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1.
The Internet has provided traditional retailers a new means with which to serve customers. Consequently, many “bricks-and-mortar” retailers have transformed to “clicks-and-mortar” by incorporating Internet sales. Examples of companies making such a transition include Best Buy, Wal-Mart, Barnes & Noble, etc. Despite the increasing prevalence of this practice, several fundamental questions remain: (1) Does it pay off to go online? (2) Which is the equilibrium industry structure? (3) What is the implication of this business model for consumers? We study these issues in an oligopoly setting and show that clicks-and-mortar arises as the equilibrium channel structure. However, we find that this equilibrium does not necessarily imply higher profits for the firms: in some cases, rather, it emerges as a strategic necessity. Consumers are generally better off with clicks-and-mortar retailers. If firms align with pure e-tailers to reach the online market, we show that a prisoner’s dilemma-type equilibrium may arise. 相似文献
2.
E. Cesaratto 《Journal of Number Theory》2009,129(10):2267-2273
The paper “Euclidean algorithms are Gaussian” [V. Baladi, B. Vallée, Euclidean algorithm are Gaussian, J. Number Theory 110 (2005) 331-386], is devoted to the distributional analysis of three variants of Euclidean algorithms. The Central Limit Theorem and the Local Limit Theorem obtained there are the first ones in the context of the “dynamical analysis” method. The techniques developed have been applied in further various works (e.g. [V. Baladi, A. Hachemi, A local limit theorem with speed of convergence for Euclidean algorithms and Diophantine costs, Ann. Inst. H. Poincaré Probab. Statist. 44 (2008) 749-770; E. Cesaratto, J. Clément, B. Daireaux, L. Lhote, V. Maume, B. Vallée, Analysis of fast versions of the Euclid algorithm, in: Proceedings of Third Workshop on Analytic Algorithmics and Combinatorics, ANALCO'08, SIAM, 2008; E. Cesaratto, A. Plagne, B. Vallée, On the non-randomness of modular arithmetic progressions, in: Fourth Colloquium on Mathematics and Computer Science. Algorithms, Trees, Combinatorics and Probabilities, in: Discrete Math. Theor. Comput. Sci. Proc., vol. AG, 2006, pp. 271-288]). These theorems are proved first for an auxiliary probabilistic model, called “the smoothed model,” and after, the estimates are transferred to the “true” probabilistic model. In this note, we remark that “the smoothed model” described in [V. Baladi, B. Vallée, Euclidean algorithm are Gaussian, J. Number Theory 110 (2005) 331-386] is not adapted to this transfer and replaces it by an adapted one. However, the results remain unchanged. 相似文献
3.
Tadeusz Antczak 《Journal of Global Optimization》2009,43(1):111-140
This paper represents the second part of a study concerning the so-called G-multiobjective programming. A new approach to duality in differentiable vector optimization problems is presented. The techniques
used are based on the results established in the paper: On G-invex multiobjective programming. Part I. Optimality by T.Antczak. In this work, we use a generalization of convexity, namely G-invexity, to prove new duality results for nonlinear differentiable multiobjective programming problems. For such vector
optimization problems, a number of new vector duality problems is introduced. The so-called G-Mond–Weir, G-Wolfe and G-mixed dual vector problems to the primal one are defined. Furthermore, various so-called G-duality theorems are proved between the considered differentiable multiobjective programming problem and its nonconvex vector
G-dual problems. Some previous duality results for differentiable multiobjective programming problems turn out to be special
cases of the results described in the paper. 相似文献
4.
S. E. Derkachov 《Journal of Mathematical Sciences》2007,143(1):2773-2790
We study the general rational solution of the Yang-Baxter equation with the symmetry algebra sℓ(3). The R-operator which acts
in the tensor product of two arbitrary representations of the symmetry algebra can be represented as a product of simpler
“building blocks,” R-operators. The R-operators are constructed explicitly and have a simple structure. In such a way, we construct the general rational solution
of the Yang-Baxter equation with the symmetry algebra s sℓ(3). To illustrate the factorization in the simplest situation,
we treat also the sℓ(2) case. Bibliography: 23 titles.
Published in Zapiski Nauchnykh Seminarov POMI, Vol. 335, 2006, pp. 134–163. 相似文献
5.
Manfred Stelzer 《Mathematische Zeitschrift》2007,257(1):81-106
Relations between category and strong category are studied. The notion of a homotopy coalgebra of order r over the Ganea comonad
is introduced. It is shown that cat(X) =Cat(X) holds if a finite 1-connected complex X carries such a structure with r sufficiently large. 相似文献
6.
Ari Laptev 《Journal of Mathematical Sciences》2009,159(1):1-3
It is a great pleasure for me to write about Nina N. Uraltseva who has been one of the most supportive persons during all
my scientific career. I have learned from Nina very many things starting from the foundations of Mathematics to how to prepare
Swedish gravad lax (salted salmon). Nina is one of the most wholly beautiful persons I have ever met and, together with all
the contributors of these anniversary issues of “Problemy Matematicheskogo Analiza,” I wish her many healthy and active years
ahead.
Translated from Problemy Matematicheskogo Analiza, 40, May 2009, pp. 3–6. 相似文献
7.
Irene Benedetti 《Nonlinear Analysis: Theory, Methods & Applications》2012,75(4):2376-2377
In this paper, we define a topological index for compact multivalued maps in convex metrizable subsets of a locally convex topological vector space in order to correct the proofs of Theorems 4.1 and 4.2 in Benedetti et al. (2011) [1]. 相似文献
8.
We correct in this note a mistake in [Delort, J.-M., Existence globale et comportement asymptotique pour l'équation de Klein-Gordon quasi linéaire à données petites en dimension 1, Ann. Sci. École Norm. Sup. (4) 34 (1) (2001) 1-61], which has been indicated to us by H. Lindblad. The results of [Delort, J.-M., Existence globale et comportement asymptotique pour l'équation de Klein-Gordon quasi linéaire à données petites en dimension 1, Ann. Sci. École Norm. Sup. (4) 34 (1) (2001) 1-61] still hold true if one increases the smoothness assumption made on the Cauchy data. 相似文献
9.
Guérin Fabrice 《商业与工业应用随机模型》2010,26(5):502-508
The paper written by M. Li, S. D. Holland and W. Q. Meeker [Applied Stochastic Models in Business and Industry] presents statistical methods for automatic Crack detection based on vibrothermography sequence‐of‐image data. In particular, a matched filter used to increase the signal‐to‐noise ratio is developed. The review gives suggestions about physical approach and detection criteria. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
10.
S. E. Derkachov 《Journal of Mathematical Sciences》2007,143(1):2791-2805
We study the general rational solution of the Yang-Baxter equation with the supersymmetry algebra sℓ(2|1). The R-operator
acting in the tensor product of two arbitrary representations of the supersymmetry algebra can be represented as a product
of simpler building blocks, which are R-operators. Bibliography: 14 titles.
Published in Zapiski Nauchnykh Seminarov POMI, Vol. 335, 2006, pp. 164–187. 相似文献
11.
N.G. (Dick) de Bruijn was the first to develop a formal language suitable for the complete expression of a mathematical subject matter. His formalization does not only regard the usual mathematical expressions, but also all sorts of meta-notions such as definitions, substitutions, theorems and even complete proofs. He envisaged (and demonstrated) that a full formalization enables one to check proofs automatically by means of a computer program. He started developing his ideas about a suitable formal language for mathematics in the end of the 1960s, when computers were still in their infancy. De Bruijn was ahead of his time and much of his work only became known to a wider audience much later. In the present paper we highlight de Bruijn’s contributions to the formalization of mathematics, directed towards verification by a computer, by placing these in their time and by relating them to parallel and later developments. We aim to explain some of the more technical aspects of de Bruijn’s work to a wider audience of interested mathematicians and computer scientists. 相似文献
12.
Flix Galindo 《Applied and Computational Harmonic Analysis》2004,16(3):174-181
J.R. Partington and B. Ünalmı
consider in their 2001 paper [J.R. Partington, B. Ünalmı
, Appl. Comput. Harmon. Anal. 10 (1) (2001) 45–60] the windowed Fourier transform and wavelet transform as tools for analyzing almost periodic signals. They establish Parseval-type identities and consider discretized versions of these transforms in order to construct generalized frame decompositions. We have found a gap in the construction of generalized frames in the windowed Fourier transform case; we comment on this gap and give an alternative proof. As for the wavelet transform case, in [J.R. Partington, B. Ünalmı
, Appl. Comput. Harmon. Anal. 10 (1) (2001) 45–60] the generalized frame decomposition is done only for the simplest wavelet, the Haar wavelet; we show how to construct generalized frame decompositions for a wide family of wavelets. 相似文献
13.
V. N. Kublanovskaya 《Journal of Mathematical Sciences》2007,141(6):1654-1662
A new method (the RP-q method) for factorizing scalar polynomials in q variables and q-parameter polynomial matrices (q ≥
1) of full rank is suggested. Applications of the algorithm to solving systems of nonlinear algebraic equations and some spectral
problems for a q-parameter polynomial matrix F (such as separation of the eigenspectrum and mixed spectrum of F, computation
of bases with prescribed spectral properties of the null-space of polynomial solutions of F, and computation of the hereditary
polynomials of F) are considered. Bibliography: 10 titles.
__________
Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 334, 2006, pp. 149–164. 相似文献
14.
Penny Smith 《Journal of Mathematical Analysis and Applications》2002,276(2):628-641
We continue part I of this paper. Here in part II, comparison principles are proved for non-smooth sub and super solutions (with non-smooth Cauchy data) of semilinear hyperbolic PDE in compact regular domains of R+×R+ when n?3. 相似文献
15.
Sergueï A. Nazarov Adlia Sequeira Juha H. Videman 《Journal de Mathématiques Pures et Appliquées》2001,80(10):445
In this paper our objective is to provide physically reasonable solutions for the stationary Navier–Stokes equations in a two-dimensional domain with two outlets to infinity, a semi-strip Π− and a half-plane K. The same problem in an aperture domain, i.e. in a domain with two half-plane outlets to infinity, has been studied but only under symmetry restrictions on the data. Here, we assume that the main asymptotic term of the solution takes an antisymmetric form in K and apply the technique of weighted spaces with detached asymptotics, i.e. we use spaces where the functions have prescribed asymptotic forms in the outlets.After first showing that the corresponding Stokes problem admits a unique solution if and only if certain compatibility conditions are satisfied, we write the Navier–Stokes equations as a perturbation of the Stokes problem and the crucial compatibility condition as an algebraic equation by which the flux becomes determined. Assuming that the coefficient of the main (antisymmetric) asymptotic term of the solution in K does not vanish and that the data are sufficiently small, we use a contraction principle to solve the Navier–Stokes system coupled with the algebraic equation.Finally, we discuss the ill-posedness of the Navier–Stokes problem with prescribed flux. 相似文献
16.
Michel Leblond 《Numerical Linear Algebra with Applications》2002,9(2):181-193
In computer graphics, in the radiosity context, a linear system Φx=b must be solved and there exists a diagonal positive matrix H such that H Φ is symmetric. In this article, we extend this property to complex matrices: we are interested in matrices which lead to Hermitian matrices under premultiplication by a Hermitian positive‐definite matrix H. We shall prove that these matrices are self‐adjoint with respect to a particular innerproduct defined on ?n. As a result, like Hermitian matrices, they have real eigenvalues and they are diagonalizable. We shall also show how to extend the Courant–Fisher theorem to this class of matrices. Finally, we shall give a new preconditioning matrix which really improves the convergence speed of the conjugate gradient method used for solving the radiosity problem. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
17.
Tadeusz Antczak 《Journal of Global Optimization》2009,43(1):97-109
In this paper, a generalization of convexity, namely G-invexity, is considered in the case of nonlinear multiobjective programming problems where the functions constituting vector
optimization problems are differentiable. The modified Karush-Kuhn-Tucker necessary optimality conditions for a certain class
of multiobjective programming problems are established. To prove this result, the Kuhn-Tucker constraint qualification and
the definition of the Bouligand tangent cone for a set are used. The assumptions on (weak) Pareto optimal solutions are relaxed
by means of vector-valued G-invex functions. 相似文献
18.
Penny Smith 《Journal of Mathematical Analysis and Applications》2002,275(2):693-710
In parts I, II, and III combined of this paper, we define a notion of viscosity solution for these equations and existence is proved by a Perron-like method. Here, in part I, we prove useful identities, and a maximum-like principle for smooth sub(super) solutions of the standard wave equation. We define a new potential theoretic (P) notion of solution, subsolution and supersolution, and a related potential type (P) Cauchy problem for semilinear second order hyperbolic equations. 相似文献
19.
G.M. Coclite H. Holden 《Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire》2008,25(4):833-836
We correct the proof of [G.M. Coclite, H. Holden, The Schrödinger–Maxwell system with Dirac mass, Ann. Inst. H. Poincaré Anal. Non Linéaire 24 (5) (2007) 773–793, Lemma 4.1]. 相似文献
20.
《商业与工业应用随机模型》2003,19(4):361-361
The original article to which this Erratum refers was published in Applied Stochastic Models in Business and Industry 2003: 19 (3); 245–268 相似文献