共查询到20条相似文献,搜索用时 312 毫秒
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计算区间二型模糊集的质心(也称降型)是区间二型模糊逻辑系统中的一个重要模块。Karnik-Mendel(KM)迭代算法通常被认为是计算区间二型模糊集质心的标准算法。尽管如此,KM算法涉及复杂的计算过程,不利于实时应用。在各种改进类算法中,非迭代的Nie-Tan(NT)算法可节省计算消耗。此外,连续版本NT(CNT,continuous version of NT)算法被证明是计算质心的准确算法。本文比较了离散版本NT算法中求和运算和连续版本NT算法中求积分运算,通过四个计算机仿真例子证实了当适度增加区间二型模糊集主变量采样个数时,NT算法的计算结果可以精确地逼近CNT算法。 相似文献
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《European Journal of Operational Research》1998,104(3):549-558
Four multi-objective linear programming algorithms are implemented on microcomputer software packages and a large field experiment is conducted using the implemented algorithms. Two new algorithms which incorporate formal models of decision maker behavior are tested along with two established algorithms which include no formal models of decision maker behavior. The new algorithms are shown to outperform the established algorithms. 相似文献
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Al WenbaoSchool of Science Beijing University of Posts Telecommunications Beijing China 《中国科学A辑(英文版)》2004,47(6):812-820
In this paper, we present neighborhood-following algorithms for linear programming. When the neighborhood is a wide neighborhood, our algorithms are wide neighborhood primal-dual interior point algorithms. If the neighborhood degenerates into the central path, our algorithms also degenerate into path-following algorithms. We prove that our algorithms maintain the O(n~(1/2)L)-iteration complexity still, while the classical wide neighborhood primal-dual interior point algorithms have only the O(nL)-iteration complexity. We also proved that the algorithms are quadratic convergence if the optimal vertex is nondegenerate. Finally, we show some computational results of our algorithms. 相似文献
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本文给出了数值求解非线性发展方程的全离散非线性Galerkin算法,即将空间离散时的谱非线性Galerkin算法和时间离散的Euler差分格式相结合,得到了显式和隐式两种全离散数值格式,相应地也考虑了显式和隐式的Galerkin全离散格式,并分别分析了上述四种全离散格式的收敛性和复杂性,经过比较得出结论;在某些约束条件下,非线性Galerkin算法和Galerkin算法具有相同阶的收敛速度,然而前 相似文献
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Parallel algorithms and test case results for the solution of the unconstrained optimization problem are presented. The algorithms involve the use of pseudo-conjugate directions (directions which tend to become conjugate as the solution is approached). It is shown that the algorithms are both fast and robust. Although all the algorithms of this paper involve the parallel execution of linear search procedures, a critical differentiation can be made among them, depending on whether the linear searches are performed along the same direction (parallel unidirectional algorithms) or different directions (parallel multidirectional algorithms). 相似文献
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Fast decoding algorithms for short codes based on modifications of maximum likelihood decoding algorithms of first order Reed-Muller codes are described. Only additions-subtractions, comparisons and absolute value calculations are used in the algorithms. Soft and hard decisions maximum likelihood decoding algorithms for first order Reed-Muller and the Nordstrom-Robinson codes with low complexity are proposed. 相似文献
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S. P. Uryas'ev 《Journal of Optimization Theory and Applications》1991,71(2):359-388
This paper deals with new variable-metric algorithms for nonsmooth optimization problems, the so-called adaptive algorithms. The essence of these algorithms is that there are two simultaneously working gradient algorithms: the first is in the main space and the second is in the space of the matrices that modify the main variables. The convergence of these algorithms is proved for different cases. The results of numerical experiments are also given. 相似文献
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Xinzhen Zhang Guanglu Zhou Louis Caccetta Mohammed Alqahtani 《Frontiers of Mathematics in China》2017,12(6):1409-1426
We consider approximation algorithms for nonnegative polynomial optimization problems over unit spheres. These optimization problems have wide applications e.g., in signal and image processing, high order statistics, and computer vision. Since these problems are NP-hard, we are interested in studying on approximation algorithms. In particular, we propose some polynomial-time approximation algorithms with new approximation bounds. In addition, based on these approximation algorithms, some efficient algorithms are presented and numerical results are reported to show the efficiency of our proposed algorithms. 相似文献
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We present two algorithms for multivariate numerical integration of smooth periodic functions. The cubature rules on which these algorithms are based use fractional parts of multiples of irrationals in combination with certain weights. Previous work led to algorithms with quadratic and cubic error convergence. We generalize these algorithms so that one can use them to obtain general higher order error convergence. The algorithms are open in the sense that extra steps can easily be taken in order to improve the result. They are also linear in the number of steps and their memory cost is low. 相似文献
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《Optimization》2012,61(3):427-440
New algorithms for enumerating all circuits of a directed graph are presented. These algorithms are backtrack algorithms, by which we intended to avoid fruitless computations. The best results give algorithms involving heuristic rules. To receive numerical comparisons additionally the algorithms of DÖRFLER/MÜHL-BACHER, TIERNAN/SYSLO and BJELKINA were programmed and tested in FORTRAN (CDC 3300) and (or) ALGOL (ICL 4130). 相似文献
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The paper considers two extragradient-like algorithms for solving variational inequality problems involving strongly pseudomonotone and Lipschitz continuous operators in Hilbert spaces. The projection method is used to design the algorithms which can be computed more easily than the regularized method. The construction of solution approximations and the proof of convergence of the algorithms are performed without the prior knowledge of the modulus of strong pseudomonotonicity and the Lipschitz constant of the cost operator. Instead of that, the algorithms use variable stepsize sequences which are diminishing and non-summable. The numerical behaviors of the proposed algorithms on a test problem are illustrated and compared with those of several previously known algorithms. 相似文献
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《Journal of Computational and Applied Mathematics》1998,92(1):15-35
A new approach of iterative Monte Carlo algorithms for the well-known inverse matrix problem is presented and studied. The algorithms are based on a special techniques of iteration parameter choice, which allows to control the convergence of the algorithm for any column (row) of the matrix using different relaxation parameters. The choice of these parameters is controlled by a posteriori criteria for every Monte Carlo iteration. The presented Monte Carlo algorithms are implemented on a SUN Sparkstation. Numerical tests are performed for matrices of moderate in order to show how work the algorithms. The algorithms under consideration are well parallelized. 相似文献
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In this paper, we study the weak and strong convergence of two algorithms for solving Lipschitz continuous and monotone variational inequalities. The algorithms are inspired by Tseng’s extragradient method and the viscosity method with Armijo-like step size rule. The main advantages of our algorithms are that the construction of solution approximations and the proof of convergence of the algorithms are performed without the prior knowledge of the Lipschitz constant of cost operators. Finally, we provide numerical experiments to show the efficiency and advantage of the proposed algorithms. 相似文献
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Sorting algorithms are developed in the setting of iterative multilevel methods. These algorithms borrow aggregation techniques from algorithms used for the numerical solution of elliptic partial differential equations which are of optimal order in running time and storage space for structured problems. A computationally inexpensive preconditioner drives random data chosen from known distributions towards a special case for which the new sorting algorithms are of optimal order. 相似文献
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In this work, several multilevel decoupled algorithms are proposed for a mixed Navier-Stokes/Darcy model. These algorithms are based on either successively or parallelly solving two linear subdomain problems after solving a coupled nonlinear coarse grid problem. Error estimates are given to demonstrate the approximation accuracy of the algorithms. Experiments based on both the first order and the second order discretizations are presented to show the effectiveness of the decoupled algorithms. 相似文献
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Prabir Daripa 《Central European Journal of Mathematics》2012,10(1):204-216
Some application driven fast algorithms developed by the author and his collaborators for elliptic partial differential equations
are briefly reviewed here. Subsequent use of the ideas behind development of these algorithms for further development of other
algorithms some of which are currently in progress is briefly mentioned. Serial and parallel implementation of these algorithms
and their applications to some pure and applied problems are also briefly reviewed. 相似文献
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Jinde Wang 《Annals of Operations Research》1991,31(1):371-384
This paper summarizes the main results on approximate nonlinear programming algorithms investigated by the author. These algorithms are obtained by combining approximation and nonlinear programming algorithms. They are designed for programs in which the evaluation of the objective functions is very difficult so that only their approximate values can be obtained. Therefore, these algorithms are particularly suitable for stochastic programming problems with recourse.Project supported by the National Natural Science Foundation of China. 相似文献