• 한국화재소방학회논문지
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• 제30권3호
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• pp.79-85
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• 2016

원자력발전소의 방화지역에서 전기적인 단락, 지락, 전기회로 개방 등의 전기 문제로 화재가 발생할 수 있다. 전기 화재가 발생할 경우 안전계통 및 관련기기의 안전정지 기능이 상실된다. 이러한 사고를 예방하기 위하여 안전계통은 다중성, 독립성으로 설계되어 있다. 그러나 케이블 화재시 운전원은 오동작, 잘못된 지시 및 계측으로 발전소 상황을 잘 못 판단하여 적절한 조치를 하지 못할 수 있다. 따라서 주제어실 화재시 케이블 기능상실온도에서 최소 운전원 조치 요구시간인 5분은 매우 중요하다. 본 논문에서 주제어실 화재시 케이블의 기능상실온도 시간을 분석하여 운전원 조치시간이 충분한지 평가하여 주제어실 화재에 대한 안전성을 확인하였다.

• Smart Structures and Systems
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• 제23권6호
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• pp.627-639
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• 2019

Passive control may not provide enough damping for a stay cable since the control devices are often restricted to a low location level. In order to enhance control performance of conventional passive dampers, a new type of damper integrated with a rotary electromagnetic damper providing variable damping force and a flywheel serving as an inertial mass, called the rotary electromagnetic inertial mass damper (REIMD), is presented for suppressing the cable vibrations in this paper. The mechanical model of the REIMD is theoretically derived according to generation mechanisms of the damping force and the inertial force, and further validated by performance tests. General dynamic characteristics of an idealized taut cable with a REIMD installed close to the cable end are theoretically investigated, and parametric analysis are then conducted to investigate the effects of inertial mass and damping coefficient on vibration control performance. Finally, vibration control tests on a scaled cable model with a REIMD are performed to further verify mitigation performance through the first two modal additional damping ratios of the cable. Both the theoretical and experimental results show that control performance of the cable with the REIMD are much better than those of conventional passive viscous dampers, which mainly attributes to the increment of the damper displacement due to the inertial mass induced negative stiffness effects of the REIMD. Moreover, it is concluded that both inertial mass and damping coefficient of an optimum REIMD will decrease with the increase of the mode order of the cable, and oversize inertial mass may lead to negative effect on the control performance.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.455-457
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• 2007

The objective of this study is development of a installed working robot for a troy cable with mobile and tension system. In this paper, an approach to designing controllers for dynamic hybrid Tension/Mobile control of a installed robot for a troy wire cable is presented. Mobile control system of robot is designed based on equation of dc motor and motion for moving robot and tension control system is designed based on equation of ac servomotor for generating torque and dynamic equation of a wire cable. The control parameters is determined by simulation in independence operation of two system.

• 반도체디스플레이기술학회지
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• 제11권2호
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• pp.17-21
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• 2012

This study developed a high-temperature, high-pressure dynamic pressure sensor using LGT(lanthanum gallium tantalate). The sensitivity of the fabricated dynamic pressure sensor was 2.1 mV/kPa and its nonlinearity was 2.5%FS. We confirmed that the high-temperature dynamic pressure sensor operated stably in high-temperature environment at $500^{\circ}C$. The developed dynamic pressure sensor using LGT is expected to be applicable not only to gas turbines but also in various industrial areas in duding airplanes and power stations.

• 한국전산구조공학회논문집
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• 제34권4호
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• pp.243-254
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• 2021

이 논문에서는 박스형 전력구의 지진응답해석에 사용되는 응답변위법(Response Displacement Method, RDM)의 보수성을 평가하였다. 이를 위하여 25가지 전력구 단면과 각 전력구에 대한 2개의 지반조건을 고려한 총 50개 예제를 선정하였다. 응답변위법에 의한 해석은 다음과 같은 세 가지 방법을 적용하였다: (1) 단일코사인방법, (2) 이중코사인방법, (3) 부지응답해석법. 그리고 이들 응답변위법의 보수성을 평가하기 위하여 지반-구조물 상호작용을 고려한 동적해석법으로 구한 응답과 비교하였다. 비교결과, 설계지진력을 결정하는 방법 중에서 부지응답해석법이 가장 변동폭이 작았으며, 이중코사인방법이 가장 보수적인 결과를 보였다. 마지막으로 이중코사인방법을 적용할 때, 응답변위법에 의한 부재력이 동적해석에 의한 값보다 클 확률이 80% 이상이 되기 위한 지반강성 보정계수 C값으로 기능수행수준에서 0.9, 붕괴방지수준에서 0.7을 추천하였다.

• 한국군사과학기술학회지
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• 제19권5호
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• pp.559-566
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• 2016

Cables for Towed Array Sonar System(TASS) were developed. In order to verify the performance of cables, environmental and operational conditions as well as functional requirements were investigated during design stage. Double armored high and low voltage integrated cable for towed body and two kinds of cables, armored and light weight power and optic hybrid cables for towed array sensor system were developed by modeling and simulation. Customized manufacturing process and test method, such as foam extrusion and dynamic fatigue test were applied to this development. In conclusion, underwater towed hybrid cable with high tensile strength and compact structure were developed.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.770-771
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• 2015

본 논문에서는 발전소 전기설비 및 구축비용의 상당부분을 차지하는 케이블의 손실자원을 최소화하고, 효율적인 케이블 자재관리가 가능한 케이블 드럼 스케줄링 자동화를 제안하고 구현하였다. 구현된 케이블 드럼 스케줄링은 기존 수기방식의 케이블 드럼 계산에 소요되는 소비시간을 최소화하고, 종류별 케이블들을 케이블 드럼 총용량에 최적화함으로써 전기설비 생산성을 향상시킬 수 있다.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2396-2406
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• 2021

The Pacific Earthquake Engineering Research (PEER) Center has been developing a performance-based earthquake engineering (PBEE) methodology, which is based on explicit determination of performance, e.g., monetary losses, in a probabilistic manner where uncertainties in earthquake ground motion, structural response, damage estimation, and losses are explicitly considered. To carry out the PEER PBEE procedure for a component of the nuclear power plant (NPP) such as the cable tray system, hazard curve and spectra were defined for two hazard levels of the ground motions, namely, operation basis earthquake, and safe shutdown earthquake. Accordingly, two sets of spectral compatible ground motions were selected for dynamic analysis of the cable tray system. In general, the PBEE analysis of the cable tray in NPP was introduced where the resulting floor motions from the time history analysis (THA) of the NPP structure should be used as the input motion to the cable tray. However, for simplicity, a finite element model of the cable tray was developed for THA under the effect of the selected ground motions. Based on the structural analysis results, fragility curves were generated in terms of specific engineering demand parameters. Loss analysis was performed considering monetary losses corresponding to the predefined damage states. Then, overall losses were evaluated for different damage groups using the PEER PBEE methodology.

• Journal of Power Electronics
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• 제16권5호
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• pp.1743-1751
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• 2016

The increasing demand for high voltage DC grids resulting from the continuous installation of offshore wind farms in the North Sea has led to the concept of multi-terminal direct current (MTDC) grids, which face some challenges. Power (current) flow control is a challenge that must be addressed to realize a reliable operation of MTDC grids. This paper presents a reduced switch count topology of a current flow controller (CFC) for power flow and current limiting applications in MTDC grids. A simple control system based on hysteresis band current control is proposed for the CFC. The theory of operation and control of the CFC are demonstrated. The key features of the proposed controller, including cable current balancing, cable current limiting, and current nulling, are illustrated. An MTDC grid is simulated using MATLAB/SIMULINK software to evaluate the steady state and dynamic performance of the proposed CFC topology. Furthermore, a low power prototype is built for a CFC to experimentally validate its performance using rapid control prototyping. Simulation and experimental studies indicate the fast dynamic response and precise results of the proposed topology. Furthermore, the proposed controller offers a real solution for power flow challenges in MTDC grids.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.830-834
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• 2013

This study presents a method to monitor cable force of a long-span cable-stayed bridge using a smart piezoelectric sensor system. The following approaches are implemented in order to achieve the objective. Firstly, the method to utilize piezoelectric materials for the health monitoring of stay cables is presented. For strain measurement of a stay cable, a PZT-embedded smart skin is designed to overcome the difficulties of bonding PZT sensors directly on stay cables. Secondly, a piezoelectric strain monitoring system for stay cables is designed. For the operation of the sensor board, the Imote2 sensor platform is used to provide the computation, wireless communication and power supply units. The feasibility of the proposed monitoring system is then evaluated on a full-scale cable of a cable-stayed bridge.