一种ECC加固SRAM空间可靠性评估算法

在SRAM抗辐射加固设计中,纠错编码(Error Correcting Code,ECC)是一种解决空间环境中SRAM单粒子翻转效应的有效方法。但目前国内外对于基于ECC加固的SRAM可靠性评估体系的研究并不完全成熟,还没有一个统一的标准。基于空间环境下SRAM所产生软错误的错误分布图样特性和错误重叠特性,对已有的基于ECC加固的SRAM空间可靠性评估方案进行修正,得到了一种更加精确的评估模型。     

镶嵌式铂热敏电阻环境可靠度评估及失效分析

依据镶嵌式铂热敏电阻Pt1000企业标准及国军标,进行了环境试验,并采用经典法、信赖法和贝叶斯方法,对镶嵌式铂热敏电阻pt1000进行了环境可靠度评估,推断出热敏电阻环境可靠度。利用环境试验所暴露的问题,指出该热敏电阻高温环境可靠度较低,为进一步改进工艺,提高产品质量提供了依据。同时,进行了产品的失效分析,总结出敏感铂膜高温性能变化是导致热敏电阻失效的主要因素。     

基于可靠度的LDPC译码算法及其性能分析

由于低密度奇偶校验码(LDPC)具有逼近香农(Shannon)极限的优良性能和可实现高速编译码的潜力,使之成为信道编码领域最受瞩目的研究热点之一。主要研究对象是LDPC码的译码算法。先后介绍了LDPC码的基本概念和原理、编译码的结构原理和基于可靠度的迭代大数逻辑译码算法(RBI-MLGD)流程。译码算法是LDPC码的关键,译码复杂度的高低直接影响着系统的实现。通过Visual C++6.0编写该译码算法程序,并对该码字在8比特和4比特的量化参数下进行了算法仿真,结合Matlab 7.1对获得的数据进行画图,得到了针对该码字在RBI-MLGD算法下的译码效果。     

LED可靠性评估的加速寿命试验设计方法

介绍了一种关于发光二极管（LED）可靠性评估的加速寿命试验设计方法。通过这个方法,在针对LED的性能退化现象和运行不稳定问题进行加速试验设计时,可以在已知目标可靠度和置信度的前提下,定量地确定满足可靠性要求的试验用样本量、加速应力水平以及试验时间。同时,用于发光二极管加速寿命试验的基本设计思想,可以广泛地应用于常见电子元器件的器件产品质量认证或可靠性评估等试验设计中。     

快速电磁计量软件包设计及应用

在现代电磁现象随处可见的信息时代中,电磁场理论被广泛应用到科学技术的各个领域中,比如移动通讯、无线电波传播、雷达技术、天线、卫星通信、微波电子线路等,各种不同形式的应用对电磁场理论提出了较高的要求,但是全新的应用对电磁场问题的快速求解也越来越依赖.为了满足工程使用的需求,电磁学就要不断的改善及改进,从而能够解决计算机存储量及运算速度不断发展,从而使其受到限制的问题.将计算机技术及数值算法相结合,提高复杂目标问题求解的快速性及精准性,为电磁使用提供基础.基于此,本文就对快速电磁计算软件包的设计进行研究,并且对其的应用进行描述.     

基于AHP的雷达模拟器评估影响因素权重设计算法研究

利用AHP层次分析法设计雷达模拟器软件算法。提出了一种基于层次分析法设计软件评估中各影响因素权重的新的方法,该方法能够较准确量化各影响因素所占比重,同以前的通过专家估测方法确定权重相比,这种方法更科学性,抛弃了主观色彩,通过计算矩阵,快速计算出各权重数值,并且可以经过简单验证,证实设计的权重值是否合理。所得到的结果和专家的推测结果进行比较,证明了这种权重设计算法在模拟器评估中的可行性。     

决策树算法在应急预案评估中的应用分析

为了有效应对各种突发事件,国家编制了各种突发事件应急预案。这些预案,需要有一定的方法评估它们的有效性。首先,论述了当前一些预案评估的相关研究成果和评估方法,并且针对这些评估方法的优缺点,提出了采用基于大样本的决策树算法评估预案的方法;其次,通过对评估指标数据类型的分析,采用聚类算法实现对评估指标进行分类。该方法可以有效的减少预案评估中人为因素的影响,对应急预案评估的研究具有指导意义。     

计算机加固评价平台的研究与设计

本文基于加固计算机评价目标,设计了计算机加固评价平台,平台模块包括基础数据模块、数据采集模块、数据处理模块、评估模型模块和评价分析模块。论文重点论述了基于灰色模型的加固评估模型和基于第三方测试数据的评价模型。通过论文设计的计算机加固评价平台,提高了计算机加固评价的准确性。     

计算机算法设计研究与思考

计算机算法设计课程是计算机学科的核心课程。本文介绍了计算机算法设计课程的特点,并且分析了存在的问题,提出了改进措施。     

An algorithm to solve integer programming problems: An efficient tool for reliability design

In many reliability design problems, the decision variables can only have integer values. The redundancy allocation is an example of one such problem; others include spare parts allocation, or repairmen allocation, which necessitate an integer programming formulation. In other words, integer programming plays an important role in system reliability optimization. In this paper, an algorithm is presented which provides an exact, simple and economical solution to any general class of integer programming problems and thereby offers reliability designers an efficient tool for system design. The algorithm can be used effectively to solve a wide variety of reliability design problems. The scope of use of this algorithm is also indicated and the procedure is illustrated by an example.     

An algorithm for computing the reliability of weighted-k-out-of-nsystems

This paper constructs a new k-out-of-n model, viz, a weighted-k-out-of-n system, which has n components, each with its own positive integer weight (total system weight=w), such that the system is good (failed) if the total weight of good (failed) components is at least k. The reliability of the weighted-k-out-of-n:G system is the complement of the unreliability of a weighted-(w-k+1)-out-of-n:F system. Without loss of generality, the authors discuss the weighted-k-out-of-n:G system only. The k-out-of-n:G system is a special case of the weighted-k-out-of-n:G system wherein the weight of each component is 1. An efficient algorithm is given to evaluate the reliability of the weighted-k-out-of-n:G system. The time complexity of this algorithm is O(n.k)     

An improved algorithm for coherent-system reliability

This paper presents a simpler and more efficient algorithm (LVT), based on the one proposed by Veeraraghavan and Trivedi (VT), to calculate system reliability using `sum of disjoint products' and `multiple variable inversion' (MVI) techniques. A proposition, a state space division idea, and a theorem are introduced. To compare LVT with several well known MVI algorithms (viz. VT, KDH88, CAREL) the 4 algorithms are implemented on the same platform (Solaris), and the execution-time comparison shows the computational saving achieved by LVT is appreciable     

An improved algorithm for symbolic reliability analysis

The authors describe an efficient Boolean algebraic algorithm to compute the probability of a union of nondisjoint sets as applied to symbolic reliability analysis. Coherent networks and fault-trees with statistically-independent components characterized by their minimal pathsets or cutsets are used as examples for generating the nondisjoint sets. The algorithm uses the concept of multiple variable inversion originally proposed by A. Grnarov et al. (1979). The authors illustrate improvements in the use of the multiple variable inversion technique for this problem using two examples. The algorithm is extended to compute the reliability importance of a given component (sensitivity of system reliability to the component reliability). A computer program implementing the modified algorithm is used to solve and obtain measured time complexities for a large set of network and fault tree models     

A hierarchical reliability analysis for circuit design evaluation

We suggest a computationally efficient and flexible strategy for assessment of reliability of integrated circuits. The concept of hierarchical reliability analysis proposed relies on doing reliability assessments during the design and layout process [reliability computer aided design (RCAD)]. Design rules are suggested based on calculations of steady-state mechanical stresses built up in interconnect graphs and trees due to electromigration. These design rules identify a large fraction of interconnect graphs in a typical design as immune to electromigration-induced failure. The stated design rules are an extension of the Blech-length concept to interconnect graphs. Our suggested new strategy will have important implications for design and layout processes as design limits for a given technology are reached     

The recursive variance-reduction simulation algorithm for network reliability evaluation

This paper proposes a new formulation of the recursive variance-reduction Monte Carlo estimator of the /spl kappa/ terminal unreliability parameter of communication systems. This formulation allows significant reduction in the simulation execution time, as demonstrated by experimental results.     

On improved confidence bounds for system reliability

In this paper, new bounding strategies are presented to improve confidence interval estimation for system reliability based on component level reliability, and associated uncertainty data. Research efforts have been focused on two interdependent areas: 1) development & improvement of analytical approaches for quantifying the uncertainty associated with the system reliability estimate when data regarding component reliability is available; and 2) based on these analytical approaches, generating statistical inference methods that can be used to make accurate estimations about the reliability of a system. The analytical approach presented relies on a recursive rationale that can be applied to obtain the variance associated with the system reliability estimate, provided the system can be decomposed into a series-parallel configuration. The bounding procedure is independent of parametric assumptions regarding component time to failure, and can be applied whenever component reliability data are available. To assess the validity of the proposed procedure, three test cases have been analyzed. For each case, Monte-Carlo simulation has been used to generate component failure data, based on nominal component reliability values. Based on these simulated data, lower bounds have been constructed, and then compared against nominal system reliability to generate an expected confidence level. The results obtained exhibit a significant improvement in the accuracy of the confidence intervals for the system reliability when compared with existing approximation methods. The procedure described is effective, relatively simple, and widely applicable.     

A new recursive algorithm for the reliability evaluation of a distributed program

The reliability of a distributed program is very sensitive to the ways of file distribution, and communication system topology. It is usually much more complex to analyze the reliability of distributed program than that of the network reliability. This paper presents a distributed program reliability analysis algorithm that is developed based on the concept of sharp operation. The algorithm provides a (E−n+2) * E memory space requirement and O(n+E+E*N_t) computation time, where E is the number of edges, n is the number of nodes, and N_t is the number of file spanning trees in the corresponding graph of distributed system, respectively. Compared with existing algorithms, the proposed algorithm is considered more economic both in time and space.     

An efficient algorithm for computing global reliability of anetwork

Global reliability of a network is defined and then evaluated using spanning trees of the network graph. An algorithm for generating spanning trees (termed, appended spanning trees) that are mutually disjoint is proposed. Each appended spanning tree represents a probability term in the final global reliability expression. The algorithm gives the global reliability of a network directly. It is illustrated with an example. The algorithm is fast, requires very little memory, is adaptable to multiprocessors, and can be terminated at an appropriate stage for an approximate value of global reliability     

一种评估软件可靠性的方法

首先介绍了模糊综合评判法的概念,接着论述了模糊综合评判法的评估方法和步骤,并简单介绍了综合评判的四种模型,最后运用模糊评估方法评估了某通信网综合网络管理系统的软件系统的可靠性。