• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.19 no.40
• /
• pp.341-349
• /
• 1996

In this paper, we deal with the problem of maintenance policies for an air filter system in clean room. Two types of maintenance policies are considered, one based on the reliability of equipment and the other one determined by the total cost including minimal repair cost. For these models, we obtain the structure of the optimal maintenance Policy which minimize the total cost. Finally we give the numerical example.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2016.05a
• /
• pp.261-262
• /
• 2016

In Korea, Green building certification system had been operated for more than 10 years and Expired certification buildings are ever-increasing. However, post management of building and qualification standard for re-certification(G-SEED) aren't exist, certificated green building don't have smoothly maintenance and management. Therefore, analysing the status and situation of similar system such as building maintenance and management, to suggest the direction of evaluation for green standard for energy and environmental design.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.6
• /
• pp.1103-1107
• /
• 2016

The automatic tensioning device of the catenary system constantly maintains the tension of the trolley wire by absorbing the variations due to the elasticity of the line caused by temperature variation. The tension plays an important role in affecting the electric motorcar operation directly. This paper suggests the methodology of the life cycle extension and the maintenance of the automatic tensioning device by means of performance diagnosis of the pulley type automatic tensioning device which has been commonly used for the electric railway system. Through conducting performance diagnosis and comparative test for the wornout pulley type automatic tensioning device by replacing the components such as the bearing and the bearing shaft without replacing all the assembly, the tensioning device is analyzed whether it is properly functioned. Provided that the maintenance regulation is reinforced so as to implement the bearing replacement through periodical precise inspection along with random check-up inspection which is now carried out by the operating organizations, it is ensured that the life cycle extension and the reduction of maintenance cost of the tensioning device could be achieved.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.2
• /
• pp.233-239
• /
• 2016

In this paper, a maintenance system is developed for LNG-FPSO topside and hullside equipment based CBM (Condition Based Maintenance) methodology. First, the development system defined the PWBS(Product Work Breakdown Structure) of major equipment of LNG-FPSO. Second, the development system developed the failure analysis, economic evaluation for optimal maintenance plan and database systems that save and manage information about equipment, failure mode, failure rate and failure cause. Finally, the verification of the development system was applied to the inlet system of topside and the pump tower system of hullside and the system was confirmed the effectiveness of CBMS(Condition Based Maintenance System).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2019.05a
• /
• pp.205-207
• /
• 2019

Special training soldier for thermal equipment during army heavy equipment maintenance education is small training equipment and many trainees have few opportunities for practical training, and there is a high risk of safety accidents during maintenance training. Because practical training is limited and repeated practice is difficult, a training system is needed. In this study, we propose a virtual training system that can reduce the training cost beyond the time and space, enable realistic experiential training, reflect the standard maintenance manual, and train teamwork. The virtual training system using the virtual augmented reality is a system that can reduce the cost beyond the space and time and can be practically practiced. The first-person virtual training system using HMD, which is the three-dimensional display system proposed in this study, is suitable for army thermal equipment maintenance education system. The proposed system is expected to be useful for maintenance training of other equipments and other groups because it has good scalability.

• Korean Management Science Review
• /
• v.9 no.1
• /
• pp.41-52
• /
• 1992

The QOS(Quality of Service) recognized by the customer will become the most important thing under the competitive telecommunications market. Korea Telecom is going to develop many system to manage the telecommunication network, to improve the level of QOS, and to increase the revenue. Operation and Maintenance Adiministration System is one of the systems developed to meet those purposes efficiently. This system gathers qualities data from telephone offices or operation centers and analyze the results of QOS improvement activities and evaluate overall QOS. And also system makes it possible to improve the cost/effectiveness of operation and maintenance of telecommunication network. Operation and Maintenance Administration System has four functional modules, i.e., the user interface module, the database management module, the QOS management module, and the database conversion module. The purpose of this study is to develop the QOS management program, one of the four functional modules of the system,using FOCUS 4GL/DBMS. Since Operation and Maintenance Administration System is developed using FOCUS 4GL, every user can handle and maintain the system very easily and reduce system backlogs.

• Journal of the Korean Society for Railway
• /
• v.7 no.3
• /
• pp.271-277
• /
• 2004

This paper is concerned with the reliability centered maintenance (RCM) of the Automated Guideway Transit (AGT) vehicle system. Korea Railroad Research Institute (KRRI) has developed the AGT vehicle system from 1999 to 2004. The provisions for a specific maintenance system including RAMS (reliability, availability, maintainability & safety) of AGT vehicle system is necessary for maintaining good operation conditions. RCM is a process used to determine what must be done to ensure that any system continues to do whatever its users want it to do in its present operating conditions. Therefore, we introduce RCM in details and describe how RCM should be applied to AGT vehicle system on Gyeong-San test line. Analyses to approach RCM to AGT vehicle system are demonstrated in the seven steps that contain each main task and detailed operating conditions.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.1288-1290
• /
• 2003

The maintenance CALS system for car of urban transit is a part of standardization and development of urban transit system, and We have been performed the establishment of maintenance CALS system from 2001 to 2005. The RAMS for management computerization system are utilized in a variety of CALS system for user's convenience and safety in maintenance. Ever since its inception though, the urban transit has searched for ways to improve reliability, availability, maintainability and safety of the railway subsystem. In this paper, This system include RAMS(reliability, availability, maintainability and safety) and expert system of the vehicles shall be enhanced in the future.

• Journal of Applied Reliability
• /
• v.11 no.4
• /
• pp.433-445
• /
• 2011

Duty cycle is determined as the ratio of operating time to total time. Duty cycle in reliability prediction is one of the significant factors to be considered. In duty cycle application, non-operating time failure rate has been easily ignored even though the failure rate in non-operating period has not been proved to be small enough. Ignorance of non-operating time failure rate can result in over-estimated system reliability calculation. Furthermore, utilization of duty cycle in reliability prediction has not been evaluated in its effectiveness. In order to address these problems, two reliability models, such as MIL-HDBK-217F and RIAC-HDBK-217Plus, were used to analyze non-operating time failure rate. This research has proved that applying duty cycle in 217F model is not reasonable by the quantitative comparison and analysis.

• Journal of the Korean Society for Railway
• /
• v.14 no.3
• /
• pp.216-221
• /
• 2011

An important problem in reliability analysis for repairable systems is to model the maintenance effect. The most of researches have assumed two extreme cases; one is perfect maintenance and the other is minimal maintenance. However, many of maintenances performed by domestic subway operators are imperfect maintenances which have the effect between both of two extreme cases. This article deals with the problem determining the imperfect preventive maintenance intervals based on failure data in units of the PDS(passenger door system) in Metro EMU. This paper deals with a case study on determining imperfect maintenance interval by using the level of maintenance effect through reliability analysis of PDS.