Flexible thin-film GaAs solar cells with rear micro-pattern

Jang Yujeong,Yun Yeojun,Moon Sunghyun,Lee Minhyung,Lee Jaejin 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.79 No.8

Current thin-film GaAs solar cells have a planar resar ohmic contact structure, which might be related to losses due to the photon absorption in the highly doped contact layer. Reducing the rear contact ratio can improve photon absorption through the enhanced back reflection. In this study, by etching the rear p-GaAs contact layer with metal-assisted chemical etching, the micropillar structures consisting of square patterns were formed on the GaAs solar cells, which led to improved reflection and the cell performance. We compared the current density, reflectance, and external quantum efficiency of the solar cells according to the pattern size. The power conversion efficiency was improved from 10.67 to 11.21% for the GaAs singlejunction solar cell as compared to that with a planar surface under AM 1.5G illumination.

학교 공동체 문화 형성을 위한 미술 표현 결과의 공유와 소통 방안

장유정(Yujeong JANG),현은령(Eunryung HYUN) 한국조형교육학회 2024 造形敎育 Vol.91 No.-

본 연구는 학교 공동체 문화 형성을 위한 방안으로 학교 구성원인 학생이 제작한 작품을 공유와 소통의 대상으로 선정하여 그 방법을 논의하였다. 이를 위해 먼저 인류의 삶과 예술을 통한 공유와 소통의 의미를 탐색하고, 2022 개정 교육과정 속 공동체 문화 형성과 공유와 소통의 특성을 살펴보았다. 이를 통해 공유와 소통의 특성에 맞춰 학습 영역과 내용을 탐구하고, 일정한 체계가 있는 프로세스를 바탕으로 방법을 제안하였다. 또한, 방법의 효과성을 높이는 다양한 플랫폼 활용 방안을 사례로 제시하였다. 결과적으로 본 연구는 현행 교육과정을 바탕으로 공동체 문화 형성을 위한 한 가지 방안으로 공유와 소통의 활용 방안을 제안하였다는 점, ‘표현-공유와 소통-확장 주제 활동’이라는 프로세스를 통해 방안의 체계성을 구성하였다는 점, 현시대의 기술과 학교 환경을 고려하여 효율성 높은 플랫폼을 활용할 수 있도록 제안하였다는 점에서 학교 미술교육의 시의성 있는 변화에 도움을 줄 수 있을 것으로 기대한다. This study discusses how to form a school community culture by selecting the works produced by students, who are members of the school, as targets for sharing and communication. To do so, this study first ex-plored the meaning of sharing and communication through human life and art, and examined the character-istics of sharing and communication and the formation of community culture in the 2022 revised curriculum. Through this, this study explored the learning areas and contents according to the characteristics of shar-ing and communication, and proposed a method based on a systematic process. In addition, this study presented examples of how to utilize various platforms to increase the effectiveness of the method. As a result, this study is expected to contribute to timely changes in school art education in that it proposed the use of sharing and communication as a way to form a community culture based on the current curricu-lum, organized the systematicity of the method through the process of 'expression-sharing & communica-tion-expansion theme activities,' and proposed the use of highly efficient platforms in consideration of cur-rent technology and school environment.

유선 드론을 활용한 24시간 감찰 시스템

장유정(Jang YuJeong),권예진(Kwon YeJin),전유림(Jeon YuRim) 한국정보과학회 2016 한국정보과학회 학술발표논문집 Vol.2016 No.12

대학생 자작 자동차 외관 형상 디자인 및 유체흐름에 관한 연구

장유정(Yujeong Jang),박정빈(Jeongbin Park),박준서(Junseo Park),김동환(Donghwan Kim),신은우(Eunwoo Shin),손병래(Byeongrae Son),손우민(Woomin Son),이동욱(Dongwook Lee),김의진(Euijin Kim),노회훈(Hoehun Noh),오태원(Taewon Oh) 한국자동차공학회 2021 한국자동차공학회 학술대회 및 전시회 Vol.2021 No.11

에듀테크를 통한 고등학교 미술교과의 ‘교육과정-수업-평가-기록’ 일체화 적용 사례연구

장유정(Yujeong Jang),현은령(EunRyung Hyun) 학습자중심교과교육학회 2023 학습자중심교과교육연구 Vol.23 No.20

목적 본 연구는 ‘교육과정-수업-평가-기록’ 일체화를 목표로 고등학교 미술교과 수업을 개발하고, 이를 현장에 적용하여 그 효과성을 살펴봄으로써 미술교육에서 에듀테크 적용 가능성을 살펴보는 데 그 목적이 있다. 방법 이를 위해 2015 개정 교육과정 기반의 고등학교 미술과 성취기준을 기반으로 활동 과정에서 에듀테크의 적극적 활용이 가능한 ‘디지털 콜라주’ 수업을 내용 요소로 개발하였다. 효과성은 충북의 일반계 여자고등학교 2학년 학생들과 수업을 적용한 미술교사를 대상으로 검증하였다. 분석을 목표로 수집된 주요 자료는 수업 진행 참여 관찰, 학생과 교사의 디지털 수행과정 기록, 생기부 평가 기록 자료 등이다. 이후 보다 면밀한 결과를 도출하기 위해 참여 교사 및 학생과의 심층 면담을 실시하였다. 결과 에듀테크를 활용한 미술 수업은 학생들에게 자료 탐색 및 구성에 물리적으로 쉬운 접근을 가능케 하였다. 학생들은 접근성이 용이한 디지털 기술을 통해 스스로 미술 활동을 구성하면서 도전적이고 적극적으로 수업에 참여하였다. 또한, 교사에게는 에듀테크의 디지털 플랫폼을 통해 수업의 전 과정을 효과적으로 관리할 수 있게 되어 ‘교육과정-수업-평가-기록’의 일체화를 이루는데 도움을 주었다. 결론 에듀테크는 고등학교 미술교육에 필요한 교육 목표를 효과적으로 발현시킬 수 있는 계기를 마련하고, 수업의 새로운 소통 관계를 맺게 하여 독특한 경험을 제공할 수 있었다. 또한, 학생 스스로 자신의 학습 활동을 지속적으로 기록할 수 있게 하여, 학생기록부의 주요 자원을 학생 스스로 제공할 수 있도록 하였다. 이러한 에듀테크의 역할은 학생 중심의 학생기록부가 될 수 있도록 도움을 주어 질적으로 보다 더 충실한 학생기록부가 될 수 있도록 도왔다. 본 연구는 학교 환경과 예산 등을 고려해 고차원의 에듀테크를 사용할 수 없었지만. 미술 수업 전반에서 에듀테크의 활용이 어떠한 방식으로 학교 현장에 이루어질 수 있는가에 대한 아이디어를 제시하는데 그 의의가 있다. Objectives This study aims to figure out possibility of applying EduTech in high school art classes. To find out the applicability, this study developed high school art classes with the purpose of integrating ‘curriculum-class-eval-uation-recording’, and examined the effectiveness by applying those classes in the school. Methods To achieve the objectives, based on achievement standards of high school art in 2015 revised curricu-lum, a “digital collage” class that can actively utilize EduTech was developed as a content element. The effective-ness was verified from art teachers who applied EduTech classes for second-year students of girls' high schools in Chungbuk. The data collected for analysis include participatory observation of classroom, digital performance records of students and teachers, and evaluation records from students record. After that, in-depth interviews with teachers and students were conducted to derive more detailed results. Results Art classes using EduTech made it possible for students to access data search and organization easily physically. Students participated in the classes challengingly and actively while organizing art activities on their own using accessible digital technology. Moreover, teachers were able to effectively manage the entire course through EduTech's digital platform, helping to achieve the integration of “curriculum-class-evaluation-recording.” Conclusions EduTech could provide a unique experience by giving an opportunity to effectively reveal educational goals for high school art classes and establishing novel communication relationships. Also, students were able to continuously record their own learning so students could provide the main resources for their student record. This role of EduTech helped student record become student-centered so that the student record could become more qualitatively substantial. Although this study unable to use high-level EduTech considering the environment and budget, it is meaningful to imply ideas on how the use of EduTech can be carried out in the school throughout art classes.

Understanding Other Laws for Clearance Level Radioactive Waste Focused on Chemically Decontaminated Uranium Contaminated Soil Waste

YuJeong Choi,YunGun Jung,Chongyoung Cho,Seungjin Han,SangMo Hwang,Wonhyuk Jang 한국방사성폐기물학회 2024 한국방사성폐기물학회 학술논문요약집 Vol.22 No.1

NO₂ Sensing Characteristics of Si MOSFET Gas Sensor Based on Thickness of WO₃ Sensing Layer

( Yujeong Jeong ),( Seongbin Hong ),( Gyuweon Jung ),( Dongkyu Jang ),( Wonjun Shin ),( Jinwoo Park ),( Seung-ik Han ),( Hyungtak Seo ),( Jong-ho Lee ) 한국센서학회 2020 센서학회지 Vol.29 No.1

This study investigates the nitrogen dioxide (NO₂) sensing characteristics of an Si MOSFET gas sensor with a tungsten trioxide (WO₃) sensing layer deposited using the sputtering method. The Si MOSFET gas sensor consists of a horizontal floating gate (FG) interdigitated with a control gate (CG). The WO₃ sensing layer is deposited on the interdigitated CG-FG of a field effect transistor(FET)- type gas sensor platform. The sensing layer is deposited with different thicknesses of the film ranging from 100 nm to 1 μm by changing the deposition times during the sputtering process. The sensing characteristics of the fabricated gas sensor are measured at different NO₂ concentrations and operating temperatures. The response of the gas sensor increases as the NO₂ concentration and operating temperature increase. However, the gas sensor has an optimal performance at 180℃ considering both response and recovery speed. The response of the gas sensor increases significantly from 24% to 138% as the thickness of the sensing layer increases from 100 nm to 1 μm. The sputtered WO₃ film consists of a dense part and a porous part. As reported in previous work, the area of the porous part of the film increases as the thickness of the film increases. This increased porous part promotes the reaction of the sensing layer with the NO₂ gas. Consequently, the response of the gas sensor increases as the thickness of the sputtered WO₃ film increases.

Barometric Pressure Sensor with Air Pocket Integrated with MOSFETs on the Same Substrate

Dongkyu Jang,Gyuweon Jung,Yujeong Jeong,Seongbin Hong,Jong-Ho Lee 대한전자공학회 2020 Journal of semiconductor technology and science Vol.20 No.3

In this paper, we propose a process to efficiently integrate barometric pressure sensors and MOSFETs on the same chip and show the measured results from these devices. The barometric sensor and MOSFETs are fabricated on the same Silicon substrate using CMOS process technology. The main process steps for the fabrication of the barometric sensor and MOSFETs are explained. Air pockets are connected around the barometric sensor and improve the sensitivity of the barometric sensor. The barometric sensor has a 0.5 μm thin diaphragm, which can reduce the size of the barometric sensor. The operating characteristics of the barometric sensor and the MOSFETs fabricated on the same substrate are verified.

문경 자연유산의 지질학적 가치

곽유정(Yujeong Kwak),주지원(Jiwon Ju),Enkhjin Munkhbayar,김우열(Wooyeal Kim),이찬희(Chanhee Lee),장윤득(Yun-Deuk Jang) 대한지질학회 2018 대한지질학회 학술대회 Vol.2018 No.10

Directed Differentiation of Pluripotent Stem Cells by Transcription Factors

Oh, Yujeong,Jang, Jiwon Korean Society for Molecular and Cellular Biology 2019 Molecules and cells Vol.42 No.3

Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have been used as promising tools for regenerative medicine, disease modeling, and drug screening. Traditional and common strategies for pluripotent stem cell (PSC) differentiation toward disease-relevant cell types depend on sequential treatment of signaling molecules identified based on knowledge of developmental biology. However, these strategies suffer from low purity, inefficiency, and time-consuming culture conditions. A growing body of recent research has shown efficient cell fate reprogramming by forced expression of single or multiple transcription factors. Here, we review transcription factor-directed differentiation methods of PSCs toward neural, muscle, liver, and pancreatic endocrine cells. Potential applications and limitations are also discussed in order to establish future directions of this technique for therapeutic purposes.