16.11.2006KEG seminar1 ISWC 2006 5 th International Semantic Web Conference Athens, GA, USA,...
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Transcript of 16.11.2006KEG seminar1 ISWC 2006 5 th International Semantic Web Conference Athens, GA, USA,...
16.11.2006 KEG seminar 1
ISWC 2006
5th International Semantic Web Conference
Athens, GA, USA, November 2006http://iswc2006.semanticweb.org
16.11.2006 KEG seminar 2
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)
16.11.2006 KEG seminar 3
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
16.11.2006 KEG seminar 4
Semantic Web Challenge
• http://challenge.semanticweb.org/• 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
16.11.2006 KEG seminar 5
Workshops
• 20 proposals• 13 selected (9)• http://iswc2006.semanticweb.org/
workshop_tutorial/workshops.htm• Our special interest in Ontology Matching
• Tutorials• http://iswc2006.semanticweb.org/
workshop_tutorial/tutorials.htm
16.11.2006 KEG seminar 6
Ontology Matching (1/3)
• http://om2006.ontologymatching.org/• 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
16.11.2006 KEG seminar 7
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
16.11.2006 KEG seminar 8
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
16.11.2006 KEG seminar 9
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
• www.tagcommons.org• Volunteer needed• Open-source style project• Contextual tagging (www.realtravel.com)
16.11.2006 KEG seminar 10
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
– http://www.ksg.harvard.edu/digitalcenter/– http://www.ksg.harvard.edu/netgov/html/index.htm
16.11.2006 KEG seminar 11
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
16.11.2006 KEG seminar 12
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
16.11.2006 KEG seminar 13
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
16.11.2006 KEG seminar 14
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
16.11.2006 KEG seminar 15
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
16.11.2006 KEG seminar 16
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– 1st phase constructing virtual documents (vectors,
weights - TFIDF)– 2nd phase computation of relatedness (cosine
measure in VSM)– 3rd partitioning by bisection algorithm -> dendrogram
with block mappings at different levels of granularity– 4th extracting of the optimal black mappings– example: {Month, Day, Year} with {Date}
16.11.2006 KEG seminar 17
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)
16.11.2006 KEG seminar 18
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
16.11.2006 KEG seminar 19
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
16.11.2006 KEG seminar 20
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)
16.11.2006 KEG seminar 21
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• http://www.eclipse.org/emft/projects/eodm/
– UML profile as a extension to UML
– MDA: meta-metamodel layer (M3), metamodel layer (M2), model layer (M1), and instance layer (M0)
16.11.2006 KEG seminar 22
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)
16.11.2006 KEG seminar 23
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 (www.livejournal.com), age, size
– 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
16.11.2006 KEG seminar 24
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– 1st phase table extraction: utilize visual features
(visual rendition of the Web page)– 2nd phase expressing by means of table ont.– 3rd phase content spotting: keyword spotters and type
spotters using domain ontology (next derive additional facts)
16.11.2006 KEG seminar 25
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
16.11.2006 KEG seminar 26
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
16.11.2006 KEG seminar 27
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
16.11.2006 KEG seminar 28
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
16.11.2006 KEG seminar 29
ISWC 2006 at hand
• Photos taken by participants (now 705 photos)– http://www.flickr.com/groups/iswc/pool/
• Videos from ISWC2006 conference – http://seminars.ijs.si/iswc2006/