• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.100-109
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• 2019

Maintainability indicates the extent to which maintenance can be done easily and quickly. The consideration of maintainability is crucial to reduce the operation and support costs of weapon systems, but if the maintainability is evaluated after the prototype production is done and necessitates design changes, it may increase the cost and delay the schedule. The evaluation should verify whether maintenance work can be performed, and support the designers in developing a design to improve maintainability. In previous studies, the maintainability index was calculated using the graph theory at the early design phase, but evaluation accuracy appeared to be limited. Analyzing the methods of evaluating the maintainability using fuzzy logic and 3D modeling indicate that the design of a system with good maintainability should be done in an integrated manner during the whole system life cycle. This paper proposes a method to evaluate maintainability using SysML-based modeling and simulation technique and fuzzy logic. The physical design structure with maintainability attributes was modeled using SysML 'bdd' diagram, and the maintainability was represented by an AHP matrix for maintainability attributes. We then calculated the maintainability using AHP-based weighting calculation and fuzzy logic through the use of SysML 'par' diagram that incorporated MATLAB. The proposed maintainability model can be managed efficiently and consistently, and the state of system design and maintainability can be analyzed quantitatively, thereby improving design by early identifying the items with low maintainability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6214-6220
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• 2015

A track circuit has used stably more than 100 years for detecting train position, but solution of track circuit sort circuit incapacity due to a rust is necessary for side line in station yard, coast line and level crossing for conventional line in rural line. Domestically, Axle Counter System(ACS) has partially used for Hot Box System for high speed line and turnout for CBTC system. In contrast, most of countries has used ACS not only trunk line but also rural line and its application has increased for metro, electric car and industrial railway. In this paper, we has verified the operating status of ACS which installed with existing track circuit through log analsis to implement pilot application in mail track and turnout in station yard. And interface test with interlocking system has conducted at Obong shunting yard, as well as Cheongju station and has analyzed test result. Based on a test result, we made fail safe design, manufacturing skill and established system requirement specification for the smooth operation and maintenance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.3
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• pp.142-156
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• 2019

[Purpose] It aims to suggest the differential factors to enhance the customer satisfaction and to activate the shopping in the convenience store (CVS). [Methodology] Convenience store service convenience (CVS SERVCON) was developed at the first time and the gap of relative importance level between the owners and the consumers was assessed by AHP analysis method..[Findings] First, the importance of access convenience was assessed as the first priority in both CVS owners' group and the consumers' group, while the detailed elements showed the differences which required the improvements. Based on the consumers' assessment, the importance of location was relatively low. They assessed relatively high on 24 hours operation of CVS and personal services. Second with respect to the transaction convenience, CVS owners' group rated it as the fourth priority while the consumers' group rated as the second, which requires the improvement. Third in terms of benefit utility and value-added service of post-benefit convenience which are the sub-factors of benefit convenience, the rate on the importance from the consumers showed higher than that from the owners, which requires the improvement. [Implications] Based on this study results, CVS operating companies are anticipated to be able to satisfy the customers, moreover, to secure the loyal customers if they concentrate the resources to develop the differentiation strategy on the areas where the consumers' demands are high while performs the maintenance strategy on the areas where their demands are low. In addition, this study contributed the theoretical expansion of SERVCON upon development of CVS SERVCON to comply with its definition.

• Journal of the Korea Institute of Building Construction
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• v.20 no.6
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• pp.555-566
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• 2020

Recently, the aging of public facilities in Korea have accelerated, and the existing framework for facility management is shifting toward to facility asset management in terms of performance-based proactive control. Therefore, the operation of public facility involves both safety assurance from the deteriorated facilities and management capabilities for sustainable maintenance in the required valuation and level of service, such as valuation of facility assets, life-cycle management plans, financing, and so on. In this study, the Facility Asset Management Indicator(FAMI) has been developed for public facility asset management, and it provides the quantitative management grade, based on international standards, such as ISO 55000 series and International Infrastructure Management Manual(IIMM). The FMMI includes 10 key areas to apply a diagnosis model into management capabilities, 113 detailed elements, and 5 maturity grades. As the importance of public facility asset management is increasing constantly, this is expected to identify previously the strengths and weaknesses of public facility operating institutions. Eventually, they can obtain the effective ways to improve their own capabilities, minimize the public funds, establish the strategies for innovating the current management structures, and operate stably the facilities in the required performance.

• Journal of the Korean Geosynthetics Society
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• v.21 no.4
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• pp.79-91
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• 2022

Recently, the frequency of damage to slopes for highways, railways, and complexes has been increasing according to abnormal climates such as heavy rainfall or snowfall. Rapid Hardening Composite Mat (RHCM) could be a satisfactory alternative because it has the advantages that large-scale earthwork is not essential and the period for restoration is minimized. Also, this method does not require heavy machines and a phase of maintenance for slopes against the shotcrete method or planted slope protection, which are representative slope protection methods. Furthermore, the curing time is shorter than Geosynthetic Concrete Composite Mat (GCCM). Therefore, RHCM could be useful for emergency restoration work. Thus, in this study, the strength and duration of RHCM are estimated, compared, and analyzed with GCCM. As a result of the laboratory test, the strength of RHCM is greater 51%, and the duration is larger 69% than GCCM.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.285-292
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• 2014

BIM (Building Information Modeling) is a new paradigm that includes construction life-cycle, and BIM has become mandatory regulation according to the Public Procurement Service since 2016, which accelerates its application. BIM is now expand from architectural field to infrastructure industry. Through pilot projects, BIM has been challenged with verification process. This trend has affected to maintenance and operation (M&O) phase of construction life-cycle. Advanced country has already published their research and result with feasibility study and guidelines. In this paper, we conduct the feasibility study to adopt BIM-based infrastructure management system. Bridges and tunnels were selected as application target, and benefit/cost ratio were used. The result shows that BIM-based infrastructure management system is feasible when the level of detail is more than "Medium" in bridge, and "High" in tunnel.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.535-541
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• 2020

A conventional elastic material replacement and performance evaluation are very complicated and time-consuming, and it is difficult to know when to replace the elastic material in advance. By comparing with the product limit and the functional limit, the necessity of elastic material replacement and the improvement of track support stiffness according to replacement can be immediately demonstrated based on experimental data. Using an evaluation system of track support stiffness, the performance evaluation data for elastic materials obtained through field tests using software for track support stiffness is integrated and managed on the administrator's computer. Therefore, the replacement plan is established and maintenance history is managed by identifying the replacement time and location of elastic materials. It is possible to evaluate the performance and condition of the elastic material at the various points during the working time of the track inspection and the track performance (track support stiffness) and durability of the elastic material (aging level, spring stiffness variation rate, etc.) at the operation condition. The elastic material could be replaced timely, and the deterioration of the elastic material can be continuously monitored.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.8-16
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• 2018

This study examined the long-term behavior of a roadbed using high-speed railway concrete track and roadbed measurement data and evaluated the long-term performance of the track and roadbed. Recently, high-speed railway track type has been adopted as a concrete slab. On the other hand, the concrete track is vulnerable to roadbed settlement. In the case of gravel tracks, it is easy to restore the original state by maintenance even if the roadbed settles. On the other hand, in the case of the concrete track, if excessive settlement of the roadbed occurs, cracks are generated continuously on the slabs and sleepers, resulting in greatly reduced usability. For this reason, it is difficult to restore the original state only by partial maintenance. In this paper, a long-term performance evaluation was carried out on a concrete track during operation by monitoring the measurement data of sensors buried from the beginning of construction for approximately 3 years after the high-speed railway opened. Performance evaluation methods include a performance evaluation of track/roadbed when the train passes, long-term track and roadbed performance evaluation, analysis of the track/roadbed effect on long-term settlement and analysis of the factors influencing long-term settlement. The trail response of KTX-Sancheon was greatest in the track/roadbed performance evaluation by train. The results of the long-term track and roadbed performance evaluation were measured within the standard values. The track and roadbed performance impact assessment with long-term settlement was strongly related to TCL settlement. The influences of the water content and groundwater level were verified by analyzing the external factors of long-term settlement. Through such a method, the stability of a track/roadbed can be secured.

• Journal of Digital Convergence
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• v.10 no.6
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• pp.71-82
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• 2012

The interest in SLA in accordance with the development of IT outsourcing has increased due to the rapid development of information systems. Moreover, an awareness and necessity for the Information System Operating Audit has increased while an effective IT service management operations for information systems is needed desperately. However, information system operations and maintenance instructions of the National Information Society Agency operates due to the current information system operation, but the experience and the interpretation of the auditor determine the decision in the field. This paper introduces an operating audit model for the efficient management. This model is derived from the Korea Information Society Agency's operating instructions of the Information Systems Audit and their inspection services. The audit checklists were derived from the areas of service planning, service delivery, service support, and service management. Consequently, the operating audit model was proposed, and the suitability of this model was verified by experts' opinions on the survey.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.2
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• pp.114-119
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• 2008

With the improvement of industrial society, the high quality electrical energy, simplification of operation and maintenance, ensuring reliability are being required. We request urgently change a $SF_6$ for an environment friendly gas insulation material. In this paper the experiments of breakdown characteristics by pressure and gap change of Imitation-Air in model GIS(Gas Insulated Switchgear) were described. Also assess of breakdown characteristics about Imitation-Air and $SF_6$. It is considered in this paper that the results are fundamental data for electric insulation design of Distribution Power Facilities which will be studied and developed in the future. The pressure to be confronted to $SF_6$ gas 1[atm] for Distribution Power Facilities is Imitation-Air 3[atm]. And we could make an environment friendly gas insulation material with maintaining dielectric strength by Imitation-Air which generates a lower level of the global warming effect.