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981.
We consider a situation in which a manufacturer has to select the product(s) to sell as well as the selling price and production quantity of each selected product. There are two substitutable products in the consideration set, where product 2 has a higher quality and reservation price than that of product 1. By considering the cannibalization effect that depends on the selling price of each product, the manufacturer needs to evaluate the profit function associated with three different product line options: sell both products or only one of the 2 products. In order to examine the impact of costs, capacity, and competition on the optimal product line selection, optimal price, and optimal production quantity analytically, we present a stylized model in this paper so that we can determine the conditions under which a particular option is optimal. 相似文献
982.
C.V. Pao 《Journal of Mathematical Analysis and Applications》2010,372(2):351-399
This paper is concerned with a class of fourth-order nonlinear elliptic equations with nonlocal boundary conditions, including a multi-point boundary condition in a bounded domain of Rn. Also considered is a second-order elliptic equation with nonlocal boundary condition, and the usual multi-point boundary problem in ordinary differential equations. The aim of the paper is to show the existence of maximal and minimal solutions, the uniqueness of a positive solution, and the method of construction for these solutions. Our approach to the above problems is by the method of upper and lower solutions and its associated monotone iterations. The monotone iterative schemes can be developed into computational algorithms for numerical solutions of the problem by either the finite difference method or the finite element method. 相似文献
983.
Dong-mei Jiang 《Applied mathematics and computation》2010,217(8):3898-3902
A new approach is constructed to obtain exact travelling wave solutions for a differential-difference equation by means of the property of the symmetrical Fibonacci sine and cosine function. As its illustration, some explicit and exact travelling wave solutions of Hybrid lattice, discretized mKdV lattice and modified Volterra lattice are obtained by computing the solutions of a lattice introduced by Wadati. 相似文献
984.
Ai-Li Yang 《Applied mathematics and computation》2010,216(6):1715-1722
Based on the HSS (Hermitian and skew-Hermitian splitting) and preconditioned HSS methods, we will present a generalized preconditioned HSS method for the large sparse non-Hermitian positive definite linear system. Our method is essentially a two-parameter iteration which can extend the possibility to optimize the iterative process. The iterative sequence produced by our generalized preconditioned HSS method can be proven to be convergent to the unique solution of the linear system. An exact parameter region of convergence for the method is strictly proved. A minimum value for the upper bound of the iterative spectrum is derived, which is relevant to the eigensystem of the products formed by inverse preconditioner and splitting. An efficient preconditioner based on incremental unknowns is presented for the actual implementation of the new method. The optimality and efficiency are effectively testified by some comparisons with numerical results. 相似文献
985.
986.
Summary We have applied the Tiwary approach to calculate the opticaloscillator strengths, of both the length and velocity forms, for
the inner-shell excitation1s
2
2s
2
2p
6
3s
2
S
e
→1s
2
2s
2
2p
5
3s
2
2
P
0
transition in Ca X, Sc XI, Ti XII, Cu XIX, Zn XX, Br XXV and Kr XXVI ions of the sodium isoelectronic sequence employing
Hartree-Fock (HF) and configuration interaction (CI) wave functions of both the initial and final states involved in the transition.
Our present calculated results demonstrate that the Tiwary approach is capable of yielding encouraging results.
A part of this work was done while the author was Research Director and Professor, CNRS Laboratory, University of Paris-Sud
and Observatoire de Paris, Meudon, Paris, France. 相似文献
987.
T. Schilling O. Theissen G. Gompper 《The European physical journal. E, Soft matter》2001,4(1):103-114
We investigate the dynamical behavior of lamellar phases in ternary amphiphilic systems of water, oil and amphiphile. The
interaction between the amphiphilic monolayers is described by the steric interaction due to thermal fluctuations for uncharged,
and by electrostatic interactions for charged systems. The dynamics of the system is determined by the hydrodynamics of the
fluid layers. The basic parameters of our model are the viscosities of the two solvents, the average thicknesses of the oil
and water layers, and the bending rigidity. The model allows to consider different monolayer interactions across the oil and
water layers. Relaxation rates are calculated for arbitrary wave vectors parallel and perpendicular to the average monolayer
plane. We find that there is a quite complex crossover behavior from a law for small parallel wave vectors to a law for large . We discuss the relevance of our result for the interpretation of dynamic light-scattering and neutron-spin-echo experiments
for these systems.
Received 7 December 1999 相似文献
988.
989.
Numerous versions of the Lanczos τ-methods have been extensively used to produce polynomial approximations for functions verifying
a linear differential equation with polynomial coefficients. In the case of an initial-value problem, an adapted τ-method
based on Chebyshev series and the use of symbolic computation lead to a rational approximation of the solution on a region
of the complex plane. Numerical examples show that the simplicity of the method does not prevent a high accuracy of results.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
990.
D.V. Fisher Y. Maron 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,14(3):349-359
Accurate treatment of the plasma density effects requires a detailed knowledge of the spatial distribution of individual ions
around a test ion. In the present work, rigorous expressions are derived for the main 2- and 3-particle spatial distribution
functions involving the nearest neighbor (NN) and the next-nearest neighbor (NNN) ions. These expressions, valid for both
ideal and nonideal plasmas, present the distributions as functionals of the potentials U
NN and U
NNN at the nearest and next-nearest ion locations. All of the distribution functions except one are derived and discussed in
the present work for the first time ever. For utilization of our results in practical calculations, we suggest semi-empirical
expressions for U
NN and U
NNN in the ion-ion coupling parameter range 0 ?Γ < 1. In order to test the accuracy of our expressions for U
NN and U
NNN we conduct Molecular Dynamics (MD) simulations. The simulations utilize the pure Coulomb particle-particle interaction potentials,
regularized at close range to avoid classical Coulomb collapse, and are free from the assumptions made to find U
NN and U
NNN. Thus, the results of the MD simulations provide an independent test of our theoretical results. Excellent agreement has
been found between the results of the theory and of the MD simulations. Finally, we outline the implications of the present
findings on the problem of tunneling and charge exchange in dense plasmas.
Received 27 October 2000 and Received in final form 30 January 2001 相似文献