• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.77-81
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• 2019

식생전이에 따른 기간분리는 해외 및 국내 논문에서 식생영향을 받지 않는 곡선식과의 차이를 검토하고, 측정성과별 분류를 통해 곡선식을 개발하는 방법이 제시하고 있으나 적용기간 설정에 대한 구체적인 방법이 없다. 또한 상하류 비교를 통해 기간분리의 적정성을 검토할 수 있다고 명시되어 있으나 비교 관측소가 없는 경우 검토에 어려움이 있다. 본 연구는 2017년 수위-유량관계곡선식의 적용시간 결정에서 현장 식생모니터링 자료와 함께 연간 수온변화를 참고 자료로 활용하였다. 연간 수온자료를 산정하기 위해 측정된 수온과 해당 기온에 대한 상관관계식을 개발하였다. 또한 산포가 발생하는 측정성과는 생성된 연간 수온자료를 참고하여 전이여부를 판단하였다. 2018년은 2017년의 계절별 수온변화 자료 및 수집된 주요 수중식생의 생활사를 참고하여 연간 측정계획에 활용하였으며, 수위-유량관계곡선식 개발 시 동일한 방법을 사용하였다. 2017년은 가뭄으로 인해 수중식생에 의한 전이가 활발했던 기간으로 측정성과에 대해 식생영향 최고 기간과 최대 기간의 동일수위에 대해서 유량을 비교한 결과 $0.003m^3/s{\sim}1.099m^3/s$의 범위를 보였다. 유출량 비교의 경우 기간분리를 적용하지 않았을 경우 약 40.1% 과대 산정되었다. 2018년은 잦은 강우로 인해 수중식생의 이탈 및 전이 영향수위의 발생빈도가 비교적 적어 동 수위 유량을 비교한 결과 $0.19m^3/s{\sim}0.49m^3/s$의 범위를 보였다. 연 유출량을 비교한 결과, 기간분리를 고려하지 않은 경우가 약 39.6%로 과소 산정되었다. 따라서 본 연구사례를 통해 식생에 의한 기간분리가 발생하는 지점에 대해서 비교적 합리적인 측정주기 계획을 위한 확립 근거와 기간분리 적용기간에 대한 합리적인 자료로 활용 될 수 있을 것이다.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.444-460
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• 2017

The duration of volunteering can be analyzed in terms of commitment and attachment. Previous studies have investigated the duration of volunteering predominantly from the perspective of commitment. Alternatively, this study focuses on the concept of attachment and investigates the characteristics of those who volunteer habitually over their whole life, regardless of the regularity and the intensity of the volunteer work. In so doing, the study attempts to identify factors associated with the attachment to volunteering. Data came from a sample of 8,415 participants, ages over twenty who responded to all the surveys of the Korea Welfare Panel Study, from Wave 1 to 10. Zero-inflated negative bionomial regression model was employed to analyze the total number of volunteering in the past ten years. Findings show that people with high attachment to volunteering were those with religion, less education, and a strong sense of reciprocity. Based on the findings, we provide the practical implications for the improved operation and management of volunteer organizations.

• Environmental and Resource Economics Review
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• v.27 no.3
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• pp.545-567
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• 2018

This study applied and compared Poisson model, negative binomial model, zero inflated Poisson model, and zero inflated negative binomial model to estimate determinants of employed labour quantity. To estimate each of models, this study used fisheries census data which were obtained at microdata integrated service running by Statistics Korea. The study selected zero inflated negative binomial model according to the Vuong test and Likelihood-ratio test. In addition, the study estimated fishing village's practical changes on employed labour quantity as analyzing changes from 2010 to 2015. The results showed that the household with fishing vessels and high selling price had a significant effect on decrease of the labour quantities. Meanwhile, the longer work experience of the household, the more significant the increase in the labour quantities. In conclusion, this study presented that capitalized fishing household and the acceleration of aging had a significant impact on the change in the labour quantities.

• Korean Journal of Poultry Science
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• v.50 no.1
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• pp.41-50
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• 2023

Over the last decade, avian influenza (AI) has been considered an emerging disease that would become the next pandemic, particularly in countries like South Korea, with continuous animal outbreaks. In this situation, risk assessment is highly needed to prevent and prepare for human infection with AI. Thus, we developed the risk assessment matrix for a high-risk area of human infection with AI in South Korea based on the notion that risk is the multiplication of hazards with vulnerability. This matrix consisted of highly pathogenic avian influenza (HPAI) in poultry farms and the number of poultry-associated production facilities assumed as hazards of avian influenza and vulnerability, respectively. The average number of HPAI in poultry farms at the 229-municipal level as the hazard axis of the matrix was predicted using a negative binomial regression with nationwide outbreaks data from 2003 to 2018. The two components of the matrix were classified into five groups using the K-means clustering algorithm and multiplied, consequently producing the area-specific risk level of human infection. As a result, Naju-si, Jeongeup-si, and Namwon-si were categorized as high-risk areas for human infection with AI. These findings would contribute to designing the policies for human infection to minimize socio-economic damages.

• Korean Journal of Remote Sensing
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• v.32 no.3
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• pp.263-274
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• 2016

In this study, we compared the Precipitable Water Vapor (PWV) data derived from the radiosonde observation at Sokcho observatory and the PWV data at Sokcho Global Navigation Satellite System (GNSS) observatory provided by Korea Astronomy and Space Science Institute, for the summer of 2007~2014, and analyzed the radiosonde diurnal and rainfall-dependent bias according to radiosonde sensor types. In the scatter diagram of the daytime and nighttime radiosonde PWV data and GNSS PWV data, dry bias was found in the daytime radiosonde observation as known in the previous study and dry bias of RSG-20A sensor was larger than other sensors. Overall, the tendency that the wet bias of the radiosonde PWV increased as GNSS PWV decreased and the dry bias of the radiosonde PWV increased as GNSS PWV increased. The quantitative analysis of the bias and error of the radiosonde PWV data showed that the mean bias decreased in the nighttime except for 2007, 2008 summer. In comparison for summer according to the presence or absence of rainfall, RS92-SGP sensor showed the highest quality.

• Korean Journal of Ecology and Environment
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• v.42 no.2
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• pp.200-211
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• 2009

A mathematical modeling program called Soil and Water Assessment Tool (SWAT) developed by USDA was applied to Kyongan stream watershed. It was run under BASINS (Better Assessment Science for Integrating point and Non-point Sources) program, and the model was calibrated and validated using KTMDL monitoring data of 2004${\sim}$2008. The model efficiency of flow ranged from very good to fair in comparison between simulated and observed data and it was good in the water quality parameters like flow range. The model reliability and performance were within the expectation considering complexity of the watershed and pollutant sources. The results of pollutant loads estimation as yearly (2004${\sim}$2008), pollutant loadings from 2006 were higher than rest of year caused by high precipitation and flow. Average non-point source (NPS) pollution rates were 30.4%, 45.3%, 28.1% for SS, TN and TP respectably. The NPS pollutant loading for SS, TN and TP during the monsoon rainy season (June to September) was about 61.8${\sim}$88.7% of total NPS pollutant loading, and flow volume was also in a similar range. SS concentration depended on precipitation and pollution loading patterns, but TN and TP concentration was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. SWAT based on BASINS was applied to the Kyongan stream watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading including point and non-point sources in watershed scale.