• The Bulletin of The Korean Astronomical Society
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• v.32 no.1
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• pp.92.1-92.1
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• 2007

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1682-1691
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• 2018

Natural ester is a suitable substitute for mineral oil and has been widely used in AC transformer in many countries. In order to further application of natural ester in direct current (DC) equipment, it is needed to investigate its long term insulation property under DC condition. In this paper, a thermal ageing experiment was conducted for both mineral oil-paper and natural ester-paper insulation. The DC breakdown and space charge characteristics of insulation paper impregnated with natural ester and mineral oil was compared. Results show that the resistivity of the paper immersed in natural ester and mineral oil both increase as the ageing goes on. While insulation paper impregnated with natural ester has higher resistivity and DC breakdown voltage than the paper impregnated with mineral oil. The DC breakdown voltage for the oil impregnated insulation paper being DC pre-stressing is higher than that without pre-stressing. The average DC breakdown field strength difference between the test with pre-stressing and without pre-stressing clearly shows that there is an apparent enhancement effect for the homo-charge injection on the DC breakdown.

• Bulletin of the Korean Mathematical Society
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• v.38 no.4
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• pp.787-795
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• 2001

For the generalized nilpotent spaces, e.g. the locally nilpotent space, the residually locally nilpotent space and the space satisfying the condition ($T^{*}$) or ($T^{**}$), we find the pullback property of them. Furthermore we investigate some fiber properties of the space satisfying the condition ($T^{*}$) or ($T^{**}$), especially locally nilpotent space.

• 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.36.2-36.2
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• 2018

Cosmic reionization era in the early universe was playing a leading part on making the present universe we know. However, we have not been able to reveal the main contributor to the cosmic reionization to date. Faint quasars have been mentioned as the alternative due to the uncertainty of the faint end slope of the quasars luminosity function. With the availability of the deep (~25mag) images from Subaru Hyper Suprime-Cam (HSC) Strategic Program survey, we have tried to find more quasar with low luminosity in the ELAIS-N1 field. Faint quasar candidates were selected from several multi-band color cut criteria based on the track of the simulated quasar at z ~ 5. The Infrared Medium-deep Survey (IMS) and The UKIRT Infrared Deep Sky Survey (UKIDSS) - Deep Extragalactic Survey (DXS) provide J band information which is used to cover the relatively long wavelength range of quasar spectra. To search the reliable candidates with possible Lyman break, medium-band observation was performed by the SED camera for QUasars in EArly uNiverse(SQUEAN) in the McDonald observatory and Seoul National University 4k Camera(SNUCAM) in the Maidanak observatory. Photometric redshifts of the observed candidates were estimated from chi-square minimization. Also, we predicted the importance of the faint quasar to the cosmic reionization from the expected number density of the faint quasar.

• Journal of the Korean Institute of Rural Architecture
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• v.22 no.3
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• pp.9-16
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• 2020

The trend emphasizes children-oriented, play-oriented ecological education programs for children's ecological education. And most of these nature -friendly and eco-friendly education takes place outdoors. Therefore, outdoor space planning is important in childcare facilities. This case study aims to analyze the actual conditions of outdoor spaces in daycare centers and to provide standard data for outdoor space planning. In order to provide basic data on the improvement direction and planning standards of outdoor spaces, this present study conducted the composition, utilization status and related problems of outdoor spaces for nature -friendly ecological education in childcare facilities. Accordingly, outdoor space planning for ecological education should consider outdoor space characteristics such as free and easy accessibility between indoor and outdoor spaces, openness of space, flexibility, dynamic/static space, and nature affinity. Therefore, for an ecological education environment, children should be able to freely approach nature and play in the natural environment without any restrictions and artificial controls. Also, in urban areas, natural environment such as parks and open spaces should be considered as outdoor play spaces for children.

• Architectural research
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• v.22 no.4
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• pp.113-122
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• 2020

Hospital architecture must be planned as a therapeutic space. Numerous studies have proven that exposure to nature has a healing effect. However, research on the architecture itself about this issue is still insufficient. This study analyzed Le Corbusier's Venice hospital project and its architectural configurations with nature. Le Corbusier had been interested in blurring the interior/exterior line to draw nature inside. In his projects, nature was conceived in an abstract sense as "something green." However, in the hospital project, natural elements including vegetation, the lagoon, and light, and the landscape scenery they created, were considered in the harmony of the architectural space. The architectural spaces with courtyards, pilotis, and roof gardens provided views and direct access to nature, and in the interior spaces, the connections to these external spaces and the permeation of views of nature and sunlight were incorporated. Many spaces provided the possibility to actually encounter nature, with a variety of indoor/outdoor space configurations rather than a merely passive placing of some natural elements. This project is considered to be an important reference for contemporary hospital architecture, since the architectural space and nature connected through various spatial configurations also in healthcare programs. As Le Corbusier emphasized, sunlight, vegetation, and also architectural space should be an essential factor in therapeutic hospital architecture planning.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.93-93
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• 2004

• Journal of KIISE:Software and Applications
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• v.34 no.4
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• pp.368-376
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• 2007

How to represent the search space is as important as which search algorithm to use for finding natural-looking paths for moving NPC (non-player character) in computer games. Recently, various state space representation methods which have been developed for computer games are being used while A* algorithm dominates as the preferred search algorithm. These representation methods show some drawbacks such as the size of state space is too large, there is no guarantee for optimality, the path found is not natural-looking, and the generation of nodes and links is not automatic by depending on a level designer. In this paper the requirements for natural-looking paths are introduced and to find paths satisfying these requirements, the use of the generalized visibility graphs which is the extended version of the visibility graph in Robotics is proposed.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.4
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• pp.59-67
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• 2015

There are several methods for building optimal eco-villages in a narrow territory. To derive a new optimal eco-village factors by combining environmental factors from ubiquitous sensor network and topography factors, this study attempted to investigate ecological spaces of specific human settlements, to compare those with the spatial analytical results on natural real settlements, and to draw a construction plan for an optimal ecological village. This study presented a new milestone for building eco-villages in the large or small village units of the entire country in the fact that we can find a living space to make natural healing possible by integrating ecological factors and wellbeing spatial configuration using more healthy natural space. Also, this study proposed a practical method to do so.