新颖的移动代理动态数据完整性保护协议

通过引入攻击者能力来对完整性的强弱进行划分和定义，在此基础上，分析了合谋情况下对动态数据进行截断攻击的问题，并给出了一个新颖的移动代理数据保护协议，该协议通过引入反向签名机制，形成一条从源节点到当前节点的信任链，实现对漫游路径的完整性保护，很好地解决了合谋情况下对动态数据的截断攻击，为自由漫游移动代理提供了更强的完整性保护。还使用形式化方法对协议的安全属性进行了分析验证。     

单小区模型的掉话率分析

掉话率是无线通信网络中最重要的关键性能指标(KPI)之一,本文分析了中国移动在讨论网络性能评估方法时提出的3个不同的掉话率计算公式,通过建立一个单小区的模型,使用一些合理的假设和分析,从理论上确定了一个最为准确的计算公式.     

电力系统连锁故障快速预测方法研究

近年来,电力系统大停电事故时有发生,而连锁故障是导致其发生的重要诱因,快速、准确地预测连锁故障可能的发展路径对预防大停电事故的发生具有重要的指导意义。针对过载主导型的连锁故障发展模式,充分利用连锁故障的前后因果关联性特点,定义关联性指标,提出基于故障路径树的连锁故障快速预测方法。该方法采用模糊聚类算法对关联性指标进行分类,选取关联性指标最高的一类支路为下级故障环节,在有效减少计算量的同时,改进了现有预测方法的不足。最后,对IEEE39节点系统进行仿真分析,仿真结果验证了所提预测方法的快速性和正确性。     

配网故障指示器最优配置研究

为了实现故障指示器的经济性配置,提出一个关于故障指示器最优配置的目标函数。从经济性的角度出发,研究最佳的故障指示器安装位置和安装数目,期望在缩短故障定位时间的基础上,最大程度地降低设备安装和运行成本,达到经济上的最优化。应用免疫算法对该目标函数进行求解,并对一个小型网络进行故障指示器配置分析,进行算法仿真。仿真结果表明,从经济性的角度分析故障指示器的配置问题是可行的,故障指示器应该安装在合适的地方才能实现最大效益的利用。     

Perspectives in environmental restoration and nature conservation in lakes

The developments in water quality management, environmental protection and nature conservation are characterized by interacting physical, social and institutional responses. Resilience towards change and time lags in responses occur in the ecosystem and in society as well. Both delays contribute to frequently observed inadequate management. Prevention or curtailment of environmental deterioration requires awareness of the frequently lengthy creeping and hidden degradation in the ecosystem and a proactive decision-making structure in society. Although the terms environmental protection and nature conservation are mostly dealt with as more or less synonymous, yet a certain dissimilarity between the objectives of nature conservation and of environmental protection can be pointed out. Some potential consequences for lake protection are discussed.     

基于广义动态约束的红外目标追踪研究

将红外目标的运行状态划分为不同的测量阶段。首先确定选择的时刻状态,进行参数化动态预测,然后写出红外目标状态转移方程,最后计算最优函数值。其核心思想是把目标追踪问题转为阶段变量,逐时间段内实现最优,在预定的时刻追踪达到最佳效果。最后通过仿真验证了算法的有效性。     

On the resilience of P2P botnet footprints in the presence of legitimate P2P traffic

Botnet is a distributed platform for illegal activities severely threaten the security of the Internet. Fortunately, although their complicated nature, bots leave some footprints during the C&C communication that have been utilized by security researchers to design detection mechanisms. Nevertheless, botnet designers are always trying to evade detection systems by leveraging the legitimate P2P protocol as C&C channel or even mimicking legitimate peer‐to‐peer (P2P) behavior. Consequently, detecting P2P botnet in the presence of normal P2P traffic is one of the most challenging issues in network security. However, the resilience of P2P botnet detection systems in the presence of normal P2P traffic is not investigated in most proposed schemes. In this paper, we focused on the footprint as the most essential part of a detection system and presented a taxonomy of footprints utilized in behavioral P2P botnet detection systems. Then, the resilience of mentioned footprints is analyzed using three evaluation scenarios. Our experimental and analytical investigations indicated that the most P2P botnet footprints are not resilient to the presence of legitimate P2P traffic and there is a pressing need to introduce more resilient footprints.     

石灰稳定法处理过湿土路基试验研究

苏南平原地区土层的含水量高、粘粒含量高、变形大，一般不能直接作为高等级公路的路基。为了降低建设费用，充分利用当地材料作为路基填土，公路施工中广泛使用土中掺入石灰作为改良土的性质的方法。文章介绍苏州的两种天然土、控制含水量的素填土和不同石灰掺入量的石灰稳定土的回弹模量试验，结果表明天然土和素填土的回弹模量较低且随含水量的增加而迅速降低；石灰稳定土的回弹模量与土类、土的压实度、石灰含量、养护龄期等有显著的关系。     

Uninterrupted Ethernet using failure‐adaptive spanning trees

Failure recovery is a critical performance issue in large‐scale Ethernet networks. The standard mechanisms of link‐failure recovery in spanning tree protocol (STP) and rapid STP may cause interruptions of data transmission because of long recovery time. Several previous approaches construct multiple alternative trees to avoid such interruptions caused by single or multiple failed links based on multiple STP. However, the prototypical protocol of standard root election would result in the same root switch for different spanning trees. Hence, the alternative trees may become invalid if a failed link appears in more than 1 spanning tree. Our scheme, failure‐adaptive spanning trees (FAST), improves the resilience of Ethernet with multiple spanning trees. It avoids simultaneous faults of multiple spanning trees by incorporating a new approach to electing an appropriate root switch for each spanning tree. Failure‐adaptive spanning trees also use active links of alternative spanning trees for data transmission. The paths of different spanning trees can thus act as shortcuts to shorten frame paths. The experimental results demonstrate that FAST can sustain network throughput under multiple link failures. The FAST also balances both link and switch loads.     

基于FPGA的激光脉冲编码研究

对目标指示信号进行编码能够有效的降低敌方的干扰,详细介绍了激光指示信号3种编码样式,即脉冲间隔编码（PCM）、有限位随机周期脉冲序列编码和伪随机码。对3种编码的特点进行了全面的分析,并从原理上说明了激光脉冲编码的生成机理。通过Modelsim软件对2种脉冲编码进行了仿真研究,并对有限位随机周期脉冲序列编码和伪随机码的特点进行了比较,伪随机码具有更好的保密性和抗干扰能力。