• 복식문화연구
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• 제30권5호
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• pp.675-688
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• 2022

The purpose of this study is to analyze the body type characteristics of tall adult men aged 20 to 69 years to present base material on body dimensions for men's clothing companies. The research method comprised statistical analysis of 3D measurements after selecting items from the 8th Korean human body size survey related to the torso body types of 495 adult men who were at least 178cm tall. As a result, six factors were extracted, and the total explanatory variable of the entire factor was shown to be 80.499%. As a result of cluster analysis using this as an independent variable, three types were derived: Type 1, "a normal body type with an oval cross-sectional shape" (37.6%), with a larger vertical size and an oval chest cross-sectional shape compared to other types; Type 2: a "cylindrical thick body shape" (31.1%), which is the first stage of BMI obesity, with narrow shoulders and a cylindrical shape with a round cross-section; Type 3, "a body shape with broad shoulders and developed chest parts" (31.3%), with a horizontal size similar to Type 2 above the waist, but similar to Type 1 below. The results of this study are expected to be used as a basis for a clothing dimension system and clothing development for tall men reflecting the characteristics of the torso.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.709-713
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• 2004

Characteristics of laser-assisted wet etching of titanium in phosphoric acid were investigated to examine the feasibility of this method for fabrication of high aspect ratio microchannels. Laser power, number of scans, etchant concentration, position of beam waist and scanning speed were taken into consideration as the major process parameters exerting the temperature distribution and the cross sectional profile of etched channels. Experimental results indicated that laser power influences on both etch width and depth while number of scans and scanning speed mainly affect on the etch depth. At a low etchant concentration, the cross sectional profile of an etched channel becomes a U-shape but it gradually turns into a V-shape as the concentration increases. On the other hand, surface of the laser beam focus with respect to the sample surface is found to be a key factor determining the bubble dynamics and thus the process stability. It is demonstrated that metallic microchannels with different cross sectional profiles can be fabricated by properly controlling the process parameters. Microchannels of aspect ratio up to 8 with the width and depth ranges of 8∼32 m and 50∼300 m, respectively, were fabricated.

• Steel and Composite Structures
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• 제35권3호
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• pp.371-384
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• 2020

The steel-concrete double composite girder in the negative flexural region combines an additional concrete slab to the steel bottom flange to prevent the local steel buckling, however, the additional concrete slab may lower down the neutral axis of the composite section, which is a sensitive factor to the tensile stress restraint on the concrete deck. This is actually of great importance to the structural rationality and durability, but has not been investigated in detail yet. In this case, a series of 5.5 m-long composite girder specimens were tested by negative bending, among which the bottom slab configuration and the longitudinal reinforcement ratio in the concrete deck were the parameters. Furthermore, an analytical study concerning about the influence of bottom concrete slab thickness on the cracking and sectional bending-carrying capacity were carried out. The test results showed that the additional concrete at the bottom improved the composite sectional bending stiffness and bending-carrying capacity, whereas its effect on the concrete crack distribution was not obvious. According to the analytical study, the additional concrete slab at the bottom with an equivalent thickness to the concrete deck slab may provide the best contributions to the improvements of crack initiation bending moment and the sectional bending-carrying capacity. This can be applied for the design practice.

• 대한조선학회지
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• 제25권4호
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• pp.28-38
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• 1988

본 논문은 선박저항 추정을 위한 통계해석 방법을 기술하고 있다. 조파저항계수 추정식은 조파저항이론을 이용하여 선체주요치수와 횡단면적계수들로부터 유도하였으며, 그 회귀계수들은 저항시험 결과들을 회귀 분석하여 얻었다. 형상영향계수 추정식은 선체주요지수, 횡단면적와 저항시험결과들로부터 순수하게 회귀분석하여 얻었다. 또한 선체주요지수는 바꾸지 않고 횡단면적곡선만을 변화시켜 조파저항을 최소로 해주는 방법을 제시하였다. 이 방법들은 산적화물선의 저항성능 추정에 적용하였다. 그리고 조파저항이 최소가 되는 수정선형을 도출해 냈으며, 이로인한 유효동력의 절감효과를 저항시험을 통해 확인하였다.

• 설비공학논문집
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• 제9권4호
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• pp.561-571
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• 1997

In this paper, the fundamental equations are developed for the pulsatile laminar flow generated by changing the oscillatory flow with $0{\leq}f{\leq}48Hz$ into a steady one with $0{\leq}Re{\leq}2500$ in a rigid circular pipe. Analytical solutions for the wave propagation factor k, the axial distributions of cross-sectional mean velocity $u_m$ and pressure p are schematically derived and confirmed experimentally. The axial distributions of centerline velocity and pressure were measured by using Pitot-static tubes and strain gauge type pressure transducers, respectively. The cross-sectional mean velocity was calculated from the centerline velocity by applying the parabolic distribution of the laminar flow and it was confirmed by using the ultrasonic flowmeter. It was found that the axial distributions of cross-sectional mean velocity and pressure agree well with theoretical ones and depend only on the Reynolds number Re and angular velocity $\omega$.

• 아태비즈니스연구
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• 제11권4호
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• pp.243-254
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• 2020

Purpose - This paper explores whether overnight returns measured from the last closing price to today's opening price explain the cross-section of stock returns. Design/methodology/approach - This study is conducted using the Korean stock market data from 1998 to 2018, obtained from DataGuide database. The analysis begins with portfolio-level tests, followed by firm-level cross-sectional regressions. Findings - First, when decile portfolios sorted on the daily average of overnight returns in the previous months, the highest decile portfolio exhibits a significant negative risk-adjusted return. This suggests that stocks with higher average overnight returns are temporarily overvalued due to buying pressure from investors. Second, at least 6 months of persistence exists in average overnight returns, which is in line with the results reported by Barber, Odean and Zhu (2009) that investor sentiment persists over several weeks. Finally, Fama-MacBeth cross-sectional regression of expected returns after controlling for a variety of firm characteristic variables such as firm size, book-to-market ratio, market beta, momentum, liquidity, short-term reversal, the slope coefficient for overnight returns remains negative and statistically significant. Research implications or Originality - Overall, the evidence consistently suggests that overnight return is considered as a new priced factor in the cross-section of expected returns. The findings of this paper not only adds to finance literature, but also could be useful to practitioners in making stock investment decision.

• 보건교육건강증진학회지
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• 제21권4호
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• pp.1-13
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• 2004

This study conducted descriptive literature review on adolescent smoking and the related factors to realize significance of adolescent smoking onset in Korea and to identify risk factors of smoking incidence. Korean adolescent smoking status was generated based on the cumulated data of the Korean Association of Smoking and Health. Risk factors of adolescent smoking were identified based on 18 studies written in English, with cross-sectional research design and published as a peer-reviewed journal article between 1994 and 2003. The results were as follows. 1. Korean adolescent smoking rate was the highest among OECD affiliated countries; in particular, male adolescent smoking incidence was very serious. 2. Risk factors related to smoking of adolescent population were personal factor, friend factor, family factor, and mass-media factor. Demographic characteristics, attitudes on smoking, and willingness of smoking, and health behaviors were selected as personal factor of smoking. 3. Best friends smoking was a strong factor of students' smoking set. Prevalent popularity of smoking in peer-group allowed students to feel free to smoking. 4. Concerning family factor related to smoking status, parents' smoking and sibling's smoking were significant indicators of adolescent smoking status. 5. Seeing smoking behaviors and scenes through films, TV shows, drama, and advertisement was a significant risk factor of adolescent smoking status.

• 아태비즈니스연구
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• 제12권1호
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• pp.121-134
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• 2021

Purpose - This study examines whether flight-to-liquidity (FTL) explains the dynamic liquidity risk on stock returns, and whether it has a significant influence on determinants the cross-section of stock returns. Design/methodology/approach - This study suggests a new risk factor, dynamic liquidity hedge portfolio (DLP), to reflect the dynamic impact of liquidity risk on stock returns and the Fama-MacBeth 2 stage regression analysis is employed in order to analyze the data. Findings - First, the DLP factor shows more positive and significant beta for the small or illiquidity stocks. Second, the DLP shows a different influence than SMB (size risk factor), HML (value risk factor), NMP (liquidity risk factor), FTVOL (total volatility factor) in determining the cross-section of stock returns. In addition, the DLP has a statistically significant risk premium of around 5%, which is relatively larger than other risk factors. Research implications or Originality - This study has academic value in terms of newly confirming that the DLP factor has a more significant impact on cross-sectional determination of stock returns than other risk factors by proposing a conditional liquidity factor that can explain the FTL phenomenon.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 봄 학술발표회논문집
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• pp.92-99
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• 2000

The nondimensional differential equations governing the buckling loads of tapered columns with both clamped ends and its boundary conditions are derived, in which the effects of shear deformations are included. These equations are solved numerically using a numerical integration technique and a bracketing method to obtain the buckling loads of columns. Four types of cross-sectional shape are considered in the numerical examples. The parametric studies of shear deformation effects on the buckling loads such as cross-sectional shape factor, shear coefficient, ratio of modulus of elasticity, slenderness ratio and section ratio are reported in tables and figures.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.809-812
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• 1999

This research analyzed the factors for crack generation and proposed the recommended construction methods for the efficient crack control of underground RC box structures under the roadway. The selected main factors were: details of contraction joints, ratio of crack control rebars in longitudinla direction, and placement of flyash concrete. These factors were tested on the actual structures and the significance of each factor was analyzed, The results show that the flyash concrete placement and the inducting minor cracks in a certain direction by adopting contraction joints are practical and efficient methods to control cracks. The significance of crack generating factors increases as the sectional loss of contraction joint spacing increase. It was recommeded that the sectional loss should be higher than 20 percent to maximize the crack generating effects. It was not possible to verify the effect of crack control rebar spacing, but it was estimated that the ratio of crack control rebar should be increased to minimize cracks.