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A color image encryption scheme based on a 2D coupled chaotic system and diagonal scrambling algorithm
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作者 苏静明 方士辉 +1 位作者 洪炎 温言 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期233-243,共11页
A novel color image encryption scheme is developed to enhance the security of encryption without increasing the complexity. Firstly, the plain color image is decomposed into three grayscale plain images, which are con... A novel color image encryption scheme is developed to enhance the security of encryption without increasing the complexity. Firstly, the plain color image is decomposed into three grayscale plain images, which are converted into the frequency domain coefficient matrices(FDCM) with discrete cosine transform(DCT) operation. After that, a twodimensional(2D) coupled chaotic system is developed and used to generate one group of embedded matrices and another group of encryption matrices, respectively. The embedded matrices are integrated with the FDCM to fulfill the frequency domain encryption, and then the inverse DCT processing is implemented to recover the spatial domain signal. Eventually,under the function of the encryption matrices and the proposed diagonal scrambling algorithm, the final color ciphertext is obtained. The experimental results show that the proposed method can not only ensure efficient encryption but also satisfy various sizes of image encryption. Besides, it has better performance than other similar techniques in statistical feature analysis, such as key space, key sensitivity, anti-differential attack, information entropy, noise attack, etc. 展开更多
关键词 color image encryption discrete cosine transform two-dimensional(2D)coupled chaotic system diagonal scrambling
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Heat Kernel Estimates on Simple Random Walks and On-Diagonal Upper Bounds
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作者 Runquan Zuo Yuxiao Yan +2 位作者 Zishan Zhu Liwen Yao Qihao Han 《Journal of Applied Mathematics and Physics》 2024年第10期3613-3625,共13页
We primarily provide several estimates for the heat kernel defined on the 2-dimensional simple random walk. Additionally, we offer an estimate for the heat kernel on high-dimensional random walks, demonstrating that t... We primarily provide several estimates for the heat kernel defined on the 2-dimensional simple random walk. Additionally, we offer an estimate for the heat kernel on high-dimensional random walks, demonstrating that the heat kernel in higher dimensions converges rapidly. We also compute the constants involved in the estimate for the 1-dimensional heat kernel. Furthermore, we discuss the general case of on-diagonal estimates for the heat kernel. 展开更多
关键词 Heat Kernel Simple Random Walk On-diagonal Estimate
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Criteria Condition for Generalized Diagonally Dominant Matrices 被引量:3
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作者 田素霞 《Chinese Quarterly Journal of Mathematics》 CSCD 2001年第1期102-106,共5页
In this paper, we provide some new necessary and sufficient conditions for generalized diagonally dominant matrices and also obtain some criteria for nongeneralized dominant matrices.
关键词 generalized diagonally dominant matrices Positive diagonal matrix criteria condition
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The Distribution of Eigenvance of Product Diagonal Dominance Matrix 被引量:1
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作者 杨益民 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第3期32-40,共9页
Let DD_0(R)={A∈C^(n×#)||Rea_(ii)Rea_(jj)|≥A_iA_j,i≠j,i,j∈N}.PD_0(R)={A∈C^(n×#)||Rea_(ii)Rea_(kk)|≥A_iA_jA_k,i≠j≠k,i,j,k∈N}. In this paper,we show DD_0(R)PD_0(R),and the conditions under which the nu... Let DD_0(R)={A∈C^(n×#)||Rea_(ii)Rea_(jj)|≥A_iA_j,i≠j,i,j∈N}.PD_0(R)={A∈C^(n×#)||Rea_(ii)Rea_(kk)|≥A_iA_jA_k,i≠j≠k,i,j,k∈N}. In this paper,we show DD_0(R)PD_0(R),and the conditions under which the numbers of eigen vance of A∈PD_0(R)\DD_0(R)are equal to the numbers of a_(ii),i∈N in positive and negative real part respectively.Some couter examples are given which present the condnions can not be omitted. 展开更多
关键词 MATRIX diagonal dominance EIGENVALUE DISTRIBUTION
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Diagonal街区的理念
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作者 熊燕 《山西建筑》 2004年第16期9-10,共2页
介绍了Diagonal街区的理论 ,阐述了Diagonal属于主要大街的一部分 ,指出在Diagonal街区的建筑不仅服务于一个目标 ,而且包含着多样的城市功能和办公空间及住宅 ,组成一个完整的街区。
关键词 diagonal街区 城市功能 办公空间 建筑景观
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Analysis of factors affecting diagonal tension and compression capacity of corner joints in furniture frames fabricated with dovetail key 被引量:2
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作者 Mosayeb Dalvand Ghanbar Ebrahimi +1 位作者 Akbar Rostampour Haftkhani Sadegh Maleki 《Journal of Forestry Research》 SCIE CAS CSCD 2013年第1期155-168,共14页
This study was conducted to analyze the effect of joint type, and numbers and types of dovetail keys on diagonal tension and compression performance of corner joints in a furniture frame. Joint members were cut from w... This study was conducted to analyze the effect of joint type, and numbers and types of dovetail keys on diagonal tension and compression performance of corner joints in a furniture frame. Joint members were cut from white fir lumber. Butted and mitered joints were constructed with one and two dovetail key(s) with butterfly and H shapes. Joints were glued by polyvinyl acetate (PVAc) and cynoacrylate (CA). Compression capacity of joints was higher than diagonal tension. Mitered joints were stronger than butted ones. Butterfly dovetail keys were superior to H shape keys. Double keys performed better than single key. Experimental joints glued with PVAc were stronger than those glued with CA glue and control specimens. In terms of strength, butterfly dovetailed joints were comparable with doweled joints. 展开更多
关键词 diagonal tension diagonal compression dovetail key JOINTS LUMBER
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Diagonally loaded SMI algorithm based on inverse matrix recursion 被引量:7
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作者 Cao Jianshu Wang Xuegang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第1期160-163,共4页
The derivation of a diagonally loaded sample-matrix inversion (LSMI) algorithm on the busis of inverse matrix recursion (i.e.LSMI-IMR algorithm) is conducted by reconstructing the recursive formulation of covarian... The derivation of a diagonally loaded sample-matrix inversion (LSMI) algorithm on the busis of inverse matrix recursion (i.e.LSMI-IMR algorithm) is conducted by reconstructing the recursive formulation of covariance matrix. For the new algorithm, diagonal loading is by setting initial inverse matrix without any addition of computation. In addition, a corresponding improved recursive algorithm is presented, which is low computational complexity. This eliminates the complex multiplications of the scalar coefficient and updating matrix, resulting in significant computational savings. Simulations show that the LSMI-IMR algorithm is valid. 展开更多
关键词 Robust adaptive beamforming Space-time adaptive processing (STAP) diagonal loading Inverse matrix recursion
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GEAR CRACK EARLY DIAGNOSIS USING BISPECTRUM DIAGONAL SLICE 被引量:4
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作者 Li WeihuaZhang GuicaiShi TielinYang ShuziSchool of Mechanical Scienceand Engineering,Huazhong University of Scienceand Technology,Wuhan 430074, China 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2003年第2期193-196,共4页
A study of bispectral analysis in gearbox condition monitoring is presented.The theory of bispectrum and quadratic phase coupling (QPC) is first introduced, and then equationsfor computing bispectrum slices are obtain... A study of bispectral analysis in gearbox condition monitoring is presented.The theory of bispectrum and quadratic phase coupling (QPC) is first introduced, and then equationsfor computing bispectrum slices are obtained. To meet the needs of online monitoring, a simplifiedmethod of computing bispectrum diagonal slice is adopted. Industrial gearbox vibration signalsmeasured from normal and tooth cracked conditions are analyzed using the above method. Experimentsresults indicate that bispectrum can effectively suppress the additive Gaussian noise andchracterize the QPC phenomenon. It is also shown that the 1-D bispectrum diagonal slice can capturethe non-Gaussian and nonlinear feature of gearbox vibration when crack occurred, hence, this methodcan be employed to gearbox real time monitoring and early diagnosis. 展开更多
关键词 condition monitoring gear crack early diagnosis quadratic phase coupling bispectrum diagonal slice
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Adaptive diagonal loaded minimum variance beamforming applied to medical ultrasound imaging 被引量:2
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作者 刘昊霖 张志宏 刘东权 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第5期1826-1832,共7页
In order to enhance the robustness and contrast in the minimum variance(MV) beamformer, adaptive diagonal loading method was proposed. The conventional diagonal loading technique has already been used in the MV beamfo... In order to enhance the robustness and contrast in the minimum variance(MV) beamformer, adaptive diagonal loading method was proposed. The conventional diagonal loading technique has already been used in the MV beamformer, but has the drawback that its level is specified by predefined parameter and without consideration of input-data. To alleviate this problem, the level of diagonal loading was computed appropriately and automatically from the given data by shrinkage method in the proposed adaptive diagonal loaded beamformer. The performance of the proposed beamformer was tested on the simulated point target and cyst phantom was obtained using Field II. In the point target simulation, it is shown that the proposed method has higher lateral resolution than the conventional delay-and-sum beamformer and could be more robust in estimating the amplitude peak than the MV beamformer when acoustic velocity error exists. In the cyst phantom simulation, the proposed beamformer has shown that it achieves an improvement in contrast ratio and without distorting the edges of cyst. 展开更多
关键词 medical ultrasound imaging minimum variance BEAMFORMING diagonal loading delay-and-sum BEAMFORMING CONTRAST ROBUSTNESS
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The theoretical study on diagonal wave interaction with perforated-wall breakwater with rock fill 被引量:2
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作者 LIU Hongjie LIU Yong LI Yucheng 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2009年第6期103-110,共8页
The interaction of diagonal waves with perforated-wall breakwater partially filled with rock fill is studied using the linear potential theory. By means of the matched eigenfunction expansion method, an analytical met... The interaction of diagonal waves with perforated-wall breakwater partially filled with rock fill is studied using the linear potential theory. By means of the matched eigenfunction expansion method, an analytical method is presented to calculate the reflection coefficient and the wave force coefficient of the breakwater. The calculated results of the reflection coefficient for limiting cases are the same to the existing results. The main effect factors of the reflection coefficient and the wave force coefficient are analyzed by numerical examples. With the increasing of thickness of rock fill, the wave force coefficient on the perforated wall generally decreases, while the reflection coefficient increases. With the increasing of the incident angle of the wave, the reflection coefficient of the breakwater first decreases, reaches its minimum, and then increases monotonously. 展开更多
关键词 diagonal wave perforated wall rock fill reflection coefficient wave force
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Online blind source separation based on joint diagonalization 被引量:2
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作者 Li Ronghua Zhou Guoxu Yang Zuyuan Xie Shengli 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第2期229-233,共5页
A new algorithm is proposed for joint diagonalization. With a modified objective function, the new algorithm not only excludes trivial and unbalanced solutions successfully, but is also easily optimized. In addition, ... A new algorithm is proposed for joint diagonalization. With a modified objective function, the new algorithm not only excludes trivial and unbalanced solutions successfully, but is also easily optimized. In addition, with the new objective function, the proposed algorithm can work well in online blind source separation (BSS) for the first time, although this family of algorithms is always thought to be valid only in batch-mode BSS by far. Simulations show that it is a very competitive joint diagonalization algorithm. 展开更多
关键词 blind source separation joint diagonalization nonconvex optimization
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NONNULL DISTRIBUTION OF THE LIKELIHOOD RATIO CRITERION FOR TESTING THE EQUALITY OF DIAGONAL BLOCKS WITH BLOCKWISE INDEPENDENCE 被引量:5
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作者 A. K. Gupta C. C. Chao(Bowling Green State University Bowling Green, OH 43403-0221 C. C. ChaoJacksonville State Univesity Jacksonville, AL 36265) 《Acta Mathematica Scientia》 SCIE CSCD 1994年第2期195-203,共9页
In this paper, the nonnull moments and the distributions of the likelihood ratio criterion for testing the equality of diagonal blocks with blockwise independence under certain alternatives have derived.
关键词 RATIO BLOCKWISE CRITERION diagonal DISTRIBUTION EQUALITY FOR INDEPENDENCE LIKELIHOOD NONNULL
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Tracking multiple targets in MIMO radar via adaptive asymmetric joint diagonalization with deflation 被引量:3
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作者 ZHANG Zhengyan ZHANG Jianyun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第4期731-741,共11页
In view of the low performance of adaptive asymmetric joint diagonalization(AAJD), especially its failure in tracking high maneuvering targets, an adaptive asymmetric joint diagonalization with deflation(AAJDd) al... In view of the low performance of adaptive asymmetric joint diagonalization(AAJD), especially its failure in tracking high maneuvering targets, an adaptive asymmetric joint diagonalization with deflation(AAJDd) algorithm is proposed. The AAJDd algorithm improves performance by estimating the direction of departure(DOD) and direction of arrival(DOA) directly, avoiding the reuse of the previous moment information in the AAJD algorithm.On this basis, the idea of sequential estimation of the principal component is introduced to turn the matrix operation into a constant operation, reducing the amount of computation and speeding up the convergence. Meanwhile, the eigenvalue is obtained, which can be used to estimate the number of targets. Then, the estimation of signal parameters via rotational invariance technique(ESPRIT) algorithm is improved to realize the automatic matching and association of DOD and DOA. The simulation results show that the AAJDd algorithm has higher tracking performance than the AAJD algorithm, especially when the high maneuvering target is tracked. The efficiency of the proposed method is verified. 展开更多
关键词 MIMO radar low complexity angles tracking adaptiveasymmetric joint diagonalization with deflation (AAJDd) high ma-neuvering target
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THE STRESS SUBSPACE OF HYBRID STRESS ELEMENT AND THE DIAGONALIZATION METHOD FOR FLEXIBILITY MATRIX H 被引量:2
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作者 张灿辉 冯伟 黄黔 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2002年第11期1263-1273,共11页
The following is proved: 1) The linear independence of assumed stress modes is the necessary and sufficient condition for the nonsingular flexibility matrix; 2) The equivalent assumed stress modes lead to the identica... The following is proved: 1) The linear independence of assumed stress modes is the necessary and sufficient condition for the nonsingular flexibility matrix; 2) The equivalent assumed stress modes lead to the identical hybrid element. The Hilbert stress subspace of the assumed stress modes is established. So, it is easy to derive the equivalent orthogonal normal stress modes by Schmidt's method. Because of the resulting diagonal flexibility matrix, the identical hybrid element is free from the complex matrix inversion so that the hybrid efficiency, is improved greatly. The numerical examples show that the method is effective. 展开更多
关键词 hybrid stress finite element Hilbert stress subspace diagonalization method for flexibility matrix
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Hybrid reconstruction algorithm for computed tomography based on diagonal total variation 被引量:1
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作者 Lu-Zhen Deng Peng He +3 位作者 Shang-Hai Jiang Mian-Yi Chen Biao Wei Peng Feng 《Nuclear Science and Techniques》 SCIE CAS CSCD 2018年第3期172-180,共9页
Inspired by total variation(TV), this paper represents a new iterative algorithm based on diagonal total variation(DTV) to address the computed tomography image reconstruction problem. To improve the quality of a reco... Inspired by total variation(TV), this paper represents a new iterative algorithm based on diagonal total variation(DTV) to address the computed tomography image reconstruction problem. To improve the quality of a reconstructed image, we used DTV to sparsely represent images when iterative convergence of the reconstructed algorithm with TV-constraint had no effect during the reconstruction process. To investigate our proposed algorithm, the numerical and experimental studies were performed, and rootmean-square error(RMSE) and structure similarity(SSIM)were used to evaluate the reconstructed image quality. The results demonstrated that the proposed method could effectively reduce noise, suppress artifacts, and reconstruct highquality image from incomplete projection data. 展开更多
关键词 COMPUTED TOMOGRAPHY (CT) Sparse-view reconstruction diagonal total variation (DTV) COMPRESSIVE sensing (CS)
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Integration of a field-effect-transistor terahertz detector with a diagonal horn antenna 被引量:1
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作者 Xiang Li Jian-dong Sun +2 位作者 Zhi-peng Zhang V V Popov Hua Qin 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第6期539-542,共4页
Efficient coupling of terahertz electromagnetic wave with the active region in a terahertz detector is required to enhance the optical sensitivity. In this work, we demonstrate direct integration of a field-effect-tra... Efficient coupling of terahertz electromagnetic wave with the active region in a terahertz detector is required to enhance the optical sensitivity. In this work, we demonstrate direct integration of a field-effect-transistor(FET) terahertz detector chip at the waveguide port of a horn antenna. Although the integration without a proper backshot is rather preliminary, the noise-equivalent power is greatly reduced from 2.7 nW/Hz^(1/2) for the bare detector chip to 76 pW/Hz^(1/2) at340 GHz. The enhancement factor of about 30 is confirmed by simulations revealing the effective increase in the energy flux density seen by the detector. The simulation further confirms the frequency response of the horn antenna and the onchip antennas. A design with the detector chip fully embedded within a waveguide cavity could be made to further enhance the coupling efficiency. 展开更多
关键词 terahertz detector high electron mobility transistor diagonal horn
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Chaotic diagonal recurrent neural network 被引量:1
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作者 王兴元 张诣 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第3期520-524,共5页
We propose a novel neural network based on a diagonal recurrent neural network and chaos, and its structure and learning algorithm are designed. The multilayer feedforward neural network, diagonal recurrent neural net... We propose a novel neural network based on a diagonal recurrent neural network and chaos, and its structure and learning algorithm are designed. The multilayer feedforward neural network, diagonal recurrent neural network, and chaotic diagonal recurrent neural network are used to approach the cubic symmetry map. The simulation results show that the approximation capability of the chaotic diagonal recurrent neural network is better than the other two neural networks. 展开更多
关键词 diagonal recurrent neural network CHAOS cubic symmetry map
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NONLINEAR BENDING THEORY OF DIAGONAL SQUARE PYRAMID RETICULATED SHALLOW SHELLS 被引量:1
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作者 XIAO Tan(肖潭) +1 位作者 LIU Ren-huai(刘人怀) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2001年第7期747-755,共9页
Double-deck reticulated shells are a main form of large space structures. One of the shells is the diagonal square pyramid reticulated shallow shell, whose its upper and lower faces bear most of the load but its core ... Double-deck reticulated shells are a main form of large space structures. One of the shells is the diagonal square pyramid reticulated shallow shell, whose its upper and lower faces bear most of the load but its core is comparatively flexible. According to its geometrical and mechanical characteristics, the diagonal square pyramid reticulated shallow shell is treated as a shallow sandwich shell on the basis of three basic assumptions. Its constitutive relations are analyzed from the point of view of energy and internal force equivalence. Basic equations of the geometrically nonlinear bending theory of the diagonal square pyramid reticulated shallow shell are established by means of the virtual work principle. 展开更多
关键词 diagonal square pyramid reticulated shallow shell sandwich shell NONLINEARITY
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Entropy Number of Diagonal Operator 被引量:1
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作者 Jin Chen Wenjing Lu +2 位作者 Hanyue Xiao Yanan Wang Xin Tan 《Journal of Applied Mathematics and Physics》 2019年第3期738-745,共8页
In this paper, the entropy number of diagonal operator is discussed. On the one hand, the order of entropy number of the finite dimensional diagonal operator Dm:? (1&#8804;q&#60;p&#8804;&#8734;) is est... In this paper, the entropy number of diagonal operator is discussed. On the one hand, the order of entropy number of the finite dimensional diagonal operator Dm:? (1&#8804;q&#60;p&#8804;&#8734;) is estimated. On the other hand, the order of entropy number of a class of in finite dimensional diagonal operator D: lp&#8594;lq(1&#8804;q&#60;p&#8804;&#8734;) is estimated. 展开更多
关键词 ENTROPY NUMBER The Finite DIMENSIONAL diagonal OPERATOR The INFI nite DIMENSIONAL diagonal OPERATOR
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New Criteria for Judging Generalized Strictly Diagonally Dominant Matrix 被引量:1
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作者 ZHANG Jin-song 《Chinese Quarterly Journal of Mathematics》 2015年第2期166-171,共6页
Generalized strictly diagonally dominant matrices play a wide and important role in computational mathematics, mathematical physics, theory of dynamical systems, etc.But it is difficult to judge a matrix is or not gen... Generalized strictly diagonally dominant matrices play a wide and important role in computational mathematics, mathematical physics, theory of dynamical systems, etc.But it is difficult to judge a matrix is or not generalized strictly diagonally dominant matrix.In this paper, by using the properties of α-chain diagonally dominant matrix, we obtain new criteria for judging generalized strictly diagonally dominant matrix, which enlarge the identification range. 展开更多
关键词 generalized strictly diagonally dominant matrix CRITERIA s-chain diagonallydominant matrix
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