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敏感性问题“随机变量和”回答模型 总被引:5,自引:0,他引:5
孔圣元,孟生旺.敏感性问题“随机变量和”回答模型.数理统计与管理,1998,17(2),35~39.本文依据概率论中“随机变量和”的分布理论,对敏感性问题的调查,提出了一个新模型,即“随机变量和”回答模型,实现了敏感性问题的问卷调查。本文给出了模型的最优估计量及其方差的计算公式,讨论了模型参数的合理选择,同时还得出了一个有趣的结果:“随机化回答模型”包含在“随机变量和”回答模型之中。 相似文献
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Musa-Okumoto模型和逆线性模型是研究软件可靠性的重要模型,给出了在分组数据下,M-O模型和逆线性模型中参数的最大似然估计及其存在的充分性条件,指出了[4]中的错误,并且给出了一个实例。 相似文献
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本文从规划区土地利用状况出发,建立了居民分布的引力模型和概率模型,在规划区就业人口分成就业区就业人口和居住区服务就业人口的基础上,研究了运用模型分布这两种就业人口的方法,并建立分布全部居民的模型,最后给出了模型应用实例. 相似文献
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具有测量误差的非线性模型的Bayes估计 总被引:1,自引:0,他引:1
测量中大量的函数模型都是非线性回归模型.当回归变量含有一定的测量误差时,我们得到非线性测量误差模型.本讨论了这种模型中未知参数具有正态先验分布时的参数Bayes估计方法,并对这种估计进行了影响分析,证明了删除模型与均值漂移模型中参数的Bayes估计相同,利用Cook统计量给出了删除模型下参数的Bayes估计的影响度量. 相似文献
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关于可信性模型的若干评注 总被引:6,自引:0,他引:6
可信性模型是经验费率厘定中最重要的方法,本文在简述可信性概念的发展简史并强调了有限扰动可信性和最精确可信性的区别后,重点剖析了最精确可信性的理论基础,且详尽地解释了导出(修正)Buehlmann单合同可信性模型的基本思路,在阶段性地展示了建立此模型基本假定的过程后,给出了风险保费与预测值的可信性估计的简明公式,现今最基础的Buehlmann-Straub可信性模型可视为由多个相互独立,且具有相同的结构函数的(修正)Buhlmann单合同模型相嵌而成,这种组嵌方式使得估计该模型的未知结构参数成为可能,本文最后概述了可信性模型的主要进展,全文的叙述是说明性的,不步及技术性证明过程,目的在于为理解可信性模型提供一个直观与清晰的思路。 相似文献
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本文考虑了随机设计情形下一类普通的异方差回归模型,在这个模型中,假定回归函数与方差函数之间的关系服从推广的广义非线性模型,该模型在实际中很常见,广义线性模型便是其特例,首先,我们导出了均值函数的局部加权拟似然估计,然后,用它来得到方差函数的估计,并且证明了这些估计有较好的性质,最后,建立了异方差检验统计量,文中的方法很吸引人。 相似文献
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Ghali Abdallaoui 《The Journal of the Operational Research Society》1987,38(4):367-368
A new approach to the maintainability of a grade structure in a deterministic environment, using promotion control, is sought. Our main objective is to show how this manpower planning issue can be viewed in the context of transportation problems. By the same token, a condition for the maintainability of a structure will be proved to be sufficient. 相似文献
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签派可靠度是表征民用飞机可靠性的关键参数,本文以签派可靠度为顶层指标,根据民用飞机的设计需求和运行任务分析,结合民用飞机的设计特点,建立民用飞机可靠性参数体系,形成可用性、维修性、安全性3个主要一级指标和11个二级指标.应用改进的层次分析法即在层次分析法的基础上融合了聚类分析的思想,并与每位专家所构建判断矩阵的一致性程度结合起来,精确量化了各个二级指标的权重,对民用飞机可靠性影响较大的二级指标,依次为平均故障间隔时间、平均修复时间、飞行事故率.根据民用飞机可靠性的得分区间,利用模糊综合评价法针对A320机型进行了实例验证,最终实现民用飞机主流机型可靠性的评估,研究结果表明只有提高民用飞机的维修性,加强安全性,才能增强民用飞机的可靠性水平. 相似文献
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Nikolaos Limnios 《Methodology and Computing in Applied Probability》2012,14(4):895-917
The aim of this paper is to present a systematic modeling of reliability and related measures: availability, maintainability, failure rate, rate of occurrence of failures, mean times, etc., known in the literature under the term dependability. This model includes the continuous and discrete time semi-Markov processes with general state space. This is one of the most general models in reliability theory since it includes as particular cases the Markov and renewal processes. 相似文献
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《Journal of computational science》2014,5(2):233-242
Component based software system approach is concerned with the system development by integrating components. The component based software construction primarily focuses on the view that software systems can be built up in modular fashion. The modular design is a logical collection of several independent developed components that are assembled with well defined software architecture. These components can be developed in-house or can be obtained commercially from outside market making build versus buy decision an important consideration in development process. Cohesion and coupling (C&C) plays a major role in determining the system quality in terms of reliability, maintainability and availability. Cohesion is defined as the internal interaction of components within the module. On the other hand, coupling is the external interaction of the module with other modules i.e. interaction of components amongst the modules of the software system. High cohesion and low coupling is one of the important criteria for good software design. Intra-modular coupling density (ICD) is a measure that describes the relationship between cohesion and coupling of modules in a modular software system and its value lies between zero and one. This paper deals with the selection of right mix of components for a modular software system using build-or-buy strategy. In this paper, fuzzy bi-criteria optimization model is formulated for component selection under build-or-buy scheme. The model simultaneously maximizes intra-modular coupling density (ICD) and functionality within the limitation of budget, reliability and delivery time. The model is further extended by incorporating the issue of compatibility amongst the components of the modules. A case study is devised to explain the formulated model. 相似文献
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《Journal of Computational and Applied Mathematics》2002,149(1):279-296
We have been developing an advanced general-purpose computational mechanics system, named ADVENTURE, which is designed to be able to analyze a model of arbitrary shape with a 10–100 million degrees of freedom (DOFs) mesh, and additionally to enable parametric and nonparametric shape optimization. Domain-decomposition-based parallel algorithms are implemented in pre-processes (domain decomposition), main processes (system matrix assembling and solutions) and post-process (visualization), respectively. The hierarchical domain decomposition method with a pre-conditioned iterative solver (HDDM) is adopted in the main processes as one of the major solution techniques. Module-based architecture of the system with standardized I/O format and libraries are also developed and employed to attain flexibility, portability, extensibility and maintainability of the whole system. This paper describes some key technologies employed in the system, and shows some latest results including elastic stress analysis of a precise three-dimensional (3D) model of a nuclear reactor vessel with a 60 million DOF mesh on Hitachi SR2201 , and nonparametric shape optimization of a support structure for an express way with a one million DOF mesh on a PC cluster . 相似文献
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Jyh-Haw Wang Jason Sheng-Hong Tsai Jian-Syun Huang Shu-Mei Guo Leang-San Shieh 《Applied Mathematical Modelling》2013
In this paper, we present two control schemes for the unknown sampled-data nonlinear singular system. One is an observer-based digital redesign tracker with the state-feedback gain and the feed-forward gain based on off-line observer/Kalman filter identification (OKID) method. The presented control scheme is able to make the unknown sampled-data nonlinear singular system to well track the desired reference signal. The other is an active fault tolerance state-space self-tuner using the OKID method and modified autoregressive moving average with exogenous inputs (ARMAX) model-based system identification for unknown sampled-data nonlinear singular system with input faults. First, one can apply the off-line OKID method to determine the appropriate (low-) order of the unknown system order and good initial parameters of the modified ARMAX model to improve the convergent speed of recursive extended-least-squares (RELS) method. Then, based on modified ARMAX-based system identification, a corresponding adaptive digital control scheme is presented for the unknown sampled-data nonlinear singular system with immeasurable system state. Moreover, in order to overcome the interference of input fault, one can use a fault-tolerant control scheme for unknown sampled-data nonlinear singular system by modifying the conventional self-tuner control (STC). The presented method can effectively cope with partially abrupt and/or gradual system input faults. Finally, some illustrative examples including a real circuit system are given to demonstrate the effectiveness of the presented design methodologies. 相似文献
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Lur''''e系统稳定与同步的脉冲控制 总被引:2,自引:0,他引:2
提出了Lur’e系统的脉冲控制系统,利用关于脉冲系统稳定的几个定理,得到了具变化的脉冲区间的Lur'e系统镇定的充分条件;并且给出了Lur'e系统的适当参数与脉冲控制律,使得两个Lur'e系统脉冲同步。最后,给出数值例子说明本结论的有效性。 相似文献
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文章研究了噪声实验室供气系统的可靠性问题,根据供气系统的工程设计框图绘制了可靠性框图.进而得到了供气系统的可靠性表达式.根据可靠性的评估方法,结合模拟试验的数据得到了供气系统可靠性评估的定量结果.通过时评估结果的分析,给出了改进噪声实验室供气系统的工程设计从而提高其可靠性的方法. 相似文献
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《Finite Elements in Analysis and Design》1988,4(2):147-162
The structure to a geometry-based finite element preprocessing system is presented. The key features of the system are the use of geometric operators to support all geometric calculations required for analysis model generation, and the use of a hierarchic boundary-based data structure for the major data sets within the system. The approach presented can support the finite element modeling (FEM) procedures used today as well as the fully automated procedures under development. 相似文献