• The Journal of Korean Association of Computer Education
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• v.17 no.6
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• pp.49-57
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• 2014

As growing more and more interested in programming education, we need to concerned how to teach programming in school. We are presented the STEAM program based on scratch programming as a way of programming education for elementary students. We were developed STEAM program that do digital storytelling using scratch about selected science topic in order to raise interests about science and educate programming. In order to verify the effectiveness of the educational program, we analyzed the results of pre- and post-test about GALT, TTCT of experimental group and comparison group is comprised of 6th grade elementary students. In the analysis results, the education program we developed affected positive impacts on creativity, logical thinking of elementary school students.

• Journal of The Korean Association of Information Education
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• v.13 no.3
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• pp.351-358
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• 2009

This study shows how to impact on programming learning using Scratch by the learning style. Firstly, students were classified by learning styles test using the VARK questionnaire. After one semester of programming education, correlation with learning styles and various instructional factors was analyzed. Scratch-based programming education improves the cognitive effectiveness and learning satisfaction for elementary school students. Especially students with visual preference performed better on programming education based on Scratch statistically. As a result, the process of programming must be mainly considered in programming education.

• Transactions of Materials Processing
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• v.18 no.6
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• pp.465-470
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• 2009

The frictional behaviors of Cermets/Cr-Ceramics and Cu-Al coatings of piston ring were investigated. Friction tests were carried out by pin-on-disk test and materials properties of coating layer were analyzed by nano indentation tester. The effect of surface roughness of cylinder liner on the friction coefficient was analyzed. This study provided tribological data of hard and soft piston ring coatings against cylinder liner. The surface roughness does exert an influence on the average friction coefficient, with smoother surfaces generally yielding lower friction coefficients. In case of hard-coating, the scratch depth, width and pile-up height had close relationship with hardness. So the scratch width, depth and pile-up height increases with decreasing friction coefficient. But in case of soft-coating, the friction coefficients are strongly dependent on the morphological characteristics such as, scratch depth, width, pile-up height and elastic modulus.

• Journal of Welding and Joining
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• v.25 no.3
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• pp.28-36
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• 2007

A bulk amorphous NiTiZrSiSn powder produced using an inert gas atomization was sprayed by kinetic spraying process that is basically a solid-state deposition process onto a mild steel substrate. They were successfully overlaid onto the mild steel substrate. In order to evaluate the tribological behavior of the kinetic sprayed NiTiZrSiSn BMG (Bulk Metallic Glass) coatings, a partially crystallized coating and a fully crystallized coating were prepared by the isothermal heat treatments. Tribological behaviors were investigated in view of friction coefficient, hardness and amorphous phase fraction of coating layer. Surface morphologies and depth in the wear tracks were observed and measured by scanning electron microscope and alpha-step. From the examination of the scratch wear track microstructure, transition from the ductile like deformation (micro cutting) to the brittle deformation (micro fracturing) in the scratch groove was observed with the increase of the crystallinity.

• Korean Journal of Metals and Materials
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• v.49 no.9
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• pp.726-731
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• 2011

The present work shows how the flexural displacement-induced fracture strength of silicon devices, whose back surfaces have wafer grinding-induced scratch marks, depends on the crystallographic orientation. Experimental results indicate that silicon devices with scratch marks parallel to their lateral direction (i.e. reference axis in this work) are very susceptible to flexural fracture, as compared to devices with marks which deviated from the direction. The 3-point bending test shows that the fracture strength of silicon devices having marks which are oriented away from the reference axis is 2.6 times higher than that of devices with marks parallel to the axis. It was particularly interesting to see that silicon devices with identical preferred marks even reveal different fracture strengths, depending on whether the marks are involved in specific crystal planes such as {111} or {011}, called cleavage planes. This work demonstrates that silicon devices with the reference axis-aligned scratch marks not existing on such cleavage planes can have higher fracture strength approximately 20% higher than those existing on the planes.

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.05a
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• pp.14-14
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• 1996

• Journal of the Korea Furniture Society
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• v.21 no.4
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• pp.284-292
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• 2010

This research was carried out to examine the properties of fancy cherry veneer overlaid on the PF resin bonded Meranti plywood floor, which 2.5% green tea leaf powder was applied in the UV varnishes and the adhesives for scavenging the volatile organic compounds. The results were as follows: 1. The various properties of the treated samples, such as density, moisture content, thickness swelling, bending strength(MOR), adhesion shear strength, surface abrasion, curling, cyclic delamination test with boiling water, boiling property, cold-resistance and heat resistance, acid resistance and alkali resistance, and anti-contamination property showed no significant difference between the properties of the control samples. 2.5% green tea leaf powder treated floor gave a little better results than the control for surface scratch test. 2. In case of QUV and weathering test, no difference between the treated sample and control was found. 3. The floor was discolored by adding 10% green tea leaf powder to UV coating, and the floor was also discolored to light green during by the soaking test. The color of floor was not changed up to 5% addition level.

• Journal of The Korean Association of Information Education
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• v.21 no.3
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• pp.351-360
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• 2017

The purpose of this study is to analyze the effect of SW education applying design thinking on the creativity of elementary school pre-service teachers. We conducted research on 22 elementary school pre-service teachers who applied for a lecture on elementary computer education at a university in Jeju city. The pre-service teachers who did not have basic understanding of SW education and basic knowledge about scratch program which is an EPL tool for research. Therefore, we had time to learn the basic education of SW education and the basic functions of the scratch program over 18 periods before the pre-test of creativity. After conducting pre-test of creativity and conducting SW education applying design thinking over 21 hours, we conducted post-test of creativity. As a creativity test tool, TTCT pattern test forms A and B of Torrance were used. As a result of the verification, it was found that SW education applying design thinking was effective in improving creativity of elementary school pre-service teachers.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.10a
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• pp.106-114
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• 1998

Tribological investigation of ultra thin film magnetic storage disks which have two different kinds of start/stop zone of laser textured bump disk and mechanically textured disk for before CSS test and after CSS test. To measure surface roughness, height reduction before/after CSS test and obtain accurate topographies, AFM(Atomic Force Microscope) which is most powerful recently has been used. The result of statistical analysis showed that both laser textured bump height and mechanically textured zone height have been reduced about 4~7nm after 15000 cycle CSS test. Using commercial Nano-Indenter, ramping load scratch test has been performed to investigate friction characteristic for laser textured zone and mechanically textured zone before/after CSS test.

• Journal of Korean Biological Nursing Science
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• v.12 no.3
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• pp.157-165
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• 2010

Purpose: The purpose of this study was to examine the effects of recreation combined exercise program on body composition, physical fitness and depression in elderly women in rural district over a three-month follow-up period. Methods: Recreation combined exercise program (RCEP) was composed of resistance exercise, walking and recreation activity twice a week. The subjects were 52 divided in to experimental group (n=28) and control group (n=24). Arm curl, chair stand, 2 min step test, back scratch, chair sit and reach were measured as pre- or post-test data. Also, Depression was expressed using geriatric depression scale as pre- or post-test data. $X^2$ test, paired t-test and t-test were performed using SAS program. Results: Arm curl (p=.023), 2 minute step test (p<.001), back scratch (p=.004) and chair sit and reach (p=.024) showed the significant difference in the comparison between groups. Depression showed the significant difference in the comparison between groups (p=.008). Conclusion: These findings indicated the RCEP has positive influence upon increasing the physical fitness and improving the depression level. In conclusion, the regular RCEP will contribute to the improving physical and psychologic aspect in elderly women over the long period.