WSN中一种最优的汇聚节点移动方案

研究了无线传感器网络中,如何在不同的候选位置放置数据汇聚节点来最大化网络生命周期。通过定义＂放置模式＂这一概念,对数据流通模式进行分类,从而从量级上降低了需要调度的因素的数目。基于这样的理念,对问题建立了线性优化模型,来构建一种最佳的放置策略。最后,通过具体的试验验证了提出方法的有效性,说明了即使使用一个移动位置受限的汇聚节点,也会极大地提升网络生命周期。     

A new multiobjective allocator of capacitor banks and distributed generations using a new investigated differential evolution

This article has investigated a new multiobjective allocation of optimal sizing and sitting of distributed generation (DG) units and capacitor banks in simultaneous mode to improve reliability and reduce energy losses. The proposed method consists of four objectives, that is, cost of energy not supplied, system average interruption duration index, costs of energy loss and investment. A novel structure differential evolution has been suggested to solve this nonlinear complex problem and its results are compared with related values of genetic algorithm and simple differential evolutionary algorithm. In addition to the novel objective function, the other contribution of this article is proposing a new model for load and energy cost. Three types of DGs, that is, wind turbine, solar cell, and diesel generator have been used in placement process. To verify the comprehensiveness of the proposed function, three scenarios have been introduced: scenario i: first, placement of DGs, then capacitor banks, scenario ii: first, placement of capacitor banks, and then DGs, and scenario iii: simultaneous placement of DGs and capacitor banks. Simulations have been carried out on one part of practical distribution network in Metropolitan Tabriz in North West of Iran. The results of simulations have been discussed and analyzed using the five novel indices. The obtained simulation results using proposed function shows that the simultaneous placement of DGs and capacitor banks results in more reduction of the energy losses and increase improvements of reliability indices as well as voltage profile. © 2013 Wiley Periodicals, Inc. Complexity 19: 40–54, 2014     

谈谈IXIA虚拟化测试解决方案如何能帮助“化云为雨”

探讨了云计算在世界以及中国发展的趋势,介绍了在企业里部署云计算所面临的挑战。重点讲述了IXIA作为在IP测试行业有着丰富经验的公司如何利用自己的解决方案通过测试来帮助推动云在企业的落地应用。     

电视中心系统测试实践

结合本台硬盘播控系统实际,阐述了模拟向数字过渡时期电视中心系统验收测试的方法,并对测试中的几点体会进行了介绍,最后还阐述了深入使用VM700T的一些方法。     

On Using Tabu Search for Design Automation of VLSI Systems

Tabu search is a meta-heuristic problem solving technique that, when applied carefully, provides near optimal solutions in a very short time. In this paper, we have described the use of tabu search for solving problems related to very large scale integrated (VLSI) circuit design automation. Specifically, we have demonstrated the use for VLSI circuit partitioning and placement. We present a tabu search based circuit bi-partitioning technique that partitions circuits with the goal of minimizing the size of the cutset between the partitions. Then, we use tabu search techniques along with force directed placement techniques to accomplish the physical placement of VLSI circuits on regular two-dimensional arrays with the goal of minimizing the placement time. We use empirical data from partitioning and placement of benchmark circuits to test our techniques. Our methods show improvement when compared to partitioning techniques from the literature and commercially available placement tools. Relative to the literature, our tabu search bi-partitioning technique improves on the best known minimum cuts for several benchmark circuits. Relative to commercially available computer aided design tools, our tabu search based placement approach shows dramatic (20×) speedup in execution time without negative impact on the quality of the solution.     

自适应桁架形状控制中主动杆多目标最优配置

导出自适应桁架结构静态形状控制方程，这些方程在线弹性范围内适用；一般主动杆件数远小于结构杆件数目，且主动杆件的配置问题取决于控制能量和杆件强度等因素，因此基于最短行程和最小导出内力指标和模态退火组合优化算法进行了主动杆件的多目标最优配置；通过算例分析验证了本文分析方法的可行性和有效性。     

An algorithm ofk-line location for BBL in LSI/VLSI

In this paper, aK-line location algorithm for building block cells in LSI/VLSI is presented. When the relative positions of rectangular cells are given, there are 2 states according to the two orientations of a cell. It is proved that to find the optimum solution from the 2^N states can be reduced to calculate theN states inK-line algorithm. So the algorithm is shown very effective and can be used with association for cluster method in BBL placement. Under certain conditions, this method can also be used to pesudo BBL placement directly.     

基于复模态的控制力矩陀螺配置优化

由于陀螺耦合效应,系统动力学方程的特征值和特征向量皆为复数形式,不便于进行控制力矩陀螺的配置优化和控制律设计。本文基于复模态理论,构造出一种实数域上的伪模态矩阵,从而实现方程解耦。综合考虑结构模态、控制输入能量和传感器接收能量的复合优化准则,获得了控制力矩陀螺的最优配置。结果表明,采用线性二次型最优控制,能够快速将结构的响应振幅降至5%以内,验证了使用伪模态矩阵进行方程解耦的可行性及控制的有效性。     

Variance of the virtual displacement

We show that the affine structure of the 3-dimensional space is deeply enmeshed with the static laws expression. The relevance of tensorial rules for calculus in mechanics is thus enhanced. The virtual work principle is stated precisely but a little twist is given to the usual statements: the tensorial nature of the so-called virtual displacement vector is asserted to be covariant. To cite this article: C. Vallée et al., C. R. Mecanique 332 (2004).

Résumé

Nous montrons que la structure affine de l'espace tridimensionnel est fortement imbriquée avec l'expression des lois de la statique. La pertinence de l'application des règles du calcul tensoriel à la mécanique est ainsi renforcée. Le principe des travaux virtuels est établi précisément avec une seule entorse aux exposés classiques : la nature tensorielle de l'habituel vecteur déplacement virtuel est affirmée covariante. Pour citer cet article : C. Vallée et al., C. R. Mecanique 332 (2004).     

基于网格点覆盖模型的高效传感器网络节点配置算法

节点配置问题是传感器网络研究的关键问题.在DhillonS.S.的模型化方法基础上,完成了两种改进的高效节点配置算法.以最少化传感器数目为目标,通过减少局部冗余、优化整体性能以及考虑传感器检测范围的有限性,修改算法的初始化模型等方法,对现有的传感器节点配置算法进行了改进.通过仿真分析,充分验证了两种模型的可行性与性能的优越性.