• 물과 미래
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• 제21권4호
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• pp.407-414
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• 1988

본 논문의 목적은 하천 수질모형 시스템이 안정성 및 해감도이론에 의해 이론적으로 어떻게 분석되며, 그 결과 모형화를 위한 수치분석의 신뢰성과 수질 매개변수의 변화에 따른 모형의 민감성을 입증하는 것이다. 무한 Fourier 급수를 이용하여 전개한 안정성이론은 유한차분법을 사용한 모형의 수치해법을 분석하는데 있고, 1부 선형상태벡터식으로 표현되는 민감도이론은 BOD 부하, 유량, 온도와 같은 수질배개변수의 변동효과를 이론적으로 분석하는데 사용되었고, 그 연구 결과는 하천 수질모형시스템의 신뢰성을 파악할 수 있음이 입증되었다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.163-163
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• 2019

The rapidly growing global population increases the awareness of water, energy, and food security worldwide. The concept of Water, Energy, and Food nexus (hereafter, WEF nexus) has been widely introduced as a new resources management concept that integrate the water, energy, and food in a single management framework. Recently, WEF nexus analyzes not only the interconnections among the resources, but also considers the external factors (such as environment, climate change, policy, finance, etc) to enhance the resources sustainability by proper understanding of their relations. A nation-level resources management is quite complex task since multiple regions (e.g., watersheds, cities, and counties) with different characteristics are spatially interconnected and transfer the resources each other. This study proposes a multiple region WEF nexus simulation and transfer model. The model is equipped with three simulation modules, such as local nexus simulation module, regional resources transfer module, and optimal investment planning module. The model intends to determine an optimal capital investment plan (CIP), such as build-up of power plants, water/waste water treatment plants, farmland development and to determine W-E-F import/export decisions among areas. The objective is to maximize overall resources sustainability while minimize financial cost. For demonstration, the proposed model is applied to a semi-hypothetical study area with three different characterized cities. It is expected the model can be used as a decision support tool for a long-term resources management planning process.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권2호
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• pp.188-200
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• 2018

This paper proposes a single control strategy to solve the problem of trans-media vehicle difficult control. The proposed control strategy is just to control the vehicle's air navigation, but not to control the underwater navigation. The hydrodynamic model of a vehicle when entering water obliquely at low speed has been founded to analyze the motion characteristics. Two methods have been used to simulate the vehicle entering water in the same condition: numerical simulation method and theoretical model solving method. And the results of the two methods can validate the hydrodynamic model founded in this paper. The entering water motion in the conditions of different velocity, different angle, and different attack angle has been simulated by this hydrodynamic model and the simulation has been analyzed. And the change rule of the vehicle's gestures and position when entering water has been obtained by analysis. This entering water rule will guide the follow-up of a series of research, such as the underwater navigation, the exiting water process and so on.

• 한국물환경학회지
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• 제27권5호
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• pp.710-718
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• 2011

An integrated water quality management of reservoir and river would be required when the quality of downstream river water is affected by the discharge of upstream dam. In particular, for the control of downstream turbidity during flood events, the integrated modeling of reservoir and river is effective approach. This work was aimed to develop a laterally-averaged two-dimensional hydrodynamic and water quality model (CE-QUAL-W2), by which water quality can be predicted in the downstream of Yongdam dam in conjunction with the reservoir model, and to validate the model under two different hydrological conditions; wet year (2005) and drought year (2010). The model results clearly showed that the simulated data regarding water elevation and suspended solid (SS) concentration are well corresponded with the measured data. In addition, the variation of SS concentration as a function of time was effectively simulated along the river stations with the developed model. Consequently, the developed model can be effectively applied for the integrated water quality management of Yongdam dam and downstream river.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.745-746
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• 2005

• 산업경영시스템학회지
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• 제41권3호
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• pp.90-96
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• 2018

This paper proposed data driven techniques to forecast the time point of water management of the water reservoir without measuring manganese concentration with the empirical data as Juam Dam of years of 2015 and 2016. When the manganese concentration near the surface of water goes over the criteria of 0.3mg/l, the water management should be taken. But, it is economically inefficient to measure manganese concentration frequently and regularly. The water turnover by the difference of water temperature make manganese on the floor of water reservoir rise up to surface and increase the manganese concentration near the surface. Manganese concentration and water temperature from the surface to depth of 20m by 5m have been time plotted and exploratory analyzed to show that the water turnover could be used instead of measuring manganese concentration to know the time point of water management. Two models for forecasting the time point of water turnover were proposed and compared as follow: The regression model of CR20, the consistency ratio of water temperature, between the surface and the depth of 20m on the lagged variables of CR20 and the first lag variable of max temperature. And, the Box-Jenkins model of CR20 as ARIMA (2, 1, 2).

• 상하수도학회지
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• 제20권6호
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• pp.789-797
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• 2006

This study was conducted to establish the refined model for prediction of flocculation/sedimentation efficiency in factual drinking water treatment plants using model tree technique. In order to carry out machine leaning for determining each linear model, five parameters; time, coagulant dose, raw water turbidity, SCD and conductivity, which were measured and collected from the field (K_DWTP), were selected and used. The existing analytical models developed by previous researchers were used only to examine closely the mechanism of flocculation rather than to apply it for practical purpose. The refined model established using model tree technique in this study could predict the factual sedimentation efficiency accurately (below 9% of average absolute error). Also, in aspect of engineering convenience, without any additional manipulation of parameters, it can be applied to practical works.

• 한국수자원학회논문집
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• 제57권1호
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• pp.59-72
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• 2024

농업용저수지는 관개용수, 유지용수, 생활용수 등 다양한 목적을 가지고 용수공급을 수행한다. 농업용저수지는 계절과 기후 변화에 민감하게 반응하기 때문에 효율적으로 운용하기 위해선 공급량 및 유입량 계측은 필수적이며, 이러한 자료를 바탕으로 용수관리가 합리적으로 이루어져야 한다. 하지만 농업용저수지의 경우 다목적 댐에 비해 공급량 및 유입량에 대한 계측이 상대적으로 미비한 실정이며, 효율적이고 합리적인 용수 관리를 위해선 물수지 분석을 통한 농업용 저수지에서의 유입량-공급량 분석이 필요하다. 이에 ONE model, Tank model과 같은 강우유출해석모형이 개발되어 저수지 물수지 해석에 활용되고있으나, 미계측 유역에 대한 적용성 분석은 미비한 실정이다. ONE model은 기본적으로 일단위 유출계산을 위해서 설계되었으며, 해당 모형은 하나의 매개변수를 가지고 있어 Tank model의 한계로 지적되는 보정 및 미계측 유역 분석에 유리하다. 이에 15개의 댐상류 유역을 대상으로 ONE model과 Tank model을 통해 물수지를 분석하고, 두 모형의 성능을 정량적으로 비교분석하고자 R²와 NSE을 활용하였다. 모의결과에 따르면, ONE model의 R²와 NSE가 Tank model 보다 높게 나타났으며, 이는 ONE model이 미계측유역에 대한 유입량 예측에 더 적합할 것으로 평가된다.

• 대한전자공학회논문지SP
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• 제41권4호
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• pp.75-86
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• 2004

본 논문에서는 water flow model의 개념을 적용한 문서영상 이진화 방법의 속도를 개선하는 방법을 제안한다. 제안한 방법은 문서영상에서 문자 주위를 관심영역(region of interest: ROI)으로 추출하고 3차원 영상지형에서 물이 뿌려지는 영역을 관심영역 이내로 제한한다. 국부 계곡에 누적되는 물의 양은 계곡의 깊이와 경사를 이용하여 자동으로 결정된다. 그리고 계곡의 최저 지점뿐만 아니라 그 주위에도 가중치를 부여하여 물을 누적함으로써 관심영역에 해당하는 영상지형에 물을 붓는 과정을 한번만 수행하여 충분한 양의 물이 계곡에 채워지도록 한다. 계곡에 형성된 연못의 깊이는 배경과 문자의 밝기 차에 따라 다양하므로 연못의 깊이를 기준으로 문자 분리를 위한 임계치를 적응적으로 결정한다. 실제 문서영상에 대한 실험에서 제안한 방법의 수행속도가 water flow model에 기반 한 이진화 방법과 비교하여 월등히 향상되었으며 이진화 품질도 매우 우수함을 보였다.

• 한국물환경학회지
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• 제31권3호
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• pp.272-285
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• 2015

Accurate assessment of chlorophyll-a (Chl-a) concentrations in inland waters using remote sensing is challenging due to the optical complexity of case 2 waters. and the inherent optical properties (IOPs) of natural waters are the most significant factors affecting light propagation within water columns, and thus play indispensable roles on estimation of Chl-a concentrations. Despite its importance, no IOPs retrieval model was specifically developed for inland water bodies, although significant efforts were made on oceanic inversion models. So we have applied and validated a recently developed Red-NIR three-band model and an IOPs Inversion Model for estimating Chl-a concentration and deriving inland water IOPs in Lake Uiam. Three band and IOPs based Chl-a estimation model accuracy was assessed with samples collected in different seasons. The results indicate that this models can be used to accurately retrieve Chl-a concentration and absorption coefficients. For all datasets the determination coefficients of the 3-band models versus Chl-a concentration ranged 0.65 and 0.88 and IOPs based model versus Chl-a concentration varied from 0.73 to 0.83 respectively. and Comparison between 3-band and IOPs based models showed significant performance with decrease of root mean square error from 18% to 33.6%. The results of this study provides the potential of effective methods for remote monitoring and water quality management in turbid inland water bodies using hyper-spectral remote sensing.