• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.8
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• pp.799-804
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• 2011

The LFLP (Linear Fresnel Light Pipe) system uses a linear Fresnel lens to follow the sun and concentrates the parallel sunlight into a line. A LFLP daylighting system has been developed and updated to a DBLP (Double Blind Light Pipe) daylighting system to improve the overall system efficiency in the morning and afternoon. The new design consists of a double-blind style with a cone-shaped light transformer. The blinds are used to collect the sun's altitude and azimuth movements through the day. Behind the two sets of blinds is the light transformer, which is based on a parabolic-shaped light concentrator. The light transformer is designed to efficiently deliver light within a thirty-degree radial spread so that the light pipe can internally reflect the light. The results of scale-model tests are encouraging, and the efficiency is three times higher than that of the previous LFLP system.

• Korean Institute of Interior Design Journal
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• v.18 no.1
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• pp.3-10
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• 2009

The relationship between light and space is fundamental In an opera stage design. In contemporary stage design, light, color and space themselves became one of tile most important elements to express and symbolize the content of the opera. This was very different compared to the primitive and medieval opera stage design in the past. The designer tried to represent the same periodical background of the opera with exact replica of the buildings as well as costumes. In comtemporary performance art, light became one the most important aspects in design. Max Keller is one of the living pioneers in stage lighting design. This thesis that is based on his lighting experiments and projects attempts to examine how contemporary stage design and light are applied and what kind of characteristics they have. One of the Wagner's opera, "Tristan und Isolde" was selected to be further analyzed. Three different "Tristan und Isolde" opera stage designs were carefully studied in terms of how three designs are differently constructed for specific same contents of the opera. This sort of comparison study is crucial when there is a strict parameter that is the opera itself. It was found that three opera stages have very different stage designs and unique ways of expressing the opera flow and contents. However, in some parts, very similar lightings were used. This sort of multi-disciplinary study can be helpful to re-think the interior environment by applying light as a fundamental medium.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.50-56
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• 2021

This study examines 3D scanning and how it is used in the construction field. 3D scanning technology was applied to a real space and compared with drawings in the planning and construction stages. 3D scanning technology has been widely applied in the field of construction, design, construction, and safety. The results of comparing 3D scanning data with drawings are as follows. First, the external shape and dimensions do not show much difference. Second, the internal shape and dimensions are different. Third, indoor lighting layouts are different in all buildings. 3D scanning should be an essential element in the construction stage before completion and should be used for supervision tasks such as material management, improving the efficiency of construction, and safety management through continuous 3D scanning using automation and robots. Follow-up studies in the field of architecture, such as BIM and process management, will be needed.

• Journal of Korea Water Resources Association
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• v.43 no.2
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• pp.153-165
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• 2010

Large-Scale Particle Image Velocimetry (LSPIV) is an extension of particle image velocimetry (PIV) for measurement of flows spanning large areas in laboratory or field conditions. LSPIV is composed of six elements - seeding, illumination, recording, image transformation, image processing, postprocessing - based on PIV. Possible error elements at each step of Mobile LSPIV (MLSPIV), which is a mobile version of LSPIV, in field applications are identified and summarized the effect of the errors which were quantified in the previous studies. The total number of elemental errors is 27, and five error sources were evaluated previously, seven elemental errors are not effective to the current MLSPIV system. Among 15 elemental errors, four errors - sampling time, image resolution, tracer, and wind - are investigated through an experiment at a laboratory to figure out how those errors affect to velocity calculation. The analysis to figure out the effect of the number of images used for image processing on the velocity calculation error shows that if over 50 images or more are used, the error due to it goes below 1 %. The effect of the image resolution on velocity calculation was investigated through various image resolution using digital camera. Low resolution image set made 3 % of velocity calculation error comparing with high resolution image set as a reference. For the effect of tracers and wind, the wind effect on tracer is decreasing remarkably with increasing the flume bulk velocity. To minimize the velocity evaluation error due to wind, tracers with high specific gravity is favorable.

• Design Convergence Study
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• v.15 no.3
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• pp.19-41
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• 2016

This study aimed to diagnose the housing conditions of the low income single or couple elderly households. Specifically, this study divided the elderly households into total 8 housing situations according to the three factors of residential area, household composition and income level, and compare the housing satisfaction level by household situation. This study was conducted in the form of the 1:1 interview with structured questionnaire and the field study, targeting the low income single or couple elderly households over 65 years old in urban and rural areas. The 80 collected data was analyzed using the SPSS statistics program. First, the households living in the urban areas and those in the rural areas had different housing conditions. Secondly, there was a clear difference in housing conditions between the single elderly households and couple elderly households. Third, the housing conditions were different depending on the gap in income level. This research is expected to be used as a basic resource to understand their various and differentiated demands and plan the housing environment to properly meet the demand.

• Korea Science and Art Forum
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• v.29
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• pp.89-100
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• 2017

This research aims to identify spatial features of exhibition hall for trade fair and establish a theoretical model on the effects of these features on the visitor attitudes. Also, it seeks to make suggestions on the service for exhibition environment or marketing activities through empirical analysis. The survey for this research was conducted for one week from Oct. 28 to Nov. 5, 2016 at COEX in Seoul. The 320 questionnaires were distributed to the visitors of the survey period, and all of the questionnaires were returned. Excluding those considered meaningless due to a small number of answered questions, a total of 303 samples were used for empirical analysis. The empirical analysis was conducted through SPSS 24.0. The results showed that each element of spatial features of the exhibition hall has significant effects on the visitor intuitive attitude. On the other hand, only Aesthetic and Convenience of spatial features of the exhibition hall has significant effects on the visitor conative attitude As above, this research conducted empirical researches on the effects of spatial features on visitor attitudes at exhibition hall to provide guidelines for establishing strategic management schemes of exhibition space that provide more convenient and pleasant environment. Also, this research aims to suggest development directions for organizer to provide quality service and environment, turning them into comfortable spaces that communicate with the visitors.

• Journal of Satellite, Information and Communications
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• v.9 no.3
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• pp.41-46
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• 2014

In this paper, a transceiver of VLC (Visible Light Communication) using LED white lighting has been implemented. We analyzed differences between conventional wireless communication and VLC with high-speed data transmission in a variety of environments, and confirmed symbols which passed through a channel using QAM. In order to get a high data rate, we found some variables that should be considered essentially though experiments. In addition, we set a bandwidth and found an optimal gain according to the distance between transmitter and receiver. We analyzed proposed system model through Labview and finally showed a system performance. The performance showed a 2Mbps QAM data rate in real visible light indoor channels.

• Journal of the Korean Solar Energy Society
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• v.37 no.1
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• pp.39-45
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• 2017

This paper presents the effect of solar collectors on the performance of solar tracking daylighting systems. A series of measurements were made for two different types of solar collectors mounted on double axis solar trackers: Parabolic dish concentrator and Fresnel Lens. Indoor light levels were measured at different locations of an office space (longitude: 126.33 E, latitude 33.45 N) as photo sensors were placed on a task plane 80 cm above the floor. To accurately monitor the applicability of the systems, measurements were performed under clear and overcast sky conditions with the roll-screen (on the south window) in the down position. Comparing the illuminance data, the system with Fresnel lens outperformed that of parabolic dish concentrator. On clear days, the former delivered the light levels of 400~600 lux on the task plane whereas the latter recorded 100~200 lux. Depending on the amount of cloud cover, on overcast days, illuminance readings fluctuated to some extent.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.9
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• pp.758-765
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• 2001

This paper proposes a method to automatically extract stable visual landmarks from sensory data. Given a 2D occupancy map, a mobile robot first extracts vertical line features which are distinct and on vertical planar surfaces, because they are expected to be observed reliably from various viewpoints. Since the feature information such as position and length includes uncertainty due to errors of vision and motion, the robot then reduces the uncertainty by matching the planar surface containing the features to the map. As a result, the robot obtains modeled stable visual landmarks from extracted features. This extraction process is performed on-line to adapt to an actual changes of lighting and scene depending on the robot’s view. Experimental results in various real scenes show the validity of the proposed method.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.7
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• pp.813-816
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• 2005

Ear detection is an important part of an non-invasive ear recognition system. In this paper we propose human ear detection from side face images. The proposed method is made by imitating the human recognition process using feature information and color information. First, we search face candidate area in an input image by using 'skin-color model' and try to find an ear area based on edge information. Then, to verify whether it is the ear area or not, we use the SVM (Support Vector Machine) based on a statistical theory. The method shows high detection ratio in indoors environment with stable illumination.