• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.4
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• pp.52-66
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• 2021

In the aviation, airmans play a key role in aviation safety and perform tasks within a given range based on professional knowledge. If they fail to properly fulfill their obligations under the Aviation Safety Act, the Ministry of Land, Infrastructure and Transport(MOLIT) will dispose of them in accordance with the purpose of the Aviation Safety Act. However, in the case of this disposition, it does not specifically consider the circumstances of the violation, and has a limitation in that the evidence regulations are too limited, and the contents of the disposition are uniform. Therefore, this study attempted to present a plan to improve the disposition in order to improve the problem of administrative disposition for airman. To this end, we conducted a comparative analysis of the disposition of airmans through overseas cases, and Specifically, the three-stage disposition model and effectiveness were conducted in the direction of specific judgment on violations and predictability of disposition. We would like to propose a safety improvement order to increase the level of safety and proposed amendments to the law for the method of imposing a fine for negligence.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.642-646
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• 2008

Signaling system, for which ensuring safe train operation, must be a fail-safe system with higher reliability and safety. TCS has made significant improvements both on signaling system, from relay based ground signaling system to computer based on-board system, and on driving mode, form low speed and low density driving to TCS supporting high speed and high density driving. In addition, TCS has been applied to rolling stock with a wide variety of context according to the characteristics of rolling stock or railway infrastructure. In this paper, therefore, we confirmed the basic concept of ATC system and analyzed its development process in technology context via referencing international cases and ATC systems introduced and applied in Korea. Based on those analyses, we suggested the new TCS development strategy for its suitable application to high speed line, conventional line and metro, and we also provided technical considerations related to TCS application.

• Smart Structures and Systems
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• v.18 no.2
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• pp.293-315
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• 2016

Seismic isolation is often used in protecting mission-critical structures including hospitals, data centers, telecommunication buildings, etc. Such structures typically house vibration-sensitive equipment which has to provide continued service but may fail in case sustained accelerations during earthquakes exceed threshold limit values. Thus, peak floor acceleration is one of the two main parameters that control the design of such structures while the other one is peak base displacement since the overall safety of the structure depends on the safety of the isolation system. And in case peak base displacement exceeds the design base displacement during an earthquake, rupture and/or buckling of isolators as well as bumping against stops around the seismic gap may occur. Therefore, obtaining accurate peak floor accelerations and peak base displacement is vital. However, although nominal design values for isolation system and superstructure parameters are calculated in order to meet target peak design base displacement and peak floor accelerations, their actual values may potentially deviate from these nominal design values. In this study, the sensitivity of the seismic performance of structures equipped with linear and nonlinear seismic isolation systems to the aforementioned potential deviations is assessed in the context of a benchmark shear building under different earthquake records with near-fault and far-fault characteristics. The results put forth the degree of sensitivity of peak top floor acceleration and peak base displacement to superstructure parameters including mass, stiffness, and damping and isolation system parameters including stiffness, damping, yield strength, yield displacement, and post-yield to pre-yield stiffness ratio.

• Journal of Auto-vehicle Safety Association
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• v.11 no.2
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• pp.11-16
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• 2019

This paper suggests an algorithm for detecting fault of longitudinal controller in autonomous vehicles. Guaranteeing safety in fault situation is essential because electronic devices in vehicle are dependent each other. Several methods like alarm to driver, ceding control to driver, and emergency stop are considered to cope with fault. This research investigates the fault monitoring process in fail-safe system, for controller which is responsible for accelerating and decelerating control in vehicle. Residual is computed using desired acceleration control command and actual acceleration, and detection of its abnormal increase leads to the decision that system has fault. Before computing residual for controller, health monitoring process of acceleration signal is performed using hardware and analytic redundancy. In fault monitoring process for controller, a process model which is fitted using driving data is considered to improve the performance. This algorithm is simulated via MATLAB tool to verify performance.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.638-640
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• 1996

This paper presents microprocessor-based Digital Position Detection Unit using the inductive radio line and the antennas in train signaling system. This comprises the Fail-Safe system due to the dual controlled system to drive with safe-side even in events of faults, and designs the FSC(failure safe comparator). And the method of Markov Modeling is described for the reliability evaluation of system.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.346-348
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• 1997

This paper presents microprocessor-based real-time speed and position detection by inductive radio loop in new transportation system, such as magnetically levitated train system, rubber tyred train, and linear-motor car. The constant elapsed time method is used in this study for high accurate detection over a wide speed range. And for reliability and safety of the system, it is duplicated and data-bus level comparison is performed by fail-safe comparator.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.2
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• pp.169-179
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• 2010

Satisfying the same probability of loss of control and essentially two fail operative performance with a triplex computer architecture requires a lot of modification of the conventional redundancy management design techniques, previously employed in quadruplex digital flight control computer. T-50 FCS for triplex redundancy management design applied an advanced digital flight control architecture with an I/O controller which is functionally independent of the digital computer to achieve the same reliability and special failure analysis and isolation schemes for fail operational goals with a triplex configuration. The analysis results indicated that the triplex flight control system is to satisfy the safety requirement utilizing the advanced flight control techniques and the system performance of the implemented flight control system was verified by failure mode effect test.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.299-312
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• 2021

Autonomous vehicles using V2X can drive safely information on areas outside the sensor coverage of autonomous vehicles conventional autonomous vehicles. As V2X technology has emerged as a key component of autonomous vehicles, research on V2X security is actively underway research on risk analysis due to failure of V2X communication is insufficient. In this paper, the service scenario and function of autonomous driving system V2X were derived by presenting the intersection scenario of the autonomous vehicle, the malfunction was defined by analyzing the hazard of V2X. he ISO26262 Part3 process was used to analyze the risk of malfunction of autonomous vehicle V2X. In addition, a fault injection scenario was presented to verify the fail-safe of the simulation-based intersection scenario.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.731-735
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• 2006

The Rolling Stock pursues more safe, speedy and accurate operation on the increment of the passenger and the short headway. Signalling system is providing an assurance on safety and reliability of the system, which is based on fail-safe concept. Therefore we are willing to study up on MMI device for new onboard ATP/ATO equipment which is used for driver to recognize train status and fault more quickly and to solve any problem more rapidly, which can maximize the stability and reliability of the system.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.717-723
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• 2011

When the Balise(the device to transmit information between the on-board equipment and the wayside equipment) failure occurs, it may not be able to transmit data(Telegram) required for the train running. And in some cases, it may be able to cause an accident. Therefore, both the Balise failure affecting train safety running and the hazard in accordance with Balise failure require some activities to establish them. General failure mode & hazard analysis associated with the Balise are described in UNISIG SUBSET-036 spec & UNISIG SUBSET-088 spec. And, with reference to these specifications, safety activities are being performed. In recent domestic railway, the train control system applying ETCS(European Train Control System) Level 1, 2 is being serviced and is being planned, and as part of this system, the Balise is being applied. The design-method of the Balise device for each manufacturer are different, therefore the Balise failure mode & failure rate are different, either. But the functionalities & transmission-data format(Telegram) of the Balise in ETCS Level 1, 2 application for each manufacturer are identical. Accordingly, the hazard caused by function-fail can be identical, either. In order to establish these hazard, in this paper, we analyzed the detailed functions of the Balise. And we analyzed the Balise failure types & failure effects in accordance with the detailed functions.