• Title/Summary/Keyword: Radiance simulation

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Space study on Lighting Performance For Residential Buildings By using Simulation Analysis (시뮬레이션 분석기법을 이용한 주거용 건물의 공간별 채광성능 연구)

  • Lim, Tae Sub;Lim, Jung Hee;Kim, Byung Seon
    • KIEAE Journal
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    • v.13 no.3
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    • pp.97-104
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    • 2013
  • This proposed simulation-based design study is based on the design of residential high-rise buildings in South-Korea. the purpose of this study is to evaluate the amount of daylighting performance passing through building glazing according to sky conditions, orientation of windows and each space of Apartment buildings. The clear sky includes sunshine and is intense and brighter at the horizon than at the zenith, except in the area around the sun. Daylight received within a building is directly dependent upon the sun's position and the atmospheric conditions. Orientation of the building generally used to refer to solar orientation which is the siting of building with respect to solar access. Although any building will have different orientations for its different sides, the orientation can refer to a particular room, or to the most important facade of the building. north-facing windows receive twice the winter sun than east and west facing windows, allowing light and warmth into the home. They can be easily shaded from the high summer sun to help keep the house cool. Ideally, the glazing area should be between 10-25% of the floor area of the room. This paper was calculated by a Desktop Radiance program. The space dimensions were based on a unit module of real constructed apartment having divided into five sections such as living room, room1, room2, room3 and kitchen.

Simulation of TOA Visible Radiance for the Ocean Target and its Possible use for Satellite Sensor Calibration (해양 표적을 이용한 대기 상단 가시영역에서의 복사휘도 모의와 위성 센서 검보정에의 활용 가능성 연구)

  • Kim, Jung-Gun;Sohn, Byung-Ju;Chung, Eui-Seok;Chun, Hyoung-Wook;Suh, Ae-Sook;Kim, Kum-Lan;Oh, Mi-Lim
    • Korean Journal of Remote Sensing
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    • v.24 no.6
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    • pp.535-549
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    • 2008
  • Vicarious calibration for the satellite sensor relies on simulated TOA (Top-of-Atmosphere) radiances over various targets. In this study, TOA visible radiance was calculated over ocean targets which are located in five different regions over the Indian and Pacific ocean, and its possible use for the satellite sensor calibration was examined. TOA radiances are simulated with the 6S radiative transfer model for the comparison with MODIS/Terra and SeaWiFS measurements. Geometric angles and sensor characteristics of the reference satellites were taken into account for the simulation. AOT (Aerosol Optical Thickness) from MODIS/Terra, pigment concentrations from Sea WiFS, and ozone amount from OMI measurements were used as inputs to the model. Other atmospheric input parameters such as surface wind and total column water vapor were taken from NCEP/NCAR reanalysis data. The 5-day averaged radiances over all targets show that the percent differences between simulated and observed radiances are within about ${\pm}5%$ in year 2005, indicating that the calculated radiances are in good agreement with satellite measurements. It has also been shown that the algorithm can produce the SeaWiFS radiances within about ${\pm}5%$ uncertainty range. It has been suggested that the algorithm can be used as a tool for calibrating the VIS bands within about 5% uncertainty range.

Long-Distance Plume Detection Simulation for a New MWIR Camera (장거리 화염 탐지용 적외선 카메라 성능 광선추적 수치모사)

  • Yoon, Jeeyeon;Ryu, Dongok;Kim, Sangmin;Seong, Sehyun;Yoon, Woongsup;Kim, Jieun;Kim, Sug-Whan
    • Korean Journal of Optics and Photonics
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    • v.25 no.5
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    • pp.245-253
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    • 2014
  • We report a realistic field-performance simulation for a new MWIR camera. It is designed for early detection of missile plumes over a distance range of a few hundred kilometers. Both imaging and radiometric performance of the camera are studied by using real-scale integrated ray tracing, including targets, atmosphere, and background scene models. The simulation results demonstrate that the camera would satisfy the imaging and radiometric performance requirements for field operation.

New In-Orbit Pixel Correction Method

  • Kim Youngsun;Kong Jong-Pil;Heo Haeng-Pal;Park Jong-Euk;Chang Young-Jun
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.604-607
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    • 2005
  • All CCD pixels do not react uniformly even if the light of same radiance enters into the camera. This comes from the different camera optical characteristics, the read-out characteristics, the pixel own characteristics and so on. Usually, the image data of satellite camera can be corrected by the various image-processing methods in the ground. However, sometimes, the in-orbit correction is needed to get the higher quality image. Especially high frequency pixel correction in the middle of in-orbit mission is needed because the in-orbit data compression with the high frequency loss is essential to transmit many data in real time due to the limited RF bandwidth. In this case, this high frequency correction can prevent have to have any unnecessary high frequency loss. This in-orbit correction can be done by the specific correction table, which consists of the gain and the offset correction value for each pixel. So, it is very important to get more accurate correction table for good correction results. This paper shows the new algorithm to get accurate pixel correction table. This algorithm shall be verified theoretically and also verified with the various simulation and the test results.

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COMPARISONS OF MTSAT-1R INFRARED CHANNEL MEASUREMENTS WITH MODIS/TERRA

  • Han, Hyo-Jin;Sohn, Byung-Ju;Park, Hye-Suk
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.651-654
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    • 2006
  • Infrared channels of newly launched Japanese geostationary satellite, MTSAT-1R are compared with well calibrated MODIS/Terra infrared measurements at 3.7, 6.7, 11, 12 ${\mu}m$ bands. There are four steps in this intercalibration method: 1) data collection, 2) spectral response function correction, 3) data collocation, and 4) calculation of mean bias and conversion coefficients. In order to minimize the navigation error of MTSAT-1R, comparisons are made over the area in which the viewing angle of MTSAT-1R is less than 50$^{\circ}$. The calibration method was tested for August 2005 and within the 40$^{\circ}N$-40$^{\circ}S$, 100$^{\circ}$E-180$^{\circ}$E domain. The differences of spectral response functions were corrected through radiative transfer model simulation. Constructing collocated data differences in viewing geometry, observation time and space were taken into account. In order to avoid the radiance variation induced by cloud presence, clear-sky targets are selected as intercalibration target. The mean biases of 11, 12, 6.7, and 3.7 ${\mu}m$ bands are about -0.16, 0.36, 1.31, and -6.69 K, suggesting that accuracies of 3.7 ${\mu}m$ is questionable while other channels are comparable to MODIS

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Analysis of cloud cover and solar irradiance of typical meteorological data (표준기상데이터의 운량과 일사량 데이터 비교 분석)

  • Yoo, Ho-Chun;Lee, Kwan-Ho;Kang, Hyun-Gu
    • 한국태양에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.330-335
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    • 2009
  • kDomestic studies on meteorologicaldata have been carried out, however they were mostly not constant but limited to fragment compilation. The studies on solar energy, among others, have been relatively active but the measurement of solar irradiance is also limited to some extent. This study, in an effort to identify the difference in data between solar radiance and cloud cover, was intended to compare and analyze the typical meteorological data developed by Korean Solar Energy Society with the solar irradiance calculated using the typical meteorological data and cloud cover data provided by current simulation program. Monthly average solar irradiance from the meteorological data (ISO TRY) of Korea's typical meteorological data which was actuallymeasured appeared to be far below the monthly solar irradiance from the American Department of Energy. The solar irradiance calculated based on cloud cover indicates very limited difference between the two data, so the solar irradiance measured by Korean typical metrologicaldata (ISO TRY) indicated the similar value, which demonstrates the solar irradiance data from Korean Meteorological Administration is more accurate than those US National Weather Center.

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Evaluation on the Characteristics of Daylight Distributions of Grating Louver System in a Pair Glass by Computer Simulation (복층유리 격자루버시스템의 주광특성에 관한 시뮬레이션 평가)

  • Park, Byoung-Chul;Choi, An-Seop
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.12
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    • pp.1-9
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    • 2009
  • A recent research trend on the Daylight Responsive Dimming Systems, using available daylight for energy savings, is to integrate automated roller shading systems and venetian blind systems which are vertically controlling daylight to indoor based on sun profile angle. Therefore, this paper suggests Grating Louver System into a pair glass as a new shading system, which can control daylight vertically and horizontally. The optimized spacing of louvers, which is to block direct sunlight into a space, was calculated. And then, the system was simulated for analysis and evaluation of characteristics of daylight by Desktop Radiance 2.0.

Real-Time 3D Volume Deformation and Visualization by Integrating NeRF, PBD, and Parallel Resampling (NeRF, PBD 및 병렬 리샘플링을 결합한 실시간 3D 볼륨 변형체 시각화)

  • Sangmin Kwon;Sojin Jeon;Juni Park;Dasol Kim;Heewon Kye
    • Journal of the Korea Computer Graphics Society
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    • v.30 no.3
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    • pp.189-198
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    • 2024
  • Research combining deep learning-based models and physical simulations is making important advances in the medical field. This extracts the necessary information from medical image data and enables fast and accurate prediction of deformation of the skeleton and soft tissue based on physical laws. This study proposes a system that integrates Neural Radiance Fields (NeRF), Position-Based Dynamics (PBD), and Parallel Resampling to generate 3D volume data, and deform and visualize them in real-time. NeRF uses 2D images and camera coordinates to produce high-resolution 3D volume data, while PBD enables real-time deformation and interaction through physics-based simulation. Parallel Resampling improves rendering efficiency by dividing the volume into tetrahedral meshes and utilizing GPU parallel processing. This system renders the deformed volume data using ray casting, leveraging GPU parallel processing for fast real-time visualization. Experimental results show that this system can generate and deform 3D data without expensive equipment, demonstrating potential applications in engineering, education, and medicine.

A Comparative Study on Daylighting Performance Prediction of Light Tube and Dish Concentrator (광튜브와 디쉬형 집광기의 자연채광 성능 예측 및 비교 연구)

  • Oh, Seung Jin;Han, Hyun Joo;Chun, Wongee
    • Journal of Energy Engineering
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    • v.21 no.2
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    • pp.124-132
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    • 2012
  • This study presents the simulation results of Photopia when a lecture room with north-facing windows were illuminated by two different types of daylighting systems to improve the imbalance in its lighting conditions. Especially, the candela power distribution curves (CDCs) on a clear sunny day at the summer solstice, reaching $80^{\circ}$ in solar altitude, were analyzed with respect to the illuminance available at task areas (work planes). The difference between its illuminance on the north and south areas exceeded 1,000 lux without any daylighting system. This, however, decreased drastically with the application of a daylighting system. When a light tube system was introduced, it reduced from 906lx to 603lx and, even further to 308lx with the application of a dish concentrator system. Generally, the performance of a light tube system was greatly influenced by solar altitude while its effect on the dish concentrator system was rather negligible.

In-orbit Stray Light Analysis for Step and Stare observation at Geostationary Orbit

  • Oh, Eunsong;Hong, Jinsuk;Ahn, Ki-Beom;Cho, Seongick;Ryu, Joo-Hyung;Kim, Sug-Whan
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.218.2-218.2
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    • 2012
  • In the remote sensing researches, the reflected bright source such as snow, cloud have effects on the image quality of wanted signal. Even though those signal from bright source are adjusted in corresponding pixel level with atmospheric correction algorithm or radiometric correction, those can be problem to the nearby signal as one of the stray light source. Especially, in the step and stare observational method which makes one mosaic image with several snap shots, one of target area can affect next to the other snap shot each other. Presented in this paper focused on the stray light analysis from unwanted reflected bright source for geostationary ocean color sensor. The stray light effect for total 16 slot images each other were performed according to 8 band filters. For the realistic simulation, we constructed system modeling with integrated ray tracing technique which realizes the same space time in the remote sensing observation among the Sun, the Earth, and the satellite. Computed stray light effect in the results of paper demonstrates the distinguishable radiance value at the specific time and space.

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