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光流模值估计的微表情捕捉 被引量:6
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作者 姜波 解仑 +2 位作者 刘欣 韩晶 王志良 《浙江大学学报(工学版)》 EI CAS CSCD 北大核心 2017年第3期577-583,589,共8页
采用力的加速度参量展开描述人脸表情的变化过程,直接反映变化速度,从而有效捕捉表情序列中由不完全肌肉运动所引起的微表情关键帧.利用Horn-Schunck(H-S)光流法对连续运动的人脸图像序列提取运动目标的运动特征;通过光学应变张量算法,... 采用力的加速度参量展开描述人脸表情的变化过程,直接反映变化速度,从而有效捕捉表情序列中由不完全肌肉运动所引起的微表情关键帧.利用Horn-Schunck(H-S)光流法对连续运动的人脸图像序列提取运动目标的运动特征;通过光学应变张量算法,结合运动特征中的光流速度估计,推导出加速度参量;利用全局阈值算法对加速度模值和速度与张量模值作分类、比较,实现微表情图像序列关键帧的提取.采用Oulu大学SMIC微表情数据库中16个实验对象的88个微表情片段作为实验样本,平均正确识别率可达80.7%,比仅利用光学张量算法的正确识别率高12.5%.实验结果表明,所提出的加速度参量对微表情提取更具有效性. 展开更多
关键词 微表情捕捉 Horn-Schunck(H-S)光流法 加速度模值估计 全局阈 运动特征 光学应变张量
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图像去雾中的大气光强度自适应恢复算法研究 被引量:1
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作者 程炜 汤红忠 +3 位作者 朱玲 王翔 李骁 郭雪峰 《计算技术与自动化》 2017年第1期103-107,共5页
传统的单幅图像去雾方法中大气光强度仅设定为与图像最亮象素有关的经验值,容易造成去雾后的图像亮度偏暗,且某些区域色彩还原失真等问题。本文提出一种大气光强度自适应恢复算法。首先对图进行分块,根据每个图块的像素在RGB颜色空间分... 传统的单幅图像去雾方法中大气光强度仅设定为与图像最亮象素有关的经验值,容易造成去雾后的图像亮度偏暗,且某些区域色彩还原失真等问题。本文提出一种大气光强度自适应恢复算法。首先对图进行分块,根据每个图块的像素在RGB颜色空间分布在同一条线上,可求得大气光强度的方向,然后对大气光强度模值引入一个惩罚因子实现图像去雾,对去雾后图像提出大气光强度模值估计的目标函数,根据图像明暗系数的最大值与透射率的等级无关的约束条件,利用L-BFGS优化从而得到正确的大气光强度模值。实验结果证明该方法可以有效避免大气光强度估值偏差而引起的图像色彩失真,鲁棒性强,去雾后的图像具有更好的色彩还原度和清晰度,更能符合人眼视觉效果。 展开更多
关键词 大气光强度 明暗系数 模值估计 透射率
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Parameter identification and pressure control of dynamic system in shield tunneling using least squares method 被引量:10
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作者 LI Shou-ju CAO Li-juan +1 位作者 SHANGGUAN Zi-chang LIU Bo 《Journal of Coal Science & Engineering(China)》 2010年第3期256-261,共6页
An estimation approach using least squares method was presented for identificationof model parameters of pressure control in shield tunneling.The state equation ofthe pressure control system for shield tunneling was a... An estimation approach using least squares method was presented for identificationof model parameters of pressure control in shield tunneling.The state equation ofthe pressure control system for shield tunneling was analytically derived based on themass equilibrium principle that the entry mass of the pressure chamber from cutting headwas equal to excluding mass from the screw conveyor.The randomly observed noise wasnumerically simulated and mixed to simulated observation values of system responses.The numerical simulation shows that the state equation of the pressure control system forshield tunneling is reasonable and the proposed estimation approach is effective even ifthe random observation noise exists.The robustness of the controlling procedure is validatedby numerical simulation results. 展开更多
关键词 parameter identification least squares method state equation shield tunneling
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Fatigue Life Assessment of Top Tensioned Risers Under Vortex-Induced Vibrations 被引量:11
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作者 LI Xiaomin GUO Haiyan MENG Fanshun 《Journal of Ocean University of China》 SCIE CAS 2010年第1期43-47,共5页
The fatigue life of top tensioned risers under vortex-induced vibrations (VIVs) with consideration of the effect of internal flowing fluid on the riser is analyzed in the time domain.The long-term stress histories of ... The fatigue life of top tensioned risers under vortex-induced vibrations (VIVs) with consideration of the effect of internal flowing fluid on the riser is analyzed in the time domain.The long-term stress histories of the riser under VIVs are calculated and the mean stresses,the number of stress cycles and amplitudes are determined by the rainflow counting method.The Palmgren-Miner rule for cumulative damage theory with a specified S-N curve is used to estimate the fatigue life of the riser.The corresponding numerical programs numerical simulation of vortex-induced vibrations (NSVIV) which can be used to calculate the VIV response and fatigue life of the riser are compiled.Finally the influences of the riser's parameters such as flexural rigidity,top tension and internal flow velocity on the fatigue life of the riser are analyzed in detail and some conclusions are drawn. 展开更多
关键词 top tensioned riser (TTR) internal flow vortex-induced vibration (VIV) fatigue life
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Predictive ability of genomic selection models for breeding value estimation on growth traits of Pacific white shrimp Litopenaeus vannamei 被引量:4
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作者 王全超 于洋 +2 位作者 李富花 张晓军 相建海 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第5期1221-1229,共9页
Genomic selection(GS)can be used to accelerate genetic improvement by shortening the selection interval.The successful application of GS depends largely on the accuracy of the prediction of genomic estimated breeding ... Genomic selection(GS)can be used to accelerate genetic improvement by shortening the selection interval.The successful application of GS depends largely on the accuracy of the prediction of genomic estimated breeding value(GEBV).This study is a fi rst attempt to understand the practicality of GS in Litopenaeus vannamei and aims to evaluate models for GS on growth traits.The performance of GS models in L.vannamei was evaluated in a population consisting of 205 individuals,which were genotyped for 6 359 single nucleotide polymorphism(SNP)markers by specifi c length amplifi ed fragment sequencing(SLAF-seq)and phenotyped for body length and body weight.Three GS models(RR-BLUP,Bayes A,and Bayesian LASSO)were used to obtain the GEBV,and their predictive ability was assessed by the reliability of the GEBV and the bias of the predicted phenotypes.The mean reliability of the GEBVs for body length and body weight predicted by the dif ferent models was 0.296 and 0.411,respectively.For each trait,the performances of the three models were very similar to each other with respect to predictability.The regression coeffi cients estimated by the three models were close to one,suggesting near to zero bias for the predictions.Therefore,when GS was applied in a L.vannamei population for the studied scenarios,all three models appeared practicable.Further analyses suggested that improved estimation of the genomic prediction could be realized by increasing the size of the training population as well as the density of SNPs. 展开更多
关键词 genomic selection model prediction growth traits penaeid shrimp
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Numerical method for estimation of kinematical parameters for articulated rovers on loose rough terrain 被引量:1
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作者 禹鑫燚 高海波 邓宗全 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第4期505-512,共8页
Based on the study of passive articulated rover,a complete suspension kinematics model from wheel to inertial reference frame is presented,which uses D-H method of manipulator and presentation with Euler angle of pitc... Based on the study of passive articulated rover,a complete suspension kinematics model from wheel to inertial reference frame is presented,which uses D-H method of manipulator and presentation with Euler angle of pitch,roll and yaw.An improved contact model is adopted aimed at the loose and rough lunar terrain.Using this kinematics model and numerical continuous and discrete Newton's method with iterative factor,the numerical method for estimation of kinematical parameters of articulated rovers on loose and rough terrain is constructed.To demonstrate this numerical method,an example of two torsion bar rocker-bogie lunar rover with eight wheels is presented.Simulation results show that the numerical method for estimation of kinematical parameters of articulated rovers based on improved contact model can improve the precision of kinematical estimation on loose and rough terrain and decrease errors caused by contact models established based on general hypothesis. 展开更多
关键词 loose soil kinematical parameters estimation suspension kinematics articulated lunar rover nu merical solving
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Estimating the Operation Status of Steam Cracking Furnace Using Numerical Simulation with Combustion Models 被引量:3
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作者 Zhou Xianfeng Yang Yuanyi +2 位作者 Wang Guoqing Zhang Lijun Liu Yi 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第4期52-63,共12页
An accurate and complete geometric model was constructed to simulate the combustion, flow and temperature environment in the radiant section of the steam cracking furnace. Simulation of flow and radiation status has u... An accurate and complete geometric model was constructed to simulate the combustion, flow and temperature environment in the radiant section of the steam cracking furnace. Simulation of flow and radiation status has utilized the standard k-ε model and P1 model. The finite-rate/eddy-dissipation (finite-rate/ED) combustion model and non-premixed combustion model were both used to simulate accurately the combustion and the operation status of the steam cracking furnace. Three different surfaces of the steam cracking furnace were obtained from the simulation, namely:the flue gas temperature field of the entrance surface in long flame burners, the central surface location of tubes, and the crossover section surface. Detailed information on the flue gas temperature and the mass concentration fraction of these different surfaces in the steam cracking furnace can also be obtained by the simulation. This paper analyzed and compared the simulation results with the two combustion models, estimated the operation status of the steam cracking furnace, and reported that the finite-rate/ED model is appropriate to simulate the steam cracking furnace by comparing key simulation data with actual test data. This work has also provided a theoretical basis for simulating and operating the steam cracking furnace. 展开更多
关键词 steam cracking furnace operation status combustion model numerical simulation flue gas
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Motion estimation based feature selection for visual SLAM
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作者 孟旭炯 Jiang Rongxin Zhou Fan Chen Yaowu 《High Technology Letters》 EI CAS 2011年第4期433-438,共6页
Feature selection is always an important issue in the visual SLAM (simultaneous location and mapping) literature. Considering that the location estimation can be improved by tracking features with larger value of vi... Feature selection is always an important issue in the visual SLAM (simultaneous location and mapping) literature. Considering that the location estimation can be improved by tracking features with larger value of visible time, a new feature selection method based on motion estimation is proposed. First, a k-step iteration algorithm is presented for visible time estimation using an affme motion model; then a delayed feature detection method is introduced for efficiently detecting features with the maximum visible time. As a means of validation for the proposed method, both simulation and real data experiments are carded out. Results show that the proposed method can improve both the estimation performance and the computational performance compared with the existing random feature selection method. 展开更多
关键词 visual SLAM feature selection motion estimation computational efficiency CONSISTENCY extended Kalman filter (EKF)
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Asymptotic Formulas for Thermography Based Recovery of Anomalies
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作者 Habib Ammari Anastasia Kozhemyak Darko Volkov 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2009年第1期18-42,共25页
We start from a realistic half space then use to develop a mathematical asymptotic model for thermal imaging, which we analysis well suited for the design of reconstruction algorithms. We seek to reconstruct thermal a... We start from a realistic half space then use to develop a mathematical asymptotic model for thermal imaging, which we analysis well suited for the design of reconstruction algorithms. We seek to reconstruct thermal anomalies only through their rough features. With this way our proposed algorithms are stable against measurement noise and geometry perturbations. Based on rigorous asymptotic estimates, we first obtain an approximation for the temperature profile which we then use to design noniterative detection algorithms. We show on numerical simulations evidence that they are accurate and robust. Moreover, we provide a mathematical model for ultrasonic temperature imaging, which is an important technique in cancerous tissue ablation therapy. 展开更多
关键词 THERMOGRAPHY imaging asymptotic formulas small anomalies direct imaging algorithms half-space problem.
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Study on engineering audit based on Valuation
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作者 Wei Zuo Xiaoli Hu Lili Dou 《International English Education Research》 2015年第3期38-39,共2页
in the bill of quantities mode, audit department how to perform the function of supervision, control the cost of the project, to improve the infrastructure investment efficiency to have the important meaning. This art... in the bill of quantities mode, audit department how to perform the function of supervision, control the cost of the project, to improve the infrastructure investment efficiency to have the important meaning. This article from the valuation list elements of engineering audit mode based solutions, engineering audit under BOQ valuation mode is put forward from the audit information management, engineering contract claim, audit personnel quality etc.. 展开更多
关键词 list valuation project audit BIDDING
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Sequential Estimate for Generalized Linear Models with Uncertain Number of Effective Variables 被引量:1
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作者 LU Haibo WANG Zhanfeng WU Yaohua 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第2期424-438,共15页
For the generalized linear model,the authors propose a sequential sampling procedure based on an adaptive shrinkage estimate of parameter.This method can determine a minimum sample size under which effective variables... For the generalized linear model,the authors propose a sequential sampling procedure based on an adaptive shrinkage estimate of parameter.This method can determine a minimum sample size under which effective variables contributing to the model are identified and estimates of regression parameters achieve the required accuracy.The authors prove that the proposed sequential procedure is asymptotically optimal.Numerical simulation studies show that the proposed method can save a large number of samples compared to the traditional sequential approach. 展开更多
关键词 Confidence set generalized linear regression sequential sampling stopping rule
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Randomly Weighted LAD-Estimation for Partially Linear Errors-in-Variables Models
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作者 Xiaohan YANG Rong JIANG Weimin QIAN 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2015年第4期561-578,共18页
The authors consider the partially linear model relating a response Y to predictors (x, T) with a mean function x^Tβ0 + g(T) when the x's are measured with an additive error. The estimators of parameter β0 are... The authors consider the partially linear model relating a response Y to predictors (x, T) with a mean function x^Tβ0 + g(T) when the x's are measured with an additive error. The estimators of parameter β0 are derived by using the nearest neighbor-generalized randomly weighted least absolute deviation (LAD for short) method. The resulting estimator of the unknown vector 30 is shown to be consistent and asymptotically normal. In addition, the results facilitate the construction of confidence regions and the hypothesis testing for the unknown parameters. Extensive simulations are reported, showing that the proposed method works well in practical settings. The proposed methods are also applied to a data set from the study of an AIDS clinical trial group. 展开更多
关键词 Partially linear errors-in-variables LAD-estimation Randomly weighted method Linear hypothesis Randomly weighted LAD-test
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