• Title/Summary/Keyword: lighting model

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A Study on Application of Illumination Models for Color Constancy of Objects (객체의 색상 항등성을 위한 조명 모델 응용에 관한 연구)

  • Park, Changmin
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.13 no.1
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    • pp.125-133
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    • 2017
  • Color in an image is determined by illuminant and surface reflectance. So, to recover unique color of object, estimation of exact illuminant is needed. In this study, the illumination models suggested to get the object color constancy with the physical illumination model based on physical phenomena. Their characteristics and application limits are presented and the necessity of an extended illumination model is suggested to get more appropriate object colors recovered. The extended illumination model should contain an additional term for the ambient light in order to account for spatial variance of illumination in object images. Its necessity is verified through an experiment under simple lighting environment in this study. Finally, a reconstruction method for recovering input images under standard white light illumination is experimented and an useful method for computing object color reflectivity is suggested and experimented which can be induced from combination of the existing illumination models.

Parameter Estimation of the Diffusion Model for Demand Side Management Monitoring System (DSM 모니터링을 위한 확산 모형의 계수 추정)

  • Kim, Jin-O;Choi, Cheong-Hun;Kim, Jung-Hoon;Lee, Chang-Ho;Kim, Chang-Seob
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.10
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    • pp.1183-1189
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    • 1999
  • This paper presents the method of parameter estimation of diffusion model for monitoring Demand-Side Management program. Bass diffusion model was applied in this paper, which has different values according to the following parameters; coefficients of innovation, imitation and potential adopters. Though it is very important to estimate three parameters precisely, there has been no empirical way in practice. Thus, this paper presents the method of parameter estimation in case of few data with constraints to reduce the possibility of bad estimation. The constraints can be empirical results or expert's decision. Case studies show the diffusion curves and forecasted values of the peak for the high-efficient lighting. The feedback and nonlinear least-square parameter estimation methods used in this paper enable us to evaluate the status and to predict the effect of DSM program.

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Insulating Design and Test of 22.9kV Class Mini-Model Transformer Considering AC Loss (AC Loss를 고려한 22.9kV급 Mini-Model 변압기의 절연 설계 및 시험)

  • 백승명;정종만;곽동순;김해종;석복렬;김상현
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.8
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    • pp.420-424
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    • 2004
  • This paper presents experimental data from model windings with different arrangement of coil in order to provide information to design a 22.9kV class HTS transformer. Before experiment, the composite insulation of two different type of HTS transformers are investigated. The first basic of investigation is a breakdown characteristic of liquid nitrogen and flashover characteristic on the GFRP surface under ac and impulse, The second investigation is insulation design, manufacture and test of model windings. These include a AC withstand voltage test of 50 kV rms and a lighting impulse test of 150 kV at peak.

The Evaluation of Ceiling Depth Impact on Lighting and Overall Energy Consumption of a Building with Top-lighting System

  • Amina, Irakoze;Kee, Han Ki;Lee, Young-A
    • Architectural research
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    • v.22 no.1
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    • pp.13-21
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    • 2020
  • The purpose of this study was to evaluate the variation in building energy predictions caused by simulation settings related to building envelop thickness. The study assessed the ceiling depth impact on skylight energy performance through OpenStudio integrated Radiance and EnergyPlus simulation programs. A ceiling as deep as 1.5 to 3m was analyzed for skylight to roof ratios from 1% to 25%. The results indicated that the building ceiling depth negatively affected the capability of skylights to significantly reduce building energy consumption. Through a parametric analysis, the study concluded that 8%, 9%, 10% and 11% skylight to roof ratio were optimal in terms of total building energy consumption for a ceiling depth of 1.5m, 2m, 2.5m and 3m, respectively. In addition, the results showed that the usually recommended 5% skylight to roof ratio was only efficient when no ceiling depth was included in the simulation model. Furthermore, the study indicated that the building energy saved by the optimal skylight of each ceiling depth decreased as the ceiling depth deepened. The highest total building energy reduction was 9%, 7%, 5% and 3% for a ceiling depth of 1.5m, 2m, 2.5m and 3m, respectively. This study induced that the solar heat gains and daylight visible transmittance by ceiling depth were crucial in the predictions of skylight energy performance and should not be neglected through building simulation simplifications as it is commonly done in most simulation programs' settings.

Evaluation of User Satisfaction and Image Preference of University Students for Cherry Blossom Campus Trail (대학생들의 캠퍼스 벚꽃터널 산책로 이용 만족도와 이미지 선호도 평가)

  • Lee, In-Gyu;Eom, Boong-Hoon
    • Journal of Environmental Science International
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    • v.28 no.12
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    • pp.1101-1110
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    • 2019
  • This study investigated Post-Occupancy Evaluation (POE) of cherry blossom trails 'Cherry Road' in Daegu Catholic Univ. campus, at Gyeonsan-city, Korea. The evaluation focused on image preference and satisfaction of users i.e., students, using questionnaire surveys. A total 201 questionnaire samples were analyzed and most of the respondents were in the age group of 20. Frequency analysis was conducted on demographics, use behavior, reliability, and means. Factor analysis and multiple regression analysis were conducted for user satisfaction and image preference. Over 80% of visitors came with companions during daytime. The most common motives for use were strolling and walking, event and meeting, passing. For user satisfaction the mean scores were highest for landscape beauty (4.22), image improvement (4.14), campus image (4.08). Night lighting facility received the lowest score (3.32). Factor analysis concerning user satisfaction was categorized into environment-human behavior and physical factors. Multiple regression analysis showed that the overall satisfaction of user was significantly influenced by five independent variables: 'harmonious' (β=.214), 'night lighting facility' (β=.173), 'landscape beauty' (β=.208), 'lawn care' (β=.154), and 'walking trails' (β=.123). The mean scores of image variables were highest for 'beautiful' (5.81), 'bright' (5.67), and 'open' (5.64). The lowest scores was for 'quiet' (4.47). Exploratory factor analysis led to three factors being categorized: aesthetics, comforts, and simplicity. Result of multiple regression analysis indicated that the preference of space image was significantly influenced by five variables: 'bright' (β=.397), 'refreshing' (β=.211), 'cool' (β=.219), 'clean' (β=.182), and 'natural' (β=.-142). Hence, Cherry Road has a high level of user satisfaction and image evaluation, which is interpreted as having various cultural events and value for students on campus. To improve the satisfaction of Cherry Road in the future, it is necessary to secure night lighting, to manage trash cans, and to secure rest space.

Real-Time Eye Detection and Tracking Under Various Light Conditions

  • Park Ho Sik;Nam Kee Hwan;Seol Jeung Bo;Cho Hyeon Seob;Ra Sang Dong;Bae Cheol Soo
    • Proceedings of the IEEK Conference
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    • 2004.08c
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    • pp.862-866
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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 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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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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Fluorescent Lighting equipment which has a lamp shift timely display device (램프 교체 시기 표시장치를 구비한 형광등기구)

  • An, Toun-Ki;Choi, Hong-Kyoo;Lee, Guen-Moo;Park, Seung-Won;Yoon, Cheol-Gu;Lee, Jung-Eun
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.10a
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    • pp.93-96
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    • 2008
  • If a fluorescent lamp be used too much time, the filmy part of electronic emission in the lane that is attached near the tube of the cathode brings about blacking. Luminance output and luminous efficiency are decreased. So, it's necessary to replace it. if the user doesn't replace the lamp for a long time, it causes overvoltage in the lamp. Therefore, the filament might be overheated. Even the socket of the lamp might catch on fire. In this paper gives development model of the fluorescent lighting equipment which has ramp shift timely display device.

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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.