• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.21-23
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• 1989

This paper deals with the design method of Superconduting AC Generator(SCG). The establishment of design principle and design procedure of SCG are included in this study. Electric characteristics of SCG, such as synchronous reactance and subsubtransient reactance, are specified first as constraints and the size of SCG is calculated. A 20 KVA with double-shield single-rotor is chosen for case study.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1062-1067
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• 2007

This study presents an experimental technique to monitor the dynamic behavior of the railway bridge system simultaneously using multiplexed fiber Bragg grating (FBG) sensors. The measuring quantities include stains, curvatures, vertical deflections, and vertical accelerations. The strains are directly measured from multiplexed FBG sensors at various locations of the test bridge followed by curvature calculations based on the plane section assumption. Vertical deflections are then estimated using the Bernoulli beam theory and regression analysis. Finally, vertical accelerations are obtained from the numerical differentiation in time domain. In order to verify the proposed method, several conventional electric strain gauges, displacement transducers, and accelerometers are installed at the mid-span of the bridge for comparisons. A test train is passed over the bridge to monitor the dynamic response of the bridge. The monitoring results show that the multiplexed FBG sensing system is able to capture the essential behavior of the test bridge while resolving wiring problem in practice.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1074-1079
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• 2007

It is important to evaluate the effect in the maintenance of steel bridge because the fatigue of the bridge is affected by the structural characteristic of bridge such as structure type, span and steel grade, etc. In this study, we analyzed the effect of fatigue strength by the changes of span of the bridge and the steel grade in many factors which have influence on the fatigue life of the bridge. For this analysis, we selected the objective bridges and performed the structural analyses for the various parameters such as span and steel grade. The fatigue evaluations were carried out by FAST which is a program for fatigue estimation and the results were compared.

• 한국안전학회지
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• 제15권1호
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• pp.132-139
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• 2000

In this study, the fatigue life assessments of steel railway bridge in Japan National Railway were carried out. This railway bridge has been under in service from 1957, and fatigue damages were occurred at bead toe of upper part of vertical stiffeners of stringers, bead toes of scallop in lower part of vertical stiffeners in stringers and crossings of cross beams and stringers. From this study, a series of field tests were carried out by stress history measurement about above mentioned points. And as a results of stress histogram analysis, cummulative fatigue damage rate and fatigue life of these members should be calculate quantitatively. And from this estimation technique, cummulative fatigue damage rate and fatigue life of this railway bridge were strongly affected in passing tonage every year and the histories of live load.

• 한국강구조학회 논문집
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• 제8권4호통권29호
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• pp.19-29
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• 1996

In this paper, it is presumed that the stress time history was generated by simulation method and investigated compatibility in regard to the reappearance of stress time history. In this procedure, the identified frequency distribution of stress range of the steel railroad bridge varies with the rational values of cut off point and bar width. Thus, we show variable aspect of the equivalent stress range results from change of cut off point and bar width. In addition, we analyze the variable of RMC and RMS model due to the cut off point and bar width of the measured stress history which influencs the prediction of fatigue life in the steel railroad bridge. The simulated stress time history is carried out by the superposition method incorporating the vertical load with rotation moment obtained from the Hermition interpolation function, and compared with developing stress results from measured maxi mum stress. Through this study, we can estimate the remaining fatigue life from a safety point of view and comparative accuracy.

• 한국강구조학회 논문집
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• 제8권4호통권29호
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• pp.95-103
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• 1996

단순 전단연결 구조를 가진 강철도교의 세로보 단부의 절취부위에서 많은 피로균열이 발견되었으며, 이러한 부위의 피로균열은 피로손상의 전형적인 예이다. 피로균열을 가진 세로보 절취부위의 보강방법을 연구하기 위하여 가로보 및 세로보의 상부 플랜지에 인장판을 부착한 경우와 부착하지 않은 경우로 구분하여 피로실험을 수행하였다. 피로실험에 사용된 하중은 현장에서 측정된 실동응력을 기초하여 빈도해석을 통해 산정하였다. 피로실험 결과, 인장판으로 보강한 모멘트 저항 연결구조상세가 철도교에서 균열성장을 효과적으로 정지시킬 수 있는 것으로 판명되었으며, 피로손상을 가진 절취부위의 보강방법으로 제시될 수 있을 것으로 사료된다.

• 한국정보교육학회:학술대회논문집
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• 한국정보교육학회 2007년도 동계학술대회
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• pp.165-172
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• 2007

e-Learning 학습의 효율성을 극대화하기 위해서는 학습자의 인지 능력에 맞는 아이콘 설계가 중요하다. 따라서 본 연구는 e-Learning콘텐츠를 제공하고 있는 시 도 교육청 사이버 가정학습 사이트의 아이콘을 수집하여 유형별로 분석하고 초등학생들의 아이콘 인지도를 조사하였다. 의미 표현 방법상 분류에 의한 아이콘들이 고르게 높은 인지도를 나타냈고 구체적인 메타포를 이용하여 설계한 아이콘들이 인지도가 높았다. 따라서 아동들의 인지 발달에 맞는 구체적인 메타포를 이용하여 아이콘을 설계해야 할 것이다.

• 한국정보교육학회:학술대회논문집
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• 한국정보교육학회 2007년도 동계학술대회
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• pp.301-308
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• 2007

21세기 교육환경의 변화로 인해 언제 어디서나 누구든지 쉽고 편리하게 자기 주도적 학습을 할 수 있는 도구로서 이러닝이 주목받기 시작하면서, 효과적인 이러닝 활용 능력을 가진 이러닝 전문 교사의 필요성이 확대되었다. 본 논문에서는 이러닝을 선도하는 전문 교사 양성을 위한 교육과정을 개발하기 위해, 국내 이러닝 전문 인력 양성 기관의 교육과정 및 전국 16개 시 도교육청 ICT 관련 연수 과정을 분석하고, 현장 교사들을 대상으로 이러닝 관련 요구사항을 파악하여 이러닝 전문 교사 양성 교육과정을 개발하였다.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2001년도 춘계학술발표대회 논문집
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• pp.90-94
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• 2001

This study hypothesizes that the imageability of a particular environments is decided by the unity of each visual sequences. We selected Ch'angdok Palace as our subject due to its greater applicability for image construction among various Korean architectures and their street furnitures. we apply the analytical methods of formal aesthetics and symbolic aesthetics to Ch'angdok Palace's space compositional characteristics, we can find distinctive features. The conclusions are that Ch'angdok Palace contains high probability of imageability through the contrast and harmony of two themes, reality and the ideal, and the rational and the emotional.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.185-190
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• 2005

In order to evaluate that factors such as span length, member type and train loading affected on fatigue of steel railway bridges, in this paper, a series of field tests were carried out for some plate girder bridges. From the result estimated by rainflow counting method to analyze real strain-time curve obtained from the field test, it was known that the fatigue effect is more significant in the bridges having short span length and the secondary members regardless of train load types.