• Journal of the Korea Computer Graphics Society
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• v.9 no.4
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• pp.9-15
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• 2003

컴퓨터 게임, 지리정보시스템(GIS), 가상현실 분야 등에서 환경표현의 기반이 되는 지형의 렌더링 기술은 매우 중요하다. 하지만 지형정보는 일반적으로 방대한 양의 데이터로 구성되어 처리가 쉽지 않다. 지형렌더링을 수행하기 위한 여러가지 기법들 중에 쿼드트리 구조를 기반으로한 연속적 상세단계기법이 있다. 본 논문에서는 쿼드트리 기반의 연속적 상세단계에서 시각 절두체 내에서 렌더링되는 삼각형의 개수를 조절하여 프레임율을 일정하게 유지하는 기법을 제안한다. 이 방법은 인접 프레임간의 일관성을 이용하여 최근 프레임에 가중치를 줌으로써 삼각형의 개수가 급격하게 변하는 것을 막는다.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.31-31
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• 2003

목적： 통증에 대한 fMRI 연구에 있어서 differential-regression-analysis (DRA) 기법을 사용하여 대뇌 피질에서 통증 처리에 관련된 영역의 순시적인 변화를 관찰하였다. 대상 및 방법： 우선 통증과 일반적인 감각자극과의 생리학적 차이를 밝히기 위해 운동 (finger tapping) 및 시각 (flickering light) 자극 실험이 선행되었다. 통증 유발을 위해서는 50C에서 52C의 뜨거운 물을 이용한 온도자극이 왼손의 검지와 중지에 30초 동안 가해졌다. fMRI 실험은 Marconi (Philips) 1.5 T scanner를 이용하여 gradient echo EPI sequence(TR / TE / FA = 3 sec / 35 msec / 90)로 수행되었다. 감각자극과 통증자극에 대한 반응의 동적인 변화를 관찰하기 위하여 fMRI 결과 분석에 기존의 box-car function과 DRA 기법이 사용되었다.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.466-469
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• 1998

The electronic fluorescent lamp ballast can promote the lighting efficiency up to 10-20% by driving high frequency with frequency transformation technique, and can completely eliminate the flickering phenomenon occurring from 60Hz frequency. The electronic ballast provides very high energy saving effects for it has high power fact than traditional ballast, and it is convenient to use. can extend the life of fluorescent lamp for it starts at once by driving with high frequency. However electronic ballast needs high price, and it can reduce the stability and reliability. This paper provides illumination systems which drive dozens of fluorescent lamps at the same time, to overcome these shortcomings of electronic ballast and utilize the advantage of electronic ballast.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.998-1002
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• 1998

The electronic fluorescent lamp ballast can promote the lighting efficiency up to 10-20% by driving high frequency with frequency transformation technique, and can completely eliminate the flickering phenomenon occurring from 60Hz frequency. The electronic ballast provides very high energy saving effects for it has high power factor than traditional ballast, and it is convenient to use, can extend the life cycle of fluorescent lamp for it starts at once by driving with high frequency. However electronic ballast needs high price, and it has the bad stability and reliability. This paper provides illumination systems, which drive dozens of fluorescent lamps at the same time, to overcome these shortcomings of electronic ballast and utilize the advantage of electronic ballast.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.145-150
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• 2012

We present a display-based visual stimulator for psychophysical and electrophysiological visual sensitivity measurements. The stimulator offers various psychophysical visual stimuli and transfers the signals from external devices along with the stimulation signals to an electrophysiological recorder. As an experimental demonstration, we perform a visual sensitivity experiment in the mesopic vision range by using the display-based stimulator. The intensity of the steady-state visual evoked potential is observed to correlate with the luminance of the flickering visual stimulation. For the psychophysically determined detection thresholds, we determine the mesopic luminance, showing agreement with the perceived brightness within the uncertainty of the luminance measurement.

• Journal of the Korea Society for Simulation
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• v.10 no.2
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• pp.1-14
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• 2001

The layout design of component plays an important role in the design and usability of many engineering products. The Engineering artifacts of today are becoming increasingly complicated. The simulated annealing method has been applied effectively to the layout and packing problems of wafer. The main characteristics of simulated annealing method is that an optimum can be obtained from the many local optimums by controlling the temperature and introducing the statistic flickering. The objective of this study is to suggest a method to apply the simulated annealing method to the three dimensional layout design of submergible boat which has multiple constraint conditions and evaluation criteria. We describe an approach to define cost function, constraints and generate layouts using a computer. In this research three dimensional LAYout Design Optimization Program(LAYDOP ver.2) has been developed. The layout result(the total value of evaluation criteria) designed by a human layout expert has been improved by 31.0% using this program.

• International Journal of Railway
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• v.3 no.3
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• pp.106-112
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• 2010

Accidents at level crossing have large portion on train accidents, and causes economical loss by train delay and operational interruption. Various safety equipments are employed to reduce the accident at level crossing, but existing warning device, and crossing barrier are simple train-oriented protection equipments. In this paper, intelligent railway level crossing system is proposed to prevent and reduce accidents. For train driver's prompt action, image of level crossing and obstacle warning message are continuously provided to train driver through wireless communication in level crossing control zone. Obstacle warning messages, which are extracted by computer vision processing of captured image at level crossing, are recognized by train driver through message color, flickering and warning sound. It helps train driver to decide how to take an action. Meanwhile, for vehicle driver's attention, location and speed of approaching train are given to roadside equipments. We identified the effect of proposed system through test installation at Sea train and Airport level crossing of Yeong-dong line.

• IE interfaces
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• v.12 no.2
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• pp.174-179
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• 1999

This paper describes the development of low cost, miniaturized multi-function image splitter for an unmanned guard system. The essential equipments of an image splitter system consist of a video system which displays in one screen images inputted by several cameras, a frame switcher which records each image sequentially in VTR, and TBC(Time Base Control) system which prevents image flickering during image switching. Currently, the price of similar system on the market is high, system management and repair are difficult, and bulky space is required. Futhermore, since currently available frame switcher can record only 30frame/sec, if eight cameras are installed, each camera image is recorded at the low speed of 3.75frame/sec, and consequently skip some images which may be vital for legal evidence. In this research, we have solved the problem of low speed recording by recording the video screen of splitted images at 30frame/sec and zooming each image when play back.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.1016-1022
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• 2014

Kinect is a motion sensing camera released by Microsoft in November 2010 for the Xbox360 that is used to produce depth and color images. Because Kinect uses an infrared pattern, it generates holes and noises around an object's boundaries in the obtained images. The flickering phenomenon and unmatched edges also occur. In this paper, we propose a real time virtual-view video synthesis algorithm which results in a high quality virtual view by solving these problems stated above. The experimental results show that the proposed algorithm performs much better than the conventional algorithms.

• Journal of the Korean Society of Safety
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• v.24 no.1
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• pp.14-20
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• 2009

Direct numerical simulations(DNS) were performed for the prediction of transient buoyant jet diffusion flames where the Froude numbers(Fr) are 5 and 160, respectively. The thermodynamic and transport properties were evaluated using CHEMKIN package to enhance the prediction performance of the DNS code. The simulated buoyant jet diffusion flame of Fr=5 and 160 showed the transient, dynamic motion well. It was identified that the buoyant jet flames were flickered periodically, and the simulated flickering frequency of the jet diffusion flame of Fr=5 was 12.5Hz, which was in good agreement with the experimental results. The flamelet structures of the buoyant jet diffusion flames could be well understood by comparing the scalar dissipation rates(SDR) and the heat release rates(HRR) of the flames. It was found that the SDR was strongly coupled with the HRR in the buoyant jet diffusion flames.