• Journal of The Korean Association of Information Education
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• v.22 no.6
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• pp.661-669
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• 2018

As SW education has become essential since 2018 due to the revised curriculum in 2015, researches on SW education are actively being carried out. In order to understand the level of pre-service teachers' computational thinking level, we analyzed a correlation of CT element scores with each year and each grade based on the calculated Scratch project by years using the analysis tool Dr. Scratch, which was targeted for 325 students in K National University of Education who passed the scratch course from 2016 to 2018. The result indicated that there is a positive correlation between all the CT related factors and both the year and the grade. Conclusionally, it is crucial to have students undergo revising process by using an automated evaluation tool such as Dr. Scratch and cultivate ability to create and utilize required materials. Furthermore, it is necessary to educate students to utilize logical thinking elements such as complex conditions and logic operations.

• The Journal of Korean Association of Computer Education
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• v.18 no.6
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• pp.13-22
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• 2015

The purpose of this research is to develop scratch code analysis system about scratch project for assessment in computational thinking(CT) education. Recently, scratch which is event-based language is used actively in K-12 SW education but it is difficult to understand the structure of scratch project. Therefore, in this study, we developed the system that students can use it to debug their scratch project and teachers can give feedback to students or evaluate students' projects through this system, and verified its usability. We are able to use this system to facilitate students' debugging process and to evaluate students' project in K-12 SW education.

• Transactions of the Society of Information Storage Systems
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• v.5 no.2
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• pp.82-88
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• 2009

Understanding the adhesion behavior and characteristics of toner film is required to achieve image and text printing with high quality resolution. Toner can be considered as a thin film coating on a media such as paper or polymer film. Quantitative measurement of adhesion characteristics of the thin film is important to assess the reliability of the system. In this work the main objective was to investigate the adhesion characteristic between the toner and the media by ramp loading scratch test method. The scratch test may be used to obtain quantitative information about the adhesion of the film to the substrate. In the scratch test a diamond tip was used to scratch the surface of the toner film under an increasing normal load until the toner detached or fractured. The critical load (LC) was obtained from the experimental results. Also, the relationship between the critical load and the adhesive strength of the interface between the substrate and the toner was obtained by measuring the normal and tangential forces during the scratch test. Finally, theoretical analysis of the toner scratch characteristics was performed based on Benjamin and Weaver theory, Plowing model, and Laugier model.

• 한국정보교육학회:학술대회논문집
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• 2010.01a
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• pp.307-312
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• 2010

본 연구는 초등학교 4학년 학생들을 대상으로 창의적이고 자기주도적인 문제해결력 향상에 도움이 되는 프로그래밍 수업을 재량시간을 통해 진행하려 한다. 프로그래밍 수업은 전문 용어, 결과가 눈에 쉽게 보이지 않는 이유 등으로 초등학생에게는 지루하고 어려워서 적용하기에는 부담스러운 면이 있다. 이에 본 연구는 프로그래밍을 아동인지단계에 맞추어 흥미를 느끼고 쉽게 접근할 수 있는 Scratch 프로그램을 활용하여 프로그래밍 수업을 하고자 한다. 단일 집단에게 수업을 실시하고 사전사후 검사를 통하여 Scratch 프로그램을 활용한 프로그래밍 수업이 문제해결력 향상에 도움이 되는지를 검증해 보고자 한다.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.8
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• pp.108-114
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• 2003

This research describes a image-processing technique for the scratch detecting algorithm for ITO coated glass. We use the modified logical thresholding method (called adaptive logical thresholding method) for binarization of gray-scale glass image. This method is useful to the algorithm for detecting the scratch of ITO coated glass automatically without need of any prior information of manual fine-tuning of parameters.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.5
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• pp.1-9
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• 2011

This paper presents a novel scratch detection and removal approach for old film images in wavelet-domain. Various scratch detection and removal algorithms have been proposed for past decades. However, accurate scratch detection and removal with a moderate amount of computing effort is still a problem because of trade off between the quality of the film and computational load. For overcoming this problem, we first decompose an input image using a 3-level wavelet transform, and then remove the scratch by shrinking wavelet coefficients using linear interpolation. Experimental results show that the proposed algorithm can efficiently detect and remove the scratch in damaged films, and also be incorporated into old film restoration systems.

• Polymer(Korea)
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• v.33 no.4
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• pp.273-283
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• 2009

Recent research issues on the scratch behaviors of polymeric materials has been investigated. In this study, the scratch characterization of polymeric materials with respect of experimental parameters, such as nature of the material, temperature, applied load, test speed, surface treatment, scratch number of times, polymer structure/functional groups, degree of cross-linking, and crystallinity, are reviewed. In addition, the testing standards and methodologies which could quantify the scratch behaviors are introduced and the current international standards are compared and summarized. The latest technical approaches for evaluating the scratch behaviors and improving the scratch resistance of polymers are also discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1321-1322
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1267-1268
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1018-1021
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• 2003

A scratch tester was developed to evaluate the adhesive strength at interface between thin film and substrate(silicon wafer). Under force control, the scratch tester can measure the normal and the horizontal forces simultaneously as the probe tip of the equipment approaches to the interface between thin film and substrate of wafer. The capacity of each component of force sensor is 0.1 N ∼ 100 N. In addition, the tester can detect the signal of elastic wave from AE sensor(frequency range of 900 kHz) attached to the probe tip and evaluate the bonding strength of interface. Using the developed scratch tester. the feasibility test was performed to evaluate the adhesive strength of semiconductor wafer.