• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.69-77
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• 2022

Physical experiment through MBL has been used in many schools for a long time since students can check the experiment results immediately and conduct the experiment easily. However, conducting the experiment, not knowing the principle of the device or simply concentrating on the derived data has been raised as the problem of MBL experiment. To supplement this problem, this study measured the acceleration of gravity with the picket fence method, which is often used in MBL experiment, utilizing Arduino, calculated the error rate through a comparison to the actual acceleration of gravity and discussed the educational application of the experiment to measure it. As a result of the experiment, the error rate between the acceleration of gravity calculated by the experiment and the actual acceleration of gravity was about 1%, so it turned out that relatively accurate measurements were possible. Also, the sample mean of the experimental value was included in the confidence interval of 95%, so it could be concluded that it was a significant experiment. In addition, this study showed the possibility of the educational application of the experiment to measure it through the following: It can supplement the structural disadvantages of MBL; it can consider the interaction between Physics and Math; it is possible to converge with information course in STEAM education; and it is inexpensive to be equipped with the equipment. Hopefully, the physical experiment utilizing Arduino will further be revitalized in science gifted education based on this study.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.247-251
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• 2004

반도체 소자의 제조에 있어 실리콘 표면에 성장한 자연산화막을 제거하기 위해 일반적으로 습식 세정 기술이 이용되어 왔다. 하지만 소자의 최소 선폭(design rule)이 nano급으로 고집적화 됨에 따라 contact hole 바닥의 자연산화막을 깨끗이 제거하는데 있어서 그 한계를 나타나고 있다. 이에 대한 효과적인 대안 공정으로 가스 건식 세정 기술이 연구되고 있다. 본 논문에서는 한 번에 50매 이상의 웨이퍼를 처리함으로써 생산성 측면에서 월등한 배치식 설비에서 원거리 플라즈마(remote plasma) 장치에서 2.450Hz의 마이크로웨이브(${\mu}$-wave)에 의해 형성시킨 수소라디칼과 $NF_3$ 가스를 이용하여 실리콘에 결함을 주지 않고 자연산화막을 선택적으로 제거하는 공정에 대해 고찰하였다. AFM을 이용한 표면분석, TEM을 이용한 물성분석, 그리고 ToF-SIMS 및 XPS를 이용한 화학 분석을 습식 및 건식 세정을 비교 평가한 결과, 건식 세정 공정이 실리콘 표면에 결함을 주지 않고 자연산화막을 제거 할 수 있음을 확인하였다. 산화막$(SiO_2)$, 질화막$(Si_3N_4)$, 그리고 다결정 실리콘(Poly-Si) 등의 각 막질별 식각 특성을 고찰하였으며, $NH_3$의 캐리어 가스인 $N_2$의 주입량을 조절함으로써 수소라디칼 형성 효율의 개선이 가능하였으며, 이로부터 게이트와 소스/드레인 사이를 절연하기 위해 이용되는 질화막의 식각 선택비를 2배 정도 개선할 수 있었다. nano급 소자에 실장하여 평가한 결과에서 불산(HF)에 의한 습식 세정 방식에 비하여 약 $20{\sim}50%$ 정도의 contact 저항 감소 효과가 있음이 확인되었다.두 소자 모두 $40mA/cm^2$ 에서 이상적인 화이트 발란스와 같은(0.33,0.33)의 색좌표를 보였다.epsilon}_0=1345$의 빼어난 압전 및 유전특성과 $330^{\circ}C$의 높은 $T_c$를 보였고 그 조성의 vibration velocity는 약4.5 m/s로 나타났다.한 관심이 높아지고 있다. 그러나 고 자장 영상에서의 rf field 에 의한 SAR 증가는 중요한 제한 요소로 부각되고 있다. 나선주사영상은 SAR 문제가 근원적으로 발생하지 않고, EPI에 비하여 하드웨어 요구 조건이 낮아 고 자장에서의 고속영상방법으로 적합하다. 본 논문에서는 고차 shimming 을 통하여 불균일도를 개선하고, single shot 과 interleaving 을 적용한 multi-shot 나선주사영상 기법으로 $100{\times}100$에서 $256{\times}256$의 고해상도 영상을 얻어 고 자장에서 초고속영상기법으로 다양한 적용 가능성을 보였다. 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화가 선조체 영역에서 국한되어 나타나며 그 유의성이 움직임 보정 전에 비하여 낮음을 알 수 있었다. 결론: 뇌활성화 과제 수행시에 동반되는 피험자의 머리 움직임에 의하여 도파민 유리가 과대평가되었으며 이는 이 연구에서 제안한 영상정합을 이용한 움직임 보정기법에 의해서 개선되었다. 답이 없는 문제, 문제 만들기, 일반화가 가능한 문제 등으로 보고, 수학적 창의성 중 특히 확산적 사고에 초점을 맞추어 개방형 문제가 확

• Journal of Korean Elementary Science Education
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• v.41 no.4
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• pp.740-753
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• 2022

This study was conducted to develop and apply an out-of-school STEAM program model based on Social-Emotional Learning (SEL) for underprivileged students in the lower grades. To this end, a STEAM program based on SEL was developed, with the following characteristics. First, by integrating traditional STEAM learning elements and SEL elements, a structured program was designed with consistent stages, including mindfulness meditation→present an authentic situation→creative design→emotional experiences→reflection. Second, the program was structured so that elementary school students could develop mathematical thinking and scientific inquiry skills in problem-solving situations in daily life. Third, the detailed themes for each STEAM program involved storytelling-based problem situations, as well as activities centered on play and sympathy to reflect the educational needs of underprivileged students. From these characteristics, a total of five programs were developed and applied to 16 teachers and 354 lower-grade elementary school students in 16 community children centers nationwide. The results were as follows. First, while students' satisfaction with the STEAM program was 4.16, there were no significant differences in STEAM satisfaction according to gender. Second, while all students' interest and self-efficacy, which was one of sub factors of STEAM attitude, were significantly improved, no significant difference was seen in STEAM attitudes according to gender. Third, although students' SEL competencies were not significantly improved, relationship skills, which were among the sub factors of SEL competencies, were significantly improved, and there were no significant differences in SEL competencies according to gender. From these results, a discussion on the effect of the out-of-school STEAM program for underprivileged students and directions for follow-up studies was suggested.

• Journal of the Korean School Mathematics Society
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• v.20 no.2
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• pp.119-139
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• 2017

The construction in the ancient Greek era had more meanings than a construction in the present education. Based on this fact, this study examines the meaning of the current textbook. In contrast, we have extracted the meaning of the constructions in Euclid Elements. In addition, we have been thinking about what benefits can come up if the meaning of the construction in Euclid Elements was reflected in current education, and suggested a way to exploit that advantage. As results, it was confirmed that the construction in the current textbook was merely a means for introducing and understanding the congruent conditions of the triangle. On the other hand, the construction had four meanings in Euclid Elements; Abstract activities that have been validated by the postulates, a mean of demonstrating the existence of figures and obtaining validity for the introduction of auxiliary lines, refraining from intervening in the argument except for the introduction of auxiliary lines, a mean of dealing with numbers and algebra. Finally we discussed the advantages of using the constructions as a means of ensuring the validity of the introduction of the auxiliary line to the argument. And we proposed a viewpoint of construction by intervention of virtual tools for auxiliary lines which can not be constructed with Euclid tool.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.271-274
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• 2013

Considering the recent trend highlighting the importance of STEAM education, the purpose of this study is to develop scientific research activities and STEAM technology material using the smart device sensor. Drawing a picture on a map with GPS drawing application which contains elements such as IT, geographic information, sports and arts, we intent not just to install a smartphone application but also to get synergic effects and help with real cartography and geographic classes which are not experienced in the middle school curriculum, by using the functions of a smart device. Through the development of STEAM teaching material, we intended to provide a clear direction towards advancement by developing creative teaching data and teaching models which encourage students to improve their interest and creativity in science, technology, engineering, art, and mathematics.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.3
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• pp.331-340
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• 2021

As the communication industry develops, the development of SoC (System on Chip) is increasing. Accordingly, the paradigm of technology design of industries and companies is changing. In the existing process, companies purchased micro-architecture, but now they purchase ISA (Instruction Set Architecture), and companies design the architecture themselves. RISC-V is an open instruction set based on a reduced instruction set computer. RISC-V is equipped with ISA, which can be expanded through modularization, and an expanded version of ISA is currently being developed through the support of global companies. In this paper, we present benchmarking frameworks ARIA, LEA, and PIPO of Korean block ciphers in RISC-V. We propose implementation methods and discuss performance by utilizing the basic instruction set and features of RISC-V.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.82-84
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• 2022

In recent years, research has been actively conducted to solve overhead problems caused by the increase in the number of IoT devices. MQTT, one of the IoT lightweight protocols for resolving performance degradation in IoT environments, is standardized to enable efficient operation in many-to-many communication environments, but there is a security vulnerability as it does not provide encryption by default. Although TLS communication technology can be applied to solve these problems, it is difficult to meet IoT's lightweight power-saving requirements. This paper introduces the latest MQTT communication encryption trends and analyzes IoT applicability by comparing TLS encryption and payload encryption methods.

• Korean Journal of Cognitive Science
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• v.21 no.4
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• pp.627-653
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• 2010

The present study proposes and examines a new type of multiple-choice math test. In this format, the options are the intermediate derivatives of the math problem solution process rather than the final answers. This idea originates from the studies on the effect of worked-out examples. In these studies, it has been shown that students learn better when they were presented with worked-out examples than when presented with final answers by themselves. In line with these findings, we introduced the intermediate derivatives of the solution process as the options of multiple-choice items so that the test-taker will have a chance to examine the solution process. The test was implemented as a computerized test in which students can solve problems in a short answer format, and then pick a multiple-choice option which appears when requested. The experimental group had multiple-choice options which were intermediate derivatives of the solution process, and the control group had the final answers as the options as in most multiple-choice tests. The participants were 6th graders in elementary school. The posttest results revealed that the average score of the experimental group was higher than that of the control group. The results suggest that tests that use intermediate derivatives of the problem solution process as options can be used as learning tools in the classrooms. Finally, directions for further studies were discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.1 no.1
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• pp.53-68
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• 1981

Most clays under sustained load exhibit time-dependent deformation because of creep movement of soil particles and many investigators have attempted to relate their findings to the creep behavior of natural ground and to the long-term stability of slopes. Since the creep behavior of clays may assume a variety of forms depending on such factors as soil plasticity, activity and water content, it is difficult and complicated to analyse the creep behavior of clays. Rheological models composed of linear springs in combination with linear or nonlinear dashpots and sliders, are generally used for the mathematical description of the time-dependent behavior of soils. Most rheological models, however, have been proposed to simulate the behavior of secondary compression for saturated clays and few definitive data exist that can evaluate the behavior of non-saturated clays under the action of sustained stress. The clays change gradually from a solid state through plastic state to a liquid state with increasing water content, therefore, the rheological models also change. On the other hand, creep is time-dependent, and also the effect of thixotropy is time-function. Consequently, there may be certain correlations between creep behavior and the effects of thixotropy in compacted clays. In addition, the states of clay depend on water content and hence the height of the specimen under drained conditions. Futhermore, based on present and past studies, because immediate elastic deformation occurs instantly after the pressure increment without time-delayed behavior, the factor representing immediate elastic deformations in the rheological model is necessary. The investigation described in this paper, based on rheological model, is designed to identify the immediate elastic deformations and the effects of thixotropy and height of clay specimens with varing water content and stress level on creep deformations. For these purposes, the uniaxial drain-type creep tests were performed. Test results and data for three compacted clays have shown that a linear top spring is needed to account for immediate elastic deformations in the rheological model, and at lower water content below the visco-plastic limit, the effects of thixotropy and height of clay specimens can be represented by the proposed rheological model not considering the effects. Therefore, the rheological model does not necessitate the other factors representing these effects. On the other hand, at water content higher than the visco-plastic limit, although the state behavior of clays is visco-plastic or viscous flow at the beginning of the test, the state behavior, in the case of the lower height sample, does not represent the same behavior during the process of the test, because of rapid drainage. In these cases, the rheological model does not coincide with the model in the case of the higher specimens.

• Journal of Korean Home Economics Education Association
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• v.16 no.3
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• pp.81-98
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• 2004

This study is to conduct the basic study for the achievement and assessment standards for the subject of 'Human Development' and 'Food and Nutrition', which are the curricula of Vocational Home Economics High Schools. These two subjects were newly adopted in the Vocational study Section of the 2005 College Entrance Examinations. In other words, this study is to provide the basic data for implementing the quality education based on the proper assessment of the curricula. For this purpose. this study analyzed the character & objective of 'Human Development' and 'Food and Nutrition'. Secondly. through the theoretical review for the concept & necessity of absolute evaluation standards. this study ensures the concept of achievement and assessment standards. and also designs the developing measures (including procedures). The achievement standards were developed by the following 5 step procedures. (1) Analyzing the objectives & contents of curricula. (2) Designating the development field of achievement standards (3) Developing the achievement standards. (4) The assessment of achievement standards. (5) Confirming the achievement standards. The assessment standards were developed by the following 5 step procedures. (1) Analyzing the achievement standards, (2) Designating the assessment field (3) Developing the assessment standards (4) Evaluating the assessment standards (5) Confirming the assessment standards Thirdly, this study suggested the exemplary achievement standards and assessment standards for the subject of Human Development, Food and Nutrition. Future study needs some critical review for the method of developing achievement and assessment standards for the subject of Human Development, Food and Nutrition. For example. the properness of 'Contents Element' which was designated as the developing field in the achievement standards, the discussion on validity of Contents Element abstract. the base of evaluating classification in terms of low, middle and high level, and other things should be considered through critical discussion. Especially the follow-up study should include the development of various evaluating methods to enable the clear communication for the achievement and assessment standards based on abstract concept and theory, thereby it could enable the actual interpretation and practical use.