• Journal of the Korean Data and Information Science Society
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• v.15 no.1
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• pp.21-29
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• 2004

In this paper, we define an availability of repairable network system, when the states of links are modeled by alternating renewal processes. The actual availabilities of some well-known network systems are obtained. The expected numbers of failures and repairs of the network systems are also calculated.

• Journal of Korean Institute of Industrial Engineers
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• v.13 no.2
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• pp.59-63
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• 1987

An age replacement policy is considered for a system under a stepdown warranty. It is assumed that only minimal repairs are performed for failures occurred before age T.A unique optimal value of T which minimiges the expected cost rate is obtained. The cases of the free replacement warranty, prorata warranty and hybrid warranty are also considered and some numerical examples are given.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.14 no.24
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• pp.43-52
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• 1991

The short-term production planning of an automated manufacturing system is to determine the production rate of each part type or family of part types. The purpose of this paper is to develop an optimal algorithm for solving the short-term production planning problem while machine failures, repairs. and changes in demand requirements are anticipated. The problem is formulated by LP and it shows that the production surplus is approached or stays at the hedging point. In addition, the long-term average frequencies of set-us with relation to a multilevel hierarchical production planing scheme are considered An example to show the effectiveness of the algorithm is presented.

• Journal of Korean Society for Quality Management
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• v.22 no.3
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• pp.54-65
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• 1994

A hybrid warranty policy for a repairable item is considered. Assuming that minimal repairs ar e performed for failures during warranty period, present worth of warranty cost is derived from a supplier's viewpoint. An optimal preventive periodic replacement policy for the case is also derived from a user's viewpoint Numerical examples are presented in order to explain the results.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.561-566
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• 2008

The EMU of maintenance technique or system is changing on a large scale. To subway operation beginning the breakdown was born and every that time after the fact repaired. But, recently before the breakdown of the subway occurs, repairs in advance with the preventive maintenance concept which was exchanged. However, the preventive maintenance is to readjust, cleaning, tighten and the oil the repetition by the worker simple experience. This study on introduces the EMU of maintenance method which applies a automatic inspection equipment from the study contributing which develops the preventive maintenance system.

• Journal of architectural history
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• v.16 no.5
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• pp.21-40
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• 2007

Choryang-weagwan which was the largest international trading place between Joseon Dynasty and Tokugawa Shogunate had been maintained from 1678 through 1872 in Busan. Particularly, they had 21 times repairing constructions for 200 years since its establishment. It is noticeable that Joseon Dynasty permitted Tokukawa Shogunate to construct main pavilions and guesthouses as his style due to the good-neighbor policy between two countries, and Tokukawa Shogunate struggled to achieve his own culture in that place under the supervision of Joseon Dynasty. For satisfying his needs, the architectural craftsmen of Tokukawa Shogunate were mobilized by the chief of construction company which was called kumi-gasira in the most of cases. When they came to Busan for the construction, they brought their own architectural tools. On the one hand, the carpenters and workers of Joseon Dynasty were organized by the traditional construction superintendents which were called Gamdong-gwan and they had to carry out their responsibilities with Japanese technicians at the same workplace. Judging from this fact, the construction site of Weagwan was the good place for exchanging the architectural technology between two countries. This study especially focuses on Tokukawa Shogunate craftsmen who made the repairs of Dongwan-samdaechung in 1727 such as carpenters(Dai-ku), sawyers(ko-biki), and surveyors(Tsue-tsuki) and their tools such as Hatsuri(=Masakari) and Yo-ki(=Oh-no). The constructions in this period, there were not only the repairs of 3 major pavilions including the trading center, but also one of the most active repairing constructions comparing with other period, therefor these were important constructions to shows us repairing construction of Choryang-weagwan of those days.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.3
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• pp.239-246
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• 2017

RC(Reinforced Concrete) structures can keep their performance during intended service life through initial service life and extension of the life through repairs. In the deterministic repairing method, cost and the related $CO_2$ emission increase with step-shaped escalation, however continuous results can be obtained through probabilistic repairing technique, and this is capable of reducing $CO_2$ emission through $CO_2$ absorption. In the work, repairing timing and $CO_2$ emission/absorption are evaluated based on the different methods like deterministic and probabilistic manner. The probabilistic technique considering $CO_2$ absorption with carbonation progress is evaluated to be very effective to reduction of $CO_2$ emission through extension of initial and additional service life due to repairs. When the variations of the service life from initial construction and repair material can be determined, the proposed technique can contribute to reduction of cost and $CO_2$ with decreasing repairing number.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.2
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• pp.191-198
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• 2010

This study investigated that the stress reduction of single edge cracked plates with patch repairs according to different type of patching such as material, size and thickness of patch and adhesive as well as single sided or double sided patches. As a numerical tool, the p-convergent partial layerwise model has been employed. The proposed model is formulated by assuming piecewise linear variation of in-plane displacement and a constant value of out-of-plane displacements across thickness. The integrals of Legendre polynomials are chosen to define displacement fields and Gauss-Lobatto numerical integration is implemented in order to directly obtain maximum values occurred at the nodal points of each layer without other extrapolation techniques. Also, total strain energy release rate method is adopted to obtain stress intensity factors. Numerical examples are presented not only to demonstrate the stress reduction effect in terms of non-dimensional stress intensity factor and deflection with respect to different type of patch repairs, but also the accuracy of proposed model.

• Advances in pediatric surgery
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• v.1 no.1
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• pp.8-17
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• 1995

The clinical experience of 2,340 inguinal hernia repaired by one pediatric surgeon on 2,079 children at Hanyang University Hospital from September 1979 to December 1993 was analyzed. Of 2,046 patients who had primary hernia repairs at Hanyang University Hospital, 1,636 were male and 410 female, and 55.5% of hernias occurred on the right side, 36.0% on the left, and 8.6% were bilateral. The patients presented hernia under the age of 12 months were 45.3% and those performed herniotomy under the age of 12 months were 25.5%. Birth weight was less than 2.5kg in 111 patients(8.7%) of 1,279 data available patients. Ninety(6.6%) of 1,354 data available patients were premature(<37wks gestation). The proportions of bilateral inguinal hernia and the onset age under 12 months of life in low birth weight babies and premature babies were higher than in full-term babies. Incarcerated inguinal hernia occurred in 327 patients(16.0%) of whom 8 patients were strangulated hernias. The occurrence of incarceration inversely related with age of patients. The subsequent contralateral inguinal hernia following unilateral hernia repairs occurred in 80 patients(4.3%) among which 72 were male and 8 were female. The incidence of contralateral inguinal hernia was more frequent in boys(4.8%) than girls (2.2%) and in cases after left herniotomy(6.4%) than after right herniotomy(2.9%). Sixty percent of contralateral inguinal hernia developed within 1 year after primary hernia repair. The recurrence of inguinal hernia occurred in 6 patients(0.27%) treated at our hospital primarily. There were one or more associated congenital anomalies in 83 patients of which congenital heart diseases were the most common. Sliding hernia occurred in 25 patients consisted of 5 boys and 20 girls. Family history was noted in 35 patients and there were 28 sets of monozygotic and 3 sets of dizygotic twins.

• Composites Research
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• v.17 no.4
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• pp.68-73
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• 2004

An analytical study was conducted to characterize the fatigue crack growth behavior of pre-cracked aluminum plates repaired with asymmetric bonded composite patch. For single-sided repairs, due to the asymmetry and the presence of out-of$.$plane bending, crack front shape would become skewed curvilinear started from a uniform through-crack profile, as observed from Previous studies. Therefore, for the accurate investigation of fatigue behavior, it is necessary to predict the actual crack front evolution and take it into consideration in the analysis. In this study, the fatigue analysis of single-sided repairs considering crack front shape development was conducted by implementing three-dimensional successive finite element method coupled with linear elastic fracture mechanics (LEFM) concept, which enables the growing crack front to be directly traced and modeled in a step by step way. Through conducting present analysis technique, crack path of the patched plate as well as the fatigue life was evaluated with sufficient accuracy. The analytical predictions of both the crack front shape evolution and the fatigue life were in good agreement with the experimental observations.