• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.104.1-104.1
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• 2011

가볍고, 유연성(flexibility)을 갖는 박막(thin film)형 플랙서블 태양전지(flexible solar cell)는 상황에 따른 형태의 변형이 가능하여, 휴대가 간편하고, 기존 혹은 신규 구조물의 지붕(rooftop)등에 설치가 용이하여, 차세대 성장 동력 분야에서 각광받고 있다. 그러나 아직까지 플랙서블 태양전지는 제작시 열에 의한 기판의 변형, 기판 이송시 너울 현상, 대면적 패터닝(patterning) 기술 등 많은 어려움 등으로 웨이퍼나 글라스 기판에 제조된 태양전지 대비 낮은 광전환 효율을 갖는다. 따라서 본 연구에서는 플랙서플 태양전지 성능개선을 위해 3.5세대급 ($450{\times}450cm^2$) 스퍼터(sputter), 금속유기 화학기상장치 (MOCVD), 플라즈마 화학기상장치 (PECVD), 레이저 가공장치 (Laser scriber)를 이용하여 a-Si:H/a-SiGe:H 이중접합(tandem)을 갖는 태양전지를 제작하였고, 광 변환효율 특성을 평가하였다. 전도도(conductivity), 라만(Raman)분광 및 UV/Visible 분광 분석을 통하여 박막의 전기적, 구조적, 광학적 물성을 평가하여 단위박막의 물성을 최적화 했다. 또한 제작된 태양전지는 쏠라 시뮬레이터 (Solar Simulator)를 이용하여 성능 평가를 수행하였고, 상/하부층의 전류 정합 (current matching)을 위해 외부양자효율 (external quantum efficiency) 분석을 수행하였다. 제작된 이중접합 접이식 태양전지로 소면적($0.25cm^2$)에서 8.7%, 대면적($360cm^2$ 이상) 8.0% 이상의 효율을 확보하였으며, 성능 개선을 위해 대면적 패턴 기술 향상 및 공정 기술 개선을 수행 중이다.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.411-412
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• 2013

최근 UV LED는 생화학 및 의료 산업에서 많은 각광을 받고 있다. 특히, 360nm 이하의 파장대를 갖는 UV LED는 치료 기술, 센서, 물이나 공기 등의 정화와 같은 목적으로 특별한 관심이 쏠리고 있다 [1]. 이러한 지속적인 연구를 통하여 현재까지 UV LED는 거대한 성장을 이루어 왔다. 하지만 이러한 노력에도 불구하고, 360 nm 이하의 UV LED는 여전히 오믹 접촉과 전류 분산이 원활하지 못하다는 문제점을 가지고 있다. 이것은 UV LED의 외부 양자 효율을 감소시키고, 더 나아가 극도로 낮은 광 추출 효율을 초래한다. 최근 이러한 문제를 해결하고자, 투명 전도성 산화물(TCO)을 금속 전극과 p-AlGaN 사이에 삽입해주는데, 현재 가장 널리 사용되는 TCO 물질은 ITO 이다 [2]. 하지만 ITO 물질은 상대적으로 작은 밴드갭(3.3~4.3 eV)과 단파장 빛이 가지는 큰 에너지로 인하여 deep-UV 영역에서는 빛이 투과하지 못하고 대부분 흡수된다 [3]. 따라서 본 연구에서는 기존의 박막형 ITO 투명 전극에 비해 투과도 손실을 최소화할 수 있는 mesh, grid 기반의 투명전극을 연구하였다. Fig. 1과 같이 $5{\mu}m$, $10{\mu}m$, $20{\mu}m$ 간격으로 이루어진 mesh, grid 구조의 투명전극을 구현하여 투과도 손실을 최소화하면서 우수한 전기적 특성을 확보하기 위한 구조 최적화 연구를 진행하였다. 본 연구를 위해 mesh, grid 구조의 ITO 전극 패턴을 photolitho 공정으로 형성하였으며, e-beam 증착법으로 60 nm 두께의 ITO 전극을 형성 후 질소 분위기/$650^{\circ}$에서 30초 동안 RTA 공정을 진행하였다. Fig. 1에서 볼 수 있듯이 mesh, grid의 간격이 증가할수록 투명 전극이 차지하는 면적이 감소하여 투과도는 향상되는 반면, 투명 전극과 p-GaN과의 접촉 면적 또한 감소하므로 오믹 특성이 저하된다. 따라서 투과도 손실을 최소화하면서 우수한 전기적 특성을 확보하기 위해 mesh는 $20{\mu}m$, grid는 $10{\mu}m$ 간격의 구조로 각각 최적화하였다. 그 결과 박막 기반의 ITO 투명전극 대비 최대 약 10% 향상된 투과도를 확보하였으며, I-V Curve 결과를 통하여 p-GaN 기판과 mesh 구조의 ITO 전극 사이에 박막 기반의 투명 전극과 비슷한 수준인 $0.35{\mu}A(@5V)$의 전기적 특성을 확보하였다. 결과적으로 mesh, grid 기반 투명전극의 구조 최적화를 통하여 p-GaN과 원활한 오믹 접촉을 형성하는 동시에 기존 박막형 ITO 투명 전극 구조보다 높은 투과도를 확보할 수 있었다.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.62-62
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• 2012

지구온난화 및 환경오염의 영향으로 선진국을 중심으로한 환경규제가 심해지면서, 홈 텍스타일 분야에서는 세계 패션 트렌드 및 소비자 선호에 부응한 친환경 섬유소재 개발, 웰빙 시대에 적합한 기능성 및 고감성 제품개발을 통한 차별화가 요구되고 있다. 최근의 섬유산업의 동향도 인체에 무해한 천연적인 섬유소재에 많은 관심이 증대됨에 따라 개인의 건강 뿐만 아니라 환경을 생각하는 생활패턴인 친환경섬유의 개발이 새로운 트렌드로 떠오르고 있는 실정이다. 헴프는 일년생 식물로서 학명은 Cannabis sativa L.이다. 헴프섬유의 장점으로 내구성 및 내수성, 항균성 등이 우수한 것으로 보고되고 있으나 양질의 원료 확보, 세섬도 추출 기술 및 combing 기술 등의 부족으로 100% 헴프 세 번수 방적사의 제조가 어려워 주로 면섬유와의 혼합소재로 제조되어 왔다. 최근 들어, 친환경 소재로서 박테리아 성장 억제 기능을 가진 재생섬유인 Tencel 소재를 이용하여 stiff한 Hemp의 성질에 유연성을 추가하여 촉감을 개선함과 동시에, Tencel과 Hemp를 혼용함으로써 soft touch부터 harsh touch까지 혼용율에 의한 다양한 감성을 느끼게 함으로써 용도의 다양화 추구가 시도되어 왔다. Hemp의 거친 느낌을 완화시키고 Tencel의 박테리아 억제 기능과 Hemp의 항균기능, 방충, 탈취기능이 상호 보완되어 친환경적이고 위생적인 다용도 홈 인테리어 및 가구용 직물 등의 제품으로 Hemp/Tencel 복합사가 많이 사용되고 있다. 본 연구는 Hemp와 Tencel의 혼용율의 변화에 따른 복합사의 물리적 특성을 확인하기 위하여 천연복합 태번수 방적사 최적 사설계 이론을 적용하여 Hemp 섬유 혼용율에 따른 사의 물성분석을 함으로써 Hemp/Tencel 방적사 최적 공정 조건을 결정하기 위한 사설계 이론 결과와 실험결과를 비교 분석하고자 한다. 최적 천연 Hemp복합방적사 사설계의 이론화 및 사 물성 DB화 그리고 태번수 Hemp사의 물성분석 및 이들을 DB화 함으로써 가구용 직물로 많이 사용되는 친환경 Hemp 소재사의 방적성 향상을 꾀하고자 한다. 이를 위해서 제조한 방적사의 Dry heat shrinkage와 Wet heat shrinkage를 측정하여 확인하였고 인장시험기를 이용하여 Tenacity, Initial Modulus, breaking strain을 측정 분석하였다. 방적사의 표면 특성은 영상 현미경 시스템을 사용하여 ${\times}40$ 배율로 측정하여 확인하였다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.5
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• pp.442-454
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• 2017

As the demand for meat products has steadily increased in Korea, so the livestock industry has full grown. However, the opening of import meat products is taking a toll on the local industry. Cost reduction on livestock feed, which comprises the majority of costs involved in the industry is urgent to gain a competitive edge. As Internet of Things (IoT) technologies are being applied across a multiple of industries, so are the cases of applied Smart Farm technology for efficient production. The following research aims to utilize IoT technologies to measure, in real time, the rate of depletion of feed and remaining amount and to propose an effective automated reorder & delivery system. First, a method of utilization of ultrasonic and temperature/humidity sensors to obtain corresponding data of remaining feed in the Feedbin is proposed. In addition, a method of sending the obtained data via on-the-farm gateway to Supply Chain Management (SCM) servers is proposed. Finally, utilization of the stored data to construct an automated reorder & delivery service system is proposed. It is in the researcher's intention to contribute to and enable the local livestock industry with the application of various IoT services.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.4
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• pp.317-323
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• 2008

The interest in the marine leisure sports is rapidly growing, due to the increases of the leisure time in the five working day per week and the increases of GNP. The regional governments are trying to attract massive investments into the marine leisure industry through international exhibitions and yacht rallies: However, the domestic demand patterns don't increase in contrast to those advanced countries. Up to now, few studies have been made on the industrial factors for the promotions of the marine leisure sports. In this study, variables affecting the marine leisure sports were analyzed into economical, social factors and so on. The correlations between the environmental variables and the number of the leisure boats per 1,000 persons were analyzed. Lastly, prospective suggestions were made for the developments of the marine leisure sport industries through comparisons of the domestic environmental factors with those of the advanced countries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.699-708
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• 2017

The service industry, as a new growth engine, has become more important in response to changes in the global economy and the industrial environment. Developed countries have promoted the competitiveness of the service industry and have enhanced economic added value. Developing new services requires extensive resources. Therefore, cooperation and network building capabilities with customers, suppliers, and various knowledge creation agencies are critical sources of competitiveness. This study classified the Korean service industry by industrial type in order to enhance innovation competence.The Korean service industry lags behind that of developed countries, and this study analyzed the differences of innovation results according to collaboration partners by the classified industry. By adopting a method that applies industrial classification by Dialogic's innovation pattern, this study showed external cooperation results were different by industrial type. Analysis results revealed that companies cooperate with customers and competitors in many cases; however, product innovation was higher for companies that collaborated with private service companies. In the 'Innovation in services' industry, industry cooperation with universities showed organizational innovation achievements. In the 'Innovation through services' industry, cooperation with customers positively affected marketing innovation achievements. Consequently, the need to foster consulting firms and universities that can professionally collaborate with companies is implied in order to enhance the Korean service industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.95-104
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• 2018

The structures and energies of the anhydrate and hydrate (hydrate rate: h of 1) states of L-alanine (LA) and glycine (G) were calculated by quantum chemical calculations (QCCs) using B3LYP/6-31G(d,p) for four types of conformers (${\beta}$-extended: ${\Phi}/{\Psi}=t-/t+$, $PP_{II}$: g-/t+, $PP_{II}$-like: g-/g+, and ${\alpha}$-helix: g-/g-). In LA and G, which have an imino proton (NH), three conformation types of ${\beta}$-extended, $PP_{II}$-like, and ${\alpha}$-helix were obtained, and water molecules were inserted mainly between the intra-molecular hydrogen bond of $CO{\cdots}HN$ in $PP_{II}$-like and ${\alpha}$-helix, and attached to the CO group in ${\beta}$-extended. In LA and G, $PP_{II}$-like conformers were most stable in the anhydrate and hydrate states, and the result for LA was different from some experimental and theoretical results from other studies reporting that the main stable conformation of alanine oligopeptide was $PP_{II}$. The formation pattern and stability of the conformation of the oligopeptide was strongly dominated by the presence/absence of intra-molecular hydrogen bonding of $CO{\cdots}HN$, or the presence/absence of an $NH_2$ group in the starting amino acid.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.3194-3200
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• 2012

The aim of the paper is systematically to organize the historical facts of financial IT development process through various tracking and proved knowledge, it is to propose the direction and the advanced frame of core-banking model in next generation for the year 2020s. To achieve it, this study variously analyzed the meaningful pattern of development process of financial IT by backtracking life-cycle of Core-Banking model and it presented new model of Core-Banking for the past 40 years. In research findings, the life cycle of financial IT system and core-banking model have been analyzed about 10 years and the longest model of life cycle is about 33 years. As a result, It proved to be desirable that the advanced frame of the Core-Banking model adds the functions of business hub and product life cycle management to basic frame of its existing model in the future. In addition, big bang development method of new next generation system must be sublated. Also, They need to be initiated more business-oriented than IT-oriented. Along with this, the financial IT should be developed into the convergence industry, and it needs to extend the systematization of Core-Banking model studies and more professionals. Finally, this study has arranged the financial IT development process in domestic and presents new frame through analyzing intensively the Core-Banking model for the first time Therefore, it can be contributed to serve the guideline regarding the direction in new next generation system.

• Journal of the Korean Regional Science Association
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• v.34 no.3
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• pp.55-68
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• 2018

This paper aims to analyze the changes of the population distribution of metropolitan area by the development of the new town-type innovative city, focusing on the case of the Daegu Innovative City. Using dataset in the survey of population trend and the migration statistics microdata provided by the Statistics Korea, we decomposed population changes of Daegu and surrounding regions into natural increase and social increases(net migration). As a result of the analysis, Dong-gu, where the Daegu Innovation City is located, experienced population growth due to its increase of net migration, whereas the total population in Daegu been decreasing continuously between 2007 and 2016. In particular, the occurrence of high net migration to Dong-gu in 2014 showed a pattern consistent with the completion of the Daegu Innovative City development and the relocation of government institutions from the Seoul metro area. As a result of analyzing the migration to Dong-gu, the population moved from the Seoul metro area was 6.9% of the total, while the population moving from the other 7 gu-gun areas in Daegu (35.8%) and the surrounding regions (8.2%) were significantly high. In particular, the migration to Dong-gu were from neighboring areas, such as Suseong-gu, Buk-gu and Gyeongsan-si. Therefore, the development of the new town-type innovative city could accelerate toward sprawling urban structure.

• Journal of Nutrition and Health
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• v.30 no.3
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• pp.336-348
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• 1997

The objectives of this study were to examine the growth pattern of infants by anthropometric measurement according to the 5 feeding practices of infants with the subject of two hundred healthy newborn babies from their birth till sixty month of age at intervals of two months. Breast group(BF, n=38), formula group(FF, n=102) and mixed group(ME, n=14) were fed breast milk, formula milk, breast and formula milk, from birth till 6 mo. of age, respectively. Convert 1 group (C1F, n=14) and covert 2 group(CF, n=32) were fed breast milk and mixed milk at 2 mo. of age afterthat switched to formula milk, respectively. From these, the following results were made. All the infants of this study showed superiority to Korean standard growth rate in regards to each growth item for each month age. In the case of males, at their birth, the subscapular skinfold thickness and the total skin fold thickness in the BF group was significantly larger than in MF group and FF group(p<0.05). At 6th month age, the chese circumference of MF group was 45.9cm, and significantly larger than those of BF, FF and C2F groups(p<0.05). In the case of females, at theri birth and 2nd month age, there was no difference among all the feeding groups in regards to each growth rate. At 4th month age, the Kauf index of C1F group was 16.21 and significantly lower than those of four groups(p<0.05). And total skinfold thickness in BF group was larger than in C1F group. The increase rate per month age of all growth items were larger at 2nd month age than at the later months both in males and in females. And until 2nd month age males showed more increase than females in regards to each growth item but after 2nd month age, this sapect did not show up. Multiple linear regression was used to determine predictive factors for infant growth. It was expected that at 6th month age, in the measurement of head circumference and chest circumference and cross-sectional fat area, BF-males were bigger by 22-39% of the explanation index than the infants of other groups. As a result, in spite of the significant lower intakes of energy and nutrients in breast-fed infants than in formula-fed infants, breast-fed infants showed more growth than the average of Korean infant standard growth rate at every month age, and showed no significant growth difference among feeding groups.