• Journal of Institute of Control, Robotics and Systems
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• v.21 no.4
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• pp.367-371
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• 2015

In this paper, a novel localization method for a monocular camera is proposed by using a feature-based probabilistic map. The localization of a camera is generally estimated from 3D-to-2D correspondences between a 3D map and an image plane through the PnP algorithm. In the computer vision communities, an accurate 3D map is generated by optimization using a large number of image dataset for camera pose estimation. In robotics communities, a camera pose is estimated by probabilistic approaches with lack of feature. Thus, it needs an extra system because the camera system cannot estimate a full state of the robot pose. Therefore, we propose an accurate localization method for a monocular camera using a probabilistic approach in the case of an insufficient image dataset without any extra system. In our system, features from a probabilistic map are projected into an image plane using linear approximation. By minimizing Mahalanobis distance between the projected features from the probabilistic map and extracted features from a query image, the accurate pose of the monocular camera is estimated from an initial pose obtained by the PnP algorithm. The proposed algorithm is demonstrated through simulations in a 3D space.

• The Korean Journal of Zoology
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• v.33 no.2
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• pp.133-140
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• 1990

In monocular vision, bead and eye optokinetic nystagmus (OKN) display directionnal asymmetry, in lower vertebrates such as chickens, T-N stimulation being more efficient in evoking this visuomotor reflex than N-T stimulation. The N-T component of monocular OKN is significantly weaker in chickens. Coil recordings and observation showed that in adult chickens, prolonged monocular visual deprivation by unilateral eyelid suture provoked significant and progressive increase of the N-T component in chickens. This plasticity phenomenon involved the eye and head OKN in chickens. The administration of THIP, a GABA agonist, abolished reversibly the increase of the N-T component in chickens. This fact suggests that the GABAergic system could be involved in determining this plasticity phenomenon observed in adult lower vertebrates.

• Smart Structures and Systems
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• v.24 no.5
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• pp.607-616
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• 2019

The video deflectometer based on digital image correlation is a non-contacting optical measurement method which has become a useful tool for characterization of the vertical deflections of large structures. In this study, a novel imaging model has been established which considers the variations of pitch angles in the full image. The new model allows deflection measurement at a wide working distance with high accuracy. A monocular video deflectometer has been accordingly developed with an inclination sensor, which facilitates dynamic determination of the orientations and rotation of the optical axis of the camera. This layout has advantages over the video deflectometers based on theodolites with respect to convenience. Experiments have been presented to show the accuracy of the new imaging model and the performance of the monocular video deflectometer in outdoor applications. Finally, this equipment has been applied to the measurement of the vertical deflection of Yingwuzhou Yangtze River Bridge in real time at a distance of hundreds of meters. The results show good agreement with the embedded GPS outputs.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.767-771
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• 2003

In this study, stereo vision system is applied to a mobile manipulator for effective tasks. The robot can recognize a target and compute the position of the target using a stereo vision system. While a monocular vision system needs properties such as geometric shape of a target, a stereo vision system enables the robot to find the position of a target without additional information. Many algorithms have been studied and developed for an object recognition. However, most of these approaches have a disadvantage of the complexity of computations and they are inadequate for real-time visual servoing. However, color information is useful for simple recognition in real-time visual servoing. In this paper, we refer to about object recognition using colors, stereo matching method, recovery of 3D space and the visual servoing.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.5
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• pp.411-417
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• 2005

In this study, stereo vision system is applied to a mobile manipulator for effective tasks. The robot can recognize a target and compute the potion of the target using a stereo vision system. While a monocular vision system needs properties such as geometric shape of a target, a stereo vision system enables the robot to find the position of a target without additional information. Many algorithms have been studied and developed for an object recognition. However, most of these approaches have a disadvantage of the complexity of computations and they are inadequate for real-time visual servoing. Color information is useful for simple recognition in real-time visual servoing. This paper addresses object recognition using colors, stereo matching method to reduce its calculation time, recovery of 3D space and the visual servoing.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.3
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• pp.267-274
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• 2009

Recently, UAVs (Unmanned Aerial Vehicles) are expected much as the Unmanned Systems for various missions. These missions are often based on the Vision System. Especially, missions such as surveillance and pursuit have a process which is carried on through the transmitted vision data from the UAV. In case of small UAVs, monocular vision is often used to consider weights and expenses. Research of missions performance using the monocular vision is continued but, actually, ground and target model have difference in distance from the UAV. So, 3D distance measurement is still incorrect. In this study, Mean-Shift Algorithm, Optical Flow and Subspace Method are posed to estimate the relative depth. Mean-Shift Algorithm is used for target tracking and determining Region of Interest (ROI). Optical Flow includes image motion information using pixel intensity. After that, Subspace Method computes the translation and rotation of image and estimates the relative depth. Finally, we present the results of this study using images obtained from the UAV experiments.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.3
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• pp.75-81
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• 2009

Purpose: The purpose of this controlled study was to determine the effectiveness of vision therapy for accommodative infacility in children. Methods: 10 children 9 to 13 years of age with symptomatic accommodative infacility were divided into a treatment group (n=6) and a contol group (n=4). The treatment group received 12 weeks of vision therapy while the control group received nothing. Results: The visual symptom assessed by COVD-QOL score for the treatment group showed both statistically and clinically significant reduction from 27.50${\pm}$5.68 to 12.00${\pm}$7.24 (p<0.01). Also, there were statistically and clinically significant improvement in the clinical measures of monocular accommodative facility of right eye (from 0.67${\pm}$1.03 cpm to 15.42${\pm}$4.85 cpm; p<0.001) and binocular accommodative facility (from 0.33${\pm}$0.82 cpm to 13.92${\pm}$3.58 cpm; p<0.001). In contrast, there were no significant improvement in symptoms and in the clinical measures of monocular and binocular accommodative facility for the control group (p>0.05). Conclusion: Vision therapy is an effective mode of treatment in eliminating symptoms and improving accommodative facility in children with accommodative infacility.

• Science of Emotion and Sensibility
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• v.15 no.4
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• pp.477-488
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• 2012

The effort of implementing realistic 3-D depth on 2-D images has been continued persistently with a theoretical understanding of depth perception and its related technical development. The present article briefly reviews a number of popular stereoscopes for studying stereoscopic depth perception according to their implementation principles, and introduces a behavioral experiment as a technical example in which the active-shutter glasses were used. In the present study, participants were tested for their visual memory against perceived depth among a set of items. The depth of the memory and test items was manipulated to be 1) monocular, 2) binocular, or 3) both-monocular-and-binocular respectively. The memory performance was worst in the binocular-depth condition, and best however in the both-monocular-and-binocular condition. These results indicate that visual memory may benefit more from monocular depth than stereoscopic depth, and further suggest that the storage of depth information into visual memory would require both binocular and monocular information for its optimal memory performance.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.371-376
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• 2014

Purpose: The aim of this study was to explore the effect of artificially decreased eye in normal vision on eye-hand coordination (EHC) when using the Lee-Ryan Eye-Hand Coordination Test recently reported. Methods: Eleven adults with normal vision aged $29.46{\pm}5.94$ years participated for this study where a non-dominant eye artificially induced moderate refractive amblyopic vision at near by adding a plus lens conducted EHC tasks and then did the test again under normal vision following 2 weeks. To investigate the ability of EHC, 7 tasks including individually different level of difficulty in the Lee-Ryan EHC Test were selected to compare and analyze EHC in terms of two independent variables such as time taken and the number of errors. Results: In time taken, subjects with artificially decreased vision took more time than normal vision under monocular conditions (p=0.013), while those with the decreased vision completed their tasks faster than normal vision under binocular conditions (p=0.001). In the number of errors, subjects with the decreased vision made more mistakes (p<0.001) as shown in time taken, whereas there was no difference between monocular and binocular viewing conditions in the decreased vision. Conclusions: Unlike previous EHC tests including limitations for application, deficit in EHC can be screened by the Lee-Ryan EHC Test developed based on simple computer-based system. Therefore, it is considered that further studies relevant to deficits in visual function such as amblyopia will be carried out in clinics as well as research.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.12
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• pp.1205-1211
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• 2008

This paper describes methods to estimate 3-D position of target with respect to reference frame through monocular image from unmanned aerial vehicle (UAV). 3-D position of target is used as information for surveillance, recognition and attack. In this paper. 3-D position of target is estimated to make guidance and control law, which can follow target, user interested. It is necessary that position of target is measured in image to solve 3-D position of target. In this paper, kalman filter is used to track and output position of target in image. Estimation of target's 3-D position is possible using result of image tracking and information of UAV and camera. To estimate this, two algorithms are used. One is methode from arithmetic derivation of dynamics between UAV, carmer, and target. The other is LPV (Linear Parametric Varying). These methods have been run on simulation, and compared in this paper.