• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1582-1585
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• 2010

로봇은 인간의 생명과 밀접하게 관련되어 있기 때문에 높은 안전성과 신뢰성이 요구된다. 특히 최근에는 지능형 서비스 로봇의 등장과 더불어 증가되는 로봇 개발환경의 복잡성 문제와 로봇의 신속한 개발 및 유지보수 문제를 해결하기 위해 컴포넌트 기반의 로봇 플랫폼에 대한 연구가 증가하고 있으며, 특히 로봇 플랫폼을 구성하는 컴포넌트의 장애문제 해결이 중요한 이슈로 대두되고 있다. 따라서 본 논문에서는 컴포넌트 기반 로봇의 결점분류 절차를 제시하고 로봇의 결점타입과 로봇 플랫폼과의 상관관계를 분석하고 로봇 플랫폼에 결점타입을 매핑하여 최종적으로 컴포넌트 기반 로봇의 결점분류 모델을 제안한다.

• Journal of the Korean Society for Railway
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• v.9 no.6 s.37
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• pp.739-745
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• 2006

The role of maintenance in railway is going to be extended to improve the reliability of railway system in the aspect of Asset management gradually. In this paper, the meaning of reliability and safety in RCM which has been applied in order to improve the efficiency of maintenance is deduced. And the analysis task of reliability and safely which has been recommended in railway standards such as EN50126 and IEC62278 is reviewed in the aspect of RCM. Finally, the several ways are proposed to apply RCM to railway system through the comparison between the RCM procedure and the analysis procedure for the reliability and safety in railway standards. Hereafter, if the analysis of reliability and safety is performed with the concept of RCM in the beginning of railway business, it will be more efficient to improve the reliability and manage the railway asset.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.473-481
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• 2015

The flood and environment surveillance network on riverside is a network requiring a way to efficiently manage the information from all kinds of sensors, along with an optical communication device that can deliver high-quality video information at high speed. Since on-site prompt recovery is very important especially for communication problems that occurred due to cut-off or aged network, various researches have been carried out on this. However, because the security against outside hacking or outside intrusion with illegal purposes is very important for environment surveillance network, such as the national backbone network, an efficient network maintenance and repair should be enabled while satisfying security and reliability at the same time. A characteristic of requirement is that when security is improved, the efficiency of maintenance and repair drops as they are conflicting to each other. Therefore, this research proposed a system in order to satisfy the conflicting requirement and improve security, by developing a one-way Bypass TAP and an android-based smartphone app that can enable efficient network maintenance and repair.

• Journal of the Korean Society for Railway
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• v.18 no.3
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• pp.186-193
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• 2015

In this paper, a reliability growth analysis for a next-generation high-speed train was conducted. First, the high-speed train was decomposed into 6 sub-systems and main equipment of the high-speed train was derived from functional diagrams. Next, failure rates were calculated for each sub-system from the failure data obtained during commissioning tests. Then, reliability growth analysis was conducted for the high-speed train using the Duane model. The results show that activities to increase reliability were carried out throughout the test runs from the reliability growth results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5D
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• pp.497-504
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• 2010

In this paper, the author presents a reliability estimation technique to analyze the effects of traffic loads on pavement mean life based on the national highway database of Suwon and Uijeongbu region from 1999 to 2008. The estimation of the mean life, its standard deviation and reliability for pavement sections are calculated by using an appropriate distribution, Lognormal distribution, based on reliability theory. Furthermore, the probability paper method and Maximum likelihood estimation are both used to estimate parameters. The author found that mean life of newly constructed sections and over-layed sections is about 6.5 to 7.9 years and 7.3 to 9.1 years, respectively. The author also ascertained that the results of cumulative failure probability for pavement life between the proposed methods and observed data are similar. Such an assessment methodology and measures based on reliability theory can provide useful information for maintenance plans in pavement management systems as long as additional life data on pavement sections are accumulated.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.694-696
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• 2019

현재 4차 산업 혁명과 가상화폐에 대한 전 세계적인 관심으로 블록체인 시스템이 급부상하고 있다. 현재 구현중심인 국내외 블록체인 시장에서 무수히 많은 블록체인 기반 플랫폼들이 등장과 함께 오류가 발생하고 있다. 하지만 블록체인 시스템의 신뢰성, 확장성, 안정성 등에 대한 검증은 누구도 하고 있지 않다. 이런 문제 해결을 위해 Go language로 구성된 블록체인 코드를 분석할 수 있는 정적분석기를 통한 품질 가시화 방법을 제안한다. 이를 통하여 Blockchain Code의 내부 복잡도를 식별하고자한다. 즉, 코드 내부를 가시화하고 개발자가 보다 쉽게 코드를 유지보수 할 수 있으며 블록체인 시스템의 소프트웨어 공학적인 고품질화가 가능하다.

• Journal of the Korean Society for Railway
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• v.19 no.5
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• pp.672-684
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• 2016

UIC Codes 714R & 715R recommend the use of line classifications and their usage in maintenance work by employing notional traffic loads. However, the classification has not been applied to local lines and, therefore, a new line classification system based on UIC 714R has been proposed in this study. For this, various classification models of UIC, Germany, and UK have been studied first and equivalent traffic loads based on Korail's report, as well as on train timetables, have been derived. The results of the classifications have been compared with those of major European countries and it has been shown that the proposed classification is equivalent to the average value in the European cases. The line classification can be fully utilized during the decision making process of maintenance work and will also be used to model the Reliability Centered Maintenance (RCM) in the future.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.3
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• pp.69-75
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• 2014

The priority of repair areas are chosen with the probability distribution of 0.3mm wide crack and carbonation induced corrosion. Data is analyzed and evaluated based on the 28 section of Precise Inspection for Safety and Diagnosis (PISD) in seoul. As the crack is distributed in log-normal, the carbonation and cover are in normal distribution. To have rational in repair sections among 503 sheets of underground structure, it is adopted the reliability index as well as the environment factors: strength, sonic speed, $CO_2$ concentration, corrosion, and content of chloride.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.593-598
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• 2022

Recently, data production has seen explosive growth, and the storage systems to store these big data safely and quickly is evolving in various ways. A typical configuration of storage systems is the use of SSDs with fast data processing speed as a RAID group that can maintain reliable data. However, since NAND flash memory, which composes SSD, has the feature that deterioration if writes more than a certain number of times are repeated, can increase the likelihood of simultaneous failure on multiple SSDs in a RAID group. And this can result in serious reliability problems that data cannot be recovered. Thus, in order to solve this problem, we propose a method of throttling IOs so that each SSD within a RAID group leads to a different life-end. The technique proposed in this paper utilizes SMART to control the state of each SSD and the number of IOs allocated according to the data pattern used step by step. In addition, this method has the advantage of preventing large amounts of concurrency defects in RAID because it induces differential lifetime finishes of SSDs.

• Korean Journal of Construction Engineering and Management
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• v.17 no.4
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• pp.57-65
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• 2016

This study found a proper parametric life distribution based on maintenance history data of each bridge member under the jurisdiction of the Korea Expressway Corporation for the past 10 years by introducing the concept of reliability and suggested a measure to calculate the mean life and reliability of each bridge member using the parameter obtained with the maximum-likelihood classification. As a result of analyzing the exponential distribution, weibull distribution and log normal distribution being utilized frequently in order to find the parametric life distribution type which well described the life data of each bridge member, it was found that the log normal distribution and weibull distribution described the characteristics of the relevant life data the best. As a result of calculating the mean life of each bridge member based on the estimated parameter, the average life of the steel bridge coating was 18.51 years which was the longest, followed by the bridge deck as 17.56 years. The mean life of the drainage facility and the bridge bearing were 12.27 years and 12.57 years respectively, showing the shortest life.