Correlation of the SGS (sub-grid scale) velocity between the two phases in an isotropic gas-particle two-phase flow was numerically investigated with FDF model. The results show the SGS gas velocity seen by the partic...Correlation of the SGS (sub-grid scale) velocity between the two phases in an isotropic gas-particle two-phase flow was numerically investigated with FDF model. The results show the SGS gas velocity seen by the particles varies with the relative velocities between particle phase and gas phase. The relative velocity between the two phases produces the effect of the anisotropic turbulence on the particles. The variation of Stokes number influences the magnitude of the interaction between the two phases.展开更多
针对单幅图像中的行人检测问题,提出了基于自适应增强算法(Adaboost)和支持向量机(Support vector machine,SVM)的两级检测方法,应用粗细结合的思想有效提高检测的精度.粗级行人检测器通过提取四方向特征(Four direction features,FDF)...针对单幅图像中的行人检测问题,提出了基于自适应增强算法(Adaboost)和支持向量机(Support vector machine,SVM)的两级检测方法,应用粗细结合的思想有效提高检测的精度.粗级行人检测器通过提取四方向特征(Four direction features,FDF)和GAB(Gentle Adaboost)级联训练得到,精密级行人检测器用熵梯度直方图(Entropy-histograms of oriented gradients,EHOG)作为特征,通过支持向量机学习得到.本文提出的EHOG特征考虑到熵,通过分布的混乱程度描述,具有分辨行人和类似人的物体能力.实验结果表明,本文提出的EHOG、粗细结合的两级检测方法能准确地检测出复杂背景下不同姿势的直立行人,检测精度优于以往Adaboost方法.展开更多
This paper focuses on the fast rate fault detection filter (FDF) problem for a class of multirate sampled-data (MSD) systems. A lifting technique is used to convert such an MSD system into a linear time-invariant disc...This paper focuses on the fast rate fault detection filter (FDF) problem for a class of multirate sampled-data (MSD) systems. A lifting technique is used to convert such an MSD system into a linear time-invariant discrete-time one and an unknown input observer (UIO) is considered as FDF to generate residual. The design of FDF is formulated as an H∞ optimization problem and a solvable condition as well as an optimal solution are derived. The causality of the residual generator can be guaranteed so that the fast rate residual can be implemented via inverse lifting. A numerical example is included to demonstrate the feasibility of the obtained results.展开更多
The problem of fault detection for linear discrete timevarying systems with multiplicative noise is dealt with.By using an observer-based robust fault detection filter（FDF） as a residual generator,the design of the ...The problem of fault detection for linear discrete timevarying systems with multiplicative noise is dealt with.By using an observer-based robust fault detection filter（FDF） as a residual generator,the design of the FDF is formulated in the framework of H ∞ filtering for a class of stochastic time-varying systems.A sufficient condition for the existence of the FDF is derived in terms of a Riccati equation.The determination of the parameter matrices of the filter is converted into a quadratic optimization problem,and an analytical solution of the parameter matrices is obtained by solving the Riccati equation.Numerical examples are given to illustrate the effectiveness of the proposed method.展开更多
基金support of National Natural Science Foundation of China(Grant No:1077216211132008)+1 种基金the Major Projects on Control and Rectification of Water Body Pollution(GrantNo.2009ZX07424-001)the Qianjiang Talent Project(Grant No.2010R10035)
文摘Correlation of the SGS (sub-grid scale) velocity between the two phases in an isotropic gas-particle two-phase flow was numerically investigated with FDF model. The results show the SGS gas velocity seen by the particles varies with the relative velocities between particle phase and gas phase. The relative velocity between the two phases produces the effect of the anisotropic turbulence on the particles. The variation of Stokes number influences the magnitude of the interaction between the two phases.
文摘针对单幅图像中的行人检测问题,提出了基于自适应增强算法(Adaboost)和支持向量机(Support vector machine,SVM)的两级检测方法,应用粗细结合的思想有效提高检测的精度.粗级行人检测器通过提取四方向特征(Four direction features,FDF)和GAB(Gentle Adaboost)级联训练得到,精密级行人检测器用熵梯度直方图(Entropy-histograms of oriented gradients,EHOG)作为特征,通过支持向量机学习得到.本文提出的EHOG特征考虑到熵,通过分布的混乱程度描述,具有分辨行人和类似人的物体能力.实验结果表明,本文提出的EHOG、粗细结合的两级检测方法能准确地检测出复杂背景下不同姿势的直立行人,检测精度优于以往Adaboost方法.
基金Supported by National Natural Science Foundation of P. R. China (60374021)the Natural Science Foundation of Shandong Province (Y2002G05)the Youth Scientists Foundation of Shandong Province (03BS091, 05BS01007) and Education Ministry Foundation of P. R. China (20050422036)
文摘This paper focuses on the fast rate fault detection filter (FDF) problem for a class of multirate sampled-data (MSD) systems. A lifting technique is used to convert such an MSD system into a linear time-invariant discrete-time one and an unknown input observer (UIO) is considered as FDF to generate residual. The design of FDF is formulated as an H∞ optimization problem and a solvable condition as well as an optimal solution are derived. The causality of the residual generator can be guaranteed so that the fast rate residual can be implemented via inverse lifting. A numerical example is included to demonstrate the feasibility of the obtained results.
基金supported by the National Natural Science Foundation of China (61174121,61121003)the National High Technology Researchand Development Program of China (863 Program) (2008AA121302)+1 种基金the National Basic Research Program of China (973 Program)(2009CB724000)the Research Fund for the Doctoral Program of Higher Education of China
文摘The problem of fault detection for linear discrete timevarying systems with multiplicative noise is dealt with.By using an observer-based robust fault detection filter（FDF） as a residual generator,the design of the FDF is formulated in the framework of H ∞ filtering for a class of stochastic time-varying systems.A sufficient condition for the existence of the FDF is derived in terms of a Riccati equation.The determination of the parameter matrices of the filter is converted into a quadratic optimization problem,and an analytical solution of the parameter matrices is obtained by solving the Riccati equation.Numerical examples are given to illustrate the effectiveness of the proposed method.
