共查询到20条相似文献,搜索用时 99 毫秒
1.
Cristian Barbarosie Anca‐Maria Toader 《Mathematical Methods in the Applied Sciences》2005,28(9):1089-1114
We prove bounds on the homogenized coefficients for general non‐periodic mixtures of an arbitrary number of isotropic materials, in the heat conduction framework. The component materials and their proportions are given through the Young measure associated to the sequence of coefficient functions. Upper and lower bounds inequalities are deduced in terms of algebraic relations between this Young measure and the eigenvalues of the H‐limit matrix. The proofs employ arguments of compensated compactness and fine properties of Young measures. When restricted to the periodic case, we recover known bounds. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
2.
Let Kq(n,R) denote the minimum number of codewords in any q-ary code of length n and covering radius R. We collect lower and upper bounds for Kq(n,R) where 6 ≤ q ≤ 21 and R ≤ 3. For q ≤ 10, we consider lengths n ≤ 10, and for q ≥ 11, we consider n ≤ 8. This extends earlier results, which have been tabulated for 2 ≤ q ≤ 5. We survey known bounds and obtain some new results as well, also for s-surjective codes, which are closely related to covering codes and utilized in some of the constructions.AMS Classification: 94B75, 94B25, 94B65Gerzson Kéri - Supported in part by the Hungarian National Research Fund, Grant No. OTKA-T029572.Patric R. J. Östergård - Supported in part by the Academy of Finland, Grants No. 100500 and No. 202315. 相似文献
3.
Given , we consider the following problem: find , such that where or 3, and in . We prove and error bounds for the standard continuous piecewise linear Galerkin finite element approximation with a (weakly) acute triangulation.
Our bounds are nearly optimal. In addition, for d = 1 and 2 and we analyze a more practical scheme involving numerical integration on the nonlinear term. We obtain nearly optimal and error bounds for d = 1. For this case we also present some numerical results.
Received July 4, 1996 / Revised version received December 18, 1997 相似文献
4.
Vyacheslav M. Abramov 《Queueing Systems》2008,59(1):63-86
In this paper continuity theorems are established for the number of losses during a busy period of the M/M/1/n queue. We consider an M/GI/1/n queueing system where the service time probability distribution, slightly different in a certain sense from the exponential
distribution, is approximated by that exponential distribution. Continuity theorems are obtained in the form of one or two-sided
stochastic inequalities. The paper shows how the bounds of these inequalities are changed if further assumptions, associated
with specific properties of the service time distribution (precisely described in the paper), are made. Specifically, some
parametric families of service time distributions are discussed, and the paper establishes uniform estimates (given for all
possible values of the parameter) and local estimates (where the parameter is fixed and takes only the given value). The analysis
of the paper is based on the level crossing approach and some characterization properties of the exponential distribution.
Dedicated to Vladimir Mikhailovich Zolotarev, Victor Makarovich Kruglov, and to the memory of Vladimir Vyacheslavovich Kalashnikov. 相似文献
5.
The Two-Dimensional Finite Bin Packing Problem (2BP) consists of determining the minimum number of large identical rectangles, bins, that are required for allocating without overlapping a given set of rectangular items. The items are allocated into a bin with their edges always parallel or orthogonal to the bin edges. The problem is strongly NP-hard and finds many practical applications. In this paper we describe new lower bounds for the 2BP where the items have a fixed orientation and we show that the new lower bounds dominate two lower bounds proposed in the literature. These lower bounds are extended in Part II (see Boschetti and Mingozzi 2002) for a more general version of the 2BP where some items can be rotated by
. Moreover, in Part II a new heuristic algorithm for solving both versions of the 2BP is presented and computational results on test problems from the literature are given in order to evaluate the effectiveness of the proposed lower bounds. 相似文献
6.
7.
In this paper, we introduce a new combinatorial invariant called q-binomial moment for q-ary constant weight codes. We derive a lower bound on the q-binomial moments and introduce a new combinatorial structure called generalized (s, t)-designs which could achieve the lower bounds. Moreover, we employ the q-binomial moments to study the undetected error probability of q-ary constant weight codes. A lower bound on the undetected error probability for q-ary constant weight codes is obtained. This lower bound extends and unifies the related results of Abdel-Ghaffar for q-ary codes and Xia-Fu-Ling for binary constant weight codes. Finally, some q-ary constant weight codes which achieve the lower bounds are found.
相似文献
8.
In the present paper, we give some new convergence results of the global GMRES method for multiple linear systems. In the case where the coefficient matrix A is diagonalizable, we derive new upper bounds for the Frobenius norm of the residual. We also consider the case of normal matrices and we propose new expressions for the norm of the residual. 相似文献
9.
Bernd Heidergott Arie Hordijk Haralambie Leahu 《Mathematical Methods of Operations Research》2009,70(1):99-127
This paper provides strong bounds on perturbations over a collection of independent random variables, where ‘strong’ has to
be understood as uniform w.r.t. some functional norm. Our analysis is based on studying the concept of weak differentiability. By applying a fundamental result from the theory
of Banach spaces, we show that weak differentiability implies norm Lipschitz continuity. This result leads to bounds on the
sensitivity of finite products of probability measures, in norm sense. We apply our results to derive bounds on perturbations
for the transient waiting times in a G/G/1 queue.
This research is supported by the Technology Foundation STW, applied science division of NWO and the technology programme
of the Ministry of Economic Affairs. 相似文献
10.
Sanna Ranto 《Designs, Codes and Cryptography》2011,60(1):81-89
A subspace C of the binary Hamming space F
n
of length n is called a linear r-identifying code if for all vectors of F
n
the intersections of C and closed r-radius neighbourhoods are nonempty and different. In this paper, we give lower bounds for such linear codes. For radius r = 2, we give some general constructions. We give many (optimal) constructions which were found by a computer search. New
constructions improve some previously known upper bounds for r-identifying codes in the case where linearity is not assumed. 相似文献
11.
12.
The boundary function method [A. B. Vasil'eva, V. F. Butuzov, and L. V. Kalachev, The boundary function method for singular perturbation problems, SIAM Studies in Applied Mathematics, Philadelphia, 1995] is used to build an asymptotic expansion at any order of accuracy of a scalar time‐harmonic wave scattered by a perfectly reflecting doubly periodic surface with oscillations at small and large scales. Error bounds are rigorously established, in particular in an optimal way on the relevant part of the field. It is also shown how the maximum principle can be used to design a homogenized surface whose reflected wave yields a first‐order approximation of the actual one. The theoretical derivations are illustrated by some numerical experiments, which in particular show that using the homogenized surface outperforms the usual approach consisting in setting an effective boundary condition on a flat boundary. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
13.
Stphane Ballet 《Finite Fields and Their Applications》1999,5(4):230
From the existence of algebraic function fields having some good properties, we obtain some new upper bounds on the bilinear complexity of multiplication in all extensions of the finite field
q, where q is an arbitrary prime power. So we prove that the bilinear complexity of multiplication in the finite fields
qn is linear uniformly in q with respect to the degree n. 相似文献
14.
We consider homogenization of a scale of p-Poisson equations in RN. Some new bounds of the effective energy are proved and compared with the non-linear Wiener -and Hashin-Shtrikman bounds. Moreover, we point out concrete nontrivid examples where these bounds even coincide. Some new examples of “optimal” microstructures are presented. 相似文献
15.
J. Sunklodas 《Acta Appl Math》2008,102(1):87-98
In the present paper, we consider L
1 bounds for asymptotic normality for the sequence of r.v.’s X
1,X
2,… (not necessarily stationary) satisfying the ψ-mixing condition. The L
1 bounds have been obtained in terms of Lyapunov fractions which, in a particular case, under finiteness of the third moments
of summands and the finiteness of ∑
r≥1
r
2
ψ(r), are of order O(n
−1/2), where the function ψ participates in the definition of the ψ-mixing condition.
相似文献
16.
André Draux 《Numerical Algorithms》2000,24(1-2):31-58
Some methods of numerical analysis, used for obtaining estimations of zeros of polynomials, are studied again, more especially
in the case where the zeros of these polynomials are all strictly positive, distinct and real. They give, in particular, formal
lower and upper bounds for the smallest zero. Thanks to them, we produce new formal lower and upper bounds of the constant
in Markov-Bernstein inequalities in L
2 for the norm corresponding to the Laguerre and Gegenbauer inner products. In fact, since this constant is the inverse of
the square root of the smallest zero of a polynomial, we give formal lower and upper bounds of this zero. Moreover, a new
sufficient condition is given in order that a polynomial has some complex zeros.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
17.
M. Z. Garaev 《Mathematical Notes》2000,68(5-6):713-720
In the paper a method for finding lower bounds of the L
1-norm of some exponential sums is described. 相似文献
18.
In a recent paper by Li (Ref. 1), a scheme was proposed to convexify an efficient frontier for a vector optimization problem by rescaling each component of the vector objective functions by its p-power. For sufficiently large p, it was shown that the transformed efficient frontier is cone-convex; hence, the usual linear scalarization (or supporting hyperplane) method can be used to find the efficient solutions. An outstanding question remains: What is the minimum value of p such that the efficient frontier can be convexified? In this note, we answer the above question by deriving some theoretical lower bounds for p.
相似文献19.
Carlo Blundo Sebastià Martín Barbara Masucci CarlEs Padró 《Designs, Codes and Cryptography》2004,33(3):241-260
A metering scheme is a method by which an audit agency is able to measure the interaction between servers and clients during a certain number of time frames. Naor and Pinkas (Vol. 1403 of LNCS, pp. 576–590) proposed metering schemes where any server is able to compute a proof (i.e., a value to be shown to the audit agency at the end of each time frame), if and only if it has been visited by a number of clients larger than or equal to some threshold h during the time frame. Masucci and Stinson (Vol. 1895 of LNCS, pp. 72–87) showed how to construct a metering scheme realizing any access structure, where the access structure is the family of all subsets of clients which enable a server to compute its proof. They also provided lower bounds on the communication complexity of metering schemes. In this paper we describe a linear algebraic approach to design metering schemes realizing any access structure. Namely, given any access structure, we present a method to construct a metering scheme realizing it from any linear secret sharing scheme with the same access structure. Besides, we prove some properties about the relationship between metering schemes and secret sharing schemes. These properties provide some new bounds on the information distributed to clients and servers in a metering scheme. According to these bounds, the optimality of the metering schemes obtained by our method relies upon the optimality of the linear secret sharing schemes for the given access structure. 相似文献
20.
We determine lower and upper bounds for the size of a hyperplane of the dual polar space DW(5, q). In some cases, we also determine all hyperplanes attaining these bounds. 相似文献