• 컴퓨터교육학회논문지
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• 제17권6호
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• pp.49-57
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• 2014

프로그래밍 교육에 관심이 많아지면서 교육현장에서 프로그래밍을 어떻게 가르칠 것인가에 대한 방법적 고민이 필요하다. 본 연구는 초등학교 학생들을 대상으로 하는 프로그래밍 교육을 위한 방법으로 스크래치 프로그래밍 중심의 STEAM 교육 프로그램을 제시하였다. 스크래치 프로그래밍을 통해 선정된 과학 주제를 디지털 스토리텔링을 하여 과학에 대한 흥미를 높이고 프로그래밍을 학습하는 STEAM 교육 프로그램을 개발하였다. 개발한 프로그램의 교육효과를 분석하기 위해 초등학교 6학년 학생들을 실험집단에게 선정하여 개발한 교육 프로그램을 투입하였고 사전 사후검사 결과를 분석하였다. 분석 결과 본 연구에서 개발한 교육프로그램이 초등학생의 논리적 사고력과 창의력 신장에 도움을 주는 것으로 나타났다.

• 정보교육학회논문지
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• 제13권3호
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• pp.351-358
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• 2009

이 연구에서는 학습 스타일이 프로그래밍 교육의 효과에 어떤 영향을 미치고 있는지 고찰하였다. 우선 VARK 체크리스트를 활용하여 학습자들의 학습 스타일을 분석하고, 한 학기동안 프로그래밍 교육을 실시 한 뒤 학습자의 학습 스타일이 미친 영향과 여러 교수-학습 활동의 변인들과 상관관계를 알아보았다. 결과적으로 스크래치를 활용한 프로그래밍 교육은 학습의 인지적 영역에 대한 효과성과 만족도에 긍정적 영향을 주었다. 특히 Visual 성향의 학습자들에게서 스크래치 활용의 성과가 통계적으로 높게 나타났다. 따라서 초등학생의 프로그래밍 과정이 학습 효과에 큰 영향을 주었다고 볼 수 있다.

• 소성∙가공
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• 제18권6호
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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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• 제25권3호
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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.

• 대한금속재료학회지
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• 제49권9호
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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.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1996년도 재료학회 춘계학술발표회
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• pp.14-14
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• 1996

• 한국가구학회지
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• 제21권4호
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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.

• 정보교육학회논문지
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• 제21권3호
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• pp.351-360
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• 2017

본 연구는 디자인 사고를 적용한 SW교육이 초등학교 예비교사의 창의성에 미치는 효과를 분석하였다. 제주 소재 한 대학교 초등컴퓨터교육 강좌를 신청한 학부 1학년 22명의 초등학교 예비교사들을 대상으로 연구를 실시하였다. 연구대상인 예비교사들은 SW교육에 대한 기본적인 이해를 하지 못하고 있을 뿐만 아니라 연구에 사용할 EPL 도구인 스크래치 프로그램에 대한 기초적인 지식을 갖추지 못하였다. 따라서 창의성 사전검사 이전에 18차시에 걸쳐 SW교육에 대한 기본 교육과 스크래치 프로그램의 기본 기능을 학습하는 시간을 가졌다. 창의성 사전검사를 실시하고 21시간에 걸쳐 디자인 사고를 적용한 SW교육을 진행한 후 창의성 사후검사를 실시하였다. 창의성 검사도구로는 Torrance의 TTCT 도형 검사지 A, B형을 사용하여 분석하였다. 검증 결과, 디자인 사고를 적용한 SW교육이 초등학교 예비교사들의 창의성 향상에 효과적인 것으로 나타났다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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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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• 제12권3호
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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.