Discrete‐time analysis of MAP/PH/1 multiclass general preemptive priority queue

We use the matrix‐geometric method to study the MAP/PH/1 general preemptive priority queue with a multiple class of jobs. A procedure for obtaining the block matrices representing the transition matrix P is presented. We show that the special upper triangular structure of the matrix R obtained by Miller [Computation of steady‐state probabilities for M/M/1 priority queues, Oper Res 29(5) (1981), 945–958] can be extended to an upper triangular block structure. Moreover, the subblock matrices of matrix R also have such a structure. With this special structure, we develop a procedure to compute the matrix R. After obtaining the stationary distribution of the system, we study two primary performance indices, namely, the distributions of the number of jobs of each type in the system and their waiting times. Although most of our analysis is carried out for the case of K = 3, the developed approach is general enough to study the other cases (K ≥ 4). © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 662–682, 2003.     

A note on “resource flexibility with responsive pricing”

We revisit the capacity investment decision problem studied in the article “Resource Flexibility with Responsive Pricing” by Chod and Rudi [Operations Research 53, (2005) 532–548]. A monopolist firm producing two dependent (substitutable or complementary) products needs to determine the capacity of one flexible resource under demand risk so as to maximize its expected profit. Product demands are linear functions of the prices of both products, and the market potentials are random and correlated. We perform a comparative statics analysis on how demand variability and correlation impact the optimal capacity and the resulting expected profit. In particular, C&R study this problem under the following assumptions/approximations: (i) demand intercepts follow a bivariate Normal distribution; (ii) demand uncertainty is of an additive form; (iii) and under approximate expressions for the optimal capacity and optimal expected profit. We revisit Propositions 2, 3, 4, 5, and 10 of C&R without these assumptions and approximations, and show that these results continue to hold (i) for the exact expressions for the optimal expected profit and optimal capacity, and (ii) under any arbitrary continuous distribution of demand intercepts. However, we also show that the additive demand uncertainty is a critical assumption for the C&R results to hold. In particular, we provide a case of multiplicative uncertainty under which the C&R results (Propositions 2 and 3) fail. © 2010 Wiley Periodicals, Inc. Naval Research Logistics 2010     

Rolling‐horizon replenishment: Policies and performance analysis

We consider a rolling‐horizon (RH) replenishment modeling framework under which a buyer can update demand information and inventory status, modify order quantities committed previously, place an advanced order for a new period at the end of the RH, and move along in time seamlessly. We show that the optimal order policy for the two‐period RH problem is a dual‐threshold type for updating period(s) plus a base‐stock type for the advanced order. We provide analytical formulas and algorithms to compute the optimal thresholds and the optimal base‐stock level exactly. With our analytical results and numerical procedures, we demonstrate the significant value of RH replenishment in matching supplies to demands more closely. We also show that with RH updating (flexibility), the value of additional demand information beyond the RH diminishes quickly. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

内隐自尊、外显自尊及其交互作用对应对方式的影响研究

为了探讨内隐自尊、外显自尊及其交互作用对应对方式的影响,我们采用实验设计方法对某大学60名学生进行研究,选用自尊量表（SES）、应对方式问卷（CSQ）和内隐测验程序（IAT）施测。结果显示：一是内隐自尊、外显自尊存在低相关;二是外显自尊在积极、消极两种应对方式上主效应显著;三是不同外显自尊水平下,内隐自尊对积极应对方式有不同的影响。即高外显自尊水平下,高内隐自尊者比低内隐自尊者应用更多的积极应对方式;低外显自尊水平下,内隐自尊水平不影响积极应对方式的应用。由此可见,自尊类型影响个体应对方式,要培养个体安全的高自尊以促使个体在压力面前更多使用积极应对方式。     

软件测试质量管理设计分析与思考

本文介绍了软件生存周期的概念和特点,论述了软件测试质量管理设计的目标和主要内容,提出了软件测试质量管理设计的总体方案,并简要地阐述了测试质量管理的7个关键库的主要内容。     

基于公理设计理论装备保障系统级别设计研究

针对装备保障系统级别设计领域的特点和不足,在深入分析装备保障系统级别设计概念的基础上,运用公理设计原理,建立装备保障系统级别分析模型,并对装备保障系统级别设计目标进行了＂目标-设计＂的分解,将原来复杂的级别设计问题分解成由若干个模块构成的简单设计策略问题,保证了设计过程中不耦合,实现了装备保障系统级别设计的科学性、创新性,确保了级别设计的准确性。     

浅谈提高氯化钾镀锌后钝化膜附着力

本文介绍了如何提高氯化钾镀锌后钝化膜的附着力及改进措施。     

关于对影响磷化膜因素的试验研究

本文通过对表面磷化处理中一些影响磷化膜防腐能力的因素进行试验研究,提出了提高磷化膜防腐能力的看法,并提供试验方法与结果。     

推动国民经济动员建设向常态化转进

文章论述了新世纪新阶段,国民经济动员建设跨入发展模式转变、功能任务拓展的关键阶段,各级要确立系统准备、常态运行的理念,统筹兼顾战时应战、急时应急、平时服务需要,积极稳妥地推进各项准备常态化发展。     

Kernel estimation of quantile sensitivities

Quantiles, also known as value‐at‐risks in the financial industry, are important measures of random performances. Quantile sensitivities provide information on how changes in input parameters affect output quantiles. They are very useful in risk management. In this article, we study the estimation of quantile sensitivities using stochastic simulation. We propose a kernel estimator and prove that it is consistent and asymptotically normally distributed for outputs from both terminating and steady‐state simulations. The theoretical analysis and numerical experiments both show that the kernel estimator is more efficient than the batching estimator of Hong 9 . © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009