This Page goes even deeper into the semantic Rabbit Hole to explain some of the Decisions made in the Spoc-Web Implementation. We try to avoid confusing Details and to convey the broad and important Ideas without sacrificing too much Accuracy. We hope not to violate Correctness though. Please feed back any Errors You find in these Documents.
One of the Goals for the semantic Web is for the Computer to "understand" the Data in the World Wide Web. Among others this means, the Computer can
The Calculus for these Operations is called First-Order- or Predicate-Logic. The Algorithms for this are an intense Research Topic since the first Artificial Intelligence Wave in the early 1980s. Unfortunately their Runtime Performance is often very low and there is a Risk of non terminating Processes. Additionally the näive Handling of Rules and Proposition can allow to construct inconsistent or contradictionary Systems.
Since then Research has identified several Levels of Languages together with their associated Inference Engines/ Algorithms with reasonable Performance. Also, as Experience shows, the predicted Worst Case Runtimes are rarely encountered. Thus the current Reasoning Engines become useful for a growing Number of Applications.
The Distinction between these Languages usually too detailed for the Purposes of Spoc-Web, therefore several closely overlapping Concepts between these Languages, together with their URIs have been merged into unique Conceps in Spoc-Web.
The Logic Languages in this Sections are ordered by "Inferential and Expressive Power". Usually this Power also increases the Complexity and decreases Performance.
Spoc-Web is designed to share Data between Databases. This requires a common Language that is established by fundamental RDF Classes and Relations defined by the W3C in the Namespaces rdf, rdfs and owl.
While the W3C uses URIs to denote Things, Spoc-Web uses integer Numbers for Speed and Compactness. To facilitate Integration, most of the fundamental Classes have fixed IDs below 1000. This allows Applications to hard-code them into their Code. These Definitions are included in the initial Database You downloaded together with the Spoc-Web Application.
Among these are:
These are some of the important Namespaces defined in Spoc-Web. You can also directly inspect them in Spoc-Web itself, e.g. by entering their ID into the Search Dialog.
|330||rdf||http://www.w3.org/1999/02/22-rdf-syntax-ns#||RDF Core Definitions like Resource, Class|
|332||xsd||http://www.w3.org/2001/XMLSchema#||XML Value Types like string, float, int etc.|
|334||foaf||http://xmlns.com/foaf/0.1/||Friend of a Friend Classes, an early and widespread RDF Language used to describe Relations among People|
|335||dc||http://purl.org/dc/elements/1.1/||Dublin Core Classes, defined by Librarians to describe Books and Documents in the World wide Web|
|337||dbp||http://dbpedia.org/||DBPedia Core Namespace, heavily used in Wikipedia|
|338||dbpprop||http://dbpedia.org/property/||DBPedia Property Definitions|
|362||yago||http://dbpedia.org/class/yago/||A unified Ontology, merged from WordNet and DbPedia|
short for Upper Mapping and Binding Exchange Layer, is a strict subset of OpenCyc, providing the Cyc data in an RDF ontology. Because it is subset of OpenCyc concepts and relationships, mappings to UMBEL can take advantage of the reasoning engines within Cyc.
|365||dbpedia-owl||http://dbpedia.org/ontology/||The DBpedia Ontology is a shallow, cross-domain ontology, which has been manually created based on the most commonly used infoboxes within Wikipedia.|
|505||swap||http://www.w3.org/2000/10/swap/||"Semantic Web Application Platform", some of the first Definitions for the Semantic Web by the W3C|
|367||cyc||http://sw.cyc.com/concept/||Cycorp "Cyc" Namespace, a first Generation AI (Artificial Intelligence) Project mostly financed by the USA DARPA (Defense advanced Research Project Agency).|
|323||rdfs||Resource||These two Classes have been merged into a single Spoc-Web Class called "Resource~Things", because their Distinction is too narrow for general Purposes.|