bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parameter estimation for the EOQ lot‐size model: Minimax and expected value choices
Authors: Lowe Timothy J. , Schwarz Leroy B. 
Published: May 2007

AbstractThis article provides formulas for estimating the parameters to be used in the basic EOQ lot‐size model. The analysis assumes that the true values of these parameters are unknown over known ranges and perhaps nonstationary over time. Two measures of estimator “goodness” are derived from EOQ sensitivity analysis. Formulas are given for computing the minimax choice and the minimum expected value choice for the parameter estimates using both measures of estimator “goodness”. A numerical example is included.
Optimal replacement under additive damage in randomly varying environments
Authors: Waldmann K.‐H. 
Published: May 2007

AbstractA system is subject to a sequence of randomly occurring shocks. Each shock causes a random amount of damage which accumulates additively. Any of the shocks might cause the system to fail. The shock process is in some sense related to an environmental process in order to describe randomly varying external factors of an economical and/or technical nature as well as internal factors of a statistical nature. A discrete time formulation of the problem is given. Sufficient conditions are found for optimality of a generalized control‐limit rule with respect to the total cost criterion: Whenever the accumulated damage s is not less than a specified critical number t(i), depending on the environmental state i, replace the system by a new one; otherwise do not replace it. Moreover, bounds are given for these critical numbers.
The effect of stochastic time delays on the reliability of isolated impulse systems
Authors: Bendell A. 
Published: May 2007

AbstractThis article concerns the effect of stochastic time delays in the operation of components upon system reliability for isolated impulse systems, for which component delays have hitherto been treated as deterministic. These are systems, such as automatic protective devices, which remain idle for most of their lives but which are required to respond with the utmost speed to input signals arising at arbitrary isolated time instants. System failure can arise from components failing to operate, or from being too slow to operate so that the systems operation is too slow to meet requirements. During operation components are usually subjected to greater stresses than during idling, so that it is assumed that components are subjected to increased failure tendencies during the time it takes them to perform their functions. The effect of stochastic time delays on the evaluation of systems reliability is considered, and a hierarchy of complexity associated with the physical nature of the delays in series and redundant configurations is exposed. Some simple exponential illustrations are presented.
The proper balancing of repair and preventive maintenance activities in the determination of coordinated shipboard allowance lists
Authors: Landsdowne Zachary F. , Morey Richard C. 
Published: May 2007

AbstractThe determination as to the cost‐effective number of spares for given types of items or equipment to be carried on board various types of ships is studied. This spare pool, known as the ship's COSAL, must provide prespecified levels of protection against stockouts for all uses of that item on board the given ship. This article derives and illustrates the methodology for optimally trading off the reduction in the ship's COSAL that can be gained by improving repair/resupply capabilities or by lowering the failure rate of the equipment through more or different types of preventive maintenance. A flexible class of preventive maintenance/repair response functions to cost is studied which are nonlinear and exhibit realistic diminishing returns. Two different types of assumptions are possible regarding the interdependencies of the resupply times across different ship types. A tractable budget allocation method is presented which can be used in a multiitem, multiship, multiechelon repair environment where there is one budget to cover all spares, all repair/resupply, and preventive maintenance activities. The technique incorporates different criticalities of shortages by type of ship and item. It can be used either in a budget building mode or a budget execution mode.
A transportation problem with competition
Authors: Marchi Ezio , Tarazaga Pablo 
Published: May 2007

AbstractThe classic transportation problem can be generalized with many carriers and one owner. From the formulation the competition in sense of game theory naturally appears. Here we present and solve this problem using a generalized n‐person game. Besides the same composition properties about solutions and regarding zones, related results are considered. Finally, the problem in which there is a modification of the set of destinations assigned to the carriers is also studied.
Armed services recruiting research: Issues, findings, and needs
Authors: Morey Richard C. , McCann John M. 
Published: May 2007

AbstractManning the nation's armed services will continue to be a crucial issue for the remainder of the 1980s. With the projected growth of the services during this decade, the downturn in the 17–21‐year‐old male population, and the possible upturn in the economy, the ability of the services to meet their respective quality and quantity recruiting goals becomes of central concern. The accurate estimation of the supply for various types of recruits becomes especially important when one views the nearly $1 billion budgeted annually for recruiting and the impact that any military pay raises can have on the DOD's manpower costs of over $40 billion annually. In addition, perceived difficulties in recruiting can impact on weapon systems design decisions, authorized manning levels, and exacerbate the debate concerning the draft; hence, it is clear that few issues today warrant more attention than improving the efficiency and effectiveness of military recruiting. This article provides an introduction and review of some of the key issues involved in modeling and estimating the supply of military recruits. It summarizes and compares the findings of selected econometric models, all of which are based on enlistment experience since the introduction of the All‐Volunteer Force in 1973. It also presents some new insights and directions for research dealing with simultaneity, validation, generation of rigorous confidence intervals, and data base selection. It concludes by listing some of the research needs to be addressed in the future.
Some branch‐and‐bound procedures for fixed‐cost transportation problems
Authors: Cabot A. Victor , Erenguc S. Selcuk 
Published: May 2007

AbstractIn this article we present three properties that will improve the performance of branch‐and‐bound algorithms for fixed‐cost transportation problems. By applying Lagrangian relaxation we show that one can develop stronger up and down penalties than those traditionally used and also develop a strengthened penalty for nonbasic variables. We also show that it is possible to “look ahead” of a particular node and determine the solution at the next node without actually calculating it. We present computational evidence by comparing our developments with existing procedures.
On the optimal policies of an exponential machine repair problem
Authors: Lehtonen Tapani 
Published: May 2007

AbstractWe consider an exponential repair model with s machines and one repairman. The machines' failure rates are equal but the repair rate may change from machine to machine. The repairman repairs the failed machines one at a time and in the course of his work he may even interrupt repairing one machine and start another. We compare repair policies and prove an optimality result by means of stochastic order. The proof is based on representing the compared models simultaneously in a special way and comparing then the sample paths of the interesting stochastic processes.
Disaggregation in economic models
Authors: Tiplitz Charles 
Published: May 2007

AbstractThis article illustrates numerically that the adjustment path of the economy will not show how a national policymaker may be misled by overaggregation until it is too late for correction. Labor and other resources are overaggregated in the equilibrating mechanism of most economic models, tending to mislead policymakers regarding both the amount and direction of change of important variables. Overaggregation also hides important constraints and tradeoffs which masks opportunities to use slack resources. In turn, this creates unnecessary dilemmas, such as that between inflation and unemployment which plagued the progress of the Humphrey‐Hawkins Bill. The article first illustrates the hypothesis using simple models. Then its relevance to current analysis and planning is discussed.
A family of games on 1,∞)2 with payoff a function of y/x
Authors: Heuer G. A. 
Published: May 2007

AbstractA two‐parameter class of games on 1,∞)2 is studied. The games may be regarded as analogs of Silverman games, having continuous payoff function in place of a step function of y/x. This change is motivated by a desire to move toward a model for competitive situations where the penalty for overspending increases with the amount of overspending. There are some similarities to games with bell‐shaped kernel. For most of the region considered in the plane of the two parameters there are solutions of finite type, which are obtained explicitly. There are, however, pockets in this plane where no optimal strategies have been found and possibly where none of finite type exist.
Continuous‐time markov decision processes with nonzero terminal reward
Authors: Jo Kyung Y. 
Published: May 2007

AbstractIn this article we consider a continuous‐time Markov decision process with a denumerable state space and nonzero terminal rewards. We first establish the necessary and sufficient optimality condition without any restriction on the cost functions. The necessary condition is derived through the Pontryagin maximum principle and the sufficient condition, by the inherent structure of the problem. We introduce a dynamic programming approximation algorithm for the finite‐horizon problem. As the time between discrete points decreases, the optimal policy of the discretized problem converges to that of the continuous‐time problem in the sense of weak convergence. For the infinite‐horizon problem, a successive approximation method is introduced as an alternative to a policy iteration method.
The stochastic duel with time‐dependent hit probabilities
Authors: Ancker C. J. 
Published: May 2007

AbstractThe fundamental stochastic duel considers two opponents who fire at each other at either random continuous or fixed‐time intervals with a constant hit probability on each round fired. Each starts with an unloaded weapon, unlimited ammunition, and unlimited time. The first to hit wins. In this article we extend the theory to the case where hit probabilities are functions of the time since the duel began. First, the marksman firing at a passive target is considered and the characteristic function of the time to a hit is developed. Then, the probability of a given side winning the duel is derived. General solutions for a wide class of hit probability functions are derived. Specific examples of both the marksman and the duel problem are given.
Quadratic forms in spherical random variables: Generalized noncentral x2 distribution
Authors: Cacoullos T. , Koutras M. 
Published: May 2007

AbstractLet X denote a random vector with a spherically symmetric distribution. The density of U = X'X, called a “generalized chi‐square,” is derived for the noncentral case, when μ = E(X) ≠ 0. Explicit series representations are found in certain special cases including the “generalized spherical gamma,” the “generalized” Laplace and the Pearson type VII distributions. A simple geometrical representation of U is shown to be useful in generating random U variates. Expressions for moments and characteristic functions are also given. These densities occur in offset hitting probabilities.
Estimating the common location parameter of exponential distributions with censored samples
Authors: Chiou Wen‐Jau , Cohen Arthur 
Published: May 2007

AbstractConsider the problem of estimating the common location parameter of two exponential distributions when censored samples are taken. The unique minimum variance unbiased estimator (UMVUE) is found along with an expression for its variance. The asymptotic distribution is given for a special case and a generalized Bayes property is exhibited. Extensions include the case of k > 2 populations. Also the UMVUE is found for P(Y > X) and certain reliability functions.
Optimal policy of continuous and discrete replacement with minimal repair at failure
Authors: Nakagawa Toshio 
Published: May 2007

AbstractThis article considers combined continuous and discrete replacement with minimal repair at failure, in which a unit is replaced at time T or at number N of uses. Both optimal time T* and number N* to minimize the expected cost rate are discussed. They are found by unique solutions of equations when the hazard rates are monotonously increasing. A numerical example is given.
Application of disjunctive programming to the linear complementarity problem
Authors: Ramarao B. , Shetty C. M. 
Published: May 2007

AbstractIn this article we address the question of developing deep cuts for disjunctive programs using rectilinear distance measures. The method is applied to linear complementarity problems where the matrix M need not be copositive plus. Some modifications that are needed as a computational expediency are discussed. The computation results for matrix M of size up to 30 × 30 are discussed.
Layered defense of deceptively based ICBMs
Authors: Bracken Jerome 
Published: May 2007

AbstractThe basing of ICBMs is a fundamental problem of defense analysis. Deceptive basing and antiballistic missile defense are two of the methods available to attempt to insure that there are ICBMs surviving after undergoing an attack. This article treats tradeoffs among missiles, silos or shelters, exoatmospheric interceptors, and endoatmospheric interceptors. Most of the analysis deals with 200 missiles, the number of MX missiles which were recommended to be moved among the 4600 shelters of the Multiple Protective Shelter (MPS) deployment, though some variants in the number of missiles (from 115 to 400) are also treated here. The basic reference point of the analysis is the provision of 1000 ICBM warheads delivered in a second strike. The combination of exoatmospheric interceptors and endoatmospheric interceptors is referred to as “layered defense.” Warheads are destroyed by interceptors after the warheads separate from the missile which carries them. Exoatmospheric interceptors are assumed to achieve a non‐nuclear kill, while endoatmospheric interceptors are assumed to achieve either a non‐nuclear or nuclear kill, depending on the technology available to both sides. Exoatmospheric interceptors may be capable of protecting value targets against the warheads of a second strike. To the extent that this can be achieved, they facilitate a first strike with relative impunity and hence are destabilizing. This article explores various layered defense topics.
Some pros and cons of MIL‐STD‐414
Authors: Perry Darrell D. 
Published: May 2007

AbstractMIL‐STD‐414 has been in existence in its original form since 1957. Obviously, there are some things that are right about 414. But there are some changes to the standard that are long overdue. This article presents some pros and cons of 414 and a recommendation that it be replaced by a MIL‐STD‐414A. Two concerns regarding ANSI/ASQC Z1.9 are discussed.
Minimum cost sampling plans using bayesian methods
Authors: Lorenzen Thomas J. 
Published: May 2007

AbstractThis article considers a general method for acceptance/rejection decisions in lot‐by‐lot sampling situations. Given arbitrary cost functions for sampling, accepting, and rejecting (where the cost can depend on the quality of the item) and a prior distribution on supplier quality, formulas are derived that lead to the minimal cost single‐staged inspection plan. For the Bernoulli case, where each item is classified as acceptable or defective, the formulas simplify immensely. A computer code for solving the Bernoulli case is given.
Bilateral phase‐type distributions
Authors: Shanthikumar J. G. 
Published: May 2007

AbstractIn this article we define a class of distributions called bilateral phase type (BPH), and study its closure and computational properties. The class of BPH distributions is closed under convolution, negative convolution, and mixtures. The one‐sided version of BPH, called generalized phase type (GPH), is also defined. The class of GPH distributions is strictly larger than the class of phase‐type distributions introduced by Neuts, and is closed under convolution, negative convolution with nonnegativity condition, mixtures, and formation of coherent systems. We give computational schemes to compute the resulting distributions from the above operations and extend them to analyze queueing processes. In particular, we present efficient algorithms to compute the steady‐state and transient waiting times in GPH/GPH/1 queues and a simple algorithm to compute the steady‐state waiting time in M/GPH/1 queues.
A finite algorithm for concave minimization over a polyhedron
Authors: Benson Harold P. 
Published: May 2007

AbstractWe present a new algorithm for solving the problem of minimizing a nonseparable concave function over a polyhedron. The algorithm is of the branch‐and‐bound type. It finds a globally optimal extreme point solution for this problem in a finite number of steps. One of the major advantages of the algorithm is that the linear programming subproblems solved during the branch‐and‐bound search each have the same feasible region. We discuss this and other advantages and disadvantages of the algorithm. We also discuss some preliminary computational experience we have had with our computer code for implementing the algorithm. This computational experience involved solving several bilinear programming problems with the code.
Three‐machine flowshop stochastic scheduling to minimize distribution of schedule length
Authors: Frostig E. , Adiri I. 
Published: May 2007

AbstractThis article studies a special case of stochastic three‐machine, permutation flowshop scheduling. It is proved that a sequence where processing times on the first and third machines are in a monotone nondecreasing and nonincreasing order of the likelihood ratio, respectively, and on the second machine are equally distributed, minimizes distribution of schedule length.
Sensitivity analysis of the optimal location of a facility
Authors: Drezner Zvi 
Published: May 2007

AbstractWe perform a sensitivity analysis of the Euclidean, single‐facility minisum problem, which is also known as the Weber problem. We find the sensitivity of the optimal site of the new facility to changes in the locations and weights of the demand points. We apply these results to get the optimal site if some of the parameters in the problem are changed. We also get approximate formulas for the set of all possible optimal sites if demand points are restricted to given areas, and weights must be within given ranges, which is a location problem under conditions of uncertainty.
Estimating critical path and arc probabilities in stochastic activity networks
Authors: Fishman George S. 
Published: May 2007

AbstractThis article describes a new procedure for estimating parameters of a stochastic activity network of N arcs. The parameters include the probability that path m is the longest path, the probability that path m is the shortest path, the probability that arc i is on the longest path, and the probability that arc i is on the shortest path. The proposed procedure uses quasirandom points together with information on a cutset ℋ of the network to produce an upper bound of O[(log K)N−|ℋ|+1/K] on the absolute error of approximation, where K denotes the number of replications. This is a deterministic bound and is more favorable than the convergence rate of 1/K1/2 that one obtains from the standard error for K independent replications using random sampling. It is also shown how series reduction can improve the convergence rate by reducing the exponent on log K. The technique is illustrated using a Monte Carlo sampling experiment for a network of 16 relevant arcs with a cutset of ℋ = 7 arcs. The illustration shows the superior performance of using quasirandom points with a cutset (plan A) and the even better performance of using quasirandom points with the cutset together with series reduction (plan B) with regard to mean square error. However, it also shows that computation time considerations favor plan A when K is small and plan B when K is large.
Customer delays in M/M/c repair systems with spares
Authors: Berg M. , Posner M. J. M. 
Published: May 2007

AbstractA service center to which customers bring failed items for repair is considered. The items are exchangeable in the sense that a customer is ready to take in return for the failed item he brought to the center any good item of the same kind. This exchangeability feature makes it possible for the service center to possess spares. The focus of the article is on customer delay in the system—the time that elapses since the arrival of a customer with a failed item and his departure with a good one—when repaired items are given to waiting customers on a FIFO basis. An algorithm is developed for the computation of the delay distribution when the item repair system operates as an M/M/c queue.
On the solution of some approximate continuous review inventory models
Authors: Das Chandrasekhar 
Published: May 2007

AbstractThis article compares two types of approximating strategies for solving some continuous review inventory models noniteratively. One of these strategies is to approximate the normalized loss integral by an exponential function whereas the other strategy is to estimate the loss integral as a quadratic function of the right‐tail probability. It is found that the latter method is significantly more accurate and versatile than the former method. Theoretical arguments are given to emphasize that both the right‐tail probability and the loss integral are key functions involved in those models. Therefore, a good strategy should be not only to estimate these two functions, but also to retain the interrelationships between them. The quadratic method is better than the exponential method primarily because of the latter property.
Optimal refueling strategies for a mixed‐vehicle fleet
Authors: Mehrez Abraham , Stern Helman I. 
Published: May 2007

AbstractThe problem treated here involves a mixed fleet of vehicles comprising two types of vehicles: K1 tanker‐type vehicles capable of refueling themselves and other vehicles, and K2 nontanker vehicles incapable of refueling. The two groups of vehicles have different fuel capacities as well as different fuel consumption rates. The problem is to find the tanker refueling sequence that maximizes the range attainable for the K2 nontankers. A tanker refueling sequence is a partition of the tankers into m subsets (2 ≤ m ≤ K1). A given sequence of the partition provides a realization of the number of tankers participating in each successive refueling operation. The problem is first formulated as a nonlinear mixed‐integer program and reduced to a linear program for a fixed sequence which may be solved by a simple recursive procedure. It is proven that a “unit refueling sequence” composed of one tanker refueling at each of K1 refueling operations is optimal. In addition, the problem of designing the “minimum fleet” (minimum number of tankers) required for a given set of K2 nontankers to attain maximal range is resolved. Also studied are extensions to the problem with a constraint on the number of refueling operations, different nontanker recovery base geometry, and refueling on the return trip.