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101.
We consider an order acceptance and scheduling model with machine availability constraints. The manufacturer (machine) is assumed to be available to process orders only within a number of discontinuous time intervals. To capture the real-life behavior of a typical manufacturer who has restrictions of time availability to process orders, our model allows the manufacturer to reject or outsource some of the orders. When an order is rejected or outsourced, an order-dependent cost of penalty will occur. The objective is to minimize the makespan of all accepted orders plus the total penalty of all rejected/outsourced orders. We study the approximability of the model and some of its important special cases. 相似文献
102.
Model reduction techniques such as Proper Generalized Decomposition (PGD) are decision-making tools that are about to revolutionize many domains. Unfortunately, their computation is still problematic for problems involving many parameters, for which one has to face the “curse of dimensionality”. An answer to this challenge is given in solid mechanics by the so-called “parameter-multiscale PGD”, which is based on Saint-Venant's principle. In this article, a model problem composed of up to a thousand parameters is presented, showing that the method is able to overcome the “curse of dimensionality”. 相似文献
103.
藏文编码字符集构件集 总被引:3,自引:1,他引:2
于洪志 《西北民族学院学报》1998,(1)
本文论述了藏文信息结构和构件拆分的原理,采用统计方法,建立了藏文编码字符集构件集,用已编码的藏文字符表示未编码的藏文外字具体字型的结构和内容,说明厂构件集的选取与排序,论证了它的可行性,以期建立全藏文编码体系。 相似文献
104.
R. Divakar D. Sundararaman V.S. Raghunathan 《Progress in Crystal Growth and Characterization of Materials》1997,34(1-4):263-269
AlCuFe quasicrystal has been considered a novel icosahedral quasicrystal in as much as it can be produced in both thermodynamically stable and metastable state. It is also recognised to be a face centred structure. The system has been studied extensively in the recent past and several contentious results have been obtained. For example, evidences have been presented for both reversible and irreversible transformation of the quasicrystalline phase to the crystalline phases. Similarly, distinct transition metal sites have been proposed based on the Mossbauer studies. A subsequent study of this in fact shows an absence of such distinct sites. It has been shown that in this system, vacancy type of defects of very large concentrations exist. Many of these factors bring into question, the various structural models that have been postulated to explain the icosahedral structure obtained in the system. A critical examination of these various aspects of the AlCuFe quasicrystal is presented. 相似文献
105.
A poset P=(X,) is m-partite if X has a partition X=X1Xm such that (1) each Xi forms an antichain in P, and (2) xy implies xXi and yXj where i<j. In this article we derive a tight asymptotic upper bound on the order dimension of m-partite posets in terms of m and their bipartite sub-posets in a constructive and elementary way. 相似文献
106.
Let A be a quaternion algebra over a number field k and assume that A satisfies the Eichler condition so that some infinite place of k is unramified in A. Let L be a quadratic extension of k which embeds in A. Let Rk denote the ring of integers of k and let B be an Rk-order in L. Suppose that is an Eichler order of A of square-free level S. In this paper, we determine when there exists an embedding σ:L→A over k which gives an optimal embedding of B into in the sense that . This generalises previous work of Eichler [M. Eichler, Zur Zahlentheorie der Quaternionenalgebren, J. Reine Angew. Math. 195 (1955) 127–155] and Chinburg and Friedman [T. Chinburg, E. Friedman, An embedding theorem for quaternion algebras, J. London Math. Soc. 60 (1999) 33–44]. 相似文献
107.
Roy Meshulam 《Order》2008,25(2):153-155
Let L be a finite lattice and let . It is shown that if the order complex satisfies then |L| ≥ 2
k
. Equality |L| = 2
k
holds iff L is isomorphic to the Boolean lattice {0,1}
k
.
Research supported by the Israel Science Foundation. 相似文献
108.
Mean-value theorems and extensions of the Elliott-Daboussi theorem on additive arithmetic semigroups
Wen-Bin Zhang 《The Ramanujan Journal》2008,15(1):47-75
We present more general forms of the mean-value theorems established before for multiplicative functions on additive arithmetic
semigroups and prove, on the basis of these new theorems, extensions of the Elliott-Daboussi theorem. Let
be an additive arithmetic semigroup with a generating set ℘ of primes p. Assume that the number G(m) of elements a in
with “degree” ∂(a)=m satisfies
with constants q>1, ρ
1<ρ
2<⋅⋅⋅<ρ
r
=ρ, ρ≥1, γ>1+ρ. For the main result, let α,τ,η be positive constants such that α>1,τ
ρ≥1, and τ
α
ρ≥1. Then for a multiplicative function f(a) on
the following two conditions (A) and (B) are equivalent. These are (A) All four series
converge and
and (B) The order τ
ρ mean-value
exists with m
f
≠0 and the limit
exists with M
v
(α)>0.
相似文献
109.
The authors characterize the order boundedness of weighted composition operators acting between Dirichlet type spaces. 相似文献
110.
Risk-adjusted distributions are commonly used in actuarial science to define premium principles. In this paper, we claim that an appropriate risk-adjusted distribution, besides satisfying other desirable properties, should be well-behaved under conditioning with respect to the original risk distribution. Based on a sequence of such risk-adjusted distributions, we introduce a family of premium principles that gradually incorporate the degree of risk-aversion of the insurer in the risk loading. Members of this family are particular distortion premium principles that can be represented as mixtures of TVaRs, where the weights in the mixture reflect the attitude toward risk of the insurer. We make a systematic study of this family of premium principles. 相似文献