供应链环境下客户满意度评价的未确知均值聚类模型

未确知均值聚类结合未确知理论和聚类理论构造未确知测度作为集合隶属度来表示样本与各类间的隶属关系.从产品合格、柔性、可靠性等几方面对影响供应链客户满意度的因素进行分析,构建供应链环境下的客户满意度评价指标体系.在此基础上,应用未确知均值聚类理论对供应链环境下的客户满意度进行综合评价,得出聚类结果,找出各类类中心,并给出样本属于各类的隶属度,较好的解决了对供应链环境下客户满意度的分类问题,最后以实例来论证该方法的可行性和有效性.     

企业并购中风险的识别与评估研究

为准确识别、度量和降低企业并购风险,在对企业并购因素进行识别和定性分析基础上,建立了一套较全面的企业并购风险多层次评估指标体系,同时利用未确知理论给出了一种适合企业并购特点的未确知测度风险评估模型.模型结构严谨、精细,并通过实例验证了该评估模型的科学有效性.     

未确知RBF神经网络及其在故障诊断中的应用

建立未确知RBF神经网络.特点是:综合了未确知系统与神经网络的优点,充分利用已知样本所提供的先验信息,给出了期望输出隶属度的计算方法,网络输出合理且具有良好的可解释性.将未确知RBF神经网络应用于故障诊断领域,取得了很好的效果.     

未确知期望在顶煤冒放性分析中的应用

地下工程本身具有未确知性,预对厚煤层进行放顶煤开采,需对其顶煤的冒放性进行准确地分析,传统的平均法和经验法往往不能对客观事物进行准确地评价.通过求解影响顶煤冒放性诸多影响因素的未确知期望,可实现对顶煤冒放性进行合理的评价与分类,为厚煤层进行放顶煤开采提供科学的依据.根据计算结果所得结论与实际相符,方法在处理地下工程等未确知问题中值得进一步研究探讨.     

基于未确知有理数的施工网络研究

提出未确知有理数用于施工网络计划,介绍未确知有理数概念、运算、未确知期望.建立未确知施工网络计划,提出未确知施工网络计划关键线路计算模型,确定关键线路和未确知施工工期.讨论不确定性网络计划的研究.     

基于指标分类权重与未确知测度的装备战场损伤等级评估模型

成功的战场抢修是战斗力的"倍增器",而快速、准确的战场损伤评估是战场抢修决策和战场态势预测的前提.针对战场损伤评估中的未确知性,首先引入专家可信度对指标值进行处理;其次,通过指标本身输出的信息熵客观地确定指标的分类权重;接着在未确知数学理论及算法基础上给出了一种新的装备战场损伤等级评估模型,最后对某火炮的战损等级情况进行评判.结果表明:模型不仅能够组合多个损伤因素的估计问题,而且能够处理由不确定性信息导致的未确知性,并给出未知信息的置信度,较准确地反映了装备战场损伤程度,是装备战场损伤等级评估的一种有效工具.     

未确知集

分析了模糊集与R ough集两种不确定性集合的异同,指出模糊集中存在的不足和缺陷,在此基础上定义一种新的不确定性集合称作未确知集.在未确知集中模糊集的不足与缺陷得到弥补与修正,并且未确知集具有普通集合的含义.通过分析未确知集与模糊集的相同点及本质区别来论证未确知集存在与值得研究的价值.最后例举了常用的未确知隶属函数的构造方法.     

板梁组合结构可靠性分析的随机边界元法

本文用随机边界元法分析了随机荷载作用下具有随机边界条件的正交各向异性板、梁组合结构的可靠性.文中首先给出正交各向异性板、梁组合结构的边界积分方程,进而基于随机边界元法建立了随机结构可靠性分析方法和得到用于计算正交各向异性板、梁组合结构可靠性指标的公式.算例表明了本文方法的有效性.     

结构的失效可能度及模糊概率计算方法

依据模糊可能性理论,系统地建立含模糊变量时结构的可靠性计算模型。旨在解决模糊结构、模糊-随机结构和模糊状态假设下结构的可靠性计算问题。所建模型可给出模糊结构失效的可能度和模糊-随机结构失效概率的可能性分布。研究表明:对同时含模糊变量和随机变量的混合可靠性计算问题,把失效概率(或可靠度)作为模糊变量,能更客观地反映系统的安全状况。算例分析说明了文中方法的合理性和有效性。     

低碳经济范式下能源结构优化程度评价研究

我国的能源瓶颈突出表现为结构性矛盾。本文以能源经济学为理论支撑,从低碳经济发展对能源结构要求的角度,提出了社会经济效益、能源规划效益、环境效益等三个维度,并分析了各个维度的构成要素;综合运用粗糙集理论和AHP法进行指标约简和权值计算,构建了低碳经济范式下能源结构优化程度评价指标体系。在此基础上,对各评价指标设置分级标准,通过未确知测度评价模型对2010年我国10个省份的能源结构优化程度进行多指标综合测度与评价,阐明了该评价方法的科学有效性及评价结果的合理性。     

随机结构系统基于可靠性的优化设计

提出了以梁板（薄板）为基体的随机结构系统（即结构元件的面积、长度、弹性模量和强度等均为随机变量）在随机载荷作用下,基于可靠性的优化设计方法．给出了随机结构系统安全余量和系统可靠性指标的敏度表达式;给出最佳矢量型算法．首先是用改进的一次二阶矩和随机有限元法求出安全余量的可靠性指标的表达式,然后用概率网络估算(PNET)法求出系统失效概率的公式,对该式两边求导得出了系统可靠性指标的敏度表达式,进而用最佳矢量型算法进行优化设计．在优化迭代过程中,采用梯度步和最佳矢量步相结合的方法进行计算．最后给出了一个算例,说明该方法计算效率高,收敛稳定,适合工程应用．     

An efficient third-moment saddlepoint approximation for probabilistic uncertainty analysis and reliability evaluation of structures

This paper presents an efficient third-moment saddlepoint approximation approach for probabilistic uncertainty analysis and reliability evaluation of random structures. By constructing a concise cumulant generating function (CGF) for the state variable according to its first three statistical moments, approximate probability density function and cumulative distribution function of the state variable, which may possess any types of distribution, are obtained analytically by using saddlepoint approximation technique. A convenient generalized procedure for structural reliability analysis is then presented. In the procedure, the simplicity of general moment matching method and the accuracy of saddlepoint approximation technique are integrated effectively. The main difference of the presented method from existing moment methods is that the presented method may provide more detailed information about the distribution of the state variable. The main difference of the presented method from existing saddlepoint approximation techniques is that it does not strictly require the existence of the CGFs of input random variables. With the advantages, the presented method is more convenient and can be used for reliability evaluation of uncertain structures where the concrete probability distributions of input random variables are known or unknown. It is illustrated and examined by five representative examples that the presented method is effective and feasible.     

随机结构动力反应和可靠性分析

本研究随机动力荷载作用下随机结构反应有限元分析方法，提出了随机结构动力反应和基于随机抗力可靠性计算公式。     

基于M~x/G/1排队模型的信息系统软件失效风险分析方法研究

研究首先对信息系统软件节点进行数学建模,然后根据M^x/G/1排队模型及分布函数,针对信息系统软件的可靠性,给出了由威胁利用软件脆弱性所导致的信息系统节点失效,以及由此所带来的损失风险计算模型,并以银行的柜面业务系统所安装的Windows和Linux操作系统为例,给出了详细的计算过程.风险分析模型突破了目前沿用的经典六因素模型,将系统可靠性的定量分析方法引入其中,从而有效的避免了风险分析方法中对主观因素的依赖.     

Interval optimization based line sampling method for fuzzy and random reliability analysis

For structural system with fuzzy variables as well as random variables, a novel algorithm for obtaining membership function of fuzzy reliability is presented on interval optimization based Line Sampling (LS) method. In the presented algorithm, the value domain of the fuzzy variables under the given membership level is firstly obtained according to their membership functions. Then, in the value domain of the fuzzy variables, bounds of reliability of the structure are obtained by the nesting analysis of the interval optimization, which is performed by modern heuristic methods, and reliability analysis, which is achieved by the LS method in the reduced space of the random variables. In this way the uncertainties of the input variables are propagated to the safety measurement of the structure, and the membership function of the fuzzy reliability is obtained. The presented algorithm not only inherits the advantage of the direct Monte Carlo method in propagating and distinguishing the fuzzy and random uncertainties, but also can improve the computational efficiency tremendously in case of acceptable precision. Several examples are used to illustrate the advantages of the presented algorithm.     

道路行车系统中人的可靠性研究

随着人-车-路-环境系统复杂性的增加和交通事故数量的上升,新型交通设备对其使用者的素质与适应性提出了全面的要求,要提高道路行车系统的整体可靠性,必须对人的可靠性进行分析研究.从人的生理、心理、教育训练、驾车技能等因素对驾驶员可靠性的相关影响进行了探讨.分析了影响驾驶员的可靠性因素,研究了驾驶员的可靠性模型,提出建立有助于驾驶员可靠性分析研究的综合数据库,最后从理论上分析总结了提高驾驶员可靠性的措施从而得出提高道路行车安全的有效途径.     

Modeling and analysis of system reliability using phase‐type distribution closure properties

Phase‐type distribution closure properties are utilized to devise algorithms for generating reliability functions of systems with basic structures. These structures include series, parallel, K‐out‐of‐N, and standby structures with perfect/imperfect switch. The algorithms form a method for system reliability modeling and analysis based on the relationship between the system lifetime and component lifetimes for general structures. The proposed method is suitable for functional system reliability analysis, which can produce reliability functions of systems with independent components instead of only system reliability values. Once the system reliability function is obtained, other reliability measures such as the system's hazard function and mean time to failure can be obtained efficiently using only matrix algebra. Dimensional and numerical comparisons with computerized symbolic processing are also presented to show the superiority of the proposed method.     

Reliability Importance and Invariant Optimal Allocation

The reliability importance of a component is a partial derivative of the system reliability with respect to this component reliability. When all components are i.i.d., the reliability importance is called the B-importance. Relationships between reliability allocation and the reliability importance for general coherent systems are explored. The invariant optimal allocation is an allocation related only to the relative ordering rather than the magnitude of the component reliabilities. A strong heuristic method (LK heuristic) is developed to search for an ideal allocation through the application of the reliability importance.The following conclusions are drawn: if there exists an invariant optimal allocation for a system, the optimal allocation is to assign component reliabilities according to the B-importance ordering. Furthermore, the allocation generated by the LK heuristic is the optimal allocation.     

基于改进自适应混沌控制的逆可靠度分析方法

自适应混沌控制方法是一种高效、稳健的逆可靠度分析方法,但在求解强非线性凹功能函数时,计算效率仍然有待提高,且可能会陷入局部最优.通过对混沌控制因子更新策略进行改进,提出了基于改进自适应混沌控制的逆可靠度分析方法.数值算例分析表明:该方法能够有效地改善混沌控制因子自适应选取时的合理性,具有更好的收敛性和更高的计算效率,为结构可靠度分析和可靠度优化问题提供了更加高效、稳健的求解途径.