• 제목/요약/키워드: Quantitative Reliability Evaluation

검색결과 226건 처리시간 0.024초

SWOT 분석을 통한 대학 입학 전형에서 비교과 영역 평가 전략 탐색 (An Exploring Study on the Evaluation Strategies of the Extra-Curricula Area for Admission to a University using SWOT Analysis)

  • 허균;성은모
    • 수산해양교육연구
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    • 제24권2호
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    • pp.234-245
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    • 2012
  • This study aims to analyze the factors of the extra-curricula area in personal school performance record and propose the practical strategies for entrance examination affairs on this area. To address this goal, we have applied a SWOT analysis with related documents and research results. We found out five strengths: (S1) Link the students' experience to right people for the university, (S2) Quantitative Indicators, (S3) Qualitative Indicators, (S4) Link to other evaluation factors, and (S5) Analysis of Human Resource. The weakness included: (W1) Fairness, (W2) Reliability, (W3) Difficulties to set standards, (W4) Difficulties to set environments, and (W5) Lack of systemic experience of an evaluation. We also discovered five opportunities (O1) Recognition of public education, (O2) The need of national support, (O3) The importance of autonomy, (O4) Specialization, and (O5) Networks. Finally, threat factors consisted of: (T1) Frequent change of educational policy, (T2) Increasing of private education, (T3) Lack of information and preparation time, and (T4) The accuracy and reliability of personal school records. Based on these results, we suggested practical strategies with these four dimensions: S-O, W-O, S-T, and W-T.

주행 구동 유니트의 가속 수명 시험 및 분석 (Accelerated Life Test and Analysis of Track Drive Unit for an Excavator)

  • 이용범;박종호
    • 유공압시스템학회논문집
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    • 제2권2호
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    • pp.1-7
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    • 2005
  • For the reliability evaluation of the track drive unit(TDU), firstly, we analyzed the major failure modes through FMEA(failure mode & effects analysis), FTA(failure tree analysis), and 2-stage QFD(quality function deployment), and then quantitatively determined the priority order of test items. The Minitab analysis was also performed for prediction of life distribution and parameters of TDU by use of field failure data collected from 430 excavators for two years. In addition, we converted the fluctuation load in field conditions into the equivalent load, and for evaluation of the accelerated lift by the cumulative fatigues, the equivalent load is again divided into the fluctuation load by reference of test time. And then, by use of the test method in this paper, the acceleration factor(AF) of needle bearing inside planetary gear which is the most weakly designed part of TDU is achieved as 5.3. This paper presents the quantitative selection method of test items for reliability evaluation, the determination method of the accelerated life test time, and the method of non-failure test time based on a few of samples. And, we proved the propriety of the proposed methods by experiments using a TDU for a 30 ton excavator.

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인버터 로터리 압축기 오일 토출량 산정의 실험적 고찰 (An Experimental Study on the Estimation of Oil Discharge Rate from Inverter Rotary Compressor)

  • 신현석;변순석;태상진;문제명;김윤제
    • 한국유체기계학회 논문집
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    • 제14권3호
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    • pp.28-32
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    • 2011
  • The inverter rotary compressor discharges refrigerant and compressor oil in air-conditioning systems. The compressor oil which discharged form compressor decreases the efficiency of heat exchanger and affects the compressor operation. Recently, several studies are in progress for reducing the compressor oil. Before the reduction of compressor oil discharge rate, the quantitative measurement and evaluation method are required. In order to cope with this requirement we have developed the measurement technic of oil discharge rate. The reliability assessment was carried out approximately 0.1% of the errors with compressor performance indicators. The acceptable errors were to ensure the reliability of measurement technic. In the experiment results at several conditions, The oil discharge rate of heating operation has been confirmed average 3.7 times more than cooling operation. In this study the evaluation method and the experimental results of oil discharge rate in air-conditioning systems are presented with various operating conditions.

FMECA를 통한 전차선로 가선시스템의 신뢰도 분석에 관한 연구 (A Study on Reliability Analysis of Electric Railway Catenary System using FMECA)

  • 윤응규;최규형
    • 전기학회논문지
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    • 제64권11호
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    • pp.1618-1625
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    • 2015
  • The reliability of catenary system is very important for uninterrupted train operation as it supplies electric power to train without redundant facilities. This paper provides a systematic approach to the reliability analysis of the catenary system based on FMECA procedures defined by global standards such as MIL Std 1692a and IEC 60812. Field failure data collected from the operation and maintenance of high-speed railway catenary system for 9 years are used to derive critical failure modes and to evaluate the criticality of the failure modes. Evaluation of the criticality are carried out by quantitative procedures defined by MIL Std 1692a and by criticality matrix defined by IEC 60812. FMECA results suggests that three critical failure modes should be checked carefully during maintenance work, which include strand break of dropper and voltage equalizing wire, power supply failure of feeder. Maintenance procedure of catenary system in order of importance is suggested too. These results can be applied to maintenance planning and design of catenary system to improve the reliability of electric railway system.

에어컨디셔너 공기질 개선의 신뢰도 확보를 위한 냄새 분석 기술 연구 (Research on Odor Analysis Technology to Secure the Reliability of Air Quality Improvement in Air Conditioners)

  • 강석현;허필호;안영철
    • 한국환경과학회지
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    • 제30권1호
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    • pp.45-55
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    • 2021
  • In this study, the odor of the parts and the odor of the surrounding environment were classified and verified. In order to increase the reliability of odor quantitative/qualitative analysis, the selection criteria for 5 sensory evaluators were established, and the n-Butanol control solution for each odor intensity was periodically trained to recognize the odor intensity before sensory evaluation. In addition, although various odor thresholds have been used through several studies, verification of whether the odor intensity value obtained through GC/MSD analysis is similar to the degree to which a person directly smells and feels it. It is important to select the odor threshold that has the best correlation with the odor intensity calculated by the person smelling the odor. Finally, sampling and measuring flowing airflow and temporary odors such as odor component analysis was experimentally difficult due to limited collection space and differences in concentration of generated components. In this study, a quantitative analysis was made possible by using the low temperature concentration (cooling) trap method. Through this, it was confirmed that the correlation with the actual odor intensity was not caused by the product itself, but by the environmental factor discharged from the product after creating the odor environment.

EPDM 애자의 경제적 교체 주기에 관한 수학적 제안 (The Mathematical proposal of Economical Exchange-Cycle in EPDM)

  • 임장섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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    • pp.135-136
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    • 2008
  • In the paper, we evaluated insulation evaluation of EPDM insulator used often in power distribution lines in Korea. The selected samples for our experiment were three EPDM insulators for 22.9[kV] operated for 10 years or less. Using these samples, we observed the discharge pattern through accelerating experimental and analyzed discharge quantity using fractal theory. The validity of our fractal method were discussed and life time. reliability and quantitative analysis of the insulator was conducted through the method.

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System의 수행도를 개선시키기 위한 유전자 알고리즘의 도입에 관한 연구 (A Study on the Introduction of Genetic Algorithms for Developments Performance of System)

  • 김병석;김용범;장병집
    • 한국안전학회지
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    • 제13권4호
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    • pp.240-247
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    • 1998
  • This paper proposed a method for solving the nonlinear integer programing problem to get easily the best compromise solution while holding a nonlinear property by using the genetic algorithms. Also, this paper reported that the optimization problem of systems reliability as was solved by using the preposed method, and the numerical comparison experiments between the 0-1 LP/0-1 NP formulations were demonstrated, and from the quantitative evaluation the efficiency of the proposed method was demonstrated.

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Staggered Voting for TMR Shift Register Chains in Poly-Si TFT-LCDs

  • Lee, Seung-Min;Lee, In-Hwan
    • Journal of Information Display
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    • 제2권2호
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    • pp.22-26
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    • 2001
  • This paper presents the idea of staggered voting for the efficient TMR implementation of shift register chains for improving the yield of Poly-Si TFT-LCD driving circuits. The paper discusses the characteristic features of staggered voting and performs a quantitative evaluation of its effectiveness. Staggered voting allows us to improve the reliability of a single-voter TMR chain significantly when the probability of a voter failure is not negligible.

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학술 활동 건전성 제고를 위한 연구업적평가 개선에 관한 연구 (A Study on Improvements of Research Performance Evaluation for Enhancing the Soundness of Academic Activities)

  • 노영희;강지혜;김용환;양정모;이종욱
    • 한국비블리아학회지
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    • 제33권4호
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    • pp.93-114
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    • 2022
  • 본 연구는 올바른 연구문화 정착지원을 위한 대학의 연구업적평가 개선방안을 도출하고자 하였다. 이를 위해 국내외 연구업적평가와 관련한 사례를 조사·분석하고, 대학 교원과 연구업적평가 관계자를 대상으로 각각 설문조사와 면담조사를 실시하였다. 이를 통해 연구업적평가 원칙 수립 방향, 연구업적물 유형의 범주화 방안, 연구업적평가 방식과 절차, 필요 서류 등을 제안하였다. 구체적으로 첫째, 정량평가의 한계점을 보완하면서 평가의 타당성과 신뢰성, 투명성을 확보하기 위해 연구업적평가 시 고려해야 하는 8가지 원칙을 제시하였다. 둘째, 연구업적물의 주요 유형을 학술논문, 저서, 학술대회 발표로 범주화하였다. 셋째, 연구업적평가 방식으로는 정량 및 정성, 복수의 계량지표를 활용하는 하이브리드 평가를 제안하였다. 넷째, 연구업적평가의 절차로 총 11단계(필수 7단계)를 제시하였다. 다섯째, 연구업적 평가를 위한 주요 서류로 출판물, 평가서, 위원장 보고서 등을 제안하였다. 본 연구에서 제시된 연구업적평가 개선방안은 학문 및 연구 분야와 대학의 특성을 고려하여 유연하게 적용되어야 할 것이다.

초도양산 군수품에 대한 정량적 위험등급평가 방안 연구 (A study on the quantitative risk grade assessment of initial mass production for weapon systems)

  • 정영탁;함영훈;노태주;안만기;고경와
    • 품질경영학회지
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    • 제46권3호
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    • pp.441-452
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    • 2018
  • Purpose: The purpose of this paper is to study quantitative risk grade assessment for objective government quality assurance activities based on risk management in initial mass production for weapon systems. Methods: The Defense quality management regulations and foreign risk assessment documents are referred to analyze problems performing quality assurance actives. The failure rate data, maintainability and cost of products have been studied to quantify the risk Likelihood and impact. The analyzed data were classified as risk grade assessment through K-means Cluster Analysis method. Results: Results show that a proposed method can objectively evaluate risk grade. The analyzed results are clustered into three levels such as high, middle and low. Two products are allocated high, eleven low and seven middle. Conclusion: In this paper, quantitative risk grade assessment methods were presented by analyzing risk ratings based on objective data. The findings showed that the methods would be effective for initial mass production for weapon systems.