• Communications for Statistical Applications and Methods
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• v.16 no.5
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• pp.871-880
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• 2009

Recently, there has been much development on burn-in models in reliability area. Especially, the previous burn-in models have been extended to more general cases. For example, (i) burn-in procedures for repairable systems have been developed (ii) an extended assumption on the failure rate of the system has been proposed and (iii) a stochastic model for burn-in procedure in accelerated environment has been developed. In this paper, recent extensions and advances in burn-in models are introduced and some issues to be considered in the future study are discussed.

• Journal of Korean Society for Quality Management
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• v.23 no.4
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• pp.148-156
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• 1995

The past approach to burn-in optimization have been focused mainly in cost minimization problem during entire product life cycle. But in the case of practical application, burn-in optimization under reliability restriction might be preferred to burn-in optimization by cost minimization. Accordingly this paper shows real examples which estimate the practical burn-in period through application of heuristic method and select the best reliability model through comparison of reliability performance measures.

• Journal of the Korean Burn Society
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• v.24 no.1
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• pp.1-6
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• 2021

Purpose: The purpose of this study was to evaluate the accuracy of four prediction models in adult burn patients. Methods: This retrospective study was conducted on 696 adult burn patients who were treated at burn intensive care unit (BICU) of Hallym University Hangang Sacred Heart Hospital from January 2017 to December 2019. The models are ABSI, APACHE IV, rBaux and Hangang score. Results: The discrimination of each prediction model was analyzed as AUC of ROC curve. AUC value was the highest with Hangang score of 0.931 (0.908~0.954), followed by rBaux 0.896 (0.867~0.924), ABSI 0.883 (0.853~0.913) and APACHE IV 0.851 (0.818~0.884). Conclusion: The results of evaluating the accuracy of the four models, Hangang score showed the highest prediction. But it is necessary to apply the appropriate prediction model according to characteristics of the burn center.

• Journal of the Korean Chemical Society
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• v.39 no.10
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• pp.763-768
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• 1995

The theory previously proposed to simulate hole depth in the weak burn intensity limit is extended to examine the hole depth at arbitrary burn intensity using 3-level system model. The hole spectrum simulated using constant fluence gives different hole depth for strong burn intensity while it gives same hole depth for weak burn intensity region. The calculated hole growth curves are compared with published experimental data for oxazine720 in glycerol and tetracene in MTHF glass.

• Journal of the Korea Safety Management & Science
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• v.1 no.1
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• pp.135-143
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• 1999

This paper discusses an optimal burn-in procedure to minimize total costs based on the assumption that the failure rate pattern follows a bimodal mixed Weibull distribution. The procedure will consider warranty period as a factor of the total expected bum-in cost. A cost model is formulated to find the optimal burn-in time that minimizes the expected burn-in cost. Conditional reliability for warranty period will be discussed. An illustrative example is included to show how to use the cost model in practice.

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.719-728
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• 1999

This paper discusses an optimal burn-in procedure to minimize total costs based on the assumption that the failure rate pattern follows a bimodal mixed Weibull distribution. The procedure will consider warranty period as a factor of the total expected burn-in cost. A cost model is formulated to find the optimal burn-in time that minimizes the expected burn-in cost. Conditional reliability for warranty period will be discussed. An illustrative example is included to show how to use the cost model in prctice.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.28 no.1
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• pp.53-67
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• 2015

Objective: The aim of this study was to investigate the wound healing effect of herbal ointment, Gamijaungo, on the burn-induced model. Reports about Gamijaungo on the wound healing effect by local application in mice model or human study have published in the several domestic or internationally, but most are anecdotal and lack solid scientific evidence. Method: We observed the morphologic and histologic changes in the burn-induced mice model. we counted white blood cell and platelet changes. we confirmed VEGF, PI3K and pAkt protein expression by Western blot analysis. Result: In this study, we observed that Gamijaungo showed strong wound healing effects in the morphologic and histologic changes in the burn-induced mice model. Also we found that the significant changes of white blood cell and platelet changes by the treatment of Gamijaungo. In molecular mechanism, we got the strong positive effect by Gamijaungo treatment on angiogenesis, a key process in the formation of the granulation tissue during wound healing. Conclusion: These findings suggest the potential use of Gamijaungo as a therapeutic in thermal burn-induced skin injuries.

• Journal of Korean Society for Quality Management
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• v.24 no.4
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• pp.70-89
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• 1996

This paper discusses an optimal burn -in procedure to minimize total costs based on the assumption that some of the components are weak for stress and deteriorate faster than the main components. The procedure will define the costs of burn-in errors. An ideal burn-in consists of process in which all weak (substandard) components and no main (standard) components fail. In practice, the burn-in errors could occur for some reasons. For example, it is impossible to eliminate all weak components through burn-in, due to a nonzero proportion of defectives of the components. Probability model and cost function model are formulated to find the optimal burn-in time that minimizes the expected total cost. Several examples are included to show how to use the results.

• Nuclear Engineering and Technology
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• v.48 no.4
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• pp.1002-1008
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• 2016

An understanding of the coarsening process of the large fission gas pores in the high burn-up structure (HBS) of irradiated $UO_2$ fuel is very necessary for analyzing the safety and reliability of fuel rods in a reactor. A numerical model for the description of pore coarsening in the HBS based on the Ostwald ripening mechanism, which has successfully explained the coarsening process of precipitates in solids is developed. In this model, the fission gas atoms are treated as the special precipitates in the irradiated $UO_2$ fuel matrix. The calculated results indicate that the significant pore coarsening and mean pore density decrease in the HBS occur upon surpassing a local burn-up of 100 GWd/tM. The capability of this model is successfully validated against irradiation experiments of $UO_2$ fuel, in which the average pore radius, pore density, and porosity are directly measured as functions of local burn-up. Comparisons with experimental data show that, when the local burn-up exceeds 100 GWd/tM, the calculated results agree well with the measured data.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.2
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• pp.273-281
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• 2007

The decision of how long performing system burn-in must be answered with a probabilistic model of a system lifetime at which infant mortality failures created during assembly processes are quantified. In this paper, we propose such a model which is modified from previous results. Using the system model, we derived system reliability in terms of component and system burn-in times for the two cases of minimal repair at system failure and of component replacement and connection repair at their failure times. The procedure is illustrated with a bridge system and the optimal system burn-in times are obtained for maximizing system reliability. The result suggests that an assumption of minimal repair at system failure may underestimate the optimal burn-in time in practice.