KEG seminar1 ISWC th International Semantic Web Conference Athens, GA, USA, November

KEG seminar2 Statistics Participants from 33 countries Research track –215 submissions (217, 54, 25%) –52 accepted (24% acceptance rate) In-Use Track –Not only industry, also government, public health, and academia –42 submissions –14 accepted (1/3 acceptance rate)

KEG seminar3 Semantic Web Challenge Goal: to apply Semantic Web techniques in building online end-user applications that integrate, combine and deduce information needed to assist users in performing task Certain minimum criteria: –Meaning of data has to play a central role –Heterogeneous information sources, under diverse control –Open world assumption –(multi-media, commercial potential, scalability) Semantic Web Challenge –18 submitted Semantic Web applications –14 accepted

KEG seminar4 Semantic Web Challenge MultimediaN E-Culture demonstrator, VU Oscar Celma: Foafing the Music: Bridging the semantic gap in music recommendation –a music recommender system, based on user's profile. This means that, depending on what you like, what you listen to, where you live, etc, you get personalized music recommendations. Giovanni Tummarello et al: DBin: Enabling Semantic Web communities Falcon-S: An Ontology-Based Approach to Searching Objects and Images in the Soccer Domain. Honghan Wu, Gong Cheng, and Yuzhong Qu

KEG seminar5 Workshops 20 proposals 13 selected (9) ial/workshops.htm Our special interest in Ontology Matching Tutorials ial/tutorials.htm

KEG seminar6 Ontology Matching (1/3) Technical Papers: –Marta Sabou et al: Using the Semantic Web as Background Knowledge for Ontology Mapping –Zharko Aleksovski et al: Exploiting the Structure of Background Knowledge Used in Ontology Matching –Loredana Laera et al: Arguing Over Ontology Alignments –Christian Meilicke et al: Improving Automatically Created Mappings Using Logical Reasoning

KEG seminar7 Ontology Matching (2/3) Ontology Alignment Evaluation Initiative 2006 (OAEI) Jérôme Euzenat et al: First Results of the Ontology Alignment Evaluation Initiative 2006 Papers about systems (RiMOM, Falcon, …) Poster session: –Ondřej Šváb, Vojtěch Svátek: Combining Ontology Mapping Methods Using Bayesian Networks

KEG seminar8 Ontology Matching (3/3) Consensus building workshop –Final phase of conference track –At ISWC App. 40 minutes –Finding agreement about quite controversial mappings –Goal: feedback for involved systems, trace argumentation process (types of arguments, their order,…) –Continuation on Monday, smaller group

KEG seminar9 Keynote talk 1 Tom Gruber and RealTravel.com: Where the Social Web Meets the Semantic Web –Semantic Web and Social Web are the same Web is rather social matter –Semantic Web suitable for collective intelligence, not only collected intelligence –Ontology of Folksomony rich social tagging across applications, communities, and spaces Volunteer needed Open-source style project Contextual tagging (

KEG seminar10 Keynote talk 2 Jane Fountain: The Semantic Web and Networked Governance: Promise and Challenges –Virtual state as metaphor –Governmental issues supported by informatics (networks, information sharing, enhanced search, improved collaboration, …) –institutional perspectives on technology and governance – –

KEG seminar11 Keynote talk 3 Rudi Studer: The Semantic Web: Suppliers and Customers –Semantic Web as an interdisciplinary research –Disciplines: such as natural language processing, databases, software engineering, machine learning, knowledge representation –Semantic Web and commercial applications Existing and growing market for Corporate Semantic Web applications

KEG seminar12 Panel discussion "The Role of Semantic Web in Web 2.0: Partner or Follower?" –Web 2.0: blogs, wikis, feeds, social networking/tagging systems, also AJAX (web like a desktop application), REST –Role of SW technologies in Web 2.0? Semantics for applications

KEG seminar13 Topic areas (sections) Social Software Ontology Mapping, Merging, and Alignment Database Technologies Collaboration and Cooperation Applications of SW Technologies with Lessons Learned Machine Learning and Query Evaluation

KEG seminar14 Topic areas (sections) Rule and Ontology Languages Languages, Tools, and Methodologies for Representing and Managing Data Robust and Scalable Semantic Web Techniques Semantic Web Service Composition Knowledge Management Semantic Integration Semantic Search

KEG seminar15 Ontology Mapping, Merging, and Alignment (1/4) Antoine Zimmermann, Jérôme Euzenat: Three Semantics for Distributed Systems and their Relations with Alignment Composition –Distributed system=ontologies and alignments –Examine three different semantics of a DS –Composition operation –Simple d. s. (interpretation within the same domain), integrated d. s. (local interpretation is reconciled in a global domain using equalizing functions), contextualized d. s. (reconcilation for each pair of ontologies, they relate two local interpretation domains) –example: O1, O2, O3 with A of O1 and O2 a B of O2 a O3 – task: deduce a third alignment of O1 a O3 (composition of A and B) –Main goal: alignment composition – syntactic composition, semantic composition

KEG seminar16 Ontology Mapping, Merging, and Alignment (2/4) Wei Hu et al: Block Matching for Ontologies –A block = set of domain entitites –A block mapping = a pair of matched blocks from two ontologies –Blocks as partitioning problem –1 st phase constructing virtual documents (vectors, weights - TFIDF) –2 nd phase computation of relatedness (cosine measure in VSM) –3 rd partitioning by bisection algorithm -> dendrogram with block mappings at different levels of granularity –4 th extracting of the optimal black mappings –example: {Month, Day, Year} with {Date}

KEG seminar17 Ontology Mapping, Merging, and Alignment (3/4) Loredana Laera et al: Reaching agreement over ontology alignments –Ontologies as vocabulary for agents’ communication - > reconciliation of mismatches (reconciliation of different existing ontologies) –task: alignments agreeable for ‘both’ agents –Proposed framework: (i) a formal argument manipulation schema, (ii) agents preferences between particular kinds of arguments –Candidate mapping with a set of justifications agent with its pre-ordered of preferences and threshold (alignment rationales)

KEG seminar18 Reaching agreement over ontology alignments Various categories of arguments –Internal structure (properties of c are mapped to those of c’) –External structure (e and e’ have mapped neighbours) –Terminological (entities labels share lexical features) –Extensional (instances of e and e’ are mapped) –Semantic

KEG seminar19 Ontology Mapping, Merging, and Alignment (4/4) Vanessa Lopez et al: PowerMap: Mapping the Real Semantic Web on the Fly –Requirements for run-time mapping techniques –PowerMap algorithm Adrian Mocan et al: Formal Model for Ontology Mapping Creation –First-Order Logic as formalism for representing this model

KEG seminar20 Database Technologies Marcelo Arenas et al: Semantics and Complexity of SPARQL –Regarding complexity of SPARQL in W3C’s proposal are ambiguities, gaps and features difficult to understand –Formalization of the semantics of SPARQL Study the expressiveness and complexity Beneficial for rewriting queries, help in optimization –Focusing on the graph pattern matching facility –Optimizations based on normal forms (for graph patterns)

KEG seminar21 Rule and Ontology Languages Saartje Brockmans et al: A Model Driven Approach for Building OWL DL and OWL Full Ontologies –Support the development of ontologies using UML modeling tools (Meta-Object Facility, MOF based ontology development) –OMG standardization effort for an Ontology Definition Metamodel (ODM) – a metamodel for OWL (OWLBase Package – OWL Ontology, Class Descriptions,…; OWLDL and OWLFull Package) –Also implementation as eclipse plugin –UML profile as a extension to UML –MDA: meta-metamodel layer (M3), metamodel layer (M2), model layer (M1), and instance layer (M0)

KEG seminar22 Machine Learning and Query Evaluation Klaas Dellschaft et al: On How to Perform a Gold Standard Based Evaluation of Ontology Learning –Call for repeatable evaluation scheme –Framework for gold standard based evaluation of ontologies –New taxonomic measure for evaluation of ontology learning procedure fulfill three main criterias: multi dimensional evaluation (different kind of errors, independent measures), varying weight errors according to position of concept in hierarchy, scale interval is more even (slight error -> slight decrease of measure)

KEG seminar23 Applications of SW Technologies with Lessons Learned (1/2) Li Ding et al: Characterizing the Semantic Web on the Web ( Web aspect of the Semantic Web ) –Design a conceptual model of SW –Harvesting of Semantic Web documents on the Web –Measuring data (using model on collected dataset) Largest source websites ( age, sizewww.livejournal.com –conclusions: SW is growing steadily on the Web even when many documents are only online for a short time Most classes (>97%) have no instances and the majority of properties (>70%) have never been used Ontologies can be induced by the instantiations of ontological definition in instance space

KEG seminar24 Applications of SW Technologies with Lessons Learned (2/2) Wolfgang Holzinger et al: Using Ontologies for Extracting Product Features from Web Pages –Digital camera domain –Table ontology and meta domain ontology, reasoning about semantics of content –1 st phase table extraction: utilize visual features (visual rendition of the Web page) –2 nd phase expressing by means of table ont. –3 rd phase content spotting: keyword spotters and type spotters using domain ontology (next derive additional facts)

KEG seminar25 Languages, Tools, and Methodologies for Representing and Managing Data Michiel Hildebrand et al: /facet: A Browser for Heterogeneous Semantic Web Repositories –Browsing multiple resource types -> relatively complex queries –Real scenario portal to on-line collections of national museum (several collections from Dutch museums of paintings) –Automatic facet configuration according to underlying RDFS dataset –Also Poster as well as Semantic Web Challenge

KEG seminar26 Machine Learning and Query Evaluation Carlos Hurtado et al: A Relaxed Approach to RDF Querying –Relaxation of the query’s conditions –Not only OPTIONAL clause for querying (dropping optional triple patterns) –Moreover – replacing constants with variables or using the class and property hierarchies –Eg. relaxation: (?X,type,ConferenceArticle) -> (?X,type,Article), (?X,editorOf,?Y) -> (?X,contributorOf,?Y) –Rank results of a query

KEG seminar27 Robust and Scalable Semantic Web Techniques –Aaron Kershenbaum et al: The Summary Abox: Cutting Ontologies Down to Size Semantic Web Service Composition –Freddy Lécué et al: A formal model for semantic Web service composition

KEG seminar28 Poster session Paulo Maio et al: Building Consensus on Ontology Mapping Jingshan Huang et al: Superconcept Formation System--An Ontology Matching Algorithm for Web Applications

KEG seminar29 ISWC 2006 at hand Photos taken by participants (now 705 photos) – Videos from ISWC2006 conference –

KEG seminar30 ISWC 2007 South Korea Google trends: 1 st ontology, 1 st Semantic Web, 1 st Web 2.0