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LINEAR CONVERGENCE OF THE LZI ALGORITHM FOR WEAKLY POSITIVE TENSORS 被引量:3
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作者 Liping Zhang Liqun Qi Yi Xu 《Journal of Computational Mathematics》 SCIE CSCD 2012年第1期24-33,共10页
We define weakly positive tensors and study the relations among essentially positive tensors, weakly positive tensors, and primitive tensors. In particular, an explicit linear convergence rate of the Liu-Zhou-Ibrahim... We define weakly positive tensors and study the relations among essentially positive tensors, weakly positive tensors, and primitive tensors. In particular, an explicit linear convergence rate of the Liu-Zhou-Ibrahim(LZI) algorithm for finding the largest eigenvalue of an irreducible nonnegative tensor, is established for weakly positive tensors. Numerical results are given to demonstrate linear convergence of the LZI algorithm for weakly positive tensors. 展开更多
关键词 Irreducible nonnegative tensor weakly positive tensor Largest eigenvalue Linear convergence.
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Some properties of fuzzy positive implicative ideals in a BCK-algebras
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作者 吴从炘 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2001年第2期168-172,共5页
In this paper, we use the notion of fuzzy point to study ideal and positive implicative ideal in BCK algebras, then we clarify the links between the fuzzy point approach, the classical fuzzy approach and the ordinary ... In this paper, we use the notion of fuzzy point to study ideal and positive implicative ideal in BCK algebras, then we clarify the links between the fuzzy point approach, the classical fuzzy approach and the ordinary case. 展开更多
关键词 BCK algebra fuzzy point fuzzy positive implicative ideal positive implicative weak ideal
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Controllability of an underactuated spacecraft with one thruster under disturbance 被引量:6
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作者 Dong-Xia Wang Ying-Hong Jia +2 位作者 Lei Jin Hai-Chao Gui Shi-Jie Xu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第3期838-847,共10页
For an underactuated spacecraft using only one thruster, the attitude controllability with respect to the or- bit frame is studied in the presence of periodical oscillation disturbance, which provides a preconditional... For an underactuated spacecraft using only one thruster, the attitude controllability with respect to the or- bit frame is studied in the presence of periodical oscillation disturbance, which provides a preconditional guide on de- signing control law for underactuated attitude control sys- tem. Firstly, attitude dynamic model was established for an underactuated spacecraft, and attitude motion was described using the special orthogonal group (SO (3)). Secondly, Liou- ville theorem was used to confirm that the flow generated by the drift vector of the underactuated attitude control system is volume-preserving. Furthermore, according to Poincar6's re- currence theorem, we draw conclusions that this drift field is weakly positively poisson stable (WPPS). Thirdly, the suffi- cient and necessary condition of controllability was obtained on the basis of lie algebra rank condition (LARC). Finally, the controllable conditions were analyzed and simulated in different cases of inertia matrix with the installed position of thruster. 展开更多
关键词 Underactuated spacecraft Periodical oscilla-tion disturbance. Controllability. weakly positively poissonstable ~ Lie algebra
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Liouville Type Theorems for Nonlinear p-Laplacian Equation on Complete Noncompact Riemannian Manifolds
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作者 Guangyue HUANG Liang ZHAO 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2023年第3期379-390,共12页
In this paper,the authors study the gradient estimates for positive weak solutions to the following p-Laplacian equation△_(p)u+au^(σ)=0 on complete noncompact Riemannian manifold,where a,σare two nonzero real const... In this paper,the authors study the gradient estimates for positive weak solutions to the following p-Laplacian equation△_(p)u+au^(σ)=0 on complete noncompact Riemannian manifold,where a,σare two nonzero real constants with p≠2.Using the gradient estimate,they can get the corresponding Lionville theorem.On the other hand,by virtue of the Poincare inequality,they also obtain a Liouville theorem under some integral conditions with respect to positive weak solutions. 展开更多
关键词 P-LAPLACIAN Liouville theorem positive weak solution
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A real-time detection and positioning method for small and weak targets using a 1D morphology-based approach in 2D images 被引量:8
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作者 Min-Song Wei Fei Xing Zheng You 《Light(Science & Applications)》 SCIE EI CAS CSCD 2018年第1期1063-1071,共9页
A small and weak target detection method is proposed in this work that outperforms all other methods in terms of real-time capability.It is the first time that two-dimensional(2D)images are processed using only one-di... A small and weak target detection method is proposed in this work that outperforms all other methods in terms of real-time capability.It is the first time that two-dimensional(2D)images are processed using only one-dimensional1D structuring elements in a morphology-based approach,enabling the real-time hardware implementation of the whole image processing method.A parallel image readout and processing structure is introduced to achieve an ultra-low latency time on the order of nanoseconds,and a hyper-frame resolution in the time domain can be achieved by combining the row-by-row structure and the electrical rolling shutter technique.Experimental results suggest that the expected target can be successfully detected under various interferences with an accuracy of 0.1 pixels(1σ)under the worst sky night test condition and that a centroiding precision of better than 0.03 pixels(1σ)can be reached for static tests.The real-time detection method with high robustness and accuracy is attractive for application to all types of real-time small target detection systems,such as medical imaging,infrared surveillance,and target measurement and tracking,where an ultra-high processing speed is required. 展开更多
关键词 high robustness and accuracy 1D morphology-based approach row-by-row structure real-time detection method small and weak target detection and positioning
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Sobolev type embedding and weak solutions with a prescribed singular set 被引量:3
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作者 GUO ZongMing GUAN XiaoHong WAN FangShu 《Science China Mathematics》 SCIE CSCD 2016年第10期1975-1994,共20页
New Sobolev type embeddings for some weighted Banach spaces are established. Using such embeddings and the singular positive radial entire solutions, we construct singular positive weak solutions with a prescribed sin... New Sobolev type embeddings for some weighted Banach spaces are established. Using such embeddings and the singular positive radial entire solutions, we construct singular positive weak solutions with a prescribed singular set for a weighted elliptic equation. Our main results in this paper also provide positive weak solutions with a prescribed singular set to an equation with Hardy potential. 展开更多
关键词 positive weak solutions Sobolev type embeddings weighted elliptic equations prescribed singular sets
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Embeddings of weighted Sobolev spaces and degenerate elliptic problems 被引量:2
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作者 GUO ZongMing MEI LinFeng +1 位作者 WAN FangShu GUAN XiaoHong 《Science China Mathematics》 SCIE CSCD 2017年第8期1399-1418,共20页
New embeddings of some weighted Sobolev spaces with weights a(x)and b(x)are established.The weights a(x)and b(x)can be singular.Some applications of these embeddings to a class of degenerate elliptic problems of the f... New embeddings of some weighted Sobolev spaces with weights a(x)and b(x)are established.The weights a(x)and b(x)can be singular.Some applications of these embeddings to a class of degenerate elliptic problems of the form-div(a(x)?u)=b(x)f(x,u)in?,u=0 on??,where?is a bounded or unbounded domain in RN,N 2,are presented.The main results of this paper also give some generalizations of the well-known Caffarelli-Kohn-Nirenberg inequality. 展开更多
关键词 positive weak solutions Sobolev type embeddings weighted elliptic equations Caffarelli-Kohn- Nirenberg inequality
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Mathematical Analysis of a Chemotaxis-Type Model of Soil Carbon Dynamic
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作者 alaaeddine hammoudi oana iosifescu 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2018年第2期253-280,共28页
The goal of this paper is to study the mathematical properties of a new model of soil carbon dynamics which is a reaction-diffusion system with a chemotactic term, with the aim to account for the formation of soil agg... The goal of this paper is to study the mathematical properties of a new model of soil carbon dynamics which is a reaction-diffusion system with a chemotactic term, with the aim to account for the formation of soil aggregations in the bacterial and microorganism spatial organization(hot spot in soil). This is a spatial and chemotactic version of MOMOS(Modelling Organic changes by Micro-Organisms of Soil), a model recently introduced by M. Pansu and his group. The authors present here two forms of chemotactic terms, first a"classical" one and second a function which prevents the overcrowding of microorganisms.They prove in each case the existence of a nonnegative global solution, and investigate its uniqueness and the existence of a global attractor for all the solutions. 展开更多
关键词 Soil organic carbon dynamics Reaction-Diffusion-Advection system positive weak solutions Periodic weak solutions
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