The Unified Modeling Language is a general graphical modeling language, it hasbecome the de facto industry standard for object-oriented analysis and design. UMLuses the meta-model, the object constraint language and natural language to describethe abstract syntax and semantics. The use of meta-model strictly describes theabstract syntax of UML modeling techniques which can be used for the basis semanticdescription. OCL is suitable for expressing the constraint rules, but it is not easy to beunderstood for describing the dynamic semantics and also lacks the semantics offormalization description. In the dynamic semantics, UML used the directly naturallanguage to express. So, there are some problems such as vague and inconsistent inthe UML because those three definitions come from different structures. In order tosolve these problems, scholars have put forward the formalization of UML.In this paper, the extension of the description logic is used to describe the UMLactivity diagram to improving the accuracy semantics in UML activity diagram. Thework mainly has three aspects in the following:(1) The temporal operator was extended. Temporal-upper and temporal-lower areintroduced to the temporal operator which is in temporal logic, so the temporaloperator can describe the execution of the event, and gives the form expression andlinear calculation for the extended temporal operator.(2) The time constraint of activity diagram. Given the edges and nodes of theactivity diagram with time constraints, then the definition of the syntax of activitydiagrams with time constraints was proposed, and the concept of interval of timeconstraints was introduced, the range of application on activity diagram wasexpanded.(3) Formalization. The extended temporal operator was introduced into thedescription logic to get the temporal description logic, and the semantics and syntaxpart of temporal description logic was defined, the semantics of temporal descriptionlogic in the extended activity diagram and UML activity diagram were given. On thebasis of this semantics, transformation rules were given from the activity diagramsand the extended activity diagram to the temporal description logic. Last, exampleswere used to validate. |