• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.95-95
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• 2023

Common hydrological problems of developing countries include poor data management, insufficient measuring devices and ungauged watersheds, leading to small or unreliable data availability. This has greatly affected the adoption of artificial intelligence techniques for flood risk mitigation and damage control in several developing countries. While climate datasets have recorded resounding applications, but they exhibit more uncertainties than ground-based measurements. To encourage AI adoption in developing countries with small ground-based dataset, we propose data augmentation for regression tasks and compare performance evaluation of different AI models with and without data augmentation. More focus is placed on simple models that offer lesser computational cost and higher accuracy than deeper models that train longer and consume computer resources, which may be insufficient in developing countries. To implement this approach, we modelled and predicted streamflow data of the Asa River Watershed located in Ilorin, Kwara State Nigeria. Results revealed that adequate hyperparameter tuning and proper model selection improve streamflow prediction on small water dataset. This approach can be implemented in data-scarce regions to ensure timely flood intervention and early warning systems are adopted in developing countries.

• 한국통신학회논문지
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• 제30권11C호
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• pp.1076-1082
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• 2005

최근 수리형태학적 접근 방법을 이용하여 영상을 분할하고자 하는 연구가 계속되고 있다. 그 중에서도 분수경계 알고리듬은 기존의 에지 기반의 영상 분할 방법과 영역기반의 영상분할 방법의 장점을 모두 가지고 있는 효과적인 영상 분할 기법 중에 하나이다. 분수경계 알고리듬의 기본적인 개념은 지형학적 해석에 기반을 두고 있으며 항상 영역의 외곽에 폐곡선을 형성한다. 그러나 잡영에 매우 민감하게 반응하여 수많은 영역으로 분할되는 과분할 현상을 초래한다. 따라서 본 논문에서는 중요하지 많은 국부 최소점과 국부 최대점을 모두 제거함으로써 과분할 현상을 줄이는 제한적 워터폴 알고리듬을 제안한다. 실험결과 제안한 제한적 워터폴 방법이 다른 과분할 억제 방법보다 평균분할 영역수와 외곽선 소실 측면에서 효과적으로 영상을 분할할 수 있었다.

• 한국환경과학회지
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• 제15권5호
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• pp.461-469
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• 2006

As a frontier of Sustainable Basin Research Initiative, we commenced a scenario-driven planning and evaluation research project which is to identify the strategic policy scenarios. As a part of the project, this study attempts to estimate the ecological impacts of land cover changes using landscape indices at the whole basin level. We analyzed spatio-temporal characteristics of natural area including forest, agricultural land, water area, barren which play an important role in nature-friendly sustainable watershed management. The results of analysis shelved that the size and diversity of natural area have been reduced, while patch number and isolation have been increased in proportion to urbanization in 1974, 1995 and four future scenarios in the Ara River Basin. Also, we estimated that the natural area could be conserved to some degree in the SD or DE scenarios with a concept of environment-friendly development and lifestyle. Various strategic environment policies may be evaluated and designed on the basis of the method, that is, scenario approach and landscape ecological analysis suggested in this study.

• 한국수자원학회논문집
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• 제40권12호
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• pp.969-983
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• 2007

본 연구에서는 도시화로 인해 왜곡된 물순환을 치수, 이수, 수질관리 등의 측면에서 건전화시키기 위해 지속가능한 유역통합관리 계획을 수립하기 위한 10단계의 절차와 적용방법을 개발하여 제시하였으며 이 중 Step 2에 해당하는 문제점 도출 및 우선순위 결정 단계를 수행하였다. 유역의 잠재적인 위험도를 나타내는 홍수피해잠재능(PFD), 건천잠재능(PSD), 수질오염잠재능(PWQD), 유역평가지수(WEI)를 산정하기 위해 다기준 의사결정기법과 지속가능성평가지수 개념을 사용하였다. 사용된 다기준 의사결정 기법들은 복합계획법, 타협계획법, Regime, ELECTRE II, EVAMIX 방법이며 자료의 가용성과 목적(예비타당성, 타당성)에 따라 다르게 사용될 수 있다.

• 한국농공학회논문집
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• 제56권6호
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• pp.129-137
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• 2014

This research presents an streamflow modeling approach in a data-scarce estuary reservoir watershed which has been suffered from high salinity irrigation water problem after completion of land reclamation project in South Korea. Since limited hydrology data was available on the Iwon estuary reservoir watershed, water balance relation of the reservoir was used to estimate runoff from upstream of the reservoir. Water balance components in the reservoir consists precipitation, inflow from upstream, discharge through sluice, and evaporation. Estimated daily inflow data, which is stream discharge from upstream, shows a good consistency with the observed water level data in the reservoir in terms of EI (0.93) and $R^2$ (0.94), and were used as observed flow data for the streamflow modeling. HSPF (Hydrological Simulation Program - Fortran) was used to simulate hydrologic response of upstream of the reservoir. The model was calibrated and validated for the periods of 2006 to 2007 and 2008 to 2009, respectively, showing that values of EI and $R^2$ were 0.89 and 0.91 for calibration period, 0.71 and 0.84 for validation period.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.427-427
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• 2015

The storm water management and drainage relation are the key variable that plays a vital role on hydrological design and risk analysis. These require knowledge about spatial variability over a specified area. Generally, design rainfall values are expressed from the fixed point rainfall, which is depth at a specific location. Concurrently, determine the areal rainfall amount is also very important. Therefore, a spatial rainfall interpolation (point rainfall converting to areal rainfall) can be solved by areal reduction factor (ARF) estimation. In mainland of South Korea, for dam design and its operation, public safety, other surface water projects concerned about ARF for extreme hydrological events. In spite of the long term average rainfall (2,061 mm) and increasing extreme rainfall events, ARF estimation is also essential for Jeju Island's water control structures. To meet up this purpose, five fixed rainfall stations of automatic weather stations (AWS) near the "Hancheon Stream Watershed" area has been considered and more than 50 years of high quality rainfall data have been analyzed for estimating design rainfall. The relationship approach for the 24 hour design storm is assessed based on ARF. Furthermore, this presentation will provide an outline of ARF standards that can be used to assist the decision makers and water resources engineers for other streams of Jeju Island.

• Water Engineering Research
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• 제5권4호
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• pp.185-193
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• 2004

Estimates of annual actual evapotranspiration are needed in water balance studies, water resources management projects, and many different types of hydrologic studies. This study validated a set of 5 empirical equations of estimating annual actual evapotranspiration with climate data on 11 watersheds, and evaluated the further applicability of these forms in estimating annual runoff on watershed level. Five empirical equations generally overestimated annual evapotranspiration, with relative errors ranging $3.3\%$ to $47.2\%$. The results show that Schreiber formula can be applicable in determining annual evapotranspiration in sub-humid region that is classified by aridity index, while Zhang equation gave better results than the remaining methods in humid region. The mean differences for annual evapotranspiration bias over 11 watersheds are Zhang, Schreiber, Budyko, Pike, and Ol'dekop formula from lowest to highest. The empirical equations provide a practical tool to help water resources managers in estimating regional water resources on ungauged large watershed.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.437-440
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• 2008

In recent years, pollution load calculation has become a topic for research that resulted in the development of numerous GIS modeling methods. The existing pollution method for nonpoint source (NPS) can not be indentified and calculated the amount of the pollution precisely. This research shows that the association of typical pollutant concentrations with land uses in a watershed can provide a reasonably accurate characterization of nonpoint source pollution in the watershed using Expected Mean Concentrations (EMC). The GIS based pollution assessment method is performed for three pollutant constituents: BOD, TN, and TP. First, the runoff grid by means of the precipitation grid and runoff coefficient is estimated. Then, the NPS pollution loads are calculated by grid based method. Finally, the final outputs are evaluated by statistical technique. The results illustrate the merits of the approach. This model verified that GIS based method of estimating spatially distributed NPS pollution loads can lead to more accurate representation of the real world.

• 대한토목학회논문집
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• 제13권1호
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• pp.121-130
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• 1993

본 연구의 주요 목적은 댐 설계를 위한 유역의 비유사량 추정방법을 개발하는 것으로 유역면적 $200km^2{\sim}2,000km^2$ 정도의 중규모 유역을 대상으로 한다. 이를 위하여, 본 연구에서 개발할 비유사량 추정방법으로 통계적 방법에 의한 경험식과 미국 PSIAC 방법과 유사한 도표식 방법을 채택하였다. 이러한 방법들의 개발을 위해 본 연구에서는 과거 '60년대 이후 우리나라에서 수행된 하천유사량 실측자료 및 기존 다목적 및 발전댐 저수지 퇴사자료를 모두 수집 분석하여 비유사량 추정방법의 개발에 이용 가능한 자료 5 점을 도출하였다. 또한, 섬강, 금강상류, 내성천, 위천 등 4 개 조사유역의 8개 지점에서 하천유사량 자료를 실측하여 8개 지점에서의 연평균 비유사량을 산정하였다. 한편, 유역의 비유사량에 영향을 주는 유역특성 인자로 유역면적, 하천밀도, 강우 침식도, 식생 및 토지이용, 토양 침식성, 지형(기복 에너지), 하상재료 당 총 7 개의 유역특성인자를 선정하고, 각 인자의 정량화 방법을 제시하였다. 연구(II)에서는 이러한 유역특성 인자들과 중규모 유역에서 수집된 13 점의 이용가능한 유역 비유사량 자료를 이용하여 비유사량 추정방법을 개발한다.

• 한국조경학회지
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• 제33권6호
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• pp.51-77
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• 2006

Pond management is a critical part of overall golf course management, both during growth and maintenance modes of turf care. This study investigated 48 ponds in nine 18- or 27-hole golf courses to analyze the environmental characteristics of ponds. The research process had three phases: (1) inventory and analysis of grading plans and drainage plans, (2) field verification and interviews with greenskeepers, and (3) analyses of water quality and statistics. All data were collected from May to August in 2004. The results of this study can be summarized as follows: 1. It is desirable to site a golf course in a small watershed with high watershed eccentricity to control storm water runoff efficiently and to minimize soil erosion during construction. 2. The siting and size of a pond should be determined through a land-use analysis of the watershed for the purpose of ecological management. The bigger the forest-to-golf course ratio, the better the water quality will be. 3. The size and capacity of each individual ponds varied and there were many somewhat longish rather than round ponds. 4. There were many differences among golf courses in naturalness of the ponds, and the correlation between naturalness and area of aquatic plants was very high. 5. Analyses of pond water quality indicated that the degrees of Dissolved Oxygen, Chemical Oxygen Demanded and Suspended Solids were relatively low values but Total Phosphorus and Total Nitrogen were too high. Therefore a systematic approach is needed to solve e problem. Pesticide residues were not detected in all ponds. 6. Water depth and area of hydrophyte should be considered when designing an ecological pond. 7. All ponds used storm water as a main source of water supply and added underground water. Aquatic plants and physical methods such as water aeration and spray fountains were the main choices for maintaining a healthy aquatic environment.