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991.
Aliki D. Muradova 《Advances in Computational Mathematics》2008,29(2):179-206
In this paper a spectral method and a numerical continuation algorithm for solving eigenvalue problems for the rectangular
von Kármán plate with different boundary conditions (simply supported, partially or totally clamped) and physical parameters
are introduced. The solution of these problems has a postbuckling behaviour. The spectral method is based on a variational
principle (Galerkin’s approach) with a choice of global basis functions which are combinations of trigonometric functions.
Convergence results of this method are proved and the rate of convergence is estimated. The discretized nonlinear model is
treated by Newton’s iterative scheme and numerical continuation. Branches of eigenfunctions found by the algorithm are traced.
Numerical results of solving the problems for polygonal and ferroconcrete plates are presented.
Communicated by A. Zhou. 相似文献
992.
This contribution is focused on an acceleration of branch and bound algorithms for the uncapacitated facility location problem. Our approach is based on the well-known Erlenkotters’ procedures and Körkels’ multi-ascent and multi-adjustment algorithms, which have proved to be the efficient tools for solving the large-sized instances of the uncapacitated facility location problem. These two original approaches were examined and a thorough analysis of their performance revealed how each particular procedure contributes to the computational time of the whole algorithms. These analyses helped us to focus our effort on the most frequent procedures. The unique contribution of this paper is a new dual ascent procedure. This procedure leads to considerable acceleration of the lower bound computation process and reduces the resulting computational time. To demonstrate more efficient performance of amended algorithms we present the results of extensive numerical experiments. 相似文献
993.
994.
A. Mirone S. S. Dhesi G. van der Laan 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,53(1):23-28
Orbital ordering (OO) in La0.5Sr1.5MnO4 has been
studied using soft X-ray resonant diffraction (SXRD) at the Mn L2,3 edges
in combination with many-body cluster calculations. The SXRD intensity is modelled in second quantization using a
small planar cluster consisting of a central active Mn site with first-neighbour shells comprising O and Mn sites.
The effective Hamiltonian includes Slater-Koster parameters and charge transfer and electron correlation
energies obtained from previous measurements on manganites. The
energy dependence of the SXRD OO peak is calculated using
the Jahn-Teller distortions of the oxygen octahedra and in-plane spin correlations as adjustable parameters. These contributions
are clearly distinguished above the Néel temperature with a good spectroscopic agreement.
The results also suggest a significant charge separation between the Mn sites. 相似文献
995.
This paper is concerned with a second-order numerical method for shape optimization problems. The first variation and the second variation of the objective functional are derived. These variations are discretized by introducing a set of boundary-value problems in order to derive the second-order numerical method. The boundary-value problems are solved by the conventional finite-element method.The authors would like to express their thanks to Mr. T. Masanao, who was an undergraduate student, for his cooperation and comments. They also thank Professor Y. Sakawa of Osaka University for his encouragement.A part of this paper was presented at the IFIP Conference on Control of Boundaries and Stabilization, Clermont-Ferrand, France, 1988. 相似文献
996.
Effects of initial states on the quantum correlations in the generalized Grover search algorithm 下载免费PDF全文
Zhen-Yu Chen 《中国物理 B》2021,30(8):80303-080303
We investigate the correlations between two qubits in the Grover search algorithm with arbitrary initial states by numerical simulation. Using a set of suitable bases, we construct the reduced density matrix and give the numerical expression of correlations relating to the iterations. For different initial states, we obtain the concurrence and quantum discord compared with the success probability in the algorithm. The results show that the initial states affect the correlations and the limit point of the correlations in the searching process. However, the initial states do not influence the whole cyclical trend. 相似文献
997.
Rolling bearings act as key parts in many items of mechanical equipment and any abnormality will affect the normal operation of the entire apparatus. To diagnose the faults of rolling bearings effectively, a novel fault identification method is proposed by merging variational mode decomposition (VMD), average refined composite multiscale dispersion entropy (ARCMDE) and support vector machine (SVM) optimized by multistrategy enhanced swarm optimization in this paper. Firstly, the vibration signals are decomposed into different series of intrinsic mode functions (IMFs) based on VMD with the center frequency observation method. Subsequently, the proposed ARCMDE, fusing the superiorities of DE and average refined composite multiscale procedure, is employed to enhance the ability of the multiscale fault-feature extraction from the IMFs. Afterwards, grey wolf optimization (GWO), enhanced by multistrategy including levy flight, cosine factor and polynomial mutation strategies (LCPGWO), is proposed to optimize the penalty factor C and kernel parameter g of SVM. Then, the optimized SVM model is trained to identify the fault type of samples based on features extracted by ARCMDE. Finally, the application experiment and contrastive analysis verify the effectiveness of the proposed VMD-ARCMDE-LCPGWO-SVM method. 相似文献
998.
Shenghan Zhou Houxiang Liu Bang Chen Wenkui Hou Xinpeng Ji Yue Zhang Wenbing Chang Yiyong Xiao 《Entropy (Basel, Switzerland)》2021,23(6)
The traditional sequential pattern mining method is carried out considering the whole time period and often ignores the sequential patterns that only occur in local time windows, as well as possible periodicity. Therefore, in order to overcome the limitations of traditional methods, this paper proposes status set sequential pattern mining with time windows (SSPMTW). In contrast to traditional methods, the item status is considered, and time windows, minimum confidence, minimum coverage, minimum factor set ratios and other constraints are added to mine more valuable rules in local time windows. The periodicity of these rules is also analyzed. According to the proposed method, this paper improves the Apriori algorithm, proposes the TW-Apriori algorithm, and explains the basic idea of the algorithm. Then, the feasibility, validity and efficiency of the proposed method and algorithm are verified by small-scale and large-scale examples. In a large-scale numerical example solution, the influence of various constraints on the mining results is analyzed. Finally, the solution results of SSPM and SSPMTW are compared and analyzed, and it is suggested that SSPMTW can excavate the laws existing in local time windows and analyze the periodicity of the laws, which solves the problem of SSPM ignoring the laws existing in local time windows and overcomes the limitations of traditional sequential pattern mining algorithms. In addition, the rules mined by SSPMTW reduce the entropy of the system. 相似文献
999.
The conventional explanation of delayed-choice experiments appears to violate our causal intuition at the quantum level. I reanalyze these experiments using time-reversed and time-symmetric formulations of quantum mechanics. The time-reversed formulation does not give the same experimental predictions. The time-symmetric formulation gives the same experimental predictions but actually violates our causal intuition at the quantum level. I explore the reasons why our causal intuition may be wrong at the quantum level, suggest how conventional causation might be recovered in the classical limit, propose a quantum analog to the classical block universe viewpoint, and speculate on implications of the time-symmetric formulation for cosmological boundary conditions. 相似文献
1000.
Hongming Zhu Xiaowen Wang Yizhi Jiang Hongfei Fan Bowen Du Qin Liu 《Entropy (Basel, Switzerland)》2021,23(5)
Instance matching is a key task in knowledge graph fusion, and it is critical to improving the efficiency of instance matching, given the increasing scale of knowledge graphs. Blocking algorithms selecting candidate instance pairs for comparison is one of the effective methods to achieve the goal. In this paper, we propose a novel blocking algorithm named MultiObJ, which constructs indexes for instances based on the Ordered Joint of Multiple Objects’ features to limit the number of candidate instance pairs. Based on MultiObJ, we further propose a distributed framework named Follow-the-Regular-Leader Instance Matching (FTRLIM), which matches instances between large-scale knowledge graphs with approximately linear time complexity. FTRLIM has participated in OAEI 2019 and achieved the best matching quality with significantly efficiency. In this research, we construct three data collections based on a real-world large-scale knowledge graph. Experiment results on the constructed data collections and two real-world datasets indicate that MultiObJ and FTRLIM outperform other state-of-the-art methods. 相似文献