中国科学院机构知识库网格系统: 检索

基于激光诱导击穿光谱检测水稻叶片镉的研究 期刊论文 OAI收割
量子电子学报, 2020, 卷号: 37
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收藏 | 浏览/下载：24/0 | 提交时间：2020/10/26

spectroscopy laser induced breakdown spectroscopy heavy metal Cd comparison of experimental methods 光谱学激光诱导击穿光谱重金属Cd 实验方法对比

Accuracy assessment of approaches to spatially explicit reconstruction of historical cropland in Songnen Plain, Northeast China SCI/SSCI论文 OAI收割
2016
作者: Jiang L. Q.; Zhang, L. J.; Zang, S. Y.; Zhang, X. Z.

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收藏 | 浏览/下载：33/0 | 提交时间：2017/11/09

comparison of methods cropland cover late Qing Dynasty Songnen Plain Northeast China land-cover change climate-change system

The measuring method for low rotational speed with the frequency difference generated by radial gratings (EI CONFERENCE) 会议论文 OAI收割
2012 International Applied Mechanics, Mechatronics Automation Symposium, IAMMAS 2012, September 7, 2012 - September 9, 2012, Shenyang, Liaoning, China
Guo W.-l.; Qiao Y.-f.

收藏 | 浏览/下载：20/0 | 提交时间：2013/03/25

The new method has been proposed based on the comparison and analysis of the traditional methods for measuring rotating speed. It can guarantee real-time property with radial gratings at measuring low speed. It is clearly explained that the fundamental principle for measuring rotating speed and characters of the method and presented the constitution of the system hardware and the process flows. (2012) Trans Tech Publications Switzerland.

Control strategies and error compensation methods of high precision gyro stabilized platform (EI CONFERENCE) 会议论文 OAI收割
30th Chinese Control Conference, CCC 2011, July 22, 2011 - July 24, 2011, Yantai, China
Deng K.; Cong S.; Shen H.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

Based on the principle of gyroscope and the structure of gyro stabilized platform this paper gives the analysis and comparison of control strategies for stable platform included classical PID control and three kinds of advanced strategies: Fuzzy Control Sliding Mode Variable Structure Control and Active Disturbance Rejection Control. The compensation methods for stable platform's error are also discussed and evaluated based on the sources of error especially for the non-linear friction and gyro drift. The paper provides the reliable methods for recognizing and improving the accuracy of gyro stabilized platform from the control strategies and error compensations. 2011 Chinese Assoc of Automation.

Analysis of a diffractive microlens using the finite-difference time-domain method (EI CONFERENCE) 会议论文 OAI收割
作者: Liu Y.; Liu H.; Liu H.; Liu H.; Liu Y.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

The finite-difference time-domain (FDTD) method is used as rigorous electromagnetic analysis model to calculate the field for a diffractive microlens (DML). The FDTD is used for the entire solution rather than using a near- to far-field propagation method to obtain the far-field energy distribution thus all the results are vector based. We derived a formula to calculate the magnitude of electric field which is time dependent and can be used to graphically show the light wave propagation and focusing process through a DML. Both the comparison and the integral methods are presented to obtain wave amplitude in full solution space and the distribution of light energy behind a DML is illustrated based on the wave amplitude. The formula of diffractive efficiency of the DML is derived from a time-averaged Ponyting vector which can indicate the propagation direction of light energy. Application of these formulations in the analysis of a DML example demonstrates the high accuracy and efficiency of our method. 2010 Society of Photo-Optical Instrumentation Engineers.

A new accurate and fast algorithm of sub-pixel image registration (EI CONFERENCE) 会议论文 OAI收割
2010 IEEE 10th International Conference on Signal Processing, ICSP2010, October 24, 2010 - October 28, 2010, Beijing, China
作者: He B.

收藏 | 浏览/下载：27/0 | 提交时间：2013/03/25

In terms of large field view and multi-channel TDICCD remote sensing images previous interpolation methods and curve fitting methods are not able to achieve the high accuracy and fast registration and their noise immunity and robustness is not high. For that this paper presents a more accurate and faster method iterative pixel interpolation and surface fitting method. Firstly the method uses the some overlapping pixels between multi-channel images. Secondly the proposed technique which is based on the maximization of the correlation coefficient function combines an efficient pixel-moving interpolation scheme with surface fitting which makes use of accurate interpolation calculation and fast surface fitting in the iterative process. Finally the accuracy and speed of the algorithm is evaluated by sub-pixel registration of multi-channel images and comparison with other sorts of efficient methods. The experiment results show that the accuracy of the method reaches 0.01 pixels and it is 3 times faster than the interpolation method. In the registration of large field view and multi-channel TDICCD images the method is accurate and fast with greatly high stability noise immunity and robustness. 2010 IEEE.

Destriping method using lifting wavelet transform of remote sensing image (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
作者: He B.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

Based on the characteristic of striping noise in remote sensing images a new destriping noise technique for the improved multi-threshold method using lifting wavelet transform applied to remote sensing imagery is presented in this letter. Have used the lifting wavelet decomposition algorithm the thresholds are determined by corresponding wavelet coefficients in every scale. Remote sensing imagery is so large that the algorithm must be fast and effective. The lifting wavelet transform is easily realized and inexpensive in computer time and storage space compared with the traditional wavelet transform. We also compare the method with some traditional destriping methods both by visual inspection and by appropriate indexes of quality of the denoised images. From the comparison we can see that the adaptive threshold method can preserve the spectral characteristic of the images while effectively remove striping noise and it did better than the existed ones. 2010 IEEE.

Combination of skip-flat test with Ritchey-Common test for the large rectangular flat (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China
作者: Zhang L.; Xuan B.; Zhang L.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

The Skip-Flat test and Ritchey-Common test are the well-known methods for large flat mirrors measurement. This paper describes the theories of two methods. The combination of the Skip-Flat test with Ritchey-Common test is proposed. Simulations and experiments of the combination method for testing the large rectangular flat of high aspect ratio are shown. The results of the combination test and direct measurement are presented. In comparison of the methods the combination test is in good agreement with the direct measurement. 2010 Copyright SPIE - The International Society for Optical Engineering.

Rigorous vector analysis of diffractive microlens by using of finitedifference time-domain method (EI CONFERENCE) 会议论文 OAI收割
2009 International Conference on Optical Instruments and Technology, OIT 2009, October 19, 2009 - October 22, 2009, Shanghai, China
作者: Liu Y.; Liu H.; Liu H.; Liu H.; Liu Y.

收藏 | 浏览/下载：32/0 | 提交时间：2013/03/25

We use finite difference time domain (FDFD) method as rigorous vector analysis model to simulate the focusing process of diffractive microlens (DML). Differing with most analysis model which the near field distributions are calculated by FDTD and then far field are obtained by using of propagation method we obtain the fields in whole computational space by using of FDTD only. The advantages are that all the results are vector based and the computational time is saved greatly. In this paper we present two methods to obtain wave amplitude one is comparison method and the other is integral method. Depending on wave amplitude in the whole computational space one can conveniently obtain distributions of electric field intensity and calculate the time-average Poynting vector. We also present the formulation for calculating diffractive efficiency of DML based on time-average Poynting vector which denotes energy flow. As demonstration a DML is analyzed by using of these algorithms. The time depended graphic results of FDTD show the process of wave propagation. The distribution of electric field intensity illustrates the focusing of the normal incident light. The focus pattern in the focal plane is also show. The diffractive efficiency of the DML is calculated by using of the energy flow method in this paper. The results show the high accuracy and efficiency of the model. 2009 SPIE.

Analysis and design of No-Reference Image Quality Assessment (EI CONFERENCE) 会议论文 OAI收割
2008 International Conference on MultiMedia and Information Technology, MMIT 2008, December 30, 2008 - December 31, 2008, Three Gorges, China
作者: Wang L.; Wang L.; Wang L.

收藏 | 浏览/下载：15/0 | 提交时间：2013/03/25

No-Reference (NR) Image Quality Assessment (IQA) seeks to assign quality scores that are consistent with human perception but without an explicit comparison with the reference image. Unfortunately the field of NR IQA has been largely unexplored. The basic problems in NR IQA are discussed in this paper. and several methods used in NR IQA are explained and analyzed. Finally an overall NR IQA method is designed. It should be a synthetical index which applying fuzzy measures and fuzzy integrals incorporating Human Vision System (HVS) characteristics and adhering to the philosophy of quantifying quality through blind distortion measurement. 2008 IEEE.