SKOS thesaurus and we demonstrate how the news metadata can then be enriched using natural language processing and multimedia analysis and integrated with existing knowledge already formalized on the Semantic Web. We discuss the method we used for developing the ontology and give rationale for our design decisions. We provide guidelines for re-engineering schemas into ontologies and formalize their implicit semantics. In order to demonstrate the appropriateness of our ontology infrastructure, we present an exploratory environment for searching and browsing news items.
7. Collecting Community-based Mappings in an Ontology Repository , Natasha F. Noy,Nicholas Griffith and Mark Musen , 371-386 , [OpenAccess] , [Publisher]
   A number of ontology repositories provide access to the growing collection of ontologies on the Semantic Web. Some repositories collect ontologies automatically by crawling the Web; in other repositories, users submit ontologies themselves. In addition to providing search across multiple ontologies, the added value of ontology repositories lies in the metadata that they may contain. This metadata may include information provided by ontology authors, such as ontologies’ scope and intended use; feedback provided by users such as their experiences in using the ontologies or reviews of the content; and mapping metadata that relates concepts from different ontologies. In this paper, we focus on the ontology-mapping metadata and on community-based method to collect ontology mappings. More specifically, we develop a model for representing mappings collected from the user community and the metadata associated with the mapping. We use the model to bring together more than 30,000 mappings from 7 sources. We also validate the model by extending BioPortal—a repository of biomedical ontologies that we have developed—to enable users to create single concept-to-concept mappings in its graphical user interface, to upload and download mappings created with other tools, to comment on the mappings and to discuss them, and to visualize the mappings and the corresponding metadata.
8. Combining a DL Reasoner and a Rule Engine for Improving Entailment-based OWL Reasoning , Georgios Meditskos and Nick Bassiliades , 277-292 , [OpenAccess] , [Publisher]
   We introduce the notion of the mixed DL and entailment-based (DLE) OWL reasoning, defining a framework inspired from the hybrid and homogeneous paradigms for integration of rules and ontologies. The idea is to combine the TBox inferencing capabilities of the DL algorithms and the scalability of the rule paradigm over large ABoxes. Towards this end, we define a framework that uses a DL reasoner to reason over the TBox of the ontology (hybrid-like) and a rule engine to apply a domain-specific version of ABox-related entailments (homogeneous-like) that are generated by TBox queries to the DL reasoner. The DLE framework enhances the entailment-based OWL reasoning paradigm in two directions. Firstly, it disengages the manipulation of the TBox semantics from any incomplete entailment-based approach, using the efficient DL algorithms. Secondly, it achieves faster application of the ABox-related entailments and efficient memory usage, comparing it to the conventional entailment-based approaches, due to the low complexity and the domain-specific nature of the entailments.
9. Comparison between Ontology Distances (Preliminary Results) , Jérôme David and Jerome Euzenat , 245-260 , [OpenAccess] , [Publisher]
   There are many reasons for measuring a distance between ontologies. In particular, it is useful to know quickly if two ontologies are close or remote before deciding to match them. To that extent, a distance between ontologies must be quickly computable. We present constraints applying to such measures and several possible ontology distances. Then we evaluate experimentaly some of them in order to assess their accuracy and speed.
10. Description Logic Reasoning with Decision Diagrams: Compiling SHIQ to Disjunctive Datalog , Sebastian Rudolph,Markus Krötzsch and Pascal Hitzler , 435-450 , [OpenAccess] , [Publisher]
    We propose a novel method for reasoning in the description logic SHIQ. After a satisfiability preserving transformation from SHIQ to the description logic ALCIb, the obtained ALCIb Tbox T is converted into an ordered binary decision diagram (OBDD) which represents a canonical model for T. This OBDD is turned into a disjunctive datalog program that can be used for Abox reasoning. The algorithm is worst-case optimal w.r.t. data complexity, and admits easy extensions with DL-safe rules and ground conjunctive queries.
11. ELP: Tractable Rules for OWL 2 , Markus Krötzsch,Sebastian Rudolph and Pascal Hitzler , 649-664 , [OpenAccess] , [Publisher]
    We introduce ELP as a decidable fragment of the Semantic Web Rule Language (SWRL) that admits reasoning in polynomial time. ELP is based on the tractable description logic EL++, and encompasses an extended notion of the recently proposed DL rules for that logic. Thus ELP extends EL++ with a number of features introduced by the forthcoming OWL 2, such as disjoint roles, local reflexivity, certain range restrictions, and the universal role. We present a reasoning algorithm based on a translation of ELP to Datalog, and this translation also enables the seamless integration of DL-safe rules into ELP. While reasoning with DL-safe rules as such is already highly intractable, we show that DL-safe rules based on the Description Logic Programming (DLP) fragment of OWL 2 can be admitted in ELP without losing tractability.
12. Efficient Semantic Web Service Discovery in Centralized and P2P Environments , Dimitrios Skoutas,Dimitris Sacharidis,Verena Kantere and Timos Sellis , 583-598 , [OpenAccess] , [Publisher]
    Efficient and scalable discovery mechanisms are critical for enabling service-oriented architectures on the Semantic Web. The majority of currently existing approaches focuses on centralized architectures, and deals with efficiency typically by pre-computing and storing the results of the semantic matcher for all possible query concepts. Such approaches, however, fail to scale with respect to the number of service advertisements and the size of the ontologies involved. On the other hand, this paper presents an efficient and scalable index-based method for Semantic Web service discovery that allows for fast selection of services at query time and is suitable for both centralized and P2P environments. We employ a novel encoding of the services descriptions, allowing the match between a request and an advertisement to be evaluated in constant time, and we index these representations to prune the search space, reducing the number of comparisons required. Given a desired ranking function, the search algorithm can retrieve the top-k matches progressively, i.e., better matches are computed and returned first, thereby further reducing the search engine's response time. We show also how this search can be performed efficiently in a suitable structured P2P overlay network. The benefits of the proposed method are demonstrated through experimental evaluation on both real and synthetic data.
13. Enhancing Semantic Web Services with Inheritance , Simon Ferndriger,Abraham Bernstein,Jin Song Dong,Yuzhang Feng,Yuan-Fang Li and Jane Hunter , 162-177 , [OpenAccess] , [Publisher]
    Currently proposed SemanticWeb Services technologies allow the semantic description of Web services so that software agents are able to discover, invoke, compose and monitor these services with a high degree of automation. This is achieved by marking up services with ontology-based semantic descriptions. The OWL Services (OWL-S) ontology is an upper ontology in OWL language, providing essential vocabularies to semantically describe Web services. Currently OWL-S services can only be developed independently, if one service is unavailable then finding a suitable alternative would require an expensive and difficult global search/match. It is desirable to have a new OWL-S construct that can systematically support substitution tracing as well as incremental development and reuse for services. Introducing inheritance relationship (IR) into OWLS is a natural solution. However, OWL-S, as well as most of the other currently discussed formalisms for Semantic Web Services such as WSMO or SAWSDL, has yet to define a concrete and self-contained mechanism of establishing inheritance relationships among services, which we believe is very important for the automated creation and discovery of Web services as well as human organization of services into a taxonomy-like structure. In this paper, we extend OWL-S with the possibility to define and maintain inheritance relationships between services. Through the definition of an additional “inheritance profile”, inheritance relationships can be stated and reasoned about. Two types of IRs are allowed to grant service developers the choice to respect the “contract” between services or not. The proposed inheritance framework has also been implemented and the prototype will be discussed as well.
14. Evaluating Long-term use of the Gnowsis Semantic Desktop for PIM , Leo Sauermann and Dominik Heim , 467-482 , [OpenAccess] , [Publisher]
    The Semantic Desktop is a means to support users in Personal Information Management (PIM). Using the open source software prototype Gnowsis, we evaluated the approach in a two month case study in 2006 with eight participants. Two participants continued using the prototype and were interviewed after two years in 2008 to show their long-term usage patterns. This allows us to analyse how the system was used for PIM. Contextual interviews gave insights on behaviour, while questionnaires and event logging did not. We discovered that in the personal environment, simple has-part and is-related relations are sufficient for users to file and re-find information, and that the personal semantic wiki was used creatively to note information.
15. Exploring Semantic Social Networks Using Virtual Reality , Harry Halpin,David J. Zielinski,Rachael Brady and Glenda Kelly , 599-614 , [OpenAccess] , [Publisher]
    We present Redgraph, a generic virtual reality visualization program for Semantic Web data capable of handling large data-sets, which we demonstrate on social network data from the U.S. Patent Trade Office. We develop a Semantic Web vocabulary of virtual reality terms compatible with GraphXML to map graph visualization into the Semantic Web itself. Our approach in visualizing Semantic Web data takes advantage of user-interaction in an immersive environment to bypass a number of difficult issues in the 3-dimensional graph visualization layout problem by relying on the user themselves to interactively extrude the nodes and links of a 2-dimensional network into the third dimension. When users touch nodes in the virtual reality environment, they retrieve data formatted according to the data's schema or ontology. We applied Redgraph to social network data constructed from patents, inventors, and institutions from the United States Patent and Trademark Office in order to explore networks of innovation in computing. Using this data-set, we present the results of a user study comparing extrusion (3-D) vs. no-extrusion (2-D). The use of a 3-D interface showed that subjects led to significant improvement on answering of fine-grained questions about the data-set, but no significant difference was found broad questions about the overall structure of the data were asked. Furthermore, inference can be used to improve the visualization, as demonstrated with a data-set of biotechnology patents and researchers.
16. Extracting Semantic Constraint from Description Text for Semantic Web Service Discovery , Dengping Wei,Ting Wang,Ji Wang and Yaodong Chen , 146-161 , [OpenAccess] , [Publisher]
    Various semantic web service discovery techniques have been proposed, many of which perform the profile based service signature (I/O) matching. However, the service I/O concepts are not sufficient to discover web service accurately. This paper suggests a new method to enhance the semantic description of semantic web service by using the semantic constraints of service I/O concepts in specific context. The semantic constraints described in a constraint graph are extracted automatically from the parsing results of the service description text by a set of heuristic rules. The corresponding semantic web service matchmaker performs not only the profile’s semantic matching but also the matching of their semantic constraints with the help of a constraint graph based matchmaking algorithm. The experiment results are encouraging when applying the semantic constraint to discover semantic web services on the service retrieval test collection OWLS-TC v2.
17. Folksonomy-based Collabulary Learning , Leandro Balby Marinho,Krisztian Buza and Lars Schmidt-Thieme , 261-276 , [OpenAccess] , [Publisher]
    The growing popularity of social tagging systems promises to alleviate the knowledge bottleneck that slows the full materialization of the Semantic Web, as these systems are cheap, extendable, scalable and respond quickly to user needs. However, for the sake of knowledge workflow, one needs to find a compromise between the ungoverned nature of folksonomies and the controlled vocabulary of domain-experts. In this paper, we address this concern by first devising a method that automatically combines folksonomies with domain-expert ontologies resulting in an enriched folksonomy. We then introduce a new algorithm based on frequent itemsets mining that efficiently learns an ontology over the concepts present in the enriched folksonomy. Moreover, we propose a new benchmark for ontology evaluation, which is used in the context of information finding, since this is one of the leading motivations for using ontologies in social tagging systems, to quantitatively assess our method. We conduct experiments on real data and empirically show the effectiveness of our approach.
18. Formal Model for Semantic-driven Service Execution , Tomas Vitvar,Maciej Zaremba and Adrian Mocan , 567-582 , [OpenAccess] , [Publisher]
    Integration of heterogeneous services is often hard-wired in service or workflow implementations. In this paper we define an execution model operating on semantic descriptions of services allowing flexible integration of services with solving data and process conflicts where necessary. We implement the model using our WSMO technology and a case scenario from the B2B domain and evaluate the model according to the SWS Challenge criteria.
19. Identifying Potentially Important Concepts and Relations in an Ontology , Gang Wu,Juanzi Li,Ling Feng and Kehong Wang , 33-49 , [OpenAccess] , [Publisher]
    More and more ontologies have been published and used widely on the web such as FOAF, CYC and WordNet. In order to make good use of an ontology, especially a new and large scale ontology, we need methods to help under- stand it first. Identifying potentially important concepts and relations in an ontology is an intuitive but challeng- ing method. In this paper, inspired by the Stream of Con- sciousness theory, we first define six features for potential important concepts and relation from the ontological struc- tural point of view. Then a simple yet effective Concept- And-Relation-Ranking (CARRank) algorithm is proposed to simultaneously rank the importance of concepts and rela- tions. Different from the traditional ranking methods, the importance of concepts and the weights of relations reinforce one another in CARRank in an iterative manner. Such an iterative process is proved to be convergent both in princi- ple and by experiments. Our experimental results show that CARRank has a similar convergent speed as the PageRank- like algorithms, but a more reasonable ranking result.
20. Improving an RCC-derived Geospatial Approximation by OWL Axioms , Rolf Grütter,Thomas Scharrenbach and Bettina Bauer-Messmer , 293-306 , [OpenAccess] , [Publisher]
    An approach to improve an RCC-derived geospatial approximation is presented which makes use of OWL class inclusion axioms. The algorithm used to control the approximation combines hypothesis testing with consistency checking provided by a knowledge representation system based on description logics. Propositions about the consistency of the refined ABox w.r.t. the associated TBox when compared to baseline ABox and TBox are made. Formal proves of the divergent consistency results when checking either of both are provided. The application of the approach to a geospatial setting results in a roughly tenfold improved approximation when using the refined ABox and TBox. Ways to further improve the approximation and to automate the detection of falsely calculated relations are discussed.
21. Instanced-based Mapping between Thesauri and Folksonomies , Christian Wartena and Rogier Brussee , 356-370 , [OpenAccess] , [Publisher]
    The emergence of web based systems in which users can annotate items, raises the question of the semantic interoperability between vocabularies originating from collaborative annotation processes, often called folksonomies, and keywords assigned in a more traditional way. If collections are annotated according to two systems, e.g. with tags and keywords, the annotated data can be used for instanced based mapping between the vocabularies. The basis for this kind of matching is an appropriate similarity measure between concepts, based on their distribution as annotations. In this paper we propose a new similarity measure that can take advantage of some special properties of user generated metadata. We have evaluated this measure with a set of articles from Wikipedia which are classified according to the topic structure of Wikipedia and that are annotated by users of the bookmarking service del.icio.us as well. The results using the new measure are significantly better than those obtained using standard similarity measures proposed for this task in the literature. We argue that the measure also has benefits for instance based mapping of more traditionally developed vocabularies. Finally, this method opens possibilities for instance based mapping of annotation data in the absence of a collection described according to both systems.
22. Integrating Object-Oriented and Ontological Representations: A Case Study in Java and OWL , Colin Puleston,Bijan Parsia,James Cunningham and Alan Rector , 130-145 , [OpenAccess] , [Publisher]
    The Web Ontology Language (OWL) provides a modelling paradigm that is especially well suited for developing models of large, structurally complex domains such as those found in Health Care and the Life Sciences. OWL's declarative nature combined with powerful reasoning tools has effectively supported the development of very large and complex anatomy, disease, and clinical ontologies. OWL, however, is not a programming language, so using these models in applications necessitates both a technical means of integrating OWL models with programs and considerable methodological sophistication in knowing how to integrate them. In this paper, we present an analytical framework for evaluating various OWL-Java combination approaches. We have developed a software framework for what we call hybrid modelling, that is, building models in which part of the model exists and is developed directly in Java and part of the model exists and is developed directly in OWL. We analyse the advantages and disadvantages of hybrid modelling both in comparison to other approaches and by means of a case study of a large medical records system.
23. Involving Domain Experts in Authoring OWL Ontologies , Vania Dimitrova,Ronald Denaux,Glen Hart,Catherine Dolbear,Ian Holt and Anthony G. Cohn , 1-16 , [OpenAccess] , [Publisher]
    The process of authoring ontologies requires the active involvement of domain experts who should lead the process, as well as providing the relevant conceptual knowledge. However, most domain experts lack knowledge modelling skills and find it hard to follow logical notations in OWL. This paper presents ROO, a tool that facilitates domain experts' definition of ontologies in OWL by allowing them to author the ontology in a controlled natural language called Rabbit. ROO guides users through the ontology construction process by following a methodology geared towards domain experts’ involvement in ontology authoring, and exploiting intelligent user interfaces techniques. An evaluation study has been conducted comparing ROO against another popular ontology authoring tool. Participants were asked to create ontologies based on hydrology and environment modelling scenarios related to real tasks at the mapping agency of Great Britain. The study is discussed, focusing on the usability and usefulness of the tool, and the quality of the resultant ontologies.
24. Laconic and Precise Justifications in OWL , Matthew Horridge,Bijan Parsia and Ulrike Sattler , 323-338 , [OpenAccess] , [Publisher]
    A justification for an entailment in an OWL ontology is a minimal subset of the ontology that is sufficient for that entailment to hold. Since justifications respect the syntactic form of axioms in an ontology, they are usually neither syntactically nor semantically minimal. This paper presents two new subclasses of justifications - laconic justications and precise justications. Laconic justications only consist of axioms that do not contain any redundant parts. Precise justications can be derived from laconic justications and are characterised by the fact that they consist of flat, small axioms, which facilitate the generation of semantically minimal repairs. Formal denitions for both types of justication are presented. In contrast to previous work in this area, these definitions make it clear as to what exactly parts of axioms are. In order to demonstrate the practicability of computing laconic, and hence precise justications, an algorithm is provided and results from an empirical evaluation carried out on several published ontologies are presented. The evaluation showed that laconic/precise justications can be computed in a reasonable time for entailments in a range of ontologies that vary in size and complexity. It was found that in half of the ontologies sampled there were entailments that had more laconic/precise justications than regular justications. More surprisingly it was observed that for some ontologies there were fewer laconic/precise justications than regular justications.
25. Learning Concept Mappings from Instance Similarity , Shenghui Wang,Gwenn Englebienne and Stefan Schlobach , 339-355 , [OpenAccess] , [Publisher]
    Finding mappings between compatible ontologies is an important but difficult open problem. Instance-based methods for solving this problem have the advantage of focusing on the most active parts of the ontologies and reflect concept semantics as they are used in the real world. However such methods have not at present been widely investigated in ontology mapping, compared to linguistic and structural techniques. In this paper we approach the mapping problem as a classification problem based on the similarity between instances of concepts. We evaluate the resulting classifier on three different real-world data sets.
26. Modeling Documents by Combining Semantic Concepts with Unsupervised Statistical Learning , Chaitanya Chemudugunta,America Holloway,Padhraic Smyth and Mark Steyvers , 229-244 , [OpenAccess] , [Publisher]
    Human-defined concepts are fundamental building-blocks in constructing knowledge bases such as ontologies. Statistical learning techniques provide an alternative automated approach to concept definition, driven by data rather than prior knowledge. In this paper we propose a probabilistic modeling framework that combines both human-defined concepts and data-driven topics in a principled manner. The methodology we propose uses statistical topic models (also known as latent Dirichlet allocation models). We demonstrate the utility of this general framework in two ways. We first illustrate how the methodology can be used to automatically tag Web pages with concepts from a known set of concepts without any need for labeled documents. We then perform a series of experiments that quantify how combining human-defined semantic knowledge with data-driven techniques leads to better language models than can be obtained with either alone.
27. OWL Datatypes: Design and Implementation , Boris Motik and Ian Horrocks , 307-322 , [OpenAccess] , [Publisher]
    We analyze the datatype system of OWL and OWL 2, and discuss certain nontrivial consequences of its definition, such as the extensibility of the set of supported datatypes and complexity of reasoning. We also argue that certain datatypes from the list of normative datatypes in the current OWL 2 Working Draft are inappropriate and should be replaced with different ones. Finally, we present an algorithm for datatype reasoning. Our algorithm is modular in the sense that it can handle any datatype that supports certain basic operations. We show how to implement these operations for number and string datatypes.
28. On the Semantics of Trust and Caching in the Semantic Web , Simon Schenk , 533-549 , [OpenAccess] , [Publisher]
    The Semantic Web is a distributed environment for knowledge representation and reasoning. The distributed nature brings with it failing data sources and inconsistencies between autonomous knowledge bases. To reduce problems resulting from unavailable sources and to improve performance, caching can be used. Caches, however, raise new problems of imprecise or outdated information. We propose to distinguish between certain and cached information when reasoning on the semantic web, by extending the well known FOUR bilattice of truth and knowledge orders to FOUR-C, taking into account cached information. We discuss how users can be offered additional information about the reliability of inferred information, based on the availability of the corresponding information sources. We then extend the framework towards FOUR-T , allowing for multiple levels of trust on data sources. In this extended setting, knowledge about trust in information sources can be used to compute, how well an inferred statement can be trusted and to resolve inconsistencies arising from connecting multiple data sources. We redefine the stable model and well founded semantics on the basis of FOUR-T, and reformalize the Web Ontology Language OWL2 based on logical bilattices, to augment OWL knowledge bases with trust based reasoning.
29. Optimization and Evaluation of Reasoning in Probabilistic Description Logic: Towards a Systematic Approach , Pavel Klinov and Bijan Parsia , 213-228 , [OpenAccess] , [Publisher]
    This paper describes the first steps towards developing a methodology for testing and evaluating the performance of reasoners for the probabilistic description logic P-SHIQ(D). Since P-SHIQ(D) is a relatively new formalism for handling uncertainty in DL knowledge bases, no such methodology has been proposed so far. Moreover there are no sufficiently large probabilistic ontologies to be used as test suites. In addition, since the reasoning services in P-SHIQ(D) are mostly query oriented, there is no single problem (like classification or realization in classical DL) that could be an obvious candidate for benchmarking. All these issues make it hard to evaluate the performance of reasoners, reveal the complexity bottlenecks and assess the effect of optimization strategies. This paper aims at alleviating these important problems by making the following contributions: First, it describes a probabilistic ontology that has been developed for the real-life domain of breast cancer and which poses significant challenges for the state-of-art P-SHIQ(D) reasoners. Second, it explains a systematic approach to generating a series of probabilistic reasoning problems that allow to evaluate the reasoning performance and shed light on what makes reasoning in P-SHIQ(D) hard in practice. Finally, the paper explains the optimization strategy that helps to overcome some of the difficulties of reasoning revealed during the experiments. The impact of the strategy is also demonstrated using the developed evaluation methodology.
30. RDF123: From Spreadsheets to RDF , Lushan Han,Tim Finin,Cynthia Parr,Joel Sachs and Anupam Joshi , 451-466 , [OpenAccess] , [Publisher]
    We describe RDF123, a highly flexible open-source tool for translating spreadsheet data to RDF. Existing spreadsheet-to-rdf tools typically map only to star-shaped RDF graphs, i.e. each spreadsheet row is an instance, with each column representing a property. RDF123, on the other hand, allows users to define mappings to arbitrary graphs, thus allowing much richer spreadsheet semantics to be expressed. Further, each row in the spreadsheet can be mapped with a fairly different RDF scheme. Two interfaces are available. The first is a graphical application that allows users to create their mapping in an intuitive manner. The second is a Web service that takes as input a URL to a Google spreadsheet or CSV file and an RDF123 map file, and provides RDF as output.
31. RDFS Reasoning and Query Answering on Top of DHTs , Zoi Kaoudi,Iris Miliaraki and Manolis Koubarakis , 499-516 , [OpenAccess] , [Publisher]
    We study the problem of distributed RDFS reasoning and query answering on top of distributed hash tables. Scalable, distributed RDFS reasoning is an essential functionality for providing the scalability and performance that large-scale Semantic Web applications require. Our goal in this paper is to compare and evaluate two well-known approaches to RDFS reasoning, namely backward and forward chaining, on top of distributed hash tables. We show how to implement both algorithms on top of the distributed hash table Bamboo and prove their correctness. We also study the time-space trade-off exhibited by the algorithms analytically, and experimentally by evaluating our algorithms on PlanetLab.
32. RoundTrip Ontology Authoring , Brian Davis,Ahmad Iqbal,Adam Funk,Valentin Tablan,Kalina Bontcheva,Hamish Cunningham and Siegfried Handschuh , 50-65 , [OpenAccess] , [Publisher]
    Controlled Language (CL) for Ontology Editing tools offer an attractive alternative for naive users wishing to create ontologies, but they are still required to spend time learning the correct syntactic structures and vocabulary in order to use the Controlled Language properly. This paper extends previous work (CLOnE) which uses standard NLP tools to process the language and manipulate an ontology. Here we also generate text in the CL from an existing ontology using template-based (or shallow) Natural Language Generation (NLG). The text generator and the CLOnE authoring process combine to form a RoundTrip Ontology Authoring environment: one can start with an existing imported ontology or one originally produced using CLOnE, (re)produce the Controlled Language, modify or edit the text as required and then turn the text back into the ontology in the CLOnE environment. Building on previous methodology we undertook an evaluation, comparing the RoundTrip Ontology Authoring process with a well-known ontology editor; where previous work required a CL reference manual with several examples in order to use the controlled language, the use of NLG reduces this learning curve for users and improves on existing results for basic ontology editing tasks.
33. Scalable Grounded Conjunctive Query Evaluation over Large and Expressive Knowledge Bases , Julian Dolby,Achille Fokoue,Aditya Kalyanpur,Li Ma,Edith Schonberg,Kavitha Srinivas and Xingzhi Sun , 403-418 , [OpenAccess] , [Publisher]
    Conjunctive query answering over OWL-DL ontologies is intractable in the worst case, but we present novel techniques which allow for efficient querying of large expressive knowledge bases in secondary storage. In particular, we show that we can effectively answer conjunctive queries without building a complete completion forest for a large ABox (unlike state of the art tableau reasoners). Instead we rely on the completion forest of a dramatically reduced summary of the Abox. We demonstrate the effectiveness of this approach in Aboxes with up to 45 million assertions.
34. Semantic Grounding of Tag Relatedness in Social Bookmarking Systems , Ciro Cattuto,Dominik Benz,Andreas Hotho and Gerd Stumme , 615-631 , [OpenAccess] , [Publisher]
    Collaborative tagging systems have nowadays become important data sources for populating semantic web applications. For tasks like synonym detection and discovery of concept hierarchies, many researchers introduced measures of tag similarity. Even though most of these measures appear very natural, their design often seems to be rather ad hoc, and the underlying assumptions on the notion of similarity are not made explicit. A more systematic characterization and validation of tag similarity in terms of formal representations of knowledge is still lacking. Here we address this issue and anayze several measures of tag similarity: Each measure is computed on data from the social bookmarking system del.icio.us and a semantic grounding is provided by mapping pairs of similar tags in the folksonomy to pairs of synsets in Wordnet, where we use validated measures of semantic distance to characterize the semantic relation between the mapped tags. This exposes important features of the investigated measures and indicates which measures are better suited in the context of a given semantic application.
35. Semantic Modelling of User Interests Based on Cross-folksonomy Analysis , Martin Szomszor,Harith Alani,Ivan Cantador,Kieron O'Hara and Nigel Shadbolt , 632-648 , [OpenAccess] , [Publisher]
    The continued increase in Web usage, in particular participation in folksonomies, reveals a trend towards a more dynamic and interactive Web where individuals can organise and share resources. Tagging has emerged as the de-facto standard for the organisation of such resources, providing a versatile and reactive knowledge management mechanism that users find easy to use and understand. It is very common nowadays for users to have multiple profiles in various folksonomies, thus distributing their tagging activities. In this paper, we present a method for the automatic consolidation of user profiles accross two popular social networking sites, and subsequent semantic modelling of their interests utilising Wikipedia as a multi-domain model. We evaluate how much can be learned from such sites, and where the knowledge acquired is focussed. Results show that far richer interest profiles can be generated for users when their multiple tag clouds are combined.
36. Semantic Relatedness Measure Using Object Properties in an Ontology , Laurent Mazuel and Nicolas Sabouret , 681-694 , [OpenAccess] , [Publisher]
    This paper presents a new semantic relatedness measure on an ontology which consider especially the object properties between the concepts. Our approach relies on two hypotheses. Firstly, using only concept hierarchy and object properties, only a few numbers of paths can be considered as ``semantically correct'' and these paths obey to a given set of rules. Secondly, following a given edge in a path has a cost (represented as a weight), which depends on its type (is-a, part-of, etc.), its context in the ontology and its position in the path. We propose an evaluation of our measure on the lexical base WordNet using part-of relation with two different benchmarks. We show that, in this context, our measure outperforms the classical semantic measures.
37. Semantic Web Service Choreography: Contracting and Enactment , Dumitru Roman and Michael Kifer , 550-566 , [OpenAccess] , [Publisher]
    The emerging paradigm of service-oriented computing requires novel techniques for various service-related tasks. Along with automated support for service discovery, selection, negotiation, and composition, support for automated service contracting and enactment is crucial for any large scale service environment, where large numbers of clients and service providers interact. Many problems in this area involve reasoning, and a number of logic-based methods to handle these problems have emerged in the field of Semantic Web Services. In this paper, we build upon our previous work where we used Concurrent Transaction Logic (CTR) to model and reason about service contracts. We significantly extend the modeling power of the previous work by allowing iterative processes in the specification of service contracts, and we extend the proof theory of CTR to enable reasoning about such contracts. With this extension, our logic-based approach is capable of modeling general services represented using languages such as WS-BPEL.
38. Statistical Learning for Inductive Query Answering on OWL Ontologies , Nicola Fanizzi,Claudia d'Amato and Floriana Esposito , 195-212 , [OpenAccess] , [Publisher]
    A family of parametric language-independent kernel functions defined for individuals in OWL ontologies is presented. These functions enable the exploitation of statistical learning for various ontology mining tasks. Namely, the novel kernel functions are integrated with a support vector machine for inducing simple mathematical models that can used for performing classification through an alternative mode w.r.t. logical reasoning. Besides we also present a method for adapting the kernel to the knowledge base through stochastic optimization. An inductive approach based on machine learning may be useful especially to cope with the inherent incompleteness of the knowledge bases. The system implementing the whole framework has been tested in some experiments on query answering with real ontologies drawn from standard repositories.
39. Supporting Collaborative Ontology Development in Protégé , Tania Tudorache,Natasha F. Noy,Samson Tu and Mark Musen , 17-32 , [OpenAccess] , [Publisher]
    Ontologies are becoming so large in their coverage that no single person or a small group of people can develop them effectively and ontology development becomes a community-based enterprise. In this paper, we discuss requirements for supporting collaborative ontology development and present Collaborative Protege-—a tool that supports many of these requirements, such as discussions integrated with ontology-editing process, chats, and annotations of changes and ontology components. We have evaluated Collaborative Protege in the context of ontology development in an ongoing large-scale biomedical project that actively uses ontologies: the ATHENA-DSS project at the VA Palo Alto Healthcare System. Users have found the new tool effective as an environment for carrying out discussions and for recording references for the information sources and design rationale.
40. Term Dependence on the Semantic Web , Gong Cheng and Yuzhong Qu , 665-680 , [OpenAccess] , [Publisher]
    As with the decentralized nature of the Semantic Web, a lot of terms (classes and properties) have been published by various parties, to be shared for describing resources. Terms are usually defined based on other terms, and thus a directed dependence relation is formed. The study of term dependence is a foundation work and is important for many other tasks, such as ontology search, maintenance, and distributed reasoning on the Web scale. In this paper, we propose a notion of term dependence on the Semantic Web, and analyze the complex network characteristics of the term dependence graph and the vocabulary dependence graph. The graphs analyzed in our experiments are constructed from a data set that contains 1,278,233 terms in 3,039 vocabularies. The results characterize the current status of schemas on the Semantic Web in many aspects, including degree distributions, reachability, and connectivity.
41. The Expressive Power of SPARQL , Renzo Angles and Claudio Gutierrez , 114-129 , [OpenAccess] , [Publisher]
    This paper studies the expressive power of SPARQL. The main result is that SPARQL and non-recursive safe Datalog with negation have equivalent expressive power, and hence, by classical results, SPARQL is equivalent from an expressive point of view to relational Algebra. We present explicit generic rules of the transformations in both directions. Among other findings of the paper are the proof that negation can be simulated in SPARQL, that non-safe filters are superfluous, and that current SPARQL W3C semantics can be simplified to a standard compositional one.
42. Using Semantic Distances for Reasoning with Inconsistent Ontologies , Zhisheng Huang and Frank van-Harmelen , 178-194 , [OpenAccess] , [Publisher]
    Re-using and combining multiple ontologies on the Web is bound to lead to inconsistencies between the combined vocabularies. Even many of the ontologies that are in use today turn out to be inconsistent once some of their implicit knowledge is made explicit. However, robust and efficient methods to deal with inconsistencies are lacking from current Semantic Web reasoning systems, which are typically based on classical logic. In earlier papers, we have proposed the use of syntactic relevance functions as a method for reasoning with inconsistent ontologies. In this paper, we extend that work to the use of semantic distances. We show how Google distances can be used to develop semantic relevance functions to reason with inconsistent ontologies. In essence we are using the implicit knowledge hidden in the Web for explicit reasoning purposes. We have implemented this approach as part of the PION reasoning system. We report on experiments with several realistic ontologies. The test results show that a mixed syntactic/semantic approach can significantly improve reasoning performance over the purely syntactic approach. Furthermore, our methods allow to trade-off computational cost for inferential completeness. Our experiment shows that we only have to give up a little quality to obtain a high performance gain.
43. nSPARQL: A Navigational Language for RDF , Jorge Pérez,Marcelo Arenas and Claudio Gutierrez , 66-81 , [OpenAccess] , [Publisher]
    It has been largely recognized that navigational capabilities are fundamental for graph databases query languages. However, although RDF is a directed labeled graph data format, the W3C Recommendation query language for RDF, SPARQL, only provides limited navigational functionalities. This has motivated several authors to propose extensions of SPARQL, or alternative query languages, that offer functionalities for navigating RDF data. In particular, we argued in [6] that nested regular expressions are appropriate to overcome this limitation, and we proposed a query language called nSPARQL that extends SPARQL with this type of expressions. In this paper, we continue with the investigation of nSPARQL. First, we show that nested regular expressions can be evaluated efficiently; if the appropriate data structure is used to store RDF graphs, then the evaluation of a nested regular expression E over an RDF graph G can be computed in time O(|G|*|E|). Second, as RDF graphs may contain RDFS vocabulary, we study how the navigational capabilities of nSPARQL can be used to evaluate queries according to the predefined semantics of RDFS. Evaluating queries which involve the RDFS vocabulary is challenging, and there is not yet consensus in the Semantic Web community on how to define a query language for RDFS. In this respect, we show that nSPARQL is expressive enough to answer SPARQL queries involving RDFS vocabulary by directly traversing the input RDF graphs. Moreover, we also prove that nesting is necessary to obtain this result. Namely, we show that, in general, regular expressions alone cannot be used to obtain the answer of a SPARQL query involving RDFS vocabulary.

Semantic Web In Use Track Paper

1. A Process Catalog for Workflow Generation , Michael Wolverton,David Martin,Ian Harrison and Jerome Thomere , 833-846 , [OpenAccess] , [Publisher]
   As AI developers increasingly look to workflow technologies to perform complex integrations of individual software components, there is a growing need for the workflow systems to have expressive descriptions of those components. They must know more than just the types of a component's inputs and outputs; instead, they need detailed characterizations that allow them to make fine-grained distinctions between candidate components and between candidate workflows. This paper describes ProCat, an implemented ontology-based catalog for components, conceptualized as processes, that captures and communicates this detailed information. ProCat is built on a layered representation that allows reasoning about processes at varying levels of abstraction, from qualitative constraints reflecting preconditions and effects, to quantitative predictions about output data and performance. ProCat employs Semantic Web technologies RDF, OWL, and SPARQL, and builds on Semantic Web services research. We describe ProCat's approach to representing and answering queries about processes, discuss some early experiments evaluating the quantitative predictions, and report on our experience using ProCat in a system producing workflows for intelligence analysis.
2. A Semantic Data Grid for Satellite Mission Quality Analysis , Reuben Wright,Manuel Sánchez-Gestido,Asunción Gómez-Pérez,María S. Pérez-Hernández,Rafael González-Cabero and Oscar Corcho , 818-832 , [OpenAccess] , [Publisher]
   The use of Semantic Grid architecture eases the development of complex, flexible applications, in which several organisations are involved and where resources of diverse nature (data and computing elements) are shared. This is the situation in the Space domain, with an extensive and heterogeneous network of facilities and institutions. There is a strong need to share both data and computational resources for complex processing tasks. One such is moni- toring and data analysis for Satellite Missions and this paper presents the Satel- lite Mission Grid, built in the OntoGrid project as an alternative to the current systems used. Flexibility, scalability, interoperability, extensibility and efficient development were the main advantages found in using a common framework for data sharing and creating a Semantic Data Grid.
3. An Architecture for Semantic Navigation and Reasoning with Patient Data - Experiences of the Health-e-Child Project , Tamás Hauer,Dmitry Rogulin,Sonja Zillner,Andrew Branson,Jetendr Shamdasani,Alexey Tsymbal,Martin Huber,Tony Solomonides and Richard McClatchey , 737-750 , [OpenAccess] , [Publisher]
   Medical ontologies have become the standard means of record- ing and accessing conceptualized biological and medical knowledge. The expressivity of these ontologies goes from simple concept lists through taxonomies to formal logical theories. In the context of patient informa- tion, their application is primarily annotation of medical (instance) data. To exploit higher expressivity, we propose an architecture which allows for reasoning on patient data using OWL DL ontologies. The implemen- tation is carried out as part of the Health-e-Child platform prototype. We discuss the use case where ontologies establish a hierarchical clas- sification of patients which in turn is used to aid the visualization of patient data. We briefly discuss the treemap-based patient viewer which has been evaluated in the Health-e-Child pro ject.
4. Creating and Using Organisational Semantic Webs in Large Networked Organisations , Ravish Bhagdev,Ajay Chakravarthy,Sam Chapman,Fabio Ciravegna and Vita Lanfranchi , 723-736 , [OpenAccess] , [Publisher]
   Modern knowledge management is based on the organization of dynamic communities that acquire and share knowledge according to dedicated ontological schemas. However, while independence of ontological views is favored, these communities must also be able to share their knowledge with the rest of the organization. In this paper we introduce K-Forms and K-Search, a suite of Semantic Web tools for supporting distributed and networked knowledge acquisition, capturing, retrieval and sharing. They enable communities of users within or across organizations to define their own views in an intuitive way (and which are automatically turned into formal ontologies) and capture and share knowledge according to them. The tools favor reuse of existing ontologies; reuse creates as side effect a network of (partially) interconnected ontologies that form the basis for knowledge exchange among communities. The suite has been evaluated and is under release to support knowledge capture, retrieval and sharing in a large jet engine company.
5. Deploying Semantic Web Technologies for Work Integrated Learning in Industry - A comparison: SME vs. Large Sized Company , Conny Christl,Chiara Ghidini,Joanna Guss,Stefanie Lindstaedt,Viktoria Pammer,Marco Rospocher,Peter Scheir and Luciano Serafini , 709-722 , [OpenAccess] , [Publisher]
   Modern businesses operate in a rapidly changing environment. Continuous learning is an essential ingredient in order to stay competitive in such environments. The APOSDLE system utilizes semantic web technologies to create a generic system for supporting knowledge workers in different domains to learn@work. Since APOSDLE relies on three interconnected semantic models to achieve this goal, the question on how to efficiently create high-quality semantic models has become one of the major research challenges. On the basis of two concrete examples – namely deployment of such a learning system at EADS, a large corporation, and deployment at ISN, a network of SMEs – we report in detail the issues a company has to face, when it wants to deploy a modern learning environment relying on semantic web technologies. Although we describe the experiences related to a specific system, we think that our reports are of interest to a wider audience, as APOSDLE relies on many “standard” semantic web technologies and consequently inherits both their advantages and disadvantages.
6. DogOnt - Ontology Modeling for Intelligent Domotic Environments , Dario Bonino and Fulvio Corno , 790-803 , [OpenAccess] , [Publisher]
   Home automation has recently gained a new momentum thanks to the ever-increasing commercial availability of domotic com- ponents. In this context, researchers are working to provide interopera- tion mechanisms and to add intelligence on top of them. For supporting intelligent behaviors, house modeling is an essential requirement to un- derstand current and future house states and to possibly drive more complex actions. In this paper we propose a new house modeling on- tology designed to fit real world domotic system capabilities and to support interoperation between currently available and future solutions. Taking advantage of technologies developed in the context of the Se- mantic Web, the DogOnt ontology supports device/network independent description of houses, including both “controllable” and architectural el- ements. States and functionalities are automatically associated to the modeled elements through proper inheritance mechanisms and by means of properly defined SWRL auto-completion rules which ease the mod- eling process, while automatic device recognition is achieved through classification reasoning.
7. Inference Web in Action: Lightweight Use of the Proof Markup Language , Paulo Pinheiro da Silva,Deborah McGuinness,Nicholas Del Rio and Li Ding , 847-860 , [OpenAccess] , [Publisher]
   The Inference Web infrastructure for web explanations together with its underlying Proof Markup Language (PML) for encoding justification and provenance information has been used in multiple projects varying from explaining the behavior of cognitive agents to explaining how knowledge is extracted from multiple sources of information in natural language. The PML specification has increased significantly since its inception in 2002 in order to accommodate a rich set of requirements derived from multiple projects, including the ones mentioned above. In this paper, we have a very different goal than the other PML documents: to demonstrate that PML may be effectively used by simple systems (as well as complex systems) and to describe lightweight use of language and its associated Inference Web tools. We show how an exemplar scientific application can use lightweight PML descriptions within the context of an NSF-funded cyberinfrastructure project. The scientific application is used throughout the paper as a use case for the lightweight use of PML and the Inference Web and is meant to be an operational prototype for a class of cyberinfrastructure applications.
8. Introducing IYOUIT , Sebastian Boehm,Johan Koolwaaij,Marko Luther,Bertrand Souville,Matthias Wagner and Martin Wibbels , 804-817 , [OpenAccess] , [Publisher]
   We present IYOUIT, a prototype service to pioneer a context-aware mobile digital lifestyle and its reflection on the Web. The application is based on a distributed infrastructure that incorporates Semantic Web technologies in several places to derive qualitative interpretations of a user's digital traces in the real world. Networked components map quantitative sensor data to qualitative abstractions represented in formal ontologies. Subsequent classification processes combine these with formalized domain knowledge to derive meaningful interpretations and to recognize exceptional events in context histories. The application is made available on Nokia Series-60 phones and designed to seamlessly run 24/7. We also intend to demonstrate IYOUIT at the ISWC'08 and to provide it to conference attendees, based on their demand.
9. Market Blended Insight: Modeling Propensity to Buy with the Semantic Web , Manuel Salvadores,Landong Zuo,SM Hazzaz Imtiaz,John Darlington,Nicholas Gibbins,Nigel Shadbolt and John Dobree , 777-789 , [OpenAccess] , [Publisher]
   Market Blended Insight (MBI) is a project with a clear objective of making a significant performance improvement in UK business to business (B2B) marketing activities in the 5-7 year timeframe. The web has created a rapid expansion of content that can be harnessed by recent advances in Semantic Web technologies and applied to both Media industry provision and company utilization of exploitable business data and content. The project plans to aggregate a broad range of business information, providing unparalleled insight into UK business activity and develop rich semantic search and navigation tools to allow any business to 'place their sales proposition in front of a prospective buyer' confident of the fact that the recipient has a propensity to buy.
10. OntoNaviERP: Ontology-supported Navigation in ERP Software Documentation , Martin Hepp and Andreas Wechselberger , 764-776 , [OpenAccess] , [Publisher]
    The documentation of Enterprise Research Planning (ERP) systems is usually (1) extremely large and (2) combines various views from the business and the technical implementation perspective. Also, a very specific vocabulary has evolved, in particular in the SAP domain (e.g. SAP Solution Maps or SAP software module names). This vocabulary is not clearly mapped to business management terminology and concepts. It is a well-known problem in practice that searching in SAP ERP documentation is difficult, because it requires in-depth knowledge of a large and proprietary terminology. We propose to use ontologies and automatic annotation of such large HTML software documentation in order to improve the usability and accessibility, namely of ERP help files. In order to achieve that, we have developed an ontology and prototype for SAP ERP 6.0. Our approach integrates concepts and lexical resources from (1) business management terminology, (2) SAP business terminology, (3) SAP system terminology, and (4) Wordnet synsets. We use standard GATE/KIM technology to annotate SAP help documentation with respective references to our ontology. Eventually, our approach consolidates the knowledge contained in the SAP help functionality at a conceptual level. This allows users to express their queries using a terminology they are familiar with, e.g. referring to general management terms. Despite a widely automated ontology construction process and a simplistic annotation strategy with minimal human intervention, we experienced convincing results. For an average query linked to an action and a topic, our technology returns more than 3 relevant resources, while a naïve term-based search returns on average only about 0.2 relevant resources.
11. Requirements Analysis Tool: A Tool for Automatically Analyzing Software Requirements Documents , Kunal Verma and Alex Kass , 751-763 , [OpenAccess] , [Publisher]
    We present a tool, called Requirements Critic that performs a wide range of best practice analyses on software requirements documents. The novelty of our approach is its ability to perform a broad range of syntactic and semantic analyses, while allowing the users to write requirements in natural language. The crux of our syntactic analyses approach is based on using controlled syntaxes and user-defined glossaries to extract structured content about a requirements document. Semantic Web technologies are then leveraged for deeper semantic analysis of the extracted structured content to find various kinds of problems in requirements documents.
12. Supporting Ontology-based Dynamic Property and Classification in WebSphere Metadata Server , Shengping Liu,Yang Yang,Guotong Xie,Chen Wang,Feng Cao,Cassio Santos,Bob Schloss,Yue Pan,Kevin Shank and John Colgrave , 861-874 , [OpenAccess] , [Publisher]
    Metadata management is an important aspect of today's enterprise information systems. Metadata management systems are growing from tool-specific repositories to enterprise-wide metadata repositories. In this context, one challenge is the management of the evolving metadata whose schema or meta-model itself may evolve, e.g., dynamically-added properties, which are often hard to predict upfront at the initial meta-model design time; another challenge is to organize the metadata by semantically-rich classification schemes. In this paper, we present a practical system which provides support for users to dynamically manage semantically-rich properties and classifications in the IBM WebSphere Metadata Server (MDS) by integrating an OWL ontology repository. To enable the smooth acceptance of Semantic Web technologies for developers of commercial software which must run 24 hours/day, 7 days/week, the system is designed to consist of integrated modeling paradigms, with an integrated query language and runtime repository. Specifically, we propose the modeling of dynamic properties on structured metadata as OWL properties and the modeling of classification schemes as OWL ontologies for metadata classification. We present a natural extension to OQL (Object Query Language)-like query language to embrace dynamic properties and metadata classification. We also observe that hybrid storage, i.e., horizontal tables for structured metadata and vertical triple tables for dynamic properties and classification, is suitable for the storage and query processing of co-existing structured metadata and semantic metadata. We believe that our study and experience are not specific to MDS, but are valuable for the community trying to apply Semantic Web technologies to the structured data management area.
13. Thesaurus-based Search in Large Heterogeneous Collections , Jan Wielemaker,Michiel Hildebrand,Jacco van Ossenbruggen and Guus Schreiber , 695-708 , [OpenAccess] , [Publisher]
    In cultural heritage, large virtual collections are coming into existence. Such collections contain heterogeneous sets of metadata and vocabulary concepts, originating from multiple sources. In the context of the E-Culture demonstrator we have shown earlier that such virtual collections can be effectively explored with keyword search and semantic clustering. In this paper we describe the design rationale of ClioPatria, the E-Culture open-source software which provides APIs for scalable semantic graph search. The use of ClioPatria's search strategies is illustrated with a realistic use case: searching for "Picasso". We discuss details of scalable graph search, the required OWL reasoning functionalities and show why SPARQL queries are insufficient for solving the search problem.
14. Towards a Multimedia Content Marketplace Implementation Based on Triplespaces , David de Francisco,Germán Toro del Valle and Lyndon JB Nixon , 875-888 , [OpenAccess] , [Publisher]
    A Multimedia Content Marketplace can support innovative business models in the telecommunication sector. This marketplace has a strong need for semantics, co-ordination and a service-oriented architecture. Triple Space Computing is an emerging semantic co-ordination paradigm for Web services, for which the marketplace is an ideal implementation scenario. This paper introduces the developed Triple Space platform and our planned evaluation of its value to our telecommunication scenario.

Proceedings of ISWC 2008 Poster and Demo

1. A Bootstrapping Architecture for Integration of Relational Databases to the Semantic Web , Juan F. Sequeda,Syed Tirmizi and Daniel Miranker , [OpenAccess] , [Publisher]
   The vision of the Semantic Web is to create a web of data with well-defined meaning. Most data in the current web is managed by relational databases. Thus, it is imperative for the Semantic Web community to offer easily implemented solutions to bridging relational database content and RDF. Direct mappings means to use the SQL schema to create an OWL ontology and use it to represent the data in RDF. Direct mapping methods have an advantage that they are, intrinsically, automated. If a SQL-schema was created using contemporary model-driven software engineering tools, the resulting OWL ontology can be semantically rich. However, few SQL databases are so developed and therefore semantically weak. We suggest that direct-mapping methods can be integrated by a refinement process. We propose a two step bootstrapping architecture of integrating relational databases with the Semantic Web by first generating a “database-derived putative ontology” and second, refining the putative ontology with a domain ontology and database individuals.
2. A Flexible API and Editor for SKOS , Simon Jupp,Sean Bechhofer and robert Stevens , [OpenAccess] , [Publisher]
   This poster presents a programmatic interface (SKOS API) and plugin for Protege 4 for editing and working with the Simple Knowledge Organisation System (SKOS). The SKOS API has been designed to work with SKOS models at a high level of abstraction to aid developers of applications that use SKOS. We discuss SKOSEd, a tool for authoring and editing SKOS artefacts. A key aspect to the design of the API and editor is how SKOS relates to OWL and what existing OWL infrastructure can be exploited to work with SKOS.
3. A Semantic Web Service Alignment Tool , Dionysios Kehagias,Alexander García Castro,Dimitrios Tzovaras and Dimitrios Giakoumis , [OpenAccess] , [Publisher]
4. A Semantic Wiki on Cooperation in Public Administration , Bernhard Krabina , [OpenAccess] , [Publisher]
   Authorities cooperate in various ways. The Web portal www.verwaltungskooperation.at aims to share knowledge on collaboration projects. A semantic wiki approach was used to facilitate best practice documentation with Semantic Web and Web 2.0 technology. Intercommunal cooperation has a long tradition among Austrian towns, cities, and municipalities. Much like in its German-speaking neighbour countries, this issue has become a subject of increased interest to Austria and has been intensely discussed in the last years. Apart from basic analyses of intercommunal cooperation in various scientific journals or the arrangement of expert meetings; the number of practical examples of cross-municipal cooperation is growing. In 2006, the KDZ published a book on intercommunal cooperation including a description of some 50 best-practice examples. In late 2007, the decision was made to publish these examples on a Web platform in order to make them available to a broader public and to enable the static information contained in the book to become dynamic Web content, editable by interested users. The use of the latest semantic wiki technologies for the new platform www.verwaltungskooperation.at is an example of the emergence of Web 2.0 applications with semantic technologies, sometimes referred to as “Web 3.0” or “Social Semantic Web”.
5. A System to enable Relational Persistence and Semantic Web style access simultaneously for Objects , Jing Mei,Guotong Xie,Shengping Liu,Lei Zhang and Yue Pan , [OpenAccess] , [Publisher]
   Object Oriented (OO) programming is dominant in the current software development. Starting from the design of OO models for applications, developers also expect to address issues on the data of models and the semantics of models. Objects, being the data of models, could be stored in relational databases, and ontologies appear as a good candidate for capturing the semantics of models. This poster presents a method and system which elegantly generates relational schema, OWL ontology, and semantic mapping between them, for any given OO model. The resulting relational schema serves for storing objects that are defined in the input OO model, the resulting OWL ontology is assured by a semantically “close” model transformation, and the generated automation mapping between them enables relational persistence and Semantic Web style access simultaneously for objects.
6. A Visual Interface for Building SPARQL Queries in Konduit , Knud Möller,Oszkar Ambrus,Laura Dragan and Siegfried Handschuh , [OpenAccess] , [Publisher]
   This short demo description presents an extension to the Konduit tool for visual programming for the semantic desktop. Previously, Konduit required users to define filter components by manually specifying a SPARQL CONSTRUCT query. With the current work presented in this demo, we are exploring ways of building such queries visually, and aiding the use in doing it. We hope that this will make it easier to work with Konduit, which will thus appeal to more users.
7. A framework for semantic web policies , Juri Luca De Coi,Daniel Olmedilla,Piero Bonatti and Luigi Sauro , [OpenAccess] , [Publisher]
   Trust and policies are going to play a crucial role in enabling the potential of many web applications. In this paper we illustrate Protune, a system for specifying and cooperatively enforcing security and privacy policies.
8. A method to rank nodes in an RDF graph , Alvaro Graves,Sibel Adali and James Hendler , [OpenAccess] , [Publisher]
   Despite the increasing popularity of RDF as a data representation method, there is no accepted measure of the importance of nodes in an RDF graph. Such a measure could be used to sort the nodes returned by a SPARQL query or to find the important concepts in an RDF graph. In this paper we propose a graph-theoretic measure called noc-order for ranking nodes in RDF graphs based on the notion of centrality. We illustrate that this method is able to capture interesting global properties of the underlying RDF graph using study cases from different knowledge domains. We also show how well noc-order behaves even if the underlying data has some noise, i.e. superfluous and/or erroneous data. Finally, we discuss how information about the importance of different predicates either based on their informativeness, prior semantic information about them or user preferences can be incorporated into this measure. We show the effects of such modifications to the ranking method by examples.
9. ACE View - An ontology and rule editor based on controlled English , Kaarel Kaljurand , [OpenAccess] , [Publisher]
   We describe the architecture of a novel ontology and rule editor ACE View. The goal of ACE View is to simplify viewing and editing expressive and syntactically complex OWL/SWRL knowledgebases by making most of the interaction with the knowledgebase happen via Attempto Controlled English (ACE). This makes ACE View radically different from current OWL/SWRL editors which are based on formal logic syntaxes and general purpose graphical user interface widgets.
10. ACTIVE - Enabling the Knowledge-Powered Enterprise , Paul Warren and Jose Manuel Gomez-Perez , [OpenAccess] , [Publisher]
    Knowledge workers are central to an organisation’s success – yet the tools they must use often stand in the way of maximising their productivity. ACTIVE (http://www.active-project.eu), an EU FP7 integrating project, addresses the need for greater knowledge worker productivity with three integrated research themes: easier sharing of information through combining the ease-of-use of folksonomies with the richness of formal ontologies; sharing and reusing informal knowledge processes, by automatically learning those processes from the user’s behaviour and describing the processes semantically; and using machine learning techniques to describe the user’s context semantically and thereby tailor the information presented to the user to fit the current task. The results of ACTIVE are relevant to all knowledge work; they are being validated in the domains of consultancy, telecommunications and engineering.
11. AN ONTOLOGY-BASED CLUSTER ANALYSIS FRAMEWORK , Paweł Lula and Grażyna Paliwoda-Pękosz , [OpenAccess] , [Publisher]
    The main objectives of this paper are to discuss the various aspects of similarity calculations between objects and sets of objects in ontology-based environments and to propose a framework for cluster analysis in such an environment. The framework is based on the ontology specification of two core components: description of categories and description of objects. Similarity between objects is defined as an amalgamation function of taxonomy, relationship and attribute similarity. The different measures to calculate similarity that can be used in framework implementations are presented. The ontology-based data representation and the framework of cluster analysis can be useful in the area of Business Intelligence, e.g. clustering similar companies that profiles are described by ontology-based data.
12. An ontology-based service-oriented application for mobility impaired users , Dionysios Kehagias,Dimitrios Giakoumis and Dimitrios Tzovaras , [OpenAccess] , [Publisher]
    In this paper, we present the ASK-IT ambient intelligent framework. ASK-IT is built on a service-oriented architecture that uses ontologies in order to semantically annotate Web services and facilitate service discovery and retrieval. Its main aim is to enable a wide range of use cases for elderly and mobility impaired users related to the domains of transport, tourism and leisure, e-working, remote home control and social relationships amongst others. Based on specific use cases, ASK-IT gathers the requested information from a set of interconnected registered Web services and provides it on mobile devices, such as mobile phones and PDAs. We describe the general architecture of ASK-IT framework and present a set of indicative supported demonstration scenarios.
13. BioPortal: A Web Repository for Biomedical Ontologies and Data Resources , Natasha F. Noy,Nigam Shah,Benjamin Dai,Michael Dorf,Nicholas Griffith,Clement Jonquet,Michael Montegut,Daniel Rubin,Cherie Youn and Mark Musen , [OpenAccess] , [Publisher]
    Biomedical ontologies provide essential domain knowledge to drive data integration, information retrieval, data annotation, natural-language processing, and decision support. The National Center for Biomedical Ontology is developing BioPortal, a Web-based system that serves as a repository for biomedical ontologies. BioPortal defines relationships among those ontologies and between the ontologies and online data resources such as PubMed, ClinicalTrials.gov, and the Gene Expression Omnibus (GEO). BioPortal supports not only the technical requirements for access to biomedical ontologies either via Web browsers or via Web services, but also community-based participation in the evaluation and evolution of ontology content. BioPortal enables ontology users to learn what biomedical ontologies exist, what a particular ontology might be good for, and how individual ontologies relate to one another. BioPortal is available online at http://alpha.bioontology.org.
14. BioTop and ChemTop -- Top-Domain Ontologies for Biology and Chemistry , Holger Stenzhorn,Stefan Schulz,Elena Beisswanger,Udo Hahn,László van den Hoek and Erik van Mulligen , [OpenAccess] , [Publisher]
    The recent flood of data and factual knowledge in biology and medicine requires some principled approaches to their proper analysis and management. A cornerstone in this effort constitutes the precise and complete description of the fundamental entities within this domain. But although this fact is generally accepted, often biomedical ontology developments still do not adhere to some of the basic ontology design principles: For example, even very low-level domain terms lack precise and unambiguous (logical) definitions in many cases. Such issues impede the move towards semantic standardization needed for their intended knowledge managment task. Rather it leads to inconsistencies, fragmentation and overlap both within and inbetween different biomedical ontologies. In light of this we introduce BioTop and ChemTop, two top-domain ontologies containing definitions for the most important, foundational entities necesarry to describe the various phenomena in biology and chemistry. These ontologies can subsequently serve as top-level basis for creating new focused domain ontologies in biomedicine or as aid for aligning or improving existing ones.
15. Bioblitz Data on the Semantic Web , Joel Sachs,Lushan Han,Taowei Wang and Cynthia Parr , [OpenAccess] , [Publisher]
    Last summer, we represented the 1200 species observations of the First Annual Blogger Bioblitz in RDF. This allowed us to easily integrate the data with existing RDF data on natural history, taxonomy, food webs, conservation status, and invasive status. Using our Swoogle/Tripleshop approach to dataset construction, we were able to respond to a variety of ad-hoc queries Our efforts last year were external to the running of the bioblitz. For this year’s blogger bioblitz (late August), we have taken responsibility for data processing, and will encourage participants to make use of two tools we have developed that ease the process of user-generated RDF – the Spotter Firefox plug-in, and RDF123. We will encourage ISWC participants to photo-blog Karlsruhe wildlife during the conference, and to use Spotter to generate RDF of their posts. We will also attempt a full bioblitz of a suitable area near the Conference Centre. Our demo will allow users to browse the dataspace resulting from all observations, together with background data, and to issue SPARQL queries over the data.
16. BitMat: A Main-memory Bit Matrix of RDF Triples for Conjunctive Triple Pattern Queries , Medha Atre,Jagannathan Srinivasan and James Hendler , [OpenAccess] , [Publisher]
    This poster proposes BitMat, a bit matrix structure for representing a large number of RDF triples in memory and processing conjunctive triple pattern (multi-join) queries using it. The compact in-memory storage and use of bitwise operations, can lead to a faster processing of join queries when compared to the conventional RDF triple stores. Unlike conventional RDF triple stores, where the size of the intermediate join results can grow very large, our BitMat based multi-join algorithm ensures that the intermediate result set remains small across any number of join operations (provided there are no Cartesian joins). We present the key concepts of BitMat structure, its use in processing join queries, describe the preliminary experimental results with UniProt and LUBM datasets, and discuss the possible use case scenarios.
17. CMAPS Supporting the Development of OWL Ontologies , Alexander García Castro,Angela Norena,Andres Betancourt and Leyla Jael García-Castro , [OpenAccess] , [Publisher]
    In this paper, we present MAP2OWL, a software tool that allows the development of OWL ontologies as concept maps. MAP2OWL uses existing OWL constructs to represent conceptual maps; in this way, domain experts develop ontolologies in a graphical conceptual way, not having to be aware of syntactic matters, or issues related to interfaces that were designed for knowledge engineers. MAP2OWL facilitates the transitions form concepts to classes as well as relations to properties –as specified by OWL. MAP2OWL natively uses OWL; there is no translation from the concept map format to OWL. The tool is build as a Protégé plug-in, MAP2OWL establishes a real time interaction with the OWL protégé plug-in; as the concept map is being developed, an OWL file is being generated. This OWL file can, at any time, be manipulated by the Protégé OWL plug-in, or by any other Protégé Plug-in. The software can be downloaded from http://map2owl.sourceforge.net/.
18. COSIMail and COSIFile: Semantic Desktop Extensions for Email and File Management , Thomas Franz and David-Paul Mann , [OpenAccess] , [Publisher]
    In this poster, we present COSIFile and COSIMail, semantic desktop tools for enhanced file and email management that are based on the X-COSIM semantic desktop framework. They are implemented as extensions for an email client and file manager, specifically designed to enhance support for the personal information managment tasks of information organization and re-finding.
19. CROC: a Representational Ontology for Concepts , Aris van Dijk,Huib Aldewereld and Virginia Dignum , [OpenAccess] , [Publisher]
    Reidentification has been recognised as the most central job of cognition. In this paper, we motivate that concepts as abilities to reidentify, rather than classifications, should be the basis of an agent's conceptuology. Most concepts are not classes; class definitions are artificial, often context-dependent, and don't use inductive knowledge. We will present the basic concepts of CROC, a Representational Ontology for Concepts. Artificial agents can have concepts through language representations alone. Language-like representations, based on lexical concepts, plus reasoning, will be able to solve the interoperability problem to a large extent. By using these concepts, agents can interoperate without need for shared ontologies and with freedom for own conceptions.
20. Collaborative Protege: Enabling Community-based Authoring of Ontologies , Tania Tudorache,Natasha F. Noy and Mark Musen , [OpenAccess] , [Publisher]
    Ontologies are becoming so large in their coverage that no single person or a small group of people can develop them effectively and ontology development becomes a community-based enterprise. We present Collaborative Protege - an extension of the Protege ontology editor that we have designed specifically to support the collaboration process for a community of users. During the ontology-development process, Collaborative Protege allows users to hold discussions about the ontology components and changes using typed annotations; it tracks the change history of the ontology entities; it provides a chat and search functionality. Users edit simultaneously an ontology stored in a common repository. All changes made by a user are seen immediately by other users. Collaborative Protege is open source and distributed with the full installation of Protege.
21. Combining Semantic Wikis and Controlled Natural Language , Tobias Kuhn , [OpenAccess] , [Publisher]
    We demonstrate AceWiki that is a semantic wiki using the controlled natural language Attempto Controlled English (ACE). The goal is to enable easy creation and modification of ontologies through the web. Texts in ACE can automatically be translated into first-order logic and other languages, for example OWL. Previous evaluation showed that ordinary people are able to use AceWiki without being instructed.
22. Consolidating User-defined Concepts with StYLiD , Aman Shakya,Hideaki Takeda and Vilas Wuwongse , [OpenAccess] , [Publisher]
    Information sharing can be effective with structured data. However, there are several challenges for having structured data on the web. Creating structured concept definitions is difficult and multiple conceptualizations may exist due to different user requirements and preferences. We propose consolidating multiple concept definitions into a unified virtual concept. We have implemented a system called StYLiD to realize this. StYLiD is a social software for sharing a wide variety of structured data. Users can freely define their own structured concepts. Attributes of the multiple concept versions are aligned semi-automatically to provide a unified view. It provides a flexible interface for easy concept definition and data contribution. Popular concepts gradually emerge from the cloud of concepts while concepts evolve incrementally. StYLiD also supports linked data by interlinking data instances including external resources like Wikipedia.
23. Conversational Interface Agents for the Semantic Web -- a Case Study , Alexa Breuing,Thies Pfeiffer and Stefan Kopp , [OpenAccess] , [Publisher]
    The Semantic Web is about to become a rich source of knowledge whose potential will be squandered if it is not accessible for everyone. Intuitive interfaces like conversational agents are needed that can disseminate this knowledge either on request or even proactively in a context-aware manner. This paper presents work on extending one existing conversational agent, Max, with abilities to access the Semantic Web and provide the found knowledge for natural language communication.
24. Creating a Semantic Integration System using Spatial Data , Jennifer Green,Glen Hart,Catherine Dolbear,Paula Engelbrecht and John Goodwin , [OpenAccess] , [Publisher]
    Data integration is complex often requiring much technical knowledge and expert understanding of the data’s meaning. In this paper we investigate the use of current semantic tools as an aid to data integration, and identify the need to modify these tools to meet the needs of spatial data. We create a demonstrator based on the real world problem of predicting sources of diffuse pollution, illustrating the benefits of exposing the semantics of integration.
25. Designing Component-Based Semantic Web Applications with DESWAP , Olaf Hartig,Martin Kost and Johann-Christoph Freytag , [OpenAccess] , [Publisher]
    We present the DESWAP system that relieves developers of component-based Semantic Web applications of the burden of manual component selection (CS). Our system implements a novel approach to automatic CS that utilizes semantic technologies. We enable users to specify dependencies between the required components, an issue not considered by existing approaches. To realize our approach in DESWAP we developed a knowledge base with comprehensive semantic descriptions of software and their functionalities.
26. Divergent Exploration of an Ontology , Takeru Hirota,Kouji Kozaki and Riichiro Mizoguchi , [OpenAccess] , [Publisher]
    This paper discusses an ontology exploration tool which allows the users to explore an ontology according to their own perspectives. It extracts concepts from an ontology and visualizes them in a user-friendly form, i.e. conceptual map, in which the user is interested. It helps users to understand the extracted knowledge from the ontology, and contribute to integrated understanding of ontologies and domain dependent knowledge.
27. Dynamic Ontology Evolution in Open Environments , Ignazio Palmisano,Valentina Tamma,Luigi Iannone,Terry Payne and Paul Doran , [OpenAccess] , [Publisher]
    Interoperation between knowledge-based systems or agents requires common ontologies to facilitate successful information exchange. However, the openness of the Semantic Web means that the notion of there being common domain ontologies sufficient to cater for the requirements of a diverse range of consumers and producers of services has become untenable. In these types of environments it is necessary to consider that no ontology can be expected to remain unchanged throughout its lifetime. However, the dynamism and the large scale of the environment prevent the use of traditional ontology evolution techniques, where changes are mediated by a knowledge engineer [3]. We argue that the ability to estimate the impact of change a priori, i.e. before performing the change itself, is crucial, since this estimate can be used to assess the usefulness of the change. We assume that agents are capable of rational behaviour, and that they decide whether to change the ontology they commit to if the cost of the change (in terms of reclassification of knowledge) is offset by the benefits derived from the ability of a system to acquire new capabilities and therefore to achieve new tasks (or answer new queries, in the case of knowledge based systems). However, the agent’s decision making process follows the principle of bounded rationality [5]: agents operate with limited computational resources, and with partial knowledge of the environment [4]. We present an approach that evaluates the impact of change on an ontology a priori, without using reasoning, by estimating which set of axioms in an ontology is impacted by the change.
28. EUREEKA: Deepening the Semantic Web by More Efficient Emergent Knowledge Representation and Processing , Vit Novacek , [OpenAccess] , [Publisher]
    One of the major Semantic Web challenges is the knowledge acquisition bottleneck. New content on the web is produced much faster than the respective machine readable annotations, while a scalable knowledge extraction from the legacy resources is still largely an open problem. This poster presents an ongoing research on an empirical knowledge representation and reasoning framework, which is tailored to robust and meaningful processing of emergent, automatically learned ontologies. According to the preliminary results of our EUREEKA\footnote{A permutated acronym for {\it \textbf{E}asy to \textbf{U}se \textbf{E}mpirical \textbf{R}easoning about \textbf{A}utomatically \textbf{E}xtracted \textbf{K}nowledge}.} prototype, the proposed framework can substantially improve the applicability of the rather messy emergent knowledge and thus facilitate the knowledge acquisition in an unprecedented way.
29. EdHibou: a Customizable Interface for Decision Support in a Semantic Portal , Fadi Badra,Mathieu d'Aquin,Jean Lieber and Thomas Meilender , [OpenAccess] , [Publisher]
    The Semantic Web is becoming more and more a reality, as the required technologies have reached an appropriate level of maturity. However, at this stage, it is important to provide tools facilitating the use and deployment of these technologies by end-users. In this paper, we describe EdHibou, an automatically generated, ontology-based graphical user interface that integrates in a semantic portal. The particularity of EdHibou is that it makes use of OWL reasoning capabilities to provide intelligent features, such as decision support, upon the underlying ontology. We present an application of EdHibou to medical decision support based on a formalization of clinical guidelines in OWL and show how it can be customized thanks to an ontology of graphical components.
30. Evaluating the Structural Quality of Semantic Hierarchy Alignments , Cliff Joslyn,Alex Donaldson and Patrick Paulson , [OpenAccess] , [Publisher]
    We present preliminary results of applying a novel method based in metric order theory to provide a measure of the structural quality of some of the test alignments between semantic hierarchies used in the 2007 Ontology Alignment Evaluation Initiative.
31. Expanding Folksonomy Search with Ontologies , Jeff Z. Pan,Stuart Taylor and Edward Thomas , [OpenAccess] , [Publisher]
    In this paper, we propose an approach to expand folksonomy search with ontologies, which are completely transparent to users. Preliminary implementations and evaluations of this approach are promising.
32. Explanation of OWL Entailments in Protege 4 , Matthew Horridge,Bijan Parsia and Ulrike Sattler , [OpenAccess] , [Publisher]
    This poster and demo presents new OWL ontology explanation tools and facilities that are available in Protege 4. These explanations take the form of justifications. A justification is a minimal sets of axioms that is sufficient for a given entailment to hold. Justification finding services for Protege 4 are presented, including what have become de-facto explanation services such as root/derived pinpointing, and justification presentation. In addition to this, an implementation of recent theoretical work that computes so-called precise justifications is presented. Finally, preliminary work and new ideas of how justifications might be made easier to understand is a topic for discussion. All feedback and discussion is welcomed. Protege 4 is an open source, freely available OWL ontology editor.
33. Extracting Communities of Interests for Semantics-based Graph Searches , Makoto Nakatsuji,Akimichi Tanaka and Toru Ishida , [OpenAccess] , [Publisher]
    We propose an algorithm that mines blog entries to realize Semantic Web searches. It divides a graph, whose vertices are users and whose edges represent shared interests, into subgraphs - communities of interests (COIs). The algorithm allows users to identify new interests quickly and accurately. Our algorithm differs from conventional modularity-based approaches because it attaches semantic tags to the relationships between COIs or between users based on taxonomies of the content items of interest. We also introduce a mechanism to harmonize the number of users in each COI. Our two proposals raise the effectiveness of information searches.
34. Extracting Structured Knowledge for Semantic Web by Mining Wikipedia , Kotaro Nakayama , [OpenAccess] , [Publisher]
    Since Wikipedia has become a huge scale database storing wide-range of human knowledge, it is a promising corpus for knowledge extraction. A considerable number of researches on Wikipedia mining have been conducted and the fact that Wikipedia is an invaluable corpus has been conrmed. Wikipedia's impressive characteristics are not limited to the scale, but also include the dense link structure, URI for word sense disambiguation, well structured Infoboxes, and the category tree. One of the popular approaches in Wikipedia Mining is to use Wikipedia's category tree as an ontology and a number of researchers proved that Wikipedia's categories are promising resources for ontology construction by showing significant results. In this work, we try to prove the capability of Wikipedia as a corpus for knowledge extraction and how it works in the Semantic Web environment. We show two achievements; Wikipedia Thesaurus, a huge scale association thesaurus by mining the Wikipedia's link structure, and Wikipedia Ontology, a Web ontology extracted by mining Wikipedia articles.
35. Finding Equivalent Ontologies in Watson , Carlo Allocca,Mathieu d'Aquin and Enrico Motta , [OpenAccess] , [Publisher]
    We present an efficient mechanism for finding equivalent ontologies motivated by the development of the Semantic Web search engine Watson. In principle, it computes a canonical form for the ontologies, which can then be compared syntactically to assess semantic equivalence. The advantage of using this method is that the canonical form can be indexed by the search engine, reducing the search for equivalent ontologies to a usual text search operation using the canonical form. This method is therefore more suitable for a search engine like Watson than the naive comparison of all possible candidate pairs of ontologies using a reasoner.
36. Graph-Theoretic Analysis of Collaborative Knowledge Bases in Natural Language Processing , Konstantina Garoufi,Torsten Zesch and Iryna Gurevych , [OpenAccess] , [Publisher]
    We present a graph-theoretic analysis of the topological structures underlying the collaborative knowledge bases Wikipedia and Wiktionary, which are promising uprising resources in Natural Language Processing. We contrastively compare them to a conventional linguistic knowledge base, and address the issue of how these Social Web knowledge repositories can be best exploited within the Social-Semantic Web.
37. Heuristics for Automated Text-Based Shallow Ontology Generation , Mihaela Vela and Thierry Declerck , [OpenAccess] , [Publisher]
    In this poster, we describe the actual state of development of ontology learning/extraction, which is currently being designed and implemented in the context of a large European R&D project dealing with Business Intelligence applications. We propose an approach to the extension of existing domain ontologies or even to the semi-automatic ontology creation from scratch, on the base of a multi-layered processing of textual documents.
38. IYOUIT - Share, Life, Blog, Play , Sebastian Boehm,Johan Koolwaaij,Marko Luther,Bertrand Souville,Matthias Wagner and Martin Wibbels , [OpenAccess] , [Publisher]
    IYOUIT is a prototype mobile service to pioneer a context-aware digital lifestyle and its reflection on the Web. The service is made freely available and leverages Semantic Web technology to implement smart application features. We intend to not only present and demonstrate IYOUIT at ISWC’08 but also to provide it to conference attendees, based on their demand.
39. Indexing Social Semantic Data , George Fletcher and Peter Beck , [OpenAccess] , [Publisher]
    To be successful, Personal Information Management (PIM) solutions must be built on top of a robust data management infrastructure. Such an infrastructure must efficiently and unobtrusively support the requirements of PIM. At present, the design of data management infrastructures for PIM is in its infancy. In particular, indexing, a fundamental data management technology, is still not well understood in this domain. Indexes are necessary for efficient querying and exploration of data. This poster will describe our ongoing efforts to design index structures specifically tailored to the social semantic data managed by PIM systems.
40. Knowledge Provenance in Virtual Observatories: Application to Image Data Pipelines , Peter Fox,Deborah McGuinness and Paulo Pinheiro da Silva , [OpenAccess] , [Publisher]
    Scientific data services are increasing in usage and scope, and with these increases comes growing need for access to provenance information. Our goal is to design and implement an extensible provenance solution that is deployed at the science data ingest time. In this paper, we describe our work in the setting of a particular set of data services in the area of solar coronal physics. The paper focuses on one existing federated data service and one proposed observatory. Our claim is both that the design and implementation are useful for the particular scientific image data services we designed for, but further that the design provides an operational specification for other scientific data applications. We highlight the need for and usage of semantic technologies and tools in our design and implemented service.
41. LENA - Browsing RDF Data More Complex Than Foaf , Jörg Koch and Thomas Franz , [OpenAccess] , [Publisher]
    We present LENA, a web-based RDF browser that supports the rendering of complex RDF data based on criteria expressed as SPARQL queries. The user interface of LENA enables to switch between different views onto the presented data enabling users to browse the data with respect to individual interests or expertise.
42. Language as a Foundation of the Semantic Web , Gerard de Melo and Gerhard Weikum , [OpenAccess] , [Publisher]
    This paper aims to show how language-related knowledge may serve as a fundamental building block for the Semantic Web. We present a system of URIs for terms, languages, scripts, and characters, which are not only highly interconnected but also linked to a great variety of resources on the Web. Additional mapping heuristics can then be used to derive new links.
43. Learning Semantic Web Rules within the Framework of SHIQ+log , Francesca Alessandra Lisi and Floriana Esposito , [OpenAccess] , [Publisher]
    In this paper we face the problem of learning Semantic Web rules within a decidable instantiation of the $\mathcal{DL}$+log framework which integrates the DL $\mathcal{SHIQ}$ and positive \textsc{Datalog}. To solve the problem, we resort to the methodological apparatus of Inductive Logic Programming.
44. Learning of OWL Class Descriptions on Very Large Knowledge Bases , Sebastian Hellmann,Jens Lehmann and Sören Auer , [OpenAccess] , [Publisher]
    The vision of the Semantic Web is to make use of semantic representations on the largest possible scale - the Web. Large knowledge bases such as DBpedia, OpenCyc, GovTrack, and others are emerging and are freely available as Linked Data and SPARQL endpoints. Exploring and analysing such knowledge bases is a significant hurdle for Semantic Web research and practice. As one possible direction for tackling this problem, we present an approach for obtaining complex class descriptions from objects in knowledge bases by using Machine Learning techniques. We describe how we leverage existing techniques to achieve scalability on large knowledge bases available as SPARQL endpoints or Linked Data. Our algorithms are made available in the open source DL-Learner project and can be used in real-life scenarios by Semantic Web applications.
45. MDS++: Supporting Ontology-based Dynamic Classification in WebSphere Metadata Server , Shengping Liu,Yang Yang,Guotong Xie,Chen Wang,Feng Cao,Cassio Santos,Robert Schloss,Yue Pan,Kevin Shank and John Colgrave , [OpenAccess] , [Publisher]
    Metadata management systems are growing from tool-specific repositories to enterprise-wide metadata repositories. In this context, one challenge is the management of the evolving metadata whose schema or meta-model itself may evolve, e.g., dynamically-added properties, which are often hard to predict upfront at the initial meta-model design time; another challenge is to organize the metadata by semantically-rich classification schemes. In this paper, we demonstrate a practical system which provides support for users to dynamically manage semantically-rich properties and classifications in the IBM WebSphere Metadata Server (MDS) by integrating an OWL ontology repository. To enable the smooth acceptance of Semantic Web technologies, the system is designed to consist of integrated modeling paradigms, with an integrated query language and runtime repository.
46. Making URIs published on Data Web RDF dereferencable , Jing Mei,Guotong Xie,Yuan Ni,Shengping Liu,Hanyu Li and Yue Pan , [OpenAccess] , [Publisher]
    Nowadays, more and more URIs reside on DataWeb, as published for linked open data, dereferencing URIs challenges the current Web to embrace Semantic Web. Although, quite a few practical recipes for publishing URIs have been provided to make URIs dereferencable, we believe a fundamental investigation of publishing and dereferencing URIs would contribute a forward compatibility with the RDF and OWL upper layers in the Semantic Web architecture. In this paper, we propose to make URIs published on Data Web RDF dereferencable, and we formalize such a requirement in an RDF-compatible semantics. Also, the dereferencing operation is defined in an abstract URI syntax, such that URIs, as interpreted as described resources, would be RDF dereferencable by default. Accompanied by a live demonstration, the poster demo explanation would elaborately discuss and seriously address issues on Data Web URIs, which were or have been taken for granted. Additionally, for case study, Metadata Web, a Data Web of enterprise-wide models, is explored. The URIs on Metadata Web is published as RDF dereferencable. Such an implementation of universal meta data management across the enterprise enables the metadata federation such that global query, search and analysis could be conducted on top of the Metadata Web.
47. Modeling Online Presence , Milan Stankovic , [OpenAccess] , [Publisher]
    In this paper, we introduce the notion of Online Presence, a concept related to user’s presence on online services. We identify interoperability issues in the field of exchange of the online presence data and propose a solution in building a common model for semantic representation of online presence data. We present the Online Presence Ontology (OPO) together with benefits such an ontology could bring.
48. NITELIGHT: A Graphical Editor for SPARQL Queries , Alistair Russell and Paul Smart , [OpenAccess] , [Publisher]
    Query formulation is a key aspect of information retrieval, contributing to both the efficiency and usability of many semantic applications. A number of query languages, such as SPARQL, have been developed for the Semantic Web; however, there are, as yet, few tools to support end users with respect to the creation and editing of semantic queries. In this paper we present NITELIGHT, a graphical tool for semantic query design. NITELIGHT uses a Visual Query Language (VQL), called vSPARQL, which provides graphical formalisms for SPARQL query specification. NITELIGHT is a highly reusable Web-based component, and it can be easily embedded in a variety of different Web applications. This paper provides an overview of the NITELIGHT tool and the vSPARQL specification.
49. OmniCat: Automatic Text Classification with Dynamically Defined Categories , Maciej Janik and Krys Kochut , [OpenAccess] , [Publisher]
    We present OmniCat, an ontology-based text categorization method that classifies documents into a dynamically defined set of categories specified as contexts in the domain ontology. The method does not require a training set and is based on measuring the semantic similarity of the thematic graph created from a text document and the ontology fragments created by the projection of the defined contexts. The domain ontology together with the defined contexts effectively becomes the classifier, as it includes all of the necessary semantic and structural features of the classification categories. With the proposed approach, we can also dynamically change the classification categories without the need to retrain the classifier. In our experiments, we used an RDF ontology created from the full version of the English language Wikipedia to categorize a set of CNN documents and a subset of the Reuters RCV1 corpora. The high accuracy achieved in our tests demonstrates the effectiveness of the proposed method and applicability of Wikipedia for semantic text categorization.
50. Ontology Alignment Using Multiple Contexts , Jeff Partyka,Neda Alipanah,Latifur Khan,Bhavani Thuraisingham and Shashi Shekhar , [OpenAccess] , [Publisher]
    Ontology alignment involves determining the semantic heterogeneity between two or more domain specifications by considering their associated concepts. Our approach considers name, structural and content matching techniques for aligning ontologies. After comparing the ontologies using concept names, we examine the instance data of the compared concepts and perform content matching using value types based on N-grams and Entropy Based Distribution (EBD). Although these approaches are generally sufficient, additional methods may be required. Subsequently, we compare the structural characteristics between concepts using Expectation-Maximization (EM). To illustrate our approach, we conducted experiments using authentic geographic information systems (GIS) data and generate results which clearly demonstrate the utility of the algorithms while emphasizing the contribution of structural matching.
51. Optimizing SPARQL Queries over Disparate RDF Data Sources through Distributed Semi-Joins , Jan Zemánek,Simon Schenk and Vojtech Svatek , [OpenAccess] , [Publisher]
    With the ever-increasing amount of data on the Web available at SPARQL endpoints the need for an integrated and transparent way of accessing the data has arisen. It is highly desirable to have a way of asking SPARQL queries that make use of data residing in disparate data sources served by multiple SPARQL endpoints. We aim at providing such a capability and thus enabling an integrated way of querying the whole Semantic Web at a time.
52. Product modelling and the Semantic Web , Michel Böhms,David Leal and henson graves , [OpenAccess] , [Publisher]
    This poster describes the scope and current work of the W3C Product Modelling Incubator Group.
53. Progress Report from the RDB2RDF XG , Ashok Malhotra , [OpenAccess] , [Publisher]
    In February, the W3C initiated the RDB2RDF Incubator Group chartered to set direction in the area on mapping Relational Databases to RDF. In these few months we have made significant progress. There is a substantial Wiki that catalogs existing tools and approaches and we have the start of a recommendation to the W3C for further work. The poster session will discuss existing approaches to mapping Relational data to RDF and will entertain discussion on how to make progress in this area.
54. Pronto: Probabilistic Ontological Modeling in the Semantic Web , Pavel Klinov and Bijan Parsia , [OpenAccess] , [Publisher]
    This demonstration illustrates the benefits of probabilistic ontological modeling for uncertain domains in the Semantic Web. It is based on Pronto - probabilistic OWL reasoner that allows modelers to complement classical OWL ontologies with probabilistic statements. In addition to Pronto's features and capabilities, a great deal of the demonstration will be devoted to presenting modeling patterns, typical pitfalls, desirable as well as incidental consequences of probabilistic reasoning. The testbed will be the prototype of the Breast Cancer Risk Assessment ontology that we have developed to evaluate Pronto.
55. ROO: Involving Domain Experts in Authoring OWL Ontologies , Ronald Denaux,Vania Dimitrova,Anthony G. Cohn,Catherine Dolbear and Glen Hart , [OpenAccess] , [Publisher]
    This demonstration presents ROO, a tool that facilitates domain experts' definition of ontologies in OWL by allowing them to author the ontology in a controlled natural language called Rabbit. ROO guides users through the ontology construction process by following a methodology geared towards domain experts’ involvement in ontology authoring, and exploiting intelligent user interfaces techniques. An experimental study with ROO was conducted to examine the usability and usefulness of the tool, and the quality of the resultant ontologies. The findings of the study will be presented in a full paper at the ISWC08 research track [2]. The proposed demonstration will provide hands-on experience with the tool and will illustrate its main functionality.
56. Ranking Semantic Similarity Association in Semantic Web , Shahdad Shariatmadari,Ali Mamat,Hamidah Ibrahim and Norwati Mustapha , [OpenAccess] , [Publisher]
    Discovering and ranking complex relationships in the semantic web is an important building block of semantic search applications. Although semantic web technologies define relations between objects but there are some complex (hidden) relationships that are valuable in different applications. Currently, users need to discover the relations between objects and find the level of semantic similarity between them. (I.e. find two similar papers). This paper presents a new approach for ranking semantic similarity association in semantic web document, based on semantic association concept.
57. Realizing Semantic Web Portal Using Available Semantic Web Technologies and Tools , Lidia Rovan , [OpenAccess] , [Publisher]
    Portals allow easy access to information by integrating heterogeneous applications or data sources in consistent way. It gives users a personalized and restricted view of domain information. Standard portal features could be improved employing semantic web technologies. Although portals are now experiencing serious growth just as number of available semantic web tools, number of semantic web portals is negligible. In accordance to observed acceptance problems guidelines for developing semantic web portals are proposed.
58. Relation Discovery from the Semantic Web , Marta Sabou,Mathieu d'Aquin and Enrico Motta , [OpenAccess] , [Publisher]
    Several Semantic Web specific tasks such as ontology learning/extension or ontology matching rely on identifying relations between two given concepts. Scarlet is a technique for discovering relations between two given concepts by exploring ontologies available on the Semantic Web as a source of background knowledge. By relying on semantic web search engines such as Watson, Scarlet automatically identifies and combines relevant information from multiple and heterogeneous online ontologies. Scarlet has already been used successfully to support a variety of tasks, but is also available as a stand alone component that can be reused in various other applications. This poster will be accompanied by a demo of Scarlet's functionality available through its Web based user interface.
59. Reusing Knowledge from the Semantic Web with the Watson Plugin , Mathieu d'Aquin,Marta Sabou and Enrico Motta , [OpenAccess] , [Publisher]
    The recent growth of the Semantic Web increases the amount of ontologies that can be reused, but also makes more difficult the tasks of finding, selecting and integrating reusable knowledge for ontology engineering. For this reason, we developed the Watson plugin, a tool which aims to facilitate large scale knowledge reuse by extending an ontology editor with the features of the Watson Semantic Web search engine. With this plugin, it is possible to discover, inspect and reuse ontology statements originating from various online ontologies directly in the ontology engineering environment.
60. SPARQL+, SPARQLScript, SPARQL Result Templates - SPARQL Extensions for the Mashup Developer , Benjamin Nowack , [OpenAccess] , [Publisher]
    SPARQL lowers the barrier to RDF-based mashup development. It does, however, not support write operations, useful constructs like aggregates, the ability to combine and post-process query results, or human-oriented result formats. This paper describes a set of extensions that largely reuse SPARQL's intuitive syntax to provide query aggregates and update functionality (SPARQL+), result processing and chained queries across multiple endpoints (SPARQLScript), and result templating. The combination of these extensions enables the creation of mashups not only from distributed data sources, but also from portable application components.
61. SUBLIMA: a software stack for Inter-operable Topic-Centred Information Portals , Robert Engels and David Norheim , [OpenAccess] , [Publisher]
    In order to be more flexible in publishing information and improve accessibility of information for end-users, Oslo Municipality has funded the SUBLIMA project [25]. Within this project a stack of open source Semantic Web and Content Management System (CMS) compo- nents is used in order to deliver a flexible solution for publication of meta-data from libraries. Queries from a specific front-end are automat- ically dispatched to the available SPARQL end-points [23] in a pool of library and archive based installations. Returning results are presented to the user in an integral manner. The final delivery consists of an open source software stack based on Semantic Web Technology and W3C stan- dards. Finally resulting in a well-defined and approved stack of software, major efforts has been spent on licensing issues, immaturity of compo- nent parts, ill-defined documentation of software and conversion of older bases into OWL [5]. Experiences and problems have been discussed with and reported into the respective communities.
62. SUITS4RDF: Incremental Query Construction for the Semantic Web , Enrico Minack,Wolf Siberski,Gideon Zenz and Xuan Zhou , [OpenAccess] , [Publisher]
    With the advance of the Semantic Web technology, increasing data will be annotated with computer understandable structures (i.e. RDF and OWL), which allow us to use more expressive queries to improve our ability in information seeking. However, constructing a structured query is a laborious process, as a user has to master the query language as well as the underlying schema of the queried data. In this demo, we introduce SUITS4RDF, a novel interface for constructing structured queries for the Semantic Web. It allows users to start with arbitrary keyword queries and to enrich them incrementally with an arbitrary but valid structure, using computer suggested queries or query components. This interface allows querying the Semantic Web conveniently and efficiently, while enabling users to express their intent precisely.
63. SemTree: Ontology-Based Decision Tree Algorithm for Recommender Systems , Amancio Bouza,Gerald Reif,Abraham Bernstein and Harald Gall , [OpenAccess] , [Publisher]
    Recommender systems play an important role in support- ing people when choosing items from a overwhelming huge number of choices. So far, no recommender system makes use of domain knowledge. We are modeling user prefer- ences with a machine learning approach to recommend peo- ple items by predicting the item ratings. Specifically, we pro- pose SemTree, an ontology-based decision tree learner, that uses a reasoner and an ontology to semantically generalize item features to improve the effectiveness of the decision tree built. We show that SemTree outperforms comparable ap- proaches in recommending more accurate recommendations considering domain knowledge.
64. Semantic Data Integration and Registration: Application to heterogeneous atmosphere and volcanic data sources , Deborah McGuinness,Peter Fox,AK Sinha,Robert Raskin,Abdelmounaam Rezgui and Patrick West , [OpenAccess] , [Publisher]
    We present our work on semantically-enabled data and schema registration in the setting of a scientific data integration project: SESDI (Semantically-Enabled Scientific Data Integration), which aims initially to integrate heterogeneous volcanic and atmospheric chemical compound data in support of assessing the atmospheric effects of a volcanic eruption. We use semantic methods through out the project, however in this paper and demonstration, we will highlight issues related to our work on data and schema registration and integration. In this process, we will demonstrate how we are re-using previously developed ontologies and how those ontologies are being used to provide a “smart: data integration capability aimed at interdisciplinary scientific research.
65. Semantic Image Annotation and Retrieval with IKen , Dominic Mainz,Katrin Weller and Jürgen Mainz , [OpenAccess] , [Publisher]
    In this paper we introduce IKen, a platform for image retrieval enhanced by semantic annotations. The paper discusses work in progress and reports the current state of IKen. This comprises the functionalities for annotating photos with an underlying ontology, search features based on these annotations and the development of the domain ontology used for annotation.
66. Semantic Knowledge Sharing within a Collaborative Work Environment , Sang Keun Rhee,Jihye Lee and Myon-Woong Park , [OpenAccess] , [Publisher]
    Knowledge sharing is vital in collaborative work environments, and sharing resources within a contextual knowledge structure constructed based on a collective intelligence of the people working in a same environment can aid better communication. In this paper, we discuss a semantic knowledge structure for effective knowledge shraing and communication, and present a Wiki-based knowledge sharing system for research projects with effective navigation means.
67. Semantic Web Technologies for Digital Preservation: the SPAR project , Gautier Poupeau and Emmanuelle Bermès , [OpenAccess] , [Publisher]
    The national library of France (BnF) is in the process of setting up a digital preservation repository, named SPAR (Système de Préservation et d’Archivage Réparti – Distributed Preservation and Archiving System). The infrastructure for the system, bought in 2005, is designed to support 1,5 petabytes of storage by 2014. The software components of the system are currently developped by Atos Origin. The design of the SPAR system is based on the major digital preservation standard, the OAIS model1. The architecture is composed of several modules connected via web services and based on open source components. One of the main components of the system is the data management module : it will use RDF data stored in a RDF triple store. We explain here why RDF is relevant for digital preservation and how it will be implemented in SPAR.
68. Semantic framework for complex knowledge domains , Marta Gonzalez,Stefano Bianchi and Gianni Vercelli , [OpenAccess] , [Publisher]
    Large amounts of scientific digital contents, potentially available for public sharing and reuse, are nowadays held by scientific and cultural institutions which institutionally collect, produce and store information valuable for dissemination, work, study and research. Semantic technology offers to these stakeholders the possibility to integrate dispersed heterogeneous yet related resources and to build value-added sharing services (overcoming barriers such as knowledge domain complexity, different classification, languages, data formats and localization) by exploiting knowledge formalisation and semantic annotation. Applications in real cases are anyway often hampered by difficulties related to the proper formalization of scientific knowledge domains (ontology engineering) and the description of contents (semantic annotation). Difficulties that become even more relevant when dealing with complex knowledge domains (vast domain + certain level of dynamicity) that formalize heterogeneous resources coming from scattered sources. This paper illustrates the lessons learnt in applying the Semantic Web specifications to support content management and sharing in scientific complex knowledge domains using mixed - formal/informal - annotation and ontology learning approaches to overcome the difficulties posed by dealing with complex knowledge domains such as the aquatic domain.
69. Skipforward---a lightweight ontology-based peer-to-peer recommendation system , Malte Kiesel and Sven Schwarz , [OpenAccess] , [Publisher]
    Skipforward is a distributed recommendation system using a lightweight ontology approach for formalizing opinions about item features. Items can be things such as songs or board games; example item features are the genre of a song or the degree of chance in a board game. Every user of the system is free to add new items and statements about existing items to the system. Naturally, opinions may differ between users---the system even encourages people to express dissent by supporting negation for item features. Skipforward allows discussions for any item feature as well as displaying these discussions in a way similar to web forums.
70. TagCare: A Personal Portable Tag Repository , Evgeni Golov,Katrin Weller and Isabella Peters , [OpenAccess] , [Publisher]
    This paper presents TagCare as a tool which allows users to maintain their personal tagging vocabulary and to carry it along different platforms. TagCare collects the tags which a user has applied within several social software tools. These personal tags may be edited and structured, e.g. interrelated with hierarchical and other semantic relations.
71. Taking Enterprise Search to the Next Level , Kay-Uwe Schmidt,Daniel Oberle and Klaus Deissner , [OpenAccess] , [Publisher]
    Enterprise search is vital for today's enterprises. The ongoing growth of information in enterprises demands new solutions for finding relevant information in the information space. The personalization of search results is one promising approach in solving this challenge. Additionally, ontologies stoke expectations of easing the information integration process for federated search results by their formal and declarative nature. In this poster we present our novel approach of an ontology-based personalized enterprise search. We introduce an ontology-based federation layer for bridging the heterogeneity of the different knowledge sources in an enterprise.
72. The TW Wine Agent: A Social Semantic Web Demo , James Michaelis,Li Ding and Deborah McGuinness , [OpenAccess] , [Publisher]
    The Tetherless World (TW) Wine Agent extends the original Stanford Knowledge Systems Laboratory (KSL) Wine Agent to support collective recommendations on food-wine pairings. This is done to (1) demonstrate the advance of Semantic Web technologies, including OWL DL reasoning, SPARQL, provenance explanation, and semantic wikis, and (2) show how the Semantic Web can be integrated into Social Web applications. A live demo is available at http://onto.rpi.edu/wiki/wine, which is designed for use on mobile phones as well as standard browsers.
73. Thinkbase: A Visual Semantic Wiki , Christian Hirsch,John Grundy and John Hosking , [OpenAccess] , [Publisher]
    Thinkbase is a visual navigation and exploration tool for Freebase, an open, shared database of the world’s knowledge. Thinkbase extracts the contents, including semantic relationships, from Freebase and visualizes them using an interactive visual representation. Providing a focus plus context view the visualization is displayed along with the Freebase article. Thinkbase provides a proof of concept of how visualizations can improve and support Semantic Web applications. The application is available via http://thinkbase.cs.auckland.ac.nz.
74. Toward an Ontology for Finite Algebras , Bella Manoim and Robert W. McGrail , [OpenAccess] , [Publisher]
    The authors present a case for an ontology of finite algebras. This vocabulary is a direct response to the limitations of the formats employed by first-order model searchers, such as Mace4, and specialized software, such as UACalc. It will support a semantically rich format for algebra storage and interchange intended to improve the efficiency of computational discovery processes in universal algebra. The class of finite quandles is considered as a case study in order to understand some of the challenges of designing such a knowledge base.
75. Towards Reactive Semantic Web Policies: Advanced Agent Control for the Semantic Web , Jose Julio Alferes,Ricardo Amador,Philipp Kärger and Daniel Olmedilla , [OpenAccess] , [Publisher]
    The Semantic Web envisions a distributed environment with well-defined data that can be understood and used by machines in order to, among others, allow intelligent agents to automatically perform tasks on our behalf. In the past, different Semantic Web policy languages have been developed as a powerful means to describe a system's behavior by defining statements about how the system must behave under certain conditions. With the growing dynamics of the Semantic Web the need for a reactive control based on changing and evolving situations arises. This paper presents preliminary results towards a framework for the specification and enforcement of reactive Semantic Web policies, which can be used in order to allow agents to automatically perform advanced and powerful tasks, which can neither be addressed by existing Semantic Web policy languages nor by recent efforts towards reactivity on the Semantic Web.
76. Towards Semantic File System Interfaces , Sebastian Faubel and Christian Kuschel , [OpenAccess] , [Publisher]
    In this paper we present our hypothesis that transition to semantic file system interfaces is possible by computing the organization of hierarchical file systems from semantic web data.
77. Towards Social Webtops Using Semantic Wiki , Jie Bao,Li Ding,Deborah McGuinness and James Hendler , [OpenAccess] , [Publisher]
    The fast-growing Web 2.0 applications promote explicit so- cial structure and explosive data on the Web, and enable the realization of social webtops, where users use web ap- plications to collaboratively organize and share online data. In this work, we show that semantic wiki technologies are suitable for building a social webtop. We also identify two key issues in realizing social webtop applications on seman- tic wiki and present our initial investigation with live demos: (i) popular concept modeling mechanisms used by webtop applications can be supported by semantic wiki; and (ii) provenance-aware data personalization mechanisms can be added as semantic wiki extensions to better support collab- orative data management on a webtop.
78. UMRR: Towards an Enterprise-Wide Web of Models , Jing Mei,Guotong Xie,Lei Zhang,Shengping Liu,Robert Schloss,Yue Pan and Yuan Ni , [OpenAccess] , [Publisher]
    Metadata that describes the structure and semantics of data sources takes a significant role in enterprise information integration. Enterprise information integration always involves an increasing set of types of metadata that are dispersed in various repositories, modeled by various tools, represented in various formats. There is a crucial requirement to break the “Tower of Babel” among different types of metadata to enable better understanding, more comprehensive governance and analysis. Towards the goal of a simplified framework for metadata representation, federation, search and analysis, in the UMRR (Unified Metadata Registry and Repository) project at IBM, we propose and implement an open Web architecture for universal metadata management, where the Resource Description Framework (RDF) is adopted to represent the underlying metadata that are in various formats and the “Linked Data” method is leveraged to build a web of models. Our demonstration illustrates the effectiveness of this architecture to enable the metadata federation such that the global query, search and analysis on the metadata are feasible. Additionally, we also demonstrate that the proposed architecture could easily leverage Web 2.0 technologies, such as social bookmaking, tagging and RSS feeds, etc. for collaborative metadata management.
79. Unifying Semantic Wikis and Semantic Web Applications , Daniel Schwabe and Miguel Rezende da Silva , [OpenAccess] , [Publisher]
    Many Semantic Wiki Engines have been developed in response to a semi-structured domain of application. Nevertheless these engines take very few advantages of the structured model on their viewing and editing interfaces. In this paper we present HyperDEWiki implementation where we combine Semantic Wiki and model-based Semantic Web Application allowing specialized interfaces and navigation. The tool is also intended to support domain ontology evolution.
80. Unleash the power of Semantic Web in the Enterprise , Georg Schmidt and Igor Novakovic , [OpenAccess] , [Publisher]
    An important requirement to the enterprise IT is the ability to manage information with high flexibility. Semantic web research and resulting technologies are therefore getting more and more vital within business processes. One question is how to get the research work - done at universities or within corporations - into the enterprise easily. One possible answer to this question is the availability of an open source information processing framework, which meets the requirements of an enterprise. This framework should be mature and flexible enough to design any application. To move towards such a flexible architecture, which is able to process vast amounts of information in an enterprise, a joint development by BROX and Empolis, has been started on Eclipse.
81. Visualization of the Search Results of the Semantic Web Search Engines , Xianyong Fang,Christian Jacquemin and Frédéric Vernier , [OpenAccess] , [Publisher]
    The Semantic Web calls for a new generation of search query visualizer that can rely on the document metadata. For this purpose, we present the design of WebViser a visualizer and browser of search results organized along three dimensions: a class based representation of documents on carousels, a stack structure of classes according to their ranking, and a meta carousel for the localization of class stacks associated with different queries. In addition links that connect documents through metadata comparison are displayed in such a way that link overlaps and visualization cluttering are minimized. A qualitative evaluation provides interesting insights on the users’ appropriation of the interface and demonstrates that this system is an effective complementary to the traditional explorer for Semantic Web search engines.
82. Web Search With Document Space Adapted Ontologies , Stein L. Tomassen , [OpenAccess] , [Publisher]
    An increasing number of recent information retrieval systems make use of ontologies to help the users clarify their information needs and come up with semantic representations of documents. In this paper, we present an approach that utilizes ontologies to enhance the effectiveness of large-scale search systems for the Web. The ontology concepts are adapted to the domain terminology by computing a feature vector for each concept. We explain how these feature vectors are constructed and finally present some results.
83. http://ontologydesignpatterns.org [ODP] , Valentina Presutti,Enrico Daga,Aldo Gangemi and Alberto Salvati , [OpenAccess] , [Publisher]
    We present ontologydesignpatterns.org (ODP), a semantic web portal about ontology design patterns based on wiki technology, which aims at supporting a community around best practices for ontology design. ODP offers services for evaluation and training about ontology patterns, and a repository of OWL ontologies. ODP fosters several kinds of participation, from anonymous, read-only access to open-rating and quality-committee membership. Based on semantic wiki components, we have developed EvalWF, an extension for supporting evaluation workflows able to manage the entire lifecycle of a pattern, from submission to certification.
84. oWSD: A Tool for Word Sense Disambiguation in Its Ontology Context , Xia Wang , [OpenAccess] , [Publisher]
    Word sense disambiguation (WSD) technology is very important to Semantic web/web 2.0 and Ontology as well. There still has no easy-to-use WSD tool available. This paper demonstrates a simple and very efficient tooL. It does WSD in an Ontology context and get the right word senses from WordNet\cite{WordNet}. This tool is very useful to natural language process and Ontology related applications.
85. semSL: Tagging and Data Linking for Second Life , Michael Schneider,Felix Kratzer and Kai Mainzer , [OpenAccess] , [Publisher]
    We present semSL, an approach to bring Semantic Web technologies into Second Life. Second Life is a virtual 3D world, in which users can communicate, build objects, and explore the land of other users. There are different kinds of entities in Second Life, which can be locations, objects, or events. Many of these entities are of potential interest to users. However, searching for entities is difficult in Second Life, since there is only a very limited way to describe entities. With semSL it becomes possible for every user to add arbitrary tags or key/value pair based descriptions to entities in Second Life, or to create typed links between entities. Such typed links can even be established between entities in Second Life and resources from the Semantic Web. The description data for all such entities is centrally stored at a server external to Second Life. The data is encoded in RDF, and is publicly accessible via a SPARQL endpoint. This should not only lead to significant improvements for searching operations, but will also allow for flexible data integration between data from semSL and data from other sources on the Semantic Web.