• Title/Summary/Keyword: Storm

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Estimation of Annual Energy Production Based on Regression Measure-Correlative-Predict at Handong, the Northeastern Jeju Island (제주도 북동부 한동지역의 MCP 회귀모델식을 적용한 AEP계산에 대한 연구)

  • Ko, Jung-Woo;Moon, Seo-Jeong;Lee, Byung-Gul
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.6
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    • pp.545-550
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    • 2012
  • Wind resource assessment is necessary when designing wind farm. To get the assessment, we must use a long term(20 years) observed wind data but it is so hard. so that we usually measured more than a year on the planned site. From the wind data, we can calculate wind energy related with the wind farm site. However, it calculate wind energy to collect the long term data from Met-mast(Meteorology Mast) station on the site since the Met-mast is unstable from strong wind such as Typhoon or storm surge which is Non-periodic. To solve the lack of the long term data of the site, we usually derive new data from the long term observed data of AWS(Automatic Weather Station) around the wind farm area using mathematical interpolation method. The interpolation method is called MCP(Measure-Correlative-Predict). In this study, based on the MCP Regression Model proposed by us, we estimated the wind energy at Handong site using AEP(Annual Energy Production) from Gujwa AWS data in Jeju. The calculated wind energy at Handong was shown a good agreement between the predicted and the measured results based on the linear regression MCP. Short term AEP was about 7,475MW/year. Long term AEP was about 7,205MW/year. it showed an 3.6% of annual prediction different. It represents difference of 271MW in annual energy production. In comparison with 20years, it shows difference of 5,420MW, and this is about 9 months of energy production. From the results, we found that the proposed linear regression MCP method was very reasonable to estimate the wind resource of wind farm.

Spatial Analysis of Typhoon Genesis Distribution based on IPCC AR5 RCP 8.5 Scenario (IPCC AR5 RCP 8.5 시나리오 기반 태풍발생 공간분석)

  • Lee, Sungsu;Kim, Ga Young
    • Spatial Information Research
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    • v.22 no.4
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    • pp.49-58
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    • 2014
  • Natural disasters of large scale such as typhoon, heat waves and snow storm have recently been increased because of climate change according to global warming which is most likely caused by greenhouse gas in the atmosphere. Increase of greenhouse gases concentration has caused the augmentation of earth's surface temperature, which raised the frequency of incidences of extreme weather in northern hemisphere. In this paper, we present spatial analysis of future typhoon genesis based on IPCC AR5 RCP 8.5 scenario, which applied latest carbon dioxide concentration trend. For this analysis, we firstly calculated GPI using RCP 8.5 monthly data during 1982~2100. By spatially comparing the monthly averaged GPIs and typhoon genesis locations of 1982~2010, a probability density distribution(PDF) of the typhoon genesis was estimated. Then, we defined 0.05GPI, 0.1GPI and 0.15GPI based on the GPI ranges which are corresponding to probability densities of 0.05, 0.1 and 0.15, respectively. Based on the PDF-related GPIs, spatial distributions of probability on the typhoon genesis were estimated for the periods of 1982~2010, 2011~2040, 2041~2070 and 2071~2100. Also, we analyzed area density using historical genesis points and spatial distributions. As the results, Philippines' east area corresponding to region of latitude $10^{\circ}{\sim}20^{\circ}$ shows high typhoon genesis probability in future. Using this result, we expect to estimate the potential region of typhoon genesis in the future and to develop the genesis model.

Application of a Grid-Based Rainfall-Runoff Model Using SRTM DEM (SRTM DEM을 이용한 격자기반 강우-유출모의)

  • Jung, In-Kyun;Park, Jong-Yoon;Park, Min-Ji;Shin, Hyung-Jin;Jeong, Hyeon-Gyo;Kim, Seong-Joon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.13 no.4
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    • pp.157-169
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    • 2010
  • In this study, the applicability of SRTM(The Shuttle Radar Topography Mission) DEM(Digital Elevation Model) which is one of the remotely sensed shuttle's radar digital elevation was tested for use as the input data in a grid-based rainfall-runoff model. The SRTM DEM and digital topographic map derived DEM(TOPO DEM) were building with 500m spatial resolution for the Chungju-Dam watershed which located in the middle east of South Korea, and stream-burning method was applied to delineate the proper flow direction for model application. Similar topographical characteristics were shown as a result of comparing elevation, flow-direction, hydrological slope, number of watershed cell, and profile between SRTM DEM and TOPO DEM. Two DEMs were tested by using a grid-based rainfall-runoff model named KIMSTORM with 6 storm events. The results also showed no significant differences in average values of relative error for both peak runoff(0.91 %) and total runoff volume(0.29 %). The results showed that the SRTM DEM has applicability like TOPO DEM for use in a grid-based rainfall-runoff modeling.

Scientific Missions and Technologies of the ISSS on board the NEXTSat-1

  • Choi, Cheong Rim;Sohn, Jongdae;Lee, Jun-Chan;Seo, Yong Myung;Kang, Suk-Bin;Ham, Jongwook;Min, Kyoung-Wook;Seon, Jongho;Yi, Yu;Chae, Jang-Soo;Shin, Goo-Hwan
    • Journal of Astronomy and Space Sciences
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    • v.31 no.1
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    • pp.73-81
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    • 2014
  • A package of space science instruments, dubbed the Instruments for the Study of Space Storms (ISSS), is proposed for the Next Generation Small Satellite-1 (NEXTSat-1), which is scheduled for launch in May 2016. This paper describes the instrument designs and science missions of the ISSS. The ISSS configuration in NEXTSat-1 is as follows: the space radiation monitoring instruments consist of medium energy particle detector (MEPD) and high energy particle detector (HEPD); the space plasma instruments consist of a Langmuir probe (LP), a retarding potential analyzer (RPA), and an ion drift meter (IDM). The space radiation monitoring instruments (MEPD and HEPD) measure electrons and protons in parallel and perpendicular directions to the geomagnetic field in the sub-auroral region, and they have a minimum time resolution of 50 msec for locating the region of the particle interactions with whistler mode waves and electromagnetic ion cyclotron (EMIC) waves. The MEPD measures electrons and protons with energies of tens of keV to ~400 keV, and the HEPD measures electrons with energies of ~100 keV to > ~1 MeV and protons with energies of ~10 MeV. The space plasma instruments (LP, RPA, and IDM) observe irregularities in the low altitude ionosphere, and the results will be compared with the scintillations of the GPS signals. In particular, the LP is designed to have a sampling rate of 50 Hz in order to detect these small-scale irregularities.

Computation of Criterion Rainfall for Urban Flood by Logistic Regression (로지스틱 회귀에 의한 도시 침수발생의 한계강우량 산정)

  • Kim, Hyun Il;Han, Kun Yeun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.6
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    • pp.713-723
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    • 2019
  • Due to the climate change and various rainfall pattern, it is difficult to estimate a rainfall criterion which cause inundation for urban drainage districts. It is necessary to examine the result of inundation analysis by considering the detailed topography of the watershed, drainage system, and various rainfall scenarios. In this study, various rainfall scenarios were considered with the probabilistic rainfall and Huff's time distribution method in order to identify the rainfall characteristics affecting the inundation of the Hyoja drainage basin. Flood analysis was performed with SWMM and two-dimensional inundation analysis model and the parameters of SWMM were optimized with flood trace map and GA (Genetic Algorithm). By linking SWMM and two-dimensional flood analysis model, the fitness ratio between the existing flood trace and simulated inundation map turned out to be 73.6 %. The occurrence of inundation according to each rainfall scenario was identified, and the rainfall criterion could be estimated through the logistic regression method. By reflecting the results of one/two dimensional flood analysis, and AWS/ASOS data during 2010~2018, the rainfall criteria for inundation occurrence were estimated as 72.04 mm, 146.83 mm, 203.06 mm in 1, 2 and 3 hr of rainfall duration repectively. The rainfall criterion could be re-estimated through input of continuously observed rainfall data. The methodology presented in this study is expected to provide a quantitative rainfall criterion for urban drainage area, and the basic data for flood warning and evacuation plan.

A study on the determination of location of the detention pond in trunk sewer for reducing runoff amounts (우수유출저감을 위한 간선저류지 위치선정에 관한 연구)

  • Lee, Sung Ho;Yoon, Sei Eui;Lee, Jae Joon
    • Journal of Korea Water Resources Association
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    • v.50 no.4
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    • pp.223-232
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    • 2017
  • The ability to defend against floods in urban areas was weakened, because the increase in the impervious rate of urban areas due to urbanization and industrialization and the increase in the localized torrential rainfall due to abnormal climate. In order to reduce flood damage in urban areas, various runoff reduction facilities such as detention ponds and infiltration facilities were installed. However, in the case of domestic metropolitan cities, it is difficult to secure land for the installation of storm water reduction facilities and secure the budget for improving the aged pipelines. Therefore, it is necessary to design a storage system (called the detention pond in trunk sewer) that linked the existing drainage system to improve the flood control capacity of the urban area and reduce the budget. In this study, to analyze the effect of reducing runoff amounts according to the volume of the detention pond in trunk sewer, three kinds of virtual watershed (longitudinal, middle, concentration shape) were assumed and the detention pond in trunk sewer was installed at an arbitrary location in the watershed. The volume of the detention pond in trunk sewer was set to 6 cases ($1,000m^3$, $3,000m^3$, $5,000m^3$, $10,000m^3$, $20,000m^3$, $30,000m^3$), and the installation location of the detention pond in trunk sewer was varied to 20%, 40%, 60%, and 80% of the detention pond upstream area to the total watershed area (DUAR). Also, using the results of this study, a graph of the relationship and relational equation between the volume of the detention pond in trunk sewer and the installation location is presented.

Effectiveness of Settling Treatment System to Reduce Urban Nonpoint Source Pollutant Load by First Flush (초기 강우에 의한 도시 유역 비점오염 부하의 유입 저감을 위한 침강 처리 시설 적용 타당성 분석)

  • Kim, Jaeyoung;Seo, Dongil;Lee, Tongeun
    • Journal of Korean Society of Environmental Engineers
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    • v.39 no.3
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    • pp.140-148
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    • 2017
  • The effectiveness of the first flush treatment system using settling process was evaluated to reduce urban nonpoint source pollutant loads to surface water during storm events. A pilot scale system was constructed and tested in the field and surface runoff samples were collected automatically according to pre-defined conditions. Nine rainfall events were tested and average removal efficiencies of TSS (Total Suspended Solid), TP (Total Phosphorus) and TN (Total Nitrogen) were evaluated as 87.4%, 75.3%, and 43.6%, respectively. Concentration and removal efficiency of pollutants were found to be affected by an amount of rainfall and rainfall intensities of the respective events. This seemed to be caused by the greater particulate fractions of first flushed samples than the samples collected in later time periods during the same rainfall events. The study showed that it is possible to remove a significant portion of the nonpoint source pollutant loads in initial rainfall runoff by using a simple settling process for TSS and TP without requiring additional power or chemicals.

The Debate on Net Neutrality: Evidences, Issues and Implications (망중립성 논의의 쟁점과 함의)

  • Chung, Dong-Hun
    • Informatization Policy
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    • v.25 no.1
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    • pp.3-29
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    • 2018
  • The Federal Communications Commission voted to repeal net neutrality protections on December 14, 2017. This is the very opposite decision of the net neutrality rule that the Obama administration has consistently maintained. The ensuing storm from the repeal of net neutrality protections has an extensively effect enough on individuals and businesses to cover the entire spectrum, and the impact is hard to assess in the U. S. content industry, which dominates the worldwide Internet content and platform market. On the other hand, Korea's net neutrality protections have been firmly pursued, and there is no sign of change even after the decision happened in the U. S. Net neutrality is not a simple theme that is associated with the Constitution, such as freedom of expression, as well as the issue of network enhancement to prepare for 5G. Accordingly, this study examines how the net neutrality has been carried out in the U. S. and Korea over the years, and provides the issues of Internet enhancement, perspectives of ISP and ICP, and implications for the Constitution, market economy, fair competition and zero rating. This research delivers future direction and implications of domestic net neutrality policies.

A Study to Construct a Decision-making Checklist through the Analysis of Past Disaster Case (과거 재난사례분석을 통한 재난 의사결정 체크리스트 구성에 관한 연구)

  • Seo, Kyungmin;Rheem, Sankyu;Choi, Woojung
    • Journal of the Society of Disaster Information
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    • v.16 no.2
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    • pp.248-266
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    • 2020
  • Purpose: The purpose of this study is to create a checklist for each type of disaster and to suggest a method for establishing an appropriate response system and making accurate and rapid decision-making. Method: In order to derive checklist factors, previous case analyses (Tropical Storm Rusa (2002), Typhoon Maemi (2003), and Typhoon Chaba (2016) were conducted for typhoon disaster. Grouping was conducted to derive checklist factors by analyzing general status (climate and weather) information and characteristics by case. Result: The case study was divided into national level and county level. In terms of national unit, eight forecasts were included: weather forecast, typhoon landing status, typhoon intensity, typhoon radius, central pressure, heavy rain conditions, movement speed, and route. Local governments should reflect regional characteristics, focusing on the presence or absence of similar typhoons (paths) in the past, typhoon landing time, regional characteristics, population density, prior disaster recovery, recent disaster occurrence history, secondary damage, forecast warning system. A total of eight items were derived. Conclusion: In the event of a disaster, decision making will be faster if the checklist proposed in this study is used and applied. In addition, it can be used as the basic data for disaster planners' response plans in case of disasters, and it is expected to be a more clear and quick disaster preparedness and response because it reflects local characteristics.

Violence Experiences of Community Mental Health Nurse (지역사회 정신보건간호사의 폭력경험)

  • Kim, Mi-Hye;Kim, Han-Na;Shin, Yoon-Mee;Oh, Hyun-Mi;Lee, Jeong-Seop
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8626-8636
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    • 2015
  • This study is a qualitative study to disclose the meaning and reality of violence experiences of the mental health nurses by the phenomenological approach. This study is done with the participation of 9 community mental health nurses who have work experiences more than 3 years in the city of S, from Nov 7, 2014 till Dec 21, 2014. The result of the study revealed that the violence experiences of this study participants may be categorized into 4 categories, 'a small boat running into a storm', 'open sea', 'a small boat lost of the sign post', 'a captain controlling the rudder' and may be identified with 11 theme cluster and 32 theme.Therefore violence from patients who have experienced mental health nurse could be found to affect even the identity of the mental health nurse as well as threaten safety of professionals. This may threaten the quality of service provided to the patient, so we have to accept reality as a serious problem. Also it has been preceded by what the support program development of the nursing organization for the nurse who is violence victims with preparing for violence Prevention. As the result we suggest that you prepare a practical measures for the safety and quality nursing services performed by mental health nurses.