• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1272-1274
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• 2002

It is very important to ensure system safety during the process of developing a system, Railway system is also devoting a great portion for the safety. Nowadays many countries leading railway industry have their own system assessment process according to the situation of their train control system. In this paper, a preprocess to establish system safety requirement is represented in the railway signalling system. We also adopt electronic interlocking system for an example.

• Journal of the Korea Safety Management & Science
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• v.11 no.4
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• pp.139-145
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• 2009

The present study is to investigate the effect of wave-structure interaction such as wave oscillation. The theoretical method is based upon the linear diffraction theory obtained by the boundary element method. The water depth and incident wave period in fluid region are assumed to be constant. To investigate the wave interaction due to offshore structures, the numerical program has been developed and the simulation has been carried out by varying the conditions of distance and width of offshore structures. This study can effectively be utilized for safety assessment to various breakwater systems and layout of offshore breakwater in the ocean and coastal field. It can give information for the safety to construct offshore structure and revetment in coastal region.

• Journal of the Korean Society of Safety
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• v.19 no.4 s.68
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• pp.69-73
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• 2004

The flash point is one of the most important combustible properties used to determine the potential for the fire and explosion hazards of industrial material and the fire point is the temperature of the flammable liquid at which there will be flaming combustion, sustained 5 seconds in response to the pilot flame. In this study, the flash point and fire point were measured to present raw data of the flammable risk assessment for alcohols, using Tag open-cup apparatus(ASTM D 1310-86). The measured values were compared with the calculated values based on 0.78 times stoichiometric concentration. The values calculated by the proposed equations were in good agreement with the measured values.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1858-1863
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• 2007

Railway systems are one of the best mass transit systems and many people have prevented incidents/accidents and reduced fatalities remarkably. Especially we have tried analyzing and finding the measures to prevent catastrophic accidents like train collision, derailment and fire because of their severities. It is important to assess the safety performances of railway systems like crash-worthiness analysis, body, derailment affecting factor analysis and so on for reducing and finding out the reasonable causes of disastrous accidents. In this paper the refined top-level system requirements to build-up national infra for assessing railway safety performance and the procedures and methodology for reviewing, verifying and validating infra requirements are explained. Basically the authors have used system engineering processes to analyze and verify the requirements and installation procedures and have tried maximizing the practicality of the various safety assessment systems.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.3
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• pp.300-305
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• 2013

LOOP(Loss of Offsite Power) and SBO(Station Blackout) events have been occurring in nuclear power plants should be reviewed and be controlled on important electrical equipments by professional engineer to prevent and to safety improvement from safety assessment and reliability analysis report. LOOP and SBO occasionally happened by internal or external causes. This paper contained that LOOP frequency in the United States NPPs and in the domestic NPPs have compared and analyzed data by the past lessons and probabilistic statistics. Additionally will be installed MG(Mobile Generator) according to the lessons of Fukushima nuclear accident in Japan, which CDF(Core Damage Frequency) and LOOP frequency have reconsidered. And this paper proposed to reduce reliability criteria using PSA(Probabilistic Safety Analysis).

• Journal of the Korean Society of Safety
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• v.28 no.1
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• pp.74-80
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• 2013

This study describes structural reliability analysis of actively-controlled structure for which random vibration analysis is incorporated into the first-order reliability method (FORM) framework. The existing approaches perform the reliability analysis based on the RMS response, whereas the proposed study uses the peak response for the reliability analysis. Therefore, the proposed approach provides us a meaningful performance measure of the active control system, i.e., realistic failure probability. In addition, it can deal with the uncertainties in the system parameters as well as the excitations in single-loop reliability analysis, whereas the conventional random vibration analysis requires double-loop reliability analysis; one is for the system parameters and the other is for stochastic excitations. The effectiveness of the proposed approach is demonstrated through a numerical example where the proposed approach shows fast and accurate reliability (or inversely failure probability) assessment results of the dynamical active control system against random seismic excitations in the presence of parametric uncertainties of the dynamical structural system.

• Journal of Auto-vehicle Safety Association
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• v.11 no.3
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• pp.7-12
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• 2019

AEB (Autonomous Emergency Braking system), a system in which vehicles automatically recognize forward objects or pedestrians and actively brake when forward collisions are expected, has been mandated by NHTSA (National Highway Traffic Safety Administration) and IIHS (Insurance Institute for Highway Safety) for all vehicles sell in the United States since 2022, and AEB research is also actively underway in korea. In this study, it can be confirmed that the passenger injury is reduced according to the AEB detection distance when it is assumed that the AEB is mounted in the actual event generated from KIDAS (Korea New Car Assessment Program) data through various analysis programs.

• Journal of the Korean Society of Safety
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• v.34 no.5
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• pp.7-14
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• 2019

The type III vessel, which is used to store high-pressure hydrogen gas, is made by wrapping the vessel's liner with carbon fiber composite materials for strength performance and lightening. The liner seals the internal gas and the composite resists the internal pressure. The properties of the fiber composite material depends on the angle and thickness of the fiber. Thus, engineers should consider these various design variables. However, it significantly increases the design cost due to the trial and error under designing based on experience or experiments. And, for aluminum liners, fatigue loads due to using and charging could give a huge impact on the performance of the structure. However, fatigue failure does not necessarily occur in the position under the highest load in use. Therefore, for hydrogen storage vessel, fatigue evaluation according to design patterns is essential because stress distribution varies depend on composite layer patterns. This study performed an optimization analysis and evaluated a high-pressure hydrogen storage vessel to minimize these trial and error and improve the reliability of the structure, while simultaneously conducting fatigue assessment of all patterns derived from the optimization analysis process. The results of this study are thought to be useful in the strength improvement and life design of composite reinforced high-pressure storage vessels.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.675-683
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• 2017

Total mercury (T-Hg) and methyl mercury (MeHg) were determined in marine fisheries (41 species, n=87) commonly consumed in Korea, using a gold amalgamation method and gas chromatography-cold vapor atomic fluorescent spectroscopy, respectively. Concentrations of T-Hg and MeHg in all samples (31 fish, 4 crustaceans, 4 cephalopods, and 2 gastropod species) were in the range of 0.016-0.495 (mean, 0.093) mg/kg-wet and not detected-0.338 (mean, 0.067) mg/kg-wet, respectively. The concentrations of MeHg in marine fisheries were significantly correlated with T-Hg concentrations (P<0.001). The highest mean concentrations of T-Hg and MeHg were found in fish species, followed by crustaceans. The contribution of MeHg to T-Hg was in the range of 64-95% (mean, 83%) in cephalopods, 28-98% (mean, 69%) in fish, and 26-88% (mean, 57%) in crustaceans. The weekly intakes of T-Hg and MeHg by fisheries consumption for the Korean general population were estimated to be 0.463 and $0.338{\mu}g/kg$ body weight/week, respectively. The concentrations and intakes of T-Hg and MeHg were less than the allowable residue levels and in the range of 12 to 17% of the provisional tolerable weekly intake (PTWI) applied in Korea.

• Journal of Ginseng Research
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• v.38 no.4
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• pp.239-243
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• 2014

Background: To investigate the antidiabetic effects of hydrolyzed ginseng extract (HGE) for Korean participants in an 8-wk, randomized, double-blinded, placebo-controlled clinical trial. Methods: Impaired fasting glucose participants [fasting plasma glucose (FPG) ${\geq}5.6mM$ or < 6.9mM who had not been diagnosed with any disease and met the inclusion criteria were recruited for this study. The 23 participants were randomly divided into either the HGE (n = 12, 960 mg/d) or placebo (n = 11) group. Outcomes included measurements of efficacy (FPG, postprandial glucose, fasting plasma insulin, postprandial insulin, homeostatic model assessment-insulin resistance, and homeostatic model assessment-${\beta}$) and safety (adverse events, laboratory tests, electrocardiogram, and vital signs). Results: After 8 wk of HGE supplementation, FPG and postprandial glucose were significantly decreased in the HGE group compared to the placebo group. No clinically significant changes in any safety parameter were observed. Our study revealed that HGE is a potent antidiabetic agent that does not produce noticeable adverse effects. Conclusion: HGE supplementation may be effective for treating impaired fasting glucose individuals.