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71.
开放式数控系统域建模研究 总被引:1,自引:0,他引:1
域工程是解决系统抽象设计的有效手段,本文从这个角度,探讨了开放式数控体系结构的建模方法并对轴控制为例为加以体阐述。 相似文献
72.
The paper provides the results of preliminary research on the application of evolutionary computation to integrated structural
design in which a complex design support tool automatically conducts both conceptual and detailed design. In the paper, a
brief overview of the state of the art in evolutionary computation and its applications to structural design is provided.
Next, Inventor 2000 is described, a unique research and structural design tool developed by the authors at George Mason University that combines
an evolutionary computation component with a system for wind forces analysis, and a system for the analysis, design and optimisation
of steel structures. The paper also presents the results of four structural design experiments conducted with Inventor 2000.
The objective of experiments was to investigate various forms of evolutionary computation as applied to structure design.
Finally, the paper provides the initial research conclusions and recommendations for further research. 相似文献
73.
本文对开放式系统的安全域进行了讨论,对安全域之间的关系进行了阐述,针对安全域模型,结合安全域的多级安全的特点,对安全域模型进行了研究。对于开放分布式系统的多级安全域的特点,提出采用自治Agent来实现的多域安全框架。 相似文献
74.
Authentication and authorization in many distributed systems rely on the use of cryptographic credentials that in most of
the cases have a defined lifetime. This feature mandates the use of mechanisms able to determine whether a particular credential
can be trusted at a given moment. This process is commonly named validation. Among available validation mechanisms, the Online Certificate Status Protocol (OCSP) stands out due to its ability to carry
near real time certificate status information. Despite its importance for security, OCSP faces considerable challenges in
the computational Grid (i.e. Proxy Certificate’s validation) that are being studied at the Global Grid Forum’s CA Operations
Work Group (CAOPS-WG). As members of this group, we have implemented an OCSP validation infrastructure for the Globus Toolkit
4, composed of the CertiVeR Validation Service and our Open GRid Ocsp (OGRO) client library, which introduced the Grid Validation Policy. This paper summarizes our experiences on that work and the results obtained up to now. Furthermore we introduce the prevalidation concept, a mechanism analogous to the Authorization Push-Model, capable of improving OCSP validation performance in Grids.
This paper also reports the results obtained with OGRO’s prevalidation rules for Grid Services as a proof of concept.
相似文献
Oscar MansoEmail: |
75.
According to the characteristics of opencast coal resources and dragline technology system application in China, the structure and shifting step of transport passage are optimized in this paper. Typical coal transport passage is analyzed in aspects such as the internal dump occupation, dragline operation efficiency, coal transport distance, upper stripping distance and shifting quantities. The middle passage should be given priority in thick overburden open pit mine because the dragline system is only responsible for part stripping task. According to characteristics of middle passage, the transport passage is divided into parallel climbing, vertical climbing and horizontal transport. In addition, the transport passage structure optimization model and shifting distance optimization model are established in this paper. The case study in Heidaigou open pit mine shows that, the parallel climbing height is accounted for about 60% of the total height, and reasonable shifting distances of the first mining area and the second mining area are 240 and 320 m. Sensitivity analysis shows that, the total passage height has important influence on the shifting step, so it is with the stripping height and passage construction cost to the passage structure. 相似文献
76.
《国际计算机数学杂志》2012,89(1-4):177-188
Systematic prefix codes play an important role in coding theory, we relate them with the problem of the partition of a free (sub-) monoid into two free sub-monoids. We show too that among the dual codes of a systematic prefix code A there exists one and only one which appears in the automaton recognizing A *. The characterization of this automaton and some corollaries stated here will allow us to show in further note that systematic prefix codes are involved in the structure of any regular prefix code. Work done under CNR contract No. R-l7-02-417-0-A. 相似文献
77.
王风 《长沙通信职业技术学院学报》2013,12(1):23-25
OpenGL被认为是高性能图形和交互式视景处理的标准,可以制作出顺畅的3D效果,且性能也是非常出色的。所以在当今的三维绘制领域,其占据了不可动摇的位置。我国的三维创作发展起步相当晚,必须努力钻研迎头赶上。 相似文献
78.
79.
根据网络管理工作的常见需求,以Google Maps、PHP及相关开源网管技术整合的方式,设计基于WebGIS的网络管理系统。实现了拓扑发现、基于电子地图的网络晴雨表和服务检测、Atmega128微控制器数据中心机房状态检测、基于R T M P的实时曲线、故障告警、资产查询、用户故障报修、网管日志等功能。介绍了系统的设计思路,主要功能及实现方法。 相似文献
80.
The nature, definition, typical services, utility and future developments in Open Patent Services (OPS) are described. This is with particular reference to the European Patent Office (EPO), and German Patent and Trademark Office (GPTO) systems. The impact of OPS on both information providers and users is discussed. 相似文献