• Smart Structures and Systems
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• 제11권5호
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• pp.453-476
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• 2013

DuraMote is a remote sensing system developed for the "NIST TIP project: next generation SCADA for prevention and mitigation of water system infrastructure disaster". It is designed for supervisory control and data acquisition (SCADA) of ruptures in water pipes. Micro-electro mechanical (MEMS) accelerometers, which record the vibration of the pipe wall, are used detect the ruptures. However, the performance of Duramote cannot be verified directly on a water distribution system because it lacks an acceptable recordable level of ambient vibration. Instead, a long-span cable-stayed bridge is an ideal test-bed to validate the accuracy, the reliability, and the robustness of DuraMote because the bridge has an acceptable level of ambient vibration. The acceleration data recorded on the bridge were used to identify the modal properties of the structure and to verify the performance of DuraMote. During the test period, the bridge was subjected to heavy rain, wind, and a typhoon but the system demonstrates its robustness and durability.

• 한국정보통신학회논문지
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• 제22권7호
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• pp.935-942
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• 2018

정확한 강수량의 측정은 댐 및 하천의 운영, 농어촌 및 산림녹화, 안전관리 등 사용분야가 광범위하며, 재난재해를 대비하고 강우발생시 경제적인 효과를 얻기 위해서 필요하다. 본 연구에서는 집수형 강수량계의 성능을 분석할 수 있는 통합검증시스템에 의한 강수량계 종류별 특성시험을 실시하였다. 전도형 강수량계는 0.0041 mm, 무게식 강수량계는 0.0045 mm, 표면장력식 강수량계는 0.0039 mm으로 불확도가 산출되었으며, 강수량계의 종류 및 특성에 따른 불확도는 크게 다르지 않음을 알 수 있었다. 이러한 특성시험을 통하여 강수량계 종류에 따른 기상관측 및 수문관측 데이터의 신뢰성을 확보하고자 하였다.

• 한국수자원학회논문집
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• 제39권8호
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• pp.717-726
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• 2006

본 연구에서는 상층기상자료, 자동 기상 관측망 자료 및 신경망기법을 사용하여 단시간 강우 예측 모형을 개발하였다. 호우를 동반한 이송 기상 시스템의 이동 경로가 라디오존데로부터 획득할 수 있는 상층기상 자료 즉 상층 풍향자료와 동일한 방향으로 이동한다는 가정 하에 원거리에서 발생하는 기상현상의 발달과정을 판단 할 수 있는 알고리즘을 개발하고, 이러한 원거리 입력 자료와 예측하고자 하는 값 사이의 비선형 상관관계를 연결하는 기법으로 인공 신경망 기법을 도입하였다. 개발된 모형을 2002년 태풍 루사로 인하여 큰 피해를 입은 감천지역에 적용하였다. 포항과 오산의 라디오존데에서 획득한 700mb에서의 풍향자료와 5년의 자료기간을 가지는 350개의 자동 기상 관측망 자료를 입력 자료로 사용하였으며 결과는 상층 풍향자료를 사용한 경우에 상관계수가 0.41에서 0.73으로 개선되었으며 숙련도도 35%향상되었다. 모형의 개선도를 나타내는 통계치의 개선을 통해 상층기상자료를 활용한 강우예측 모형이 단지 지상 강우계 자료만 사용한 예측보다 개선된 결과를 보여줌을 알 수 있다.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.54-55
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• 2015

Increase of impervious areas due to expansion of housing area, commercial and business building of urban is resulting in property change of stormwater runoff. Also, rapid urbanization and heavy rain due to climate change lead to urban flood and debris flow damage. In 2010 and 2011, Seoul had experienced shocking flooding damages by heavy rain. All these have led to increased interest in applying LID and decentralized rainwater management as a means of urban hydrologic cycle restoration and Natural Disaster Prevention such as flooding and so on. Urban development is a cause of expansion of impervious area. It reduces infiltration of rain water and may increase runoff volume from storms. Low Impact Development (LID) methods is to mimic the predevelopment site hydrology by using site design techniques that store, infiltrate, evaporate, detain runoff, and reduction flooding. Use of these techniques helps to reduce off-site runoff and ensure adequate groundwater recharge. The contents of this paper include a hydrologic analysis on a site and an evaluation of flooding reduction effect of LID practice facilities planned on the site. The region of this Case study is LID Rainwater Management Demonstration District in A-new town and P-new town, Korea. LID Practice facilities were designed on the area of rainwater management demonstration district in new town. We performed analysis of reduction effect about flood discharge. SWMM5 has been developed as a model to analyze the hydrologic impacts of LID facilities. For this study, we used weather data for around 38 years from January 1973 to August 2014 collected from the new town City Observatory near the district. Using the weather data, we performed continuous simulation of urban runoff in order to analyze impacts on the Stream from the development of the district and the installation of LID facilities. This is a new approach to stormwater management system which is different from existing end-of-pipe type management system. We suggest that LID should be discussed as a efficient method of urban disasters and climate change control in future land use, sewer and stormwater management planning.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.384-386
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• 2003

GPS observation has been performed at Khon Kaen in northeast Thailand to investigate the Precipitable Water Vapor (PWV) change since August 2001 by using a Trimble 4000SSi receiver. The data obtained in the period from March to June in 2002 were processed by using CAMIT software to obtain the Zenith Tropospheric Delay (ZTD) at every one hour referring to some IGS stations around Thailand. We estimated the Zenith Hydrostatic Delay (ZHD) at every three hours with barometer data at Khon Kaen of Thai Meteorological Department, The Zenith Wet Delay (ZWD) was obtained by subtracting ZHD from ZTD and PWV can be calculated from ZTD. The results obtained shows that PWV changes with a large amplitude in March and April before the monsoon onset, and also we can see steep PWV increases before rain and decreases after rain. In May and June after the onset, the PWV is almost constant to be 60 to 70 mm, but there is a semi-diurnal change which has high PWV values at about 8 and 20 o'clock in local time.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.183-183
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• 2021

Deep learning methods and their application have become an essential part of prediction and modeling in water-related research areas, including hydrological processes, climate change, etc. It is known that application of deep learning leads to high availability of data sources in hydrology, which shows its usefulness in analysis of precipitation, runoff, groundwater level, evapotranspiration, and so on. However, there is still a limitation on microclimate analysis and prediction with deep learning methods because of deficiency of gauge-based data and shortcomings of existing technologies. In this study, a real-time rainfall prediction model was developed from a sky image data set with convolutional neural networks (CNNs). These daily image data were collected at Chung-Ang University and Korea University. For high accuracy of the proposed model, it considers data classification, image processing, ratio adjustment of no-rain data. Rainfall prediction data were compared with minutely rainfall data at rain gauge stations close to image sensors. It indicates that the proposed model could offer an interpolation of current rainfall observation system and have large potential to fill an observation gap. Information from small-scaled areas leads to advance in accurate weather forecasting and hydrological modeling at a micro scale.

• 생태와환경
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• 제40권2호
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• pp.234-243
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• 2007

청계천 복원이후 하천수질의 생태학적 평가를 하기 위하여 청계천을 비롯한 인접수역 중랑천 및 한강 본류를 대상으로 강우 전후 조류 및 수질변화와 현장수에 대한 조류성장잠재력(AGP)을 조사하였다. 조사는 청계천(정점 1, 2), 중량천(정점 3), 두 하천의 합류부(정점 4), 한강 본류의 상류(정점 5)및 하류(정점 6)등 총 6개 정점을 선정하여 2006년 하계(강우 이 전 7월 25일, 강우 이 후 8월 28일)에 각각 1회씩 실시하였다. 한편, AGP조사를 위해 각 정점에서 채수한 현장수를 공시종 남조 Microcystis aeruginosa 배양계에 1/6, 2/6, 3/6씩 각각 첨가하고, 온도 $25^{\circ}C$, 광조건 100 ${\mu}mol$ photons $m^{-2}s^{-1}$ (14h : 10h LD cycle)에서 11일간 배양하였다. 조사결과, 총질소는 중랑천과 청계천의 합류부에서 높았는데, 특히 후자는 강우 전후 각각 14.4, 18.5 mg $L^{-1}$를 기록하며 가장 높았다. 총인 역시 중랑천과 청계천의 합류부에서 높았는데, 총질소의 경우와 같이 정점 4의 총인은 강우 전후 각각 1.1, 1.3 mg $L^{-1}$를 기록하며 가장 높았다. 엽록소-${\alpha}$는 강우 후에는 중랑하수처리장 방류지점을 포함하고 있는 청계천과 중랑천의 합류부인 정점 4에서 매우 높았으며 가장 우점한 조류는 Cyclotella sp.로 조사되었다. 현장수에 대한 AGP조사결과, 강우 전에는 대조구에 비해 모든 정점에서 높은 성장을 보였으나, 강우 후에는 대조구에 비해 전반적으로 낮은 성장을 나타냈다. 다만, 강우 후에는 현장수 첨가량이 증가함에 따라 대조구와 큰 차이를 보이지 않았는데 이는 강우에 의한 영양물질의 증가가 원인인 것으로 판단되었다. 따라서 청계천을 포함한 조사하천들은 평상시에는 비교적 안정된 생태계를 유지하고 있으나 집중강우시 영양물질 유입으로 인한 하류의 조류번식 가능성이 우려되며, 특히 중량천의 수질개선이 시급한 것으로 판단되었다.

• 한국물환경학회지
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• 제36권5호
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• pp.423-430
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• 2020

To improve the low treatment efficiency of sewage treatment plants, the separated sewer system must be maintained to provide an adequate flow rate and quality of the sewage under the effect of inflow. In this study, data from five locations of Namsuk, Dukgok1, Dukgok2, Kanggu, and Opo were used to conservatively calculate the inflow water volume. The sewer flow and rainfall data were collected in 2017. The factors in the standard method used to calculate the inflow of the combined sewer pipes including "rainy days", "rainfall impact period", and "period for basal sewer" were defined as 3 mm/day, continuous rain for two days, and two weeks prior to the inflow generation, respectively. "Rainy days", "rainfall impact period", and "period for basal sewer" were conservatively adjusted to 5 mm/day, continuous rain for five days, and three weeks prior to the inflow generation, respectively. As a results of the adjustment, the linearity (r²) was improved except for in Dukgok1. This implies that the conservative adjustment made in this study could improve the management quality of sewer pipes. Also, the linear correlation coefficient (a_i) between inflow and rainfall showed a large difference between the target locations, which can be another monitoring factor affecting the quality of sewer pipes. To improve the correlation based on the individual characteristics of the locations in Korea, the automatic algorithm for the inflow calculation should be developed by innovative intellectual technologies for application to the entire national area.

• 자원환경지질
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• 제30권1호
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• pp.25-33
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• 1997

The purpose of this study is to examine the feasibility of using stable isotopes as a hydrologic tracer, and to elucidate the groundwater circulation system and the source of S component dissolved in thermal water of the Chonju Jukrim thermal spring district based on the O, H and S isotopic variabilities of environmental materials including bedrock, rainwater, surface water, shallow subsurface water and thermal spring water. The ${\delta}^{18}O$ and ${\delta}D$ of subsurface waters and surface water show highly restricted range and plotted on the same meteoric water line as a ${\delta}D=8{\delta}^{18}O+19$ line, and derivate from the mean annual isotopic composition of the rain water but are analogous to those of rain waters precipitated during winter season, indicating that ground waters are originated from the meteoric water and are strongly affected by the seasonal variation of air mass. Thermal spring waters are more depleted in ${\delta}^{18}O$ and ${\delta}D$ than those of shallow ground water and surface water. It can be explained by the difference of recharge area. The hydrochemical properties of subsurface waters and surface water devide into two groups: $Ca(HCO_3)_2$ type including shallow subsurface water and surface water, and $Na(HCO_3)$ type of thermal spring waters. The ${\delta}^{34}S$ values of thermal spring water show very high positive and quitely distinct from those of shallow subsurface water and surface water that are similar to those of bed rocks, indicating that sulfate dissolved in thermal spring water has not only a terrigenic origin, but also originates partially from the foreign source containing very heavy ${\delta}^{34}S$ component such as an ancient sea water. However, the presence of $H_2S$ can not be ignore the affact of the isotopic fractionation to explaine the heavy ${\delta}^{34}S$ of thermal spring water. Overall, the Oxygen and Hydrogen stable isotopes can identify the source and the circulation system of the natural waters and the S-isotopes can provide a crucial clue on tracing the dissolved material transports in the circulation system of the natural water.

• 한국수자원학회논문집
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• 제56권7호
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• pp.461-470
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• 2023

본 연구는 겨울철 적설 관측에 사용되는 전도형 강수량계 가열 시스템의 최적 온도, 위치, 제어 방식을 도출하기 위해 수행하였다. 수수구, 외부, 내부를 가변적으로 제어 가능한 전도형 강수량계를 제작하여 실내·외 실험을 수행하였다. 실내 실험은 강수량계 가열시스템의 성능비교와 적정온도를 도출하기 위해 항온항습챔버에서 수행되었다. 이후 다설지인 대관령에 위치한 구름물리선도센터에서 실외실험을 수행하여 실내실험 결과를 검증하였다. 분석 결과, 수수구의 가열 온도는 10~30℃, 내부 가열 온도는 70℃가 최적으로 확인되었다. 또한, 측정 지연을 최소화하기 위한 가열 장치의 최적 위치는 강수량계 외부, 수수구 테두리, 수수구 수직면으로 확인되었다. 본 연구 결과는 겨울철 고체 강수 측정을 위한 강수량계 가열 시스템의 운영 조건에 대한 기초자료로 활용이 가능할 것으로 판단된다.