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101.
To keep open network more efficacious and secure, it is necessary that a nice trust model and method of trust management must be developed. The reason why traditional trust models are incomplete in their function to manage trust is explained, and a general model based on hybrid trust model and introducer protocol is provided.The hybrid model is more flexible and efficacious to manage trust compared with hierarchy model and Web model.The introducer protocol is a better solution to build, maintain and refresh the trust relationship in open network environment. 相似文献
102.
研制了一块微操作机器人控制板,采用USB接口通信和C8051单片机做规划器。介绍了PDIUSBD12和C8051F236的内部结构、性能指标,并给出了波导耦合机器人控制系统软硬件和系统结构设计。该控制板在实际工作中运行良好,性能稳定。 相似文献
103.
Although user interfaces represent an essential part of software systems, the Unified Modeling Language )UML) seems to have been developed with little specific attention given to user interface issues. Several researchers have investigated integrating interface modeling techniques with UML. In UML, one models tasks using extended activity diagrams rather than by incorporating a completely new notation into UML. UMLi also addresses the relationships between use cases, tasks, and views, and thoroughly addresses the relationship between tasks and the data on which they act. UMLi is probably the most technically mature proposal for interface development in UML. 相似文献
104.
da Silva E.L. Finardi E.C. 《Parallel and Distributed Systems, IEEE Transactions on》2003,14(8):721-729
The objective of the long-term operating planning problem is to determine the optimum strategy for the generation of electricity, aiming toward the minimization of total operating cost over the planning period. In a competitive electricity market, with the participation of a significant number of hydroplants, such as in Brazil, precision modelling for operating planning is required so that a better use of hydraulic resources can be obtained. We present a long-term operating planning model based on an individual power plant representation. In order to support the high computational burden, a suitable parallel processing algorithm is proposed. 相似文献
105.
概念级设计是实时嵌入式系统设计自动化的第一步 ,由于它的性能直接关系到整个系统的设计质量 ,所以也是非常重要的一步 .除了对所设计系统的功能进行描述、验证之外 ,概念级设计还应该对所设计系统的性能进行分析 .否则 ,如果将错误带到下一阶段 ,将会使整个设计付出沉重的代价 .在简单介绍了实时嵌入式系统的自动化设计原理 ,并分析了目前人们采用的三种概念级设计方法缺点之后 ,文章提出了基于 SDL / MSC描述与验证的 ,适用于单 FPGA或多 FPGA系统的概念级设计方法 .这种方法包括系统的 SDL/ MSC描述与验证、有向无环图 (DAG)的产生、DAG子图划分等几部分 .在文章的最后 ,还指出了这种设计方法存在的不足 相似文献
106.
Brandao Jacobina C. Beltrao de Rossiter Correa M. Nogueira Lima A.M. Cabral da Silva E.R. 《Industry Applications, IEEE Transactions on》2003,39(5):1333-1342
This paper presents two reduced-switch-count AC drive systems. One of the configurations was conceived to operate with a two-phase motor and the other one with a three-phase motor. The drive systems provide both bidirectional power flow and power factor control. Pulsewidth modulation techniques for the converter control are discussed. Experimental results are presented. 相似文献
107.
Smith P. Shah M. da Vitoria Lobo N. 《Intelligent Transportation Systems, IEEE Transactions on》2003,4(4):205-218
This paper presents a system for analyzing human driver visual attention. The system relies on estimation of global motion and color statistics to robustly track a person's head and facial features. The system is fully automatic, it can initialize automatically, and reinitialize when necessary. The system classifies rotation in all viewing directions, detects eye/mouth occlusion, detects eye blinking and eye closure, and recovers the three dimensional gaze of the eyes. In addition, the system is able to track both through occlusion due to eye blinking, and eye closure, large mouth movement, and also through occlusion due to rotation. Even when the face is fully occluded due to rotation, the system does not break down. Further the system is able to track through yawning, which is a large local mouth motion. Finally, results are presented, and future work on how this system can be used for more advanced driver visual attention monitoring is discussed. 相似文献
108.
Thomas K. Hirsch Alexandre Da S. Rocha Fabiano D. Ramos Telmo R. Strohaecker 《Metallurgical and Materials Transactions A》2004,35(11):3523-3530
Plasma nitriding of tool materials is common practice to improve the wear resistance and lifetime of tools. Machining-induced
compressive residual stresses in shallow layers of some tenths of microns are observed accompanied by other characteristic
properties of machined surfaces in these high-strength materials. After plasma nitriding of M2 high-speed steel, previously
induced compressive residual stresses remain stable and the depth of diffusion layers decreases with increasing compressive
residual stresses. This article reports investigations of plasma nitrided samples with different levels of residual stresses
induced prior to the nitriding process. For comparison, experiments with bending load stresses during plasma nitriding have
also been carried out. The plasma nitriding treatment was performed at constant temperature of 500 °C with a gas mixture of
5 vol pct N2 in hydrogen. Nitriding time was varied from 30 to 120 minutes. All samples were characterized before and after plasma nitriding
concerning microstructure, roughness, microhardness, chemical composition, and residual stress states. Experimental results
are compared with analytical calculations on (residual) stress effects in diffusion and show a clear effect of residual and
load stresses in the diffusion of nitrogen in a high-strength M2 tool steel. 相似文献
109.
In this paper, we focus on the strategic design of supply chain networks. We propose a mathematical modeling framework that captures many practical aspects of network design problems simultaneously but which have not received adequate attention in the literature. The aspects considered include: dynamic planning horizon, generic supply chain network structure, external supply of materials, inventory opportunities for goods, distribution of commodities, facility configuration, availability of capital for investments, and storage limitations. Moreover, network configuration decisions concerning the gradual relocation of facilities over the planning horizon are considered. To cope with fluctuating demands, capacity expansion and reduction scenarios are also analyzed as well as modular capacity shifts. The relation of the proposed modeling framework with existing models is discussed. For problems of reasonable size, we report on our computational experience with standard mathematical programming software. In particular, useful insights on the impact of various factors on network design decisions are provided. 相似文献
110.
介绍了国产酚醛层压板制成的阻性板室在宇宙线测试条件下的特性,效率达到95%左右,时间分辨的半高宽为2.25ns。 相似文献