自适应超混沌系统修正广义同步及其电路实现

运用自适应控制方法,实现超混沌Chen系统的同结构投影同步,并能辨识出响应系统的未知参数。首先通过采用MATLAB进行数字仿真,表明该自适应控制方法的可行性以及系统的参数辨识作用。其次利用EWB仿真设计模拟电路,结果与MATLAB的仿真结果相吻合,从而进一步证明了该自适应控制方法的有效性和系统参数辨识方法。     

三模冗余中局部重构及模块同步技术研究

传统的三模冗余方法仅能容错,无法进行故障修复,当两个模块出错时系统将无法正常工作;采用局部动态可重构技术虽然可以修复故障,但修复后的模块与其他模块状态不同步,无法立即工作,需等待系统完成当前任务后重新同步,在同步前如果另有模块发生故障,系统仍将无法工作。本文对三模冗余系统中的模块同步方法进行了研究,当某一故障模块被重构修复后,可以迅速与其他模块同步,尽快加入系统工作,避免因故障积累造成的系统失效。该方法可以有效缩短冗余模块从故障修复到重新加入系统工作之间的等待时间,大大提高三模冗余的可靠性。     

自动化测试中基于GUI非标准控件的识别和应用

图形用户界面(GUI)中Windows第三方非标准控件识别率不高,对基于Windows第三方控件的应用软件进行自动化测试一直是软件自动化测试中的难题,本文基于Windows消息机制提出了一种解决第三方控件识别的设计方案,该方案通过自动化测试软件发送Windows消息,而Windows应用程序捕获消息并解析传递的xml数据,从而准确定位到图形界面的某一控件,并模拟测试软件对其控件操作已达到自动化识别的目的,实践证明,基于该方案构建的测试系统具有良好的测试效果。     

基于认证的IPv6地址自动分配

IPv6地址的自动配置技术实现了即插即用功能,但也对网络的安全带来了隐患。结合准入控制技术、在IPv6地址自动配置过程中加入认证机制,这既保留了IPv6地址的即插即用特性,又从源头上保证了接入网络的安全性。     

Enhancing self-scheduling algorithms via synchronization and weighting

Existing dynamic self-scheduling algorithms, used to schedule independent tasks on heterogeneous clusters, cannot handle tasks with dependencies because they lack the support for internode communication. To compensate for this deficiency we introduce a synchronization mechanism that provides inter-processor communication, thus, enabling self-scheduling algorithms to handle efficiently nested loops with dependencies. We also present a weighting mechanism that significantly improves the performance of dynamic self-scheduling algorithms. These algorithms divide the total number of tasks into chunks and assign them to processors. The weighting mechanism adapts the chunk sizes to the computing power and current run-queue state of the processors. The synchronization and weighting mechanisms are orthogonal, in the sense that they can simultaneously be applied to loops with dependencies. Thus, they broaden the application spectrum of dynamic self-scheduling algorithms and improve their performance. Extensive testing confirms the efficiency of the synchronization and weighting mechanisms and the significant improvement of the synchronized–weighted versions of the algorithms over the synchronized-only versions.     

Triage Drift: A Workplace Study in a Pediatric Emergency Department

This paper presents a workplace study of triage work practices within an emergency department (ED). We examine the practices, procedures, and organization in which ED staff uses tools and technologies when coordinating the essential activity of assessing and sorting patients arriving at the ED. The paper provides in-depth empirical observations describing the situated work practices of triage work, and the complex collaborative nature of the triage process. We identify and conceptualize triage work practices as comprising patient trajectories, triage nurse activities, coordinative artefacts and exception handling; we also articulate how these four features of triage practices constitute and connect workflows, organize and re-organize time and space during the triage process. Finally we conceptualize these connections as an assessing and sorting mechanism in collaborative work. We argue that the complexities involved in this mechanism are a necessary asset of triage work, which calls for a reassessment of the concept of triage drift.     

最小约简问题的一个免疫离散粒子群算法

把求决策表最小属性约简问题归结为一个不含非线性约束的0-1组合优化问题,证明了两个问题之间最优解的等价性.针对问题的特性,对原有的二进制粒子群算法进行改进,引入基于决策表差别矩阵的疫苗接种机制以及k-精英保优策略,由此提出一个免疫二进制粒子群算法并用于求解转化后的组合优化问题.仿真计算结果表明该算法有效地提高了获得最小属性约简的可能性,同时还具有较快的收敛速度.与其它类型的最小属性约简算法相比较,该算法取得明显的改进效果.     

多样性监控的免疫微粒群算法

标准微粒群算法的种群多样性随进化变差是造成陷于局部最优的主要原因,本文提出了一种多样性监控的免疫微粒群算法.利用多样性函数对种群的多样性进行监控,并在多样性下降到一定程度时,引入免疫机制中的克隆选择算子和免疫记忆特性来对粒子进行更新,从而有效地克服了微粒群算法易陷于局部最优以及对多峰值函数搜索效果不佳的缺点.用经典benchmark测试函数对算法进行仿真实验,实验结果表明该算法比标准微粒群算法有着更好的收敛性能.     

面向移动节点定位的传感器网络动态休眠调度机制

由于能量受限的传感器节点一般多采用低功耗的工作方式,即在休眠状态和唤醒状态之间切换,因此,当对移动节点进行定位时,锚节点可能会因为处于休眠状态而没有响应移动节点的定位请求,从而导致定位失败.提出一种基于预唤醒的动态休眠调度机制P-SWIM,该机制提前通知移动节点周边的锚节点进入全勤的工作方式,而网络内其他锚节点则仍然处于低功耗的工作方式.通过P-SWIM,目标节点能够有效地维持足够高的锚节点连通度,从而保证了定位的成功率和精度.实验结果表明,移动节点定位方法采用P-SWIM相比于采用静态休眠调度机制(如RIS和GAF)能够显著地提高定位性能,且P-SWIM引入的运行功耗也是3种机制中最低的,比RIS和GAF最多可节省47.6%和60.2%的功耗.     

基于图论聚合度的动态分层路由算法

讨论无线传感器网络簇的组成问题及其形式化描述,提出节点聚合度的概念并引入簇首的生成过程,给出一种新的优化路由算法。对算法的设计思想和工作过程,包括簇首的选举与簇建立、簇重组与自愈机制进行了分析与讨论。仿真结果显示,与传统的随机簇首生成算法和最小ID算法相比,该算法降低了簇内节点的重叠度,均衡了网络节点的能量消耗,延长了网络的生存时间。