Electroreflectance study of CuIn1xGaxSe2 thin film solar cells

조현준,전동환,고병수,성시준,황대규,강진규,김대환 한국물리학회 2014 Current Applied Physics Vol.14 No.3

We have investigated the optical properties of CuIn1xGaxSe2 (CIGS) thin film solar cells using their electroreflectance (ER) at room temperature. The ER spectra exhibited one broad and two narrow signal regions. Using the photoluminescence (PL) and photocurrent (PC) spectra, the peaks in the low-energy region (1.02e1.35 eV) can be assigned to the CIGS thin film. The PC results implied that the peaks in the high-energy region (2.10e2.52 eV) can be assigned to the CdS band-gap energy. Using the applied bias voltage, the broad signals in the 1.35e2.09 eV region can be assigned to the FranzeKeldysh oscillation (FKO) due to the internal electric field. The ER spectra exhibited a distorted CdS signal for the CIGS thin film solar cell with low shunt resistance and efficiency.

디킨스의 『두 도시 이야기』에 나타난 근대성과 멜로드라마

조현준 대한영어영문학회 2019 영어영문학연구 Vol.45 No.2

The paper aims to analyze the microscopic narrative so called ‘herstory,’ female or feminist viewpoints on history of modernity in terms of melodrama in The Tale of Two Cities (1859) by Charles Dickens. The historical background of The Tale of Two Cities is the revolutionary period in France and England from 1775 to 1793 including the French Revolution and the American Revolutionary War. The novel not only represents the historical development of human rights in the birth of modern subjectivity based on reason and rationality, but also releases melodramatic explosive power of extravagant emotions, feelings, and affects. The main historical drive to move rational male modern subjects like Alexandre Manette, Charles Darnay, and Javis Lorry in the turbulent era, comes from emotional female subjects like Lucie Manette and Terese Defarge. And hidden narratives of her-story control the manifested history because the decisive motives of the French Revolution and final transformation of Sydney Carton from a meaningless machine to a sacrificial Christ are derived from the herstory about Teresa’s revenge and Lucie’s love. The significance of herstory with respect to melodramatic subjective feelings can shed new light on the buried affects in the narratives under the surface of objective modern history.

중국 FTA 정책의 정치경제적 목적과 결정요인

조현준,이인구 한국동북아경제학회 2007 동북아경제연구 Vol.19 No.1

This paper examines political-economic purposes of China’s FTA policy and analyze the determinants for China to select its FTA partner countries. There are two broad categories - (1) diplomacy and security and (2) economic interest. From the first point of view, China appears to have located herself in the center of the Eurasian FTA in the long-term blueprint to parallel EU, FTAA. It appears that China want to acquire a grand-regional hegemony over the whole of Asia, through strengthening its leadership and to offset the US influences in the region to form a Sino-centric regionalism. In terms of economic interest, main concerns include: securing energy and raw material sources overseas; evading trade dispute; inducing recognition of China’s MES(Market Economy Status); enhancing industrial competitiveness; facing pressure from the US on trade sanctions against China; and promoting the West China and Northeast China development, etc. China seems to prioritize FTA partner countries among the countries in the vicinity, developing countries or third world countries and non Western ones. More specifically, China tends to prioritize countries that can be used as roundabout routes for its export to the western markets, countries that will help China to secure sources for energy and raw materials, and also those that can give an edge to the enhancement of industrial competitiveness and promotion of the West and Northeast China development. As to Sino-Korea FTA, China’ purposes appear to be centered on non-economic factors, rather than economic interest. Especially, China appears to pay heed to a leadership in intra-regional FTA initiatives, being afraid of losing initiative to the US or Japan.

UMTS의 DSCH를 위한 패킷 스케줄링 모의실험 모델

조현준 전주대학교 공학기술종합연구소 2002 전주대학교 공학기술종합연구소 학술논문집 Vol.8 No.1

As wireless networks resources are expected to be limited for the multimedia services, we need to develop the effective packet scheduling algorithms for wireless networks to provide required QoS (Quality of Service). Recently, UMTS(Universal Mobile Telecommunications System) is recognized as a standard for 3rd generation of wireless networks and DSCH(Down-link Shared Channel) is very effective multiplexing method in UMTS. So, it is inevitable to develope an effective packet scheduling algorithms for DSCH in UMTS. This paper describes n simulation model for the performance analysis of packet scheduling algorithms in DSCH. The model consists of wireless network module, flows manager module and traffic generator module. For the verification of the simulation model, the simulator based on the model is implemented by PARSEC simulation tool and the results are compared with known performance characteristics.

바실러스 서브틸리스 유래 내생포자 표면 단백질 A를 이용한 매개체 활용 락케이즈 반응 기반 아플라톡신 B1 육안 검출법

조현준,하준모,김소영,김영완 한국식품과학회 2023 한국식품과학회지 Vol.55 No.6

This study presents a visual detection method for aflatoxin B1 (AFB1) based on mediator-assisted laccase reaction for AFB1 oxidation. After complete oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) by an endospore coat protein A from Bacillus subtilis at pH 4, subsequent supplementation of AFB1 as the analyte in 160 mM NaOH led to decolorization through the reaction with AFB1 without re-oxidation of the reduced ABTS. Due to the reaction at a double ratio of oxidized ABTS radical and AFB2, complete decolorization was observed in the samples containing AFB1 higher than the half concentration of the subjected ABTS. Upon employing 30 μM ABTS, the decolorization in the samples containing AFB1 higher than 20 μM could be recognized with the naked eye. Although the lowest detection criterion is quite high compared to the regulation levels for AFB1, the visual detection method used in this study shows a potential as an on-site quality control method for AFB1.

플라즈마 처리된 CIGS 박막으로 제작된 태양전지의 특성 연구

조현준,배인호,고병수 한국물리학회 2012 New Physics: Sae Mulli Vol.62 No.2

RF plasma treatments of CIGS thin films grown by using the co-evaporation process were performed with Ar, O_2 and N_2gases, respectively. After plasma treatments, solar cells with Al:ZnO/i-ZnO/CdS/CIGS structures were fabricated. The surface structures of the CIGS thin films after plasma treatments were investigated with SEM and AFM measurements, and the electrical properties of manufactured solar cell are discussed based on the current-voltage measurement. In the Ar plasma treatment, the open-circuit voltage decreased more compared with the other reaction gases. In O_2 and N_2, plasma gases reacted with defects on the CIGS surface; consequently, surface defects decreased. A carrier type inversion in the near-surface region of the CIGS thin film occurred for the N_2 plasma treatment. 동시 증발법(co-evaporation)으로 Mo이 증착된 소다라임(soda lime) 유리위에 성장시킨 CIGS 박막을 Ar, O_2 및 N_2 분위기에서 각각 RF 플라즈마 처리하였다. 플라즈마 처리 후 태양전지 특성 연구를 위하여Al:ZnO/i-ZnO/CdS/CIGS 구조로 제작하였다. 플라즈마 처리에 따른 CIGS 박막의 표면 변화를 SEM 및 AFM 측정으로 관측하였으며, 제작된태양전지는 전류-전압 측정으로 전기적인 특성을 조사하였다. Ar 플라즈마 처리된 태양전지의 개방전압 저하효과가 가장 크게 나타났으며,반응성 가스인 O_2 및 N_2 플라즈마의 경우 CIGS 박막 표면의물리적인 특성을 변화시켰다.

CdS/CIGS 박막의 열처리 온도에 따른 Photoluminescence 특성

조현준,김대환,최상수,배인호 한국진공학회 2011 한국진공학회 학술발표회초록집 Vol.41 No.-

國外旅行 引率者의 專門職化에 관한 硏究

조현준 한국관광학회 1998 관광학연구 Vol.22 No.2

방사성폐기물 처리용 대용량 유리용융로 개발

조현준,김천우 한국방사성폐기물학회 2015 한국방사성폐기물학회 학술논문요약집 Vol.2015 No.05

A comparative study of teaching-learning-self-study algorithms on benchmark function optimization

조현준,Faisal Ahmed,김태영,김범석,여영구 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.3

In typical optimization problems, the number of design variables may be large and their influence on the specific objective function can be complicated; the objective function may have some local optima while most chemical engineers are interested only in the global optimum. For any new optimization algorithms, it is essential to validate their performance, compare with other existing algorithms and check whether they provide the global optimum solutions, which can be done effectively by solving benchmark problems. In this work, seven typical optimization algorithms including the newly proposed TLBO (Teaching-learning-based optimization) based algorithms such as the TLSO (Teaching-learning-self-study optimization) algorithm have been reviewed and tested by using a set of 20 benchmark functions for unconstrained optimization problems to validate the performance and to assess these optimization algorithms. It was found that the TLSO algorithm shows the fastest convergence speed to the optimum and outperforms other algorithms for most test functions.