• Journal of Science Education
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• v.46 no.2
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• pp.212-221
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• 2022

In this study, we propose an analytical model to elucidate the formation of electric fields between two parallel conducting plates. Using nine Gaussian surfaces, we investigated the charge redistributions and electric fields formed by parallel conducting plates when two charged plates get close together. The electric charges are redistributed via a new electrostatic equilibrium to create the electric field of each plates. As a result, the electric field start from + electrode plate to - electrode plate via inducing a new electrostatic equilibrium, implying that the application of Gaussian surfaces to only one of the electrodes of parallel-plate capacitors is deserved. The results will help undergraduate students understand the charge redistribution and the electric field formation in parallel-plate capacitors in a reasonable manner.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2088-2092
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• 2009

비점오염원은 면으로 분포하는 오염원으로 강우시 지표유출에 의해 유출되기 때문에 발생지점 및 발생량 추정이 어려우며, 이에 대한 처리가 어려운 실정이다. 현재 점오염원의 처리는 어는 정도 도달한 선진국에서는 비점오염원이 가장 중요한 오염원으로 대두되고 있는 실정이다. 따라서, 본 연구에서는 소양호 상류유역의 지류하천인 내린천, 인북천, 북천을 대상으로 부영영화를 일으키는 수질인자 BOD, COD, SS, T-N, T-P를 대상으로 강우량에 따른 수질농도가 변화하는 양상을 고찰하였다. 연구결과, 강우시 기간이 6월 ${\sim}$ 8월에 오염물질의 유출이 크게 발생하는 것을 알 수 있었으며, 연구지점 모두 비강우시에는 1급수의 수질상태를 보였으나, 강우시에는 3급수 이하의 수질로 악화되는 것을 알 수 있었다. 또한, 각 지류하천으로부터 유입되는 부하량을 추정하여 유역면적대비 유출량 - 오염부하량의 회귀식을 작성하였다. 끝으로, 유출량비를 이용하여 각 지류 하천의 유역면적대비 연간 총 오염유출량을 산정하였다.

• Archives of design research
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• v.11 no.1
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• pp.99-108
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• 1998

The purpose of this study was to exanune the effects of learning training program on university students' creativity. In order to accomplish this purpJse of the study effectively, the following research hypotheses were posited: (Hypothesis 1) The treJltment group trained with the learning program will perform better in technic.al class. (Hypothesis 2) The treatment group trained with the learning program will show the higher degree of progress in diagram creativity than the pre-treatment group. The result of the study were summarized as follows: First, regarding the effects of training, there appeared a significant difference between the groups of post-treatment class and pre-treatment class in the use of learning strategies. Second. there appeared a significant difference between the group of post-treatment class and pre-treatment class in diagranl creativity.

• Journal of Semiconductor Engineering
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• v.1 no.1
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• pp.57-63
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• 2020

Complementary metal-oxide-semiconductor (CMOS) technology is now facing a power scaling limit to increase integration density. Since 1970s, multi-valued logic (MVL) has been considered as promising alternative to resolve power scaling challenge for increasing information density up to peta-scale level by reducing the system complexity. Over the past several decades, however, a power-scalable and mass-producible MVL technology has been absent so that MVL circuit and system implementation have been delayed. Recently, compact MVL device researches incorporating multiple-switching characteristics in a single device such as 2D heterojunction-based negative-differential resistance (NDR)/transconductance (NDT) devices and quantum-dot/superlattices-based constant intermediate current have been actively performed. Meanwhile, wafer-scale, energy-efficient and variation-tolerant ternary-CMOS (T-CMOS) technology has been demonstrated through commercial foundry. In this review paper, an overview for MVL development history including recent studies will be presented. Then, the status and its future research direction of MVL technology will be discussed focusing on the T-CMOS technology for peta-scale information processing in semiconductor chip.

• Journal of Science Education
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• v.43 no.3
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• pp.382-399
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• 2019

This study suggests how to use tablet PC application to improve the cognitive functions of the elderly. As a part of lifelong education, this study analyzes cases of developing and applying smart application programs to contribute to the enhancement of science education as an elderly education. For the research, we set the direction of the program and developed the programs 'Coloring,' 'Building lights,' 'Matching shapes,' and 'Pressing button' accordingly. As a result of applying the program to nine participants, each program has a positive effect on the improvement of cognitive function of the elderly. This shows the possibility of using smart applications as a cognitive function enhancement program for the elderly.

• Journal of Science Education
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• v.44 no.2
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• pp.197-204
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• 2020

In order to teach the nature of science which is one of the goals of science education, the aesthetic model of science was developed into a two-dimensional model through theoretical reviews on the aesthetic aspect of science. We represented 10 kinds of scientific experiments that scientists thought are beautiful in the aesthetic space of science. This paper tried to represent the greatest and famous scientific experiments in the history of science into the aesthetic space of science to find the suitability or usefulness of that model. At the same time, we were able to develop measuring tools as the Likert-scale with pictures of scientific experiments. Through this, we propose various teaching approaches on the nature of science (NOS) based on the aesthetic model of science and the potential for utilization in measuring the effects of the ways of teaching NOS.

• Journal of Science Education
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• v.44 no.2
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• pp.259-272
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• 2020

This study aims at investigating the effects of collective promotion on the attainment of literacy, numeracy, and essential life skills by primary school pupils and also to find out if the policy of collective promotion meets its objective of minimization of wastage in basic education. The study used written tests for pupils in the final class (Level II, class 6) to collect data in some selected English-speaking primary schools in Meme Division of Cameroon. Descriptive statistics and a one way ANOVA were used for analyzing data. The results revealed that the policy of collective promotion negatively affects the attainment of literacy, numeracy, and essential life skills of pupils in Kumba, Meme Division. Teachers who assisted in the study through personal communication with the researcher argued that collective promotion in basic education does not achieve its objective of minimizing wastage of educational resources; neither does it positively improve the literacy, numeracy, and essential life skills of pupils. This study recommends that the policy of collective promotion can be revisited and that focus be placed not only on minimizing wastage of resources but also on investing on quality education system so as to equip the would-be leaders of tomorrow with skills, knowledge, and attitudes which will make them functional and responsible citizens in their society.

• Journal of Semiconductor Engineering
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• v.2 no.3
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• pp.136-141
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• 2021

This paper analyzes the tree expansion for multiple-input multiple-output (MIMO) detection in the viewpoint of hardware implementation. The tree expansion is to calculate path metrics of child nodes performed in every visit to a node while traversing the detection tree. Accordingly, the tree-expansion unit (TEU), which is responsible for such a task, has been an essential component in a MIMO detector. Despite the paramount importance, the analyses on the TEUs in the literature are not thorough enough. Accordingly, we further investigate the hardware complexity of the TEUs to suggest a guideline for selection. In this paper, we focus on a pair of major ways to implement the TEU: 1) a full parallel realization; 2) a transformation of the formulae followed by common subexpression elimination (CSE). For a logical comparison, the numbers of multipliers and adders are first enumerated. To evaluate them in a more practical manner, the TEUs are implemented in a 65-nm CMOS process, and their propagation delays, gate counts, and power consumptions were measured explicitly. Considering the target specification of a MIMO system and the implementation results comprehensively, one can choose which architecture to adopt in realizing a detector.

• Journal of Science Education
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• v.43 no.1
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• pp.1-16
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• 2019

This exploratory study is aimed at exploring the validity of the Science Motivation Questionnaire (SMQ) developed for university students, to measure the science motivation of middle school students and analyze the differences on gender and country factors of SMQ. A total of 371 students participated in this study: 171 middle school students from the USA and 200 secondary students from Korea. All participants were enrolled in the STEM program and activities in Utah, USA (for US students) and at a Korean university institute for gifted and talented students (for Korean students). In this study, exploratory and confirmatory factor analyses and latent mean analysis were used to analyze the gender and country differences. The results indicated that the 25 items of SMQ scale were theoretically meaningful and valid for middle school students. The latent mean difference by gender indicated that male students have higher intrinsic motivation, career motivation, grade motivation, and self-determination than female students. Moreover, a significant difference exists in these factors between the two countries. Further findings reveal that Korean students scored higher than US students in terms of the aforementioned factors. This study will provide significant insights in and contribution to science motivation issues in STEM education and the development of design-based engineering programs.

• Journal of Science Education
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• v.43 no.1
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• pp.173-193
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• 2019

An expert teachers' instruction can be helpful to other teachers because good teaching effectively guides students to develop meaningful learning. Feynman is an excellent physics lecturer as well as one of the greatest physicists of the 20th century who presented and explained physics with his unique teaching style based on his great store of knowledge. However, it is not easy to capture and visualize teaching because it is not only the complex phenomena interrelated to various factors with the content to be taught but also the tacit representation. In this study, the framework of knowledge & belief based on the integrated mental model theory was used as a tool to capture and visualize complex and tacit representation of Feynman's teaching of 'The theory of gravitation,' a chapter in The Feynman Lectures on Physics. Feynman's teaching was found to go beyond the transmission of physics concepts by showing that components of the framework of knowledge & belief were effectively intertwined and integrated in his teaching and the storyline was well-organized. On the basis of these discussions, the implications of Feynman's teaching analyzed within the framework of knowledge & belief for physics teacher education are derived. Finally, the characteristics of the framework of knowledge & belief as tools for the analysis of teaching are presented.