• 폴리머
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• 제26권5호
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• pp.599-606
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• 2002

본 연구에서는 DDS로 경화된 4관능성 에폭시 (TGDDM)/폴리아마이드이미드 (PAI) 블렌드의 PAI 함량에 따른 블렌드계의 열적, 기계적 및 형태학적 특성에 대해 연구하였다 경화된 시편의 경화거동과 열안정성은 DSC와 TGA로 각각 조사하였다. 또한 $K_{IC}$ 는 UTM을 사용하여 측정하였으며, TGDDM/PAI 블렌드의 상거동과 최종 모폴로지는 SEM을 사용하여 관찰하였다. 그 결과 PAI 함량이 증가할수록 경화온도와 경화활성화 에너지는 감소하였다 경화온도와 경화활성화 에너지의 감소는 PAI 주쇄의 2차 아민이 co-initiator로서 사용되었기 때문인 것으로 사료된다. 그러나 분해활성화 에너지와 $K_{IC}$ 값은 각각 PAI 함량 5, 10 phr까지 증가하다 그 이상치 한량에서는 감소하는 경향을 보였다. 이러한 결과들은 에테르화에 의한 사슬절단 반응에 기초하여 설명되었다. 그리고 SEM에 의한 모폴로지 관찰로부터 블렌드계의 co-continuous 구조가 확인되었다.

• Structural Engineering and Mechanics
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• 제35권1호
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• pp.123-126
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• 2010

• 한국웰니스학회지
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• 제6권3호
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• pp.13-21
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• 2011

The purpose of this study was to examine the potential predictors of leisure behavior intention using the theory of planned behavior(TPB). A convenience sample of 369 participants was obtained from university students in Korea and America. For the purposes of this study, potential predictors of leisure behavior intention were selected from the following categories: attitude, subject norm, perceived behavior control, group conformity and face saving. In order to better understand the dynamics of the TPB process that influenced leisure behavior intention, this study used structural equation modeling(SEM) to test the TPB model. According to the results, attitude, subject norm, and perceived behavior control influenced to leisure behavior intention of both Korean and American university students and face saving influenced to leisure behavior intention of Korean university students. However, group conformity did not influence to leisure behavior intention of either Korean and American university students. For future study, more specific and decomposed factors are recommended to understand leisure behavior intention in theoretical way.

• 성인간호학회지
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• 제26권1호
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• pp.78-88
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• 2014

Purpose: The purpose of this study was to construct a structural equation model (SEM) that would describe the binge drinking among Korean undergraduate students. Methods: Model construction was based on the theory of planned behavior and prototype/willingness model, using the variables; intention, attitude, descriptive norm, and prototype perception of binge drinking, alcohol use disorders identification test (AUDIT), and binge drinking behavior. The analysis of data was done with both SPSS 20.0 for descriptive statistics and AMOS 20.0 for SEM. Results: The binge drinking intention was found to have a significantly direct effect in influencing binge drinking behavior. In addition, attitude, descriptive norm, and prototype perception of binge drinking were found to have a significantly direct effect in influencing binge drinking intention. The final modified model yielded $x^2$=374.2 (p<.001), df=174, $x^2/df$=2.15, GFI=.87, AGFI=.82, NFI=.89, PNFI=.73 RMSEA=.07, and CFI=.94. Conclusion: This study constructed a model that addressed the factors related to binge drinking and described the relationship of these factors in influencing binge drinking among Korean undergraduate students. Findings from this study can contribute to designing appropriate prevention strategies to reduce problem related binge drinking in undergraduate students.

• The Journal of Asian Finance, Economics and Business
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• 제9권9호
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• pp.351-360
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• 2022

This study aims to determine the factors that can influence investors in selecting stocks in the Indonesian capital market to establish an optimal portfolio, and find phenomena that occurred during the COVID-19 pandemic so that buying interest / the number of investors increased in the Indonesian capital market. This study collection technique uses primary data obtained from the survey questionnaire and secondary data which is market data, stock price movement data sourced from the Indonesia Stock Exchange, Indonesian Central Securities Depository, and Bank Indonesia, as well as empirical literature on behavior finance, investment decision, and interest in buying stock. The method used in this research is the survey questionnaire analysis with the SEM (statistical approach). The results of the analysis using SEM show that investor behavior influences the stock-buying interest, investor behavior, and the stock-buying interest influences investor decision-making. However, risk management does not influence investor-decision making. This occurs when the investigator's psychological capacity produces more decision information by decreasing all potential biases, allowing the best stock selection model to be selected. When the investigator's psychological capacity creates more decision information by reducing biases, the optimum stock selection model can be chosen.

• Structural Engineering and Mechanics
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• 제81권5호
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• pp.575-589
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• 2022

In order to enhance the greenness in the strain-hardening composites and to reduce the high cost of typical polyvinyl alcohol fiber reinforced engineered cementitious composite (PVA-ECC), an affordable strain-hardening composite with green binder content has been proposed. For optimizing the strain-hardening behavior of cementitious composites, this paper investigates the effects of polypropylene fibers on the first cracking strength, fracture properties, and micromechanical parameters of cementitious composites. For this purpose, digital image correlation (DIC) technique was utilized to monitor crack propagation. In addition, to have an in-depth understanding of fiber/matrix interaction, scanning electron microscope (SEM) analysis was used. To understand the effect of fibers on the strain hardening behavior of cementitious composites, ten mixes were designed with the variables of fiber length and volume. To investigate the micromechanical parameters from fracture tests on notched beam specimens, a novel technique has been suggested. In this regard, mechanical and fracture tests were carried out, and the results have been discussed utilizing both fracture and micromechanical concepts. This study shows that the fiber length and volume have optimal values; therefore, using fibers without considering the optimal values has negative effects on the strain-hardening behavior of cementitious composites.

• 한국응용과학기술학회지
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• 제38권4호
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• pp.963-973
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• 2021

본 연구는 계획행동이론(Theory of Planned Behavior ; TPB)을 바탕으로 코로나-19 환경에서 대학생이 인식하는 생활체육과 참여의사 및 참여행동에 관하여 인과 관계(SEM)를 적용하여 대학생이 인식하는 생활체육을 탐색하고, 생활체육 종목을 예측하기 위한 기초자료를 제공하고자 하였다. 이를 위해 2020년 12월 1일 ~ 2021년 5월 1일까지 표본계획에 의해 모바일 프로그램인"서베이 몽키"를 사용하여 총 267명 분석에 사용했다. 연구결과 계획행동이론는 생활체육 참여의사와 통계적으로 유의미한 정(+)의 상관관계가 있는 것으로 나타났다. TPB는 생활체육 참여행동에 통계적으로 유의미한 정(+)의 상관관계가 있는 것으로 나타났으며, 생활체육 참여의사는 생활체육 참여행동과 통계적으로 유의미한 정(+)의 상관관계가 있는 것으로 나타났다.

• International Journal of Korean Welding Society
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• 제2권2호
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• pp.19-25
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• 2002

In recent years, techniques for micro-assembly with high repeatability under a scanning electron microscope (SEM) are required to construct highly functional micro-devices. Adhesion phenomenon is more significant for smaller objects, because adhesional force is proportional to size of the objects while gravitational force is proportional to the third power of it. It is also known that adhesional force between micro-objects exposed to Electron Beam irradiation of SEM increases with the elapsed time. Therefore, mechanical manipulation techniques using a needle-shaped tool by adhesional force are often adopted in basic researches where micro-objects are studied. These techniques, however, have not yet achieved the desired repeatability because many of these could not have been supported theoretically. Some techniques even need the process of trial-and-error. Thus, in this paper, mechanical and adhesional micro-manipulation are analyzed theoretically by introducing new physical factors, such as adhesional force and rolling-resistance, into the kinematic system consisting of a sphere, a needle-shaped tool, and a substrate. Through this analysis, they are revealed that how the micro-sphere behavior depends on the given conditions, and that it is possible to cause the fracture of the desired contact Interfaces selectively by controlling the force direction in which the tool-tip loads to the sphere. Based on the acquired knowledge, a mode diagram, which indicates the micro-sphere behavior for the given conditions, is designed. By referring to this mode diagram, the practical technique of the pick and place manipulation of a micro-sphere under an SEM by the selective interface fracture is proposed.

• Structural Engineering and Mechanics
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• 제29권5호
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• pp.567-579
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• 2008

To gain understanding of the applicability of CFRP cables in super long-span cable-stayed bridges, by taking a 1400 m cable-stayed bridge as example, mechanics performance including the static behavior under service load, dynamic behavior, wind stability and seismic behavior of the bridge using either steel or CFRP cables are investigated numerically and compared. The results show that viewed from the aspect of mechanics performance, the use of CFRP cables in super long-span cable-stayed bridges is feasible, and the cross-sectional areas of CFRP cables should be determined by the principle of equivalent axial stiffness.

• 한국사회복지학
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• 제50권
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• pp.131-155
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• 2002

본 연구는 부모의 폭력 및 지지행동이 자녀의 이성교제폭력에 영향을 미치는지 탐색하고 그 영양의 경로를 살펴보았다. 구체적으로, 부모의 폭력/지지행동과 이성교제폭력 사이를 갈등해결기술, 우울, 비행이 매개하는지 확인하였다. 또한 부모의 행동이 자녀의 성별에 따라 이성교제폭력에 다른 영양을 주는지 조사했다. 부모의 행동과 관련된 세 개 변인은 부부폭력, 아동학대, 부모지지이다. 본 연구의 표본은 전체 14개 대학의 이성교제 경험이 있는 760명 남녀 대학생이다. 구조방정식 모형분석을 사용해서 밝혀진 결과를 요약하면 다음과 같다. 아동학대 경험은 이성교제폭력의 확률을 높이고 있었으며 아동학대와 이성교제폭력을 매개하는 요인으로 비행행동만이 검증되었다. 아동기의 학대경험은 성별에 관계없이 비행을 통해 이성교제폭력으로 이어지는 과정을 일관되게 보여준다. 선행연구와 달리, 본 자료에서는 부모간 폭력을 목격한 경험은 이성교제관계에서 발생하는 폭력과 상관관계가 없는 것으로 확인되었다. 분석결과에 의하면, 부모의 폭력행동보다 부모의 지지 수준이 자녀의 폭력에 더욱 큰 영양을 주는 것으로 나타났다. 낮은 수준의 부모지지는 자녀의 갈등해결기술, 우울, 비행에 영양을 주면서 이성교제폭력과 연관되어 있었다. 부모의 비지지적인 태도는 특히 여성들의 갈등해결기술을 약화시키며, 남성들의 비행횟수를 늘리는 것으로 밝혀졌다. 이러한 결과들을 기초로 이성교제폭력을 줄이기 위한 실천적 방법들이 제시되었다.