A vicious script detection method based on statistic is proposed by analyzing the vicious script in the hypertext markup language(HTML).We utilize the judgment matrix approach which is one of the subjective weighting ...A vicious script detection method based on statistic is proposed by analyzing the vicious script in the hypertext markup language(HTML).We utilize the judgment matrix approach which is one of the subjective weighting approaches to set the different weights for various statistic methods.Then we make use of the weighted geometric method to perfect the statistic results.Experimental results show the validity of this method.展开更多
Using semi-tensor product of matrices, the controllability and stabilizability of finite automata are investigated. By expressing the states, inputs, and outputs in vector forms, the transition and output functions ar...Using semi-tensor product of matrices, the controllability and stabilizability of finite automata are investigated. By expressing the states, inputs, and outputs in vector forms, the transition and output functions are represented in matrix forms.Based on this algebraic description, a necessary and sufficient condition is proposed for checking whether a state is controllable to another one. By this condition, an algorithm is established to find all the control sequences of an arbitrary length. Moreover, the stabilizability of finite automata is considered, and a necessary and sufficient condition is presented to examine whether some states can be stabilized. Finally, the study of illustrative examples verifies the correctness of the presented results/algorithms.展开更多
A near-field three-dimensional(3 D)imaging method combining multichannel joint sparse recovery(MJSR)and fast Gaussian gridding nonuniform fast Fourier transform(FGGNUFFT)is proposed,based on a perfect combination of t...A near-field three-dimensional(3 D)imaging method combining multichannel joint sparse recovery(MJSR)and fast Gaussian gridding nonuniform fast Fourier transform(FGGNUFFT)is proposed,based on a perfect combination of the compressed sensing(CS)theory and the matched filtering(MF)technique.The approach has the advantages of high precision and high efficiency:multichannel joint sparse constraint is adopted to improve the problem that the images recovered by the single channel imaging algorithms do not necessarily share the same positions of the scattering centers;the CS dictionary is constructed by combining MF and FGG-NUFFT,so as to improve the imaging efficiency and memory requirement.Firstly,a near-field 3 D imaging model of joint sparse recovery is constructed by combining the MF-based imaging method.Secondly,FGG-NUFFT and reverse FGG-NUFFT are used to replace the interpolation and Fourier transform in MF-based imaging methods,and a sensing matrix with high precision and high efficiency is constructed according to the traditional imaging process.Thirdly,a fast imaging recovery is performed by using the improved separable surrogate functionals(SSF)optimization algorithm,only with matrix and vector multiplication.Finally,a 3 D imagery of the near-field target is obtained by using both the horizontal and the pitching interferometric phase information.This paper contains two imaging models,the only difference is the sub-aperture method used in inverse synthetic aperture radar(ISAR)imaging.Compared to traditional CS-based imaging methods,the proposed method includes both forward transform and inverse transform in each iteration,which improves the quality of reconstruction.The experimental results show that,the proposed method improves the imaging accuracy by about O(10),accelerates the imaging speed by five times and reduces the memory usage by about O(10~2).展开更多
Accidents and injuries related to work are major occupational health problems in most of the industrialized countries.Traditional approaches to manage workplace safety in mines have mainly focused on job redesign and ...Accidents and injuries related to work are major occupational health problems in most of the industrialized countries.Traditional approaches to manage workplace safety in mines have mainly focused on job redesign and technical aspects of engineering systems.It is being realized that compliance to rules and regulations of mines is a prerequisite;however,it is not sufficient to achieve further reduction in accident and injury rates in mines.Proactive approaches are necessary to further improve the safety standards in mines.Unsafe conditions and practices in mines lead to a number of accidents,which in turn may cause loss and injury to human lives,damages to property,and loss of production.Hazard identification and risk assessment is an important task for the mining industry which needs to consider all the risk factors at workplaces.Applications of risk management approaches in mines are necessary to identify and quantify potential hazards and to suggest effective solutions.In this paper,the following risk estimation techniques were discussed:(i)DGMS(Directorate General of Mines Safety,India)risk rating criterion,and(ii)a matrix based approach.The proposed tools were demonstrated through an application in an opencast coal mine in India.It was inferred that the risk assessment approach can be used as an effective tool to indentify and control hazards in mines.展开更多
本文主要研究了一个特殊非对称量子阱中的二阶非线性光学极化率 ,并且利用量子力学中的密度矩阵算符理论和迭代方法导出了二次谐波极化率的解析表达式 .最后 ,以典型的 Ga As/ Al Ga As非对称量子阱为例作了数值计算 .数值结果表明 ,较...本文主要研究了一个特殊非对称量子阱中的二阶非线性光学极化率 ,并且利用量子力学中的密度矩阵算符理论和迭代方法导出了二次谐波极化率的解析表达式 .最后 ,以典型的 Ga As/ Al Ga As非对称量子阱为例作了数值计算 .数值结果表明 ,较大的二次谐波极化率与系统的非对称性有关 ,系统的非对称性越大 。展开更多
基金Sponsored by the National 242 Information Security Project (2005A10 )and( 2007F40)the National Defence Basic Scientific Research Project(C1120060497)
文摘A vicious script detection method based on statistic is proposed by analyzing the vicious script in the hypertext markup language(HTML).We utilize the judgment matrix approach which is one of the subjective weighting approaches to set the different weights for various statistic methods.Then we make use of the weighted geometric method to perfect the statistic results.Experimental results show the validity of this method.
基金supported by the National Natural Science Foundation of China(61174094)the Tianjin Natural Science Foundation of China(13JCYBJC1740014JCYBJC18700)
文摘Using semi-tensor product of matrices, the controllability and stabilizability of finite automata are investigated. By expressing the states, inputs, and outputs in vector forms, the transition and output functions are represented in matrix forms.Based on this algebraic description, a necessary and sufficient condition is proposed for checking whether a state is controllable to another one. By this condition, an algorithm is established to find all the control sequences of an arbitrary length. Moreover, the stabilizability of finite automata is considered, and a necessary and sufficient condition is presented to examine whether some states can be stabilized. Finally, the study of illustrative examples verifies the correctness of the presented results/algorithms.
基金supported by the National Natural Science Foundation of China(61771369 61775219+5 种基金 61640422)the Fundamental Research Funds for the Central Universities(JB180310)the Equipment Research Program of the Chinese Academy of Sciences(YJKYYQ20180039)the Shaanxi Provincial Key R&D Program(2018SF-409 2018ZDXM-SF-027)the Natural Science Basic Research Plan
文摘A near-field three-dimensional(3 D)imaging method combining multichannel joint sparse recovery(MJSR)and fast Gaussian gridding nonuniform fast Fourier transform(FGGNUFFT)is proposed,based on a perfect combination of the compressed sensing(CS)theory and the matched filtering(MF)technique.The approach has the advantages of high precision and high efficiency:multichannel joint sparse constraint is adopted to improve the problem that the images recovered by the single channel imaging algorithms do not necessarily share the same positions of the scattering centers;the CS dictionary is constructed by combining MF and FGG-NUFFT,so as to improve the imaging efficiency and memory requirement.Firstly,a near-field 3 D imaging model of joint sparse recovery is constructed by combining the MF-based imaging method.Secondly,FGG-NUFFT and reverse FGG-NUFFT are used to replace the interpolation and Fourier transform in MF-based imaging methods,and a sensing matrix with high precision and high efficiency is constructed according to the traditional imaging process.Thirdly,a fast imaging recovery is performed by using the improved separable surrogate functionals(SSF)optimization algorithm,only with matrix and vector multiplication.Finally,a 3 D imagery of the near-field target is obtained by using both the horizontal and the pitching interferometric phase information.This paper contains two imaging models,the only difference is the sub-aperture method used in inverse synthetic aperture radar(ISAR)imaging.Compared to traditional CS-based imaging methods,the proposed method includes both forward transform and inverse transform in each iteration,which improves the quality of reconstruction.The experimental results show that,the proposed method improves the imaging accuracy by about O(10),accelerates the imaging speed by five times and reduces the memory usage by about O(10~2).
文摘Accidents and injuries related to work are major occupational health problems in most of the industrialized countries.Traditional approaches to manage workplace safety in mines have mainly focused on job redesign and technical aspects of engineering systems.It is being realized that compliance to rules and regulations of mines is a prerequisite;however,it is not sufficient to achieve further reduction in accident and injury rates in mines.Proactive approaches are necessary to further improve the safety standards in mines.Unsafe conditions and practices in mines lead to a number of accidents,which in turn may cause loss and injury to human lives,damages to property,and loss of production.Hazard identification and risk assessment is an important task for the mining industry which needs to consider all the risk factors at workplaces.Applications of risk management approaches in mines are necessary to identify and quantify potential hazards and to suggest effective solutions.In this paper,the following risk estimation techniques were discussed:(i)DGMS(Directorate General of Mines Safety,India)risk rating criterion,and(ii)a matrix based approach.The proposed tools were demonstrated through an application in an opencast coal mine in India.It was inferred that the risk assessment approach can be used as an effective tool to indentify and control hazards in mines.
基金Natural Science Foundation of Guangdong Province and Guangzhou Committee of Science and Technology
文摘本文主要研究了一个特殊非对称量子阱中的二阶非线性光学极化率 ,并且利用量子力学中的密度矩阵算符理论和迭代方法导出了二次谐波极化率的解析表达式 .最后 ,以典型的 Ga As/ Al Ga As非对称量子阱为例作了数值计算 .数值结果表明 ,较大的二次谐波极化率与系统的非对称性有关 ,系统的非对称性越大 。
