Trustworthy Semantic WebsOutlineToday’s WebFrom Today’s Web to the Semantic WebLayered Approach: Tim Berners Lee’s Vision www.w3c.orgApplications: Web ServicesKnowledge ManagementBusiness to Consumer E-CommerceBusiness to Business E-CommercePersonal AgentsSemantic Web TechnologiesExplicit metadataOntologiesOntology Engineering?LogicOverview of Web ServicesService Oriented Architectures (SOA)Web ServicesWeb Services Description LanguageUDDISOAPWDSL with XMLSecuritySlide 24Security: Examples XACML, SAML, WSSOASISFederated IdentityTrustworthy Semantic WebsDr. Bhavani ThuraisinghamThe University of Texas at DallasLecture #3Semantic Web, Web Services and SecurityOutlineToday’s WebFrom web to semantic webApplications and TechnologiesLayered ApproachWeb Services IntroductionToday’s WebHigh recall, low precision: Too many web pages resulting in searches, many not relevantSometimes low recallResults sensitive to vocabulary: Different words even if they mean the same thing do not results in same web pagesResults are single web pages not linked web pagesFrom Today’s Web to the Semantic WebMachine understandable web pagesActivities on the web such as searching with little or no human interventionTechnologies for knowledge management, e-commerce, interoperability]Solutions to the problems faced by today’s web-Retrieving appropriate web pages, sensitive to vocabulary etc. -Semantic web applications includingLayered Approach: Tim Berners Lee’s Visionwww.w3c.orgApplications: Web ServicesWeb Services refers to the technologies that allow for making connections. Services are what you connect together using Web Services.A service is the endpoint of a connection. Also, a service has some type of underlying computer system that supports the connection offered. The combination of services - internal and external to an organization - make up a service-oriented architecture.Knowledge ManagementCorporation Need-Searching, extracting and maintaining information, uncovering hidden dependencies, viewing informationSemantic web for knowledge management-Organizing knowledge, automated tools for maintaining knowledge, question answering, querying multiple documents, controlling access to documentsBusiness to Consumer E-CommerceUsers shopping on the web; wrapper technology is used to extract information about user preferences etc. and display the products to the userUse of semantic web: Develop software agents that can interpret privacy requirements, pricing and product information and display timely and correct information to the use; also provides information about the reputation of shopsFuture: negotiation among the behalf of the userBusiness to Business E-CommerceOrganizations work together and carrying out transactions such as collaborating on a product, supply chains etc. With today’s web lack of standards for data exchangeUse of semantic web: XML is a big improvement, but need to agree on vocabulary. Future will be the use of ontologies to agree on meanings and interpretationsPersonal AgentsAgents are essentially processes that have evolved from object-oriented programming; agent is an active objectsAgents will use metadata to find resources on the web; ontologies will be used to interpret statements; logic will be used for drawing conclusionsAgents will not completely replace humans; but will make the tasks of the humans much easier.Example: John is a president of a company. He needs to have a surgery for a serious but not a critical illness. With current web he has to check each web page for relevant information, make decisions depending on the information providedWith the semantic web, the agent will retrieve all the relevant information, synthesize the information, ask John if needed, and then present the various options to John and also makes recommendationsSemantic Web TechnologiesExplicit metadata-XML, RDF, etc.Ontologies (e.g, OWL)Logic/Rules (e.g., RuleML, SWRL)Explicit metadataMetadata is data about dataNeed metadata to be explicitly specified so that different groups and organizations will know what is on the webUsing metadata, one can then carry out various activities such as searching, integration and executing actionsMetadata specification languages include XML and RDFOntologiesExplicit and formal specification of conceptualization describes a domain of discourseConsists of concepts and prelateships between themWeb searches can exploit ontologies to facilitate the search processOntology languages include XML, RDF, OWLOntology Engineering?Tools and Techniques to-Create Ontologies-Specify Ontologies-Maintain Ontologies-Query Ontologies-Evolve Ontologies-Reuse Ontologies-Incorporate features such as security, data quality, integrityLogicLogic can be used to specify facts as well as rulesNew facts and derived from existing facts based on the inference rulesDescriptive Logic is the type of logic that has been developed for semantic web applicationsExample Logic-based languages: SWRL, RuleMLSemantic web vs. Artificial Intelligence-Goal of Artificial Intelligence is to build an intelligent agent exhibiting human-level intelligence-Goal of the semantic web is to enable machine understandable web pagesOverview of Web ServicesService Oriented ArchitecturesWeb Services Description LanguageUDDISOAPWSDL with XMLSecurity OASISFederated identityService Oriented Architectures (SOA)A service-oriented architecture is essentially a collection of services. ; These services communicate with each other. A service is a function that is well-defined, self-contained, and does not depend on the context or state of other servicesThe communication can involve either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed.The technology of web services is the most likely connection technology of service-oriented architectures. Web services essentially use XML Technology create a robust connection.A service consumer sends a service request message to a service provider ; The service provider returns a response message to the service consumer. The request and subsequent response connections are defined in some way that is understandable to both the service consumer and service provider.A service provider can also be a service
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