• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1994년도 추계학술대회 논문집
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• pp.173-181
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• 1994

Process design is one of the most important fields in metal forming, where the finite element method has appeared a useful method for industrial applications. In this study, a program using the rigid plastic finite element has been developed for preform design in three-dimensional plastic deformation. The surface integration for calculation of the friction between die and workpiece has been implemented with care in numerical treatment. The developed program is applied to a precision coining process for designing an optimal punch.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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• pp.544-551
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• 2002

Tn this paper we propose a systematic methodology for setting up master plans of knowledge management(KM). The proposed methodology is developed based on both the previous KM theories and the experience from industry fields. The methodology is consist of four stages: 1) setting up strategic directions, 2) analyzing the current status, 3) designing KM models, and 4) making KM master plans. We expect that the proposed methodology will be used in the various organizations as an efficient and effective planning tool when setting up master plans of KM.

• 한국구조물진단유지관리공학회 논문집
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• 제6권2호
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• pp.167-174
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• 2002

흙막이 구조물은 한정된 부지의 효율적인 활용 차원에서 고층건물, 개착식 지하철, 지하상가 등의 건설을 위해 시공되는 가설구조물이다. 최근 들어, 교량, 터널, 도로 등의 설계와 시공에 관련된 표준화 작업과 DB화 작업이 활발히 이루어지고 있다. 이러한 구조물의 설계와 시공에 관련된 각종 통계 자료가 축적되고 여러 문제점들이 분석되어 실제 설계 시공에 많이 반영되고 있다. 그러나, 건설현장에서 많이 설계 시공이 되는 흙막이 구조물과 관련해서는 DB화 작업이 전무할 뿐만 아니라 이를 통한 활용이 이루어지지 않고 있다. 따라서, 본 논문은 흙막이 구조물에 관련된 100개 현장의 설계와 시공에 대한 지적사항들을 분류하였으며, 이 자료를 기초로 하여, 분류체계를 구성하였으며, 흙막이 구조물의 설계와 시공에 관련된 중요 고려사항을 DB 프로그램으로 개발하였다.

• Structural Engineering and Mechanics
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• 제45권1호
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• pp.1-18
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• 2013

The typhoon wind characteristics designing for buildings or bridges located in complex terrain and typhoon prone region normally cannot be achieved by the very often few field measurement data, or by physical simulation in wind tunnel. This study proposes a numerical simulation procedure for predicting directional typhoon design wind speeds and profiles for sites over complex terrain by integrating typhoon wind field model, Monte Carlo simulation technique, CFD simulation and artificial neural networks (ANN). The site of Stonecutters Bridge in Hong Kong is chosen as a case study to examine the feasibility of the proposed numerical simulation procedure. Directional typhoon wind fields on the upstream of complex terrain are first generated by using typhoon wind field model together with Monte Carlo simulation method. Then, ANN for predicting directional typhoon wind field at the site are trained using representative directional typhoon wind fields for upstream and these at the site obtained from CFD simulation. Finally, based on the trained ANN model, thousands of directional typhoon wind fields for the site can be generated, and the directional design wind speeds by using extreme wind speed analysis and the directional averaged mean wind profiles can be produced for the site. The case study demonstrated that the proposed procedure is feasible and applicable, and that the effects of complex terrain on design typhoon wind speeds and wind profiles are significant.

• Wind and Structures
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• 제18권5호
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• pp.473-495
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• 2014

Localized wind events, in the form of tornadoes and downbursts, are the main cause of the large number of failure incidents of electrical transmission line structures worldwide. In this study, a numerical model has been developed to study the behaviour of self-supported transmission lines under various tornado events. The tornado wind fields used were based on a full three-dimensional computational fluid dynamics analysis that was developed in an earlier study. A three-dimensional finite element model of an existing self-supported transmission line was developed. The tornado velocity wind fields were then used to predict the forces applied to the modelled transmission line system. A comprehensive parametric study was performed in order to assess the effects of the location of the tornado relative to the transmission line under F2 and F4 tornado wind fields. The study was used to identify critical tornado configurations which can be used when designing transmission line systems. The results were used to assess the sensitivity of the members' axial forces to changes in the location of the tornado relative to the transmission line. The results were then used to explain the behaviour of the transmission line when subjected to the identified critical tornado configurations.

• 공학교육연구
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• 제19권4호
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• pp.3-13
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• 2016

The purpose of this study was to investigate engineering professors' perceptions on the key competencies for engineering students (i.e. creativity, problem solving, designing, field application, etc.) and their instructional efforts to promote the competencies. The guiding research questions included 1) to what extent engineering professors perceived the key competencies as the important qualification that engineering students should obtain in college, 2) to what extent the professors put in a great deal of effort to promote such competencies in their teaching, and 3) how their perceptions on the key competencies correlated with their instructional practice. Two hundred fifteen engineering professors affiliated to diverse fields voluntarily participated in the study and filled out 5 point-Likert scale survey items. In results, despite of some range of variation on their perceptions according to the fields, most of the engineering professors highly valued the four key competencies. However, compared to the perceptions, engineering professors in some engineering fields relatively less focused on promoting the competencies in their teaching practice.

• Journal of Computational Design and Engineering
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• 제2권2호
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• pp.88-95
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• 2015

Recently, fiber composite materials have been attracting attention from industry because of their remarkable material characteristics, including light weight and high stiffness. However, the costs of products composed of fiber materials remain high because of the lack of effective manufacturing and designing technologies. To improve the relevant design technology, this paper proposes a novel simulation method for deforming fiber materials. Specifically, given a 3D model with constant thickness and known fiber orientation, the proposed method simulates the deformation of a model made of thick fiber-material. The method separates a 3D sheet model into two surfaces and then flattens these surfaces into two dimensional planes by a parameterization method with involves cross vector fields. The cross vector fields are generated by propagating the given fiber orientations specified at several important points on the 3D model. Integration of the cross vector fields gives parameterization with low-stretch and low-distortion.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.414-427
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• 2020

The finite element method is used to simulate the navigation of an ice-area bulk carrier in broken ice fields. The ice material is defined as elastic, and the simulations are accomplished at four model speeds and three ice concentrations. The movements of ice floes in the simulation are consistent with those in the model test, and the percentage deviation of the numerical ice resistance from the ice resistance in the model test can be controlled to be less than 15 %. The key characteristics of ice loads, including the average ice loads, extreme ice loads, and characteristic frequency, are analyzed thoroughly in a comprehensive manner. Moreover, the effects of sailing speed and ice concentration on the ice loads are analyzed. In particular, the stress distribution of ice floes is presented to help understand how model speed and concentration affect the ice loads. The "ice pressure" phenomenon is observed at 90 % ice concentration, and it is realistically reflected both in the time―and frequency―domain ice force curves.

• 컴퓨터교육학회논문지
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• 제6권1호
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• pp.79-86
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• 2003

본 연구자들은 ICT 활용 교육을 위한 초등교육 지도안을 온라인상에서 작성하고 활용할 수 있는 Web기반 전자지도안 시스템을 개발하였다. 개발된 온라인 전자지도안 시스템 은 ICT 교수-학습 과정안 자료를 데이터베이스화하여 체계적으로 관리할 수 있도록 하였으며, 교수-학습 과정안의 공유, 활용, 저장성의 극대화를 도모하여 학교 정보화에 이바지할 수 있다. 이렇게 개발된 시스템이 현장에서 활용되면서 나타난 교육적 효과 및 문제점을 분석하여 해결 방안을 제시하는 것은 시스템의 개발 못지않게 중요하다고 할 수 있다. 따라서 본 연구에서는 첫째, 본 시스템 개발을 위한 ICT 활용 교수 학습 과정안 형태의 구안과정과 둘째, 본 시스템의 설계와 구현 방법의 개요, 그리고 셋째, 초등학교 현장에서 적용하면서 나타난 시스템의 효과와 문제점 분석 및 개선방안을 제시하였다. 본 연구를 통하여 초등교육에서 사용하게 될 전자 교육 시스템의 개발 과정 및 활용 상의 고려사항과 문제점의 해결 방안에 대한 교육적 근거를 제공하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1784-1787
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• 2002

Two-dimensional (2-D) digital filters are widely useful inn image processing and other 2-D digital signal processing fields, but designing 2-D filters is much more difficult than designing one-dimensional (1-D) ones. This paper provides a new insight into the existing singular value decomposition (SVD)-based design approach in the sense that the SVD-based design can be performed more efficiently by exploiting the symmetries of the given 2-D magnitude specifications. By using the specification symmetries. only half of the 1-D filters (sub-filters) need to be designed. which significantly simplifies the design process and reduces the computer storage required for 1-D sub-filter coefficients. Another novel point of this paper si that an objective criterion is proposed for selecting appropriate sub-filter orders in order to reduce the hardware implementation cost. A design example is given to illustrate the effectiveness of the SVD-based design approach by exploiting specification symmetry and new order-selecting criterion.