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281.
This paper considers the search for an evader concealed in one of two regions, each of which is characterized by its detection probability. The single-sided problem, in which the searcher is told the probability of the evader being located in a particular region, has been examined previously. We shall be concerned with the double-sided problem in which the evader chooses this probability secretly, although he may not subsequently move: his optimal strategy consists of that probability distribution which maximizes the expected time to detection, while the searcher's optimal strategy is the sequence of searches which limits the evader to this expected time. It transpires for this problem that optimal strategies for both searcher and evader may generally be obtained to a surprisingly good degree of approximation by using the optimal strategies for the closely related (but far more easily solved) problem in which the evader is completely free to move between searches. 相似文献
282.
After first formulating the problem of the Marine Environmental Protection program of the Coast Guard as a multiple-objective linear program, we investigate the applicability and limitations of goal programming. We point out how the preemptive goal-programming approach is incompatible with utility preferences. Then we observe the tendency of optimal solutions for standard linear goal programs to occur at extreme points. We also note problems of more general approaches, such as dealing with additively separable approximations to preferences. 相似文献
283.
We consider the problem of maximizing the number of on‐time jobs on two uniform parallel machines. We show that a straightforward extension of an algorithm developed for the simpler two identical parallel machines problem yields a heuristic with a worst‐case ratio bound of at least . We then show that the infusion of a “look ahead” feature into the aforementioned algorithm results in a heuristic with the tight worst‐case ratio bound of , which, to our knowledge, is the tightest worst‐case ratio bound available for the problem. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006 相似文献
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Edward J. Dudewicz 《海军后勤学研究》1970,17(1):69-78
Suppose that observations from populations π1, …, πk (k ≥ 1) are normally distributed with unknown means μ1., μk, respectively, and a common known variance σ2. Let μ[1] μ … ≤ μ[k] denote the ranked means. We take n independent observations from each population, denote the sample mean of the n observation from π1 by X i (i = 1, …, k), and define the ranked sample means X [1] ≤ … ≤ X [k]. The problem of confidence interval estimation of μ(1), …,μ[k] is stated and related to previous work (Section 1). The following results are obtained (Section 2). For i = 1, …, k and any γ(0 < γ < 1) an upper confidence interval for μ[i] with minimal probability of coverage γ is (? ∞, X [i]+ h) with h = (σ/n1/2) Φ?1(γ1/k-i+1), where Φ(·) is the standard normal cdf. A lower confidence interval for μ[i] with minimal probability of coverage γ is (X i[i] – g, + ∞) with g = (σ/n1/2) Φ?1(γ1/i). For the upper confidence interval on μ[i] the maximal probability of coverage is 1– [1 – γ1/k-i+1]i, while for the lower confidence interval on μ[i] the maximal probability of coverage is 1–[1– γ1/i] k-i+1. Thus the maximal overprotection can always be calculated. The overprotection is tabled for k = 2, 3. These results extend to certain translation parameter families. It is proven that, under a bounded completeness condition, a monotone upper confidence interval h(X 1, …, X k) for μ[i] with probability of coverage γ(0 < γ < 1) for all μ = (μ[1], …,μ[k]), does not exist. 相似文献
288.
Paul Meyer James 《海军后勤学研究》1968,15(3):459-468
Learning curves have been used extensively to predict future costs in the airframe and other industries. This paper deals with the effect of perturbations induced by design changes on the learning curves. Equations that are developed and applied make it possible to predict future costs accurately in a perturbed environment. The formulations can be used effectively in EDP programs. 相似文献
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J. J. Lagemann 《海军后勤学研究》1967,14(1):89-99
A new method has been developed f o r solving the transportation problem. This method is a modification and a generalization of the method for solving the multiple assignment problem developed by Dr. A. J. Hoffman and Dr. H. M. Markowitz. This method is of interest for several reasons. In the first place it is significantly different from all other methods for solving the trans -portation problem known to the author. Secondly, it is moderately simple touse and understand. Thirdly, and perhaps most important, it has proved to be very adaptable tri high-speed computer operations. It is now being used by several branches of the armed services. 相似文献