• Title/Summary/Keyword: channel morphology

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The Evaluation of Small Scaled Stream Naturalness for Stream Channel Restoration (소하천 환경조성사업의 평가를 위한 소하천자연도 평가)

  • Ahn, Tae-Jin
    • Journal of Korea Water Resources Association
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    • v.40 no.5
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    • pp.359-369
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    • 2007
  • In this study the evaluation method for riverine naturalness proposed previously by other researcher has been modified to assess stream naturalness of small scaled streams. Two evaluation items have been added to the previously proposed method. That is, the modified method for evaluating naturalness of small scaled streams contains 16 evaluation items with two categories - river morphology and river environments. The three evaluation items have been improved based on the results of stream configuration and characteristics investigation. To prepare evaluation index for channel configuration of small scaled stream, 55 small scaled streams have been selected to analyze sinuosity, wavelength, etc. It has been shown that the values of sinuosity are around 1.2 and one wavelength appears approximately every 500 m in the sample streams. An equation implied diversity for width of normal flow has been proposed to add the evaluation index for diversity of channel width. The every 500 m 1,000 m along small scaled stream is also recommended through the investigation as the interval of evaluation unit. The modified method has been applied to the DangWang stream to estimate the effect of stream rectification project. It has shown that the proposed method would appropriately reflect channel morphology and environments before and after the rectification project.

Analysis on Channel Morphology and Rock Resistance by Difference of Bedrock Types between Upper and Lower Reach (상.하류의 기반암 차이에 따른 하천의 형태와 암석의 저항력 분석)

  • Lee, Gwang-Ryul
    • Journal of the Korean Geographical Society
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    • v.42 no.1 s.118
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    • pp.27-40
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    • 2007
  • The streams evolve to diverse forms influenced by various factors such as rock resistance tectonic process, sediments and discharge. This study focuses on erosion resistance of rocks among these factors. The morphology of plane and longitudinal profile has been analysed in upper and lower reach of 6 streams using GIS; Yeoryong-cheon, Heungjeong-cheon, Duhak-cheon, Daehwa-cheon, Namcheon-cheon, Guryong-cheon, having distinct bedrock types between upper and lower reach. While the basins of granite have gentle slope, low concavity and wide valley area, those of gneiss form steep slope, high concavity and narrow valley area. However, the basins of sedimentary rock make steep slope and high relief in main channel, the other features show some differences in each stream. Among the various morphological features, the indices on slope and concavity of main channel, drainage density, ratio of valley area, average slope and average relief of the basin which have clear differences between rocks in upper and lower reach are calculated to interpret the erosion resistance of rocks in upper and lower reach. As a result, the upper reaches composed of gneiss have the highest erosion resistance, sedimentary rocks in upper and lower reaches show moderate resistance, and granite reaches generally have the lowest resistance except the upper reaches bordered by sedimentary rock.

Effect of Nafion Chain Length on Proton Transport as a Binder Material (수소이온 전달 특성에 미치는 바인더로 활용 가능한 나피온의 주쇄 길이의 영향)

  • Kang, Hoseong;Park, Chi Hoon
    • Membrane Journal
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    • v.30 no.1
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    • pp.57-65
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    • 2020
  • The purpose of this study was to compare the water channel morphology and the proton conductivity by changing the number of repeating units of the polymer backbone of PEMs, and to present a criterion for selecting an appropriate polymer model for MD simulation. In the model with the shortest polymer main chain, the movement of the main chain and the sulfonic acid group was observed to be large, but no change in the water channel morphology was found. In addition, due to the nature of the proton transport ability that is most affected by the water channel morphology, the proton conductivity did not show a significant correlation with the length of the polymer backbone. These results provide important information, particularly for the preparation of ionomers for binders. In general, a low molecular weight polymer electrolyte material is used for a binder ionomer. Since the movement of the main chain/sulfonic acid group is improved, it can play a role of enclosing the catalyst layer well. However, there is no change in its proton conducting performance. In conclusion, the preparation of ionomers for binders will require molecular weight and structure design with a focus on physical properties rather than proton transfer performance.

Transfer Characteristics of Poly-Si TFTs with Laser Energy Change

  • You, Jae-Sung;Kim, Young-Joo;Jung, Yun-Ho;Seo, Hyun-Sik;Kang, Ho-Chul;Lim, Kyong-Moon;Kim, Chang-Dong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.401-404
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    • 2004
  • Transfer characteristics of poly-Si TFTs within process window of laser energy are investigated. In terms of surface morphology and transfer characteristics, process window of laser crystallization is evaluated. While maximum mobility exists in lower edge of process window in n-channel TFTs, maximum mobility exists in higher edge of process window in p-channel TFTs.

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Bipolar Characteristics of Organic Field-effect Transistor Using F16CuPc with Active Layer ($F_{16}CuPC$를 활성층으로 사용한 유기전계효과트랜지스터의 바이폴라 특성연구)

  • Lee, Ho-Shik;Park, Young-Pil;Cheon, Min-Woo;Kim, Tae-Gon;Kim, Young-Phyo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.303-304
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    • 2009
  • We fabricated organic field-effect transistors (OFETs) based a fluorinated copper phthalocyanine. ($F_{16}CuPc$) as an active layer. And we observed the surface morphology of the $F_{16}CuPc$ thin film. The $F_{16}CuPc$ thin film thickness was 40nm, and the channel length was $50{\mu}m$, channel width was 3mm. We observed the typical current-voltage (I-V) characteristics and capacitance-voltage (C-V) in $F_{16}CuPc$ FET and we calculated the effective mobility.

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Electrical Properties of Field Effect Transistor using F16CuPc (F16CuPc를 이용한 Field Effect Transistor의 전기적 특성 연구)

  • Lee, Ho-Shik;Park, Young-Pil;Cheon, Min-Woo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.389-390
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    • 2008
  • We fabricated organic field-effect transistors (OFETs) based a fluorinated copper phthalocyanine ($F_{16}CuPc$) as an active layer. And we observed the surface morphology of the $F_{16}CuPc$ thin film. The $F_{16}CuPc$ thin film thickness was 40nm, and the channel length was $50{\mu}m$, channel width was 3mm. We observed the typical current-voltage (I-V) characteristics and capacitance-voltage (C-V) in $F_{16}CuPc$ FET and we calculated the effective mobility.

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Properties of FET using Activative Materials with F16CuPc (F16CuPc를 활성층으로 사용한 FET의 특성 연구)

  • Lee, Ho-Shik;Park, Young-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.04b
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    • pp.43-44
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    • 2009
  • We fabricated organic field-effect transistors (OFETs) based a fluorinated copper phthalocyanine ($F_{16}CuPc$) as an active layer. And we observed the surface morphology of the $F_{16}CuPc$ thin film. The $F_{16}CuPc$ thin film thickness was 40nm, and the channel length was $50{\mu}m$, channel width was 3mm. We observed the typical current-voltage (I-V) characteristics and capacitance-voltage (C-V) in $F_{16}CuPc$ FET and we calculated the effective mobility.

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Microstructures and Mechanical Behavior of 2024 Al Alloys Deformed by Equal Channel Angular Pressing (2024 Al 합금의 ECAP 공정에 따른 미세조직 변화와 강도특성)

  • Kim, Seon-Hwa;Choi, Yong-Lak
    • Korean Journal of Materials Research
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    • v.16 no.1
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    • pp.68-74
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    • 2006
  • 2024 Al alloys were severely deformed by equal channel angular pressing(ECAP) to obtain an ultrafine grain structure. The more deformation amount increased, the more grain size decreased. Most of the grain structure were changed from elongated to equiaxed shape with increasing pass number. The morphology of S' phases was also changed from rod-type to spherical type. The grain size of 6 passed specimen was 100 to 200 nm, and the size of S' phases was about 10 nm in the microstructure. XRD measurements have revealed that the texture formed by plastic deformation disappeared in the 6 passed specimen. SP test results described that the start of crack propagation occurred at the transition zone between plastic bending and membrane stretching because of small elongation. The maximum strength of ECA pressed specimen increased 1.9 GPa to 2.9 GPa with increasing pass number.

Electrical Properties of FET using F16CuPc (F16CuPc를 이용한 FET의 전기적 특성 연구)

  • Lee, Ho-Shik;Park, Young-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.504-505
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    • 2008
  • We fabricated organic field-effect transistors (OFETs) based a fluorinated copper phthalocyanine ($F_{16}CuPc$) as an active layer. And we observed the surface morphology of the $F_{16}CuPc$ thin film. The $F_{16}CuPc$ thin film thickness was 40nm, and the channel length was $50{\mu}m$, channel width was 3mm. We observed the typical current-voltage (I-V) characteristics and capacitance-voltage (C-V) in $F_{16}CuPc$ FET and we calculated the effective mobility.

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Multi-channel Real Time Arrhythmia Detection System (다중채널 실시간 부정맥 검출 시스템 설계에 관한 연구)

  • 이경중;송향봉
    • Journal of Biomedical Engineering Research
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    • v.8 no.2
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    • pp.215-222
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    • 1987
  • This paper describes the design of a real time arrhythmia detection system using five variables : heart rate, QS width, morphology, alls deviation, and ST segment. To detect individual variables for four patients, we designed multi-processor system. The results of the analysis derived from simulators and 50 patients are compared with the medical diagnoses. The results show that the analysis was able to detect irregularly occuring arrhythmia which does not show up in routine medical examination.

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