• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.264-267
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• 2006

This paper describes the accident analysis by modeling the current transformer mounting in meaium voltage metal-clad switchgear(MCSG). In analyzing the accident the reconstruction at the current transformer mounting(VCB connecting guide) has to be taken into account. The accident was modelled as a 3-phase ground fault mounting between the end plate of a high voltage lines and the safety shutter at the current transformer mounting of the VCB inside the metal clad switchgear. Since the outside maintenance of the metal clad switchgear is restricted by the enclosed compartments, its circumference has to be kept clean. Through the reconstruction results, it was confirmed that the fault of the enclosed switchboard could be reduced when the shutter made of Fe material was changed into an insulation.

• Smart Media Journal
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• v.6 no.3
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• pp.57-63
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• 2017

The most important, essential prerequisite for the improvement of vehicle license plate recognition is the acquisition of high-quality vehicle images. Because typical images acquired from roads are affected by different environmental factors including the time of day, sunlight, and the weather, the brightness and the shape of the license plates in the images are inconsistent. To this end, many image corrections are performed, resulting in slower recognition and lower recognition rate. Therefore, in this study, we used the images acquired from roads to test the proposed method for fast capturing of vivid, high-quality vehicle images by measuring the brightness around license plates during real-time image capturing to control in real time the factors, such as shutter speed, brightness, and gain of the camera, that affect the brightness and the quality of the images.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.110-116
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• 2012

To analyze flow characteristics and performance of the side jet thruster with 4 shutters and rectangular nozzles, a 3-D simulation has been implemented. Numerical calculations for three rotation anlgles of the shutter, have been conducted. Internal recirculation in a chamber and asymmetric flow structure in a nozzle were observed. In addition, the more shutter rotated, the more asymmetries of flow increased, and this phenomena resulted in thrust bias. The degrees of thrust bias and thrust performance with the rotation angles of the shutter were predicted and comparisons with theoretical thrust were made.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.2
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• pp.63-70
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• 2013

To analyze flow characteristics of the side jet thruster with 4 shutters and rectangular nozzles, a 3-D simulation has been implemented. Numerical calculations for two rotation angles of the shutter, have been conducted. Internal recirculation in a chamber and asymmetric flow structure in a nozzle were observed. In addition, the more shutter rotated, the more asymmetries of flow increased, and this phenomena resulted in thrust bias. The degrees of thrust bias and thrust performance with the rotation angles of the shutter were predicted and compared with theoretical thrust.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2935-2940
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• 2007

To diagnose circulatory diseases in the viewpoint of hemodynamics, we need to get quantitative hemodynamic information of blood flows related with the vascular diseases with high spatial resolution of tens micrometer and high temporal resolution in the order of millisecond. For investigating in-vivo hemodynamic phenomena, a new diagnosing technique combining medical radiography and PIV method was newly proposed and developed. This angiographic PIV technique consists of a medical X-ray tube, an X-ray CCD camera, a shutter module for double pulses of X-ray, and a synchronizer. The feasibility of the angiographic PIV technique was tested and quantitative flow velocity field distribution of a flow inside an opaque conduit was acquired by the developed system. It can be used for measuring flow phenomena of nontransparent fluids inside opaque conduits.

• Journal of Biomedical Engineering Research
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• v.21 no.6
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• pp.607-614
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• 2000

본 논문은 가상환경 노출에 따른 가상멀미와 같은 인체의 영향을 평가하기 위한 연구이다. 이를 위해 20명의 피험자를 대상으로 하여 30분 동안의 가상현실 환경 노출 전과 노출 후에 나타나는 인체의 영향을 분석하였다. 실험평가를 위한 파라미터로는 SSQ test, COP, flicker test, 체온변화, 심박수 변화, 그리고 눈 깜빡임 값들이 이용되었다. 3D 입체영상의 제시는 LSG에 의해서 이루어졌으며, 특히 flicker test시에서는 모니터, LSG, HMD를 모두 사용하여 피로도를 측정, 비교하였다. 본 연구결과, 가상현실 환경의 노출 전 보다 노출 후에서 SSQ score, COP, 체온, 눈 깜빡임, 그리고 심박수가 증가함을 알 수 있다.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.5
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• pp.426-431
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• 2008

In this paper, an improved AE system for digital still camera is proposed. AE system is auto exposure system to maintain optimized brightness of output image. But there is limitation for mobile devices to get high quality image with the conventional AE algorithm, because of organizational restriction of system. The conventional research has been studied only electronic shutter and AGC on the AE algorithm. In this paper, we suggest new AE algorithm included target setting, frame delay, Gamma Correction as well as electronic shutter and AGC to get high quality image. The proposed algorithm show improved result at control speed and ability of luminance expression.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.10
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• pp.399-406
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• 1985

In this paper transparent PLZT ceramics for the composition of 9/65/35 (La/Zr/Ti ) are fabricated using hotpress and the possibility of application to optical shutter is examined by obtaining the On-Off characteristics of specimens. The ferroelectric E-P hysteresis loop exhibits slim loop suitable for the quadratic electrooptic effect. Measurements of the electrooptic effect show that specimens have the quadratic electrooptic effect but the light intensities as functions of electric field exhibit butterfly type hysteresis curves because of its slightly large saturation remanent polarization and coercive field. On-Off characteristics are obtained by electric fields of-6 kv/cm and +2kv/cm. As a result of experiments, 9/65/35 PLZT ceramics can be applied to optical shutter but construction with other composition which has more slim hysteresis loop is desired for obtaining the Off state by zero electric field.

• Journal of Information Display
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• v.11 no.2
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• pp.57-62
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• 2010

A method of characterizing time-sequential stereoscopic 3D displays based on the measurement of the temporal behavior of the systems vs. the grey levels is proposed. An Nvidia 3D vision kit with a 3D-ready SAMSUNG 2233RZ LCD display is characterized in the paper. OPTISCOPE SA especially designed for the precise measurements of the luminance and temporal behavior of LCD displays was used. The transmittance and response time of the shutter glasses was first evaluated. Then the grey-to-grey response times of the display were measured. The 2D and 3D behaviors of the display were then compared. Finally, the temporal behavior of the complete system was modeled, and the grey-level variations on one view were deduced as a function of the synchronization and level of the other eye. The main sources of imperfection were identified and quantified, and a full computation of the system performances was done.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.8-13
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• 2017

Compare with other communication system based RF technology, Optical Camera Communication (OCC) has limitation on data rate due to the low frame rate of camera. The limitation on data rate can be solved with multiple-input and multiple-output (MIMO) technology; and it is the final target of all researches on OCC. The MIMO topology can be implemented easily without breaking out the architecture of image sensor. For image sensor classification, there are two architectures have been developed: rolling shutter and global shutter. The operation of two techniques is different so the performance is also different. In this paper we analyze and evaluate the performance of the MIMO architecture for OCC.