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Application of shifted lattice model to 3D compressible lattice Boltzmann method
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作者 黄好雨 金科 +1 位作者 李凯 郑晓静 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期312-320,共9页
An additional potential energy distribution function is introduced on the basis of previous D3Q25 model,and the equilibrium distribution function of D3Q25 is obtained by spherical function.A novel three-dimensional(3D... An additional potential energy distribution function is introduced on the basis of previous D3Q25 model,and the equilibrium distribution function of D3Q25 is obtained by spherical function.A novel three-dimensional(3D)shifted lattice model is proposed,therefore a shifted lattice model is introduced into D3Q25.Under the finite volume scheme,several typical compressible calculation examples are used to verify whether the numerical stability of the D3Q25 model can be improved by adding the shifted lattice model.The simulation results show that the numerical stability is indeed improved after adding the shifted lattice model. 展开更多
关键词 lattice Boltzmann method shifted lattice model compressible flow finite volume method
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基于改进Theil指数和Shift-Share模型的2012—2021年中国产业偏离分析
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作者 高孝伟 张颖昆 +1 位作者 李华 王苏梦 《资源与产业》 2024年第1期15-24,共10页
文章首先通过对现有文献的梳理和分析,发现针对产业偏离的测算,传统的产业偏离度E系数、Theil指数及Shift-Share模型均存在一定的缺陷,E系数和Theil指数的缺陷主要体现在计算原理方面,而Shift-Share模型的缺陷主要表现在参照系选择的合... 文章首先通过对现有文献的梳理和分析,发现针对产业偏离的测算,传统的产业偏离度E系数、Theil指数及Shift-Share模型均存在一定的缺陷,E系数和Theil指数的缺陷主要体现在计算原理方面,而Shift-Share模型的缺陷主要表现在参照系选择的合理性和数据采集的可行性方面。然后,基于现有模型的基本原理,提出了更为合理和更具可操作性的产业偏离测算方法,再采用实证研究的方法,根据2012—2021年的数据,对中国的产业偏离情况进行具体分析,得出尽管中国存在产业偏离,但产业偏离度在逐渐减小。最后,基于修正模型的计算结果,并结合当前的国际国内环境,提出如下政策建议:1)第一产业要依靠创新和科技引领,促进农村劳动力在城乡间有序转移,实现农业生产的规模化和现代化;2)第二产业要加快产业的升级换代,建立和保持独立、自主、完整的工业体系,加大在基础研究方面的投入,尽早突破美西方的技术封锁;3)第三产业的发展重点应该在金融和科教两个方面,要进一步提升香港地区、上海和北京等城市的世界金融中心地位,依靠金融创新来规避现行国际金融体系的不利约束和影响,同时要将科教兴国战略落到实处,努力探索适合中国国情的从小学到大学各阶段的教育模式。 展开更多
关键词 三次产业 偏离度 THEIL系数 shift-Share模型 产业结构优化
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Discussion on the Impact of“Shift System”Teaching Model of Physical Education on Students’Mental Health
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作者 Lanmin Shang 《Journal of Contemporary Educational Research》 2023年第12期71-76,共6页
The“shift system”teaching model of physical education is an emerging education model that aims to improve students’independent choice and personalized development.However,there are also some challenges in the pract... The“shift system”teaching model of physical education is an emerging education model that aims to improve students’independent choice and personalized development.However,there are also some challenges in the practical application of this model.For example,there are mental health issues for some students including difficulty in adaptation,social interaction,high psychological pressure,etc.Based on this,this article analyzes the impact of the“shift system”teaching model of physical education on students’mental health and explores the optimization path of the physical education“shift system”teaching model in order to promote students’mental health and all-round development. 展开更多
关键词 Physical education shift system”teaching model STUDENTS Mental health IMPACT
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Existence of Forced Waves and Their Asymptotic for Leslie-Gower Prey-Predator Model with Nonlocal Effects under Shifting Environment
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作者 Qingru Guo Hongmei Cheng 《Journal of Applied Mathematics and Physics》 2023年第6期1737-1754,共18页
In this paper, we prove the existence of forced waves for Leslie-Gower prey-predator model with nonlocal effects under shifting environment. By constructing a pair of upper and lower solutions with the method of monot... In this paper, we prove the existence of forced waves for Leslie-Gower prey-predator model with nonlocal effects under shifting environment. By constructing a pair of upper and lower solutions with the method of monotone iteration, we can obtain the existence of forced waves for any positive constant shifting speed. Finally, we show the asymptotical behavior of traveling wave fronts in two tails. 展开更多
关键词 Leslie-Gower Prey-Predator model Nonlocal Effects shifting Environment Forced Waves
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Regime Shifts in the North Pacific Simulated by a COADS-driven Isopycnal Model 被引量:9
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作者 王东晓 王佳 +1 位作者 吴立新 刘征宇 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2003年第5期743-754,共12页
The Miami Isopycnal Coordinate Ocean Model (MICOM) is adopted to simulate the intevdecadal variability in the Pacific Ocean with most emphasis on regime shifts in the North Pacific. The computational domain covers 60&... The Miami Isopycnal Coordinate Ocean Model (MICOM) is adopted to simulate the intevdecadal variability in the Pacific Ocean with most emphasis on regime shifts in the North Pacific. The computational domain covers 60°N to 40°S with an enclosed boundary condition for momentum flux, whereas there are thermohalirie fluxes across the southern end as a restoring term. In addition, sea surface salinity of the model relaxes to the climatological season cycle, which results in climatological fresh water fluxes. Surface forcing functions from January 1945 through December 1998 are derived from the Comprehensive Ocean and Atmospheric Data Set (COADS). Such a numerical experiment reproduces the observed evolution of the interdecadal variability in the heat content over the upper 400-m layer by a two-year lag. Subduction that occurs at the ventilated thermocline in the central North Pacific is also been simulated and the subducted signals propagate from 35°N to 25°N, taking about 8 to 10 years, in agreement with the expendable Bathy Thermograph observation over recent decades. Interdecadal signals take a southwest-ward and downward path rather than westward propagation, meaning they are less associated with the baroclinic planetary waves. During travel, the signals appear to conserve potential vorticity. Therefore, the ventilated thermocline and related subduction are probably the fundamental physics for interdecadal variability in the mid-latitude subtropics of the North Pacific. 展开更多
关键词 North Pacific ventilated thermocline regime shift isopycnal model
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Model update mechanism for mean-shift tracking 被引量:3
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作者 PengNingsong YangJie LiuErqi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第1期52-57,共6页
In order to solve the model update problem in mean-shift based tracker, a novel mechanism is proposed. Kalman filter is employed to update object model by filtering object kernel-histogram using previous model and cur... In order to solve the model update problem in mean-shift based tracker, a novel mechanism is proposed. Kalman filter is employed to update object model by filtering object kernel-histogram using previous model and current candidate. A self-tuning method is used for adaptively adjust all the parameters of the filters under the analysis of the filtering residuals. In addition, hypothesis testing servers as the criterion for determining whether to accept filtering result. Therefore, the tracker has the ability to handle occlusion so as to avoid over-update. The experimental results show that our method can not only keep up with the object appearance and scale changes but also be robust to occlusion. 展开更多
关键词 MEAN-shift TRACKING model update Kalman filter hypothesis testing.
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MODEL SHIFT AND STRANGE ATTRACTOR ON MBIUS STRIP
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作者 陈芳跃 陈凤娟 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2003年第7期845-852,共8页
A new model shift mapping was given in bilateral symbol space. It is topologically conjugate with the traditional shift mapping. Similar to Smale Horseshoe, a model was constructed correspondent to the model shift map... A new model shift mapping was given in bilateral symbol space. It is topologically conjugate with the traditional shift mapping. Similar to Smale Horseshoe, a model was constructed correspondent to the model shift mapping, i.e., a class of mapping on Mbius strip was given. Its attractors' structure and dynamical behaviour were described. 展开更多
关键词 model shift mapping Mbius strip CHAOS strange attractor
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Low-Energy Kπ Phase Shifts in Chiral SU(3) Quark Model
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作者 HUANG Fei ZHANG Zong-Ye YU You-Wen 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第4X期665-669,共5页
The low-energy region kaon-pion S- and P-wave phase shifts with isospin I = 1/2 and I = 3/2 are dynamically studied in the chiral SU(3) quark model by solving a resonating group method equation. The model parameters a... The low-energy region kaon-pion S- and P-wave phase shifts with isospin I = 1/2 and I = 3/2 are dynamically studied in the chiral SU(3) quark model by solving a resonating group method equation. The model parameters are taken to be the values fitted by the energies of the baryon ground states and the kaon-nucleon elastic scattering phase shifts of different partial waves. As a preliminary study the s-channel q(-q) annihilation interactions are not included since they only act in the very short range and are subsequently assumed to be unimportant in the low-energy domain. The numerical results are in qualitative agreement with the experimental data. 展开更多
关键词 Kπ相位转换 手性对称 夸克模型 介子 同位旋 弹性散射
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Correlation of ^1H NMR Chemical Shift for Aqueous Solutions by Statistical Associating Fluid Theory Association Model 被引量:2
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作者 许波 李浩然 +2 位作者 王从敏 许映杰 韩世钧 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2005年第2期280-284,共5页
^1H NMR chemical shifts of binary aqueous mixtures of acylamide, alcohol, dimethyl sulphoxide (DMSO), and acetone are correlated by statistical associating fluid theory (SAFT) association model. The comparison between... ^1H NMR chemical shifts of binary aqueous mixtures of acylamide, alcohol, dimethyl sulphoxide (DMSO), and acetone are correlated by statistical associating fluid theory (SAFT) association model. The comparison between SAFT association model and Wilson equation shows that the former is better for dealing with aqueous solutions. Finally, the specialties of both models are discussed. 展开更多
关键词 核磁共振技术 水溶液 氢键 敏感性 温度 热力学性质
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Solving the Jaynes-Cummings Model with Shift Operators Constructed by Means of the Matrix-Diagonalizing Technique
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作者 周洁 苏洪轶 +2 位作者 张福林 张宏标 陈景灵 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第1期10-13,共4页
The Jaynes-Cummings model is solved with the raising and lowering(shift) operators using the matrix-diagonalizing technique. Bell nonlocality is also found to be present ubiquitously in the excitation states of the ... The Jaynes-Cummings model is solved with the raising and lowering(shift) operators using the matrix-diagonalizing technique. Bell nonlocality is also found to be present ubiquitously in the excitation states of the model. 展开更多
关键词 Solving the Jaynes-Cummings model with shift Operators Constructed by Means of the Matrix-Diagonalizing Technique JCM
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Investigation on the Doppler shifts induced by 1-D ocean surface wave displacements by the first order small slope approximation theory:comparison of hydrodynamic models
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作者 王运华 张彦敏 郭立新 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第7期230-237,共8页
Based on the first order small slope approximation theory (SSA-I) for oceanic surface electromagnetic scattering, this paper predicts the Doppler shifts induced by wave displacements. Theoretical results from three ... Based on the first order small slope approximation theory (SSA-I) for oceanic surface electromagnetic scattering, this paper predicts the Doppler shifts induced by wave displacements. Theoretical results from three distinct hydrody- namic models are compared: a linear model, the nonlinear Barrick model, and the nonlinear Creamer model. Meanwhile, the predicted Doppler shifts are also compared with the results associated to the resonant Bragg waves and the so-called long waves in the framework of the two-scale model. The dependences of the predicted Doppler shifts on the incident angle, the radar frequency, and the wind speed are discussed. At large incident angles, the predicted Doppler shifts for the linear and nonlinear Barrick models are found to be insensitive to the wind speed and this phenomenon is not coincident with the experimental data. The conclusions obtained in this paper are promising for better understanding the properties of time dependent radar echoes from oceanic surfaces. 展开更多
关键词 Doppler shifts sea surface model SSA-I electromagnetic scattering
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Model for Reduction of Iron Oxide Pellet with a C-O-H-N Gas Mixture Considering Water Gas Shift Equilibrium in the Gas While It Diffuses through the Product Layer
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作者 Viswanathan N. Numi Bharath N. Ballal 《Journal of Chemistry and Chemical Engineering》 2013年第7期666-670,共5页
关键词 气体混合物 水煤气变换 还原氧化 扩散 铁颗粒 收缩核模型 型号 科恩
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Existence of Many Blue Shifted Galaxies in the Universe by Dynamic Universe Model Came True
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作者 Satyavarapu Naga Parameswara Gupta 《Open Journal of Modelling and Simulation》 2017年第1期113-144,共32页
There are many blue shifted Galaxies in our universe. Here we will see old simulations to make such predictions from the output graphs using SITA simulations. There are four new simulations also presented here. In the... There are many blue shifted Galaxies in our universe. Here we will see old simulations to make such predictions from the output graphs using SITA simulations. There are four new simulations also presented here. In these sets of simulations, different point masses are placed in different distances in a 3D Cartesian coordinate grid;and these point masses are allowed to move on universal gravitation force (UGF) acting on each mass at that instant of time at its position. The output pictures depict the three dimensional orbit formations of point masses after some iterations. In an orbit so formed, some Galaxies are coming near (Blue shifted) and some are going away (Red shifted). In this paper, the simulations predicted the existence of a large number of Blue shifted Galaxies, in an expanding universe, in 2004 itself. Over 8300 blue shifted galaxies have been discovered extending beyond the Local Group by Hubble Space Telescope (HST) in the year 2009. Thus Dynamic Universe model predictions came true. 展开更多
关键词 DYNAMIC UNIVERSE model Blue shifted GALAXIES HUBBLE Space Telescope (HST) SITA Simulations
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Properties of Linear Entropy in k-Photon Jaynes-Cummings Model with Stark Shift and Kerr-Like Medium
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作者 廖庆洪 Muhammad Ashfaq Ahmad +1 位作者 王月媛 刘树田 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第5期931-936,共6页
The time evolution of the linear entropy of an atom in k-photon Jaynes-Cummings model is investigatedtaking into consideration Stark shift and Kerr-like medium. The effect of both the Stark shift and Kerr-like medium ... The time evolution of the linear entropy of an atom in k-photon Jaynes-Cummings model is investigatedtaking into consideration Stark shift and Kerr-like medium. The effect of both the Stark shift and Kerr-like medium onthe linear entropy is analyzed using a numerical technique for the field initially in coherent state and in even coherentstate. The results show that the presence of the Kerr-like medium and Stark shift has an important effect on theproperties of the entropy and entanglement. It is also shown that the setting of the initial state plays a significant rolein the evolution of the linear entropy and entanglement. 展开更多
关键词 斯塔克位移 线性熵 KERR介质 K光子 S模型 STARK效应 属性 时间演化
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基于Mean Shift的视觉目标跟踪算法综述 被引量:31
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作者 顾幸方 茅耀斌 李秋洁 《计算机科学》 CSCD 北大核心 2012年第12期16-24,共9页
基于Mean Shift的视觉跟踪算法具有计算复杂度低、调节参数少、稳健性较好和易于工程实现等优点,是目前视觉跟踪领域的重要研究方向。首先介绍了经典的Mean Shift跟踪算法,分析了此跟踪框架存在的缺陷。然后从目标模型表达、模型更新、... 基于Mean Shift的视觉跟踪算法具有计算复杂度低、调节参数少、稳健性较好和易于工程实现等优点,是目前视觉跟踪领域的重要研究方向。首先介绍了经典的Mean Shift跟踪算法,分析了此跟踪框架存在的缺陷。然后从目标模型表达、模型更新、尺度与方向估计、抗遮挡跟踪和快速目标跟踪等5个方面详细地综述了Mean Shift跟踪算法的发展与改进。针对上述每个方面,对典型方法与最近研究成果进行了介绍与评述。最后展望了Mean Shift跟踪今后的研究方向与发展趋势。 展开更多
关键词 视觉跟踪 均值漂移 目标模型
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Shift-Share区域经济评价模型及其扩展研究 被引量:11
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作者 董麓 付灵芝 朱少杰 《统计与信息论坛》 CSSCI 2011年第6期9-13,共5页
讨论了Shift-Share模型的经济思想,指出现有研究反映经济信息的片面性。对Shift-Share方法进行了扩展,提出了产业结构效率新概念,并诠释了其经济思想,构造了更具经济评价和政策意义的区域产业结构分析统计模型,用具体案例介绍了模型使... 讨论了Shift-Share模型的经济思想,指出现有研究反映经济信息的片面性。对Shift-Share方法进行了扩展,提出了产业结构效率新概念,并诠释了其经济思想,构造了更具经济评价和政策意义的区域产业结构分析统计模型,用具体案例介绍了模型使用方法。 展开更多
关键词 shift-Share模型 产业结构 区域经济评价
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基于Shift-Share模型的“镰刀弯”地区粮食增产结构变动分析——兼论玉米种植结构调整 被引量:7
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作者 余晓洋 田帅 +1 位作者 吕一 刘帅 《中国农业资源与区划》 CSCD 北大核心 2017年第5期14-20,共7页
[目的]"镰刀弯"地区玉米种植面积大幅度增加,粮食种植结构单一,为确保粮食安全稳定、多元化发展,需要明确该地区粮食生产结构中不同作物的变化特点和竞争优势。[方法]文章运用ShiftShare模型对"镰刀弯"地区的粮食... [目的]"镰刀弯"地区玉米种植面积大幅度增加,粮食种植结构单一,为确保粮食安全稳定、多元化发展,需要明确该地区粮食生产结构中不同作物的变化特点和竞争优势。[方法]文章运用ShiftShare模型对"镰刀弯"地区的粮食作物生产结构和竞争力优势进行比较,分析了水稻、玉米、薯类、豆类以及其他作物的结构和竞争力优势差异。[结果]"镰刀弯"地区内部不同区域之间不同作物的结构优势和竞争力优势差异明显,其主要原因在于不同作物的播种面积和单位面积产量增长变动速度不同。[结论]"镰刀弯"地区粮食种植结构的调整,尤其是玉米种植面积的调减,应当充分考虑不同作物之间的优势差异,在满足可持续发展和市场需求且不形成过度供给的情况下,增加优势作物的种植,最终形成合理的种植结构和区域布局。 展开更多
关键词 粮食增产结构 玉米种植结构 优势差异 shift-SHARE 模型 “镰刀弯”地区
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铁电光伏效应的理论机制及其研究进展
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作者 杨甜甜 魏杰 《电子元件与材料》 CAS 北大核心 2024年第3期253-263,共11页
近期,铁电体的反常光伏效应在太阳能光伏领域引起了广泛关注。基于体光伏效应的铁电光伏器件的内部机制与基于p-n结的传统光伏器件不同。体光伏效应是指在缺乏反演对称性的材料中产生稳定的光电流和超过带隙的光电压。尽管体光伏效应具... 近期,铁电体的反常光伏效应在太阳能光伏领域引起了广泛关注。基于体光伏效应的铁电光伏器件的内部机制与基于p-n结的传统光伏器件不同。体光伏效应是指在缺乏反演对称性的材料中产生稳定的光电流和超过带隙的光电压。尽管体光伏效应具备巨大应用潜力,但其内部机制尚不明确。回顾了铁电体中铁电光伏效应的理论发展历程和最新进展,重点讨论了体光伏效应的内部机制和理论模型。揭示了对体光伏效应现象与弹道电流、位移电流机制的理论理解及其实验研究。最后,讨论了体光伏效应在未来应用中所面临的机遇和挑战。 展开更多
关键词 铁电光伏效应 体光伏效应 综述 弹道模型 位移电流模型
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基于CamShift的自适应颜色空间目标跟踪算法 被引量:22
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作者 徐琨 贺昱曜 王卫亚 《计算机应用》 CSCD 北大核心 2009年第3期757-760,共4页
CamShift算法只适于特定颜色目标的跟踪,针对这一不足,提出了自适应颜色空间目标跟踪算法。依据当前测量值,根据类间平均距离动态选择当前颜色空间。颜色空间更新判断机制的引入,降低了颜色空间更新带来的时间开销。实验结果表明,该算... CamShift算法只适于特定颜色目标的跟踪,针对这一不足,提出了自适应颜色空间目标跟踪算法。依据当前测量值,根据类间平均距离动态选择当前颜色空间。颜色空间更新判断机制的引入,降低了颜色空间更新带来的时间开销。实验结果表明,该算法可以更准确地在复杂背景下的跟踪各种色彩的目标。 展开更多
关键词 目标跟踪 连续自适应均值漂移算法 颜色空间选择
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基于直方图比的背景加权的Mean Shift目标跟踪算法 被引量:6
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作者 王晓卫 王旭东 贺明 《强激光与粒子束》 EI CAS CSCD 北大核心 2016年第5期13-17,共5页
针对Mean Shift跟踪算法目标模型中背景像素所造成的目标跟踪定位的偏差,提出了一种基于直方图比的背景加权的目标表示方法。该方法使用由目标核直方图和背景直方图的对数似然比值推导出的隶属度因子作为权值,通过只对目标模型进行加权... 针对Mean Shift跟踪算法目标模型中背景像素所造成的目标跟踪定位的偏差,提出了一种基于直方图比的背景加权的目标表示方法。该方法使用由目标核直方图和背景直方图的对数似然比值推导出的隶属度因子作为权值,通过只对目标模型进行加权变换,而不变换目标候选模型的方法,增强了目标和背景的可分性,有效减少了跟踪过程中背景像素的干扰,提高了目标定位的准确性。仿真实验结果表明算法的有效性。 展开更多
关键词 目标跟踪 均值平移算法 目标模型 背景加权 直方图比
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