Research And Implementation Of Layout Algorithm For Ontology Graphical Modeling Based On OWL

With the ontology research in-depth, a variety of ontology modeling tools has emerged.You can easily build complex Ontology, some can import and export ontology files, andgraphical display the ontology. However, the graphical ontology model is usually contains alarge number of nodes and complex relationship lines, with graphical way to show the entireontology model is difficult to achieve a good effect. So at present a lot of ontology buildingtools only display the part of ontology elements, such as class, instance, other major elementsand the relationships among them. This kind of display mode can clearly show main structureof the ontology, but it limits the people to control the global ontology, which makes peoplehard to accurate understanding of the internal structure of ontology and deeper informationmining to the ontology. Therefore, This paper aims to study the suitable layout algorithms forontology models to make graphical ontology models can be global display and can clear showthe relationship between each element. The layout must have a good readability andconvenient for people to understand the ontology and deeper mining ontology information.This layout algorithm needs to achieve the following goals:1)A clear hierarchicalrelationships, the relationships between the nodes can be show;2)Make the number of edgecrossing as little as possible, and improve consistency of the edges;3)Make the number ofcross between edges and nodes as little as possible;4)The nodes cannot overlap;5)The areashould be as small as possible.In order to achieve the above algorithm goal, this paper first analyses the owl language,summarize the owl element characteristics, and illustrate the owl graphical modeling method.Then it analyses the present general layout algorithms in detail, and summarize its advantagesand disadvantages. Then three layout algorithms will be researched and realized: A geneticalgorithm based on simulated annealing, an improved radiation type layout algorithm and ahierarchical layout algorithm. Finally, this paper analyses and compares experimental resultsof the three kinds of layout algorithms, summarize the advantages and disadvantages of eachalgorithm and its applicable scope.