• Title/Summary/Keyword: evaluation of reliability

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Reliability Assessment Considering PLOC and Unified Evaluation via Analytic Network Process (PLOC를 고려한 배전계통의 신뢰도 계산 및 ANP에 의한 종합적 평가)

  • Lee, Buhm;Kim, Yong-Ha
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.14 no.3
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    • pp.59-67
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    • 2000
  • This paper describes the unified reliability evaluation with partial loss of continuity for Inchon international airport distribution system which is complex and difficult system to implement. To evaluate reliability considering line limitation and voltage drop of the system, PLOC technique which is based on deterministic evaluation technique and failure mode & effective analysis method is employed. And reliability indices calculation method is used. Finally, to evaluate the system performance and to improve the reliability of the system, Analytic network process method is employed. As a result, calculating accurate reliability, finding weak points, and expansion scheduling of the system is possible.

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An Algorithm for Computing the Source-to-Terminal Reliability in the Network with Delay (시간제약하의 네트워크 신뢰성 계산에 대한 알고리즘)

  • Hong, Sun-Sik;Lee, Chang-Hun
    • Journal of Korean Institute of Industrial Engineers
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    • v.12 no.1
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    • pp.133-138
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    • 1986
  • In this paper, we are modeling the problem of the reliability evaluation in the network with delay. The triconnected decomposition and factoring algorithm for the network reliability, known as the most efficient algorithm, does not work in this constrained problem. So, we propose some ideas that reduce the above constrained problem to the general network reliability problem. We also present an algorithm for the reliability evaluation in the network with delay based on these ideas.

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On the Study of Software Reliability in Quality Testing Metrics (소프트웨어 신뢰도 품질 평가 메트릭에 대한 연구)

  • Jung Hye-Jung
    • Journal of Internet Computing and Services
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    • v.7 no.2
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    • pp.151-160
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    • 2006
  • Software quality evaluation system and software evaluation criterion have to be defined to evaluate software reliability. In this study, we develop software reliability quality metrics for evaluating of software reliability and research for testing of suitable criteria of software reliability. To accomplish a study successfully, we have to estimate the failure time of software using the number of software bugs. Software reliability is very important in software quality. We propose the estimation of software reliability. We propose the software reliability metrics and the software testing method that the basis of international standard ISO/IEC 9126 in software testing metrics.

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Reliability Analysis of Emotion Evaluation EPA.PAD Model in Each Design Field (디자인 분야별 EPA.PAD 감성평가모형의 신뢰도 분석)

  • Kim, Ji-Hye;Lee, Jin-Sook
    • Science of Emotion and Sensibility
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    • v.17 no.1
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    • pp.79-92
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    • 2014
  • This study is aimed at minimizing the errors in using a sensitivity evaluation model that could occur when sensitivity analysis method is actively used for design evaluation. To extract words of a contrantion-type model by product, interior space, and streetscape design, primary word refinement was conducted with the words extracted from preceding studies. The analysis revealed that 19 words were used in all three fields. A reliability analysis revealed that different words had a bad impact on the reliability in each field. The applicability was reviewed through reliability analysis of EPA model as contraction-type and PAD model as inference-type. The results are as follows. Although the reliability of the contrantion-type model was higher than that of inference-type model in all three fields, the differences in Cronbach's Alpha were small. Also, When the reliability was analyzed after deleting the words that had a bad impact on reliability, the differences in the reliability's coefficients were clearly significant. Therefore, it is necessary to select words suitable for sensitivity evaluation target and objectivity of the evaluation can be boosted by using a proper model. Analysis of the sensitivity evaluation model suitable for future environmental evaluation should be analyzed with various statistical methods, beyond verification of reliability.

Reliability evaluation plan of Rocket motor system (고체 추진기관 시스템의 신뢰성 평가 방안)

  • Kwon, Tag-Man;Jung, Ji-Sun;Shim, Hang-Geun;Jang, Ju-Su
    • Journal of Applied Reliability
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    • v.11 no.4
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    • pp.399-407
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    • 2011
  • Reliability evaluation of One-Shot system which flies at speed of Mach must be evaluated as the result of many firing tests. But many firing tests are impossible because of budget deficit. Consequently the reliability prediction which substitutes firing tests is used. The accuracy of reliability prediction is decided according to a quantity of accumulated test data. If the test data is insufficient, the direction of prediction can not be set. So we propose the reliability prediction method which applies MIL-HDBK-217 Plus. MIL-HDBK-217 Plus is described about reliability prediction method without sufficient test data. So we apply MIL-HDBK-217 Plus to the rocket motor system, and we accomplish a modeling and a reliability prediction about the system.

Reliability and Validity Analysis of an Instrument for Pattern Identification and Evaluation in Chemotherapy-Induced Peripheral Neuropathy (항암제 유발 말초신경병증 변증평가도구의 신뢰도 및 타당도 평가)

  • Park, Ji-hye;Jung, In-chul;Lee, Seo-hyun;Lee, Suk-hoon;Choi, Seok-cheol;Yoo, Hwa-seung
    • The Journal of Internal Korean Medicine
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    • v.37 no.4
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    • pp.631-644
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    • 2016
  • Objectives: The purpose of this study was to evaluate the reliability and validity of an instrument for pattern identification and evaluation in chemotherapy-induced peripheral neuropathy (CIPN).Methods: The study consisted of 66 patients with CIPN (visual analog scale ≥30 mm, Eastern Cooperative Oncology Group ≤2). The test-retest reliability of the instrument for pattern identification and evaluation in CIPN was tested twice with the same patients in one week.Results: Pearson’s coefficient test-retest reliability of the instrument was 0.601-0.777. The internal reliability of each part was 0.619-0.811. To confirm the validity of the instrument for pattern identification and evaluation for CIPN, the correlation between the score for each identification pattern and that of other CIPN instruments was analyzed. The results revealed a positive correlation between the Functional Assessment of Cancer Therapy-General and CIPN-20.Conclusion: The reliability of the instrument for pattern identification and evaluation in CIPN was moderate, and the validity analysis revealed a positive correlation.

SYSTEM RELIABILITY-BASED EVALUATION OF BRIDGE SYSTEM REDUNDANCY AND STRENGTH (체계신뢰성에 기초한 교량의 시스템여용성 및 저항강도 평가)

  • 조효남;이승재;임종권
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.10a
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    • pp.240-247
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    • 1993
  • The precise prediction of reserved carrying capacity of bridge as a system is extremely difficult especially when the bridges are highly redundant and significantly deteriorated or damaged. This paper is intended to propose a new approach for the evaluation of reserved system carrying capacity of bridges in terms of equivalent system-strength, which may be defined as a bridge system-strength corresponding to the system reliability of the bridge. This can be derived from an inverse process based on the concept of FOSM form of system reliability index. It may be emphasized that this approach is very useful for the evaluation of the deterministic system redundancy and reserve strength which are measured in terms of either probabilistic system redundancy factor and reserve factor or deterministic system redundancy factor and reserve factor. The system reliability of bridges is formulated as a parallel-series model obtained from the FAM(Failure Mode Approach) based on the major failure mechanisms. AFOSM and IST methods are used for the reliability analysis of the proposed models. The proposed approach and method for the system redundancy and reserve safety/strength are applied to the safety assessment of actual RC and steel box-girder bridges. The results of the evaluation of reserved system safety or bridge system-strength in terms of the system redundancy and the system safety/strength are significantly different from those of element reliability-based or conventional methods.

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Nondestructive Evaluation Technology and Reliability of Products

  • Lee, Joon-Hyun;Lee, Seung-Suck
    • Proceedings of the Korean Reliability Society Conference
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    • 2001.06a
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    • pp.235-238
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    • 2001
  • It is well known that the reliability of materials of mechanical products is becoming more and more important not only for assurance of quality, but for international competition of products. In order to assure the reliability of materials or mechanical products nondestructive evaluation (NDE) techniques are playing more important roles. The existence of Internal defects in materials or mechanical parts is served as crack initiation site during the various loading condition. Historically, nondestructive evaluation (NDE) technique has been used almost exclusively for detecting microscopic discontinuities In materials or mechanical parts after they have been in service to expand the role of the NDE to include all aspects of materials production and application. Research efforts are being directed at developing and perfecting NDE techniques capable of monitoring (1) materials production processes (2) material integrity following transport, storage and fabrication and (3) the amount and rate of degradation during service. In addition, efforts are underway to develop technique capable of quantitative discontinuity sizing, permitting determination of response using fracture mechanics analysis, as well as techniques for quantitative materials characterization to replace the qualitative techniques used in the past. In this paper, the important role of NDE technology for reliability assurance of materials/mechanical parts is introduced.

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Development of Tie Line Constrained Equivalent Assisting Generator Model (TEAG) For Reliability Evaluation of NEAREST -Ⅲ

  • Tran TrungTinh;Choi Jae-Seok;Kim Hyung-Chul;Moon Seung-Il;Billinton Roy
    • KIEE International Transactions on Power Engineering
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    • v.5A no.1
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    • pp.31-39
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    • 2005
  • This paper illustrates a tie line constrained equivalent assisting generator (TEAG) model considering forced outage rates of transmission systems for reliability evaluation of interconnected power systems. Interconnections between power systems can provide improved levels of reliability. It is expected that the TEAG model developed in this paper will prove useful in the solution to problems related to the effect of transmission system uncertainties in the reliability evaluation of interconnected power systems. It is important that interconnection between power systems can provide the improved levels of reliability. Therefore, It is expected that the TEAG model developed in this study will provide some solution among many problems for interconnected power systems as an optimal tie line capacity and a connected point between assisting systems and assisted system. The characteristics and validity of this developed TEAG considering transmission systems are introduced by case study of three IEEE MRTS interconnected.

Linkage of Damage Evaluation to Structural System Reliability (손상평가와 구조물 신뢰성과의 연계)

  • Park, Soo Yong
    • Journal of Korean Society of Steel Construction
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    • v.15 no.1
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    • pp.41-50
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    • 2003
  • Nondestructive Damage Evaluation (NDE) techniques yield the damage location and its size from the modal characteristics of pre-damaged and post-damaged structures. To predict the system reliability of the aging structure, results from the NDE are integrated into the element/component failure probabilities. The element/component failure probabilities can be calculated from failure functions for each element/component with the aid of techniques from a structural reliability analysis. In this paper, a method to estimate the system reliability of a structure that is based on the reliabilities of elements/components in a given structure is presented. The efficacy of the combination of the nondestructive damage detection and the structural reliability evaluation is demonstrated using pre-damaged and post-damaged modal data obtained from numerical simulations of a rigid frame.