• 한국항해학회지
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• 제22권4호
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• pp.45-50
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• 1998

A recently constructed commercial ship is a complexive integrated system like a small city in which has a generator, power distributing facilities, various radio equipments and high power circuit breakers are installed. Therfore it could make a malfunction of the microprocessor in the various control units which are so important during the ocean voyage of larger ship. This paper has studied whether is properly required or not on the view of the actual electro magnetic compatibility status on the electromagnetic interference and suceptibility test requirments listed on the IACS (International Association of the Classification Society). Through these results, we are looking forward to the new suggestions of the Electro Magnetic Compatibility test in order to reduce the malfunction in the ship regarding test item, test level, and test condition.

• 전기학회논문지
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• 제59권11호
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• pp.2089-2092
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• 2010

There are many cases that interrupt the production process because of malfunctions caused by electronic circuit boards which control equipment, but it is difficult to distinctly identify the causes in many cases. Especially, CMOS devices with the control logic circuit return automatically to normal state after their own faults. Therefore it is not easy to analyze the problems with electronic circuit boards. Recently, nuclear power plant experienced a failure due to the malfunction of electronic circuit boards and it was identified that the reason of the malfunction was because of latch-up phenomenon caused by external surge in electronic devices. This paper presents the causes and the phenomenon of latch-up by experiment and also a way using counter EMF diodes, noise filters and surge protective devices to prevent latch-up phenomenon from electronic circuit boards, finally confirms the effectiveness of the result by experiment.

• 한국안전학회지
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• 제32권6호
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• pp.89-97
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• 2017

The tuned mass damper (TMD) system was first proposed as an efficient vibration control method for high-rise buildings, and multiple TMD (MTMD) system was then proposed for the purpose of improving the robust performance. Thereafter, the active TMD (ATMD) is proposed to improve the vibration control performance over the TMD and MTMD systems. However, this system may experience an system-instability problem in case of the actuator malfunction. In order to overcome such limitations of actuator malfunction causing the instability of the structural system, in this study, we investigate the feasibility of the multiple ATMD (MATMD) system that facilitates both advantages of the MTMD and ATMD. Numerical example demonstrates that, when the proposed system is designed to have the same capacity as the ATMD, it shows a similar control performance to the ATMD, but also has very good adaptive control performance against the emergency situations such as actuator failures.

• Journal of Mechanical Science and Technology
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• 제18권11호
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• pp.1961-1968
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• 2004

The design of a reliable and failsafe control system requires that sensor failures be detected and identified within acceptable time limit so that system malfunction can be prevented. This paper presents a model-based approach to sensor fault detection with applications to vehicle stability control systems. The effectiveness of the proposed method is illustrated through test data-based evaluation. Vehicle test data-based evaluation results show that the proposed fault management scheme can be used for the design of a failsafe VSCs.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1195-1201
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• 2011

Since the release of safety standard IEC 61508 which defines functional safety of electronic safety-related systems, SIL(Safety Integrity Level) certification for railway systems has gained lots of attention lately. In this paper, we propose a new design technique of the computer board for train control systems with high reliability and safety. The board is designed with TMR(Triple Modular Redundancy) using a certified SIL3 Texas Instrument(TI)'s TMS570 MCU(Micro-Controller Unit) to guarantee safety and reliability. TMR for the control device is implemented on FPGA(Field Programmable Gate Array) which integrates a comparator, a CAN(Controller Area Network) communication module, built-in self-error checking, error discriminant function to improve the reliability of the board. Even if a malfunction of a processing module occurs, the safety control function based on the proposed technique lets the system operate properly by detecting and masking the malfunction. An RTOS (Real Time Operation System) called FreeRTOS is ported on the board so that reliable and stable operation and convenient software development can be provided.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.237-239
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• 2021

무인 감시설비의 고장과 오작동으로 인해 담당자가 무인 감시시설에 도착할 때까지 생기는 시간 지연과 침입자의 침입으로 인한 시설물 절도, 파손 그리고 정보유출 피해가 발생할 수 있다. 또한, 장비 고장과 오작동으로 인해 관리자의 상시점검으로 인한 추가비용이 발생한다. 본 논문에서는 무인 감시설비 오작동을 보완하기 위해 실시간으로 감시설비를 진단하여 문제 발생에 관한 내용을 표시하고 자동으로 설비 전원을 복구하며 담당자에게 문자메시지로 상황을 알리는 시스템을 제안한다. 제안한 시스템은 영상장치(CCTV), 음향장비, 투광등 장치 등의 무인 감시설비 주요 시설물로 이루어진 감시설비, 이 감시설비 정보를 판단할 수 있는 통합형 네트워크 비디오 레코더 장치(NVR), 전원을 제어하는 장치, 그리고 실시간으로 문자메시지를 보낼 수 있는 SMS 서버로 구성되어있다. 실험을 통하여 제안된 시스템의 유효성을 검증하였다.

• 동력기계공학회지
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• 제2권2호
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• pp.73-80
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• 1998

The identification of drilling joint dynamics which consists of drilling and structural dynamics and the on-line time series detection of malfunction process is substantial not only for the investigation of the static and dynamic characteristics but also for the analytic realization of diagnostic and control systems in drilling. Therefore, We have discussed on the comparative assessment of two recursive time series modeling algorithms that can represent the drilling operation and detect the abnormal geometric behaviors in precision roundshape machining such as turning, drilling and boring in precision diemaking. For this purpose, simulation and experimental work were performed to show the malfunctional behaviors for drilling operation. For this purpose, a new two recursive approach (Recursive Extended Instrument Variable Method : REIVM, Recursive Least Square Method : RLSM) may be adopted for the on-line system identification and monitoring of a malfunction behavior of drilling process, such as chipping, wear, chatter and hole lobe waviness.

• International Journal of Internet, Broadcasting and Communication
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• 제13권3호
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• pp.169-177
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• 2021

Recently, the use of electric and electronic control systems is increasing in the automobile industry. This increase in the electric and electronic control system greatly increases the complexity of designing a vehicle, which leads to an increase in the malfunction of the system, and a safety problem due to the malfunction is becoming an issue. Based on IEC 61508 relating to the functional safety of electrical/electronic/programmable electronics, the ISO 26262 standard specific to the automotive sector was first established in 2011, and a revision was published in 2018. Malfunctions due to system failure are covered by ISO 26262, but ISO/PAS 21448 is proposed to deal with unintended malfunctions caused by changes in the surrounding environment. ISO 26262 sets out safety-related requirements for the entire life cycle. Functional safety analysis includes FTA (Fault Tree Analysis), FMEA (Failure Mode and Effect Analysis), and HAZOP (Hazard and Operability). These analysis have limitations in dealing with failures or errors caused by complex interrelationships because it is assumed that a failure or error affecting the risk occurs by a specific component. In order to overcome this limitation, it is necessary to apply the STPA (System Theoretic Process Analysis) technique.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2804-2807
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• 2011

As computer-based train control system became used widely, reliability and safety assessment of the computer is getting more important. A fault on a computer can cause a malfunction of train control system, and this can lead an accident. So where reliability and safety is highly required TMR is used. In this paper, the method of data sharing and voting for TMR processing is proposed, designed and verified.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.391-391
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• 2000

Manufacturing process generally exhibits major or minor variations due to deviation of raw materials, equipment degradation, controller malfunction, and so on. Extensive research based on multivariate statistical process control has been done to monitor the unstable states and indicate a corrective action. A prototype of intelligent operation support system ("ISYS-MSPC") has been developed as a tool that supports the enhanced operation to guarantee the high productivity and a uniform high quality product. This system has been applied to the industrial batch and continuous processes and its performance has been validated .