화합물 박막 태양전지 적용을 위한 CuInS₂ 나노분말의 제조 및 특성 평가

이대걸(Dae-Girl Lee),이남희(Nam-Hee Lee),오효진(Hyo-Jin Oh),윤영웅(Yeong-Ung Yun),황종선(Jong-Sun hwang),김선재(Sun-Jae Kim) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.7

Chalcopyrite based sollar cells have received much attention because of their tunable electronic and optical properties. As a typical ternary chalcopyrite material, CuInS₂ has been considered as one of the most popular and promising candidates as absorber materials for photovoltaic applications because of its high absorption coefficient and environmental consideration. In this study, CuInS₂ powders have been synthesized using polyol process of a mixture of copper nitrate, indium nitrate, and thiourea with various stoichiometric molar ratios in ethylene glycol at 196℃. As boiling time goes by, the color of metal ion mixed solutions were changed transparent green to dark green and finally turned to black by reduction of OH- radicals. The prepared powders were fully characterized using SEM, XRD. The particle shape of black colored powders showed sphere with about 50 ㎚ in particle size compared to those with dark green colored powders showed irregular shape with about 1 ㎛ in particle size. The XRD results showed highly crystallized CuInS₂.

Polyol process를 이용한 태양전지용 CulnS₂ 나노분말 제조 및 특성평가

이대걸(Dae-Girl Lee),이남희(Nam-Hee Lee),오효진(Hyo-Jin Oh),윤영웅(Yeong-Ung Yun),황종선(Jong-Sun hwang),김선재(Sun-Jae Kim) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.4

In this study, CuInS₂ powders have been synthesized using polyol process of a mixture of copper nitrate, indium nitrate, and thiourea with various stoichiometric molar ratios in ethylene glycol at 196℃. As boiling time goes by, the color of metal ion mixed solutions were changed transparent green to dark green and finally turned to black by reduction of OH? radicals. The prepared powders were fully characterized by SEM, XRD and UV-Vis. The particle shape of black colored powders showed sphere with about 30 ㎚ in particle size compared to those with dark green colored powders showed irregular shape with about 1 ㎛ in particle size. The XRD results showed highly crystallized CuInS₂. The UV?, Vis spectra showed broad shoulder at 430 and 780 ㎚ corresponding to 2.78 and 1.58 eV for the dark green colored one and black colored one, respectively.

신이식 초기에 발견된 Parvovirus B19 감염에 의한 순수 적혈구 무형성증

오효진 ( Hyo Jin Oh ),천종운 ( Jong Woon Cheon ),안동직 ( Dong Jik Ahn ),김상경 ( Sang Gyung Kim ),안기성 ( Ki Sung Ahn ),이인희 ( In Hee Lee ) 대한신장학회 2005 Kidney Research and Clinical Practice Vol.24 No.3

저시력 장애인을 위한 객체인식 기반의 AR 보행 앱 설계 및 구현

오효진 ( Hyo-jin Oh ),김채연 ( Chae-yeon Kim ),박주하 ( Ju-ha Park ),이혜빈 ( Hye-bin Lee ),임양규 ( Yang-gyu Lim ) 한국정보처리학회 2023 한국정보처리학회 학술대회논문집 Vol.30 No.2

시각장애인의 독립보행은 많은 위험 부담과 어려움을 안고 있다. 본 연구는 이러한 어려움을 해결하고자 사용자에게 GPS를 통해 목적지까지 안전한 경로로 안내하는 기능을 제공한다. 사물 인식 알고리즘을 통해 주행 시 필요한 장애물 판별과 신호등의 색상 등을 인식한다. 그리고 아두이노 초음파 센서를 활용하여 장애물과 사용자 간의 거리를 인식하고, 블루투스 모듈을 통해 측정한 값을 송신하여 구간별에 따라 사용자에게 경고음을 울린다. 더 나아가 AR 기능을 통해서 장애물을 입체적으로 강조하여 표시함으로써 저시력 장애인들이 장애물과 충돌하는 것을 예방한다.

Titanate nanotube를 이용한 ECD의 전기화학적 특성연구

오효진(Hyo-Jin Oh),이남희(Nam-Hee Lee),이대걸(Dae-Girl Lee),윤영웅(Yeong-Ung Yun),황종선(Jong-Sun Hwang),김선재(Sun-Jae Kim) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.7

전압을 인가하였을 때 전계방향에 의해 가역적으로 색이변화하는 현상을 전기변색(electrochromism)이라고 한다. 이러한 전기채색현상을 보이는 물질을 전기채색물질(electrochromism materials)이라고 하며, 전기채색 물질에 의한 소자를 전기채색소자(electrochromism device : ECD)라고 한다. 전기채색현상은 투과율(transmittance), 반사율 (reflectance)의 가역적이며 가시적인 변화이고, 전기화학적인 산화환원 반응과 관련이 있다. 따라서 본 연구에서는 Titanate nanotube(TNT)를 제조하고 전기변색 소자(ECD)에 응용하였다. SEM, XRD, UV-Vis등을 이용하여 재료학적 분석을 시행하였으며, 전기화학적 테스트로 cyclic voltammetry를 측정 하였다. 그 결과 TNT 분말은 직경 약 20 ~ 30 ㎚, 길이 약 500 ~ 600 ㎚ 의 입자형상을 나타내었으며, X-선 회절시험결과 H₂Ti₂O? · H₂O의 층상구조를 나타내었다. 제조된 막은 FTO glass 위에 PEI/(TNT/TBAOH)n-1/PDDA의 순으로 코팅되었다. 전기화학적 테스트를 위하여 2전극 시스템을 제작하였으며, 여러 종류의 액체 전해질을 제작하여 cycle voltammetry를 시행하였다. 그 결과, 각각의 전해질에서 “-”영역의 산화환원전위 피크가 뚜렷하게 나타났으며, 짙은 갈색으로의 채색현상을 나타냈다. 본 연구의 결과로서 TNT 박막을 이용한 ECD은 광조절 유리로서 뿐만 아니라, 여러 전기채색 디바이스에 응용될 것으로 사료된다.

초등 저학년 단순언어장애 아동의 읽기능력

오효진(Hyo Jin Oh),이윤경(Yoon Kyoung Lee) 한국언어치료학회 2007 言語治療硏究 Vol.16 No.4

The purpose of this study was to investigate word recognition and reading comprehension ability of children with specific language impairments and the relationship between reading comprehension and word recognition and language skills. The participants were 8 lower graders with specific language impairments in elementary school and 8 normal children that matched on chronological age with children with specific language impairments. Two reading tasks(word recognition and reading comprehension task) and two language tasks(vocabulary and the syntax comprehension test) were used. Result of this study were as fallows: First, Children with specific language impairment were showed significantly lower performance than normal children in word recognition task. Children with specific language impairment was showed significantly lower performance grapheme-phoneme non-correspondent than grapheme -phoneme correspondent as normal children. Second, Children with specific language impairment were showed significantly lower performance than normal children in reading comprehension task. Reading comprehension were significant differences depending on reading tasks. Two groups were showed lower performance the passage comprehension than the sentence comprehension task. Third, there were correlations between reading comprehension, word recognition and language skills in two groups. The correlation was strong between reading comprehension nd word recognition and between word recognition and vocabulary in children with specific language impairments.

노동법을 보완하는 노동조례의 사례와 특성

오효진(Oh, Hyo-jin) 경기연구원 2019 GRI 연구논총 Vol.21 No.4

Labor law has modified the principles of modern civil law to ensure the equal balance of bargaining power between employees and employers, thus ensuring the human dignity of employees. However, globalization, neo-liberalism and technological progress have shown limitations of the protection system of labor law, resulting in skepticism about the role of labor law. This study seeks to explore the potential of the labor ordinances as an alternative to complement labor law through examples and characteristics of the labor ordinances enacted reflecting the economic and social situation related to the crisis that labor law is experiencing recently. First of all, this study examines the legislative intent and substances of the following ordinances respectively : living wage ordinance, employee directors ordinance, freelance ordinance and ordinance of labor human rights education. Subsequently, this thesis discuss the characteristics of the labor ordinances suitable for supplementing the labor law, which enables faster legislation and application than an act, ensures the improve worker protection, makes various legislative attempts reflecting local nature, and contributes to the actual implementation of participatory democracy. On the other hand, limiting features of the labor ordinances in supplementing labor law are suggested, which are the constraint of subjects of the labor ordinances, the difficulty in securing the binding force in the private sector, and the lack of stability and systemicity. And alternatives to overcome these problems are followed also. The conclusion argues that, despite its limitations, labor ordinances legislation can function as a complementary alternative to the crisis of labor law and explains the need for active legislative action through the role and solidarity of local workers and civic groups.

컨테이너 종합운송물류체인 평가를 위한 개념적 모형

오효진(Hyo-Jin Oh),송용석(Yong-Seok Song),김태원(Tae-Won Kim),남기찬(Ki-Chan Nam) 한국항해항만학회 2003 한국항해항만학회 학술대회논문집 Vol.3 No.-

Thanks to the theory of the economics of scale, container vessel has been getting bigger and bigger, leading to the launching of 8,000 TEU vessels recently and the getting 10,000 TEU vessels on drawing table. However, the economics of container transportation needs to be evaluated with respect to the total transport chain including shipping, port, feeder and inland transport sector. This paper, therefore, tries to present the conceptual models for the evaluation of container transport chain including mega vessels over 10,000 TEU. 해상 구간에서의 선박 운항과 관련된 단위 비용이 선박 대형화에 비례하여 감소한다는 규모의 경제에 근거하여 최근 8,000 TEU급 선박이 운항을 개시하였고, 10,000 TEU급 이상 초대형선(mega ship)이 설계 단계에 있다. 그러나, 컨테이너 운송의 경제성은 해상 운송 뿐만 아니라 피더 및 내륙 운송 비용 등을 포함하는 총비용 관점에서 고려되어야 한다. 이러한 측면에서 본 논문은 기존 컨테이너 선박과 최근 운항을 개시한 8,000 TEU급 선박 그리고 설계 단계에 있는 10,000 TEU급 이상의 초대형 선박을 대상으로 경제성 및 서비스 수준을 평가하기 위한 개념적인 모형을 제시하는 것을 목적으로 한다.

전기변색 TNT 박막의 제조 및 특성 평가

오효진(Hyo-Jin Oh),이남희(Nam-Hee Lee),윤영웅(Yeong-Ung Yun),이대걸(Dae-Girl Lee),황종선(Jong-Sun Hwang),김선재(Sun-Jae Kim) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.4

본 연구에서는 Titanate Nanotube (TNT)를 LBL-SA (layer-by-layer self-assembling) method을 이용하여 전기변색 (electrochromism device, ECD) 소자에 적 용하고자 하였다. TNT 분말은 10M NaOH와 TiO₂를 혼합한 후 autoclave에서 130℃, 48시간 동안 수열합성하여 제조하였다. 주사전자현미경 (SEM)으로 TNT 분말의 형상을 관찰한 결과, 직경 20~30㎚, 길이 500~600㎚의 튜브 형상을 나타내었으며, X-선 회절시험 (XRD) 결과 층상구조로 확인되었다. 코팅 물질의 표면 전하를 이용한 LBL-SA method에 적용시키기 위해 수용액 중에서 TNT 업자 표면 전하를 TBAOH (tetrabutlammonium hydroxide)를 적정하여 제타 전위 값이 -40㎷로 최대가 되도록 하였으며, 이때 pH 값은 9로 나타났다. 2전극 시스템을 이용하여 cycle voltammetry를 측정한 결과, -0.5~1.5V 영역에서 산화환원전위 피크가 뚜렷하게 나타났으며, 짙은 갈색으로 변색되는 것을 확인하였다. 본 연구 결과로서 TNT 박막은 전기를 인가하였을 때 n-type 반도체 성질을 갖는 것으로 나타났으며, 앞으로 display 연구 분야에 적용할 수 있을 것으로 주목된다.

잉크젯 프린팅을 이용한 초박막 투명 TiO₂ 코팅층 제조

윤초롱(Cho-Rong Yoon),오효진(Hyo-Jin Oh),이남희(Nam-Hee Lee),Guo Yupeng,이원재(Won-Jae Lee),박경순(Kyeong-Soon Park),김선재(Sun-Jae Kim) 한국표면공학회 2007 한국표면공학회지 Vol.40 No.4

Dye sensitized solar cells(DSSC) are the most promising future energy resource due to their high energy efficiency, low production cost, and simple manufacturing process. But one problem in DSSC is short life time compared to silicon solar cells. This problem occurred from photocatalytic degradation of dye material by nanometer sized TiO₂ particles. To prevent dye degradation as well as to increase its life time, the transparent coating film is needed for UV blocking. In this study, we synthesized nanometer sized TiO₂ particles in sols by increasing its internal pressure up to 200 bar in autoclave at l20℃ for 10 hrs. The synthesized TiO₂ sols were all formed with brookite phase and their particle size was several ㎚ to 30 ㎚. Synthesized TiO₂ sols were coated on the backside of fluorine doped tin oxide(FTO) glass by ink jet printing method. With increasing coating thickness by repeated ink jet coating, the absorbance of UV region (under 400 ㎚) also increases reasonably. Decomposition test of titania powders dispersed in 0.1 mM amaranth solution covered with TiO₂ coating glass shows more stable dye properties under UV irradiation, compared to that with as-received FTO glass.