• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.05a
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• pp.2-2
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• 2003

• Journal of the Korean institute of surface engineering
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• v.41 no.6
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• pp.341-350
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• 2008

In friction stir welding for 6061-T6 with various traveling speed and rotation speed conditions, the best mechanical characteristics presented in traveling speed of 507 mm/min and rotation speed of 1100RPM. The maximum tensile strength and yield strength increased with the increasing of traveling speed. The result of the electrochemical characteristic evaluation in friction stir welding at optimum conditions for 6061-T6 Al alloy presented a good characteristics compare to base metal.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.440-445
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• 2011

Dynamic characteristic analysis is required in developing SMT mounter system with high installation speed and position precision, because of vibration source occurred by positioning head. This paper presents the method of improving dynamic characteristic of SMT(Surface Mount Technology) mounter with finite element method and modal test. The design direction is that natural frequencies of SMT mounter must be higher than the vibration source. In addition, the effect of input shaping on residual vibration reduction is investigated by simulating the response of a first-order system.

• Journal of the Korean institute of surface engineering
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• v.25 no.1
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• pp.40-49
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• 1992

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.2
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• pp.141-148
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• 2003

Concrete surface is a part that resists chiefly to carbonation by carbonic acid gas, affluence of rainwater and air, deterioration by freezing thawing, salt damage by seawater, and other chemical erosion etc. Therefore, this research analyzed physical characteristic and durable characteristic of concrete eliminated glut water and bubble of concrete surface using CON-SILK that is permeated with dehydration. As a research result, concrete using CON-SILK was improved, in comparison with concrete using general formwork, in physical performance and durability of concrete, as surface hardness, carbonation resistivity, and salt content permeation resistivity etc. Therefore, we could know that it is effective to use CON-SILK in performance elevation of concrete surface.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.11a
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• pp.53-58
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• 2001

Fractal dimension is the method to measure the roughness and the irregularity of something that cannot be defined obviously by Euclidean dimension. And the analysis method of this dimension don't need perfect, accurate boundary and color like analysis lot diameter, perimeter, aspect or reflectivity of wear particles or surface. If we arranged the morphological characteristic of various wear particle by using the characteristic of fractal dimension, it might be very efficient to the diagnosis of driving condition. In order to describe morphology of various wear particle, the wear test was carried out under friction experimental conditions. And fractal descriptors was applied to boundary and surface of wear particle with image processing system. These descriptors to analyze shape and surface wear particle are boundary fractal dimension and surface fractal dimension.

• Journal of the Korean institute of surface engineering
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• v.44 no.5
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• pp.207-212
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• 2011

In this study, the change in diffusion coefficient and wear characteristic with depth in the carbonitriding layer of SCM415 steel was discussed. To determine the diffusion coefficient, depth profile of carbon was measured from the surface using the Glow Discharge Spectrometer. In otherwise, measurements of carbide fraction, micro vickers hardness of surface and observation of microstructure have been implemented through the SEM image. $Fe_3$(C,N) layer and effective depth were increased as the time for carbonitriding takes longer. According to wear experiment, the results showed that wear resistance was improved by $Fe_3$(C,N) layer and effective depth.

• Journal of the Korean Society of Safety
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• v.16 no.3
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• pp.61-67
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• 2001

In this study the electrical and mechanical characteristics of PET films ore analyzed after plasma surface treatment. After plasma treatment, the surface potential decay, surface potential and dielectric property were evaluated to analyze the electrical insulating property, and the tensile strength was measured as the mechanical characteristic. When plasma treatment was conducted for less than 10 minutes, it was found that the electrical insulating property was improved through evaporation of low molecular weight materials md cleaning of surface. However, for more than 10 minutes, the insulating property of plasma treated PET films was decreased due to excessive discharge energy. The tensile strength was hardly changed by Plasma treatment.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.445-448
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• 2004

Recently, bridge deck overlay with latex modified concrete is widely applied in domestic. the capacity of bridge deck overlay depends on bond state on the surface. factors that have an effect on bond state are clean condition on the surface, absence of surface microcracking, absence of laitance, overlay curing. In this study, it is researched that characteristic of bond strength according to moisture condition on the surface and the removal method of concrete. As a result, it shows high bond strength in dry condition when w/c is $31\%$ and in moisture condition when w/c is $38\%$ respectively. characteristic of bond strength according to the removal method of concrete shows high bond strength when using water-jets rather than jackhammers.

• Journal of the Korean institute of surface engineering
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• v.34 no.4
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• pp.313-320
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• 2001

It is well known that the amount of hot-dip Zn coated sheet steels used for automotive is rapidly increasing. As hot-dip steel sheets show good corrosion resistance and excellent formability, the demand for outer panel of automotive has been increased in order to satisfy with the requirement of high surface qualify. There are many kinds of factors influencing on the surface quality and the dross control in the galvanising bath is regarded as one of the most important thing. In this study the characteristic and growing behavior of dross in the galvanizing bath were investigated and the effect of dross on the surface defect of GA was surveyed. The dross defects on the GA sheet steels result from bottom dross whose diameter are larger 50$\mu\textrm{m}$ in the Zn pot. Dross-free state exist for about 30 hours from starting time of GA production.