• International Journal of Reliability and Applications
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• v.11 no.1
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• pp.41-53
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• 2010

In the present paper we develop a mathematical model that facilitates the calculation of reliability of a complex repairable system having three units namely super priority, priority and ordinary. The system is analyzed with the application of Gumbel Hougaard copula when different types of repair possible at a particular state due to deliberate failure. Various reliability measures such as reliability, MTTF and profit function have been evaluated by using supplementary variable and Laplace transform techniques.

• Journal of Applied Reliability
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• v.11 no.3
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• pp.213-224
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• 2011

In this paper, we analyze statistically the data set of first leak time of water pipeline. We classify first the leak time data by pipe type, location, diameter of pipe and, length of pipe. We perform the analysis of variance to indicate that there are significant difference of mean of the time between levels of the factor and also compare the distribution of levels using the multiple box-plot. When there are the difference of the mean, we perform the least significant test to find out what levels of the facor has a different mean.

• Journal of the Korean Data and Information Science Society
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• v.25 no.4
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• pp.893-901
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• 2014

A certain number of products are sold each month and some of them are returned for repair. In this study both return rate and cumulative return rate are shown on the graph to show the general trend of how many products are returned as time goes by. Next this type of summary data can be considered as a conglomeration of both left and right censored data. So reliability analysis is attempted for this type of summary data. Lastly, left censored data can be traced to find the exact time period during which the product has been claimed. In that case the left censored data can be taken as failure data. So similar type of reliability analysis is attempted for the resulting right censored data.

• The Korean Journal of Applied Statistics
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• v.24 no.3
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• pp.515-521
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• 2011

In this paper we consider failure detection equipment that which find failures in repairable systems and enable repair operations. In practical situations, failure detection equipment may come across troubles that can cause the omissions in detecting system failures and have a serious effect on system reliability. We analyze this effect through the appropriate modeling of Markov processes.

• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.3
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• pp.300-305
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• 2013

LOOP(Loss of Offsite Power) and SBO(Station Blackout) events have been occurring in nuclear power plants should be reviewed and be controlled on important electrical equipments by professional engineer to prevent and to safety improvement from safety assessment and reliability analysis report. LOOP and SBO occasionally happened by internal or external causes. This paper contained that LOOP frequency in the United States NPPs and in the domestic NPPs have compared and analyzed data by the past lessons and probabilistic statistics. Additionally will be installed MG(Mobile Generator) according to the lessons of Fukushima nuclear accident in Japan, which CDF(Core Damage Frequency) and LOOP frequency have reconsidered. And this paper proposed to reduce reliability criteria using PSA(Probabilistic Safety Analysis).

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.10a
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• pp.85-90
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• 1990

Current steel pile foundation design is bared an WSD, but the reliability based design method is more rational than the WSD. For this reason, this study proposes a reliability Index of the pile foundation by LFD which is most common type of pile foundation, and also proposes the theoretical bases of nominal safety factors of stability analysis by introducing the reliability theory. The measured bearing capacity data are analyzed to the descriptive statistics and classified into the four models of uncorrelated -normal(UNNO), uncorrelated -nonnormal(UNNN), correlated -normal(CONO), and correlated nonnormal (CONN). This study presents the comparisons of reliability index and check points using the AFSOM with respect to the four models as well as BASIC program.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.2
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• pp.216-229
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• 1995

The main purpose of this study was to develop and validate a scale for measuring situation\ulcornerspecific anxiety that consumers experience while shopping for ready\ulcornerto-wear clothes. A 92 five-point items, Likert type scale, entitled the RMCCAS(The Ready\ulcornerMade Clothes Consumer Anxiety Scale) was developed and administered to 354 female college students. Data collected were subjected to a series of statistical analysis: item analysis, factor analysis, estimation of validity and reliability and descriptive statistics. A second-order factor analysis conducted to 15 factors obtained from a first-order factor analysis yieled three factors; Fitness of Fashion and Design to indiviuality and time(scale 1), Reliance on Price and Quality including Suitableness of Material and Color(scale 2), and Practicality in Dressing and Maintaining(scale 3). Obtained concurrent validity of the RMCCAS subscales with the trait anxiety were .056(subscale I), .082(subscale 2), .033(subscale 3), and .050(total scale). that with state anxiety were .421(subscale I), .217(subscale 2), .198 (subscale 3), and .407(total scale); that with the CP AS were. 721(subscale 1), .789(subscale 2), .570(subscale 3), and .841(total scale). All of the obtained coefficients of Cronbach alpha, split\ulcornerhalf reliability, and test-retested reliability over an interval of. 8 weeks were above .80. Besides, descriptive data from the RMCCAS satisfactorily supported conditions required for the normal distribution of obtained scores. In conclusion, a close exa:nination of validity, reliability, and descriptive statistics of the RMCCAS indicates that three subscales including the scale have a resonable scaling-prop\ulcornererties. Further research is suggested for obtaining norms for more representative target samples and for tapping the possibility of using subsea Ie 2 as a unidimensional measure .

• International Journal of Reliability and Applications
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• v.11 no.1
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• pp.1-16
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• 2010

In this paper we will discuss the stochastic analysis of a three state semi-Markov reliability model. Maximum likelihood procedure will be used to obtain the estimators of the parameters included in this reliability model. Based on the assumption that the lifetime and repair time of the system units are generalized linear failure rate random variables, the reliability function of this system is obtained. Also, the distribution of the first passage time of this system will be derived. Some important special cases are discussed.

• Structural Engineering and Mechanics
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• v.69 no.4
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• pp.399-405
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• 2019

The present study assessed the reliability-based reinforcement ratio of FRP reinforced concrete structure applying recycled coarse aggregate (RCA) concrete. The statistical characteristics of FRP bars and RCA concrete were investigated from the previous literatures and the mean value and standard deviation were employed for the reliability analysis. The statistics can be regarded as the material uncertainty for configuring the probability distribution model. The target bridge structure is the railway bridge with double T-beam section. The replacement ratios of RCA were 0%, 30%, 50%, and 100%. From the probability distribution analysis, the reliability-based reinforcement ratios of FRP bars were assessed with four cases according to the replacement ratio of RCA. The reinforcement ratio of FRP bars at RCA 100% showed about 17.3% higher than the RCA 0%, where the compressive strength at RCA 100% decreased up to 27.5% than RCA 0%. It was found that the decreased effect of the compressive strength of RCA concrete could be compensated with increase of the reinforcement ratio of FRP bars. This relationship obtained by the reliability analysis can be utilized as a useful information in structural design for FRP bar reinforced concrete structures applying RCA concrete.