车辆路径问题的可靠性研究

首先分析车辆路径问题中随机因素,以及现有考虑行程时间波动的车辆路径问题,从而确立以配送车辆为研究对象,建立对应的行程时间可靠性模型,以不超过规定值,用来适应处理交通状态的不确定性。通过粒子群算法求解,验证表明,考虑道路运行的不确定对车辆调度的影响,制定的车辆调度方案能够更加可靠,对于配送过程更加有效。     

应急物流网络弹性初探

首先,从弹性的定义和内涵出发,结合应急物流的特性,可以把应急物流网络弹性分成柔性、可靠性来研究。通过对这两种属性的研究,总结出弹性的概念和内涵,找出影响应急物流网络弹性的规律。接着,分别研究了这两种属性的概念及度量方法,并针对应急物流特性提出了参考的度量方法,这为应急物流网络弹性研究作好了铺垫。最后,根据应急物流网络性质,提出了一些应急物流网络弹性的研究方向和方法。     

军事供应链可靠性管理研究综述

首先对军事供应链可靠性管理的研究背景进行了阐述,从军事供应链、供应链可靠性的概念、度量、定量分析方法和研究模型等方面,对军事供应链可靠性的研究现状进行回顾和评述,最后对进一步研究的问题提出展望。     

On estimating the reliability after sequentially estimating the mean: The exponential case

Sequential estimation problems for the mean parameter of an exponential distribution has received much attention over the years. Purely sequential and accelerated sequential estimators and their asymptotic second-order characteristics have been laid out in the existing literature, both for minimum risk point as well as bounded length confidence interval estimation of the mean parameter. Having obtained a data set from such sequentially designed experiments, the paper investigates estimation problems for the associatedreliability function. Second-order approximations are provided for the bias and mean squared error of the proposed estimator of the reliability function, first under a general setup. An ad hoc bias-corrected version is also introduced. Then, the proposed estimator is investigated further under some specific sequential sampling strategies, already available in the literature. In the end, simulation results are presented for comparing the proposed estimators of the reliability function for moderate sample sizes and various sequential sampling strategies.     

A Framework for Reconsidering the Lake Wobegon Effect

The Lake Wobegon Effect (LWE) describes the potential measurement-error bias introduced into survey-based analyses of education issues. Although this effect potentially applies to any student-report variable, the systematic overreporting of academic achievements such as grade point average is often of preeminent concern. This concern can be easily circumvented if official records data are available; however, many researchers can only access student-reported data. In this article, the authors examine whether using student-survey data in place of official records data meaningfully biases regression estimates. They motivate their contribution by noting a useful statistical feature of overreporting on bounded variables such as grade point average. Specifically, the misreports will be negatively correlated with the true grade point average, yielding a form of nonclassical measurement error that actually counteracts the bias. The authors connect this observation to reliability ratios used in labor economics, which are simple ways to adjust for attenuation bias, when needed. In two applications, we find that it is unnecessary to correct for the LWE bias because it is so small.     

论会计信息的相关性与可靠性

会计信息的可靠性和相关性是构成会计信息质量特征的两个重要方面,它们存在着相辅相成、此消彼长的关系,本文从相关性和可靠性的内涵和外延入手分析,详细阐述了两者的对立面,并就如何协调两者的关系提出自己的观点.     

有优先权的混贮备可修系统的模糊可靠性分析

研究了有优先权的3个不周型部件和1个修理设备组成的混贮备可修系统,利用普通可靠性和模糊可靠性的基础理论,在转换开关完全可靠的情形下建立了系统模糊可靠性模型,利用模糊数学的原理和方法、马尔可夫型可修系统的研究方法和Maplel 1．0软件,得到了该系统的一些模糊可靠性指标,并给出算例。     

Temporal stability of preferences and willingness to pay for natural areas in choice experiments: A test–retest

The main objective of this paper is to test the temporal stability of stated preferences and willingness to pay (WTP) values from a Choice Experiment (CE) in a test–retest. The same group of participants was asked the same choice tasks in an internet-based CE, conducted twice with a time interval of one year without interviewer interference. We examine choice consistency at individual choice task level and transferability of the underlying indirect utility function and associated WTP values. The results show that choices are consistent in 57 percent of the choice occasions. Comparison of the choice models over time shows that the estimated preference and scale parameters are significantly different, suggesting that choice behaviour changed between the two surveys. Differences between marginal WTP estimates for individual choice attributes are statistically significant only at the 10 percent level. However, we show that this can result in significantly different WTP values for policy scenarios. The instability of estimated mean WTP values for different policy scenarios asks for caution when including WTP values in cost-benefit analysis.     

Regulatory effects on the market penetration and capacity of reliability differentiated service

This paper investigates the effects of alternative forms of regulation on the market penetration and capacity that are determined by a profit-maximizing monopolist providing reliability differentiated service to consumers. Both price cap and rate of return regulation lead to larger capacity and market penetration than in the absence of regulation. These forms of regulation also lead to larger consumer surplus than in the absence of regulation. A minimum reliability standard reduces market penetration, and this reduction may lead to a decrease in consumer surplus.