内存泄漏故障静态分析研究

目前研究人员主要采用静态测试技术实施对内存泄漏故障的检测,其基本思想就是依据待测程序的控制流图来设计特定的算法以检测内存泄漏问题,但这些方法的不足之处主要是控制流图的表示方式上未含有进一步可用信息,因此所设计的算法不能很好地执行该故障的检测任务.为此,定义了一种用于内存泄漏故障检测的控制流图,提出控制流图可达路径生成算法,然后根据生成的路径进行内存泄漏故障的检测与分析.实验证实,该方法取得了理想的效果.     

An expert system for fault diagnosis in internal combustion engines using probability neural network

An expert system for fault diagnosis in internal combustion engines using adaptive order tracking technique and artificial neural networks is presented in this paper. The proposed system can be divided into two parts. In the first stage, the engine sound emission signals are recorded and treated as the tracking of frequency-varying bandpass signals. Ordered amplitudes can be calculated with a high-resolution adaptive filter algorithm. The vital features of signals with various fault conditions are obtained and displayed clearly by order figures. Then the sound energy diagram is utilized to normalize the features and reduce computation quantity. In the second stage, the artificial neural network is used to train the signal features and engine fault conditions. In order to verify the effect of the proposed probability neural network (PNN) in fault diagnosis, two conventional neural networks that included the back-propagation (BP) network and radial-basic function (RBF) network are compared with the proposed PNN network. The experimental results indicated that the proposed PNN network achieved the best performance in the present fault diagnosis system.     

面向方面软件动态耦合的度量

耦合性是两个模块间相互作用的测度。面向方面编程是一种新的编程范型,它支持关注点的分离。目前,对于面向方面软件耦合度量的常用方法是对软件进行结构分析和静态代码分析。然而,由于系统中的动态绑定以及代码中大量无用的方面代码导致静态度量结果无法精确地反映程序运行时的实际耦合。首先提出适用于面向方面软件的动态耦合度量框架。接着,在该框架的基础上,根据不同的耦合关系类型,形式化定义了动态耦合度量指标集,并验证数学属性。最后,讨论了动态耦合度量工具的实现。     

列车折关检测系统分析及数据处理算法研究

折角塞门非正常关闭问题至今仍是列车制动系统中一个未完全解决的难题.文章介绍了列车折关检测系统原理,分析了检测系统中的主要功能模块;针对检测数据处理的关键技术,给出了相应解决算法,实验表明处理算法理想有效.     

Immersed boundary method and lattice Boltzmann method coupled FSI simulation of mitral leaflet flow

Coupling the immersed boundary (IB) method and the lattice Boltzmann (LB) method might be a promising approach to simulate fluid-structure interaction (FSI) problems with flexible structures and moving boundaries. To investigate the possibility for future IB-LB coupled simulations of the heart flow dynamics, an IB-LB coupling scheme suitable for rapid boundary motion and large pressure gradient FSI is proposed, and the mitral valve jet flow considering the interaction of leaflets and fluid is simulated. After analyzing the respective concepts, formulae and advantages of the IB and LB methods, we first explain the coupling strategy and detailed implementation procedures, and then verify the effectiveness and second-order accuracy of the scheme by simulating a benchmark case, the relaxation of a stretched membrane immersed in fluid. After that, the diastolic filling jet flow between mitral leaflets in a simplified 2D left heart model is simulated. The model consists of the simplified transmitral passage of the heart and two curvilinear leaflets. In the simulation, the atrial and ventricular pressure histories of normal human are specified as boundary conditions, and the leaflets are treated as fibers that interact with the fluid to define their deformations and movements. The resulting opening and closing movements of the leaflets and the flow patterns of the filling jet are qualitatively reasonable and compare well with existing numerical and measured data. It is shown that this IB-LB coupling method is feasible for treating flexible boundary FSI problems with rapid boundary motion and large pressure gradient, the results of the mitral leaflet flow are valuable for understanding the transmitral FSI dynamics, and it is possible to simulate the more realistic 3D heart flow by the scheme in the future.     

校园局域网常见故障的解决办法及网络安全问题

本文对校园局域网络常见的故障以及网络安全问题作简要分析,从硬件与软件的角度针对不同类型故障,分别分析了产生的原因,探讨了一些解决问题的方法,这对校园网络管理和维护工作具有一定的借鉴意义。     

一种基于PCNN的指纹特征提取算法

具有生物背景的脉冲耦合神经网络具有自适应提取指纹特征的特性,基于此,首次提出了一种指纹图像特征提取的新方法一一自适应耦合神经网络点火统计图的,此图不仅包含了指纹图像的灰度特征,还包含相邻像素之间的几何位置信息。此方法具有运算速度快及对旋转、平移、尺度不变性,是许多指纹特征提取算法不具备的优点。最后给出了部分实验的结果,以验证该方法的有效性．     

片上网络容错路由算法分析和评价

片上网络技术是借鉴并行分布式计算机及传统计算机网络的概念解决片上多核系统的通信问题。片上网络代替片上总线通信,解决了片上总线结构所引起的可扩展性、效率、面积、功耗等问题。然而,片上网络在数据传输过程中可能由于各种原因产生故障,因此片上网络可靠性研究是当前一个研究热点。首先总结了片上网络故障分类,比较和分析了当前片上网络容错算法并给出其优势和缺陷,最后对全文进行总结,并给出了片上网络容错算法的展望。     

基于图的谱分割技术的面向对象软件系统分解*

主要是以一种带权类依赖图作为面向对象系统的UML类图的抽象表示,其中类依赖图的各边上权值对应于类图中的相应关系。针对带权类依赖图运用代数图论中图的Laplace谱的连通特性以迭代分割的方式对其进行划分,得到所需开发的系统构件。通过实验表明,该方法是一种有效的面向对象软件系统分解方法,并且分解所得到的构件具有较高的内聚性。     

偶联剂及其应用

本文综述了国内外各种偶联剂的类型、化学结构和偶联机理。简要介绍了它们在填充复合材料中的应用。