• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1113-1118
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• 2004

Ballasted track is constructed in consideration of the maintenance. The application time and frequency of MTT(Multiple Tie Tamper) and BS(Ballast Cleaner) depend on track geometry measurements. This paper presents the application of Ground Penetrating Radar(GPR), Falling Weight Deflectometer(FWD), and Portable Ballast Sampler (PBS) to evaluate the effects of track geometry due to substructure deterioration and to build a reliable substructure evaluation system.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.10b
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• pp.1-18
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• 2001

Recently advanced composite materials have been successfully used in the civil infrastructure application due to its many advantages such as light weight, high strength, corrosion resistance. Demand for longer service life, increased durability and reduced maintenance have prompted such developments. In this article, characteristics of composite materials, fabrication process, case studies for various field and future of advanced composite materials for civil infrastructures is presented.

• Knowledge Management Research
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• v.3 no.1
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• pp.41-60
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• 2002

This paper defines measurement index items and weight of the index for the purpose of developing a performance measurement index that balancedly measures performance of B2B electronic commerce. The deductive research is used for the development of measurement index items and Analytic Hierarchy Process(AHP) method for the development of weight of the index. This paper has four performance measurement perspectives-finance, partners, business process and human resources, which based the existing researches of balanced performance measurement. This researchers developed eleven second level criteria and twenty-six indexes under four perspectives through the deductive method and expert interviews, weighted on the perspectives, criteria and indexes in accordance with the forms of e-marketplace-vertical and horizontal. As a result, the most important indexes are the maintenance of partners and the efficiency of operation process in the vertical e-marketplace. In the horizontal e-marketplace, the collection of partners, development and prediction processes are more important than other indexes.

• Journal of Power System Engineering
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• v.10 no.3
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• pp.73-80
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• 2006

The main advantages of the Dry CVT with V-belt, which has been popular in Asia, are a simple mechanism, less maintenance and low cost. The important factors which have an influence on the performance of the CVT are the weight of the centrifugal roller, the change of axial distance and spring force. Based on an experiment, the effects of load torque, speed ratio, and revolution of both the driving pulley and the driven pulley during the alteration of the axial distance, roller weight and spring constant were studied.

• International Journal of Safety
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• v.11 no.2
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• pp.1-4
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• 2012

The falling accidents have increased in the structure and heavy industries. Therefore, a various falling prevention systems with safety block and lanyard have been supplied in order to prevent falling accidents and acquire the long life and cost down for the maintenance. However, there are not the reliable and domestic the falling prevention system until now. Almost systems were imported from U.S.A, Japan, U.K and Germany. The structural safety of the imported safety block is satisfied sufficiently, but it has heavy weight due to the cover with the aluminum and thickness. So, many workers are not feeling themselves. Thus, the aim of this work is to develop a commercial safety block that has a light weight and strength. And the cost efficiency of the system and safety for workers also will be improved remarkably.

• Proceedings of the Safety Management and Science Conference
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• 2005.05a
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• pp.51-57
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• 2005

There are very large differences on the standards of gross weight and single axle weight for commercial motor vehicles between international and Korean standards. Short Wheelbase Truck are produced and run only in Korea. It has very serious effects on the durabilities of bridges and roads and makes logistic competitive power fall back and overconsuming energy. This paper deals with a comparative study of the international standards with Korean, grasps the drawbacks and makes up the suggestions to strengthen the logistic competitive power of Korea and reduce the maintenance cost for the roads and the consumption of energy.

• Journal of Ocean Engineering and Technology
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• v.18 no.1
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• pp.16-21
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• 2004

In general, core materials of rubble mound breakwater are used at a restricted range of 0.015㎥～0.03㎥. However, it is not satisfied with the standard design in over fifty percent of the cases. In this study, model tests and numerical analysis are employed to examine the range of core material that has no problem with capacity maintenance and stability of rubble mound breakwater. Model tests measure the porosities that are mixed in various ratios, to classify core materials by three parameters. The slope stability of rubble mound breakwater is investigated, using numerical analysis, with a friction angle and a unit weight. The change of unit weight, which is followed by the mixed rate of size core material, has no large affect on slope stability, and there is no problem with ensuring slope stability of the rubble mound breakwater.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.203-204
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• 2017

In case of developing a guide-rail type window cleaning robot, only the first prototype has been developed. In this study, it was considered that the size and the load of the window cleaning robot was not optimized, and through the structural analysis of the self-weight of the window cleaning robot, the stress concentration area was derived and the concentrated stress was quantified. Analysis showed that the upper rail shaft had a bending stress of 9.964Mpa and the bolt had a shear stress of 19.544Mpa. The results of this study will be used as basic data for designing future prototypes.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.224-225
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• 2013

Most of the building exterior wall cleaning robots use a water jet device for spraying water. However this method is sprayed excessive water usage than water quantity required for cleaning. And setting weight of the water pump cleaning device increase the weight of the building exterior wall cleaning robot. Therefor, this paper suggest that the mechanisms scatter minimal cleaning water using a spinning device of the building exterior wall cleaning robot.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.57-60
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• 2004

A domestic's freight stock is about 14,000 cars. Most of them is consisted of casting bogie type. Casting bogie type has some problems such as maintenance, part abrasion, running safety etc. Now a day casting bogie type have replaced with welded type bogie for high speed. The maximum speed of the container freight car is 70km/h limit at empty weight condition in case of casting type bogie frame. So there are some difficulty in commercial service for high speed coaches. Then we should re-decide whether the casting bogie type has speed up 90km/h limit at empty weight through out the vibration characteristic.