• Title/Summary/Keyword: High-$T_{c}$

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Development of Image Post-processing System for the Cerebral Perfusion Information Mapping of MR Image (MR영상의 뇌관류 정보 Mapping을 위한 영상후처리 시스템개발)

  • 이상민;강경훈;장두봉;김광열;김영일;신태민
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.1
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    • pp.131-138
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    • 2000
  • This paper works on development of an algorithm for mapping of cerebral perfusion parameters using the gamma-variate curve fitting. The signal intensity variate curve according to time measured in each pixel of perfusion MRI is nonlinear, and various hemodynamic parameters are not computed accurately. Levenberg-Marquardt algorithm(LMA), nonlinear optimum algorithm with high convergent speed and stability, is used to compute them. That is, the signal intensity variate curve is fitted by the gamma-variate function. Various hemodynamic parameters - Cerebral Blood Volume(C.B.V), Mean Transit Time(M.T.T), Cerebral Blood Flow(C.B.F), Time-to-Peak(T.T.P), Bolus Arrival Time(B.A.T), Maximum Slope(M.S) - are computed using LMA.

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Epitaxial thickness during low-temperature Si(001) growth: effect of substrate vicinality (저온 Si(001) 저온 성장중 에피텍시 두께: 기판 vicinality의 영향)

  • Lee, N.-E.
    • Journal of the Korean Vacuum Society
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    • v.8 no.4B
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    • pp.519-523
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    • 1999
  • Epitaxial thickness $t_e(T_s)$ of Si films grown at the substrate temperature $T_s$=80~30$0^{\circ}C$ by ultra-high vacuum ion-beam sputter deposition onto nominally-singular, [100]-miscut Si(001) was measured. $t_e(T_s)$ values of films grown on vicinal Si(001) substrates were decreases compared to those of films grown on nominally-singular Si(001). Evolution of surface roughness measured by atomic force microscopy of films grown at $300^{\circ}C$ showed that the increases step density in vicinal substrates increases the tendency toward unstable growth resulting in larger surface roughness, which in turn decreases te.

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Autoimmunity and intestinal colonization by Candida albicans in patients with type 1 diabetes at the time of the diagnosis

  • Gursoy, Semra;Kockar, Tuba;Atik, Sezen Ugan;Onal, Zerrin;Onal, Hasan;Adal, Erdal
    • Clinical and Experimental Pediatrics
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    • v.61 no.7
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    • pp.217-220
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    • 2018
  • Purpose: Type 1 diabetes mellitus (T1DM) is a chronic and immune-mediated disease, which is characterized by the progressive destruction of pancreatic beta cells. T1DM precipitates in genetically susceptible individuals through environmental factors. In this study, we aimed to evaluate the impact of autoimmunity and intestinal colonization of Candida albicans on the development of T1DM. Methods: Forty-two patients newly diagnosed with T1DM and 42 healthy subjects were included in this monocentric study. The basic and clinical characteristics of the patients were recorded. T1DM-, thyroid-, and celiac-associated antibodies were evaluated. Stool cultures for C. albicans were performed to assess whether or not gut integrity was impaired in patients with T1DM. Results: The evaluation of T1DM- and thyroid-associated antibodies showed that the prevalences of islet cell antibodies and antithyroperoxidase positivity were higher in the study patients than in the patients in the control group. Furthermore, the direct examination and culture of fresh stool samples revealed that 50% of the patients with T1DM and 23.8% of the control subjects had fungi (C. albicans). Conclusion: Through this study, we suggest that the presence of intestinal C. albicans colonization at the time of the diagnosis of T1DM may indicate impairment of normal intestinal microbiota. We also suggest that there may be a tendency of T1DM in patients with a high prevalence of intestinal C. albicans.

Analysis of Vegetation-Environment Telationships of Main Wild Vegetables on Short-term Income Forest Products, in Korea (단기소득임산물 자생지 주요 산채류 식생과 환경의 상관관계 분석)

  • Kim, Hyoun-Sook;Lee, Sang-Myong;Lee, Joongku
    • Korean Journal of Environment and Ecology
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    • v.33 no.4
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    • pp.447-452
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    • 2019
  • This study was conducted in 2016-2017 to provide the basic ecological data needed to establish environmental conditions for the cultivation of wild vegetables. It used TWINSPAN to classify the vegetation structure of natural habitats of wild vegetable nationwide and DCCA ordination to analyze the correlation between the by community structure and environmental factors. We performed TWINSPAN on 100 taxa with high importance values in 91 plots of major habitats of wild vegetables. The vegetation was classified into Cirsium setidens and Synurus deltoides group, Ligularia fischeri and Hemerocallis fulva group, Adenophora divaricata var. manshurica group, Platycodon grandiflorum and Aster scaber group, Aralia elata and Pteridium aquilinum group, and Pimpinella brachycarpa and Osmunda japonica group communities. We then performed DCCA ordination of 11 communities classified by TWINSPAN and 11 environmental factors. The results showed that the altitude had the strongest correlation with the vegetation. The Cirsium setidens, Synurus deltoids, and Lifularia fischeri communities were distributed in areas with similar environmental factors such as high altitude, gentle slope, and nutrient. The Aralia elata and Osmunda japonica communities were distributed in the location environment with low altitude, pH, O.M, T-N, $Ca^{2+}$, and C.E.C. The Hemerocallis fulva community was distributed in the location environment with moderate northeastern and northwestern slope, low altitude and pH, and high $P_2O_5$, whereas the Adenophora divaricata var. manshurica community was distributed in the location environment with gentle southeastern and southwestern slope, high altitude and pH, and low $P_2O_5$, which was the opposite tendency of the location environment from Hemerocallis fulva community. The Platycodon grandiflorum community was distributed in the location environment with gentle southwestern slope, low altitude, pH, O.M, T-N, $P_2O_5$, $Ca^{2+}$, and C.E.C., and high $Mg^{2+}$. The Pteridium aquilinum community was distributed in the location environment with southwestern slope, low altitude, O.M, T-N, C.E.C, $P_2O_5$, $Ca^{2+}$, and $K^+$. The Aster scaber and Pimpinella brachycarpa communities were widely distributed in many plots with various location environments.

Ohmic contact formation of polycrystalline 3C-SiC for high-temperature MEMS applications (초고온 MEMS용 다결정 3C-SiC의 Ohmic Contact 형성)

  • Ohn, Chang-Min;Chung, Gwiy-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.406-407
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    • 2006
  • This paper describes the ohmic contact formation between a TiW film as a contact material deposied by RF magnetron sputter and polycrystalline 3C-SiC films deposied on thermally grown Si wafers. The specific contact resistance (${\rho}_c$) of the TiW contact was measured by using the C-TLM. The contact phase and interfacial reaction between TiW and 3C-SiC at high-temperature were also analyzed by XRD and SEM. All of the samples didn't show cracks of the TiW film and any interfacial reaction after annealing. Especially, when the sample was annealed at $800^{\circ}$ for 30min., the lowest contact resistivity of $2.90{\times}10^{-5}{\Omega}cm^2$ was obtained due to the improved interfacial adhesion.

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