Journals >Opto-Electronic Engineering
Contents
2013
Volume: 40 Issue 5
22 Article(s)
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Research Article
PI-PI Controller for the Time Delay Control System of FSM
TANG Tao, YANG Tao, HUANG Yongmei, FU Chenyu, and GUO Haifan
One of the main limitations to CCD-Based system is the time delay in the control loop of Fast Steering Mirror (FSM). The stability of closed loop and its bandwidth is entirely dependent on this term. Time delay is usually difficult to compensate. Therefore, a tentative approach to the implementation of a CCD-based tracOne of the main limitations to CCD-Based system is the time delay in the control loop of Fast Steering Mirror (FSM). The stability of closed loop and its bandwidth is entirely dependent on this term. Time delay is usually difficult to compensate. Therefore, a tentative approach to the implementation of a CCD-based tracking control system with a simple PI-PI controller is proposed. The controller is to add an integrator into PID controller, resulting in two integrators in the control loop of fast steering mirror. First, a detailed model of CCD-based tracking loop is designed to analyze the characteristic of the close loop system, and then the results of parameters for the PI-PI and I controller are given. At last, the performance of the closed loop system with the two different controllers is compared. Although the bandwidth of error attenuation with PI-PI controller is little smaller than that of I controller, the error attenuation at low frequency is enhanced greatly. The experiment results are in great accordance with the theoretical analysis..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 1 (2013)
An Active Disturbance Rejection Controller of the Stable Loop Structure Resonance of an Opto-electronic Platform Servo System
ZHOU Tao
The structure resonance perhaps causes the unstable system, which limits the tracking precision and the dynamic response speed of an airborne opto-electronic platform servo system. According to the zero-pole assignment principle, an active disturbance rejection controller is designed with a nominal control input. The aThe structure resonance perhaps causes the unstable system, which limits the tracking precision and the dynamic response speed of an airborne opto-electronic platform servo system. According to the zero-pole assignment principle, an active disturbance rejection controller is designed with a nominal control input. The active disturbance rejection controller is used to compensate the stable loop structure resonance of the opto-electronic platform servo system. Simulation experiment results demonstrate that the controller could inhibit the structure resonance influence on the servo system and increase the stable loop velocity tracking precision of the opto-electronic platform. Moreover, it is robust to the parameters’ changes of the structure resonance model..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 6 (2013)
Test System for Theodolite Tracking Control System Based on RTW and Visual Simulation
XIONG Shuai, FU Chengyu, and LIU Zidong
Testing on theodolite tracking control system is very important for the theodolite development. The function structure of the simulation test system was established. Real-time Workshop (RTW) was used to realize the tracking control algorithm fast. The virtual target motion scenes, which accord with the theodolite imagiTesting on theodolite tracking control system is very important for the theodolite development. The function structure of the simulation test system was established. Real-time Workshop (RTW) was used to realize the tracking control algorithm fast. The virtual target motion scenes, which accord with the theodolite imaging character and effect and satisfy various simulation test demands, were rendered real-time based on the visual simulation technology. The practical applications show that this simulation test system can be used to test theodolite tracking control system and solve the limitation of traditional indoor test methods. It is not only convenient and fast, but also targeted and repeatable. The test system is quite useful to analyze and design theodolite tracking control system..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 13 (2013)
Visual Object Tracking Algorithm Based on Distribution Fields Descriptor
WANG Xian, ZHANG Fangsheng, SONG Sulin, and FENG Kaikai
A novel visual object tracking method based on distribution fields descriptor is proposed to solve the problem how to describe the object effectively and adapt to the change of environmental in visual tracking. Firstly, a distribution fields descriptor is used to build the object model. Then, the object is tracked by pA novel visual object tracking method based on distribution fields descriptor is proposed to solve the problem how to describe the object effectively and adapt to the change of environmental in visual tracking. Firstly, a distribution fields descriptor is used to build the object model. Then, the object is tracked by particle filter algorithm. The model is updated online. It can reduce the impact of varying illumination and partial occlusion, thereby enhancing the efficiency of object tracking. The proposed algorithm runs in real time and performs favorably against state-of-the-art algorithms on challenging sequences. The experimental results indicate that the proposed algorithm is effective for tracking and has good performance in complex scene..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 21 (2013)
Outfield Calibration Method of Camera’s Position and Attitude on Photoelectric Theodolite Based on Bundle Adjustment
HOU Haixiao, JIA Haozheng, and WU Heng
Measuring precision and imaging quality are affected by position and attitude for cameras on photoelectric theodolite largely. A method of calibration outfield for the camera on photoelectric theodolite is presented based on the principles of photogrammetry in position and attitude. Firstly, the mathematical model of cMeasuring precision and imaging quality are affected by position and attitude for cameras on photoelectric theodolite largely. A method of calibration outfield for the camera on photoelectric theodolite is presented based on the principles of photogrammetry in position and attitude. Firstly, the mathematical model of calibration was established and the calibration mark image outfield was obtained. Secondly, the angle was corrected by identified images and the parameters of the camera in position and attitude were calculated by using the bundle adjustment method. Finally, the precision analysis is made. Testing result shows that the calibration precision is reliable by this method..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 28 (2013)
Robust Ground Target Tracking Using Multi-resolution Motion Prior
SUN Kang, and ZHOU Zhiqiang
During terminal guidance phase of electro-optical precision-guided weapons, basic inverse compositional template matching algorithm can not deal with robust target tracking in high-dynamic environment due to its theoretical limitations. An inverse compositional tracking algorithm using multi-resolution motion prior is During terminal guidance phase of electro-optical precision-guided weapons, basic inverse compositional template matching algorithm can not deal with robust target tracking in high-dynamic environment due to its theoretical limitations. An inverse compositional tracking algorithm using multi-resolution motion prior is proposed to deal with this problem. The novel method divides tracking problem into two phases of off-line training and on-line tracking. During training phase, multi-resolution priori error Jacobian matrices are obtained according to the principle of “coarse-to-fine”. Using this priori knowledge, the new tracker can achieve robust tracking without increasing on-line computation complexity. Comparative experiments confirm the good convergence properties of the algorithm under high-dynamic environment. Meanwhile, the algorithm also has a good stability against the disturbances of target image rotation, scale and illumination changes, etc..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 34 (2013)
Image Tracking System of Binocular Multi-FOV Sun-photometer
LI Jianyu, LI Duoyang, WEI Heli, XU Qingshan, and JIANG Qingwu
Binocular Multi-FOV Sun-photometer (BMFOVSP) is used to measure the optical properties of cirrus. In order to solve the localized problem of traditional sun-photometer tracking sun inaccurate by using four-quadrant detector when the cloud is in homogeneous, image tracking system of BMFOVSP is developed by using image pBinocular Multi-FOV Sun-photometer (BMFOVSP) is used to measure the optical properties of cirrus. In order to solve the localized problem of traditional sun-photometer tracking sun inaccurate by using four-quadrant detector when the cloud is in homogeneous, image tracking system of BMFOVSP is developed by using image processing technology to track sun. The all-weather and full automatic sun tracking in the absence of drizzle is achieved by adopting the double modes tracking technology with the combination of both calendar-check tracking and image processing technology tracking. The tracking accuracy is higher than one minute of angle. The system fits BMFOVSP for measuring the optical properties of cirrus. It also can be applied to other occasions which require high sun tracking accuracy. Gross structure, system principle and the design of imaging unit are introduced. The methods of both calendar- check tracking and image tracking are represented in detail. The reliability and stability of system are analyzed. The graphs of tracking effect are shown, which means the proposed tracking system can track sun primely and have high tracking accuracy..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 40 (2013)
Ultrabroadband Supercontinuum in a High Birefringence Photonic Crystal Fiber
ZHANG Xiaojuan
Nonlinear transmission and supercontinuum generation with femtosecond pulse in a new designed high birefringence photonic crystal fiber are numerically simulated and analyzed by using split-step Fourier algorithm. The influences of the center wavelength, the peak power, the half-width and the polarization direction of Nonlinear transmission and supercontinuum generation with femtosecond pulse in a new designed high birefringence photonic crystal fiber are numerically simulated and analyzed by using split-step Fourier algorithm. The influences of the center wavelength, the peak power, the half-width and the polarization direction of the input pulse on supercontinuum are discussed in detail. It is shown that the supercontinuum could be broadened to an ultra-wide wavelength range of 550-2200nm. If the center wavelength of the input femtosecond pulse is close to that of the inflexion of the dispersion curves, the spectrum will be up to the widest range. The generated supercontinuum becomes wider with increasing the peak power and the pulse half-width of the input pulse. The width of the supercontinuum will become narrower if the input polarization direction gets away from both principal axis directions. Accordingly the new designed high birefringence photonic crystal fiber could be effectively applied to the generation of ultrabroadband supercontinuum..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 50 (2013)
Error Modeling and Compensation of FOG in Swaying Motion
GAO Xin, YAN Jizhong, XIE Liangping, and WANG Jingxian
Angular velocity measurement error exists in swaying motion Fiber Optic Gyroscope (FOG), which constrains FOG strap-down system’s performance under severe angular motion. Based on automatic control theory and FOG’s closed-loop control scheme, the reason for FOG’s swaying error was analyzed and found out that the angulaAngular velocity measurement error exists in swaying motion Fiber Optic Gyroscope (FOG), which constrains FOG strap-down system’s performance under severe angular motion. Based on automatic control theory and FOG’s closed-loop control scheme, the reason for FOG’s swaying error was analyzed and found out that the angular acceleration is the main factor for FOG’s swaying error. Then a simplified FOG’s swaying error model was built up and the compensation algorithm was proposed. Finally, according to the equivalent input principal, it is experimented to test and compensate FOG’s swaying error under different swaying frequencies. Test results show that the compensation algorithm has the capability of reducing FOG’s swaying error by an order of magnitude..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 58 (2013)
Maritime Video Image Defogging Method Based on Assisted Signal Empirical Mode Decomposition
WANG Xiaotonga, GUO Jiaa, JIN Xina, XU Guanleib, and MA Yuea
Lacking of local or global extrema in the area of the sea and sky of the image causes the failure of the traditional Bi-dimensional Empirical Mode Decomposition (BEMD). The frequency characteristic of BEMD is analyzed, and the construction method of the high-frequency assisted signal is given. The high-frequency assistLacking of local or global extrema in the area of the sea and sky of the image causes the failure of the traditional Bi-dimensional Empirical Mode Decomposition (BEMD). The frequency characteristic of BEMD is analyzed, and the construction method of the high-frequency assisted signal is given. The high-frequency assisted signal is added to the original video image signal, and then we obtain the closest frequency components to the assisted signal of the original signal by subtracting the decomposed intrinsic mode component (IMC) to the assisted signal of IMC. Moreover, the different frequency components of the original signal can be obtained. Solving the problem of lacking of local or global extrema of the maritime image, this assisted signal BEMD is applied to the enhancement of maritime degraded image, and the acquired result is consistent with that of the currently accepted HE’s algorithm..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 64 (2013)
A Seam-line Removal Method Based on Curve Fitting
CHENG Hong, ZHENG Yue, SUN Wenbang, and ZHANG Fengjing
A novel seam-line removal method based on curve fitting is put forward. Firstly, the proposed method modifies the gray value around the original seam-line by curve fitting. And then the texture massage is added to the pixels which are obtained by the process of curve fitting. This step is aimed to avoid the character lA novel seam-line removal method based on curve fitting is put forward. Firstly, the proposed method modifies the gray value around the original seam-line by curve fitting. And then the texture massage is added to the pixels which are obtained by the process of curve fitting. This step is aimed to avoid the character loss of gray changing. Thus, the gray value can change smoothly and the texture character can be remained as well. Finally, the result image with good sense of sight is got after weighted fusion and fine adjustment. Apart from that, a method for confirming the correction width is proposed according to the average gray difference between the two sides of the seam-line, and it is proportional to the gray difference. Experiment results show that the method is effective and easy to be realized. In addition to the elimination of sudden change in gray, the texture character of this method is better saved than that of the common methods. The seam-line is eliminated smoothly and the visual effect is good. The proposed method is also applicable especially when the difference of gray is above ten..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 72 (2013)
A Blurriness Assessment Method Based on Maximal Oriented Gradient
WANG Baoyun, ZHANG Rong, and YIN Dong
A blurriness metric method based on Maximal Oriented Gradient (MOG) is proposed. In this method, a set of filters are used to get oriented gradient maps from original image at first. Then, oriented masking is used to suppress gradient values. At last, a set of MOGs, which is extracted from the suppressed values, are usA blurriness metric method based on Maximal Oriented Gradient (MOG) is proposed. In this method, a set of filters are used to get oriented gradient maps from original image at first. Then, oriented masking is used to suppress gradient values. At last, a set of MOGs, which is extracted from the suppressed values, are used to predict the blurriness of the original image. Experiments of algorithm consistency and sensitivity show that new method has a good performance, and experiments on cross-distortion data prove that the proposed method is stable and applicable..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 79 (2013)
Multi-focus Image Fusion Algorithm Based on Composite Incentive Model in Surfacelet Domain
ZHANG Baohua, Lü Xiaoqi, and ZHANG Chuanting
According to the ability of limited decomposition directional subband and difficult to suppress noise based on the traditional multi-scale analysis, a multi-focus image fusion method based on Surfacelet transform and composite incentive model is proposed. Original images are decomposed by Surfacelet transform to obtainAccording to the ability of limited decomposition directional subband and difficult to suppress noise based on the traditional multi-scale analysis, a multi-focus image fusion method based on Surfacelet transform and composite incentive model is proposed. Original images are decomposed by Surfacelet transform to obtain a number of different frequency band sub-images. A composite incentive model is built based on the characteristics of the low frequency sub-band and high-frequency sub-band coefficients, namely improved-sum-modified-Laplacian and spatial frequency are selected as external stimulus of compound PCNN. Fusion coefficients are preferred by compound PCNN and the results are improved. The experimental results show that grayscale distribution of the fusion image is more dispersed and coherent image texture details are outstanding. The algorithm overcomes the traditional multi-focus image fusion defects, and the objective evaluation indexes show that this method is superior to that of Laplace, Discrete Wavelet Transform (DWT) and PCA traditional image fusion methods..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 88 (2013)
Investigation of GPU-based Ultrasound Elastography
PENG Bo, CHEN Yong, and LIU Dongquan
In order to improve the calculation speed of ultrasound elastograms, two common ultrasound elastography methods based on Graphics Processing Unit (GPU) were investigated. After giving an introduction about the two common methods, the GPU-based approaches to rapidly estimate tissue strain was proposed. The two GPU-basedIn order to improve the calculation speed of ultrasound elastograms, two common ultrasound elastography methods based on Graphics Processing Unit (GPU) were investigated. After giving an introduction about the two common methods, the GPU-based approaches to rapidly estimate tissue strain was proposed. The two GPU-based approaches were tested in simulation signals and real signals by scanning a tissue-mimicking phantom respectively．Experimental results show that the GPU-based Normalized Cross Correlation (NCC) implementation is about 42 times faster than that based on CPU platform with the same elasticity image quality. At the same time, the GPU-based Phase Zero Estimation (PZE) approach is about 65 times faster than that corresponding implementation on CPU by increasing data throughput..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 97 (2013)
Robust Digital Image Stabilization Using Local Feature Points
GUO Xiaoran, and CUI Shaohui
To overcome the undesirable shakes of a camera and to implement the image stabilization in a real time, a digital image stabilization approach based on local feature points was proposed. Local feature points have been widely investigated in solving problems in image processing, pattern recognition and computer vision, To overcome the undesirable shakes of a camera and to implement the image stabilization in a real time, a digital image stabilization approach based on local feature points was proposed. Local feature points have been widely investigated in solving problems in image processing, pattern recognition and computer vision, such as feature matching, object detection, target tracking and image navigation. First, the Harris algorithm is proposed to select key points in the image sequence where image motion happened due to vehicle or platform vibration, and Normalized Cross Correlation (NCC) matching algorithm is used to match local feature points between reference frame and current frame, here, a novel bi-directional search strategy is proposed to extract the more robust feature points. Second, the Random Samples Consensus (RANSAC) algorithm is adapted to eliminate the wrong matching points, and the reserved matching feature point is taken into affine motion model to yield global motion vector. Finally, jitter parameters are extracted from global motion vector, and original image sequence is compensate. The experimental results demonstrate that the proposed DIS approach can process affine motion of image sequence fast and efficiently, accuracy lower than 1 pixel, and have a better robustness. This approach can be used in moving vehicle cameras system..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 106 (2013)
Texture Image Segmentation Using UTPLBP
FAN Yahui, FU Randi, JIN Wei, and YIN Caoqian
Local Binary Pattern (LBP) is a kind of effective local texture description operator, which is widely used in many fields, like image processing, machine vision, etc, for its excellent rotation invariance. This paper mainly analyzes and improves the characteristics of LBP texture features, puts forward the Uniform ThreLocal Binary Pattern (LBP) is a kind of effective local texture description operator, which is widely used in many fields, like image processing, machine vision, etc, for its excellent rotation invariance. This paper mainly analyzes and improves the characteristics of LBP texture features, puts forward the Uniform Three-Patch LBP (UTPLBP) secondary statistic texture features and explores its application in the image segmentation. Regarding Brodatz texture image, UTPLBP operator is used to extract its texture features, and then the image is segmented by Support Vector Machine (SVM) algorithm. Experiment result demonstrates that UTPLBP operator can describe image texture information accurately and its secondary statistic texture features with strong robustness can distinguish different texture image. Compared with the traditional methods, the accuracy is better than ninety-three percent..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 113 (2013)
Extension Characteristics of the Depth of Field for Microscopic System
ZOU Shuang, XU Zhongbao, and Lü Qinghua
The depth of field of standard optical imaging system can be extended by introducing a pure phase pupil mask. A pupil mask which contains three zones with “0、π” phase is presented. By modulating the pupil of the imaging system, the Modulation Transfer Function (MTF) of the system has showed defocus-independent. TherefoThe depth of field of standard optical imaging system can be extended by introducing a pure phase pupil mask. A pupil mask which contains three zones with “0、π” phase is presented. By modulating the pupil of the imaging system, the Modulation Transfer Function (MTF) of the system has showed defocus-independent. Therefore, the loss of system’s imaging information is avoided meanwhile the depth of the field is enlarged. Finally, the large depth of field system is simulated by Zemax as well as the traditional optical system. From the experimental results, we can draw the conclusion that the binary phase mask has successfully extended the depth of field of imaging system with a higher resolution..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 120 (2013)
Design of Aspherics Lenses Shaping System on Gaussian Beam
FENG Ke, and LI Jinsong
Application value of the Gaussian beam with flat-top shaping and some main shaping methods were introduced. Because of the advantages of aspherics, aspherics shaping method was studied, Fermi Dirac function was chosen as a flat-top beam distribution model, and the relationship between its flat-top distribution and the Application value of the Gaussian beam with flat-top shaping and some main shaping methods were introduced. Because of the advantages of aspherics, aspherics shaping method was studied, Fermi Dirac function was chosen as a flat-top beam distribution model, and the relationship between its flat-top distribution and the characteristic parameters was analyzed. By analyzing aspherics shaping principle theoretically, according to the law of conservation of energy and ray tracing function, aspheric surface form expression was deduced. Considering the processing factors, the effects of system parameters on the spherical degree was analyzed. And then, by choosing appropriate parameters, MATLAB software was used to solve numerical solution of mapping relation and surface shape curve and fit to get aspheric coefficient. By using ZEMAX optical software to make system modeling, the output beam of light intensity distribution and propagation characteristic could be gotten through the physical optics propagate-POP simulation. As a result, output beam of the flat-top quality is close to the expected effect, and its error mainly comes from numerical calculation accuracy and edge diffraction..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 127 (2013)
Effect of Glass Preform on Form of Abnormal Aspherical Lens
YIN Shaohui, WANG Feng, ZHU Kejun, and CHEN Fengjun
Glass preform is able to affect form of abnormal aspherical lens as its irregular shape. Different preforms were investigated by numerical simulation to discuss how to affect form of abnormal aspherical lens. A typical abnormal aspherical lens was chosen as target lens, and the globular and cylindrical glasses were choGlass preform is able to affect form of abnormal aspherical lens as its irregular shape. Different preforms were investigated by numerical simulation to discuss how to affect form of abnormal aspherical lens. A typical abnormal aspherical lens was chosen as target lens, and the globular and cylindrical glasses were chosen as preforms. Using advanced nonlinear finite element program of MSC.Marc, the form process of the abnormal aspherical lens was simulated. Based on the simulations, the formability, the residual stress and the form precision were analyzed and compared. It can be inferred that the glass preform of cylindricity is more suitable for forming abnormal aspherical lens..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 133 (2013)
Analysis of Curing Stress Magnitude about Low Stress Optical
Structure Adhesives under Stable Temperature
LIAO Jiasheng, GONG Yan, YUAN Wenquan, and LUO Cong
Based on a special bonding structure, a new experiment device was designed to research the relation of low stress optical structure adhesives between internal stress and time. Through the experiment based on electrical method,the structure’s curing property was oppositely deduced by monitoring deformation of the bondedBased on a special bonding structure, a new experiment device was designed to research the relation of low stress optical structure adhesives between internal stress and time. Through the experiment based on electrical method,the structure’s curing property was oppositely deduced by monitoring deformation of the bonded object (steel piece) core. Firstly, the theoretical law of structure adhesives’ curing process is analyzed. Then, two low stress structure adhesives 3140RTV and UV295 were chosen to be tested for a week, and the curve gotten from the experiment was analyzed. Taking advantage of Finite Element Method (FEM) software with a little theoretical hypothesis, influence of residue stress of the two structure adhesives on steel piece was calculated, and the result answers which structure adhesive is better. The calculation result and the experiment curves’ analysis further explain the purpose and significance of the experiment..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 138 (2013)
High Grey Level and High Refresh Rate to the LED Screen Based on PWM
YUAN Shengchun, LIU Yan, and ZHAO Xiaoming
The high refresh rate and more gray information are very important for using PWM to achieve grey level, such as full color LED screen. The standard LED display control system either realized good gray and the low refresh rate, or realized the high refresh rate and not achieving full gray information. A mean field segmeThe high refresh rate and more gray information are very important for using PWM to achieve grey level, such as full color LED screen. The standard LED display control system either realized good gray and the low refresh rate, or realized the high refresh rate and not achieving full gray information. A mean field segmentation method is proposed to achieve high intensity high refresh rate. To a certain extent, though brightness efficiency, about 10%~30% is reduced, gray display effect can be better improved and high dynamic refresh rate can be reached at the same time..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 5, 145 (2013)
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