• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.113-118
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• 2021

The guided weapon system should ensure economical operation and user safety. In particular, in the case of guided weapon systems developed in the form of a guaranteed bomb, the standards for maintaining reliability considering the long-term storage environment are presented during the development stage, and an optimized inspection cycle is required to maintain this. This study calculated the reliability through a trend test, fitness test, and distribution analysis using a mathematical model based on the maintenance status and shooting results during the inspection period for OO missiles currently in operation for a long time in the military. Through this, it was applied to the inspection period model (Martinez) set during the development stage to determine if the improved inspection period can be utilized. Finally, by synthesizing the data from these studies, a policy management plan was developed according to the extension of the inspection period. The One-Shot system was operated at the inspection period set when it was developed. The study analyzed the actual failure and maintenance data to reset the efficient inspection period.

• Journal of the Korean housing association
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• v.14 no.4
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• pp.69-76
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• 2003

Considering the present development situation of rental apartment since 1982, the supply of rental housing for low-income dwellers has contributed a amount of quantities, but has been deficient qualities in housing policy. To propose the device of remodeling for low-income dwellers in deteriorated apartment, this study investigated the characteristics of maintenance cost and the residents'consciousness of remodeling by rental apartment types. The results of this study were as follows; The annual maintenance cost of permanent rental apartment was 14,249 won/$\textrm{m}^2$$.$yr, that of fifty years period rental apartment was 13,372 won/$\textrm{m}^2$$.$yr. In the case of remodeling in deteriorated heating system, the principal decision factor of choice was showed “economics” as priority. Residents in rental apartment preferred remodeling to reconstruction, and unit heating system to central heating system.

• Proceedings of the Korean Statistical Society Conference
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• 2005.11a
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• pp.73-78
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• 2005

This paper considers a preventive maintenance policy following the expiration of renewing warranty, Most preventive maintenance models assume that each PM costs a fixed predetermined amount regardless of the effectiveness of each PM. However, it seems more reasonable to assume that the PM cost depends on the degree of effectiveness of the PM activity. In this paper we consider a periodic preventive maintenance policy following the expiration of renewing warranty when the PM cost is an increasing function of the PM effect. The optimal number and period for the periodic PM policy with effect dependent cost that minimize the expected cost rate per unit time over an infinite time span are obtained.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.222-223
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• 2022

The purpose of the study is to derive maintenance items in dwelling unit of apartment after the liability period for defect security. In according with the Apartment Housing Management, the managers of apartment maintain facilities in public and develop a long-term repair plan. However, Apartment unit housing is a private area and is managed facilities individually by residents or owners. As the facility ages, it is necessary to derive items in dwelling unit of apartment that need to maintain performance. Therefore, this paper analyzed the history of repairing facilities through complaints about rental housing units.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.39
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• pp.89-98
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• 1996

This paper is concerned with cost analysis model in free -replacement policy under the periodic maintenance policy The free-replacement policy with minimal repairable item is considered as follows; in a manufacturer's view point operating unit is periodically replaced, if a failure occurs between minimal repair and periodic maintenance time, unit is remained in a failure condition. Also unit undergoes minimal repair at failures in minimal-repair interval. Then total expected cost per unit time is calculated according to maintenance period Tin a viewpoint of consumer's. The expected costs are included repair cost and usage cost: operating, fixed, minimal repair and loss cost. Numerical example is shown in which failure time of item has beta distribution.

• Asian-Australasian Journal of Animal Sciences
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• v.1 no.4
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• pp.185-187
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• 1988

A total of 22 energy balance trials were done for calves fed a liquid milk replacer, calf starter and second cut mixed hay during weaning period. Milk replacer supplied 50% of the total dietary energy, calf starter 42% and hay 8% Live weight of calves averaged 64.6 ($S.D.{\pm}7.8$) kg and daily gain 0.54 (${\pm}0.22$) kg. The metabolizability of gross energy averaged 0.751. A regression was calculated relating energy retention (ER, $kJ/kg^{0.75}$) to the intake of metabolizable energy (IME, $kJ/kg^{0.75}$): $$ER=0.69({\pm}0.09)IME-395,\;r=0.888,\;P<0.01,\;S.E.{\pm}7.1$$. Metabolizable energy for maintenance (MEm) was calculated to be $572kJ/kg^{0.75}$ when ER = 0. The amount of IME over MEm for an individual animal (MEg, $kJ/kg^{0.75}$) was regressed on average daily gain (ADG, kg) by the method of regression through the origin: $$MEg=364({\pm}55)ADG,\;r=0.634,\;P<0.01,\;S.E.{\pm}12$$. The amount of ME required for maintenance and growth was estimated to be $936kJ/kg^{0.75}$.

• Annals of Pediatric Endocrinology and Metabolism
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• v.23 no.4
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• pp.226-228
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• 2018

Various endocrine dysfunctions occur during chemotherapy, including hypoglycemia. However, reports of hypoglycemia associated with 6-mercaptopurine (6-MP) are rare. Herein, we report an 8-year-old boy with severe symptomatic hypoglycemia likely due to 6-MP during chemotherapy. He had been diagnosed with acute lymphoblastic leukemia 3 years previously and was in the maintenance chemotherapy period. Treatment included oral dexamethasone, methotrexate, and 6-MP, of which only 6-MP was administered daily. Hypoglycemic symptoms appeared mainly at dawn, and his serum glucose dropped to a minimum of 37 mg/dL. Laboratory findings showed nothing specific other than increased serum cortisol, free fatty acids, ketone, alanine aminotransferase, and aspartate aminotransferase. Under the hypothesis of hypoglycemia due to chemotherapy drugs, we changed the time of 6-MP from evening to morning and recommended him to ingest carbohydrate-rich foods before bedtime. Hypoglycemia improved dramatically, and there was no further episode during the remaining maintenance chemotherapy period. To the best of our knowledge, this is the first report of this type of hypoglycemia occurring in an Asian child including Korean.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.341-348
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• 2002

The purpose of maintenance monitoring is to offer the objective and continuous data in order to be lasting security affirmation and best fitted maintenance of tunnel structure. Though recently the examples of maintenance monitoring which Is applied to tunnel are rapidly increasing, long-term measured monitoring actual results and rationally analysis method researches are wholly lacking. In this study, it is analyzed that the relationship of stress and reinforcement stress of concrete lining, i.e., last support materials of tunnel through regression analysis based on the monitoring result of the subway tunnel, which was accomplished the monitoring for long period, passing the weathering. Also, through the analysis of the stress and the safety of concrete lining, it is estimated that the frequency of maintenance monitoring and the in-situ application of the criteria value of management.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.235-236
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• 2010

Since many structures in the sea environment are damaged by chloride, appropriate repair strategy is required. Therefore in the paper, optimum period for the RC structure's repair is calculated with consideration of economic efficiency. Moreover, when the concrete members are repaired with the other material such as polymer mortar forr section restoration, their expected service life also calculated to predict more accurate repair period during the life span.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.54-59
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• 2008

The poor maintenance and management of HVAC systems finally lead to the shortening of the life expectancy and result in the increase of operating costs and energy consumptions due to low efficiencies. Also, it is essential to try to develop ways to adequately maintain and to use the building facilities efficiently in order to preserve earth environment and the limited resource. In this study, an analysis on the maintenance and management cost for HVAC systems was carried out with the capacity of equipment. Besides, the LCC(Life Cycle Cost) based analysis was carried out to verify the effect of the doing maintenance and management. As the results, the case of the good maintenance and management is able to save LCC to 11 % than the case of the poor method.