• 대한영양사협회학술지
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• 제12권3호
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• pp.277-288
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• 2006

The purpose of this study was to assess the energy expenditure and investigate the relationship between related variables of 57 dieticians in Youngdong-area. The average daily number of steps was found to be 9358.0$\pm$2714.3 steps/day on weekdays and 7862.9$\pm$2504.9 steps/day during weekends. Hourly step rates on weekdays and weekends came to 570.6$\pm$249.8 steps/hr and 564.0$\pm$224.8 steps/hr, respectively. Activity coefficient of subjects was higher on weekdays (1.56) than weekends (1.51, p<0.05). Resting energy expenditure estimated by the Harris-Benedict formula, WHO/NAO/FAO formula as well as formulas based on body surface area and DRIs (Dietary Reference Intake for Koreans) were calculated to be 1333.7$\pm$89.5kcal/day, 1351.0$\pm$123.3kcal/day, 1388.5$\pm$100.3kcal/day and 1295.9$\pm$90.8kcal/day, respectively. Using these resting energy expenditures and the activity coefficients, daily energy expenditures were calculated to be from 2039.7kcal/day to 2183.5kcal/day on weekdays and from 2016.1kcal/day to 2159.2kcal/day on weekends. Meanwhile energy intakes of subjects on weekdays and weekends were 1594.7$\pm$698.3kcal and 2152.9$\pm$768.0kcal, respectively. The activity coefficient (1.49) of dieticians who managed less than 500 meals per day was significantly lower than that of dieticians who served more than 500 meals per day. Dieticians of schools located in rural areas had higher activity coefficient (1.59) than those of schools located in urban or island settings. These results suggest that work analysis and development of management strategies are necessary to improve dieticians' productivity.

• Earthquakes and Structures
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• 제12권2호
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• pp.153-163
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• 2017

The underlying goal of the present paper is to investigate soil and structural uncertainties on impedance functions and structural response of soil-shallow foundation-structure (SSFS) system using Monte Carlo simulations. The impedance functions of a rigid massless circular foundation resting on the surface of a random soil layer underlain by a homogeneous half-space are obtained using 1-D wave propagation in cones with reflection and refraction occurring at the layer-basement interface and free surface. Firstly, two distribution functions (lognormal and gamma) were used to generate random numbers of soil parameters (layer's thickness and shear wave velocity) for both horizontal and rocking modes of vibration with coefficients of variation ranging between 5 and 20%, for each distribution and each parameter. Secondly, the influence of uncertainties of soil parameters (layer's thickness, and shear wave velocity), as well as structural parameters (height of the superstructure, and radius of the foundation) on the response of the coupled system using lognormal distribution was investigated. This study illustrated that uncertainties on soil and structure properties, especially shear wave velocity and thickness of the layer, height of the structure and the foundation radius significantly affect the impedance functions, and in same time the response of the coupled system.

• 한국지진공학회논문집
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• 제2권1호
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• pp.23-34
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• 1998

연약한 지반위에 기초한 유연한 구형 액체 저장탱크의 Rocking 운동에 대한 3차원 지진응답을 규명하기 위해서 동적 유체-구조 물-지반 계의 상호작용 해석방법을 개발하였다. 수평방향 병진 운동과 Rocking 운동을 받는 3차원의 구형 탱크의 운동 지배방정식을 Rayleigh-Ritz 방법을 적용하여 유도하였고 기반암위 토층의 표면에 놓인 강체 기초의 동적 강성행렬과 유체-구조물 계의 지배방정식을 결합하여 계산하였다.

• 한국식품영양과학회지
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• 제34권2호
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• pp.196-201
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• 2005

본 연구에서는 실측 휴식대사량과 신장, 체중, 성별, 나이, 제지방 등을 적용한 예측 기초대사량 공식 3가지를 비교하여 어느 예측 공식 이 우리 나라의 젊은 여성들에게 적합한지를 알아보았고, 실측 휴식대사량과 신장, 체중, 체표면적, 체질량지수, 제지방량, 체지방량 및 체지방율과의 상관관계를 분석하고, 예측 공식을 유도하였다. 20∼24세의 건강한 여대생 120명을 연구 대상으로 12시간 금식한 후 30분간 산소섭취량과 이산화탄소 생성량을 측정하여 실측 휴식대사량을 구하였고, 체성분분석은 생체전기저항법(Bioelectrical impedence analysis)으로 측정하였으며, 예측 기초대사량은 Harris-Benedict 공식 , WHO/FhO/UNU 공식 과 Cunnin gham 공식을 이용하였다. 실험 결과 실측 휴식대사량은 1257.3$\pm$147.9 kcal/day이었으며, 성별에 따라 신장, 체중과 나이를 적용한 Harris-Benedict 공식으로 구한 예측 기초대사량은 실측 휴식 대사량보다 116.04$\pm$122.8 kcal/day 높게 나타났으며, WHO/FAO/UNU 공식은 32.7$\pm$115.6 kcal/day 높게, Cunningham 공식은 69.7$\pm$116.2 kcal/day 낮게 나타났으며, 상관분석을 통하여 제지방량을 적용하여 기초대사량을 계산하는 Cunningham 공식이 실측 휴식대사량과 가장 밀접한 관계를 보였다. 실측 휴식 대사량에 영향을 주는 요인들로 제지방, 체표면적과 체중이 순서대로 상관관계가 높게 나타났고, 그 외 신장, 체질량지수, 체지 방량과 체지방율은 기초대사량과의 연관성이 낮은 것으로 조사되었다. 기초대사량과 관련하여 분석한 요인들 가운데 상관성이 가장 높은 제지방량(FFM)을 독립변수로 하고 측정한 기초대사량을 종속변수로 하여 회귀 분석한 결과 RMR=-569.86+48.27(FFM), $R^2$=0.5514로 나타났다.

• Structural Engineering and Mechanics
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• 제65권4호
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• pp.465-476
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• 2018

This article investigates buckling behavior of a multi-phase nanocrystalline nanobeam resting on Winkler-Pasternak foundation in the framework of nonlocal couple stress elasticity and a higher order refined beam model. In this model, the essential measures to describe the real material structure of nanocrystalline nanobeams and the size effects were incorporated. This non-classical nanobeam model contains couple stress effect to capture grains micro-rotations. Moreover, the nonlocal elasticity theory is employed to study the nonlocal and long-range interactions between the particles. The present model can degenerate into the classical model if the nonlocal parameter, and couple stress effects are omitted. Hamilton's principle is employed to derive the governing equations and the related boundary conditions which are solved applying an analytical approach. The buckling loads are compared with those of nonlocal couple stress-based beams. It is showed that buckling loads of a nanocrystalline nanobeam depend on the grain size, grain rotations, porosities, interface, elastic foundation, shear deformation, surface effect, nonlocality and boundary conditions.

• 한국수산과학회지
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• 제29권6호
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• pp.837-842
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• 1996

The resting cyst of Gymnodinium catenatum was found in the surface sediments collected from Chinhae Bay in October, 1991. This is the first record of the species in the Korean waters. The relative abundance was low with the maximum of $1.7\%$. The colonial motile form consisting of four cells was observed in 1992 from the excystment of the cyst collected from the Wonmun Bay in Chinhae Bay. No blooms caused by G. catenatum has been observed in Chinhae Bay during the survey.

• International Journal of Precision Engineering and Manufacturing
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• 제9권2호
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• pp.3-7
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• 2008

Vibratory conveyors are widely used in industry to transport granular materials and products. A theoretical point mass model for vibratory conveying was studied. The results agreed well with experimental observations. The model theory included the resting, sliding and flight states of the material. Each state was considered separately when determining the equations of motion. For the coefficients of restitution, values of zero for the normal component and 0.8 for the tangential component were found to be appropriate for modeling the collisions of the granular particles with the conveying surface. The vibration angle had a large influence on the mode and rate of transport. There was an optimum vibration angle for a given set of conditions. The optimum vibration angle decreased and was better defined as the coefficient of friction increased. The results suggest the existence of an optimum dimensionless track acceleration (throw number), which does not support general industrial practice in which the track acceleration is limited when the feed cycle becomes erratic and unstable.

• Journal of Chest Surgery
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• 제18권4호
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• pp.663-666
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• 1985

Whatever a surgeon choose aortic prosthesis in aortic stenosis, it will always provoke some degree of obstruction to flow due to its smaller effective orifice area to tissue annulus. Occasionally, we meet small aortic annulus to his or her body surface area in aortic valve replacement. The small annulus remains a problem in that both tissue and mechanical prosthesis have significant pressure gradients between LV and aorta in resting or exercising states. In these circumstances, diverse surgical procedures, such as tilting disc prosthesis, supraannular position of aortic prosthesis, and enlargement of aortic root [including aortoventriculoplasty, translocation of aortic valve, & double outlet of LV by valved conduit], were applied. We experienced one case of aortic stenosis with small aortic annulus. Systolic pressure gradients between LV & aorta were 90 mmHg. Diameter of annulus was 19 mm. So we performed patch enlargement of aortic root by Manouguian and AVR with St. Jude medical valve 23 mm.

• 비파괴검사학회지
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• 제26권1호
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• pp.7-11
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• 2006

기계부품의 세라믹 코팅 층은 사용 중 그 표면특성이 변하므로 잔류수명 예측과 신뢰성 확보를 위해 비파괴적으로 세라믹 코팅 층의 특성을 평가하는 것은 매우 중요하다. 이를 위해 본 인구는 AISI 1045 강과 오스테나이트 스테인리스 304 강 모재위에 매우 얇은 TiN 세라믹 층을 코팅한 시편에 내하여 누설 레일리(Rayleigh) 표면파를 이용한 TiN 코팅부재의 특성평가를 시도하였다. 후방복사 측정기법으로 코팅 층 내의 표면파의 전파특성이 평가되었고 표면 거칠기, 코팅 층 두께, 마모조긴 둥이 다양한 시편들에 대해 후방복사 프로파일이 측정되었다. 후방복사 프로파일의 정점각과 크기는 시편의 조건들에 따라 민감하게 변하였고, 정점각의 증가는 코팅 층 접합 강도의 저하로 설명되었다. 결과들은 후방복사 기법을 이용한 표면파의 분산성 평가가 코팅 층의 특성 평가에 매우 유용함을 보여주었다.

• Progress in Superconductivity
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• 제10권1호
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• pp.1-5
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• 2008

Magnetocardiography (MCG) is a non-contact, non-invasive, and harmless diagnostic tool to detect the abnormal electrical conductivities of the heart caused by the various coronary artery disease or cardiac muscular disease. The purpose of this study is to identify whether MCG signals and MCG parameter values vary depending on the location of sensor assembly. It will be an important reference for the standard measurement. Four healthy male subjects (33.3$\pm$6.3 years) participated in this study. Basal recording was made at 20 mm apart from the chest surface. All subjects were requested to take a regular breathe while MCG was taken. The gap between the chest surface and the bottom of the sensor assembly was 20, 40, 60, and 80 mm. Recording was made using 64 channel MCG system (Axial type, first order gradiometer) developed by Korea Research Institute of Standards and Science (KRISS). After resting for two minutes in a supine position on the bed in magnetically shielded room, MCG were recorded for 30 s. As the sensor location is getting away from the chest surface signal, the amplitude of R and T wave peak decreases to 70% (at 40 mm gap), 50% (at 60 mm), and 37% (at 80 mm) of the reference strength measured (y = $1.3903e^{-0.0169x}$, $R^2$ = 0.99; where y=amplitude remained after reduction, x=distance between chest surface and sensor location). The regression equations may be used as a good reference to calculate how much strength will be decreased by the distance. In MCG parameters, most values of parameters were decreased as the gap was increased. As an example, the current moment at T-wave peak reduced to 52% (at 40 mm gap), 33% (at 60 mm), and 19% (at 80 mm). However, the difference caused by the gap could be reduced by considering the distance when the MCG parameters were calculated. The study results can be used as a useful reference to design the baseline and the sensor location.