一种有效的数据共享环境多数据源选择算法

针对数据共享环境多数据源选择MDSS(multiple data sources selection)问题,基于Pareto最优理论提出了MDSSA(MDSS algorithm)算法.该算法借助崭新的基于法线测量的非线性路径代价方程计算出到每个数据源的最优路径集合,进而通过代价对比确定实施数据访问的最佳数据源及路径,极大地缩小了搜索空间,在搜索到有效路径的同时,确保了算法的响应时间.大量仿真实验表明,MDSSA算法是有效的.     

再生混凝土的应用现状与性能分析

对再生混凝土的现状做了比较详细的分析,总结了国内外在再生混凝土研究应用方面的各项进展和已取得的成果,并从微观结构和宏观性能两方面分析了再生混凝土的特点,提出了进一步改善再生混凝土性能建议,以便于更好的利用再生资源。     

市政工程电气专业施工图审查中的几个常见问题探讨

针对在市政工程电气专业施工图设计中的几个常见问题,从负荷等级的确定、照明功率密度值、加氯间安全设计、电缆敷设、等电位安全、电气节能、防雷及接地等多个方面总结了常犯的错误,并对国家相关规范、标准提出修正意见,可供市政工程电气专业设计人员参考。     

基于CISCO路由器的包过滤防火墙的设计与实现

随着Internet的迅猛发展 ,网络安全已经成为一个不容忽视的问题。在内网与外网之间放置防火墙是实现网络安全的主要措施 ,如何以最小的成本实现内部网络的相对安全就是企业所关注的。本文拟简单介绍防火墙的分类 ,重点讲述包过滤防火墙的原理 ,并给出实例 ,阐述如何利用CISCO路由器 ,设计与实现包过滤防火墙 ,限制外网对内网、DMZ区对非DMZ区以及内网对外网的访问。     

互感器油中添加剂引起的油色谱异常的分析

分析了互感器中变压器油色谱异常的原因,指出了在变压器油中加入添加剂应审慎.     

YNA联结平衡牵引变压器三相侧的短路阻抗推导

应用多绕组变压器理论,并根据YNA联结平衡牵引变压器的基本电磁关系,得出了二相侧的T型等效电路,导出了YNA联结平衡牵引变压器平衡条件以及三相侧的短路阻抗计算公式.     

电流互感器密封失效引起的绝缘故障

首先介绍了油浸式电流互感器和SF₆电流互感器的整体绝缘结构,以近期多地出现的电流互感器绝缘故障为切入点,分析了电流互感器绝缘击穿的原因。通过电流互感器的解体检查进一步推断出设备故障的根源为互感器密封失效,针对油浸式电流互感器的金属膨胀器渗漏、SF₆电流互感器爆破片破损引发的密封失效现象,提出了运行维护建议和预防措施。     

Open Source Software Movement: A Challenging Opportunity for the Development of China's Software Industry

The software industries in developing countries are facing enormous challenges in order to grow amid fierce competition of import from the software makers in developed countries. Open source software (OSS) movement, which is a particular phenomenon in the software industries, seems to be a challenging opportunity for the developing countries that wants to move their own software industries up the value chain. This paper, using China as an example, identifies the issues that need to be addressed for the software industry, as well as the special characteristics of software products that need to be dealt with carefully. It proposes promoting OSS as a strategy the Chinese government should adopt to grow the software industry and the specific actions that should be taken.     

基于BFA-Elman的电力负荷可靠性预测系统设计

针对现有负荷预测系统耗时长且精度较差等问题,文中设计了一种基于BFA-Elman的电力负荷可靠性的预测系统.利用细菌觅食算法(BFA)优化Elman网络模型的结构参数获得最佳的权值和阈值,同时避免Elman网络陷入局部最优.通过结合BFA和Elman网络构建BFA-Elman电力负荷预测模型,以实现可靠的预测.利用历史...     

Group-based user pairing for virtual MIMO in LTE

A user pairing method is proposed to improve the throughput gain of virtual multiple input multiple output (virtual MIMO) in 3G long-term evolution (LTE).The approach taken in this study separated the user pairing into four steps 1) the users are divided into two groups according to their signal-to-noise ratio (SNR), and different user pairing metrics are proposed for each group; 2) the scheduler chooses a user for transmitting by a given rule; 3) the scheduler searches the pairing candidate for the selected user in each group; 4) the scheduler chooses the final pairing user from the co-group and crossover-group candidates by using a marginal utility function, to balance fairness and efficiency.The method can improve the throughput of users with high SNR, and guarantee fairness for users with low SNR, so it can be used in 3G LTE systems.The article provides both theoretical analysis and simulation results to support the idea.