• 대한토목학회논문집
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• 제10권3호
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• pp.1-6
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• 1990

다지점지진하중(多支點地震荷重)을 받는 사경문(四徑問) 연속철도교양(連續鐵道橋梁)의 동적거동(動的擧動)을 응답(應答)스펙트럼법(法)에 의하여 조사(調査)하였다. 소진복(小振福)의 진동(振動)과 재료(材料)의 선형(線形)-탄성거동(彈性擧動)을 가정(假定)하였으며, 지반(地盤)-구조물(構造物) 상호작용(相互作用) 효과(效果)는 무시(無視)하였고, 교량(橋梁)의 횡방향(橫方向) 등답(應答)만을 고려(考慮)하였다. 응답(應答)스펙트럼해석(解析)의 결과(結果)는 시간이력해석결과(時間履歷解析結果)와 비교(比較)되었으며 모우드 최대치(最大値)와 지지점운동(支持點運動)의 중량(重量)은 여러가지 조합법칙(組合法則) 즉(卽), Square-Root-Of-Sum-Squares, Double Sum, 그리고 P-Norm Rule을 적용(適用)하였다.

• 한국지반신소재학회논문집
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• 제13권3호
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• pp.31-38
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• 2014

지오그리드 감쌈 쇄석말뚝 공법은 지오그리드의 인장구속효과로 인해 연약지반에 시공된 쇄석말뚝의 지지력을 증가시켜주는 공법이다. 본 연구에서는 토목섬유 감쌈 쇄석말뚝(GESC)공법의 설계에 적용할 수 있는 토목섬유 인장저항력과 극한지지력을 산정할 수 있는 합리적인 설계법을 제안하였다. 제안된 설계방법의 적적성을 평가하기 위해 부산 경전선 연약지반 시험시공 결과로부터 산출된 GESC의 극한지지력과 설계법에의해 산정된 극한지지력을 비교 검증하였다. 연구결과 GESC 설계법에 의해 산정된 지지력이 현장시험의 지지력 보다 크게 나타나는 것으로 검토되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1093-1094
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• 2006

City Train Technology that is large and complex system and consists of mechanical, electronic, electric, materials, computer, communication, civil/track etc. is very important area of railway industry, national fundamental industry. The standardization of city train system as a public transportation method and foundation of national economy is very important in order to do effective operation and to get fundamental technology, and the information system of the standards is required to operate the city train system effectively. By building data base of city train system design knowledge using computer-aided system engineering tool-Cradle, the system development issues and the design solutions are used by all engaged persons, and are managed by modeling and documentation. And this system will support architecture design consistently and effectively by applying this system to formalize early development process, to system requirements and configuration management, to system interface analysis and management and to system behavior analysis etc.. This study is for construction of data base of system design knowledge through making data base of many kinds of standards using CASE tool based on System Engineering Process, and introduces a model to support concurrent engineering for all engineers involved in system development allowing access to standard DB through Web from anywhere and at anytime.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.158-167
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• 2008

The quality control of compacted fills has been carried out by evaluating relative densities and coefficients of soil reaction. These measures have several limitations regarding repeatability and reliability of field measurements, and difficulties to use in the fills including large grain size as gravels and boulders. Also, the density is not directly related to the design parameter such as resilient modulus. A preliminary investigation for the usage of the stiffness as a control measure has been carried out. In the laboratory, the stiffness (P-wave velocity) was measured during compaction tests. The stiffness at the optimal moisture content was proposed to use a target control parameter likewise maximum dry density. A field method to match the target stiffness was also proposed by considering easiness of the method and availability of equipment. The most phenomenal feature of the method is that the control parameter (stiffness) is closely related to resilient modulus and can be consistently used from the design stage to the field control during construction.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1514-1518
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• 2009

Recently, railroad construction has been increased all over the world and as the train is getting high-speeded, there has been a need for guaranteed safety, so that a requirement for heath monitoring techniques for destruction that generated by gradually accumulated damages is now increasing. Especially the rail is crucial part that contact with wheel directly and delivers the train's load to a sleeper. It needs a technique that can guarantee a safety by sensing the possible cracks. In this paper, when train's load applied to the rail, strain distribution that introduced to entire length of rail is monitored using optical fibre. Optical fibre is used as a medium for measuring the strain and BOCDA (Brillouin Optical Correlation Domain Analysis) system is organized for measuring the distributed variation that implied to optical fibre. Optical fibre is attached at lower flange where tension is maximized when the load of train applied to the rail and strain gauge is implied together to compare the accuracy of measurement.

• Steel and Composite Structures
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• 제22권6호
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• pp.1239-1259
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• 2016

The modified couple stress-based third-order shear deformation theory is presented for sigmoid functionally graded materials (S-FGM) plates. The advantage of the modified couple stress theory is the involvement of only one material length scale parameter which causes to create symmetric couple stress tensor and to use it more easily. Analytical solution for dynamic instability analysis of S-FGM plates on elastic medium is investigated. The present models contain two-constituent material variation through the plate thickness. The equations of motion are derived from Hamilton's energy principle. The governing equations are then written in the form of Mathieu-Hill equations and then Bolotin's method is employed to determine the instability regions. The boundaries of the instability regions are represented in the dynamic load and excitation frequency plane. It is assumed that the elastic medium is modeled as Pasternak elastic medium. The effects of static and dynamic load, power law index, material length scale parameter, side-to-thickness ratio, and elastic medium parameter have been discussed. The width of the instability region for an S-FGM plate decreases with the decrease of material length scale parameter. The study is relevant to the dynamic simulation of micro structures embedded in elastic medium subjected to intense compression and tension.

• 한국안전학회지
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• 제31권3호
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• pp.68-74
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• 2016

This paper presents a new strengthening method of underground box structures against seismic loads for anti-seismic capacity improvement. A threaded steel member with pressure devices(so called 'Pre-flexed member system') is used to improve seismic capacity of the RC box structure. The pre-flexed member system is fixed the corner of opening after chemical anchor was installed by drilling hole on the box structure. The structural performance was evaluated analytically. Two bracing types of strengthening methods were used; conventional bracing method and I-bracing pressure system. For the performance evaluation, seismic analyses were performed on moment and shear resisting structures with and without strength member system. Numerical results confirmed that the proposed pre-flexed member system can enhance the seismic capacity of the underground RC box structures.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권9호
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• pp.509-514
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• 2002

The aim of this research is to find out how the common earth network affects the level of the traction return current in the $2{\times}25 kV$ Power Supply System. The traction return current plays a significant role in the operation of the facilities near the rails. It is shown that the common earth network in the $2{\times}25 kV$ power supply system not only minimizes the level of the traction return current, but also increases the safety of the working crew on the railways. In order to determine the relationship between common earth network and the traction return current, we investigated the earth system of the Gyongbu High Speed Line that is constructed following the SNCF regulations. We carried out the field test in the Osong station. The results of the test show that the common earth network minimizes the effect of the traction return current. We also find that the simulated results are very similar to the test results. We concluded that the results of the test can be applied for the rest of the Gyongbu High Speed Line under construction.

• 전기학회논문지P
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• 제53권2호
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• pp.89-93
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• 2004

Supervisory Control And Data Acquisition(SCADA) of electric power system refersto the system that displays, monitors and executes the control commands for remote electric power system. KNR's existing electric power control system is built on UNIX platform such that it costs more for system construction, and people with UNIX skills can only be an operator who controls and manages the system. Moreover, since the system is mainly operated in local offices, system operators must communicate with local operators to investigate the cause of the accident and react the accident every time the system fails. As a new integrated SCADA system is constructed, establishment of small-unit electric power control system, that alters local electric power control system in designated stations, is required. In this study, the electric power control system, which accommodates all functions of UNIX-based SCADA system and facilitates operation and even maintenance for local operators, is to be developed. In order to develop small-unit electric power control system, the industrial automation program, "Cimon", is used. The small-unit electric power control system that accommodatesRTU and newly installed electronic switchboard is being developed and tested at Chulam station of KNR.

• 한국방재안전학회논문집
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• 제10권2호
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• pp.1-6
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• 2017

사물 인터넷(IOT)을 기반으로 한 지하철 재난 조기경보 및 승객 대피를 위한 재난전조 시스템 개발 연구가 이미 선행연구를 통해 수행하였다. 본 논문에서는 역에 설치된 센서 데이터를 분석하여 재난을 신속 하게 감지하기 위한 후속 연구이다. 특히, 본 연구는 초기 시스템 구축 시 센서의 설치 위치에 따라 다를 수 있는 환경변화를 고려한 마할라노비스 거리를 기반으로 통계적 방법론을 개발하였다.