• 한국지리정보학회지
• /
• 제19권1호
• /
• pp.106-119
• /
• 2016

홍수 및 침수 등의 자연재해로부터 예방, 대비, 복구, 대응을 위한 기초자료로 홍수위험지도, 홍수피해지도, 재해정보지도, 침수흔적도 등 지도 제작에 있어서 홍수범람해석이 핵심적인 내용을 수반한다. 본 연구에서는 한강 살리기 사업 이후의 충주댐부터 팔당댐까지의 남한강 구간에 대하여 하도 특성 및 유역특성을 분석하고, 하천기본계획상 계획홍수위를 이용하여 홍수 시나리오를 선정하였다. 하천의 흐름특성을 고려하여 HEC-RAS를 이용한 1차원 부등류 해석, FLUMEN을 이용하여 상습수해지역인 여주, 양평, 충주지구에 대해 2차원 부정류 해석을 실시함으로써 홍수범람해석을 하였다. 남한강 구간에 대해 각 지천별로 100년, 200년, 500년 빈도해석을 하였으며, 침수심 0.5m에 해당되는 100년 빈도는 2,379.8ha, 200년 빈도는 3,155.2ha, 500년 빈도는 3,995.3ha의 홍수피해면적이 산정되었다. 침수흔적도와 비교분석함으로써 하천정비기본계획, 토지이용계획, 홍수방어대책, 치수대책 등의 수립 및 신속한 호우피해 예상지역의 정보 취득으로 대피정보 제공을 위한 재해정보지도 구축의 중요한 의사결정 자료가 될 것으로 사료된다.

• 환경영향평가
• /
• 제21권5호
• /
• pp.715-724
• /
• 2012

In this study, we simulated water temperature in the downstream according to withdrawal types of dam using EFDC model. Three scenarios were assumed as water was released from the surface layer, the middle layer, and the bottom layer at intervals of 10m depth. In case of the surface layer withdrawal, the water temperature rose from March and lowered gradually after it reached a peak in August. The middle and the bottom layers effluence temperatures were lower than the surface layer temperature by maximum $15.9^{\circ}C$(in July), but after September, temperature inversion appeared. It was advantageous for the surface layer withdrawal to decrease cold damage and fog in downstream area and was possible to the middle and the bottom layers withdrawal from August to September. However, the reliability of model should be improved by accumulating the real-time information of water temperature.

• 한국지진공학회논문집
• /
• 제18권6호
• /
• pp.271-278
• /
• 2014

Seismic intensity deduced from instrumental data has been evaluated using the empirical relationship between intensity and peak ground acceleration (PGA) during an earthquake. The Japan Meteorological Agency (JMA) developed a seismic intensity meter, which can estimate the real-time seismic intensity from seismic motions observed at a local site to evaluate the damage during the earthquake more correctly. This paper proposes a practical application of the JMA intensity to dams during the 2013 earthquake in Yeongcheon, Korea. In the present paper, seismic intensity was estimated from the relationships between accelerations observed at Yeongcheon Dam. Estimated seismic intensities were in the range of 0 to 3, which was verified from the displacements of dams and the variation of the ground water level observed at Yeongcheon dam during the earthquake. The JMA intensity, which is determined by considering the frequency, duration of cyclic loading, etc., was 0 (zero) and there was no damage to Yeoncheon dam during the earthquake.

• 대한기계학회논문집A
• /
• 제25권8호
• /
• pp.1189-1196
• /
• 2001

The objective of this paper is to investigate the applicability of acoustic emission(AE) technique to monitor the progress of the thermal shock damage on alumina ceramic. For this purpose, alumina ceramic specimen was heated in the furnace and then was quenched in the water tank. When the specimen was quenched in the water tank, complex AE signals due to the initiation of micro-cracks and boiling effect were generated by the progress of thermal shock damage. These mixed AE signals have to be classified for monitoring the degree of the thermal shock damage of alumina ceramics. In this paper, the mixed AE signals generated from both the boiling effect and the crack initiation under thermal shock test was analyzed. The characteristics of AE signals were also discussed by considering the variation of bending strength and Yongs modulus of specimens.

• 한국물환경학회지
• /
• 제29권1호
• /
• pp.45-54
• /
• 2013

This study analyzes the reduction effects of runoff and flood damage through different arrangements of stormwater storage facilities. Three scenarios based on the spatial allocation of storage capacity are used: concentrated, decentralized and combinative. The characteristics of runoff and flood damage by scenario are compared. The XP-SWMM model is used for runoff simulation by the probable rainfall of return period. The result shows that the concentrated arrangement of storage facilities is most effective to reduce the amount of peak flow and to delay the time of peak flow. Yet, while the concentrated arrangement is most effective to reduce the inundation damage, it is not effective to reduce runoff volume. The decentralized arrangement is most effective to reduce runoff volume. The combinative arrangement is effective not only the runoff reduction but also the reduction of flood damage. The result indicates that the flood mitigation strategies against heavy rainfall need to consider decentralized on-site arrangement for the reduction of runoff volume along with concentrated off-site arrangement of storage facilities.

• Archives of Pharmacal Research
• /
• 제23권4호
• /
• pp.413-417
• /
• 2000

The effect of ischemia/reperfusion-induced neuronal damage on the memory impairment were investigated using active avoidance and Morris water maze tasks in Wistar rats. Focal ischemia was induced by 1 h occlusion of the right middle cerebral artery (MCA) of Wistar male rats. Reperfusion was induced by releasing the occlusion and restoring the blood circulation for 24 h. The acquisition and preservation memory tested by active avoidance showed a significant difference between the sham and ischemia/reperfusion group. The water maze acquisition performance was also significant difference between sham and ischemia/repefusion groups in both latency and moving distance. The infarction volume was increased by the ischemia/reperfusion. Furthermore, the cresyl violet staining of the ischemia/reperfusion brain showed severe neuronal damage (pyramidal cell loss) in the cortex in addition to the striatum lesion of brain. This study shows that pyramidal cell damage in the cortex lesion may be partially related to memorial disturbance in the ischemia/reperfusion brain injury.

• 한국해양공학회지
• /
• 제32권6호
• /
• pp.458-465
• /
• 2018

Ice-going ships such as icebreakers, icebreaking tankers, and icebreaking LNG carriers are subjected to wave loads in open water and ice loads in ice-covered water. In terms of the ship's structural design, the local ice load is important. The fatigue failure due to repeated ice loads is also important. ISO 19906 specifies the assessment of the fatigue limit for a polar offshore structures. In addition, Lloyd's Register refers to fatigue damage based on ShipRight FDA ICE. In ShipRight FDA ICE, the fatigue damage indices due to wave and ice loads are simply presented as 0.5 for each load. It also states that the sum of the two fatigue damage indices should not exceed one. This study calculated and analyzed the fatigue damage index and fatigue life considering ARAON's voyage schedules and the assumed Antarctic voyage based on data measured during the Arctic voyage of ARAON in 2010.

• 보존과학연구
• /
• 통권7호
• /
• pp.265-277
• /
• 1986

The degradation of wood is maimly caused by biological and thermal factor. In general, the field of wood preservation can be divided into two broadcategories; namely the deterioration, protection of wood, and the teatment of wood with preservatives. Wood in sea or brackish water incurs marine borer damage, consisting of attack by marine animal and also wood on land suffers severely from insect damage. But the largest wood degradation is caused by microorganism. Animals that attack wood in a marine environment are especially destructive in warm water-regions, little was achieved in their control recently. Therefore this manuscript only introduce the importance of wood deterioration caused by marine animal.

• 한국농공학회논문집
• /
• 제63권5호
• /
• pp.1-11
• /
• 2021

Soil moisture plays a critical role in hydrological processes, land-atmosphere interactions and climate variability. It can limit vegetation growth as well as infiltration of rainfall and therefore very important for agriculture sector and food protection. Recently, due to the increased damage from drought caused by climate change, there is a frequent occurrence of shortage of agricultural water, making it difficult to supply and manage stable agricultural water. Efficient water management is necessary to reduce drought damage, and soil moisture management is important in case of upland crops. In this study, soil moisture was calculated based on the water balance model, and the suitability of soil moisture data was verified through the application. The regional soil moisture was calculated based on the meteorological data collected by the meteorological station, and applied the Runs theory. We analyzed the spatiotemporal variability of soil moisture and drought impacts, and analyzed the correlation between actual drought impacts and drought damage through correlation analysis of Standardized Precipitation Index (SPI). The soil moisture steadily decreased and increased until the rainy season, while the drought size steadily increased and decreased until the rainy season. The regional magnitude of the drought was large in Gyeonggi-do and Gyeongsang-do, and in winter, severe drought occurred in areas of Gangwon-do. As a result of comparative analysis with actual drought events, it was confirmed that there is a high correlation with SPI by each time scale drought events with a correlation coefficient.

• Structural Engineering and Mechanics
• /
• 제84권2호
• /
• pp.181-206
• /
• 2022

This paper presents experimental modal analysis and static load testing results to validate the accuracy of dynamic parameters-based damage locating indices in RC structures. The study investigates the accuracy of different dynamic-based damage locating indices compared to observed crack patterns from static load tests and how different damage levels and scenarios impact them. The damage locating indices based on mode shape curvature and mode shape fourth derivate in their original forms were found to show anomalies along the beam length and at the supports. The modified forms of these indices show higher sensitivity in locating single and multi-cracks at different damage scenarios. The proposed stiffness reduction index shows good sensitivity in detecting single and multi-cracks. The proposed anomalies elimination procedure helps to remove the anomalies along the beam length. Also, the adoption of the proposed weighting method averaging procedure and normalization procedure help to draw the overall crack pattern based on the adopted set of modes.