• Nuclear Engineering and Technology
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• 제32권1호
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• pp.34-45
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• 2000

This study is concerned with the experimental test and numerical analysis of the heat transfer and solidification of the molten metal pool with overlying coolant with boiling. In the test, the metal pool is heated from the bottom surface and coolant is injected onto the molten metal pool. Experiments were performed by changing the test section bottom surface temperature of the metal layer and the coolant injection rate. The two-phase boiling coolant experimental results are compared against the dry test data without coolant or solidification of the molten metal pool, and against the crust formation experiment with subcooled coolant. Also, a numerical analysis is performed to check on the measured data. The numerical program is developed using the enthalpy method, the finite volume method and the SIMPLER algorithm. The experimental results of the heat transfer show general agreement with the calculated values. The present empirical test and numerical results of the heat transfer on the molten metal pool are apparently higher than those without coolant boiling. This is probably because this experiment was performed in concurrence of solidification in the molten metal pool and the rapid boiling of the coolant. The other experiments were performed without coolant boiling and the correlation was developed for the pure molten metal without phase change.

• 설비공학논문집
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• 제8권3호
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• pp.338-350
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• 1996

A numerical analysis is carried out to study the two-dimensional steady state natural convection from vertical wires immersed in cold pure water. The surface of the wire is $0^{\circ}C$ unifrom temperature. Results of the analysis are presented for free stream temperature from $0^{\circ}C$ to $25^{\circ}C$ and the aspect ratio N from $5.26{\times}10^{-3}$ to $1.0{\times}10^{-3}$. The effects of the density extremum and aspect ratio on the flow pattern and the heat transfer characteristics are discussed As the aspect ratio N becomes larger, in the range of $1.0^{\circ}C{\leq}T_{\infty}{\leq}4.4^{\circ}C$ and $6{^{\circ}C}{\leq}T_{\infty}{\leq}17^{\circ}C$, the effect of Pr number on the heat transfer is shown to be more significant than the aspect ratio. Investigating into the effect of the density extremum on the heat transfer from wires, the new heat transfer correlations are suggested with the relation of average Nu mumber vs. modified Ra number. Here, the coefficient values C of correlations are presented as the function of density extremum parameter $R^*$. The effects of the density extremum parameter are also discussed.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.70-70
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• 2018

As science and technology has developed, human could be flourished especially at the aspect of agriculture and medicine. However, the traditional knowledge of them has stopped being used, which leads to extinctions of it. Korea National Arboretum had surveyed the ethnobotanical uses of Gangwon-do from 2006 to 2017. 522 taxa were defined as ethnoplants through 21469 sheets thanks to 355 respondents who composed 279 females, 73 males and three refused to answer. Analysis of ethnoplants had conducted to provide the excavation of the new plants for industries of agriculture and medication, as well as the evidence for protection of TK and benefit derived from it. Aster scaber Thunb. had been found as the most citated taxa by 0.6591 RFC figure, Pinus desiflora Seibold & Zucc. was found to have the extensive categories of use. Aralia elata (Miq.) Seem. showed the highest figure of CI value. In the index of RI, Pinus desiflora Seibold & Zucc. appeared again, as well as CV, cultural value. For evaluation of the usages of ethnoplants IAR figures are analyzed. The fiber has shown the biggest figure of IAR, despite the dyes are placed the smallest figure.

• 한국항해항만학회지
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• 제30권5호
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• pp.321-329
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• 2006

이 연구의 최종목적은 기존의 선박용 자기 컴퍼스를 대체할 수 있는 디지털 컴퍼스 개발에 있다. 우선, 3축의 고정밀 프럭스-게이트센서와 소형 스텝 모터를 이용하여 새로운 디지털 컴퍼스 장치를 개발하였다. 그리고 기존 자차측정 방법과 달리 선박의 선회 없이 자동으로 자차의 분석과 수정이 가능하도록 기존 자차이론에 칼만필터 개념을 접목시킨 새로운 자차수정 이론을 제안하였다. 개발한 디지털 컴퍼스와 제안한 자차수정 방법의 유효성을 실습선 '새누리호'를 이용한 성능평가 실험을 통하여 유효성을 검증하였다.

• 한국농촌건축학회논문집
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• 제3권2호
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• pp.57-70
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• 2001

The spatial composition of Korean traditional houses is based on the relation of spaces in the background of humanism, society, and composition. According to the analysis of it in this study, we make conclusions as follows; 1) Two compositive axises are formed according to age, sex and status which are the main factors of society and culture in the traditional society. 2) The house of '口-shaped' type in the traditional houses concentrates to the interior. To the exterior, it has the closed and conservative system. The wall in the outside of An-Chae intercepts the sight outward and the extension of space, while the wall in the inside is composed of doors and windows which make the sight and space concentrate to the interior. On the contrary, the doors and windows of Sarang-bang and Nu-maru of Sarang-chae open and extend to the exterior. 3) The spatial composition of the traditional houses is composed of geometrical order system and organic order system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.281-283
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• 1994

The impedance characteristics of planar ICP have been measured and compared with the theoretical results obtained by the field equation. The resistance of the total impedance had a maximum point and the inductance decreased monotonically as the electron density increased from $2.5{\times}10^{10}cm^{-3}$ to $7{\times}10^{11}cm^{-3}$ and the Pressure from 1mT to 50mT. The impedance characteristics were also dependent on the profile of the electron density. The effective collision frequency, ${\nu}_{eff}$ was $9.0{\times}10^6Hz$ at 5mT and $.5{\times}10^7Hz$ at 100mT. The effective collision frequency at 5mT was not so different from that at 100mT and it is doe to the reduction of the discharge channel cross-section at high pressure. The estimated effective collision frequency from the simulation data was of the same order as the measured one.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2019년도 춘계학술발표대회
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• pp.653-656
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• 2019

현대 사회에서의 생체인식 기술의 발전을 통해 홍채, 지분 등의 정보를 사용하여 사용자의 신원확인 등이 가능하게 되었으며, 생체정보의 유출/위조 방지에 대한 중요성이 높아지면서 관련 연구가 활발히 이루어 지고 있다. 본 논문에서는 홍체 전체의 이미지에 삽입하거나 동공의 중심에 가까운 DCT(Discrete Cosine Transform)영역에 삽입방법, 동공 중심과 눈매의 영역을 검출하여 거리 및 DC 계수를 통하여 삽입 위치를 선택하는 방법 등 홍채영상 속 워터마크를 삽입하여 유출/위조된 홍채 영상을 검출하는 방법에서의 워터마크 삽입위치에 관한 방법을 연구하고, CASIA Irisimage Database ver 4.0의 워터마크를 삽입하여 NC(Normalized Correlation)의 값을 비교하여 워터마크 삽입 실험을 검증하였다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2019년도 춘계학술발표대회
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• pp.649-652
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• 2019

최근에 카메라를 사용하여 물체를 인식하고 수량을 측정하는 연구가 진행되고 있다. 하지만 건축 자재와 같이 인접한 동일 물체의 경우, 인식과 측정이 어려우며, 이와 관련된 연구는 부족한 실정이다. 본 논문에서는 이러한 문제를 해결하기 위해 딥러닝과 드론을 사용하는 방법을 통하여 자재 더미의 윗면과 측면의 촬영, 드론 로그를 사용하한 드론 높이와 Yaw값 획득, 영상 내 자재 종류와 영역 정보 등 미리 학습된 딥러닝 모델을 사용한 획득방법, 드론 촬영 시의 Yaw값 차이를 이용해 윗면과 측면이 공통으로 가지는 직선 검색, 자재 더미의 가로, 세로, 높이의 비율 등을 통한 각 화소 비율과 자재 개수의 영역별 가상의 체적값 분석, 드론의 화각, 높이를 사용한 체적 사진측량값 획득, 가상 체적과 사진측량법 사이의 오차 최소화 비율 등을 연구하였다.

• Bulletin of the Korean Chemical Society
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• 제8권5호
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• pp.372-376
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• 1987

Acetone solution of quinoline-8-carbaldehyde reacts with $[Rh(cod)(PPh_3)_2] PF_6$and $[Ir(cod)(PPh_3)_2] PF_6$ to yield $[Rh(NC_9H_6CO)(H)(PPh_3)_2(CH_3COCH_3)] PF_6$ (1) and $[Ir(NC_9H_6CO)(H)(PPh_3)_2(CH_3COCH_3)] PF_6$ (2), respectively. The compound $[Ir(cod)(PPh_3)_2] PF_6$ also reacts with $Ph_2PC_6H_4-o-CHO$ in the acetone / $H_2O$ mixture to give $[Ir(Ph_2PC_6H_4-o-CO)(H)(PPh_3)_2(CH_3COCH_3)] PF_6$ (3). Compounds 1, 2, and 3 were characterized by infrared, $^1H$ NMR, $^{31}P$ NMR spectra and conductivity measurement. The $^1H$ NMR spectra of 1, 2, and 3 support the presence of a terminal hydride that is cis to the phosphine. The IR band of 3 at 2185 $cm^{-1}$, which is assigned to $\nu$(Ir-H), and the hydride cleavage reaction of 3 with $CCl_4$, provide evidence for the Ir-H bond.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.182-187
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• 2006

This research presented the heat resistance characteristics of heat sink which is newly designed through the experiment. For the same volume and base plate of heat sinks, the experiment of heat transfer characteristics was conducted for forced convection of layered type heat sink. The heat transfer and pressure drop characteristics of the layered type heat sink were compared for the various kinds of fin pitches, fin heights and heights of heat sink. The results show that thermal resistance is decreased as the height of heat sink increases and the fin height and fin pitch decrease, From the experimental data of layered type heat sink, the correlation equation of Nusselt number was obtained as follows ; $$Nu=0.845{\cdot}Re^{0.393}{\cdot}(\frac{f_h}{D_h})^{0.160}{\cdot}(\frac{f_p}{D_h})^{0.372}{\cdot}(\frac{H_{hs}}{D_h})^{-0.942}$$