• Journal of Applied Reliability
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• v.17 no.3
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• pp.207-212
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• 2017

Purpose: This article provides an efficient cushion molding method for improving reliability of the rotation driving system. Method: Allowable stress level for cushion is calculated by using physical characteristics of the rotation driving system. In addition, various test units are manufactured and used to conduct the rebound resilience, the burst pressure and the alternating load test. Results: Actual allowable stress level and test results of the rebound resilience, the burst pressure and the alternating load test are provided. Conclusion: The cushion manufactured by the compression molding method gives more preferable characteristics for improving the reliability of the rotation driving system.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.1
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• pp.23-38
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• 1995

ELEECTRE is a less demanding and potentially Bffective multiattribute evaluation method for pre-editing proeedure. The method, however, was developed based on probabilistic mathematicsand its reliability has never'been emprieally tested. This article examined the reliability of ELECTRo under various conditions of linear and non-linear utility func- tions using a Monte-Carlo shnulation, and found the method eausea a considerably high rate of error. To enhance the reliability of ELECTRE, two ways of modi(ication - adjust- ment of threshold values of concordance and discordance matrices, and adjustment of the required nunlber of probably-dominant alternatives to eliminate a probably-dominated alternative - were suggested, and their effctiveness was also tesed by a Monte-Carlo simulation. The simulation result chows that these modifications cponsiderably improve the reliability of ELECTRE, and yet maintain a reasonably high level of efficiency. Through these modifications, ELECTRE can be used as an efficient and feliable pre-editing method. Ways to implement ELECTRE in the construction of plainning decision support systens were discussed. The impli(els combination of this method and other multiattribute evaluation methods will help to create more effective decision suport systems.

• Proceedings of the KIEE Conference
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• summer
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• pp.39-41
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• 2004

This paper presents a analytical method for the reliability evaluation of distribution system, including the distributed generations. Unlike the generators of transmission system, those of distribution system have complexities in analyzing and determining the operation. In the process of evaluate reliability, it could be shown that the analytical method is simpler than the monte-carlo simulation. Modeling technique of distributed generation to analysis distribution system reliability using frequency and duration method is proposed in this paper, and is compared with the simulation method as a result of the distribution system reliability evaluation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.5
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• pp.1040-1048
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• 2016

Recently, the studies of integrated reliability analysis for combat systems are actively progressing. Especially, the research of integrated reliability analysis is emphasized to overcome limitations of the previous studies. In this paper, we propose a calculation technique for integrated hit probability based on front and side hit probabilities that analyzed in previous studies to improve the time-effectiveness. Also, we find out the integrated reliability of each component based on the integrated hit probability which is calculated, and we propose the method which applied the reliability block diagram technique to analyze the whole combat system of the reliability by function kills. For verifying the proposed method, we applied the proposed method to armored fighting vehicle model. The proposed method considers crew which does not considered the element in the previous study and expects to enhance the accuracy of reliability analysis and the time-effectiveness compared with the previous study.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.106.1-106
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• 2002

$\textbullet$ Current status of reliability estimation techniques for robot systems $\textbullet$ Description of Bayesian Belief Nets(BBN) With an example $\textbullet$ Description of proposed reliability estimation method which combines all information necessary $\textbullet$ Application example of the method : the reactor inspection robot $\textbullet$ Results from the reliability estimation of reactor inspection robot $\textbullet$ Discussion on the proposed method (advantages and problems) $\textbullet$ Conclusion

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1991.04a
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• pp.34-42
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• 1991

This study is directed for the development of an efficient system-level Importance Sampling Technique for system reliability analysis of bridge structures Many methods have been proposed for structural reliability assessment purposes, such as the First-order Second-Moment Method, the Advanced Second-Moment Method, Computer Simulation, etc. The Importance Sampling Technique can be employed to obtain accurate estimates of the required probability with reasonable computation effort. Based on the observation and the results of application, it nay be concluded that Importance Sampling Method is a very effective tool for the system reliability analysis.

• Journal of the Korean Society of Safety
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• v.38 no.5
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• pp.43-50
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• 2023

With the advent of industrialization, consumers and end-users demand more reliable products. Meeting these demands requires a comprehensive approach, involving tasks such as market information collection, planning, reliable raw material procurement, accurate reliability design, and prediction, including various reliability tests. Moreover, this encompasses aspects like reliability management during manufacturing, operational maintenance, and systematic failure information collection, interpretation, and feedback. Improving product reliability requires prioritizing it from the initial development stage. Failure mode and effect analysis (FMEA) is a widely used method to increase product reliability. In this study, we reanalyzed using the FMEA method and proposed an improved method. Domestic railways lack an accurate measurement method or system for maintenance, so maintenance decisions rely on the opinions of experienced personnel, based on their experience with past faults. However, the current selection method is flawed as it relies on human experience and memory capacity, which are limited and ineffective. Therefore, in this study, we further specify qualitative contents to systematically accumulate failure modes based on the Failure Modes Table and create a standardized form based on the Master FMEA form to newly systematize it.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.10
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• pp.1291-1298
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• 2011

This paper proposes a new reliability estimation method for one-shot systems using quantal response data, which is based on a parametric estimation method. The proposed method considers the time-variant failure ratio of the quantal response data and it can overcome the problems in parametric estimation methods. Seven reliability estimation methods in the literature were compared with the proposed method in terms of the accuracy of reliability estimation in order to verify the proposed method. To compare the accuracy of reliability estimation, the SSEs (Sum of Squared Error) of the reliability estimation results for the different estimation methods were evaluated according to the various numbers of samples tested. The proposed method provided more accurate reliability estimation results than any of the other methods from the results of the accuracy comparison.

• Journal of Korean Institute of Industrial Engineers
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• v.36 no.4
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• pp.212-218
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• 2010

This paper shows accuracy comparison results of reliability estimation methods for one-shot systems with respect to sample sizes. To compare accuracy in reliability estimation methods, quantal-response data, characterizing one-shot systems, were simulated using failure times of LED obtained through the accelerated life test, and then the true reliability over time was evaluated using the failure times. The simulated quantal-response data were used to estimate the true reliability through applying reliability estimation methods in open literature. Accuracy of each reliability estimation method was compared in terms of both SSE (Sum of Squared Error) and MSE (Mean Squared Error), and then estimation trend for each method is found. Feasible bounds which true reliability would exist within were estimated through applying the found trends to quantal-response data set of a real weapon system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1989.10a
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• pp.34-39
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• 1989

Recent trends in design standards development have encouraged the use of probabilistic limit sate design concepts. Reliability analysis adopted in those advanced countries have the potentials that they afford for symplifying the design Process arid placing it on a consistent reliability based for various construction materials. This study is proposed in the reliability analysis of plane frame structures using second-order moment method(Level-II they). Lind-Hasofer's minimum distance method is use in the derivation of an mathematical algorithm as well as an determination of Correlation cofficients, reliability index and total reliability index depending on the multiple failure modes. In addition. This study is employed as a practical tool for the approximate reliability analysis. Results of the numerincal analysis showed that the difference between the reliability index of the failure probability of the multiple failure modes and the total reliability index of the failure probability with the simultaneous failure modes deviated nearly 3∼10% depending on tile performance functions.