• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.2
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• pp.76-82
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• 2006

High-strength, High-durability concrete appearance was embossed by benevolence who quality for each raw material that become factor that is direct in concrete manufacture and the special quality is very important and request properties of matter were also strengthened more. Specially, natural resources of good quality were abundant past in occasion of aggregate and unlike concrete request strength past that the importance was less relatively the quality enemy than cement because is also not big, importance of aggregate quality great veried as concrete strength and request properties of matter about durability are strengthened more on extreme displacement. Mixing four who is original and mixs special quality examination of domestic three Four-Stick Games by Chaechwiwon and age Four-Stick Games and crushed sand examined concrete quality characteristic that use mortar and concrete quality characteristic, special quality of North Korea sun guardian mountain three Four-Stick Games that is imported from the North Korea, North Korea sun guardian mountain three Four-Stick Games etc..

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.841-846
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• 2002

As growing of industrialization and increasing of population. the quantities of waste are rapidly growing in the earth. It cause some problems such as the waste of natural resources and environmental pollution. In this context, recycling waste glass as a material of concrete has a great advantage environmentally and economically. On that score, other contries have start recycling waste glass widely and accoumulatig the technology of manufacturing equipment and construction. However, few studies have been done in this country. Therefore, this study was conducted freeze-thaw resistance test and neutralization reaction test to analyze the durability properties of steel fiber reinforced concrete containing waste glass as fine aggregate and containing industrial by-products(Fly ash).

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.286-289
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• 2008

Wind turbine industry is booming and spending a lot on research for improving the performance of its present machines and increasing their capacity. Wind turbine requires service life of about 20 years and each components of wind turbine requires high durability, because installation and maintenance costs are more expensive than generated electricity by wind-turbine. So the design of wind turbine must be verified in various condition before production step. For this work, high reliability model for analysis is required. Drivetrain model is modeled by multibody dynamic modeling method. The model constituted with rotor blades, hub, main shaft, gear box, high speed shaft and generator. Natural frequency and torsional stiffness of drivetrain are calculated and analyzed.

• Journal of the Korean Society for Railway
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• v.8 no.2
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• pp.182-187
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• 2005

Air spring system was widely accepted for railway vehicle secondary suspension to reduce and absorb the vibration and noise. The low natural frequency ensures a comfortable ride and an invariably good stiffness. In this paper, the characteristics and durability test was conducted in laboratory by using servo-hydraulic fatigue testing system to reliability evaluation of air spring for electric railway vehicle. The experimental results show that the characteristics and durability of domestically developed productions are shown in good results. And to guarantee the adaption of air spring, the ride comfort and air pressure variation were measured in train test on subway line.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.52-53
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• 2016

Mechanical properties and durability of recycled aggregate concrete was known to decrease due to the adhesive mortar of recycled aggregate. But in this study, As the result of chloride diffusion resistance of recycled fine aggregate mortar, the mechanical properties are reduced according to the increase of the substitute ratio of recycled fine aggregate. But the chloride diffusion coefficient was almost same with natural fine aggregate mortar.

• Economic and Environmental Geology
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• v.32 no.2
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• pp.203-208
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• 1999

The main objective of this study is to suggest a new assessment method of the influence of weathering due to salt crystallization on the engineering property of rock. For this purpose, various sources of salt and salt crystallization were investigated, and artificially accelerated weathering tests were carried out. In natural envionment, weathering rate is very slow and weathering process involves complex mechanisms. Therefore artificial weathering test is essential for systematic analysis. Arificial weathering test is defined as test which controls weathering rate and agents by controlling arificial environmental condition. In this study, salt crystallization test was selected among various artificial weathering test methods, for its important role in weathering. Change of various stone properties were detexted. The change of physical properties by salt crystallization were observed as follows : 72% in Brazilian tensile strength and 72% in Slake durability. These results explain the importance of salt crystallization in the mechanical behaviour and properties of stone.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.583-586
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• 2012

Wind turbine industry is booming and spending a lot on research for improving the performance of its present machines and increasing their capacity. Wind turbine requires service life of about 20 years and each canponents of wind turbine requires high durability, because installation and maintenance costs are more expensive than generated electricity by wind-turbine. So the design of wind turbine must be verified in various condition before production step. For this work, high reliability model for analysis is required. Drivetrain model is modeled by multibody dynamic modeling method. The model constituted with rotor blades, hub, main shaft, gear box, high speed shaft and generator. Natural frequency and torsional stiffness of drivetrain are calculated and analyzed.

• Journal of Applied Reliability
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• v.5 no.1
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• pp.149-165
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• 2005

Air spring system was accepted for railway vehicle secondary suspension to reduce and absorb the vibration and noise. The low natural frequency ensures a comfortable ride and an invariably good stiffness. In this paper, the characteristics and durability test was conducted in laboratory by using servo-hydraulic fatigue testing system to reliability evaluation of air spring for electric railway vehicle. The experimental results show that the characteristics and durability of domestic development productions are obtained the good results. And to guarantee the adaption of air spring, the ride comfort and air pressure variation were measured in train test on subway line.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.209-210
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• 2016

Mechanical properties and durability of recycled aggregate concrete was known to decrease due to the adhesive mortar of recycled aggregate. But in this study, As the result of chloride diffusion resistance of recycled fine aggregate mortar, the mechanical properties are reduced according to the increase of the substitute ratio of recycled fine aggregate. But the chloride diffusion coefficient was almost same with natural fine aggregate mortar.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.145-148
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• 2005

Recently, because of the increase of management system about waste concrete and the policy of recycling promotion of government, the use of recycled aggregate is rapidly increasing nowadays. But, due to the poverty of quality and the lack of KS standard, the use of recycled fine aggregate is not active. Therefore, it was intended to compare and investigate effects which types of sand and replacement ratio of recycled fine aggregate. As the result of this study, in the case of the recycled replacement ratio of 25$\%$, fresh and engineering properties were higher than those of natural fing aggregates with the exception of durability. Also, because quality according to types of fine aggregate shows the difference between various properties, it was considered that the profound study for this result would be necessary.