• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
• /
• pp.327-330
• /
• 2002

This paper proposes the simulation algorithm of rear lamp of car using a ray tracing method that models transmission and refraction of light frequently used in computer graphics At first. To reproduce an image accurately. incident on a sight of viewer, we propose the backward ray tracing method based on spectral distribution representing physical characteristics of illuminant and object used in real. We implement the reproduction algorithm of rear lamp image applying the Bouguer-Beer's law to an optical absorptive phenomenon. As the result, more realistic image can be reproduced.

• 한국전기전자재료학회논문지
• /
• 제27권3호
• /
• pp.162-166
• /
• 2014

We propose an analysis method of an autostereoscopic display system with lenticular lens array using finite ray-tracing method that is verified by the geometrical optics. In the present work, we adopt the cylinder equation for the mathematical expression of the lenticular lens. For the calculation of the direction cosine of the transmitted ray, we first calculate the refracting point at bottom of the lens and the direction cosine of the incident ray that propagating through the lens by the Snell's law, and then apply to finite ray-tracing method. Finally, we obtain the simulation results for the intensity distribution of the ray at optimal viewing distance. From these results, we confirm the realization of 3D image that exists separately according to the viewing position at an optimal viewing distance.

• 조명전기설비학회논문지
• /
• 제28권6호
• /
• pp.7-14
• /
• 2014

We proposed a new algorithm to improve the calculation speed of forward ray tracing method which was quite a problem in conventional Monte Carlo algorithm. To verify the accuracy and the effect of improving calculation speed, we directly compared integrating sphere characteristics with conventional ray tracing algorithm under the same condition which was referred in a reference paper. By applying new algorithm to an absolute reflectometer, we calculated the degree of errors which were caused by baffle and port characteristics to find optimal system design condition.

• 한국전자파학회논문지
• /
• 제18권11호
• /
• pp.1231-1236
• /
• 2007

본 논문에서는 무선 망 설계에 필요한 전파 특성 예측을 위한 방법 중 하나인 광선 추적법의 속도 향상 방법을 제시했다. 빠르고 정확한 광선 추적을 위해 ray tube라는 매개체를 이용하여 전파의 반사, 투과, 회절을 계산하는데, 건물 등의 방해물이 많을수록 계산 시간이 매우 늘어나는 문제점을 해결하기 위해 중복된 계산을 줄이는 방법들을 제시했다.

• 한국통신학회논문지
• /
• 제21권7호
• /
• pp.1668-1676
• /
• 1996

This paper presents the evaluation of an angular spectrum-based method used to calculate scattering pattern of a three-dimensional object modelled as a collection composed of vertical sectional two-dimensional images. This is done via comparing a proposed method with two existing methods, i.e., a Fresnel hologram method and a ray-tracing method, in terms of computatioal complexities and reconstructed results. Maathematical derivations for each methods are reviewed and implementing procedures are described in detail, along with the amount of computaions required from the implementation point of view, rather than from the mathematical point of view. We show simulation results in which the Fresnel holoram method dose not exhibit promising results although it requires the least computation. Moreover, it is also shown that the proposed method, even with much less computational requirement than the ray-tracing method, produces good performances asmuch as the ray-tracing method does.

• 소성∙가공
• /
• 제16권1호
• /
• pp.25-30
• /
• 2007

The present study covers an integrated simulation method to evaluate optical performance of an aspheric plastic lens by connecting a finite element (FE) analysis of injection molding with a ray tracing simulation. Traditional ray tracing methods have based on the assumption that the optical properties of a lens are homogeneous throughout the entire volume. This assumption is to a certain extent unrealistic for injection-molded plastic lenses because material properties vary at every point due to the injection molding effects. To take into account the effects of the inhomogeneous optical properties of the molded lens, a new.ay tracing scheme is proposed in conjunction with a FE analysis of the injection molding. A numerical scheme is developed to calculate ray paths on every element layer with more realistic information of the refractive indices which can be obtained through the FE analysis. This information is then used to calculate the ray paths based on the FE mesh of which nodal points have unique index values. The proposed tracing scheme is implemented on the tracing of an aspheric lens, and its validity is ascertained through experimental verification.

• 소음진동
• /
• 제9권6호
• /
• pp.1131-1136
• /
• 1999

NIC@E is the software developed by authors. The program provides the noise level in outdoors due to various noise source types : construction machines including blast sources, railroad vehicles and automobiles. It operates in the Windows system. In this paper, a highway traffic noise has been evaluated using various types of approach : Ray-tracing method, NIRI method, JAS method. In order to compare the noise estimation performance for various models, a measurement is conducted on a 8 lane express highway at the distance of 25 m and 50 m from the lane. The result shows that the ray tracing and JAS model predict the measured value well within 2dB deviaton. The NIRI model, however, underestimates the highway noise level, as the distance between the source and receiver increases.

• 한국컴퓨터그래픽스학회논문지
• /
• 제23권3호
• /
• pp.55-64
• /
• 2017

본 논문에서는 실시간 모바일 레이트레이싱에서 사실적인 그림자를 생성하기 위한 새로운 그림자 생성 기법을 제시한다. 일반적으로 레이트레이싱에서는 그림자 광선을 샘플링 하여 부드러운 그림자를 생성한다. 지금까지 이런 생성 방법은 처리해야 할 광선의 수를 증가시키기 때문에 성능 저하의 요인이 되어왔다. 제안하는 소프트 쉐도우 생성 기법과 하드웨어 구조는 선택적 그림자 생성과 삼각형 주소 캐싱을 통해 샘플링에 의한 성능 저하를 최소화시킴으로써 이런 문제를 해결하였다. 제안된 하드웨어 구조는 모바일 레이트레이싱 하드웨어에 통합 가능한 수준이며, FPGA상에서 성능 평가 되었다. 평가 결과 제안된 기법의 성능은 4, 8, 그리고 16 샘플에 대해서 이전 기법 대비 평균 40%, 50% 그리고 56% 수준으로 향상 되었으며, 우리는 제안된 하드웨어 구조를 통해 실시간으로 소프트 쉐도우를 생성할 수 있음을 확인하였다.

• Transactions on Electrical and Electronic Materials
• /
• 제11권4호
• /
• pp.194-196
• /
• 2010

A study is presented of improved road light design for drivers and pedestrians with the use of a ray- or reverse ray-tracing method. Many existing road lights are unsuitable for drivers and pedestrians because of serious problems such as glare effect or randomicity of illuminated areas. This situation has arisen because in customary design methods the emphasis has been on simple factors such as luminance or electrical power. However a high luminance or electrical power consumption, alone, do not guarantee bright and good road lighting. So we have applied a ray-tracing method to the design of a road light reflector with the goals of ensuring that illuminated objects on the road can be seen more clearly and that the illuminating light is more comfortable for the eyes of drivers and pedestrians. We have set design targets for factors such as the uniformity of lighting on the road area per road light, the shading angles and the continuous luminance uniformity on long lengths of road. For set heights of the eyes of drivers and pedestrians eyes we have calculated a design guideline for the achievement of the above design targets. Then we designed a road light reflector using the reverse ray-tracing approach. Also we have achieved the same luminance on the road with almost half the power consumption, through the reduction of lighty loss. In an ideal design optimum parameters are suggested to be a shading angle of 75 degrees and a luminance uniformity of 0.5 on the road area. This reflector performance is achievable with a 250 watt power consumption ceramic discharge metal light source.

• 한국통신학회논문지
• /
• 제38A권12호
• /
• pp.1110-1116
• /
• 2013

3D-ray tracing tool은 신호의 반사, 투과, 그리고 회절까지 고려하여 3차원 공간에서 더욱 정확한 네트워크 성능을 분석하기 위한 소프트웨어이다. 통신표준에서는 통신 자원을 효율적으로 제공하기 위해 소형셀을 포함한 Heterogeneous Networks (HetNets)을 도입하고 있다. 매크로셀에 비해 좁아진 커버리지를 사용하는 소형셀 환경에서는 3D 공간에서 성능분석이 중요해 졌다. 또한 지형구조와 건물의 배치 그리고 3D 빔포밍(beamforming) 기술 등의 사용으로 인해 네트워크 환경이 복잡해지기 때문에 기존의 2차원 수학적 모델들을 이용하여 성능을 분석하기에는 어려움이 따른다. 본 논문에서는 소형셀 네트워크 성능을 더욱 효율적으로 분석하기 위한 3D-ray tracing tool을 활용한 성능평가 방법을 소개한다. 성능평가 결과 기존의 방법보다 3D-ray tracing tool을 활용한 성능평가 방법이 소형셀 환경에서 더욱 적합하다는 결론을 내렸다.