中国科学院机构知识库网格系统: 检索

PID control of glucose concentration in subjects with type 1 diabetes based on a simplified model: An in silico trial (EI CONFERENCE) 会议论文 OAI收割
10th World Congress on Intelligent Control and Automation, WCICA 2012, July 6, 2012 - July 8, 2012, Beijing, China
作者: Yu L.

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An artificial pancreas system (APS) mimics the function of a real pancreas through monitoring a diabetic's blood glucose and administering the right dose of insulin via an automatic control loop. It is hailed as a promising cure of diabetes though this technology is still years away from commercial use due to a few technological bottlenecks. The simulation model of insulin-glucose metabolism of type 1 diabetes mellitus (T1DM) is an essential part of APS. In order to simplify the parameter identification task so that the model can be implemented electronically with ease this paper presents a simplified model based on Routh approximation model reduction method. The results show that the approximation error between the simplified model and the original model is so small that can be neglected. Based on the simplified model a PID controller is designed to maintain normoglycemia (90mg/dl) in subjects with T1DM. The in silico simulation results show that the glucose concentration is controlled well the risk of hyperglycemia and hypoglycemia is reduced a lot. This suggests that the simplified model describes the insulin-glucose metabolism process accurately and the PID control algorithm is well-suitable to guide the further development of an APS. 2012 IEEE.

Design and demonstration of micro multi-step mirrors and light source in micro FTIR (EI CONFERENCE) 会议论文 OAI收割
6th IEEE International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2011, February 20, 2011 - February 23, 2011, Kaohsiung, Taiwan
Liang Z.; Fu J.; Feng C.; Liang J.

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To obtain high resolution high signal-to-noise ratio (SNR) high reliability and real time in wide spectral range we study the space modulation Micro Fourier Transform Spectrometer (FTS) based on multi-step mirrors covering the spectral range of 3-5m and 8-12 m in theory and experiment. The influences of spectrum reconstruction caused by the diffraction and extended light source in Fourier Transform Infrared Spectrometer (FTIR) are analyzed. A method to reduce the noises in spectrum reconstruction and the relationship between coherent intensity and solid angle of light source are discussed. An extended light source with suitable size is chosen considering the requirement of SNR and spectrum resolving power in the optical design. Furthermore the fabrication of micro multi-step mirrors which is the core part of FTS is investigated. Three methods for fabricating multi-step micro mirrors are demonstrated. 2011 IEEE.

Optimization on motion estimation algorithm based on H. 264 (EI CONFERENCE) 会议论文 OAI收割
2010 3rd International Conference on Advanced Computer Theory and Engineering, ICACTE 2010, August 20, 2010 - August 22, 2010, Chengdu, China
Wen X.; Li G.

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Motion estimation is a very important part of video compression. As a result of using precision of motion vector in H.264 encoder the computational cost increases rapidly and motion estimation is the most time-consuming stage. In this paper based on the UMHexagonS algorithm an optimized algorithm is proposed based on the dynamic search window selection big hexagon and small hexagon search mode respectively which saves motion estimation time effectively with a little quality loss. Experiments with some typical video sequences show that compared to the original UMHexagonS algorithm this new algorithm can save about 17.851 % motion estimation time and reduce the complexity of original scheme as well as enhance the real time performance of encoder and almost has no changes in the reconstructed picture quality and bitrates. 2010 IEEE.

Quaternion based assessment method for color image fusion algorithms (EI CONFERENCE) 会议论文 OAI收割
2010 3rd International Congress on Image and Signal Processing, CISP 2010, October 16, 2010 - October 18, 2010, Yantai, China
作者: Wang Y.; Wang Y.; Wang Y.; Wang Y.; Wang Y.

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A new approach to assess the performance of color image fusion algorithms is proposed. The color information is fully used by this method. Quaternions are used to encode the pixels in a color image into a quaternion matrix. Local variance of the luminance layer of the color image is taken as the real part of a quaternion then the three RGB channels of the color image are encoded into the three imaginary parts of a quaternion. The angle between the singular value feature vectors of the quaternion matrices corresponding to one of the source image and the fused image is used to measure their structural similarity. Edge information transferring is used to balance the sensitivity of the assessment methods. Experimental results show that the proposed assessment method is better consistent with the HVS than some of the state-of-the-art method. Accurate assessment results can be given by the proposed method for various of color image fusion algorithms by using the source images and the fused image. 2010 IEEE.

Color image quality assessment based on quaternion representation for the local variance distribution of RGB Channels (EI CONFERENCE) 会议论文 OAI收割
2009 2nd International Congress on Image and Signal Processing, CISP'09, October 17, 2009 - October 19, 2009, Tianjin, China
Yuqing W.; Ming Z.

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In this paper Quaternions are used to describe the structural information of a color image in order to assess its quality. The representation method is different from conventional models in that some information that is sensitive to human eyes is reinforced by using local variance. It encodes the local variance distribution of the RGB channels of a color image into the three imaginary parts of a quaternion. The luminance layer of the color image is taken as the real part of the quaternion. The distance between the singular value feature vectors of the source image block and the distorted image block which are described by quaternion matrices is calculated. The final assessment result is calculated by using the mid point of the distances. The experimental results show that the assessment results of the proposed assessment method are more consistent with the Human Visual System than those of the conventional assessment methods. 2009 IEEE.

Assessment of color image fusion algorithms based on quaternion singular value decomposition (EI CONFERENCE) 会议论文 OAI收割
MIPPR 2009 - Remote Sensing and GIS Data Processing and Other Applications: 6th International Symposium on Multispectral Image Processing and Pattern Recognition, October 30, 2009 - November 1, 2009, Yichang, China
作者: Wang Y.; Wang Y.; Wang Y.; Wang Y.; Wang Y.

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In this paper a new approach to objectively assess the performance of image fusion algorithms is proposed. It is based on the quaternion representation for the structural information of color images. Quaternions are used to encode the pixels of a color image into a quaternion matrix. Local variance of the luminance layer of color image is taken as the real part of a quaternion then the three RGB channels of the color image are encoded into the three imaginary parts of the quaternion. The angle between the singular value feature vectors of the quaternion matrices corresponding to the source image and the fused image is used to measure the structural similarity of them. Different weight is given to the source images by using variance. The experiment results show that the proposed assessment method is consistent with the HVS. The color information of a color image can be fully used by this method. It can give an accurate assessment result for each fusion algorithm by using the source images and the fused image. 2009 Copyright SPIE - The International Society for Optical Engineering.

The automatic photoresist coating machine on the spherical surface (EI CONFERENCE) 会议论文 OAI收割
2009 IEEE International Conference on Mechatronics and Automation, ICMA 2009, August 9, 2009 - August 12, 2009, Changchun, China
作者: Li Y.; Li Y.; Li Y.; Li Y.; Wang H.

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The photoresist coating is an important micro machining process widely applied in engineering. The formed film should be uniform and enough thin to assure the quality of final pattern whose line width is micrometer or nanometer. It is more difficult to process it on the spherical surface than on the flat. In this work mathematic model of film thickness on the spherical surface is proposed by using hydromechanics. The key factors that influence the film thickness are obtained from the analysis of coating process. Then the rational parameters which be controlled by the automatic photoresist coating machine can be final set up according to the result of the coating experiments. And the accuracy analysis of the key part which is used for the main process is performed by the error analytics. This machine not only makes the whole coating process automation but also monitors the film quality in real time. It is adequate for aspheric surface also. 2009 IEEE.

Color image quality assessment based on quaternion singular value decomposition (EI CONFERENCE) 会议论文 OAI收割
1st International Congress on Image and Signal Processing, CISP 2008, May 27, 2008 - May 30, 2008, Sanya, Hainan, China
作者: Liu W.; Wang Y.; Wang Y.; Wang Y.; Wang Y.

收藏 | 浏览/下载：19/0 | 提交时间：2013/03/25

An effective assessment method for color image is proposed. It is based on the quaternion description for the structural information of color image. The local variance of the luminance layer of color image is taken as the real part of a quaternion then the three RGB channels of the color image are encoded into the three imaginary parts of the quaternion. The angle between the singular value feature vectors of the quaternion matrices correspond to the reference image and the distorted image is used to measure the structural similarity of the two images. Results from experiments show that the proposed method is better consistent with the human visual characteristics than MSE PSNR and SSIM. The images whose size is different from that of the reference image can also be assessed by this method. 2008 IEEE.

Research on the support structure of the primary mirror of large-aperture telescope (EI CONFERENCE) 会议论文 OAI收割
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Large Mirrors and Telescopes, July 8, 2007 - July 12, 2007, Chengdu, China
Yang W.; Jingxu Z.

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Large-aperture telescope can be used in surveying battlefield researching landform searching object real-time monitoring imaging detecting and identifying spatial targets and so on. A large-aperture telescope for achieving high resolution power is designed to monitor spatial target and image in real time. Real-time monitoring plays an important role in military conflicts. The orbit parameter of object quantity geometrical shape parameter and so on can be obtained by detect spatial target. With the development of optical technology people require larger aperture in optics-electronic (OE) system. By increasing optical aperture the ability of collecting light and resolution power in the system can be enhanced. But the support structure of the primary mirror of large-aperture telescope will be a very difficult problem. With the increase of primary mirror aperture the weight of the primary mirror will become larger than before. The root mean square (rms) of the primary mirror is affected by many factors such as deadweight deformation of heat environment and so on. Due to the primary mirror of telescope is an important component of telescope system. By reducing the weight of primary mirror precision of the system is ensured. During the designing phase one can consider the supporting project of the primary mirror synthetically and analyze it roundly according to technical requirement of optical system and the effect factors. The final structural design can be reasonable. In an astronomical telescope the surface of reflector is an important part for collecting dark radiation of celestial bodies. Its surface shape will have an effect on collecting efficiency of telescope radiant energy directly. So the rms must be very high. Optical system of large aperture small wavelength and small focus can receive maximal light intensity. For ground-based optical astronomical telescope the design proposed in the paper can satisfy the requirement of the possible minimum atmosphere seeing at astronomical observatory site and exert the use efficiency of the telescope adequately. So the accuracy of the traditional surface of reflector can assure that 90% of all the light energy can be focused on within the angle diameter range of the minimum atmosphere seeing then 100% of light energy should be focused on the angle diameter range of minimum atmosphere seeing. Because the rms of mirror is very high precise surface machining and accurate the support of mirror are very important tasks during designing and manufacturing the telescope. In the paper various support techniques of a large-aperture telescope primary mirror are discussed and a 3.5 meter telescope system at the Starfire Optical Range (SOR) overviewed simply which was operated by the Directed Energy Directorate of the Air Force Research Laboratory Kirtland AFB NM USA from the ground-based O-E system for the observations of spatial target. We also analyze Theoretical elastic deformation of the Steward Observatory 2.3 meter mirror is analyzed.

Error analysis and test study of fiber optic gyroscope north-finder (EI CONFERENCE) 会议论文 OAI收割
Advanced Sensor Systems and Applications II, November 8, 2004 - November 12, 2004, Beijing, China
Zhang Z.; Sun J.; Wu K.

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North-finder system is an important application of the inertial technology. It provides true north azimuth information to f all kinds of ground-based equipment. This paper designed a dynamic automatic north-finder based on the modulation output of fiber optic gyroscope (FOG). In this scheme the sine output signal of the FOG was sampled and disposed and then the real north of surveyed point on the surface of earth was calculated. The deviation caused by the base tilt was compensated by an accelerator. The output signals of FOG and accelerator were computed combined with the position sampled from increasing encoder by digital signal processor. Successive rotating technique was adopted to modulate the FOG signal periodically. Most of the low frequency part of random gyro drift errors was compensated. The north-finder accuracy was improved compared with the traditional static measuring method. The test result shows the FOG automatic north-finder obtains 2' true north angle accuracies within not more than three minutes can meet the orientation need of artillery terrain measurement vehicle armored car unmanned drive vehicle geodetic survey and tunnel exploration.