Explicit steady state solutions for a particular M(x)/M/1 queueing system

An explicit steady state solution is determined for the distribution of the number of customers for a queueing system in which Poisson arrivals are bulks of random size. The number of customers per bulk varies randomly between 1 and m, m arbitrary, according to a point multinomial, and customer service is exponential. Queue characteristics are given.     

Optimal investment,pricing and replacement of computer resources

The problem of multiple-resource capacity planning under an infinite time horizon is analyzed using a nonlinear programming model. The analysis generalizes to the long term the short-run pricing model for computer networks developed in Kriebel and Mikhail [5]. The environment assumes heterogeneous resource capacities by age (vingate), which service a heterogeneous and relatively captive market of users with known demand functions in each time period. Total variable operating costs are given by a continuous psuedoconcave function of system load, capacity, and resource age. Optimal investment, pricing, and replacement decision rules are derived in the presence of economies of scale and exogenous technological progress. Myopic properties of the decision rules which define natural (finite) planning subhorizons are discussed.     

A markov chain version of the secretary problem

This paper deals with the Secretary Problem where n secretaries are interviewed sequentially and the best k must be hired. The values of the secretaries are observed as they are interviewed, but beforehand only the distributions of these values are known. Furthermore, the distributions of two successive secretaries' values are governed by a Markov chain. Optimal hiring policies for finite n and limiting optimal policies as k and n approach infinity are obtained.     

Flowshop sequencing problem with ordered processing time matrices: A general case

The ordered matrix flow shop problem with no passing of jobs is considered. In an earlier paper, the authors have considered a special case of the problem and have proposed a simple and efficient algorithm that finds a sequence with minimum makespan for a special problem. This paper considers a more general case. This technique is shown to be considerably more efficient than are existing methods for the conventional flow shop problems.     

用小波包变换降低 MCM 系统中并存的脉冲干扰和窄带干扰的影晌

小波包变换可以给出信号精细的时频局域化特性，本文通过对信号进行小波包变换，导出了用小波包变换实现多载波调制（MCM）的系统模型，在此基础上研究了用小波包时频分解特性对信号进行变换，从而降低MCM系统中并存的脉冲噪声和窄带干扰的影响，并给出了如何选取时频单元进行变换的算法。     

快速JPDA算法的递归和并行实现

本文从联合关联事件的构造出发，讨论关联假设事件的分层构造，以达到降低计算量的目的。这里的层次可从０取到Ｌ，０层表示没有任何目标能够跟当前的观测数据关联，Ｌ层表示共有Ｌ个目标可以跟当前扫描得到的观测数据相关联。本文的关联事件的构造中，各层次的搜索具有递归性并可以独立进行，因而可以并行实现。文中还将本文的方法跟有关文献作了比较，并且给出相应的计算机仿真实验及其结果。     

潜艇上浮运动数值计算方法的研究与验证

预报潜艇上浮运动是探索研究潜艇上浮运动控制规律以及潜艇安全上浮的前提。就潜艇上浮运动的数值计算方法和计算流程进行了详细介绍,对数值计算方法中的湍流模型及离散格式等进行了优选。基于模型上浮试验结果,对数值计算的不确定度进行了分析且对数值计算结果进行了验证。证明了该数值计算的可靠性,并发现数值计算结果与试验结果很接近,验证了该数值计算方法的可行性,说明该数值计算方法和试验可为潜艇上浮运动的研究提供参考和借鉴。     

Scheduling workers in a constricted area

A generalization of the equi-partitioning problem, termed the 2D-Partition Problem, is formulated. The motivation is an aircraft maintenance scheduling problem with the following characteristics. The complete maintenance overhaul of a single aircraft requires the completion of some 350 tasks. These tasks require a varying number of technicians working at the same time. For large subsets of these 350 tasks, the constraining resource is physical space—tasks must be completed in a physical space of limited size such as the cockpit. Furthermore, there is no precedence relationship among the tasks. For each subset, the problem is to schedule the tasks to minimize makespan. Let m denote the maximum number of technicians that can work at the same time in the physical area under consideration. We present optimization algorithms for m = 2 and 3. © 1996 John Wiley & Sons, Inc.     

A lost sales (S — 1, S) perishable inventory system with renewal demand

This article analyzes a one-to-one ordering perishable inventory model with renewal demands and exponential lifetimes. The leadtimes are independently and exponentially distributed and the demands that occur during stock out periods are lost. Although the items are assumed to decay at a constant rate, the output process is not renewal and the Markov renewal techniques are successfully employed to obtain the operating characteristics. The problem of minimizing the long run expected cost rate is discussed and numerical values of optimal stock level are also provided. © 1996 John Wiley & Sons, Inc.     

An exact aggregation/disaggregation algorithm for large scale markov chains

Many Markov chain models have very large state spaces, making the computation of stationary probabilities very difficult. Often the structure and numerical properties of the Markov chain allows for more efficient computation through state aggregation and disaggregation. In this article we develop an efficient exact single pass aggregation/disaggregation algorithm which exploits structural properties of large finite irreducible mandatory set decomposable Markov chains. The required property of being of mandatory set decomposable structure is a generalization of several other Markov chain structures for which exact aggregation/disaggregation algorithms exist. © 1995 John Wiley & Sons, Inc.