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Search Results: 1 - 10 of 78247 matches for " Xuegang Chen "
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A Variational Model for Removing Multiple Multiplicative Noises  [PDF]
Xuegang Hu, Yan Hu
Open Journal of Applied Sciences (OJAppS) , 2015, DOI: 10.4236/ojapps.2015.512075
Abstract: The problem of multiplicative noise removal has been widely studied in recent years. Many methods have been used to remove it, but the final results are not very excellent. The total variation regularization method to solve the problem of the noise removal can preserve edge well, but sometimes produces undesirable staircasing effect. In this paper, we propose a variational model to remove multiplicative noise. An alternative algorithm is employed to solve variational model minimization problem. Experimental results show that the proposed model can not only effectively remove Gamma noise, but also Rayleigh noise, as well as the staircasing effect is significantly reduced.
An Improved Moving Object Detection Algorithm Based on Gaussian Mixture Models  [PDF]
Xuegang Hu, Jiamin Zheng
Open Journal of Applied Sciences (OJAppS) , 2016, DOI: 10.4236/ojapps.2016.67045
Abstract: Aiming at the problems that the classical Gaussian mixture model is unable to detect the complete moving object, and is sensitive to the light mutation scenes and so on, an improved algorithm is proposed for moving object detection based on Gaussian mixture model and three-frame difference method. In the process of extracting the moving region, the improved three-frame difference method uses the dynamic segmentation threshold and edge detection technology, and it is first used to solve the problems such as the illumination mutation and the discontinuity of the target edge. Then, a new adaptive selection strategy of the number of Gaussian distributions is introduced to reduce the processing time and improve accuracy of detection. Finally, HSV color space is used to remove shadow regions, and the whole moving object is detected. Experimental results show that the proposed algorithm can detect moving objects in various situations effectively.
The Stability and Numerical Dispersion Study of the ADI-SFDTD Algorithm
Zongxin Liu,Yiwang Chen,Xin Xu,Xuegang Sun
Modern Applied Science , 2011, DOI: 10.5539/mas.v5n6p157
Abstract: In this letter, the alternating-direction-implicit (ADI) technique is applied to Symplectic finite-difference time-domain (SFDTD) method, the curl operator is endued with two different styles when doing computation from the th progression to th progression. It holds the advantages of both ADI-FDTD and SFDTD, not only eliminating the restriction of the Courant-Friedrich-Levy (CFL), but also holding the inner characteristics of Maxwell’s equations. The analytical accuracy and efficiency of the proposed method is verified good.
The Analysis of the Synthetic Range Profile Based on Doppler Filter Bank using FFT
Wei Peng,Xuegang Wang,Kesong Chen,Bin Tang
Information Technology Journal , 2009,
Abstract: A wideband imaging architecture based on subbanding and Doppler filter bank using FFT is developed and its performance is analyzed in detail. The theoretical analysis shows that owing to Doppler dispersion, the target’s range profile will produce distortion with the increase in target velocity. The distortion includes range shift and amplitude deformation. At the same time, two related theoretical formulas are deduced for the calculation of the range shift value and evaluation of the amplitude deformation extent of a moving target's range profile formed by the proposed imaging architecture and thereby the maximum critical velocity is derived. When target velocity is less than the maximum critical velocity, a moving target’s range profile with acceptable distortion can be obtained. Specific conclusions are verified with some simulations.
Geometric Correlation between Dirac Equation and Yang-mills Equation/ Maxwell Equation
Xuegang Yu
Physics , 2011,
Abstract: The problem about geometric correspondence of Dirac particle and contain quality item of Yang-Mills equation has always not been solved.This paper introduced the hyperbolic imaginary unit in Minkowski space, established a classes of Dirac wave equations with t'Hooft matrices.In lightlike region of Minkowski space,we can discuss the hermitian conjugate transformation of Dirac positive particle and antiparticle, find the space-time corresponding points of Dirac particle,and draw Feynman clip-art though the geometrical relation between timelike region and lightlike region.The coupling of motion equation of Dirac positive particle and antiparticle can get Klein-Gordon equation, when it reach classical approximate we can get Schrodinger equation,and this illustrated that p meson or m meson may be composite particle. Using the relation of timelike region and lightlike region in Minkowski momentum space to renormalize the rest mass of particles,we can describe the geometric relation between rest mass and electromagnetic mass of particles. Then, we can elicit the Yang-Mills equation with electromagnetic mass through four Dirac wave equations with the hermitian conjugate transformation relation, and further launch the common forms of Maxwell equations.
Paired-domination Number in Cubic Graphs
立方图的对控制数

Chen Xuegang,Sun Liang,Xing Huaming,
陈学刚
,孙良,邢化明

数学物理学报(A辑) , 2007,
Abstract: 设G=(V,E)是一个简单图,对任意的顶点子集合S■V,GS]表示图G中由S所导出的子图.如果S是G的一个控制集并且GS]包含至少一个完备匹配,则称S是G的一个对控制集.G中对控制集的最少的顶点数称为G的对控制数,记为γp(G).该文证明了对任意有n点的连通立方图G,γp(G)≤(3n)/5.
Tanshinol Attenuates the Deleterious Effects of Oxidative Stress on Osteoblastic Differentiation via Wnt/FoxO3a Signaling
Yajun Yang,Yanjie Su,Dongtao Wang,Yahui Chen,Tie Wu,Gang Li,Xuegang Sun,Liao Cui
Oxidative Medicine and Cellular Longevity , 2013, DOI: 10.1155/2013/351895
Abstract: There is now increasing evidence which suggests a pivotal role for oxidative stress in the development and progression of osteoporosis. We confirm herein the protective effects of natural antioxidant Tanshinol against oxidative stress in osteoblastic differentiation and the underlying mechanism. Our results show that hydrogen peroxide (H2O2) leads to accumulation of reactive oxygen species (ROS), decrease in cell viability, cell cycle arrest and apoptosis in a caspase-3-dependent manner, and inhibition of osteoblastic differentiation. Tanshinol reverses these deleterious consequence triggered by oxidative stress. Moreover, under the condition of oxidative stress, Tanshinol suppresses the activation of FoxO3a transcription factor and expressions of its target genes Gadd45a and catalase (CAT) and simultaneously counteracts the inhibition of Wnt signalling and expressions of target genes Axin2, alkaline phosphatase (ALP), and Osteoprotegerin (OPG). The findings are further consolidated using FoxO3a siRNA interference and overexpression of Tcf4. The results illustrate that Tanshinol attenuates oxidative stress via down-regulation of FoxO3a signaling, and rescues the decrease of osteoblastic differentiation through upregulation of Wnt signal under oxidative stress. The present findings suggest that the beneficial effects of Tanshinol may be adopted as a novel therapeutic approach in recently recognized conditions of niche targeting osteoporosis. 1. Introduction Extensive evidence indicates that “oxidative stress” theory has currently been proposed as a new intensive mechanism that the development and progression of osteoporosis are in connection with an increase of oxidative stress, which leads to degenerative disease of bone tissue [1, 2]. Understanding of oxidative stress is currently a substantial topic of investigation with the aim of developing new ways to diminish negative effects of oxidative damage on bone metabolism [3]. Starting in their mid-40s, both genders experience a progressive decrease in bone mass and bone quality [2], associated with aging [4], some illnesses, or use of medications, such as diabetes or excessive exposure to glucocorticoids [5–7]. Notwithstanding, as for the evidence for physiological levels of reactive oxygen species (ROS) helpful in sustaining cellular function [8], it is generally believed that excessive accumulation of ROS causes oxidative stress and destroys proteins, lipids, and DNA, consequentially leading to cell death [9]. Based on current understanding of the cellular events of bone formation phase in the process
Effect of atmospheric environment on the attenuation coefficient of light in water
Juan Liu,Jiulin Shi,Yijun Tang,Kaixing Zhu,Yuan Ge,Xuegang Chen,Xingdao He,Dahe Liu
Physics , 2014,
Abstract: The attenuation coefficient of 532 nm light in water under different atmospheric conditions was investigated. Measurements were made over a two-year period at the same location and show that the attenuation coefficient is significantly influenced by the atmospheric environment. It is lowest when the atmospheric pressure is high and temperature is low, and is highest when the atmospheric pressure is low and temperature is high. The maximum attenuation coefficient of pure water in these studies was about three times the minimum value. The mechanism of the phenomena is discussed. These results are also important in underwater acoustics.
Towards Effective Bus Lane Monitoring Using Camera Sensors  [PDF]
Xu Li, Xuegang Yu, Ke He
Wireless Sensor Network (WSN) , 2011, DOI: 10.4236/wsn.2011.35020
Abstract: City administrators need to guarantee bus priority in urban public transportation. Building large-scale dedicated bus lanes is a cost-effective solution but it suffers from illegal utilization of dedicated bus lines by other non-permitted vehicles. In general, two systems can be utilized for bus lane monitoring: road-side system and bus mounted system. Although the former one has the advantage in terms of larger surveillance coverage, the investment cost makes it less feasible because of scalability issue. In this paper, we focus on bus mounted system to improve surveillance coverage without additional infrastructure cost. We introduce DoubleChecking, a cooperative violator identification scheme that can accurately pick out those non-permitted vehicles or violators. DoubleChecking is designed to improve the surveillance coverage of bus mounted system by using communications/cooperation between mounted camera sensors and existing camera sensors around intersections. Through theoretical analysis and simulation results, we show that DoubleChecking yields good performance for violator identification.
OPTIMIZING COMBINATION ON OPTICAL IMAGE PARAMETEKS IN IMAGE EVALUATION
象质评价中光学参数的最佳匹配

Zhao Anqing,Li Jianbai,Wei Senquan,Yu Baoling,Chen Xuegang,Wan Xiong,Zhang Xiaolin,
赵安庆
,李剑白

光子学报 , 1995,
Abstract: Some formulae on correlative match of both optical aperture and wave aberrationto determine image quality are derived in the paper. The optimizing match zone on opticalaperture and wave aberration is found theoretically and experimentally,The result is important different from traditional criterion on image quality.
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