IVOA RM, VOResources, Identifiers, InterfacesChenzhou CUIAgendaWhy Registry?IVOA Resource Metadata 1.01VOResource 0.10IVOA Identifiers 1.1IVOA Registry Interfaces 1.02Semantic WebCurrent WebResources: identified by URIs untyped Links: href, src, . limited, non-descriptive User: Exciting world - semantics of the resource, however, gleaned from content Machine: Very little information available - significance of the links only evident from the context around the anchor. Semantic WebResources: Globally Identified by URIs or Locally scoped (Blank) Extensible Relational Links: Identified by URIs Extensible Relational User: Even more exciting world, richer user experience Machine: More processable information is available (Data Web) Computers and people: Work, learn and exchange knowledge effectively Semantic Web一种能让计算机理解的新型Web内容形 式 “The Semantic Web is an extension of the current web in which information is given well -defined meaning, better enabling computers and people to work in cooperation.“ - Tim Berners-Lee, James Hendler, Ora Lassila, The Semantic Web, Scientific American, May 2001 MetadataMetadata: data for dataDublin Core MetadataThe role of Resource RegistriesUsed to discover and locate resourcesdata and servicesthat can be used in a VO applicationResource: anything that is describable and identifiable.Besides data and services: organizations, projects, software, Presently concerned with simple set of resource typesRegistry: a list of resource descriptionsExpressed as structured metadata to enable automated processing and searchingAn Overview of Data DiscoveryYou can search the main VO registries to find resources based on descriptive criteriaNVO Registries are “coarse-grained”You can find organizations, archives, catalogsWont find images, celestial objects, table records AstroGrid Registries are “fine-grained”Table columns, individual images and associated metadataRegistry framework contains multiple registries:searchable registriespublishing registriesLocal Publishing Registry Local Searchable RegistryFull Searchable RegistryLocal Publishing RegistryFull Searchable RegistryData CentersVO ProjectsSpecialized Portals & ServicesRegistry FrameworkLocal Publishing Registry Local Searchable RegistryFull Searchable RegistryLocal Publishing RegistryFull Searchable RegistryData CentersVO ProjectsSpecialized Portals & ServicesRegistry Frameworkharvest (pull)Local Publishing Registry Local Searchable RegistryFull Searchable RegistryLocal Publishing RegistryFull Searchable RegistryData CentersVO ProjectsSpecialized Portals & ServicesRegistry Frameworkharvest (pull) replicateLocal Publishing Registry Local Searchable RegistryFull Searchable RegistryLocal Publishing RegistryFull Searchable RegistryData CentersVO ProjectsSpecialized Portals & ServicesRegistry Frameworkharvest (pull) replicateselective harvestingLocal Publishing Registry Local Searchable RegistryFull Searchable RegistryLocal Publishing RegistryFull Searchable RegistryData CentersVO ProjectsSpecialized Portals & ServicesClient Applicationssearch queriesRegistry FrameworkLocal Publishing Registry Local Searchable RegistryFull Searchable RegistryLocal Publishing RegistryFull Searchable RegistryData CentersVO ProjectsSpecialized Portals & ServicesClient Applicationssearch queriesRegistry FrameworkOverview of PublishingResources are published if one can use VO facilities to find them.Multiple layers of publishingStarts with registry description of resourceData Access Services Incremental exposure for incremental effortWho are you? How you publish depends on what you want to publish.An individual with a small data collectionAn archive centerSomeone with a cool servicePersistent Archives:Tools for Federation Registering your resources with a VO publishing registryEnter description into registration form at one of the available NVO registries:STScI/JHU Registry: http:/nvo.stsci.edu/voregistry/NCSA Registration Portal: http:/nvo.ncsa.uiuc.edu/nvoregistration.htmlCaltech Carnivore: http:/mercury.cacr.caltech.edu:8080/carnivore/If you have a large number of resources to register, you can run your own registry on your own siteNCSA VORegistry-in-a-Box http:/nvo.ncsa.uiuc.edu/VO/software/Caltech Carnivore: http:/mercury.cacr.caltech.edu:8080/carnivore/What can/should you register?Should: your OrganizationDeclares yourself as a publisher with an IDShould: your CollectionCan: your existing servicesBrowser-based services: e.g. search pageTraditional CGI servicesWeb ServicesThe next level Implement and register one or more standard servicesCone SearchSimple Image AccessSkyNode*Simple Spectral Access* *standard still in developmentPersistent Archives:Tools for FederationResource Metadata: XML Schema Classes of Resources Organisation, DataCollection, Service, RegistrySpecific classes inherit from generic Organi