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101.
102.
This paper presents a new class of valid inequalities for the single-item capacitated lot sizing problem with step-wise production costs (LS-SW). Constant sized batch production is carried out with a limited production capacity in order to satisfy the customer demand over a finite horizon. A new class of valid inequalities we call mixed flow cover, is derived from the existing integer flow cover inequalities by a lifting procedure. The lifting coefficients are sequence independent when the batch sizes (V) and the production capacities (P) are constant and when V divides P. When the restriction of the divisibility is removed, the lifting coefficients are shown to be sequence independent. We identify some cases where the mixed flow cover inequalities are facet defining. We propose a cutting plane algorithm for different classes of valid inequalities introduced in the paper. The exact separation algorithm proposed for the constant capacitated case runs in polynomial time. Computational results show the efficiency of the new class mixed flow cover compared to the existing methods. 相似文献
103.
On <Emphasis Type="Italic">l</Emphasis><Subscript>2,<Emphasis Type="Italic">p</Emphasis></Subscript>-circle numbers 总被引:1,自引:1,他引:0
W.-D. Richter 《Lithuanian Mathematical Journal》2008,48(2):228-234
Circle numbers are defined to reflect the Euclidean area-content and, for p ≠ 2, suitably defined non-Euclidean circumference properties of the l
2,p
-circles, p ∈ [1, ∞]. The resulting function is continuous, increasing, and takes all values from [2, 4].
The actually chosen dual l
2,p
-geometry for measuring the arc-length is closely connected with a generalization of the method of indivisibles of Cavalieri
and Torricelli in the sense that integrating such arc-lengths means measuring area content. Moreover, this approach enables
one to look in a new way into the co-area formula of measure theory which says that integrating Euclidean arc-lengths does
not yield area content except for p = 2.
The new circle numbers play a natural role, e.g., as norming constants in geometric measure representation formulae for p-generalized uniform probability distributions on l
2,p
-circles. 相似文献
104.
孔洞受压的统一极限分析 总被引:1,自引:0,他引:1
采用俞茂宏统一强度理论分别就平面应变和平面应力总是对受压孔洞进行了极限分析,得到了各自的统一解形式。以往的基于Tresca、Mises、双剪屈服准则以及Mohr-Coulomb强度理论的极限解均为本文统一解的特例。此解可以适应于广泛的不同性质的各灯材料,合理也得出不同材料的相应解。 相似文献
105.
描述用单光束激光复活制银盐白光显示反射全息图的技术,本技术的关键:1)母全息图的颜色必须恢复到满足其布拉格条件;2)复制所用的光波与记录母全息图时的参考的相同;(3)复制所用的激光采用平行偏振,以减少界面反射;94)采用白糖溶液作为折射率匹配液,取得极佳效果。 相似文献
106.
《Optimization》2012,61(4):1033-1055
We found an interesting relation between convex optimization and sorting problem. We present a parallel algorithm to compute multiple order statistics of the data by minimizing a number of related convex functions. The computed order statistics serve as splitters that group the data into buckets suitable for parallel bitonic sorting. This led us to a parallel bucket sort algorithm, which we implemented for many-core architecture of graphics processing units (GPUs). The proposed sorting method is competitive to the state-of-the-art GPU sorting algorithms and is superior to most of them for long sorting keys. 相似文献
107.
108.
In order to solve a quadratic 0/1 problem, some techniques, consisting in deriving a linear integer formulation, are used.
Those techniques, called “linearization”, usually involve a huge number of additional variables. As a consequence, the exact
resolution of the linear model is, in general, very difficult.
Our aim, in this paper, is to propose “economical” linear models. Starting from an existing linearization (typically the so-called
“classical linearization”), we find a new linearization with fewer variables. The resulting model is called “Miniaturized”
linearization. Based on this approach, we propose a new linearization scheme for which numerical tests have been performed. 相似文献
109.
The solution of a screw dislocation under time-harmonic condition is obtained in an infinite isotropic plane by means of the Fourier transform method. The stress components reveal the familiar Cauchy singularity at the location of dislocation. The solution is employed to derive integral equations for a plane weakened by cracks and cavities. Cavities are considered as closed curved cracks without singularity. Several examples are solved and the stress intensity factor of cracks and hoop stress on cavities are obtained. 相似文献
110.
在部分相干理论的基础上,分别用表观传递函数和能量分布作评价指标,计算了部分相干光学系统的最佳象面位置,并讨论了其与相干度、空间频率及象差的关系。 相似文献