To meet the demanding needs of nuclear power plant supervision, TRASYS 1 in close collaboration with TEE (TRACTEBEL Energy Engineering) have developed a new generation of computer systems, known as DIMOS. A first inst...
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To meet the demanding needs of nuclear power plant supervision, TRASYS 1 in close collaboration with TEE (TRACTEBEL Energy Engineering) have developed a new generation of computer systems, known as DIMOS. A first installation of DIMOS (involving 150.000 lines of ADA code for the application software) was completed in August 1991 at the nuclear power plant at Doel (Belgiím) and since this time has been ensuring the supervision of the production units 1 and 2. Apart from ADA 2 , including ADA tasking and messages passing, the major technological challenge was the choice of a distributed configuration including 15 computers around a double Ethernet LAN 3 , running either VAX/VMS 4 or VAXELN 5 . The design is post-partioned thus ensuring that the code is independant of the distribution. The structured analysis of the user requirements was performed using the YOURDON methodology. The general and detailed design were implemented under the strict application of the Hierarchical Object Oriented Design (HOOD 6 ) methodology. DIMOS was designed using a HOOO case tool from which the ADA code is generated.
An Express - based Information Management System is presented as a kernel for integration of distributed heterogeneous systems in CIM. Concepts and instances shared by the integrated CIM components as well as administ...
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An Express - based Information Management System is presented as a kernel for integration of distributed heterogeneous systems in CIM. Concepts and instances shared by the integrated CIM components as well as administrative met-information is included in the Information System architecture. A discussion of the experimental results, weaknesses and benefits of our current implementation and limitations of the Express language is made in the framework of a prototype developed in the Esprit Project CIM-PLATO
We consider iterative algorithms of the form x:=f(x), executed by a parallel or distributed computing system. We first consider synchronous executions of such iterations and study their communication requirements, as ...
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We consider iterative algorithms of the form x:=f(x), executed by a parallel or distributed computing system. We first consider synchronous executions of such iterations and study their communication requirements, as well as issues related to processor synchronization. We also discuss the parallelization of iterations of the Gauss-Seidel type. We then consider asynchronous implementations whereby each processor iterates on a different component of x, at its own pace, using the most recently received (but possibly outdated) information on the remaining components of x. While certain algorithms may fail to converge when implemented asynchronously, a large number of positive convergence results is available. We classify asynchronous algorithms into three main categories, depending on the amount of asynchronism they can tolerate, and survey the corresponding convergence results. We also discuss issues related to their termination.
The Systolic Hypertension in the Elderly Program (SHEP) Pilot was a collaborative clinical trial that distributed to the clinics all dataprocessing tasks except for randomization assignment codes and morbidity and mo...
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The Systolic Hypertension in the Elderly Program (SHEP) Pilot was a collaborative clinical trial that distributed to the clinics all dataprocessing tasks except for randomization assignment codes and morbidity and mortality data. The clinics used customized programs to enter and verify data interactively, to maintain their own local master files, and to transmit the data electronically to the Coordinating Center. We measured quality control based on criteria from centralized as well as distributed models: the error rate for baseline forms was 0.5 per 1000 items. Ninety-eight percent of the forms were query-free, and a central reentry of the data in a 5% sample yielded a miskey rate of 2 per 1000 items. The potential problems of distributed data processing are vulnerability of the local master files and the time demands on Coordinating Center programmers for maintaining clinic computer systems. The advantages are the active involvement of clinical staff in their own quality control, the functional accessibility of the clinics to the Coordinating Center in controlling protocol decisions and data monitoring, and the level of accuracy, completeness, and timeliness of the data that can be achieved.
The computer systems developed during the 1960s and 1970s made very little impact on management decision. Management Information System design was constrained by three factors — the technology was large‐scale and in...
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The computer systems developed during the 1960s and 1970s made very little impact on management decision. Management Information System design was constrained by three factors — the technology was large‐scale and inevitably centralised and controlled by dataprocessing staff; the systems were designed by specialist staff who rarely understood the business requirements; and managers themselves had little knowledge or “hands‐on” experience of computers. In the 1980s a greater awareness of the need for planning and better use of personnel information, coupled with the development of distributedprocessing systems, has presented personnel management with opportunities to use computing technology as a means of increasing the professionalism of practising personnel managers. Effective use will only occur if the implementation of technology is matched by appraisal of skills and organisation within personnel departments. Staff will need a minimum level of computing expertise and some managers will need skills in modelling, particularly financial modelling. The relationship between personnel and dataprocessing needs careful redefining to build a link between the two and dataprocessing staff need to design and communicate an end‐user strategy.
For the control of measurements as well as for taking over and pre-processing of the measurement data the NMR-spectrometer BS 487 C/TESLA has been connected on-line with an AMCA 80-microcomputer. This experimental equ...
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For the control of measurements as well as for taking over and pre-processing of the measurement data the NMR-spectrometer BS 487 C/TESLA has been connected on-line with an AMCA 80-microcomputer. This experimental equipment has been integrated in the local computer network ATLAS. For the data transmission and the computer coupling the CAMAC-system has been used. The storage and time intensive programmes for the spectra evaluations are-running in the EG-1040 computer. The data transfer is controlled by the help of a two-party, cooperative communication type protocol. The data acquisition and processing work in dialogue are running under real-time conditions.
Rapid prototyping of software and hardware is recognized as a very important step in timely, cost-effective system development. The complexity inherent in designing distributed computing systems and distributed proble...
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Rapid prototyping of software and hardware is recognized as a very important step in timely, cost-effective system development. The complexity inherent in designing distributed computing systems and distributed problem solutions emphasizes the need for effective rapid prototyping tools. ADL/ADS is a testbed user interface tool for experimentation with critical research and design issues pertaining to distributed data processing (DDP). The experimenter expresses a candidate distributed system in terms of “experiment objects”, along with attributes and relationships. The experiment objects represent hardware, software, and “behavior”. This paper provides a brief overview of ADL/ADS, and gives especial emphasis to the Behavior Prototyping Language (BPL) within ADL/ADS. BPL is designed for expressing Behavior Modules (B_MODULEs)—the most versatile of the behavior objects. BPL incorporates set-theoretical approaches, and provides syntax designed for effectively describing manipulations of experiment objects, and their attributes and relationships.
The success of videotex in 1984 is measured in terms of its contribution to cost effective and productive distributed data processing. Videotex systems are installed in over 200 sites in the UK and contribute signific...
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The success of videotex in 1984 is measured in terms of its contribution to cost effective and productive distributed data processing. Videotex systems are installed in over 200 sites in the UK and contribute significantly to the commercial success of a wide variety of organizations. In this article, the authors provide a set of commonsense rules, based on experience, for dataprocessing managers and others investigating the implementation of open systems in the corporate environment and beyond.
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