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A variation pixels identification method based on kernel spatial attraction model and local entropy for robust endmember extraction
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作者 赵春晖 田明华 +1 位作者 齐滨 王玉磊 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第8期1990-2000,共11页
A variation pixels identification method was proposed aiming at depressing the effect of variation pixels, which dilates the theoretical hyperspectral data simplex and misguides volume evaluation of the simplex. With ... A variation pixels identification method was proposed aiming at depressing the effect of variation pixels, which dilates the theoretical hyperspectral data simplex and misguides volume evaluation of the simplex. With integration of both spatial and spectral information, this method quantitatively defines a variation index for every pixel. The variation index is proportional to pixels local entropy but inversely proportional to pixels kernel spatial attraction. The number of pixels removed was modulated by an artificial threshold factor α. Two real hyperspectral data sets were employed to examine the endmember extraction results. The reconstruction errors of preprocessing data as opposed to the result of original data were compared. The experimental results show that the number of distinct endmembers extracted has increased and the reconstruction error is greatly reduced. 100% is an optional value for the threshold factor α when dealing with no prior knowledge hyperspectral data. 展开更多
关键词 variation pixels hyperspectral SIMPLEX variation index local entropy kernel spatial attraction
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Influence and Local Influence for Explained Variation in Survival Analysis
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作者 Refah Alotaibi 《Journal of Mathematics and System Science》 2014年第8期523-545,共23页
The amount of explained variation R2 is an overall measure used to quantify the information in a model and especially how useful the model might be when predicting future observations, explained variation is useful in... The amount of explained variation R2 is an overall measure used to quantify the information in a model and especially how useful the model might be when predicting future observations, explained variation is useful in guiding model choice for all types of predictive regression models, including linear and generalized linear models and survival analysis. In this work we consider how individual observations in a data set can influence the value of various R2 measures proposed for survival analysis including local influence to assess mathematically the effect of small changes. We discuss methodologies for assessing influence on Graf et al.'s R2G measure, Harrell's C-index and Nagelkerke's R2N. The ideas are illustrated on data on 1391 patients diagnosed with Diffuse Large B-cell Lymphoma (DLBCL), a major subtype ofNon-Hodgkin's Lymphoma (NHL). 展开更多
关键词 INFLUENCE local influence C-index explained variation.
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Systems of generalized vector quasi-variational inclusions and systems of generalized vector quasi-optimization problems in locally FC-uniform spaces
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作者 丁协平 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2009年第3期263-274,共12页
In this paper, we introduce some new systems of generalized vector quasi-variational inclusion problems and system of generalized vector ideal (resp., proper, Pareto, weak) quasi-optimization problems in locally FC-... In this paper, we introduce some new systems of generalized vector quasi-variational inclusion problems and system of generalized vector ideal (resp., proper, Pareto, weak) quasi-optimization problems in locally FC-uniform spaces without convexity structure. By using the KKM type theorem and Himmelberg type fixed point theorem proposed by the author, some new existence theorems of solutions for the systems of generalized vector quasi-variational inclusion problems are proved. As to its applications, we obtain some existence results of solutions for systems of generalized vector quasi-optimization problems. 展开更多
关键词 KKM type theorem Himmelberg type fixed point theorem system of generalized vector quasi-variational inclusions system of generalized vector optimization problems locally FC-uniform space
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NEW SIMPLE SMOOTH MERIT FUNCTION FOR BOX CONSTRAINED VARIATIONAL INEQUALITIES AND DAMPED NEWTON TYPE METHOD 被引量:3
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作者 乌力吉 陈国庆 《应用数学和力学》 EI CSCD 北大核心 2005年第8期988-996,共9页
By introducing a smooth merit function for the median function, a new smooth merit function for box constrained variational inequalities (BVIs) was constructed. The function is simple and has some good differential pr... By introducing a smooth merit function for the median function, a new smooth merit function for box constrained variational inequalities (BVIs) was constructed. The function is simple and has some good differential properties. A damped Newton type method was presented based on it.Global and local superlinear/quadratic convergence results were obtained under mild conditions, and the finite termination property was also shown for the linear BVIs. Numerical results suggest that the method is efficient and promising. 展开更多
关键词 箱约束变分不等式 全局收敛 超线性收敛 有限步收敛
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NEW SIMPLE SMOOTH MERIT FUNCTION FOR BOX CONSTRAINED VARIATIONAL INEQUALITIES AND DAMPED NEWTON TYPE METHOD 被引量:2
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作者 Ulji(乌力吉) CHEN Guo-qing(陈国庆) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第8期1083-1092,共10页
By introducing a smooth merit function for the median function, a new smooth merit function for box constrained variational inequalities (BVIs) was constructed. The function is simple and has some good differential ... By introducing a smooth merit function for the median function, a new smooth merit function for box constrained variational inequalities (BVIs) was constructed. The function is simple and has some good differential properties. A damped Newton type method was presented based on it. Global and local superlinear/ quadratic convergence results were obtained under mild conditions, and the finite termination property was also shown for the linear BVIs. Numerical results suggest that the method is efficient and promising. 展开更多
关键词 box constrained variational inequalities global convergence local superlinear or quadratic convergence finite termination property
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GURTIN-TYPE VARIATIONAL PRINCIPLES FOR DYNAMICS OF A NON-LOCAL THERMAL EQUILIBRIUM SATURATED POROUS MEDIUM 被引量:22
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作者 YangXiao 《Acta Mechanica Solida Sinica》 SCIE EI 2005年第1期37-45,共9页
Based on the porous media theory and by taking into account the efects of the pore fuid viscidity, energy exchanges due to the additional thermal conduction and convection between solid and fuid phases, a mathematical... Based on the porous media theory and by taking into account the efects of the pore fuid viscidity, energy exchanges due to the additional thermal conduction and convection between solid and fuid phases, a mathematical model for the dynamic-thermo-hydro-mechanical coupling of a non-local thermal equilibrium fuid-saturated porous medium, in which the two constituents are assumed to be incompressible and immiscible, is established under the assumption of small de- formation of the solid phase, small velocity of the fuid phase and small temperature changes of the two constituents. The mathematical model of a local thermal equilibrium fuid-saturated porous medium can be obtained directly from the above one. Several Gurtin-type variational principles, especially Hu-Washizu type variational principles, for the initial boundary value problems of dy- namic and quasi-static responses are presented. It should be pointed out that these variational principles can be degenerated easily into the case of isothermal incompressible fuid-saturated elastic porous media, which have been discussed previously. 展开更多
关键词 non-local thermal equilibrium thermal-mechanical coupling mathematical model variational principle porous media theory
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Variational Approach for the Adapted Solution of Backw ard Stochastic Differential Equations with Locally Lipschitz Diffusion Coefficients 被引量:1
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作者 谢臻赟 刘奕 《Journal of Donghua University(English Edition)》 EI CAS 2012年第4期341-350,共10页
One existence integral condition was obtained for the adapted solution of the general backward stochastic differential equations(BSDEs). Then by solving the integral constraint condition, and using a limit procedure, ... One existence integral condition was obtained for the adapted solution of the general backward stochastic differential equations(BSDEs). Then by solving the integral constraint condition, and using a limit procedure, a new approach method is proposed and the existence of the solution was proved for the BSDEs if the diffusion coefficients satisfy the locally Lipschitz condition. In the special case the solution was a Brownian bridge. The uniqueness is also considered in the meaning of "F0-integrable equivalent class" . The new approach method would give us an efficient way to control the main object instead of the "noise". 展开更多
关键词 backward stochastic differential equation (BSDE) variational approach locally Lipschitz condition EXISTENCE Fointegrable equivalent class UNIQUENESS Brownian bridge
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Robust SLAM localization method based on improved variational Bayesian filtering 被引量:1
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作者 Zhai Hongqi Wang Lihui +1 位作者 Cai Tijing Meng Qian 《Journal of Southeast University(English Edition)》 EI CAS 2022年第4期340-349,共10页
Aimed at the problem that the state estimation in the measurement update of the simultaneous localization and mapping(SLAM)method is incorrect or even not convergent because of the non-Gaussian measurement noise,outli... Aimed at the problem that the state estimation in the measurement update of the simultaneous localization and mapping(SLAM)method is incorrect or even not convergent because of the non-Gaussian measurement noise,outliers,or unknown and time-varying noise statistical characteristics,a robust SLAM method based on the improved variational Bayesian adaptive Kalman filtering(IVBAKF)is proposed.First,the measurement noise covariance is estimated using the variable Bayesian adaptive filtering algorithm.Then,the estimated covariance matrix is robustly processed through the weight function constructed in the form of a reweighted average.Finally,the system updates are iterated multiple times to further gradually correct the state estimation error.Furthermore,to observe features at different depths,a feature measurement model containing depth parameters is constructed.Experimental results show that when the measurement noise does not obey the Gaussian distribution and there are outliers in the measurement information,compared with the variational Bayesian adaptive SLAM method,the positioning accuracy of the proposed method is improved by 17.23%,20.46%,and 17.76%,which has better applicability and robustness to environmental disturbance. 展开更多
关键词 underwater navigation and positioning non-Gaussian distribution time-varying noise variational Bayesian method simultaneous localization and mapping(SLAM)
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Integrating host biological and ecological variables to predict probability of haemosporidian infection in raptors
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作者 Kai Gao Xuemei Yang +1 位作者 Xi Huang Wenhong Deng 《Avian Research》 SCIE CSCD 2024年第2期255-264,共10页
Variations in host traits that influence their exposure and susceptibility may impact probability of vector-transmitted diseases.Therefore,identifying the predictors of infection probability is necessary to understand... Variations in host traits that influence their exposure and susceptibility may impact probability of vector-transmitted diseases.Therefore,identifying the predictors of infection probability is necessary to understand the risk of disease outbreaks during expanding environmental perturbation.Here,we conducted a large survey based on microscopic examination and molecular analysis of haemosporidian parasite infection in raptors rescued at the Beijing Raptor Rescue Centre.Combining these data with biological and ecological variables of the raptors,we determined predictors that affect the probability of haemosporidian infection using generalized linear mixed models and multimodel inference.Our results showed that infection probability exhibited considerable variation across host species in raptors,and body mass,sex,and evolutionary history played relatively weaker roles in driving infection probability.Instead,activity pattern,age,geographic range size,migration distance,and nest type were important predictors of the probability of haemosporidian infection,and the role of each predictor differed in the three main haemosporidian genera(Plasmodium,Haemoproteus,and Leucocytozoon).This macro-ecological analysis will add to our understanding of host traits that influence the probability of avian haemosporidian infection and will help inform risk of emerging diseases. 展开更多
关键词 Activity pattern Emerging infectious diseases Infection probability Interspecific variation migratory exposure
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A note on localized transition in the spin-boson model by variational calculation
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作者 陈芝得 侯志兰 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第7期2701-2706,共6页
We present mathematical analyses of the evolution of solutions of the self-consistent equation derived from variational calculations based on the displaced-oscillator-state and the displaced-squeezed-state in spin-bos... We present mathematical analyses of the evolution of solutions of the self-consistent equation derived from variational calculations based on the displaced-oscillator-state and the displaced-squeezed-state in spin-boson model at a zero temperature and a finite temperature. It is shown that, for a given spectral function defined as J(w) = π∑k Ck^2 = π/2αw^8w^1-s, there exists a universal sc for both kinds of variational schemes, the localized transition happens only for 2 s ≤ sc, moreover, the localized transition is discontinuous for s 〈 sc while a continuous transition always occurs when s = sc. At T = 0, we have sc = 1, while for T ≠ 0, sc = 2 which indicates that the localized transition in super-Ohmic case still exists, manifesting that the result is in discrepancy with the existing result. 展开更多
关键词 spin-boson model localized transition variational calculation
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Generalized Bi quasi variational Inequalities in Locally Convex Topological Vector Spaces
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作者 曾六川 《Chinese Quarterly Journal of Mathematics》 CSCD 1999年第3期43-53, ,共11页
In this paper we investigate generalized bi quasi variational inequalities in locally convex topological vector spaces. Motivated and inspired by the recent research work in this field,we establish several existence t... In this paper we investigate generalized bi quasi variational inequalities in locally convex topological vector spaces. Motivated and inspired by the recent research work in this field,we establish several existence theorems of solutions for generalized bi quasi variational inequalities,which are the extension and improvements of the earlier and recent results obtained previously by many authors including Sun and Ding [18],Chang and Zhang [23] and Zhang [24]. 展开更多
关键词 generalized bi quasi variational inequality locally convex topological vector space bilinear functional
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Study on noise in simultaneous geomagnetic difference data caused by the effect of S_q local-time variation
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作者 任熙宪 《Acta Seismologica Sinica(English Edition)》 CSCD 2006年第1期87-92,共6页
A new concept is suggested on tectonomagnetic research about the noise in simultaneous geomagnetic difference data caused by the effect of Sq local-time variation, together with the method of theoretical calculation. ... A new concept is suggested on tectonomagnetic research about the noise in simultaneous geomagnetic difference data caused by the effect of Sq local-time variation, together with the method of theoretical calculation. The level of the noise and its contribution to the total noises of the differences data are analyzed. The result indicates that the noise increases linearly with the increase of the distance between the two stations in the range of 40° longitude-difference, and its increasing rate is about 0.4 nT/(°)at latitude 40°N. The example calculated at a pair of sites with longitude-difference 0.357°, shows that the noise is about one fifth of the total noises of the difference data on geomagnetic quiet-day. 展开更多
关键词 solar-quiet-day variation Sq local-time variation same latitude simultaneous difference data noise
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A Local Reference Frame Construction Method Based on the Signed Surface Variation
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作者 Xiaopeng YAN Wei ZHOU +3 位作者 Rencan PENG Wenliang PAN Lei WANG Guoxin HU 《Journal of Geodesy and Geoinformation Science》 2021年第3期25-37,共13页
A fast local reference frame(LRF)construction method based on the signed surface variation is proposed,which can adapt to the real-time applications such as self-driving,face recognition,object detection.The z-axis of... A fast local reference frame(LRF)construction method based on the signed surface variation is proposed,which can adapt to the real-time applications such as self-driving,face recognition,object detection.The z-axis of the LRF is generated based on the concavity of the local surface of keypoint.The x-axis is constructed by the weighted vector sum of a set of projection vectors of the local neighborhoods around keypoint.The performance of the proposed LRF is evaluated on six standard datasets and compared with six state-of-the-art LRF construction methods(e.g.,BOARD,FLARE,SHOT,RoPS and TOLDI).Experimental results validate the high repeatability,robustness,universality and time efficiency of our method. 展开更多
关键词 signed surface variation local reference frame point cloud feature extraction
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PARAMETRIC VARIATIONAL PRINCIPLE BASED ELASTIC-PLASTIC ANALYSIS OF COSSERAT CONTINUUM 被引量:2
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作者 Zhang Hongwu Wang Hui Chen Biaosong Xie Zhaoqian 《Acta Mechanica Solida Sinica》 SCIE EI 2007年第1期65-74,共10页
A new algorithm is developed based on the parametric variational principle for elastic-plastic analysis of Cosserat continuum. The governing equations of the classic elastic-plastic problem are regularized by adding r... A new algorithm is developed based on the parametric variational principle for elastic-plastic analysis of Cosserat continuum. The governing equations of the classic elastic-plastic problem are regularized by adding rotational degrees of freedom to the conventional translational degrees of freedom in conventional continuum mechanics. The parametric potential energy princi- ple of the Cosserat theory is developed, from which the finite element formulation of the Cosserat theory and the corresponding parametric quadratic programming model are constructed. Strain localization problems are computed and the mesh independent results are obtained. 展开更多
关键词 Cosserat model parametric variational principle quadratic programming method strain localization
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Elevational Variation in Reproductive Strategy of a Widespread Lizard:High-Elevation Females Lay Fewer but Larger Eggs 被引量:1
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作者 Gideon Gywa DEME Xin HAO +2 位作者 Liang MA Baojun SUN Weiguo DU 《Asian Herpetological Research》 SCIE CSCD 2022年第3期198-204,共7页
Identifying how reproductive strategies such as the trade-off between clutch size versus egg mass vary with elevational gradients is essential for our understanding of life-history evolution.We studied lacertid lizard... Identifying how reproductive strategies such as the trade-off between clutch size versus egg mass vary with elevational gradients is essential for our understanding of life-history evolution.We studied lacertid lizards(Eremias argus)in China,from six populations at different altitudes,to assess elevational variation in reproductive strategy.We found significant between-population variation in maternal body size and clutch mass,but these variations were not explained by elevational differences.However,high-elevation females tended to produce smaller clutches of larger eggs compared with their low-elevation counterparts,demonstrating an elevational change in the trade-off between egg size and number.The egg size-number trade-off is a reproductive strategy that may favor large offspring,better enabling them to survive severe and unpredictable environments found at high elevations. 展开更多
关键词 between-population variation clutch size egg size elevational gradient Eremiasargus local adaptation reproductive output
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Generalized Quasi Variational-Type Inequalities
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作者 Mohammad Kalimuddin Ahmad Salahuddin . 《Applied Mathematics》 2012年第1期56-63,共8页
In this paper, we define the concepts of (η,h)-quasi pseudo-monotone operators on compact set in locally convex Hausdorff topological vector spaces and prove the existence results of solutions for a class of generali... In this paper, we define the concepts of (η,h)-quasi pseudo-monotone operators on compact set in locally convex Hausdorff topological vector spaces and prove the existence results of solutions for a class of generalized quasi variational type inequalities in locally convex Hausdorff topological vector spaces. 展开更多
关键词 GENERALIZED QUASI variationAL Type Inequalities (GQVTI) h)-Quasi Pseudo-Monotone Operator locally Convex HAUSDORFF Topological Vector Spaces Compact Sets BILINEAR Functional Lower SEMICONTINUOUS Upper SEMICONTINUOUS
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Locally Defined Operators and Locally Lipschitz Composition Operators in the Space WBVp(·)([a, b])
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作者 José Atilio Guerrero Odalis Mejía Nelson Merentes 《Advances in Pure Mathematics》 2016年第10期727-744,共18页
We give a neccesary and sufficient condition on a function such that the composition operator (Nemytskij Operator) H defined by acts in the space and satisfies a local Lipschitz condition. And, we prove that ever... We give a neccesary and sufficient condition on a function such that the composition operator (Nemytskij Operator) H defined by acts in the space and satisfies a local Lipschitz condition. And, we prove that every locally defined operator mapping the space of continuous and bounded Wiener p(&#183;)-variation with variable exponent functions into itself is a Nemytskij com-position operator. 展开更多
关键词 Generalized variation p(·)-variation in Wiener’s Sense Variable Exponent CONVERGENCE Helly’s Theorem local Operator
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A Local Binary Pattern-Based Method for Color and Multicomponent Texture Analysis
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作者 Yao Taky Alvarez Kossonou Alain Clément +1 位作者 Bouchta Sahraoui Jérémie Zoueu 《Journal of Signal and Information Processing》 2020年第3期58-73,共16页
Local Binary Patterns (LBPs) have been highly used in texture classification <span style="font-family:Verdana;">for their robustness, their ease of implementation an</span><span style="fo... Local Binary Patterns (LBPs) have been highly used in texture classification <span style="font-family:Verdana;">for their robustness, their ease of implementation an</span><span style="font-family:Verdana;">d their low computational</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">cost. Initially designed to deal with gray level images, several methods based on them in the literature have been proposed for images having more than one spectral band. To achieve it, whether assumption using color information or combining spectral band two by two was done. Those methods use micro </span><span style="font-family:Verdana;">structures as texture features. In this paper, our goal was to design texture features which are relevant to color and multicomponent texture analysi</span><span style="font-family:Verdana;">s withou</span><span style="font-family:Verdana;">t any assumption.</span></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Based on methods designed for gray scale images, we find the combination of micro and macro structures efficient for multispectral texture analysis. The experimentations were carried out on color images from Outex databases and multicomponent images from red blood cells captured using a multispectral microscope equipped with 13 LEDs ranging </span><span style="font-family:Verdana;">from 375 nm to 940 nm. In all achieved experimentations, our propos</span><span style="font-family:Verdana;">al presents the best classification scores compared to common multicomponent LBP methods.</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">99.81%, 100.00%,</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">99.07% and 97.67% are</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">maximum scores obtained with our strategy respectively applied to images subject to rotation, blur, illumination variation and the multicomponent ones.</span> 展开更多
关键词 Multispectral Images local Binary Patterns (LBP) Texture Analysis Rotation Invariance Illumination variation Blurring Invariance
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Existence of Solutions to Generalized Vector Quasi-variational-like Inequalities with Set-valued Mappings
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作者 GAO DA-PENG FENG SHI-QIANG 《Communications in Mathematical Research》 CSCD 2014年第1期90-96,共7页
In this paper, we introduce and study a class of generalized vector quasivariational-like inequality problems, which includes generalized nonlinear vector variational inequality problems, generalized vector variationa... In this paper, we introduce and study a class of generalized vector quasivariational-like inequality problems, which includes generalized nonlinear vector variational inequality problems, generalized vector variational inequality problems and generalized vector variational-like inequality problems as special cases. We use the maximal element theorem with an escaping sequence to prove the existence results of a solution for generalized vector quasi-variational-like inequalities without any monotonicity conditions in the setting of locally convex topological vector space. 展开更多
关键词 generalized vector quasi-variational-like inequality maximal element theorem upper semicontinuous diagonal convexity locally convex topological vector space
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一类耦合Ginzburg-Landau系统的局部极小解
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作者 熊晨 高琦 《数学物理学报(A辑)》 CSCD 北大核心 2023年第2期321-340,共20页
该文考虑耦合Ginzburg-Landau系统整体解中一类特殊的解—局部极小解的相关性质,证明了局部极小解的环绕度一定是n±∈{0,±1}.同时,该文还证明了局部极小解的两个分量中其中一个为零,而另一个不为零,即物理中的少核涡旋现象.
关键词 椭圆方程组 局部极小解 变分法
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