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International Conference on Signal Processing Proceedings (ICSP)

作者： Feng Xue Jiaqi Liu Zhifeng Li Gang Meng National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China

ISBN: (纸本)9781479921898

We propose a generalized cross validation (GCV) as a novel criterion for estimating a point spread function (PSF) from the degraded image only. The PSF is obtained by minimizing this new objective functional over a family of Wiener processings. Based on this estimated PSF, we then perform deconvolution using our recently developed SURE-LET algorithm. The GCV-based criterion is exemplified with a number of parametric PSF, involving a scaling factor that controls the blur size. A typical example of such parametrization is the Gaussian kernel. The experimental results demonstrate that the GCV minimization yields highly accurate estimates of the PSF parameters, which also result in a negligible loss of visual quality, compared to that obtained with the exact PSF. The highly competitive results outline the great potential of developing more powerful blind deconvolution algorithms based on this criterion.

关键词： Optical filters Abstracts Estimation Fluorescence Noise reduction Integrated optics Optical imaging

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A blur-sure-let algorithm to blind PSF estimation for deconvolution

A blur-sure-let algorithm to blind PSF estimation for deconv...

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IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC)

作者： Feng Xue Jiaqi Liu Chengguo Liu Gang Meng National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China

In this paper, we consider blind deconvolution that consists of PSF (point spread function) estimation and non-blind deconvolution. It has been proved that blur-SURE - a modified version of SURE (Stein's unbiased risk estimate) - is a valid criterion for parametric PSF estimation. The key contribution of this work is to propose a fast algorithm for the blur-SURE minimization. Incorporating a linear combination of multiple smoother matrices with different but fixed regularization parameters, the optimal regularized processing is obtained by a closed-form solution. This linear parametrization of the processing greatly accelerates the minimization. The extensive experiments show the significant improvement of computational time. The low computational complexity enables the blur-SURE criterion to be readily applied to more complicated parametric forms of PSF.

关键词： Deconvolution Abstracts Minimization Estimation

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Carbon Nanostructures: Covalently Connected Carbon Nanostructures for Current Collectors in Both the Cathode and Anode of Li–S Batteries (Adv. Mater. 41/2016)

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Advanced Materials 2016年第41期28卷

作者： Song Jin Sen Xin Linjun Wang Zhenzhen Du Lina Cao Jiafeng Chen Xianghua Kong Ming Gong Junling Lu Yanwu Zhu Hengxing Ji Rodney S. Ruoff Department of Materials Science and Engineering CAS Key Laboratory of Materials for Energy Conversion iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) University of Science and Technology of China Hefei 230026 China School of Chemistry and Chemical Engineering Hefei University of Technology Hefei 230009 China Hefei National Laboratory for Physical Sciences at the Microscale and Center for Micro‐ and Nanoscale Research and Fabrication University of Science and Technology of China Hefei 230026 China Department of Chemical Physics and CAS Key Laboratory of Materials for Energy Conversion University of Science and Technology of China Hefei 230026 China Material Test and Analysis Lab Engineering and Materials Science Experiment Center University of Science and Technology of China Hefei 230026 China Center for Multidimensional Carbon Materials (CMCM) Institute for Basic Science (IBS) Center at the Ulsan National Institute of Science & Technology (UNIST) Campus Department of Chemistry and School of Materials Science UNIST Ulsan 689‐798 South Korea

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Composite data fusion algorithm for miniature vehicles building navigation base in formation flying

Composite data fusion algorithm for miniature vehicles build...

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IEEE Workshop on Signal Processing Systems (SIPS)

作者： Runle Du Jiaqi Liu Zhifeng Li Zhenhong Niu Zhiye Jiang Yadong Yang National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China (100076) China Academy of Launch Vehicle Technology Beijing China (100076)

When multiple miniature vehicles with individual position and inter-vehicle distance measurement ability collaborate in a formation, navigation base can be established by data fusion in a decentralized and standalone scheme. A Composite Data Fusion (CDF) algorithm which combines Least Square Error and Kalman Filtering is proposed in this paper to build navigation base with optimized computing stress. In CDF, Enhanced LSE is incorporated as the preprocessing stage to build a coarse estimation and handle temporary or permanent group number failure. KF stage is then built to further alleviate noises in the pre-processed estimations In CDF, the dynamic model can be much simpler than KF, so the computation load is reduced while the result still has the advantage of high precision. Simulation results show that, when the fault rate of measurement in each vehicle goes 5 thousandth, the result is still acceptable. The computation time of the proposed method is less than three percent of that of KF, while its precision is almost the same to that of KF.

关键词： Vehicles Kalman filters Navigation mathematical model Equations Data integration

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Fast data fusion algorithm for building navigation base in formation flying

Fast data fusion algorithm for building navigation base in f...

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19th International Conference on Automation and Computing, ICAC 2013

作者： Du, Runle Liu, Jiaqi Jiang, Zhiye Liu, Guojuan National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing 100076 China

ISBN: (纸本)9781908549082

When multiple miniature vehicles with inter-vehicle distance measurement ability collaborate in a formation, navigation base can be established without external assisting systems. Shared navigation data is fused to compensate the drift of navigation system and the noise from distance measurement. Existing algorithms like Least Squared Error (LSE) can process nonlinear measurements at high speed, but the noise level of result is high. Kalman Filtering can achieve lower noise level, but it needs huge amount of calculation. The amount of calculation rendered it unsuitable for onboard computing systems. To reduce the computation load of the data fusion algorithm and maintain high precision, Fast Data Fusion (FDF) algorithm which combines LSE and KF is proposed. In this algorithm, LSE is used as the preprocessing stage to build a coarse estimation and KF is then used to further alleviate noises in the pre-processed estimations. In FDF, the dynamic model can be much simpler than KF, so the computation load is reduced while the result still has the advantage of high precision. Simulation results show that, proposed method uses no more than 2.5% of computation time of Kalman Filtering and achieved matching precision. © 2013 Chinese Automation and Computing Society in the UK - CACS.

关键词： Navigation systems

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An Updated Estimation of Radiative Forcing due to CO_2 and Its Effect on Global Surface Temperature Change

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Advances in Atmospheric sciences 2013年第4期30卷 1017-1024页

作者：张华张若玉石广玉 Laboratory for Climate Studies China Meteorological Administration National Climate Center Atmosphere Science Academy Nanjing University of Information Science and Technology State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics

New estimations of radiative forcing due to CO2 were calculated using updated concentration data of CO2 and a high-resolution radiative transfer model. The stratospheric adjusted radiative forcing （ARF） due to CO2 from the year 1750 to the updated year of 2010 was found to have increased to 1.95 W m-2, which was 17% larger than that of the IPCC＇s 4th Assessment Report because of the rapid increase in CO2 concentrations since 2005. A new formula is proposed to accurately describe the relationship between the ARF of CO2 and its concentration. Furthermore, according to the relationship between the ARF and surface temperature change, possible changes in equilibrium surface temperature were estimated under the scenarios that the concentration of CO2 increases to 1.5, 2, 2.5, 3, 3.5 and 4 times that of the concentration in the year 2008. The result was values of ＋2.2℃, ＋3.8℃, ＋5.1℃, ＋6.2℃, ＋7.1℃ and ＋8.0℃ respectively, based on a middle-level climate sensitivity parameter of 0.8 K （W m 3）-1. Non-equilibrium surface temperature changes over the next 500 years were also calculated under two kinds of emission scenarios （pulsed and sustained emissions） as a comparison, according to the Absolute Global Temperature change Potential （AGTP） of CO2. Results showed that CO2 will likely continue to contribute to global warming if no emission controls are imposed, and the effect on the Earth-atmosphere system will be difficult to restore to its original level.

关键词： CO2 radiative forcing surface temperature change Global Temperature change Potential

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Analysis of primary parameters estimation with space time processing in forward scatter radar

Analysis of primary parameters estimation with space time pr...

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IET International Radar Conference 2013

作者： Chao, Zhou Yan, Zhu Can Cheng, Hu Rong, Liu Xiang Insititute of Intelligent Structure and System Soochow University Suzhou China Department of Electronic Engineering Beijing Institute of Technology Beijing China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematical Beijing China

ISBN: (纸本)9781849196031

The Doppler shift, azimuth and elevation angles estimation is the precondition of target tracking and SISAR imaging in forward scatter radar (FSR). With the utilization of a spacetime processing (STP) algorithm, the Doppler shift and azimuth angle or elevation angle can be jointly estimated. The impacts of the observation interval and multipath interference on parameters estimation accuracy are analyzed. The quasioptimal observation interval is given after considering the contradiction between the frequency resolution and dynamic error. The correctness of these analyses is verified by quantitative simulation results.

关键词： Parameter estimation

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Fast Data Fusion Algorithm for Tracking Maneuvering Target by Vehicle Formation

Fast Data Fusion Algorithm for Tracking Maneuvering Target b...

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IEEE Radar Conference

作者： Runle Du Jiaqi Liu Yonghai Wang Zhifeng Li Chunyue Gao National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing Aero-Top Hi-Tech Corporation Ltd.

ISBN: (纸本)9781467357920

When multiple flying vehicles with bearing-only tracking collaborate in locating a target, observation data fusion is required to compensate the drift of navigation system, the noise from observation system, and the unknown maneuvering of target object. Kalman Filtering of nonlinear observation data needs a huge amount of computation, and will cause trouble to onboard embedded computing systems. Least Squared Error (LSE) can process nonlinear measurements at high speed, but the observation noise may be amplified due to the intrinsic deficiency. In this paper, a Fast Data Fusion algorithm is proposed. It combined these two methodologies. LSE is used as the preprocessing stage to build a coarse estimation and Kalman Filtering is used to further eliminate noises from preprocessed estimations. Simulation results show that, proposed method uses no more than 3% of computation time of Kalman Filtering and achieved similar or even better target locating precision.

关键词： Formation Flying Bearing-only Tracking Passive Target Location Fast Data Fusion Kalman Filtering

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Statistical analysis and simulation method of forward scattering clutter in bistatic radar

Statistical analysis and simulation method of forward scatte...

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IET International Radar Conference 2013

作者： Chuan-fang Zhang Chang-jiang Liu Cheng Hu Xiang-rong Liu School of Information and Electronics Beijing Institute of Technology China 100081 National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematical Beijing China

The research of statistical properties and simulation methods of radar clutter have vital importance to the design, simulation and development of radar systems. Based on the analysis of some experimental data of forward scattering radar (FSR) clutter, it was found that under low wind speed and narrow dynamic range, the amplitude of FSR clutter was subject to K distribution; while under high wind speed or wide dynamic range, it was subject to lognormal distribution; the clutter power spectrum was subject to the fourth-order all-pole model. With the above statistical analysis, the forward scatter coherent clutter was simulated using a method combining zero-memory nonlinear transformation with spherically invariant random process. The statistical characteristics of the simulated clutter were identical to those of the measured clutter, which verified the validity of this method.

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Statistical analysis and simulation method of forward scattering clutter in bistatic radar

Statistical analysis and simulation method of forward scatte...

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IET International Radar Conference 2013

作者： Zhang, Chuan-Fang Liu, Chang-Jiang Hu, Cheng Liu, Xiang-Rong Beijing Institute of Technology School of Information and Electronics Beijing 100081 China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematical Beijing China

ISBN: (纸本)9781849196031

The research of statistical properties and simulation methods of radar clutter have vital importance to the design, simulation and development of radar systems. Based on the analysis of some experimental data of forward scattering radar (FSR) clutter, it was found that under low wind speed and narrow dynamic range, the amplitude of FSR clutter was subject to K distribution;while under high wind speed or wide dynamic range, it was subject to lognormal distribution;the clutter power spectrum was subject to the fourth-order all-pole model. With the above statistical analysis, the forward scatter coherent clutter was simulated using a method combining zero-memory nonlinear transformation with spherically invariant random process. The statistical characteristics of the simulated clutter were identical to those of the measured clutter, which verified the validity of this method.

关键词： Radar clutter

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