Gas turbine Rotor ECT 검사 기술 개발

Hunhee Kim(김훈희),Jaeseok park(박재석),Junwoo Kim(김준우) 한국비파괴검사학회 2022 한국비파괴검사학회 춘계학술대회 초록집 Vol.2022 No.5

풍력 블레이드 초음파 검사 기술 개발

Hunhee Kim(김훈희),Jaeseok park(박재석),Junwoo Kim(김준우) 한국비파괴검사학회 2022 한국비파괴검사학회 춘계학술대회 초록집 Vol.2022 No.5

Relaxing interfacial dipole by inducing PEDOT:PSS in colloidal quantum dot photovoltaics to improve efficiency

Hunhee Lim,Min-Jae Choi,Yeon Sik Jung 한국고분자학회 2016 한국고분자학회 학술대회 연구논문 초록집 Vol.41 No.2

Investigation of H2S gas response in resistor- and FET-type gas sensors

Hunhee Shin,Gyuweon Jung,Seongbin Hong,Yujeong Jeong,Wonjun Shin,Jinwoo Park,Donghee Kim,Kangwook Choi,Byung-Gook Park,Jae-Joon Kim,Jong-Ho Lee 대한전자공학회 2022 대한전자공학회 학술대회 Vol.2022 No.6

Exploring Predictive Factors of Academic Probation Using Data Mining Approach

Hunhee Lee,Namhyoung Kim 대한산업공학회 2021 Industrial Engineeering & Management Systems Vol.20 No.1

The purpose of this study is to develop the early prediction model for academic probation to encourage retention of students at universities. For this study, various data from the administration system and learning environment of G University in South Korea were collected. We constructed the predictive model by applying logistic regression to collected data using new variables related to campus activities. To solve the class-imbalance problem, we applied data mining techniques. This study is significant in that the model is based on structured real data by using education data mining approach from the academic administrative system we can access. Predictive factors of academic probation were revealed and educational implications of developed predictive were discussed.

Comparative Study of 4H-SiC Epitaxial Layers Grown on 4° Off-Axis Si- and C-Face Substrates Using Bistrimethylsilylmethane Precursor

Lee, Hunhee,Kim, Hyunwoo,Seo, Han Seok,Lee, Dohyun,Kim, Changhyun,Lee, Suhyeong,Kang, Hongjeon,Heo, Jaeyeong,Kim, Hyeong Joon The Electrochemical Society 2015 ECS journal of solid state science and technology Vol.4 No.8

<P>In situ H<SUB>2</SUB> etching and homoepitaxial growth of 4H-SiC have been carried out on 4° off-axis Si-face and C-face substrates by low-pressure chemical vapor deposition. We systematically analyzed H<SUB>2</SUB> etching characteristics and epitaxial growth of 4H-SiC substrates on two different polarities using an organosilicon source material, bistrimethylsilylmethane (C<SUB>7</SUB>H<SUB>20</SUB>Si<SUB>2</SUB>). The effects of the growth conditions, such as growth temperature and source flow rate on the surface morphology, crystallinity, polytype conversion, defect generation, and structural imperfection of the epilayers on different polar surfaces, were investigated. High-quality epitaxial layers were successfully grown at low temperature range of 1320–1440°C on the Si-face and 1500°C on the C-face. A low source flow rate of 5–10 sccm was also preferred to grow defect-free epilayers.</P>

전문대학생의 국어 기초학습능력 향상 프로그램의 운영 효과

김훈희 ( Hunhee Kim ) 사단법인 아시아문화학술원 2020 인문사회 21 Vol.11 No.5

본 연구의 목적은 전문대학생들의 국어 기초학습능력 향상을 위한 프로그램 운영 후, 학업적 자기효능감과 학업적 실패내성에 대한 전·후 차이를 파악하여 프로그램의 효과를 검증하는 것이다. 연구대상은 J대학 신입생 전체 학생들에게 국어 진단평가를 실시한 후 성적하위자들 중 프로그램에 참여한 48명을 최종 실험군 대상자로 선정하였다. 자료분석은 SPSS 22.0을 이용하였다. 연구결과, 자기효능감은 사전조사 시 실험군(85.81)과 대조군(84.17)에 차이가 없었지만, 사후조사에서는 실험군(94.67)과 대조군(84.62) 사이에 유의한 차이가 있었다. 실패내성은 사전조사 시 실험군(85.50)과 대조군(81.06)에 차이가 없었지만, 사후조사에서는 실험군(93.42)과 대조군(84.35) 사이에 유의한 차이가 있었다. 결론적으로, 기초학습능력 향상 프로그램은 학생들의 학업적 자기효능감과 학업적 실패내성을 높여 학교생활적응에 도움을 준다. 후속 연구에서는 학업성취의 주요 변인으로 교수·학습의 상호작용과 기초학습증진의 관련성에 대한 탐구가 필요함을 제언하였다. The purpose of this study is to analyze the effects of program to improve college students’ Korean language basic learning competencies by examining the difference of academic self-efficacy and failure tolerance. The subject of the study was constituted with 48 students among lower grades through Korean language diagnosis evaluation to all freshmen of J college. For statistical processing and analysis, SPSS 22.0 was used. As a result of the study, in self-efficacy there was no difference between experimental (85.81) and control group (84.17) at the pretest, but a significant difference between the experimental (94.67) and control group (84.62) at the posttest. In failure tolerance, there was no difference between the experimental (85.50) and control group (81.06) at the pretest, but a significant difference between the experimental (93.42) and control group (84.35) at the posttest. In conclusion, the basic learning competencies improvement program helps school adjustment by enhancing their academic self-efficacy and academic failure tolerance. In subsequent research, it is necessary to explore the effect of the interaction between the instructor and the learner.

언어네트워크 분석방법을 활용한 국내 ‘예비교사 교육’ 연구동향 분석

김훈희 ( Hunhee Kim ),권충훈 ( Choonghoon Kwon ) 아시아문화학술원 2018 인문사회 21 Vol.9 No.4

본 연구의 목적은 ‘예비교사 교육’을 주제어로 2013년부터 2017년까지 한국연구재단 등재 학술지 및 등재 후보 학술지에 게재된 연구논문들을 언어네트워크 분석방법을 활용하여 연구동향을 분석하는 것이다. 연구대상은 5개년 동안 총 1,106 편의 연구논문 제목들이다. 연구방법은 연구제목의 중심 핵심어 추출을 위해 박한우와 Loet Leydesdorff(2004)가 개발한 한국어 텍스트 분석 소프트웨어인 KrKwic(Korean Key Words in Context) 프로그램을 사용하였다. 주요 핵심어의 언어네트워크 분석 프로그램은 Analytic Technology사의 UCINET6 프로그램(ver.6.645)과 NetDraw 프로그램(ver. 2.161)이다. 연구결과는 다음과 같다. 첫째, 주요 핵심어 추출 결과는 예비유아교사(425), 예비교사(156), 예비초등교사(152), 경험(123), 교육실습(106)의 순으로 상위 출현빈도로 분석되었다. 둘째, 주요 핵심어들 간의 언어네트워크 밀도는 0.592이며, 핵심어 평균 연결정도는 23.1개 정도로 나타났다. 그리고 주요 핵심어의 언어네트워크 특성 분석을 위해 3종의 중심성(연결정도, 근접, 매개 중심성)값을 확인하고, 그 결과를 언어네트워크 지도로 제시하였다. 향후 ‘예비교사 교육’에 관한 연구동향을 학교급 별로 분석을 함으로써 교사교육 프로그램 구안에 기여를 하고자 한다. The purpose of this study is to investigate research trends in the field of preliminary teacher education by analyzing the papers published in KCI registered journals and journals for listing. The subjects of the study were 1,106 articles from 2013 to 2017 (recently 5 years). In order to extract the key words in the title of the study, KrKwic (Korean Key Words in Context), Korean text analysis software developed and distributed by Park, Han-woo and Loet Leydesdorff (2004) Program. The semantic network analysis program for major key words is the UCINET6 program (ver. 6.645) and the NetDraw program (ver.2.161). The results of the study are as follows. First, major key word extraction results were obtained from preliminary kindergarten teacher (425), preliminary (156), preliminary elementary teacher (152), experience (123), teaching practicum (106). Second, the density of semantic network among major key words is 0.592, and the average degree of major key words is about 23. In a dense network, the connections between the key words are activated and a wide variety of topics are covered. In order to analyze and present the characteristics of semantic networks of major key words, three kinds of centrality (degree, closeness, betweenness) were verified and the results were presented as a semantic network map. In the future, by analyzing research trends of preliminary teacher education based on education levels, this paper will contribute to design and develop teacher education program.

차세대 태양전지의 계면 개질 전략

임훈희(Hunhee Lim),최민재(Min-Jae Choi),정연식(Yeon Sik Jung) 한국태양광발전학회 2016 Current Photovoltaic Research Vol.4 No.3

Third-generation photovoltaics are of low cost based on solution processes and are targeting a high efficiency. To meet the commercial demand, however, significant improvements of both efficiency and stability are required. In this sense, interfacial engineering can be useful key to solve these issues because trap sites and interfacial energy barrier and/or chemical instability at organic/organic and organic/inorganic interfaces are critical factors of efficiency and stability degradation. Here, we thoroughly review the interfacial engineering strategies applicable to three representative third-generation photovoltaics - organic, perovskite, colloidal quantum dot solar cell devices.

부채널 공격에 안전한 전자서명 알고리즘 연구

이훈희(HunHee Lee),홍석희(SeokHie Hong) 한국정보보호학회 2021 정보보호학회논문지 Vol.31 No.2

부채널 공격은 수학적으로 증명된 암호 알고리즘의 안전성을 손상시킬 수 있는 강력한 기술이다. 본 논문에서는 국제 표준 디지털 서명 알고리즘인 DSA(Digital Signature Algorithm)에 대한 부채널 공격 방법과 기존 대응 방법 중 가장 안전한 Kim 등이 제안한 알고리즘을 분석 하였다. 또한, Kim 등이 제안한 알고리즘의 문제점을 개선하여 안전성은 높이고 연산량은 줄이는 새로운 DSA 서명 알고리즘을 제안한다. Kim 등이 제안한 알고리즘은 모든 오류 주입 공격에 안전하지만 전력 분석 공격에 대해서는 고려되지 않았으며, 연산량이 크다는 단점이 있다. 본 논문에서 제안하는 알고리즘은 난수 2개를 사용하여 Kim 등의 대응 방법과 유사하지만, 기존 알고리즘과 달리 서명 연산 중 비밀키 값이 난수와의 곱셈으로 수행되기 때문에 오류 주입 공격뿐만 아니라 전력 분석 공격에도 안전하며, 연산 효율은 약 34% 향상 되었다. Side channel attack is a powerful technique that can threaten the security of mathematically proven cryptographic algorithms. In this paper, side channel attack methods for DSA(Digital Signature Algorithm) and an algorithm proposed by Kim, the safest among existing countermeasures, were analyzed. In addition, a new DSA signature algorithm was proposed that increases safety and computational efficiency by improving the problems of Kim’s algorithm. The Kim’s algorithm is secure against all fault injection attacks, but it’s not considered for power analysis attacks and requires a lot of computation. The new algorithm proposed in this paper is similar to the Kim’s algorithm by using two nonce, but it’s secure against not only fault injection attacks but also power analysis attacks, because secret key is multiplied by a nonce and used to generate the signature. Also, the computational efficiency was improved by about 34% compared to the Kim’s algorithm.