• 한국안전학회지
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• 제32권4호
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• pp.66-72
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• 2017

Recently, the use of high-strength concrete is increasing due to the trend of constructing high-rise and long span structures. The benefit of using the high-strength concrete is that it increases the durability and strength while it reduces the cross-sectional area of the bridge deck slabs. Moreover, it offers more safety as these bridge deck slabs applying high-strength requires strict structural performance verification. In this study, the fatigue performance of the bridge deck slabs applying 80 MPa high-strength concrete was verified through various experiments. The experimental results showed that the specimens satisfy the conditions of flexural strength, punching shear strength, deflection and cracking. In conclusion, the bridge deck slabs designed by 80 MPa high-strength concrete are enough safe despite of its low thickness.

• 대한가정학회지
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• 제44권3호
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• pp.51-59
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• 2006

The purpose of this study is to determine the relevant variables of parent-leadership that influence family strength based on the transformational leadership and transactional leadership proposed by Bernard M. Bass and to investigate the primary impact of leadership on the subordinate's job satisfaction and job involvement to his/her supervisor. Therefore, this study will provide implications for the family through a diagnosis of the effect by leadership. The results of this research are as follows : 1) How is the relationship of parent-leadership and family strength? A positive correlation was found between transformational leadership scores and family strength. A negative correlation was found between nontransactional leadership scores and family strength. 2) How had transformational leadership and transactional leadership affected on the family strength? Transformational leadership had the strongest effect on family strength. How had the 7 sub- factors of transformational/transactional leadership affected family strength? Idealized influence and contingent reward had strong effect on family strength but management by except had a negative effect on family strength.

• PNF and Movement
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• 제20권1호
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• pp.125-134
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• 2022

Purpose: The aim of this study was to establish an association between grip strength and gait variability in the elderly. Methods: The participants in this experiment (n = 20) were aged 65 or older. Power grip and lateral pinch forces were obtained in grip strength tests, and spatiotemporal gait parameters were collected from IMU sensors during 6 min actual walking to test the gait of participants. The collected gait parameters were converted to coefficient of variation (CV) values. To confirm the association between grip strength and gait variability, a partial correlation analysis was conducted in which height, weight, and gait speed were input as controlling variables. Results: Grip power showed a significant negative correlation with the stride length CV (r = -0.52), and the lateral pinch force showed a significant negative correlation with the stance CV (r = -0.65) and swing CV (r = -0.63). Conclusion: This study reveals that gait variability decreases as grip strength increases, although height, weight, and gait speed were controlled. Thus, grip strength testing, a simple aging evaluation method, can help identify unstable gait in older adults at risk of falling, and grip strength can be utilized as a non-invasive measurement method for frailty management and prevention.

• 한국공간구조학회논문집
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• 제4권4호
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• pp.137-144
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• 2004

Recently, as steel structures become higher and more long-spanned, application of high-strength steels is increasing gradually. However, criteria and example for design of high-strength steel are not built up. exiting criteria for structural steels is not proper for economical design of high-strength steel. Moreover, exiting criteria will be decrease the fatigue performance of steel bridge using high-strength steel. Therefore, criterion for application of high-strength steel must be established. In this paper, the behavior of plate girder using high-strength vertical stiffeners was clarified by carrying out layer elastic-plastic finite element analysis using finite deformation theory. In order to optimize the design and construction of plate girder using high-strength vertical stiffener, criterion for application of high-strength vertical stiffener is proposed.

• 자동차안전학회지
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• 제11권1호
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• pp.40-47
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• 2019

First, three point bending analysis for the inclined press door impact beam was carried out to investigate inclination angle effect on the maximum strength with varying support distance. Next, for the system model with spring elements representing body stiffness at door mounting area, the bending structural behavior of impact beam mounted on vehicle was estimated. The mounting distance and inclination angle were changed and the beam bending buckling strength was presumed at the head displacement below which spring stiffness change has little effect on the load. Finally strength ratio to predict the bending buckling strength of impact beam mounted on vehicle from three point bending maximum strength of fixed support distance was suggested.

• 한국의상디자인학회지
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• 제15권2호
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• pp.57-64
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• 2013

As the clothing materials have been more functional and advanced, the cotton fabrics for dress shirts or blouses have been more qualified and the sewability for high degree of completion has been required. This study aims to identify the seam strength depending on the change of stitch density of fine cotton fabrics by fabric and thread and so the general seam performance of fine cotton fabrics by analyzing the seam efficiency and breaking mode of seams. For an experiment, 3 kinds of fine cotton fabrics and 2 kinds of threads were selected and the sample was made by changing the stitch density by four steps. Then, the seam strength was measured. Next, the seam efficiency and breaking mode of seams were analyzed on the basis of the results of seam strength measurement. The results are as follows: All fabrics showed the similar tendency in seam strength. The seam strength is related to the tensile strength and thread strength, it increased only to a certain stitch density. When the stitch density exceeded a certain level, fabrics were destroyed or threads were cut. Then, the seam strength didn't increase. Furthermore, the more the seam strength increased, the more the seam efficiency increased. For increasing the maximum stitch density, it was required to use the fabrics and threads which had similar properties, in other words, the high thread strength for the high tensile strength and the low thread strength for the high tensile strength.

• 인지과학
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• 제34권1호
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• pp.21-38
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• 2023

본 연구는 인출 연습의 난이도 수준과 범주와 범주 내 자극의 연합강도가 기억억제에 미치는 효과를 알아보기 위해 수행되었다. 기존의 연구들은 대부분 인출 연습 범주 내 비 인출 연습 단어의 연합강도나 정서가, 물리적 특성 조작을 통해 같은 인출 연습 동안 떠오르는 정도를 조작해 억제가 이루어지는지 연구되었다. 따라서 인출 연습 시 인출 자극의 인출 정도의 난이도가 달라질 때 어떻게 억제가 발생되는지 연구될 필요성이 있다. 인출의 난이도는 인출 학습 시 제시되는 떠올려야 하는 단어의 자음과 모음의 제시 정도를 통해 어려운 조건, 보통 조건, 쉬운 조건의 세 수준으로 조작되었다. 또한 추가적으로 범주와 범주 내 단어들 간의 연합강도가 조작되었다. 기존의 연구에서는 범주와 범주 내 단어들 간의 연합강도가 강한 조건에서는 인출 유도 망각이 발생된 반면, 범주와 범주 내 단어들 간의 연합강도가 약한 조건에서는 인출 유도 망각이 발생되지 않았다. 본 연구에서는 인출 난이도에 따라 억제 과정이 다르게 나타날 경우 범주와의 연합강도에 따라 기존의 연구결과와 다르게 나올 가능성을 탐구하였다. 연구 결과 범주와 범주 내 단어들의 연합강도가 강한 조건에서는 인출 난이도가 어려운 조건과 보통 조건에서 인출 유도 망각이 관찰된 반면, 인출 난이도가 쉬운 조건에서는 인출 유도 망각이 관찰되지 않았다. 그리고 연합 강도가 약한 조건에서는 인출 난이도가 어려운 조건에서 인출 유도 망각의 경향성을 보인 반면, 난이도가 보통 조건과 쉬운 조건에서는 인출 유도 망각이 나타나지 않았다. 이러한 결과는 인출 난이도에 따라서 기억 억제가 다르게 나타날 가능성이 시사된다.

• 한국디지털건축인테리어학회논문집
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• 제11권2호
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• pp.31-39
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• 2011

Concrete-filled steel tube(CFT) columns have become popular for building construction due to not only composite effect of steel tube and infilled concrete, but also more economical. The purpose of this paper is to propose the applicable boundary formula of width-to-thickness ratio for rectangular steel tube as using CFT column. A parametric study was performed taking width-to-thickness ratio of rectangular steel tube and compressive strength of concrete as the main parameter. The strength of concrete are selected to 30, 60, 90MPa. The non-linear analysis was adopted in order to take into account the effect of concrete strength. Finally, from the test and analysis results, the effect of increasing strength according to concrete strength and width-to-thickness of steel tube and plastic behavior of specimens were verified distinctly.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 1999년도 Proceedings of Pre-symposium of the 10th ISWPC
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• pp.186-191
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• 1999

Results are shown on the preparation and characterization of homopolymer of 2-methacryloyloxyethyl isocyanate(MOI) ad copolymers of MOI with styrene synthesized by radical polymerization. The significant effectiveness of the polymers as additives for paper dry and wet strength was found. Dry strength can be increased by 75% and wet strength retention of sheets can reach 30% based on the increased dry strength and about 50% based on the dry strength of untreated sheet. Based on isocyanate group consumption, copolymers containing less isocyanate can give better effect than homopolymer in sheet wet strength improvement. Furthermore, the base paper containing a small amount of polyallylamine hydrochloride was used for polymer treatment and got higher wet strength improvement.

• 한국콘텐츠학회논문지
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• 제14권4호
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• pp.267-276
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• 2014

본 연구는 장애인가족을 대상으로 장애인가족이 경험하는 가족스트레스가 가족적응에 미치는 영향을 파악하고, 가족스트레스와 가족적응의 영향관계에서 가족건강성의 매개효과를 검증하는 것이다. 분석결과, 장애인가족이 경험하는 가족스트레스는 가족적응에 부적인 영향을 미치는 것으로 나타났으며, 가족건강성을 투입한 매개효과의 검증결과, 가족스트레스가 가족건강성을 매개로 가족적응에 부적인 영향을 미치는 완전 매개효과가 발견되었다. 이를 토대로 가족스트레스 관리 및 가족건강성 증진을 통한 장애인 가족적응을 위한 제언을 제시하였다.