• Journal of Institute of Control, Robotics and Systems
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• v.19 no.4
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• pp.379-384
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• 2013

We propose a new global positioning method for the indoor mobile robots. The multiple indoor lights fixed in ceiling are used as the landmarks of positioning system. The ceiling images are acquired by the fisheye lens camera mounted on the moving robot. The position and orientation of the lights are extracted by binarization and labeling techniques. Also the boundary lines between ceiling and walls are extracted to identify the order of each light. The robot position is then calculated from the extracted position and known position of the lights. The proposed system can increase the accuracy and reduce the computation time comparing with the other positioning methods using natural landmark. Experimental results are presented to show the performance of the method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3141-3147
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• 2010

The most important cause for shortening LED lighting efficiency and life is the junction temperature rises and, to solve this problem, various studies such as thermally efficient packaging, highly conductive material development, contact resistance improvement or heat sink optimization have been studied. However, most studies so far assumed that the LED lights are in the atmosphere, and thermal performance has not been therefore reported when the LED lights are mounted on the ceiling with ceiling unit. Thus, this study investigates the variation of junction temperature of the MR16 LED light under actual installation conditions and more accurate thermal design for the efficiency and life of LED lights is therefore achieved.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.140-145
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• 2012

The purpose of this study is to understand the change of impression by comparing the uniformity lighting with the compound lighting. In previous study, we proposed a light controlling method to harmonize daylight from a window and artificial lights from a ceiling and obtained the results to support our method. We referred this method as the Adjusted Compound-Lighting Model (AC Model). The model claims that lighting in a room with a side-window are perceived as harmonious when the overall light distribution in the room is well approximated by a compound of lights from the window and the entire ceiling. The experiment is carried out with the scaled-models and mock-up spaces that were supposed to be an office space. One is lit by the uniform lighting and the other by the compound lighting in each experimental space. In order to present varying illuminance distributions, thetwo variables were used in this study. One was the ratio of thelight from the window and ceiling in the standard and evaluation box. The standard box was provided by the ratio of 20% to 40% from the window and 80% to 60% from the ceiling as two lighting ratio patterns [Wu20(=Cu80) and Wu40(=Cu60)]. And the evaluation box was provided by the light ratio of 0% to 40 from the window and 100% to 60% from the ceiling [Wcp0(=Ccp100), Wcp20(=Ccp80) and Wcp40(=Ccp60)]. The other variable was themean illuminance level in both boxes. Two level of mean illuminance (700lx and 300lx) were used in this experiment. Each lighting condition was established at equal horizontal mean illuminance level, held constant near 700lx or 300lx in both boxes. Both of them were similar in the shape of distribution when there were same ratios of lights from the window and the ceiling. Subjects were asked to evaluate the point of difference by semantic differential rating on their overall impression after comparing with two rooms. The results showed that the impressions of compound lighting were more positive score than that of uniformity lighting on the items of 'dim-bright', 'dislike-like', 'artificial-natural' and 'closed-open', and that there was no significant difference in impressions between two spaces on other items.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.313-314
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• 2006

• Korean Institute of Interior Design Journal
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• v.20 no.3
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• pp.161-171
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• 2011

The purpose of this study is to examine the preferences about component elements of Public Space of apartment housing in Daegu. This study is based on the survey of thirty nine apartment complex in seventeen construction companies to create images and component elements types. Also, by using an questionnaire analysis derived from a precedent study, component elements in the porch and interior common space of apartment residents are comprehended. The survey analysis of the porch is researched and divided according to a form of porch, designs and lights of ceiling. Interior common space is analyzed by several elements; forms of core, designs and lights of ceiling, design of walls and floors, necessity of windows, and necessity of public facilities. The questionnaire is composed of 40 items and it was returned by one hundred sixty two respondents. As a result of the study, After the enforcement of price deregulation, the porch and interior common space of apartments has had improved quality. However, by questionnaire survey of respondents showed preferences of each element and necessary facilities. Thus, i hope that this study is an excellent source for apartment design.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.1
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• pp.10-16
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• 2013

This study performed a subjective evaluation of the Semantic Differential (SD) method for living room activities to evaluate the living room lighting environment and investigated the relationship between these through luminance distribution in the space. As a result, three factors-"lightness", "emotion" and "calmness"-have been grouped together. According to the analysis of experimental variables, difference has been observed depending on color temperature, the dimming of the ceiling & cove lights and the use of down lights and a bracket. 'Conversation with Family', 'Having Fun with Family', 'Entertaining Guests' and 'Reading a Book or Newspaper' requires "lightness". In terms of "emotion"-centered activities, 'Watching TV' is the highest, but all three factors are related. In terms of "calmness"-centered activities, 'Relaxing' is the highest.

• Journal of Biomedical Engineering Research
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• v.13 no.2
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• pp.141-146
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• 1992

The propagation, reflection and scattering characteristics of the near Infra-red lights were experimented in order to check the feasibility of non-restrained biotelemetry using indirect transmitted light. The results of the experiments show that 3 kinds of walls examined are not specular reflectors but almost perfect diffuse surfaces with slight directivity and that light in a local point is spread out and fills the room uniformly by repeating the reflection and scattering at walls, ceiling, floor. These results also explain the fact that the diffusely reflected light can be utilized as the carrier of biotelemetry even after several scattering and reflections.

• Journal of the Optical Society of Korea
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• v.19 no.6
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• pp.586-591
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• 2015

In recent years, along with the rapid development of LED technology, indoor positioning systems based on visible light communication (VLC) have been researched. In this paper, we propose an accurate indoor positioning method using white-light LEDs and a dual image sensor. Indoor LED lights are located at the ceiling in a room and broadcast information on their positions using VLC technology. A mobile device with a dual image sensor receives LED position information by VLC and estimates its position and azimuth angle. Simulation and experimental results are given to show the performance of the proposed indoor positioning system.

• Journal of the Korea Furniture Society
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• v.26 no.1
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• pp.92-99
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• 2015

The following research focused on developing a new concept of lighting design with design factors which considered combining common natural objects with feelings. The purpose of this research is to write a thesis that deals with the whole process of developing a design for 'FEELighting' that is applicable to daily life through developing a form of lighting, which prioritizes feelings rather than materials, forms, or functions, and enhance the quality of people's lives. In particular, the process has been materialized by defining a new concept of 'FEELighting' (Feeling + Lighting), researching and analyzing the original and unfamiliar correlation between feeling and lighting, and choosing the embedded acrylics lighting items that can undergo small quantity batch production. As a result, prototypes of various forms of lightings that could be applied to daily lives -ceiling lights, wall light lamps, and table lamps-, which were made by combining numerous common natural objects and surpassed simple function and created to surpass simple lighting function, were presented through every process of design development.

• Journal of the Korean housing association
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• v.21 no.1
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• pp.79-88
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• 2010

The purpose of this study is to examine the design characteristic about the public space of privately-built apartment housing after the enforcement of price deregulation in Daegu. The public space of the multi-family housing is monotonous and closed according to the position of an elevator and a stair hall by the 1990's. However, the housing has been gentrified since 2000 because of demands of residents and purpose for selling in lots. Thus, the recognition of the apartments has changed and this change has led to extend the living territory and magnify the role of the public space where help interact with neighbors. This study is based on the survey of thirty nine apartment complex. Also, by using an analysis derived from a precedent study, design elements in approach and interior space of apartment residents are comprehended. The characteristic of the porch is researched and divided according to a roof of porch, form as the door, material of roof, wall, the ceiling and floor. Interior space is analyzed by several elements; forms of core, forms, materials and lights of ceiling, materials of walls and floors, existence and nonexistence of windows, and extra interior components etc. As a result of the study, After the enforcement of price deregulation, the public space of apartments has had improved quality in materials and design and the community center for residents such as waiting rooms and spots facilities has appeared. However, the traffic line of interior space has been very intricate. Also, sports facilities and waiting areas are limited to some apartments.