• Title/Summary/Keyword: lighting condition

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Block Based Face Detection Scheme Using Face Color and Motion Information

  • Kim, Soo-Hyun;Lim, Sung-Hyun;Cha, Hyung-Tai;Hahn, Hern-Soo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.13 no.4
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    • pp.461-468
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    • 2003
  • In a sequence of images obtained by surveillance cameras, facial regions appear very small and their colors change abruptly by lighting condition. This paper proposes a new face detection scheme, robust on complex background, small size, and lighting conditions. The proposed method is consisted of three processes. In the first step, the candidates for the face regions are selected using face color distribution and motion information. In the second stage, the non-face regions are removed using face color ratio, boundary ratio, and average of column-wise intensity variation in the candidates. The face regions containing eyes and mouth are segmented and classified, and then they are scored using their topological relations in the last step. To speed up and improve a performance the above process, a block based image segmentation technique is used. The experiments have shown that the proposed algorithm detects faced regions with more than 91% of accuracy and less than 4.3% of false alarm rate.

A Study on the Comparison of the Illuminance Values from Daylight Simulation and Mock-up Experiment for Suitable Application of Lighting Simulation (적합한 조명시뮬레이션 사용을 위한 주광 시뮬레이션과 Mock-up 실험 비교에 관한 연구)

  • Kim, Yu-Sin;Choi, An-Seop
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.1
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    • pp.35-44
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    • 2010
  • Available daylight in inside offers comfortable view environment, and psychological and physical advantages to people in a room. Architectural design has a need for daylight prediction. But it is difficult to predict the illuminance values in daylight system. Using various Daylight simulation software is easy and simple, but we can find different results under the same conditions. This study compares with illuminance values from simulation (Lightscape 3.2, Relux 2007, Radiance 3.9) and Mock-up experiment with a same space and parameter of daylight (location of space and window, date, time and sky condition).

A Development of Video Monitoring System on Real Time (실시간 영상감시 시스템 개발)

  • Cho, Hyun-Seob
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.2
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    • pp.240-244
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    • 2007
  • Non-intrusive methods based on active remote IR illumination fur eye tracking is important for many applications of vision-based man-machine interaction. One problem that has plagued those methods is their sensitivity to lighting condition change. This tends to significantly limit their scope of application. In this paper, we present a new real-time eye detection and tracking methodology that works under variable and realistic lighting conditions. Based on combining the bright-pupil effect resulted from IR light and the conventional appearance-based object recognition technique, our method can robustly track eyes when the pupils are not very bright due to significant external illumination interferences. The appearance model is incorporated in both eyes detection and tracking via the use of support vector machine and the mean shift tracking. Additional improvement is achieved from modifying the image acquisition apparatus including the illuminator and the camera.

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Simulation and Performance Evaluation of the Self-Adaptive Light Control System (자가-적응 조명 제어 소프트웨어의 시뮬레이션 및 성능 평가)

  • Lee, Junhyi;Lee, Euijong;Baik, Doo-Kwon
    • Journal of the Korea Society for Simulation
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    • v.25 no.2
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    • pp.63-74
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    • 2016
  • This research aims to perform the simulation of self-adaptive lighting control software, and to evaluate the performance of the implemented system. In this text, Self-adaptive software means what detects unexpected changes in surrounding environment by self-monitoring during its run-time, and satisfies demanded condition by adjusting its operation. This is a research about the lighting control system which is operating with the fundamental of self-adaptation concept in IoT(Internet of Things) environment. The system, which is proposed in this text, operates adaptation onto the request of a defined user as recognizing the changes of surrounding environment. This text introduces a relating simulation scenario, system architecture, architecture valuation basis,, and executed evaluation of performance by processing simulations.

Performance Evaluation of 2-Dimensional Light Source using Mercury-free Flat Fluorescent Lamps for LCD Backlight Applications

  • Park, Joung-Hu;Cho, Bo-Hyung;Lee, Ju-Kwang;Whang, Ki-Woong
    • Journal of Power Electronics
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    • v.9 no.2
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    • pp.164-172
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    • 2009
  • Recently, 2-dimensional flat light sources have been attracting much attention for its use in LCD backlight applications because of its high luminous efficiency and uniformity. A long-gap discharge, mercury-tree flat fluorescent lamp has been developed, which shows a high brightness ($>5000\;cd/m^2$) and high luminous efficacy (60 lm/W). Additionally, it has a wide operating margin and stable driving condition with the aid of an auxiliary electrode. For driving the lamp, a narrow pulse power to maintain the glow discharge state is required. Since there has been no research for this kind of lamp driving, this paper proposes a newly developed short-pulse, high-voltage lamp-driving scheme. The proposed lamp system uses a ballast with a coupled-inductor in order to raise the short pulse voltage up to the lamp ignition level and to obtain energy-recovery action during the glow discharge mode. The operation principles are presented and also the system performances such as the lighting efficiency, spatial and angular uniformities are evaluated by hardware experiments. The results show that the proposed lighting system is a good candidate for the next-generation of LCD backlight systems.

The Effect of Plants and Waterscape Facilities on the Thermal Indoor Environment (실내에서 식물과 수경시설이 온열환경에 미치는 영향)

  • 정연승;박인환
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.1
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    • pp.19-28
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    • 1999
  • This survey is to investigate the effect of plants and waterscape facilities on the thermal indoor environment and to provide basic data for proper plant cultivation to enhance indoor landscape. The survey of the measure of comfort on the indoor environment for the residents of Taegu shows that the measure of comfort on the thermal-environment, which consist of temperature and humidity, has more negative responses than the measure on lighting . are . sound environment, which consists of air freshness, lighting condition and sound environment. The experiments on the effect of the amount of leaves and the distance of plants on the indoor thermal-environment are made. The experimental results illustrate that, as the capacity of a plant becomes greater and the distance from the plant shorter, the falling effect of temperature and the rising effect of humidity on the top of the plant are taken higher than on the side of the plant. When the same amount of leaves is set up, the distance range of the rising effect of humidity becomes wider than that of the falling effect of temperature. The investigation of the effect of waterscape facilities on the indoor thermal-environment shows that temperature and humidity of the space with installed waterscape facilities are lower and higher than without facilities, respectively.

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Color Image Retrieval from Database Using Graph Representation (그래프 표현을 이용한 컬러 영상 데이터베이스 검색기법)

  • 박인규;윤일동;이상욱
    • Journal of Broadcast Engineering
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    • v.1 no.1
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    • pp.74-83
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    • 1996
  • In this paper, an effective color image retrieval algorithm is proposed based on the graph representation. Also we propose a color constancy algorithm to remove the effect of illumination change. Illumination condition of an image can be transformed to that of reference image using the proposed color constancy algorithm, so that the effect of dirrerent lighting is significantly alleviated. Then, we represent a color image as a graph with several nodes and edges in the histogram space, and finally two images are matched by compared two graphs representing them. The simulation results show that the proposed 3-step algorithm performs well for various conditions, including different lighting, translation, rotation, and scaling of the object in the image. In addition, the proposed algorithm is very fast compared to the geometry-based matching technique.

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A Study on the Harmonic of the electrical Installations in Apartment Housing (아파트 전기설비에서의 고조파 실태 분석 연구)

  • 이기홍;성세진
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.2
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    • pp.105-110
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    • 2001
  • To analysis the effect by the Harmonics through Power facilities in Apartment housing, This paper measured the Harmonics at Lighting Transformer, Power Transformer and Services-entrance Conductors of electrical installation in apartment housing. The measured result is following as : 1) The Harmonics at Lighting Transformer is generated in the large of the 5th Harmonics. 2) The Harmonics at Power Transformer is generated in the large of the 5th and 7th Harmonics. And then 3) The THD at the Services-entrance Conductors is average 2.4[%], which is compared to the measuring Voltage, this meaning value is good condition until now against Harmonics effect. But, So the large capacitance of household electrical alliances with rectifiers in the future considered the effect of Harmonics at the Electric Power planning in apartment Housing.

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Face Recognition Method Robust to Change in Lighting Condition (조명의 변화에 강건한 얼굴인식)

  • Nam, Kee-Hwan;Han, Jun-Hee;Park, Ho-Sik;Lee, Young-Sik;Jung, Yen-Gil;Ra, Sang-Dong;Bae, Cheol-Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.1137-1140
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    • 2005
  • The work presented in this paper describes a Hidden Markov Model(HMM)-based framework for face recognition and face detection. The observation vectors used to characterize the statics of the HMM are obtained using the coefficients of the Karhuman-Loves Transform(KLT). The face recognition method presented in this paper reduces significantly the computational complexity of previous HMM-based face recognition systems, while slightly improving the recognition rate. In addition, the suggested method is more effective than the exiting ones in face extraction in terms of accuracy and others even under complex changes to the surroundings such as lighting.

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Real-Time Eye Detection and Tracking Under Various Light Conditions (다양한 조명하에서 실시간 눈 검출 및 추적)

  • 박호식;배철수
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.2
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    • pp.456-463
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    • 2004
  • Non-intrusive methods based on active remote IR illumination for eye tracking is important for many applications of vision-based man-machine interaction. One problem that has plagued those methods is their sensitivity to lighting condition change. This tends to significantly limit their scope of application. In this paper, we present a new real-time eye detection and tacking methodology that works under variable and realistic lighting conditions. Based on combining the bright-Pupil effect resulted from IR light and the conventional appearance-based object recognition technique, our method can robustly track eyes when the pupils ale not very bright due to significant external illumination interferences. The appearance model is incorporated in both eyes detection and tacking via the use of support vector machine and the mean shift tracking. Additional improvement is achieved from modifying the image acquisition apparatus including the illuminator and the camera.