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61.
Kh. D. Ikramov 《Mathematical Notes》1996,60(6):649-657
LetR be a (real or complex) triangular matrix of ordern, say, an upper triangular matrix. Is it true that there exists a normaln×n matrixA whose upper triangle coincides with the upper triangle ofR? The answer to this question is “yes” and is obvious in the following cases: (1)R is real; (2)R is a complex matrix with a real or a pure imaginary main diagonal, and moreover, all the diagonal entries ofR belong to a straight line. The answer is also in the affirmative (although it is not so obvious) for any matrixR of order 2. However, even forn=3 this problem remains unsolved. In this paper it is shown that the answer is in the affirmative also for 3×3 matrices. 相似文献
62.
The Study of Minimax Inequalities, Abstract Economics and Applications to Variational Inequalities and Nash Equilibria 总被引:6,自引:0,他引:6
In this survey, a new minimax inequality and one equivalent geometricform are proved. Next, a theorem concerning the existence of maximalelements for an LC-majorized correspondence is obtained.By the maximal element theorem, existence theorems of equilibrium point fora noncompact one-person game and for a noncompact qualitative game withLC-majorized correspondences are given. Using the lastresult and employing 'approximation approach', we prove theexistence of equilibria for abstract economies in which the constraintcorrespondence is lower (upper) semicontinuous instead of having lower(upper) open sections or open graphs in infinite-dimensional topologicalspaces. Then, as the applications, the existence theorems of solutions forthe quasi-variational inequalities and generalized quasi-variationalinequalities for noncompact cases are also proven. Finally, with theapplications of quasi-variational inequalities, the existence theorems ofNash equilibrium of constrained games with noncompact are given. Our resultsinclude many results in the literature as special cases. 相似文献
63.
64.
65.
66.
N. X. Tan 《Journal of Optimization Theory and Applications》2004,123(3):619-638
Quasivariational inclusion problems are formulated and sufficient conditions on the existence of solutions are shown. As special cases, we obtain several results on the existence of solutions of general vector ideal, proper, Pareto, weak quasioptimization problems, quasivariational inequalities, and vector quasiequilibrium problems. Further, we prove theorems on the existence for solutions of systems of these inclusions. As a corollary, we obtain an ideal minimax theorem concerning vector functions. 相似文献
67.
Roberto Montemanni 《4OR: A Quarterly Journal of Operations Research》2003,1(3):257-260
A survey of the results described in the authors PhD thesis (Montemanni 2001) is presented. The thesis, which was supervised by Prof. Derek H. Smith and Dr. Stuart M. Allen, has been defended in January 2002 at the University of Glamorgan (U.K.). The thesis proposes new heuristic algorithms, based on well-known meta-heuristic paradigms, and new lower bounding techniques, based on linear programming, for the fixed spectrum frequency assignment problem.Received: May 2003, Revised: May 2003, AMS classification:
90C27, 90C59,05C90, 90C05Roberto Montemanni: Present address: Istituto Dalle Molle di Studi sullIntelligenza Artificiale (IDSIA), Galleria 2, 6928 Manno-Lugano, Switzerland (e-mail: roberto@idsia.ch) 相似文献
68.
John D. Weeks 《Journal of statistical physics》2003,110(3-6):1209-1218
By combining the upper and lower bounds to the free energy as given by the Gibbs inequality for two systems with the same intermolecular interactions but with external fields differing from each other only in a finite region of space , we show that the corresponding equilibrium densities must also differ from each other somewhere in . We note that the basic equations of density functional theory arise naturally from a simple rearrangement and reinterpretation of the terms in the upper bound Gibbs inequality for such systems and briefly discuss some of the complications that occur when the intermolecular interactions of the two systems also differ. 相似文献
69.
Let
be a sequence of complex numbers such that
as
. For
close to the imaginary axis, upper bounds of the indicator of a nonzero entire function of exponential type with minimal growth vanishing on
is obtained. These bounds give sufficient conditions for the system of exponents
to be incomplete in an unbounded domain in
. 相似文献
70.
F. Crisciani R. Purini 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,31(4):571-575
The present note deals with Munk's ocean model and proposes an alternative approach to find its solution, with special regard
to the western boundary layer. We introduce a suitable “distance” between the related Sverdrup streamfunction and all the
admissible streamfunctions which are valid in the western boundary layer. We prove that such distance has a minimum that singles
out a unique solution. Unlike the traditional method, this procedure works without assuming a priori any dynamic boundary
condition.
Received 16 July 2002 Published online 6 March 2003
RID="a"
ID="a"e-mail: fulcri@itt.ts.cnr.it 相似文献