develop a mentation This paper considers the priority facility primal-dual 3-approximation algorithm for procedure, the authors further improve the location problem with penalties： The authors this problem. Combining...develop a mentation This paper considers the priority facility primal-dual 3-approximation algorithm for procedure, the authors further improve the location problem with penalties： The authors this problem. Combining with the greedy aug- previous ratio 3 to 1.8526.展开更多
A simple and effective greedy algorithm for image approximation is proposed. Based on the matching pursuit approach, it is characterized by a reduced computational complexity benefiting from two major modifications. F...A simple and effective greedy algorithm for image approximation is proposed. Based on the matching pursuit approach, it is characterized by a reduced computational complexity benefiting from two major modifications. First, it iteratively finds an approximation by selecting M atoms instead of one at a time. Second, the inner product computations are confined within only a fraction of dictionary atoms at each iteration. The modifications are implemented very efficiently due to the spatial incoherence of the dictionary. Experimental results show that compared with full search matching pursuit, the proposed algorithm achieves a speed-up gain of 14.4-36.7 times while maintaining the approximation quality.展开更多
P k |fix| C max problem is a new scheduling problem based on the multiprocessor parallel job, and it is proved to be NP hard problem when k ≥3. This paper focuses on the case of k =3. Some new observations and new te...P k |fix| C max problem is a new scheduling problem based on the multiprocessor parallel job, and it is proved to be NP hard problem when k ≥3. This paper focuses on the case of k =3. Some new observations and new techniques for P 3 |fix| C max problem are offered. The concept of semi normal schedulings is introduced, and a very simple linear time algorithm Semi normal Algorithm for constructing semi normal schedulings is developed. With the method of the classical Graham List Scheduling, a thorough analysis of the optimal scheduling on a special instance is provided, which shows that the algorithm is an approximation algorithm of ratio of 9/8 for any instance of P 3|fix| C max problem, and improves the previous best ratio of 7/6 by M.X.Goemans.展开更多
This paper presents a multi-ANN approximation approach to approximate complex non-linear function. Comparing with single-ANN methods the proposed approach improves and increases the approximation and generalization ab...This paper presents a multi-ANN approximation approach to approximate complex non-linear function. Comparing with single-ANN methods the proposed approach improves and increases the approximation and generalization ability, and adaptability greatly in learning processes of networks. The simulation results have been shown that the method can be applied to the modeling and identification of complex dynamic control systems.展开更多
我们考察组合优化中的若干基础问题,包括背包问题、子集和问题以及卷积问题。我们希望探索这些问题运行时间最优的算法,即在某些广为接受的复杂性假设下该算法的运行时间应当是(几乎)最优的。最近几年,利用加性组合对经典组合优化问题...我们考察组合优化中的若干基础问题,包括背包问题、子集和问题以及卷积问题。我们希望探索这些问题运行时间最优的算法,即在某些广为接受的复杂性假设下该算法的运行时间应当是(几乎)最优的。最近几年,利用加性组合对经典组合优化问题的算法研究取得了重要的进展,特别地,对背包与子集和问题的若干变种,研究者们得到了运行时间与复杂性下界几乎一致的伪多项式时间算法和多项式时间近似方案。本文将选择其中具有代表性的若干成果展开综述,旨在展示目前已经被研究者们所注意到的加性组合定理与离散优化问题间的联系。特别地,我们将探讨:(ⅰ)有限加和定理及其在背包问题与子集和问题中的应用;(ⅱ) S zemerédi-Vu和集定理及其在子集和问题中的应用;(ⅲ) Balog-Szemerédi-Gowers定理及其在有解单调卷积问题中的应用。展开更多
基金supported by the National Natural Science Foundation of China under Grant No.11371001
文摘develop a mentation This paper considers the priority facility primal-dual 3-approximation algorithm for procedure, the authors further improve the location problem with penalties： The authors this problem. Combining with the greedy aug- previous ratio 3 to 1.8526.
文摘A simple and effective greedy algorithm for image approximation is proposed. Based on the matching pursuit approach, it is characterized by a reduced computational complexity benefiting from two major modifications. First, it iteratively finds an approximation by selecting M atoms instead of one at a time. Second, the inner product computations are confined within only a fraction of dictionary atoms at each iteration. The modifications are implemented very efficiently due to the spatial incoherence of the dictionary. Experimental results show that compared with full search matching pursuit, the proposed algorithm achieves a speed-up gain of 14.4-36.7 times while maintaining the approximation quality.
文摘P k |fix| C max problem is a new scheduling problem based on the multiprocessor parallel job, and it is proved to be NP hard problem when k ≥3. This paper focuses on the case of k =3. Some new observations and new techniques for P 3 |fix| C max problem are offered. The concept of semi normal schedulings is introduced, and a very simple linear time algorithm Semi normal Algorithm for constructing semi normal schedulings is developed. With the method of the classical Graham List Scheduling, a thorough analysis of the optimal scheduling on a special instance is provided, which shows that the algorithm is an approximation algorithm of ratio of 9/8 for any instance of P 3|fix| C max problem, and improves the previous best ratio of 7/6 by M.X.Goemans.
文摘This paper presents a multi-ANN approximation approach to approximate complex non-linear function. Comparing with single-ANN methods the proposed approach improves and increases the approximation and generalization ability, and adaptability greatly in learning processes of networks. The simulation results have been shown that the method can be applied to the modeling and identification of complex dynamic control systems.
文摘我们考察组合优化中的若干基础问题,包括背包问题、子集和问题以及卷积问题。我们希望探索这些问题运行时间最优的算法,即在某些广为接受的复杂性假设下该算法的运行时间应当是(几乎)最优的。最近几年,利用加性组合对经典组合优化问题的算法研究取得了重要的进展,特别地,对背包与子集和问题的若干变种,研究者们得到了运行时间与复杂性下界几乎一致的伪多项式时间算法和多项式时间近似方案。本文将选择其中具有代表性的若干成果展开综述,旨在展示目前已经被研究者们所注意到的加性组合定理与离散优化问题间的联系。特别地,我们将探讨:(ⅰ)有限加和定理及其在背包问题与子集和问题中的应用;(ⅱ) S zemerédi-Vu和集定理及其在子集和问题中的应用;(ⅲ) Balog-Szemerédi-Gowers定理及其在有解单调卷积问题中的应用。
