• 한국농공학회논문집
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• 제57권4호
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• pp.121-133
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• 2015

The TANK model has been widely used in rainfall-runoff modeling due to its simplicity of concept and computation while achieving forecast accuracy. A major barrier to the model application is to determine parameter values for ungauged watersheds, leading to the need of a method for the parameter estimation. The objective of this study was to develop regression equations for estimating the 3th TANK model parameters considering their variations for the ungauged watersheds. Thirty watersheds of dam sites and stream stations were selected for this study. A genetic algorithm was used to optimize TANK model parameters. Watershed characteristics used in this study include land use percent, watershed area, watershed length, and watershed average slope. Generalized equations were derived by correlating to the optimized parameters and the watershed characteristics. The results showed that the TANK model, with the parameters determined by the developed regression equations, performed reasonably with 0.60 to 0.85 of Nash-Sutcliffe efficiency for daily runoff. The developed regression equations for the TANK model can be applied for the runoff simulation particularly for the ungauged watersheds, which is common for upstream of agricultural reservoirs in Korea.

• 비파괴검사학회지
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• 제27권2호
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• pp.148-156
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• 2007

섬유복합재료의 역학적인 관점에서 볼 때 PVA-ECC (polyvinyl alcohol-engineered cementitious composite)의 섬유분산성 평가는 매우 중요한 요소이다. 그러나 PVA 섬유의 낮은 명암비 때문에 시멘트계 재료와 섬유를 구별하기가 어려우므로, PVA-ECC의 섬유분산성 평가를 하기에는 어려운 점이 있다. 이 연구에서는 이러한 문제점을 해결하기 위하여 PVA-ECC 내의 섬유분산성을 평가할 수 있는 새로운 방법을 제시하였다. 형광의 원리를 이용하여 섬유복합재료 단면에서 PVA 섬유가 초록빛을 발하는 이미지를 얻었고, PVA-ECC 시편에 대한 섬유분산성은 형광 현미경에 부착된 CCD (charge coupled device) 카메라를 통하여 얻어진 이미지를 이미지 프로세싱 기법과 통계적인 방법을 이용하여 평가하였다. 또한 형상분석을 통하여 섬유의 방향성이 분산성에 미치는 영향을 파악하였으며, 판별함수기법과 분수령 알고리즘을 이용하여 섬유 검출 성능을 향상시킬 수 있는 기법을 제시하였다.

• 한국환경과학회지
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• 제26권4호
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• pp.433-445
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• 2017

In recent years, the United States has used the Load Duration Curve (LDC) method to identify water pollution problems, considering the size of the pollutant load in the entire stream flow condition to effectively evaluate Total Maximum Daily Loads (TMDLs). A study on the improvement of the target water quality evaluation method was carried out by comparing evaluations of two consecutive years of water quality and LDC data for 41 unit watersheds (14 main streams and 27 tributaries). As a result, the achievement rate of the target water quality evaluation method, according to current regulations, was 68-93%, and that by the LDC method was 82-93%. Evaluating the target water quality using the LDC method results in a reduction in the administrative burden and the total amount of planning as compared to the current method.

• 한국수자원학회논문집
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• 제51권9호
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• pp.761-768
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• 2018

기후변화와 기후변화 외적인 요인으로 인해 지하수자원은 고갈되어가고 있다. 지하수자원의 효율적인 관리를 위해 유역 단위의 지하수자원 관리 취약시기 평가 방법을 개발하였다. 유역 단위의 취약시기 평가는 취약 지역 평가와 소유역에 대한 취약시기 평가를 독립적으로 진행하여 각각의 지수를 산정하였다. 취약 지역 평가 지수를 표준화하여 독립적으로 진행한 취약시기 평가 지수에 적용하여 유역 단위의 취약시기 평가 방법을 개발하였으며, 개발한 방법을 낙동강 상류 지역인 봉화군, 안동시, 예천군, 문경시, 상주시에 적용하였다. 그 결과 상주의 8월이 0.278로 가장 취약한 것으로 나타났으며, 안동시는 1년 중 8개월간 5개 지역 중 지하수자원 관리에 취약한 것으로 나타났다. 개발된 방법을 이용하여 지하수자원의 시공간을 고려한 효율적인 관리방안을 모색할 수 있을 것이다.

• 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.

• 한국조경학회지
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• 제25권2호
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• pp.73-81
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• 1997

The main purpose of this study was to develop a new method for evaluation of stream naturalness in order to appraise and prescribe for streams effectively in the process of ecological restoration of stream corridors. The results are as follows : 1) For this purpose six factors were selected on considering the spatial axes of stream corridor variation and total 20 descriptors about the physical structure were selected. 2) The calculation of S.N.I. for each segment was consisted of three steps, such as calculation of S.N.I.s of the individual descriptors, averaging all the descriptors's for each factor, and finally averaging the factors's for the Total S.N.I. 3) The evaluation unit was decided to be 100m size. The score system ranging 1~5 was adopted. Weighting parameters of factors were unified with each other. 4) A GIS model was adopted for classification, calculation, querying, analysing, and presenting S.N.I. information. And the format of S.N.I. maps including statistical graphs and other spatial watershed information was designed for the GIS odel. The naturalness of stream corridor was was investigated by the naturalness of habitat, and assessed by the descriptors focused on physical structure, therefore the S.N.I. can manifest prescriptions for restoration of the stream corridor. On the other hand because some evaluation factors such as water quality, water volume, fauna, flora, functions of stream exosystem has been excluded, S.N.I. could have some limits on representing the full aspects of stream naturalness. This evaluation method is hypothetical one, so it would be investigated through iterative applicatons.

• 한국농공학회논문집
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• 제65권1호
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• pp.1-13
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• 2023

Various techniques for bias correction and statistical downscaling have been developed to overcome the limitations related to the spatial and temporal resolution and error of climate change scenario data required in various applied research fields including agriculture and water resources. In this study, the characteristics of three different statistical dowscaling methods (i.e., SQM, SDQDM, and BCSA) provided by AIMS were summarized, and climate change scenarios produced by applying each method were comparatively evaluated. In order to compare the average rainfall characteristics of the past period, an index representing the average rainfall characteristics was used, and the reproducibility of extreme weather conditions was evaluated through the abnormal climate-related index. The reproducibility comparison of spatial distribution and variability was compared through variogram and pattern identification of spatial distribution using the average value of the index of the past period. For temporal reproducibility comparison, the raw data and each detailing technique were compared using the transition probability. The results of the study are presented by quantitatively evaluating the strengths and weaknesses of each method. Through comparison of statistical techniques, we expect that the strengths and weaknesses of each detailing technique can be represented, and the most appropriate statistical detailing technique can be advised for the relevant research.

• Journal of information and communication convergence engineering
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• 제16권2호
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• pp.114-124
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• 2018

This paper illustrates a vision-based vehicle positioning method at an intersection to support the C-ITS. It removes the minor shadow that causes the merging problem by simply eliminating the fractional parts of a quotient image. In order to separate the occlusion, it firstly performs the distance transform to analyze the contents of the single foreground object to find seeds, each of which represents one vehicle. Then, it applies the watershed to find the natural border of two cars. In addition, a general vehicle model and the corresponding space estimation method are proposed. For performance evaluation, the corresponding ground truth data are read and compared with the vision-based detected data. In addition, two criteria, IOU and DEER, are defined to measure the accuracy of the extracted data. The evaluation result shows that the average value of IOU is 0.65 with the hit ratio of 97%. It also shows that the average value of DEER is 0.0467, which means the positioning error is 32.7 centimeters.

• 한국농공학회논문집
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• 제58권4호
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• pp.67-74
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• 2016

Load Duration Curve (LDC) can be used as a method for load management of point and non-point pollution source because the LDC easily assesses the water quality corresponding to hydrological changes in a watershed. Recently, the application of LDC to total pollution load management is a growing interest in Korea. In this regard, A desktop-based LDC assessment system was developed in this study to provide convenience to users in water quality evaluation. The developed system can simply produce the LDC by using streamflow and water quality data involved in its database. Also, The system can quantitatively inform the success or failure of the achievement for a target water quality at monthly scale. Furthermore, seasonal water quality and point/non-point pollution load in a watershed can be estimated by this system. We expect that the developed system will contribute to establish local and national policies regarding water management and total pollution load management because of its advantages such as the pollution tracking investigation and the analysis of water quality and pollution loading amount in an ungauged watershed.

• 한국방재학회 논문집
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• 제9권3호
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• pp.117-126
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• 2009

유역종합치수계획 수립 시 유역 내 적용이 가능한 구조물적 비구조물적 치수계획은 매우 광범위하고, 특히 그 중에서도 구조물적 홍수방어 시설들의 특성은 매우 다양하다. 이들을 조합하여 유역의 홍수 저감능력을 최대화 하는 최적대안을 선정하는 것은 쉬운 일이 아니며, 현재 구조물적 홍수방어 후보대안에 대한 적절한 평가 기준이나 다양한 홍수방어 후보대안들 중 최적대안의 선정에 관한 지침 또한 미흡한 실정이다. 본 연구에서는 유역종합치수계획의 구조물적 홍수방어 후보대안들에 대한 치수경제성 및 정책성 평가 결과를 바탕으로 최적대안을 선정하는 과정에서, 의사결정기법 중의 하나인 계층화분석기법을 도입하여 적용함으로써 평가항목들 간의 가중치 결정 및 최적대안을 도출하는 과정을 예시하였다. 후보대안들 각각의 하위 세부 평가항목들의 가중치 결정에는 계층화분석기법 전용 프로그램인 Expert Choice 11.5를 활용하였으며, 연구 결과를 바탕으로 유역종합치수계획의 구조물적 홍수방어 최적대안 선정에 있어 보다 표준화된 절차를 제시하였다.