中国科学院机构知识库网格系统: 检索

Comparison of cavern formation in massive salt blocks with single-well and two-well systems 期刊论文 OAI收割
JOURNAL OF THE CHINESE INSTITUTE OF ENGINEERS, 2016, 卷号: 39, 期号: 8, 页码: 954-961
作者: Yi, Liang; Ren, Song; Li, Yin-Ping; Jiang, De-Yi; Chen, Jie

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收藏 | 浏览/下载：28/0 | 提交时间：2018/06/05

Salt cavern solution mining single-well system two-well system construction rate

Optimum design of laser encoding and decoding on laser beam-riding guidance (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Frontiers of Manufacturing and Design Science, ICFMD 2011, December 11, 2011 - December 13, 2011, Taichung, Taiwan
作者: Yang L.; Yang L.

收藏 | 浏览/下载：33/0 | 提交时间：2013/03/25

Operating principle of laser beam-riding guidance was set forth. Based on the principle of spatial frequency-encoding experimental results demonstrated that the receiver can receive correctly the encoded signal and can decode the signal an optimum laser encoding mode was designed measurement for the missdistance is feasible and all the performance parameters satisfy the demand. (2012) Trans Tech Publications which can transfer continuous laser into pulse laser that represents different position information. Then the mathematic model of deviation from target is built Switzerland. a modified encoding pattern was presented which is composed of two light paths crossed 90. Azimuth information of target is given in orthogonal coordinate system and deviation from target is linearity. As well as characteristic distribution of spatial laser field is analyzed. Corresponding decoding mode was presented by testing in 2 kilometers outdoor

On the Cauchy problem for the two-component Camassa-Holm system 期刊论文 OAI收割
MATHEMATISCHE ZEITSCHRIFT, 2011, 卷号: 268, 期号: 1-2, 页码: 45-66
作者: Gui, Guilong; Liu, Yue

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收藏 | 浏览/下载：19/0 | 提交时间：2018/07/30

Besov spaces Blow-up Local well-posedness Two-component Camassa-Holm system Wave-breaking

The ship-borne infrared searching and tracking system based on the inertial platform (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者: Li Y.; Zhang H.; Zhang H.; Li Y.; Li Y.

收藏 | 浏览/下载：37/0 | 提交时间：2013/03/25

As a result of the radar system got interferenced or in the state of half silent it can cause the guided precision drop badly In the modern electronic warfare therefore it can lead to the equipment depended on electronic guidance cannot strike the incoming goals exactly. It will need to rely on optoelectronic devices to make up for its shortcomings but when interference is in the process of radar leading especially the electro-optical equipment is influenced by the roll pitch and yaw rotation it can affect the target appear outside of the field of optoelectronic devices for a long time so the infrared optoelectronic equipment can not exert the superiority and also it cannot get across weapon-control system "reverse bring" missile against incoming goals. So the conventional ship-borne infrared system unable to track the target of incoming quickly the ability of optoelectronic rivalry declines heavily.Here we provide a brand new controlling algorithm for the semi-automatic searching and infrared tracking based on inertial navigation platform. Now it is applying well in our XX infrared optoelectronic searching and tracking system. The algorithm is mainly divided into two steps: The artificial mode turns into auto-searching when the deviation of guide exceeds the current scene under the course of leading for radar.When the threshold value of the image picked-up is satisfied by the contrast of the target in the searching scene the speed computed by using the CA model Least Square Method feeds back to the speed loop. And then combine the infrared information to accomplish the closed-loop control of the infrared optoelectronic system tracking. The algorithm is verified via experiment. Target capturing distance is 22.3 kilometers on the great lead deviation by using the algorithm. But without using the algorithm the capturing distance declines 12 kilometers. The algorithm advances the ability of infrared optoelectronic rivalry and declines the target capturing time by using semi-automatic searching and reliable capturing-tracking when the lead deviation of the radar is great. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Evaluation of the operating range for ground-based infrared imaging tracking system (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者: Zhang Z.-D.

收藏 | 浏览/下载：48/0 | 提交时间：2013/03/25

Ground-based infrared imaging tracking system (GIITS) is of great importance for aerial target warning and guard. The operating range is one of the key performance specifications on the other which should be calculated calculate the radiation power received on the detector in order to analysis whether the output signal meets the detection requirements or not analyzed and studied during the whole GIITS design process. The operating range is mostly influenced by a few factors without considering the effect of the background radiation. By improving of the traditional method including atmospheric attenuation a new operating range calculation model of the GIITS was established based on two requirements. One is that the image size of observed target should meet the requirement of the processor signal extraction. The number of the pixel occupied by target image should be more than 9. The other is that the signal noise ratio (SNR) of the GIITS should not be less than 5 to meet the requirements of the target detection probability and spatial frequency. The SNR calculation equation in form of energy is deduced and the radiation characteristic of the observed target and background are analyzed. When evaluate the operating range of the GIITS using the new method the performance of GIITS and feature of target and background. This paper firstly makes analysis and summarization on the definite localizations of the traditional operating range equation of the GIITS. The localizations are mainly in two aspects. On one hand we should successively calculate two operating range values according to two requirements mentioned above and choose the minimum value as the analytic result. In the end the dispersion of the image and the effect of image dispersion are not considered in the traditional method an evaluation of operating range for fighter aircraft is accomplished as an example. The influence factors in every aspect on operating range were explored by the calculated result. The new operating range calculation model provides the theoretical basis for the design and applications as well as the comprehensive evaluation of a GIITS. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Research on computer control strategy for optical electric tracking system (EI CONFERENCE) 会议论文 OAI收割
2011 IEEE International Conference on Mechatronics and Automation, ICMA 2011, August 7, 2011 - August 10, 2011, Beijing, China
作者: Li M.

收藏 | 浏览/下载：23/0 | 提交时间：2013/03/25

In this paper mathematic model and computer control strategy for optical electrical tracking system have been researched and discussed. First the system's structure and its work process have been analyzed. Second according to the system's moving law the system's mathematic model has been built. As to the computer control strategy trigger guiding two closed loop PID control method as well as compound control method have been applied to satisfy the tracking accuracy. Third we apply the bilinear transformation to get the digital system and the sample time is 800Hz. The simulation results indicate that the maximum tracking error can be limited to less than 0.5 and the regulator time can be 0.04s. Then the control project resonance frequency should be more than 200Hz and the sample frequency should be more than 400Hz to meet the control accuracy requirement. So we can conclude that the system indexes such as swiftness high accuracy as long as real time have been satisfied. And the requirement of mechanical property has been present which is very useful to mechanical working. 2011 IEEE.

Research on servo controller for high speed tracking system (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Mechatronic Systems and Automation Systems, MSAS 2011, July 23, 2011 - July 24, 2011, Xi'an, China
作者: Li M.

收藏 | 浏览/下载：17/0 | 提交时间：2013/03/25

To meet requirement of swiftness and minimization for the tracking system as well as realize horizontal high accuracy tracking measurement the automatic servo tracking measurement system has been designed. The two closed loop control bisection method and compound control have been applied into the system. Experimental results show that the maximum tracking error can be limited to less than 0.5and the regulator time can be 0.04s. The control project resonance frequency should be more than 200Hz and the sample frequency should be more than 400Hz to meet the control accuracy requirement. And these specific mechanical properties indexes are useful to mechanical working to make sure the design can be realization. So the research in this paper has important value to the engineering practice. (2011) Trans Tech Publications.

High accuracy star image locating and imaging calibration for star sensor technology (EI CONFERENCE) 会议论文 OAI收割
6th International Symposium on Precision Engineering Measurements and Instrumentation, August 8, 2010 - August 11, 2010, Hangzhou, China
作者: Wang Y.; Wang Y.; Wang Y.; Wang Y.; Wang Y.

收藏 | 浏览/下载：21/0 | 提交时间：2013/03/25

Today aircraft attitude measurement technology plays an important role in an aircraft system because it can provide orientation for aircraft in action. Lately star sensor technology used in aircraft attitude measurement has become more and more popular because of its high accuracy light weight without attitude accumulation errors and other advantages. There are three main steps for star sensor to measure aircraft attitude star image locating star identification and attitude tracking. The latter two steps are based on the accuracy of star image locating. So it's critical to make efforts to advance the accuracy of star image locating. Some imaging errors such as spherical aberration or coma aberration also have negative effect on the accuracy of star image locating of which the effect is necessarily reduced as well. At the beginning of this article the structure of star sensor hardware is introduced. Secondly three methods for star image locating are described specifically which are traditional centroid method Gauss quadric fitting method and improved Gauss quadric fitting method. Subsequently an imaging calibration method is described for the purpose of reducing the effect of imaging errors. Finally the experiment shows that the accuracy of the star sensor is 2-arc-second. 2010 SPIE.

Novel method for optimizing polishing tool-path in CCOS based on weighted-iterative algorithm (EI CONFERENCE) 会议论文 OAI收割
4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, November 19, 2008 - November 21, 2008, Chengdu, China
作者: Zhang X.-J.; Wang X.; Wang X.; Wang X.; Wang X.-K.

收藏 | 浏览/下载：40/0 | 提交时间：2013/03/25

In Computer Controlled Optical Surfacing (CCOS) polishing tool-path is the base of solving other control parameters such as dwell time. In order to improve the fabrication results of polishing off-axis aspheric a novel method to optimize the tool-path is discussed in this paper. The optimizing method named weighted-iterative algorithm is according to the balance principle of the particle system. The power factor of each dwell point represents the requirement of dwell density. Considering the factors which influence the polishing result the power factors cosist of three elements include constant error distribution and dwell distance of workpiece edge. The tool-path is solved by numerical iterative method. In the end an error data is simulated with actual parameters using the matrix-based algorithm with two different tool-paths. The one is X-Y uniform spacing model and the other one is to optimize it based on the first. The comparison shows that the results of the optimized one are much better than traditional one especially the rms convergence rate. Theory of the algorithm is simple and exercisable and it satisfies practical requirement as well. 2009 SPIE.

CR image filter methods research based on wavelet-domain hidden markov models (EI CONFERENCE) 会议论文 OAI收割
ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China
作者: Wang J.-L.; Wang J.-L.; Li D.-Y.; Wang Y.-P.

收藏 | 浏览/下载：18/0 | 提交时间：2013/03/25

In the procedure of computed radiography imaging we should firstly get across the characters of kinds of noises and the relationship between the image signals and noises. Based on the specialties of computed radiography (CR) images and medical image processing we have study the filtering methods for computed radiography images noises. On the base of analyzing computed radiography imaging system in detail the author think that the major two noises are Gaussian white noise and Poisson noise. Then the different relationship of between two kinds of noises and signal were studied completely. By considering both the characteristics of computed radiography images and the statistical features of wavelet transformed images a multiscale image filtering algorithm which based on two-state hidden markov model (HMM) and mixture Gaussian statistical model has been used to decrease the Gaussian white noise in computed images. By using EM (Expectation Maximization) algorithm to estimate noise coefficients in each scale and obtain power spectrum matrix then this carried through the syncretized two Filter that are IIR(infinite impulse response) Wiener Filter and HMM according to scale size and achieve the experiments as well as the comparison with other denoising methods were presented at last.