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31.
32.
Ya-Ling Cheng Bing-Hung Chen 《Journal of the Chinese Institute of Chemical Engineers》2007,38(5-6):501-504
In this report, the scientific productivity of Year 2006 of chemical engineering professionals in Taiwan was analyzed carefully with information retrieved from the database of the ISI Web of Science. The distributions of number of authors with x publication versus the number of publication x follows a general power-law trend, which coincidently comply with the Pareto distribution. The power-law indices found ranges from −1.64 to −2.22, which is consistent with values reported in the literature investigated for periods of 1907–1916 and 1969–2004. 相似文献
33.
Based on a rearrangement inequality by Hardy, Littlewood, and Polya, we define two-operator algebras for independent random variables. These algebras are called Huffman algebras since the Huffman algorithm on these algebras produces an optimal binary tree that minimizes the weighted lengths of leaves. Many examples of such algebras are given. For the case with random weights of the leaves, we prove the optimality of the tree constructed by the power-of-2 rule, i.e., the Huffman algorithm assuming identical weights, when the weights of the leaves are independent and identically distributed. 相似文献
34.
拼图是使用不同形式的素材进行组装的合成艺术.文中介绍了一种崭新的拼图创作方法,通过挑选主题相关的网络图像的前景抠图来表现一幅输入图像,能够生成奇异的具有阿奇姆博多风格的拼图.鉴于网络图像数据的海量规模,总能够找到合适的前景抠图来匹配输入图像的各个分割部分;通过将挑选的前景抠图按照一定的规则进行组装,使其在整体上可以从形状和颜色表现输入图像,而在局部每个前景抠图仍然可以辨识.实验结果和用户体验表明,采用文中方法可以有效地生成具有娱乐性的阿奇姆博多拼图. 相似文献
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36.
Biogeography-based optimization (BBO) is a new evolutionary optimization method inspired by biogeography. In this paper, BBO is extended to a multi-objective optimization, and a biogeography-based multi-objective optimization (BBMO) is introduced, which uses the cluster attribute of islands to naturally decompose the problem. The proposed algorithm makes use of nondominated sorting approach to improve the convergence ability effciently. It also combines the crowding distance to guarantee the diversity of Pareto optimal solutions. We compare the BBMO with two representative state-of-the-art evolutionary multi-objective optimization methods, non-dominated sorting genetic algorithm-II (NSGA-II) and archive-based micro genetic algorithm (AMGA) in terms of three metrics. Simulation results indicate that in most cases, the proposed BBMO is able to find much better spread of solutions and converge faster to true Pareto optimal fronts than NSGA-II and AMGA do. 相似文献
37.
Amir Hossein NikoofardHossein Hajimirsadeghi Ashkan Rahimi-KianCaro Lucas 《Applied Soft Computing》2012,12(1):100-112
This paper presents a proposal for multiobjective Invasive Weed Optimization (IWO) based on nondominated sorting of the solutions. IWO is an ecologically inspired stochastic optimization algorithm which has shown successful results for global optimization. In the present work, performance of the proposed nondominated sorting IWO (NSIWO) algorithm is evaluated through a number of well-known benchmarks for multiobjective optimization. The simulation results of the test problems show that this algorithm is comparable with other multiobjective evolutionary algorithms and is also capable of finding better spread of solutions in some cases. Next, the proposed algorithm is employed to study the Pareto improvement model in two complex electricity markets. First, the Pareto improvement solution set is obtained for a three-player oligopolistic electricity market with a nonlinear demand function. Then, the IEEE 30-bus power system with transmission constraints is considered, and the Pareto improvement solutions are found for the model with deterministic cost functions. In addition, NSIWO algorithm is used to analyze this system with stochastic cost data in a risk management problem which maximizes the expected total profit but minimizes the profit risk in the market. 相似文献
38.
1 INTRODUCTIONTheorthorhombicalloysareofgreattech nolog icalinterestinhightemperatureapplicationssincetheyhaveagoodbalanceamongst 相似文献
39.
空冷淬火Cu-Zn-Al合金马氏体结构及稳定化现象 总被引:1,自引:0,他引:1
利用X射线衍射强度分析、透射电镜观察、相变点测量等方法研究了空冷淬火态Cu18Zn14Al合金马氏体结构及其稳定化现象。认为该合金空冷淬火可获得长程有序完全的M18R马氏体,其有序组态为Al原子与Cu原子、Zn原子与Cu原子两种近邻(nn)有序(K=偶,H+K/2=奇),以及产生K=奇的衍射中Al原子与Zn原子次近邻(nnn)有序。其基面原子分布为:Ⅰ—1425Al+1125Cu、Ⅱ—Cu、Ⅲ—1825Zn+725Cu。与此相对应,该合金相应为Heusler结构。该合金在充分有序化的条件下仍存在马氏体稳定化。 相似文献
40.
CARBON ORDERING IN Fe-1.83C MARTENSITE Ⅰ. Crystal Structure of a Conventional Ordered Phase 总被引:1,自引:0,他引:1
采用电子衍射方法对Fe-1.83C马氏体室温时效时产生的有序相结构进行研究,确定其结构为偏离化学计量成分Fe_4C的γ′-Fe_4结构,称为γ′-Fe_xC(Ⅰ)(x=4-11)。碳原子位于单胞的1/2,1/2,1/2位置。该有序相单胞尺寸为:(a_M,c_M分别为马氏体单胞的a和c轴长度),它与母相完全共格,位向关系为(001)_Ⅰ∥(001)_M,[100]_Ⅰ∥[110]_M。根据γ′-Fe_xC(Ⅰ)晶体结构计算出的有序相衍射花样与实验得到的衍射花样全部吻合。 相似文献