信息系统结构层次分析与系统可靠性

在信息系统结构设计中,适量的设备冗余是提高系统整体可靠性的有效手段之一,但对哪些设备冗余才能以较少的投资获取较高的可靠性则是首先要解决的问题。文章通过对信息系统Ｐｅｔｒｉ网模型的层次结构分析在这方面取得了一定的进展,较好地克服了在冗余设备选择上的经验性和片面性,并通过对信息系统不同层次网络的冗余策略、所需设备的数量、以及相应的系统可靠度之间的对比,给出了一些定量的分析结果,以供参考。     

可靠性优化的蚁群算法

建立了可靠性冗余优化模型，分析了各种优化方法的优缺点。采用模拟退火算法、遗传算法和蚁群算法分别解决了此问题，并通过实例，结果表明蚁群算法比较有效。     

基于粒子群优化算法的系统可靠性优化

系统可靠性优化问题是典型的NP难题,建立了可靠性冗余优化模型,采用粒子群优化算法对其进行求解。通过对其它文献中仿真实例的计算和结果对比,表明了算法对求解可靠性优化问题的可行性和有效性。     

基于LCC的电力设备更新维修决策

综合考虑配电网影响电力设备更新维修的相关因素,基于LCC全寿命周期理论,以提高供电可靠性和运行经济性为目标函数,建立配电网电力设备更新维修的优化数学模型.采用遗传算法对优化模型进行求解,最后在实例中,验证该模型的可用性与实用性,给出分年度需要进行更新检修设备及设备的更新检修方案.     

串并联系统中支持实时替换的混合冗余策略优化

在需要长时间可靠运行的软件系统中,由于持续运行时间和任务响应速度的要求增加,工作组件在被探测到失效后将被冗余组件实时替换.但现有可靠性优化研究通常假设冷备份冗余在所有积极冗余组件失效后才使用.针对支持实时替换的混合冗余策略,对其冗余度优化分配进行研究.该策略不仅能够保障系统可靠性,而且能够保障系统性能,故选用实时可用性和任务完成效率两类约束条件,建立冗余配置代价最小化模型.基于马尔可夫链理论对可靠性及性能两类系统指标进行定量分析;采用数值计算方法对非线性的状态分析模型进行计算;改进二元组编码遗传算法对上述优化问题进行求解.采用实例对串并联系统中实时可用性及任务完成效率的分析进行了说明,并对优化冗余分配模型进行了验证.实验结果表明,在相同冗余度下,支持实时替换的混合冗余策略在任务完成效率方面优于传统的混合冗余策略.所以,在相同约束条件下不同混合冗余策略需要采用不同的冗余优化配置方案.     

遗传算法在全终端网络可靠性优化中的应用

在计算机通信网络建设过程中,通信主干网的高可靠性一直是广大设计者和用户所关心的重大问题。分析了通信主干网的全终端可靠性优化设计问题,建立了一种新的可靠性优化模型,并利用遗传算法对该模型进行了优化求解。计算机仿真实验结果表明：遗传算法在解决此类问题上是有效的。     

ERP环境下基于遗传算法的采购模型

本文提出在ERP环境中利用遗传算法优化采购模型。通过分析现行ERP系统中采购模型建立的方法,提出问题,同时对问题进行描述,在此基础上建立采购数学模型,给出遗传算法求解数学模型的步骤,并分析模型给出改进意见。     

并行遗传算法在软件可靠性优化中的应用

基于并行遗传算法将软件系统的可靠性优化问题表达为一类带约束条件的组合优化问题，并采用并行遗传算法中的岛屿模型和迁移策略，较好地改善了搜索性能。模拟实验表明：并行遗传算法有效地提高了运行速度和求解质量。     

基于遗传算法的基坑支护协同演化处理模型

分析了基于遗传算法的协同演化优化方法及深基坑支护的特点。提出了用基于遗传算法的协同演化优化方法来求解基坑支护层次性优化问题的模型，并给出了约束处理和目标函数转换的策略。实例表明所提出的策略是可行有效的。     

基于遗传算法的星载计算机可靠性冗余优化研究

针对小卫星系统可靠度函数非线性的特点,建立其可靠性冗余优化模型并提出一种基于遗传算法的冗余优化方法.通过对不同遗传算法的仿真过程和结果的对比分析,并对特定计算步骤加以改进,找到了最佳计算方案.仿真结果表明,该算法应用于星载计算机系统冗余优化中具有可行性和高效性.     

一种故障诊断的贝叶斯优化算法研究*

提出一种基于改进贝叶斯优化算法的故障模式聚类算法,通过结合贝叶斯优化算法中的先验知识来提高算法的可靠性和全局收敛性。将改进的优化算法应用到高维数据最优统计聚类分析中,可快速优化聚类参数,得到全局最优解。以飞行控制系统操纵面的故障诊断为例进行仿真验证,结果表明该算法结构简单、故障识别可靠。     

串并联系统可靠性优化的蚁群算法

为获得高可靠性,串并联系统的设计中常采用不同型号的元件,由于系统中元件有数量型号等的限制,每一元件又有重量、费用、可靠度等标志,所以串并联系统可靠性优化问题为典型的NP-难问题。采用两种不同的状态转移规则和与系统属性紧密相关的信息素更新规则,通过局部循环和整体循环分别搜索代表各子系统结构和系统结构的解向量,用蚁群算法成功地解决了元件可选择不同类型的串并联系统可靠性优化问题,仿真结果表明,蚁群算法可以在相对短的时间内较快地找到问题的最优解,蚁群算法与其它元启发式算法一样,可以有效克服求解组合优化的计算复杂度问题。     

Reliability evaluation and optimal design in heterogeneous multi-state series-parallel systems

This paper addresses the heterogeneous redundancy allocation problem in multi-state series-parallel reliability structures with the objective to minimize the total cost of system design satisfying the given reliability constraint and the consumer load demand. The demand distribution is presented as a piecewise cumulative load curve and each subsystem is allowed to consist of parallel redundant components of not more than three types. The system uses binary capacitated components chosen from a list of available products to provide redundancy so as to increase system performance and reliability. The components are characterized by their feeding capacity, reliability and cost. A system that consists of elements with different reliability and productivity parameters has the capacity strongly dependent upon the selection of constituent components. A binomial probability based method to compute exact system reliability index is suggested. To analyze the problem and suggest an optimal/near-optimal system structure, an ant colony optimization algorithm has been presented. The solution approach consists of a series of simple steps as used in early ant colony optimization algorithms dealing with other optimization problems and offers straightforward analysis. Four multi-state system design problems have been solved for illustration. Two problems are taken from the literature and solved to compare the algorithm with the other existing methods. The other two problems are based upon randomly generated data. The results show that the method can be appealing to many researchers with regard to the time efficiency and yet without compromising over the solution quality.     

多智能体系统一致性的递阶结构设计

针对多智能体系统的一致性协作,研究了以提高群体一致性收敛速度为目标的多层递阶拓扑结构设计问题.首先讨论了满足物理拓扑约束并具有更优性能的递阶拓扑结构存在的可能性.在此基础上,根据一致性问题的收敛时间性能指标,将递阶结构设计转化为一个与多层递阶系统中所有子图拉普拉斯矩阵特征值相关的优化问题.通过将连通图转换为若干点导出子图和它们之间的关联图,提出一个该优化问题的双层拓扑结构设计算法,并基于该算法发展了满足物理拓扑结构约束的多层递阶结构设计算法.仿真算例表明由此设计的递阶协作过程可有效加快多智能体群体一致性的收敛速度.     

Sequencing Optimization in k-out-of-n Cold-Standby Systems Considering Mission Cost

The k-out-of-n: G heterogeneous cold-standby system structure is a widely used fault-tolerant system design method, where the sequence in which the different system elements are initiated can greatly affect the system reliability and mission cost. This paper considers the optimal standby element sequencing problem (SESP) for such systems. Given the desired cold-standby redundancy level and fixed set of element choices, the objective of the optimal system design is to select the initiation sequence of the system elements so as to minimize the expected system mission cost while meeting a certain level of system reliability constraint. Based on a discrete approximation of time-to-failure distributions of the system elements, the system reliability and expected mission cost are evaluated simultaneously using a numerical method. A genetic algorithm is used as an optimization tool for solving the formulated SESP problem for k-out-of-n: G heterogeneous cold-standby systems. Examples are given to illustrate the considered problem and the proposed solution methodology.     

Optimization of the structure of multifunctional information systems according to the criterion of a required value of the efficiency ratio

A model of the reliability of multifunctional information systems is proposed. Based on this model an integral estimation of the reliability of such systems is obtained, expressed in the form of an efficiency ratio. An algorithm for optimization of a multifunctional information system according to the criterion of a required value of the efficiency ratio of the system is presented. The algorithm is illustrated by an example.     

Reliability Measure Based on Average Loss of Capacity

We present an effective measure of system reliability based on average loss of call capacity that is appropriate for telecommunication hardware. We are led to consider a system consisting of units with many states with appropriately chosen performance effectiveness indices, while all atomic units are binary. In this respect, this effective measure of partial system availability is a variant of customer-centered reliability methodology. We also identify the importance of a new structure called a 'pool' that behaves as a hybrid of series and parallel configurations. We present an algorithm for approximately calculating partial system unavailability, which solves the system decomposition problem for arbitrarily complex highly reliable systems made of hierarchically arranged k-out-of-n sub-structures. The algorithm agrees with our intuition for important special cases and has been programmed into an object oriented software tool. This method has been successfully used for the reliability analysis of Globalstar^TM gateways.     

求解大规模系统可靠性问题的修正和声搜索算法

针对大规模系统可靠性问题, 提出一种修正和声搜索(MHS) 算法. 该算法修改了和声搜索(HS) 算法的搜索机制, 以当前最优解为研究对象, 随机选取不同维数进行即兴创作, 并修正步长(BW) 的调整方式, 均衡算法的全局搜索和局部搜索. 对经典的大规模系统可靠性问题进行求解, 数值结果表明, 所提出算法优于其他文献中的6 种和声搜索算法. 与最近提出的求解此类问题的各种算法进行实验对比, 实验结果表明所提出算法在整体上具有良好的优化性能.

     

基于GO法的瓦斯报警器可靠性分析

针对于瓦斯报警器的多态问题,采用了GO法对其可靠性进行分析。根据瓦斯报警器的工作原理与结构特点建立GO图。并在GO图的基础上对瓦斯报警器系统进行了定性和定量的分析运算,得到了瓦斯报警器的系统状态概率和系统的最小割集,用于分析报警器系统不同故障的产生原因。通过运算分析表明：GO法同样适用于多状态系统的可靠性分析。     

RFID在便携式智能导览系统中的应用

针对传统的人工导览方式中存在的不灵活及信息量少等问题,本文利用射频识别技术设计了一款便携式智能导览系统,导览器通过读取放置在任何位置的IC卡的ID号完成相应信息的播报,具有使用寿命长、可靠性高、便携方便等特点.本文主要介绍了非接触IC卡原理、导览系统的结构、导览器的硬件实现及多国语言模式切换软件算法的设计,推导了多国语...