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71.
本文应用Galerkin方法和Leray-Schauder不动点原理,建立了一类IMAq方程的第二初边值问题解的存在唯一性。 相似文献
72.
73.
In this paper, we develop a compositional denotational semantics for prioritized real-time distributed programming languages.
One of the interesting features is that it extends the existing compositional theory proposed by Koymanset al (1988) for prioritized real-time languages preserving the compositionality of the semantics. The language permits users to
define situations in which an action has priority over another action without the requirement of preassigning priorities to
actions for partially ordering the alphabet of actions. These features are part of the languages such as Ada designed specifically
keeping in view the needs of real-time embedded systems. Further, the approach does not have the restriction of other approaches
such as prioritized internal moves can pre-empt unprioritized actions etc. Our notion of priority in the environment is based
on the intuition that a low priority action can proceed only if the high priority action cannot proceed due to lack of the
handshaking partner at that point of execution. In other words, if some action is possible corresponding to that environment
at some point of execution then the action takes place without unnecessary waiting. The proposed semantic theory provides
a clear distinction between the semantic model and the execution model — this has enabled us to fully ensure that there is
no unnecessary waiting. 相似文献
74.
Sorin G. Nastea Ophir Frieder Tarek El-Ghazawi 《Journal of Parallel and Distributed Computing》1997,46(2):93
We considered the load-balanced multiplication of a large sparse matrix with a large sequence of vectors on parallel computers. We propose a method that combines fast load-balancing with efficient message-passing techniques to alleviate computational and inter-node communications challenges. The performance of the proposed method was evaluated on benchmark as well as on synthetically generated matrices and compared with the current work. It is shown that, by using our approach, a tangible improvement over prior work can be obtained, particularly for very sparse and skewed matrices. Moreover, it is also shown that I/O overhead for this problem can be efficiently amortized through I/O latency hiding and overall load-balancing. 相似文献
75.
针对如何合理制定隧道建设引起的路面沉降控制基准的难题,以行车舒适性控制标准为出发点,同时考虑既有公路的不平整度和隧道建设引起的路面沉降槽形态特征,基于理论推导提出了一个较完整的解决方案. 首先,选择行车竖直方向上振动加速度为舒适性指标;其次,采用理想正弦函数加以刻画公路路面纵断面曲线,通过求导得到行车竖直方向振动加速度与既有公路的纵断面曲线特征参数的关系;再次,用Peck公式描述隧道建设引起的路面沉降槽形态特征,通过求导得到行车竖直方向上振动加速度与沉降槽形态参数的关系;然后,根据叠加原理可得到行车最大竖直方向上振动加速度的计算公式,该公式考虑了既有公路的不平整度和隧道建设引起的路面沉降的影响;最后,基于加速度值与人体主观感觉的关系,提出了路面沉降控制基准确定公式. 结果表明:行车舒适性与既有公路纵断面曲线的波长成正比,与振幅成反比;行车舒适性与路面沉降槽宽度系数成正比,与隧道中心线处路面最大沉降值成反比;行车舒适性与行车速度的平方成反比例. 通过适当降低行车速度是放宽沉降控制基准的有效方法. 相似文献
76.
The present research introduces a new mechanism by which emotion can affect evaluation. On the basis of the self-validation hypothesis (R. E. Petty, P. Bri?ol, & Z. L. Tormala, see record 2002-12575-003), the authors predicted and found that emotion can influence evaluative judgments by affecting the confidence people have in their thoughts to a persuasive message. In each study, participants first read a strong or weak persuasive communication. After listing their thoughts about the message, participants were induced to feel happy or sad. Relative to sad participants, those put in a happy state reported more thought confidence. As a consequence, the effect of argument quality on attitudes was greater for happy than for sad participants. These self-validation effects generalized across different emotion inductions, different persuasion topics, and different measures of thought confidence. In one study, happy and sad conditions each differed from a neutral affect control. Most important, these metacognitive effects of emotion only occurred under high elaboration conditions. In contrast, individuals with relatively low motivation to think showed a main effect of emotion on attitudes, regardless of argument quality. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
77.
Stuart C. Shapiro 《Minds and Machines》1995,5(4):517-524
Computationalism, the notion that cognition is computation, is a working hypothesis of many AI researchers and Cognitive Scientists. Although it has not been proved, neither has it been disproved. In this paper, I give some refutations to some well-known alleged refutations of computationalism. My arguments have two themes: people are more limited than is often recognized in these debates; computer systems are more complicated than is often recognized in these debates. To underline the latter point, I sketch the design and abilities of a possible embodied computer system. 相似文献
78.
“Words lie in our way” 总被引:1,自引:1,他引:0
Bruce J. MacLennan 《Minds and Machines》1994,4(4):421-437
The central claim of computationalism is generally taken to be that the brain is a computer, and that any computer implementing the appropriate program would ipso facto have a mind. In this paper I argue for the following propositions: (1) The central claim of computationalism is not about computers, a concept too imprecise for a scientific claim of this sort, but is about physical calculi (instantiated discrete formal systems). (2) In matters of formality, interpretability, and so forth, analog computation and digital computation are not essentially different, and so arguments such as Searle's hold or not as well for one as for the other. (3) Whether or not a biological system (such as the brain) is computational is a scientific matter of fact. (4) A substantive scientific question for cognitive science is whether cognition is better modeled by discrete representations or by continuous representations. (5) Cognitive science and AI need a theoretical construct that is the continuous analog of a calculus. The discussion of these propositions will illuminate several terminology traps, in which it's all too easy to become ensnared. 相似文献
79.
分布并行系统的并行程序设计环境 总被引:1,自引:0,他引:1
分布式并行计算机系统中,由于没有共享内存以支持处理机间的数据交换,因而需采用messagepassing的方式实现并行计算中处理机间的数据通讯,并行程序设计环境作为程序员使用并行计算机系统工具,对于并行处理技术以及并行计算机系统的发展与推广应用都有重要的作用,本文将分布基于messagepassing的并行计算机系统中的并行程序设计环境的基本问题,并介绍几种典型的并行程序设计环境。 相似文献
80.
异种语言编写的程序相互调用,是程序设计者为利用已有软件资源而经常涉及的实用技巧,本文基于C应用程序调用VAX/RGL图形库绘图的实践,探讨VAX/VMS环境中C语言与FORTRAN语言的接口方法,其关键在于弥补两者采用的VAX过程调用参数机构上的差异。然后介绍笔者利用该方法为RGL实现的一个C程序接口软件。 相似文献