• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.3
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• pp.328-333
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• 2012

Current differential GPS (DGPS) system consists of reference station (RS), integrity monitor (IM), and control station (CS). The RS computes the pseudorange corrections (PRC) and generates the RTCM messages for broadcasting. The IM receives the corrections from the RS broadcasting and verifies that the information is within tolerance. The CS performs realtime system status monitoring and control of the functional and performance parameters. The primary function of a DGPS integrity monitor is to verify the correction information and transmit feedback messages to the reference station. However, the current algorithms for integrity monitoring have the limitations of integrity monitor functions for satellite outage or anomalies. Therefore, this paper focuses on the detection and identification methods of satellite anomalies for maritime DGPS RSIM. Based on the function analysis of current DGPS RSIM, it first addresses the limitation of integrity monitoring functions for DGPS RSIM, and then proposes the detection and identification method of satellite anomalies. In addition, it simulates an actual GPS clock anomaly case using a GPS simulator to analyze the limitations of the integrity monitoring function. It presents the brief test results using the proposed methods for detection and identification of satellite anomalies.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1335-1337
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• 2003

한국형 고속 전철 과제는 6년의 과제 기간을 가시는 국가 연구 사업으로, 한국 실정에 적합한 차세대 고속 전철을 시험 제작하여 운용하는 것이 목적이다. 시속 350 km/h의 운행 속도를 목표로 하는 한국형 고속 전철은 현재 개발이 완료되어, 시험 주행 트랙에서 증속을 위한 시험 운행을 계속하고 있다. 한국형 고속 전철은 열차 내 각종 제어 장치들 간의 데이터 교환를 위해서 실시간 네트워크인 열차통신 네트워크(Train Communication Network; TCN)를 사용한다. 약 10년간의 표준 보완 기간을 거쳐서 1999년 국제 표준으로 확정된 TCN(IEC61373)은 열차 전용의 실시간 통신 네트워크로 열차 장치의 제어 및 진단에 적합한 다양한 기능과 특징을 가지고 있다. 한국형 고속전철은 열차의 주 제어 및 감시를 담당하는 주관 제어장치(SCU, Supervisory Control Unit)와 열차 안전에 중요한 역할을 하는 자동 열차 제어 장치(ATC, Automatic Train Control)을 포함하는 55개의 제어 장치들이 TCN으로 연결되어서 상호간의 데이터 교환을 수행하도록 구성되어 있다. 본 논문에서는 한국형 고속전철에 사용될 TCN의 구조와 실제 필드에 사용되어지기 위해서 필수적으로 필요한 네트워크의 고장 진단 기법에 대해서 설명한다.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.8
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• pp.1111-1116
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• 2011

Power distribution systems onboard vessels are typically configured without any live line connected to hulls for earthing purpose, where the line to hull voltages are affected and deformed depending on the impedances consisting of insulation resistances and distributed capacitances between power lines and hull. An insulation fault at power lines causes the line to hull voltages to increase to a higher level which brings more possibilities to electric shock and deterioration of insulation material. This study focuses on how to configure a module which enables to continuously monitor the voltages between power line and hull based on the vector diagram by analyzing the neutral point of 3 phase voltages and the algorithm for plotting method on the PC monitors.

• Journal of the Korean Institute of Gas
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• v.9 no.3 s.28
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• pp.38-43
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• 2005

There is monitored amount operation variables and controlled by operating conditions and loads at many facilities using gas also chemical plants. The process fault which can be indicated by operators, is occurred when the abnormal state was accumulated continuously owing to physical failure, external disturbance or human error. This is studied a Early Warning System which is to estimate process status by real-time monitoring operation variables and to early warning before it will be occurred process fault.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.4
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• pp.92-99
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• 1997

This paper proposed a control method to improve the efficiency of monitoring method by applying the nural network for an alarm processing method(APM)in an elevator facility of apartment complex. This APM is based on the cumulative generalized delta rule of backpropagation in neural network.It was used to infer the minimum alarms among multi-fired alarms, and then the inferred alarm can be dis¬played maintenance information of facility by using a pre-defined troubleshoot knowledge base. For validating the proposed monitoring method of this thesis, simulation results are compared with the operation of existing monitoring system and the way of alarm processing. The simulation method used to the three case of virtual scenario. As comparison results, a proposed method in this paper could be proved the applied possibility of an neural network and the performance in fields of facilities maintenance.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.292_293
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• 2009

현재 산업발달로 인한 전력수요 증가와 IT산업의 혁신적인 발달로 고장으로 인한 정전 발생시 사회생활에 미치는 영향이 커지게 되었다. 위성도시의 발달로 인한 지중선로는 필연적으로 증가하고 있으며 지중선로의 특이 환경은 점검 및 유지보수등의 고정밀도를 요한다. 장거리 지중선로의 문제점으로 초고압케이블에 대한 가시적인 또는 주기적인 점검으로 설비상태를 파악하기에는 한계가 존재할 수밖에 없다. 이에 본 논문은 인력순시에 한계를 극복하고 무선통신장비 등을 이용하여 지중선로내 과학화 장비를 이용한 상시감시 체계를 소개하고자 한다.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.777-782
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• 2005

The importance of emergency diesel generator(EDG) has confirmed in the safety evaluation of PSA and the study on aging of EDG has been progressed actively as a part of the project of nuclear plant aging research in the U.S.A. As the result, the concept of performance evaluation is being transferred from statistical analysis of test results to performance monitoring and trending analysis for monitoring of aging and reliability. Recently, the study related aging characteristic and reliability for EDGS has begun in Korea. Consequently, the efficient performance monitoring based systematic and integrated monitoring and failure diagnostic technology is necessary. In the research, the knowledge basis of monitoring parameters for EDGS is constructed, and the prototype monitoring and diagnosis system applicable to Pielstick EDG is developed.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.85-88
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• 2011

석유 등 화석연료로 인한 지구온난화 문제와 더불어 일본 대지진 이후 원자력발전의 안전에 의문이 제기 되면서 신재생에너지에 대한 관심이 한층 고조되고 있다. 이에 발맞추어 국가정책으로 녹색성장 정책이 실행됨에 따라 2030년까지 전체 에너지원 중 신에너지전원의 비중을 전체 에너지원의 11%로 확대하는 정책을 적극적으로 추진하고 있다. 따라서 신재생에너지를 통하여 얻은 전기에너지를 저장하여 사용 할 수 있는 2차 전지에 대한 연구가 다수의 산업 현장에서 각광을 받고 있다. 최근 2차 전지는 Smart Grid 및 전기자동차분야에서 폭넓게 사용 되면서 정확한 출력전압, SOC 및 충-방전 예상 시간을 추정하여 2차 전지의 과충전, 과방전으로 인하여 생기는 고장 및 사고를 미연에 방지하고 2차 전지 사용 시 편의성을 제공하기 위한 시스템에 대한 연구가 필요한 실정이다. 본 논문은 이런 실정에 맞추어 LabVIEW 프로그램을 활용하여 2차 전지의 상태를 실시간으로 감시 및 제어하는 프로그램을 제작함으로써, 사고 시 2차 전지에 가해지는 피해 방지 및 관리 시 발생하는 여러 문제점에 대한 효율적인 해결 방안을 제시하고자 한다.

• The KIPS Transactions:PartA
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• v.16A no.6
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• pp.481-488
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• 2009

GIS is used to isolate large power electrical equipment using SF6 gas. While GIS has simple structure, it has few break down, relatively high reliability. But it is hard to check up faults for reason of pressure. Faults of GIS should have a ripple effect on community and be hard to recovery. Consequently, GIS imports a preventive diagnostic system to find internal faults in advance. It is most important that reliability on the GIS preventive diagnostic system, because it estimates abnormality of system by analysis result of collected data. But, exist system which used central data management is low efficiency, and hard to guarantee timeliness and accuracy of data. To guarantee timeliness and accuracy, the GIS preventive diagnostic system needs accordingly to use a real-time middleware. So, in this paper, to improve reliability of the GIS preventive diagnostic system, we use a middleware based on TMO for guaranteeing timeliness of real-time distributed computing. And we propose an improved GIS preventive diagnostic system applying data acquisition, monitoring and control methods based on the TMO model. The presented system uses the Communication Control Unit(CCU) for distributed data handling which is supported by TMO. CCU can improve performance of the GIS preventive diagnostic system by guaranteeing timeliness of data handling process and increasing reliability of data through the TMO middleware. And, it has designed to take full charge of overload on a data acquisition task had been processed in an exist server. So, it could reduce overload of the server and apply distribution environment from now. Therefore, the proposed system can improve performance and reliability of the GIS preventive diagnostic system and contribute to stable operation of GIS.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.5
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• pp.502-510
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• 2009

Laser Inertial Navigation System(LINS) consists of Ring Laser Gyroscopes(RLG) and accelerometers. RLG has a lock-in region in which there is zero output for input angular rates less than 0.1deg/sec. The lock-in region is generated by the imperfect mirrors in RLG. To avoid the lock-in region, sinusoidal motion which is called dither motion is applied on RLG. Therefore without the fault in LINS, the dither motion must be measured by RLG/accelerometer. In this paper, we propose the method to detect the fault of LINS through checking out whether or not the dither motion is always measured by RLG/accelerometer using the Fast Fourier Transformation(FFT) on the real time. The feasibility of the fault detection method proposed in this paper is verified through the stationary and van test.