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991.
Analytical modelling of the work flow through flexible manufacturing systems (FMSs), based on closed queueing network models, has been successfully applied to the early stages of design and analysis of FMSs. This paper describes the advantages of using multiple job-class closed queueing networks for modelling realistic situations occurring in FMSs. The general modelling of FMSs by closed queueing networks is first reviewed. The way Solberg's CAN-Q—a single job-class queueing-based package—deals with several part types is clarified. A new model called MULTIQ, allowing multiple pallet types, each of which is used by several part types, is proposed. Results are derived using the data from an existing FMS. The use of the MULTIQ model for optimization purposes is suggested by some examples. 相似文献
992.
ASYMMETRY PARAMETERS AND DIFFERENTIAL CROSS SECTIONS FOR PHOTOIONIZATION-EXCITATION OF HELIUM 下载免费PDF全文
Asymmetry parameter β2 for photoionization of helium leaving the He+ ion in the n=2 level and differential cross sections(DCSs) in the n=2,3,4 levels with photon emission angle θ=900 are provided at photon energies 69-76.8 eV employing the R-matrix method with a 20-term target representation, in which five polarization orbitals \bar{6}l are included. The asymmetry parameter β2 and the DCS, in the n=2 level in the region of 69-73 eV, are in good agreement with available experimental and theoretical results. Above the n=3 threshold, we present new theoretical results along with measurements. No theoretical and experimental results can be used to compare with the present calculations of the DCSs for photoionization into the He+ ion in the n=3,4 levels. 相似文献
993.
994.
从单模激光场的增益-噪声模型出发,导出了激光场定态强度分布函数,研究了定态分布函数的极值点随加性噪声、乘性噪声和注入信号的变化情况。结果表明,乘性噪声是使激光系统出现一级相变类比的关键因素,注入信号使相变行为减弱,而加性噪声却使得定态分布中极值点的数量和位置出现来回跳跃式变化。 相似文献
995.
此文计算了Z=18-82的原子在北京同步辐射4B9A束线的白色X光照射下的光电离积分截面G值。结果表明,有三个G值较大的区域,Z=18-20,39-47和59-82,最大值分别为3.8×10-6,1.6×10-5和3.5×10-5photons·cm2/s。同时,估计了平衡时主要多重电荷态离子数目,分析了用同步辐射和离子阱进行多重电荷态实验的新的候选原子,讨论了有关实验方法和技术。 相似文献
996.
Wang Yongjiang Shen Shengpen Xia Tiejun Wu Zhehua Zhu Jinmin 《Applied physics. B, Lasers and optics》1988,46(2):191-195
The atomic density, the buffer gas pressure, and the voltage dependence of the 510.6 nm laser line shape and its temporal evolution emitted from a Cu/CuBr vapor laser are measured. It is found that the monochromaticity of these laser lines can be improved greatly at a relative high buffer gas pressure. The temporal evolution of the line shape offers a stereoscopic view of a laser pulse. The sequence of appearance of the peaks of the line shape is governed by the intensity of the hyperfine component of the copper line. 相似文献
997.
998.
In some organizational applications, the principle of allocation (PoA) and scale advantage (SA) oppose each other. While PoA
implies that organizations with wide niches get punished, SA holds that large organizations gain an advantage because of scale
efficiencies. The opposition occurs because many large organizations also possess wide niches. However, analyzing these theoretical
mechanisms implies a possible trade-off between niche width and size: if both PoA and SA are strong, then organizations must
be either focused or large to survive, resulting in a dual market structure, as proposed by the theory of resource partitioning.
This article develops a computational model used to study this trade-off, and investigates the properties of organizational
populations with low/high SA and low/high PoA. The model generates three expected core “corner” solutions: (1) the dominance
of large organizations in the strong SA setting; (2) the proliferation of narrow-niche organizations in the strong PoA setting;
and (3) a bifurcated or dual market structure if both SA and PoA are present. The model also allows us to identify circumstances
under which narrow-niche (specialists) or wide-niche (generalists) organizations thrive. We also use the model to examine
the claim that concentrated resource distributions are more likely to generate partitioned or bifurcated populations. We also
investigate the consequences of environments comprised of ordered versus unordered positions. 相似文献
999.
A p-adic variation of the Ran(dom) Sa(mple) C(onsensus) method for solving the relative pose problem in stereo vision is developed.
From two 2-adically encoded images a random sample of five pairs of corresponding points is taken, and the equations for the
essential matrix are solved by lifting solutions modulo 2 to the 2-adic integers. A recently devised p-adic hierarchical classification algorithm imitiating the known LBG quantization method classifies the solutions for all
the samples after having determined the number of clusters using the known intra-inter validity of clusterings. In the successful
case, a cluster ranking will determine the cluster containing a 2-adic approximation to the “true” solution of the problem. 相似文献
1000.
Eric Berberich Efi Fogel Dan Halperin Michael Kerber Ophir Setter 《Mathematics in Computer Science》2010,4(1):67-91
We describe the algorithms and implementation details involved in the concretizations of a generic framework that enables
exact construction, maintenance, and manipulation of arrangements embedded on certain two-dimensional orientable parametric
surfaces in three-dimensional space. The fundamentals of the framework are described in a companion paper. Our work covers
arrangements embedded on elliptic quadrics and cyclides induced by intersections with other algebraic surfaces, and a specialized
case of arrangements induced by arcs of great circles embedded on the sphere. We also demonstrate how such arrangements can
be used to accomplish various geometric tasks efficiently, such as computing the Minkowski sums of polytopes, the envelope
of surfaces, and Voronoi diagrams embedded on parametric surfaces. We do not assume general position. Namely, we handle degenerate
input, and produce exact results in all cases. Our implementation is realized using Cgal and, in particular, the package that provides the underlying framework. We have conducted experiments on various data sets,
and documented the practical efficiency of our approach. 相似文献