• Journal of Environmental Impact Assessment
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• v.26 no.1
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• pp.68-77
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• 2017

In order to estimate the non-point pollution loads from each watersheds among 209 watersheds, the calibration and validation of HSPF model were carried out based on 2012 in 2013 years. In the case of flow rate, R2 of calibration and validation were 0.71~0.93 and 0.71~0.79, which were relatively good values. With the respect to calibration of water quality, % differences between measured and simulated values were 0.4 ~ 9.7 of DO, BOD 0.5 ~ 30.2% and TN 1.9~28.6% except for Hwhangkang B site. In case of validation, DO was 0.2 ~ 13.7%, BOD 1.3~23% and TN 0.5~24.3% excluding Hwhangkang B. However, since the concentration of TP was very small compared with other items, the range of difference was large as 0.8~55.3%. level. As the result of calculating annual accumulative BOD loads for each watershed, it was found that RCH 123 (Uryeong, Gyeongsangnamdo), RCH 121 (Jinju, Gyeongsangnamdo) and RCH 92 (Daegu) were the high ranked. The unit watersheds including various landuse type susch as forest and agricultural sites in mainstream areas have a higher BOD nonpoint pollution load than those in dam regions. However, the results of the annual cumulative loading of the basins for nutrients did not appear to be consistent with the BOD annual cumulative loading ranks. Other factors that represent watershed characteristics such as landslope and soiltypes, including landuse pattern, have been found to be closely related to nonpoint pollutant loads.

• Journal of Environmental Impact Assessment
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• v.27 no.5
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• pp.509-520
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• 2018

The impact of meteorological condition on surface $PM_{10}$ concentrations in South Korea was quantitatively simulated from 2010 to 2014 using WRF (ver.3.8.1) and CMAQ (5.0.2) model. The result showed that seasonal standard deviations of PM10 induced by change of weather conditions were $4.8{\mu}g/m^3$, $1.7{\mu}g/m^3$, $1.7{\mu}g/m^3$, $4.2{\mu}g/m^3$ for spring, summer, autumn and winter compared to 2010, respectively, with the annual mean standard deviation of about $2.6{\mu}g/m^3$. The results of 18 regions in South Korea showed standard deviation of more than $1{\mu}g/m^3$ in all regions and more than $2{\mu}g/m^3$ in Seoul, Northern Gyeonggi, Southern Southern Gyeonggi, Western Gangwon and Northern Chungcheong in South Korea.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1125-1138
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• 2014

In this study, we applied an advanced non-parametric low-flow frequency analysis using boundary kernel by Representative Concentration Pathways (RCPs) climate change scenarios through Arc-SWAT long-term runoff model simulation at the Gwangdong storage reservoir located in Taeback, Gangwondo. The results show that drought frequency under RCPs was expected to increase due to reduced runoff during the near future, and the variation of low-flow time series was appeared greatly under RCP8.5 scenario, respectively. The result from drought frequency of Median flow in the near future (2030s) compared historic period, the case of 30-year low-flow frequency was increased (the RCP4.5 shows +22.4% and the RCP8.5 shows +40.4%), but in the distant future (2080s) expected increase of drought frequency due to the reduction of low-flow (under RCP4.5: -4.7% and RCP8.5: -52.9%), respectively. In case of Quantile 25% flow time series data also expected that the severe drought frequency will be increased in the distant future by reducing low-flow (the RCP4.5 shows -20.8% to -60.0% and the RCP8.5 shows -30.4% to -96.0%). This non-parametric low-flow frequency analysis results according to the RCPs scenarios have expected to consider to take advantage of as a basis data for water resources management and countermeasures of climate change in the mid-watershed over the Korean Peninsula.

• Journal of Korea Water Resources Association
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• v.51 no.3
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• pp.235-246
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• 2018

The main purpose of this study is to suggest a methodology for identifying vulnerable region in Choyang creek basin susceptible to soil losses based on runoff aggregation structure and energy expenditure pattern of natural river basin within the framework of power law distribution. To this end geomorphologic factors of every point in the basin of interest are extracted by using GIS, which define tractive force and stream power as well as drainage area, and then their complementary cumulative distributions are graphically analyzed through fitting them to power law distribution to identify the sensitive points within the basin susceptible to soil losses with respect to scaling regimes of tractive force and stream power. It is observed that the range of vulnerable region by scaling regime of tractive force is much narrower than by scaling regime of stream power. This result seems to be due to the tractive force is a kind of scale dependent factor which does not follow power law distribution and does not adequately reflect energy expenditure pattern of river basins. Therefore, stream power is preferred to be a more reasonable factor for the evaluation of soil losses. The methodology proposed in this study can be validated by visualizing the path of soil losses, which is generated from hill-slope process characterized by local slope, to the valley through fluvial process characterized by drainage area as well as local slope.

• Tuberculosis and Respiratory Diseases
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• v.57 no.2
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• pp.148-159
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• 2004

Background : This study was conducted to evaluate the survival benefit of the bronchial arterial embolization (BAE) for patients presenting with non-traumatic hemoptysis. Methods : The clinical data were retrospectively collected from the medical records and the Order Communicating Systems (OCS). The information dealing with death was collected from national death certificates. After enrolled patients were divided with two group such as BAE group (patients who were managed with BAE) and non-BAE group (patients who were managed with conservative modality), the survival benefit of BAE was estimated during the observational period of 24 months through using the Kaplan-Meier survival graph and the Cox-proportional hazard regression analysis. Results : The number of total cases was 272. Of these, BAE group involved 63 and non-BAE group involved 209. 69 cases had the malignant pulmonary lesions, 149 cases had non-malignant chronic lung lesion such as the mycobacteria infection, fungus ball, or bronchiectasis (BE), and 54 cases had the other pathologic conditions. For each sub-groups such as 'malignant lung lesion' group, 'non-malignant chronic lung lesion' group as well as about all cases, the adjusted hazard ratios (HRs) of BAE for death was not significantly different compared to the conservative management. But the adjusted HRs as to underlying causes such as 'malignant lung lesion' group and 'the other conditions' group increased significantly compared to 'non-malignant chronic lung lesion' group. Conclusion : There was no significant survival benefit by BAE procedure on survival in patients presenting with non-traumatic hemoptysis.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.348-359
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• 2017

Recently, various public transportation activation policies are being implemented in order to mitigate traffic congestion in metropolitan areas. Especially in the metropolitan area, the bus information system has been introduced to provide information on the current location of the bus and the estimated arrival time. However, it is difficult to predict the travel time due to repetitive traffic congestion in buses passing through complex urban areas due to repetitive traffic congestion and bus bunching. The previous bus travel time study has difficulties in providing information on route travel time of bus users and information on long-term travel time due to short-term travel time prediction based on the data-driven method. In this study, the path based long-term bus travel time prediction methodology is studied. For this purpose, the training data is composed of 2015 bus travel information and the 2016 data are composed of verification data. We analyze bus travel information and factors affecting bus travel time were classified into departure time, day of week, and weather factors. These factors were used into clusters with similar patterns using self organizing map. Based on the derived clusters, the reference table for bus travel time by day and departure time for sunny and rainy days were constructed. The accuracy of bus travel time derived from this study was verified using the verification data. It is expected that the prediction algorithm of this paper could overcome the limitation of the existing intuitive and empirical approach, and it is possible to improve bus user satisfaction and to establish flexible public transportation policy by improving prediction accuracy.

• Journal of Korea Water Resources Association
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• v.46 no.10
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• pp.1017-1028
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• 2013

The purpose of this research is to develop an Integrated Water Resources Evaluation Index (IWREI) which can used to assess the performance of water resources projects in a regional perspective focusing on three major sectors including water use, flood, and river environment in water resources policies. The IWREI is estimated by integrating the Water Use Vulnerability Index (WUVI), the Flood Vulnerability Index (FVI), and the River Environment Vulnerability Index (REVI) which represent the vulnerability in each sector. These indices consist of total 26 indicators selected from the pressure indicators representing the causes of damages in water use, flood, and river environment, the state indicators and the response indicators. The estimated index describes the vulnerability and effectiveness of policies with five levels: Low, Medium Low, Medium, Medium High, and High. The results of evaluating total 115 hydrological units in Korea using the WUVI, FVI, REVI, and IWREI indicate that the project effectiveness in water resources policies is clearly verified by the improved index results compared to the past (early 1990s). Regional vulnerability and evaluation indices developed in this research could be used to establish goals of water resources policy and to select priority regions for project implementation.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.56-56
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• 2019

우리나라는 최근 기후변화로 인하여 가뭄의 빈도와 강도가 점점 증가하고 있는 추세이며, 이에 따른 농업가뭄 현상은 매년 발생하고 있는 실정이다. 2000년 이후부터 무상으로 공급되고 있는 농업용수에 대해 농민 물이용 손실을 저감하고, 물부족에 대비한 선제적인 가뭄대응의 일환으로 물절약 교육 및 홍보를 통한 농민 물절약의 중요성 인식으로 2015년에 "농업농촌부문 가뭄대응 종합대책"에 농민 절수교육 및 홍보를 통한 물절약 추진 과제가 포함되었다. 농민 물절약 교육을 통한 농민의 가뭄에 대한 경각심과 물절약 실천의 중요성을 인식시키고, 농업인의 자발적인 물절약 실천을 통한 효율적 수자원 이용을 도모하는데 그 의의가 있다. 이에 따라 2016년 농민 물절약교육 모델이 개발되었으며, 2017년에는 물절약 교육 모델의 현장적용을 위한 시범교육이 실시되었다. 또한 "2018년 정부 가뭄종합대책" 중 가뭄대책 실천의 일환으로 물절약 교육 및 홍보실시 확대 추진을 위해 2018년도에는 2016년과 2017년에 실시한 농민 물절약 시범교육을 바탕으로 물절약 교육 모델의 실용화를 위한 농민 물절약 교육 전문인력 양성을 실시하였다. 본 연구에서 진행한 물절약 교육 전문인력 양성 프로그램은 농업용수의 물공급 및 관리기관인 한국농어촌공사 지사단위 유지관리 직원을 대상으로 하였으며, 전국적으로 경기 강원권, 충청권, 호남권, 경상 제주권의 4개 권역으로 나누어 상 하반기 교육을 실시하여 총 322명의 교육인력을 양성하였다. 전문인력양성 교육은 물절약 교육에 대한 전반적인 이해와 현장적용을 위해 농민 물절약 교육 이수단계별교육 내용 및 교육 방법을 이해하고, 각 단계별 교육을 직접 실습해 보는 시간으로 구성하였다. 교육 이수 후에는 교육생의 학습에 대한 이해도 및 교육 만족도를 조사하고 기타 교육에 대한 의견수렴을 위해 설문조사를 실시하였다. 그 결과, 교육생의 대부분이 농민 대상 물절약 교육의 필요성을 매우 공감하는 것으로 나타났으며, 물절약 교육의 지속적인 실천 및 전국적인 확대를 위해 별도의 예산 및 인력지원의 필요성을 강조하였다. 교육과정을 완료 후에는 수료증을 수여하였으며, 본 연구에서 개발한 물절약 교육의 현장적용을 위한 물절약 교육 강사용 교재를 배포함으로 본 교육을 이수한 전문인력의 농민 물절약 교육에 활용하도록 하였다.

• Journal of Korean Library and Information Science Society
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• v.53 no.2
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• pp.215-239
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• 2022

All public libraries are local public goods and cultural infrastructures whose ideological pillars are publicly operated, free, and open to all. This identity is justified when the public library provides various knowledge information, various programs, and community space to local residents within the service area, and ultimately contributes to the cultural development of the nation and society. To this end, the country and local governments must expand the number of individuals that meet legal standards, deploy competent professionals, and provide facilities and spaces that are easy to access and use. However, if there is a gap in infrastructure and services between regional public libraries, it causes inequality in access and use of residents, which inevitably leads to information gap and cultural welfare gap. Therefore, this study was analyzed the relative gap using the location quotient, key infrastructure indicators and service indicators of public libraries of regional government in Korea and basic local government in the Chungnam region from the viewpoint that the balanced development and capacity building of public libraries must precede the establishment of a public library in Chungnam region as a life-friendly knowledge information service institution, culture enjoyment and lifelong learning space. Based on the results, a method to resolve the gap was suggested by dividing the elements of gaps in public libraries into accessibility, core infrastructure, and services, focusing on vulnerable cities and counties in the Chungnam region.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.387-387
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• 2022

기존 홍수기시 댐 운영은 예측 강우와 실시간 관측 강우를 이용하여 댐 운영 모형을 수행하며, 예측 결과에 따라 의사결정 및 댐 운영을 실시하게 된다. 하지만 이 과정에서 반복적인 분석이 필요하며, 댐 운영 모형 수행자의 경험에 따라 예측 결과가 달라져서 반복작업에 대한 자동화, 모형 수행자에 따라 달라지지 않는 예측 결과의 일반화가 필요한 상황이다. 이에 댐 운영 모형에 AI 기법을 적용하여, 다양한 강우 상황에 따른 자동 예측 및 모형 결과의 일반화를 구현하고자 하였다. 이를 위해 수자원 분야에 적용된 국내외 129개 연구논문에서 사용된 딥러닝 기법의 활용성을 분석하였으며, 다양한 수자원 분야 AI 적용 사례 중에서 댐 운영 예측 모형에 적용한 사례는 없었지만 유사한 분야로는 장기 저수지 운영 예측과 댐 상·하류 수위, 유량 예측이 있었다. 수자원의 시계열 자료 활용을 위해서는 Long-Short Term Memory(LSTM) 기법의 적용 활용성이 높은 것으로 분석되었다. 댐 운영 모형에서 AI 적용은 2개 분야에서 진행하였다. 기존 강우관측소의 관측 강우를 활용하여 강우의 패턴분석을 수행하는 과정과, 강우에서 댐 유입량 산정시 매개변수 최적화 분야에 적용하였다. 강우 패턴분석에서는 유사한 표본끼리 묶음을 생성하는 K-means 클러스터링 알고리즘과 시계열 데이터의 유사도 분석 방법인 Dynamic Time Warping을 결합하여 적용하였다. 강우 패턴분석을 통해서 지점별로 월별, 태풍 및 장마기간에 가장 많이 관측되었던 강우 패턴을 제시하며, 이를 모형에서 직접적으로 활용할 수 있도록 구성하였다. 강우에서 댐 유입량을 산정시 활용되는 매개변수 최적화를 위해서는 3층의 Multi-Layer LSTM 기법과 경사하강법을 적용하였다. 매개변수 최적화에 적용되는 매개변수는 중권역별 8개이며, 매개변수 최적화 과정을 통해 산정되는 결과물은 실측값과 오차가 제일 적은 유량(유입량)이 된다. 댐 운영 모형에 AI 기법을 적용한 결과 기존 반복작업에 대한 자동화는 이뤘으며, 댐 운영에 따른 상·하류 제약사항 표출 기능을 추가하여 의사결정에 소요되는 시간도 많이 줄일 수 있었다. 하지만, 매개변수 최적화 부분에서 기존 댐운영 모형에 적용되어 있는 고전적인 매개변수 추정기법보다 추정시간이 오래 소요되며, 매개변수 추정결과의 일반화가 이뤄지지 않아 이 부분에 대한 추가적인 연구가 필요하다.