• Title/Summary/Keyword: 신뢰성(reliability)

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OVERVIEW OF RELIABILITY AND RELIABILITY CASE STUDIES

  • Murthy, D.N.P.
    • Proceedings of the Korean Reliability Society Conference
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    • 2004.04a
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    • pp.3-11
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    • 2004
  • Failure is the termination of the ability of an item to perform a required function.[IEC 50]. Equipment fails, if it is no longer able to carry out its intended function under the specified operational conditions for which it was designed.(omitted)

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Reliability of Phased Mission Systems of where Phase Durations are Random Variables

  • Kim, Kuk
    • Proceedings of the Korean Reliability Society Conference
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    • 2002.06a
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    • pp.263-272
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    • 2002
  • Reliability of multi-phased mission system is represented where redundant components are repairable. Failures and repairs of components follow Markovian property Under some constraints, 4 models are available. Two models are represented here. The solutions are obtained as recursive equations using Markov model and eigenvalue system.

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A Study on Performance Test Method for Wireless Gas Safety Devices (무선가스안전기기를 위한 성능시험 방안에 관한 연구)

  • Oh, Jeong Seok
    • Journal of the Korean Institute of Gas
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    • v.22 no.5
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    • pp.72-78
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    • 2018
  • Recent trends in gas safety devices are actively developing and researching wireless gas safety devices in response to the development of wireless technologies and the needs of customers. Although there is controversy over the reliability of wireless, the strength of wireless convenience is increasing the introduction of gas safety devices, a reasonable performance evaluation method is needed to verify the safety and reliability of these devices. This paper amis to propose designing and manufacturing performance assesment equipment and methods for evaluating performance so that the safety and reliability of wireless gas safety devices can be verified and distributed smoothly. So, this study reviews the functions and methods of verifying reliability and safety by investing domestic and foreign the related wireless gas safety devices, produces equipments capable of testing major functions, and presents key performance assessment item and test methods that satisfy the reliability and safety requirements of wireless gas safety devices.

Reliability-Based Design of Shallow Foundations Considering The Probability Distribution Types of Random Variables (확률변수의 분포특성을 고려한 얕은기초 신뢰성 설계)

  • Kim, Chang-Dong;Kim, Soo-Il;Lee, Jun-Hwan;Kim, Byung-Il
    • Journal of the Korean Geotechnical Society
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    • v.24 no.1
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    • pp.119-130
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    • 2008
  • Uncertainties in physical and engineering parameters for the design of shallow foundations arise from various aspects such as inherent variability and measurement error. This paper aims at investigating and reducing uncertainty from deterministic method by using the reliability-based design of shallow foundations accounting for the variation of various design parameters. A probability distribution type and statistics of random variables such as unit weight, cohesion, infernal friction angle and Young's modulus in geotechnical engineering are suggested to calculate the ultimate bearing capacities and immediate settlements of foundations. Reliability index and probability of failure are estimated based on the distribution types of random variables. Widths of foundation are calculated at target reliability index and probability of failure. It is found that application and analysis of the best-fit distribution type for each random variables are more effective than adoption of the normal distribution type in optimizing the reliability-based design of shallow foundations.

Structural reliability analysis of offshore structure at cold region (저온해역에서의 해양구조물에 대한 구조신뢰성 해석)

  • 이주성
    • Journal of Ocean Engineering and Technology
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    • v.11 no.3
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    • pp.8-19
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    • 1997
  • In this study an adequate type of offshore structure at the Sakhalin region as cold region is proposed and its structural design results are presented based on the reliability analysis. Structural safety assessment has been carried out for the proposed offshore structure at the Sakhalin area as designed by the reliability method. And a rational design procedure is presented based on the reliability analysis. Followings are drawn through the present study : - Four colum TLP structure is proposed as an adequate offshore structure type at the cold region like the Sakhalin region and the reliability-based structural design results are presented. It is seen that the proposed type is a more adequate and economic than the fixed type. - Safety assessment of the proposed structure applying the extended incremental load method is performed. - Referring the allowable safety level for offshore structures it has been found present TLP structure has sufficient structural safety at the system level as well as at the component level.

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A Study on Reliability Based Design Criteria for the Steel Highway Bridge (강도로교(鋼道路橋)의 신뢰성(信賴性) 설계규준(設計規準)에 관한 연구(硏究))

  • Cho, Hyo Nam;Kim, Woo Seok;Lee, Cheung Bin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.5 no.1
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    • pp.43-53
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    • 1985
  • This study proposes a reliability based design criteria for the steel bridge (H-beam, plate-girder and composite-beam), which is most common type of steel bridge, and also proposes the theoretical bases of nominal safety factors as well as load and rasistance factors based on the reliability theory. Major 2nd moment reliability analysis and design theories including both Cornell's MFOSM (Mean First Order 2nd Moment) Methods and Lind-Hasofer's AFOSM(Advanced First Order 2nd Moment) Methods are summarized and compared, and it has been found that Lind-Hasofer's approximate and an approximate Log-normal type reliability formula are well suited for the proposed reliability study. A target reliability index (${\beta}_0=3.5$) is selected as an optimal value considering our practice based on the calibration with the safety pravisions of the current steel bridge design code. Galambo's theory is used for the derivation of the algorithm for the evaluation of uncertainties associated with resistences by LRFD Format and SGST Format, whereas the magnitude of the uncertainties associated with load effects are chosen primarily by considering our level of practice. It may be concluded that the proposed LRFD reliability based design provisions for the steel highway bridge give more rational design than the current standard code for steel highway bridge.

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The Analyses of Gaps in Reliability and Quality Performance among the Levels of Supply Chain Orientation of Korean Foreign Direct Investment Firms (한국 해외직접투자기업의 공급사슬지향성의 수준에 따른 신뢰성과 품질 성과의 차이분석)

  • Bae, Hee-Sung;Kim, Eun-Soo
    • Korea Trade Review
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    • v.43 no.3
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    • pp.147-168
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    • 2018
  • Korean foreign direct investment (FDI) firms procure cheap raw materials, produce goods in developing countries featuring low rent and labor costs, and sell goods in world market. In this regard, global supply chain management is important to Korean FDI firms. The objective of this study is to analyze gaps in the performance of reliability and quality of supply chain orientations. To achieve this objective, this study confirms theoretical relationships between variables through prior research, selects measuring variables, and analyzes data collected from Korean FDI firms. Results are as follows; First, there is a gap in reliability performance among the levels of supply chain orientation. Managers should check the level of their supply chain orientation and make strategic and structural efforts to improve reliability performance. Second, there is a gap in quality performance among the levels of supply chain orientation. To improve quality performance, managers should identify the level of their supply chain orientation. In addition, managers can enhance quality performance on the basis of strategic and structural efforts.

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The Relationship Influence between Characteristics of Smartphone Tourism Information and Reliability of Tourist Information Perceived by University Students: Gender differences (대학생이 인식하는 스마트폰 관광정보서비스 특성과 관광정보 신뢰성에 대한 영향 관계 : 성별에 따른 차이분석)

  • Na, Jeong-mi;Yeo, Young-suk
    • The Journal of the Convergence on Culture Technology
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    • v.4 no.2
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    • pp.115-122
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    • 2018
  • This study investigates characteristics of smartphone tourism information service and influence on reliability of tourist information among university students. A total of 251 students attending university in Gwang-ju city and South Jeolla provence participated in this research. Data was collected for 5 days at 5 different university campus, 2 in South Jeolla provence and 5 in Gwang-ju city, from October 23 to October 27, 2017. The result of this study showed that the female-group tends to use mostly every tourism service in the category far more than the male-group. Moreover, the informational quality factor among characteristics of smartphone tourism information influences on reliability of tourist information in the male-group while the ease-of-use factor among characteristics of smartphone tourism information influences on reliability of tourist information the female-group.

Development for Reliability Quality and Performance Evaluate Model of Fingerprint Recognition System (지문인식시스템의 신뢰성 품질 성능 평가모델 개발)

  • Eom, Woo-Sik;Jeon, In-Oh
    • The Journal of the Korea Contents Association
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    • v.11 no.2
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    • pp.79-87
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    • 2011
  • Although products with the fingerprint recognition system currently show a rapid growth in quantity, it is also true that efforts to consider the product quality have been lacking until now. Accordingly, this paper analyzed technological elements with domestic and foreign market situations for products with the fingerprint recognition system to develop an evaluation model to support the quality increase by evaluating aspects of product quality for the knowledge information security, identifying the level of quality and deriving directions for improvements. A model for the reliability quality evaluation was constructed that can be applied comprehensively to non-functional elements that have not been done in the existing evaluations central to the security functions by analyzing requirements for the security, performance and reliability in consideration of features on products. It is considered that this paper can make contributions to the overall quality increase for products with the knowledge information security by reflecting features and trends for the fingerprint recognition products and building a model for the reliability and evaluation to perform evaluations by product.