• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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• pp.273-276
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• 2008

As the rapid and various changing of social aspects, the structures are getting bigger, higher and more complex. The importance of evacuation is on the rise as increased using frequency of multiplex sale facility and it's high population density. According to the result of a survey with 4 domestic wholesales mart's population density, the average and maximum was 0.41(人/$m^2$) and 0.46(人/$m^2$). considering evacuation dangerousness, the maximum value will be suitable for computation of evacuation capacity and this will be submitted as a basic data for computation of evacuation capacity.

• ETRI Journal
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• 제19권3호
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• pp.259-280
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• 1997

This paper briefly explains the configuration of CDMA Mobile System (CMS) test bed. The measured fading and delay results of CDMA signal in Taejon area are shown. In comparison to other cellular systems, there are more parameters in the CDMA systems that affect system performance and capacity. We performed the optimization test of the selected parameters and present the effect of each parameter on the performance. This paper presents the capacity and performance test results of CMS. The capacity test was performed on ETRI site of three sectors in Taejon area. The performance tests include call completion rate, busy hour call attempt, and the delay characteristics of voice.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 기초기술학술발표회
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• pp.57-76
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• 2002

As piling works in urban area increasing, SIP which is low noise & vibration piling method is taking place of driven pile which has good bearing charateristics and economics. Since SIP has been used for more than 15 years and it's application is increasing year by year, however, accurate analysis of bearing mechanism of SIP is not enough. So the design of SIP is much more conservative than driven pile. This paper is aimed to analyse the bearing charateristics of 103 SIPs constructed in Korea to give rational design criteria. Research result shows that bearing capacity of SIP is 40% lower than that of driven pile and conservative Meyerhof(equation omitted) method produced closer result to load test results than other design method. And this result show that to use optimised design criteria for the economic SIP design, quality control criteria must be settled down to produce high in-situ bearing capacity.

• 한국지반공학회지:지반
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• 제10권3호
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• pp.5-16
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• 1994

본 논문은 향후 현장에서 유용하게 사용될 수 있는 사질토층에 있어서 정방형 얕은 기초의 지지력 향상을 위한 새로운 Geogrid 보강토 방법을 제시하고자 하였다. 기계 기초, 철로 제방, 그리고 지진 예상 지역의 구조물 기초 등에 대한 지반은 Geogrid로 보강하는 것이 필수적이다. 보강되지 않은 사질토층과 보강된 사질토층에 대한 지지력을 비교하였으며 또한 극한 지지력을 증대시키기 위해 보강재의 길이, 설치 간격 및 폭을 평가하였다. 모형 실험 결과 Geogrid보강재는 중간 정도의 밀도를 가진 사질토층에서 극한 지지력이 상당량 증가됨을 알 수 있었다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1996년도 봄 학술발표회 논문집
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• pp.202-211
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• 1996

A number of typical type of steel-box pedestrian bridges are constructed in the metropolitan highway or heavy traffic urban area. Although it has the advantage of speedy construction because of its simple structural form and prefabricated erection method, it has been reported that many of these bridges are deteriorated or damaged and thus are in the state such that it would give unsafe and uncomfortable feeling to pedestrians. In the paper, for the realistic assessment of safety and residual earring-capacity of deteriorated and/or damaged steel box pedestrian bridges, an interactive non-linear limit state model are formulated based on the von Mises' combined stress yield criterion. It is demonstrated that the proposal model is effective for the reliability-based safety assessment and residual carrying-capacity evaluation of steel-box pedestrian bridges. In addition, this study suggests an effective and practical field load test method for pedestrian bridges.

• 한국구조물진단유지관리공학회 논문집
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• 제3권2호
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• pp.141-146
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• 1999

Recently, many existing bridges has been evaluated for maintenance and protection of collapse. In this study, field measurement according to truck loads tests on the reinforce concrete T beam bridge was carried out. Comparing the results of load test and structural analysis using the moments of inertia of gross section, crack section and effective section, and the moments of inertia of section considering depth of crack, it is conclude that the evaluation of load carrying capacity using the stress modification factor from structural analysis using the moments of inertia of gross section is more rational than using the other moments of inertia of sections.

• 한국초전도ㆍ저온공학회논문지
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• 제16권1호
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• pp.27-31
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• 2014

2G HTS tapes are widely used for various electric machines. In addition, stacked or parallel connected HTS tapes are essentially used to raise transport current level for large capacity electric machines. Therefore, critical current characteristic of stacked tapes need to be studied. Recently developed 2G HTS tapes are fabricated with various defects doping so that tapes possess pinning center to improve the critical current characteristic. During this process, the critical current is determined minimum value in not perpendicular magnetic field but a specific magnetic field angle according to the reported research. However, the effects of magnetic field angle to critical current of multi-stacked 2G HTS tapes have not been examined. In this paper, field coil which is a race-track coil wound by using an HTS tape with iron-core was fabricated to apply angle adjustable magnetic field to the 2G HTS tape samples. We measured critical current of single and multi-stacked two tapes that have different characteristic depending on various magnetic field angle and magnitude in liquid nitrogen environment. Furthermore, results of single and multi-stacked tapes were compared and analyzed.

• 한국초전도ㆍ저온공학회논문지
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• 제23권4호
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• pp.30-34
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• 2021

Superconducting magnets have paved the way for opening new horizons in designing an electromagnet of a high field magnetic resonance imaging (MRI) device. In the first phase of the superconducting MRI magnet era, low-temperature superconductor (LTS) has played a key role in constructing the main magnet of an MRI device. The highest magnetic resonance (MR) field of 11.7 T was indeed reached using LTS, which is generated by the well-known Iseult project. However, as the limit of current carrying capacity and mechanical robustness under a high field environment is revealed, it is widely believed that commercial LTS wires would be challenging to manufacture a high field (>10 T) MRI magnet. As a result, high-temperature superconductor together with the conducting cooling approach has been spotlighted as a promising alternative to the conventional LTS. In 2020, the Korean government launched a national project to develop an HTS magnet for a high field MRI magnet as an extent of this interest. We have performed a design study of a 7 T 320 mm winding bore HTS MRI magnet, which may be the ultimate goal of this project. Thus, in this paper, design study results are provided. Electromagnetic design and analysis were performed considering the requirements of central magnetic field and spatial field uniformity.

• 한국전자파학회논문지
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• 제20권8호
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• pp.761-769
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• 2009

본 논문에서는 FM 라디오 수신을 위한 차량용 온-글래스 안테나 간의 채널 용량과 다이버시티 이득에 대하여 연구하였다. 안테나 간의 상관 계수 및 채널 용량은 도심 환경에 해당하는 Rayleigh 채널 환경과 안테나의 시뮬레이션 3차원 복사 패턴을 이용하여 계산하였다. 직선형 안테나와 L자형 안테나를 이용하여 채널 용량을 계산하였고 안테나의 급전 위치 및 L자형 안테나의 형상을 변화시켜 채널 용량 변화를 확인하였다. 실제 세단에 적용가능한 급전 위치를 가지며 채널 용량이 높은 안테나 형상을 후면 글래스에 인쇄하여 야외 약전계 지역에서 FM 수신 출력을 측정하였으며, 안테나 수신 신호 간의 상관 계수는 0.65로 낮은 값을 보였다 차량용 온-글래스 안테나에서 높은 다이버시티 이득을 얻기 위해서는 안테나 간의 급전 위치가 최대한 이격되어야 하며, 급전간 거리가 일정 이상 확보되었을 때에는 안테나의 편파가 달라야 함을 확인하였다.

• 한국지반공학회논문집
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• 제19권5호
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• pp.343-354
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• 2003

재하판과 실제기초의 크기가 상이하므로 평판재하시험으로부터 실제 기초지반의 지지력 및 침하량을 산정할 때, Scale Effect가 고려되어야 한다. 본 논문에서는 5종류의 모형기초지반을 형성하고, 크기가 각각 l0cm, 15cm, 20cm, 25cm인 4가지 크기의 정사각형 평판으로 재하시험을 실시하여 재하판의 크기에 따른 지지력 및 침하 특성을 분석하였다. 또한 분석된 결과를 토대로 하여, 평판재하시험으로부터 실제기초의 지지력 및 침하량을 산정할 때, 모래와 점토의 혼합비율에 따라 Scale Effect를 합리적으로 고려할 수 있도록 식을 제안하였으며, 식에서 지지력 산정계수(a,b)와 침하량 산정계수(c,d)는 모래와 점토의 혼합비율에 따라 구할 수 있도록 그림으로 제시하였다. 지금까지는 현장기초지반에 대한 지지력 및 침하량을 합리적으로 평가할 수 없어 비경제적인 시공이 되어왔으나, 본 연구에서 제안한 지지력 및 침하량 산정방법에서는 모래와 점토의 혼합비율을 고려하여 기초지반의 지지력 및 침하량을 보다 합리적으로 추정할 수 있으므로 기초지반의 안정성 여부에 대한 확신과, 또한 경제적인 시공이 가능할 것으로 판단된다.