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Padé approximations of quantized-vortex solutions of the Gross–Pitaevskii equation
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作者 Weiru Chen Shanquan Lan +3 位作者 Xiyi Liu Jiexiong Mo Xiaobao Xu Guqiang Li 《Communications in Theoretical Physics》 SCIE CAS CSCD 2021年第8期171-181,共11页
Quantized vortices are important topological excitations in Bose–Einstein condensates. The Gross–Pitaevskii equation is a widely accepted theoretical tool. High accuracy quantized-vortex solutions are desirable in m... Quantized vortices are important topological excitations in Bose–Einstein condensates. The Gross–Pitaevskii equation is a widely accepted theoretical tool. High accuracy quantized-vortex solutions are desirable in many numerical and analytical studies. We successfully derive the Padéapproximate solutions for quantized vortices with winding numbers ω = 1, 2, 3, 4, 5, 6 in the context of the Gross–Pitaevskii equation for a uniform condensate. Compared with the numerical solutions, we find that(1) they approximate the entire solutions quite well from the core to infinity;(2) higher-order Padé approximate solutions have higher accuracy;(3) Padé approximate solutions for larger winding numbers have lower accuracy. The healing lengths of the quantized vortices are calculated and found to increase almost linearly with the winding number. Based on experiments performed with 87Rb cold atoms, the healing lengths of quantized vortices and the number of particles within the healing lengths are calculated, and they may be checked by experiment. Our results show that the Gross–Pitaevskii equation is capable of describing the structure of quantized vortices and physics at length scales smaller than the healing length. 展开更多
关键词 Gross-Pitaevskii equation padéapproximation quantized-vortex solution
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ORTHOGONAL POLYNOMIALS AND DETERMINANT FORMULAS OF FUNCTION-VALUED PADE-TYPE APPROXIMATION USING FOR SOLUTION OF INTEGRAL EQUATIONS 被引量:2
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作者 顾传青 潘宝珍 吴蓓蓓 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第6期853-860,共8页
To solve Fredholm integral equations of the second kind, a generalized linear functional is introduced and a new function-valued Padé-type approximation is defined. By means of the power series expansion of the s... To solve Fredholm integral equations of the second kind, a generalized linear functional is introduced and a new function-valued Padé-type approximation is defined. By means of the power series expansion of the solution, this method can construct an approximate solution to solve the given integral equation. On the basis of the orthogonal polynomials, two useful determinant expressions of the numerator polynomial and the denominator polynomial for Padé-type approximation are explicitly given. 展开更多
关键词 generalized linear functional function-valued padé-type approximation Fredholm integral equation orthogonal polynomial determinant formula
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A generalized Padé approximation method of solving homoclinic and heteroclinic orbits of strongly nonlinear autonomous oscillators 被引量:1
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作者 李震波 唐驾时 蔡萍 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第12期78-84,共7页
An intrinsic extension of Pad′e approximation method, called the generalized Pad′e approximation method, is proposed based on the classic Pad′e approximation theorem. According to the proposed method, the numerator... An intrinsic extension of Pad′e approximation method, called the generalized Pad′e approximation method, is proposed based on the classic Pad′e approximation theorem. According to the proposed method, the numerator and denominator of Pad′e approximant are extended from polynomial functions to a series composed of any kind of function, which means that the generalized Pad′e approximant is not limited to some forms, but can be constructed in different forms in solving different problems. Thus, many existing modifications of Pad′e approximation method can be considered to be the special cases of the proposed method. For solving homoclinic and heteroclinic orbits of strongly nonlinear autonomous oscillators, two novel kinds of generalized Pad′e approximants are constructed. Then, some examples are given to show the validity of the present method. To show the accuracy of the method, all solutions obtained in this paper are compared with those of the Runge–Kutta method. 展开更多
关键词 generalized pad′e approximation method homoclinic and heteroclinic orbits strongly nonlinear oscillators
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Degeneracy Cases of Generalized Inverse Function-Valued Padé Approximation 被引量:1
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作者 潘宝珍 顾传青 《Journal of Shanghai University(English Edition)》 CAS 2004年第3期258-263,共6页
A new generalized inverse function-valued Padé approximation (GIFPA) was defined. Existence condition of GIFPA was given and its uniqueness theorem was proved. All possible degeneracy cases of GIFPA were discusse... A new generalized inverse function-valued Padé approximation (GIFPA) was defined. Existence condition of GIFPA was given and its uniqueness theorem was proved. All possible degeneracy cases of GIFPA were discussed and constructed. An example was given to illustrate its application. 展开更多
关键词 Generalized inverse function-valued padé approximation (GIFPA) degeneracy cases existence and uniqueness.
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Least-squares function-valued Padé-type approximation and its application in solving integral equations 被引量:1
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作者 潘宝珍 刘利九 《Journal of Shanghai University(English Edition)》 CAS 2010年第1期66-70,共5页
To solve the Fredholm integral equations of the second kind, a new notion of the least-squares orthogonal polyno- mials of function-valued Pade-type approximation is introduced. On the basis of the error formula, the ... To solve the Fredholm integral equations of the second kind, a new notion of the least-squares orthogonal polyno- mials of function-valued Pade-type approximation is introduced. On the basis of the error formula, the least-squares function: valued Pad&type approximation is constructed. Their existence and uniqueness are studied. A recursive computation formula of the least-squares function-valued Padetype approximation is given. In the end, an example is given to show that the method is effective and stable. 展开更多
关键词 least-squaxes orthogonal polynomial function-valued pade-type approximation Fredholm integral equation
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An Approximation Method for Singular Trudinger-Moser Inequality
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作者 ZHU Maochun XU Wenyan JIANG Rou 《应用数学》 北大核心 2025年第1期64-70,共7页
In this paper,we construct a power type functional which is the approximation functional of the Singular Trudinger-Moser functional.Moreover,we obtain the concentration level of the functional and show it converges to... In this paper,we construct a power type functional which is the approximation functional of the Singular Trudinger-Moser functional.Moreover,we obtain the concentration level of the functional and show it converges to the concentration level of singular Trudinger-Moser functional on the unit ball. 展开更多
关键词 Singular Trudinger-Moser inequality approximation functional Concentration level
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Statistical analysis on the validity of the cold plasma approximation for chorus waves based on Van Allen Probe observations and their effects on radiation belt electrons
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作者 AoJun Ren Jiang Yu +2 位作者 Jing Wang ZuZheng Chen XiaoMan Liu 《Earth and Planetary Physics》 EI CAS 2025年第1期159-170,共12页
Theoretical analysis has demonstrated that the dispersion relation of chorus waves plays an essential role in the resonant interaction and energy transformation between the waves and magnetospheric electrons.Previous ... Theoretical analysis has demonstrated that the dispersion relation of chorus waves plays an essential role in the resonant interaction and energy transformation between the waves and magnetospheric electrons.Previous quantitative analyses often simplified the chorus dispersion relation by using the cold plasma assumption.However,the applicability of the cold plasma assumption is doubtful,especially during geomagnetic disturbances.We here present a systematic statistical analysis on the validity of the cold plasma dispersion relation of chorus waves based on observations from the Van Allen Probes over the period from 2012 to 2018.The statistical results show that the observed magnetic field intensities deviate substantially from those calculated from the cold plasma dispersion relation and that they become more pronounced with an increase in geomagnetic activity or a decrease in background plasma density.The region with large deviations is mainly concentrated in the nightside and expands in both the radial and azimuthal directions as the geomagnetic activity increases or the background plasma density decreases.In addition,the bounce-averaged electron scattering rates are computed by using the observed and cold plasma dispersion relation of chorus waves.Compared with usage of the cold plasma dispersion relation,usage of the observed dispersion relation considerably lowers the minimum resonant energy of electrons and lowers the scattering rates of electrons above tens of kiloelectronvolts but enhances those below.Furthermore,these differences are more pronounced with the enhancement of geomagnetic activity or the decrease in background plasma density. 展开更多
关键词 chorus waves cold plasma approximation dispersion relations scattering rates
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Normal moveout for long offset in isotropic media using the Padé approximation 被引量:1
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作者 Song Han-Jie Zhang Jin-Hai Yao Zhen-Xing 《Applied Geophysics》 SCIE CSCD 2016年第4期658-666,738,739,共11页
The nomaal moveout correction is important to long-offset observations, especially deep layers. For isotropic media, the conventional two-term approximation of the normal moveout function assumes a small offset-to-dep... The nomaal moveout correction is important to long-offset observations, especially deep layers. For isotropic media, the conventional two-term approximation of the normal moveout function assumes a small offset-to-depth ratio and thus fails at large offset-to-depth ratios. We approximate the long-offset moveout using the Pade approximation. This method is superior to typical methods and flattens the seismic gathers over a wide range of offsets in multilayered media. For a four-layer model, traditional methods show traveltime errors of about 5 ms for offset-to-depth ratio of 2 and greater than 10 ms for offset-to-depth ratio of 3; in contrast, the maximum traveltime error for the [3, 3]-order Pade approximation is no more than 5 ms at offset-to-depth ratio of 3. For the Cooper Basin model, the maximum oft'set-to-depth ratio for the [3, 3]-order Pade approximation is typically double of those in typical methods. The [7, 7]-order Pade approximation performs better than the [3.3]-order Pade armroximation. 展开更多
关键词 pade approximation long offset normal moveout isotropic medium
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Exceptional Set for Diophantine Approximation with Primes of Two Squares and Three Biquadrates
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作者 LIU Minmin ZHANG Min LI Jinjiang 《数学进展》 北大核心 2025年第1期18-36,共19页
Suppose thatλ_(1),λ_(2),λ_(3),λ_(4),λ_(5)are nonzero real numbers,not all of the same sign,andλ_(1)/λ_(2)is irrational and algebraic.Let V be a well-spaced sequence,δ>0.In this paper,it is proved that,for ... Suppose thatλ_(1),λ_(2),λ_(3),λ_(4),λ_(5)are nonzero real numbers,not all of the same sign,andλ_(1)/λ_(2)is irrational and algebraic.Let V be a well-spaced sequence,δ>0.In this paper,it is proved that,for anyε>0,the number of v∈V with v≤N such that the following inequality|λ_(1)p_(1)~2+λ_(2)p_(2)~2+λ_(3)p_(3)~4+λ_(4)p_(4)~4+λ_5p_5~4-v|<v^(-δ)has no solution in prime variables p_(1),p_(2),p_(3),p_(4),p_(5)does not exceed O(N^(29/32+2δ+ε)). 展开更多
关键词 Diophantine approximation exponential sum Davenport-Heilbronn method prime variable
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Smoluchowski-Kramers Approximation for Stochastic Differential Equations under Discretization
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作者 Li Ge 《应用概率统计》 北大核心 2025年第4期622-635,共14页
This paper studies the Smoluchowski–Kramers approximation for a discrete-time dynamical system modeled as the motion of a particle in a force field.We show that the approximation holds for the drift-implicit Euler–M... This paper studies the Smoluchowski–Kramers approximation for a discrete-time dynamical system modeled as the motion of a particle in a force field.We show that the approximation holds for the drift-implicit Euler–Maruyama discretization and derive its convergence rate.In particular,the solution of the discretized system converges to the solution of the first-order limit equation in the mean-square sense,and this convergence is independent of the order in which the mass parameterμand the step size h tend to zero. 展开更多
关键词 stochastic differential equations Smoluchowski-Kramers approximation driftimplicit Euler-Maruyama scheme convergence rate
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A Note on Pad Approximants Pairs as Limits of Algebraic Polynomials Pairs of Weighted Best Approximation in Orlicz Spaces
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作者 F.E.Levis 《Analysis in Theory and Applications》 CSCD 2015年第3期253-259,共7页
In this short note, we show the behavior in Orlicz spaces of best approximations by algebraic polynomials pairs on union of neighborhoods, when the measure of them tends to zero.
关键词 Best approximation pair pad′e approximant pair Orlicz spaces.
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Orthogonal Polynomials and Padé Approximation
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作者 Faiz Ahmad (Department of Mathematics, Quaid i Azam University, Pakistan) 《Advances in Manufacturing》 SCIE CAS 1998年第2期24-27,共4页
The diagonal Padé approximants for exp ( x ), tan x and tanh x are obtained in a simple manner by using the property of Legendre polynomials that on P r1 (x) is orthogonal to every polynomial o... The diagonal Padé approximants for exp ( x ), tan x and tanh x are obtained in a simple manner by using the property of Legendre polynomials that on P r1 (x) is orthogonal to every polynomial of lower degree. Gauss's quadrature formula is used to find the denominators of some functions. 展开更多
关键词 orthogonal polynomials padé approximation
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Function-valued partial Padé-type approximation method for estimating eigenvalues of Fredholm integral equation of the second kind
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作者 顾传青 沈进东 《Journal of Shanghai University(English Edition)》 CAS 2007年第6期531-535,共5页
Abstract A new function-valued partial Padé-type approximation was introduced in the polynomial space, and an explicit determinant formula was derived by means of some orthogonal polynomials. This method can be a... Abstract A new function-valued partial Padé-type approximation was introduced in the polynomial space, and an explicit determinant formula was derived by means of some orthogonal polynomials. This method can be applied to estimating surplus eigenvalues of the Fredholm integral equation of the second kind when its partial eigenvalues have been known, and at the same time, it can be applied to solving the approximating solution of the given equation. 展开更多
关键词 linear functional function-valued partial padé approximation DETERMINANT Fredholm integral equation of thesecond kind eigenvalue.
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Evolutionary Safe Padé Approximation Scheme for Dynamical Study of Nonlinear Cervical Human Papilloma Virus Infection Model
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作者 Javaid Ali Armando Ciancio +4 位作者 Kashif Ali Khan Nauman Raza Haci Mehmet Baskonus Muhammad Luqman Zafar-Ullah Khan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第9期2275-2296,共22页
This study proposes a structure-preserving evolutionary framework to find a semi-analytical approximate solution for a nonlinear cervical cancer epidemic(CCE)model.The underlying CCE model lacks a closed-form exact so... This study proposes a structure-preserving evolutionary framework to find a semi-analytical approximate solution for a nonlinear cervical cancer epidemic(CCE)model.The underlying CCE model lacks a closed-form exact solution.Numerical solutions obtained through traditional finite difference schemes do not ensure the preservation of the model’s necessary properties,such as positivity,boundedness,and feasibility.Therefore,the development of structure-preserving semi-analytical approaches is always necessary.This research introduces an intelligently supervised computational paradigm to solve the underlying CCE model’s physical properties by formulating an equivalent unconstrained optimization problem.Singularity-free safe Padérational functions approximate the mathematical shape of state variables,while the model’s physical requirements are treated as problem constraints.The primary model of the governing differential equations is imposed to minimize the error between approximate solutions.An evolutionary algorithm,the Genetic Algorithm with Multi-Parent Crossover(GA-MPC),executes the optimization task.The resulting method is the Evolutionary Safe PadéApproximation(ESPA)scheme.The proof of unconditional convergence of the ESPA scheme on the CCE model is supported by numerical simulations.The performance of the ESPA scheme on the CCE model is thoroughly investigated by considering various orders of non-singular Padéapproximants. 展开更多
关键词 Nonlinear cervical cancer epidemic non-singular padéapproximants approximate solutions computational biology
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Some Algebraic Properties of Generalized Inverse Matrix-Valued Padé Approximation
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《Advances in Manufacturing》 SCIE CAS 2000年第4期275-278,共4页
关键词 MATH approximation pad Some Algebraic Properties of Generalized Inverse Matrix-Valued
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THE ORTHOGONAL POLYNOMIALS AND THE PADE'APPROXIMATION
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作者 Faiz Ahmad (Department of Mathemahcs, Quaid-Azam University, Islamabad, Pakistan) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1998年第7期663-668,共6页
The diagonal Pade' approximates for exp(x). tanx and tanhx are obtained in asimple manner by using the property of Legendre polynomials that on [ -1, 1] Pn (x)is orthogonal to every polynomial of lower degree. Gau... The diagonal Pade' approximates for exp(x). tanx and tanhx are obtained in asimple manner by using the property of Legendre polynomials that on [ -1, 1] Pn (x)is orthogonal to every polynomial of lower degree. Gauss's quadrature formula is used tofined the denomiators of some functions. 展开更多
关键词 orthogonal polynomials pade' approximation Legendrepolynomials numerical approxiamtion
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Magnetic interface forward and inversion method based on Padé approximation
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作者 Zhang Chong Huang Da-Nian +2 位作者 Zhang Kai Pu Yi-Tao Yu Ping 《Applied Geophysics》 SCIE CSCD 2016年第4期712-720,740,共10页
The magnetic interface forward and inversion method is realized using the Taylor series expansion to linearize the Fourier transform of the exponential function. With a large expansion step and unbounded neighborhood,... The magnetic interface forward and inversion method is realized using the Taylor series expansion to linearize the Fourier transform of the exponential function. With a large expansion step and unbounded neighborhood, the Taylor series is not convergent, and therefore, this paper presents the magnetic interface forward and inversion method based on Pade approximation instead of the Taylor series expansion. Compared with the Taylor series, Pade's expansion's convergence is more stable and its approximation more accurate. Model tests show the validity of the magnetic forward modeling and inversion of Pade approximation proposed in the paper, and when this inversion method is applied to the measured data of the Matagami area in Canada, a stable and reasonable distribution of underground interface is obtained. 展开更多
关键词 pade approximation magnetic interface fand inversion method Taylor seriesexpansion
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A reconfigurable array with adaptive approximation using dual threshold accuracy
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作者 SHAN Rui SONG Yupeng LIAO Wang 《High Technology Letters》 2025年第3期226-237,共12页
With the growing demand for compute-intensive applications such as artificial intelligence(AI)and video processing,traditional reconfigurable array processors fail to meet the requirements of high-performance computin... With the growing demand for compute-intensive applications such as artificial intelligence(AI)and video processing,traditional reconfigurable array processors fail to meet the requirements of high-performance computing and related domains,primarily due to their high power consumption and low energy efficiency.To address this limitation,this paper proposes an accuracy-adaptive approxi-mate reconfigurable array architecture featuring preset dual thresholds and support for four computa-tional accuracy levels,enabling flexible adaptation to diverse application needs.The architecture in-tegrates a self-adaptive mechanism that dynamically adjusts computational precision based on real-time error threshold feedback.To evaluate the proposed architecture,the you only look once version 5(YOLOv5)deep neural network algorithm is parallelized and deployed on the approximate recon-figurable array.Experimental results demonstrate that the architecture achieves an 18.93%reduc-tion in power consumption compared with conventional reconfigurable structures operating in full-pre-cision mode.Additionally,the design exhibits superior energy efficiency and reduced computational resource utilization,thereby significantly enhancing the overall performance and applicability of reconfigurable array processors in power-sensitive scenarios. 展开更多
关键词 reconfigurable computing approximate computing low power ENERGY-EFFICIENT
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Stable Routh-Padé-type approximation in model reduction of interval systems
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作者 顾传青 杨健 《Journal of Shanghai University(English Edition)》 CAS 2010年第5期369-373,共5页
An interval Pade-type approximation is introduced and then Routh-Pade-type method (IRPTM) is presented to model reduction in interval systems. The denominator in reduced model is obtained from the stable Routh table... An interval Pade-type approximation is introduced and then Routh-Pade-type method (IRPTM) is presented to model reduction in interval systems. The denominator in reduced model is obtained from the stable Routh table, and its numerator is constructed by the interval Pade-type definition. Compared to the existing Routh-Pade method, IRPTM does not need to solve linear interval equations theoretical analysis shows that IRPTM has example is given to illustrate our method. Hence, we do not have to compute smaller computational cost than that interval division in the process. Moreover, of Routh-Pade method. A typical numerical 展开更多
关键词 interval system model reduction Routh-table pade-type approximant Routh-pad6-type method
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On approximation of Bernstein-Stancu operators in movable interval
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作者 WAGN Feng-feng YU Dan-sheng 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第1期85-101,共17页
In the present paper,we obtain the converse results of approximation of a newly introduced genuine Bernstein-Durrmeyer operators in movable interval.We also get the moments properties of an auxiliary operator which ha... In the present paper,we obtain the converse results of approximation of a newly introduced genuine Bernstein-Durrmeyer operators in movable interval.We also get the moments properties of an auxiliary operator which has its own independent values.The moments of the auxiliary operators play important roles in establishing the main result(Theorem 4). 展开更多
关键词 Bernstein-Stancu operators movable interval approximation rates Voronovskaja's asymptotic estimate
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