Features of object-oriented databases (OODBs) that are important for computer-aided softwareengineering (CASE) are identified. the questions of whether OODBs can provide adequate performance for CASE, what adequate p...
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ISBN:
(纸本)0818619155
Features of object-oriented databases (OODBs) that are important for computer-aided softwareengineering (CASE) are identified. the questions of whether OODBs can provide adequate performance for CASE, what adequate performance is, and what would be a good performance metric for CASE on OODBs are examined. Among the other issues considered are: whether there is a preferred OODB data model for CASE applications;whether it is preferable to categorize OODBs as supporting an external object-oriented model or as providing orthogonal persistence to an existing language;and what functionality OODBs provide that relational DBs do not (and vice versa).
the database analyzer and predictor (DBAP) is a CASE (computer-aided softwareengineering) tool supporting design and tuning of IDMS (integrated data-management system) DB/DC applications. It is an interactive system,...
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ISBN:
(纸本)0818619155
the database analyzer and predictor (DBAP) is a CASE (computer-aided softwareengineering) tool supporting design and tuning of IDMS (integrated data-management system) DB/DC applications. It is an interactive system, completely integrated withthe IDMS online environment and providing the database designer with a comprehensive set of performance analysis models evaluating principal aspects of the database system performance. Close coupling of the workload analysis models withthe computer system model provides a means for predicting the response-time behavior of the modeled database system. the performance-oriented database methodology, supported by a menu-driven user interface, guides the users through the database design, as well as existing database system tuning and capacity-planning projects.
Methods are discussed to enhance the efficiency and speed of data compression techniques in DBMS (database management systems). Arithmetic coding utilizes the skewness of character distribution by assigning larger int...
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ISBN:
(纸本)0818619155
Methods are discussed to enhance the efficiency and speed of data compression techniques in DBMS (database management systems). Arithmetic coding utilizes the skewness of character distribution by assigning larger intervals (code ranges) to characters having higher probabilities of occurrence. A scheme is presented which effectively increases the code ranges of individual characters by splitting the interval assignment into different groups. this decreases the rate of interval narrowing and hence improves the compression efficiency. Hardware assistance for arithmetic and tree-based coding is also discussed and high-speed VLSI algorithms for data compression are presented. the proposed algorithms give rates that are an order of magnitude faster than currently attainable encoding speeds.
An expert system for nuclear engineering allows the engineer to find good configurations to refuel reactor cores, and enables the researcher to discover new refueling configuration synthesis heuristics far more easily...
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Experimentation with several methods of providing efficient communication facilities for distributed database systems is described. these studies give insight into the delays incurred by applications running on distri...
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ISBN:
(纸本)0818619155
Experimentation with several methods of providing efficient communication facilities for distributed database systems is described. these studies give insight into the delays incurred by applications running on distributed systems. Five different mechanisms for local interprocess communication (two variations with message queues, named pipes, shared memory, and UDP sockets) have been implemented, compared, and analyzed. the most efficient of these is three times as fast as UDP for 1000-byte messages. Kernel-level software multicast and hardware multicast have also been implemented and their performance analyzed. the results show the significant advantage of using these techniques instead of using multiple sends and receives at the user level. the design of a facility that allows the dynamic addition of user-level protocols such as two-phase commit, clock synchronization, etc. to an operating system kernel is presented. the facility is based on a simple stack-based language that provides the functionality and security required.
Maximum likelihood soft decision decoding of block and lattice codes has recently gained renewed interest. this is partially due to the major role of block and lattice codes in block-coded modulation techniques for ba...
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this paper introduces the architecture and initial algorithms for Pixel-Planes 5, a heterogeneous multi-computer designed both for high-speed polygon and sphere rendering (1M Phong-shaded triangles/ second) and for su...
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ISBN:
(纸本)0897913124
this paper introduces the architecture and initial algorithms for Pixel-Planes 5, a heterogeneous multi-computer designed both for high-speed polygon and sphere rendering (1M Phong-shaded triangles/ second) and for supporting algorithm and application research in interactive 3D graphics. Techniques are described for volume rendering at multiple frames per second, font generation directly from conic spline descriptions, and rapid calculation of radiosity form-factors. the hardware consists of up to 32 mathoriented processors, up to 16 rendering units, and a conventional 1280 × 1024-pixel frame buffer, interconnected by a 5 gigabit ring network. Each rendering unit consists of a 128 × 128-pixel array of processors-with-memory with parallel quadratic expression evaluation for every pixel. Implemented on 1.6 micron CMOS chips designed to run at 40MHz, this array has 208 bits/pixel on-chip and is connected to a video RAM memory system that provides 4,096 bits of off-chip memory. Rendering units can be independently reassigned to any part of the screen or to non-screen-oriented computation. As of April 1989, both hardware and software are still under construction, with initial system operation scheduled for fall 1989.
We consider a network of communicating software tasks in a distributed system. Over the period of interest they are permanent concurrent entities, statically allocated to processors. Tasks communicate by messages sent...
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STOCAL-II (computer Assisted Learning of STOchastic methods) is an instructional software for teaching random vibrations and applied stochastic processes. It is based on and is an extension of the well-known determini...
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ISBN:
(纸本)0872626598
STOCAL-II (computer Assisted Learning of STOchastic methods) is an instructional software for teaching random vibrations and applied stochastic processes. It is based on and is an extension of the well-known deterministic instructional software, CAL, which has facilities for matrix operations and for static and dynamic structural analysis, including static condensation and eigenvalue solution. STOCAL-II works both interactively and in batch mode, and has on-line graphics capability. It consists of more than 30 commands for stochastic analysis (in addition to the CAL commands), which are in four groups: (1) generation and estimation of random variables and processes, (2) frequency-time domain transformation, (3) stationary and nonstationary response of linear systems, and (4) statistics of extremes of stationary random processes. the commands are structured so as to enhance the instructional aspects of the operations rather than their efficiency. the software works on IBM-PC/XT or AT microcomptuers.
Initial work during the last ten years for defining and prototyping software Development Management systems has prepared the ground for presenting the concepts for the year 2000 DMS. DMS product evolution, features, &...
ISBN:
(纸本)0897912608
Initial work during the last ten years for defining and prototyping software Development Management systems has prepared the ground for presenting the concepts for the year 2000 DMS. DMS product evolution, features, 'approach, concepts and philosophy', future year 2000 concepts and current DMS prototype implementation are discussed. Finally, an offspring of the DMS project, EduSET: Educational softwareengineering Tool, is outlined.
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