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IET International Radar Conference 2015

作者： L. Gao Z. Y. Jiang J. Q. Liu H. Y. Liu J. L. Bai F. Xu H. Li S. Y. Chen L. Sun Y. B. Bian J. Wang Y. S. He National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics P.O. box 9200 Beijing 100076 China Chinese Academy of Sciences Beijing Beijing CN

ISBN: (纸本)9781510822023

This paper presents a development of a narrowband hightemperature superconducting filter with high selectivity. The center frequency of this filter is 8.625 GHz and the 3 dB bandwidth is 156 MHz (a fractional bandwidth of 1.81 %). In order to achieve high band edge steepness, we introduce a 10-resonator quasi-elliptic function response with two pairs of transmission zeros in the cascaded quadruplet coupling structure. The filter was manufactured on a 2-in-diameter 0.5-mm-thick MgO wafer with double-sided YBCO films. The measured results show a midband insertion loss of 0.58 dB and a return loss better than 16 dB. Band edge steepness reaches over 3.82 dB/MHz at both the high and low frequency edges. The 60 dB rectangle ratio is less than 1.19. The out-of-band rejection is over 60 dB at 17.8 MHz from the 3 dB band edge.

关键词： High-temperature superconducting (HTS) X-band microwave filter transmission zeros

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Performance test of Fourier transform infrared imaging spectrometer

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Guangxue Jingmi Gongcheng/Optics and Precision Engineering 2015年 23卷 190-196页

作者： Li, Jian-Hua Xue, Feng Xue, Lian Li, Zhi-Feng Liu, Jia-Qi National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing100076 China

The paper researches the measurement methods of key parameters of Fourier transform imaging spectrometers. Firstly, the physical meaning of the key parameter Noise Equivalent Spectral Radiance (NESR) was introduced and corresponding calculation model, test principle and data processing method were given. Then, a calibrated black body was used as radiation source, the performance parameters of Fourier transform imaging spectrometer for mid-wavelength and long-wavelength were tested experimentally, including the NESR, radiometric accuracy and spectral errors. test results show that the average NESRs of infrared imaging spectrometer for long-wavelength at 10 μm is 21.4 nW/(cm2·sr·cm-1) and that for mid-wavelength at 4.6 μm is 4.6 nW/(cm2·sr·cm-1). The radiometric accuracies of the spectrometer is less than 0.4 K and 2 K for long-wave and mid-wave, respectively. The spectral errors of the spectrometer for both mid-wavelength and long-wavelength are less than half of the spectral resolution. These parameters are all in the normal range, which verifies the feasibility of test method. It provides references for the periodically measurement of imaging spectrometers. © 2015, Chinese Academy of sciences. All right reserved.

关键词： Temperature measurement

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A novel GCV-based criterion for parametric PSF estimation 12

A novel GCV-based criterion for parametric PSF estimation

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2014 12th IEEE International Conference on Signal Processing, ICSP 2014

作者： Xue, Feng Liu, Jiaqi Li, Zhifeng Meng, Gang National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing100076 China

ISBN: (纸本)9781479921881

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. © 2014 IEEE.

关键词： Optical transfer function

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Structuring interactive artificial bee colony forecasting model in foreign exchange rate forecasting with consumer confidence index and conventional microeconomics factors

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ICIC Express Letters, Part B: Applications 2016年第4期7卷 895-901页

作者： Tsai, Pei-Wei Liu, Chia-Han Zhang, Jilin Chang, Jui-Fang College of Information Science and Engineering Fujian University of Technology No. 3 Xueyuan Road University Town MinhouFuzhou350118 China Key Laboratory for Automotive Electronics and Electric Drive of Fujian Province Fujian University of Technology No. 3 Xueyuan Road University Town MinhouFuzhou350118 China Department of International Business National Kaohsiung University of Applied Sciences No. 415 Chien-Kong Road Kaohsiung City80778 Taiwan Department of Mathematics and Physics Fujian University of Technology No. 3 Xueyuan Road University Town MinhouFuzhou350118 China

Existing methods used in the foreign exchange rate forecasting are mostly in the branch of the time series methods. The time series models usually do not focus on the short-term forecasting, but the chronic forecasting. Models for the short-term forecasting still remains blank. In addition, conventional foreign exchange rate forecasting methods only consider the factors in microeconomics. No psychological factors are collected in the forecasting process. The forecasting method, which simultaneously considers both the technical and the psychological factors, is not revealed. Answering the needs of short- term foreign exchange rate forecasting and the comprehensive consideration of technical and psychological factors, the new foreign exchange rate forecasting model based on Interactive Artificial Bee Colony (IABC) is proposed. In this paper, IABC algorithm is employed to create a foreign exchange rate forecasting model. Our proposed forecasting model not only utilizes the conventional factors in microeconomics, but also includes the Consumer Confidence Index (CCI) in the consideration as one of the reference data for estimating the foreign exchange rate. In our proposed forecasting model, the reference data include indices announced daily, weekly, and monthly. The output is composed of all reference indices and a set of weighting, which is corresponding to the indices. In our design, IABC plays the role to properly rate the significance of each index and to provide a set of weighting to combine the indices, together, to form a single forecasting value. The final output of our proposed forecasting model is the forecasted foreign exchange rate for the next day. In order to test the accuracy of our proposed method, 4 years of the historical data in 2011 to 2014 are included in the experiments. The forecasting error is about 0:07‰ in average, the maximum forecasting error over all test periods is 0:21‰, and the minimum forecasting error over all test periods is zero. In a

关键词： Optimization

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Pulse Phase Modulation for On-Off Thruster Pair

Pulse Phase Modulation for On-Off Thruster Pair

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IEEE Aerospace Conference

作者： Runle Du Jiaqi Liu Li Zhang Lu Gao National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics

ISBN: (纸本)9781479916191

On-Off thrusters have limitation both at minimum on-time and minimum off-time, so the output is nonlinear pulses. Use on-off thrusters to provide linear or near linear control force is a fundamental and important research topic. Existing previous works do not overcome the limitation of on-time and off-time constraints, so the output is only an approximation of demanded force output. In this paper, Pulse Phase modulation (PP) is proposed to generate linear output through on-off thruster pair. PP modulation exploited the dynamic output curve of thrusters. By adjusting phase difference of thruster pair that installed in the opposite direction, thrust output can be linear proportional to demanded force output. PP modulation breaks the limitation caused by minimum on-time and off-time, and thus achieves high continuity of thrust output. For practical engineering implementation, two approximate methods are proposed as double frequency phase modulation and quadruple frequency phase modulation. Theoretical analysis and experimental results are provided to prove that PP modulation can yield much better precision in stabilizing space vehicles.

关键词： THRUSTER phase modulation on-off Punctuality phase difference Output off time Time constraints Polypropylenes Space vehicles Pairing

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A novel GCV-based criterion for parametric PSF estimation

A novel GCV-based criterion for parametric PSF estimation

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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

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

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Polar Coordinate Lattice Boltzmann Kinetic Modeling of Detonation Phenomena

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Communications in Theoretical physics 2014年第11期61卷 737-748页

作者：林传栋许爱国张广财李英俊 State Key Laboratory for GeoM echanics and Deep Underground Engineering China University of Mining and Technology National Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Center for Applied Physics and Technology MOE Key Center for High Energy Density Physics Simulations College of Engineering Peking University State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology State Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences

A novel polar coordinate lattice Boltzmann kinetic model for detonation phenomena is presented and applied to investigate typical implosion and explosion processes. In this model, the change of discrete distribution function due to local chemical reaction is dynamically coupled into the modified lattice Boltzmann equation which could recover the Navier–Stokes equations, including contribution of chemical reaction, via the Chapman–Enskog *** the numerical investigations, the main focuses are the nonequilibrium behaviors in these processes. The system at the disc center is always in its thermodynamic equilibrium in the highly symmetric case. The internal kinetic energies in different degrees of freedom around the detonation front do not coincide. The dependence of the reaction rate on the pressure, influences of the shock strength and reaction rate on the departure amplitude of the system from its local thermodynamic equilibrium are probed.

关键词： lattice Boltzmann method detonation wave nonequilibrium behavior polar coordinate

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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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Detecting Changes in Precipitation and Temperature Extremes over China Using a Regional Climate Model with Water Table Dynamics Considered

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Atmospheric and Oceanic science Letters 2014年第2期7卷 103-109页

作者： QIN Pei-Hua XIE Zheng-Hui WANG Ai-Wen The National Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences School of Applied Science Beijing Information and Science Technology University

Simulations were conducted with the regional climate model RegCM incorporating water table dynamics from 1 September 1982 to 28 August 2002 to detect precipitation and temperature extremes. Compared with observed r10(number of days with precipitation ≥ 10 mm d–1), RegCM3_Hydro(the regional climate model with water table dynamics considered) simulated rain belts, including those in southern China and the middle and lower reaches of the Yangtze River, and provided data for arid to semi-arid areas such as the Heihe River Basin in northwestern China. RegCM3_Hydro indicated a significant increasing trend of r95p(days with daily precipitation greater than the 95th percentile of daily amounts) for the Yangtze, Yellow, and Pearl River basins, consistent with r95p observations. The Haihe River Basin was also chosen as a specific case to detect the effect of groundwater on extreme precipitation using peaks over threshold(POT)-based generalized Pareto distribution(GPD) with parameters estimated by the L-moment method. Quantile plots showed that all but a few of the plotted points were distributed near diagonal lines and the modeled data fitted well with the samples. Finally, the effects of water table dynamics on temperature extremes were also evaluated. In the Yellow River Basin and Songhuajiang River Basin, the trends of the number of warm days(TX95n) from RegCM3_Hydro matched observed values more closely when water table dynamics were considered, and clearly increasing numbers of warm days from 1983 to 2001 were detected.

关键词： climatic extreme groundwater runoff river basin regional climate

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A Stability Analysis of Hybrid Schemes to Cure Shock Instability

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Communications in Computational physics 2014年第5期15卷 1320-1342页

作者： Zhijun Shen Wei Yan Guangwei Yuan National Key Laboratory of Science and Technology on Computational Physics Institute of Applied Physics and Computational MathematicsP.O.Box 8009-26Beijing 100088China Center for Applied Physics and Technology HEDPSPeking UniversityBeijing 100871China.

The carbuncle phenomenon has been regarded as a spurious solution produced by most of contact-preserving *** hybrid method of combining high resolution flux with more dissipative solver is an attractive attempt to cure this kind of non-physical *** this paper,a matrix-based stability analysis for 2-D Euler equations is performed to explore the cause of instability of numerical *** combining the Roe with HLL flux in different directions and different flux components,we give an interesting explanation to the linear numerical *** on such analysis,some hybrid schemes are compared to illustrate different mechanisms in controlling shock *** experiments are presented to verify our analysis *** conclusion is that the scheme of restricting directly instability source is more stable than other hybrid schemes.

关键词： Godunov methods numerical shock instability hybrid scheme.

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