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91.
We introduce a class of set-functions on the set of natural numbers, which are called super-measures. Super-measures are then
utilized to characterize a certain class of topological measures (previously called quasi-measures, see below) which arises
naturally. The members of this class of topological measures are called finitely defined, and are shown to be dense in the
set of all topological measures.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
92.
Christopher L. Henley 《Journal of statistical physics》1997,89(3-4):483-507
This paper considers the Monte Carlo dynamics of random dimer coverings of the square lattice, which can be mapped to a rough
interface model. Two kinds of slow modes are identified, associated respectively with long-wavelength fluctuations of the
interface height, and with slow drift (in time) of the system-wide mean height. Within a continuum theory, the longest relaxation
time for either kind of mode scales as the system sizeN. For the real, discrete model, an exactlower bound ofO(N) is placed on the relaxation time, using variational eigenfunctions corresponding to the two kinds of continuum modes 相似文献
93.
Christian Prins 《Journal of Mathematical Modelling and Algorithms》2002,1(2):135-150
The basic Vehicle Routing Problem (VRP) consists of computing a set of trips of minimum total cost, to deliver fixed amounts of goods to customers with a fleet of identical vehicles. Few papers address the case with several types of vehicles (heterogeneous fleet). Most of them assume an unlimited number of vehicles of each type, to dimension the fleet from a strategic point of view. This paper tackles the more realistic tactical or operational case, with a fixed number of vehicles of each type, and the optional possibility for each vehicle to perform several trips. It describes several heuristics, including a very efficient one that progressively merges small starting trips, while ensuring that they can be performed by the fleet. This heuristic seeks to minimize the number of required vehicles as a secondary objective. It outperforms classical VRP heuristics, can easily handle various constraints, and gives very good initial solutions for a tabu search method. The real case of a French manufacturer of furniture with 775 destination stores is presented. 相似文献
94.
95.
In this article we present a new, general but simple, microscopic expression for time-dependent solvation energy of an ion.
This expression is surprisingly similar to the expression for the time-dependent dielectric friction on a moving ion. We show
that both the Chandra-Bagchi and the Fried-Mukamel formulations of solvation dynamics can be easily derived from this expression.
This expression leads to an almost perfect agreement of the theory with all the available computer simulation results. Second,
we show here for the first time that the mobility of a light solute ion can significantly accelerate its own solvation, specially
in the underdamped limit. The latter result is also in excellent agreement with the computer simulations. 相似文献
96.
Numerical analysis of a shock-wave solution of the Enskog equation obtained via a Monte Carlo method
In this paper a planar stationary shock-wave-like solution of the Enskog equation obtained via a Monte Carlo technique is studied; both the algorithm used to obtain the solution and the qualitative behavior of the macroscopic quantities are discussed in comparison with the corresponding solution of the Boltzmann equation. 相似文献
97.
Marek Janata 《Discrete Mathematics》2007,307(16):2002-2007
Let T be a family of graphs. A T-packing of a graph G is a subgraph of G, components of which are isomorphic to members of T. We are concerned with families T, such that in every graph G, the subsets of vertices that can be saturated by some T-packing form a collection of independent sets of a matroid. The main purpose of this paper is to introduce a new class of families with this property. 相似文献
98.
We provide analogues of Carathéodory's theorem for integer cones and apply our bounds to integer programming and to the cutting stock problem. In particular, we provide an NP certificate for the latter, whose existence has not been known so far. 相似文献
99.
100.
Cristina Bazgan W. Fernandez de la Vega Marek Karpinski 《Random Structures and Algorithms》2003,23(1):73-91
It is known that large fragments of the class of dense Minimum Constraint Satisfaction (MIN‐CSP) problems do not have polynomial time approximation schemes (PTASs) contrary to their Maximum Constraint Satisfaction analogs. In this paper we prove, somewhat surprisingly, that the minimum satisfaction of dense instances of kSAT ‐formulas, and linear equations mod 2, Ek‐LIN2, do have PTASs for any k. The MIN‐Ek‐LIN2 problems are equivalent to the k‐ary versions of the Nearest Codeword problem, the problem which is known to be exceedingly hard to approximate on general instances. The method of solution of the above problems depends on the development of a new density sampling technique for k‐uniform hypergraphs which could be of independent interest. © 2003 Wiley Periodicals, Inc. Random Struct. Alg., 23: 73–91, 2003 相似文献