• Journal of KIISE:Information Networking
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• v.31 no.3
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• pp.280-288
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• 2004

In Ad Hoc Networks, a connection breaks due to the irregular movement of mobile nodes and the inherent characteristics of the wireless medium such as the interference and the multi-path fading. AODV, a typical on-demand routing protocol in Ad Hoc networks, uses the local repair mechanism to cope with the connection breaks. This paper proposes an efficient route maintenance scheme for AODV, named as AODV-ERM, by utilizing hello messages. The proposed AODV-ERM scheme can recover some link breaks efficiently without relying on the expensive local repair process, thereby reducing the repair time. To show the effectiveness of the proposed scheme, we performed extensive simulation with NS2. The simulation results show that the proposed scheme can reduce the repair time effectively and thus, increase the overall packet delivery ratio.

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.914-919
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• 2017

While industry understands the importance of keeping equipment operational and well maintained, the importance of tracking maintenance information in reliability models is often overlooked. Prognostic models can be used to predict the failure times of critical equipment, but more often than not, these models assume that all maintenance actions are the same or do not consider maintenance at all. This study investigates the influence of integrating maintenance information on prognostic model prediction accuracy. By incorporating maintenance information to develop maintenance-dependent prognostic models, prediction accuracy was improved by more than 40% compared with traditional maintenance-independent models. This study acts as a proof of concept, showing the importance of utilizing maintenance information in modern prognostics for industrial equipment.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1203-1207
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• 2005

At this point of time that it is required to improve educational environment and the function of educational facilities as well as interests on educational facility business is increasing, it is actual situation that unsystematic maintenance of educational facility is not being able to cope with the change caused by introducing the 7^th curriculum. Also, in spite of enormous career in maintenance work, the function is not properly performed because of unsystematic management. In case of educational facility manager, he parallels performing general administrative work and facilities maintenance work not as a maintenance expert but as a member of administration office. So there are difficulties in performing maintenance work, and systematic maintenance work cannot be expected because of lacking maintenance manual. Therefore, in this research, I would like to investigate and analyze the status of educational facilities and to elicit the point of issue as a basic research to save maintenance expenses and to make pleasant educational environment.

• Journal of the Korea Institute of Building Construction
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• v.24 no.3
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• pp.355-362
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• 2024

The sustained upkeep of apartment buildings necessitates ongoing maintenance and timely repairs, particularly given their complex nature due to extensive areas, common facilities, and multiple residential and service structures. Additionally, the need for cost-effective maintenance is paramount for ensuring safety, preserving value, and maintaining economic efficiency. However, the multitude of external variables influencing apartment complex maintenance, coupled with the challenges in data collection, have resulted in limited research in this domain. To address this gap, the current study aims to develop a framework for predicting maintenance costs utilizing deep learning techniques, grounded in real-world apartment complex maintenance cost data. This study intends to provide a practical and valuable contribution to the field of apartment complex management, empowering stakeholders with enhanced predictive capabilities for optimizing maintenance strategies and resource allocation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.27-30
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• 2011

Analysis data of basics which are used for LCC(Life Cycle Cost) analysis of buildings and maintenance plan, are demanded to secure according as replacement cycle of repairs of apartment houses has come. However, investigation techniques and systems for investigating condition of deterioration of apartment houses, have not been made yet in Korea. For this reason, this study was wanted to make investigation techniques and systems, so the process for maintenance of apartment houses was researched and the required quality and deterioration factors of interior/exterior materials were investigated. As a result Check-List for investigating condition of deterioration, was made. if this is used during a nonscheduled, a routine, a regular and a urgency check, the methodical investigation will be achieved. Furthermore, if this is used for maintenance of apartment houses, it will be helped to select the repair cycle and the long-term repair plan.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.271-272
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• 2021

The maintenance and repair work of sidewalk block pavement is a construction that requires a large amount of budget to be invested every year. It is important to establish an appropriate standards for estimating construction cost to ensure proper budgeting and quality. In this study, the standards for estimating the cost of maintenance and construction work for sidewalk blocks that can be applied to the construction volume classified according to the site conditions, construction type, and equipment use differentiated from new construction was established. As a result, the daily construction volume was presented by reflecting excavator and truck as equipment in the combination of paver and common worker. The re-installation was applied by separating the construction volume of sections with general blocks and induction/raised blocks based on the installation of sidewalk blocks after demolition. Generally if block cutting is necessary, the precision construction conditions using a cutting machine were taken into consideration to secure the construction quality. In addition, it has been revised to apply classified construction volume into A and B-Type depending on the park and site conditions.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.80-80
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• 1994

• Journal of the Korean Institute of Educational Facilities
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• v.19 no.5
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• pp.21-28
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• 2012

Current maintenance costs of the educational facilities have been determined by the years of services according to their foundation year. However, these maintenance costs have not considered maintenance and repairing. Therefore, this study suggests a new method to recalculate the years of services of schools by using the data of maintenance and repairing which is stored in the CAD drawing of the educational facilities. Also, since the data of maintenance and repairing has to be kept only for 5 years, the data is limited for the BTL project which has a maintenance period of 20 years. Thus, this study developed a new model to expand 5 years' data to the period of 20 years. This proposed model is expected to contribute in the maintenance and repairing of the BTL project.

• Journal of the military operations research society of Korea
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• v.22 no.1
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• pp.142-155
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• 1996

In this research, our objective is to develop a model which could evaluate the maintenance capability for a maintenance battalion in the mechanized division. To analyze the maintenance system, we obtained various data related to maintenance capability and described the maintenance process as a network type. This network type model is then translated to SLAM-II network model to simulate the system. The simulation model can be operated by using appropriate input data and simulation results are obtained. The simulation model can be applied in various way. Through the simulation we could find the bottle neck point in the maintenance process. Also the maximum capability of maintenance with on hand asset and the wartime supportability can be evaluated. The mode provides sensitivity analysis by changing various imput data such as the number of repairmen, repair time, failure rate and so on.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.1
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• pp.1-7
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• 2007

This paper addresses a the maintenance system based on the concept of RAMS (Reliability, Availability, Maintenance, Safety) for the effective maintenance of the urban transit. A systematic approach for developing a cost-effective maintenance strategy based on the component reliability of the system in question is performed according to the following steps : definition of function, functional failures of the systems, construction of RBD (Reliability Block Diagram), and the calculation of reliability indices. The developed preventive maintenance system generates maintenance plan and repair request based on the analysed RAMS data of components and maintenance experience.