Diagnosis of leakage faults with I DDQ

Recently there has been renewed interest in fault detection in static CMOS circuits through I _DDQ monitoring. This work shows that, in addition to fault detection, accurate fault diagnosis may be performed using a combination of current and voltage observations. The proposed system combines a simple single fault model for test generation with a more realistic multiple defect model for diagnosis, and as a result requires only minor modifications to existing stuck-at fault ATPG software. The associated hardware is sufficiently simple that on-board implementation is possible. Experimental results demonstrate the effectiveness of the method on a standard-cell ASIC.     

基于混沌预测的宽带DVB-RCS卫星接入信道动态分配方案研究

该文概述了基于卫星数字视频广播-反向信道系统(DVB-RCS)标准的宽带卫星通信网的特点,并重点研究了多址接入信道的动态分配策略,在利用混沌理论对网络中的自相似业务流量进行预测的基础上,提出了一种新型混合按需分配多址接入方案。该文还利用OPNET软件建立了仿真系统,用于比较不同方案的性能。仿真结果表明,在高信道负载以及网络中业务流具有较高自相似程度的条件下,该文所提出方案具有更优越的性能。     

Improved Defect and Fourier Transform Infrared Spectroscopy Analysis for Prediction of Yield for HgCdTe Multilayer Heterostructures

The ability to accurately predict HgCdTe focal plane array (FPA) performance using nondestructive, postgrowth wafer analysis is of great importance. These predictions, if accurate, reduce costs by screening the wafers prior to processing, and selecting only those wafers that are most likely to yield FPAs that meet program specifications. In this paper, we examine the use of a macrodefect inspection tool, the NSX 1255, from August Technology. This inspection tool has the ability to measure defects 0.5 μm and larger and store the location and size data to a file. We have then, through the use of custom written software, been able to analyze these data on a wafer by wafer basis. We have also incorporated the use of a thin film transmission matrix model to analyze room-temperature Fourier transform infrared spectroscopy (FTIR) transmission spectra. This technique, which is applied to the entire wafer surface, can be used to determine the individual layer thicknesses as well as their compositions. Then, using analytical expressions for bandgap, absorption, and index of refraction, we can predict responsivity and quantum efficiency. Through the use of these two inspection tools and our analysis software, we are able to overlay FPA die information and perform statistics on a die-per-die basis. This allows us to effectively “pass” or “fail” each FPA based on the program specifications. We are then able to set a minimum criterion for the number of FPAs that pass on any given wafer. That wafer is then sent off to processing if it meets this criterion. Furthermore, knowing why a wafer fails before it reaches processing allows for real time feedback to the epilayer growth process. This allows for run-to-run adjustments in order to keep as many wafers within specifications as possible and increases yield overall. (Received October 24, 2006; accepted Feburary 26, 2007)     

Design of coating for broadband polarization- independent beam splitters and analysis of its optical performance

Thebeamsplitters(BS)havedemonstratedwideap plicationinmanyopticalsystemsandplayakeyrolein interferometryandholography[1].ThemechanismofBScanbedividedintotwocategories:oneutilizesthereflec tionandrefractionontheinterfacebetweentwodielec tricmedia;theotheru…     

Numerical analysis of thermal distortion of the mirror in space-to-ground laser communication links

Thereis cold-heat exchange under the large tempera-ture gradient in the space environment ,andin space-to-ground laser communication links the optical reflectorson a satellite in orbit someti mes need to be placed out-side the capsule.Therefore,tremendous thermal distor-tions will occur onthe optical mirror surface,which maybring shift andspreading ofits reflectedfocus andthere-by influences the performance of space-to-ground lasercommunicationlinks . Although there are many reports on thermal…     

I DDQ testing: A review

Quiescent power supply current (I _DDQ ) testing of CMOS integrated circuits is a technique for production quality and reliability improvement, design validation, and failure analysis. It has been used for many years by a few companies and is now receiving wider acceptance as an industry tool. This article begins with a brief history of CMOS ICs to provide perspective on the origin of I _DDQ testing. Next, the use of I _DDQ testing for IC quality improvement through increased defect and fault detection is described. Then implementation issues are considered, including test pattern generation software, hardware instrumentation, limit setting, IC design guidelines, and defect diagnosis. An extended reference list is provided to help the reader obtain more information on specific aspects.     

Quietest: A methodology for selecting I DDQ test vectors

Even high stuck-at fault coverage manufacturing test programs cannot assure high quality for CMOS VLSI circuits. Measurement of quiescent power supply current (I _DDQ ) is a means of improving quality and reliability by detecting many defects that do not have appropriate representation in the stuck-at fault model. Since each I _DDQ measurement takes significant time, a hierarchical fault analysis methodology is proposed for selecting a small subset of production test vectors for I _DDQ measurements. A software system QUIETEST has been developed on the basis of this methodology. For two VLSI circuits QUIETEST selected less than 1% of production test vectors for covering all modeled faults that would have been covered by I _DDQ measurement for all of the vectors. The fault models include leakage faults and weak faults for representing defects such as gate oxide shorts and certain opens.     

A μ Approach to Robust Stability Analysis of nD Discrete Systems

This paper considers the robust stability analysis problem of multidimensional (nD) discrete systems. It is shown that the problems of stability test and stability margin computation for an nD system described by Roesser model can be recast into analysis problems in a unified way, thus can be solved effectively by using the commercially available software package. Several numerical examples are presented to illustrate the new methods.     

Optical-fiber distributed temperature sensor: design and realization

Through analyzing theoretically the temperature effect of the optical-fiber Raman backscattering, a distributed temperature sensor is designed based on the single-mode fiber. Demodulation methods of temperature transduction are compared, and then the demodulation method using the ratio of the anti-Stokes and the Stokes Raman backscattering intensity is adopted. Both the hardware composition and the software realization of the system are introduced in detail. The experiment shows that the distinguishing ability of the temperature and that of the space are 1℃ and 2 m, respectively, and that the system response time is about 180 s with a sensing range of 5 km and with a temperature measurement range of 0-100℃.     

Novel video coding algorithm based on 3D-binDCT

In this paper we propose a three dimensional multiplierless discrete cosine transform（DOT） with lifting scheme called 3D-binDCT. Based on 3D-binDCT, a novel video coding algorithm without motion estimation/compensation is proposed. It uses the 3D-binDCT to exploit spatial or temporal redundancy. The computation of binDOT only needs shift and addition operations, thus the computational complexity is minimized. DO coefficient prediction, modified scan mode and arithmetic coding techniques are also adopted. Extensive simulation results show that the proposed coding scheme provides higher coding efficiency and improves visual aualitv, and it is easy to be realized by software and hardware.     

基于功能性测试的软件质量模糊综合评判

对功能测试结果进行软件质量评估的方法进行了研究,将模糊数学的理论方法应用于功能性测试软件质量的综合评判中,提出了软件质量量化的评判方法。文中以一个实例证明该方法的可行性,为软件质量保证中的质量评估提供了一种新方法。     

Software maintenance: The need for standardization

Hardware and software maintenance are contrasted. The key difference between the two-the ease with which software can be changed-leads to the need for managing software change. Standardization of software maintenance is proposed as a method for managing software change. A model of software maintenance is advanced as the foundation for standardizing software maintenance     

基于Jenkins的持续集成测试环境插件开发

现代软件规模已经极具膨胀,软件测试所占用的时间的比例也越来越大,如何提供高效,快速,自动化,可定制的继承测试环境已经成为软件行业亟待解决的问题.DevOps和持续集成是一种软件开发实践,对于提高软件开发效率并保障软件开发质量提供了理论基础.Jenkins是一个开源软件项目,提供了一个开放易用的软件平台,使持续集成和自动化测试成为可能.     

Optimal software release policies for a non-homogeneous software error detection rate model

Optimal software release policies, which decide when to stop testing a software system and transfer it to the user, are discussed for a software reliability growth model with nonhomogeneous error detection rate. Two evaluation criteria, i.e. total expected software cost and software reliability, are introduced. The optimal software release policies respectively derived for each criterion and those simultaneously evaluating both criteria are discussed. Numerical examples on those optimal software release policies are presented for illustration.     

Visionen zum Entwurf universeller Kommunikationsnetze von morgen

The design of conventional telecommunications is based on high reliability, availability, security and, most important scarcity, of resources. About 90% of switch software and hardware is needed to comply with these requirements. However, are these assumptions still valid in a world where one fibre can deliver all the traffic in the Austrian switching network, where processing power and storage capacity double every one to one and a half years and where Wi-Fi networks promise ubiquitous wireless broadband access? Internet is an option, but it is not designed for the particularities of voice traffic. This article revisits the underlying design assumptions for today’s telecommunications network and tries to answer the question: How would you design a telecom network if bandwidth, processing power, storage capacity and frequencies were abundant?     

软件复用与软件构件技术

软件复用是在软件开发中避免重复劳动的解决方案。通过软件复用,可以提高软件开发的效率和质量。近十几年来,面向对象技术出现并逐步成为主流技术,为软件复用提供了基本的技术支持软件复用研究重新成为热点,被视为解决软件危机,提高软件生产效率和质量的现实可行的途径。     

嵌入式软件仿真开发系统的研究

为了给嵌入式软件开发者提供一个调试与测试嵌入式软件运行情况的"软"运行平台,我们开发了嵌入式软件仿真开发系统.本文在对嵌入式软件的开发和仿真调试器两部分进行简述之后,重点介绍了嵌入式软件仿真运行环境的仿真技术.     

A New Methodology for Predicting Software Reliability in the Random Field Environments

This paper presents a new methodology for predicting software reliability in the field environment. Our work differs from some existing models that assume a constant failure detection rate for software testing and field operation environments, as this new methodology considers the random environmental effects on software reliability. Assuming that all the random effects of the field environments can be captured by a unit-free environmental factor,$eta$, which is modeled as a random-distributed variable, we establish a generalized random field environment (RFE) software reliability model that covers both the testing phase and the operating phase in the software development cycle. Based on the generalized RFE model, two specific random field environmental reliability models are proposed for predicting software reliability in the field environment: the$gamma$-RFE model, and the$beta$-RFE model. A set of software failure data from a telecommunication software application is used to illustrate the proposed models, both of which provide very good fittings to the software failures in both testing and operation environments. This new methodology provides a viable way to model the user environments, and further makes adjustments to the reliability prediction for similar software products. Based on the generalized software reliability model, further work may include the development of software cost models and the optimum software release policies under random field environments.     

基于通用数字声纳平台的软件备份技术研究

按照软件工程的思想,运用读取代码、验证代码、备份代码的方法备份系统软件,通过对专用存贮芯片的代码重写,解决专用存贮介质上软件备份的难题,实现通用与专用存贮介质的软件备份,达到通用数字声纳平台软件备份研究的目的。为数字声纳装备的软件维护,特别是军用声纳装备的战场快速保障提供了借鉴参考,具有重要的现实意义。该文从软硬件两方面解决了专用存贮介质上声纳软件备份的难题;实现了多种文件系统及不同存贮格式上的系统软件备份;在软件备份研究中汲取了软件工程的思想。     

商业固体激光器设计软件应用研究

利用计算机软件对固体激光器进行数值分析对于激光器设计与优化具有重要的理论指导意义。按照软件来源不同,目前固体激光器设计软件可分为个人开发软件和专用商业软件两种。由于专用商业软件较个人开发软件具有更高的集成度和计算效率而被广泛应用到实践中。采用商业固体激光器设计软件的典型代表ASLD,理论设计了一台典型的调Q激光器,并实际测试了该激光器的输出效果。通过分析理论仿真和实验结果之间的误差得出如下结论:使用商业软件进行固体激光器设计时的确能显著提高设计效率,但也需要对软件使用的物理模型有足够的了解。当软件采用的物理模型能够满足实际需求时,输入合理的初始参数,该软件才能正常工作。当软件采用的物理模型精度不够时,仍然需要进行二次开发或者重新开发。