• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.549-554
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• 2003

EPRI PPM (Performance Prediction Methodology), a method used for the prediction of required thrust of valves, can not be applied to unbalanced-disk globe valves operated in the fluid when the fluid temperature is above $150^{\circ}F$ because the thrust increase caused by the friction between the valve disk and body is not considered in the PPM. In order to apply PPM to the valves, EPRI suggested new friction prediction method to be added in the code. This paper analyzes the applicability of the prediction method comparing the disk-to-body friction load predicted from the method with the measured friction load from the field tests. The maximum values from the prediction method and those obtained from the test were 268lbs and about 1500lbs, respectively. It is included that the prediction method should be improved for the realistic prediction of disk-to-body friction load.

• KIEAE Journal
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• 제7권5호
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• pp.65-71
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• 2007

The purpose of this study was to analyze the difference of thermal sensation by radiant floor heating as ecological design element. The experimental investigations were carried out in climate chamber, and subjects were 34 college-age females in good health. The experimental variable was radiant heat by floor heating, and experimental controlled conditions were indoor temperature, relative humidity, and air velocity in climate chamber and clothing value and activity of subjects. The results are as follows. (1) Indoor temperature($21{\pm}0.5^{\circ}C$) in climate chamber were maintained as controlling. Clothing values of the subjects were controlled as average 0.73 clo. In the floor heating-off, globe temperature was average $23.2^{\circ}C$(22.4~24.1), but in the floor heating-on, globe temperature was average $24.8^{\circ}C$(23.0~25.5). (2) In the floor heating-off, thermal sensation rating was average -1.03(slightly cool), in the floor heating-on, thermal sensation rating was average +1.03(slightly warm). (3) There were the differences of thermal sensation by radiant floor heating although indoor temperatures were maintained in an equal state. (4) The thermal sensation rating was tending upward according as the globe temperature was getting higher.

• 한국산학기술학회논문지
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• 제17권7호
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• pp.734-739
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• 2016

선형으로 움직이는 글로브 밸브의 목적은 주로 유량을 제어할 수 있도록 설계 되어 있으며, 디스크의 움직임으로 인해서 유량을 제어가 가능하게 된다. 본 논문은 유량계수를 예측하기 위해서 전산유동해석 프로그램인 ANSYS-CFX로 유동해석을 진행 하였고 본 해석에서 사용되는 글로브 밸브 모델을 시제품과 동일한 형상의 크기로 설계하였다. 유량계수는 밸브 전개 시 $16.5^{\circ}C$의 맑은 물이 전후의 압력차 1psi로 흐를 때 그때의 유량을 말한다. 다시 말해서 밸브의 크기를 결정할 수 있는 중요한 요인이 된다. 밸브의 유량계수와 유량을 해석을 통해서 얻어낼 수 있었고, 그 해석으로 인해서 분당 0~0.1gal 유량을 제어할 수 있는 정밀제어 글로브 밸브를 개발 할 수 있었다. 유동해석과 실험의 결과로 유량계수를 서로 비교하였으며 그 결과로 인해서 유량계수의 오차율이 매우 작음을 확인하였고, 해석의 신뢰성을 확보하였다. 따라서 실험 없이 해석만으로 충분히 유량계수의 경향성을 파악하는데 크게 어려움이 없음을 보여주었다.

• 생물환경조절학회지
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• 제19권1호
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• pp.25-30
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• 2010

본 시험은 제주에서 무가온 하우스 재배시 아티초크의 정식시기가 생육 및 수량에 미치는 영향을 구명코자 'Imperial Star'와 'Green Globe' 2품종을 사용하여 정식 시기는 전반기 5회(2월 25일~4월 30일), 후반기 6회(7월 30일~12월 15일)로 하였다. 전반기 정식에 있어서 화뢰 출현은 5~6월에 이루어졌는데 'Imperial Star' 품종이 'Green Globe' 품종에 비해 빨랐다. 첫 수확은 2월 25일 정식한 'Imperial Star' 품종에서 6월 16일로 가장 빨랐다. 수량은 전반기 정식의 경우 2월 25일 정식한 'Imperial Star' 품종에서 856kg/10a로 가장 많았다. 4월 15일 이후 정식에서는 두 품종이 모두 화뢰 출현이 이루어지지 않아 연내 수확이 불가능 하였다. 후반기 정식의 경우 화뢰 출현은 모든 처리구에서 이듬해 2월 하순~4월 중순경에 이루어졌으며 7월 30일 정식한 'Imperial Star' 품종에서 2월 26일로 'Green Globe' 품종에 비해 18일 빨랐다. 첫 수확은 4월 초순부터 가능하였으며 수량은 7월 30일 정식한 'Green Globe' 품종에서 2,127kg/ 10a로 가장 많았으며, 이후 정식시기가 늦어짐에 따라 감소되었다. 정식시기를 전반기와 후반기로 나누어 정식일에 따른 생육과 수량을 비교한 결과, 제주지역 무가온 하우스에서 아티초크의 연내 수확을 위해서는 2월 25일 정식이, 이듬해 수확을 위해서는 7월 30일~10월 15일 사이에 정식하는 것이 생육 및 수량성에서 바람직할 것으로 생각되었으며 정식시기가 전반기일 경우는 'Imperial Star' 품종을 후반기일 경우는 'Green Globe' 품종을 선택하는 것이 유리할 것으로 생각 되었다.

• 한국환경교육학회:학술대회논문집
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• 한국환경교육학회 1996년도 21세기를 위한 환경교육의 정보화·세계화
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• pp.40-46
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• 1996

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.3-10
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• 2005

• The Korean Journal of Ecology
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• 제19권5호
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• pp.403-416
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• 1996

Global natural vegetation mapping (GNVM) system was developed for estimating potential forest area of the globe. With input of monthly mean temperature and monthly precipitation observed at weather stations, the system spherically interpolates them into 1°×1°grid points on a blobe, converts them into vegetation types, and produces a potential vegetation map and a potenital vegetation area. The spherical interpolation was based on negative exponential function fed from the constant radius stations with oval weighing method which is latitudinally elongated weighing in temperature and longitudinally elongated weighing in precipitation. The temperature values were corrected for altitude by applying a linear lapse-rate (0.65℃ / 100m) with reference to a built-in digital terrain map of the globe. The vegetation classification was based upon Koppen’s sKDICe. The potential forest area is estimated for 6.96 Gha (46.24％) of the global land area (15.05 Gha).

• 한국주거학회논문집
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• 제10권1호
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• pp.75-84
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• 1999

The purpose of this study is to identify the characteristics of the thermal environment, and to analyze the relationship between the thermal reactions and the skin temperatures in the lying position in the radiant floor heating system. The results are as follows: 1) The globe temperature was nearly equal to the operative temperature in the room. 2) The floor surface temperature and the globe temperature were 26.4$^{\circ}C$ and 23.6$^{\circ}C$, respectively when the whole body temperature was at neutral point. 3) The mean temperature of the six skin parts was 31.3$^{\circ}C$ (cold thermal environment); 34.1$^{\circ}C$ (neutral thermal environment); 35.1$^{\circ}C$ (hot thermal environment).

• 한국유체기계학회 논문집
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• 제10권1호
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• pp.41-48
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• 2007

The effect of the upstream flow conditions on the disc stability of the swing check valves was investigated at various upstream flow disturbance sources and distances from the tested check valves. The experimental loop was designed and installed to measure the disc positions, disc back stop load, and differential pressure at flow velocities lot 3 inch and 6 inch swing check valves. The selected disturbance sources are elbow and globe valve. The effect of the disc fluctuation is different depending on the type of disturbance and the distance between the disturbance and the check valve. Disturbances generated by elbow and globe valve located upstream from check valve create greater and more violent disc motion than uniform flow.

• 한국유체기계학회 논문집
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• 제6권4호
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• pp.29-37
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• 2003

This study was undertaken to verify the effect of flow coefficient when a globe control valve was attached by different type of fitting. The valve flow coefficient is usually determined by measuring the flow rate and the pressure drop with the connection of straight pipe through the valve. The effect of different fitting that is mounted on the downstream of the valve is studied. Four types of fittings and three distances between the valve and a downstream fitting are compared parametrically to investigate the effect on the flow coefficient of it. Measured flow coefficient and numerically predicted value by using computational fluid dynamics were compared in detail. It is concluded that the flow coefficient is reduced if the fitting is attached after a valve, but the effect of different type of fitting is not crucial.