• 한국자기공명학회논문지
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• 제12권2호
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• pp.74-80
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• 2008

The local structure of defects in undoped, Si-doped, and neutron irradiated free standing GaN bulk crystals, grown by hydride vapor phase epitaxy, has been investigated by employing electron magnetic resonance(EMR), Raman scattering and cathodoluminescence. The GaN samples were irradiated to a dose of $2{\times}10^{17}$ neutrons in an atomic reactor at Korea Atomic Energy Research Institute. There was no appreciable change in the Raman spectra for undoped GaN samples before and after neutron irradiation. However, a forbidden transition, $A_1$(TO) mode, appeared for a neutron irradiated Si-doped GaN crystal. Cathodoluminescence spectrum for the neutron irradiated Si-doped GaN crystal became much broader or was much more broadened than that for the unirradiated one. The observed EMR center with the g value of 1.952 in a neutron irradiated Si-doped GaN may be assigned to a Si-related complex donor.

• 한국주거학회논문집
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• 제16권3호
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• pp.1-7
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• 2005

The purpose of this study was to analyze the relationship of the floor classification and the main-living behavior, and the tendency of using furniture and space by surveying the situations of using An-bang space by apartment dwellers. An-bang is a factor that influences on the unit-plan organization, the whole spatial arrangements, and the spatial relation and size, and has the most severe friction between the tradition and western culture. Given seeing the results shown in the main-living behavior by floor type, that the rest and TV watching were shown to be high in terms of a free-standing type can be said that An-bang is more for the individual rest than far the purpose of family harmony. On the other hand, that the family courtesy was shown to be a little higher a sitting-down type, could be understood that the sitting-down style, which is a traditional living mode, is appearing in An-bang.

• 한국주거학회논문집
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• 제13권6호
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• pp.31-39
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• 2002

The purpose of this study is to examine the exterior remodeling examples of urban houses which have been changed to be mixed-use buildings with commercial use, and to guide the future exterior remodeling. Some of the research results are as follows: 1) Exterior remodeling of commercialized urban detached houses is focused on two-dimensional changes of exterior surface, rather than on three-dimensional changes of mass or shape. 2) Unlike commercial buildings generally relying on signboards to express their commercial nature, the exterior-renovated houses with commercial uses mainly rely on the image of whole building shape based on exterior materials and colors. 3) Installations of free-standing walls and double skins are preferred as exterior remodeling techniques, due to the structural limitation of exterior walls.

• 통합자연과학논문집
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• 제6권3호
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• pp.170-175
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• 2013

Silicon nanowires were detached and obtained from silicon nanowire arrays on silicon substrate using a ultrasono-method. Silicon nanowire arrays on silicon substrate were prepared with an electroless metal assisted etching of p-type silicon. The etching solution was an aqueous HF solution containing silver nitrate. SEM observation shows that well-aligned nanowire arrays perpendicular to the surface of the silicon substrate were produced. After sonication of silicon nanowire array, an individual silicon nanowire was confirmed by FESEM. Optical characteristics of SiNWs were measured by FT-IR spectroscopy. The surface of SiNWs are terminated with hydrogen.

• 통합자연과학논문집
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• 제6권3호
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• pp.183-186
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• 2013

Well defined 1-dimentional (1-D) photonic crystals of polystyrene replicas have been successfully obtained by removing the porous silicon from the free-standing rugate porous silicon/phenylmethylpolysiloxane composite film. Rugate porous silicon was prepared by an electrochemical etching of silicon wafer in HF/ethanol mixture solution. Exfoliated rugate porous silicon was obtained by an electropolishing condition. A composite of rugate porous silicon/phenylmethylpolysiloxane composite film was prepared by casting a toluene solution of phenylmethylpolysiloxane onto the top of rugate porous silicon film. After the removal of the template by chemical dissolution, the phenylmethylpolysiloxane castings replicate the photonic features and the nanostructure of the master. The photonic phenylmethylpolysiloxane replicas are robust and flexible in ambient condition and exhibit an excellent reflectivity in their reflective spectra. The photonic band gaps of replicas are narrower than that of typical semiconductor quantum dots.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1996년도 가을 학술발표회 논문집
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• pp.70-77
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• 1996

In this study, sliding response analysis of free standing structure such as multi-purpose nuclear spent fuel storage cask is peformed. The governing factors of sliding response are aspect ratio of structure and ground acceleration. The vertical acceleration component is very important factor in the sliding response of the structure. Based on the mathematical model, computer program is developed using direct forward integration method to predict the sliding response. Using the program, several parametric studies were made for sinusodial ground motion and for El Centre 1940 earthquake and Mexico 1973 earthquake. From the results, it is known that the frequency content and duration of strong motion affect the sliding of the structure.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.188-190
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• 2006

본 연구에서는 Anodic Aluminum Oxide(AAO) 템플레이트를 이용하여 전기도금법으로 일정한 길이와 고밀도 대면적의 Nickel nanorod를 제작하였다. 전기도금법으로 AAO-템플레이트내를 채우는 방법으로 제작되었다. 그 결과 직경 $80{\sim}100$ nm, 길이 $0.5{\mu}m$ 가량의 균일한 nanorod를 직경 40mm, 두께 $0.8{\mu}m$의 대면적 원형 AAO-템플레이트에 가득 채우는데 성공 하였으며 AAO 템플레이트는 제거되어 기판 위에 free-standing 되는 구조로 제작 되었다

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.221-224
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• 2005

The purpose of this study is to introduce design practice for transverse reinforcement in piles where the top of the pile is free-standing above the ground in accordance with AASHTO LRFD Design Specification. Based on the relevant requirements, the amount and spacing of transverse spiral reinforcement is given for the two different pile types, namely piles with pile cap and pile bents. In addition, a recommended design procedure is introduced depending on the predicted behaviour of the piles from the analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1558-1560
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• 1998

Macroporous silicon diaphragms 20 to $200{\mu}m$ thick have been formed on p-type silicon by anistropic etching in TMAH solution and then by electrochemical etching in HF-ethanol-water solution with an applied current. The pores have a pore diameter of $1.5{\sim}2{\mu}m$, with a depth of $20{\sim}30{\mu}m$ and are not interconnected, which are in sharp contrast to the porous silicon reported previouly for similarly doped p-Si. The fabrication of macroporous silicon and free-standing diaphragms is expected to offer new applications for microsensors, micro-machining, and separators.

• 대한가정학회지
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• 제44권4호
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• pp.159-173
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• 2006

The purpose of this study was to investigate the seating style of children between Korea and USA viewed from activity analysis in child-care centers. Observation and depth-interview method were used for data collection. Ninety-eight children aged from 38 to almost 62 months were observed for five minutes three times during an indoor free play period in Korea and USA in 2003 and 2004. The results of the research were as follows. There were significant differences between the postures of Korean and American children. Korean children maintained floor-seating postures longer than chair-seating and standing postures. The factors such as sex, age and physical environment influenced the children's seating style, while playing-type influenced their posture. This study will contribute to our understanding of the physical environment and children's seating style according to culture.