2차 버퍼층 ZnMgO 박막의 Mg/(Mg+Zn) 비율 조절을 통한 SnS 박막 태양전지 효율 향상

이효석,조재유,윤성민,정채환,허재영,Lee, Hyo Seok,Cho, Jae Yu,Youn, Sung-Min,Jeong, Chaehwan,Heo, Jaeyeong 한국재료학회 2020 한국재료학회지 Vol.30 No.10

In the recent years, thin film solar cells (TFSCs) have emerged as a viable replacement for crystalline silicon solar cells and offer a variety of choices, particularly in terms of synthesis processes and substrates (rigid or flexible, metal or insulator). Among the thin-film absorber materials, SnS has great potential for the manufacturing of low-cost TFSCs due to its suitable optical and electrical properties, non-toxic nature, and earth abundancy. However, the efficiency of SnS-based solar cells is found to be in the range of 1 ~ 4 % and remains far below those of CdTe-, CIGS-, and CZTSSe-based TFSCs. Aside from the improvement in the physical properties of absorber layer, enormous efforts have been focused on the development of suitable buffer layer for SnS-based solar cells. Herein, we investigate the device performance of SnS-based TFSCs by introducing double buffer layers, in which CdS is applied as first buffer layer and ZnMgO films is employed as second buffer layer. The effect of the composition ratio (Mg/(Mg+Zn)) of RF sputtered ZnMgO films on the device performance is studied. The structural and optical properties of ZnMgO films with various Mg/(Mg+Zn) ratios are also analyzed systemically. The fabricated SnS-based TFSCs with device structure of SLG/Mo/SnS/CdS/ZnMgO/AZO/Al exhibit a highest cell efficiency of 1.84 % along with open-circuit voltage of 0.302 V, short-circuit current density of 13.55 mA cm^-2, and fill factor of 0.45 with an optimum Mg/(Mg + Zn) ratio of 0.02.

원발급성폐쇄각발작에서 스펙트럼 빛간섭단층촬영을 이용한 황반부 신경절세포-내망상층의 두께변화

이효석,박용석,박상우,Hyo Seok Lee,Yong Seok Park,Sang Woo Park 대한안과학회 2014 대한안과학회지 Vol.55 No.8

Purpose: This study was conducted to measure macular ganglion cell-inner plexiform layer (mGC-IPL) thickness in patients with a history of unilateral single attack of acute primary angle closure (APAC) and to compare it with that of unaffected fellow eyes 8 weeks after resolution using spectrum domain optical coherence tomography (SD-OCT). Methods: Medical records of 24 patients with history of first episode of unilateral APAC were reviewed retrospectively. Eight weeks after APAC, mGC-IPL thickness and peripapillary retinal nerve fiber layer thickness were measured with SD-OCT and analyzed in eyes affected by APAC (group 1) and fellow eyes (group 2). Results: There were no significant differences between the groups with regard to best corrected visual acuity, spherical equivalent, central corneal thickness, or axial length (<em>p</em> > 0.05). There were no significant differences in mGC-IPL thickness in the superotemporal, superior, or superonasal sectors (<em>p</em> > 0.05). However, average, inferonasal, inferior, and inferotemporal sectors of group 1 were significantly thinner than those of group 2 (<em>p</em> = 0.002, 0.002, 0.001, 0.001, respectively). In addition, average mGC-IPL difference between affected eyes and fellow eyes showed a statistically significant correlation with attack duration (correlation coefficient = 0.249, <em>p</em> = 0.019). Conclusions: Normalization of elevated intraocular pressure as soon as possible after APAC onset is recommended in order to reduce mGC-IPL loss, and measurements of mGC-IPL thickness can be helpful for follow-up of APAC patients. J Korean Ophthalmol Soc 2014;55(8):1167-1173

수포각막병증에서 치료레이저각막절제술의 단독시행 또는 양막이식술과 동시시행의 치료효과 비교

이효석,오한진,윤경철,Hyo Seok Lee,Han Jin Oh,Kyung Chul Yoon 대한안과학회 2013 대한안과학회지 Vol.54 No.8

Purpose: We evaluated the therapeutic effects of phototherapeutic keratectomy (PTK) with or without amniotic membrane transplantation (AMT) in patients who had symptomatic bullous keratopathy with poor visual potential. Methods: Twenty-five eyes of 25 patients with bullous keratopathy were reviewed retrospectively. Ten eyes (group A) were treated with PTK, and the other 15 eyes (group B) were treated with combined PTK and AMT. Changes of vision and symptoms, re-epithelization time, recurrence of bulla, central corneal thickness measured by anterior segment optical coherence tomography, and postoperative complications were analyzed. Results: At post-operative 3 months, visual acuity improved in 2 patients in both A and B groups. Nine patients in group A (90%) and 13 patients in group B (86.7%) showed symptom improvement. Mean re-epithelization time was 12.40 ± 4.33 days in group A and 8.13 ± 1.19 days in group B (p > 0.05). In both groups, central corneal thickness decreased postoperatively without statistically significant difference between groups. At the final follow-up visit, epithelial bulla had not recurred in 7 eyes (70.0%) in group A and 12 eyes (80.0%) in group B. No postoperative complication was detected. Conclusions: PTK alone appears comparable to the combined treatment of PTK and AMT in terms of symptom improvement, re-epithelization time and recurrence rate.

주파수변화에 따른 콘크리트 FRP 보강 구조물의 박리탐사 연구

이효석(Lee Hyo-Seok),임홍철(Rhim Hong-Chul),우상균(Woo Sang-Kyun),송영철(Song Young-Chul) 한국구조물진단유지관리학회 2006 한국구조물진단학회 학술발표회논문집 Vol.10 No.1

With a growing concern about the state of infrastructure worldwide, the demand for the development of reliable nondestructive testing techniques (NDT) is ever increasing. Among possible NDT techniques, microwave method is proven to be effective in fast and non-contact inspection of concrete structures and inclusions inside concrete. It is also found that the microwave method has a potential in detecting the delamination between fiber reinforced polymer (FRP) plate and concrete. On the other hand, ultrasonic method can be another way to find the delamination. In this paper, the research work needed for the development of a reliable microwave method and ultrasonic method is studied in actual measurements of concrete specimens reinforced with FRP. Concrete specimens are made with FRP and artificial delamination inside. A microwave measurement system with horn antennas with high center frequency and broad frequency bandwidth are used to image inside concrete specimens for the detection of debonding between concrete and FRP. Also, the equipment of ultrasonic method which is commercialized are used at the same condition. Both of the results are analyzed in comparison of each other. Microwave and ultrasonic methods have been used for the detection of debonding between concrete and fiber-reinforced plastic (FRP).

미국 문화전쟁의 애국주의적 기원과 영어에 대한 인식의 문제

이효석(Lee, Hyo-Seok) 부산대학교 인문학연구소 2013 코기토 Vol.- No.74

From the beginning of its history, the U. S. has been a multi-ethnic nation composed of immigrants from all of the world. Its ruling elite have tried ‘to Americanize’ them into one by the banner of ‘E Pluribus Unum’, that is, ‘One Out of Many.’ For the government, the English language seemed to be a means to unite all the citizens of various ethnic and cultural origins. The ‘culture war’ between multiculturalists and monoculturalists has been fought in America for a long time. Theodore Roosevelt, the 26th American president, was one of the politicians who try to repudiate the other cultures and languages and to prohibit non-English speakers from voting. Only by one language, he thought, can America be united to one great nation. Likewise, Samuel Huntington believes that advocates of multiculturalism and diversity are kinds of anti-western ideologues. His arguments seem to force immigrants or aliens to learn English and to be assimilated into the culture of WASP. This paper makes a general survey of the phases of the culture war between the American intellectuals since the 1980s, and tries to explain the monoculturalist arguments to be a replica of that of Roosevelt. In this sense, Henry James was more open than his contemporaries including Roosevelt who criticized severely the novelist.

윌리엄 골딩의 『파리대왕』 : 현대정치와 시뮬라시옹 Modern Politics of Simulation

이효석 ( Hyo Seok Lee ) 한국현대영미소설학회 2007 현대영미소설 Vol.14 No.1

브렌든 비언의 『인질』과 탈식민 주변부 작가의 곤경

이효석 ( Hyo Seok Lee ) 한국제임스조이스학회 2014 제임스조이스저널 Vol.20 No.2

A writer, in the postcolonial situation, may be faced with difficult missions of resisting to the colonization on the one hand, and struggling against the top-down elite of his nation. Brendan Behan, for example, was fighting against both ideologies of imperialism and nationalism, when he turned himself from a IRA soldier into a dramatist. This predicament seems to be the same with other writers from the former colonial nations of Asia, Africa, Latin America, etc. Why didn’t he hide the hot hostility to the new governments of Eamon de Valera and Cosgrave, not to mention of England? It is because the Irish leaders could not show their ability to satisfy the material and spiritual poverty of the people, while oppressing and depressing them by censoring and arresting the opposing citizens. In The Quare Fellow and The Hostage, the postcolonial regimes of Ireland followed the same bad manners of imperial social system and continued the dissatisfaction and discontent of the Irish people. Behan, in his The Hostage, is telling us three points: first, it is inappropriate for a nation after independence to resort to the nationalist and imperialist dichotomy of enemy and friend. Second, the postcolonial movement of a nation should begin with political, economical, and cultural democratization. Last, the new order of postcolonial nation should not discriminate those minorities for their marginalities such as whores, aliens, homosexuals, and black people: Colette, the Russian sailor, Rio rita, Princess Grace in The Hostage should have their own seat in the new society.

마르틴 오 카인의「브라이트시티로 가는 길」

이효석(Lee, Hyo-seok) 새한영어영문학회 2013 새한영어영문학 Vol.55 No.2

The purpose of this paper is to understand the reality of the Irish peasants and women misunderstood both by the myth of Irish nationalism and by the prejudice of British imperialism through Mairtin O Cadhain’s “The Road to Brightcity.” It is well known that till the early nineteenth century the popular British media tended to represent the Irish peasant as “Paddy,” a comic, drunken buffoon. The picture of Irish peasant, however, was turned from the middle of the century to that of a dangerous subhuman, a White Negro or the human chimpanzee. To the British public the peasant incarnated the barbarism and savagery of Irish rural life. But the Irish nationalist discourse challenged the dehumanized picture by the English; it began to portray the peasant as a noble, honest, and organic. They became a spiritual figure, the archetype of the Celtic Ireland. From Pan-Celtic movement, through Gaelic League and Literary Revival, the peasant appeared to be the source of imagination for reviving and revitalizing the colonial Ireland. “The Road to Brightcity,” set in the time around the First World War and the Irish War of Independence, shows the reality of the life-world of Irish peasantry through the tragic-comic journey to Brightcity by Brid, a young peasant woman. Signified by the “crucifying” walk to the city, her life implies that the peasant community is located between hope and despair, life and death, joy and terror, restraint and desire, holy and worldly, reality and fantasy, individual and community, nature and civilization, etc. O Cadhain wants to tell us that the world of peasant society is neither barbaric nor mythic, as imagined respectively by the Irish patriotic nationalists and the British ethnic imperialist. He knows that its tradition is invaded both by the threatening wave of civilization and materialism, and also by myth and prejudice.

독점규제법상 차별취급의 부당성 판단기준

이효석 ( Hyo Seok Lee ) 한국경쟁법학회 2012 競爭法硏究 Vol.25 No.-

BIM기반 물량산출 가이드라인 체계구축을 위한 공종분류체계에 대한 연구

이효석(Lee, Hyo-Seok),배재훈(Bae, Jae-Hoon),김성연(Kim, Sung-Yeon),한충희(Han, Choong-Hee),이준복(Lee, Jun-Bok) 대한건축학회 2013 대한건축학회 학술발표대회 논문집 Vol.33 No.2