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作者：Chari, MK; Feo, TA; Provan, JS
作者单位：University of North Carolina; University of North Carolina Chapel Hill; University of Texas System; University of Texas Austin
摘要：The Delta-Wye Approximation Procedure (DWAP) is a procedure for estimating the two-terminal reliability of an undirected planar network G = (V, E) by reducing the network to a single edge via a sequence of local graph transformations. It combines the probability equations of Lehman - whose solutions provide bounds and approximations of two-terminal reliability for the individual transformations-with the Delta-Wye Reduction Algorithm of the second two authors - which performs the corresponding ...
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作者：Abate, J; Choudhury, GL; Whitt, W
作者单位：AT&T; Nokia Corporation; Nokia Bell Labs; AT&T; AT&T; Nokia Corporation; Nokia Bell Labs
摘要：We continue to focus on simple exponential approximations for steady-state tail probabilities in queues based on asymptotics. For the G/GI/1 model with i.i.d. service times that are independent of an arbitrary stationary arrival process, we relate the asymptotics for the steady-state waiting time, sojourn time, and workload. We shaw that the three asymptotic decay rates coincide and that the three asymptotic constants are simply related. We evaluate the exponential approximations based on the ...
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作者：Kubiak, W; Lou, SXC; Wang, YM
作者单位：California State University System; California State University San Marcos; Bank of Montreal; University of Toronto
摘要：This paper considers a reentrant job shop with one hub machine which a job enters K limes. Between any two consecutive entries into the hub: the job is processed on other machines. The objective is to minimize the total Bow time. Under two key assumptions, the bottleneck assumption and the hereditary order (HO) assumption on the processing times of the entries, it is proved that there is an optimal schedule with the shortest processing time (SPT) job order and a dynamic programming algorithm i...
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作者：DellAmico, M
摘要：We consider Job-Shop and Flow-Shop scheduling problems with two machines, no more than two operations per job, and Time Lags, i.e., a minimum time interval between the completion rime of the first operation and the starting time of the second one. We give complexity results for the preemptive and nonpreemptive cases and study the relationship between the two problems. For the Flow-Shop problem we give lower bounds and upper bounds and analyze their worst-case performances. Finally we define a ...
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作者：Hazen, GB; Pellissier, JM
作者单位：Loyola University Chicago
摘要：Stochastic trees are semi-Markov processes represented using tree diagrams. Such trees have been found useful for prescriptive modeling of temporal medical treatment choice. We consider utility functions over stochastic trees which permit recursive evaluation In a graphically intuitive manner analogous to decision tree rollback. Such rollback is computationally intractable unless a low-dimensional preference summary exists. We present the most general classes of utility functions having specif...
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作者：Hu, JQ
摘要：In this paper, we study the departure process of the GI/G/1 queue. We develop a simple recursive procedure to calculate the MacLaurin series of its moments and covariances with respect to a parameter in the service time. Based on this recursive procedure the explicit formulas of the coefficients of these MacLaurin series can be obtained in terms of derivatives of the probability density function of the interarrival time evaluated at zero and the moments of the interarrival time and the service...
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作者：LEcuyer, P
摘要：We analyze the random number generators obtained by combining two or more multiple recursive generators. We study the lattice structure of such combined generators and argue that combination is a good way of obtaining robust generators, based on a recurrence with many nonzero coefficients, and which also possess a fast implementation.
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作者：Tassiulas, L
作者单位：University System of Maryland; University of Maryland College Park
摘要：Demands for service arrive at random times, in random locations, in a region of the plane. The service time of each demand is random. A server that travels with constant speed moves from demand to demand providing service. The server spends its time either in providing service or in traveling. The objective is to route the server, based on the location of the current demands on the plane and the anticipated demand arrivals, such that the time spent in traveling is minimal and the service is pr...
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作者：Thompson, RG; Dharmapala, PS; Gatewood, EJ; Macy, S; Thrall, RM
作者单位：University of Houston System; University of Houston; University of Houston System; University of Houston; Rice University
摘要：The University of Houston (UH) Small Business Development Centers (SBDCs) were analyzed by Data Envelopment Analysis (DEA) and Assurance Region (AR) methods. The DEA/AR analyses were made for 11 DMUs in 1990 and 1991 and for 13 DMUs in 1992. The DEA ratio (CCR) method was applied to Model I in all three years; unique optimal solutions to the DEA-inefficient DMUs were verified. Also, ARs were applied to eliminate some DEA-efficient DMUs requiring unreasonable multipliers to maximize efficiency....
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作者：Wein, LM; Zenios, SA
作者单位：Massachusetts Institute of Technology (MIT)
摘要：We study pooled (or group) testing as a cost-effective alternative for screening donated blood products (sera) for HIV; rather than test each sample individually, this method combines various samples into a pool, and then tests the pool. A group testing policy specifies an initial pool size, and based on the HIV test result, either releases all samples in the pool for transfusion, discards all samples in the pool, or divides the pool into subpools for further testing. We develop a hierarchical...
