• Architectural research
• /
• v.14 no.2
• /
• pp.75-83
• /
• 2012

Buildings that are more than 10 years old generally have considerable repair and replacement costs due to the rapid deterioration of their systems. For public buildings in particular, which have national and social significance, considerable effort is required not only to ensure a long life cycle and safety but also to minimize the overall public expense. Along with increasing repair and replacement requirements, however, there have been problems related to the establishment of an accurate facility management budget. To address these concerns, a repair and replacement cost management system was constructed. This system manages both invested maintenance and forecast costs to establish a reasonable repair and replacement planning process and budget. The effectiveness of the system was verified through a pilot test targeting one of public Corporation (K).

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2004.04a
• /
• pp.447-453
• /
• 2004

Various structural materials have been used in construction projects using stones, connotes, and steels materials. Among of these projects, concretes may use widely because concretes have high compressive strength, and comparatively easy maintenance and management. Reinforced concrete Buildings will be deteriorated as time passed. These problems will be accelerated by propagation of cracks. In order to manage such cracks, time, efforts and expense are required. In this study, leakages of fluorescence and adhesive material were investigated using glass sensors that were embedded in a model beam and column. In addition, currents in glass pipe sensor were observed to find leakage of liquid in glass pipes. Progressive cracks were generated by fracture of glass me sensor. In this investigation, a reinforcement clothing system was wrapped for a glass pipe sensor, The glass pipe sensor that can make control and reinforce cracks simultaneously.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2001.05a
• /
• pp.731-736
• /
• 2001

In this thesis, the study on controlling of cracks of concrete box culvert in early ages is presented. The optimum construction method and economical analysis were proposed also through the experiment of the material and field test. As a result of the experiment of the material, using fly ash, CSA expansive agent and BELITE cement(type IV) showed good result in the control of cracks induced by heat of hydration and shrinkage. As a result of construction test analysis, the maintenance time of form system did not show a big difference in controlling of cracks. Control of distribution of reinforcement, spacing of expansion joint and use of BELITE cement showed big differences in the control of cracks in early ages. As a result of economical analysis, control of construction variables before construction can make it possible to reduce the repair expense.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2007.05a
• /
• pp.393-396
• /
• 2007

Recently one level higher intelligent switching board than established one by the application of intelligent building and digital system are being constructed. Therefore facility's high efficiency, high degree satisfaction, miniaturaization, standardization through application of communication technology and monitoring and controlling by computer system utilized by web-basis power control system and electric IT are practiced. Especially network must be constructed through unified IBS server that monitors every educational institute's switching boards in real time control system. And I intend to create methods to save energy and raise electricity quality by power demand prediction and remote-controled management and operation. In this thesis I intend to suggest measures of forming unified system through researching educational institute's ways of constructing switching board and status analysis and overcoming technical difficulties in user's side and saving and maintenance expense.

• Journal of the Korean Society for Railway
• /
• v.9 no.2 s.33
• /
• pp.200-205
• /
• 2006

Subway widely used as a major mean of public transportation both at home and abroad contributes to ease chronic traffic congestion in cities. However, subway operating expense is expected to increase continuously because subway requires vast amount of money at the construction stage, huge sum of maintenance cost is spent during operation, and passenger needs for more convenient facilities is increasing. on the contrary to enormous operating expenses, fare that is occupying most of operating income doesn't come up to its prime cost causing chronic operating deficit. It is urgent to prepare fare system improvement measures to increase operating income in order to resolve financial difficulty of a subway operating organization. Therefore, the current study analyzed present condition and problems of subway fare system, and suggested improvement measures such as improvement of fare adjustment procedure, improvement of free-ride system, diversification of ticket, etc.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.163-169
• /
• 2003

The vertical roller mill is the important machine grinding and mixing various crude materials in the manufacturing process of portland cement. Table liner is one of grinding elements of vertical roller mill and is subjected to the cyclic bending stress by rollers load and the centrifugal force by rotation of table. It demands $4{\times}10^7$ cycle but has $4{\times}10^6{\sim}8{\times}10^6$ cycle. It fractures at the edge of grinding path of outside roller. The repair expense for it amounts to 30% of total maintenance of vertical roller mill. Therefore, this study shows the fracture mechanism of table liner for vertical roller mill using HDM and fatigue analysis

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1680-1684
• /
• 2010

CBTC(Communication-Based Train Control) system which is based on wireless communication can provide high density operation of the train using location tracking between ground and onboard train. It can also reduces maintenance expense because it does not require the ground equipment for tracking circuit and signal flag and so on. Recently, research and interest have been done on CBTC system. The high-speed trains up to 300km/h experience multi-path fading channel which bring about the performance degradation of wireless CBTC system. In this paper, we consider MIMO (Multi-Input Multi-Output) antenna-based CBTC system for trains with Alamoutip-type space-time diversity transmission for reliable communication. Also we model a channel considering practical environment and evaluate performance improvement of proposed CBTC system.

• Journal of Korean Society of Water and Wastewater
• /
• v.27 no.2
• /
• pp.233-239
• /
• 2013

Sampling rate of Hydraulic pressure data, depending on the intended use of the water distribution system is an important factor. If sampling interval of hydraulic data is short, that will be more useful but it demand a lot of expense for maintenance. In this study, based on simulation of water distribution system 2 khz data, statistical techniques of student t distribution, non-exceedance probability using the optimal sampling rate for research.

• Journal of the Korean Society for Railway
• /
• v.6 no.4
• /
• pp.252-256
• /
• 2003

Smart materials can adapt to changes of environment like living organs in nature such that they can maximize the performance and minimize the maintenance expense of engineering systems. Such materials have been paid attention ten years ago and applied in the area of industry, aerospace, transportation and civil structures. This paper summarizes smart material technology and shows some application examples in railway vehicles. Also, its future of smart material technology in railway vehicle technology is envisaged based on its possibility and practical aspect.

• Corrosion Science and Technology
• /
• v.4 no.1
• /
• pp.29-32
• /
• 2005

A various structural materials are used in construction projects such as a stone, concrete, steel materials. Between of them, concrete are used widely. The compressive strength of concrete is high, and its maintenance and management is comparatively easy. The R.C Building will be superannuated as time passes. This program is generated by propagation of cracks. In order to manage such cracks, time and efforts, expense, etc. are required. In this study, glass sensors were embedding in a model beam and column and leakage of fluorescence and adhesive material was investigated. Further, currents in glass pipe were observed to find the leakage of liquid in glass pipes. Progressive cracks generated by cause the fracture of glass pipes. Therefore, the liquid become to flow and electric current stops, and the cracked part of the member can be found easily. Moreover, the adhesive delays progressive cracking system that responds in air, and the life of a structure can be made to extend. The purpose of this research is to develop of low price sensors that can perform of self-diagnosis in addition to ability of concrete repair concrete to damage.