摘要:

AbstractAn area to be defended consists of separated point targets. These targets are subject to an attack in which the offensive weapons are assumed to arrive simultaneously. The defense has area defenders, each of which is capable of intercepting any attacker. The defense has no impact‐point prediction; that is, it has no knowledge of any attacker's destination prior to allocation of area interceptors. For a given attack, the defense wishes to allocate its interceptors to maximize the total expected survival value of the targets. For a given attack size, the offense seeks a strategy to minimize total expected surviving value against best defense. We determine an optimal defensive strategy directly and develop an algorithm to determine an optimal attack and the optimal value of the min‐max problem. A dynamic programming technique is used to obtain integer solutions, and illustrative computational results are provi

ISSN:0894-069X    

DOI:10.1002/1520-6750(199106)38:3<289::AID-NAV3220380302>3.0.CO;2-Q

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe large body of work on stochastic duels represents an attempt to model combat situations, or parts of it, by means of formal probability models. Most, but not all, of the existing stochastic duel models, however, relate to static posture and fail to capture dynamic aspects as well as tactical considerations that may be present. In this article we propose a simple model of a two‐on‐one duel in which dynamic and tactical aspects are considered. The model represents a combat situation that is typical of a battle in which a maneuvering force attacks a smaller defending unit that is sta

ISSN:0894-069X    

DOI:10.1002/1520-6750(199106)38:3<303::AID-NAV3220380303>3.0.CO;2-F

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractA new heuristic method is presented for the resolution of multiresource constrained conflicts in project scheduling. In attempting to find a minimal makespan solution, the algorithm employs a simple procedure to generate a feasible solution with no backtracking. A postanalysis phase then applies a hill‐climbing search. The solution method is different from existing heuristic methods in that it repairs resource conflicts rather than constructs detailed schedules by dispatching activities. Resource‐violating sets of activities are identified which must be prevented from concurrent execution because this would violate resource constraints. Repairs are made by imposing an arc to sequence two activities in such a resource violating set. Computational results are compared with those of existing heuristics for the minimal makespan prob

ISSN:0894-069X    

DOI:10.1002/1520-6750(199106)38:3<315::AID-NAV3220380304>3.0.CO;2-7

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractWe examine the static sequencing problem of ordering the processing of jobs on a single machine so as to minimize the average weighted flow time. It is assumed that all jobs have zero ready times, and that the jobs are grouped into classes with the property that setup tasks are only required when processing switches from jobs of one class to jobs of another class. The time required for each setup task is given by the sum of a setdown time from the previous class and a setup time for the new class. We show that an algorithm presented in the literature for solving a special case of this problem gives suboptimal solutions. A number of properties of the optimal solution are derived, and their use in algorithms is evaluated. Computational results are presented for both a branch‐and‐bound procedure and a simpler depth‐first s

ISSN:0894-069X    

DOI:10.1002/1520-6750(199106)38:3<333::AID-NAV3220380305>3.0.CO;2-0

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractWe consider the parallel replacement problem in which there are both fixed and variable costs associated with replacing machines. Increasing maintenance costs motivate replacements, and the fixed replacement cost provides incentive for replacing machines of different ages together in “clusters.” We prove two intuitive results for this problem. First, it is never optimal to split a cluster of like‐aged machines, and second, it is never optimal to replace newer clusters before older clusters. By incorporating these two results into an algorithmic approach, we vastly reduce the amount of computation required to identify an optimal replacement p

ISSN:0894-069X    

DOI:10.1002/1520-6750(199106)38:3<351::AID-NAV3220380306>3.0.CO;2-U

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe concept of parallel operations has been widely used in manufacturing and data processing. However, not many efficient methods have been proposed to reduce job tardiness. This article proposes an efficient heuristic to minimize the mean tardiness of a set of tasks with known processing times and due dates for single andmparallel machines. For the single‐machine case, the proposed heuristic is compared with the well‐known Wilkerson and Irwin algorithm; for themparallel machine case, it is compared with an extension of the Wilkerson‐Irwin algorithm. We also introduce a simple dispatching rule, and it is compared with some existing dispatching rules. The comprehensive simulation results show that the proposed heuristic performs better than the Wilkerson‐Irwin algorithm at a significantly reduced computation

ISSN:0894-069X    

DOI:10.1002/1520-6750(199106)38:3<367::AID-NAV3220380307>3.0.CO;2-I

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe problem of optimal dynamic sequencing for a single‐server multiclass service system with only unit storage (buffer) space ateachqueue is considered. The model is applicable to many computer operating and telecommunicating systems (e.g., polling systems). Index policies to minimize costs for the special case of symmetric arrival rates are derived. Simulations suggest that using these indices provides a substantial improvement over cyclic schedule

ISSN:0894-069X    

DOI:10.1002/1520-6750(199106)38:3<383::AID-NAV3220380308>3.0.CO;2-D

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThis article analyzes a model of a multiechelon inventory system: The exogenous demands form independent compound‐Poisson processes. Each location follows a base‐stock policy. The transit times between locations may be stochastic. Instead of assuming independent transit times, we follow an approach closer to the standard treatment of single‐location models. We develop procedures to compute steady‐state performance measures, including average backorders and average inventories. The model and the analysis generalize those of Svoronos and Zipkin, who treat the case of pure Poisson

ISSN:0894-069X    

DOI:10.1002/1520-6750(199106)38:3<397::AID-NAV3220380309>3.0.CO;2-3

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractUntil recently, fast algorithms for the maximum flow problem have typically proceeded by constructing layered networks and establishing blocking flows in these networks. However, in recent years, newdistance‐directedalgorithms have been suggested that do not construct layered networks but instead maintain adistance labelwith each node. The distance label of a node is a lower bound on the length of the shortest augmenting path from the node to the sink. In this article we develop two distance‐directed augmenting path algorithms for the maximum flow problem. Both the algorithms run inO(n2m) time on networks withnnodes andmarcs. We also point out the relationship between the distance labels and layered networks. Using a scaling technique, we improve the complexity of our distance‐directed algorithms toO(nmlogU), whereUdenotes the largest arc capacity. We also consider applications of these algorithms to unit capacity maximum flow problems and a class of parametric maximum flow pro

ISSN:0894-069X    

DOI:10.1002/1520-6750(199106)38:3<413::AID-NAV3220380310>3.0.CO;2-J

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractAn algorithm for determining the optimal, unidirectional flow path for an automated guided vehicle system with a given facility layout is presented. The problem is formulated as an integer program. The objective is to minimize the total distance traveled by vehicles subject to the constraint that the resulting network consists of a single strongly connected component. A specialized branch‐and‐bound solution procedure is discussed in det

ISSN:0894-069X    

DOI:10.1002/1520-6750(199106)38:3<431::AID-NAV3220380311>3.0.CO;2-C

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY