Computational astrophysics seeks to develop numerical models which help elucidate the nature of astronomical systems. Such models must not only adequately describe the underlying physics which give rise to phenomena t...
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ISBN:
(纸本)0897913272
Computational astrophysics seeks to develop numerical models which help elucidate the nature of astronomical systems. Such models must not only adequately describe the underlying physics which give rise to phenomena that have been observed, but must also be predictive in asserting what future observations might unfold. Any model which is in conflict with physical observations, clearly, must be discarded or amended to reflect reality. As a computational modelling tool we find APL useful for testing astrophysical hypotheses, and extending the domain of our observationally based knowledge. Using APL to build, test, and expand astrophysical models frees the investigator from the mechanical drudgery of computer programming, thereby allowing the researcher to concentrate on understanding the physical *** a quantitative example of how relatively complex astrophysical phenomena can be explored with ease using APL, we have developed a structure model for white dwarf stars. The model presented here considers such effects as Coulomb interactions between electrons and nucleons, inverse beta decays, and the effects of the general theory of relativity on the condition of hydrostatic equilibrium. This structure model is valid for zero-temperature stars of varying chemical compositions, ionic partitions, and central densities; and is applicable over a wide range of partial and total degeneracy regimes.
In a natural language processing system, a large amount of ambiguity and a large branching factor are hindering factors in obtaining the desired analysis for a given sentence in a short time. In this paper, we are pro...
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In this paper, the task allocation problem has been addressed in the context of plant structure. A process plant consists of a number of active inter-connected processes. The topology of the plant has been captured us...
In this paper, the task allocation problem has been addressed in the context of plant structure. A process plant consists of a number of active inter-connected processes. The topology of the plant has been captured using a simple process model. The plant topology and other design considerations have been incorporated in a generalised 0-1 mixed integer programming format to generate an optimal design. This provides the necessary design flexibility to allocate control tasks without violating the plant redundancies and structural constraints. A control task allocation problem has been solved for a thermal power plant showing the usefulness of the method.
In summary, the ROSE system has been designed to allow efficiency to be combined with fiexibility for support of interactive computergraphics applications. The object paradigm is exploited throughout all aspects of t...
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作者：
R. BaeckerDynamic Graphics Project
Computer Systems Research Institute and Department of Computer Science University of Toronto Toronto ONT Canada
To make computer programs for comprehensible, the presentation of program source text, program documentation, and program execution needs to be enhanced. A number of techniques and tools developed to achieve these end...
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ISBN:
(纸本)0897912586
To make computer programs for comprehensible, the presentation of program source text, program documentation, and program execution needs to be enhanced. A number of techniques and tools developed to achieve these ends are described. One of these is a design for the effective presentation of source text in the C programming language using high-quality digital typography; a processor which implements the design is also given. Some experimental evidence is summarized to demonstrate that the resulting source text presentation is significantly more readable and comprehensible than the presentation conventionally used today. Brief descriptions are given of two other techniques, the development of a system of structured program documentation incorporating both text and graphics and the portrayal of program execution with colored computer animation.< >
A method is developed for the measurement of short-range visual motion in image sequences, making use of the motion of image features such as edges and points. Each feature generates a Gaussian activation profile in a...
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A method is developed for the measurement of short-range visual motion in image sequences, making use of the motion of image features such as edges and points. Each feature generates a Gaussian activation profile in a spatiotemporal neighborhood of specified scale around the feature itself; this profile is then convected with motion of the feature. The authors show that image velocity estimates can be obtained from such dynamic activation profiles using a modification of familiar gradient techniques. The resulting estimators can be formulated in terms of simple ratios of spatiotemporal filters (i.e. receptive fields) convolved with image feature maps. A family of activation profiles of varying scale must be utilized to cover a range of possible image velocities. They suggest a characteristic speed normalization of the estimate obtained from each filter in order to decide which estimate is to be accepted. They formulate the velocity estimators for dynamic edges in 1-D and 2-D image sequences, as well as that for dynamic feature points in 2-D image sequences.< >
This paper describes and evaluates the design of four virtual controllers for use in rotating three-dimensional objects using the mouse. Three of four of these controllers are "new" in that they extend tradi...
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ROSE is an experimental database system for CAD/CAM applications that organizes a database into entries and relationships. The data model of ROSE is an extension of the relational model and the data manipulation langu...
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This paper focuses on the problem of management of CAD data by investigating the use of the software engineering principles of data abstraction and object-oriented programming as means for managing the volume and comp...
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In order to make computer programs more readable, understandable, appealing, memorable, and maintainable, the presentation of program source text needs to be enhanced over its conventional treatment. Towards this end,...
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