• Journal of the Korean Academy of Clinical Electrophysiology
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• v.10 no.1
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• pp.39-44
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• 2012

Purpose : This study purposed to analyze how dynamic stabilization exercise on an unstable surface, and static stabilization exercise on muscle strength and endurance. Methods : For this study we sampled 9 people for the unstable surface dynamic stabilization exercise group, 9 for the stable surface static stabilization exercise group, and 9 for the control group. In order to examine muscle strength and endurance, we measured changes in the maximal voluntary isometric contraction (MVIC) using a dynamometer before, 3 weeks after, and 6 weeks after the experiment. Results : First, with regard to change in muscle strength, flexion strength showed a significant change in interaction by time (p<0.05). Extension strength showed a significant change in interaction by time (p<0.05). Second, with regard to change in endurance, flexion endurance showed a significant change in interaction by time (p<0.05). Extension endurance showed a significant change in interaction by time (p<0.05). Conclusion : In conclusion, this study confirmed significant changes in interaction between the groups and by time with regard to changes in muscle strength and endurance. These results suggest the potential of surface dynamic stabilization exercise as a clinical intervention.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.4 s.34
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• pp.59-65
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• 2005

It is very important to detect land cover/land use change from the past and to use it for future urban plan. This paper investigated the application of Landsat satellite imagery for detecting urban growth and assessing its impact on surface temperature in the region. Land cover/land use change detection was carried out by using 30m resolution Landsat satellite images and hierarchial approach was introduced to detect more detail change on the changing area through high resolution aerial photos. Also, surface temperature according to land cover/land use was calculated from Landsat TM thermal infrared data and compared with real temperature to analyze the relationship between urban expansion and surface temperature. As a result, the urban expansion has raised surface radiant temperature in the urbanized area. The method using remote sensing data based on GIS was found to be effective in monitoring and analysing urban growth and in evaluating urbanization impact on surface temperature.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1767-1772
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• 2008

A microcantilever is a well-known MEMS structure for sensing bio-chemical molecules. When bio-chemical molecules are adsorbed on the microcantilever's surface, resonance frequency shift is generated. There are two issues in this phenomena. The first one is which one between mass change and surface stress change effects is more dominant on the resonance frequency shift. The second one is what will be the performance change when the boundary condition is changed from cantilevers to double clamped beams. We have studied the effect of surface stress change and compared it with that of mass change by using FEM analysis. Furthermore, for microstructures having different boundary conditions, we have studied Q-factor, which determines the detection limit of micro/nano mechanical sensors.

• Transactions of Materials Processing
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• v.19 no.4
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• pp.236-241
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• 2010

The frictional behavior of bare steel sheet highly depends on surface roughness. It was investigated that the change of surface roughness of bare steel sheet due to deformation for each forming mode. The flat type friction test was done to check the effect of surface roughness change on frictional characteristics of bare steel sheet. As increasing the deformation, the Ra value was increased at stretching forming mode and drawing forming mode, however the change of Pc showed different trends. The Pc was decreased as increasing stretch deformation but increased at compression deformation. At drawing forming mode, the friction coefficient was increased as deformation was increased after initial big drop with drawing oil. As deformation was increased, the friction coefficient was decreased with drawing oil at stretching forming mode. The results show that the deformation changes the surface roughness and frictional characteristics of steel sheet but the effect depends on the forming mode.

• Journal of Conservation Science
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• v.32 no.2
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• pp.155-165
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• 2016

This study aimed at verifying the effect of hydroxypropyl cellulose(HPC) treatment on polyethylene glycol(PEG)-treated waterlogged wood for surface stabilizing. This research investigated macroscopic and microscopic appearance, color change, weight change, and dimensional change. And effect of HPC was verified through variance analysis (ANOVA) and least significant difference test(LSD). HPC formed thin layer on the surface of wood specimen, and blocked the pore of tracheid and the gap between the crack. Specimens without deterioration showed no invisible change except HPC 1,000,000 treatment group. Whitening was appeared at the sound surface of HPC 1,000,000 treated wood. Specimens with deterioration showed a little color difference change by external moisture adsorption. Thin layer of HPC on the surface of wood specimen was maintained after the deterioration, and this HPC layer significantly suppressed the weight and dimensional change by moisture adsorption.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.10a
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• pp.64-74
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• 1996

The meachanism for cutting epoxy resins specimens which were specially provided was experimentally investigated to obtain a fine surface finish. the specimens were cut the three-dimensional undrer dry conditions using a lathe. the relationship between the topography of the cut surface due to the change rate of temperature of the cutting condition using sintered carbides (P20, K10, KT150) was investigated. the main results obtained are as follows: 1) The change rate of temperature of the cutting edge is increased in nearly proportion ot cutting speed feed rate depth of cut. 2)The profile of surface roughness were regulated k10 but irregulated P20 KT150. 3) The surface roughness value decreased K10 rather than P20 KT150. 3) The surface roughness value decreased K10 rather than P20 KT 150.4)The cutting resistance increased thrust force rather than cutting force due to the visco-elastic material of epoxy resins.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.75-78
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• 2002

In this paper, we investigated the change of wettability, surface potential decay and surface resistivity caused by thermal-treated and plasma-treated FRP respectively for finding out the influence of electrical characteristics on the surface of polymer composites. For the change of wettability, the contact angle of thermal-treated specimen with the high temperature of 200$^{\circ}C$ increased. But that of plasma-treated specimen decreased. The characteristic of surface potential decay shows the tendency of the remarkable decrease on plasma-treated specimens, but no difference on thermal-treated specimen compared with untreated one. Also, for the surface resistivity, it shows the same trend compared with the change of contact angle. We can conclude that the degradation phenomena of epoxy surface are dominated by the induction of hydrophilicity and hydrophobicity.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.22-24
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• 2004

The land use has changed rapidly since 1960s in accordance with urbanization in Seoul Metropolitan Region. As a result, the urban microclimate has undergone changes as well. This study aims to recognize trend of the urban heat island change which is caused by land use change during urbanization in large city. Thermal data of Landsat TM images in 1987 and 1999 were for land surface temperature change detection in the study.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.1-17
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• 2004

It is improtant that performing prophylaxis procedure on an infected implant surface in order to treat peri-implantitis should not change the surface roughness and composition, so that the surface can be recovered to almost same condition as initial implant surface. This thesis, therefore, studied an effect of various oral hygiene instrument on implant surface. A surface roughness measurement instrument and an infection electron microscope were used to observe a change on surface. The purpose of this study was to obtain a clinical guidelines during implant care and peri-implantitis treatment. The result were as follows 1. Ra values (surface roughness value) at experimental group 1, group 2, and group 5 were increased significantly as compared with comparison group(p<0.05). 2. When compared experimental group 1 with each experimental groups at which prohylaxis procedure was performed, mean values of Ra at experimental group 2, group 3, group 6, and group 7 were decreased significantly(p<0.05). 3. Mean value of Ra was lowest at experimental group 2, and highest at experimental group 2, and highest at experimental group 5. 4. Analysis of SEM showed that was significant surface change at experimental group 2, group 3, group 4, group 5, and group 6 as compared with comparison group(X1000). 5. Analysis fo EDX showed that a quantity of Ti on surface for experimental group 6 was very similar to that for comparison group. In conclusion, air-powder abrasive and citric acid, plastic instrument are safe methods to use for performing prophylaxis procedure on implant care or for cleaning and sterilization process on treatment of peri-implantitis, based on the result that those method did not affect implant surface roughness and Ti composition.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.4
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• pp.367-371
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• 2003

In order to determine the effective way of measuring the Mode I stress intensity factor for a material containing a two-dimensional surface crack by means of the alternating current potential drop(ACPD) technique, the change in magnetic flux density between crack surfaces and above the specimen surface due to load was studied theoretically. The magnetic flux density in the air between crack surfaces is uniform and above the specimen surface is not changed by increasing the load in the material. Therefore, the change in potential drop due to load in a measuring system which was designed to induce a large amount of electro-motive force was caused by the change in internal inductance of material, the change in the mutual inductance between internal inductance of material and measuring system and the change in the mutual inductance between internal inductance of material and power supply line.