At present, near-surface shear wave velocities are mainly calculated through Rayleigh wave dispersion-curve inversions in engineering surface investigations, but the required calculations pose a highly nonlinear globa...At present, near-surface shear wave velocities are mainly calculated through Rayleigh wave dispersion-curve inversions in engineering surface investigations, but the required calculations pose a highly nonlinear global optimization problem. In order to alleviate the risk of falling into a local optimal solution, this paper introduces a new global optimization method, the shuffle frog-leaping algorithm （SFLA）, into the Rayleigh wave dispersion-curve inversion process. SFLA is a swarm-intelligence-based algorithm that simulates a group of frogs searching for food. It uses a few parameters, achieves rapid convergence, and is capability of effective global searching. In order to test the reliability and calculation performance of SFLA, noise-free and noisy synthetic datasets were inverted. We conducted a comparative analysis with other established algorithms using the noise-free dataset, and then tested the ability of SFLA to cope with data noise. Finally, we inverted a real-world example to examine the applicability of SFLA. Results from both synthetic and field data demonstrated the effectiveness of SFLA in the interpretation of Rayleigh wave dispersion curves. We found that SFLA is superior to the established methods in terms of both reliability and computational efficiency, so it offers great potential to improve our ability to solve geophysical inversion problems.展开更多
In recent years,the volume of information in digital form has increased tremendously owing to the increased popularity of the World Wide Web.As a result,the use of techniques for extracting useful information from lar...In recent years,the volume of information in digital form has increased tremendously owing to the increased popularity of the World Wide Web.As a result,the use of techniques for extracting useful information from large collections of data,and particularly documents,has become more necessary and challenging.Text clustering is such a technique;it consists in dividing a set of text documents into clusters(groups),so that documents within the same cluster are closely related,whereas documents in different clusters are as different as possible.Clustering depends on measuring the content(i.e.,words)of a document in terms of relevance.Nevertheless,as documents usually contain a large number of words,some of them may be irrelevant to the topic under consideration or redundant.This can confuse and complicate the clustering process and make it less accurate.Accordingly,feature selection methods have been employed to reduce data dimensionality by selecting the most relevant features.In this study,we developed a text document clustering optimization model using a novel genetic frog-leaping algorithm that efficiently clusters text documents based on selected features.The proposed approach is based on two metaheuristic algorithms:a genetic algorithm(GA)and a shuffled frog-leaping algorithm(SFLA).The GA performs feature selection,and the SFLA performs clustering.To evaluate its effectiveness,the proposed approach was tested on a well-known text document dataset:the“20Newsgroup”dataset from the University of California Irvine Machine Learning Repository.Overall,after multiple experiments were compared and analyzed,it was demonstrated that using the proposed algorithm on the 20Newsgroup dataset greatly facilitated text document clustering,compared with classical K-means clustering.Nevertheless,this improvement requires longer computational time.展开更多
Intrigued by our recent experimental work(H.Yamaguchi and X.D.Ni-u,J.Fluids Eng.,133(2011),041302),the present study numerically investigate theflow-structure interactions(FSI)of three rigid circular particles aligned ...Intrigued by our recent experimental work(H.Yamaguchi and X.D.Ni-u,J.Fluids Eng.,133(2011),041302),the present study numerically investigate theflow-structure interactions(FSI)of three rigid circular particles aligned moving in an inclined channelflow at intermediate Reynolds numbers by using a momentum-exchanged immersed boundary-lattice Boltzmann method.A"frog-leap"phenomenon observed in the experiment is successfully captured by the present simulation and flow characteristics and underlying FSI mechanisms of it are explored by examining the ef-fects of the channel inclined angles and Reynolds numbers.It is found that the asym-metric difference of the vorticity distributions on the particle surface is the main cause of the"frog-leap"when particle moves in the boundary layer near the lower channel boundary.展开更多
由于光网络中的路径跳数过多或距离偏大,使寻找可用的频谱资源难度增加,导致光网络动态频谱利用率降低、网络效益较少且阻塞率较高,为此,提出基于蛙跳博弈优化算法的光网络动态频谱分配方法。采用OHM(Optimized Link State Routing Prot...由于光网络中的路径跳数过多或距离偏大,使寻找可用的频谱资源难度增加,导致光网络动态频谱利用率降低、网络效益较少且阻塞率较高,为此,提出基于蛙跳博弈优化算法的光网络动态频谱分配方法。采用OHM(Optimized Link State Routing Protocol using the Highway Model)路由算法,选择与业务请求对应,且满足跳数最小、调制等级最高的候选路径,找到可用的频谱资源。根据获取的频谱资源,在光网络中将最大频隙号在所有链路中最小作为目标,构建光网络动态频谱分配的目标函数。并在约束条件下,采用蛙跳博弈优化算法对目标函数求解,获取的解即为光网络动态频谱分配最优结果。实验结果表明,该方法的阻塞率低、频谱利用率高、网络收益高,具有实用性。展开更多
基金supported by the National Natural Science Foundation of China(No.41374123)
文摘At present, near-surface shear wave velocities are mainly calculated through Rayleigh wave dispersion-curve inversions in engineering surface investigations, but the required calculations pose a highly nonlinear global optimization problem. In order to alleviate the risk of falling into a local optimal solution, this paper introduces a new global optimization method, the shuffle frog-leaping algorithm （SFLA）, into the Rayleigh wave dispersion-curve inversion process. SFLA is a swarm-intelligence-based algorithm that simulates a group of frogs searching for food. It uses a few parameters, achieves rapid convergence, and is capability of effective global searching. In order to test the reliability and calculation performance of SFLA, noise-free and noisy synthetic datasets were inverted. We conducted a comparative analysis with other established algorithms using the noise-free dataset, and then tested the ability of SFLA to cope with data noise. Finally, we inverted a real-world example to examine the applicability of SFLA. Results from both synthetic and field data demonstrated the effectiveness of SFLA in the interpretation of Rayleigh wave dispersion curves. We found that SFLA is superior to the established methods in terms of both reliability and computational efficiency, so it offers great potential to improve our ability to solve geophysical inversion problems.
基金This research was supported by a grant from the Research Center of the Center for Female Scientific and Medical Colleges Deanship of Scientific Research,King Saud University.
文摘In recent years,the volume of information in digital form has increased tremendously owing to the increased popularity of the World Wide Web.As a result,the use of techniques for extracting useful information from large collections of data,and particularly documents,has become more necessary and challenging.Text clustering is such a technique;it consists in dividing a set of text documents into clusters(groups),so that documents within the same cluster are closely related,whereas documents in different clusters are as different as possible.Clustering depends on measuring the content(i.e.,words)of a document in terms of relevance.Nevertheless,as documents usually contain a large number of words,some of them may be irrelevant to the topic under consideration or redundant.This can confuse and complicate the clustering process and make it less accurate.Accordingly,feature selection methods have been employed to reduce data dimensionality by selecting the most relevant features.In this study,we developed a text document clustering optimization model using a novel genetic frog-leaping algorithm that efficiently clusters text documents based on selected features.The proposed approach is based on two metaheuristic algorithms:a genetic algorithm(GA)and a shuffled frog-leaping algorithm(SFLA).The GA performs feature selection,and the SFLA performs clustering.To evaluate its effectiveness,the proposed approach was tested on a well-known text document dataset:the“20Newsgroup”dataset from the University of California Irvine Machine Learning Repository.Overall,after multiple experiments were compared and analyzed,it was demonstrated that using the proposed algorithm on the 20Newsgroup dataset greatly facilitated text document clustering,compared with classical K-means clustering.Nevertheless,this improvement requires longer computational time.
基金This study was supported by the National Natural Science Foundation of China(NSFC No.11372168)the Second-batch Leading Talent Project of Guangdong Province of China,the Personal Research Starting Founding of Shantou University of China,the Natural Sci-ence Foundation of Guangdong Province of China and the Academic Frontier Research Project on "Next Generation Zero-emission Energy Conversion System"of Ministry of Education,Culture,Sports,Science and Technology in JapanThe financial support is gratefully acknowledged.
文摘Intrigued by our recent experimental work(H.Yamaguchi and X.D.Ni-u,J.Fluids Eng.,133(2011),041302),the present study numerically investigate theflow-structure interactions(FSI)of three rigid circular particles aligned moving in an inclined channelflow at intermediate Reynolds numbers by using a momentum-exchanged immersed boundary-lattice Boltzmann method.A"frog-leap"phenomenon observed in the experiment is successfully captured by the present simulation and flow characteristics and underlying FSI mechanisms of it are explored by examining the ef-fects of the channel inclined angles and Reynolds numbers.It is found that the asym-metric difference of the vorticity distributions on the particle surface is the main cause of the"frog-leap"when particle moves in the boundary layer near the lower channel boundary.
文摘由于光网络中的路径跳数过多或距离偏大,使寻找可用的频谱资源难度增加,导致光网络动态频谱利用率降低、网络效益较少且阻塞率较高,为此,提出基于蛙跳博弈优化算法的光网络动态频谱分配方法。采用OHM(Optimized Link State Routing Protocol using the Highway Model)路由算法,选择与业务请求对应,且满足跳数最小、调制等级最高的候选路径,找到可用的频谱资源。根据获取的频谱资源,在光网络中将最大频隙号在所有链路中最小作为目标,构建光网络动态频谱分配的目标函数。并在约束条件下,采用蛙跳博弈优化算法对目标函数求解,获取的解即为光网络动态频谱分配最优结果。实验结果表明,该方法的阻塞率低、频谱利用率高、网络收益高,具有实用性。
