The TMO (Time-triggered, Message-triggered object) structuring scheme has the goal of improving productivity in the design of complex real-time computer systems (RTCSs). The TMO scheme facilitates a new paradigm in de...
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The TMO (Time-triggered, Message-triggered object) structuring scheme has the goal of improving productivity in the design of complex real-time computer systems (RTCSs). The TMO scheme facilitates a new paradigm in designing RTCSs called the GG (General-form, timeliness-Guaranteed) design paradigm. Its essence is to realize real-time computing with a common and general design style, not alienating the mainstream computing industry and yet allowing system engineers to confidently produce certifiable RTCSs for safety-critical applications. The TMO structuring scheme is a syntactically simple but semantically major extension of the conventional object structuring approaches, and its support tools can be based on various well-established object-oriented programming languages and on ubiquitous commercial real-time operating system kernels. The scheme enables a reduction of the designer's efforts in guaranteeing timely service capabilities of information systems. We discuss the major features of the TMO structuring approach for real-time computer systems and its potential for use in the telecommunication application domain. Some of the major computing requirements that are imposed by a large class of telecommunication applications are identified and then we discuss on how well the TMO approach can satisfy these requirements. As an illustration, we also present the top-down design of a simple, yet concrete multi-party video conferencing application using the TMO structuring scheme. Finally, the major benefits of the TMO structuring scheme in the design of complex RTCSs are discussed.
This paper is based on the experiences of developing the Bridge system as an integrated metadata management system for statistical offices. Investigating metadata systems in different European statistical offices it t...
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This paper is based on the experiences of developing the Bridge system as an integrated metadata management system for statistical offices. Investigating metadata systems in different European statistical offices it turned out that metadata is required from within several processes and for quite different purposes. In many cases metadata is purpose related, i.e. metadata is located in different places and quite often in a redundant way. Moreover, problems arise in handling different versions of metadata and providing metadata for different languages. Bridge has been developed as an integrated metadata system (IMS) to overcome such problems as redundancy, different user interfaces and others caused by heterogeneous metadata environments. How an IMS like Bridge is able to integrate distributed metadata systems and the possibilities to solve problems of different versions for metadata as well as multilingual support for document objects is shown in this paper.
Existing computer systems and user-interface command languages for application in computational mechanics have been so far mostly developed by applying traditional, non-OO techniques. As a consequence, they are often ...
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Existing computer systems and user-interface command languages for application in computational mechanics have been so far mostly developed by applying traditional, non-OO techniques. As a consequence, they are often hampered by severe limitations in code extensibility, reusability, robustness and correctness and require excessive programming efforts in development, testing and maintenance. In order to overcome these difficulties, newly designed systems should take advantage of OO concepts and tools at all levels, including the code user interface. We present a practical experience in this direction - applying OO concepts and tools in the design and prototype implementation of a new language specifically for computational mechanics applications. It is concluded, that the OO techniques and tools applied in this research provide software developers with the technology to rapidly produce sophisticated languages without being overly concerned with the underlying intricacies of their construction.
The proceedings contains 23 papers on the technology of object-orientedlanguages and systemstools 25. Topics discussed include: objectoriented development based on polymorphism patterns and optimization to reduce e...
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The proceedings contains 23 papers on the technology of object-orientedlanguages and systemstools 25. Topics discussed include: objectoriented development based on polymorphism patterns and optimization to reduce executable code sizes;design patterns in garbage collection;direct-manipulation editors;patterns for finding object within designs;multithreading;automatic generation of bridging code for assessing C++ from Java;animating formal specifications;class-based models;interactive analysis of object architectures;object modeling;multidimensional objects;attribute types and bracket implementations;and objectoriented business models.
Issues relevant to the steering mechanism for object-oriented scientific computations are examined in this paper. The concept of computation steering is delineated, and its benefits are discussed based on past experie...
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Issues relevant to the steering mechanism for object-oriented scientific computations are examined in this paper. The concept of computation steering is delineated, and its benefits are discussed based on past experiences with its application to scientific computations. Experiences of using an object-oriented scripting language called Python to steer C++ applications are presented in further details. It is found that Python and C++ can be combined in an elegant way which combines the benefits of steering and the advantages of using an efficient object-oriented language for scientific modeling.
In this paper a more formal approach to objectoriented information modeling [8] is proposed. The five basic associations (dependency, reference, composition, subtyping and symmetric relationship) are defined mathemat...
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In this paper a more formal approach to objectoriented information modeling [8] is proposed. The five basic associations (dependency, reference, composition, subtyping and symmetric relationship) are defined mathematically, but may still be used in a graphical notation in a user-friendly way. In this way, it is possible to obtain an information model with a strict mathematical meaning without additional effort.
object-oriented programming techniques support construction of reusable and extensible code. However, class-based languages have poor support for implementing type-orthogonal behavior and extending non-leaf classes, w...
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object-oriented programming techniques support construction of reusable and extensible code. However, class-based languages have poor support for implementing type-orthogonal behavior and extending non-leaf classes, which results in implementations with poor performance or limited functionality. This paper presents dynamic slots, a mechanism for extending objects at run-time. We show how this mechanism can be used to build efficient implementations of type-orthogonal abstractions. Dynamic slots are statically typed and have been integrated into the BETA programming language. Measurements of a persistent store show that they significantly improve performance.
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