• Journal of Astronomy and Space Sciences
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• v.19 no.3
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• pp.187-196
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• 2002

We performed CCD photometric observations of the eclipsing binary Y Cam with a pulsating component, for 16 nights from November 2000 to May 2001 using a V filter attached to the 61-cm reflector at Sobaeksan Optical Astronomy Observatory. Our V light curve and Broglia & Marin's (1974) BV ones were analyzed with Mode 2 for a detached Roche model as well as Model 5 for a semi-detached one in the Wilson-Devinney code. From the analysis, we found the following results: 1) It is hardly discernible from only light curve synthesis which model between the detached and semi-detached ones is a real Roche model of Y Cam. 2) There exist the third light of about 2% and 3% in B and V light curves of Y Cam, respectively. 3) The light curve solution is immune from the light variation due to the pulsation of the primary component of Y cam. However, the detached model rather than the semi-detached one has slightly better fitted to the observations which were get rid of the pulsation effect. 4) The absolute dimensions of Y Cam were calculated for two Roche models.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.645-650
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• 2000

this paper deals with HVDC Light(High Voltage Direct Current) system using space vector PWM(SVPWM) method. Because the system of this paper has d-q control scheme for HVDC Light system. HVDC Light system represented in this paper is capable of controlling active and reactive power independently. For this system. V-I curve and control methods are proposed. Also this paper describes the design of a digital system for applications in power converters such as those that would be used in the next generation of HVDC system. Finally HVDC system is implemented using DSP TMS320C31

• Journal of KIISE
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• v.43 no.4
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• pp.399-403
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• 2016

Deferred Shading is a shading technique that postprocesses pixels in the screen space, following geometry-only rendering passes with depth buffering. Unlike typical shadow mapping techniques, this technique allows us to render shadows from multiple light sources without changing the structure of the rendering pipelines. This paper presents a deferred shadow mapping technique and its extension to soft shadows using mipmapping. Our technique first generates visibility maps from light sources, and blurs the visibility maps for deferred shading. This strategy leads to efficient soft-edged shadows, but does not incorporate depth variation, producing light bleeding to some extent. In order to suppress the light-bleeding artifacts, we also propose a depth-adaptive mipmap sampling technique in the screen space.

• KIEAE Journal
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• v.8 no.1
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• pp.53-60
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• 2008

The daylighting affects on the human biological cycles and physiological alterations. Daylighting is also an important element in visual comfort and it sometimes influences the quality of vision. Therefore the absence of natural light during the day brings contradictory result. To solve the problems of natural light lack and provide sufficient daylight in interior spaces, it might be necessary to apply some daylighting systems. One of these systems, light pipe system, which is simple, cheep and easily constructed, is very useful to apply for small buildings. The light pipe is simple means of directing daylighting (diffuse and direct lighting)into interior space. In order to application of light pipe system in Korea, it is necessary to optical data of light pipe system. This study aims to evaluate preliminary experiment of the daylighting environment of light pipe system. Light pipe system, that aspect ratio is 1:2(diameter and length), was installed in a windowless mock-up with $27m^2$. The mock-up model was constructed as a prototype of Korean office surface. Illuminance was measured with a Topcon IM-5 Luxmeter to evaluate the distribution of the illuminance on a floor. The indoor and outdoor illuminance and the internal/external illuminance ratio are compared to discuss with in the graphs. Luminance was measured with Radiant imaging Promertric 1400 that is digital photometer to evaluate the distribution of luminance on interior surface. The contrast of luminance is discussed with table and graphs.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.417-418
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• 2013

등대의 문화재 지정을 확대하고 관리방안을 개선해야 한다. 그리고 등대를 친수공간으로만이 아니라 문화예술 콘텐츠로 활용해야 한다.

• Korean Institute of Interior Design Journal
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• no.30
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• pp.68-77
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• 2002

From ancient to modern architecture, the light in the architecture spaces as the only changing factor, was the most important theme contributing vitality to the space and judging its character and expression. The efforts, to acquire both natural-physical light and internally experienced spiritual-supernatural light, had been revealed in several ways of the architecture from the ancient architecture. It was the main issues on the christian architecture. In this study, 1 have intended to determine how the light, the most important factor on the christian architecture symbolizing the blessing of God and forming the pious and restrained spaces has been expressed in the church spaces. For this purpose, I have compared and analysised the examples of the using the light, to the arts of the modern maestros of architecture and newly constructed churches in Korea on the way of light input pattern by the shape of windows. The results from the examples show that the most outstanding point of the modern christian architecture compare to the past, is that the natures of the inputted light has many diversities by the architects. And I reached the fact that the constructers by their own will to acquire the intended light, they are chose progressive light expressing methods through the shape of windows.

• KIEAE Journal
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• v.15 no.2
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• pp.27-35
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• 2015

Purpose: Healthcare is on the whole a personal and critical service that consumer's use, whereas hospitalization is as a rule painful, because nature nurtures and Sun Light Luminosity for healthcare settings is considered healing. The performance and design of climate responsive buildings such as AKU requires a detailed study of attributes of climate both at micro as well as macro level. The therapeutic value of contact with nature through window view, greenery and landscape is calculated there. Method: A two prong strategy is been devised for this article, at micro level three typical morphologies are analysed by creating same environment of neighboring building on sun shading chart, radiation and temperature range. Since the analysis of local climate helps to determine the design strategies for hospital Healing Environment which is suitable for Karachi climate; in order to track the macro climatic behaviour, a considerable analysis of psychometrics chart for AKU Karachi are designed on Climate Consultant (CC) and analysed by Machine Learning. Climate Consultant proposes different design strategies suitable for Karachi. And on the other hand time wise illumination sources for clinical area which are then measured on psychrometric chart- according to singular space: multi patient admission, secondly: acute ambulatory ward, and tertiary: multi windowed space according to the mushrabiyah and sky light pattern. Result: Our findings support the hypothesis that windowed wall is 75-80% more healing wall; an accelerated evidence was found for healing at macro level if the form of the hospital is designed according to the climatologically preferences, whereas at micro level: the light resource becomes the staff attentiveness determinant. In Conclusion evidence was provided that the actual form of luminosity results consequently in satisfaction while light entering from several set of windows and other sources might be valued if design according to the healing environment. The data added on the sun shading chart to calculate rays entraining into space in patient room equal to 124416.21 Watts/ meter $m^2$ is calculated as precise healing rate-and is confirmed by questionnaire from patients belonging from each clinical stage having different illnesses.

• KIEAE Journal
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• v.11 no.6
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• pp.71-79
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• 2011

There are high recognitions on the importance of comforts in Elderly living environment, but the circumstance is that studies on seniors facility space itself are approached only in planning level, and studies on lighting environment which is significantly associated with the comfort in the indoor environment of seniors where they actually spend the majority of their time are not that active. This study was intended to deduce cozy bedroom environment to which existing elderly care facility can be improved by using light shelf the lighting system with the advantage of being able to serve both as building sun visor and lighting window simultaneously in order to analyze the interior environment of bedroom space of elderly care facility the indoor space where the aged spend the majority of their life and examine the directions for the improvement of existing building lighting system through remodeling and renovation. In this study, lighting performance analysis was done in a way that the windows of the bedroom unit in existing facility were set in southbound direction based on two standard types and were put under initial simulation with the use of Autodesk Revit 2011, and after the simulation results were converted to Green Building Studio gbXML file to be used in ECOTECT, Daylight Autonomy a dynamic simulation and static natural lighting simulation the existing method of calculating daylight factors were deduced through Ecotect Analysis 2011. In conclusion, exiting standard model was found in such a condition that the daylight factors for both type A and type B were above 5% the proper standard value, and required improvement. In case light shelf the natural lighting system was attached, the daylight factor was improved to proper standard value for type A, and also was improved above existing facility for type B.

• Journal of the Korean Institute of Educational Facilities
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• v.27 no.3
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• pp.3-14
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• 2020

The purpose of this study is to discuss the planning direction of educational spaces to support children's healthy and creative learning based on bio_philic theory. This study analyzed the characteristics of the application of biophilic patterns in children's education space through case analysis. The conclusion of this study is summarized as follows. As a result of the analysis of children's classroom space, the pattern of 'A(Visual connection with nature), F(Dynamic & Diffuse Light), K(Prospect)' shows high application rate, but the pattern of 'C(Non-Rhythmic Sensory Stimuli), G(Connection with Natural Systems), I(Material Connection with Nature)' shows low application rate. In particular, there is a lack of connection with patterns such as hearing, smell, touch, taste stimulation and water experience, and curiosity through exploration of nature about 'B(Non-visual connection with nature), E(Presence of Water), N(Risk/Peril)' changes in nature and ecosystem. In the corridor and rest space, the pattern of 'A(Visual connection with nature), D(Thermal & Airflow Variability), F(Dynamic & Diffuse Light), G(Connection with Natural Systems), K(Prospect)' shows high application rate, but 'B(Non-visual connection with nature)' shows low application rate. In addition, the application of patterns related to the stimulation of curiosity through direct exploration of nature and the exploration of the patterns of 'E(Presence of Water), N(Risk/Peril)' is insufficient. Therefore, in the case of classroom spaces, the active use of nature as it is should be considered within the scope that does not cause visual confusion, and it should provide an area that can be experienced through the five senses. And corridors and rest spaces should be designed to introduce more active natural elements as spaces to recover stress caused by learning. In other words, the characteristics of children's education facilities need to be connected between classroom space, corridor, rest space and external space. This study is meaningful in that it analyzes and derives the application characteristics of 'biophilic design' which affects the 'Attention Restoration' of children's educational spaces through foreign cases.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.55.4-56
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• 2018

Linear Astigmatism Free - Three Mirror System (LAF-TMS) is the linear astigmatism free off-axis wide field telescope with D = 150 mm, F/3.3, and $FOV=5.51^{\circ}{\times}4.13^{\circ}$. We report the design and analysis results of its mirrors and optomechanical structures. Tolerance allowance has been analyzed to the minimum mechanical tolerance of ${\pm}0.05mm$ that is reasonable tolerance for fabrication and optical alignment. The aluminum mirrors are designed with mounting flexure features for the strain-free mounting. From Finite Element Analysis (FEA) results of mounting torque and self-weight, we expect 33 - 80 nm RMS mirror surface deformations. Shims and the L-bracket are mounted between mirrors and the mirror mount for optical alignment. The mirror mount is designed with four light-weighted mechanical parts. It can stably and accurately fix mirrors, and it also suppresses some of stray light.