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141.
Horst W. Hamacher Martine Labbé Stefan Nickel Anders J.V. Skriver 《Annals of Operations Research》2002,110(1-4):33-53
Locating a facility is often modeled as either the maxisum or the minisum problem, reflecting whether the facility is undesirable (obnoxious) or desirable. But many facilities are both desirable and undesirable at the same time, e.g., an airport. This can be modeled as a multicriteria network location problem, where some of the sum-objectives are maximized (push effect) and some of the sum-objectives are minimized (pull effect).We present a polynomial time algorithm for this model along with some basic theoretical results, and generalize the results also to incorporate maximin and minimax objectives. In fact, the method works for any piecewise linear objective functions. Finally, we present some computational results. 相似文献
142.
We study the vibration of an elastic thin shell which is pre-constrained by a large displacement with a small deformation. In this first Note we prove the solutions exist and we investigate both the interior regularity and the boundary regularity which is known to be important in the shape differentiation of hyperbolic equations. To cite this article: J. Cagnol, J.-P. Zolésio, C. R. Acad. Sci. Paris, Ser. I 334 (2002) 161–166 相似文献
143.
We prove that if T is a tournament of order n > 6 in which any 4-sub-tournament is hamiltonian or transitive, then T is reconstructible in the sense of Ulam. 相似文献
144.
Lahiouel R. Pierre J. Siaud E. Galera R. M. Besnus M. J. Kappler J. P. Murani A. P. 《Zeitschrift für Physik B Condensed Matter》1987,67(2):185-191
Magnetic properties, electrical resistivity, specific heat and magnetic excitations have been investigated in Heusler phases CeInAg2–xCux. The hybridization continuously increases from CeInAg2 (antiferromagnetic Kondo lattice) to CeInCu2 (heavy fermion compound). The specific heat coefficient for this last compound is found to reach 1.2 J/mole. K2 at 1.4 K, the Kondo temperature is 6 K and the Wilson ratio is close to 2. 相似文献
145.
146.
F. F. Éfendiev 《Mathematical Notes》1992,51(2):204-207
Translated from Matematicheskie Zametki, Vol. 51, No. 2, pp. 139–143, February, 1992. 相似文献
147.
A. S. Parkins C. W. Gardiner M. L. Stéyn-Ross 《Zeitschrift für Physik B Condensed Matter》1991,83(3):413-424
We examine the effect of dissipation on coherent quantum tunnelling between the two lowest levels of a double-well system using an adjoint equation approach developed previously in the treatment of quantum-optical problems. Dissipation is modelled by a linear coupling to a bath of harmonic oscillators. The high frequency portion of the bath is adiabatically eliminated using a cumulant expansion technique, which generates frequency renormalisation terms. Making a low temperature assumption, an approximate two-level model is developed in the form of three coupled stochastic differential equations. With a decorrelation approximation, the two-level equations can be solved to yield familiar results. However, the adjoint equation also permits the use of direct stochastic simulation as a means of solution, and simulations are carried out for a range of parameters. A comparison with the decorrelation approximation is made. 相似文献
148.
Principles and recent developments in ultrasound contrast agents 总被引:6,自引:1,他引:5
The behaviour of gas bubbles and gas encapsulated spheres as echographic contrast agents is reviewed. Compared with rigid spheres, gas bubbles are superior scattering agents and they offer a number of useful properties which can be exploited in a variety of ways. The analysis of their velocity of sound, back-scatter intensity, second harmonic emission and resonant frequency opens up new perspectives in the development of contrast agents for echocardiographic research with potential clinical applications. 相似文献
149.
In this paper we present photoionization cross sections of the Cu and Al dimers and tetramers. The local spin density method is applied to calculate the electronic structure and the ground state potential. The cross sections are calculated using the continuum multiple scattering method, and a basic analysis of the photoionization process is given within the independent particle picture. 相似文献
150.
L Soltés 《Biomedical chromatography : BMC》1992,6(1):43-49
The paper presents results and experience obtained in the isolation of a number of basic polar/non-polar solutes (drugs, their metabolites and structural derivatives) from biological samples by using the separation minicolumns Separcol SI and Separcol SI C18 L/T. The aim was to provide insight into some simple procedures yielding optimal selectivity/specificity of the isolation of the studied solutes either by proper selection of the sorbent or by applying sophisticated elution schemes which use to advantage different properties of the eluents/solvents. 相似文献