容错节能无线传感器网络中可靠覆盖问题的解决方案

基于生成最小覆盖的k集合覆盖启发式算法,提出了分簇结构下解决簇内观测区域可靠覆盖问题的高效节能方案,即可靠覆盖方案.最小覆盖是一个可以完全覆盖观测区域的传感器节点最小集合,可靠覆盖方案使用的1-损毁最小覆盖拓扑结构是两个最小覆盖的迭加.通过1-损毁最小覆盖间的轮流工作延长网络可用时间,体现节能效果;通过增加一个冗余最小覆盖,屏蔽来自单个最小覆盖的节点失效,体现容错效果.在该方案中,介绍簇头节点和簇内成员的交互协议,并使用快速覆盖替换算法处理可能的节点失效.仿真实验显示,该方案能够高效地利用有限的能量,显著延长网络工作时间,同时将由节点失效而产生的漏测次数保持在较低值.     

Global optimization of feature weights and the number of neighbors that combine in a case-based reasoning system

Abstract: Case-based reasoning (CBR) often shows significant promise for improving the effectiveness of complex and unstructured decision-making. Consequently, it has been applied to various problem-solving areas including manufacturing, finance and marketing. However, the design of appropriate case indexing and retrieval mechanisms to improve the performance of CBR is still a challenging issue. Most previous studies on improving the effectiveness of CBR have focused on the similarity function aspect or optimization of case features and their weights. However, according to some of the prior research, finding the optimal k parameter for the k-nearest neighbor is also crucial for improving the performance of the CBR system. Nonetheless, there have been few attempts to optimize the number of neighbors, especially using artificial intelligence techniques. In this study, we introduce a genetic algorithm to optimize the number of neighbors that combine, as well as the weight of each feature. The new model is applied to the real-world case of a major telecommunication company in Korea in order to build a prediction model for customer profitability level. Experimental results show that our genetic-algorithm-optimized CBR approach outperforms other artificial intelligence techniques for this multi-class classification problem.     

一个移动智能体位置管理与可靠通信的算法

对于移动智能体应用环境下的可靠通信问题,已有的支撑系统和相关研究或不能满足要求或存在缺陷.提出了一个面向移动智能体位置管理与可靠通信的新算法,它保证在智能体的移动行为不可预测的情况下,能可靠的完成消息传递,并承诺消息传递的exactly-once语义.     

RMTP协议的时延分析

RMTP(reliable multicast transport protocol)是一种通过修复服务器(repair server)本地恢复来提供可靠性的组播协议.对改进的RMTP协议的时延性能进行建模分析.推导了数据包自发送主机发出到成功地被一个随机选择的接收主机接收之间的平均时延公式.分析表明,随着丢失率的增长,RMTP的时延性能恶化点将迅速下降;随着每个修复服务器下连接尾链路数量的增加,RMTP的时延性能恶化点也将下降.但是,随着尾链路总数量的增加而保持每个修复服务器连接的尾链路数量不变,RMTP的时延性能的变化很小.仿真结果较好地验证了分析的有效性.     

单调矩阵搜索算法设计与应用

本文提出了单调矩阵搜索问题一个统一的算法框架和实现策略，使得可在线性时间内求得矩阵搜索问题的解，并将此算法框架应用于设计凸多边形所有顶点最远邻点问题的高效算法。     

Optimal Routing Designs in Self-healing Communications Networks

Self-healing communication networks that allow re-routing of demands through switching processes at designated nodes are studied. It is shown how network utilization, demand throughput and reliability of such networks can be studied simultaneously to achieve an optimal design for all three. This is done through a max–min–max multi-commodity network flow formulation of the routing problem in which it is ensured that maximum network throughput is achieved with minimum loss of demands that are blocked due to single switching node failures. It is shown that a node-path linear programming approximation to the multi-commodity network flow formulation solves the problem for medium and large network sizes in moderate computational times.     

Remote sensing support for national forest inventories

National forest inventory programs are tasked to produce timely and accurate estimates for a wide range of forest resource variables for a variety of users and applications. Time, cost, and precision constraints cause these programs to seek technological innovations that contribute to measurement and estimation efficiencies and that facilitate the production and distribution of an increasing array of inventory data, estimates, and derived products. Many of the recent innovations have involved remotely sensed data and related statistical estimation techniques. Current applications of remote sensing in support of national forest inventories are reviewed for three areas: (1) observation or measurement, meaning using remotely sensed data in lieu of field observations or measurements; (2) estimation, meaning calculation of traditional inventory areal estimates such as forest area or volume per unit area; and (3) mapping. Future applications focus on two areas: augmenting field measurements with remotely sensed data obtained from lidar sensors and Internet accessible map-based estimation.     

实现电力监控嵌入式系统可靠数据交换的串行通信Agent

基于任务Agent的设计理念,开发了一种实现电力监控嵌入式系统可靠数据交换的串行通信Agent模块。这种模块实现了串行通信的全程代理。采用这种模块的嵌入式系统,只要对接口的双口RAM进行访问即可完成不同系统间的可靠数据交换,从而使串行通信变得非常方便且更加可靠。同时,采用这种模块还能有效地缩短产品的开发周期。详细地介绍了这种串行通信Agent模块的设计思想、基本原理和实现方法。     

惯性冲击对低真空封装的RF MEMS电容开关性能的影响

分析了外界惯性冲击对低真空封装的旁路电容式RF MEMS开关性能的影响.得到了近似计算外界惯性冲击引起位移的解析式.在已知最大容许插入损耗和外部惯性冲击环境条件下,MEMS开关支撑梁的最小机械刚度常数以及外部惯性冲击引起的插入损耗可以根据该式得到.通过RF MEMS电容式开关实例,表明设计低真空封装的RF MEMS电容式开关时应考虑外部环境因素.可见,RF MEMS开关用低真空封装可以减小空气阻尼、改善开关速度和执行电压的同时,开关的性能却容易受外界环境因素的影响.该研究对低真空封装的RF MEMS电容式开关的优化设计很有意义.     

MPE2S: 基于多路径纠删编码的无线传感器网络可靠传输策略

传输可靠性是衡量无线传感器(Wireless sensor networks, WSN)网络性能的一个重要指标. 针对节点故障会影响网络传输稳定性和可靠性的问题, 提出了基于多路径纠删编码的 无线传感器网络可靠传输策略(Multi-paths and erasure encoding strategy, MPE2S). 根据反映链路质量的最优最差蚂蚁系统的信息素归一化值, 在相邻等级节点间建立多条互不交叉的传输路径, 将源数据包经纠删编码的 数据片沿多条路径分配和传输以实现负载均衡和故障容错. 理论分析和仿真结果表明,MPE2S具有较高数据包接收率、数据准确率和能效性, 体现了良好的故障容错性、数据传输稳定性和可靠性.