A HIERARCHICAL CONTROL METHOD FOR REACTIVE POWER OPTIMIZATION IN LARGE-SCALED INTERCONNECTED POWER SYSTEMS

This paper presents a new hierarchical and coordinative control method for reactive power optimization in large-scale interconnected power systems. It combines the interconnection forecast method for hierarchical control in large-scale steady state industrial systems with the incremental linear programming method for reactive power optimization in real time. The results of applying the method to power system examples show that the method not only solves the problem of high dimension in order, but also keeps the advantages of the incremental linear programming method. The proposed method is also suitable for the security analysis of reactive power correction in large-scale interconnected power systems.     

Compressed Code of Fractal Image and Secure Communication with Chaos

Based on the fractal theory, using quarter tree in neighborhood method and Bang-Bang control method, the steady control of the chaotic in the secure communication is realized. A simulation circuit has been designed based on driving responding theory, then, its synchronization is simulated on the computer.     

一种基于混沌同步的保密通信方案的设计

提出了一种新的基于混沌同步的保密通信方案。首先在发射端和接收端分别构建一个驱动系统及相应的响应系统。在发射端将信息信号调制到混沌变量中成为混沌传输信号,然后基于Lyapunov稳定性理论使两混沌系统达到同步,在接收端对混沌传输信号进行解调从而恢复出信息信号,混沌系统的初始条件和系统参数作为解调密钥。理论分析和数值仿真结果表明该方案是可行的。     

闽东地区国营林场提高经济效益的主要途径

本义分析了闽东地区国营林场由于种种原因,在较长一段时间经济上处于贫困落后状况,影响了林业扩大再生产及林场各项建设事业的发展。在“改革、开放、搞活”方针指导下,闽东国营林场充分利用资源优势,坚持以林为主、调整产业布局,优化经济结构,大力发展种植业、木材多层次加工利用,加快资源开发利用步伐等,收到明显效果。1988年全区国营林场总收入达770万元,为10年前的7.7倍,森林资源也有较大幅度增长。走出了一条以短养长,以林养林,脱贫致富之路,巩固和发展了国营林场事业。     

江宁区创建“平安农机”示范街镇的思路与措施

江宁区是南京的一个新市区。在创建“平安农机”活动中,紧密结合本区实际,因地制宜,抓住重点,发挥优势,形成特色。共创建“平安农机”示范街镇3个,“平安农机”示范村21个。“平安农机”示范户420户。农机安全生产社会化监管网络初步建立,农机安全管理长效机制得到完善,农机安全生产责任得到落实,创建工作取得阶段性的成效。     

河北省失地农民就业和社会保障问题研究——关于廊坊市、涿州市失地农民的调查报告

长期以来,我国存在的城乡二元经济体制,导致了城乡居民就业和社会保障制度的明显差距。通过对失地农民边缘化的原因进行了分析,提出了引入市场机制,保护农民的土地财产权利;建立合理的经济补偿机制;建立完善的社会保障机制,为失地农民提供长效保障的政策建议。     

Image Secure Communication Based on Logistic Map

The chaotic sequences generated by logistic map are used as the carrier, and the image secure communication scheme is proposed based on that the sequences possess a good correlation property. Promising results are obtained on Lenna image by computer simulation. The obtained results indicate that the transmitted source image can be correctly recovered and the proposed scheme is reliable when transmitter and receiver using identical initial value even under the situations of a noisy channel. However, the tiny difference of initial value between transmitter and receiver will result in failure to communication. Finally, the quality of recovered source image is assessed, and the approximate formula of bit-error rate in term of code length is also obtained.     

基于Lorenz系统的高保密通信系统

提出了一种基于Lorenz模型的混沌调制的保密通信系统,通过将传统加密技术采用的扩展密钥思想用到混沌数字加密中去.给出一个秘钥,利用逻辑斯蒂映像格子和位操作替代加密秘钥产生一系列扩展秘钥.该操作使系统对秘钥值更灵敏,实现了Lorenz混沌加密系统的高保密性.     

邮件防毒及邮件网关的选择策略

在网络环境下,病毒传播的速度和范围大大加快,网络已经成为近年来病毒传播的主要途径,而其中通过E-mail传播是病毒在网络上传播的一个最主要的途径之一。本文在介绍病毒邮件及垃圾邮件传播的主要模式前提下,分析了针对邮件系统的保护措施,并结合本单位在选购邮件网关的实践,给出选购邮件网关时的关键注意事项。