As modern weapons and equipment undergo increasing levels of informatization,intelligence,and networking,the topology and traffic characteristics of battlefield data networks built with tactical data links are becomin...As modern weapons and equipment undergo increasing levels of informatization,intelligence,and networking,the topology and traffic characteristics of battlefield data networks built with tactical data links are becoming progressively complex.In this paper,we employ a traffic matrix to model the tactical data link network.We propose a method that utilizes the Maximum Variance Unfolding(MVU)algorithm to conduct nonlinear dimensionality reduction analysis on high-dimensional open network traffic matrix datasets.This approach introduces novel ideas and methods for future applications,including traffic prediction and anomaly analysis in real battlefield network environments.展开更多
Scattering media pose a significant barrier to non-invasive biomedical imaging,as conventional wavefront shaping methods rely on invasive guide stars or costly nonlinear modalities.Here,we introduce an improved approa...Scattering media pose a significant barrier to non-invasive biomedical imaging,as conventional wavefront shaping methods rely on invasive guide stars or costly nonlinear modalities.Here,we introduce an improved approach that enables high-fidelity,non-invasive fluorescence imaging through scattering media by combining the linear fluorescence mechanism with efficient computational optimization.The method leverages a genetic algorithm guided by variance maximization to dynamically optimize speckle,non-invasively exciting an individual fluorescent bead by∼10-fold enhancement in target intensity ratio.This process generates a precise system point spread function(PSF),which drives a convex optimization-based deconvolution framework to reconstruct obscured targets.Remarkably,the technique eliminates the need for complex scanning systems,achieving rapid wide-field imaging with structural similarity(SSIM)indices exceeding 0.997(for beads).We demonstrate robust imaging of both discrete beads and continuous fibers behind scattering media,revealing resolution superior to that of conventional speckle cross-correlation methods.The method provides a pathway for non-invasively visualizing fluorescent objects behind scattering media.展开更多
To reduce the vibration in the suspension, semi active suspension system was employed. And its CARMA model was built. Two adaptive control schemes, the minimum variance self tuning control algorithm and the pole con...To reduce the vibration in the suspension, semi active suspension system was employed. And its CARMA model was built. Two adaptive control schemes, the minimum variance self tuning control algorithm and the pole configuration self tuning control algorithm, were proposed. The former can make the variance of the output minimum while the latter can make dynamic behavior satisfying. The stability of the two schemes was analyzed. Simulations of them show that the acceleration in the vertical direction has been reduced greatly. The purpose of reducing vibration is realized. The two schemes can reduce the vibration in the suspension and have some practicability.展开更多
Fengyun-4 A(FY-4 A) belongs to the second generation of geostationary meteorological satellite series in China. Its observations with high frequency and resolution provide a better data basis for monitoring of extreme...Fengyun-4 A(FY-4 A) belongs to the second generation of geostationary meteorological satellite series in China. Its observations with high frequency and resolution provide a better data basis for monitoring of extreme weather such as sudden flood disasters. In this study, the flood disasters occurred in Bangladesh, India, and some other areas of South Asia in August 2018 were investigated by using a rapid multi-temporal synthesis approach for the first time for removal of thick clouds in FY-4 A images. The maximum between-class variance algorithm(OTSU;developed by Otsu in 2007) and linear spectral unmixing methods are used to extract the water area of flood disasters. The accuracy verification shows that the water area of flood disasters extracted from FY-4 A is highly correlated with that from the high-resolution satellite datasets Gaofen-1(GF-1) and Sentinel-1 A, with the square correlation coefficient R2 reaching 0.9966. The average extraction accuracy of FY-4 A is over 90%. With the rapid multi-temporal synthesis approach used in flood disaster monitoring with FY-4 A satellite data, advantages of the wide coverage, fast acquisition,and strong timeliness with geostationary meteorological satellites are effectively combined. Through the synthesis of multi-temporal images of the flood water body, the influence of clouds is effectively eliminated, which is of great significance for the real-time flood monitoring. This also provides an important service guarantee for the disaster prevention and reduction as well as economic and social development in China and the Asia-Pacific region.展开更多
文摘As modern weapons and equipment undergo increasing levels of informatization,intelligence,and networking,the topology and traffic characteristics of battlefield data networks built with tactical data links are becoming progressively complex.In this paper,we employ a traffic matrix to model the tactical data link network.We propose a method that utilizes the Maximum Variance Unfolding(MVU)algorithm to conduct nonlinear dimensionality reduction analysis on high-dimensional open network traffic matrix datasets.This approach introduces novel ideas and methods for future applications,including traffic prediction and anomaly analysis in real battlefield network environments.
基金National Natural Science Foundation of China(62175198,62335018,12127805,62005309,61991452,U22A2092)Open Science Foundation of the Key Laboratory of Hepatobiliary Technology of Mengchao(2024ZDSY1001)Youth Innovation Promotion Association of the Chinese Academy of Sciences。
文摘Scattering media pose a significant barrier to non-invasive biomedical imaging,as conventional wavefront shaping methods rely on invasive guide stars or costly nonlinear modalities.Here,we introduce an improved approach that enables high-fidelity,non-invasive fluorescence imaging through scattering media by combining the linear fluorescence mechanism with efficient computational optimization.The method leverages a genetic algorithm guided by variance maximization to dynamically optimize speckle,non-invasively exciting an individual fluorescent bead by∼10-fold enhancement in target intensity ratio.This process generates a precise system point spread function(PSF),which drives a convex optimization-based deconvolution framework to reconstruct obscured targets.Remarkably,the technique eliminates the need for complex scanning systems,achieving rapid wide-field imaging with structural similarity(SSIM)indices exceeding 0.997(for beads).We demonstrate robust imaging of both discrete beads and continuous fibers behind scattering media,revealing resolution superior to that of conventional speckle cross-correlation methods.The method provides a pathway for non-invasively visualizing fluorescent objects behind scattering media.
文摘To reduce the vibration in the suspension, semi active suspension system was employed. And its CARMA model was built. Two adaptive control schemes, the minimum variance self tuning control algorithm and the pole configuration self tuning control algorithm, were proposed. The former can make the variance of the output minimum while the latter can make dynamic behavior satisfying. The stability of the two schemes was analyzed. Simulations of them show that the acceleration in the vertical direction has been reduced greatly. The purpose of reducing vibration is realized. The two schemes can reduce the vibration in the suspension and have some practicability.
基金Supported by the National Key Research and Development Program of China(2018YFC1506500)。
文摘Fengyun-4 A(FY-4 A) belongs to the second generation of geostationary meteorological satellite series in China. Its observations with high frequency and resolution provide a better data basis for monitoring of extreme weather such as sudden flood disasters. In this study, the flood disasters occurred in Bangladesh, India, and some other areas of South Asia in August 2018 were investigated by using a rapid multi-temporal synthesis approach for the first time for removal of thick clouds in FY-4 A images. The maximum between-class variance algorithm(OTSU;developed by Otsu in 2007) and linear spectral unmixing methods are used to extract the water area of flood disasters. The accuracy verification shows that the water area of flood disasters extracted from FY-4 A is highly correlated with that from the high-resolution satellite datasets Gaofen-1(GF-1) and Sentinel-1 A, with the square correlation coefficient R2 reaching 0.9966. The average extraction accuracy of FY-4 A is over 90%. With the rapid multi-temporal synthesis approach used in flood disaster monitoring with FY-4 A satellite data, advantages of the wide coverage, fast acquisition,and strong timeliness with geostationary meteorological satellites are effectively combined. Through the synthesis of multi-temporal images of the flood water body, the influence of clouds is effectively eliminated, which is of great significance for the real-time flood monitoring. This also provides an important service guarantee for the disaster prevention and reduction as well as economic and social development in China and the Asia-Pacific region.
