• Title/Summary/Keyword: Current observation

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Report of East Sea Crossing by Underwater Glider (수중 글라이더를 이용한 동해 횡단 사례 보고)

  • Park, Yo-Sup;Lee, Shin-Je;Lee, Yong-Kuk;Jung, Seom-Kyu;Jang, Nam-Do;Lee, Ha-Woong
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.17 no.2
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    • pp.130-137
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    • 2012
  • The underwater glider using conception of Lagrangian method, is a new observation platform to understand the properties of the ocean vertically. In 2011 March, KORDI made a first successful autonomous trip from Hupo to west coast of Uleungdo piloting Littoral Glider of Alaska Native Technology LLC. The journey considered many environmental variables and route vigilantly selected, the glider covered 177 km horizontally and took approximately 6 days (153 hours). Despite the existence of 1 kt eddy current, Sound velocity sampling was conducted from 5 meters and reaching maximum of 200 meters depth at each dive. It successfully collected sound velocity and temperature profile at every 5 seconds totaling up to 1408 profiles using SVT&P sensor. During the flight it was also a mission to check the diverse modes of the glider i.e. spiral, waypoints, heading, drift and hover could function without a defect in a given situation. These modes were thoroughly monitored and it could be considered that the glider handled it well during the flight. As a result of this test flight, it was evident that the given underwater glider could operate under 2kt current environment with users defined heading and depth, also with the payload up to 5 kg without changing internal buoyancy.

Current and Future Changes in the Type of Wintertime Precipitation in South Korea (현재와 미래 우리나라 겨울철 강수형태 변화)

  • Choi, Gwang-Yong;Kwon, Won-Tae
    • Journal of the Korean Geographical Society
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    • v.43 no.1
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    • pp.1-19
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    • 2008
  • This study intends to clarify the characteristics and causes of current changes in wintertime precipitation in Korea and to predict the future directions based on surface observational $(1973/04\sim2006/07)$ and modeled (GFDL 2.1) climate data. Analyses of surface observation data demonstrate that without changes in the total amount of precipitation, snowfall in winter (November-April) has reduced by 4.3cm/decade over the $1973\sim2007$ period. Moreover, the frequency and intensity of snowfall have decreased; the duration of snow season has shortened; and the snow-to-rain day ratio (STDR) has decreased. These patterns indicate that the type of wintertime precipitation has changed from snow to rain in recent decades. The snow-to-rain change in winter is associated with the increases of air temperature (AT) over South Korea. Analyses of synoptic charts reveal that the warming pattern is associated with the formation of a positive pressure anomaly core over northeast Asia by a hemispheric positive winter Arctic Oscillation (AO) mode. Moreover, the differentiated warming of AT versus sea surface temperature (SST) under the high pressure anomaly core reduces the air-sea temperature gradient, and subsequently it increases the atmospheric stability above oceans, which is associated with less formation of snow cloud. Comparisons of modeled data between torrent $(1981\sim2000)$ and future $(2081\sim2100)$ periods suggest that the intensified warming with larger anthropogenic greenhouse gas emission in the $21^{st}$ century will amplify the magnitude of these changes. More reduction of snow impossible days as well as more abbreviation of snow seasons is predicted in the $21^{st}$ century.

A Study on the Flood Reduction in Eco-Delta City in Busan using Observation Rainfall and Flood Modelling (관측 강우와 침수모의를 이용한 부산 에코델타시티 수해저감에 관한 연구)

  • Kim, YoonKu;Kim, SeongRyul;Jeon, HaeSeong;Choo, YeonMoon
    • Journal of Wetlands Research
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    • v.22 no.3
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    • pp.187-193
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    • 2020
  • The increase in the area of impervious water due to the recent abnormal weather conditions and rapid urbanization led to a decrease in the amount of low current, resulting in an increase in the amount of surface runoff. Increased surface runoff is causing erosion, destruction of underwater ecosystems, human and property damage in urban areas due to flooding of urban river. The damage has been increasing in Korea recently due to localized heavy rains, typhoons and floods. As a countermeasure, the Busan Metropolitan Government will proceed with the creation of the Eco-Delta City waterfront zone in Busan with the aim of creating a future-oriented waterfront city from 2012 to 2023. Therefore, the current urban river conditions and precipitation data were collected by utilizing SWMM developed by the Environment Protection Agency, and the target basin was selected to simulate flood damage. Measures to reduce flood damage in various cases were proposed using simulated data. It is a method to establish a disaster prevention plan for each case by establishing scenario for measures to reduce flood damage. Considering structural and non-structural measures by performing an analysis of the drainage door with a 30-year frequency of 80 minutes duration, the expansion effect of the drainage pump station is considered to be greater than that of the expansion of the drainage door, and 8 scenarios and corresponding alternatives were planned in combination with the pre-excluding method, which is a non-structural disaster prevention measure. As a result of the evaluation of each alternative, it was determined that 100㎥/s of the pump station expansion and the pre-excluding EL.(-)1.5m were the best alternatives.

The Past, Present and Future Strategies of Korean Social Work in Hospice and Palliative Care (한국 호스피스.완화의료 사회복지의 과거, 현재 그리고 미래 전략)

  • Lee, Young Sook
    • Journal of Hospice and Palliative Care
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    • v.16 no.2
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    • pp.65-73
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    • 2013
  • The objective of this paper is to suggest future goals and strategies for social work in hospice and palliative care in Korea by understanding its historical background. Both literature review and participant observation were performed to examine historical data relating to social work in hospice and palliative care in Korea. Also reviewed were the current trends with a focus on the roles of social workers in the said arena, qualifications, education, research and medical insurance policy. First of all, the roles of social workers do not appear to be clearly defined in the field of hospice and palliative care, which seems to lead to the lack of recognition as professional workers. The qualification standard for social workers in hospice and palliative care remains inadequate. Second, there seems to be insufficient professional social worker training resources, in terms of both the number of educators and training programs. Third, social workers in Korea produce significantly less publications than those in other professions. There is also a dearth of qualified evidence-based research that is needed to prove benefits of intervention and ultimately for policy implications. Last, the current medical insurance policy needs to be revised to secure fees for social work services and dedicated full-time social workers in hospice and palliative care. Korea needs to approach social work in hospice and palliative care with specific goals to develop future strategies. Related infrastructure and an executive structure should be established via networking and partnership with academic societies, associations and schools.

Effects of High-Intensive Exercise Duration on Hematologic Properties and Cytokines in Rats (고강도운동 지속시간이 rat의 혈액학적 조성과 사이토카인에 미치는 영향)

  • Hyun, Kyung-Yae
    • Journal of Life Science
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    • v.21 no.7
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    • pp.1039-1045
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    • 2011
  • The effects of duration and time-dependent, high-intensity exercise on hematological properties and inflammation-related parameters in rats were studied. 20, 60, and 120 min of high-intensive exercise were performed daily for 8 weeks. None of the complete blood count (CBC) factors were affected by the exercise, except for the leukocyte concentration which, in the 20 min group, showed an increase of 47% compared to the control, but this was decreased after 60 min by 30% compared to the control. As exercise was performed for 60 min or longer, serum concentrations of $Fe^{++}$, unsaturated iron biding capacity (UIBC), and total iron biding capacity (TIBC) were significantly elevated in comparison to the control, where 20 min of exercise did not show any change. Both levels of interleukin-6 (IL-6), a pro-inflammatory cytokine, and interleukin-10 (IL-10), an anti-inflammatory cytokine in the serum, were elevated in response to the high-intensity exercise, however the rate of IL-6 increase was higher than the rate of exercise intensity increase, thus the offset of inflammation might be suggested. The concentration of nitric oxide (NO) in the serum became high in response to the exercise. Overall, the current observation suggests that inflammation-like responses to high-intensity exercise might be due to high circulation of blood flow and high oxygen requirement, resulting in systemic damages. However, under the current high-intensity exercise conditions, more than 20 min of exercise might not be suggested for health care purposes.

Entering and Leaving Behaviour of Fish Schools to Set-net in the Coast of Cheju Island (제주도 연안 정치망에 입·출망하는 어군의 행동)

  • Kim, Seong-Hyun;Kim, Mun-Kwan;Kim, Suk-Jong;Park, Jeong-Sik
    • Journal of Fisheries and Marine Sciences Education
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    • v.10 no.2
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    • pp.211-225
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    • 1998
  • A field experiment was carried out for fishes on entering time to a set-net, swimming speed, current speed and direction at the Dongbok-Ri coast on Cheju Island. The results of the experiment are as follows : 1. The observation results from 07:00 to 18:00 showed that coral fish, flying fish, horse mackerel, drub mackerel and striped mullet enter the set-net from 07:00 to 14:00 mainly. 2. From the result of analyzing relationships between entering time and tide, coral fish and horse mackerel tend to enter the set-net on turn of tidal current and ebb respectively. 3. The leaving rates of coral fish, flying fish, drub mackerel, and striped mullet from the set-net were 13%, 45%, 50%, and 100%, respectively but all horse mackerel remained in the net. 4. The swimming speed of coral fish, flying fish, horse mackerel and drub mackerel are 5~25cm/sec, 20~50cm/sec, 15~45cm/sec and 10~30cm/sec, respectively and their dominant speeds are 10~15cm/sec(55%), 30~35cm/sec(30%), 30~40cm/sec(60%), and 15~20cm/sec(60%), respectively.

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A Study on the Development of GIS based Integrated Information System for Water Quality Management of Yeongsan River Estuary (영산강 하구역 수질환경 관리를 위한 GIS기반 통합정보시스템 개발에 관한 연구)

  • Lee, Sung Joo;Kim, Kye Hyun;Park, Young Gil;Lee, Geon Hwi;Yoo, Jea Hyun
    • Journal of Wetlands Research
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    • v.16 no.1
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    • pp.73-83
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    • 2014
  • The government has recently carried out monitoring to attain a better understanding of the current situation and model for prediction of future events pertaining to water quality in the estuarine area of Yeongsan River. But many users have noted difficulties to understand and utilize the results because most monitoring and model data consist of figures and text. The aim of this study is to develop a GIS-based integrated information system to support the understanding of the current situation and prediction of future events about water quality in the estuarine area of Yeongsan River. To achieve this, a monitoring DB is assembled, a linkages model is defined, a GUI is composed, and the system development environment and system composition are defined. The monitoring data consisted of observation data from 2010 ~ 2012 in the estuarine area of Yeongsan River. The models used in the study are HSPF (Hydrological Simulation Program-Fortran) for simulation of the basin and EFDC (Environmental Fluid Dynamics Code) for simulation of the estuary and river. Ultimately, a GIS based system was presented for utilization and expression using monitoring and model data. The system supports prediction of the estuarine area ecological environment quantitatively and displays document type model simulation results in a map-based environment to enhance the user's spatial understanding. In future study, the system will be updated to include a decision making support system that is capable of handling estuary environment issues and support environmental assessment and development of related policies.

Variations of the Sea Surface Temperature Distribution and the Shelf Fronts in the Cheju Strait and the Korea Strait (한국 남해연안의 해표면 수온분포와 천해전선의 변동 특성)

  • 양성기
    • Journal of Environmental Science International
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    • v.3 no.2
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    • pp.111-128
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    • 1994
  • The distributions of sea surface temperature across the Cheju Strait and the Korea Strait have been measured by using a thermometer installed on board No.1 Cheju, a ferry that operates regularly between Pusan and Seogwipo. The data from 14 October 1991 to 15 August 1992 were analyzed in this paper. A clear temperature front is wormed at the adjacent sea of Geomundo, and its position is not fixed and moves north and south. The slow northward movement of the front can easily be traced, but the southward movement from March to October is obscure. The temperature contrast in the Cheju Soait and the Korea Strait is very we in this period. Some periodical fluctuations with a period of several tens of days are observed in the region of the temperature front from November to February. This fluctuation seems to be caused by winter heat flux exchange and the strong southeastward wind force. The result shows that continous observation of the sea surface temperature distribution across the Cheju Strait and the Korea Strait yields a good method for monitoring the presence of Tsushima Warm Current and the fluctuations of South Korea Coastal Water. The formation and structure of shelf front in the Cheju Strait and the Korea Strait was analysed based on the detailed oceanographic data observed during the period of 1990-1992. The analysis shows that well-defined fronts were formed through yearly around the Chuja Island, particularly, in summer. In nature, its structure and formation position can be changed easily from year % year and by season. But, in region of the Korea Strait this front is relatively weak.

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Three-Dimensional Mixing Characteristics in Seomjin River Estuary (섬진강 하구역의 3차원 혼합특성 연구)

  • Kim, Jong-Kyu;Kwak, Gyeong-Il;Jeong, Jeong-Ho
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.11 no.3
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    • pp.164-174
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    • 2008
  • In this study we try to identify the three-dimensional mixing characteristics of Seomjin River discharges in Seomjin River Estuary and Gwangyang Bay using a seasonal field observation (CTD) during spring tide and a three-dimensional numerical model with EFDC (Environmental Fluid Dynamics Code). The tidal elevation conditions of the four main tidal harmonic constituents on the open boundary and river discharges and thermal effluents at the specific boundary are considered. The calculated harmonic constants of tide and tidal current agreed well with those of observations at two stations for tide and two stations for tidal current. The model successfully reproduced well known the estuarine circulation in Seomjin River Estuary where tide and river discharges are dominant forcings. In the winter mean discharges case, tidal currents move Seomjin River discharges in Seomjin River mouth and in the summer mean discharges case, river flows move Seomjin River discharges near ae Seomjin River Estuary. A three-dimensional mixing characteristics of Seomjin River Estuary show well a three-dimensional estuarine circulation and thermal effluents effect to the seasonal variation of river discharges.

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The Current Methods of Landslide Monitoring Using Observation Sensors for Geologic Property (지질특성 관측용 센서를 이용한 산사태 모니터링 기법 현황)

  • Chae, Byung-Gon;Song, Young-Suk;Choi, Junghae;Kim, Kyeong-Su
    • Journal of Sensor Science and Technology
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    • v.24 no.5
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    • pp.291-298
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    • 2015
  • There are many landslides occurred by typhoons and intense rainfall during the summer seasons in Korea. To predict a landslide triggering it is important to understand mechanisms and potential areas of landslides by the geological approaches. However, recent climate changes make difficult to predict landslide based on only conventional prediction methods. Therefore, the importance of a real-time monitoring of landslide using various sensors is emphasized in recent. Many researchers have studied monitoring techniques of landslides and suggested several monitoring systems which can be applicable to the natural terrain. Most sensors of landslide monitoring measure slope displacement, hydrogeologic properties of soils and rocks, changes of stress in soil and rock fractures, and rainfall amount and intensity. The measured values of each sensor are transmitted to a monitoring server in real-time. The ultimate goal of landslide monitoring is to warn landslide occurrence in advance and to reduce damages induced by landslides. This study introduces the current situation of landslide monitoring techniques in each country.