• Title/Summary/Keyword: 코로나 대전 과정

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Simulation of Corona Charging Process in Electret for Sensor Materials (센서재료용 일렉트렛트의 코로나 대전 과정 시뮬레이션)

  • Park, Geon-Ho
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2012.07a
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    • pp.421-422
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    • 2012
  • 본 연구에서는 코로나 대전된 고분자의 열자격전류(Thermally Stimulated Current; 이하 TSC) 데이터를 기반으로 코로나 대전 과정을 유한요소법(Finite Element Method; 이하 FEM)을 이용하여 시뮬레이션하였다. $DC -5{\sim}-8[kV]$의 고전압을 고분자에 인가하여 형성시킨 일렉트렛트를 온도 범위 $-100{\sim}+200[^{\circ}C]$에서 얻은 TSC 데이터의 대전 과정을 조사하기 위하여 FEM으로 시뮬레이션을 수행하여 공간에서 코로나 대전 과정을 추정하였다.

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A Case Study on the Practice of Health Domain in Physical Education Classes for Female Students during COVID-19 (코로나 시기의 여학생 건강영역 체육수업 실천에 관한 사례연구)

  • Han, Dong-Soo;Kim, Yun-Sang;Yi, Joo-Wook
    • Journal of Digital Convergence
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    • v.19 no.2
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    • pp.489-500
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    • 2021
  • The purpose of this study is to explore the experience and meaning of health domain in physical education practice process for female students, which can be used online. This study would like to provide physical education teachers with implications to revitalize female students' physical education. The research method used case study. Data composition and analysis used group interviews, in-depth interviews and field data. The results of study was first, the changes in classes and school sports after COVID-19 were divided into self-portraits of reality and school sports in COVID-19. Second, the new challenge was categorized into the practice process of the new online class in physical education and the change of movement for oneself. The discussion suggested the need for sympathetic consideration and communication in Corona-19, a path from crisis to opportunity. Follow-up studies should continue to study about girls' various experience participated in physical education classes, collaboration of the teacher learning community that teaches girls' classes and utilizing method of platforms and ICT that can motivate girls' physical education classes.

Class Conflict and Empathetic Society in Korea: Crisis Management in the COVID-19 Era (한국 계층갈등의 지형과 공감사회: 코로나 시대의 극복방안)

  • Suh, Moon-Gi
    • Journal of the Economic Geographical Society of Korea
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    • v.23 no.3
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    • pp.197-208
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    • 2020
  • This study attempts to identify the structure of class conflict in Korea and to suggest an alternative framework for a empathetic society. The objective and subjective level of satisfaction with life and class consciousness are in direct proportion, and status consistency signifies polarization. Distorted distribution structures and cultural values make income disparity and property disputes widen, which in turn lead to educational divides and status fixations, refracting or blocking the possibility of social mobility. By overcoming the COVID-19 crisis, it is not appropriate to go back to the past but to correct wrong consciousness and practices in the past, and the consistency between the state and members of society must be re-established. Through the process of innovation at the economic, global, and digital level, a major transformation is required in the new normal era, which prioritizes social development for human values. The conflict resolution depends on the solidarity of the community as a social foundation, since an empathetic society needs the trust and communication of the members of the society.

The Simulation of Corona Charging Process in Polytetrafluoroethylene Electret using Finite Element Method (유한요소법을 이용한 PTFE 일렉트렛트의 코로나 대전 과정 시뮬레이션)

  • 이수길;유재웅;박건호;김충혁;이준웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1994.05a
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    • pp.94-98
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    • 1994
  • In this study, the thermally stimulated current(TSC) of corona charged PTFE film was studied and the simulation of corona charging process was also calculated by finite element method. The electrets which were formed by appling high voltages(DC-5∼-8[kV]) to PTFE film were experimented to measure TSC in the temperature range of -100∼+200 [$^{\circ}C$] and then the finite element method was accomplished to examine corona charging process using a obtained physical constants. It is confirmed that the charging negative corona is profitable as the applications are manufactured because the time constant of negative corona is much larger than it of positive corona. And it is attempted to estimate the corona charging process in space using simulation.

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Development of Electret to Improve Output and Stability of Triboelectric Nanogenerator (마찰대전 나노발전기의 출력 및 안정성 향상을 위한 일렉트렛 개발)

  • Kam, Dongik;Jang, Sunmin;Yun, Yeongcheol;Bae, Hongeun;Lee, Youngjin;Ra, Yoonsang;Cho, Sumin;Seo, Kyoung Duck;Cha, Kyoung Je;Choi, Dongwhi
    • Korean Chemical Engineering Research
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    • v.60 no.1
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    • pp.93-99
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    • 2022
  • With the rapid development of ultra-small and wearable device technology, continuous electricity supply without spatiotemporal limitations for driving electronic devices is required. Accordingly, Triboelectric nanogenerator (TENG), which utilizes static electricity generated by the contact and separation of two different materials, is being used as a means of effectively harvesting various types of energy dispersed without complex processes and designs due to its simple principle. However, to apply the TENG to real life, it is necessary to increase the electrical output. In addition, stable generation of electrical output, as well as increase in electrical output, is a task to be solved for the commercialization of TENG. In this study, we proposed a method to not only improve the output of TENG but also to stably represent the improved output. This was solved by using the contact layer, which is one of the components of TENG, as an electret for improved output and stability. The utilized electret was manufactured by sequentially performing corona charging-thermal annealing-corona charging on the Fluorinated ethylene propylene (FEP) film. Electric charges artificially injected due to corona charging enter a deep trap through the thermal annealing, so an electret that minimizes charge escape was fabricated and used in TENG. The output performance of the manufactured electret was verified by measuring the voltage output of the TENG in vertical contact separation mode, and the electret treated to the corona charging showed an output voltage 12 times higher than that of the pristine FEP film. The time and humidity stability of the electret was confirmed by measuring the output voltage of the TENG after exposing the electret to a general external environment and extreme humidity environment. In addition, it was shown that it can be applied to real-life by operating the LED by applying an electret to the clap-TENG with the motif of clap.

Digital twin river geospatial information, water facility modeling, and water disaster response system (디지털 트윈 하천 공간정보 구축, 시설물 모델링 및 수재해 대응 시스템 구축 사례)

  • Park, DongSoon;Yoo, Hojun;Kim, Taemin
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.6-6
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    • 2022
  • 최근 수재해에 대응하기 위한 물관리 환경은 기후변화에 따른 홍수 피해 심화와 댐과 하천 시설의 노후화 점증, 하천관리일원화 등 정책적 변화, 그리고 포스트코로나 디지털 혁신 등 복합적 대전환 시대 진입에 따라 복잡다단한 양상을 보이고 있다. 디지털 트윈은 디지털 대전환(digital transformation) 시대 다양한 산업 영역에서 지능화와 생산성 향상을 목적으로 도입되고 있다. 본 국가 시범사업에서는 170 km에 달하는 섬진강 유역 전체를 대상으로 홍수에 대응하기 위한 디지털 트윈 플랫폼(K-Twin SJ)을 구축하고 있다. 본 플랫폼은 국가 인프라 지능정보화 사업의 일환으로 시작되었으며, 공간정보와 시설물 모델링, 홍수 분석 등 수재해에 대응하기 위한 수자원 분야의 다학제적인 강소기업들과 K-water에서 컨소시엄을 구성하여 추진하고 있다. 본 사업의 내용은 섬진강 댐-하천 유역에 대하여 고정밀도 3D 공간정보화, 실시간 물관리 데이터 연계, 홍수 분석 시뮬레이션, AI 댐 운영 최적화, AI 사면 정보 생성, 하천 제방 안전성 평가, AI 지능형 CCTV 영상분석, 간이 침수피해 예측, 드론 제약사항 조사 체계 개발을 포함하고 있다. 물관리 데이터와 하천 시설정보를 트윈 플랫폼 상에서 위치기반으로 시각화 표출하기 위해서는 유역의 공간정보를 3차원으로 구축하는 과정이 필수적이다. 따라서 GIS 기반의 섬진강 하천 중심 공간정보 구축을 위해 유역의 국가 정사영상과 5m 수치표고모형(DEM)은 최신성과를 협조 받아 적용하였으며, 홍수 분석을 위한 하천 중심 공간정보는 신규 헬기에 LiDAR 매핑을 수행하여 0.5m 급 DEM을 신규 구축하였다. 또한 하천 시설물 중 섬진강댐과 79개 주요 하천 횡단 교량과 3개 보 시설을 지상기준점 측량과 드론 매핑, 패턴 방식의 경량화 작업을 통해 트윈에 탑재할 수 있는 시설물 3D 객체 모델을 제작하였다. 홍수 분석을 위해서는 섬진강 유역에 대해 K-Drum, K-River, K-Flood 모델을 구축하였으며, AI 하천 수위 예측 학습 모델을 개발하였다. 섬진강 디지털 트윈 유역 물관리 플랫폼을 통해 데이터 기반의 똑똑한 물관리를 구현하고자 한다.

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A Study on the Simulation of the Corona Charging Process of Polypropylene Electret Cell Using Finite Element Method (유한요소법을 이용한 폴리프로필렌 일렉트렛트 셀의 코로나 대전과정 시뮬레이션에 관한 연구)

  • Lee, Su-Kil;Park, Geon-Ho;Jung, Il-Hyung;Jang, Kyung-Uk;Lee, Joon-Ung
    • Proceedings of the KIEE Conference
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    • 1993.11a
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    • pp.169-171
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    • 1993
  • In order to estimate space charging process in the corona charging apparatus which has been used to make polymer electret cell, the electrical properties of 30[${\mu}m$] thick polypropylene film were obtained from TSC measurement after corona charging between copper knife electrode and aluminum cylinder electrode with the voltage of -8, -7, -6, -5 (kV). And, the electrostatic contour and the electric field vector were calculated using Finite Element Method with the electrical properties obtained from TSC spectra analysis. The edge effect around the edge of knife electrode affects electrostatic contour on the surface of specimen and the electric field concentration inside the polymer. As a result the uneven charging state in the electret cell due to the mistake of design was calculated, and the optimal design of corona charging apparatus opprobriate to various specimen was come to be practicable.

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Analysis of the Experiences and Perceptions of Teachers Participating in the Development of Content-Based Online Science Class Videos, and the Characteristics of the Developed Class Content (콘텐츠 활용형 온라인 과학 수업 동영상 개발에 참여한 교사들의 경험과 인식, 개발된 수업 콘텐츠의 특징 분석)

  • Shin, Jung Yun;Park, Sang Hee
    • Journal of The Korean Association For Science Education
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    • v.40 no.6
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    • pp.595-609
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    • 2020
  • The purpose of this study is to analyze the experiences of teachers who participated in the development of online science class videos in the context of covid-19, their perception of online science class, and the characteristics of the online science class content developed by teachers. A survey and interviews were conducted with ten elementary school teachers who made online science class videos themselves. Also the characteristics of the online science class were investigated by analyzing the online science class video produced by the participants. As a result, participants in the study recognized the lack of production time, difficulty in filming and editing, concerns over misconceptions, the problem of solving copyrights for existing materials, and the burden of external disclosure. Although it was a teacher who had experience producing online science class video contents, no research participants actively answered the merits of online science class. On the other hand, the study participants cited that the shortcomings of online science classes were that students had fewer opportunities for inquiry and lack of communication or interaction. In particular, these shortcomings were thought to have a great influence on the quality of online science classes, especially in making inquiry classes difficult. Some teachers took a negative view that online science classes could not completely replace face-to-face classes. However, if multiple teachers are presented with supplementary teaching activities that complement the content-based online teaching method, the method of combining online science classes and face-to-face classes is not. Through the analysis of the contents of the online science class, the introduction and arrangement steps of the online science class were similar to the process of the face-to-face science class, but the inquiry step and the conceptual explanation step showed a big difference from the face-to-face science class.

Effectiveness of 「Food Safety and Health」Program as a Home Economics Elective Course in High School (고등학교 가정계열 선택과목 「식품안전과 건강」교육과정의 운영 효과)

  • Park, Mi Jeong;Choi, Seong-Youn;Lee, Sim-Yeol;Kim, Yoo Kyeong;Jung, Lan-Hee;Kim, Yookyung;Kim, Jin-A;Lee, Jeong Gyu;Goh, Misun;Yu, Nan Sook
    • Journal of Korean Home Economics Education Association
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    • v.33 no.2
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    • pp.135-152
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    • 2021
  • The purpose of this study was to examine the effectiveness of the curriculum implementation of 「Food Safety and Health」, a Home Economics elective course, for high school students. Accordingly, several units of the 「Food Safety and Health」curriculum were piloted in six high schools in Chungbuk, Gyeonggi, Daejeon, and Sejong, and 1,199 questionnaires collected from students who participated in the classes were analyzed. The results are as follows. The 「Food Safety and Health」class had a significant effect on improving the total score of 'food safety and health' knowledge of high school students and scores for sub-dimensional area. Compared to the pre-test, the overall rate of correct answers for the post-test has increased by 7.99%p, and schools that implemented the relevant unit class relatively more had higher improvement scores. In addition, the 「Food Safety and Health」class has positively changed the eating behavior of high school students, and had a significant effect on having a habit of eating a variety of foods evenly. High school students who participated in the 「Food Safety and Health」class evaluated their classes very positively (4.27 out of 5 points), and responded that the content of the class was interesting, easy to understand, and helpful for their diet in daily life. According to the responses to the open-ended questions, students responded that the class was helpful in acquiring food-related knowledge in their real lives, while there were so many limitations for experiencing lab class and group activities due to COVID 19. In preparation for the high school credit system, this study is meaningful that it has expanded the elective courses in home economics area, as well as the right to choose subjects for high school students.