共查询到20条相似文献,搜索用时 15 毫秒
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A new algorithm to predict partial sheet cavity behavior on hydrofoils is proposed. The proposed algorithm models the unsteady partial cavitation using Boundary Element Method (BEM). In the proposed method the spatial iterative scheme is removed by means of a new approach determining the instantaneous cavity length. This iterative scheme is required in conventional algorithms to obtain the cavity length at each time step. Performance of the new algorithm for various unsteady cavitating flows with different reduced frequencies, cavitation numbers, hydrofoil geometries and inflow conditions are investigated. Comparison between the obtained results using the proposed method and those of conventional ones indicates that the present algorithm works well with sufficient accuracy. Moreover, it is shown that the proposed method is computationally more efficient than the conventional one for unsteady sheet cavitation analysis on hydrofoils. 相似文献
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讨论了一类线性半无限最优规划模型的求解算法.采用松弛方法解其系列子问题LP(T_k)及DLP(T_k),基于松弛策略和在适当的假设条件下,提出了一个我们称之为显式算法的新型算法.新算法的主要改进之处是算法在每一步迭代计算时,允许丢弃一些不必要的约束.在这种方式下,算法避免了求解系列太大规模的子问题.最后,基于提出的显式修正算法,并与传统割平面方法和已有文献中的松弛修正算法、对同一问题作了初步的数值比较实验. 相似文献
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Yılmaz Delice Emel Kızılkaya Aydoğan Uğur Özcan Mehmet Sıtkı İlkay 《4OR: A Quarterly Journal of Operations Research》2017,15(1):37-66
In this paper, a new two-sided U-type assembly line balancing (TUALB) procedure and a new algorithm based on the particle swarm optimization algorithm to solve the TUALB problem are proposed. The proposed approach minimizes the number of stations for a given cycle time as the primary objective and it minimizes the number of positions as a secondary objective. The proposed approach is illustrated with an example problem. In order to evaluate the efficiency of the proposed algorithm, the test problems available in the literature are used. The experimental results show that the proposed approach performs well. 相似文献
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We propose an algorithm for constrained global optimization to tackle non-convex nonlinear multivariate polynomial programming
problems. The proposed Bernstein branch and prune algorithm is based on the Bernstein polynomial approach. We introduce several
new features in this proposed algorithm to make the algorithm more efficient. We first present the Bernstein box consistency
and Bernstein hull consistency algorithms to prune the search regions. We then give Bernstein contraction algorithm to avoid
the computation of Bernstein coefficients after the pruning operation. We also include a new Bernstein cut-off test based
on the vertex property of the Bernstein coefficients. The performance of the proposed algorithm is numerically tested on 13
benchmark problems. The results of the tests show the proposed algorithm to be overall considerably superior to existing method
in terms of the chosen performance metrics. 相似文献
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Liying Liu Shengwei Yao Zengxin Wei 《Journal of Computational and Applied Mathematics》2008,220(1-2):422-438
In this paper, a new nonmonotone MBFGS algorithm for unconstrained optimization will be proposed. Under some suitable assumptions, the global and superlinear convergence of the new nonmonotone MBFGS algorithm on convex objective functions will be established. Some numerical experiments show that this new nonmonotone MBFGS algorithm is competitive to the MBFGS algorithm and the nonmonotone BFGS algorithm. 相似文献
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A new recursive algorithm for searching the global minimizer of a function is proposed when the function is observed with noise. The algorithm is based on switches between the stochastic approximation and the random search. The combination of SA with RS is not a new idea in such combination, the difficulty consists in creating a good switching rule and in designing an efficient method to reduce the noise effect. The proposed switching rule is easily realizable, the noise reducing method is effective, and the whole recursive optimization algorithm is simply calculated. It is proved that the algorithm a.s. converges to the global minimizer and is asymptotically normal. In comparison with existing methods, the proposed algorithm not only requires much weaker conditions, but also is more efficient as shown by simulation. 相似文献
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The minimax optimization model introduced in this paper is an important model which has received some attention over the past years. In this paper, the application of minimax model on how to select the distribution center location is first introduced. Then a new algorithm with nonmonotone line search to solve the non-decomposable minimax optimization is proposed. We prove that the new algorithm is global Convergent. Numerical results show the proposed algorithm is effective. 相似文献
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This study suggests a novel quantum immune algorithm for finding Pareto-optimal solutions to multiobjective optimization problems based on quantum computing and immune system. In the proposed algorithm, there are distinct characteristics as follows. First, the encoding method is based on Q-bit representation, and thus a chaos-based approach is suggested to initialize the population. Second, a new chaos-based rotation gate and Q-gates are presented to perform mutation and improve the quality of the population, respectively. Finally, especially, a new truncation algorithm with similar individuals (TASI) is utilized to preserve the diversity of the population. Also, a new selection operator is proposed to create the new population based on TASI. Simulation results on six standard problems (ZDT6, CP, SP, VNT, OSY and KIT) show the proposed algorithm is able to find a much better spread of solutions and has better convergence near the true Pareto-optimal front compared to the vector immune algorithm (VIS) and the elitist non-dominated sorting genetic system (NSGA-II). 相似文献
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《Applied Mathematics Letters》2007,20(4):405-411
In this work, combining the generalized projection techniques with the idea of a strongly sub-feasible direction method, a new algorithm for solving systems of nonlinear inequalities is presented. At each iteration of the proposed algorithm, the search direction is yielded by just one new explicit formula. The proposed algorithm is proved not only to possess global and strong convergence but also to be able to produce a solution in a finite number of iterations. Finally, some interesting numerical results are reported. 相似文献
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The quadratic sum-of-ratios fractional program problem has a broad range of applications in practical problems. This article will present an e?cient branch-and-bound algorithm for globally solving the quadratic sum-of-ratios fractional program problem. In this algorithm, lower bounds are computed by solving a series of parametric relaxation linear programming problems, which are established by utilizing new parametric linearizing technique. To enhance the computational speed of the proposed algorithm, a rectangle reducing tactic is used to reject a part of the investigated rectangle or the whole rectangle where there does not contain any global optimal solution of the quadratic sum-of-ratios fractional program problem. Compared with the known approaches, the proposed algorithm does not need to introduce new variables and constraints. Therefore, the proposed algorithm is more suitable for application in engineering. 相似文献
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根据块三对角矩阵的特殊分解,给出了求解块三对角方程组的新算法.该算法含有可以选择的参数矩阵,适当选择这些参数矩阵,可以使得计算精度较著名的追赶法高,甚至当追赶法失效时,由该算法仍可得到一定精度的解. 相似文献
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整数规划的布谷鸟算法 总被引:1,自引:0,他引:1
布谷鸟搜索算法是一种新型的智能优化算法.本文采用截断取整的方法将基本布谷鸟搜索算法用于求解整数规划问题.通过对标准测试函数进行仿真实验并与粒子群算法进行比较,结果表明本文所提算法比粒子群算法拥有更好的性能和更强的全局寻优能力,可以作为一种实用方法用于求解整数规划问题. 相似文献
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针对一类具有不确定性区间数多指标信息的聚类分析问题,依据传统的基于数值信息的FCM聚类算法的思路,提出了一种新的聚类分析算法。章首先描述了具有区间数多指标信息的聚类分析问题;其次给出了基于区间数多指标信息的关于最优划分和最优聚类中心确定的两个定理;然后给出了基于区间数多指标信息的FCM聚类算法的计算步骤。该算法的特点是聚类中心的表现形式为精确的数值,给出的两个定理说明了该聚类算法的收敛性。最后,通过给出一个算例说明了本给出的聚类算法。 相似文献
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A new smoothing function of the well-known Fischer–Burmeister function is given. Based on this new function, a smoothing Newton-type method is proposed for solving second-order cone programming. At each iteration, the proposed algorithm solves only one system of linear equations and performs only one line search. This algorithm can start from an arbitrary point and it is Q-quadratically convergent under a mild assumption. Numerical results demonstrate the effectiveness of the algorithm. 相似文献
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Jingyong Tang Guoping He Li Dong Liang Fang Jinchuan Zhou 《Applications of Mathematics》2013,58(2):223-247
In this paper we introduce a new smoothing function and show that it is coercive under suitable assumptions. Based on this new function, we propose a smoothing Newton method for solving the second-order cone complementarity problem (SOCCP). The proposed algorithm solves only one linear system of equations and performs only one line search at each iteration. It is shown that any accumulation point of the iteration sequence generated by the proposed algorithm is a solution to the SOCCP. Furthermore, we prove that the generated sequence is bounded if the solution set of the SOCCP is nonempty and bounded. Under the assumption of nonsingularity, we establish the local quadratic convergence of the algorithm without the strict complementarity condition. Numerical results indicate that the proposed algorithm is promising. 相似文献