基于KISOMAP-LDA-KNN算法TE过程故障诊断研究

针对化工连续生产过程的时序性及非线性等特征,文章提出了一种基于KISOMAP-LDA-KNN的非线性故障辨识方法。首先采用核等距映射（KISOMAP）算法在保持训练数据内在几何结构下进行非线性降维,然后使用线性判别（LDA）算法保持数据的最佳分类效果下进行降维,完成过程的特征提取,最后用K近邻（KNN）算法进行模式分类。将上述方法应用到TE过程,仿真结果验证了该故障诊断方法有较高的辨识能力。     

PKI网络信任模型的分析与研究

信任模型是整个网络安全体系的基础,决定了在网络上采用信任的形式与采用该形式带来的信任风险,并提供了建立和管理信任关系的框架。可见,对于信任模型的研究在网络安全中非常重要。文章着重分析了基于PKI的各类信任模型的信任机制、认证过程及其存在优缺点,指出了各类信任模型对网络信息安全产生影响的主要原因。通过总结与对比,指出了PKI信任模型的设计策略与发展趋势。     

基于WebGIS的成都市基准地价信息系统的构建

以ASP.NET2.0为开发工具,GeoMedia WebMap 6.0为GIS平台,针对决策层、土地管理工作者、社会公众对基准地价信息的需求,设计并开发了成都市中心城区基准地价信息系统,该系统提供了成都市基准地价信息的查询、统计与分析、制图等功能一体化的网络地理信息服务,从而为管理、决策提供服务和参考,以及为公众提供成都市基准地价信息的查询、浏览服务。     

SPARC V8仿真系统设计与实现

嵌入式软件实时性、嵌入特性、反应性等特点,使得仿真测试成为嵌入式软件系统测试的一种有效测试方法。针对SPARC V8体系结构特点,综合考虑硬件系统工作流程和仿真器性能要求,提出了一种全数字仿真测试平台的设计方案。采用有限状态机构建系统模型,并对CPU仿真框架,内存系统框架,指令集仿真和测试用例生成方法等关键问题进行研究,实现了SPARC V8微处理器的内核仿真器和仿真调试器。仿真模型易于控制、移植,解决了传统测试环境中依赖硬件、灵活性差、错误难以定位等问题。     

Data-driven testing methodology for RFID systems

A radio-frequency identification (RFID) system including hardware and software may be updated from time to time after first time deployment. To ensure the reliability of the system, extensive tests are required. However, enumerating all test cases is infeasible, especially when the tests involve time-consuming hardware operations. To solve this problem, we propose a testing methodology for RFID systems which does not enumerate all test cases but rather those which are representative. A clustering method is adopted in selecting representative test cases. Although a small number of selected test cases are run, we can still obtain a relatively high bug detection rate compared with running the enumerated test cases. Our extensive experiments show the efficiency and effectiveness of our testing methodology.     

A multi-objective decision making model for the vendor selection problem in a bifuzzy environment

In this paper, we focus on the vendor selection problem (VSP) for material supply in large-scale water conservancy and hydropower construction projects, and establish a corresponding model to solve this problem. After stating the problem, we introduce some basic knowledge of level-2 fuzzy sets and the way to transform them to normal fuzzy sets. Then we use the CCP model to handle the bifuzzy objective functions and constraints, based on a series of preparations, we transform the multi-objective integer model under bifuzzy environment into a deterministic model, then use particle swarm optimization (PSO) to solve this problem. The model is illustrated with an actual application to construction material supply.     

Robust anti-sliding control of autonomous vehicles in presence of lateral disturbances

Path following control problem of autonomous vehicles is investigated, concerning both unmeasurable sliding effects and lateral disturbances which lead to some difficulties in designing autonomous control under complex environment. To deal with the sliding effects, sideslip angles are modeled and reconstructed by estimating the tire cornering stiffness, which plays important role in analyzing the sliding effects. To this end, a Luenberger-type observer is designed, which is able to identify the tire cornering stiffness adaptively even in presence of time-varying lateral disturbances. Furthermore, to guarantee high-precision guidance, a sliding mode controller is designed based on chained system theory, and this controller is shown to be robust to both the lateral disturbances and the inaccuracy of the sliding reconstruction. Simulations illustrate that the proposed methods can reconstruct the sliding angles and provide high-accuracy anti-sliding control even in presence of the time-varying lateral disturbances.     

基于文本挖掘与功能相似性的疾病基因预测

现有疾病基因预测方法大多利用致病基因的各类注释信息进行预测,但仍有很多疾病没有任何注释信息。针对该问题,提出一种基于文本挖掘与功能相似性的疾病基因预测方法,通过数据挖掘获取疾病的相关基因本体术语,利用功能相似性分析基因与疾病之间的相关程度,并根据该相关程度对所有候选基因进行排序,从而识别出致病基因。测试结果显示,该方法能有效预测没有已知功能注释的致病基因。     

基于文件拆分与高斯消去的线性方程组求解

针对集群系统内存不足导致大规模矩阵无法调入的情况,设计并实现一种基于文件拆分与高斯消去的线性方程组求解算法,将大规模系数矩阵文件连续拆分为多个规模可控的子文件进行存储和计算,使服务器空闲内存小且具有较好的计算能力。在ABEEMσπ模型中的应用结果表明,当Altix3700服务器任务提交量大、CPU占有率高时,该算法仍可以计算出蛋白质分子的电荷分布。     

振动故障诊断的Petri网模型及系统实现

针对机械振动故障的传播特点,提出5种故障诊断的Petri网模型及其相应的故障诊断算法,用软件工程方法进行分析、设计和实现,得到机械振动故障诊断的Petri网系统。实践证明该方法能降低故障误诊率和漏诊率,解决复杂环境下机械振动故障诊断和故障预报的难题。