In order to resolve the conflict between the limited resources of embedded devices and the growing amount of massive image data to be shown, a solution for fast images rendering in embedded devices is proposed and imp...In order to resolve the conflict between the limited resources of embedded devices and the growing amount of massive image data to be shown, a solution for fast images rendering in embedded devices is proposed and implemented. First, an improved algorithm of a multi-resolution file-pyramid construction which is used for the organization of massive image data is presented. Then, a strategy, adopting technologies such as view-dependent levels of detail, target-tiles quick search and tiles seamless connection, is presented for fast scheduling and viewing of images. The results show that compared with the solution of multi-scale image representations based on wavelet, the proposed solution can improve the rendering speed, and the rendering speed does not depend on the image size, though it increases some data storage space. And the proposed solution is suitable for embedded devices and friendly experience.展开更多
Detecting the moving vehicles in jittering traffic scenes is a very difficult problem because of the complex environment.Only by the color features of the pixel or only by the texture features of image cannot establis...Detecting the moving vehicles in jittering traffic scenes is a very difficult problem because of the complex environment.Only by the color features of the pixel or only by the texture features of image cannot establish a suitable background model for the moving vehicles. In order to solve this problem, the Gaussian pyramid layered algorithm is proposed, combining with the advantages of the Codebook algorithm and the Local binary patterns(LBP) algorithm. Firstly, the image pyramid is established to eliminate the noises generated by the camera shake. Then, codebook model and LBP model are constructed on the low-resolution level and the high-resolution level of Gaussian pyramid, respectively. At last, the final test results are obtained through a set of operations according to the spatial relations of pixels. The experimental results show that this algorithm can not only eliminate the noises effectively, but also save the calculating time with high detection sensitivity and high detection accuracy.展开更多
Si hybrid solar cells have attracted tremendous research attention in recent years because of their low production costs and high performance. However, flexible Si hybrid solar cells have rarely been reported owing to...Si hybrid solar cells have attracted tremendous research attention in recent years because of their low production costs and high performance. However, flexible Si hybrid solar cells have rarely been reported owing to the difficulty of fabricating single-crystalline Si with good flexibility. In this study, we fabricated flexible Si/PEDOT：PSS hybrid solar cells with micro-pyramid-structured Si light absorbers using a facile approach. Compared with planar flexible hybrid solar cells with a power-conversion efficiency of 4%, solar cells with micro-pyramid-structured Si light absorbers have a higher efficiency of 6.3%. External quantum efficiency and electrochemical impedance spectroscopy measurements revealed that the solar cells with micro-pyramid-structured Si light absorbers exhibited a pronounced light-harvesting enhancement in the spectra region of 400-1,000 nm and had a smaller series resistance and larger recombination resistance compared with the planar cells, yielding a higher efficiency. Additionally, in mechanical-bending tests, the flexible solar cells with micro-pyramid-structured Si light absorbers exhibited an excellent performance stability after bending for 600 cycles. Our findings lay the foundation for the real-world applications of flexible Si/PEDOT：PSS hybrid solar cells in next-generation portable electronics.展开更多
Experiments were conducted to investigate the deformation of cantilever sandwich beams with pyramidal truss cores subjected to impact by a projectile at their tips.A new technique was employed to the fabrication of sa...Experiments were conducted to investigate the deformation of cantilever sandwich beams with pyramidal truss cores subjected to impact by a projectile at their tips.A new technique was employed to the fabrication of sandwich beams with pyramidal truss cores.For a better observation of large deformation of specimens during impact process,a high-speed digital video camera was successfully used to capture the instant shapes of the deformed beams.A projectile collection device was designed and installed to avoid the projectile flying away from the beam tips after impact and thus the kinetic energy imparted to the beams was measurable.The experiments show that the sandwich beams have a superior shock resistance compared to the monolithic beams of the same material and mass.Further,finite element simulations were performed to gain insight into the deformations and plastic energy absorptions in the sandwich beams.展开更多
基金The National Public Benefit Research Foundation of China (No. 201111013-02)
文摘In order to resolve the conflict between the limited resources of embedded devices and the growing amount of massive image data to be shown, a solution for fast images rendering in embedded devices is proposed and implemented. First, an improved algorithm of a multi-resolution file-pyramid construction which is used for the organization of massive image data is presented. Then, a strategy, adopting technologies such as view-dependent levels of detail, target-tiles quick search and tiles seamless connection, is presented for fast scheduling and viewing of images. The results show that compared with the solution of multi-scale image representations based on wavelet, the proposed solution can improve the rendering speed, and the rendering speed does not depend on the image size, though it increases some data storage space. And the proposed solution is suitable for embedded devices and friendly experience.
基金Project(61172047)supported by the National Natural Science Foundation of China
文摘Detecting the moving vehicles in jittering traffic scenes is a very difficult problem because of the complex environment.Only by the color features of the pixel or only by the texture features of image cannot establish a suitable background model for the moving vehicles. In order to solve this problem, the Gaussian pyramid layered algorithm is proposed, combining with the advantages of the Codebook algorithm and the Local binary patterns(LBP) algorithm. Firstly, the image pyramid is established to eliminate the noises generated by the camera shake. Then, codebook model and LBP model are constructed on the low-resolution level and the high-resolution level of Gaussian pyramid, respectively. At last, the final test results are obtained through a set of operations according to the spatial relations of pixels. The experimental results show that this algorithm can not only eliminate the noises effectively, but also save the calculating time with high detection sensitivity and high detection accuracy.
基金Acknowledgements This work was supported by the National Basic Research Program of China （973 Program, No. 2011CB302103）, National Natural Science Foundation of China （Nos. 11274308 and 21401202）, the Hundred Talent Program of the Chinese Academy of Sciences, and the CAS/SAFEA International Partnership Program for Creative Research Teams.
文摘Si hybrid solar cells have attracted tremendous research attention in recent years because of their low production costs and high performance. However, flexible Si hybrid solar cells have rarely been reported owing to the difficulty of fabricating single-crystalline Si with good flexibility. In this study, we fabricated flexible Si/PEDOT：PSS hybrid solar cells with micro-pyramid-structured Si light absorbers using a facile approach. Compared with planar flexible hybrid solar cells with a power-conversion efficiency of 4%, solar cells with micro-pyramid-structured Si light absorbers have a higher efficiency of 6.3%. External quantum efficiency and electrochemical impedance spectroscopy measurements revealed that the solar cells with micro-pyramid-structured Si light absorbers exhibited a pronounced light-harvesting enhancement in the spectra region of 400-1,000 nm and had a smaller series resistance and larger recombination resistance compared with the planar cells, yielding a higher efficiency. Additionally, in mechanical-bending tests, the flexible solar cells with micro-pyramid-structured Si light absorbers exhibited an excellent performance stability after bending for 600 cycles. Our findings lay the foundation for the real-world applications of flexible Si/PEDOT：PSS hybrid solar cells in next-generation portable electronics.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11032001 and 10602005)
文摘Experiments were conducted to investigate the deformation of cantilever sandwich beams with pyramidal truss cores subjected to impact by a projectile at their tips.A new technique was employed to the fabrication of sandwich beams with pyramidal truss cores.For a better observation of large deformation of specimens during impact process,a high-speed digital video camera was successfully used to capture the instant shapes of the deformed beams.A projectile collection device was designed and installed to avoid the projectile flying away from the beam tips after impact and thus the kinetic energy imparted to the beams was measurable.The experiments show that the sandwich beams have a superior shock resistance compared to the monolithic beams of the same material and mass.Further,finite element simulations were performed to gain insight into the deformations and plastic energy absorptions in the sandwich beams.
