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141.
Dominique de Werra 《Graphs and Combinatorics》2003,19(2):263-278
The theorem of Birkhoff – von Neumann concerns bistochastic matrices (i.e., matrices with nonnegative real entries such that
all row sums and all column sums are equal to one). We consider here real matrices with entries unrestricted in sign and we
extend the notion of permutation matrices (integral bistochastic matrices); some generalizations of the theorem are derived
by using elementary properties of graph theory.
Received: October 10, 2000 Final version received: April 11, 2002 相似文献
142.
Yisheng Huang 《Southeast Asian Bulletin of Mathematics》2003,26(4):575-582
Prove that the notion of positive implicative BCI-algebras coincides with that of weakly positive implicative BCI-algebras, thus the whole results in the latter are still true in the former, in particular, one of these results answers definitely the first half of J. Meng and X.L. Xin’s open problem: Does the class of positive implicative BCI-algebras form a variety? The second half of the same problem is: What properties will the ideals of such an algebra have? Here, some further properties are obtained. 相似文献
143.
Simos Meintanis George Iliopoulos 《Annals of the Institute of Statistical Mathematics》2003,55(1):137-151
In this paper a class of goodness-of-fit tests for the Rayleigh distribution is proposed. The tests are based on a weighted
integral involving the empirical Laplace transform. The consistency of the tests as well as their asymptotic distribution
under the null hypothesis are investigated. As the decay of the weight function tends to infinity the test statistics approach
limit values. In a particular case the resulting limit statistic is related to the first nonzero component of Neyman’s smooth
test for this distribution. The new tests are compared with other omnibus tests for the Rayleigh distribution. 相似文献
144.
Effects of uncertainties in the domain on the solution of Dirichlet boundary value problems 总被引:1,自引:0,他引:1
Summary. A domain with possibly non-Lipschitz boundary is defined as a limit of monotonically expanding or shrinking domains with
Lipschitz boundary. A uniquely solvable Dirichlet boundary value problem (DBVP) is defined on each of the Lipschitz domains
and the limit of these solutions is investigated. The limit function also solves a DBVP on the limit domain but the problem
can depend on the sequences of domains if the limit domain is unstable with respect to the DBVP. The core of the paper consists
in estimates of the difference between the respective solutions of the DBVP on two close domains, one of which is Lipschitz
and the other can be unstable. Estimates for starshaped as well as rather general domains are derived. Their numerical evaluation
is possible and can be done in different ways.
Received October 16, 2001 / Revised version received January 16, 2002 / Published online: April 17, 2002
RID="*"
ID="*" The research was funded partially by the National Science Foundation under the grants NSF–Czech Rep. INT-9724783 and
NSF DMS-9802367
RID="**"
ID="**" Support for Jan Chleboun coming from the Grant Agency of the Czech Republic through grant 201/98/0528 is appreciated 相似文献
145.
Massoud Pourmahdian 《Archive for Mathematical Logic》2003,42(5):415-421
We prove that for any simple theory which is constructed via Fr?issé-Hrushovski method, if the forking independence is the
same as the d-independence then the stable forking property holds.
Received: 22 January 2001 /
Published online: 19 December 2002
This article is part of the author's D-Phil thesis, written at the University of Oxford and supported by the Ministry of
Higher Education of Iran. The author would like to thank the Institute for Studies in Theoretical Physics and Mathematics
(IPM), Tehran, Iran, for its financial support whilst working on this article.
Mathematics Subject Classification (2000): 03C45
Key words or phrases: Generic structures – Fr?issé-Hrushovski method – Predimension – Simple theories – Stable theories – Stable forking conjecture 相似文献
146.
Let f(2m,k) be the Maximum k-diameter of k-regular k-connected graphs on 2m vertices. In this paper we give an algorithm and prove that we can construct k-regular k-connected graphs on 2m vertices with the maximum k-diameter using it. We also prove some known results about f(2m,k) and verify that we can get some unknown values of f(2m,k) by our algorithm.
Received: December 1, 2000 Final version received: March 12, 2002
Acknowledgments. We thank the referee for many useful suggestions. 相似文献
147.
We define the index of composition λ(n) of an integer n ⩾ 2 as λ(n) = log n/log γ(n), where γ(n) stands for the product of the primes dividing n, and first establish that λ and 1/λ both have asymptotic mean value 1. We then establish that, given any ɛ > 0 and any integer
k ⩾ 2, there exist infinitely many positive integers n such that . Considering the distribution function F(z,x) := #{n < x : λ(n) > z}, we prove that, given 1 < z < 2 and ɛ > 0, then, if x is sufficiently large,
this last inequality also holding if z ⩾ 2. We then use these inequalities to obtain probabilistic results and we state a conjecture. Finally, using (*), we show
that the probability that the abc conjecture does not hold is 0.
Research supported in part by a grant from NSERC.
Re?u le 17 décembre 2001; en forme révisée le 23 mars 2002
Publié en ligne le 11 octobre 2002 相似文献
148.
F J Vasko D D Newhart K L StottJr F E Wolf 《The Journal of the Operational Research Society》2003,54(1):11-20
The traditional, uncapacitated facility location problem (UFLP) seeks to determine a set of warehouses to open such that all retail stores are serviced by a warehouse and the sum of the fixed costs of opening and operating the warehouses and the variable costs of supplying the retail stores from the opened warehouses is minimized. In this paper, we discuss the partial coverage uncapacitated facility location problem (PCUFLP) as a generalization of the uncapacitated facility location problem in which not all the retail stores must be satisfied by a warehouse. Erlenkotter's dual-ascent algorithm, DUALOC, will be used to solve optimally large (1600 stores and 13?000 candidate warehouses) real-world implemented PCUFLP applications in less than two minutes on a 500?MHz PC. Furthermore, a simple analysis of the problem input data will indicate why and when efficient solutions to large PCUFLPs can be expected. 相似文献
149.
S A Starbird 《The Journal of the Operational Research Society》2003,54(1):32-39
Coordinated replenishment is a supply chain policy that affects many operational performance measures, including cost, lead time, and quality. In this paper, we develop a mathematical model of a simplified supply chain in which conformance quality is one of the supplier's decision variables and both the supplier and its customer are trying to minimize expected annual cost. Our expected cost model includes the important quality costs (appraisal, prevention, internal failure, and external failure) as well as holding, set-up, and ordering costs. Our results indicate that coordination leads to a decline in total cost but that coordination does not necessarily lead to an improvement in quality. In other words, buyers who are using coordinated replenishment may be trading higher quality for lower cost. 相似文献
150.
In a recent paper, Hwang and Hahn considered inventory replenishment problems for an item with an inventory-level-dependent demand rate and a fixed lifetime. They developed an EQQ model under the situation of considering the first-in–first-out (FIFO) issuing policy. First, this paper reconsiders Hwang and Hann's problem by employing the last-in–first-out (LIFO) issuing policy, which is more practical in the retail industry. An inventory model is developed. Secondly, the concavity of the objective function is proved. Thirdly, this paper presents conditions where the present model has a unique optimal solution and a method for finding the global optimal solution. A simple solution procedure and sensitivity analyses of parameters are also provided. 相似文献