• 제목/요약/키워드: Flooding

검색결과 1,693건 처리시간 0.027초

선박 침수사고를 대비한 비상용 배수시스템 용량추정 프로세스에 관한 연구 (Estimation Process for the Capacity of Emergency Drainage System on a Ship after Flooding Accident)

  • 박병수;김성수;이순섭;강동훈;조현국
    • 수산해양교육연구
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    • 제28권6호
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    • pp.1739-1750
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    • 2016
  • This paper proposed a process for estimating the required capacity of emergency drainage system on a ship when the ship encounters a flooding accident. The process was established by selecting target vessel, making a scenario of flooding accident, considering static behavior of flooding water and the effect of ship motion due to ocean condition. In order to obtain the object of the research, MATLAB codes were developed for analyzing of static behavior of flooding water. Additionally, Ansys AQWA-NAUT was used to analyze the motion of the ship under an ocean condition and then the effect of ship motion was considered when the static behavior of flooding water was studied. The research exploited a trawler as a target vessel, and estimate the necessary capacity of the trawler's emergency drainage system by simulating a flooding water in the vessel.

Nitrogen Uptake and Growth of Soybean Seedlings under Flooding Stress

  • Won Jun-Yeon;Ji Hee-Chung;Cho Jin-Woong
    • 한국작물학회지
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    • 제51권2호
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    • pp.118-122
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    • 2006
  • This experiment was carried out on plastic pots ($40cm{\times}25cm{\times}30cm$) filled with sand soil at greenhouse using two soybean cultivars with small seed; one was Pungsannamulkong (PSNK) recognized as a tolerant cultivar against excessive water stress and the other one was Sobaeknamulkong (SBNK) recognized as a susceptible cultivar. Seed was sown with 30 plants of 2 hills, and the amount of applied fertilizer was N; 3.0 g, P; 3.0 g, and K; 3.4 g per $m^2$ with all basal fertilizations. Plants were grown under photoperiod of natural light with day temperature of $31{\pm}5^{\circ}C$ and night temperature of $22{\pm}1^{\circ}C$. The flooding treatment was done for 3, 5, 7 and 10 days by filling pots with tap water up to 1 cm above the level of the soil surface when plants were 2 days after emerging. Nitrogen uptake by leaves of soybeans decreased significantly by the flooding after 6 days. This significant reduction of N uptake by flooding was evidently recognized from the chlorosis of leaves. The dry matter of flooded soybean seedlings significantly decreased compared to non-flooded soybean seedlings at 10 days. The dry matter of roots also showed similar result of the shoot. Shoots had more N reduction than roots under the flooding. This N reduction was more pronounce in SBNK than in PSNK. Chlorophyll content of flooded soybeans showed decreasing or non-increasing tendency, and the reduction of chlorophyll content was more in SBNK than in PSNK from the flooding stress. Nitrate content of soybean seedlings with flooding stress showed decreasing tendency in shoot and root parts. Ammonium content, however, was higher in flooding stress compared to the non-flooding. Flooding caused a remarkable change in the AA (amino acid) composition and TAA (total amino acid) concentration in the leaves of soybean seedlings.

하천복원을 위한 버드나무속 식물의 내침수성 실험 연구 (Study on Flooding Tolerance of Salix Species for Ecological Restoration of the River)

  • 김은진;강준구;여홍구;김종태
    • 한국습지학회지
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    • 제16권4호
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    • pp.327-333
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    • 2014
  • 하천 생태 기능 증대 등 하천복원을 위한 식생 조성 시 내침수성이 강한 식물을 도입해야 하며 이를 위해 침수기간에 따른 하천식물의 생육특성 연구가 반드시 필요하다. 따라서 본 연구에서는 버드나무속 식물을 대상으로 식물키, 엽수, 녹색정도, 건중량 등을 측정하여 내침수성 및 침수기간에 따른 성장률을 분석하였으며 탁수에 의한 침수실험 결과와 비교하였다. 실험 결과 갯버들, 버드나무, 왕버들 중 내침수성이 가장 강한 식물은 버드나무이며 정수 상태의 침수는 고탁수 침수보다 고사 가능성이 매우 낮았다. 또한 버드나무속 식물은 20일 이하의 침수 시 비침수 조건보다 식물의 생장에 도움을 주는 것으로 나타났다.

무선 센서 네트워크에서의 적응적 재전송 노드 선택에 의한 효율적인 Flooding 알고리즘 (An Efficient Flooding Algorithm with Adaptive Retransmission Node Selection for Wireless Sensor Networks)

  • 최승준;유상조
    • 한국통신학회논문지
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    • 제32권11B호
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    • pp.673-684
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    • 2007
  • 본 논문에서는 무선 센서 네트워크에서 노드의 simple flooding에 의해 발생되는 broadcast storm problem을 해결하기 위한 크로스 레이어 기반의 효율적인 flooding 기법인 FARNS (Flooding algorithm with Adaptive Retransmission Nodes Selection)를 제안한다. FARNS는 MAC과 PHY에서 각각 이웃노들의 식별 정보와 수신신호강도 정보를 수집하여 패킷의 재전송에 사용될 재전송 후보 노드를 선택하여 모든 노드가 수신 패킷의 재전송을 시도하여 발생하는 불필요한 에너지의 낭비를 방지한다. 성능평가를 위한 모의 실험에서는 패킷의 수신비율과 전송비율, 평균중복패킷의 수와 오버헤드 등의 평가기준에서 FARNS가 다른 flooding 기법들보다 우수한 성능을 보인다. 또한, 재전송 동작에서 사용되는 노드들의 비율을 조절함으로써 다양한 네트워크 환경에서의 요구사항을 만족시키는 동시에 broadcast storm problem을 해결한다.

링크상태 라우팅 프로토콜의 효율적인 플러딩 (Efficient Flooding in Link-State Routing Protocols)

  • 박무성;이승형
    • 한국통신학회논문지
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    • 제39B권5호
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    • pp.326-328
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    • 2014
  • 본 논문에서는 링크상태 라우팅 프로토콜을 위한효율적인 LSA(Link State Advertisements) 플러딩(flooding) 방식을 제안한다. 링크상태(Link State) 라우팅 프로토콜은 유선 환경에서 널리 사용되고 있는 프로토콜로서, 노드의 링크 상태가 변경이 된 경우에 네트워크의 모든 이웃 노드에게 LSA를 플러딩 한다. 유선 환경과 다르게 무선 환경에서는 링크의 상태 변화가 빈번하게 발생되기 때문에 LSA의 오버헤드가 문제로 발생하게 된다. 본 논문에서는 무선 환경에서 사용 가능한 효율적인 LSA 플러딩 방식을 제안한다.

Active Timeout을 이용한 SYN Flooding 공격의 해결 (Defending against SYN Flooding Attacks based on Active Timeout)

  • 서정석;차성덕
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (1)
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    • pp.361-363
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    • 2004
  • 서비스 거부(denial of service) 공격의 일종인 SYN flooding 공격은 TCP/IP 프로토콜의 오류로 인해 발생한다. 기존의 SYN flooding 해결 연구들은 대부분 방화벽이나 라우터에서 패킷을 감시하여 불법적으로 판단된 패킷을 걸러내는 방법을 사용하였다. 따라서 기존의 연구들은 방화벽이나 라우터에 많은 부하를 주게 된다. 본 연구에서는 방화벽이나 라우터의 도움을 받지 않고, 기존의 네트워크 환경이나 운영체제에 큰 변화를 가하지 않으면서, 서버 시스템 자체만으로 SYN flooding 공격에 효율적으로 대응할 수 있는 방법을 제시하고자 한다.

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무선 센서 네트워크 상에서 에너지 효율적인 제한된 영역 조절 플러딩 (Energy Efficient Restricted Angle-Control Flooding in Wireless Sensor Networks)

  • 박은령;박명순
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제16권7호
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    • pp.804-808
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    • 2010
  • 본 논문에서는 네트워크에 분포된 센서 노드의 밀도와 노드의 제한된 에너지를 고려하여 데이터를 전송하는 Restricted Angle-control Flooding기법을 제안한다. 제안하는 기법은 특히 목적지에 가까워질수록 데이터 전송에 참여하는 노드의 수를 효율적으로 줄임으로써 불필요한 Broadcast 메시지를 제한하여 에너지 효율성을 높일 수 있으며, 노드의 Failure나 네트워크의 장애로 인한 Hole 발생시 Hole의 판단 기준에 따라 기존의 Flooding 방식 혹은 Forwarding area를 넓히는 Hole-Detection을 통하여 메시지 전송의 효율성을 높인다. 성능 평가를 통하여 노드 수가 증가할수록 기존의 Flooding에 비하여 메시지 전송시 소비되는 노드의 에너지와 전송률, 네트워크의 Lifetime면에서 우수하다는 것을 보여준다.

하수관거시설의 침수대응 운영·관리 실태 연구 (II) (Survey on sewerage operation/management planning for flooding (II))

  • 류재나;차영주;오재일;현인환;김영란;장대환
    • 상하수도학회지
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    • 제23권3호
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    • pp.271-276
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    • 2009
  • Under current design standard, sewers are designed to drain stormwater generated up to 10 year return period of storms. This implies sewer flooding could occur from rainfall exceeding a 10 year return period. 5, 10, 20 and 30 year return period of storm intensities were calculated for 22 locations (cities) of meterological stations over the nation and compared to the recorded rainfall intensities for the last 30 years. The comparison resulted in the numbers of year maximum rainfall intensities exceeded each return period. Using the questionnaire survey for "the incidences of flooding since 1980" of the previous paper (Survey on sewerage operation/management planning for flooding (I)), the actual rainfall records on the date of flooding events were analyzed to demonstrate the number of flooding events caused by the exceedance of sewer capacity. For the last 30 years, more than 6 years of year maximum rainfall intensity (20%) were larger than the 10 year return period of storm in 4 cities of the 22 used for the first analysis. The number of rainfall records that exceeded the 10 year return period was 50 of the 260 actual flooding events investigated from the survey.

Soybean Improvement for Drought, Salt and Flooding Tolerance

  • Pathan, Safiullah;Nguyen, Henry T.;Sharp, Robert E.;Shannon, J. Grover
    • 한국육종학회지
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    • 제42권4호
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    • pp.329-338
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    • 2010
  • Drought, salinity and flooding are three important abiotic factors limiting soybean production worldwide. Irrigation, soil reclamation, and drainage systems are not generally available or economically feasible for soybean production. Therefore, productive soybean varieties with tolerance are a cost effective means for reducing yield losses due to these factors. Genetic variability for higher tolerance to drought, salt and flooding is important. However, only a small portion of nearly 200,000 world soybean accessions have been screened to find genotypes with tolerance for use in breeding programs. Evaluation for tolerance to drought, salinity and flooding is difficult due to lack of faster, cost effective, repeatable screening methods. Soybean strains with higher tolerance to the above stresses have been identified. Crosses with lines with drought, salt and flooding tolerance through conventional breeding has made a significant contribution to improving tolerance to abiotic stress in soybean. Molecular markers associated with tolerance to drought, salt and flooding will allow faster, reliable screening for these traits. Germplasm resources, genome sequence information and various genomic tools are available for soybean. Integration of genomic tools coupled with well-designed breeding strategies and effective uses of these resources will help to develop soybean varieties with higher tolerance to drought, salt and flooding.

강우사상과 침수 실측자료를 이용한 도시침수 양상 관계분석 (Analysis of the urban flood pattern using rainfall data and measurement flood data)

  • 문혜진;조재웅;강호선;이한승;황정근
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2020년도 학술발표회
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    • pp.95-95
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    • 2020
  • Urban flooding occurs in the form of internal-water inundation on roads and lowlands due to heavy rainfall. Unlike in the case of rivers, inundation in urban areas there is lacking in research on predicting and warning through measurement data. In order to analyze urban flood patterns and prevent damage, it is necessary to analyze flooding measurement data for various rainfalls. In this study, the pattern of urban flooding caused by rainfall was analyzed by utilizing the urban flooding measuring sensor, which is being test-run in the flood prone zone for urban flooding management. For analysis, 2019 rainfall data, surface water depth data, and water level data of a street inlet (storm water pipeline) were used. The analysis showed that the amount of rainfall that causes flooding in the target area was identified, and the timing of inundation varies depending on the rainfall pattern. The results of the analysis can be used as verification data for the urban inundation limit rainfall under development. In addition, by using rainfall intensity and rainfall patterns that affect the flooding, it can be used as data for establishing rainfall criteria of urban flooding and predicting that may occur in the future.

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