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71.
72.
工件有到达时间的两机器自由作业稠密时间表 总被引:2,自引:0,他引:2
对于两机器自由作业加工总长问题,工件带有到达时间,我们证明了稠密时间表的性能比为1.5。 相似文献
73.
根据1/2波节自聚焦(GRIN)透镜中光的传输特性,提出了一种新颖的测量微小角位移的模型,通过对模型中光线传输和几何关系的理论分析,推导了待测角位移与光耦合效率之间的传递函数.针对模型对测量范围的限制,提出了一种可行的拓宽测量范围的方法.研究结果表明,该模型不但测量范围宽,而且测量准确度高,线性度好. 相似文献
74.
75.
Clara Löh 《Mathematische Zeitschrift》2006,253(1):197-218
Measure homology is a variation of singular homology designed by Thurston in his discussion of simplicial volume. Zastrow
and Hansen showed independently that singular homology (with real coefficients) and measure homology coincide algebraically
on the category of CW-complexes. It is the aim of this paper to prove that this isomorphism is isometric with respect to the ℓ1-seminorm on singular homology and the seminorm on measure homology induced by the total variation. This, in particular, implies
that one can calculate the simplicial volume via measure homology – as already claimed by Thurston. For example, measure homology
can be used to prove Gromov's proportionality principle of simplicial volume. 相似文献
76.
We present a new approach that permits efficient performance analysis of kanban systems with general demand processes, material
arrival processes, and service times. The approach is based on parametric characterization of the traffic processes (arrival
and departure) in the network and uses two-moment approximations to estimate performance measures at individual stations.
We derive traffic flow constraints that are particular to closed queuing networks with synchronization stations and use these
to establish relationships between the parameters characterizing arrival and departure processes at the stations in the network.
The resultant set of non-linear equations is solved to estimate network performance measures. Numerical studies show that
the approach is not only fast but also reasonably accurate when compared to simulation. These studies also provide insights
with respect to the impact of different types of variability on the performance of a kanban system. This work also provides
a fundamental building block that can be used in the analysis of multi-stage kanban systems.
AMS Subject Classifications 68M20, 60K20, 90B05, 90B30 相似文献
77.
This paper examines the performance of Commodity Trading Advisors (CTAs) using fixed and variable benchmarking models. In
order to avoid the troublesome passive and active commodity and managed futures benchmarks (indices) when examining the performance
of CTAs, we innovate by using data envelopment analysis (DEA). Because this alternative class has non-linear returns due to
long/short positions, and derivatives (i.e., dynamic trading strategies), DEA can alleviate the problems usually associated
with these indices. The effectiveness of using benchmarking models in a DEA setting will provide investors with an alternative
technique in assessing the performance and identifying efficient CTAs. 相似文献
78.
关于Banach空间中凸泛函的广义次梯度不等式 总被引:2,自引:0,他引:2
本文在前人^[1,2]的基础之上,以凸泛函的次梯度不等式为工具,将Jensen不等式推广到Banach空间中的凸泛函,导出了Banach空间中的Bochner积分型的广义Jensen不等式,给出其在Banach空间概率论中某些应用,从而推广了文献[3—6]的工作. 相似文献
79.
We investigate analytical properties of a measure geometric Laplacian which is given as the second derivative w.r.t. two atomless finite Borel measures μ and ν with compact supports supp μ ? supp ν on the real line. This class of operators includes a generalization of the well‐known Sturm‐Liouville operator as well as of the measure geometric Laplacian given by . We obtain for this differential operator under both Dirichlet and Neumann boundary conditions similar properties as known in the classical Lebesgue case for the euclidean Laplacian like Gauß‐Green‐formula, inversion formula, compactness of the resolvent and its kernel representation w.r.t. the corresponding Green function. Finally we prove nuclearity of the resolvent and give two representations of its trace. 相似文献
80.
A spectrum sharing system with primary and secondary nodes, each equipped with an arbitrary number of antennas, is investigated. Particularly, the outage performance of an underlay cognitive system is analytically studied, in the case when the end-to-end () communication is established via an intermediate relay node. To better enhance the communication, successive interference cancellation (SIC) is adopted, which compensates for both the transmission power constraint and the presence of interference from primary nodes. Both the relay and secondary receiver perform unordered SIC to successively decode the multiple streams, whereas the decode-and-forward relaying protocol is used for the communication. New closed-form expressions for the outage performance of each transmitted stream are derived in terms of finite sum series of the Tricomi confluent hypergeometric function. In addition, simplified yet tight approximations for the asymptotic outage performance are obtained. Useful engineering insights are manifested, such as the diversity order of the considered system and the impact of interference from the primary nodes in conjunction with the constrained transmission power of the secondary nodes. 相似文献