中国科学院机构知识库网格系统: 检索

Quantitative combination load forecasting model based on forecasting error optimization 期刊论文 OAI收割
COMPUTERS & ELECTRICAL ENGINEERING, 2022, 卷号: 101, 页码: 11
作者: Deng, Song; Chen, Fulin; Wu, Di; He, Yi; Ge, Hui

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收藏 | 浏览/下载：58/0 | 提交时间：2022/08/22

Gene expression programming Data noise reduction Load forecasting error Combination load forecasting

Calculation of verticality in large-aperture optical centering machinery turning 会议论文 OAI收割
Shanghai, China, 2020-06-29
作者: Yu, Lei; Xing, Fu; Shifa, Kang; Xihong, Fu

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收藏 | 浏览/下载：38/0 | 提交时间：2020/12/21

Optical Machinery Turning Collimation Perpendicularity Least squares fitting Error combination

Influence and simulated correction of tip/tilt phase error on fiber laser coherent beam combination 期刊论文 OAI收割
ACTA PHYSICA SINICA, 2011, 卷号: 60, 期号: 11
作者: Geng Chao; Li Xin-Yang; Zhang Xiao-Jun; Rao Chang-Hui

收藏 | 浏览/下载：51/0 | 提交时间：2015/09/21

fiber laser coherent beam combination tip/tilt phase error dynamic analysis

Reentry guidance based on feedback linearization (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronics, Communications and Control, ICECC 2011, September 9, 2011 - September 11, 2011, Ningbo, China
Li D.-W.

收藏 | 浏览/下载：51/0 | 提交时间：2013/03/25

This paper presents a new reentry guidance algorithm for RLV (Reusable Launching Vehicle). The algorithm consists of two integrated components: trajectory planning algorithm and tracking algorithm. The most striking feature of algorithm here lies in that both planning and tracking are executed directly in height-velocity space which is different from the methodology of configuration of drag in traditional shuttle guidance. In the session of trajectory planning all trajectory constraints can be expressed with upper bound and lower bound in height-velocity space then a linear interpolation is carried to search the nominal trajectory satisfying the requirement of downrange and target constraints. Then the tracking algorithm uses feedback linearization method to track this nominal profile and meet all constraints. Another typical feature of this algorithm is the strategy of downrange extension using FPA (flight path angle) controller to fulfill the requirement of large downrange. Proper combination of planning-tracking algorithm and FPA controller can bring great flexibility and adaptability to reentry guidance. The algorithm is proved to be robust enough to accommodate the model error and noises in the dynamics. 2011 IEEE.

Design and test of pointing mirror assembly for spaceborne remote sensing camera (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronics, Communications and Control, ICECC 2011, September 9, 2011 - September 11, 2011, Ningbo, China
作者: Chen W.

收藏 | 浏览/下载：47/0 | 提交时间：2013/03/25

In order to ensure the surface figure of the pointing mirror (460mm long 290mm wide) in spaceborne remote sensing camera Silicon Carbide was selected as the mirror material. The form of composite triangular and rectangular and the combination of open and closed back was explored in the lightweight design. A new kinematic mount and flexible structure in axis is used to hold the mirror around the lateral surface. The structure can minimize distortions induced by coefficient of thermal expansion mismatch among the materials. This eliminates the bending of the integral mount under the weight of the mirror. Optical performance of the mirror was analyzed under gravity load and temperature load using finite element method. Predicted surface figure error based on the removal of bias tilt and power was calculated using an in-house Matlab script for mirrors. The pointing mirror assembly was tested using open loop servo control. And the surface figure was checked using interferometer. Surface figure accuracy is better than 1/30 ( 632.8nm rms). The results show that the kinematic mount induces minimal figure error on the optical surface. 2011 IEEE.

Cycle slip detection using multi-frequency GPS carrier phase observations: A simulation study 期刊论文 OAI收割
ADVANCES IN SPACE RESEARCH, 2010, 卷号: 46, 期号: 2, 页码: 144-149
作者: Wu, Y.

收藏 | 浏览/下载：35/0 | 提交时间：2015/08/19

GPS Cycle slip Gross error Multi-frequency combination

Study on chromaticity balance for LED exposure system (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2007 - Laser, Ultraviolet, and Terahertz Technology, September 9, 2007 - September 12, 2007, Beijing, China
作者: Meng Z.; Meng Z.

收藏 | 浏览/下载：34/0 | 提交时间：2013/03/25

A standard white light compounding algorithm based on combination of CCD illumination acquisition with computer control is presented for LEDs. The computer adjust and control the working current of LEDs by using three-color LEDs illumination acquired by CCD camera achieved chromaticity coordinates error between compounded white light and standard white light D65 less than the threshold beforehand setted by this technique then acquiring needed standard white light. Compounded white light meet the chromaticity error demand that is able to be changed at the same time the CCD illumination acquisition system is eliminated. The proposed algorithm improved the light energy utilization efficiency of LED and eliminated the offset of central wavelength and chromaticity coordinates due to work current change of LEDs. Experimental results show that the proposed algorithm achieved lesser chromaticity error uv=0.001 relative to standard white light D65 enhanced chromaticity uniformity of illumination field.

Study on chroma balance based on grating spectrometer for LED (EI CONFERENCE) 会议论文 OAI收割
Light-Emitting Diode Materials and Devices II, November 12, 2007 - November 14, 2007, Beijing, China
作者: Meng Z.; Meng Z.

收藏 | 浏览/下载：45/0 | 提交时间：2013/03/25

A standard white light compounding algorithm based on combination of choma coordinates acquisition system with computer working current control system is presented for three-color LED. The chroma coordinates acquisition system consist of grating spectrometer and integrating sphere. The computer adjust and control the working current of three-color LED then achieved chroma coordinates error between the compounded white light and standard white light D65 until the chroma coordinates is less than the threshold beforehand set by this technique. The compounded white light meet the chroma error demanded that is able to be changed at the same time the chroma coordinates acquisition system and the working current control system are eliminated. The proposed algorithm the offset of central wavelength and the change of chroma coordinates due to working current variety for LEDs. Experimental results show that the proposed algorithm achieved lesser chroma error uv=0.001 relative to standard white light D65 enhanced chroma uniformity of illumination field.

Design of a scene simulator in land-based aerospace lab with the man-made light source system based on quantum theory (EI CONFERENCE) 会议论文 OAI收割
Optoelectronic Devices and Integration II, November 12, 2007 - November 15, 2007, Beijing, China
作者: Fang W.; Yi W.

收藏 | 浏览/下载：54/0 | 提交时间：2013/03/25

The paper presents a method with the technique of combination filtering of spectrum and the technique of DSP control for the simulation and recognition of the spontaneously lightening object and stellar map in the universe. The magnitude and the spectrum of a star can be simulated in a wide dynamic range. We established the mathematical models of the Vega's visible light spectrum and luminous flux density. Tungsten-halogen lamp as a light source is used to fit the linear light of the spontaneously lightening object in the universe. Through the experiment it shows that the more sub-channels there are while filtering spectrum in the visible spectrum and the more degrees the variable neutral density filters and the narrow-band attenuators have more close to the actual spectrum the simulated spectrum is. It is proved that using the PID technique is beneficial to the output of the accurate and steady radiation from the light sources. The experiment shows that the using of this method can get perfect result in fitting and simulating the spectrum magnitude and the stellar map of the spontaneously lightening object . The analysis of the consistent result and the experimental error is also discussed in detail in this paper.

Study on color model conversion for camera with neural network based on the combination between second general revolving combination design and genetic algorithm (EI CONFERENCE) 会议论文 OAI收割
ICO20: Illumination, Radiation, and Color Technologies, August 21, 2005 - August 26, 2005, Changchun, China
作者: Li Z.; Zhou F.; Wang C.; Li Z.

收藏 | 浏览/下载：46/0 | 提交时间：2013/03/25

Munsell color system is selected to establish the mutual conversion between RGB and L*a*b* color model for camera. The color luminance meter and CCD camera synchronously measure the same color card XYZ value is gotten from the color luminance meter the training error is 0.000748566 it can show that the method combining second general revolving combination design with genetic algorithm can optimize the hidden-layer structure of neural network. Using the data of testing set to test this network and calculating the color difference between forecast value and true value the color picture captured from CCD camera is expressed for RGB value as the input of neural network and the L*a*b* value converted from XYZ value is regarded as the real color value of target card which the difference is not obvious comparing with forecast result the maximum is 5.6357 NBS namely the output of neural network. The neural network of two hidden-layers is considered the minimum is 0.5311 NBS so the second general revolving combination design is introduced into optimizing the structure of neural network and the average of color difference is 3.1744 NBS. which can carry optimization through unifying project design data processing and the precision of regression equation. Their mathematics model of encoding space is gained and the significance inspection shows the confidence degree of regression equation is 99%. The mathematics model is optimized by genetic algorithm optimization solution is gotten and function value of the goal is 0.0007168. The neural network of the optimization solution is trained