• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.524-529
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• 1998

Analogous problem for a gear dynamics where helical gears excite logitudinal forces in the shaft is studied. These shaft forces excite the supporting gear housing through bearing, causing structural vibration. In this study, shaft is modeled as a rod, and bearing is modeled by a massless spring. A simple model for gear housing is a clamped circular plate. To model this force transmission, the transfer functions from the shaft to a clamped circular plate are analytically derived by using the spectral method and four-pole parameter. Finally, radiated noise is computed, using the acoustic relations due to plate surface vibration.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1300-1303
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• 1996

In this paper a typical problem is examined that a light, general aviation airplane, such as Cessna or Navion, in gliding turn flight shows helical-dive phenomenon when pilots try to stop the descent by using elevator only. It is known from pilot's experience that in a certain flight trim it is impossible to recover from helical-dive by using elevator only. From this study it is shown that helical-dive phenomenon is involved with longitudinal/lateral dynamics coupling to airplane's aerodynamics. Also this phenomenon consists of three parts of flight dynamics; first of all, fast longitudinal motion occurs, then is followed by a little slow lateral motion, and finally logitudinal/lateral coupled motion is fully developed.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1521-1527
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• 2009

This study is aimed to analyze the floe patterns and thermal characteristics by computer simulation under the variations of fire strength for the logitudinal tunnel, from which flow and heat distributions are predicted in the longitudinal tunnel. Through the results of numerical computations, followings are found; one is that the volume flow rate is discontinuously increasing as closer to fire location, and the other is that a critical design to get the faster flow rate is required because of existence of backlayer flow for the high fire strength in view of safety for the people in fire of the tunnel.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 가을 학술발표회 논문집
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• pp.57-62
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• 1990

This paper is to study the effect of rectilinear confinement in high-strength concrete subjected to a monotonically increasing compressive axial loads. To investigate behavior of columns rectilinearly confined with lateral ties and longitudinal rebars, twelve specimens including two plain concrete specimens were tested. The main variables in this study are volumetric ratio of lateral ties, cistribution of lateral ties, yield strength of logitudinal steel, ratio of area of longitudinal steel to the area of cross section. The test results were not only compared with an empirical model for the stress-strain curve of rectilinearly confined high-strength concrete but also the existing model. The empirical model used calculating column capacity shows better agreement with the test results tham the existing model.

• Journal of Nutrition and Health
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• 제26권9호
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• pp.1098-1109
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• 1993

The purpose of this study was to investigate macro-mineral contents in human milk longitudinally from 2 days to 12 weeks postpartum. Milk samples were collected from 34 healthy lactating women. Calcium, Phosphorus, magnesium, sodium and potassium were analyzed. Concentrations of the minerals except for magnesium differed significantly within the lactation period. The levels of sodium and potassium declined linearly over the first 12 weeks of lactation, but that of phosphorus increased. Statistically significant quadratic trends were observed in phosphorus and sodium concentrations. There was no significant correlation between maternal age and mineral concentrations throughout the lactations period. In addition, no significant differences were found between the primipara and the multipara for mineral concentrations in human milk. Mineral intake of lactating women did not affect the individual mineral concentrations of milk. However, the protein and fat intake of lactating women had a significant correlation with sodium and potassium concentrations. The following four pairs of minerals : potassium and calcium, potassium and phosphorus, sodium and magnesium, and calcium and phosphorus showed a positive correlation with each other in human milk.

• 소음진동
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• 제8권5호
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• pp.908-913
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• 1998

Analogous problem for a gear dynamics where helical gears excite logitudinal forces in the shaft is studied. These shaft forces excite the supporting gear housing through bearing, causing structural vibration. In this study, shaft is modeled as a rod, and bearing is modeled by a massless spring. A simple model for gear housing is a clamped circular plate. To model this force transmission, the transfer functions from the shaft to a clamped circular plate are analytically derived by using the spectral method and four-pole parameter. Finally, radiated noise is computed, using the acoustic relations due to plate surface vibration.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2001년도 제23회 KOSCO SYMPOSIUM 논문집
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• pp.111-118
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• 2001

Many previous researches on the premixed flame in a tube have treated the unsteady flame behaviors but more detailed and fundamental research has been necessary. The study on the flame stabilization condition in a tube and the unsteady behaviors were carried out in recent years. In this paper, a mean velocity variation larger than the burning velocity was introduced to the stabilized flame for a period longer than the reaction time scale in order to examine the unsteady behavior of flame propagation. Through our previous work it was found that the effects of non-unity Lewis number on the flame extinction was negligible in the extinction by the boundary layer even though they were important in the extinction by the acoustic instability. In this paper we carried out an analytic approach to explain the previous experimental results. It showed that the heat loss, from a flame to the wall, is not a sufficient condition but a required one for the growth of the extinction boundary layer. In addition, the quenching and the flame stretch, under a strong unsteady flow field, are the main causes of the eventual extinction.

• 한국농촌건축학회논문집
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• 제12권1호
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• pp.49-56
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• 2010

This paper is aimed to clarify field technique of non-educated constructors in timber structure of korean-style secondary station(Gong-So) on the annex of catholic church. The main object of this study is Sin-Sung and Su-Bun secondary stations which post-lintel structure was 2high columns(Go-Ju) 5beams(Ryang) in Jeon-Buk area of Korea. We reached the following conclusion. Firstly, these secondary stations are required a lots of space for number of persons with the introduction of basilica plane. These plans have different intervals in the layout. Secondly, they constructed the holy space by using high columns(Nae-Jin-Go-Ju). The former problems of plan layout are sloved by reinforcement and replacement eaves and rafter of logitudinal. Thirdly, the elements showed the natural feature such as irregular wooden floor, arch-type head pentrating tie and a ceiling. In the end, we knew that non-educated constructor had found a way in the problem for accepting unreasonable work.

• 한국콘텐츠학회논문지
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• 제15권8호
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• pp.226-235
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• 2015

본 연구는 사회적 배제가 중고령 장애인의 빈곤에 미치는 영향을 파악하고자 소득, 노동, 건강, 주거, 교육, 사회참여의 6가지 사회적 배제요인을 연구모형에 포함하여 이 요인들이 빈곤에 미치는 영향을 분석하였다. 또한 지역별 특성을 파악하기 위해 도시와 농어촌 거주 중고령 장애인의 사회적 배제 및 빈곤 실태를 비교 분석하였다. 이를 위해 고령화연구패널 4차년도 자료에서 45세 이상 중고령 장애인 640명을 추출하여 로지스틱 회귀분석을 실시하였다. 연구 결과, 사회적 배제요인 중 노동, 주거, 교육이 중고령 장애인의 빈곤에 유의한 영향을 주었다. 지역별로 살펴보면, 도시 지역의 경우, 나이가 적고, 배우자가 없으며, 일을 하지 않고, 집을 소유하지 않은 중고령 장애인이 빈곤에 처할 확률이 높았다. 농촌 지역에 거주하는 중고령 장애인은 나이가 적고, 배우자가 없는 경우 빈곤할 확률이 높았다. 이러한 연구결과를 토대로 중고령 장애인의 사회적 배제 및 빈곤 감소를 위한 정책적 함의를 제시하였다.

• 한국산학기술학회논문지
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• 제22권4호
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• pp.167-174
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• 2021

본 연구는 자유학기제의 참여가 학교생활만족감과 수업흥미에 미치는 효과에 대해서 알아보고 그 효과가 종단적으로 지속되는지 알아보기 위하여 수행되었다. 연구 대상자는 대도시에 거주 중인 중학생으로서 자유학기제에 참여한 실험집단 451명과 자유학기제에 미참여한 통제집단 466명으로 자유학기제가 종료된 이후 매 년 3차년도까지 자료를 수집·분석하였다. 학교생활만족감의 분석 결과, 자유학기제 참여한 실험집단이 참여하지 않은 통제집단보다 통계적으로 유의하게 높았으며 이 경향은 2차년도까지 지속되었지만 3차년도에는 그 차이가 나타나지 않았다. 수업 흥미 중 주지교과 수업의 분석 결과, 3년 간 실험집단과 통제집단 간의 유의미한 차이가 없었다. 예체능 수업 흥미에 대한 분석 결과, 자유학기제 시행집단이 미 시행집단 보다 1차년도, 2차년도에는 통계적으로 유의하게 높았으나 3차년도에는 유의미한 차이가 없었다. 이러한 연구결과는 자유학기제의 지속적 효과를 위하여 단기적 운영에서 벗어나 장기적이고 체계적인 제도 마련과 운영이 필요함을 시사한다.