• Title/Summary/Keyword: flooding

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

  • PARK, Byung-Soo;KIM, Sung-Soo;LEE, Soon-Sup;KANG, Dong-Hoon;CHO, Hyun-Kuk
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.6
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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
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.2
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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.

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

  • Kim, Eun Jin;Kang, Joon Gu;Yeo, Hong Koo;Kim, Jong Tae
    • Journal of Wetlands Research
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    • v.16 no.4
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    • pp.327-333
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    • 2014
  • The vegetation composition for river restoration requires the introduction of plants which have strong flooding tolerance. A study of the growth characteristics of river plants according to the period of flooding is essential. Accordingly, this study measured shoots, leaf number, leaf greenness, dry weight of the plants of Salix species, analyzed their growth rate according to flooding tolerance and the period of flooding, and contrasted the results with those of a flooding experiment in turbid water. The results of this experiment showed that Koreensis is the plant which has the strongest flooding tolerance and flooding in fresh water leads to a much lower risk of the plants being withered than in high turbid water. In addition, the results showed that the condition of the period of flooding of twenty days and under contributes to more growth and development of the plants of Salix species than the condition of non-flooding.

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

  • Choi, Seung-Joon;Yoo, Sang-Jo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.11B
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    • pp.673-684
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    • 2007
  • In this paper, we introduce an FARNS (Flooding algorithm with Adaptive Retransmission Nodes Selection). It is an efficient cross layer-based flooding technique to solve broadcast storm problem that is produced by simple flooding of nodes in wireless sensor network. FARNS can decrease waste of unnecessary energy by preventing retransmission action of whole network node by deciding retransmission candidate nodes that are selected by identification in MAC and distance with neighborhood node through received signal strength information in PHY. In simulation part, we show the results that FARNS has excellent performance than the other flooding schemes in terms of broadcast forwarding ratio, broadcast delivery ratio, number of redundancy packets and overhead. And FARNS can adjust of node ratio for retransmission operation, it can solve broadcast storm problem as well as meet the requirements of various network environments.

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

  • Park, Moosung;Rhee, Seung-Hyong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.5
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    • pp.326-328
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    • 2014
  • In this paper we propose an efficient algorithm for LSA(Link State Advertisements) flooding. Link state routing protocols have been widely adopted in wired networks. When link state change occurs, a LSA is flooded into the whole network. The overhead of LSA flooding may be a big problem in wireless networks because their link states can be changed frequently. We propose an efficient flooding method that optimizes the flooding processes in wireless networks.

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

  • 서정석;차성덕
    • Proceedings of the Korean Information Science Society Conference
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    • 2004.10a
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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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Energy Efficient Restricted Angle-Control Flooding in Wireless Sensor Networks (무선 센서 네트워크 상에서 에너지 효율적인 제한된 영역 조절 플러딩)

  • Park, Eun-Ryung;Park, Myong-Soon
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.7
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    • pp.804-808
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    • 2010
  • In this paper, we propose Restricted Angle-control Flooding considered density network of sensor nodes and node‘s limit energy. Restricted Angle-control Flooding, increase energy efficiency by reducing unnecessary candidate nodes involved in forwarding closer to the destination. And The Hole when faced with our proposal to raise rates data through Hole Detection which is sender‘s forwarding area is extended or broadcast to the entire network. Compared to the traditional flooding, we show the superiority at the node’s energy consumption, data rate and network lifetime through the performance.

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

  • Ryu, Jaena;Cha, Young Joo;Oh, Jeill;Hyun, In Hwan;Kim, Young-Ran;Chang, Dae-Hwan
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.3
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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
    • Korean Journal of Breeding Science
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    • v.42 no.4
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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.

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

  • Moon, Hye Jin;Cho, Jae Woong;Kang, Ho Seon;Lee, Han Seung;Hwang, Jeong Geun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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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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