• Geomechanics and Engineering
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• 제13권5호
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• pp.715-742
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• 2017

Earth berms are often left in place to support retaining walls or piles in order to eliminate horizontal struts in excavations of soft soil areas. However, if the excavation depth is relatively large, an earth berm-supported retaining system may not be applicable and could be replaced by a multi-bench retaining system. However, studies on multi-bench retaining systems are limited. The goal of this investigation is to study the deformation characteristics, internal forces and interaction mechanisms of the retaining structures in a multi-bench retaining system and the failure modes of this retaining system. Therefore, a series of model tests of a two-bench retaining system was designed and conducted, and corresponding finite difference simulations were developed to back-analyze the model tests and for further analysis. The tests and numerical results show that the distance between the two rows of retaining piles (bench width) and their embedded lengths can significantly influence the relative movement between the piles; this relative movement determines the horizontal stress distribution in the soil between the two rows of piles (i.e., the bench zone) and thus determines the bending moments in the retaining piles. As the bench width increases, the deformations and bending moments in the retaining piles decrease, while the excavation stability increases. If the second retaining piles are longer than a certain length, they will experience a larger bending moment than the first retaining piles and become the primary retaining structure. In addition, for varying bench widths, the slip surface formation differs, and the failure modes of two-bench retained excavations can be divided into three types: integrated failure, interactive failure and disconnected failure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.378-380
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• 2001

The railway signaling system consists of computerized vital devices. Therefor it is important to validate the required functions of developed signaling system. To verify the condition and functions of signaling functions, the plentiful laboratory test is required. To achieve this, the emulation S/W for signaling test-bench is needed. The object-oriented concept for trackside signaling equipments emulation is described in this paper.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.740-754
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• 2015

This paper focuses on the reverse blocking busbar protection scheme with aim to improve the speed of its operation and at the same time to increase operational reliability, flexibility and stability of the protection during external and internal faults by implementation of the extended functionality provided by the IEC61850 standard-based protective Intelligent Electronic Devices (IEDs). The practical implementation of the scheme by the use of IEC 61850 standard communication protocol is investigated. The proposed scheme is designed for a radial type of a distribution network and is modeled and simulated in the DigSILENT software environment for various faults on the busbar and its outgoing feeders. A laboratory test bench is built using three ABB IEDs 670 series that are compliant with the IEC 61850 standard, CMC 356 Omicron test injection device, PC, MOXA switch, and a DC power supplier. Two types of the reverse blocking signals between the IEDs in the test bench are considered: hard wired and Ethernet communication by using IEC 61850 standard GOOSE messages. Comparative experimental study of the operational trip response speeds of the two implementations for various traffic conditions of the communication network shows that the performance of the protection scheme for the case of Ethernet IEC 61850 standard-based communication is better.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 춘계학술대회 논문집
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• pp.269-275
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• 2000

The railway signaling system consists of microcomputerized vital devices on board and ground, which are connected to one another by track circuits, and interlocking equipment for route control. Therefore it is important to validate the required functions of developed system and interface between developed signaling systems. To verify the conditions and functions of signaling logic, the laboratory prototype test bench, which consists of personal computers with software module and Ethernet LAN, will be developed. In this paper general design of signaling system test bench for high-speed rail is described and developed software module is presented.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 춘계학술대회 논문집
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• pp.315-321
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• 1999

The railway signaling system consists of microcomputerized vital devices on board and ground, which are connected to one another by track circuits, and interlocking equipment for route control, The software plays a major role in these microcomputer-based vital systems. Therefore it is important to design the software and validate the required levels of safety and reliability To verify the conditions and functions of signaling logic, the laboratory prototype test bench, which consists of personal computers, VME system and Ethernet LAN, will be developed. In this paper general design of signaling system test bench for high-speed rail is described and some developed subprogram is presented.

• 대한전자공학회논문지TC
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• 제48권12호
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• pp.1-8
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• 2011

일반 산업분야에서는 활발히 진행되고 있는 KOLAS(Korea Laboratory Accreditation Scheme) 시험기관 인정이 스위치, 라우터등의 네트워크장비 분야에서는 인정 현황을 찾아 볼수 없다. 즉 기관의 자체 시험이나 BMT(Bench Marking Test)를 통하여 네트워크장비에 대한 평가를 진행하고 있지만 공인 시험기관에서 발행하는 시험성적서와는 품질에 차이가 있다. 공공기관 또는 기타 사업자가 요청하는 공인기관 시험성적서의 수요가 증가함에 따라 국내에서도 네트워크 장비에 대한 공인시험기관 인정이 조속히 이루어 져야 한다. 따라서 본 논문에서는 한국인정기구에서 요구하는 네트워크장비 분야에 대한 국제공인 시험기관 인정 추진 과정에서 분석한 측정불확도와 프로그램을 통해, 효율적인 추진 방향을 제시하고자 한다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.348-351
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• 2003

Trichloroethylene, which is one of the representative DNAPL, has been found in underground water sources as a result of the manufactural use, and disposal of the chemical. In this research, in situ air sparging method was chosen to reduce the TCE concentration from the source zone. The concentration reduction in the source zone resulting from air sparging is simulated using the modified STOMP Water-Air operational mode in a two dimensional axisymmetric domain and bench scale test is conducted to analyze the performance of air sparging. The results of laboratory tests are compared with numerical simulations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1420-1422
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• 2000

The railway signaling system consists of micro-computerized vital devices on board and ground, which are connected to one another by track circuits, and interlocking equipment for route control. Therefore it is important to validate the required functions of developed system and interface between developed signaling systems. To verify the conditions and functions of signaling functions, the laboratory prototype test bench, which consists of personal computers LAN, will be developed. In this paper design of signaling system test-bench for high-speed signaling is described and developed software module are presented.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제26권2호
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• pp.39-47
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• 2020

Purpose: Clinical laboratory of hospital has been demanded to extension or relocation regarding with the test number increase and analyzer development. Space area criteria per test numbers, lab functions, hospital bed and lab staffs are needed for draft space programing. So, the purpose of this study is to provide the space area guideline of clinical laboratory for space calculation in planning and design the spatial environment. Methods: Literature review has been used in checking the standards and guidelines. And questionnaire surveys to laboratory supervisors in hospitals have been conducted for the data collection. 60 answers have been analysed statistically by MS Excel program. Results: The result of this study can be summarized into three way calculations. The first one shows that the basic standard workspace and distance is applied in lab design. The second one shows that average space area criteria resulted from case studies is applied by 19㎡ per one staff, 0.9~1.0㎡ per one bed, and lastly linear length calculation of workbenches and analyzers on the bench top and floor mount, is multiplying it by the sum of the counter depth plus aisle width. Implications: In updating the space area calculation guidelines, it is necessary to cooperate with medical staffs and designers.

• Journal of Power Electronics
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• 제14권3호
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• pp.580-591
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• 2014

This paper concerns a three-phase self-excited induction generator used for autonomous power generation. It presents a robust control strategy which makes it possible to maintain the frequency quasi constant during the voltage regulation without any control loop on this variable. This strategy, which also prevents the machine disengagement, uses as power converter a simple dimmer. The obtained theoretical and/or numerical results are validated on a laboratory test bench that allows the analysis of this control law effectiveness.