• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.2
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• pp.267-275
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• 2023

As aged infrastructures have been increased, the importance of accurate maintenance costs and proper budget allocation for infrastructure become prominent under limited resources. This study proposed a mapping algorithm between representative defects, repair methods, and the estimated maintenance costs for concrete bridges. In this regard, using BMS (Bridge Management System) data analysis, bridge repair methods were classified and matched with defects according to their locations, types, and sizes. In addition, the maintenance costs were estimated based on the amount of work-load and quantity per unit using CSPR (Cost Standard Production Rate). As a result, the level of accuracy was an average of 85.1 % compared with the actual bill of quantity for Seoul bridge maintenance. The accuracy of maintenance costs is expected to be enhanced by considering the various site conditions such as pier height, extra charge conditions, additional equipment, etc.

• Journal of the Korean housing association
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• v.21 no.6
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• pp.71-80
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• 2010

The purpose of this study is to classify defects of the residential building by analyzing the defect specified by prequalification of residential building reconstruction and to suggest the solution of the problem which can be arisen during each stage of plan, construction and maintenance. By sorting the main defects which is specified by pre-qualification of residential building reconstruction for three years from August 2006 to August 2009 into 4 catagories and analyzing the cause of the defects, we draw the way of maintenance to prevent the defects and make pleasant residential environment. The reason for the frequent defects from residential building is mainly deterioration. It occured on the finishing more than on the structure, which means that residents can find defects easier on the finishing than the structure and clear the demand for repair. The result of analyzing of pre-qualification of residential building reconstruction is that the defects mostly caused small, masonry constructed and lower apartment. The apartment which is not into legal right for maintenance naturally have more defects than the others. In conclusion, it is necessary to establish a law of obligation duty of the maintenance of small apartment.

• Journal of the military operations research society of Korea
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• v.37 no.1
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• pp.147-159
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• 2011

Recently, the military service period has been shortened continuously. Meanwhile, more skilled airmen are needed as the complexity of weapon systems increase. This phenomenon could lead to a disastrous result such as deteriorating the level of the readiness and the fighting power. We suggest a method to improve recruit's maintenance capability rapidly by assigning airmen to jobs appropriate to their characteristics using Datamining methods (K-menas and CART). We focus on the assigning method for air force's air-munition maintenance airmen since they are requested more skilled than other airmen. Grouping airmen with k-means method and devising classification rule with CART algorithm, we found that airmen's proficiency arrival period could be shortened by 1.79 months when they are assigned in the suggested way.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.1
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• pp.113-120
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• 1999

Due to the heterogeneous nature of a concrete, periodic inspections are compulsory to maintenance of quality of concrete structures. The major object of this study is to analyze and investigate experimentally the experimental equation for the estimate of compressive strength of prestressed concrete. In this study, surface hardness method, ultrasonic method are investigated to evaluate strength of concrete specimens. Specimens are cast in laboratory and cores are cut from specimens in order to estimate the accurate strength. These values are used to compare with calculated values from test data. The result shows that the proposed equation can reproduce the results at prestressed concrete beam girders more appropriately than previous equations.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.221-227
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• 2005

This study has suggested the base data for decision of maintenance ranking and estimation of maintenance effect in the maintenance project of sewers as based on investigation of the defective rate in the sewer through Infiltration/Inflow(I/I) and CCTV analysis. It also analyzed the correlation between I/I and defective rate of sewer. As the result of this study, (1) Defective items of sewer was found out one item each 12.97m with an average. (2) By regression analysis, I/I has high correlation with defective rate of sewer like that $R^2$ is 0.7806. (3) The first thing in the item with bad influence on the I/I was joint badness and secondary was cross connection.

• Geomechanics and Engineering
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• v.29 no.3
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• pp.369-376
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• 2022

Accurately evaluating and predicting the performance of facilities is a key task in establishing a maintenance strategy for facilities. The importance of performance evaluation is becoming more pronounced, especially when the aging of facilities requires a huge budget. In this study, performance assessment models were developed for road and railway tunnels. Delphi analysis was performed to identify sub-elements necessary to evaluate the performance of a tunnel. The relative importance of the evaluation factors was derived from the AHP analysis. The correlation analysis was performed between each assessment factor and the final result to verify the significance of the model. For the correlation analysis, the survey data measured through precision safety diagnosis in tunnels in use was applied. The cost effectiveness analysis was also conducted according to the scenarios with different composition of performance factors in order to improve the practical applicability of the evaluation model developed in this study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.469-475
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• 2021

In order to effectively maintain and manage river facilities, on going data collection of associated objects is important. However, the existing data acquisition methods of using a total station, a global navigation satellite system, or a terrestrial laser scanner have limitations in terms of cost/time/manpower when acquiring spatial information data on river facilities distributed over a wide and long area, unlike general facilities. In contrast, a mobile mapping system (MMS), which acquires data while moving its platform, acquires precise spatial information data for a large area in a short time, so it is suitable for use in the maintenance of linear facilities around rivers. As a result of applying a MMS to a research area of 4 km, 184,646,099 points were acquired during a 20-minute data acquisition period, and 378 cross-sections were extracted. By comparing this with computer-drawn river plans, it was confirmed that efficient levee management using a MMS is possible.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.1
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• pp.63-72
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• 2019

The purpose of this study is that investigated the characteristics of integral planning related factors using the history and culture of Mojiko. It is a small city that has been urbanized after the opening of the port for logistics transportation in the modern period of Japan. As the function of the logistics city, which is the factor of the expansion of the town, declined, Mojiko applied the retro concept to the harbor which has lost its popularity due to the regional characteristics of the city to increase and revitalize local visits. Mojiko has steadily promoted the retro style of landscape and town development over 30 years, focusing on 18 Historical buildings and modern infrastructure. We analyzed characteristics of integrated urban planning include the regulation, landscape institution. Moreover, we suggest the result of the designation process of a core scenery maintenance district and the components of the plan after the designation analysis and provide essential data for revitalizing the field based on the historic city for the cultural establishment and beautiful town in the future. And deliver vital data to reviving the area based on the historical city culture establishment and beautiful town in the future.

• Journal of Korea Multimedia Society
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• v.15 no.1
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• pp.148-165
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• 2012

Applying maintenance simulation using virtual mockup in product design phase enables maintainability test before prototyping physical products, and it is expected to reduce product development costs. The simulation results can be reused as contents of service manuals and RAM (Reliability, Availability, Maintainability) analysis data. Maintenance simulation should provide realistic representation of physical property of virtual product, assembly relation between parts and manipulation process to verify feasibility of product design. The simulation system should be extended to collaborative virtual environment to perform collaborative maintenance procedures. In this paper, the three layered system architecture and the physics based collaborative interaction technique are proposed to extend current maintenance simulation into collaborative virtual environment. The proposed system was implemented as ViMMS (Virtual Mockup Maintenance Simulation system), and compared with case study results of VADE (Virtual Assembly Design Environment). As a result, the ViMMS encompassed broader range of maintenance tasks by using physics based collaborative interaction technique.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.843-846
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• 2008

There are a lot of municipalities that do not grasp even by the current state of having public facilities though various management&maintenance researches have been done. Therefore this research aimed to make it to the foundation of the maintenance management plan establishment of the municipality in the future through investigating, analyzing the current state of management&maintenance of the public facilities. Tn the beginning, I collected data through a questionnaire of the community facilities of the municipality. To read the current state of the management condition of the object facilities from the collection data, I applied the radar chart that used the deviation value of the evaluation index and PPM matrix. As a result of the analysis, I discovered that there is a municipality thought to having efficient facilities maintenance management.