Vehicular Channels: Characteristics,Models and Implications on Communication Systems Design

Wireless Personal Communications - The application of information and communication technologies to road transportation systems can significantly improve safety and traffic flow. This requires...     

半电波暗室背景噪声处理分析

针对半电波暗室在测试过程中常见的一些异常背景噪声,建立了一个辐射骚扰测试系统,通过仿真软件每日对场地的背景噪声进行监测并记录数据,最后得出半电波暗室背景噪声优化处理的一些方法。     

Real-Time Adaptive Background Modeling for Multicore Embedded Systems

Current trends in microprocessor design integrate several autonomous processing cores onto the same die. These multicore architectures are particularly well-suited for computer vision applications, where it is typical to perform the same set of operations repeatedly over large datasets. These memory- and computation-intensive applications can reap tremendous performance and accuracy benefits from concurrent execution on multi-core processors. However, cost-sensitive embedded platforms place real-time performance and efficiency demands on techniques to accomplish this task. Furthermore, parallelization and partitioning techniques that allow the application to fully leverage the processing capabilities of each computing core are required for multi-core embedded vision systems. In this paper, we evaluate background modeling techniques on a multicore embedded platform, since this process dominates the execution and storage costs of common video analysis workloads. We introduce a new adaptive backgrounding technique, multimodal mean, which balances accuracy, performance, and efficiency to meet embedded system requirements. Our evaluation compares several pixel-level background modeling techniques in terms of their computation and storage requirements, and functional accuracy for three representative video sequences, across a range of processing and parallelization configurations. We show that the multimodal mean algorithm delivers comparable accuracy of the best alternative (Mixture of Gaussians) with a 3.4× improvement in execution time and a 50% reduction in required storage for optimal block processing on each core. In our analysis of several processing and parallelization configurations, we show how this algorithm can be optimized for embedded multicore performance, resulting in a 25% performance improvement over the baseline processing method.     

Constrained Information Combining: Theory and Applications for LDPC Coded Systems

This paper tightens previous information combining bounds on the performance of iterative decoding of binary low-density parity-check (LDPC) codes over binary-input symmetric-output channels by tracking the probability of erroneous bit in conjunction with mutual information. Evaluation of the new bounds as well as of other known bounds on different LDPC ensembles demonstrates sensitivity of the finite dimensional iterative bounds to lambda₂, the fraction of edges connected to degree 2 variable nodes     

Modules and Behaviours in nD Systems Theory

This paper is intended both as an introduction to the behavioural theory of nD systems, in particular the duality of Oberst and its applications, and also as a bridge between the behavioural theory and the module-theoretic approach of Fliess, Pommaret and others. Our presentation centres on Pommaret's notion of a system observable, and uses this concept to provide new interpretations of known behavioural results. We discuss among other subjects autonomous systems, controllable systems, observability, transfer matrices, computation of trajectories, and system complexity.     

The Social Implications of Health Care Communication Systems

This paper discusses some of the changes that might take place in this nation's health care system with the advent of national health insurance. These changes include structural reforms, planning and regulation, and the introduction of quality assurance mechanisms. The paper argues that a health care system will evolve that is both aggregated and regulated; and it foresees that computer and communication technologies will play significant roles in this evolution. The paper concludes by discussing some potentially harmful social consequences of these developments.     

一种扩展故障安全系统理论

本文以广义故障安全系统理论和扩展故障安全概念为基础,提出了一种扩展故障安全系统理论,它包括电路的扩展故障安全特性的有关定义、基本电路的模块结构及模块之间互连的条件等内容。     

家用变频空调器控制电路原理与维修技术

随着人民生活水平的提高，家用空调进入千家万户，但传统的空调能耗大，长期使用需要支付大量的电费，特别是能源日益紧张的今天，推广节能技术成为当务之急。在这种情况下，变频调速技术最近几年在我国得到了迅速发展，本文结合美的KFR-50LW/FBPY变频空调器，重点分析了家用变频空调器控制电路的基本原理和维修技术，对于工程技术人员快捷的维修变频空调器，家庭人员更好的用好变频空调，更好地满足人民日益增长的物质生活的需要，有着十分重要的意义。     

A Family of P Systems for Solving Linear Equations

Solving linear equations is one of the fun-damental problems in numerical calculation and has a wide application in many science and engineering fields. We present a family of P systems to solve linear equations in which the coeffi cients are real numbers. An instance is given to illustrate the feasibility and eff ectiveness of our designed P systems. Our work contributes to make P sys-tems to solve more complicated computation problems ef-fectively.     

试谈“信号与系统”课程理论与实践之结合

"信号与系统"是高校电工程和信息科学类甚至更多专业的一门重要基础课程。为了进一步提高课程质量,当前改革的首要任务是与理论分析密切配合大力加强工程案例的应用,本文给出了大量新颖生动的应用案例,并指出这些案例的选取背景和原则。最后笔者研究了在加强工程应用的同时如何拓展和深化数学工具之应用。     

脊波导族的多极理论分析

本文提出用多极理论准解析法计算不满足多极理论展开条件的脊波导本征值问题,介绍计算二维Helmholtz方程边值问题的多极理论准解析法计算规则,实例计算结果表明：多极理论准解析法具有较高的计算精度,是计算复杂截面波导本征值问题的一种有效方法,可以很方便地应用于复杂截面波导工程问题的设计与计算。     

基于全变分理论的红外图像背景抑制

针对红外单帧图像的小目标检测问题,提出基于全变分理论的背景杂波抑制的改进算法。构建以能量函数极值最优化为主体的全变分模型,结合自适应步长和非单调性线搜索条件,形成改进的全变分算法,在红外图像背景抑制方面取得良好效果。经过仿真实验测试几种算法的抑制效能,分析结果表明改进算法的检测性能较传统算法在杂波抑制、减少边缘虚警等方面均有优势,能够满足实时性要求,且适用于复杂背景的工程实现。     

Frequency Response Envelopes of a Family of Uncertain Discrete-Time Systems

An efficient technique is presented for the calculation of the exact amplitude and phase frequency response envelopes (Bode envelopes) of an infinite impulse response filter (i.e., a real rational function in a complex variable) with interval uncertainty in the coefficients. In the first stage, the order of complexity is reduced from 2ⁿ to n², using the structure of the value set. In the second stage, the problem is completely solved by calculating the frequency response of a finite number of pertinent transfer functions with fixed coefficients. The computations involved in this stage consist of finding a number of zeros of certain polynomials plus some combinatorics. The algorithm extends easily to complex coefficient filters with box uncertainties. Also, the problem trivializes for complex filters with disk uncertainties. However, this latter case leads to extremely simple and completely analytic bounds for the frequency response envelopes of both real and complex coefficient filters.     

基于蓝牙的家庭监控报警系统

本文提出基于蓝牙技术的家庭监控报警系统,并对系统所用到的ROK101 007蓝牙模块和S3C4510B微处理器做了简要描述,论述了系统的硬件及软件设计并给出了程序流程图.该系统能够实时监控终端探测设备的信息,并同监控中心交换数据,当有突发事件时,系统能够及时发出报警.     

Extension Modules in Behavioral Linear Systems Theory

For certain signal spaces, the algebraic concept of extension modules yields a full classification of system theoretic properties such as controllability and autonomy. The present paper summarizes the results of various authors on the subject, and unifies them in the language of extension modules. The computation of extension modules is based on the computation of syzygies (i.e., kernels of module homomorphisms). This can be done constructively, using the theory of Gröbner bases.     

Unleashing the Effectiveness of Process-Oriented Information Systems: Problem Analysis, Critical Success Factors, and Implications

Process-oriented information systems (IS) aim at the computerized support of business processes. So far, contemporary IS have often fail to meet this goal. To better understand this drawback, to systematically identify its rationales, and to derive critical success factors for business process support, we conducted three empirical studies: an exploratory case study in the automotive domain, an online survey among 79 information technology professionals, and another online survey among 70 business process management experts. This paper summarizes the findings of these studies, puts them in relation with each other, and uses them to show that ";process orientation"; is scarce and ";process awareness"; is needed in IS engineering.     

Minimum-Error Splitting Algorithm for a Dual Layer LCD Display—Part I: Background and Theory

A Dual Layer high dynamic range liquid crystal display (LCD) can be built by stacking two panels one on top of the other. In this way, the dynamic range is theoretically squared and the bit depth is also increased. However, in order to minimize the parallax and reconstruction errors, dedicated splitting algorithms are needed to generate the two images which drive the panels. In this paper, we present an algorithm, based on variational techniques, which seeks the joint minimization of both errors. We propose a simplified visible difference metric that exploits some limitations of the human visual system and can be easily incorporated into an optimization algorithm. The image splitting task is formulated as a quadratic programming problem, which can be efficiently solved by means of appropriate numerical methods. Preliminary tests on medical images showed that the algorithm has good performances and appears robust with respect to the parameter adjustment.