星载软件系统错误传播研究与分析

针对星载软件系统因宇宙射线和环境扰动而产生的软件错误及错误传播问题,研究星载软件系统错误传播分析方法.利用该方法从信号和模块2个层面评测软件的可靠性,并根据结果对系统信号或模块的脆弱性进行分析,找出系统较为脆弱的信号与模块,以及最可能传播错误的信号传播路径.定义信号与模块的错误传播率、暴露率等参数,设计参数的计算方法,...     

基于软件故障注入的星载系统错误传播研究

设计了信号故障传播率的计算方法,在此基础上设计了根据信号故障传播率进行故障注入实验,并根据故障注入实验的结果绘制错误传播图的方法.根据实验结果和错误传播图可以从信号和模块两个层次对系统进行分析,找出最为脆弱的部分,即找出最可能传播故障的信号和模块,以及最可能传播故障的一条路径.据此可对系统的可靠性做出评测.工作在高辐射环境下的各类软件系统,如星载系统,在运行过程中可能会因环境的扰动发生SEU现象,本文利用软件故障注入技术对这种现象进行模拟,进行故障注入实验,实验结果表明我们设计的算法能有效地对系统的可靠性做出评测.     

错误流模型:硬件故障的软件传播建模与分析

无论是可靠性工程还是软件可靠性中的可靠性模型,都难以描述硬件故障在程序中的传播问题.首先建立了计算数据流模型,并以无穷存储机器的指令集为例,说明可以为任意程序建立计算数据流图.在计算数据流模型的基础上,进一步建立了错误流模型.把计算过程中的错误分成物理错误和传播错误两种,通过分析这两种错误的本质和传播规律,给出了6条有关错误传播的规则和2条独立定律.根据这些规则和定律,能够计算出在程序运行过程中,任意时刻在任意位置上出现错误的概率.最后以一个简单的无穷存储机器程序为例,简要地展示了错误流模型描述硬件故障在     

基于错误传播分析的软件脆弱点识别方法研究

在太空环境中,软件系统经常受到各种辐射现象的影响.在此类环境下,寻找软件脆弱点主要是考虑环境扰动对该软件的影响.文中提出了一种由环境扰动引入的软件脆弱点的分析方法.首先在对软件系统模块化的基础上,通过在两个层面上分析错误在软件中的生成及其传播过程,给出寻找软件脆弱点的理论框架,随后进一步给出该框架中一些参数的实验估计方法,最后给出该框架在某卫星光纤陀螺捷联航姿控制系统上的应用.应用结果令人满意.     

软件中的错误传播研究

随着计算机技术的广泛应用，计算机软件的安全性显得越来越重要。为了保证软件的安全可靠，必须了解软件可能的错误行为，井采取相应的补救措施来提高其性能。本文采用了基于软件故障注入的方法，对计算机软件中数据状态错误的传播行为进行了研究。结果发现，在给定位置注入的数据状态错，要么所有的都会传播到输出，要麽一个也不会传播到输出。这表明软件测试中的大量数据状态的错误行为，可以通过少量的数据状态错误行为来进行模拟。     

一种引入复杂网络理论的软件数据流脆弱点识别方法

研究了卫星LTE上行同步系统在单粒子效应影响下软件数据流错误的脆弱点识别问题,并针对现有错误传播分析方法对大容量数据处理软件脆弱点识别存在较大偏差的问题,结合星载LTE上行同步处理大容量数据处理需求,引入复杂网络理论,提出一种基于网络节点度的软件数据流脆弱点识别方法.该方法以错误传播分析方法为基础,通过定义单粒子翻转错误渗透率,采用矩阵化描述方法构建了错误传播网络模型,将软件数据流脆弱点挖掘问题转换为网络关键节点挖掘问题,以一定的虚警概率搜索所有的局部极值,从而实现该虚警概率下全部的数据流脆弱点挖掘.仿真结果表明,该方法可有效识别星载LTE上行同步处理大容量数据处理中的脆弱点.     

软件配置错误诊断与修复技术研究

软件的多样性、复杂性、灵活性和高度可定制性对系统的正确配置提出了挑战,配置错误已经成为影响应用服务质量的关键问题之一.很多学者和研究机构致力于配置错误的检测、诊断和故障修复的相关技术和方法研究,以提高复杂应用系统的可用性和可靠性.为系统了解软件配置错误相关的研究现状和进展,建立了一种多方面、多角度的分析框架对该领域的主要研究工作进行分类总结和分析评价,该分析框架覆盖了方法类型、方式和适用范围这3个方面的多个角度.基于该分析框架的分析结果,总结了当前软件配置错误相关研究中存在的问题,并针对今后该领域的研究趋势进行了展望,对继续和深入研究具有一定的指导意义.     

用于电路级仿真软故障注入的自动化方法

为了克服电路级仿真故障注入评估软错误敏感性时烦琐费时的缺陷,提出一种将注入过程自动化的方法.使用LL(k)语法分析技术自动解析Spice网表,以自动提取故障注入目标的信息;由程序将网表自动展平,克服了多次例化的子电路无法注入单故障的问题;通过对展平后网表的遍历而自动插入表征软错误的电流源;开发了一个电路级软错误注入器HSECT-SPI,并针对ISCAS'85和ISCAS'89 Benchmark电路进行了故障注入实验,结果表明:文中方法适于自动分析单元和模块电路的软错误敏感性,并可指导高可靠集成电路的设计.     

光学仿真软件的系统架构设计

针对当前光学仿真技术的发展,为了更好的对光束在光波导器件中的实际传输过程进行仿真,从而更为准确地分析和描述光学现象及光学过程,在有限差分光束传播算法理论基础上,采用模块化方法设计光学仿真软件系统架构。系统架构主要包括布局编辑、仿真计算以及图形输出等三个模块,各个模块间通过接口进行数据处理。根据系统架构模块分析开发的光学仿真软件完成了各种光波导器件的编辑绘制、场分布计算以及波导仿真结果的图形可视化输出,并通过仿真实例的仿真过程及结果的数据对比分析验证了该软件系统设计对光束传播过程仿真的有效性,以及在集成光学研究中的实用价值。     

基于Agent的分布式软件部署系统框架的研究

针对分布式环境中的多模块软件的部署需求,提出了基于Agent的分布式软件部署的系统框架.在该框架下,对分布式软件参数描述语言进行定义和对分布式系统中的多节点机器的信息进行建模,提出可配置的分布式软件部署的决策算法,并在多Agent通信机制下对软件部署过程进行协同决策,实现了分布式软件的智能部署.     

An evaluation model for dependability of Internet-scale software on basis of Bayesian Networks and trustworthiness

Internet-scale software becomes more and more important as a mode to construct software systems when Internet is developing rapidly. Internet-scale software comprises a set of widely distributed software entities which are running in open, dynamic and uncontrollable Internet environment. There are several aspects impacting dependability of Internet-scale software, such as technical, organizational, decisional and human aspects. It is very important to evaluate dependability of Internet-scale software by integrating all the aspects and analyzing system architecture from the most foundational elements. However, it is lack of such an evaluation model. An evaluation model of dependability for Internet-scale software on the basis of Bayesian Networks is proposed in this paper. The structure of Internet-scale software is analyzed. An evaluating system of dependability for Internet-scale software is established. It includes static metrics, dynamic metrics, prior metrics and correction metrics. A process of trust attenuation based on assessment is proposed to integrate subjective trust factors and objective dependability factors which impact on system quality. In this paper, a Bayesian Network is build according to the structure analysis. A bottom-up method that use Bayesian reasoning to analyses and calculate entity dependability and integration dependability layer by layer is described. A unified dependability of the whole system is worked out and is corrected by objective data. The analysis of experiment in a real system proves that the model in this paper is capable of evaluating the dependability of Internet-scale software clearly and objectively. Moreover, it offers effective help to the design, development, deployment and assessment of Internet-scale software.     

构件软件的回归测试复杂性度量

基于构件的软件构建方法目前被广泛使用在软件开发中,用于减少软件开发的工程成本和加快软件开发进度.在软件维护过程中,由于构件更新或者新版本的发布,基于构件的系统会受到影响,需要进行回归测试.对于指定的软件修改需求,维护者可以实施不同的修改手段.不同的修改手段会导致不同的回归测试复杂性,这种复杂性是软件维护成本和有效性的重要因素.目前的研究没有强调构件软件的回归测试复杂性问题.基于修改影响复杂性模型和度量,提出一种回归测试的复杂性度量框架.该度量框架包括两个部分:基于图的模型和形式化度量计算.该度量可以有效表示构件软件分别在构件和系统层面的回归测试复杂性因素,可视化地体现复杂性变化.然后根据模型,提出具体的度量计算方式.最后,通过实验研究,针对同一个构件软件的相同修改需求,利用若干个实验组进行独立修改实施,然后比较回归测试的复杂性.实验结果表明,所提出的度量方式是可行和有效的.     

Software dependability evaluation based on Markov usage models

A general technique for computing optimal state transition probabilities for software tests, based on a Markov usage model, is developed. The optimization criterion is maximum precision of unbiased dependability estimates derived from the test results. Three different dependability measures are considered: (i) risk, (ii) safety, and (iii) reliability. As input, pre-information on failure probabilities and losses in case of failure related with single operations is used. The optimization itself is done by means of a numerical procedure which is fast because of the convexity of the underlying stochastic optimization problem. The procedure can be improved by the construction of a distribution with a common lower bound on state transition probabilities; this distribution may also be used in the more general context of structural statistical testing of software.     

一种结合AADL和IMC的系统可靠性建模方法

随着嵌入式软件在安全关键领域广泛应用,系统可靠性随着其规模、复杂度和性能需求的不断提升而愈显重要。结构分析设计语言AADL是应用于嵌入式领域的体系结构建模、分析和验证的重要手段。由于AADL是一种半形式化模型,需要精确描述其语义才能进行定量分析。提出一种基于AADL的系统可靠性建模方法。首先,结合AADL模型和AADL错误模型附件,得到AADL可靠性模型;然后,提出一种模型转换方法,将AADL可靠性模型的基本元素和错误传播等特殊元素转换到交互式马尔科夫链模型IMC,进行可靠性定量分析;最后,结合法国空中交通控制系统的实例,证明该方法的可行性和有效性。     

基于评价软件测试的有效性问题研究

随着软件产业的迅猛发展,软件产品的规模越来越大,复杂度越来越高,但是软件产品质量却变得越来越难以控制。在软件测试过程中,因为多方面的因素,常常会导致一些错误和失效,为了改善测试过程、使测试过程变得更为有效,需要对软件测试过程进行一个补充,那就是对软件测试的有效性进行评价。本文介绍了评价软件测试有效性工作的一般流程,并提出了一系列用于精确度量测试有效性的度量指标。     

An empirical validation of object-oriented metrics in two different iterative software processes

Object-oriented (OO) metrics are used mainly to predict software engineering activities/efforts such as maintenance effort, error proneness, and error rate. There have been discussions about the effectiveness of metrics in different contexts. In this paper, we present an empirical study of OO metrics in two iterative processes: the short-cycled agile process and the long-cycled framework evolution process. We find that OO metrics are effective in predicting design efforts and source lines of code added, changed, and deleted in the short-cycled agile process and ineffective in predicting the same aspects in the long-cycled framework process. This leads us to believe that OO metrics' predictive capability is limited to the design and implementation changes during the development iterations, not the long-term evolution of an established system in different releases.     

A fuzzy-filtered neuro-fuzzy framework for software fault prediction for inter-version and inter-project evaluation

Fault Prediction is the most required measure to estimate the software quality and reliability. Several methods, measures, aspects and testing methodologies are available to evaluate the software fault. In this paper, a fuzzy-filtered neuro-fuzzy framework is introduced to predict the software faults for internal and external software projects. The suggested framework is split into three primary phases. At the earlier phase, the effective metrics or measures are identified, which can derive the accurate decision on prediction of software fault. In this phase, the composite analytical observation of each software attribute is calculated using Information Gain and Gain Ratio measures. In the second phase, these fuzzy rules are applied on these measures for selection of effective and high-impact features. In the last phase, the Neuro-fuzzy classifier is applied on fuzzy-filtered training and testing sets. The proposed framework is applied to identify the software faults based on inter-version and inter-project evaluation. In this framework, the earlier projects or project-versions are considered as training sets and the new projects or versions are taken as testing sets. The experimentation is conducted on nine open source projects taken from PROMISE repository as well as on PDE and JDT projects. The approximation is applied on internal version-specific fault prediction and external software projects evaluation. The comparative analysis is performed against Decision Tree, Random Tree, Random Forest, Naive Bayes and Multilevel Perceptron classifiers. This prediction result signifies that the proposed framework has gained the higher accuracy, lesser error rate and significant AUC and GM for inter-project and inter-version evaluations.     

可信度理论与测试

软件的可靠性估计、程序结构及测试之间存在着重要的联合,针对一个程序及其输入值有限集,可以由测试来处理所精心定义的程序状态。但是,程序测试的基本理论仍不明了,其部分原因是测试的目标不明确,对测试或者测试方法的评价也没有统一的标准,测试不应该以纠错为最终目标,其最终目标应该是精度量被估测软件的可靠性。其于这个目标,需要提出蝗可信度理论,并以它为基础,明确应该使用什么样的测试方法及测试环境。目前可信度理     

Communication metrics for software development

Presents empirical evidence that metrics on communication artifacts generated by groupware tools can be used to gain significant insight into the development process that produced them. We describe a test-bed for developing and testing communication metrics, a senior-level software engineering project course at Carnegie Mellon University, in which we conducted several studies and experiments from 1991-1996 with more than 400 participants. Such a test-bed is an ideal environment for empirical software engineering, providing sufficient realism while allowing for controlled observation of important project parameters. We describe three proof-of-concept experiments to illustrate the value of communication metrics in software development projects. Finally, we propose a statistical framework based on structural equations for validating these communication metrics