• Title/Summary/Keyword: 가시도

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A Study on the Application of Ventilation Equipment in an Underground Fire (지하공간 화재시 배연장비의 활용에 관한 연구)

  • Lee, Sung-Ryong;Han, Dong-Hoon
    • Tunnel and Underground Space
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    • v.20 no.2
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    • pp.92-96
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    • 2010
  • In this study, experiments were conducted to evaluate the effectiveness of ventilation equipment in underground fires. Two type of Ventilators were used in experiments. Experiments were carried out using ethanol square pool fire. Maximum heat release rate was about 460kW. Visibility and temperature distribution were evaluated according to mechanical ventilation. In blower type ventilation, visibility was increased and temperature was lowered.

A Watchman route with Minimum links in the Weakly Visible Polygons (약 가시성 다각형에서 최소 링크를 가진 경비원 경로)

  • 류상률
    • Journal of the Korea Computer Industry Society
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    • v.3 no.1
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    • pp.35-44
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    • 2002
  • The watchman routes which an watchman patrols the interior of given polygon moving along the route are classified to minimum length or minimum links. The watchman route with minimum links has minimum changes of direction and a weakly visible polygon consists of two chains which have mutually weakly visibility. In this paper, we present an Ο($n^2$) time algorithm for finding the watchman route with minimum links in the weakly visible polygons, where n is the number of vertices of a given polygon.

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Feeding Habits of Pseudoblennius cottoides (가시망둑 (Pseudoblennius cottoides)의 식성)

  • HUH Sung-Hoi;KWAK Seok Nam
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.1
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    • pp.37-44
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    • 1998
  • Feeding habits of Pseudoblennius cottoides collected from the eelgrass bed in Kwangyang Bay from January 1994 to December 1994 were studied. Pseudoblennius cottoides was a carnivore which mainly consumed fishes, caridean shrimps, and amphipods. Its diets included small Quantities of tanaids, copepods, isopods, mysids, and polychaetes. It showed ontogenetic changes in feeding habits. Fishes were heavily selected as the body size of P. cottoides increases. Fishes and caridean shrimps were major prey organisms for all seasons.

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A Cloud Classification Using Fuzzy Method (퍼지 기법을 이용한 구름 분류)

  • Cho, Hyun-Hak;Kim, Kwang-Baek
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.05a
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    • pp.355-359
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    • 2009
  • 본 논문에서는 퍼지 기법을 이용하여 구름의 종류를 분석하는 방법을 제안한다. 본 논문에서는 가시 영상과 적외 영상을 대상으로 육지 영역은 RGB 컬러 정보 중에 G 채널 값의 수치가 높고, 바다영역에서는 B 채널 값의 수치가 높다는 정보를 이용한다. 이 정보를 이용하여 육지 영역에서는 R과 B 채널 값을 적용하고, 바다 영역에서는 R과 G 채널 값을 적용한다. 가시 영상과 적외 영상에서 임계치를 적용하여 잡음(구름 이외의 영역)을 제거하고, 잡음을 제거한 영상에서 육지 영역과 바다 영역을 구분한 후, 각 R, G, B 채널 정보를 퍼지 기법에 적용하여 구름 영역을 판별한다. 그리고 가시영상과 적외 영상에 모두 포함된 구름 영역에 대해서는 두 영상을 합성하여 구름을 판별한다. 제안된 기법을 구름 분류에 적용한 결과, 제안된 방법이 기존의 양자화를 적용한 방법보다 구름의 분류 성능이 개선된 것을 확인하였다.

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가시광 무선 통신의 기술 특징 분석

  • Jang, Su-Yeong
    • Information and Communications Magazine
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    • v.26 no.5
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    • pp.15-22
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    • 2009
  • 본고에서는 가시광 통신에 사용되는 여러 가지 기술 특성을 간단하게 기술하고자 하였다. 광원과 감지기에 대한 기술 사항을 간단히 소개하였으며 그들의 기술 특성을 표시하는 방법에 대하여 간단히 기술하였다.

The characteristics of Mn-TiO2 catalyst for visible-light photocatalyst (Mn-TiO2 촉매의 가시광촉매 특성)

  • Kim, Moon-Chan
    • Analytical Science and Technology
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    • v.24 no.6
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    • pp.493-502
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    • 2011
  • The catalyst works for visible-light region was characterized. Toluene, xylene, MEK and ammonia were used as reactants. The decomposition efficiency was compared between visible-light photocatalyst and UV-light one. UV-photocatalyst can be activated with UV-light wave length of 280~360 nm. However, visible-light photocatalyst can be activated with visible wave length of 400~750 nm. This result was found by using UV-Vis absorbance. A lot of materials were doped to visible light photocatalyst in order to increase its performance. Platinum was added to visible light photocatalyst with manganese in order to increase performance of the visible light photocatalyst. MTMS (Methyl tri methoxy silane) was used as a binder. Contact angle was analyzed varying with amount of binder. Contact angle was increased with increasing the amount of MTMS. As a result, the hydrophilic property of photocatalyst with MTMS binder was decreased due to its hydrophobic one. And Mn-$TiO_2$ catalyst had an excellent anti-bacterial property.