• Korea Multimedia Society
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• v.8 no.1
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• pp.76-85
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• 2004

1960년대 시작된 컴퓨터 그래픽스에 관한 연구는 그 목표를 사진과 같은 영상을 만들어 내는데 두었다. 지난 30년간 포토리얼리즘이라는 용어로 대변되듯, 기존 컴퓨터 그래픽스의 궁극적인 관심은 얼마나 실제와 같은 영상을 만들 수 있는가에 집중되었다. 이러한 전통적인 컴퓨터 그래픽스는 레디오시티나 광선추적법같이 사물의 물리적인 특성이나 역학적인 특징을 그대로 흉내 내어 매우 사실적인 영상을 만들어내었다.(중략)

• Proceedings of the Korean Information Science Society Conference
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• 2002.10d
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• pp.436-438
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• 2002

가상내시경에서 효과적인 진단과 사용자의 편의를 위해서는 자동순항(navigation) 기능이 필요하다. 자동순항을 위해서는 장기의 내벽과 충돌을 피하면서 부드럽게 카메라의 이동방향을 전환할 수 있어야 한다. 본 논문에서는 광선추적법(ray-casting)에 기반한 충돌회피기법과 그를 이용한 효율적인 순항 방법을 제안한다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.30 no.5
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• pp.14-21
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• 2001

축구 전용구장이 가지는 여러 지붕구조의 특성에 따라 경기장 잔디면의 조도 및 자연광량을 몬테카를로 방법과 광선추적기법을 적용하여 개발된 컴퓨터 프로그램에 의해 예측하고, 설계안에 의해 부족한 잔디면의 자연광량을 보충할 수 있는 인공조명시설의 제작방법을 레디언스(Radiance) 프로그램을 이용한 시뮬레이션 결과로부터 도출하여 제시하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.3
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• pp.43-48
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• 2018

Offset parabolic antenna have been widely used for satellite communication system. To locate feedhorn on antenna system, it requires arbitrary structure which forces to fix on system. However, arbitrary scatterer increases sidelobe level of elevation axis. To solve this problem, we need to predict which angle level is increased by arbitrary scatterer simply. Because conventional simulation method takes a long time to simulate parabolic antenna system and needs exclusive software. In this paper we can calculate sidelobe angle simply by using raytracing method, check coincidence between calculated and simulated result and show how arbitrary scatterer affects sidelobe lavel of elevation axis of offset parabolic antenna depending on angle and location of arbitrary structure.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.1
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• pp.35-39
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• 2008

In this paper, we have developed a propagation loss prediction software with GUI (Graphic User Interface) functions, based on the geometrical ray optics model, which can predict radio parameters for the deployment of wireless indoor network. The program has two numerical modules consisted with electrical image and ray launching methods to implement UTD theory. The simulated results are compared with reported data measured in the foreign building environments for office and '一' type corridor, and measured and simulated results for the propagation loss agree with each other quite well. Simulation results for '一' type corridor and 'T' type corridor propagation environment are shown for reference.

• Journal of the Korea Computer Graphics Society
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• v.23 no.3
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• pp.123-133
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• 2017

Cache performance is an important factor in hardware system. We proceed with a cache simulation to analyze the cache performance suitable for sound rendering. In addition, we introduce hardware models based on ray tracing used in geometric method and studies to improve cache performance. Cache simulation is performed on various conditions for cache size, way and block. Various simulations can be found to influence the cache hit rate. We compare cache simulation results with actual hardware performance to analyze cache performance suitable for sound rendering.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.2
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• pp.211-218
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• 1998

In this paper, we analyze various errors in prediction results of ray tracing propagation model for microcellular environments. It is shown that improper electrical parameters of building materials and limitations of diffraction orders can cause high errors in prediction results. Especially, the effect of errors in building database on prediction results is considered in detail. It is also shown that the prediction error increases as the resolution of building map data is getting worse, and the error is analyzed depending on LOS and NLOS domains. Based on the results obtained by the analysis developed in this paper, 5 m resolution is suitable for the building map data if the maximum prediction error is required to be below 6 dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.5
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• pp.766-776
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• 1999

In this paper to evaluate the performance of the polarization diversity and the space diversity in the indoor environment, we used 3D Ray-tracing simulation. This model is capable of predicting small scale fading characteristics of the channel for evaluating the performances of both the polarization and the space diversity scheme. The measurement and simulation results show that the polarization diversity and the space diversity are expected to be efficiently used for the indoor environments. Moreover, the results show that the proposed polarization diversity technique using directional dual polarization microstrip array antennas has more diversity gain than the conventional polarization and space diversity using dipole antenna.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.4
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• pp.49-53
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• 2018

Parabolic offset antenna is widely used for wireless communication system. The general structure of parabolic offset antenna system is composed of supporting stand and RF devices under parabolic reflector. However sidelobe distortion in gain pattern is occurred by supporting stand and RF devices. Depending on position of subsidiary devices, angle of sidelobe distortion can be changed. In this paper we describe method for sidelobe distortion suppression using raytracing. We calculate 3D vector for sidelobe distortion suppression zone by raytracing method and compare when subsidiary device is in sidelobe distortion suppression zone or not. By comparison, we show method for parabolic antenna sidelobe distortion suppression.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.4
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• pp.11-21
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• 2000

This paper proposes a new algorithm for a mobile robot that detects and tracks a moving target, keeping it in the view range of the robot. The sensor system consists of a camera and a line light source. The camera system is placed so that the line light projected into the ground from the light source forms its image along the horizontal center line of the CCD array of the camera. The deformation of the line image from the horizontal center line contains the information on existence of a moving object, its velocity, and position. Since the proposed algorithm reduces the region of the image to be searched, it reduces the computational complexity significantly comparing to the conventional image processing algorithms. The performance of the proposed algorithm has been tested by implementing on a mobile robot.