• Management Science and Financial Engineering
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• v.14 no.1
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• pp.65-86
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• 2008

In this paper, we have considered the multicriteria quadratic plant location problem. In addition to the allocation costs, the maintenance costs of the plants are also considered. The objective functions considered in this paper are quadratic in nature. The given problem is reduced to the problem with linear objective function. The method of Fernandez and Puerto (2003) is applied to solve the reduced problem. It is illustrated with help of examples. The effect of the change in the allocation and maintenance costs on allocation of plants to the clients has also been discussed.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.265-271
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• 2007

To develop the most effect maintenance system of urban MAGLEV train which is being developed based on system engineering, logistics belong to special system engineering were applied to maintenance system and Integrated Logistic Supports (ILS) were employed to tailor every step of MAGLEV project. Since ILS had not been applied to domestic train project, the followings were studied to validate ILS: 1) case studies on maintenance procedures at home and abroad, 2) overview of standardized process of ILS, 3) Comparison and analysis of relationship between RAMS and ILS, 4) Application of ILS to MAGLEV maintenance system and other domestic train system.

• Structural Monitoring and Maintenance
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• v.2 no.2
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• pp.133-143
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• 2015

Civil engineering infrastructure is aging and requires cost-effective maintenance strategies to enable infrastructure systems operate reliably and sustainably. This paper presents an approach for determining risk-cost balanced repair strategy of corrosion damaged reinforced concrete structures with consideration of uncertainty in structural resistance deterioration. On the basis of analytical models of cover concrete cracking evolution and bond strength degradation due to reinforcement corrosion, the effect of reinforcement corrosion on residual load carrying capacity of corroded reinforced concrete structures is investigated. A stochastic deterioration model based on gamma process is adopted to evaluate the probability of failure of structural bearing capacity over the lifetime. Optimal repair planning and maintenance strategies during the service life are determined by balancing the cost for maintenance and the risk of structural failure. The method proposed in this study is then demonstrated by numerical investigations for a concrete structure subjected to reinforcement corrosion. The obtained results show that the proposed method can provide a risk cost optimised repair schedule during the service life of corroded concrete structures.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.6
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• pp.685-695
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• 2003

The purpose of this study was to identify dynamic relationship structure in fashion Internet shopping mall and to present marketers to perform marketing strategy in e-CRM, focusing on trust and commitment. 473 customers who had purchased fashion products in fashion internet shopping mall had participated in the survey. Finally, 470 were used into data analysis. The data was analyzed by factor analysis, t-test, ANOVA, correlation analysis and Structural Equation Model(SEM) using AMOS program. As the results, 'economic benefits' and 'service' variables had the positive effects on 'trust'. Especially, 'service' had the major effect on 'trust'. 'Trust' and 'product information quality' had the positive effects on 'emotional commitment'. 'Trust', 'economic benefits' and 'reputation' had the positive effects on calculus commitment, while contents had the negative effect. Also, 'emotional' and 'calculus' commitment had positive effects on 'relationship maintenance intention'. 'Emotional commitment' had higher effect on 'relationship maintenance intention' than 'calculus commitment'. 'Calculus commitment' had the positive effect on discontinue relationship intention when shopping mall made mistakes. The results of this study provide e-CRM marketing strategy for marketers of fashion internet shopping mall.

• Journal of the military operations research society of Korea
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• v.34 no.3
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• pp.41-51
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• 2008

Advanced high-tech weapons have enormous affect on combat strength in modern warfare. However, lack of maintenance can cause decrease in equipment operating rate as well as decrease in expectation on demonstrative effect of combat strength during wartime. Therefore it is essential for combat readiness that the optimum requirement of equipment maintenance cost are forecasted and included in the budget. In this paper, the trend of equipment maintenance cost about K-111 1/4t military vehicle is first analyzed by evaluating the performance data of field operation. Secondly, based on above analyzed results, the forecasting model of equipment maintenance cost is designed. Finally, by applying this forecasting model, suggestion and estimation method of equipment maintenance cost have presented for the foreseeable future.

• Journal of the Korean Institute of Gas
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• v.21 no.4
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• pp.16-20
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• 2017

Current maintenance system are unable to suggest solid basis of maintenance for roating and static equipment. When a filure occurs, replacement or repair without proper process of failure cause analysis would often result in even greater risk. Therefore in this study, a procedure of Reliability Centred Maintenance is develped in order to perform maintenance in preventive mainer (PM), and to effectively manage risk of any equipment based on failure types and respective rates of failure. Ultimately an equipment with higher risk will be monitored which will lead to effectively prevent and manage any major accident.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.915-916
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• 2012

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.69-84
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• 2006

Reports on the comparison of clinical effect between non-surgical and surgical therapy, and the change of the clinical parameters during maintenance phase have been rarely presented in Korea. This study was to observe the clinical changes during maintenance phase of 6 months in patients with chronic periodontitis treated by non-surgical or surgical therapy in Department of Periodontics, Chonnam National University Hospital. Among the systemically healthy and non-smoking patients with moderate to severe chronic periodontitis, twenty eight patients (mean age: 47.5 years) treated by non-surgical therapy (scaling and root planning) and nineteen patients (mean age: 47.3 years) treated by surgical therapy (flap surgery) were included in this study. The periodontal supportive therapy including recall check and oral hygiene reinforcement was started as maintenance phase since 1 month of healing after treatment. Probing depth, gingival recession. clinical attachment level and tooth mobility were recorded at initial, baseline and 1, 2, 3 and 6 month of maintenance phase. The clinical parameters were compared between the non-surgical and surgical therapies using Student t-test and repeated measure ANOVA by initial probing depth and surfaces. Surgical therapy resulted in greater change in clinical parameters than non-surgical therapy. During the maintenance phase of 6 months, the clinical effects after treatment had been changed in different pattern according to initial probing depth and tooth surface. During maintenance phase, probing depth increased more and gingival recession increased less after surgical therapy, compared to non-surgical therapy. The sites of initial probing depth less than 3 mm lost more clinical attachment level, and the sites of initial probing depth more than 7 mm gained clinical attachment level during maintenance phase after non-surgical therapy, compared to surgical therapy. Non-surgical therapy resulted in greater reduction of tooth mobility than surgical therapy during maintenance phase. These results indicate that the clinical effects of non-surgical or surgical therapy may be different and may change during the maintenance phase.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.274-283
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• 2016

The study of maintenance planning is important in military weapon systems because it can improve their availability and reduce the operational and maintenance cost during the total life cycle. In maintenance planning, it is important to determine the preventive maintenance task and its optimal interval. This paper focuses on the hard time task, which is one of the preventive maintenance tasks. A hard time task removes an item or restorative action before some specified maximum age limit to prevent functional failure. The Monte-Carlo simulation model was proposed to help understand the cost effectiveness of a hard time task. In the simulation, various shape parameters of the Weibull distribution and cost ratio of corrective maintenance to preventive maintenance were assumed. Using a Monte-Carlo simulation, a quantified cost saving effect and optimal preventive maintenance interval were suggested.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.175-183
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• 2020

This study suggests a solution regarding the effects of apartment facility maintenance and fire safety facility maintenance on the residential satisfaction of residents. The results are as follows. Firstly, facility maintenance had a negative effect on residential satisfaction. Analysis revealed that residential satisfaction decreased the more breakdowns there were in the facilities. This revealed that when maintenance staff neglect the residents' complaints due to the repetitive aspect of their jobs, there was a negative effect on residential satisfaction; therefore, residential satisfaction must be increased by maintaining the facilities well and training support for maintenance staff. Secondly, fire safety facilities had a negative effect on residential satisfaction. Analysis revealed that residential satisfaction decreased the more malfunctions there were in the fire safety facilities and the more replacements there were in fire fighting equipment. This revealed the importance of safety and the fact that the apartment heavily relies on fire safety facilities because there may be a low awareness regarding safety; therefore, maintenance staff must lower the damage from fire safety facilities and to increase the residential satisafaction of residents. Lastly, there needs to be repetitive training and education for residents regarding fire fighting and evacuating in accordance with the fire fighting plan as a means to strengthen residents' safety awareness.