The Semantic Web- It's not just for searching anymore!.ppt

1、19 June 2008,GBC/ACM Monthly Meeting,1,The Semantic Web: Its not just for searching anymore!,Ken Baclawski Northeastern University Vistology,19 June 2008,GBC/ACM Monthly Meeting,2,The Semantic Web and the wide variety of emerging applications,Introduction to the Semantic Web General classification a

2、nd recognition of opportunities Interoperability and integration Web Services and composite applications Records management Examples of projects and applications Project Halo Collaboration tools Cognitive radio Policy awareness Behavioral health Epidemiology and disease tracking Recent developments,

3、19 June 2008,GBC/ACM Monthly Meeting,3,The Semantic Web,The World Wide Web is a versatile infrastructure for basic data availability. The main emphasis was on human-mediated interactions via web browsers but new uses are rapidly increasing. These new uses can benefit from semantic technologies.,19 J

4、une 2008,GBC/ACM Monthly Meeting,4,The Resource Description Framework,RDF is a language for representing information about resources in the web. While RDF is expressed in XML, it has different semantics. The document-centric semantics of XML is replaced by a semantics based on triples: (subject, pre

5、dicate, object). RDF decouples information from the containing document.,19 June 2008,GBC/ACM Monthly Meeting,5,RDF Semantics,All relationships are explicit and labeled with a property resource. The distinction in XML between attribute and containment is dropped, but the containment relationship mus

6、t be labeled on a separate level. This is called striping.,19 June 2008,GBC/ACM Monthly Meeting,6,Element Hierarchy,XML Element Hierarchy,19 June 2008,GBC/ACM Monthly Meeting,7,19 June 2008,GBC/ACM Monthly Meeting,8,m1,carbon monoxide,Molecule,c1,o1,Atom,C,O,Bond,atom,atom,rdf:type,rdf:type,rdf:type

7、,title,rdf:type,bond,rdfs:subClassOf,rdfs:subClassOf,atomRef,atomRef,RDF graph for carbon monoxide,19 June 2008,GBC/ACM Monthly Meeting,9,The Web Ontology Language,OWL is based on RDF and has three increasingly general levels: OWL Lite, OWL-DL, and OWL Full. OWL adds many new features to RDF: Functi

8、onal properties Inverse functional properties (database keys) Local domain and range constraints General cardinality constraints Inverse properties Symmetric and transitive properties,19 June 2008,GBC/ACM Monthly Meeting,10,Class Constructors,OWL classes can be constructed from other classes in a va

9、riety of ways: Intersection (Boolean AND) Union (Boolean OR) Complement (Boolean NOT) Restriction Class construction is the basis for description logic.,19 June 2008,GBC/ACM Monthly Meeting,11,OWL Semantics,An OWL ontology defines a theory of the world. States of the world that are consistent with t

10、he theory are called interpretations of the theory. A fact that is true in every interpretation is said to be entailed by the theory. Logical inference in OWL is defined by entailment. Entailment can be counter-intuitive, especially when it entails that two resources are the same.,19 June 2008,GBC/A

11、CM Monthly Meeting,12,Identifying opportunities,Domain knowledge Technical background Community organization Identify urgent needs Understand the trends Short-term evolution Possible paradigm shifts Semantic technology is only one part of any solution but it can be an important enabler.,19 June 2008

12、,GBC/ACM Monthly Meeting,13,Search and retrieval,Data is typically stored in either record/data structures or natural language. Need is to search and retrieve both kinds of data for a single query. There are several trends. More semantics Integration with other services Semantic technologies are mor

13、e than just a fancy search and retrieval mechanism.,19 June 2008,GBC/ACM Monthly Meeting,14,Interoperability of legacy systems,Legacy systems and databases are characterized by: A large variety of formats High degree of complexity Many technologies of various ages Need to interoperate and integrate

14、Trend is toward encoding more semantics in the data representation itself. Opportunity to develop products and services for interoperability and integration.,19 June 2008,GBC/ACM Monthly Meeting,15,Web services and composite applications,The web is being used not only for retrieval of data but also

15、for using tools and services. The need is to find the required services, and to get them to communicate with each other. The trend is to use semantic annotation to describe/advertise services, to express requests, and to represent the responses, but the level of semantic annotation is very uneven. T

16、he opportunity is to built agile workflow management tools that can deal with the differing levels of semantic annotation.,19 June 2008,GBC/ACM Monthly Meeting,16,Simple Semantic Web Architecture and Protocol (SSWAP),SSWAP is a protocol for semantic web services. See http:/sswap.info Unlike other pr

17、otocols, SSWAP uses a single format and protocol for description, registration, discovery and invocation. SSWAP was developed using OWL as its basis, and OWL inference is fundamental to its operation.,19 June 2008,GBC/ACM Monthly Meeting,17,Records management,Solving an electronic record problem wil

18、l add little to the existing paper-based records if the systems are not interoperable. Simply automating paper-based processes has relatively little impact on productivity. Gains in efficiency and improved customer relationships require a change in the overall process of service delivery.,19 June 20

19、08,GBC/ACM Monthly Meeting,18,Records Opportunity,Develop event ontologies that: Support interoperability Are independent of workflows and processes Are compatible with existing processes Develop products that: Assist organizations to evolve toward electronic data management Serve the interests of m

20、any stakeholders,19 June 2008,GBC/ACM Monthly Meeting,19,Halo Program at Vulcan,Knowledge Representation in Practice: Project Halo and the Semantic Web by Mark Greaves The vision: a scalable knowledge representation and reasoning system Gets better with increasing scale Embraces uncertain and incomp

21、lete information The system: scientific question-answering,19 June 2008,GBC/ACM Monthly Meeting,20,Halo Pilot,Pilot project was on AP Chemistry. Typical question: “What are the reaction products if metallic copper is heated strongly with concentrated sulfuric acid?” Answer: Cu2+, SO2(g), and H2O Sho

22、uld also be able to explain the answer.,19 June 2008,GBC/ACM Monthly Meeting,21,Halo Pilot,SRI, Ontoprise and Cycorp competed. The challenge achieved an AP level 3 on 70 pages of the Chemistry AP syllabus. Cost: $10K per page Most errors were due to lack of domain expertise by the ontology developer

23、s.,19 June 2008,GBC/ACM Monthly Meeting,22,Halo Phase II,Knowledge acquisition performed by subject matter experts (not computer scientists) Expanded to cover Physics and Biology Cost: $100 per page Achieved the same AP level. http:/,19 June 2008,GBC/ACM Monthly Meeting,23,Halo Project today,Goal is

24、 to achieve an AP level 4. Scale up the knowledge acquisition Offshoring in India Large scale collaborative ontology development Semantic Wikis Ultimate goal is a Digital Aristotle Semantically enabled collaboration is an important new emphasis.,19 June 2008,GBC/ACM Monthly Meeting,24,Collaboration

25、tools,People need to collaborate to solve problems. The need is to support rapid team formation and problem solving even when the people are geographically dispersed. The trend is to use wikis and blogs rather than face-to-face meetings. The challenge is to develop tools that facilitate collaboratio

26、n over the web without losing the advantages of face-to-face meetings.,19 June 2008,GBC/ACM Monthly Meeting,25,Wikis,Wikis are a popular tool for collaboration. They have been used for rapid team formation and collaboration. They have a number of disadvantages: Mix of natural language and untyped li

27、nks. Focus is on simplicity and presentation, not structure and semantics.,19 June 2008,GBC/ACM Monthly Meeting,26,Semantic Wikis,A wiki with an underlying knowledge model (ontology) is a semantic wiki. Data in the wiki is annotated with meta-data in RDF or OWL. Links are typed and annotated, also i

28、n RDF or OWL. Machines can infer new facts from the explicitly asserted facts. Search and retrieval are facilitated by the semantics. Interoperability is greatly improved.,19 June 2008,GBC/ACM Monthly Meeting,27,Semantic Media Wiki,Media Wiki is the technology of Wikipedia and related web sites. Sem

29、antic Media Wiki is a large ($100M+) EU project based in Karlsruhe. The Halo project provided the Halo extension. Fine grained access will soon be available via the PMWX project.,19 June 2008,GBC/ACM Monthly Meeting,28,Cognitive Radios,Capabilities of a cognitive radio: information collection and fu

30、sion; self-awareness; awareness of constraints and requirements; query by user, self or other radio; command execution; dynamic interoperability at any stack layer; situation awareness and advise; negotiation for resources.,19 June 2008,GBC/ACM Monthly Meeting,29,Definition of a cognitive system,can

31、 reason, using substantial amounts of appropriately represented knowledge can learn from its experience so that it performs better tomorrow than it did today can explain itself and be told what to do can be aware of its own capabilities and reflect on its own behavior can respond robustly to surpris

32、e,19 June 2008,GBC/ACM Monthly Meeting,30,Multiple levels of communication,19 June 2008,GBC/ACM Monthly Meeting,31,Physical Layer Ontology,19 June 2008,GBC/ACM Monthly Meeting,32,Some Data Link layer hierarchies,19 June 2008,GBC/ACM Monthly Meeting,33,Data Link WiFi Frame Hierarchy,19 June 2008,GBC/

33、ACM Monthly Meeting,34,Role of Semantic Technology in Cognitive Radio,Interoperability Flexible querying and Run-time modifiability Programming language reflection allows the algorithm to be queried at run time without having any explicit pre-programmed monitoring capability. Validation Formalizatio

34、n allows one to check the consistency of protocols. Self-awareness Communication nodes can understand their own structure and modify their functioning at run-time based on this understanding. Policy management.,19 June 2008,GBC/ACM Monthly Meeting,35,Policy Awareness,An important trend that is drivi

35、ng cognitive radio is the need for radios for flexible use of spectrum However, any use of the spectrum must conform to legal policies. Policies are expressed as rules. Ontologies make it possible to specify regulations for wireless communications, including complex, dynamic policies for spectrum ma

36、nagement.,19 June 2008,GBC/ACM Monthly Meeting,36,Decision Analysis,Important part of policy and development processes. Formal annotation of decisions and their analyses can have many benefits. Integration with the process Recognition of need to reconsider when circumstances evolve Decisions can be

37、delayed Decisions can be reused for other situations An annotated decision is called a rationale,19 June 2008,GBC/ACM Monthly Meeting,37,Rationale Ontology,Rationale,Artifact,Choice,Decision Analysis,Informal Discussion,Influence Diagram,Decision Tree,Decision Table,analysis,issue,Evidence,evidence*

38、,criterion*,decision,alternative*,isa,isa,isa,isa,isa,isa,19 June 2008,GBC/ACM Monthly Meeting,38,Policy Decision Example,Investment Level in Brain Health Intervention Techniques,Ageism,Fertility Rate,Age of Population,Ethical Concerns,Standard of Living,Brain Health Level,Brain Health Policy Ration

39、ale,criterion,alternative,analysis,Census data,evidence,Brain Health Issue,issue,affects,19 June 2008,GBC/ACM Monthly Meeting,39,References,M. Kokar, K. Baclawski and D. Brady. Uses of Ontologies for Cognitive Radios. In Spectrum Efficiency and Cognitive Radio Technology, Bruce, A., Fette (Ed). Newn

40、es. (August, 2006) V. Duggar and K. Baclawski. Integration of Decision Analysis in Process Life-Cycle Models. In International Workshop on Living with Uncertainties. (November 5, 2007),19 June 2008,GBC/ACM Monthly Meeting,40,Behavioral Health,Medical ontologies have resulted in advances in standardi

41、zation, information sharing and automation not previously possible in medicine In contrast, the development of ontologies for behavioral medicine is decades behind. Ontologies for behavioral health have the potential for important advances Facilitating the growth of the discipline itself More rapid

42、development of automated systems for effecting health behavior change Improving scalability, tailorability and adaptability,19 June 2008,GBC/ACM Monthly Meeting,41,19 June 2008,GBC/ACM Monthly Meeting,42,System Architecture,19 June 2008,GBC/ACM Monthly Meeting,43,Concepts in the ontologies,19 June 2

43、008,GBC/ACM Monthly Meeting,44,Conversational Planning,19 June 2008,GBC/ACM Monthly Meeting,45,Disease Knowledge Using Biological Taxonomy, and Environmental Ontologies,Collaboration with Neil Sarkar of the Marine Biological Laboratory Biomedical knowledge relevant to the study of infectious disease

44、s is currently in a variety of heterogeneous data sources Citation databases Health reports Molecular databases Understanding infectious diseases requires Environmental and geo-location Biodiversity and biomedical resources,19 June 2008,GBC/ACM Monthly Meeting,46,Disease Knowledge Sources,Research L

45、iterature Citation Indexes Medline of the US National Library of Medicine Agricola of the US National Agricultural Library Health Reports Global Outbreak Alert and Response Network (GOARN) of the World Health Organization Program for Monitoring Emerging Diseases (ProMED) of the International Society

46、 for Infectious Diseases,19 June 2008,GBC/ACM Monthly Meeting,47,Biodiversity Sources,Biodiversity Heritage Library Global Biodiversity Information Facility (GBIF) hosted by the University of Copenhagen Encyclopedia of Life Many others,19 June 2008,GBC/ACM Monthly Meeting,48,Some Background Ontologi

47、es,NCBI Taxonomy of the US National Center for Biotechnology Information Alpha taxonomy associated with molecular data (GenBank) Environmental ontology (EnvO) Emerging Open Biomedical Ontology (OBO) of biological habitats Geo-location instance hierarchy (Gaz) Emerging OBO instance hierarchy of geo-l

48、ocations,19 June 2008,GBC/ACM Monthly Meeting,49,Geographic distribution of hantavirus disease outbreaks (boxes) and genetic samples (helices),Geographic distribution of biodiversity information for the two most common US deer mouse species,Example of integration of disease knowledge, genetic inform

49、ation, biodiversity information and geographical information,19 June 2008,GBC/ACM Monthly Meeting,50,Recent Developments,RDF storage provided by database vendors Oracle has both a product and an active Database Semantic Technologies Group Many RDF stores are layered on a general purpose RDBMS: Jena,

50、 Sesame, RDQL, Non-relational RDF storage products Siderean, Tucana, OWLIM, Allegro Graph, ,19 June 2008,GBC/ACM Monthly Meeting,51,Open Ontology Repository (OOR),Recent initiative of the Ontolog Forum The purpose of the initiative is to promote the global use and sharing of ontologies by: 1. establishing a hosted registry-repository; 2. enabling and facilitating open, federated, collaborative ontology repositories; 3. establishing best practices for expressing interoperable ontology and taxonomy work in registry-repositories.,