• Journal of the Korea Safety Management & Science
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• v.6 no.4
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• pp.139-153
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• 2004

Korea Railroad Research Institute(KRRI) has developed the rubber-tired AGT system from 1999 to 2004. The rubber-tired AGT vehicle is now on test for its performance and function in the Gyeong-San test line. In this paper, we provide the reliability management plan to assure required the RAMS(reliability, availability, maintainability 8t safety) of the AGT vehicle system.

• Proceedings of the Safety Management and Science Conference
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• 2004.11a
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• pp.171-182
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• 2004

Korea Railroad Research Institute(KRRI) has developed the rubber-tired AGT system from 1999 to 2004. The rubber-tired AGT vehicle is now on test for its performance and function in the Gyeong-San test line. Tn this paper, we provide the reliability management plan to assure required the RAMS(reliability, availability, maintainability & safety) of the AGT vehicle system.

• Journal of the Earthquake Engineering Society of Korea
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• v.24 no.2
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• pp.59-65
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• 2020

The empirical Green's function method is applied to the foreshock and the mainshock of the 2016 Gyeongju earthquake to simulate strong ground motions of the mainshock and scenario earthquake at seismic stations of seven metropolises in South Korea, respectively. To identify the applicability of the method in advance, the mainshock is simulated, assuming the foreshock as the empirical Green's function. As a result of the simulation, the overall shape, the amplitude of PGA, and the duration and response spectra of the simulated seismic waveforms are similar with those of the observed seismic waveforms. Based on this result, a scenario earthquake on the causative fault of Gyeongju earthquake with a moment magnitude 6.5 is simulated, assuming that the mainshock serves as the empirical Green's function. As a result, the amplitude of PGA and the duration of simulated seismic waveforms are significantly increased and extended, and the spectral amplitude of the low frequency band is relatively increased compared with that of the high frequency band. If the empirical Green's function method is applied to several recent well-recorded moderate earthquakes, the simulated seismic waveforms can be used as not only input data for developing ground motion prediction equations, but also input data for creating the design response spectra of major facilities in South Korea.

• Journal of the Korean Society of Safety
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• v.30 no.3
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• pp.13-19
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• 2015

Railway vehicle equipment goes back again to the state just before when failure by the repair. In repairable system, we are interested in the failure interval. As such, a statistical model of the point process, NHPP power law is often used for the reliability analysis of a repairable system. In order to derive a quantitative reliability value of repairable system, we analyze the failure data of the air brake system of the train line 7. The quantitative value is the failure intensity function that was modified, converted into a cost-rate function. Finally we studied the optimal number and optimal interval in which the costs to a minimum consumption point as cost-rate function. The minimum cost point was 194,613 (won/day) during the total life cycle of the braking system, then the optimal interval were 2,251days and the number of optimal preventive maintenance were 7 times. Additionally, we were compared to the cost of a currently fixed interval(4Y) and the optimum interval then the optimal interval is 3,853(won/day) consuming smaller. In addition, judging from the total life, "fixed interval" is smaller than 1,157 days as "optimal interval".

• Journal of the Korea Safety Management & Science
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• v.4 no.4
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• pp.137-146
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• 2002

In order to investigate the effect of irradiation by $^{60}Co-\gamma$rays as well as the e thermal treatment on the dielectric deterioration in ethylene propylene rubber, insulating material for electric cables used in atomic power plants, charging discharging current, residual built- up voltage and dielectric properties are measu discussed in this study. Variance in the characteristic of relative dielectric constant as a function of tem was observed in relatively high dose of irradiation. Since glass transition tem appeared at tens of degree Celsius below zero, the characteristic is attributed orientation polarization. Dielectric loss is generally increased, with increasing d irradiation in the characteristic of dielectric loss as a function of temperature, No d loss by thermal treatment was observed. Dielectric resistance decreases with increa of irradiation in the characteristic of charging current as a function of temperature be considered that dielectric resistance seems to be recovered by thermal treatm characteristic of discharging current as a function of time in the specimen less ir become similar to that of the unirradiated, when thermal treated. A peak is shown residual built- up voltage as a function of time, and the corresponding time of the shorten as increasing dose of irradiation. It is also observed that the corresponding the peak is lengthened by thermal treatment.

• Journal of the Korean Society of Safety
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• v.32 no.1
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• pp.53-59
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• 2017

Safety inspection activities of the facilities including the electricity, gas, building, and firefighting, etc. are individual checks by the separate law of each government department, comprehensive inspections for the specific managed facilities or during a weak season, and national safety overall diagnostics for the disaster prevention. Thus, types of the inspections are various and they have been carried out repeatedly as well as duplicately. That can make the people or institutes to take such inspections feel great burdens. Therefore, the investigation on the current situation of the individual inspection by the separate law for the electricity, gas, building, and firefighting, etc. as well as of various others by the government needs to be carried out and according to the results the repetitive and duplicated inspections should be reduced and converged to one comprehensive one. In this regard, we proposed solutions to improve the government safety inspection system, function, and role.

• KSBB Journal
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• v.22 no.3
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• pp.139-145
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• 2007

An oriental medicinal database was used from medicinal plants for screening of anticancer agents. The prescription frequency and dosage of medicinal plats in 170 anticancer prescriptions were analyzed. From the total prescription score of each medical plant, it was found that high-scored medicinal plants have been widely studied in the previous research on the cancer treatment. Consequently, dangui, hwangui, banha, bachul, jinpy, insam, bacjakyak, deahwang, chungoong, jimo, chunnamsung, omija, hyunggae, huekchook, banggi, boclyung, osooyou were selected as raw materials for the screening of anticancer agents.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.13 no.1
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• pp.9-17
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• 2001

A probability of failure of armor units on rubbJe-mound breakwater are evaluated by using the direct method for reliability analysis, which is represented as a function of safety factor that has been extensively used in practical design. The reliability function is fonnulated based on Hudson formula suggested for designing the stable size of armor units on rubble-mound breakwater. Several kinds of stability coefficient are applied separately to calculate the probability of failure with respect to the type of armor units, breaking/nonbreaking and the correlation coefficients between random variables. [n addition, the sensitivity analyses are carried out to investigate quantitatively into the effects of each random variable in the reliability function on the probability of failure.

• Journal of Wetlands Research
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• v.5 no.1
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• pp.41-52
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• 2003

The flood damage reduction studies have been performed by the channel improvement plan and the levee has mainly constructed with the freeboard concept. However, the freeboard concept might be an inappropriate choice as a safety factor of the levee because many uncertainties are involved in the procedure of the channel improvement plan studies. So, we considered the uncertainties In the discharge-probability, stage-discharge, and stage-damage functions and estimate the expected annual damage. The Monte Carlo technique for uncertainty analysis is used. As our results, the expected annual damage with uncertainty shows the larger value than without uncertainty. Since the expected annual damage with uncertainty already considers the safety factor it is the proper result. However, the expected annual damage without uncertainty does not consider the safety factor yet. Thus, if the expected annual damage without uncertainty considers the freeboard concept, it could be compared with the expected annual damage with uncertainty for the evaluation of the overestimation or underestimation of the levee construction.

• Journal of Ginseng Research
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• v.34 no.1
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• pp.68-75
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• 2010

This study sought to optimize the extraction and enzymatic treatment conditions of Panax ginseng leaves, stems, and roots for the production of fermented ginseng. The optimization enhanced the extraction of total saccharide, a nutrient and growth-activating factor for Lactobacillus bacteria. The hydrolysis of ginseng leaves, stems, and roots was tested with eight enzymes (Pentopan, Promozyme, Celluclast, Ultraflo, Pectinex, Ceremix, Viscozyme, and Tunicase). The enzymatic hydrolysis conditions were statistically optimized by the experimental design. Optimal particle size of ginseng raw material was <0.15 mm, and optimal hydrolysis occurred at a pH of 5.0-5.5, a reaction temperature of 55-$60^{\circ}C$, a Ceremix concentration of 1%, and a reaction time of 2 hr. Ceremix produced the highest dry matter yield and total saccharide extraction. Ginseng leaves were found to be the most suitable raw material for the production of fermented ginseng because they have higher carbohydrate and crude saponin contents than ginseng roots.