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Automatic image enhancement by learning adaptive patch selection

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Frontiers of Information Technology & Electronic Engineering 2019年第2期20卷 206-221页

作者： na LI Jian ZHANG School of Science and Technology Zhejiang International Studies University

Today, digital cameras are widely used in taking photos. However, some photos lack detail and need enhancement. Many existing image enhancement algorithms are patch based and the patch size is always fixed throughout the image. Users must tune the patch size to obtain the appropriate enhancement. In this study,we propose an automatic image enhancement method based on adaptive patch selection using both dark and bright channels. The double channels enhance images with various exposure problems. The patch size used for channel extraction is selected automatically by thresholding a contrast feature, which is learned systematically from a set of natural images crawled from the web. Our proposed method can automatically enhance foggy or under-exposed/backlit images without any user interaction. Experimental results demonstrate that our method can provide a significant improvement in existing patch-based image enhancement algorithms.

关键词： Image enhancement Contrast enhancement Dark channel Bright channel Adaptive patch based processing

Analytical Criteria for Local Activity of CNN with Two-port and Application to Biochemical Model

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 305-314页

作者： Lequan Min na Yu Applied Science School University of Science and Technology BeijingBeijing 100083China

The analytic criteria are presented for the local activity theory in two-port Cellular Neural Network (CNN) cells with three local state variables, and the application to a Biochemical Model CNN (BMCNN) is given for coupling in series of two enzymes whose prototype was studied by Decroly and Goldbeter. The bifurcation diagrams of the BMCNN's show that there does not exist a locally passive domain, and the computer simulation exhibited that convergent patterns, oscillatory patterns or chaotic patterns may emerge if the selected cell parameters are located in locally active unstable domains but nearby the edge of chaos domain. In particular, the coexistence of multiple oscillations was observed in the corresponding triple cell couples of the BMCNN's with the same initial conditions.

关键词： Cellular neural networks

Lateral Flight Stability of Two Hovering Model Insects

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Journal of Bionic Engineering 2014年第3期11卷 439-448页

作者： na Xu Mao Sun Ministry-of-Education Key Laboratory of Fluid Mechanics Beihang University Beijing 100191 P. R. China

The longitudinal disturbance motion of different insects at hovering flight has the same modal structure. Here, we consider the case of lateral motion. The lateral dynamic flight stability of two model insects, hoverfly and honeybee, at hovering flight is studied. The method of computational fluid dynamics is applied to compute the stability derivatives. The techniques of eigenvalue and eigenvector analysis are used to solve the equations of motion. Results show that the lateral disturbance motion of the hoverfly has three natural modes of motion： an unstable divergence mode, a stable oscillatory mode and a stable subsidence mode, and the flight is unstable; while the honeybee has a different modal structure （a stable slow subsidence mode, a stable fast subsidence mode, and a nearly neutrally stable oscillatory mode） and the flight is nearly neutrally stable. The change in modal structure between the two insects is due to their roll-moment/side-velocity derivative having different sign, and the sign difference is because that the hoverfly has a relatively small, but the honeybee has a relatively large, distance between the wing roots and the center of mass. Thus, unlike the case of longitudinal motion, for lateral motion, some insects have different modal structures and stability properties from others.

关键词： insect hovering flight dynamic flight stability modal structure

BOUNDS ON AVERAGE CONTROLLED DIRECT EFFECTS WITH AN UNOBSERVED RESPONSE VARIABLE

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Journal of Systems Science & Complexity 2011年第6期24卷 1154-1164页

作者： na SHAN Jianhua GUO Key Laboratory for Applied Statistics of Ministry of Education School of Mathematics and Statistics Northeast Normal University Changchun 130024 China School of Basic Science Changchun University of Technology Changchun 130012 China

This paper considers the problem of estimating the bounds on the average controlled direct effects （ACDEs） of a treatment variable on an unobserved response variable in the presence of unobserved confounders between an intermediate variable and the response variable. When the response variable is observed, Cai, et al.（2008） derived the formulas for the sharp bounds on the ACDEs. When the response variable is unobserved, the authors propose a graphical criterion for selecting variables affected by the response variable to derive the formulas for the bounds on the ACDEs, which is an extension of the result of Kuroki（2005） to ACDEs. The results enable us not only to judge from the graph structure whether the bounds on the ACDEs can be expressed through observed variables when the response variable is unobserved, but also to provide their formulas when the answer is affirmative.

关键词： Average controlled direct effect causal network d-separation

Chaotification of a Continuous Stable Complex Network via Impulsive Control

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Journal of Systems Science & Complexity 2015年第6期28卷 1271-1278页

作者： LIU na GUAN Zhihong School of Electric and Information Engeering Zhengzhou University of Light Industry

A method is proposed to chaotify a class of complex networks via impulsive control, when the orbits of the impulsive systems are confined in a bounded area. Based on computing the largest Lyapunov exponent, theoretical results and algorithmic analysis are given in details. Finally, numerical simulations are presented to illustrate the effectiveness of the method.

关键词： Chaotification complex network impulsive control largest Lyapunov exponent

CRABP1-mediated non-canonical retinoic acid signaling in motor neurons and neural stem cells

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Neural Regeneration Research 2024年第6期19卷 1169-1170页

作者： Li-na Wei Department of Pharmacology University of Minnesota Medical SchoolMinneapolisMNUSA

Retinoic acid(RA),the active metabolite of vitamin A(the retinoids),elicits a wide spectrum of biological activities critical to the development and health of most of the organ systems including the nervous systems(Corcoran et al.,2002).The effects of RA are mediated by two very distinct pathways;the first is manifested in the nucleus by binding to a large family of nuclear RA receptors(RARs)to regulate proper expression of RAtargeted genes.

关键词： canonical spectrum critical

Cooling of hybrid stars with spin down compression

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Research in Astronomy and Astrophysics 2009年第12期9卷 1351-1358页

作者： Miao Kang Xiao-Dong Wang Na.na Pan College of Physics and Electronics Henan University Kaifeng 475004 China College of Mathematics and Physics Chongqing University of Posts and TelecommunicationsChongqing 400065 China

We study the cooling of hybrid stars coupled with spin-down. Due to the spindown of hybrid stars, the interior density continuously increases and different neutrino reactions may be triggered （from the modified Urca process to the quark and nucleon direct Urca process） at different stages of evolution. We calculate the rate of neutrino emissivity of different reactions and simulate the cooling curves of the rotational hybrid stars. The results show that the cooling curves of hybrid stars clearly depend on a magnetic field if the direct Urca reactions occur during the spin-down. Comparing the results of the rotational star model with the transitional static model, we find the cooling behavior of the rotational model is more complicated; the temperature of the star is higher, especially when direct Urca reactions appear in the process of rotation. Then, we find that the predicted temperatures of some rotating hybrid stars are compatible with the pulsar＇s data which are in contradiction with the results of the transitional method.

关键词： dense matter -- stars: rotation -- equation of state

Conditional Symmetries and Solutions to a Class of Nonlinear Diffusion-Convection Equations

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Communications in Theoretical Physics 2006年第4X期46卷 668-674页

作者： JI Li-na Center for Nonlinear Studies Northwest University Xi'an 710069 China Department of Mathematics Northwest University Xi'an 710069 China Information and Management Science College Henan Agricultural University Zhengzhou 450002 China

The present paper discusses a class of nonlinear diffusion-convection equations with source. The method that we use is the conditional symmetry method. It is shown that the equation admits certain conditional symmetri... 详细信息

关键词： symmetry nonlinear diffusion-convection equation conditional symmetry exact solution

Entire Solution of the Degenerate Fisher Equation

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Acta Mathematicae Applicatae Sinica 2017年第1期33卷 75-82页

作者： Li-na WANG School of Science Beijing Technology and Business University Beijing 100048 China

This paper deals with the solutions defined for all time of the degenerate Fisher equation. Some solutions are obtained by considering two traveling fronts with critical speed that come from both sides of the X-axis and mix. Unfortunately, the entire solutions which behave as two opposite wave fronts with non-critical speed approaching each other from both sides of the X-axis can not be obtained, because the essential difficulty originates from the algebraic decay rate of the fronts with non-critical speed.

关键词： entire solution degenerate Fisher traveling front