Real-Time Method for Detecting Harmonic and Reactive Currents of Single-Phase Circuits

According to the characteristics of single-phase circuits and demand of using active filter for real-time detecting harmonic and reactive currents, a detecting method based on Fryze＇s power definition is proposed. The results of theoretical analysis and simula- tion show that the proposed method is effective in realtime detecting of instantaneous harmonic and reactive currents in single-phase circuits. When only detecting the total reactive currents, this method does not need a phase-locked loop circuit, and it also can be used in some special applications to provide different compensations on the ground of different requirements of electric network. Compared with the other methods based on the theory of instantaneous reactive power, this method is simple and easy to realize.     

L2空间内的抛物函数展开

本文根据经典的本征函数展开理论,推导了任意平方可积函数空问内的抛物函数展开式,并且给出了一个展开实例,作为对理论的验证。本文结果可应用于求解与电磁散射和天线有关的一类问题中。     

Investor Protection, Ownership Structure and Corporate Valuation

Introduction The extent of legal protection of investors in acountry is an important determinant of the develop-ment of its financial markets[1,2]. In contrast to thedevelopment of Chinese economy, the developmentof stock market is not very satisfying. Co…     

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将交通流模型表示成拟线性一阶双曲型偏微分方程组;按照方程组中的系数值，对交通流的各种宏观模型进行了分类;依据特征线的特征速度是否小于宏观运动速度，模型是否依赖外来的速度一密度平衡关系以及模型代表的交通流特点等三项指标对模型进行了评价.结果表明有三种比较理想的交通流模型.     

性能化防火设计中火灾场景设计的内容和方法

为了提高火灾场景设计的合理性,介绍了火灾场景设计的内容和方法,分析了现有主要火源热释放速率模型及其优缺点.结合某商场性能化防火设计,探讨了火灾场景设计的原则和步骤,提出了火灾场景设计的完整过程应包括：起火点位置的设定、最大热释放速率的确定和火灾蔓延特性的分析等.     

基于GPS的实时机车运行信息传输系统

利用铁路既有的列车无线调度通信系统和铁路分组交换网络，结合GPS技术，提出了一种实现机车运行信息实时传输的方案。采用话音压缩／扩展和数据同传，使无线列调在原来只传输话音的基础上增加了数据传送，数据仓库又使得这些信息能在铁路相关部门实现共享，可实现机车中低速率的数据传输。     

Novel Blind Robust Watermarking Based on Chaotic Mixing

This paper proposed a novel blind robust watermarking scheme. Multi-bits watermark is embedded in the chaotic mixed image blocks. Energy of the watermark is spread to all region of the blocks instead of some individual pixels, which entitles the watermark with imperceptibility and high robustness. A class of 1-D Markov chaotic maps is employed to perform image block mixing and watermark encryption ensures security of the system.To prove the validity of this proposed scheme, some objective comparisons with the popular spread spectrum scheme were also presented. The simulation results show that this scheme can survive processing such as high-ratio JPEG compression, Gaussian noise pollution and histogram equalization.     

从广济桥稳定性评价及抢险保护设计浅谈古代石拱桥现状评估和保护整治

对杭州广济桥的稳定性评价及抢险保护设计进行简要介绍,阐述现状调查、测量检测评估、数值仿真分析在稳定性评价中的作用,以及对抢险保护设计中桥体修复加固、长期跟踪监测等内容的介绍,在此基础上进一步探讨古代石拱桥现状评估和保护整治思路和方法,为更好地保护古代石拱桥提出参考性建议。     

桥梁结构钢筋的锈蚀成因与防治

从桥梁结构钢筋锈蚀的成因,对结构产生的影响及其预防、维修几个方面进行了较为深入的研究和探讨,以期使桥梁混凝土结构由于钢筋的锈蚀而引起的桥梁结构强度下降,耐久性降低,结构安全性得不到保障,甚至遭到严重破坏的现象能得到设计和施工者们更加广泛的重视和借鉴。     

基于粗糙集属性理论和差分进化算法的交通事故黑点成因分析

道路交通事故黑点作为交通事故的高发段,造成了大量的人员死亡和财产损失.文章首先运用粗糙集属性理论对诱发交通事故的因素进行评价分析,接着采用差分进化法筛选出主要影响因素,提出相应治理措施,并以兰州市滨河路交通事故黑点分析为例进行了说明,验证了该方法的实用性.