• Title/Summary/Keyword: Illumination simulation

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High-Quality Global Illumination Production Using Programmable Graphics Hardware (프로그래밍 가능한 그래픽스 하드웨어를 사용한 고품질 전역 조영 생성)

  • Cha, Deuk-Hyun;Chang, Byung-Joon;Ihm, In-Sung
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.414-419
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    • 2008
  • 3D rendering is a critical process for a movie production, advertisement, interior simulation, medical and many other fields. Recently, several effective rendering methods have been developed for the photo-realistic image generation. With a rapid performance enhancement of graphics hardware, physically based 3D rendering algorithm can now often be approximated in real-time games. However, the high quality of global illumination, required for the image generation in the 3D animation production community is a still very expensive process. In this paper, we propose a new rendering method to create photo-realistic global illumination effect efficiently by harnessing the high power of the recent GPUs. Final gathering routines in our global illumination module are accelerated by programmable graphics hardware. We also simulate physically based light transport on a ray tracing based rendering algorithm with photon mapping effectively.

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Predicted Performance of the Integrated Artificial Lighting System in Relation to Daylight Levels (채광시스템과 인공조명설비의 통합기술 및 성능평가연구)

  • Kim, G.;Kim, J.T.
    • Journal of the Korean Solar Energy Society
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    • v.22 no.3
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    • pp.47-56
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    • 2002
  • The office is an excellent candidate for implementing daylighting techniques because of the relatively high electric lighting power densities and long daytime use pattern. The quantity of light available for a space can be translated in term of the amount of energy savings through a process of a building energy simulation. To get significant energy savings in general illumination, the electric lighting system must be incorporated with a daylight - activated dimmer control. A prototype configuration of an office interior has been established and the integration between the building envelope and lighting and HVAC systems is evaluated based on computer modeling of a lighting control facility. First of all, an energy-efficient luminaire system is designed for both a totally open-plan office interior and a partitioned office. A lighting design and analysis program, Lumen-Micro 2000 predicts the optimal layout of a conventional fluorescent lighting fixture to meet the designed lighting level and calculates unit power density, which translates the demanded amount of electric lighting energy. A dimming control system integrated with the contribution of daylighting has been applied to the operating of the artificial lighting. Annual cooling load due to lighting and the projecting saving amount of cooling load due to daylighting under overcast diffuse sky are evaluated by a computer software, ENER-Win. In brief, the results from building energy simulation with measured daylight illumination levels and the performance of lighting control system indicate that daylighting can save over 70 percent of the required energy for general illumination in the perimeter zones through the year. A 25 % of electric energy for cooling may be saved by dimming and turning off the luminaires in the perimeter zones.

Energy Consumptions and Daylight Illumination levels of a Multi-beded Patient Room according to the Window Shapes and Shading (창의 형태 및 차양 계획에 따른 다인 병실의 에너지소비량과 주광조도의 평가 및 분석)

  • Choi, Changdae;Kwon, Soonjung;Kim, Sunsook
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.18 no.3
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    • pp.29-39
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    • 2012
  • Window and shading designs have a great influence on energy consumption and daylighting in buildings. As far as energy is concerned, small window area is advantageous. But it is not good to the patient healing in hospital. So it is important to find out the optimum window shape which is favorable for both energy consumption and patient healing. In this study, annual energy consumption and daylight illumination levels were analyzed according to the window shapes and shading devices for a multi-beded patient room in hospitals. The simulations were conducted for 19 different cases by COMFEN 4.0 computer simulation program. The results of this paper are as follows. First, window to wall area ratio and shading devices have great influences on annual energy consumption. But it is a problem in that they decrease significantly daylight level in bed room. Second, considering the same energy consumption, reducing the width of window rather than the hight of window is desirable for the secure of daylight level. Third, increase of the number of horizontal shade is not desirable in south face of the building for the energy consumption and daylight level. Fourth, sun shade is not necessary in north face of the building for the energy consumption and daylight level.

Dimmable Spatial Intensity Modulation for Visible-light Communication: Capacity Analysis and Practical Design

  • Kim, Byung Wook;Jung, Sung-Yoon
    • Current Optics and Photonics
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    • v.2 no.6
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    • pp.532-539
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    • 2018
  • Multiple LED arrays can be utilized in visible-light communication (VLC) to improve communication efficiency, while maintaining smart illumination functionality through dimming control. This paper proposes a modulation scheme called "Spatial Intensity Modulation" (SIM), where the effective number of turned-on LEDs is employed for data modulation and dimming control in VLC systems. Unlike the conventional pulse-amplitude modulation (PAM), symbol intensity levels are not determined by the amplitude levels of a VLC signal from each LED, but by counting the number of turned-on LEDs, illuminating with a single amplitude level. Because the intensity of a SIM symbol and the target dimming level are determined solely in the spatial domain, the problems of conventional PAM-based VLC and related MIMO VLC schemes, such as unstable dimming control, non uniform illumination functionality, and burdens of channel prediction, can be solved. By varying the number and formation of turned-on LEDs around the target dimming level in time, the proposed SIM scheme guarantees homogeneous illumination over a target area. An analysis of the dimming capacity, which is the achievable communication rate under the target dimming level in VLC, is provided by deriving the turn-on probability to maximize the entropy of the SIM-based VLC system. In addition, a practical design of dimmable SIM scheme applying the multilevel inverse source coding (MISC) method is proposed. The simulation results under a range of parameters provide baseline data to verify the performance of the proposed dimmable SIM scheme and applications in real systems.

Lighting Analysis and Modeling on Jokcu Court (족구장 조명설비에 대한 해석 및 모델링)

  • Kim, Deog-Goo;Oh, Seong-Bo
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.11a
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    • pp.173-177
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    • 2007
  • This paper describes the simulations on the actual measurement analysis and lighting design for recreational sports facility. Based on illumination requirements, sports may be divided into multidirectional sports and unidirectional sports. Typical multidirectional aerial sports include Jokcu. These sports require well distributed horizontal illumination and uniformity according to aiming. Therefore, this paper estimates horizontal illuminance and uniformity ratio by actual measurement of sports lighting at recreational Jokcu court in Cheju National University and evaluation of sports lighting conditions for optimal design by computer simulation.

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A Study on the Various Light Source Radiation Conditions and use of LED Illumination for Plant Factory (식물공장 각종광원의 방사조건과 LED조명의 활용에 관한 연구)

  • Yoon, Cheol-Gu;Choi, Hong-Kyoo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.10
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    • pp.14-22
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    • 2011
  • The artificial lights to be introduced for the plant factories is requiring the artificial light resources with minimizing the energy consumption to reduce the greenhouse gases which is a major cause of global warming, and maximizing the efficiency in photosynthesis effect light-wave range, in which the plants can be greatly grown and developed, and having the signal light-wave range for forming the light types. the best growing and developing environment for the plants has recently realized with utilizing the LED(Lighting Emitting Diode) lamps, as a environment-friendly green lamps, which can elevating the light efficiency with using only the specific light wave range. In this study, to provide the necessary lights for the full artificial light type of the plant factory, the following research/study and experiments has been conducting. experiments of the spectrum for each light sources, and LED, The intensity of illumination, Irradiance, Photosynthesis Photon Flux Density.

Illumination System using Two Lamps for the Projector

  • Kang, Ho-Joong;Park, Jong-Myoung;Chung, Ji-Hyouk
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1427-1429
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    • 2008
  • In this paper, an illumination system design using two lamps was proposed to improve the brightness of the projector. The proposal is based on the results from optical simulation. The prism array was applied to maintain the same optical properties, such as brightness distribution for the divergence angle and the composed beam size of the system. These were compared to those of the one UHP lamp system. The brightness of the two-lamp system, having a panel size of 0.74" and an f/2.9, increased by a factor of 1.7 when compared to the brightness of one UHP lamp system.

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The optimal window system of office buildings considering energy efficiency (에너지 효율로 본 상업용 건물의 적정 창호에 관한 연구)

  • Yoo, Ho-Chun;Oh, Young-Ho;Park, Seung-Kil
    • Journal of the Korean Solar Energy Society
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    • v.25 no.4
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    • pp.53-60
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    • 2005
  • The purpose of this study is to improve energy efficiency of windows in office buildings through the evaluation of their heating, cooling and illumination load. Energy efficiency is influenced by window size which is determined at the early stage of building design. The process of this study is as follows. First, energy performance is analysed according to the various rates of windows through computer simulation (ECOTECT). Then, the annual heating, cooling and illuminating loads according to the different window sizes are compared one another. Results indicated that the optimal window size considering energy efficiency is 50% of the surface area. When the window size is 50% of the surface area, annual maintenance expense is also smallest. Since the cost of cooling is larger than that of heating, too low indoor air temperature in summer is unfavorable based on the reasonable annual maintenance expenses.

Bandwidth-Efficient Precoding Scheme with Flicker Mitigation for OFDM-Based Visible Light Communications

  • Kim, Byung Wook;Jung, Sung-Yoon
    • ETRI Journal
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    • v.37 no.4
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    • pp.677-684
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    • 2015
  • Recently, orthogonal frequency-division multiplexing (OFDM) was applied to VLC systems owing to its high rate capability. On the other hand, a real-valued unipolar OFDM signal for VLC significantly reduces bandwidth efficiency. For practical implementation, channel estimation is required for data demodulation, which causes a further decrease in spectral efficiency. In addition, the large fluctuation of an OFDM signal results in poor illumination quality, such as chromaticity changes. This paper proposes a spectrally efficient method based on a hidden-pilot-aided precoding technology for VLC with less flickering than a conventional OFDM-based method. This approach can obtain channel information without any loss of bandwidth efficiency while ensuring illumination quality by reducing the flickering effect of an OFDM-based VLC. The simulation results show that the proposed method provides a 6.4% gain in bandwidth efficiency with a 4% reduction in flicker compared to a conventional OFDM-based method.

Illumination and Rotation Invariant Object Recognition (조명 영향 및 회전에 강인한 물체 인식)

  • Kim, Kye-Kyung;Kim, Jae-Hong;Lee, Jae-Yun
    • The Journal of the Korea Contents Association
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    • v.12 no.11
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    • pp.1-8
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    • 2012
  • The application of object recognition technology has been increased with a growing need to introduce automated system in industry. However, object transformed by noises and shadows appeared from illumination causes challenge problem in object detection and recognition. In this paper, an illumination invariant object detection using a DoG filter and adaptive threshold is proposed that reduces noises and shadows effects and reserves geometry features of object. And also, rotation invariant object recognition is proposed that has trained with neural network using classes categorized by object type and rotation angle. The simulation has been processed to evaluate feasibility of the proposed method that shows the accuracy of 99.86% and the matching speed of 0.03 seconds on ETRI database, which has 16,848 object images that has obtained in various lighting environment.