Graphical user interfaces are becoming the de facto standard for all kinds of applications on computers that range from IBM-PC compatibles to super workstations. Graphical user interfaces are. however, notoriously dif...
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Graphical user interfaces are becoming the de facto standard for all kinds of applications on computers that range from IBM-PC compatibles to super workstations. Graphical user interfaces are. however, notoriously difficult to create. In this paper we review the changing expectations of computer users which are a direct result of developments in computer graphics. The support for these changing requirements that are provided by the current standards are discussed and finally the development of object-oriented programming and its relationship to graphical user interfaces are presented. The conclusions discuss the potential benefits that the new programming methodology provides for the development of future interfaces for CACSD systems.
The object model has emerged as a useful paradigm for the structuring of distributed systems. This paper gives a brief survey of some current issues in the design and implementation of distributed systems based on the...
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ISBN:
(纸本)0444817913
The object model has emerged as a useful paradigm for the structuring of distributed systems. This paper gives a brief survey of some current issues in the design and implementation of distributed systems based on the object model. The experience gained from the design, implementation, and use of Guide, a distributed object-oriented system for co-operative applications, developed at Bull-IMAG, is presented as an illustration. Some perspectives are discussed in conclusion.
Many engineering disciplines use graphical notations with defined semantic meaning, such as Petri nets, or structure charts. The diagrams drawn in these notations represent semantic models upon which application-speci...
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ISBN:
(纸本)0444814965
Many engineering disciplines use graphical notations with defined semantic meaning, such as Petri nets, or structure charts. The diagrams drawn in these notations represent semantic models upon which application-specific operations may be performed. To handle this type of notations and their semantic models comfortably, a graphical editor can support them. As there are many different graphical notations in every discipline, reuse of general editor functionality should be supported and encouraged to save tool building effort. vis-A-vis is an object-oriented framework serving this purpose. However, instead of laying the burden of properly composing those classes on the tool builder's shoulders, vis-A-vis also contains a backbone architecture. In this paper we motivate the construction of vis-A-vis by listing the essential requirements that we had set out for a framework supporting in tool building. The scope of vis-A-vis based tools is defined, and a shea survey of the main concepts of vis-A-vis is given. An example of a System Dynamics graphical notation editor which was built within vis-A-vis illustrates these concepts and shows how little effort a tool builder has to spend to implement an editor.
The aim of the paper is to present an integrated preventive maintenance system, used to assist the engineer in the supervision of machines without shutting them down. In the IPMAS system, a module deals with the autom...
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ISBN:
(纸本)0444814841
The aim of the paper is to present an integrated preventive maintenance system, used to assist the engineer in the supervision of machines without shutting them down. In the IPMAS system, a module deals with the automatic acquisition of real measurements and the transfer of these to a knowledge based system. This computerized maintenance system allows the modeling of the machines' working states. The acquisition module allows the analysis of phenomenon, coming from real measurements. Thereby IPMAS is able to analyse a large scale of disturbances in a realistic environement. To obtain this system, we have defined a methodology based on an extension of Failure Modes, Effects and Criticality Analysis (FMECA) that has been called Preventive Maintenance FMECA (PM FMECA). This methodology directly provides the concepts used to build the knowledge base of the maintenance system. This approach is helpful to build and to structure this knowledge base. This rigourous and exhaustive methodology was used to build the generic system IPMAS. This one is consecrated to the resolution of preventive maintenance problems and could be applied to a large scale of machines,
This paper describes the approach to application specification and design via reuse at the basis of the Development Information System of the ITHACA environment. Requirements and detailed design of a specific applicat...
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ISBN:
(纸本)0444815945
This paper describes the approach to application specification and design via reuse at the basis of the Development Information System of the ITHACA environment. Requirements and detailed design of a specific application are incrementally composed by aggregating available reusable components stored in the Software Information Base repository. The paper reviews the Development information System, then focuses on two tools of the system: RECAST (Requirements Composition And Specification Tool) and Visual ADL, which help the developer in selecting reusable artifacts from the Software Base and in composing and tailoring them according to the specific needs of the application. The paper illustrates the composition approach and describes how reuse is supported via meta classes incorporating suggestions for component reuse and tailoring, and for detailed design.
Remote access techniques devised for distributed file systems are not directly applicable to the construction of distributed persistent object stores because of the differences between the two systems. This paper eval...
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ISBN:
(纸本)0444817913
Remote access techniques devised for distributed file systems are not directly applicable to the construction of distributed persistent object stores because of the differences between the two systems. This paper evaluates a number of remote access techniques that have been implemented in the Choices distributed persistent object store and their impact on performance. Unlike conventional distributed file systems, the object-oriented nature of the Choices persistent store supports user-defined types and permits remote access mechanisms and policies that are customized to reduce access overhead. The most appropriate technique for a particular persistent object depends on the behavior of the object and its relationship to other objects that are accessed. The remote access mechanism and policies supported by the Choices distributed persistent store system are specified by the designer of the store and user's may select the most appropriate schemes for an object based on their knowledge of its behavior. The mechanisms and policies include remote access, caching, and concurrency control.
One side effect of the proliferation of relational databases within a single organization is that sharing of data to access a global information base is difficult. People erroneously assume that since almost all of th...
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One side effect of the proliferation of relational databases within a single organization is that sharing of data to access a global information base is difficult. People erroneously assume that since almost all of the commercially available RDBMSs support the Structured Query Language (SQL), sharing of data is easy. Unfortunately, currently available systems only support a specific dialect of SQL. The Amadeus front-end system overcomes the data-sharing problem. With the Amadeus front-end system, database users can use one common language called Dataflow Query Language (DFQL) to access heterogeneous RDBMSs. A query specified in DFQL is correctly translated into a SQL dialect that the connected RDBMS recognizes. With this front-end approach, the user can access data from multiple databases by writing a single DFQL query, instead of writing multiple SQL queries. A prototype query builder is reimplemented using an object-oriented design. This component of Amadeus interacts with the user for creating DFQL queries. Adding a connection to a new SQL-based RDBMS requires minimum modification to the code, due to the object-oriented implementation of the query builder. This object-oriented implementation allows the smooth integration of the additional features of the query editor into the older version of Amadeus.
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