• Journal of the Society of Naval Architects of Korea
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• v.30 no.1
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• pp.115-124
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• 1993

A structural system reliability analysis is studied for the safety assessment of midship section. Probabilistically dominant collapse modes are generated by Element Replacement Method and Incrimental Load Method. In order to avoid generating the same modes repeatedly, it is branched at final plastic hinge. Using first and second order bound methods, system failure probability of midship section is computed and compared with deterministic load factor method to show the usefulness of the proposed method.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.789-795
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• 2008

In recent, the rolling stocks are gradually complicated in respect with design and production to improve the safety and reliability. Also, the reliability centered maintenance corresponding with system specification or technical requirements is needed to meet the higher quality in railway service. In present, each railway authorities are collecting the failure's data using information system, applying those for maintenance works. However, this system has not established with systematic and scientific approach. This paper represents the existing activities and plans for RCM management system for AREX's EMU.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.10a
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• pp.22-27
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• 1990

Since an eigenvalue problem in structural analysis has been recognized as an important process for the assessment of structural strength, it is usually to be carried out the eigenvalue analysis or buckling analysis of structures when the compression behabiour of the member is dorminant. In general, various variables involved in the eigenvalue problem have also shown their variability. So it is natural to apply the probabilistic analysis into such problem. Since the limit state equation for the eigenvalue analysis or buckling reliability analysis is expressed implicitly in terms of random variables involved, the probabilistic finite element method is combined with the conventional reliability method such as MVFOSM and AFOSM for the determination of probability of failure due to buckling. The accuracy of the results obtained by this method is compared with results from the Monte Carlo simulations. Importance sampling method is specially chosen for overcomming the difficulty in a large simulation number needed for appropriate accurate result. From the results of the case study, it is found that the method developed here has shown good performance for the calculation of probability of buckling failure and could be used for checking the safety of the calculation of probability of buckling failure and could be used for checking the safely of frame structure which might be collapsed by either yielding or buckling.

• Journal of the Korean Society for Railway
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• v.14 no.1
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• pp.24-30
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• 2011

Conventional slope stability analysis is focused on calculating minimum factor of safety or maximum probability of failure. To minimize inherent uncertainty of soil properties and analytical model and to reflect various analytical models and its failure shape in slope stability analysis, slope stability analysis method considering simultaneous failure probability for multi failure mode was proposed. Linear programming recently introduced in system reliability analysis was used for calculation of simultaneous failure probability. System reliability analysis for various analytical models could be executed by this method. For application analysis for embankment, the results of this method shows that system stability of embankment calculate quantitatively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.536-542
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• 2016

This case study was carried out for the purpose of surveying the awareness of safety and safety education among students in a technical high school, in order to provide the basic data for the effective education of technical high school students' safety management consciousness. The study was carried out using a questionnaire survey for which the respondents were 455 students. The results of the questionnaire were subjected to statistical processing, such as frequency analysis using SPSS for Windows version 19.0. The reliability of the questionnaire in this study is Cronbach' = 0.871~0.882. According to the survey results, the students think that the contents of the school safety education would not be of interest to them and that safety education in school would help their school life, but not be useful for their daily life.

• Journal of the Korean Institute of Gas
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• v.10 no.3 s.32
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• pp.13-19
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• 2006

As a way of improving the safety of the facilities, the risk based-inspection (RBI) was executed for the chemical facilities by using K-RBI program, which has been developed based on the API-581 based resource document (BRD). As the result of the evaluation, we found the level of the process safety management (PSM) for the applied plant, quantitative risk of the applied process, risk of static facilities and pipes, and the damage mechanism of the facilities. Thus, we could suggest a proper inspection frequency using the calculated risk of the process and the status of the facilities. The applied plant achieved a reduced inspection cost by an extension of the inspection frequency, improved productivity, improved reliability of the facilities, and a computerized history management.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.7
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• pp.303-312
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• 2006

This paper proposes the architecture and protocol of a data communication network for the safety system in nuclear power plants. First, we establish four design criteria with respect to determinability, reliability, separation and isolation, and verification/validation. Next we construct the architecture of the safety network for the following systems: PPS (Plant Protection System), ESF-CCS (Engineered Safety Features-Component Control System) and CPCS (Core Protection Calculator System). The safety network consists of 12 sub-networks and takes the form of a hierarchical star. Among 163 communication nodes are about 1600 origin-destination (OD) pairs created on their traffic demands. The OD pairs are allowed to exchange data only during the pre-assigned time slots. Finally, the communication protocol is designed in consideration of design factors for the safety network. The design factors include a network topology of star, fiber-optic transmission media, synchronous data transfer mode, point-to-point link configuration, and a periodic transmission schedule etc. The resulting protocol is the modification of IEEE 802.15.4 (LR-WPAN) MAC combined with IEEE 802.3 (Fast Ethernet) PHY. The MAC layer of IEEE 802.15.4 is simplified by eliminating some unnecessary (unctions. Most importantly, the optional TDMA-like scheme called the guaranteed time slot (GTS) is changed to be mandatory to guarantee the periodic data transfer. The proposed protocol is formally specified using the SDL. By performing simulations and validations using Telelogic Tau SDL Suite, we find that the proposed safety protocol fits well with the characteristics and the requirements of the safety system in nuclear power plants.

• Journal of Energy Engineering
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• v.8 no.2
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• pp.213-223
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• 1999

In recently, the safety system software of the nuclear power plant has been verified and validated according to ANSI/IEEE-ANS-7-4.3.2-1982 to improve the reliability. This standard requires that safety-related software should be tested in the static and dynamic environments. In case of Inadequate Core Cooling Monitoring System (ICCMS), the static test procedure and related techniques are developed but the dynamic test procedure and related techniques are not developed. Therefore, this paper discusses the undeveloped techniques, and suggests the dynamic test procedure and the program for generation of test input data. The performance of the program was identified using accident analysis report of Ulchin 3&4 Final Safety Analysis Report (FSAR).

• Journal of the Korean Society of Safety
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• v.28 no.4
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• pp.43-47
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• 2013

The purpose of this paper is to evaluate the performance of a Plug-In MCCB developed for rapid power supply restoration when the MCCB is installed in a power system and to verify its reliability. Since the developed 3 ${\Phi}$ 3 W Plug-In MCCB can be installed on and removed from a bus bar by one touch using a plug housed at the rear, it can be replaced in a short period of time. Therefore, it can quickly respond to the normalization of a power system. When the Plug-In MCCBB is installed on a bus bar, the resistance between each phase and plug was measured to be 0.46 $m{\Omega}$ in average. When the Plug-In MCCB is installed, the tension in the vertical direction was measured to be 112.78 N in average, which is greater than the tension of 50 N specified in the related regulation. The withstanding voltage tests performed 5 times repeatedly by applying 6 kV to the developed Plug-In MCCB for 60 seconds shows good withstanding voltage characteristics. In addition, both the general waterproof test using a water injection method and the insulation resistance analysis using a Mega meter showed good waterproof and insulation characteristics.

• Journal of Korean Society for Quality Management
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• v.51 no.3
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• pp.435-444
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• 2023

Purpose: To attain advanced performance certification, safety aspects along with functionality and performance are essential. Hence, this study suggests radiation leakage assessment methods for aviation security equipment during its performance certification. Methods: Detection technology guided the choice of radiation leakage assessment targets. We then detailed measurement and evaluation methods based on equipment type and operation mode. Equipment was categorized as container or box types for establishing measurement procedures. Results: We've developed specific radiation leakage assessment procedures for different types of aviation security equipment, crucial for ensuring airport safety. Using these procedures allows efficient evaluation of compliance with radiation leakage standards. Conclusion: The suggested radiation leakage assessment method aims to enhance aviation security and reliability. Future research will focus on identifying risks in novel aviation security equipment detection technologies and establishing safety standards.