• 한국심리학회지 : 문화 및 사회문제
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• 제18권2호
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• pp.191-213
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• 2012

본 연구는 노인과 대학생을 대상으로 노인에 대한 명시적 및 암묵적 태도가 연령 및 성별에 따라 어떠한 차이가 있는지 검증해보고자 하였다. 남녀 대학생 64명과 남녀 노인 64명을 대상으로 명시적 태도검사, 명시적 선호도검사와 암묵적 연합검사(IAT)를 사용하여, 노인에 대한 태도를 살펴보았다. 분석 결과, 대학생은 명시적 및 암묵적 수준 모두에서 젊은이를 더 선호하는 내집단 선호를 보인 반면, 노인의 경우에는 두 수준 모두에서 젊은이를 더 선호하는 외집단 선호를 보였으나 두 집단 모두에서 노인에 대한 명시적 및 암묵적 태도 간에는 유의미한 상관관계가 나타나지 않았다. 이에 더해, 성별 및 연령에 따른 노인에 대한 태도에서 차이가 나타났는데, 명시적 수준에서는 노인에 비해 대학생들이 노인을 더 선호하고 신뢰하는 것으로 나타난 반면, 암묵적 수준에서는 남성의 경우에는 노인이 대학생보다 노인을 더 선호하고, 여성의 경우에는 대학생 이 노인에 비해 노인을 더욱 선호하는 것으로 나타났다. 본 연구의 결과를 토대로 노인에 대한 태도를 이론 및 실제적인 측면에서 논의하였고, 마지막으로 연구의 함의 및 제한점을 역시 기술하였다.

• 호남수학학술지
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• 제37권4호
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• pp.441-455
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• 2015

In this paper, we perform a comparison study of explicit and implicit numerical methods for the equity-linked securities (ELS). The option prices of the two-asset ELS are typically computed using an implicit finite diffrence method because an explicit finite diffrence scheme has a restriction for time steps. Nowadays, the three-asset ELS is getting popularity in the real world financial market. In practical applications of the finite diffrence methods in computational finance, we typically use relatively large space steps and small time steps. Therefore, we can use an accurate and effient explicit finite diffrence method because the implementation is simple and the computation is fast. The computational results demonstrate that if we use a large space step, then the explicit scheme is better than the implicit one. On the other hand, if the space step size is small, then the implicit scheme is more effient than the explicit one.

• 한국자동차공학회논문집
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• 제3권3호
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• pp.19-28
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• 1995

The explicit scheme for finite element analysis of sheet metal forming problems has been widely used for providing practical solutions since it improves the convergency problem, memory size and computational time especially for the case of complicated geometry and large element number. The explicit schemes in general use are based on the elastic-plastic modelling of material requiring large computation time. In the present work, rigid-plastic explicit finite element method is introduced for analysis of sheet metal forming processes in which plane strain normal anisotropy condition can be assumed by dividing the whole piece into sections. The explicit scheme is in good agreement with the implicit scheme for numerical analysis and experimental results of auto-body panels. The proposed rigid-plastic explicit finite element method can be used as robust and efficient computational method for prediction of defects and forming severity.

• Journal of Mechanical Science and Technology
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• 제16권12호
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• pp.1687-1692
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• 2002

The problem analyzed here is a sheet metal forming process which requires a drawbead. The drawbead provides the sheet metal enough tension to be deformed plastically along the punch face and consequently, ensures a proper shape of final products by fixing the sheet to the die. Therefore, the optimum design of drawbead is indispensable in obtaining the desired formability. A static-explicit finite element analysis is carried out to provide a perspective tool for designing the drawbead. The finite element formulation is constructed from static equilibrium equation and takes into account the boundary condition that involves a proper contact condition. The deformation behavior of sheet material is formulated by the elastic-plastic constitutive equation. The finite element formulation has been solved based on an existing method that is called the static-explicit method. The main features of the static-explicit method are first that there is no convergence problem. Second, the problem of contact and friction is easily solved by application of very small time interval. During the analysis of drawbead processes, the strain distribution and the drawing force on drawbead can be analyzed. And the effects of bead shape and number of beads on sheet forming processes were investigated. The results of the static explicit analysis of drawbead processes show no convergence problem and comparatively accurate results even though severe high geometric and contact-friction nonlinearity. Moreover, the computational results of a static-explicit finite element analysis can supply very valuable information for designing the drawbead process in which the defects of final sheet product can be removed.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2010년도 정기 학술대회
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• pp.179-182
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• 2010

본 연구에서는 MLS 차분법을 이용하여 동역학 문제를 해석하기 위한 explicit 동적해석 알고리즘을 제시한다. 격자망이 없는 장점을 부각시키기 위해 이동최소제곱법에 근거한 Taylor 전개로부터 미분근사를 얻고 차분식을 구성했다. 지배 미분방정식의 시간항을 CDM(Central difference Method) 차분하여 빠른 속도로 동적해석을 수행하였다. 수치결과를 통해 본 연구에서 제시한 알고리즘의 정확성과 안정성을 확인할 수 있었다.

• 동력기계공학회지
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• 제8권3호
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• pp.23-29
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• 2004

In this paper, a finite element formulation using dynamic-explicit time integration scheme is used for numerical analysis of Hydro-forming processes. The lumping scheme is employed for the diagonal mass matrix and dynamic explicit formulation. Hydro-forming process for auto-body panel forming is analyzed by using dynamic-explicit finite element method. Further, the simulated results of the Hydro-forming processes are shown and discussed. Its application is being increased especially in the automotive industrial area for the cost reduction, weight saving, and improvement of strength.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.206-211
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• 1993

The explicit scheme for finite element analysis of sheet metal forming problems has been widely used for providing practical solution since it improves the convergency problem,memory size and computational time especially for the case of complicated geometry and large element number. In the present work, a basic formulation for rigid-plastic explicit finite element analysis of plain strain sheet metal forming problems has been proposed. The effect of some basic parameters involved in the dynamic analysis has been studied in detail. A direct trial-and-error method is introduced to treat contact and friction. In order to show the validity and effectiveness of the proposed explicit scheme, computation are carried out for cylindrical punch stretching and the computational results are compared with those by the implicit scheme as well as with a commercial code. The proposed rigid-plastic explicit element method can be used as a robust and efficient computational method for analysis of sheet method forming.

• 소성∙가공
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• 제9권3호
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• pp.293-303
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• 2000

Recent developments of Fe technology make it possible to apply CAD/CAE/CAM techniques successfully to the stamping die design among the automotive parts industries. Those successful applications are greatly attributable to the development of commercial S/W. Up to now most commercial S/W for the analysis of sheet metal forming is based on the dynamic explicit algorithm. The main characteristics of dynamic explicit algorithm is that there is no convergence problem if the time increment is taken less than the stability limit. The stability of the analysis is guaranteed in the commercial code, since the adequate time increment is computed from the so called "Courant Condition". However excess computing time is often pointed out in the dynamic explicit analysis according to the characteristics of process parameters taken. In the study, various parameters that may affect the stability and the method how to improve computational efficiency of analysis have been investigated.estigated.

• Kyungpook Mathematical Journal
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• 제55권4호
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• pp.983-996
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• 2015

In the paper A new parameter for Ramanujan's theta-functions and explicit values, Arab J. Math. Sc., 18 (2012), 105-119, Saikia studied the parameter $A_{k,n}$ involving Ramanujan's theta-functions ${\phi}(q)$ and ${\psi}(q)$ for any positive real numbers k and n and applied it to find explicit values of ${\psi}(q)$. As more application to the parameter $A_{k,n}$, in this paper we prove a new general theorem for explicit evaluation of Ramanujan-$G{\ddot{o}}llnitz$-Gordon continued fraction K(q) in terms of the parameter $A_{k,n}$ and give examples. We also find some new explicit values of the parameter $A_{k,n}$ and offer reciprocity theorems for the continued fraction K(q).

• 한국기계가공학회지
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• 제3권3호
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• pp.58-63
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• 2004

In the present work a finite element formulation using dynamic-explicit time integration scheme is used for numerical analysis of multi-stage stamping processes. The lumping scheme is employed for the diagonal mass matrix and dynamic explicit formulation Multi-Stage stamping is analyzed by using dynamic-explicit finite element method. Further, the simulated results for the panel stamping processes are shown and discussed. Its application is being increased especially in the stamping industrial area for the cost reduction, weight saving, and improvement of strength.