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221.
The individual and social optimum control policies for entry to an M/M//1 queue serving several classes of customers have been shown to be control-limit policies. The technique of policy iteration provides the social optimum policy for such a queue in a straightforward manner. In this article, the problem of finding the optimal control policy for the M/Ek/1 system is solved, thereby expanding the potential applicability of the solutions developed. The Markovian nature of the queueing system is preserved by considering the service as having k sequential phases, each with independent, identically distributed, exponential service times, through which a customer must pass to be serviced. The optimal policy derived by policy iteration for such a system is likely to be difficult to use because it requires knowledge of the number of phases rather than customers in the system when an arrival occurs. To circumvent this difficulty, a heuristic is used to find a good usable (implementable) solution. In addition, a mixed-integer program is developed which yields the optimal implementable solution when solved. 相似文献
222.
George C. Canavos 《海军后勤学研究》1983,30(3):465-470
A mean-squared error comparison of smooth empirical Bayes and Bayes estimators for the Weibull and gamma scale parameters is studied based on a computer simulation. The smooth empirical Bayes estimators are determined as functions of up to 15 past estimates of the parameter of interest. Results indicate that at best the mean-squared errors of the empirical Bayes estimators are about 20–40% larger than those of the corresponding squared-error optimal Bayes estimators. 相似文献
223.
Clifford C. Petersen 《海军后勤学研究》1981,28(1):157-168
Planning for a cardiovascular disease reduction program, soon to be initiated by the United States Air Force, has required an evaluation of its expected cost effectiveness. During the course of this evaluation, it was necessary to consider manpower flows and their expected changes in response to the disease reduction program. This paper describes several manpower models that were applied: a simple expected value equilibrium model; a cross-sectional model that considered the length of service of personnel; and a staffing model used to optimize the allocation of paramedics to the many Air Force bases of various sizes. The relevance of these models to the cost effectiveness evaluation is shown but the detailed cost effectiveness results are not presented. 相似文献
224.
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226.
In this paper we present some results in parametric studies on several transportation-type problems. Specifically, a characterization is obtained for the optimal values of the variables in the problem of determining an optimal growth path in a logistics system. We also derive an upper bound beyond which the optimal growth path remains the same. The results are then extended to the goal programming model and the prespecified market growth rate problem. 相似文献
227.
S. C. Agrawal 《海军后勤学研究》1974,21(2):289-297
This paper provides a method for solving mixed integer quadratic programs with the help of cutting-plane technique. 相似文献
228.
C. B. Millham 《海军后勤学研究》1974,21(2):307-317
This work considers a class of bimatrix games to which some well-known structure theorems of 0-sum matrix games can be made to generalize. It is additionally shown how to construct such games and how to generate the equilibrium points defining a given game as a member of that class. 相似文献
229.
This article presents several single-echelon, single-item, static demand inventory models for situations in which, during the stockout period, a fraction b of the demand is backordered and the remaining fraction 1 - b is lost forever. Both deterministic and stochastic demand are considered. although the case of stochastic demand is treated heuristically. In each situation, a mathematical model representing the average annual cost of operating the inventory system is developed. and an optimum operating policy derived. At the extremes b=1 and b=0 the models presented reduce to the usual backorders and lost sales cases, respectively. 相似文献
230.
The maximum likelihood estimator of the service distribution function of an M/G/∞ service system is obtained based on output time observations. This estimator is useful when observation of the service time of each customer could introduce bias or may be impossible. The maximum likelihood estimator is compared to the estimator proposed by Mark Brown, [2]. Relative to each other, Brown's estimator is useful in light traffic while the maximum likelihood estimator is applicble in heavy trafic. Both estimators are compared to the empirical distribution function based on a sample of service times and are found to have drawbacks although each estimator may have applications in special circumstances. 相似文献