• 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.

• Journal of Korea Multimedia Society
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• v.22 no.12
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• pp.1356-1367
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• 2019

This paper proposes a novel active stereo matching technique using white auxiliary stripe pattern. The conventional active stereo matching techniques that uses two cameras and an active source such as projector can accurately estimate disparity information even in the areas with low texture compared to the passive ones. However, it is difficult that the conventional active stereo matching techniques using color code patterns acquire these patterns robustly if the object is composed of various colors or is exposed to complex lighting condition. To overcome this problem, the proposed method uses an additional white auxiliary stripe pattern to get and localize the color code patterns robustly. This paper proposes a process based on adaptive thresholding and thinning to obtain the auxiliary pattern accurately. Experimental results show that the proposed method more precisely measures the stepped sample whose depth is known in advance than the conventional method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.137-140
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• 2004

광촉매의 성능을 평가하기 위해 3종류의 광촉매를 형광등 터널등기구, 고압나트륨 터널등기구, 고압나트륨 가로등기구에 코팅하고 이들 조명기구의 신설 시와 설치 1.5개월 후의 투과율을 측정하여 그 성능을 평가하였다. 그 결과 고압나트륨 터널등기구에는 광촉매 반응이 거의 일어나지 않았고, 형광등 터널등기구에서만 그 효과가 나타났다. 이것은 고압나트륨등이 자외선 영역에서 빛을 거의 방출하지 않았기 때문이다.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.494-499
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• 2007

실제 영상과 가상의 오브젝트 또는 가상의 환경에 오브젝트를 합성하는 경우 등 사실적인 합성을 결과를 얻기 위해서는 실제 환경과 같은 배경 영상의 정확한 광원 정보가 필요하다. 본 논문에서는 실내 환경을 배경으로 영상을 합성 하는 과정에 필요한 광원정보를 카메라와 Light Probe를 이용하여 촬영된 단일 영상으로부터 추정하는 기법을 제안한다. 실내에 존재하는 광원들은 정확한 위치정보를 알 수 없는 실외환경에서와 달리 제한된 공간의 원점으로부터 3차원 공간에 위치한 좌표로 나타낼 수 있다. 광원을 추정하기 위해 먼저 실내 공간에 반사도가 높은 Light Probe를 위치하고 디지털 카메라의 적정 노출을 이용하여 광원 추정에 사용할 영상을 획득한다. 광원으로 존재하는 오브젝트의 경우 짧은 노출시간에도 카메라의 영상에 획득된다. 그렇기 때문에 단일 영상에서 광원의 영역을 추정하기 위해 영상처리를 통해 노출 시간을 짧게 하여 촬영한 영상과 비슷하게 밝은 영역만 표현되도록 처리를 한다. 전 처리된 영상으로부터 밝은 영역과 어두운 영역으로 구분을 하고 밝은 영역으로부터 광원의 정보를 추정한다. 추정된 광원들은 실제 렌더링에 곧바로 적용이 가능하며, 이를 통해 배경에 적합한 렌더링 결과를 얻을 수 있다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2263-2264
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• 2008

전 세계적으로 에너지 소비가 지속적으로 증가하고 있는 가운데 석유, LNG와 같은 에너지 가격 또한 꾸준히 증가하고 있다. 이에 따라 에너지 절약을 유도하고 전력생산원가를 절감하고 전력수급의 안정을 도모하기 위한 수요관리가 대두되고 있다. 본 논문에서는 기존의 자료를 토대로 선형, 비선형 회귀분석을 실시하여 2015까지의 에너지 회피비용과 고효율 조명기기의 보급량을 추정한다. 그 후 에너지 회피비용의 변화를 고려하지 않은 현행 방식과 에너지 회피비용의 변화를 고려한 수정된 방식을 비교하여 경제성 평가에 대한 에너지회피비용의 영향에 대해 분석한다. 그리고 경제성 평가 결과를 통하여 고효율 조명기기 정책의 방향을 제시한다.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1271-1276
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• 2008

This study has explained about LED for BLU which is widely used in the kinds of display devices or lighting. It was shown that the open due to delamination were the dominant LED for BLU failure mode and mechanisms from failure analysis of LED samples. Then, we have defined failure as yellowing and 100% reduction of light output intensity of LED for BLU and acceleration factors as temperature and current in Accelerated Life Test(ALT). Finally, we have estimated the Weibull distribution, life-stress relationship, and accelerating factor is used by ALTA Software.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.69-72
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• 2002

Human face detection has many applications such as face recognition, face or facial feature tracking, pose estimation, and expression recognition. We present a new method for automatically segmentation and face detection in color images. Skin color alone is usually not sufficient to detect face, so we combine the color segmentation and shape analysis. The algorithm consists of two stages. First, skin color regions are segmented based on the chrominance component of the input image. Then regions with elliptical shape are selected as face hypotheses. They are certificated to searching for the facial features in their interior, Experimental results demonstrate successful detection over a wide variety of facial variations in scale, rotation, pose, lighting conditions.

• Korean Institute of Interior Design Journal
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• no.29
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• pp.173-180
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• 2001

The present time this country is faced with general hospital building remodeling time from the constructing age. In architecture, one of the reconstruction of consciousness, remodeling significance Is restoration of capacity a generally structure. Through this research we acquire concluding remarks. 1) In hospital extension and reconstruction works set a different counterplot proportionately with part that are the ward areas, the outpatient areas, the diagnosis/treatment areas, the supply areas, the administration areas, the education/research areas, the miscellaneous areas etc. According to department's character and use various purposes take proper measures. Then it estimation that remodeling study shall be need. 2) It is advisable the way of connection the existing facilities if it extended case. The case of K hospital has been extended outskirts the main building. As this an enlargement of a outhouse has an advantage that secure construction area at a stretch and no exert Influence on both nature lighting and construction matter. On the contrary caused [defect that is repeatedly occur a faculty relocation and the inner part alteration because of it\`s post transfer.

• ETRI Journal
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• v.44 no.1
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• pp.125-134
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• 2022

Visible light communication (VLC) systems incorporate ambient lighting and wireless data transmission, and the experienced channel in indoor VLC is a major topic that should be examined for reliable communication. In this study, it is realized that multiple transmitters in classical alignment are the forceful factors for channel characteristics. In the frequency band, fluctuations with sudden drops are observed, where the fluctuation shape is related to the source layout and receiver location. These varying frequency-selective channels need solutions, especially for mobile users, because sustained channel estimation and equalization are necessary as the receiver changes its location. It is proven that using light-emitting diodes (LEDs) with highly directional beams as sources or using a detector with a narrow field of view (FOV) in the receiver may help partially alleviate the problem; the frequency selectivity of the channel reduces in some regions of the room. For flat fading channel characteristics all over the room, LEDs should be aligned in hexagonal cellular structure, and detector FOV should be arranged according to the cell dimension outcomes.

• Journal of KIBIM
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• v.13 no.2
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• pp.29-36
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• 2023

This study explores the potential of utilizing video-based data analysis and machine learning techniques to estimate the number of occupants within a building. The research methodology involves developing a sophisticated counting system capable of detecting and tracking individuals' entry and exit patterns. The proposed method demonstrates promising results in various scenarios; however, it also identifies the need for improvements in camera performance and external environmental conditions, such as lighting. The study emphasizes the significance of incorporating machine learning in architectural and urban planning applications, offering valuable insights for the field. In conclusion, the research calls for further investigation to address the limitations and enhance the system's accuracy, ultimately contributing to the development of a more robust and reliable solution for building occupancy estimation.