• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.394-399
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• 2005

A case history is presented pertaining to high frequency piping vibration and noise caused by globe valve in the spent fuel pool cooling system of nuclear power plant. Frequency analyses were performed on the system to diagnose the problem and develop a solution to reduce the piping vibration and noise. The source of the high frequency and noise energy was traced to the globe valve located immediately downstream of the centrifugal pump by performing valve throttling test. Measurements of vibration and noise are presented to show that the high frequency vibration and noise amplitude was dependent upon the valve disc position and flow rate. Strouhal vortex shedding frequencies were generated at the exit of the globe valve which exited structural resonance of valve disc and amplified the high frequency vibration and noise. The problem was identified as an interaction between the flow inside globe valve and the valve disc structure. Attempts to reduce the vibration and noise amplitudes of the piping system were successfully achieved by the modification of guide-disc diameter and disc-edge figure The valve disc was replaced by an alternative to eliminate the source of the harmful high frequency vibration and noise.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2004년도 추계 학술대회논문집
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• pp.29-32
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• 2004

A three dimensional numerical analysis and experimental measurements were made for incompressible flows in a globe valve with three different types of plug. Characteristics of pressure drop across the valve were investigated for each type of plug at various opening positions. Numerical simulation results show a good agreement with experimental data.

• Journal of Advanced Marine Engineering and Technology
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• 제31권8호
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• pp.1013-1019
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• 2007

This paper is about structural analysis of globe valve for controlling cryogenic LNG's flow or stop in normal temperature. The used valve is demanded safety resistance for inner pressure and temperature variation caused by using it in cryogenic, high pressure surrounding. This study evaluates for safety resistance for inner pressure and temperature variation by heat transfer analysis in cryogenic surrounding, heat stress analysis in temperature variation and deformation analysis in high pressure.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.106.2-106.2
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• 2005

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.109.2-109.2
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• 2005

• 한국태양에너지학회 논문집
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• 제31권3호
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• pp.8-16
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• 2011

The objective of this study is to analyze the characteristic of thermal environment in the summer season by conducting the field observation of temperature, relative humidity, and globe temperature in some parts of the city. Observation point was divided to a densely populated area, a residential area, a green area, a waterfront green area and a suburban district by the distribution ratio of green area. In this study, the correlation between maximum temperature and globe temperature, study on index for intensity of the tropical night and the temperature distribution characteristic of measurement points by the distribution ratio of green area were analyzed. The results of this study are as follows. (1) The difference between temperature and globe temperature by the distribution ratio of green area is confirmed. The difference of nighttime is more clearly that of daytime. (2) The average temperature and globe temperature of the densely populated area($29.2^{\circ}C$, $33.7^{\circ}C$) are higher than that of the waterfront green area($27.9^{\circ}C$, $32.0^{\circ}C$) by $1.3^{\circ}C$ and $1.7^{\circ}C$, respectively. (3) The number of tropical nights has different days of tropical nights by the distribution ratio of green area of 17days for the Daegu weather station, 14days for adensely populated area, 14days for a residential area, 6days for a green area, 2days for a waterfront green area, and 2days for a suburban district. (4) The results of the slope of trend line for the effects of the temperature on globe temperature change and the intercept for the size of the impact of radiant energy gained around by the analysis of the correlation between the maximum temperature and globe temperature can be utilized objective evaluation index of the each point's artificial effects.

• 한국태양에너지학회 논문집
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• 제29권6호
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• pp.94-101
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• 2009

This study which is the fundamental work to investigate the property of urban climate compared the property of thermal environment in the downtown location and the outskirt site based on the field observation in the summer. We analysed thermal environment in the downtown location mainly by distributional characteristics during day and night with changes and correlation analysis of the air temperature, the globe temperature and the surface temperature through the simultaneous observation of the property of thermal environment at two places in real time. The summary of finding in this study is as follows. (1)It is observed on the day chosen by sample that diurnal air temperature range in the downtown location is $22.3{\sim}34.9^{\circ}C$, and diurnal air temperature range in the Outskirt site is $20.0{\sim}34.3^{\circ}C$, so, we found that the diurnal air temperature range in the outskirt site is $1.7^{\circ}C$ higher than in the downtown location. (2)In comparison of the globe temperature after sunset, we found the change of more sudden temperature drops in the outskirt site than in the downtown location. (3)It is observed on the days chosen by sample that the average of globe temperature range is $1.1^{\circ}C$, the average of surface temperature range is $1.0^{\circ}C$, and air temperature range is $2.0^{\circ}C$, thus, the we found that the average of air temperature is $1.0^{\circ}C$ higher than globe temperature and the surface temperature. (4)After the consideration of air temperature and globe temperature distribution, the highest temperature reaching time of globe temperature is one hour earlier than air temperature in the downtown location, on the other hand, although the highest temperature reaching time of globe temperature in the outskirt sites is one hour later than in the downtown location, the timelag found in the downtown location was not found in the outskirt site.

• 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.

• 대한안과학회지
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• 제59권11호
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• pp.1062-1070
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• 2018

목적: 소아청소년 환자에서 발생한 개방안구손상의 임상 양상을 분석하여 최종시력을 예측할 수 있는 인자를 알아보고, 최종시력을 예측하는 방법으로 안외상 점수(ocular trauma score, OTS)와 소아 안외상 점수(penetrating ocular trauma score, POTS)를 평가해 보고자 한다. 대상과 방법: 1993년 5월부터 2014년 4월까지 개방안구손상으로 본원에 내원한 18세 이하 소아청소년 환자 77명을 대상으로 의무기록을 후향적으로 분석하였다. 최종시력에 영향을 미칠 수 있는 인자들을 조사하였고, 최종시력을 예측하는 방법으로 OTS와 POTS를 receiver operating characteristic 곡선을 이용하여 평가해 보았다. 결과: 단변량 분석에서 20/200 미만의 초기시력, 안구파열, 7.0 mm 이상의 손상 크기, 망막박리, 수정체이탈, 총 수술 횟수는 불량한 최종시력(<20/200)과 유의한 관련성이 있었다. 반면에 20/32 이상의 좋은 최종시력의 경우 각막중심 침범 유무, 외상백내장 유무, 7.0 mm 미만의 손상 크기, 20/200 이상의 초기시력과 관련성이 있었다. OTS와 POTS 모두 최종시력을 예측하는 방법으로 진단적 가치가 있었으며, 통계적으로 두 점수 체계에 유의한 차이는 없었다. 결론: 소아청소년에게 발생한 개방안구손상에서 초기시력과 안구손상 크기는 최종시력에 영향을 주는 중요한 예측인자이다. 소아청소년 개방안구손상 환자의 최종시력 예측에 있어 기존의 안외상 점수(OTS)뿐만 아니라 소아 안외상 점수(POTS) 또한 좋은 예측도를 보여주어 둘 모두 유용한 평가 방법으로 생각된다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권4호
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• pp.373-378
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• 1998

In the midfacial fracture, the orbital region presents many additional complication unique to the orbit. Among them are ectropion, entropion, lid ptosis, injury to the lacrimal apparatus, diplopia or the late development of enophthalmos. The residual problem confronting the surgen is usually enophthalmos or diplopia. Enophthalmos becomes cosmetically obvious at 3mm and if more severe it can interfere with vision from obstruction by the orbital rim. In this clinical situation, many patients prefer the simpler intraorbital volume expansion to the more complex orbital osteotomy. In general, except in mild cases of enophthalmos, the procedure of choice is osteotomy and repositioning for zygoma fracture and volume augmentation for blow-out fracture. Late treatment is performed by volume augmentation based on the CT findings behind the axis of the globe. Inferiorly placed grafts elevate the globe, posterior superior grafts move the globe anterior and medially positioned grafts push the globe laterally. In this two cases, the patients who has stable orbitozygomatic rim, the use of calvarial bone grafts more than 3 areas around intraorbital content, we corrected late enophthalmos combined with diplopia. As result, the first patient had 2mm advance in exophthalmometric check with improvement of the diplopia gradually. The second patient had 1.5mm advance with correction of vertical ocular dystopia and cosmetically good results respectively.