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71.
沿直线的垂直方向匀速直线运动的带电直线的电场 总被引:1,自引:1,他引:0
本文利用相对论变换关系计算了沿直线的垂直方向匀速运动的带电直线的电场. 相似文献
72.
The feature selection consists of obtaining a subset of these features to optimally realize the task without the irrelevant
ones. Since it can provide faster and cost-effective learning machines and also improve the prediction performance of the
predictors, it is a crucial step in machine learning. The feature selection methods using support machines have obtained satisfactory
results, but the noises and outliers often reduce the performance. In this paper, we propose a feature selection approach
using fuzzy support vector machines and compare it with the previous work, the results of experiments on the UCI data sets
show that feature selection using fuzzy SVM obtains better results than using SVM. 相似文献
73.
Strong Vector Equilibrium Problems 总被引:3,自引:0,他引:3
Gong Xunhua 《Journal of Global Optimization》2006,36(3):339-349
In this paper, the existence of the solution for strong vector equilibrium problems is studied by using the separation theorem for convex sets. The arc-wise connectedness and the closedness of the strong solution set for vector equilibrium problems are discussed; and a necessary and sufficient condition for the strong solution is obtained. 相似文献
74.
Pure adaptive search constructs a sequence of points uniformly distributed within a corresponding sequence of nested regions of the feasible space. At any stage, the next point in the sequence is chosen uniformly distributed over the region of feasible space containing all points that are equal or superior in value to the previous points in the sequence. We show that for convex programs the number of iterations required to achieve a given accuracy of solution increases at most linearly in the dimension of the problem. This compares to exponential growth in iterations required for pure random search. 相似文献
75.
76.
Analysis of Static Simulated Annealing Algorithms 总被引:1,自引:0,他引:1
Generalized hill climbing (GHC) algorithms provide a framework for modeling local search algorithms to address intractable discrete optimization problems. This paper introduces a measure for determining the expected number of iterations to visit a predetermined objective function level, given that an inferior objective function level has been reached in a finite number of iterations. A variation of simulated annealing (SA), termed static simulated annealing (S2A), is analyzed using this measure. S2A uses a fixed cooling schedule during the algorithm execution. Though S2A is probably nonconvergent, its finite-time performance can be assessed using the finite-time performance measure defined in this paper. 相似文献
77.
First, this paper deals with lagrangean heuristics for the 0-1 bidimensional knapsack problem. A projected subgradient algorithm is performed for solving a lagrangean dual of the problem, to improve the convergence of the classical subgradient algorithm. Secondly, a local search is introduced to improve the lower bound on the value of the biknapsack produced by lagrangean heuristics. Thirdly, a variable fixing phase is embedded in the process. Finally, the sequence of 0-1 one-dimensional knapsack instances obtained from the algorithm are solved by using reoptimization techniques in order to reduce the total computational time effort. Computational results are presented. 相似文献
78.
根据热力学第一定律和理想气体状态方程推导了理想气体的热容量公式,并对理想气体在p-V图上的直线过程和循环过程的温度变化及吸热和放热进行了讨论. 相似文献
79.
带有无限到达源的Re-entrant Line的稳定性 总被引:1,自引:0,他引:1
用Foster判别准则,Weiss[13]给出了带有无限到达源的两站三步re-entrant line的稳定性的充分条件.本文用两种不同的方法得到了其稳定性的充分必要条件,即: 二维随机游动方法和Foster判别准则.同时,我们又用流体模型方法得到了系统稳定的充分条件,大大地简化了Weiss[13]的证明. 相似文献
80.
由Q-Nd:YAG脉冲激光(波长1.06μm,脉宽10 ns)烧蚀Al靶产生等离子体.观测了在低气压和直流电场条件下的Al等离子体发射光谱.研究了激光功率密度和直流电场对各谱线强度的影响,分析了谱线半高全宽与外加电压,等离子体电子温度与激光能量的变化规律.结果表明,直流电场对铝原子谱线强度有显著的增强,铝原子谱线的半高全宽与直流电场的外加电压基本上呈线性关系. 相似文献