共查询到19条相似文献,搜索用时 46 毫秒
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马尔可夫链模型在软件可靠性测试中的应用 总被引:1,自引:0,他引:1
现行的软件可靠性分析方法禁锢了人们从更简单层次对软件系统的可靠性进行研究。基于上述认识,为了缩短软件测试周期,文中提出了一种新的软件可靠性测试分析方法。该方法把马尔可夫链模型运用于软件可靠性测试中,在测试过程中使用了新的评判准则分析测试结果,通过实例证明了该评判准则的实用性和有效性。从而为更快速地评估软件的可靠性提供了可能。 相似文献
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在已有VP 控制图基础上,增加了B&L转换规则,构建了基于马尔可夫链模型的B&L VP 控制图统计性能分析模型,给出了统计性能指标ATS、AATS以及ANSW的表达式。针对2组设计参数,将构建的模型与现有VP 控制图进行了比较分析,结果表明当平均运行时间相同时,本文构建的模型在缩短报警时间和减少转换次数方面,都有着明显的优势,而且随着转换参数L的增大,这种优势会增大。 相似文献
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提出了一种改进型隐马尔可夫模型/神经网络混合分类器,该分类器将隐马尔可夫模型的时间校正能力与神经网络的静态区分能力结合在一起。它首先利用循环无跳转HMM模型对第一测试特征序列进行全状态分割。将T帧特征序列按时间演化顺序校正成N帧平均状态序列。然后 交其作为RBF网络的输入矢量进行分类。实验结果表明,该分类器比单纯的神经网络或隐马尔可夫模型分类器具有更限的分类效果。 相似文献
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本文应用广义逆解法,将多变量散乱数据曲面(超曲面)拟合,把拟合后的曲面(超曲面)作为多变量问题等值线形成的数学模型,从而把超曲面、等值面、等值线这些几何概念,与等值线形成的物理意义结合起来,使人们能够从离散数据中揭示出所蕴含的物理规律。 相似文献
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讨论了一般双线性时间序列模型BL(R,r,Q,q)的高阶(2u阶,u=1,2,…)平稳解存在的充分条件,并证明了高阶矩估计量的相和性和渐近正态性。 相似文献
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在已有VP(X)控制图基础上,增加了B&L转换规则,构建了基于马尔可夫链模型的B&L VP(X)控制图统计性能分析模型,给出了统计性能指标ATS、AATS以及ANSW的表达式.针对2组设计参数,将构建的模型与现有VP(X)控制图进行了比较分析,结果表明当平均运行时间相同时,本文构建的模型在缩短报警时间和减少转换次数方面,都有着明显的优势,而且随着转换参数L的增大,这种优势会增大. 相似文献
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On Perturbation Bounds for the Joint Stationary Distribution of Multivariate Markov Chain Models 下载免费PDF全文
Wen Li Lin Jiang Wai-Ki Ching & Lu-Bin Cui 《East Asian journal on applied mathematics.》2013,3(1):1-17
Multivariate Markov chain models have previously been proposed in for studying
dependent multiple categorical data sequences. For a given multivariate Markov
chain model, an important problem is to study its joint stationary distribution. In this
paper, we use two techniques to present some perturbation bounds for the joint stationary
distribution vector of a multivariate Markov chain with s categorical sequences.
Numerical examples demonstrate the stability of the model and the effectiveness of our
perturbation bounds. 相似文献
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Anatoly Lisnianski David ElmakiasDavid Laredo Hanoch Ben Haim 《Reliability Engineering & System Safety》2012,98(1):1-6
This paper presents a multi-state Markov model for a coal power generating unit. The paper proposes a technique for the estimation of transition intensities (rates) between the various generating capacity levels of the unit based on field observation. The technique can be applied to such units where output generating capacity is uniformly distributed. In order to estimate the transition intensities a special Markov chain embedded in the observed capacity process was defined. By using this technique, all transition intensities can be estimated from the observed realization of the unit generating capacity stochastic process. The proposed multi-state Markov model was used to calculate important reliability indices such as the Forced Outage Rate (FOR), the Expected Energy Not Supplied (EENS) to consumers, etc. These indices were found for short-time periods (about 100 h). It was shown that these indices are sensibly different from those calculated for a long-term range. Such Markov models could be very useful for power system security analysis and short-term operating decisions. 相似文献
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Computing Transition Probability in Markov Chain for Early Prediction of Software Reliability 下载免费PDF全文
Lalit Singh Hitesh Rajput Gopika Vinod A. K. Tripathi 《Quality and Reliability Engineering International》2016,32(3):1253-1263
Early prediction of software reliability provides basis for evaluating potential reliability during early stages of a project. It also assists in evaluating the feasibility of proposed reliability requirements and provides a rational basis for design and allocation decisions. Many researchers have proposed different approaches to predict the software reliability based on a Markov model. The transition probabilities in between the states of the Markov model are input parameters to predict the software reliability. In the existing approaches, these probabilities are either assumed on some knowledge or computed using analytical method, and hence, it does not give accurate predicted reliability figure. Some authors compute them using operational profile data, but that is possible only after the deployment of the software, and this is not early prediction. The work in this paper is devoted to demonstrate the computation of transition probability in the Markov reliability model taking a case study. The proposed approach has been validated on 47 sets of real data. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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本文参照直线上隐Markov模型的概念,给出有限树指标隐Markov链的定义.在该定义中,树指标隐Markov链由两个树指标随机过程组成,其中第一个树指标随机过程是树指标Markov链,是不能被直接观测到的隐藏链;第二个树指标随机过程是可被观测的且关于第一个树指标随机过程条件独立,对于树上的任意一个顶点,第二个随机过程此处的取值只信赖于隐藏链中此处的取值.最后,我们给出了树指标隐Markov链的三个等价定义. 相似文献
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We consider the analysis of sets of categorical sequences consisting of piecewise homogenous Markov segments. The sequences are assumed to be governed by a common underlying process with segments occurring in the same order for each sequence. Segments are defined by a set of unobserved changepoints where the positions and number of changepoints can vary from sequence to sequence. We propose a Bayesian framework for analyzing such data, placing priors on the locations of the changepoints and on the transition matrices and using Markov chain Monte Carlo (MCMC) techniques to obtain posterior samples given the data. Experimental results using simulated data illustrate how the methodology can be used for inference of posterior distributions for parameters and changepoints, as well as the ability to handle considerable variability in the locations of the changepoints across different sequences. We also investigate the application of the approach to sequential data from an application involving monsoonal rainfall patterns. Supplementary materials for this article are available online. 相似文献
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O. Yevkin 《Quality and Reliability Engineering International》2016,32(4):1509-1520
Approximate Markov chain method for dynamic fault tree analysis is suggested for both reparable and non‐reparable systems. The approximation is based on truncation, aggregation and elimination of Markov chain states during the process of dynamic fault tree transformation to corresponding Markov chain. The method is valid for small probabilities. For reparable systems, it is true if mean time to repair is much less than mean time to failure. Several examples are studied. Additional simplification is considered in case the system is in a steady state. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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New Approaches in Monitoring Multivariate Categorical Processes based on Contingency Tables in Phase II 下载免费PDF全文
Reza Kamranrad Amirhossein Amiri Seyed Taghi Akhavan Niaki 《Quality and Reliability Engineering International》2017,33(5):1105-1129
In some statistical process control (SPC) applications, quality of a process or product is characterized by contingency table. Contingency tables describe the relation between two or more categorical quality characteristics. In this paper, two new control charts based on the WALD and Stuart score test statistics are designed for monitoring of contingency table‐based processes in Phase‐II. The performances of the proposed control charts are compared with the generalized linear test (GLT) control chart proposed in the literature. The results show the better performance of the proposed control charts under small and moderate shifts. Moreover, new schemes are proposed to diagnose which cell corresponding to different levels of categorical variables is responsible for out‐of‐control signal. In addition, we propose EWMA–WALD and EWMA–Stuart score test control charts to improve the performance of Shewhart‐based control charts in detecting small and moderate shifts in contingency table parameters. Meanwhile, we compare the performances of two proposed EWMA‐based control charts with the ones of three existing control charts called EWMA–GLT, EWMA–GLRT and an EWMA‐type control chart for multivariate binomial/multinomial processes along with the ones of the corresponding Shewhart‐based control charts. A numerical example is given to show the efficiency of the proposed methods. Finally, the effect of parameter estimation in Phase I based on m historical contingency table on the performance of the Shewhart‐based control charts is studied. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献