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半透水边界一维固结的特征值解法 被引量:7
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作者 方开泽 《水利学报》 EI CSCD 北大核心 1989年第3期48-53,共6页
饱和土的一维固结最早由太沙基提出,并已在工程界得到广泛应用,现有各种计算公式和图表都是以透水和不透水边界来求解固结方程的。但在一些实际工程问题中,往往存在半透水边界条件,遇到这种情况通常是用数值方法来求解。本文采用特征值... 饱和土的一维固结最早由太沙基提出,并已在工程界得到广泛应用,现有各种计算公式和图表都是以透水和不透水边界来求解固结方程的。但在一些实际工程问题中,往往存在半透水边界条件,遇到这种情况通常是用数值方法来求解。本文采用特征值法求解了一面透水一面半透水以及一面半透水一面不透水这两种情况下的一维固结方程,并绘出计算图便于应用。 展开更多
关键词 半透水边界 一维固结 特征值解法 饱和土 土工试验
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用特征值解法简化工程计算
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作者 刘勇 尹邦信 《四川建筑》 2005年第5期72-73,共2页
从计算多自由度系统无阻尼自由振动的频率和振型的特征值解法入手,分别阐述了特征值解法在求解主应力、主应变过程中的应用及对运用直接刚度法计算刚架稳定问题的简化,从而肯定了特征值解法应用于工程计算中是一种即简便又适合于程序化... 从计算多自由度系统无阻尼自由振动的频率和振型的特征值解法入手,分别阐述了特征值解法在求解主应力、主应变过程中的应用及对运用直接刚度法计算刚架稳定问题的简化,从而肯定了特征值解法应用于工程计算中是一种即简便又适合于程序化的计算方法。 展开更多
关键词 特征值解法 主应力 主应变 稳定分析
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一类高阶椭圆型方程特征值的多项式特解法 被引量:6
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作者 张姊同 曹艳华 朱挺欣 《井冈山大学学报(自然科学版)》 2022年第2期8-14,共7页
通过给出一种求解高阶椭圆型偏微分方程特征值的多项式特解法,使用多项式特解作为基函数对2阶、4阶、6阶和8阶椭圆型偏微分方程进行求解,同时采用多尺度技巧降低系数矩阵的条件数,得到了稳定的数值解。数值算例表明该算法在求解高阶偏... 通过给出一种求解高阶椭圆型偏微分方程特征值的多项式特解法,使用多项式特解作为基函数对2阶、4阶、6阶和8阶椭圆型偏微分方程进行求解,同时采用多尺度技巧降低系数矩阵的条件数,得到了稳定的数值解。数值算例表明该算法在求解高阶偏微分方程特征值问题时具有精度高、效果好等方面的优越性,进一步证明了多项式特解法具有较高的精度和良好的稳定性。 展开更多
关键词 高阶椭圆型偏微分方程 特征值:多项式特解法
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多片式离合器局部高温区成因与系统稳定性研究 被引量:1
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作者 赵家昕 马彪 +2 位作者 李和言 陈漫 朱礼安 《北京理工大学学报》 EI CAS CSCD 北大核心 2014年第9期923-928,共6页
离合器在接合过程中常发生热弹性不稳定性,这是导致摩擦副表面出现局部高温区的重要原因.针对车辆换挡机构用多片式离合器,采用伽辽金法建立了离合器摩滑过程三维有限元分析模型,将温度场扰动变化问题转化为矩阵特征值问题,求解并通过... 离合器在接合过程中常发生热弹性不稳定性,这是导致摩擦副表面出现局部高温区的重要原因.针对车辆换挡机构用多片式离合器,采用伽辽金法建立了离合器摩滑过程三维有限元分析模型,将温度场扰动变化问题转化为矩阵特征值问题,求解并通过试验验证了系统发生TEI时的临界速度、摩擦界面温度扰动增长率和温度场分布的相互关系.研究表明,当离合器转速超过临界速度时,1s内温度波动由3%上升到35%,对偶钢片表面沿圆周方向出现局部高温区,符合离合器实际使用过程中出现的表面热斑和烧损痕迹.离合器对偶片及摩擦衬片厚度、半径、内外径比、摩擦材料的导热系数及弹性模量均对离合器热弹性不稳定性均有重要影响,摩擦材料热膨胀系数影响较小. 展开更多
关键词 多片式离合器 热弹性不稳定性 伽辽金法 特征值解法
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ROBUST ACOUSTIC SOURCE LOCALIZATION FOR DIGITAL HEARING AIDS IN NOISE AND REVERBERANT ENVIRONMENT 被引量:1
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作者 赵立业 李宏生 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2010年第2期176-182,共7页
A new method in digital hearing aids to adaptively localize the speech source in noise and reverberant environment is proposed. Based on the room reverberant model and the multichannel adaptive eigenvalue decompositi... A new method in digital hearing aids to adaptively localize the speech source in noise and reverberant environment is proposed. Based on the room reverberant model and the multichannel adaptive eigenvalue decomposition (MCAED) algorithm, the proposed method can iteratively estimate impulse response coefficients between the speech source and microphones by the adaptive subgradient projection method. Then, it acquires the time delays of microphone pairs, and calculates the source position by the geometric method. Compared with the traditional normal least mean square (NLMS) algorithm, the adaptive subgradient projection method achieves faster and more accurate convergence in a low signal-to-noise ratio (SNR) environment. Simulations for glasses digital hearing aids with four-component square array demonstrate the robust performance of the proposed method. 展开更多
关键词 hearing aids acoustic source localization multichannel adaptive eigenvalue decomposition (MCAED) algorithms adaptive subgradient projection method
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Joint eigenvalue estimation by balanced simultaneous Schur decomposition
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作者 付佗 高西奇 《Journal of Southeast University(English Edition)》 EI CAS 2006年第4期445-450,共6页
The problem of joint eigenvalue estimation for the non-defective commuting set of matrices A is addressed. A procedure revealing the joint eigenstructure by simultaneous diagonalization of. A with simultaneous Schur d... The problem of joint eigenvalue estimation for the non-defective commuting set of matrices A is addressed. A procedure revealing the joint eigenstructure by simultaneous diagonalization of. A with simultaneous Schur decomposition (SSD) and balance procedure alternately is proposed for performance considerations and also for overcoming the convergence difficulties of previous methods based only on simultaneous Schur form and unitary transformations, it is shown that the SSD procedure can be well incorporated with the balancing algorithm in a pingpong manner, i. e., each optimizes a cost function and at the same time serves as an acceleration procedure for the other. Under mild assumptions, the convergence of the two cost functions alternately optimized, i. e., the norm of A and the norm of the left-lower part of A is proved. Numerical experiments are conducted in a multi-dimensional harmonic retrieval application and suggest that the presented method converges considerably faster than the methods based on only unitary transformation for matrices which are not near to normality. 展开更多
关键词 direction of arrival multi-dimensional harmonic retrieval joint eigenvalue simultaneous Schur decomposition balance algorithm
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Wavelet matrix transform for time-series similarity measurement 被引量:2
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作者 胡志坤 徐飞 +1 位作者 桂卫华 阳春华 《Journal of Central South University》 SCIE EI CAS 2009年第5期802-806,共5页
A time-series similarity measurement method based on wavelet and matrix transform was proposed,and its anti-noise ability,sensitivity and accuracy were discussed. The time-series sequences were compressed into wavelet... A time-series similarity measurement method based on wavelet and matrix transform was proposed,and its anti-noise ability,sensitivity and accuracy were discussed. The time-series sequences were compressed into wavelet subspace,and sample feature vector and orthogonal basics of sample time-series sequences were obtained by K-L transform. Then the inner product transform was carried out to project analyzed time-series sequence into orthogonal basics to gain analyzed feature vectors. The similarity was calculated between sample feature vector and analyzed feature vector by the Euclid distance. Taking fault wave of power electronic devices for example,the experimental results show that the proposed method has low dimension of feature vector,the anti-noise ability of proposed method is 30 times as large as that of plain wavelet method,the sensitivity of proposed method is 1/3 as large as that of plain wavelet method,and the accuracy of proposed method is higher than that of the wavelet singular value decomposition method. The proposed method can be applied in similarity matching and indexing for lager time series databases. 展开更多
关键词 wavelet transform singular value decomposition inner product transform time-series similarity
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Decomposition of Soliton Hierarchy Associated with a Schrodinger Type Spectral Problem
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作者 XING Xiu-zhi WU Jing-zhu GENG Xian-guo 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2008年第3期453-457,共5页
The soliton hierarchy associated with a Schrodinger type spectral problem with four potentials is decomposed into a class of new finite-dimensional Hamiltonian systems by using the nonlinearized approach. It is worth ... The soliton hierarchy associated with a Schrodinger type spectral problem with four potentials is decomposed into a class of new finite-dimensional Hamiltonian systems by using the nonlinearized approach. It is worth to point that the solutions for the soliton hierarchy are reduced to solving the compatible Hamiltonian systems of ordinary differential equations. 展开更多
关键词 soliton hierarchy spectral problem Hamiltonian system
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Pseudo-invariant Eigen-Operator Method for Solving Field-Intensity-Dependent Jaynes-Cummings Model
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作者 俞挞汐 范洪义 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第2期257-260,共4页
By using Gumming (JC) model. energy-level gap of this the pseudo invariant eigen-operator method we The pseudo-invariant eigen-operator is found in JC Hamiltonian is derived. This approach seems analyze the field-in... By using Gumming (JC) model. energy-level gap of this the pseudo invariant eigen-operator method we The pseudo-invariant eigen-operator is found in JC Hamiltonian is derived. This approach seems analyze the field-intensity-dependent Jaynes terms of the supersymmetric generators. The concise. 展开更多
关键词 pseudo-invariant eigen-operator energy-level gap Jaymes-Cummings model
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Accelerating large partial EVD/SVD calculations by filtered block Davidson methods
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作者 ZHOU Yunkai WANG Zheng ZHOU Aihui 《Science China Mathematics》 SCIE CSCD 2016年第8期1635-1662,共28页
Partial eigenvalue decomposition(PEVD) and partial singular value decomposition(PSVD) of large sparse matrices are of fundamental importance in a wide range of applications, including latent semantic indexing, spectra... Partial eigenvalue decomposition(PEVD) and partial singular value decomposition(PSVD) of large sparse matrices are of fundamental importance in a wide range of applications, including latent semantic indexing, spectral clustering, and kernel methods for machine learning. The more challenging problems are when a large number of eigenpairs or singular triplets need to be computed. We develop practical and efficient algorithms for these challenging problems. Our algorithms are based on a filter-accelerated block Davidson method.Two types of filters are utilized, one is Chebyshev polynomial filtering, the other is rational-function filtering by solving linear equations. The former utilizes the fastest growth of the Chebyshev polynomial among same degree polynomials; the latter employs the traditional idea of shift-invert, for which we address the important issue of automatic choice of shifts and propose a practical method for solving the shifted linear equations inside the block Davidson method. Our two filters can efficiently generate high-quality basis vectors to augment the projection subspace at each Davidson iteration step, which allows a restart scheme using an active projection subspace of small dimension. This makes our algorithms memory-economical, thus practical for large PEVD/PSVD calculations. We compare our algorithms with representative methods, including ARPACK, PROPACK, the randomized SVD method, and the limited memory SVD method. Extensive numerical tests on representative datasets demonstrate that, in general, our methods have similar or faster convergence speed in terms of CPU time, while requiring much lower memory comparing with other methods. The much lower memory requirement makes our methods more practical for large-scale PEVD/PSVD computations. 展开更多
关键词 partial EVD/SVD polynomial filter rational filter kernel graph
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Degenerate Nonlinear Elliptic Equations Lacking in Compactness
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作者 Maria MALIN Cristian UDREA 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2016年第1期53-72,共20页
In this paper, the authors prove the existence of solutions for degenerate elliptic equations of the form-div(a(x)▽_p u(x)) = g(λ, x, |u|^(p-2)u) in R^N, where ▽_pu =|▽u|^(p-2)▽u and a(x) is a degenerate nonnegat... In this paper, the authors prove the existence of solutions for degenerate elliptic equations of the form-div(a(x)▽_p u(x)) = g(λ, x, |u|^(p-2)u) in R^N, where ▽_pu =|▽u|^(p-2)▽u and a(x) is a degenerate nonnegative weight. The authors also investigate a related nonlinear eigenvalue problem obtaining an existence result which contains information about the location and multiplicity of eigensolutions. The proofs of the main results are obtained by using the critical point theory in Sobolev weighted spaces combined with a Caffarelli-Kohn-Nirenberg-type inequality and by using a specific minimax method, but without making use of the Palais-Smale condition. 展开更多
关键词 Degenerate equations P-LAPLACIAN Sobolev weighted spaces Mountain-pass theorem
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