• 대한교통학회지
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• 제14권4호
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• pp.31-48
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• 1996

This paper develops a disaggregate model system for travel behavior of workers in a metropolitan area. We attempt to develop a set of models for predicting trip generation type, trip purpose, destination, mode choices in each trip on the way from work to home by using the concept of utility maximization of base-to-base tour. The model incorporates the concept that decisions of a trip in a trip in a travel tour depend on decisions of the trips having been made before and decisions of trip planned after of this trip, as well as on current trip conditions. As the structure of the model, the nested logit model is used to avoid a simultaneous model's complexity. The data to be used for estimating the model system are from the person trip survey which was carried out in 1981 in Nagoya metropolitan. Empirical tests of the model for Nagoya metropolitan area show encouraging results and prove the validity of the assumption of this model.

• 한국환경교육학회지:환경교육
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• 제21권3호
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• pp.1-12
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• 2008

This study is aimed at suggesting ways to develop field trip or learning materials focusing on environment of Jeju seashore in order to make an effective field trip. To perform these purposes, the contents and concepts were analyzed from environment-related 'geological unit' of elementary science textbook. Afterwards, the places having the geological features in coincidence with them are chosen, and investigated, and these regions can develop into geological teaming places for field trip. Each teaming spot focuses on understanding and finding out the characteristic geological environment of rock shore, gravel shore, sand shore, shellfish shore, and tideland shore among Jeju shores. When field trip is conducted at the preparatory stage, students can get advance knowledge on geological concepts from textbook. The activity record paper is presented at the field trip stage where students observe geological phenomena on their own. After field trip is finished, the summary stage is given to solve some problems on the basis of the observed contents. The developed data from this research have its regional limits, but is surely useful for teachers who try to plan field trip when they especially choose the right field trip spots, or plan to make the process for field trip preparation of the environmental education. Furthermore, with this survey and activities, students can take the chance to improve the learning effect through their own experience on environment of Jeju seashore.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 춘계학술발표대회 개요집
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• pp.149-151
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• 2003

The development of lightweight car bodies is the most prominent issue in the automotive industry today, in preparation of environmental regulations such as reduction of CO$_2$ emissions. Also, with the recent implementation of mandatory off-set collision test, many studies have been carried out to enhance the safety of automobiles. Recently, TRIP(Transformation Induced Plasticity) steel has developed as a prominent alternative due to its high strength and superior elongation. In this study, TRIP steel weldability is evaluated with lobe curve, continuous spot welds, shunt effect, and weld of edge position.

• 대한금속재료학회지
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• 제49권4호
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• pp.281-290
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• 2011

In order to gain better understanding of the selective surface oxidation and its influence on the galvanizability of a transformation-induced plasticity (TRIP) assisted steel containing 1.5 wt.% Si and 1.6 wt.% Mn, a model experiment has been carried out by depositing Si and Mn (each with a nominal thickness of 10 nm) in either monolayers or bilayers on a low-alloy interstitial-free (IF) steel sheet. After intercritical annealing at $800^{\circ}C$ in a $N_2$ ambient with a dew point of $-40^{\circ}C$, the surface scale formed on 590 MPa TRIP steel exhibited a microstructure similar to that of the scale formed on the Mn/Si bilayer-coated IF steel, consisting of $Mn_{2}SiO_{4}$ particles embedded in an amorphous $SiO_{2}$ film. The present study results indicated that, during the intercritical annealing process of 590 MPa TRIP steel, surface segregation of Si occurs first to form an amorphous $SiO_{2}$ film, which in turn accelerates the out-diffusion of Mn to form more stable Mn-Si oxide particles on the steel surface. During hot-dip galvanizing, particulate $Fe_{3}O_{4}$, MnO, and Si-Mn oxides were reduced more readily by Al in a Zn bath than the amorphous $SiO_{2}$ film. Therefore, in order to improve the galvanizability of 590 TRIP steel, it is most desirable to minimize the surface segregation of Si during the intercritical annealing process.

• 대한공간정보학회지
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• 제12권3호
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• pp.43-50
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• 2004

본 연구에서 교통수요 예측기법 중 통행량 분포기법의 이론적 배경에 대하여 광주광역시를 중심으로 컴퓨터 시뮬레이션을 통하여 분석 평가하고 모형에 내재되어 있는 매개변수의 특성변화를 연구하여 통행량 분포모형의 적용 타당성을 찾고자 하는데 연구의 목적이 있다. 본 연구에서는 통행분포모형의 정립을 목적으로 광주시의 20개 대존 중에서 도심지역에 해당되는 9개 존을 중심으로 한 통행목적별, 수단별, 출발 도착통행량 모형을 정립하였다. 여기에서는 기준 년도를 1996년으로 하고 2001년까지의 통행량을 분석하고 2008년도까지의 통행분포량을 예측하였다.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.164-171
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• 2003

The side impact behavior has been investigated when the high strength steel 60TRIP(Transformation Induced Plasticity) is replaced for the conventional low-carbon steel for weight reduction of an auto-body. The side impact analysis was carried out as specified in US-SINCAP with the center pillar and the side sill of the conventional steel or 60TRIP. For accurate impact analyses, the dynamic material properties are adopted with the Johnson-Cook model. The analysis results demonstrate that the penetration of the side members is remarkably reduced when 60TRIP is employed for the center pillar and the side sill replacing the conventional steel. The crashworthiness in the side impact is considerably improved with less penetration of the side members and less acceleration of the opposite floor.

• 한국콘텐츠학회논문지
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• 제20권6호
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• pp.482-497
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• 2020

본 연구는 대학생들이 해외 답사여행을 수행함에 있어 소집단 사회연결망이 어떻게 존재하고 여행기간동안에 어떻게 변화하는지 그리고 여행의 제반 성과인 답사여행 만족, 학과몰입, 교우관계 등과 어떠한 관련이 있는지를 알아보는데 목적이 있다. 한국 대학생들은 유래 없는 학교적응 문제를 겪고 있는데 이러한 현상은 대학교육이 제대로 이루어지고 있는지에 대한 의구심과 이에 대한 해결 필요성을 증대시켜주고 있다. 여행은 참가자 집단에게 강한 유대감을 제공해주기 때문에 같은 맥락으로 학생들의 해외답사여행이 학생집단 결속을 강화시킬 수 있다는 가정을 해 볼 수 있다. 해외답사여행에 참여한 31명의 대학생을 대상으로 설문조사를 실시하여 유의미한 소집단 연결망 구조의 존재 여부, 그 변화양상 그리고 관련 변수간의 영향 등을 알아보았다. 첫째로, 대학생 해외답사여행의 소집단 연결망 구조는 학생 집행부 소속 학생들이 연결 중심성의 위치에 있는 등 비교적 명시적으로 존재하고 있었다. 둘째로 출발 전과 출발 후에 연결망 구조가 변하였으며 이는 여행기간 중에 참가자간의 상호작용이 발생한 것에 기인한다. 셋째로, 소집단 연결망 구조 변화에 따라 연결중심 및 매개중심으로 이동하였다 하더라도 제반 여행성과 변수에 주는 영향은 제한적이었다. 넷째로 답사여행 만족, 학과몰입, 교우관계는 유의한 상관관계를 가지고 있었다. 논문 말미에 연구 시사점과 한계점을 포함하였다.

• 대한지구과학교육학회지
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• 제8권2호
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• pp.193-205
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• 2015

In this study, a Virtual geological Field Trip(VFT) learning program using 3D panorama virtual reality techniques was developed to learn about the Gongju city 7 area located in Chungcheongnam-do, Korea. The developed $360^{\circ}$ 3D VFT program can show every face of observational points and interact as zoom-in, zoom-out and image rotation. For the educational effects of the materials, it is provided with a compass, a protractor, enlarged images, pop-up windows, etc.. The program was applied to the class of 35 gifted students in middle school to investigate the effectiveness of the program. The results showed that positive responses of the students were 90% or more. When geological field trip problems like cost, safety, distance occur in geological learning procedure of middle school science, this VFT program can become as a supplementary learning material and a solution.

• 대한토목학회논문집
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• 제33권6호
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• pp.2503-2508
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• 2013

최근 20~30년사이 수도권 1인가구의 비율은 크게 증가하였으며, 총 인구의 감소에도 불구하고 1인가구수는 지속적으로 증가할 것으로 예상된다. 그러나 국내 교통분야에서는 1인가구 증가가 교통분야에 미치는 연구가 미흡한 실정이다. 본 연구는 수도권 가구통행실태조사를 활용하여 가구 속성별로 가구규모에 따른 통행발생의 차이를 알아보기로 하였다. 연구방법으로는 수도권 가구통행실태조사 자료에서 가구 속성과 가구원 속성, 통행 속성에 대하여 가구규모별로 통행발생횟수(/일/인)을 산출하였다. 유의성검토를 거쳐 1인가구와 타 규모(2인 이상)가구와의 비교를 통하여 1인가구만의 통행발생 특성을 분석하였다. 연구 결과로는 전체적으로 1인가구의 통행발생은 타 규모 가구의 통행발생보다 높게 나타났으며, 주택종류, 거주형태, 지역, 통행수단 속성에서도 차별된 통행발생 특성을 보여주었다. 본 연구의 결과가 1인가구의 통행발생 특성을 반영한 통행발생모형 구축 등 교통정책개발에 이바지하길 기대하여본다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 춘계학술대회 논문집
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• pp.156-160
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• 2001

The effects of TRansformation Induced Plasticity(TRIP) phenomena on the plastic deformation of 0.2C-1.5Si-1.5Mn multiphase steels have been investigated at various heat treatment and stress conditions. In order to estimate the formability, the hole expansion(HE) tests and the tensile tests were carried out. The formability evaluated from the uni-axial tensile tests was quite different from the formability measured from multi-axial HE-tests. Consequently, the formability in the multi-axial stress state decreased due to the extinction of the retained austenite relatively at earlier deformation stage and the production of irregular α' martensite. However, the defects of TRIP-steels were initiated exactly at the boundary between transformed martensite and ferrite matrix regardless of stress state. In addition, new experimental formula is proposed in order to predict the multi-axial formability of the TRIP steels from the results of uniaxial tensile test.