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基于Bessel和Meijer-G函数的楔形和锥形悬臂梁振动分析 被引量:2
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作者 周坤涛 杨涛 +2 位作者 葛根 郝淑英 张琪昌 《振动与冲击》 EI CSCD 北大核心 2022年第4期253-261,共9页
基于欧拉-伯努利梁理论,利用Lagrange法建立了楔形和锥形截面梁在外激作用下的非线性微分方程。提出了一种基于Bessel函数和Meijer-G函数线性组合的无需迭代及近似截断的振型函数,且该振型函数不依赖于楔形和锥形变截面梁的弯曲振动的... 基于欧拉-伯努利梁理论,利用Lagrange法建立了楔形和锥形截面梁在外激作用下的非线性微分方程。提出了一种基于Bessel函数和Meijer-G函数线性组合的无需迭代及近似截断的振型函数,且该振型函数不依赖于楔形和锥形变截面梁的弯曲振动的运动方程是否为标准的Bessel形式,该方法能快速求解线性基频和模态函数。随后将该方法得到的模态函数代入变截面悬臂梁非线性振动的控制方程中,得到了常微分方程的弯曲非线性系数及惯性非线性系数,最后利用多尺度法研究主共振下的幅频响应。结果表明,该方法得到的线性基频及非线性幅频响应曲线与已有文献结果高度吻合,充分验证了用该方法求解的振型函数具有很高的精确性,该方法可为楔形或锥形变截面悬臂梁模态函数解析解提供新思路。 展开更多
关键词 欧拉-伯努利梁 Lagrange法 BESSEL函数 meijer-G函数 非线性振动
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A Chart-Based Diagnostic Model for Tight Gas Reservoirs Based on Shut-in Pressure during Hydraulic Fracturing
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作者 Mingqiang Wei Neng Yang +2 位作者 Han Zou Anhao Li Yonggang Duan 《Fluid Dynamics & Materials Processing》 2025年第2期309-324,共16页
A precise diagnosis of the complex post-fracturing characteristics and parameter variations in tight gas reservoirs is essential for optimizing fracturing technology,enhancing treatment effectiveness,and assessing pos... A precise diagnosis of the complex post-fracturing characteristics and parameter variations in tight gas reservoirs is essential for optimizing fracturing technology,enhancing treatment effectiveness,and assessing post-fracturing production capacity.Tight gas reservoirs face challenges due to the interaction between natural fractures and induced fractures.To address these issues,a theoretical model for diagnosing fractures under varying leak-off mechanisms has been developed,incorporating the closure behavior of natural fractures.This model,grounded in material balance theory,also accounts for shut-in pressure.The study derived and plotted typical G-function charts,which capture fracture behavior during closure.By superimposing the G-function in the closure phase of natural fractures with pressure derivative curves,the study explored how fracture parameters—including leak-off coefficient,fracture area,closure pressure,and closure time—impact these diagnostic charts.Findings show that variations in natural fracture flexibility,fracture area,and controlling factors influence the superimposed G-function pressure derivative curve,resulting in distinctive“concave”or“convex”patterns.Field data from Well Y in a specific tight gas reservoir were used to validate the model,confirming both its reliability and practicality. 展开更多
关键词 Tight gas reservoir volume fracturing g-function fracture diagnosis complex fracture network shut-in pressure
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G-Function Solutions for Schrodinger Equation in Cylindrical Coordinates System
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作者 Amir Pishkoo Maslina Darus 《Applied Mathematics》 2014年第3期342-346,共5页
In this paper, the Schr?dinger equation is solved by Modified separation of variables (MSV) method suggested by Pishkoo and Darus. Using this method, Meijer’s G-function solutions are derived in cylindrical coordinat... In this paper, the Schr?dinger equation is solved by Modified separation of variables (MSV) method suggested by Pishkoo and Darus. Using this method, Meijer’s G-function solutions are derived in cylindrical coordinate system for quantum particle in cylindrical can. All elementary functions and most of the special functions which are the solution of extensive problems in physics and engineering are special cases of Meijer’s G-functions. 展开更多
关键词 meijer’s g-function Partial Differential Equation Modified Separation of Variables Schr?dinger Equation
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三元独立积构成的雷达杂波
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作者 扈罗全 陆全荣 谢海俊 《中国电子科学研究院学报》 2008年第4期355-360,共6页
雷达杂波的精确建模和仿真对雷达系统的优化设计起着重要作用。针对雷达杂波具有尖峰、非对称和重拖尾等非高斯特征,使用二元Rayleigh独立积和自由度为n的广义χ分布的随机变量进行级联,构造新的三元独立积随机变量。使用Mellin变换求... 雷达杂波的精确建模和仿真对雷达系统的优化设计起着重要作用。针对雷达杂波具有尖峰、非对称和重拖尾等非高斯特征,使用二元Rayleigh独立积和自由度为n的广义χ分布的随机变量进行级联,构造新的三元独立积随机变量。使用Mellin变换求得该随机变量的概率密度函数,其解析表达式含有Meijer G函数,故叫做G-分布杂波,并得到平方检波器接收的雷达杂波的概率密度函数。使用Markov扩散过程模型产生G-分布杂波的相关随机变量。仿真得到的随机序列的概率密度分布与理论值吻合很好。 展开更多
关键词 雷达杂波 独立积 非高斯分布 梅林变换 meijer G函数
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一种新型的能量检测方法及性能分析
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作者 曹开田 杭燚灵 《计算机科学》 CSCD 北大核心 2018年第B06期266-269,294,共5页
针对当前小样本情况下的能量检测(Energy Detection,ED)方法只对AWGN(Additive White Gaussian Noise)非衰落信道上的检测性能进行了近似分析的不足,利用广义Marcum Q函数的最新研究成果对小样本条件下的ED方法进行研究,推导出在瑞利衰... 针对当前小样本情况下的能量检测(Energy Detection,ED)方法只对AWGN(Additive White Gaussian Noise)非衰落信道上的检测性能进行了近似分析的不足,利用广义Marcum Q函数的最新研究成果对小样本条件下的ED方法进行研究,推导出在瑞利衰落信道下易处理的、精确的ED检测概率闭式解表达式,并对其检测性能进行了分析。理论分析和仿真结果表明,与目前采用中心极限定理(Central Limit Theorem,CLT)、多维高斯(Cube-of-Gaussian,CoG)近似法及其他近似法分析ED检测性能相比,所提方法在小样本情况下具有更稳定、更精确的检测性能。 展开更多
关键词 认知无线电 频谱感知 能量检测 检测性能 meijer’s G函数
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抛物线坐标系非傍轴矢量光束的解及聚焦特性 被引量:1
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作者 彭继 崔执凤 屈军 《激光技术》 CAS CSCD 北大核心 2014年第5期703-708,共6页
为了求解柱坐标系下非傍轴矢量波动方程,得到光束的电场解析表达式,基于轴对称情况下沿角向偏振的电场,将非傍轴近似情况下的矢量波动方程进行了抛物线坐标的转化,利用分离变量法进行了相应求解,并给出了相应的数值计算。结果表明,非傍... 为了求解柱坐标系下非傍轴矢量波动方程,得到光束的电场解析表达式,基于轴对称情况下沿角向偏振的电场,将非傍轴近似情况下的矢量波动方程进行了抛物线坐标的转化,利用分离变量法进行了相应求解,并给出了相应的数值计算。结果表明,非傍轴近似情况下,矢量波动方程的解能描述一种光束的电场,该场的解析表达式与合流超几何函数以及梅杰函数的解有关;光束的光强分布与第1类零阶贝塞尔模式光束类似;光束在近光轴处的光强表现为无限大并且沿边缘方向急剧衰减;在焦平面上沿着径向方向光强急剧减小。所得结果对于探究非傍轴近似情况下矢量光束的传输特性有一定的意义。 展开更多
关键词 激光光学 非傍轴矢量波动方程 坐标变换 合流超几何函数 梅杰函数
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DISTRIBUTION OF VOTAW'S λ_1(vc) CRITERION FOR TESTING COMPOUND SYMMETRY OF A COVARIANCE MATRIX 被引量:1
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作者 Arjun K. Gopta(Department of Mathematics and Statistics Bowling Green State University,Bowling Green, Ohio 43403-0221, USA)Data K. Nagar(Departamento de Matematicas Universidad de Antioquia, Medellin, A. A. 1226, Colombia) 《Acta Mathematica Scientia》 SCIE CSCD 1999年第1期62-80,共19页
The distribution of Votaw’s λ1(vc) criterion for testing compound symmetryof the covariance matrix of a t-variate Gaussian model has been obtained in terms ofMeijer’s G-function as well as in computable series fo... The distribution of Votaw’s λ1(vc) criterion for testing compound symmetryof the covariance matrix of a t-variate Gaussian model has been obtained in terms ofMeijer’s G-function as well as in computable series form. Special cases of the densityhave also been derived using reduction formulae for G-function. 展开更多
关键词 meijer’s g-function COMPOUND SYMMETRY INVERSE Mellin transformation bi-polarity
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Distributions of Ratios: From Random Variables to Random Matrices 被引量:1
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作者 Thu Pham-Gia Noyan Turkkan 《Open Journal of Statistics》 2011年第2期93-104,共12页
The ratio R of two random quantities is frequently encountered in probability and statistics. But while for unidimensional statistical variables the distribution of R can be computed relatively easily, for symmetric p... The ratio R of two random quantities is frequently encountered in probability and statistics. But while for unidimensional statistical variables the distribution of R can be computed relatively easily, for symmetric positive definite random matrices, this ratio can take various forms and its distribution, and even its definition, can offer many challenges. However, for the distribution of its determinant, Meijer G-function often provides an effective analytic and computational tool, applicable at any division level, because of its reproductive property. 展开更多
关键词 Matrix Variate BETA DISTRIBUTION Generalized-F DISTRIBUTION Ratios meijer g-function Wishart DISTRIBUTION RATIO
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METRIZABILITY OF SPACES AND J.NAGATA'S PROBLEM 被引量:2
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作者 高智民 《Acta Mathematica Scientia》 SCIE CSCD 2006年第1期25-30,共6页
In 1988, J.Nagata raised a problem about metrizability, The present article is an attempt to find a solution to the problem.
关键词 Metrizable space g-function weak g-function
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LIMITING WEAK-TYPE BEHAVIORS FOR CERTAIN LITTLEWOOD-PALEY FUNCTIONS 被引量:2
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作者 Xianming HOU Huoxiong WU 《Acta Mathematica Scientia》 SCIE CSCD 2019年第1期11-25,共15页
In this paper, we establish the following limiting weak-type behaviors of Littlewood-Paley g-function g_φ: for nonnegative function f∈ L^1(R^n),■and ■where f_t(x) =t^(-n)f(t^(-1) x) for t > 0. Meanwhile, the co... In this paper, we establish the following limiting weak-type behaviors of Littlewood-Paley g-function g_φ: for nonnegative function f∈ L^1(R^n),■and ■where f_t(x) =t^(-n)f(t^(-1) x) for t > 0. Meanwhile, the corresponding results for Marcinkiewicz integral and its fractional version with kernels satisfying L_α~q-Dini condition are also given. 展开更多
关键词 LIMITING BEHAVIORS weak-type bounds LITTLEWOOD-PALEY g-functions Marcinkiewicz integrals L_α~q -Dini conditions
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ON PARAMETRIC MARCINKIEWICZ INTEGRALS RELATED TO BLOCK SPACES 被引量:1
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作者 WuHuoxiong ZhangPu 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2003年第3期258-266,共9页
In this paper,the L2-boundedness of a class of parametric Marcinkiewicz integral μρ Ω,h with kernel function Ω in B 0,0 q(S n-1) for some q>1,and the radial function h(x)∈l∞(Ls)(R +) for 1<s≤∞ are... In this paper,the L2-boundedness of a class of parametric Marcinkiewicz integral μρ Ω,h with kernel function Ω in B 0,0 q(S n-1) for some q>1,and the radial function h(x)∈l∞(Ls)(R +) for 1<s≤∞ are given.The Lp(Rn)(2≤p<∞) boundedness of μ *,ρ Ω,h,λ and μ ρ Ω,h,S with Ω in B 0,0 q(S n-1) and h(|x|)∈l∞(Ls)(R +) in application are obtained.Here μ *,ρ Ω,h,λ and μ ρ Ω,h,S are parametric Marcinkiewicz integrals corresponding to the Littlewood-Paley g* λ function and the Lusin area function S,respectively. 展开更多
关键词 Marcinkiewicz integral Littlewood-Paley g-function Lusin area integral block space l∞(Ls)(R +)
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On Some Generalized Countably Compact Spaces 被引量:1
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作者 Erguang YANG 《Journal of Mathematical Research with Applications》 CSCD 2019年第5期540-550,共11页
We first give alternative expressions of some generalized countably compact spaces such as quasi-γspaces, quasi-Nagata spaces, M^#-spaces and wM-spaces with g-functions. Then by means of these expressions, we present... We first give alternative expressions of some generalized countably compact spaces such as quasi-γspaces, quasi-Nagata spaces, M^#-spaces and wM-spaces with g-functions. Then by means of these expressions, we present some characterizations of the corresponding spaces with real-valued functions. 展开更多
关键词 real-valued functions g-functions quasi-γ spaces quasi-Nagata spaces wN-spaces M#-spaces wM-spaces
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AF中继辅助TWR-FSO通信系统的性能分析
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作者 包朝园 曹阳 +1 位作者 彭小峰 邢雯珺 《激光杂志》 CAS 北大核心 2023年第10期122-127,共6页
针对大气湍流和指向误差对自由空间光通信性能的影响会随着通信距离的增大而愈发严重,基于放大转发中继(AF),提出了一种双向中继-自由空间光通信(TWR-FSO)系统方案。该系统采用差分二进制相移键控调制,建立了一个包含大气湍流和指向误... 针对大气湍流和指向误差对自由空间光通信性能的影响会随着通信距离的增大而愈发严重,基于放大转发中继(AF),提出了一种双向中继-自由空间光通信(TWR-FSO)系统方案。该系统采用差分二进制相移键控调制,建立了一个包含大气湍流和指向误差的复合衰落信道模型,其信道衰落满足Gamma-Gamma分布。利用Meijer’s G函数推导得到TWR-FSO系统中断概率和平均误码率的闭合表达式。在不同湍流强度和阈值门限条件下,对比分析了中断概率和平均误码率性能。仿真结果表明,在受到相同指向误差的条件下,当SNR=25 dB时,AF中继相较于DF中继系统的中断概率从10^(-1)量级下降到10^(-4)量级左右。当折射率结构常数为4.0×10^(-15)m^(-2/3),SNR=40 dB时,系统的误码率可以达到10^(-8)量级以下。说明AF中继下TWR-FSO系统能有效降低大气湍流和指向误差对通信系统的影响。 展开更多
关键词 放大转发中继 中断概率 平均误码率 梅耶尔G函数
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Distribution of the Sample Correlation Matrix and Applications
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作者 Thu Pham-Gia Vartan Choulakian 《Open Journal of Statistics》 2014年第5期330-344,共15页
For the case where the multivariate normal population does not have null correlations, we give the exact expression of the distribution of the sample matrix of correlations R, with the sample variances acting as param... For the case where the multivariate normal population does not have null correlations, we give the exact expression of the distribution of the sample matrix of correlations R, with the sample variances acting as parameters. Also, the distribution of its determinant is established in terms of Meijer G-functions in the null-correlation case. Several numerical examples are given, and applications to the concept of system de- pendence in Reliability Theory are presented. 展开更多
关键词 CORRELATION Normal DETERMINANT meijer g-function No-Correlation Dependence Component Formatting Style STYLING INSERT
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基于MATLAB移动通信中复杂函数优化设计 被引量:1
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作者 胡明亮 杨茂辉 付婉 《电子测量技术》 2018年第11期26-30,共5页
在通信仿真中经常会碰到较为复杂的函数,如果不对这些函数仿真程序设计进行优化,不仅会增加编程难度,还会增加程序复杂度进而占用大量CPU。以几种具有代表性的函数为例,其中包括积分、meijer-G函数、Π函数、Mellin变换等,介绍了在MATLA... 在通信仿真中经常会碰到较为复杂的函数,如果不对这些函数仿真程序设计进行优化,不仅会增加编程难度,还会增加程序复杂度进而占用大量CPU。以几种具有代表性的函数为例,其中包括积分、meijer-G函数、Π函数、Mellin变换等,介绍了在MATLAB中对这些复杂函数的多种编程处理方式。此外还给出这些程序的仿真结果,以验证编程结果的可行性和正确性。通过观察仿真程序和仿真结果这两个方面,得出最为优质的函数仿真程序设计方法。由此达到优化程序设计,降低仿真难度,提高通信仿真的工作效率的目的。 展开更多
关键词 MATLAB 仿真 积分 meijer-G函数 Π函数 Mellin变换
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A note on“Block H-matrices and spectrum of block matrices”
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作者 刘建州 黄泽军 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2008年第7期953-960,共8页
In this paper, we make further discussions and improvements on the results presented in the previously published work "Block H-matrices and spectrum of block matrices". Furthermore, a new bound for eigenvalues of bl... In this paper, we make further discussions and improvements on the results presented in the previously published work "Block H-matrices and spectrum of block matrices". Furthermore, a new bound for eigenvalues of block matrices is given with examples to show advantages of the new result. 展开更多
关键词 g-function block matrix EIGENVALUE
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BLOCK H-MATRICES AND SPECTRUM OF BLOCK MATRICES
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作者 HUANG Ting-zhu(黄廷祝) +1 位作者 LI Wen(黎稳) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2002年第2期236-240,共5页
The block H-matrices are studied by the concept of G-functions, several concepts of block matrices are introduced. Equivalent characters of block H-matrices are obtained. Spectrum localizations characterized by G-func... The block H-matrices are studied by the concept of G-functions, several concepts of block matrices are introduced. Equivalent characters of block H-matrices are obtained. Spectrum localizations characterized by G-functions for block matrices are got. 展开更多
关键词 block H-matrix SPECTRUM g-function EIGENVALUE irreducible matrix
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A LITTLEWOOD-PALEY TYPE THEOREM FOR BERGMAN SPACES
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作者 陈泽乾 欧阳威 《Acta Mathematica Scientia》 SCIE CSCD 2013年第1期150-154,共5页
In this paper, we prove that the original Littlewood-Paley g-functions can be used to characterize Bergman spaces as well.
关键词 Bergman space Hardy space Littlewood-Paley g-function
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NBCM with Flat Roll in the Finish Stand
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作者 XiangweiKONG HezhouYE +3 位作者 JianzhongXUt GuodongWANG XianghuaLIU gunweiZHANG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第2期233-235,共3页
With the development of the market, it becomes a demanding task for producers to make flexible production schedules to shorten production cycle. Schedule-free rolling is needed. If the CVC work roll of the F6 and F7 s... With the development of the market, it becomes a demanding task for producers to make flexible production schedules to shorten production cycle. Schedule-free rolling is needed. If the CVC work roll of the F6 and F7 stands in certain 2050 mm hot rolled strip mill are substituted by flat roll (aim to SFR) and the strip profile is controlled by the existing bending force, the control ability is not adequate. This fact has been tested through on-line experiment and has been given in this article. The NBCM (new backup roll crowning method) is recommended to improve the profile control ability. Finally the plastic deformation of the strip and the elastic deformation of the roll are analyzed by employing coupled calculation of rigid-plastic finite element method and G-function method, and the optimal range of the crown of backup roll is given theoretically. 展开更多
关键词 SFR NBCM Conventional roll Rigid-Plastic FEM g-function method Coupled calculation
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BOUNDEDNESS OF MULTILINEAR LITTLEWOOD-PALEY OPERATORS ON AMALGAM-CAMPANATO SPACES
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作者 Xiang LI Qianjun HE Dunyan YAN 《Acta Mathematica Scientia》 SCIE CSCD 2020年第1期272-292,共21页
In this paper,we consider the boundedness of multilinear Littlewood-Paley operators which include multilinear g-function,multilinear Lusin's area integral and multilinear Littlewood-Paley g^*λ-function.Furthermor... In this paper,we consider the boundedness of multilinear Littlewood-Paley operators which include multilinear g-function,multilinear Lusin's area integral and multilinear Littlewood-Paley g^*λ-function.Furthermore,norm inequalities of the above operators hold on the corresponding Amalgam-Campanato spaces. 展开更多
关键词 MULTILINEAR LITTLEWOOD-PALEY g-function MULTILINEAR g^*λ-function AmalgamCampanato SPACES
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