Directional response is one of the most important parameters of pyranometer,which is crucial to evaluate the performance of the pyranometer by determining the responsivityand the corresponding radiation for solar beam...Directional response is one of the most important parameters of pyranometer,which is crucial to evaluate the performance of the pyranometer by determining the responsivityand the corresponding radiation for solar beam radiation from different directions of the pyranometer. In the paper,the method for testing directional error is present,four pyranometers are tested,after data processing,the directional errors of a secondary standard CM P22 and a first class CM P11 are 4.5 W/m^2 and 8.3 W/m^2 respectively,which are within the nominal specification given by the manufacturer. M eanwhile,the directional error of a first class pyranometerF S-S6 is 11.0 W/m^2,while the value of a second class pyranometer TBQ-2-B is15.2 W/m^2,which both meet the specification for classification. The results showthat these four pyranometers can reach the levels recommended by WM O and ISO,which validates that the method is feasible and the China made pyranometers are reliable.展开更多
Palmprint recognition is an emerging biometrics technology that has attracted increasing attention in recent years. Many palmprint recognition methods have been proposed, including traditional methods and deep learnin...Palmprint recognition is an emerging biometrics technology that has attracted increasing attention in recent years. Many palmprint recognition methods have been proposed, including traditional methods and deep learning-based methods. Among the traditional methods, the methods based on directional features are mainstream because they have high recognition rates and are robust to illumination changes and small noises. However, to date, in these methods, the stability of the palmprint directional response has not been deeply studied. In this paper, we analyse the problem of directional response instability in palmprint recognition methods based on directional feature. We then propose a novel palmprint directional response stability measurement (DRSM) to judge the stability of the directional feature of each pixel. After filtering the palmprint image with the filter bank, we design DRSM according to the relationship between the maximum response value and other response values for each pixel. Using DRSM, we can judge those pixels with unstable directional response and use a specially designed encoding mode related to a specific method. We insert the DRSM mechanism into seven classical methods based on directional feature, and conduct many experiments on six public palmprint databases. The experimental results show that the DRSM mechanism can effectively improve the performance of these methods. In the field of palmprint recognition, this work is the first in-depth study on the stability of the palmprint directional response, so this paper has strong reference value for research on palmprint recognition methods based on directional features.展开更多
Azimuthal variations in site response can provide a good insight into the site amplification and seismic conditions of geohazard occurrences.In this study,multiple directional site response methods,including D-Arias(D...Azimuthal variations in site response can provide a good insight into the site amplification and seismic conditions of geohazard occurrences.In this study,multiple directional site response methods,including D-Arias(Directional-Arias),D-SER(Directional-Shaking energy ratio),D-HVSR(Directional-Horizontal to vertical spectral ratio)and D-SSR(Directional–Standard spectral ratio),are adopted to analyse seismic data of the 2013 Lushan Ms 7.0 earthquake captured by the self-established Lengzhuguan(LZG)station which consists of the complex topography of isolated ridge,large mountain and some typical micro-reliefs.The results show that the isolated ridge could cause stronger site responses than the large mountain,and whose pronounced response direction is roughly perpendicular to its ridgeline.With the growth of elevation,the siteresonant frequency decreases.The different microreliefs on the mountain cause different site responses,which present as protruding slope>linear slope.The site response mainly exists on the surficial layer of the mountain and shows that with the increase of the distance to mountain surface,the site response gets weaker,the site resonant frequency gets higher,and the pronounced response direction is perpendicular to its ridgeline.展开更多
Age related macular degeneration （AMD） is a complex progres- sive neurodegenerative disease causing blindness in 30-35 million people worldwide. It affects the macula region of the retina leading to severe vision lo...Age related macular degeneration （AMD） is a complex progres- sive neurodegenerative disease causing blindness in 30-35 million people worldwide. It affects the macula region of the retina leading to severe vision loss and legal blindness in individuals 〉 50 years of age （Wong et al., 2014）. The precise aetiology of AMD is unknown but smoking, age and genetic factors are major risk factors for AMD predisposition （Ding et al., 2009）. The genetic basis of AMD is well described with a recent study from the International AMD gene consortium （IAMDGC） reporting 52 genetic variants across 34 loci associated with the risk of AMD pathogenesis and explaining more than 50% of the genetic heritabilitv of the disease （Fritsche et al., 2016）.展开更多
On the basis of the wave energy balance equation, the response model of mean directions of locally wind-generated waves in slowly turning wind fields has been derived. The results show that in a homogeneous field, the...On the basis of the wave energy balance equation, the response model of mean directions of locally wind-generated waves in slowly turning wind fields has been derived. The results show that in a homogeneous field, the time scale of the response is not only related to the rate of wave growth, but also to the directional energy distribution and the angle between the wind direction and the mean wave direction. Furthermore, the law of change in the mean wave direction has been derived. The numerical computations show that the response of wave directions to slowly turning wind directions can be treated as the superposition of the responses of wave directions to a series of sudden small-angle changes of wind directions and the turning rate of the mean wave direction depends on the turning rate and the total turning angles of the wind direction. The response of wave directions is in agreement with the response for a sudden change of wind directions if the change in wind directions is very fast. Based on the normalized rates of wave growth under local winds presented by Wen et al. (1989), a quantitative estimate of the time scale of the response shows that the relationships between the dimensionless time scale and both the dimensionless total wave energy and the dimensionless peak frequency agree fairly well with the observations in comparison with other models.展开更多
基金supported by public sector(Meteorology)research projects(GYHY201006044)meteorological key technology integration and application projects(CMAGJ2011M68)
文摘Directional response is one of the most important parameters of pyranometer,which is crucial to evaluate the performance of the pyranometer by determining the responsivityand the corresponding radiation for solar beam radiation from different directions of the pyranometer. In the paper,the method for testing directional error is present,four pyranometers are tested,after data processing,the directional errors of a secondary standard CM P22 and a first class CM P11 are 4.5 W/m^2 and 8.3 W/m^2 respectively,which are within the nominal specification given by the manufacturer. M eanwhile,the directional error of a first class pyranometerF S-S6 is 11.0 W/m^2,while the value of a second class pyranometer TBQ-2-B is15.2 W/m^2,which both meet the specification for classification. The results showthat these four pyranometers can reach the levels recommended by WM O and ISO,which validates that the method is feasible and the China made pyranometers are reliable.
基金supported by National Science Foundation of China(No.62076086).
文摘Palmprint recognition is an emerging biometrics technology that has attracted increasing attention in recent years. Many palmprint recognition methods have been proposed, including traditional methods and deep learning-based methods. Among the traditional methods, the methods based on directional features are mainstream because they have high recognition rates and are robust to illumination changes and small noises. However, to date, in these methods, the stability of the palmprint directional response has not been deeply studied. In this paper, we analyse the problem of directional response instability in palmprint recognition methods based on directional feature. We then propose a novel palmprint directional response stability measurement (DRSM) to judge the stability of the directional feature of each pixel. After filtering the palmprint image with the filter bank, we design DRSM according to the relationship between the maximum response value and other response values for each pixel. Using DRSM, we can judge those pixels with unstable directional response and use a specially designed encoding mode related to a specific method. We insert the DRSM mechanism into seven classical methods based on directional feature, and conduct many experiments on six public palmprint databases. The experimental results show that the DRSM mechanism can effectively improve the performance of these methods. In the field of palmprint recognition, this work is the first in-depth study on the stability of the palmprint directional response, so this paper has strong reference value for research on palmprint recognition methods based on directional features.
基金supported by the National Natural Science Foundation of China(Grant No.41877235)the National Key Research and Development Program of China(Grant No.2017YFC1501000)+1 种基金China Postdoctoral Science Foundation(2020M673292)the National Science Funds for Creative Research Groups of China(Grant No.41521002)。
文摘Azimuthal variations in site response can provide a good insight into the site amplification and seismic conditions of geohazard occurrences.In this study,multiple directional site response methods,including D-Arias(Directional-Arias),D-SER(Directional-Shaking energy ratio),D-HVSR(Directional-Horizontal to vertical spectral ratio)and D-SSR(Directional–Standard spectral ratio),are adopted to analyse seismic data of the 2013 Lushan Ms 7.0 earthquake captured by the self-established Lengzhuguan(LZG)station which consists of the complex topography of isolated ridge,large mountain and some typical micro-reliefs.The results show that the isolated ridge could cause stronger site responses than the large mountain,and whose pronounced response direction is roughly perpendicular to its ridgeline.With the growth of elevation,the siteresonant frequency decreases.The different microreliefs on the mountain cause different site responses,which present as protruding slope>linear slope.The site response mainly exists on the surficial layer of the mountain and shows that with the increase of the distance to mountain surface,the site response gets weaker,the site resonant frequency gets higher,and the pronounced response direction is perpendicular to its ridgeline.
基金funding from the National Health and Medical Research Council of Australia (NHMRC) project grant 1008979Senior Research Fellowship 1028444 (PNB)+1 种基金Melbourne International research ScholarshipMelbourne International fee remission scholarship from the University of Melbourne Australia
文摘Age related macular degeneration （AMD） is a complex progres- sive neurodegenerative disease causing blindness in 30-35 million people worldwide. It affects the macula region of the retina leading to severe vision loss and legal blindness in individuals 〉 50 years of age （Wong et al., 2014）. The precise aetiology of AMD is unknown but smoking, age and genetic factors are major risk factors for AMD predisposition （Ding et al., 2009）. The genetic basis of AMD is well described with a recent study from the International AMD gene consortium （IAMDGC） reporting 52 genetic variants across 34 loci associated with the risk of AMD pathogenesis and explaining more than 50% of the genetic heritabilitv of the disease （Fritsche et al., 2016）.
文摘On the basis of the wave energy balance equation, the response model of mean directions of locally wind-generated waves in slowly turning wind fields has been derived. The results show that in a homogeneous field, the time scale of the response is not only related to the rate of wave growth, but also to the directional energy distribution and the angle between the wind direction and the mean wave direction. Furthermore, the law of change in the mean wave direction has been derived. The numerical computations show that the response of wave directions to slowly turning wind directions can be treated as the superposition of the responses of wave directions to a series of sudden small-angle changes of wind directions and the turning rate of the mean wave direction depends on the turning rate and the total turning angles of the wind direction. The response of wave directions is in agreement with the response for a sudden change of wind directions if the change in wind directions is very fast. Based on the normalized rates of wave growth under local winds presented by Wen et al. (1989), a quantitative estimate of the time scale of the response shows that the relationships between the dimensionless time scale and both the dimensionless total wave energy and the dimensionless peak frequency agree fairly well with the observations in comparison with other models.
