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61.
62.
The exploitation of the salient features of capability-based addressing environments leads to a high number of small objects existing in memory at the same time. It is thus necessary to enhance the efficiency of the mechanisms for object relocation, and to avoid congestion of input/output devices due to swapping. In this paper, we present an approach to the management of a large virtual memory space aimed at solving these problems. We insert partial information concerning the physical allocation of each object into the virtual identifier of this object. Objects are grouped into large swapping units, called pages. The page size is independent of the average object size. This results in enhanced efficiency in managing the relocation information both with regard to memory requirements and access times. The allocation of objects into pages, and the movement of pages through the memory hierarchy, are controlled by user processes. This means that programs which have knowledge of their own use of virtual memory can increase their locality of reference, diminish the number of swap operations and reduce fragmentation. 相似文献
63.
通过简化臣姿持枪射击系统,利用拉格朗日方程,建立了该射击系统的物理模型和数学模型,并通过数值模拟,论述了缓冲簧对系统动态特性的影响,最后通过实验,对无缓冲簧射击系统的动态特性参数进行验证。 相似文献
64.
介绍了用电导法测定乙酸解离常数的实验原理和步骤,给出了用计算机对电导法测定乙酸解离常数的实验数据进行处理的软件设计方法,同时给出了用Visual FoxPro 6.0编写电导法测定乙酸解离常数的处理软件的基本结构和部分程序代码。 相似文献
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66.
P2P系统在构建覆盖网络时未考虑到与物理网络的结合,导致逻辑拓扑结构与物理拓扑结构严重不匹配问题,增加P2P相邻节点间的延迟。本文提出一种基于区域划分的超级节点选取机制,将P2P网络中的节点按照物理位置划分成若干区域,保证区域内节点在物理位置上是相近的。利用MATLAB进行仿真实验,仿真实验表明使用这种机制能降低半分布式P2P网络的信息检索延迟,有效地提高检索的效率,并且具有较好的可扩展性。 相似文献
67.
The paper suggests a new methodology for secure cyber–physical systems design. The proposed methodology consists of two main cycles. The main goal of the first cycle is in design of the system model, while the second one is about development of the system prototype. The key idea of the methodology is in providing of the most rational solutions that are improving the security of cyber–physical systems. Such solutions are called alternatives and built according to functional requirements and non-functional limitations to the system. Each cycle of the methodology consists of the verification process and seven stages that are associated with the used cyber–physical system model. The objective of the verification process is in checking of constructed models and prototypes in terms of their correctness and compatibility. The model represents cyber–physical systems as sets of building blocks with network between them, takes elements internal structure into account and allows direct and reverse transformations. The novelty of the suggested methodology is in the combination of design, development and verification techniques within a single approach. To provide an example of the design methodology application, in this paper it is used to improve the semi-natural model of the railway infrastructure. 相似文献
68.
Cyber–physical systems are becoming increasingly complex. In these advanced systems, the different engineering domains involved in the design process become more and more intertwined. Therefore, a traditional (sequential) design process becomes inefficient in finding good design options. Instead, an integrated approach is needed where parameters in multiple different engineering domains can be chosen, evaluated, and optimized to achieve a good overall solution. However, in such an approach, the combined design space becomes vast. As such, methods are needed to mitigate this problem.In this paper, we show a method for systematically capturing and updating domain knowledge in the context of a co-design process involving different engineering domains, i.e. control and embedded. We rely on ontologies to reason about the relationships between parameters in the different domains. This allows us to derive a stepwise design space exploration workflow where this domain knowledge is used to quickly reduce the design space to a subset of likely good candidates. We illustrate our approach by applying it to the design space exploration process for an advanced electric motor control system and its deployment on embedded hardware. 相似文献
69.
70.
季晨 《安徽冶金科技职业学院学报》2021,31(1):56-58
将信息化教学应用于职业院校的体育教学中,可丰富教学素材、培养学生的学习兴趣、帮助教师更好地了解学生。从课程结构设置不合理、教师信息技术知识缺乏等方面分析信息化背景下职业院校体育教学困境的基础上,从利用信息技术进行有效指导、利用信息化教学进行有效放松、利用信息技术了解教学的实际效果、构建体育信息化教学环境、提升职业院校体育教师的信息化处理能力等方面提出相应的解决对策。 相似文献