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
The problem of computing a piecewise linear approximation to a surface from its sample has been a focus of research in geometry modeling and graphics due to its widespread applications in computer aided design. In thi...The problem of computing a piecewise linear approximation to a surface from its sample has been a focus of research in geometry modeling and graphics due to its widespread applications in computer aided design. In this paper, we give a new algorithm, to be called offset surface filtering (OSF) algorithm, which computes a piecewise-linear approximation of a smooth surface from a finite set of cloud points. The algorithm has two main stages. First, the surface normal on every point is estimated by the least squares best fitting plane method. Second, we construct a restricted Delaunay triangulation, which is a tubular neighborhood of the surface defined by two offset surfaces. The algorithm is simple and robust. We describe an implementation of it and show example outputs.展开更多
This paper is a further investigation of large deviations for sums of random variables Sn=i=1∑n Xi and S（t）=i=1∑N（t）Xi,（t≥0）, where {X_n,n≥1） are independent identically distribution and non-negative random...This paper is a further investigation of large deviations for sums of random variables Sn=i=1∑n Xi and S（t）=i=1∑N（t）Xi,（t≥0）, where {X_n,n≥1） are independent identically distribution and non-negative random variables, and {N（t）,t≥0} is a counting process of non-negative integer-valued random variables, independent of {X_n,n≥1}. In this paper, under the suppose F∈G, which is a bigger heavy-tailed class than C, proved large deviation results for sums of random variables.展开更多
Transfer functions between the benthic foraminiferal fauna of seventy-one sediment surface-samples retrieved from the South Yellow Sea inner shelf and the environmental factors, including the summer bottom-water salin...Transfer functions between the benthic foraminiferal fauna of seventy-one sediment surface-samples retrieved from the South Yellow Sea inner shelf and the environmental factors, including the summer bottom-water salinity(Ss), the summer bottom-water temperature(Ts) and the winter bottom-water temperature(Tw) have been developed utilizing weighted averaging partial least square regression(WA-PLS). Subsequently, the transfer functions have been applied to a late Holocene piston core SY01 from the South Yellow Sea inner shelf, established the variation curves of the Ss, Ts, and Tw during the last 3.9 cal. ka. The Ss and Ts showed a nearly synchronous trend to the published stalagmite δ18O curve from the Jiuxian Cave, meaning they could be used as reliable indicators for the summer monsoon. Similarly, the Tw could be used as an indicator for the winter monsoon for its synchronous change to the insensitive grain size variation of the core ZY-2 retrieved from the Central Yellow Sea mud area. These results suggest that transfer functions based on benthic foraminiferal fauna can be a potentially useful tool in palaeoceanographic and palaeoenvironmental research along the Chinese seaboard.展开更多
A new kind of single-polarization photonic crystal fiber(PCF) is proposed.Two kinds of multi-component glasses and the air are selected as working materials.Through using the full vector finite element method(FEM) and...A new kind of single-polarization photonic crystal fiber(PCF) is proposed.Two kinds of multi-component glasses and the air are selected as working materials.Through using the full vector finite element method(FEM) and the perfectly matched layers(PML),the polarization-maintaining characteristic and the confinement loss of the fiber are analyzed,respectively.In addition,the single-polarization region of the fiber around 1.55 ìm is discussed.Numerical simulations show that the fiber maintains single-polarization operation within the wavelength range of 1.421-1.696μm.The birefringence can reach 6.988×10-3,and the confinement loss is as low as 0.012 dB/m when 7 layers of ring holes are arranged in the cladding at λ=1.55μm.展开更多
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Project supported by the National Natural Science Foundation of China (No. 10371110) and the National Basic Research Program (973) of China (No. 2004CB318000)
文摘The problem of computing a piecewise linear approximation to a surface from its sample has been a focus of research in geometry modeling and graphics due to its widespread applications in computer aided design. In this paper, we give a new algorithm, to be called offset surface filtering (OSF) algorithm, which computes a piecewise-linear approximation of a smooth surface from a finite set of cloud points. The algorithm has two main stages. First, the surface normal on every point is estimated by the least squares best fitting plane method. Second, we construct a restricted Delaunay triangulation, which is a tubular neighborhood of the surface defined by two offset surfaces. The algorithm is simple and robust. We describe an implementation of it and show example outputs.
文摘This paper is a further investigation of large deviations for sums of random variables Sn=i=1∑n Xi and S（t）=i=1∑N（t）Xi,（t≥0）, where {X_n,n≥1） are independent identically distribution and non-negative random variables, and {N（t）,t≥0} is a counting process of non-negative integer-valued random variables, independent of {X_n,n≥1}. In this paper, under the suppose F∈G, which is a bigger heavy-tailed class than C, proved large deviation results for sums of random variables.
基金supported by the National Natural Science Foundation of China(Grant Nos.41006021,41176132)the Western Pacific Ocean System Project(Grant No.XDA11030104)
文摘Transfer functions between the benthic foraminiferal fauna of seventy-one sediment surface-samples retrieved from the South Yellow Sea inner shelf and the environmental factors, including the summer bottom-water salinity(Ss), the summer bottom-water temperature(Ts) and the winter bottom-water temperature(Tw) have been developed utilizing weighted averaging partial least square regression(WA-PLS). Subsequently, the transfer functions have been applied to a late Holocene piston core SY01 from the South Yellow Sea inner shelf, established the variation curves of the Ss, Ts, and Tw during the last 3.9 cal. ka. The Ss and Ts showed a nearly synchronous trend to the published stalagmite δ18O curve from the Jiuxian Cave, meaning they could be used as reliable indicators for the summer monsoon. Similarly, the Tw could be used as an indicator for the winter monsoon for its synchronous change to the insensitive grain size variation of the core ZY-2 retrieved from the Central Yellow Sea mud area. These results suggest that transfer functions based on benthic foraminiferal fauna can be a potentially useful tool in palaeoceanographic and palaeoenvironmental research along the Chinese seaboard.
基金supported by the Basic Research Foundation of Harbin Engineering Universitythe Special Foundation for Harbin Young Scientists (No. 2008RFQXG031)
文摘A new kind of single-polarization photonic crystal fiber(PCF) is proposed.Two kinds of multi-component glasses and the air are selected as working materials.Through using the full vector finite element method(FEM) and the perfectly matched layers(PML),the polarization-maintaining characteristic and the confinement loss of the fiber are analyzed,respectively.In addition,the single-polarization region of the fiber around 1.55 ìm is discussed.Numerical simulations show that the fiber maintains single-polarization operation within the wavelength range of 1.421-1.696μm.The birefringence can reach 6.988×10-3,and the confinement loss is as low as 0.012 dB/m when 7 layers of ring holes are arranged in the cladding at λ=1.55μm.
