• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.885-890
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• 2007

Fast Fourier Transformation(FFT) is one of the most useful way to analyze response signal for the purpose of grasping the dynamic characteristics of system. Vibration test using impact hammer is typical and simple experimental method widely used for catching hold of dynamic peculiar characters and modal behaviors of system. In this thesis, impact testing module for NI-PXI equipment is developed. The analyzing and visualizing module are developed with LabVIEW tool. A user can see quickly and easily modal shape of system after analyzing acquired data. This developed module will be expected to build up more convenient and serviceable measurement system.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 추계학술발표대회 논문집
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• pp.53-56
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• 2005

In this study, the material characterization and the dynamic behavior of 3D orthogonal woven composite materials has been studied under transverse central low-velocity impact condition by means of the micromechanical model using finite elements. To build up the micromechanical model considering tow spacing and waviness, an accurate unit structure is stacked in x-y-z direction repeatedly. First, the mechanical properties of 3D orthogonal woven composites arc obtained by means of virtual experiment using full scale Finite Element Analysis based on the DNS concepts, and the computed elastic properties arc validated by comparison to available experimental results. Second, using the implementation of this validated micromechanical model, 3D transient finite-clement analysis is performed considering contact and impact, and the impact behavior of 3D orthogonal woven composite is investigated. A comparison study with the homogenized model will be carried out in terms of global and local behaviors.

• Child Studies in Asia-Pacific Contexts
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• 제3권1호
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• pp.1-12
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• 2013

Research with parents of children with Asperger Syndrome was conducted to assess whether the level of positive parental attachment correlated positively with positive parenting behaviors and negatively with negative parenting behaviors. Participants were recruited from internet. The Parental Bonding Inventory measured parents' perception of their bonding or attachment with three aspects of their own parents: warmth, control, and care. In the Parenting Behavior Inventory, parents reported recent interaction/reaction behaviors with their child, and results focused on two aspects of parenting, supportive/engaged and hostile/coercive behaviors: each identified as problematic to parenting and attributable to a variety of specific parenting behaviors. Analysis of demographic variables for correlations with positive parenting behaviors and negative parenting behaviors were carried out by Pearson correlations. Two separate standard multiple regressions, one for positive parenting behaviors and one for negative parenting behaviors, were conducted. Findings support the hypothesis that positive early attachment experience of parents has a significant impact upon their own positive parenting skills with their child with Asperger Syndrome. However, multiple regression of negative parenting behavior found no significant negative contribution by parental attachment. Demographic variables proved to be important.

• International Journal of Precision Engineering and Manufacturing
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• 제6권1호
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• pp.36-41
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• 2005

• 대한조선학회논문집
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• 제45권6호
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• pp.735-749
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• 2008

For the development of the original technique of structural safety assessment of Cargo Containment System(CCS) in membrane type LNG carriers, it is necessary to understand the characteristics of dynamic response behavior of CCS structure under sloshing impact pressure. In the previous study, the wet drop impact response analyses of CCS structure in membrane Mark III type LNG carriers were carried out by using Fluid-Structure Interaction(FSI) analysis technique of LS-DYNA code, and were also validated through a series of wet drop experiments for the enhancement of more accurate shock response analysis technique. In this study, the characteristics of structural shock response behaviors of CCS structure were sufficiently figured out by careful examinations of the effects of specimen weight, drop height, incident angle, corrugation and stiffness of inner hull on its shock response behaviors. The shock response analysis of upward shooting fluid to inner hull was performed, and the reason of faster strain response than shock pressure one was also figured out.

• 산경연구논집
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• 제13권5호
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• pp.27-40
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• 2022

Purpose: Research on job crafting has thus far focused on how alter job demand and resources behaviors relate to employee task performance. However, job crafting behaviors do not necessarily have an impact only on task performance, but also on employees' contextual performance, a phenomenon that has little research in job crafting research. Therefore, this study aims to investigate the effect of job crafting on task performance or contextual performance and the mediating effect of work engagement between them in the Chinese context. Research design, data and methodology: In order to achieve the above research goals and test the proposed hypotheses, we used a cross-sectional design and a self-administered questionnaire to collect quantitative data from September 8, 2021 to September 27, 2021 among knowledge workers in Shandong Province various financial companies and finally analyzed 211 questionnaires. Descriptive statistics and research model analysis were performed using SPSS 25.0 Version and AMOS 27.0 Version to test the developed hypotheses. Results: The results are as follows; firstly, the study showed that job crafting of employees had a significant positive impact on task performance and contextual performance. Secondly, the higher job crafting of employees, the higher their work engagement. Thirdly, this study showed that work engagement of employees had a positive impact on task performance and contextual performance. Fourthly, we predicted and found that work engagement of employees had a positive mediating effect between job crafting and task performance and a positive mediating effect between job crafting and contextual performance. Overall, this study showed that the proactive job crafting behaviors of employees enhance their engagement for their work, which in turn improves task performance and contextual performance. Conclusions: This paper develops job crafting research by exploring the positive impact of job crafting on employees' task performance or contextual performance through their work engagement. It also proposes that both job crafting behaviors and work engagement are important approaches to improve employees' task performance or contextual performance. Practical implications for organizations, such as increasing employee' work engagement, as well as the limitations and suggestions are concluded for the future research directions.

• 한국전산유체공학회지
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• 제4권1호
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• pp.1-7
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• 1999

The numerical methodology for computing tile impact forces and water entry behaviors of high speed water entry bodies was been developed. Since the present method assumed the impact occurs within a very short time interval. the viscous effects do not have enough time to play a significant role in the impact forces, that is, the flow around a water-entry object was assumed as an incompressible potential flow and is solved by the source panel method. The elements fully submerged into the water are routinely treated, but the elements intersected by the effective planar free surface are redefined and reorganized to be amenable to the source panel method. To validate the present code, it was applied to disk, cone and ogive model and compared with experimental data. Good agreement was obtained. The water entry behavior such as the bouncing phenomena from the free surface was also simulated using the impact forces and two degree of freedom dynamic equation. Physically acceptable results were obtained.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1246-1251
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• 2003

The fracture behaviors of Zr-based bulk amorphous metals(BAMs) having compositions of $Zr_{55}Al_{10}Ni_{5}Cu_{30}$, were investigated under impact loading and quasi-static conditions. For experiments, a newly devised instrumented impact testing apparatus and the subsize Charpy specimens were used. The influences of loading rate and the notch shape on the fracture behavior of the Zr-based BAM were examined. The Zr-based BAMs showed an elastic deformation behavior without any plastic deformation on it before fracture. Most fracture energies were absorbed in the process of the crack initiation. The maximum load and fracture absorbed energy under quasi-static condition were larger than those under impact condition. However, there existed relatively insignificant notch shape effect. Fracture surfaces under impact loading were smoother than those under quasi-static loading. The absorbed fracture energy appeared differently depending on the extent of the vein-like pattern region due to the shear bands developed at the notch tip. It can be found that the fracture energy of the Zr-Al-Ni-Cu alloy is closely related with the development of shear bands during fracture.

• 한국학교보건학회지
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• 제12권1호
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• pp.45-56
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• 1999

Adolescence is vulnerable to various Health Risk Behaviors (HRB). These behaviors can affect his remaining life as well as adolescence, thus prevention of HRB is a critical issue in health education. This study is aimed to provide basic information for prevention of HRB. Thus, this study was conducted to analyze the impact of peer group's health risk behaviors on health risk perception (HRP) and that of health risk perception on health risk behaviors based on 832 respondents. The 852 subjects were selected in six middle and high schools in Seoul through random sampling. Data were collected from September, 18-October, 21, 1998, and the 832 data were analyzed after excluding the 20 incomplete and inaccurate data. Questionnaire items and measures are based on an instrument to measure Perceived Health Risk Perception, which Hodge B.C. developed in 1992. Cronbach alpha is used to test the reliability. The reliability of HRP and HRB is 0.9473, 0.8768 in this study, Statistical analysis divided into four phases. First, the impact of socio-demographic characteristics on HRP is analyzed by oneway ANOV A. Male students have lower HRP than female students. As grade goes up, HRP is getting lower. Perceived higher concern of parents and HRP are correlated. And the experience of school health education and HRP are correlated. Second, the impact of peer group's HRB on the HRP is analyzed by linear regression. Peer group's HRB and HRP are negatively correlated, Third, the impact of HRP on HRB is analyzed by linear regression. There is a correlation between high HRP and low HRB. Fourth, Powerful impact factors on HRB are analyzed by stepwise multiple regression. Grade, gender, peer group's HRB, and related HRP is entered as independent variables. Because of correlation between entered variables, three interaction variables between grade, gender, peer group's HRB and related HRP also entered, In general, peer group's HRB is the most accountable factor to HRB. And Interaction variable between HRP and peer group's HRB and HRB are negatively correlated. These results indicate that HRP may reduce the impact of peer group's HRB on HRB. Some recommendations are as follows: First, health educational programs suitable for gender and grade are required. Second, a systematic cooperation between school and home is necessary for effective prevention of HRB. Third, the educational effect for decreasing HRB by increasing HRP is statistically assisted. However, peer group has much stronger impact on HRB than subjective HRP, thus special consideration and management are necessary for peer group which does HRB more frequently.

• 한국노년학
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• 제31권3호
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• pp.463-478
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• 2011

본 연구는 노후빈곤이 주관적 건강상태에 미치는 영향을 건강행태와 사회적 지지의 매개 및 조절효과 분석을 통하여 살펴보았다. 빈곤과 건강행태 그리고 주관적 건강 사이의 유의미한 관계에도 불구하고, 기존의 연구에서는 이들 사이의 구조적인 관계에 대한 분석이 많이 이루어지지 않았다. 이에 따라 본 연구는 빈곤과 주관적 건강상태사이의 다차원적인 관계를 건강행태와 사회적 지지의 매개된 조절효과 분석을 통하여 살펴보았다. 이를 위해 고령화연구패널조사 자료를 사용하였으며, 구조방정식에 의한 매개된 조절효과 분석을 실시하였다. 본 연구결과에 의하면, 노후의 빈곤상태는 흡연이나 규칙적 운동의 부재와 같은 건강행태변수들 뿐만 아니라 주관적 건강상태에도 직접적으로 부정적인 영향을 미치는 것으로 나타났다. 특히 규칙적인 운동여부는 빈곤과 주관적 건강사이를 매개하는 유의미한 요소로 나타났고, 사회적 지지 가운데 가족이나 친구로부터의 비공식적 지지는 노후빈곤이 주관적 건강에 미치는 부정적인 영향을 완화시키는 조절효과가 있는 것으로 나타났다. 이러한 연구결과를 토대로 빈곤노인들의 건강증진을 위해서는 물질적 원조뿐만 아니라 사회적 지지가 지속적으로 필요하고, 건강증진행위 가운데 특히 규칙적인 운동을 할 수 있도록 사회체육프로그램 등의 개발도 필요할 것으로 사료된다.