• Journal of Mechanical Science and Technology
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• 제17권8호
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• pp.1113-1119
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• 2003

Experimental and numerical analyses were performed to characterize the fatigue behavior of spot welded joints in suspension mounting of a passenger car body. Static and fatigue tests were carried out for the tensile-shear and cross-tension specimens. S-N curve and fatigue strengths were obtained from the fatigue test of various specimens. Nonlinear finite element analysis showed that fatigue behavior of spot welded joints could be well estimated in terms of Von Mises stress at the nugget edge. Fatigue behavior of spot welded joint was represented by Von Mises stress better than the fatigue load.

• 한국자동차공학회논문집
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• 제24권5호
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• pp.605-611
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• 2016

Mg alloy sheet exhibits significant differences in tensile and compressive yield stress depending on the temperature, as well as variations in its hardening behavior. Such unusual behavior makes it difficult to simulate the forming process of Mg alloy sheets. Results of analysis tend to deviate significantly from the experimental data because commercial software do not completely implement the unusual hardening behavior, yield asymmetry and temperature dependent changes in the Mg alloy's material properties. In the previous study, an in-plane tension-compression cyclic tester was developed to predict the cyclic behavior of Mg alloy sheets at an elevated temperature of up to $250^{\circ}C$. A new constitutive equation was suggested to analyze the unusual behavior, and was implemented in the commercial software in the form of user subroutine. In this paper, a stamping process of Mg seat cushion panel for automotive parts was simulated using the experimental data and user subroutine. Based on the analysis, an optimal temperature condition was determined and a stamping die shape at each step was suggested in the non-isothermal stamping of Mg alloy sheets.

• Journal of Animal Science and Technology
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• 제65권4호
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• pp.748-758
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• 2023

This study was conducted to investigate the change in activity and mounting behavior in Hanwoo (Korean Native Cattle) during the peri-estrus period and its application to estrus detection. A total of 20 Hanwoo cows were fitted with a neck-collar accelerometer device, which measured the location and acceleration of cow movements and recorded the number of instances of mounting behavior by the altitude data. The data were analyzed in three periods (24-, 6-, and 2-h periods). Blood samples were collected for 5 days after the prostaglandin F2α (PGF2α) injection, and the concentrations of estradiol, progesterone, follicle-stimulating hormone, and luteinizing hormone were determined by enzyme-linked immunosorbent assays. Activity and mounting behavior recorded over 2-h periods significantly increased as estrus approached and were more efficient at detecting estrus than over 24- and 6-h periods (p < 0.05). Endocrine patterns did not differ with the variation of individual cows during the peri-estrus period (p > 0.05). Activity was selected as the best predictor through stepwise discriminant analysis. However, activity alone is not enough to detect estrus. We suggest that a combination of activity and mounting behavior may improve estrus detection efficiency in Hanwoo. Further research is necessary to validate the findings on a larger sample size.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.49-49
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• 2008

ZnO-based varistors have been widely used for voltage stabilization or transient surge suppression in electric power systems and electronic circuits. Recently, It has reported that the varistor behavior with nonlinear coefficient of 6~17 in Mn-doped ZnO. In this study we have chosen the composition of ZnO-$TeO_2-Mn_3O_4$ (ZTM) system to the purpose of whether varistor behavior appeared in doped ZnO by the solid state sintering or not. We investigated the sintering and electric properties of 0.5~3.0 at% Mn doped ZnO-1.0 at% $TeO_2$ system. Electrical properties, such as current-voltage (I-V), capacitance-voltage (C-V), and impedance spectroscopy were conducted. $TeO_2$ itself melts at $732^{\circ}C$ in air but forms the $ZnTeO_3$ phase with ZnO as increasing temperature and therefore retards the densification of ZnO to $1000^{\circ}C$. The average grain size of sintered samples was at about $3{\mu}m$ and decreased with increasing Mn contents. It was found that a good varistor characteristics were developed in ZTM system sintered at $1100^{\circ}C$ (nonlinear coefficient $\alpha$ ~ 60). The results of C-V characteristics such as barrier height ($\Theta$), donor density ($N_d$), depletion layer (W), and interface state density ($N_t$) in ZTM ceramics were $4\times10^{17}cm^{-3}$, 0.7 V, 40 nm, and $1.6\times10^{12}cm^{-2}$, respectively. It will be discussed about the stability and homogeneity of grain boundaries using distribution parameter ($\alpha$) simulated with the Z(T)"-logf plots in ZTM system.

• 한국시뮬레이션학회논문지
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• 제19권4호
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• pp.169-178
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• 2010

행위자 기반 시뮬레이션은 시스템을 구성하고 있는 개체들이 자율적인 판단과 기억에 의해 상호 영향을 주면서 주어진 환경에 대응할 때 일정 시간이 경과한 후 시스템에 어떠한 현상이 발생하는가를 관찰하기 위하여 사용된다. 본 논문에서는 팀 결성의 행태를 분석하기 위한 행위자 기반 시뮬레이션 모형을 개발하였다. 팀의 결성은 팀 구성원 개개인의 선택과 판단에 의하지만 어느 한 개인의 일방적인 의사에 의해 이루어지기 보다는 여러 구성원의 상호 관계에 의한 것이라는 점, 그리고 이렇게 구성된 팀의 성취도는 경험이 반복될수록 변화한다는 점 등이 생태학적인 접근법을 가능하게 한다. 개발한 모형은 Netlogo 4.1으로 구현하였고 모의시험을 통해 검증하였다. 모의시험의 결과는 행위자 기반 시뮬레이션의 특성인 규칙의 적용 및 판단, 기억 및 진화의 속성을 잘 묘사할 수 있음을 보여주었다. 개발한 모형을 발전시킴으로써 팀 결성의 다양한 생태학적 분석에 적용이 가능하다.

• Journal of Information Technology Applications and Management
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• 제16권3호
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• pp.113-124
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• 2009

How can action learning program promote organizational learning performance and especially project based team performance in Web-based small and medium-sized enterprises (SMEs)? This article discusses the association between project based team in action learning program and the performance of Web-based SME to be learning organization. In the case of ALPACO, action learning program that promote employee communication behavior, knowledge sharing, and organizational learning are found to be positively associated with the project based team performance and organizational learning, The results indicate that action learning program in SMEs indeed associated with greater knowledge sharing, learning communication skills and changing organizational culture. Learning organization can be, in turn, positively developed by project based team through action learning program for creating competitive advantage, Also, this study offers further support for the practical perspective on learning organization performance. The evidence from this case study suggests that the project team in action learning program playa significant role in team performance and the development of learning organization of the firm. Therefore, in the future, Web-based SMEs should consider making investments in action learning program that encourage project team's effective management in decision making, knowledge sharing, and organizational learning.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권8호
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• pp.4105-4119
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• 2017

Creativity is crucial in an ever-changing e-business environment. The creation of new value is essential for companies to gain the competitive edge and to pioneer new markets in e-business. Hence, many companies in e-business operate virtual teams as they are suitable to generate creativity. Even so, virtual teams possess the inherent weakness of a lack of cohesiveness. Hence, for a virtual team to be creative, team members should help each other and share information. This study emphasizes the importance of information sharing that is supposed to improve creativity and explains how to increase them for virtual teams. To explain these relationships, three dimensions are routinely examined in organizational behavior studies: leaders, teams, and members. As a consequence, and through empirical analysis, authentic leadership, sharing team climate, and psychological empowerment enhances information sharing and creativity through their respective roles, in addition to information sharing directly increasing creativity. To improve creativity and information sharing of virtual team members in e-business, this article has highlighted the importance of the three roles stated prior. Such factors can increase information sharing and creativity, and will help virtual teams and organizations to be more successful in e-business.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1452-1454
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• 1997

Properties of flashover in polymer insulators are very important under pollution environments. It is necessary to analyse flashover characteristics whether insulators are still safe or not. A lot of precious information can be got out of polluted polymer insulators through leakage current measurement. The behavior of partial arc discharge leads to flashover directly. It is possible to measure partial arc discharge as leakage current pulses analysis. The shape of histogram reflects degree of pollution, wetting and voltage stress level. It can be expressed by Weibull distribution function.

• 벤처창업연구
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• 제17권3호
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• pp.165-182
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• 2022

본 연구는 조직 내 창의적 리더의 존재를 지각하였을 경우 종업원의 직무만족과 혁신 행동에 유의한 영향을 미치는가를 중점적으로 고찰하였다. 또한 본 연구는 지각된 리더의 창의성과 종업원들의 직무만족, 혁신 행동 간의 관계에서 긍정심리자본, 창의적 자기효능의 매개효과를 확인하였다. 추가적으로 본 연구를 통해 리더의 창의성이 긍정심리자본 및 창의적 자기효능감에 영향을 미치는 관계에서 팀응집성의 조절된 매개효과를 확인하였다. SmartPLS 3.0 구조방정식 모형을 활용한 측정도구 검증 방법을 이용하여 확인적 요인분석 및 요인별 경로분석 실시 후 연구 모형을 실증 분석한 결과, 종업원의 지각된 리더의 창의성은 종업원의 직무만족과 혁신행동에는 직접적으로 유의한 영향을 미치지 않는 것으로 나타났다. 다만 지각된 리더의 창의성은 긍정심리자본을 매개로 직무만족과 혁신행동에 유의한 영향을 미치는 것으로 나타났다. 또한 리더의 창의성은 긍정심리자본과 창의적 자기효능감을 이중매개로 하여 종업원의 직무만족에 유의미한 영향을 미치지 않은 것으로 나타났다. 그러나 리더의 창의성은 긍정심리자본과 창의적 자기효능감을 이중매개로 해서 종업원의 혁신행동에는 유의하게 영향을 미치는 것으로 밝혀졌다. 마지막으로 팀 응집성을 조절된 매개변수로 설정해 가설을 검증한 결과, 긍정심리자본의 매개효과는 팀응집성이 높은 경우에만 유의하였으며, 창의적 자기효능감의 매개효과는 팀 응집성이 평균 이상인 경우에만 유의한 것으로 나타났다. 본 연구는 변수별 실증 분석 결과를 바탕으로 지각된 리더의 창의성과 그 중요성에 대한 시대적 요구를 고찰하고 추가적으로 조직 구성원의 직무만족 및 혁신행동에 미치는 영향 요인 변수들 간의 관계를 분석하였다. 본 연구는 긍정심리자본과 창의적 자기효능감을 고양시키기 위한 구체적인 조직 전략의 수립 방안을 제언하였다는 데에 연구의 의의가 있다.

• 한국건설관리학회논문집
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• 제19권6호
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• pp.103-114
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• 2018

PPP (Public-Private-Partnership)는 국내외 건설산업 분야에서 널리 사용되는 프로젝트이다. 일반적으로 PPP 프로젝트 팀은 건설 엔지니어, 금융기관, 계약 관리자, 투자자 등 다양한 분야의 전문가들로 구성된다. 이러한 팀 구성원의 다양성으로 인해 팀의 효율적 관리 뿐 아니라 프로젝트 자체의 원활한 수행도 어려운 상황이다. 이러한 문제의 해결책은 팀원의 시민행동 형성이라 할 수 있다. 본 연구에서는 프로젝트 시민 행동의 프로젝트 성과에 대한 실증적 조사를 수행하였다. 이를 위해 국내 건설 PPP 프로젝트 경험자를 대상으로 설문조사를 통해 데이터를 수집했다. 연구결과, 우리는 프로젝트 시민 행동이 PM의 리더십과 프로젝트 성과간에 완전 매개 효과가 있음을 확인할 수 있었다. 본 연구는 국내 건설 프로젝트 관리 분야에서 시민 행동 개념의 적용과 그 효과를 확인한 첫 번째 시도라는 점에서 학문적 중요성을 가지고 있으며, PPP 프로젝트 팀의 성공적인 업무 수행에 일조할 것으로 기대한다.