中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
首页 机构 成果 学者
  
  1. CAS IR Grid
机构
采集方式
内容类型
发表日期
学科主题
筛选

浏览/检索结果: 共13条，第1-10条 帮助

条数/页： 排序方式：
Preparation of ropivacaine loaded PLGA microspheres as controlled-release system with narrow size distribution and high loading efficiency 期刊论文  OAI收割
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 2019, 卷号: 562, 页码: 237-246
作者:  Li, Xun;  Wei, Yi;  Lv, Piping;  Wu, Youbin;  Ogino, Kenji
  |  收藏  |  浏览/下载：121/0  |  提交时间：2019/04/03
Surveillance Video Synopsis via Scaling Down Objects 期刊论文  OAI收割
ieee transactions on image processing, 2016, 卷号: 25, 期号: 2, 页码: 740-755
作者:  Li, Xuelong;  Wang, Zhigang;  Lu, Xiaoqiang
收藏  |  浏览/下载：28/0  |  提交时间：2016/10/13
Transitional compensation algorithm for correcting non-uniformity of LED display image (EI CONFERENCE) 会议论文  OAI收割
2012 2nd International Conference on Materials Science and Information Technology, MSIT 2012, August 24, 2012 - August 26, 2012, Xi'an, Shaan, China
Su W.-x.; Chen Y.-s.
收藏  |  浏览/下载：32/0  |  提交时间：2013/03/25
In order to solve the problem of high non-uniformity of LED display images which is caused by the edges of LED display panel during module splicing  transitional compensation algorithm is proposed by improving the existed correction technique named the correction technique based on CCD. First  introduce the three development stages of the LED display panel. Then  the realization progress of the transitional compensation algorithm is described in detail after elaborating the principle of transitional compensation. Finally  the algorithm is emplaned in a LED video control system to control the LED display panel whose display area is 1280960  and which is spliced by 3020 LED modules whose size are 6432. Experimental results show that this algorithm is able to reduce non-uniformity of LED display images from 29.3% before correcting to 0.95%. (2012) Trans Tech Publications  Switzerland.  
Physical layer design for free space optical communication (EI CONFERENCE) 会议论文  OAI收割
2012 International Conference on Control Engineering and Communication Technology, ICCECT 2012, December 7, 2012 - December 9, 2012, Shenyang, Liaoning, China
作者:  Wang H.;  Zhang Q.;  Guo J.;  Guo J.;  Wang H.
收藏  |  浏览/下载：30/0  |  提交时间：2013/03/25
A small size Free Space Optical Communication System is introduced  including the hardware and the hardware specified physical layer protocol. In detail  the rapid synchronization method to reduce the handshake bandwidth requirement is demonstrated. The hardware of the system includes the laser driver system  the signal amplifying and shaping system  the data interface system. The hardware specified physical layer protocol is used to interface the outer data  serialize and deserialize the data stream  check transmission errors and schedule the data transmission. The overall system is a FIFO-like system and the user can use it as if he's operating a FIFO. The system is designed mainly for terrestrial FSO link whose signal channel is the atmosphere. Due to the complex composition and activity of the atmosphere  this signal channel brings in great influence on the transmitting laser in it  for example  the absorption and scattering of the atmosphere molecules and aerosols  the scintillation of received laser power caused by the turbulence of the atmosphere  all of which results in a much higher Bit Error Rate (BER) of the communication system than wired communication systems leading to frequent resynchronization. In our system  the sampling clock is generated locally using multi-phase sampling technique rather than PLLbased clock recovery  which helps to rapid synchronization. 2012 IEEE.  
A hybrid median filter for enhancing dim small point targets and its fast implementation (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Multimedia and Signal Processing, CMSP 2011, May 14, 2011 - May 15, 2011, Guilin, Guangxi, China
Yang Q.
收藏  |  浏览/下载：22/0  |  提交时间：2013/03/25
Weak stars and middle altitude orbit satellites or high altitude orbit satellites are presented as dim point targets in images of astronomical observation. They have low intensity and occupy few pixels in image. In most situations  the background of sky is always ununiform and there exists pulse noises. Thus results in targets submerging in background noises and low signal noise ratio (SNR). Median filter is an effective method for removing pulse noise. But it can blur image after modifying gray of non-noise pixels when image has low SNR. A hybrid median filter algorithm is proposed to process low SNR dim point targets image. The newly proposed method can suppress the pulse noises  also can increase target $SNR$ and does not add extra fake targets. The time complexity of median filter is O(N2)(N is the widow size) and is difficult to implement in hardware. For quasi real time application  a fast implementation of our hybrid median filter is proposed to reduce the time complexity to O(N). Experimental results show that the newly proposed algorithm is superior to ordinary median filter and fast median filter by comparing visual effect and performance. 2011 IEEE.  
Design of motion compensation mechanism of satellite remote sensing camera (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Space Exploration Technologies and Applications, May 24, 2011 - May 26, 2011, Beijing, China
Gu S.; Yan Y.; Xu K.; Jin G.
收藏  |  浏览/下载：47/0  |  提交时间：2013/03/25
With the development of aerospace remote sensing technology  the ground resolution of remote sensing camera enhances continuously. Since there is relative motion between camera and ground target when taking pictures  the target image recorded in recording media is moved and blurred. In order to enhance the imaging quality and resolution of the camera  the image motion had to be compensated. In order to abate the effect of image motion to image quality of space camera and improve the resolution of the camera  the compensation method of image motion to space camera is researched. First  the reason of producing drift angle and adjustment principle are analyzed in this paper. This paper introduce the composition and transmission principle of image motion compensation mechanism. Second  the system adopts 80C31 as controller of drift angle  and adopts stepping motor for actuators  and adopts absolute photoelectric encoder as the drift Angle measuring element. Then the control mathematical model of the image motion compensation mechanism are deduced  and it achieve the closed-loop control of the drift angle position. At the last  this paper analyses the transmission precision of the mechanism. Through the experiment  we measured the actual precision of the image motion compensation mechanism  and compared with the theoretical analysis. There are two major contributions in this paper. First  the traditional image motion compensation mechanism is big volume and quality heavy. This has not fit for the development trend of space camera miniaturization and lightweight. But if reduce the volume and quality of mechanism  it will bring adverse effects for the precision and stiffness of mechanism. For this problem  This paper designed a image motion compensation that have some advantages such as small size  light weight at the same time  high precision  stiffness and so on. This image motion compensation can be applicable to the small optics cameras with high resolution. Second  the traditional mechanism control need to corrected  fitting and iterative for the control formula of mechanism. Only in this way  we can get the optimal control mathematical model. This paper has high precision of the control formula derived. It can achieve the high precision control without fitting  It also simplify the difficulty of control mathematical model establishment. This paper designed the range of adjusting of image motion compensation mechanism between -5 +5. Based on choosing-5  -4  -3  -2  -1  0  +1  +2  +3  +4  +4 as the expectation value of the imaginary drift angle  we get ten groups of the fact data in adjusting drift angle measured. The test results show that the precision of the drift angle control system can be achieved in 1. It can meet the system requirements that the precision of the control system is less than 3'  and it can achieve the high-precision image motion compensation. 2011 SPIE.  
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.
收藏  |  浏览/下载：43/0  |  提交时间：2013/03/25
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.  
Miniaturize photoelectric stable platform (EI CONFERENCE) 会议论文  OAI收割
2010 International Conference on Computer Application and System Modeling, ICCASM 2010, October 22, 2010 - October 24, 2010, Shanxi, Taiyuan, China
Xue W.-Q.; Wang Y.-Y.; Dai M.
收藏  |  浏览/下载：79/0  |  提交时间：2013/03/25
In order to reduce the size and weight of the gimbal in a traditional stable platform and correct the disadvantage in size of the payload  the paper first improves the gimbal which is an important component of a stable photoelectric platform  that also is an important factor in affecting the size and weight of a stability platform. In this paper  a closed-form solution of 3-DOF manipulator is designed according mechanical arm design principles. This manipulator is formed by a three joint axes whose extended line is intersected at one point. A standard orthogonal coordinate system is set up for each rod in the manipulator. And then  rotation transformation matrix expression is obtained. At last in this paper  the manipulator arm-shaped method for solving solutions is description  and also  each parameter of the gimbal is calculated when the photoelectric detection devices at bottom reach the expected position. Test results show that the photoelectric stability platform with gimbal we designed is smaller  lighter and simpler than that traditional. Also  the packaging and size of the photoelectric will not be affected with this open structure. 2010 IEEE.  
Mean shift tracking combining SIFT (EI CONFERENCE) 会议论文  OAI收割
2008 9th International Conference on Signal Processing, ICSP 2008, October 26, 2008 - October 29, 2008, Beijing, China
作者:  Xue C.
收藏  |  浏览/下载：66/0  |  提交时间：2013/03/25
A novel visual tracking algorithm to cope with occlusion and scale variation is proposed. This method combines mean shift and SIFT algorithm to track object. SIFT algorithm is invariant to rotation  translation and scale variation. But it is a timeconsuming algorithm. The wasting time is related to image size. So the proposed algorithm first adopts mean shift to initially locate object position  then SIFT operator is used to detect features in object area and model area  lastly  the proposed method matches features in these two areas and calculates the relationship between them using affine transform. According to affine transform parameters  the state of object can be adjusted in time. In order to reduce process time  an improved feature matching algorithm is proposed in this paper. Experiments show that the proposed algorithm deals with occlusion successfully and can adjust object size in time. 2008 IEEE.  
Integrated intensity, orientation code and spatial information for robust tracking (EI CONFERENCE) 会议论文  OAI收割
2007 2nd IEEE Conference on Industrial Electronics and Applications, ICIEA 2007, May 23, 2007 - May 25, 2007, Harbin, China
作者:  Wang Y.;  Wang Y.;  Wang Y.;  Wang Y.;  Wang Y.
收藏  |  浏览/下载：28/0  |  提交时间：2013/03/25
real-time tracking is an important topic in computer vision. Conventional single cue algorithms typically fail outside limited tracking conditions. Integration of multimodal visual cues with complementary failure modes allows tracking to continue despite losing individual cues. In this paper  we combine intensity  orientation codes and special information to form a new intensity-orientation codes-special (IOS) feature to represent the target. The intensity feature is not affected by the shape variance of object and has good stability. Orientation codes matching is robust for searching object in cluttered environments even in the cases of illumination fluctuations resulting from shadowing or highlighting  etc The spatial locations of the pixels are used which allow us to take into account the spatial information which is lost in traditional histogram. Histograms of intensity  orientation codes and spatial information are employed for represent the target Mean shift algorithm is a nonparametric density estimation method. The fast and optimal mode matching can be achieved by this method. In order to reduce the compute time  we use the mean shift procedure to reach the target localization. Experiment results show that the new method can successfully cope with clutter  partial occlusions  illumination change  and target variations such as scale and rotation. The computational complexity is very low. If the size of the target is 3628 pixels  it only needs 12ms to complete the method. 2007 IEEE.