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The optimal fractional Gabor transform based on the adaptive window function and its application 被引量:4
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作者 陈颖频 彭真明 +2 位作者 贺振华 田琳 张洞君 《Applied Geophysics》 SCIE CSCD 2013年第3期305-313,358,共10页
We designed the window function of the optimal Gabor transform based on the time-frequency rotation property of the fractional Fourier transform. Thus, we obtained the adaptive optimal Gabor transform in the fractiona... We designed the window function of the optimal Gabor transform based on the time-frequency rotation property of the fractional Fourier transform. Thus, we obtained the adaptive optimal Gabor transform in the fractional domain and improved the time-frequency concentration of the Gabor transform. The algorithm first searches for the optimal rotation factor, then performs the p-th FrFT of the signal and, finally, performs time and frequency analysis of the FrFT result. Finally, the algorithm rotates the plane in the fractional domain back to the normal time-frequency plane. This promotes the application of FrFT in the field of high-resolution reservoir prediction. Additionally, we proposed an adaptive search method for the optimal rotation factor using the Parseval principle in the fractional domain, which simplifies the algorithm. We carried out spectrum decomposition of the seismic signal, which showed that the instantaneous frequency slices obtained by the proposed algorithm are superior to the ones obtained by the traditional Gabor transform. The adaptive time frequency analysis is of great significance to seismic signal processing. 展开更多
关键词 FrFT generalized time bandwidth product optimal rotation factor search adaptive optimal Gabor transform spectral decomposition seismic signals
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Generalized multiple time windows model based parallel machine scheduling for TDRSS 被引量:1
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作者 LIN Peng KUANG Lin-ling +3 位作者 CHEN Xiang YAN Jian LU Jian-hua WANG Xiao-juan 《Journal of Beijing Institute of Technology》 EI CAS 2016年第3期382-391,共10页
The scheduling efficiency of the tracking and data relay satellite system(TDRSS)is strictly limited by the scheduling degrees of freedom(DoF),including time DoF defined by jobs' flexible time windows and spatial ... The scheduling efficiency of the tracking and data relay satellite system(TDRSS)is strictly limited by the scheduling degrees of freedom(DoF),including time DoF defined by jobs' flexible time windows and spatial DoF brought by multiple servable tracking and data relay satellites(TDRSs).In this paper,ageneralized multiple time windows(GMTW)model is proposed to fully exploit the time and spatial DoF.Then,the improvements of service capability and job-completion probability based on the GMTW are theoretically proved.Further,an asymmetric path-relinking(APR)based heuristic job scheduling framework is presented to maximize the usage of DoF provided by the GMTW.Simulation results show that by using our proposal 11%improvement of average jobcompletion probability can be obtained.Meanwhile,the computing time of the time-to-target can be shorten to 1/9 of the GRASP. 展开更多
关键词 parallel machine scheduling problem with generalized multiple time windows (PMGMTW) positive/negative adaptive subsequence adjustment (p/n-ASA) evolutionary asymmetric key-path-relinking (EvAKPR)
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Green Function of Generalized Time Fractional Diffusion Equation Using Addition Formula of Mittag-Leffler Function
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作者 Fang Wang Jinmeng Zhang 《Journal of Applied Mathematics and Physics》 2022年第9期2720-2732,共13页
In this paper, we use the Mittag-Leffler addition formula to solve the Green function of generalized time fractional diffusion equation in the whole plane and prove the convergence of the Green function.
关键词 Mittag-Leffler Function Mellin Transforms Generalized Time Fractional Diffusion Equation Green Function Addition Formula
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Generalized Master Equation for Space-Time Coupled Continuous Time Random Walk
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作者 刘剑 李宝河 陈晓松 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第5期1-4,共4页
The generalized master equation for the space-time coupled continuous time random walk is derived analytically, in which the space-time coupling is considered through the correlated function 9(t) ~ t^γ, 0 ≤ γ 〈... The generalized master equation for the space-time coupled continuous time random walk is derived analytically, in which the space-time coupling is considered through the correlated function 9(t) ~ t^γ, 0 ≤ γ 〈 2, and the probability density function ω(t) of a particle's waiting time t follows a power law form for large t: ω(t) ~t^-(1+α), 0 〈 α 〈 1. The results indicate that the expressions of the generalized master equation are determined by the correlation exponent 7 and the long-tailed index α of the waiting time. Moreover, the diffusion results obtained from the generalized master equation are in accordance with the previous known results and the numerical simulation results. 展开更多
关键词 GME Generalized Master Equation for Space-Time Coupled Continuous Time Random Walk
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SiZer for exploration of inhomogeneous structure in temporal distribution of earth-quakes
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作者 陈时军 贾庆华 马丽 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2005年第5期78-87,共10页
In this paper, the inhomogeneous structure of generalized seismic strain release time series (GSSRTS) of earth- quakes in East, West China and their subtectonic regions as Xinjiang, Qinghai-Xizang (Tibetan) Plateau, N... In this paper, the inhomogeneous structure of generalized seismic strain release time series (GSSRTS) of earth- quakes in East, West China and their subtectonic regions as Xinjiang, Qinghai-Xizang (Tibetan) Plateau, Northeast China, North China, South China and Taiwan have been analyzed by using the method of significant analysis on zero crossings of derivatives (SiZer). Results show that when index η for estimating GSSRTS is close to zero and bandwidth is large enough, GSSRTSs feature significant increasing in Xinjiang, Northeast China, South China and Taiwan tectonic regions and decreasing in Qinghai-Xizang (Tibetan Platean) and North China tectonic regions from January 1, 1970 to January 1, 2000. While with the dwindling of bandwidth GSSRTSs in all the above tec- tonic regions characterize clustering, that is to say, significant increasing and decreasing emerge alternatively. When η is large enough, GSSRTSs would have no significant statistical variation in most of above tectonic regions except Qinghai-Xizang (Tibetan Platean) and Taiwan where significant increasing or decreasing hold in several time intervals within limited bandwidths. 展开更多
关键词 significant analysis on zero crossings of derivatives (SiZer) nonparametric fit generalized seis- mic strain release time series (GSSRTS) subtectonic regions in China
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A Generalized Accelerated Failure Time Model to Predict Restoration Time from Power Outages
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作者 Tasnuba Binte Jamal Samiul Hasan 《International Journal of Disaster Risk Science》 SCIE CSCD 2023年第6期995-1010,共16页
Major disasters such as wildfire, tornado, hurricane, tropical storm, and flooding cause disruptions in infrastructure systems such as power and water supply, wastewater management, telecommunication, and transportati... Major disasters such as wildfire, tornado, hurricane, tropical storm, and flooding cause disruptions in infrastructure systems such as power and water supply, wastewater management, telecommunication, and transportation facilities. Disruptions in electricity infrastructure have negative impacts on sectors throughout a region, including education, medical services,financial services, and recreation. In this study, we introduced a novel approach to investigate the factors that can be associated with longer restoration time of power service after a hurricane. Considering restoration time as the dependent variable and using a comprehensive set of county-level data, we estimated a generalized accelerated failure time(GAFT) model that accounts for spatial dependence among observations for time to event data. The model fit improved by 12% after considering the effects of spatial correlation in time to event data. Using the GAFT model and Hurricane Irma's impact on Florida as a case study, we examined:(1) differences in electric power outages and restoration rates among different types of power companies—investor-owned power companies, rural and municipal cooperatives;(2) the relationship between the duration of power outage and power system variables;and(3) the relationship between the duration of power outage and socioeconomic attributes. The findings of this study indicate that counties with a higher percentage of customers served by investor-owned electric companies and lower median household income faced power outage for a longer time. This study identified the key factors to predict restoration time of hurricane-induced power outages, allowing disaster management agencies to adopt strategies required for restoration process. 展开更多
关键词 Generalized accelerated failure time model Hurricanes Investor-owned power companies Median income Power outage Restoration time
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Generalized solitary wave solutions to the time fractional generalized Hirota-Satsuma coupled KdV via new definition for wave transformation 被引量:2
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作者 Hadi Rezazadeh Aly R.Seadawy +1 位作者 Mostafa Eslami Mohammad Mirzazadeh 《Journal of Ocean Engineering and Science》 SCIE 2019年第2期77-84,共8页
In this paper,the(G′/G)-expansion method has been applied to explore new solitary wave solutions for the time fractional generalized Hirota-Satsuma coupled KdV(FGHSC KdV)system.The fractional derivative is described ... In this paper,the(G′/G)-expansion method has been applied to explore new solitary wave solutions for the time fractional generalized Hirota-Satsuma coupled KdV(FGHSC KdV)system.The fractional derivative is described with the use of conformable derivative.The results show that this method is a very useful and effective mathematical tool for solving nonlinear conformable fractional equations arising in mathematical physics.As a result,this method can also be applied to other nonlinear conformable fractional differential equations.©2019 Shanghai Jiaotong University.Published by Elsevier B.V. 展开更多
关键词 Conformable fractional derivative (G′/G)-expansion method Solitary wave solutions Time fractional generalized Hirota-Satsuma coupled KdV system.
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The Maximum Surplus Distribution before Ruin in an Erlang(n) Risk Process Perturbed by Diffusion 被引量:2
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作者 Zhen Zhong ZHANG Jie Zhong ZOU Yuan Yuan LIU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2011年第9期1869-1880,共12页
In this paper, we consider the distribution of the maximum surplus before ruin in a generalized Erlang(n) risk process (i.e., convolution of n exponential distributions with possibly different parameters) perturbe... In this paper, we consider the distribution of the maximum surplus before ruin in a generalized Erlang(n) risk process (i.e., convolution of n exponential distributions with possibly different parameters) perturbed by diffusion. It is shown that the maximum surplus distribution before ruin satisfies the integro-differential equation with certain boundary conditions. Explicit expressions are obtained when claims amounts are rationally distributed. Finally, the surplus distribution at the time of ruin and the surplus distribution immediately before ruin are presented. 展开更多
关键词 Sparre Anderson risk model generalized Erlang(n) inter-claim times integro-differential equation diffusion process maximum surplus distribution
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THE LARGE TIME CONVERGENCE OF SPECTRAL METHOD FOR GENERALIZED KURAMOTO-SIVASHINSKY EQUATIONS 被引量:1
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作者 Guo, B Xiang, XM 《Journal of Computational Mathematics》 SCIE CSCD 1997年第1期1-13,共13页
In this paper we use the spectral method to analyse the generalized Kuramoto-Sivashinsky equations. We prove the existence and uniqueness of global smooth solution of the equations. Finally, we obtain the error estima... In this paper we use the spectral method to analyse the generalized Kuramoto-Sivashinsky equations. We prove the existence and uniqueness of global smooth solution of the equations. Finally, we obtain the error estimation between spectral approximate solution and exact solution on large time. 展开更多
关键词 UN EH THE LARGE TIME CONVERGENCE OF SPECTRAL METHOD FOR GENERALIZED KURAMOTO-SIVASHINSKY EQUATIONS
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Generalized Covariant Derivative with Respect to Time in Flat Space(Ⅰ):Eulerian Description 被引量:2
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作者 Yajun Yin 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2016年第4期345-358,共14页
This paper reports a new derivative in the Eulerian description in flat space-the generalized covariant derivative with respect to time. The following contents are included:(a) the restricted covariant derivative with... This paper reports a new derivative in the Eulerian description in flat space-the generalized covariant derivative with respect to time. The following contents are included:(a) the restricted covariant derivative with respect to time for Eulerian component is defined;(b) the postulate of the covariant form invariability in time field is set up;(c) the generalized covariant derivative with respect to time for generalized Eulerian component is defined;(d) the algebraic structure of the generalized covariant derivative with respect to time is made clear;(e) the covariant differential transformation group in time filed is derived. These progresses reveal the covariant form invariability of Eulerian space and time. 展开更多
关键词 Eulerian description covariant form invariability generalized Eulerian component generalized covariant derivative with respect to time covariant differential transformation group
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Generalized Covariant Derivative with Respect to Time in Flat Space(Ⅱ):Lagrangian Description 被引量:2
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作者 Yajun Yin 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2016年第4期359-370,共12页
The previous paper reported a new derivative in the Eulerian description in flat space—the generalized covariant derivative of generalized Eulerian component with respect to time. This paper extends the thought from ... The previous paper reported a new derivative in the Eulerian description in flat space—the generalized covariant derivative of generalized Eulerian component with respect to time. This paper extends the thought from the Eulerian description to the Lagrangian description:on the basis of the postulate of covariant form invariability in time field, we define a new derivative in the Lagrangian description in flat space—the generalized covariant derivative of generalized Lagrangian component with respect to time. Besides, the covariant differential transformation group is set up. The covariant form invariability of Lagrangian space-time is ascertained. 展开更多
关键词 Lagrangian description the postulate of covariant form invariability generalized Lagrangian component generalized covariant derivative with respect to time covariant differential transformation group
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Group Analysis, Fractional Explicit Solutions and Conservation Laws of Time Fractional Generalized Burgers Equation
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作者 Gang-Wei Wang A. H. Kara 《Communications in Theoretical Physics》 SCIE CAS CSCD 2018年第1期5-8,共4页
The generalized fractional Burgers equation is studied in this paper. Using the classical Lie symmetry method, all of the vector fields and symmetry reduction of the equation with nonlinearity are constructed. In part... The generalized fractional Burgers equation is studied in this paper. Using the classical Lie symmetry method, all of the vector fields and symmetry reduction of the equation with nonlinearity are constructed. In particular, an exact solution & provided by using the ansatz method. In addition, other types of exact solution are obtained via the invariant subspace method. Finally, conservation laws for this equation are derived. 展开更多
关键词 time fractional generalized Burgers equation Lie symmetry method explicit solutions conservation laws
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Solution of the time-fractional generalized Burger-Fisher equation using the fractional re duce d differential transform method
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作者 Vahisht K.Tamboli PritiV.Tandel 《Journal of Ocean Engineering and Science》 SCIE 2022年第4期399-407,共9页
“The time-fractional generalized Burger-Fisher equation(TF-GBFE)”is used in various applied sciences and physical applications,including simulation of gas dynamics,financial mathematics,fluid mechan-ics,and ocean en... “The time-fractional generalized Burger-Fisher equation(TF-GBFE)”is used in various applied sciences and physical applications,including simulation of gas dynamics,financial mathematics,fluid mechan-ics,and ocean engineering.This equation represents a concept for the coordination of reaction systems,as well as advection,and conveys the understanding of dissipation.The Fractional Reduced Differential Transform Method(FRDTM)is used to evaluate“the time-fractional generalized Burger-Fisher equation(TF-GBFE).”Todeterminethemethod’s validity,whenthesolutionsareobtained,theyarecorrelatedto exact solutions ofα=1 order,and even for various values ofα.Three-dimensional graphs are used to depict the solutions.Additionally,the analysis of exact and FRDTM solutions indicates that the proposed approach is very accurate. 展开更多
关键词 Fractional reduced differential transform method(FRDTM) Time fractional generalized Burger-Fisher equation(TF-GBFE) Fractional calculus Caputo sense
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Lie Symmetry Analysis and Conservation Laws of a Generalized Time Fractional Foam Drainage Equation
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作者 王丽 田守富 +1 位作者 赵振涛 宋晓秋 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第7期35-40,共6页
In this paper, a generalized time fractional nonlinear foam drainage equation is investigated by means of the Lie group analysis method. Based on the Riemann–Liouville derivative, the Lie point symmetries and symmetr... In this paper, a generalized time fractional nonlinear foam drainage equation is investigated by means of the Lie group analysis method. Based on the Riemann–Liouville derivative, the Lie point symmetries and symmetry reductions of the equation are derived, respectively. Furthermore, conservation laws with two kinds of independent variables of the equation are performed by making use of the nonlinear self-adjointness method. 展开更多
关键词 a generalized time fractional nonlinear foam drainage equation Riemann–Liouville derivative Lie point symmetry symmetry reduction conservation law
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