• Proceedings of the Korean Society for Quality Management Conference
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• 2004.04a
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• pp.266-271
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• 2004

Recently, consumers require products with high-reliability and high-safety. Risk management system and product safety become more important issue In view of product liability. This paper aims to propose a risk assessment system which can be applied to product with high-reliability and high-safety, and also show an empirical application of the proposed risk assessment system for the development of motorcycle helmets.

• Proceedings of the Safety Management and Science Conference
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• 2001.05a
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• pp.217-225
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• 2001

We consider some alternative management models(IEC300, NASA AHB 5300.1, IEC1508) based on dependability, especially reliability and safety, including resources on world- wide leading standard- bodies and informations.

• Journal of the Korean Home Economics Association
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• v.50 no.5
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• pp.101-113
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• 2012

This study aims to examine consumer product safety search levels, as well as their response to safety-oriented behavior change, in a bid to use the results in the diverse policy formulation of government and business, and as basic data for securing consumer safety. The findings of this study are outlined as follows. First, for consumer safety information search access and reliability, in the case of access, accessibility via TV and other press media was high, while accessibility via education (seminars, lectures, practice and campaigns) was low. Second, consumer safety-oriented behaviors were examined before and after purchasing products; there was a significant difference associated with monthly income prior to buying products. Third, in order to determine the influence of variables related to consumer safety-oriented behaviors, consumer safety-oriented behaviors as a dependent variable underwent regression analysis; information search access and reliability, and monthly income were found to significantly influence consumer behavior.

• Journal of the Korean Society of Safety
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• v.36 no.2
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• pp.32-38
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• 2021

This paper suggests an approach to evaluate the reliability of an intelligent power module with information deficiency of prior distribution and the characteristics of censored data through Bayesian statistics. This approach used a prior distribution of Bayesian statistics using the lifetime information provided by the manufacturer and compared and evaluated diffuse prior (vague prior) distributions. To overcome the computational complexity of Bayesian posterior distribution, it was computed with Gibbs sampling in the Monte Carlo simulation method. As a result, the standard deviation of the prior distribution developed using simple information was smaller than that of the posterior distribution calculated with the diffuse prior. In addition, it showed excellent error characteristics on RMSE compared with the Kaplan-Meier method.

• Journal of the Korea Safety Management & Science
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• v.23 no.1
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• pp.71-79
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• 2021

The railroad facilities are intended for long-term operation as the initial acquisition costs necessary for infrastructure construction are high. Therefore, regular maintenance of railroad facilities is essential, and furthermore, system reliability through systematic performance evaluation is required. In this study, the signal control system of railroad electrical equipment was selected as the subject of research and the performance evaluation target facility selection study was conducted using AHP. The results of the study can contribute to the reliability of the signal control system as well as to the reliability of the railroad system, which is a higher system.

• Safety and Health at Work
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• v.8 no.3
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• pp.322-326
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• 2017

In 1992, the quality control program was introduced in Republic of Korea to improve the reliability of the work environment monitoring, which was introduced in the 1980s. The commission entrusted by the Ministry of Employment and Labor, the Occupational Safety and Health Research Institute has conducted the program for industrial hygiene laboratories including designated monitoring institutions and spontaneously participating agencies. The number of institutions that participated in the program has increased from 30 to 161. The initial conformance ratio in the participants was 43% (organic solvents) and 52% (metals). Thereafter, the conformance ratio increased rapidly and it has remained in a stable state at more than 89% since 1996. As subject materials, 13 kinds of organic solvents and 7 kinds of metals were used. To improve the capability of measurement and analysis of private institutions, educational courses were conducted annually. An assessment at the actual sites of participants was additionally introduced into the program in 2013. Thus, the program turned into a system that administrates the overall process of participants. For the future, the scope of target materials will be extended through additional items. Thus, the reliability of the results of the work environment monitoring is expected to increase accordingly.

• Smart Structures and Systems
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• v.22 no.2
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• pp.193-200
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• 2018

From the viewpoint of engineering applications, the prediction of the failure of bogies plays an important role in preventing the occurrence of fatigue. Fatigue is a complex phenomenon affected by many uncertainties (such as load, environment, geometrical and material properties, and so on). The key to predict fatigue damage accurately is how to quantify these uncertainties. A Bayesian model is used to account for the uncertainty of various sources when predicting fatigue damage of structural components. In spite of improvements in the design of fatigue-sensitive structures, periodic non-destructive inspections are required for components. With the help of modern nondestructive inspection techniques, the fatigue flaws can be detected for bogie structures, and fatigue reliability can be updated by using Bayesian theorem with inspection data. A practical fatigue analysis of welded bogies is utilized to testify the effectiveness of the proposed methods.

• Geomechanics and Engineering
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• v.21 no.6
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• pp.513-525
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• 2020

Slopes stabilised with piles are seldom analysed considering uncertainties in the parameters of the pile-slope system. Reliability analysis of the pile-slope system quantifies the degree of uncertainties and evaluates the safety of the system. In the present study, the reliability analysis of a slope stabilised with piles is performed using the first-order reliability method (FORM) based on Hasofer-Lind approach. The implicit performance function associated with the factor of safety (FS) of the slope is approximated using the response surface method. The analyses are carried out considering the design matrices formulated based on both the 2^k factorial design augmented with a centre run (2^k fact-centred design) and face-centered cube design (FCD). The finite element method is used as the deterministic model to compute the FS of the pile-slope system. Results are compared with the results of the Monte Carlo simulation. It is observed that the optimum location of the row of piles is at the middle of the slope to achieve the maximum FS. The results show that the reliability of the system is not uniform for different pile configurations, even if the system deterministically satisfies the target factor of safety (FS_t) criterion. The FS_t should be selected judiciously as it is observed that the reliability of the system changes drastically with the FS_t level. The results of the 2^k fact-centred design and FCD are in good agreement with each other. The procedure of the FCD is computationally costly and hence the use of 2^k fact-centred design is recommended, provided the response of the system is sufficiently linear over the factorial space.

• Journal of the Korean Society of Safety
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• v.6 no.3
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• pp.56-63
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• 1991

This study investigates reliability based design criteria for the erection members, and proposes practical algorithm which is based on Ellingwood's algorithm for the reliability analysis and the derivation of reliability based criteria. The magnitude of the uncertainties associated with load effects are chosen primarily by considering our level of practice. And thus the uncertainties so obtained are applied for the reliability analysis and the derivation of reliability based design criteria. A target reliability($\beta$$_{o}$=2.0) is selected as an appropriate value by analyzing the reliability levels of our current USD and WSD design standards. Them a set of load and resistance factors corresponding to the target reliability is proposed as a reliability based design provision, and furthermore a set of allowable stresses for steel having same level of reliability with the corresponding LRFD criteria is also prepared for the current WSD design provision. It may be concluded that the proposed LRFD reliability based design provisions and the corresponding allowable stresses give more rational design than the current code for erection membars.s.s.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.5
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• pp.517-523
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• 1999

The Start-up transformers or on-site stand-by transformers are installed for the start-up and shut-down of generator and emergency status in unclear power plant. The on-site power supply configuration using these transformers must be detemined by considering configuration requirements, site characteristics, reliability and availability severely because it is remarkably important for safety and benefit of plant. The start-up or stand-by power supply configuration has been determined considering only safety requirements and construction cost up to now in Korea. I study various reliability estimating methods for the prediction of availability, and estimate the unavailability for the start-up power supply system of two 1,000㎿ unclear power plants. I also detemine the reliability and unavailability and unavailavility of equipment, system and configuration using FTA method.