Task graphs have been used for the specification and analysis of real time systems for some time. We are currently developing a mobile code management system that uses such a representation for specification, analysis...
详细信息
Task graphs have been used for the specification and analysis of real time systems for some time. We are currently developing a mobile code management system that uses such a representation for specification, analysis, and execution time scheduling, dispatch, and resource allocation decisions. We describe our three level limited hierarchical task graph model. We discuss graph topology, the use of task graphs for both specification and description, and planned software engineering tools that will take advantage of our model. We concentrate on the use of task graphs to model iteration, branching structures, optional execution, and parallelism within a function execution.
Description logics are formalisms designed for a logical reconstruction of representation tools such as frames, objectoriented and semantic data models, semantic networks, type systems, and feature logics. Nowadays, ...
详细信息
Description logics are formalisms designed for a logical reconstruction of representation tools such as frames, objectoriented and semantic data models, semantic networks, type systems, and feature logics. Nowadays, description logics are also considered the most important unifying formalism for the many object centred representation languages used in areas other than knowledge representation. Important characteristics of description logics are high expressivity, together with decidability, which guarantee that reasoning algorithms always terminate with the correct answers. The article introduces temporal extensions of description logics, through the detailed analysis of a case study, involving the combination of a rather expressive description logic with the basic tense modal logic over a linear, unbounded, and discrete temporal structure. ALCQIT is the temporal description logic considered as the case study. This language is obtained by combining a standard tense logic and the non temporal description logic ALCQI with axioms. We first introduce the non temporal part of the language, and then we present its combination with the tense logic. Finally, we briefly report on how other approaches in extending description logics with time relate to the case study.
This paper describes an object-oriented application framework RADIUS, which facilitates automatic Application Delivery, Installation and Upgrade (ADIU). By extending the object-oriented programming paradigm to the doc...
详细信息
ISBN:
(纸本)0769500536
This paper describes an object-oriented application framework RADIUS, which facilitates automatic Application Delivery, Installation and Upgrade (ADIU). By extending the object-oriented programming paradigm to the document and file level, application files can be located and delivered through a mechanism similar to dynamic dispatch in most OOP languages and systems. RADIUS is designed to be document-centric. All necessary information is stored with the documents and assigned at the application developers' end and thus requires no user intervention of any kind in locating, installing and upgrading applications. RADIUS is light weight and requires,no extensions to the programming (languages and operating systems, and therefore is easy to integrate with other object or component systems.
There are a number of programmable macro systems such as Lisp's. While they can handle complex program transformation, they still have difficulty in handling some kinds of transformation typical in object-oriented...
详细信息
ISBN:
(纸本)0769500536
There are a number of programmable macro systems such as Lisp's. While they can handle complex program transformation, they still have difficulty in handling some kinds of transformation typical in object-oriented programming. This paper examines this problem and to address it, presents an advanced macro system based on ideas borrowed from reflection, Unlike other macro systems, our macro system provides metaobjects as the data structure used for the macro processing instead of an abstract syntax tree. This feature makes it easy to implement a range of transformations of object-oriented programs.
Relationships in object-oriented models are evaluated based on a formal, metamodelling approach. Various types of association and of aggregation are discussed in detail as well as other relationships such as possessio...
详细信息
ISBN:
(纸本)0818684852
Relationships in object-oriented models are evaluated based on a formal, metamodelling approach. Various types of association and of aggregation are discussed in detail as well as other relationships such as possession, containment and roles. Finally, recommendations on both semantics and notation are made for a modelling language such as OML.
Over the last two decades there has been an increase in the number of distributed objectorientedsystems being developed. To assist the development of these systems a number of objectoriented modelling techniques ha...
详细信息
ISBN:
(纸本)0769500536
Over the last two decades there has been an increase in the number of distributed objectorientedsystems being developed. To assist the development of these systems a number of objectoriented modelling techniques have been developed. The Unified Modeling Language was principally designed to combine a number of methodologies into one. As this paper identifies, there are a number of limitations which exist between the mapping of UML designs into IDL. One solution has been to introduce additional keywords into IDLs to provide richer semantics. This paper demonstrates how semantics can be added to interfaces without extending interface definition languages and hence provide software developers with a mechanism to express the dynamic constraints of a distributed objectorientedsystems.
Many object-orientedsystems provide composite objects to represent and manipulate objects having a complex structure. But only few systems provide adapted means to capture the behavior of composite Nonetheless, manag...
详细信息
ISBN:
(纸本)081868383X
Many object-orientedsystems provide composite objects to represent and manipulate objects having a complex structure. But only few systems provide adapted means to capture the behavior of composite Nonetheless, managing the global behavior of composite objects as a complicated task which encompasses several aspects: the collaboration. of the behavior of the composite object with that of its component, the management of its semantic integrity and the evolution of its behavior. Based on this taxonomy, a model is proposed for the specification, the representation and the management of the global behavior of composite objects.
暂无评论