Abstract： In order to improve the recognition accuracy of key stroke authentication, a methodology based on feature extraction of keystroke sequence is presented in this paper. Firstly, the data of the users＇ keystr...Abstract： In order to improve the recognition accuracy of key stroke authentication, a methodology based on feature extraction of keystroke sequence is presented in this paper. Firstly, the data of the users＇ keystroke feature information that has too much deviation with the mean deviation is filtered out. Secondly, the probability of each input key is calculated and 10 values which do not have the best features are selected. Thirdly, they are weighed and a score evaluating the extent to which the user could be authenticated successfully is calculated. The benefit of using a third-party data set is more objective and comparable. At last,展开更多
Based on the quadratic exponential method, this paper constructs two types of generators over finite field Fq, the digital quadratic exponential generator and quadratic exponential pseudorandom vector generator. We in...Based on the quadratic exponential method, this paper constructs two types of generators over finite field Fq, the digital quadratic exponential generator and quadratic exponential pseudorandom vector generator. We investigate the distribution of the sequence generated by the generators, and present results about their one dimensional discrepancy. The proofs are based on the estimate of certain character sum over Fq. Ift is the least period of the sequence and t≥q^1/2＋2c, then the bound of the discrepancy is O（t^-1/4q^1/8＋τ logq） for any ε 〉 0. It shows that the sequence is asymptotically uniformly distributed.展开更多
Existed evidences show that airborne transmission of human respiratory droplets may be related with the spread of some infectious disease, such as severe acute respiratory syndrome （SARS） and H1N1 pandemic. Non-phar...Existed evidences show that airborne transmission of human respiratory droplets may be related with the spread of some infectious disease, such as severe acute respiratory syndrome （SARS） and H1N1 pandemic. Non-pharmaceutical approaches, including ventilation system and personal protection, are believed to have certain positive effects on the reduction of co-occupant＇s inhalation. This work then aims to numerically study the performances of mouth covering on co-occupant＇s exposure under mixing ventilation （MV）, under-floor air distribution （UFAD） and displacement ventilation （DV） system, using drift-flux model. Desk partition, as one generally employed arrangement in plan office, is also investigated under MV. The dispersion of 1, 5 and 10 grn droplet residuals are numerically calculated and CO2 is used to represent tracer gas. The results show that using mouth covering by the infected person can reduce the co-occupant＇s inhalation greatly by interrupting direct spread of the expelled droplets, and best performance can be achieved under DV since the coughed air is mainly confined in the microenvironment of the infected person. The researches under MV show that the two interventions, mouth covering and desk partition, achieve almost the sarae inhalation for fine droplets while the inhalation of the co-occupant is lower when using mouth covering for large droplets.展开更多
This paper advances a new simplified formula for estimating variance components ,sums up the basic law to calculate the weights of observed values and a circulation method using the increaments of weights when estimat...This paper advances a new simplified formula for estimating variance components ,sums up the basic law to calculate the weights of observed values and a circulation method using the increaments of weights when estimating the variance components of traverse nets,advances the charicteristic roots method to estimate the variance components of traveres nets and presents a practical method to make two real and symmetric matrices two diagonal ones.展开更多
Aimed at the problems of infrared image recognition under varying illumination,face disguise,etc.,we bring out an infrared human face recognition algorithm based on 2DPCA.The proposed algorithm can work out the covari...Aimed at the problems of infrared image recognition under varying illumination,face disguise,etc.,we bring out an infrared human face recognition algorithm based on 2DPCA.The proposed algorithm can work out the covariance matrix of the training sample easily and directly;at the same time,it costs less time to work out the eigenvector.Relevant experiments are carried out,and the result indicates that compared with the traditional recognition algorithm,the proposed recognition method is swift and has a good adaptability to the changes of human face posture.展开更多
The principal component analysis （PCA） is one of the most celebrated methods in analysing multivariate data. An effort of extending PCA is projection pursuit （PP）, a more general class of dimension-reduction techn...The principal component analysis （PCA） is one of the most celebrated methods in analysing multivariate data. An effort of extending PCA is projection pursuit （PP）, a more general class of dimension-reduction techniques. However, the application of this extended procedure is often hampered by its complexity in computation and by lack of some appropriate theory. In this paper, by use of the empirical processes we established a large sample theory for the robust PP estimators of the principal components and dispersion matrix.展开更多
In this paper, the authors derive the asymptotic joint distributions of theeigenvalues of some random matrices which arise from components of covariance model.
基金This paper has been performed in the Project "Key Technology Research of Eavesdropping Detection in the Quantum Security Communication" supported by the National Natural Science Foundation of China
文摘Abstract： In order to improve the recognition accuracy of key stroke authentication, a methodology based on feature extraction of keystroke sequence is presented in this paper. Firstly, the data of the users＇ keystroke feature information that has too much deviation with the mean deviation is filtered out. Secondly, the probability of each input key is calculated and 10 values which do not have the best features are selected. Thirdly, they are weighed and a score evaluating the extent to which the user could be authenticated successfully is calculated. The benefit of using a third-party data set is more objective and comparable. At last,
基金Supported by the Special Fund of National Excellent Doctoral Dissertation (Grant 200060) and the National Natural Science Foundation of China (No.60373092).
文摘Based on the quadratic exponential method, this paper constructs two types of generators over finite field Fq, the digital quadratic exponential generator and quadratic exponential pseudorandom vector generator. We investigate the distribution of the sequence generated by the generators, and present results about their one dimensional discrepancy. The proofs are based on the estimate of certain character sum over Fq. Ift is the least period of the sequence and t≥q^1/2＋2c, then the bound of the discrepancy is O（t^-1/4q^1/8＋τ logq） for any ε 〉 0. It shows that the sequence is asymptotically uniformly distributed.
基金funded by Research Grant Committee of the Hong Kong SAR government (RGC No. PolyU5265/08E)
文摘Existed evidences show that airborne transmission of human respiratory droplets may be related with the spread of some infectious disease, such as severe acute respiratory syndrome （SARS） and H1N1 pandemic. Non-pharmaceutical approaches, including ventilation system and personal protection, are believed to have certain positive effects on the reduction of co-occupant＇s inhalation. This work then aims to numerically study the performances of mouth covering on co-occupant＇s exposure under mixing ventilation （MV）, under-floor air distribution （UFAD） and displacement ventilation （DV） system, using drift-flux model. Desk partition, as one generally employed arrangement in plan office, is also investigated under MV. The dispersion of 1, 5 and 10 grn droplet residuals are numerically calculated and CO2 is used to represent tracer gas. The results show that using mouth covering by the infected person can reduce the co-occupant＇s inhalation greatly by interrupting direct spread of the expelled droplets, and best performance can be achieved under DV since the coughed air is mainly confined in the microenvironment of the infected person. The researches under MV show that the two interventions, mouth covering and desk partition, achieve almost the sarae inhalation for fine droplets while the inhalation of the co-occupant is lower when using mouth covering for large droplets.
文摘This paper advances a new simplified formula for estimating variance components ,sums up the basic law to calculate the weights of observed values and a circulation method using the increaments of weights when estimating the variance components of traverse nets,advances the charicteristic roots method to estimate the variance components of traveres nets and presents a practical method to make two real and symmetric matrices two diagonal ones.
基金Sponsored by the Natural Science Fund of Heilongjiang province(Grant No. F2007-13)Science and Technology Research Projects in Office of Education of Heilongjiang province(Grant No.11531034)the Heilongjiang Postdoctoral Science Foundation(Grant No.LBH-Z06054)
文摘Aimed at the problems of infrared image recognition under varying illumination,face disguise,etc.,we bring out an infrared human face recognition algorithm based on 2DPCA.The proposed algorithm can work out the covariance matrix of the training sample easily and directly;at the same time,it costs less time to work out the eigenvector.Relevant experiments are carried out,and the result indicates that compared with the traditional recognition algorithm,the proposed recognition method is swift and has a good adaptability to the changes of human face posture.
基金The researcb was partially supported by the National Natural Science Foundation of China under Grant No.19631040.
文摘The principal component analysis （PCA） is one of the most celebrated methods in analysing multivariate data. An effort of extending PCA is projection pursuit （PP）, a more general class of dimension-reduction techniques. However, the application of this extended procedure is often hampered by its complexity in computation and by lack of some appropriate theory. In this paper, by use of the empirical processes we established a large sample theory for the robust PP estimators of the principal components and dispersion matrix.
文摘In this paper, the authors derive the asymptotic joint distributions of theeigenvalues of some random matrices which arise from components of covariance model.
