• Journal of the Korean GEO-environmental Society
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• v.20 no.4
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• pp.23-29
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• 2019

Heavy rainfall is in causing debris flow by recent climate change and causes much damage in the downstream. The debris flow from the mountainous area runs to the downstream, repeating sedimentation and erosion, and appears as a fluidized soil-water mixture. Continuity equation and momentum equation were applied to analyze the debris flow with strong mobility, and the sedimentation and erosion velocity with fine particle fractions were also applied. This study is to analyze the behavior of debris flow at the downstream end for the variation of the amount of sediments can occur in the upstream of the mountain. Analysis of sediment volume concentration at the downstream end of the channel due to the variance of the length of pavement of the granulated soils resulted in the higher the supply flow discharge and the longer the length of pavement, the greater the difference in the level of sediment concentration and the earlier the point of occurrence of the inflection point. The results of this study will provide good information for determining the erosion-sedimentation velocity rate which can detect erosion and sedimentation on steep slopes.

• Journal of Korea Water Resources Association
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• v.56 no.5
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• pp.357-362
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• 2023

The conflict between upstream and downstream regions is a representative social conflict in Korea. It is important issues in the economic and environmental aspects related to interests of property rights and water quality conservation. however, it is insufficient for studies on the economic damage and benefits between upstream and downstream by policy. We studied validity for drinking water protect zone, one of the major water conflict in Korea, by comparison between social loss by property rights restriction in the upstream and social benefits in the downstream and we proposed integrated water management policy in basin level.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.4
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• pp.71-80
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• 2011

A simple and an improved methods for the assessment of flood damage were used in previous studies, and the Multi-Dimensional Flood Damage Assessment (MD-FDA) has been applied since 2004 in Korea. This study evaluated flood damage of dam downstream using considering MD-FDA method based on GIS data. Firstly, flood water level with FLDWAV (Flood Wave routing) model was input into cross section layer based on enforcement drainage algorithm, water depth grid data were created through spatial calculation with DEM data. The value of asset of building and agricultural land according to local government was evaluated using building layer from digital map and agricultural land map from landcover map. Also, itemized flood damage was calculated by unit price to building shape, evaluated value of housewares to urban type, unit cost to crop, tangible and inventory asset of company connected with building, agricultural land, flooding depth layer. Flood damage in rainfall frequency of 200 year showed 1.19, 1.30 and 1.96 times to flood damage in rainfall frequency of 100 year, 50 year and 10 year respectively by flood damage analysis.

• Toxicological Research
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• v.23 no.3
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• pp.207-214
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• 2007

Chronic oxidative stress produced by exposure to environmental chemicals or pathophysiological states can lead animals to aging, carcinogenesis and degenerative diseases. Indirect antioxidative mechanisms, in which natural or synthetic agents are used to coordinately induce the expression of cellular antioxidant capacity, have been shown to protect cells and organisms from oxidative damages. Electrophile and free radical detoxifying enzymes, which were originally identified as the products of genes induced by cancer chemopreventive agents, are members of this protective system. The NFE2 family transcription factor Nrf2 was found to govern expression of these detoxifying enzymes, and screening for Nrf2-regulated genes has identified many gene categories involved in maintaining cellular redox potential and protection from oxidative damage as Nrf2 downstream genes. Further, studies using Nrf2-deficient mice revealed that these mutant mice showed more susceptible phenotypes towards exposure to environmental chemicals/carcinogens and in oxidative stress related disease models. With the finding that cancer chemopreventive efficacy of indirect antioxidants (enzyme inducers) is lost in the absence of Nrf2, a central role of Nrf2 in the antioxidative protective system has been firmly established. Promising results from cancer prevention clinical trials using enzyme inducers propose that pharmacological interventions that modulate Nrf2 can be an effective strategy to protect tissues from oxidative damage.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.6_2
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• pp.631-642
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• 2012

This study aims to predict inundation and flood-stricken areas more accurately by simulating flood damage caused by reversible flow of rain water in the upper water system through precise 3D terrain model and backwater output. For the upstream of the South Han-River, precise 3D terrain model was established by using aerial LiDAR data and backwater by area was output by applying the storm events of 2002 including the history of flood damage. The 3D flood simulation was also performed by using GIS Tool and for occurrence of related rainfall events, inundation events of the upriver region of water system was analyzed. In addition, the results of flood simulation using backwater were verified by making the inundation damage map for the relevant area and comparing it with flood simulation's results. When comparing with the results of the flood simulation applying uniformly the gauging station's water surface elevation used for the existing flood simulation, it is found that the results of the flood simulation using backwater are close to the actual inundation damage status. Accordingly, the causes of flood occurred in downstream of water system and upstream that has different topographic characteristics could be investigated and applying the simulation with backwater is proved more proper in order to procure accuracy of the flood simulation for the upriver region.

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.1033-1039
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• 2018

In Korea, every year during the summer season, typhoons and torrential rains cause floods and damage to property. In particular, the Imjin River basin is characterized by steep slopes, narrow upstream areas, and low flat downstream areas, which are vulnerable to floods. In addition, damages occurred due to unauthorized discharge in the Hwanggang Dam, a large dam upstream of the Imjin River in North Korea. In order to prevent such flood damage, Korea is constructing the Gunnam Flood Control Site in 2010 to prevent flood damage. However, even after the construction of the flood control zone, the flood control capacity is only 20% of the maximum water level of the Hwanggang dam. This study used LAHARZ_py program to calculate flood damage area in the northern part of Gyeonggi province. As a result, when the discharge of Hwanggang dam exceeding the flood control ability of Gunnam flood control zone occurs, damage to Yeoncheon-gun and Paju-si of Gyeonggi-do was expected. This study will be useful as a material to prepare for flood damage.

• Smart Structures and Systems
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• v.29 no.1
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• pp.167-179
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• 2022

This article develops a long-term condition assessment method for stay cables in cable stayed bridges using the monitored cable tension forces under operational condition. Based on the concept of influence surface, the matched cable tension ratio of two cables located at the same side (either in the upstream side or downstream side) is theoretically proven to be related to the condition of stay cables and independent of the positions of vehicles on the bridge. A sensor grouping scheme is designed to ensure that reliable damage detection result can be obtained even when sensor fault occurs in the neighbor of the damaged cable. Cable forces measured from an in-service cable-stayed bridge in China are used to demonstrate the accuracy and effectiveness of the proposed method. Damage detection results show that the proposed approach is sensitive to the rupture of wire damage in a specific cable and is robust to environmental effects, measurement noise, sensor fault and different traffic patterns. Using the damage sensitive feature in the proposed approach, the metrics such as accuracy, precision, recall and F1 score, which are used to evaluate the performance of damage detection, are 97.97%, 95.08%, 100% and 97.48%, respectively. These results indicate that the proposed approach can reliably detect the damage in stay cables. In addition, the proposed approach is efficient and promising with applications to the field monitoring of cables in cable-stayed bridges.

• Journal of Microbiology
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• v.43 no.6
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• pp.516-522
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• 2005

The phosphorylation of C-terminal domain (CTD) of Rpb1p, the largest subunit of RNA polymerase II plays an important role in transcription and the coupling of various cellular events to transcription. In this study, its role in DNA damage response is closely examined in Saccharomyces cerevisiae, focusing specifically on several transcription factors that mediate or respond to the phosphorylation of the CTD. CTDK-1, the pol II CTD kinase, FCP1, the CTD phosphatase, ESS1, the CTD phosphorylation dependent cis-trans isomerase, and RSP5, the phosphorylation dependent pol II ubiquitinating enzyme, were chosen for the study. We determined that the CTD phosphorylation of CTD, which occurred predominantly at serine 2 within a heptapeptide repeat, was enhanced in response to a variety of sources of DNA damage. This modification was shown to be mediated by CTDK-1. Although mutations in ESS1 or FCP1 caused cells to become quite sensitive to DNA damage, the characteristic pattern of CTD phosphorylation remained unaltered, thereby implying that ESS1 and FCP1 play roles downstream of CTD phosphorylation in response to DNA damage. Our data suggest that the location or extent of CTD phosphorylation might be altered in response to DNA damage, and that the modified CTD, ESS1, and FCP1 all contribute to cellular survival in such conditions.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2977-2982
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• 2007

Feedwater heaters of many nuclear power plants have recently experienced severe wall thinning damage, which will increase as operating time progresses. Several nuclear power plants in Korea have experienced wall thinning damage in the area around the impingement baffle - installed downstream of the high pressure turbine extraction steam line - inside number 5A and 5B feedwater heaters. At that point, the extracted steam from the high pressure turbine is two phase fluid at high temperature, high pressure, and high speed. Since it flows in reverse direction after impinging the impingement baffle, the shell wall of the number 5 high pressure feedwater heater may be affected by flow-accelerated corrosion. This paper describes the comparisons between the numerical analysis results using the FLUENT code and the down scale experimental data which effect on disclosing of the shell wall thinning of the high pressure feedwater heaters by porous plate.

• Water Engineering Research
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• v.3 no.4
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• pp.215-234
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• 2002

Uncertainty in dam breach flood routing results was analyzed in order to provide the basis fer the investigation of their effects on the flood damage assessments and dam safety risk assessments. The Monte Carlo simulation based on Latin Hypercube Sampling technique was used to generate random values for two uncertain input parameters (i.e., dam breach parameters and Manning's n roughness coefficients) of a dam breach flood routing analysis model. The flood routing results without considering the uncertainty in two input parameters were compared with those with considering the uncertainty. This paper showed that dam breach flood routing results heavily depend on the two uncertain input parameters. This study indicated that the flood damage assessments in the downstream areas can be critical if uncertainty in dam breach flood routing results are considered in a reasonable manner.