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{{Plugin| Name=Oyster| DeveloperName1=Raul Palma| LastUpdated=27.03.2008| HomepageURL=| Application=NeOn Toolkit| Topic1=Ontology Registry| License=GPL| Affiliation1=UPM| Supported ontology language1=OWL| Affiliation2=AIFB| Description=Ontology Registry}} <div style="float:left;"> = Functional Description = Oyster is a distributed registry that exploits semantic web techniques in order to provide a solution for exchanging and re-using ontologies and related entities. As an ''ontology registry'' , it provides services for storage, cataloging, discovery, management, and retrieval of ontology (and related entities) metadata definitions. To achieve these goals, Oyster implements the proposal for metadata standard OMV ( as the way to describe ontologies and related entities, supporting advanced semantic searches of the registered objects. Oyster offers a user driven approach where each peer has its own local registry of ontology metadata and also has access to the information of others registries, thus creating a virtual decentralized ontology metadata registry. The goal is a decentralized knowledge sharing environment using Semantic Web technologies that allows developers to easily share ontologies. The Oyster system (freely available under ) was designed using a service-oriented approach, and it provides a well defined API. Accessing the registry functionalities can be done using directly the API within any application, invoking the web service provided or using the included java-based GUI as a client for the distributed registry. In Oyster, ontologies are used extensively in order to provide its main functions (register metadata, formulating queries, routing queries and processing answers): * ''Creating and importing metadata:'' Oyster2 enables users to create metadata about ontologies manually, as well as to import ontology files and to automatically extract the ontology metadata available, letting the user to fill in missing values. The ontology metadata entries are aligned and formally represented according to two ontologies: (1) the OMV ontology, (2) a topic hierarchy (i.e. the DMOZ topic hierarchy), which describes specific categories of subjects to define the domain of the ontology. * ''Formulating queries:'' A user can search for ontologies using simple keyword searches, or using more advanced, semantic searches. Here, queries are formulated in terms of these two ontologies. This means queries can refer to fields like name, acronym, ontology language, etc. or queries may refer to specific topic terms. * ''Routing queries:'' A user may query a single specific peer (e.g. their own computer, because they can have many ontologies stored locally and finding the right one for a specific task can be time consuming, or users may want to query another peer in particular because this peer is a known big provider of information), or a specific set of peers (e.g. all the member of a specific organization), or the entire network of peers (e.g. when the user has no idea where to search), in which case queries are routed automatically in the network. * ''Processing results:'' Finally, results matching a query are presented in a result list. The answer of a query might be very large, and contain many duplicates due to the distributed nature and potentially large size of the P2P network. Such duplicates might not be exactly copies because the semi structured nature of the metadata, so the ontologies are used again to measure the semantic similarity between different answers and to remove apparent duplicates. = User Documentation = ===Oyster Import Wizard=== As we explained above, Oyster is a distributed registry where each node in the Oyster network has its own local registry. Currently to start the local node, we need to start a KAON2 server instance outside the NeOn toolkit (see section ''how to use it''), but in the future the local node will start within the NeOn toolkit. Oyster Import Wizard release (Oyster2ImportWizard_vx.xx) contains: * ** Contains the NeOn Plugin * ** Contains the necessary files for Oyster ***new Store (configuration file) ***O2ServerFiles (directory) ****Contains all the necessary files: ontology files, logo, etc. ***Oyster2 (directory) ****Contains kaon2.jar and run.bat ===How to install it=== *Extract (e.g. c:\Oyster2APIvx.xx) Note: The default is c:\Oyster2APIvx.xx. *Copy file "new store" to the working directory of the NeOn Tookit (e.g. where neontoolkit.exe is located) *Set the name of your peer i.e. in file "new store" change property "localPeerName" which has by default the value "myLocalPeer" *Execute run.bat to start a KAON2 instance. *Extract into NeOn_Toolkit folder. It will copy the jars files into the plugin subdirectory To change the location of the files required files, you can edit the new store configuration file and the run.bat For additional information please refer to ===How to use it=== The current version of the import wizard uses the Oyster API. The following figures show how the import wizard works. * Launch the import wizard [[Image:use1.jpg]] * Specify the conditions (i.e. OMV properties) that should be fulfilled by the ontologies we are searching [[Image:use2.jpg]] * Select an ontology from the result list [[Image:use3.jpg]] * Select the NeOn project in which will be imported the selected ontology. Note that the selected entry is the OMV metadata (not the ontology itself). However to import the ontology into the workspace we use the resourceLocator information that is the location where the actual ontology can be found [[Image:use4.jpg]] </div>