• 한국컴퓨터정보학회논문지
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• 제11권4호
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• pp.127-135
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• 2006

기존 지구의를 이용한 교육은 학습 교재와 지구의가 개별적으로 구성되어 있기 때문에 학습 내용이 단순하고 학습 단원과의 관련성이 다소 부족하다. 따라서 본 연구에서는 학습 내용과 지구의간의 연계성을 고려한 멀티미디어 기반의 교육용 지구의 시스템을 개발하였다. 본 시스템은 컴퓨터 제어를 기반으로 하는 지구의 장치와 학습용 소프트웨어로 구성된다. 지구의 장치는 태양을 중심으로 스스로 자전하는 기능을 제공하며, 컴퓨터와 지구의를 연동하여 학생들에게 보다 효과적이며 시각적인 교육 환경을 제공한다. 학습용 소프트웨어는 각 나라의 시차, 기후, 문화. 교육정보 등에 관한 멀티미디어 콘텐츠를 제공하며, 또한 이 소프트웨어는 지구의 공전을 시뮬레이션 할 수 있다. 지구의 장치는 컴퓨터와 연동하지 않을 경우 오프라인으로 동작할 수 있도록 하였다. 본 시스템은 산학협력에 의해서 개발되었으며 주요 전시회에 참가하여 좋은 반응을 받았으며 향후 상품화를 추진할 예정이다.

• Journal of Advanced Marine Engineering and Technology
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• 제31권4호
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• pp.343-349
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• 2007

This cryogenic miniature globe valve is used to transfer the liquified natural gas which temperature is $-169^{\circ}C$, supplied pressure is 30bar(3.0MPa). In the present work the temperature distribution and thermal deformation is calculated numerical the FE method is useful to predict the thermal matter of cryogenic miniature globe valve. For this reason, to optimum design of the cryogenic miniature globe valve the analysis of the parameter about bonnet has been studied. It's used 3-D modeling to analyze cryogenic globe valve, which is 1/2". Numerical study used 3-D modeling makes a decision of efficient process of product before producing in the factory. A commercial software(ANSYS 10.0) is used in the structural analysis for cryogenic globe valve.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2005년도 춘계학술발표대회 논문집
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• pp.267-270
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• 2005

The purpose of this study was to make clear the indoor environmental efficiency of front balcony 'in apartment houses during winter. The field measurements of indoor environmental elements were carried out at an ordinary house with an existing front balcony and a house renovated the front balcony into the living room. The measurements in two-subject houses were taken on simultaneously the 20$^{th}$ ${\sim}$ 21$^{th}$ of January 2003. As results, the averages indoor temperature in the ordinary house and the renovated house were same as 23.6${\circ}$C, and the averages globe temperature in two houses were same as 23.7${\circ}$C. But, estimated heating time of the renovated house was longer than that of the ordinary house. The daily ranges of indoor temperature and globe temperature in the renovated house were wider than the ordinary house. The daily ranges of indoor temperature and globe temperature in the renovated house was longer than that of the ordinary house. The uniformity ratio range of daylight in the ordinary house were calculated at 1/3.4${\sim}$1/6.2, but those of the renovated house were 1/6${\sim}$1/16.2. Therefore. it was found that indoor temperature, globe temperature and uniformity ratio of daylight in the ordinary house maintained more constant than the renovated house by green house effect and earning effect of front balcony.

• 대한기계학회논문집A
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• 제40권1호
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• pp.81-86
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• 2016

밸브는 배관의 유량을 차단 및 제어하기 위한 장치로써 게이트 밸브, 글로브 밸브, 체크 밸브 등 많은 종류가 사용되고 있다. 그 중 글로브 밸브는 고압력 조건에서의 유량조절이 용이하여 LNG 선박, 증기 배관 등에 사용된다. 본 논문에서는 글로브 밸브의 누설 문제를 구조적으로 해결하기 위해 시트의 형상을 변형하는 방법을 제시하였다. 또한 유한 요소 해석을 통해 각 모델의 응력분포와 변형량을 비교하고 이를 통하여 제안한 모델에 대한 검증을 진행하였다. 시뮬레이션 결과 제안된 모델에서 원주 방향의 변형이 줄어들고, 누설을 감소시킬 수 있는 Self-supporting 효과를 확인할 수 있었다.

• 한국과학교육학회지
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• 제30권7호
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• pp.901-907
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• 2010

The purpose of this study is to analyze methods for measuring the size of the Earth, put forth in 6 different Korean 8th grade science textbooks. The research questions are as follows: 1) Do they adequately map out the experiments for measuring the size of the earth by using the concept of the sun's altitude? 2) Do they reduce the size of the sun like as the Earth is similarly downsized to the globe? 3) Do they suggest the precise experimental conditions for selecting two equal longitudinal spots for measuring the size of the earth? 4) Do they design adequate experiments for exact measurement? 5) Do they offer a proportional expression for seeking the size of globe which is easily understood by students? 6) Do they develop experiments to measure actual size of the earth? Four graduate students and one researcher took part in this study. All conditions were unanimously agreed upon by the participants. The results are as follows. First, one publishing company must include the concept of the sun's altitude to accurately measure the size of the Earth. However, some textbooks fail to mention this. As such, the concept of the sun's altitude must be introduced to accurately measure the size of the Earth. Second, a reduced size globe is used as the actual earth so; the sun should be factored in with a reduced light value. Third, you have to lay a stress on two points at the same longitude. In other words, a shadow located at the same longitude from two randomly selected points. Most textbooks mention two points at the same longitude but two of them design the experiment with a shadow at the same longitude. Fourth, we need a method to precisely measure the angle between a stick and its shadow. The angle between the stick and the tip of its shadow is the sun's altitude difference. Fifth, we need to present more specific proportional expressions for calculating the size of the globe. Only 3 out of the 6 texts employed a proportional expression. Sixth, we need to calculate the size of the earth by accurately presenting the scale of the globe to attain the goal of the experiment. Two of the texts analyzed, designed the experiment for the purpose of calculating the size of the globe. Three of the texts designed their experiments to calculate the radius of globe which is not even relevant to the purpose of experiment.

• Journal of Advanced Marine Engineering and Technology
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• 제32권1호
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• pp.110-118
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• 2008

It is essential for the valid design of a marine flow-control valve to exactly know its flow characteristics. The present study has numerically investigated the flow characteristics inside a marine throttle-type globe valve using a kind of commercial CFD code, CFX10.0, with an adoption of the SST (Shear-Stress Transport) turbulence model. To validate the numerical approach, the flow coefficients are compared with the experimental ones. Results show that the globe valve is effective in the control of flow rate according to the opening ratio in case of the forward-direction flow, whereas it is effective in the flow shutoff in case of the reverse-direction flow. Around the inlet of the valve, a recirculation region is formed due to the blunt body shape, the turbulence intensity becomes strengthened and then an abrupt pressure loss occurs.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1808-1811
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• 2005

The prediction of AOV(air-operated valve) performance is normally evaluated by the allowable opening thrust margin for the opening and closing stroke. However, it is not easy to carry out the dynamic test measurement for all the valves in the nuclear power plant due to the safety and operating conditions. The analysis of the available and required thrust for the valve is simulated as an alternate method to turn around this obstacle. The required air pressures to the stem displacement are discussed for differential valve pressure obtained by experiment. The result of the simulation is compared with that of the experiment. SIMULINK in MATLAB was used for the simulation and the results show good agreement with the actual test carried out with Fisher globe valve.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.718-723
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• 2017

본 논문에서는 액체로켓에서 추력제어를 위해 주로 사용되는 글로브 제어밸브의 대해 주기적인 저주파 압력섭동에서 유효 단면적에 따라 변하는 임피던스 특성에 관해 해석적 연구를 수행하였다. 유효 단면적에 따라 임피던스가 증가하는 경향을 확인하였으며, 유동장 가시화를 통해 임피던스 특성 변화를 일으키는 원인에 대해 알아보았다. 향후 제어밸브의 임피던스 특성변화의 관한 정보는 공급 시스템의 임피던스를 구하는데 활용될 수 있기 때문에 포고 현상 예측의 활용될 수 있을 뿐만 아니라 포고 현상 감소를 위해 완충기 및 오리피스를 설계할 때도 도움이 될 것이다.

• 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.

• Journal of Astronomy and Space Sciences
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• 제29권2호
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• pp.221-232
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• 2012

We analyzed the manufacturing procedure, specifications, repair history, and details of celestial movements of the water-hammering type $Honsang$ (celestial globe). Results from our study on the remaining $Honsangs$ in China and Japan and on the reconstruction models in Korea were applied to our conceptual design of the water-hammering type $Honsang$. A $Honui$ (armillary sphere) and $Honsang$ using the water-hammering method were manufactured in $Joseon$ in 1435 (the 17th year of King $Sejong$). $Jang$ $Yeong-Sil$ developed the $Honsang$ system based on the water-operation method of $Shui$ $y{\ddot{u}}n$ $i$ $hsiang$ $t'ai$ in China. Water-operation means driving water wheels using a water flow. The most important factor in this type of operation is the precision of the water clock and the control of the water wheel movement. The water-hammering type $Honsang$ in $Joseon$ probably adopted the $Cheonhyeong$ (天衡; oriental escapement device) system of $Shui$ $y{\ddot{u}}n$ $i$ $hsiang$ $t'ai$ in China and the overflow mechanism of $Jagyeongnu$ (striking clepsydra) in $Joseon$, etc. In addition to the $Cheonryun$ system, more gear instruments were needed to stage the rotation of the $Honsang$ globe and the sun's movement. In this study, the water-hammering mechanism is analyzed in the structure of a water clock, a water wheel, the $Cheonhyeong$ system, and the $Giryun$ system, as an organically working operation mechanism. We expect that this study will serve as an essential basis for studies on $Heumgyeonggaknu$, the water-operating astronomical clock, and other astronomical clocks in the middle and latter parts of the $Joseon$ dynasty.