GAMA Metadata Scheme only supports a subset of OWL Lite and can be characterised as follows: <ul> <li>no inheritance is supported for classes nor for properties</li> <li>regular entities such as Person are subclasses of Entity</li> <li>classes used as enumerations are subclasses of Enumeration</li> <li>model contains definition of classes and properties + some instances of enumerations</li> <li>exactly one domain and one range must be defined for a property</li> <li>owl:DatatypeProperty is supported</li> <li>owl:SymmetricProperty is supported (inferencing)</li> <li>properties marked as owl:SymmetricProperty + owl:TransitiveProperty express "equivalence" (inferencing)</li> <li>supported datatypes: xsd:anyURI, xsd:string, xsd:date, xsd:time, xsd:integer, xsd:boolean <li>roles such as "author" or "curator" can be expressed by special "intersection" class or by multiple properties. In order to achieve better efficiency, we suggest to use multiple properties such as work.has_author.Person instead of: Work.related_role.Role.in_the_role.Person + Role.role_type.RoleType.</li> <li>owl:InverseFunctionalProperty and owl:FunctionalProperty are not fully implemented but can be used.</li> </ul> <hr/><div>Schema defined in the OWL file:</div> <a href="gama-schema-overview.png"><img src='gama-schema-overview.png' style="width:650;margin:30px" alt="GAMA Metadata Schema Overview"/></a> <br/> <hr/><div>Schema generated directly from the current repository:</div> <a href="http://research.ciant.cz/gama/GamaRepository/endpoint/visualize.php"><img src='http://research.ciant.cz/gama/GamaRepository/endpoint/visualize.php' style="width:650" alt="GAMA Metadata Schema Overview"/></a> <br/> The core element of the GAMA Metadata Schema is the Work class. Works represent abstract notion of artworks, events or other resources which may exist in various physical manifestations. (see Manifestation class) Work Since GAMA intends to provide access to several databases that use diverse terminology, having a unified thesaurus is crucial. The Term class in GAMA Metadata Schema, however, does not provide full-featured thesaurus. It is merely a list of keywords or terms. Term Divides works into categories using a hierarchy of work types Type of work Superclass for all real classes of GAMA Metadata Schema. No further inheritance is supported. Our repository only support flat structure of classes and properties. Person Represents persons, institutions or collectives depending on their membership. Collectives are members of itself. Archive Archive represents content provier's database. Actual metadata will be transferred from archives to central GAMA repository. Collection of works Collection class provides mechanism for grouping Works. List of languages as defined by ISO 639-1 http://en.wikipedia.org/wiki/List_of_ISO_639-1_codes Language TODO: Should languages also comprise accents? Manifestations may be stored on different media types. Type of media Physical representation of work (artwork, event or other resource). This includes files of any kind, physical objects such as DVD or CD media. Actual usage of properties depends on particular MediaType. Manifestation of work Superclass of all classes which act in GAMA as enumerations. An enumeration is a class which has fixed set of predefined instances. Dissimilar values from content providers' archives will be mapped to this common enumerations in order to express equivalent information. List of countries as defined by ISO 3166-1 Alpha2 http://www.iso.org/iso/country_codes/iso_3166_code_lists Country This is just an example of reification Connects the Work instance with an appropriate WorkType Thumbnail image URI to the image representing photo of a person or logo of an institution. Textual description of the collection Collection description Seizure detection in video files: detection of (epileptic) seizure causing content is needed to comply to web safety standards. The goal is that in the user interface content that puts epileptic viewers at risk is flagged as such. <p/>Also see: <a href="http://code.google.com/p/gama-gateway/issues/detail?id=33">Issue 33</a> and <a href="http://www.w3.org/TR/UNDERSTANDING-WCAG20/seizure.html">W3C on seizures</a> Also see http://code.google.com/p/gama-gateway/issues/detail?id=23 Archive Name At least one name should be defined for every archive. Can also be translated to different languages. Portal will select main manif, which has flag idx_main=TRUE. In this schema it is guaranteed that that a work will have a manifestation with flag idx_main=TRUE <a href="http://code.google.com/p/gama-gateway/issues/detail?id=23">Also see</a> Work rights Textual description of various rights such as copyright, distributon or documentation right Should the manifestation be highlighted in the frontend Highlighted Manifestation Name of the person composed of firstname, surname and other possible names in arbitrary order depending on particular archive. We suggest to follow this pattern: [surname, middlename, firstname] This property uses fulltext + btree indexes. Name At least one person_name should be available for every Person instance. Represents the URL where more information about the particular work can be found. It should be possible to use the URL directly in a web-browser. Free text describing technical data of the object. Could be filled from the output of ffmpeg. Reference to the DRM framework. Image URL URL of an image representation of the work (thumbnail) Keywords produced by the ASR (Automatic Speech Recognition) and OCR (Optical Character Recognition) component for a given manifestation. Also see http://code.google.com/p/gama-gateway/issues/detail?id=23 Interval of creation When the work has been created. This could also be expressed as time interval eg: 2007-01-01 .. 2008-10-23 Contains a URL pointing to the homepage of an archive Archive Homepage This flag indicated what kind of stream is available for a given manifestation. What is also needed for the frontend is a query like "count all works from work set X that have not any manifestation where idx_stream_avail = 1 || idx_stream_avail 2" to exclude works without any streams to show in the fronend (current checkbox in frontend "show only preview" should be renamed probably) <ul> <li>1 = preview stream available</li> <li>2 = full stream available</li> </ul> If the property is missing for a given manifestation there is no stream available. <a href="http://code.google.com/p/gama-gateway/issues/detail?id=23">Also see our issue tracker</a> Should the manifestation be displayed in the frontend Displayed Manifestation Represents interval between date of birth and death. Person's date of birth and death Also see http://code.google.com/p/gama-gateway/issues/detail?id=23 Collection title The written history of a person's life. Biography URL of thumbnail image representing the manifestation Defines the processing progress of the manifestation. <p/> Various values represent various processing states: <ul> <li>0/not present = manifestation which should not be processed</li> <li>1 = this manifestation should be processed by the indexing engine</li> <li>2 = processing started</li> <li>3 = processing ended successfully</li> <li>4 = processing ended with error</li> </ul> Manifestation processing progress TODO: What is this attribute good for ? For instance ISBN:xxxxxxx Link to person's homepage or webpage of an institution. Webpage At least one work_title should be available for every Work instance. Work titles can be translated to various languages. Work title Length of the manifestation. - Number of page in case of book manifestation - Length in seconds in case of audio-visual manifestation. We define the hierarchy of work types using this property. This is just symmetric relation between two manifestations.