• Title/Summary/Keyword: Flooding condition

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A Study on Empirical Method Analysis of Impervious Surface Using KOMPSAT-2 Image (KOMPSAT-2 위성영상을 이용한 불투수지도작성 방법에 관한 실증연구)

  • Bae, Da-Hye;Lee, Jae-Yil;Ko, Chang-Hwan;Ha, Sung-Ryong
    • Journal of Environmental Impact Assessment
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    • v.20 no.5
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    • pp.717-727
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    • 2011
  • Impervious surface affects urban climate, flood, and water pollution and has important role as basic data for urban planning and environmental and resources management uses. With a high paved rate, increased quantity of the outflown water and brings urban flooding during a heavy rain. Moreover, these non-point source pollution is getting increased the water pollution. In this regard, it is definitely important to research and keep monitoring the current situation of paved surface, which influences urban ecosystem, disaster and pollution. In this study, we suggest a method to utilize high resolution satellite image data for efficient survey on the current condition of paved surface. We analysed the paved surface condition of Dae-jeon metropolitan city area using KOMPSAT-2 image and validate its practicalness and limitation of this method.

A Study on the condensate Retention at Horizontal Integral-Fin tubes (낮은 핀을 가진 수평관의 응축액 억류에 관한 연구)

  • 한규일;조동현
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.8 no.1
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    • pp.151-165
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    • 1996
  • Relation between condensate retention and heat transfer performance is studied for condensation of CFC-11 on horizontal integral-fin tubes. Eight tubes with trapezoidally shaped integral fin density from 738fpm to 1654fpm and 10, 30 grooves are tested. The liquid retention angles are measured by the height gauge, and each tube is tested under static(non-condensing) condition (CFC-11, water) and under dynamic(condensing) condition (CFC-11). The analytical model predicts the amount of liquid retention on a horizontal integral-fin tubes within+10 percent over most of the data. Average retention angle increases as both surface tension-to-density ratio($\sigma/\rho$) and fin density(fpm) increase, The tube having a fin density of 1299~1654fpm has the best heat transfer performance. The amount of surface flooding must keep below of 40 percent for best heat transfer performance at condensation. The tube having low number of fin density must be used for fluids having high values of $\sigma/\rho$(water, (TEX)$NH_3$, ect.) and the tube having high number of fin density must be used for the fluid having low values of $\sigma/\rho$(R-11, R-22, etc.)

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A Clustering Mechanism based on Vehicle Local Information in the Vehicular Ad Hoc Network (차량 애드혹 네트워크에서 차량 자체 정보를 기반으로 한 클러스터링 기법)

  • Ahn, Sang-Hyun;Lim, Yu-Jin
    • The KIPS Transactions:PartC
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    • v.18C no.6
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    • pp.445-450
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    • 2011
  • In the vehicular ad hoc network environment, the clustering mechanism is one of the efficient mechanisms to deliver broadcast messages. Most clustering mechanisms require message exchanges between vehicles to build stable clusters, which causes overhead. In order to reduce this overhead, CF-IVC [1] proposes the mechanism to construct clusters based on the vehicle speed. However, since CF-IVC does not consider the road traffic condition and the driver's behavior, it may result in inefficient clusters. Therefore, in this paper, we propose a mechanism to establish efficient clusters based on the vehicle local information with considering the road maximum speed limit and the road traffic condition. The performance of the proposed mechanism is validated by comparing with those of the simple flooding and CF-IVC through NS-2 simulations.

Physiological responses involved in reactive oxygen species (ROS) of rice plant under alone or multi artificial stress conditions

  • Kim, Yoonha;Waqas, Muhammad;Khan, Abdul Latif;Mun, Bong-Gyu;Yun, Byung-Wook;Lee, In-Jung
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.203-203
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    • 2017
  • The Earth's climate is rapidly changing because of increasing carbon dioxide content in atmosphere so, climate prediction models anticipate that earth surface temperature will rise by 3 to $5^{\circ}C$ in next 50 to 100 years. Therefore, frequency of un-expected weather events such as drought, salinity, low or high temperature and flooding etc. will be increasing worldwide. Furthermore, increased atmosphere temperature can influence pests and pathogens spread as well. Therefore, to protect enormous grain loss from unexpected weather conditions, studies related with combine stress conditions like abiotic plus biotic stress condition are really required. Thus, our research focused on physiological responses under combined abiotic and biotic stress condition in rice plant. To induce uniform stress condition, we used NaCl (100 mM) and salicylic acid (0.5 and 1.0 mM SA) as each stress a stimulator. Each artificial abiotic and biotic stress inducer was applied to hydroponically grown rice seedlings alone or together for four day. The data were collected in a time-dependent manner [1, 2, 3 and 4 day(s) after treatment (DAT)] and were matched with our anticipation that shoot length and shoot fresh weight was decreased in solo and combined abiotic and biotic stress condition. The lipid peroxidation content was significantly increased ($1.5{\pm}0.2$ to $2.7{\pm}0.1mg$ mg of $MDA\;g^{-1}FW$) in the first two days in both stress exposed plants, and showed the opposite trend ($0.5{\pm}0.01$ to $0.1{\pm}0.001mg$ of $MDA\;g^{-1}FW$) in last two days under multi stress condition. Superoxide dismutase (SOD) activity did not showed difference in only biotic stress condition (alone 0.5 and 1.0 mM SA) as compared to control however, it was significantly increased in multi stress condition or solo abiotic stress condition whereas, catalase (CAT), and ascorbate peroxidase (APX) activities were significantly decreased in solo biotic and combined abiotic and biotic condition. In particular, both enzymes activities were more decreased in multi stress condition as compared to solo biotic stress condition. The results for relative mRNA expression level of CAT and APX enzymes were in agreement with results of spectrophotometric values. Correlation value between each stress condition and phenotypic data showed that biotic stress condition showed high correlation with activity of CAT and APX whilst, abiotic stress condition revealed significant correlation with SOD activity.

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Determination of Optimal Operation Water Level of Rain Water Pump Station using Optimization Technique (최적화 기법을 이용한 빗물펌프장 최적 운영수위 결정)

  • Sim, Kyu-Bum;Yoo, Do-Guen;Kim, Eung-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.7
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    • pp.337-342
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    • 2018
  • A rain water pumping station is a structural countermeasure to inland flooding of domestic water generated in a urban watershed. In this study, the optimal operation water level of the pump with the minimum overflow was determined based on the opinions of the person in charge of the operation of the rain water pump station. A GA (Genetic Algorithm), which is an optimization technique, was used to estimate the optimal operation water level of the rain water pump station and was linked with SWMM (Ver.5.1) DLL, which is a rainfall-runoff model of an urban watershed. Considering the time required to maximize the efficiency of the pump, the optimal operating water level was estimated. As a result, the overall water level decreased at a lower operating water level than the existing water level. For most pumps, the lowest operating water level was selected for the operating range of each pump unit. The operation of the initial pump could reduce the amount of overflow, and there was no change in the overflow reduction, even after changing the operation condition of the pump. Internal water flooding reduction was calculated to be 1%~2%, and the overflow occurring in the downstream area was reduced. The operating point of the pump was judged to be an effective operation from a mechanical and practical point of view. A consideration of the operating conditions of the pump in future, will be helpful for improving the efficiency of the pump and to reducing inland flooding.

Various Meanings of Wolji Pond Construction in Shilla Dynasty (월지 조성 목적의 중의성(重意性) 고찰)

  • Hong, Kwang-Pyo
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.34 no.3
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    • pp.67-77
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    • 2016
  • This study was initiated from question raised on existing study achievement that purpose for Wolji construction simply was to build gardens. In this research, after raising a question on existing theory about the Wolji construction, another purpose of Wolji construction is investigated. Study result is as follows. First, two questions raised on Wolji construction are "Was Wolji constructed as a garden from the beginning?" and "Was Wolji region available land as now at time of creation?" However, it was verified that the purpose of Wolji construction was to use not as a garden but as a detention pond, and the land of such region was unserviceable at time of Wolji construction. Second, in terms of locations and Topography, it was confirmed that Wolji has a favorable condition for undercurrent function as it is positioned at the end point of flow path formed by gushout water spurting from the water flooded from Bukcheon, or low and wetland. Third, from hydraulic point of view, Bukcheon always has a possibility of flooding occurrence before completing river bank build up, and such flooding damage was curved at Guhwangdongwonji, and at Wolji once again in order to prevent the damage spread into the center of Wanggyeong. Fourth, from urban planning point of view, it was confirmed that urban functions were not established in Wolji region before Wolji construction, and urban planning was completed through the opening of roads and others, after Wolji construction. Fifth, it was confirmed that inflow and outflow device of Wolji, and vertical stone platform at western side of Wolji were the facilities to provide sufficient functions as detention ponds.

Analytical Investigation of Water Transport

  • Um, Suk-Kee;Lee, Kwan-Soo;Jung, Hye-Mi
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2250-2254
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    • 2007
  • Comprehensive analytical models focusing on the anode water loss, the cathode flooding, water equilibrium, and water management strategy are developed for polymer electrolyte fuel cells. Analytical solutions presented in this study are compared with two-dimensional computational results and shows a good agreement in predicting those critical characteristics of water. General features of water concentration profile as a function of membrane thickness and current density are presented to illustrate the net effect of the back-diffusion of water from the cathode to anode and the water production by the cathode catalytic reaction on water transport over a fuel cell domain. As one of practical applications, the required humidity level of feed streams for full saturation at the channel outlets are investigated as a function of the physical operating condition. These analytical models can provide good understanding on the characteristic water

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Analysis of Small reservoir system by Flood control ability augmentation (치수능력 증대에 따른 저수지시스템 분석)

  • Park Ki-Bum;Lee Soon-Tak
    • Journal of Environmental Science International
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    • v.14 no.11
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    • pp.995-1004
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    • 2005
  • As a research establish reservoir safety operation for small dam systems. This study presents hydrologic analysis conducted in the Duckdong and Bomun dam watershed based on various rainfall data and increase inflow. Especially the Duckdong dam without flood control feature are widely exposed to the risk of flooding, thus it is constructed emergency gate at present. In this study reservoir routing program was simulation for basin runoff estimating using HEC-HMS model, the model simulation the reservoir condition of emergency Sate with and without. At the reservoir analysis results is the Duckdong dam average storage decrease $20\%$ with emergency gate than without emergency gate. Also, the Bomun dam is not affected by the Duckdong flood control augmentation.

Roconstruction of the Pulmonary Outflow Tract withou Proshetic Conduit (심장외 도관을 사용치 않고 시행한 우심실 성형술)

  • 김진국
    • Journal of Chest Surgery
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    • v.21 no.6
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    • pp.1124-1136
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    • 1988
  • Massive hemoptysis, usually rapid flooding of tracheobronchial tree and asphyxia, is associated with high mortality. We have controlled massive hemoptysis in two cases with use of bronchial artery angiography & selective bronchial artery embolization with Gelfoam particle. One case was inoperable case that was confirmed as TOF c severe pulmonary artery hypoplasia with massive hemoptysis due to hypertrophied bronchial artery and its collaterals. Another case was congenital ASD with pulmonary Aspergillosis, postop. empyema and BPF associated with massive bleeding due to erosion of hypervascular bronchial artery. We experienced dramatic improvement of general condition and cessation of massive hemoptysis for above two cases. No other problems and complication were noted during postop. hospitalization and follow-up period.

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