가속 방법을 이용하는 전파 광선 추적법에 관한 연구

권세웅(Sewoong Kwon),문현욱(Hyun Wook Moon),오재림(Jae Rim Oh),임재우(Jae-Woo Lim),배석희(Seok-Hee Bae),김영규(Young-Gyu Kim),박정수(Joungsoo Park),윤영중(Young Joong Yoon) 한국전자파학회 2009 한국전자파학회논문지 Vol.20 No.5

본 논문에서는 개선된 가시 트리 구조와 가시면 검색을 위해 효율적인 방법을 적용한 광선 추적법을 제안한다. 비슷한 특성을 갖는 트리의 노드를 재생성하지 않는 개선된 가시 트리 구조를 사용하였으며, 가시면 판별을 위해 묶음 광선(packet ray) 개념 검사점을 비균일하게 분포시키는 방법으로 경로 탐색 성능을 개선하였다. 충돌검사에서 묶음 광선를 사용함으로써 3.3배의 속도 개선을 이루었으며, 비균일 검사점 분포를 통해 1.11배의 성능향상을 이루었다. 본 광선추적법을 적용한 결과의 경우, 경로 손실에서 RMS 에러가 1.9 ㏈ 발생하여 높은 정확도를 제공할 수 있음을 보였다. In this paper, we proposed an improved ray tracing method with an amelioration of visible tree structure, a visible face determination method, and non-uniform random test point method. In a proposed visible tree structure, it reduces tree nodes by means of merging similar nodes. In a visible face determination method, it shows that a ray hit test with a packet ray method can reduce a test time. A ray tracing method involving with a packet ray hit test method can improve a tree construction time up to 3.3 times than a ray tracing method with a single ray hit test method. Furthermore, by seeding a non-uniform and random test point on a face, tree construction time is improved up to 1.11 times. Received powers from the proposed ray tracing results and measured results have good agreement with 1.9 ㏈ RMS error.

Ray-Tracing Method를 이용한 일영면적 산정방식 고찰

최정민(Choi Jeong-Min),조성우(Cho Sung-Woo) 한국태양에너지학회 2011 한국태양에너지학회 논문집 Vol.31 No.3

Nowadays, the solar expose right is very important with people's life. Therefore, in calculating the sunshine hours, the point analysis and area analysis methods are used in previous studies. Previous two methods have merits and faults. Therefore, ray-tracing method is used as a alternative. Ray-tracing method is adopted by the software of Autodesk Ecotect which is a widely used program by the architectural company and academic university. In this study first, ray-tracing methodology is studied with how to calculate the overshadowing area and, secondly, the sensitivity of the two major factors, overshadowing accuracy and sky subdivision, is analyzed. With these results, appropriate application of the ray-tracing method is presented.

큰 규모의 불규칙 조면에 의한 전자파 전파 특성

윤광렬,채용웅,Yoon Kwang-Yeol,Chai Yong-Yoong 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.4

In this paper we applied a ray tracing method to estimate the scattering characteristics from large scale random rough surfaces. For the electromagnetic field evaluation, we have used the diffracted coefficient of the knife edge diffraction for the diffracted rays and Fresnel's reflection coefficients in connection with reflected rays. In addition, we examine to search for the traced rays using the imaging method which can be obtained all rays to arrived at receivers accurately and the diffracted field from rough surfaces is considered. Numerical examples have been carried out for the scattering characteristics of an ocean wave-like rough surface and delay spread characteristics of a building-like surface. In the present work we have demonstrated that the ray tracing method is effective to numerical analysis of a rough surface scattering. 본 논문에서는 비교적 큰 규모의 불규칙 조면에 의한 산란 특성을 예측하기 위해 ray tracing 기법을 적용하였다. 전자계를 평가하기 위하여, 회절 레이(ray)에 대해서 knife edge 회절에 의한 회절 계수를 사용하였고, 반사 레이에 관해서는 Fresnel의 반사 계수를 사용하였다. 또한 레이 추적 방법에는 수신기에 도달하는 모든 레이의 경로를 정확히 찾아주는 image method를 채용하였으며, 불규칙 조면에 회절계를 고려하였다. 파도 모양의 조면에 의한 산란 특성과 빌딩 모양의 표면에 의한 지연 확산(delay spread) 특성에 대해 수치 계산하였다. 불규칙 조면에 의한 산란 특성을 수치적으로 해석하는데 ray tracing 기법을 적용하여 그 유효성을 입증하였다.

Improved Road light Design using Ray-tracing method

최대섭(Dae-Seub Choi),한정민(Jeong-Min Han),박성태(Sung-Tae Park) 대한전기학회 2008 대한전기학회 학술대회 논문집 Vol.2008 No.9

In this study, it was studied about the improved road light design for drivers and pedestrians using ray- or reverse ray-tracing method. Many of conventional road lights are not suitable for drivers and pedestrians because it has some serious problems such as glare effect or randomicity of illuminated areas. It was oriented from customary design method which was pointed at simple target such as luminance or electrical power. But it was not truth any more that the high luminance or electrical power consumption mean more bright and good road light. We studied ray-tracing method for road light reflector design to get the several goals. It means that good road light has easy for drivers and pedestrians eyes and illuminating objects on the road clearly. So, we set the design targets such as uniformity on the road area per one road light, shading angles and continuous luminance uniformity on the long distance road. We designed ideal road light conditions using ray-tracing method. We set the height of drivers and pedestrians eyes and calculated design guideline to make above design targets. Then we designed road light reflector using reverse ray-tracing method. And we achieved same luminance on the road almost half power consumption because we reduced loss of light. We achieved ideal design guide as 75 degrees of shading angles and 0.5 of luminance uniformity on the road area. Finally, we suggested reflector design for 250 watts power consumption CDM light source.

Study of Optimized Reflector Design for Road Light Using Ray-Tracing Method

최대섭(Dae-Seub Choi),한정민(Jeong-Min Han),심용식(Yong-Sik Shim),정찬웅(Chan-Oong Jeong),오선(Seon Oh) 대한전기학회 2009 전기학회논문지 P Vol.58 No.3

In this study, it was studied about the improved road light design for drivers and pedestrians using forward or reverse ray-tracing method. Many of conventional road lights are not suitable for drivers and pedestrians because it has some serious problems such as glare effect or randomicity of illuminated areas. It was oriented from customary design method which was pointed at simple target such as luminance or electrical power. But it was not truth any more that the high luminance or electrical power consumption mean more bright and good road light. We studied ray-tracing method for road light reflector design to get the several goals. It means that good road light has easy for drivers and pedestrians eyes and illuminating objects on the road clearly. So, we set the design targets such as uniformity on the road area per one road light, shading angles and continuous luminance uniformity on the long distance road. We designed ideal road light conditions using ray-tracing method. We set the height of drivers and pedestrians eyes and calculated design guideline to make above design targets. Then we designed road light reflector using reverse ray-tracing method. And we achieved same luminance on the road almost half power consumption because we reduced loss of light. We achieved ideal design guide as 75 degrees of shading angles and 0.5 of luminance uniformity on the road area. It is superior than conventional road light ability such as 0.35 of luminance uniformity of 400 watts power consumption lamp. Finally, we suggested reflector design for 250 watts power consumption CDM Iight source.

Ray-tracing 기법을 이용한 축변위 그레고리안 안테나 설계

김춘원(Chun-Won Kim) 한국항공우주학회 2014 韓國航空宇宙學會誌 Vol.42 No.6

본 논문에서는 Ray-tracing 기법을 이용하여 그레고리안 안테나의 부반사판을 축변환 후 회전하여 급전혼으로 회귀되는 전파를 없애 이득 및 정재파비를 개선 시키고 부반사판의 크기와 전체적인 부피를 줄여 효율적인 구조를 갖는 축변위그레고리안 안테나를 설계하였다. 설계된 급전혼의 방사패턴을 이용하여 급전혼-부반사판-주반사판으로 전달되는 전파의 경로를 추적하여 주반사판 개구면에서의 전계분포를 구하고 이로부터 원거리 복사패턴을 계산하는 프로그램을 작성하여 안테나 성능을 최적화 하였다. 설계된 안테나는 CST와 제작·측정을 통해 계산결과와 비교하여 이득, 빔폭, 방사패턴, 부엽준위, 반사손실이 계산 결과와 매우 유사함을 확인함으로써 Ray-tracing기법에 대한 타당성을 검증하였다. In this paper, we designed axis-displaced Gregorian antenna by using Ray-tracing method. This antenna improves gain , VSWR by rotating the axis of the sub-reflector to get rid of E-field wave returned from sub-reflector to feed horn. Therefore it reduce the sub-reflector size and the volume of antenna. This method is used to track the propagation path for radiation pattern of feed horn from feed horn to sub-reflector, main-reflector and air. We get E-field distribution of this antenna aperture and calculate antenna radiation pattern and optimize the antenna performance. The Ray-tracing Method was verified because the gain, radiation patterns, side lobe level, beam width and return loss of the designed antenna are very similar to CST simulation result and a measured result of the fabricated antenna.

음향 루우버의 삽입손실 예측연구

유왕선(Wang Seon Yu),김태민(Tae-Min Kim),김정태(Jeung-Tae Kim) 한국철도학회 2017 한국철도학회 학술발표대회논문집 Vol.2017 No.05

본 연구는 음향 루우버가 설치되어 있는 개방형 방음터널의 음향효과를 예측하기 위하여, 광음향기법을 이용하였다. 음향 루우버의 개구율이 36 %인 조건에서, 음향 루우버의 삽입손실을 잔향실에서 측정된 결과와 비교 분석하였다. 본 연구에서는 해석 모델 구성 시 동일한 잔향실을 모델링 하였으며, 소음원과 수음점의 위치를 ISO 규격에 따라 동일하게 구성하였다. 해석 결과 광음향기법을 이용한 삽입손실 예측 방법이 측정 결과 대비 유사한 것으로 분석되었으며, 추후 흡음재 종류에 따른 삽입손실 영향을 분석할 예정이다. In this study, an acoustics performance for a louver was predicted and analyzed by using a ray tracing method. As a part of the study on the partial opening type of the soundproof tunnel, the proposed aperture ratio of acoustic louver was specified as 36% opening area ratio. Since an insertion loss of the acoustic louver was measured in the reverberation chamber, the same reverberation room was modelled in the simulation. The sound source and the receiving points were constructed according to the ISO standard. The result shows that the estimation of the insertion loss based on the ray tracing method was be similar to the measured data. Extra insertion loss effect due to the sound absorbing material attachment is planning to be studied.

터널 환경에서 위성 DMB 시스템 E의 BER 성능

조한신,김도윤,문철,육종관,Jo Han-shin,Kim Do-youn,Mun Cheol,Yook Jong-gwan 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.5a

본 논문에서는 터널환경에서 위성 DMB(Digital Multimedia Broadcasting) 시스템의 BER성능을 예측하기 위한 방법 및 결과를 제시하였다. 이 방법은 ray-tracing기법을 이용해 얻을 수 있는 특정지역에 대한 채널 모델을 기반으로 하기 때문에 레일리 및 라이시안 확률 분포와 같은 기존의 수학적 모델과 통계적 특성이 일치하지 않는 임의의 페이딩 채널에 대한 BER특성을 예측할 수 있는 장점을 갖는다. ray-tracing방법을 이용하여 얻은 터널 페이딩 채널 데이터를 몬테카를로 방법을 이용한 BER 시뮬레이션에 적용하였다. 세 종류의 터널환경 모두 BER성능은 레일리 페이딩(K=0) 일 때 보다 우수하고 K=3일 때 보다 열악하였다. 또한 위성 DMB 시스템 E의 요구 BER인 0.001을 기준으로 하였을 때의 $E_b/N_0$는 레일리 페이딩 채널과 터널 페이딩 채널 사이에 $1{\sim}1.5\;dB$정도의 차이가 있음을 확인할 수 있었다. A different alternative method for simulating bit error rate(BER) performance of Satellite Digital Multimedia Broadcasting(DMB) in tunnel environments is presented. The method based on a channel model obtained by ray-tracing is able to support BER estimation over the channel presents arbitrary statistics that are difficult to fit to an analytic expression. The BER performance for System E over the tunnel fading channel that obtained by ray-tracing is predicted by the monte-carlo method. It can be observed that the BER performance for a straight tunnel channel is better than that for a line-of-sight(LOS) area in curved tunnel. Also, the BER performance for LOS areas in a curved tunnel outperforms that for non-line-of-sight(NLOS) areas in a curved tunnel. The BER performances for straight, curved LOS and curved NLOS tunnel channels are better than that for a Rayleigh channel(K=0) and less than that for a Rician channel with K=3. Moreover, for BER=10-3, it can be seen that there is approximately a $1{\sim}1.5\;dB$ difference between those three types of tunnel channels and a Rayleigh channel.

Study of a Ray-Tracing Method for Optimized Road Light Design

오선,최대섭 한국전기전자재료학회 2010 Transactions on Electrical and Electronic Material Vol.11 No.4

A study is presented of improved road light design for drivers and pedestrians with the use of a ray- or reverse raytracing 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.

초목이 포함된 건물에서의 경험적 모델을 적용한 전자파 경로 손실 예측

박기태(Ki-Tae Park),이한희(Han-Hee Lee),이재욱(Jae-Wook Lee),권종화(Jong-Hwa Kwon),형창희(Chang-Hee Hyoung),황정환(Jung-Hwan Hwang) 한국전자파학회 2023 한국전자파학회논문지 Vol.34 No.5

본 논문은 외부의 전자기파에 의한 건물 내부의 광선추적 기반의 전자파 해석 시뮬레이션에 있어 외부요소인 나무들에 의한 영향을 일반화된 경로손실 모델로써 적용하는 방안에 대하여 연구하였다. 본 연구에서 사용된 전자파 해석 모델인 광선추적법과 경로손실모델이 설명되었으며, 전자기파 해석 시뮬레이션에는 0.6 ㎓부터 6 ㎓까지의 대역을 사용하였다. 목표로 하는 건물의 전자기파 해석 시뮬레이션은 광선추적법(ray tracing)을 기반으로 하는 상용 시뮬레이션 툴인 Wireless Insite를 사용하였고, 실험환경에서 실험에 영향을 끼치는 나무들의 크기와 위치를 고려하여 경로손실 모델을 적용하여 시뮬레이션을 진행하였다. 최종적으로 경로손실 모델이 적용된 시뮬레이션 결과값과 실제 실험을 통하여 얻어진 결과값의 비교를 통하여 나무의 영향을 고려한 시뮬레이션의 정확성을 확인하였다. This study investigated the method to apply the influence of trees, which are external factors, as a generalized path loss model in the simulation of ray tracing-based electromagnetic analysis inside a building by external electromagnetic waves. The ray tracing method and path loss model, which are electromagnetic wave analysis models used in this study, were described, and the frequencies ranging from 0.6 ㎓ to 6 ㎓ were used for electromagnetic wave simulation. The electromagnetic simulation for the target building was performed using Wireless Insite, a commercially available simulation tool based on ray tracing, and a path loss model was applied considering the size and location of trees affecting the experiment in the experimental environment. Finally, the accuracy of the simulation considering the influence of trees was confirmed by comparing the simulation result value applied with the path loss model and the result value obtained through actual experiments.