• Journal of Korean Society of Industrial and Systems Engineering
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• 제30권1호
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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.

• Proceedings of the Safety Management and Science Conference
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• 대한안전경영과학회 2004년도 추계학술대회
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• pp.221-227
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• 2004

This study develops a improved gate assignment algorithm and decision support system using its algorithm to extract a assignment result minimizing a walking distance of passengers in airport and maximizing the utilization rate of avaliable gates in domestic airports. By operation support system, it may contribute greatly in efficient enlargement of airport operation and increase the airport reliability through quickly coping with takeoff and landing delay of flight due to weather change, preservation and repair of gate, etc. Also, passengers who use airport terminal can minimize time and walking distance for departure, arrival, and transit, and it may greatly reduce the additional operation cost for common gates through maximizing the utilization rate for exclusive usage gates for airplanes which use gates.

• Proceedings of the KSR Conference
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.382-388
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• 2005

SMSC(Seoul Metropolitan Subway Corporation) is substantially taking the core role of mass transit system in Seoul Metropolitan area. When it was built, the design had challenged to sharp curved tracks less than 250m radius considering the protection of buildings and cultural properties as well as the connection to ground roads. Such circumstances have required a certain extent of slack in track geometry and therefore led to the construction of ballasted track with wooden sleepers. However, the dynamic force from running on sharp curved track has caused the misalignment and abnormal failure of track geometry, and it has resulted in a frequent maintenance and repair works which require a lot of cost and manpower. In this paper, we present the construction case of maintenance-free track system by using of concrete sleeper and elastic rail fastening system to ensure the safety of both passengers and trains, and to contribute the effective maintenance for track facilities of SMSC.

• Proceedings of the KSR Conference
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.523-528
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• 2003

AS City traffic means, the electric railway of the role is overwhelming with recognizing good merits of safety, no environment disruption and accurate destination time. Currently, Korea subway are running about 290km through eight subway lines. The latest constructed subway had been made by imperoved matherials which is going on improving. Therefore, we researched this project to keep up facilites easily, repress a leakge current and reduse install cost and repair time in changing facility at overhead Contact wire system because of arc by reforming construction plan about Expansion Joint and Air Section which is regarded as weak point when facilities are fixed and maintianed of Rigid Trolley bar System. as above we can contribute various part to making useful O.C.S(overhead contact wire system)

• Proceedings of the KSR Conference
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.706-712
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• 2006

The present volume should address the unique method of deterioration analysis tailorly applicable to the study of traction motor, not existent maintenance works system with the time period standard, such as regular inspection works, maintenance works, selection for the repair works. The present volume has executed various field experiments in this method, should propose the procedures and baselines for anticipating the life expansion of traction motor and building precautional maintenance system for it, on the basis of these field experiments. The improvement scheme of traction motor maintenance system in the present volume should be to keep the out-of-order rate from unexpectedly soaring and make the cost-reduction effect through better maintenance work method.

• Journal of the military operations research society of Korea
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• 제27권1호
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• pp.58-72
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• 2001

This research deals with the weapon system RAM which is the reliability, availability and maintainability for weapon systems. This weapon system RAM is one of very important factors because it is related to the life cycle cost and combat readiness of weapon systems. Therefore, in this research we introduce the weapon system RAM and analyze the problems of weapon system RAM management during system life cycle including acquisition period. Finally we suggest an alternative to improve the weapon system RAM in various agencies which are the department of defense and army headquarter level, etc., in the process of defense acquisition.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.581-584
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• 2006

The durability of reinforced concrete structures is severely degraded by mainly corrosion due to seawater attack and chloride ion diffusion in concrete. The deterioration of durability causes high repair cost for maintenance of marine concrete structure. In this paper, high-durability materials for prevention of rebar corrosion are investigated to promote the durability in marine concrete structures. For these, the effect of the mineral materials addition(SF, FA and BFS), the modified steel(stainless and coating steel). and corrosion inhibitors are compared.

• IE interfaces
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• 제12권2호
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• pp.174-179
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• 1999

This paper describes the development of low cost, miniaturized multi-function image splitter for an unmanned guard system. The essential equipments of an image splitter system consist of a video system which displays in one screen images inputted by several cameras, a frame switcher which records each image sequentially in VTR, and TBC(Time Base Control) system which prevents image flickering during image switching. Currently, the price of similar system on the market is high, system management and repair are difficult, and bulky space is required. Futhermore, since currently available frame switcher can record only 30frame/sec, if eight cameras are installed, each camera image is recorded at the low speed of 3.75frame/sec, and consequently skip some images which may be vital for legal evidence. In this research, we have solved the problem of low speed recording by recording the video screen of splitted images at 30frame/sec and zooming each image when play back.

• Advances in concrete construction
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• 제8권2호
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• pp.91-100
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• 2019

In this paper three damaged exterior RC beam-column joints made of recycled aggregate concrete (RAC) were repaired. The aim of the study was to restore back the lost capacity of the beam-column joint to the original state or more. A relatively cheap material locally available galvanized steel welded wire mesh (GSWWM) of grid size 25 mm was used to confine the damaged region and then jacketed with cement mortar. Repaired specimens were also subjected to similar cyclic displacement as those of unrepaired specimens. Seismic parameters such as load carrying capacity, ductility, energy dissipation, stiffness degradation etc. were analyzed. Results show that repaired specimens exhibited better seismic performance and hence the adopted repairing strategies could be considered as satisfactory. These findings would be helpful to the field engineers to adopt a suitable rapid and cost efficient repairing technique for restoring the damaged frame structural joints for post earthquake usage.

• Nuclear Engineering and Technology
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• 제39권4호
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• pp.237-248
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• 2007

Sodium-cooled fast reactor is considered in France as a potential candidate for a prototype of 4th generation system to be built by 2020. A detailed working program has been launched recently to identify by 2012 the potential improvement tracks for later industrial development of these reactors. The goals for innovation are first identified: Progress of the safety with a special attention to severe accidents risk minimization and mitigation (defense in depth approach); Economic competitiveness of the system mainly by reducing the capital cost, the investment risks by enhancing in service inspection and repair capacities, and raising the availability; Sustainability with fissile material management while reducing the proliferation risk; capacity for long-lived waste transmutation.