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941.
Mason Gene Bailey Billy E. Gillett 《The Journal of the Operational Research Society》1980,31(3):257-262
An algorithm is presented for solving families of integer linear programming problems in which the problems are "related" by having identical objective coefficients and constraint matrix coefficients. The righthand-side constants have the form b + θd where b and d are conformable vectors and θ varies from zero to one.The approach consists primarily of solving the most relaxed problem (θ = 1) using cutting planes and then contracting the region of feasible integer solutions in such a manner that the current optimal integer solution is eliminated.The algorithm was applied to 1800 integer linear programming problems with reasonable success. Integer programming problems which have proved to be unsolvable using cutting planes have been solved by expanding the region of feasible integer solutions (θ = 1) and then contracting to the original region. 相似文献
942.
The problem of scheduling delivery vehicles from a number of depots to customers, subject to constraints on load and distance or time, is considered. A new algorithm is presented; this allows routes from several depots to be constructed simultaneously, subject to restrictions on numbers of vehicles at individual depots. Where too many customers require service, a flexible priority rule will select those to be served. Results for the single depot case are compared with other known algorithms; further results are given and discussed for cases of several depots. 相似文献
943.
Oscar Chisini 《Rendiconti del Circolo Matematico di Palermo》1916,42(1):59-64
An improvement of the uniqueness theorem of Wintner for the differential equationx (n)(t)=f(t, x) is given. 相似文献
944.
Helmut Schneider 《The Journal of the Operational Research Society》1978,29(12):1181-193
This paper deals with a periodic review inventory system. Methods are discussed for determining the re-order point s of an (s, S) order policy, when a certain service level is required. The results differ from those presented for a (Q, s) model which is usually considered in literature and implemented in practice. Methods are discussed for determining the re-order point of an (s, S) policy when demand is normal or gamma distributed. A numerical investigation demonstrates the applicability of the described methods. In particular, it is shown that these methods are superior to a formula that is implemented in many inventory control systems. 相似文献
945.
Mike Wright 《The Journal of the Operational Research Society》1992,43(3):195-201
Each team in the English County Cricket Championship plays against some other teams twice a year, and others only once. This paper describes a case study whose aim was to overcome this inherent unfairness by producing a four-year schedule of opponents which was as fair as possible, and could be easily seen to be fair, while still allowing for traditional rivalries. The schedule also needed to be satisfactory in regard to several other constraints and objectives. Various simple heuristics were used; these are described in some detail. Of particular interest is the effectiveness of a ‘local non-worsening’ approach when the objective is to find any feasible solution. This is equivalent to simulated annealing at a constant temperature of absolute zero. 相似文献
946.
Peter Roberts 《The Journal of the Operational Research Society》1983,34(1):71-79
A new theory of the learning process is proposed, based on the assumption that learning resembles a search programme using the branch and bound algorithm. Examples from diverse fields are given, and means of testing the theory are suggested. It is argued that the implications of the theory are important for industrial competition strategy and for energy policy. 相似文献
947.
Pekka Korhonen Margareta Soismaa 《The Journal of the Operational Research Society》1981,32(7):577-585
In this paper we are concerned with ranking various orderings of a set of alternatives to a composite order as a multiple criteria problem. The orderings (called preference orderings) can be real preference orderings or any natural orderings. The objective is to find the most preferred order of the decision maker using the preference orderings as criteria.In principle, the problem can be formulated as a multiple objective linear programming problem using the model of Bowman and Colantoni and then solved with the interactive method proposed by Zionts and Wallenius. However, the fact that we are dealing with integer variables prohibits us from applying this approach as such. We discuss the problem formulation and propose a modified approach to that of Zionts and Wallenius for solving the problem. 相似文献
948.
We obtain characterizations of positive Borel measures μ on B
n
so that some weighted holomorphic Besov spaces B
s
p
(ω,B
n
) are embedded in L
p
(d
μ). 相似文献
949.
David Kalaj 《Israel Journal of Mathematics》2011,182(1):123-147
Let ρ
Σ = h(|z|2) be a metric in a Riemann surface Σ, where h is a positive real function. Let H
r
1 = {w = f(z)} be the family of a univalent ρ
Σ harmonic mapping of the Euclidean annulus A(r
1, 1):= {z: r
1 < |z| < 1} onto a proper annulus A
Σ of the Riemann surface Σ, which is subject to some geometric restrictions. It is shown that if A
Σ is fixed, then sup{r
1: ℋ
r
1 ≠ ∅} < 1. This generalizes similar results from the Euclidean case. The cases of Riemann and of hyperbolic harmonic mappings
are treated in detail. Using the fact that the Gauss map of a surface with constant mean curvature (CMC) is a Riemann harmonic
mapping, an application to the CMC surfaces is given (see Corollary 3.2). In addition, some new examples of hyperbolic and
Riemann radial harmonic diffeomorphisms are given, which have inspired some new J. C. C. Nitsche-type conjectures for the
class of these mappings. 相似文献
950.
In this paper we consider the solution of certain convex integer minimization problems via greedy augmentation procedures.
We show that a greedy augmentation procedure that employs only directions from certain Graver bases needs only polynomially
many augmentation steps to solve the given problem. We extend these results to convex N-fold integer minimization problems and to convex 2-stage stochastic integer minimization problems. Finally, we present some
applications of convex N-fold integer minimization problems for which our approach provides polynomial time solution algorithms. 相似文献