• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.2
• /
• pp.227.1-227.1
• /
• 2012

원격탐사 광학탑재체는 촬영 방식에 따라 대상물을 응시하여 촬영하는 응시(staring)방식과 스캔하여 촬영하는 스캐닝(scanning)방식으로 나뉠 수 있다. 인공위성을 이용한 원격탐사에서는 위성의 궤도에 따라 촬영방식에 제한이 생기는데, 저궤도에서 지구관측을 하는 전자 광학 카메라의 경우 위성의 공전속도에 의해서 지표면을 스캔하는 방식으로 촬영을 수행하는 푸시브룸 스캔(push broom scan)방식이 많이 사용된다. 스캔방식으로 영상을 촬영하면 스캔에 평행한 방향과 수직인 방향의 광학적 영상품질이 달라질 수 있다. 스캔에 평행한 방향은 스캔에 의한 영상 번짐 효과가 나타나기 때문이다. 본 연구에서는 스캔에 의한 영상 번짐 효과로 발생하는 MTF 성능에 대하여 분석하였다. 검출기레벨에서의 영상 번짐 효과 및 다단계(multi-phase) 검출기를 사용했을 때의 영향에 대하여 분석하였다.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.38 no.6
• /
• pp.46-56
• /
• 2001

In this paper we propose an efficient approach for real-time eye-gaze tracking from image sequence and magnetic sensory information. The inputs to the eye-gaze tracking system are images taken by a camera and data from a magnetic sensor. The measuring data are sufficient to describe the eye and head movement, because the camera and the receiver of a magnetic sensor are stationary with respect to the head. Experimental result shows the validity of real time application aspect of the proposed system and also shows the feasibility of the system as using a new computer interface instead of the mouse.

• Journal of Korean Ophthalmic Optics Society
• /
• v.19 no.2
• /
• pp.189-198
• /
• 2014

Purpose: The present has analyzed the correlation between the direction of lens and the amount of rotation upon soft toric contact lens fitting after classifying the corneal astigmatism. Methods: Soft toric contact lens was fitted on 114 with-the-rule astigmatic eyes with total astigmatism of at least -0.75 D in their 20s and 30s according to the fitting guideline of the manufacturer and the correlation between the astigmatic degree and the rotational direction/amount of rotation was analyzed by when keeping the eyes on the front and by changing the direction of gaze. As for re-orientation movement. The speed of lens re-orientation and total amount of lens rotation was compared and analyzed by corneal astigmatism after mis-location of lens of $45^{\circ}$ to temporal and nasal direction, respectively. Results: The positive correlations were shown between corneal astigmatism and the direction of lens rotation and between corneal astigmatism and the amount of lens rotation. Meanwhile, the amount of lens rotation was different by the direction of gaze however, there was no correlation with corneal astigmatism. The speed of lens re-orientation was fastest in the group of high astigmatic degree when the lens was mis-located to both temporal and nasal directions. Conclusions: For optimal axis stabilization of toric soft lens, it is proposed that the adjustment of fitting guideline considering corneal astigmatism is necessary since the current fitting guideline is only based on total astigmatism.

• Science of Emotion and Sensibility
• /
• v.12 no.2
• /
• pp.169-180
• /
• 2009

The present study have investigated the effect of the characteristics of stereoscopic images and viewing environment on visual fatigue. We manipulated the speed of stereo images with motion-in-depth and viewing distance, which were used as representative variables of the characteristics of stereo image and viewing environment, respectively. Visual fatigue was evaluated with use of a subjective questionnaire which is consisting of 5 different and independent factors: "Eye pain", "Visual stress," "Nauseousness", "Body stiffness", and "Blurriness". In general, when viewing time increased from 10 minutes to 20 and 40 minutes, observers felt severe visual fatigue. Among other factors, only the factor score of "Nauseousness" was significantly increased as the speed of object moving in depth became faster. When viewing distance was increased, the score of "Blurriness" was decreased. These results suggest that different kind of the visual fatigue might be induced depending on characteristics of the stereo images and viewing environment.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.41 no.5
• /
• pp.57-64
• /
• 2004

We proposed the eye gaze tracking system under natural head movements, which consists of one narrow-view field CCD camera, two mirrors which of reflective angles are controlled and active infra-red illumination. The mirrors' angles were computed by geometric and linear algebra calculations to put the pupil images on the optical axis of the camera. Our system allowed the subjects head to move 90cm horizontally and 60cm vertically, and the spatial resolutions were about 6$^{\circ}$ and 7$^{\circ}$, respectively. The frame rate for estimating gaze points was 10～15 frames/sec. As gaze mapping function, we used the hierarchical generalized regression neural networks (H-GRNN) based on the two-pass GRNN. The gaze accuracy showed 94% by H-GRNN improved 9% more than 85% of GRNN even though the head or face was a little rotated. Our system does not have a high spatial gaze resolution, but it allows natural head movements, robust and accurate gaze tracking. In addition there is no need to re-calibrate the system when subjects are changed.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.44 no.6
• /
• pp.35-41
• /
• 2007

We proposed an eye gaze tracking system under natural head movements. The system consists of one CCD(charge-coupled device) camera and two front-surface mirrors. The mirrors rotate to follow head movements in order to keep the eye within the view of the camera. However, the mirror controller cannot guarantee the fast head movements, because the frame rate is generally 30Hz. To overcome this problem, we applied Kalman filter to estimate next eye position from the current eye image. In the results, our system allowed the subjects head to move 60cm horizontally and 40cm vertically, with the head movement speed about 55cm/sec and 45cm/sec, respectively. And spatial gate resolutions were about 4.5 degree and 5.0 degree, respectively, and the gaze estimation accuracy was 92% under natural head movements.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.8 no.9
• /
• pp.485-494
• /
• 2018

This study aims to summarize characteristics of teacher certification system in China and identify its problems and improvement directions through the analysis of examination contents and examination conditions and so on. The teacher certification examination in China, including written examination and interview, is dominated by Ministry of Education. And all districts and departments put into practice according to their own characteristics and practical situations. Without distinction between normal university students and non-normal university students, only when all specific conditions are met could candidates sit for the examination. Problems of teacher certification examination are as following. The limitation of examination conditions focus on educational requirements and some basic conditions, the negligence of educational experience and practical ability, and interview tends to become apparent and formalistic.

• Journal of Korea Multimedia Society
• /
• v.8 no.10
• /
• pp.1293-1305
• /
• 2005

In this paper, we propose the method of manipulating the gaze direction of 3D FPS game's character by using eye gaze detection from the successive images captured by USB camera, which is attached beneath HMD. The proposed method is composed of 3 parts. In the first fart, we detect user's pupil center by real-time image processing algorithm from the successive input images. In the second part of calibration, the geometric relationship is determined between the monitor gazing position and the detected eye position gazing at the monitor position. In the last fart, the final gaze position on the HMB monitor is tracked and the 3D view in game is control]ed by the gaze position based on the calibration information. Experimental results show that our method can be used for the handicapped game player who cannot use his (or her) hand. Also, it can increase the interest and immersion by synchronizing the gaze direction of game player and that of game character.

• The KIPS Transactions:PartB
• /
• v.12B no.4 s.100
• /
• pp.465-472
• /
• 2005

In this paper, we propose the method of manipulating the gaze direction of 3D FPS game's character by using eye gaze detection from the successive images captured by USB camera, which is attached beneath HMB. The proposed method is composed of 3 parts. At first, we detect user's pupil center by real-time image processing algorithm from the successive input images. In the second part of calibration, when the user gaze on the monitor plane, the geometric relationship between the gazing position of monitor and the detected position of pupil center is determined. In the last part, the final gaze position on the HMD monitor is tracked and the 3D view in game is controlled by the gaze position based on the calibration information. Experimental results show that our method can be used for the handicapped game player who cannot use his(or her) hand. Also, it can Increase the interest and the immersion by synchronizing the gaze direction of game player and the view direction of game character.

• The Optical Journal
• /
• s.124
• /
• pp.17-19
• /
• 2009

첨단산업분야에서 광기술의 위상이 높아지면서 '광학'에 대한 교육, 연구, 기술개발 등을 주목적으로 하는 대학의 특성화 학과들이 전국에 11개에 달하는 가운데 그중 공주대학교 영상광정보공학부(광공학전공)가 주목받고 있다. 광학분야 취업률 100% 달성, 올해 치러진 광학기사 시험에서 전체 응시자중 35.3%에 달하는 12명의 합격자를 배출했다는 점만 보더라도 차별성을 쉽게 찾을 수 있다. 이번호에서는 광학전문가들의 산실로 떠오르고 있는 공주대학교 기하공학연구실을 찾아 이준호 교수로부터 최근의 연구 활동 및 교육 방향에 관해 들어보았다.