• Title/Summary/Keyword: Ahn Ji-Jae

Search Result 508, Processing Time 0.033 seconds

Fabrication of $Cu_xSe$ thin films by selenization of $Cu_xSe$ nanoparticles prepared by a colloidal process (CIS 태양전지용 이원 화합물 $Cu_xSe$ 나노입자를 이용한 $Cu_xSe$ 박막 제조)

  • Kim, Kyun-Hwan;Ahn, Se-Jin;Yun, Jae-Ho;Gwak, Ji-Hye;Kim, Do-Jin;Yoon, Kyung-Hoon
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2009.06a
    • /
    • pp.96-98
    • /
    • 2009
  • This report summarizes our recent efforts to produce large-grained CIGS materials from porous nanoparticle thin films. In our approach, a $Cu_xSe$ nanoparticle colloid were first prepared by reacting a mixture of CuI in pyridine with $Na_2Se$ in methanol at reduced temperature. purified colloid was sprayed onto heated molybdenum-coated sodalime glass substrates to form thin film. After thermal processing of the thin film under a selenium ambient. $Cu_xSe$ colloid and thin film were characterized by scanning electron microscopy, x-ray diffraction. The optical(direct) band gap energy of $Cu_xSe$ thin films is 1.5 eV.

  • PDF

Fabrication of Flexible CIGS thin film solar cells using Polyimide substrate (Polyimide 기판을 이용한 Flexible CIGS 박막 태양전지 제조)

  • Jung, Seung-Chul;Ahn, Se-Jin;Yun, Jae-Ho;Gwak, Ji-Hye;Kim, Do-Jin;Yoon, Kyung-Hoon
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2009.06a
    • /
    • pp.153-155
    • /
    • 2009
  • In this study, we fabricated the $Cu(In,Ga)Se_2$ (CIGS) thin-film solar cells by using a polyimide substrate. The CIGS thin-film was deposited on Mo coated polyimide substrate by a 3-stage co-evaporation technique. Because the polyimide shows thermal transformation at about $400^{\circ}C$, the substrate temperature of co-evaporation process was set to below $400^{\circ}C$. Corresponding solar cell showed a conversion efficiency of 7.08 % with $V_{OC}$ of 0.58 V, $J_{SC}$ of 24.99 $mA/cm^2$ and FF of 0.49.

  • PDF

Depth map generation method using segmentation and motion information (영역분할과 움직임 정보를 이용한 깊이맵 생성 기법)

  • Kim, Su-Dong;Ahn, Jae-Woo;Seo, Young-Ho;Kim, Dong-Wook;Yoo, Ji-Sang
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • 2010.07a
    • /
    • pp.116-118
    • /
    • 2010
  • 본 논문에서는 영역 분할과 영상의 움직임 정보를 이용한 깊이맵 생성에 관한 기법을 제안하였다. 2D/3D 변환 알고리즘에서 2차원 영상에서 얻은 깊이 정보는 2차원 영상을 3차원 영상으로 변환 가능하게 하는 핵심 기술이 된다. 영역을 분할하고 계산되어진 움직임 값 (intensity)을 분할된 각 영역에 부여함으로서 깊이맵을 얻을 수 있다. 본 논문에서는 초기 단계에서 영역을 분할한 뒤, 입력 영상을 그룹화 하여 양방향 탐색을 통한 움직임 추정 연산을 수행토록 하여 보다 정확한 깊이 정보를 획득하고, 최종적으로 얻은 결과에 각 화소에 해당 되는 확률적 통계에 의한 후처리 기법을 사용하였다. 보다 정확한 깊이정보를 영역별로 지정하고, 후처리 기법을 사용함에 따라 보다 신뢰도 높은 깊이맵 영상을 생성할 수 있었다.

  • PDF

A Study for Cooperation in Aerospace Industry Between Republic of Korea and Russia (한.러 항공산업 협력방안에 관한 연구)

  • Ji, Yoong-Seon;Ahn, Jae-Mo
    • Journal of the Korean Society for Aviation and Aeronautics
    • /
    • v.19 no.4
    • /
    • pp.91-98
    • /
    • 2011
  • Korea's aerospace industry tries to achieve the exports goal in 2020, 10 billion dollars, in accordance with the "Future aviation industry development master plan", but it's skill is still not keeping pace. To secure and improve the appropriate technology, it is desperately needed to cooperate with advanced countries or companies of aerospace industry, but they are liked to manage their technology transfer or demand tremendous high price. This study presents that Russia could be a another nation which is able to cooperation on aerospace industry. Although Russia had have superior technology in aerospace industry, they have lost the competitiveness on that field after the collapse of the Soviet Union. Now, they are trying to regain their original fame in the commercialized way. So, this study suggests practical ways which South Korea and Russia may be helpful each other based on experiences working together.

Multiple Aneurysms on the Same Bifurcation Site of the Middle Cerebral Artery

  • Back, Byung-Suck;Choi, Seung-Jin;Ji, Cheol;Ahn, Jae-Geun
    • Journal of Korean Neurosurgical Society
    • /
    • v.41 no.4
    • /
    • pp.258-260
    • /
    • 2007
  • Multiple aneurysms at the same cerebral arterial branching site are rare, and have been mainly described in a few case reports in comparison with other intracranial multiple aneurysms. Most reported locations of the same artery where multiple aneurysms developed were internal carotid artery and anterior communicating artery. We experienced a very rare case of multiple aneurysms arising at the same bifurcation site of the middle cerebral artery. Only one case like this has been reported previously in the literature. We discussed the preoperative diagnosis and surgical management of such condition.

Proteomes Induced by S-Adenosyl-L-Methionine in Streptomyces coelicolor A3(2)

  • Kim Kwang-Pyo;Shin Choon-Shik;Lee Soo-Jae;Kim Ji-Hye;Young Jung-Mo;Lee Yu-Kyung;Ahn Joong-Hoon;Suh Joo-Won;Lim Yoong-Ho
    • Journal of Microbiology and Biotechnology
    • /
    • v.16 no.5
    • /
    • pp.799-803
    • /
    • 2006
  • It was reported that an accumulation of Sadenosyl-L-methionine increases production of actinorhodin in Streptomyces lividans and induces antibiotic biosynthetic genes. We also obtained the same result in Streptomyces coelicolor A3(2). Therefore, in order to identify proteins changed by the addition of S-adenosyl-L-methionine in S. coelicolor A3(2), LC/MS/MS analyses were carried out. Thirteen proteins that were not observed in the control were found.

A perspective of chemical treatment for cyanobacteria control toward sustainable freshwater development

  • Huh, Jae-Hoon;Ahn, Ji-Whan
    • Environmental Engineering Research
    • /
    • v.22 no.1
    • /
    • pp.1-11
    • /
    • 2017
  • One of the most threatening consequences of eutrophic freshwater reservoirs is algal blooming which typically occur after the long a mega drought or/and irregular rainfall under influence of climate change. The long-term experiences of chemical treatment are known as a most practical effort to reduce health concerns from human exposure of harmful cyanobacteria as well as to preserve ultimate freshwater resources. Even though these conventional chemical treatment methods do not completely solve the algal residue problem in water treatment plant or directly in the water bodies, they still have big advantages as fast and efficient removal process of cyanobacteria due to cheaper, easier to manage. This review summarizes their chemical treatment scenarios of the representative coagulants, pre-oxidants and algaecides composed to chemical compounds which immediately may help to manage severe cyanobacteria blooms in the summer seasons.

Growth Enhancement of the Microalga Tetraselmis suecica by an Extract of the Green Alga Monostroma nitidum

  • Cho Ji Young;Choi Jae Suk;Kang Se Eun;Ahn Sang Jung;Kim Joong Kyun;Hong Yong Ki
    • Fisheries and Aquatic Sciences
    • /
    • v.8 no.1
    • /
    • pp.1-5
    • /
    • 2005
  • Cell growth of the marine microalga Tetraselmis suecica was regulated by the addition of seaweed extracts in its culture medium. Of 26 species of seaweed tested, water-soluble extracts from Monostroma nitidum and Pachymeniopsis elliptica and methanol-soluble extract from Sargassum confilsum enhanced the growth of T suecica cells. The water extract of M. nitidum was the most effective, producing up to a 2-fold increase in cell density with the addition of 1 mg/mL of extract to the culture medium. Cell size, gross biochemical composition, fatty acids, and digestion efficiency all differed marginally between cultures of T suecica grown with and without the M. nitidum extract.