• 제목/요약/키워드: Tidal characteristics

검색결과 676건 처리시간 0.023초

백-밸브-마스크 환기 시 마스크 밀착방법에 따른 환기효과 비교 (Comparison of ventilation effects by mask-sealing methods during bag-valve-mask ventilation)

  • 이남종;백미례
    • 한국응급구조학회지
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    • 제22권1호
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    • pp.73-82
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    • 2018
  • Purpose: The purpose of this study was to compare the tidal volumes and airway pressures of 3 mask-sealing methods (one hand C-E, two hands C-E, and one hand O-E) for ventilation treatment. Methods: The study subjects were 45 paramedic students. Tidal volume was measured for the three sealing methods by setting a ventilator, connecting it to the masks for 2 minutes, and using Respi-trainer software. Results: Regarding general characteristics, the group of men, in upper grades, and with practical training experience and experience and experience in the implementation of bag-valve-mask ventilation provided higher tidal volumes. Regarding physical characteristics, larger hands and greater grip strength correlated with higher tidal volume. Two hands C-E generated the highest tidal volume of $483.78{\pm}34.14mL$, one hand O-E generated $449.59{\pm}51.09mL$ and one hand C-E generated $394.31{\pm}68.95mL$. Conclusion: Means of tidal volumes were statistically significantly different based on mask sealing methods (p<.001). Two hand C-E was performed by the two-persons task and was suggested as the most effective method. For the one-person task, one hand O-E was the more effective method compared to the previous one hand C-E.

Spectral Characteristics of Shallow Turbid Water near the Shoreline on Inter-tidal Flat

  • Lee, Kyu-Sung;Kim, Tae-Hoon;Yun, Yeo-Sang;Shin, Sang-Min
    • 대한원격탐사학회지
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    • 제17권2호
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    • pp.131-139
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    • 2001
  • Extraction of waterline in tidal flat has been one of the main concerns in the remote sensing of coastal region. This study aimed to define the spectral characteristics of turbid water near the shoreline and to find the appropriate spectrum to delineate the waterline at the inter-tidal flat in the western coast of Korean Peninsula. Spectral reflectance curves were obtained by the field measurements under the diverse condition of water depth and turbidity at the study area in Kyong-gi Bay. Spectroscopy measurements showed that reflectances of the exposed mudflat, shallow turbid water, and normal coastal water were significantly different by wavelength. Shallow water near the waterline showed diverse conditions of turbidity. Spectral reflectance tends to increase as turbidity increases, particularly at the visible and near infrared spectrum. At the middle infrared wavelength, tidal water showed very little reflectance regardless of the turbidity and water depth and was easily disting from the exposed tidal flat. The exact waterline between exposed tidal flat and seawater should be extracted from the image data obtained at the middle infrared wavelength.

The Tidal Flat Environments and Experiential Learning Program of Southwest Coast, Korea

  • Oh, Kang-Ho;Kim, Hai-Gyoung;Koh, Yeong-Koo;Youn, Seok-Tai;Kim, Jong-Hee
    • 대한지구과학교육학회지
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    • 제8권3호
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    • pp.251-258
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    • 2015
  • Ecosystems of the southwestern tidal flats in Korean peninsula have been seriously injured by human activities. The results are mainly due to the lack of public recognition and education on tidal flats. In particular, thoughtless visitors in tidal flats are giving rise up damages because of non-systematic experience programs to tidal flat ecosystems. Therefore, experience programs friendly to natural tidal flats are necessary as a plan to reserve tidal flats and to enhance the effects of environment education on the flats. Experience learning programs on tidal flats can divide into direct experience, indirect experience and local society works. Direct experience work must undergo tidal flats directly and consider on forming the flats with natural refinement functions. Indirect experience includes deeper knowledge on role, circumstance and ecosystems of the flats on the bases of direct experience on the flats. In addition, local society learning must have the feeling and understanding on socio-cultural characteristics of local society itself through above two works. Experience activity would be a kind of injuring one to tidal flats. However, appropriately planned experience and education works on tidal flats could be sustainable development to attract desirable human activity on coastal ecosystems.

국내 해양에너지 이론적 잠재량 산정 연구 (Resource Assessment of Theoretical Potential of Ocean Energy in Korea)

  • 황수진;조철희
    • 한국수소및신에너지학회논문집
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    • 제30권5호
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    • pp.465-472
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    • 2019
  • This paper describes the resource assessment of theoretical potential of ocean energy including tidal current energy, tidal range energy, wave energy and ocean thermal energy in Korea to provide reliable basis for feasible development plan of ocean energy. Because of different characteristics of each ocean energy resources, the resource assessment methods were established considering characteristics of each ocean energy resources. The coastal region of Korea has been divided into 10 regions. The results show that tidal current energy is abundant in Incheon-Gyunggi and Jeollanam-do and tidal range energy is abundant in Incheon-Gyunggi. And wave energy is abundant in Jeollanam-do, Jeju and Gyeongsangbuk-do and there is ocean thermal energy in Gangwon-do and Gyeongsangbuk-do.

인천만 조력에너지 개발을 위한 GIS 데이터모델링 (GIS Data Modeling Plan for Tidal Power Energy Development in Incheon Bay of Korea)

  • 오정희;최현우;박진순;이광수
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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    • pp.166.2-166.2
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    • 2011
  • Incheon Bay of Korea is one of the most famous regions for high tidal range. Ministry of Land, Transport and Maritime Affairs(MLTM) has implemented preliminary investigation for tidal power energy development in this area since 2006. Through field observations, various kinds of marine data consisting of depth and geography, marine weather, tidal currents, wave, seawater characteristics, geology, marine ecosystem and marine environment were gathered. To use these data efficiently for the determining of feasibility of developing and appropriateness of project scale, spatial data management and application system is essential. Therefore, in this study, the concept, methodology and procedure of spatial data modeling are defined for tidal energy development. Spatial data modeling consists of essential model relating to tidal energy directly and optional model including environmental factors. Essential model is composed with fundamental elements like as depth, geography, and several numerical modeling results(tide, tidal current, wave).

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조력발전용 수차발전기의 기동·정지시스템에 관한 연구 (A Study on Start·Stop System at Water Turbine-Generator for Tidal Power Plant)

  • 오민환;박철원
    • 전기학회논문지P
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    • 제63권2호
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    • pp.113-118
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    • 2014
  • Tidal power is one of new and renewable energy sources. Tidal power is generated by using the gap in the water level between the water outside and inside the embankment. All tidal power plant in Korea were being operated by import of turn-key from abroad. The know-how and technology which are the most important to build predictive control system has become increasingly difficult to obtain from advanced countries because most of them avoid to transfer, which the domestic development of the control system is needed. In this paper, a study on start stop system at water turbine-generator for tidal power plant at the beginning of development was presented. For improvement the efficiency and develope of core technology of the start stop system, the technique and characteristics of tidal power, modeling, maximum generation calculation method, and optimal control of joint control system in Sihwa tidal power plant were studied.

Property Analyses of Deposits and Landform in Tidal Flat using Satellite Image

  • Jo, Myung-Hee;Sugimori, Yasuhiro;Jo, Wha-Ryong
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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    • pp.110-115
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    • 1998
  • Through the ISODATA method, the micro-landform of Julpo-Bay tidal flat was classified into mudflat, mixedflat, and sandflat using Landsat TM image. Each showed an apparent differences in its topographical characteristics and grain size composition. For example, mudflats are formed with flat faces and tidal channel of dissected gully. Its characteristics of grain size analysis that the grains have less than mean grain size 4 phi. Its sorting is bad (higher than 1 S.D.), and it showed strongly positive skewness. But sandflat is topographically flat without tidal channel. It has developed with ripple marks. According to the grain size analysis of deposits, the soil is coarse size with 90% of sand and its sorting is well(lower than 1 S.D.) Also, it showed strongly negative skewness. Mixed flat is in between mudflat and sandflat in its characteristics.

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수치모델링 실험을 통한 서해 천수만의 조류와 조석잔차류 특성 (Characteristics of Tidal Current and Tidal Residual Current in the Chunsu Bay, Yellow Sea, Korea based on Numerical Modeling Experiments)

  • 정광영;노영재;김백진
    • 한국해안·해양공학회논문집
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    • 제25권4호
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    • pp.207-218
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    • 2013
  • 수치 모델링 실험을 활용하여 서해 천수만의 해수 유동과 그 변화를 이해하기 위한 연구를 수행했다. 모델링 실험 결과에 대한 검증을 위해 관측 자료의 조위와 조류 각각 4대 분조의 진폭과 위상을 이용하여 스킬 분석을 실시했다. 그 결과 스킬 점수는 대부분 90%가 넘는 것으로 보아 수치 모델링 실험 결과는 관측된 조위와 조류가 양호하게 일치하는 것으로 나타났다. 천수만의 조석파는 만 입구에서 안쪽으로 진행되며 북부로 갈수록 조차는 점차 증가했다. 조석파가 북부까지 도달하는데 약 10~30분의 시간이 소요되었다. 남부에서 조석파는 반시계 방향으로 회전하는 특성을 보였다. 조류는 해저 지형을 따라 남-북 방향으로 흘렀으며, 장축의 각도는 등수심선과 나란히 나타났다. 조류타원의 단축이 장축의 10% 이하로 왕복성 조류의 특성을 보였다. 수심과 해안선 등 지형적 요인에 의해 좌우되는 조석잔차류의 크기는 1~30 cm/sec의 범위를 보였고, 남쪽 수로에서 컸으며 만의 북부에서는 작았다. 조석잔차류로부터 유도된 상대와도를 통해 수 백 m에서 수 km 크기로 시계/반시계 방향으로 회전하는 와류를 확인했고, 죽도 주변에서 2쌍, 남부에서 형성된 3~4쌍의 강한 와류 특성을 파악했다.

감조하천에서 조석 전파 및 조석비대칭 (Propagation of tidal wave and resulted tidal asymmetry upward tidal rivers)

  • 강주환;조홍연
    • 한국수자원학회논문집
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    • 제54권6호
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    • pp.433-442
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    • 2021
  • 하구역으로부터 감조하천 상류로 전파되는 조석파의 특성을 고찰하기 위하여 먼저 국내 연안에서 천문조인 M2분조와 천해조인 M4분조에 대한 조화상수를 분석해 조석비대칭 현상을 파악하였다. 하구역에서 천해조가 크게 발달함에 따라 한강과 금강의 경우 창조우세, 영산강의 경우 낙조우세가 형성된다. 이러한 조석비대칭 현상은 조류속 자료를 분석함으로써 재확인할 수 있다. 조류속 분석 결과 왕복성 조류패턴을 보이는 금강하구와 영산강하구의 경우와는 달리 한강하구의 경우 강화도 주변의 복잡한 지형 및 수로에 기인하여 회전성 조류패턴이 나타나기도 한다. 그러나 잔차류를 제거할 경우 조류속 관측자료 역시 조위와 일관된 창낙조우세를 보이고 있다. 하구역에서 형성된 조석비대칭 현상은 조석파가 감조하천 상류로 전파되면서 천해조의 성장과 더불어 더욱 심화되는 경향이 있다. 하천의 마찰특성과 단면형상에 따라 조석파의 전파양상에도 차이가 발생하여 수심이 얕은 한강과 금강의 경우 SD하구로 분류되어 에너지 소산이 매우 큰 반면 수심이 깊은 영산강의 경우 WD하구로 분류되어 에너지 소산이 덜 한 것으로 나타나고 있다.

3차원 수치모형을 이용한 방조제 끝막이 구간의 수리특성분석(수공) (An Analysis of Hydraulic Characteristics in Sea Dike Closure Gap Using a Three Dimensional Numerical Model)

  • 강민구;박승우;임상준
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2000년도 학술발표회 발표논문집
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    • pp.405-411
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    • 2000
  • This study reviews qualitatively the flow characteristics around th tidal gap during seadike closures using a three-dimensional model for shallow water equations. The Princeton Ocean Model(POM) was adapted and applied to the Sihwa Seadike which was closed in 1994. The simulated flow patterns around the gap showed that tidal velocities increase with the cross-sectional area during ebb tide. The accelerated flow extended to wider zones passing the gap, and shock waves were generated. Vertical tidal velocity profiles were affected as the bottom scours developed beyond normal conditions.

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