검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 3

        1.
        2016.04 구독 인증기관·개인회원 무료
        The first record of Melon thrips, Thrips palmi Karny, was in 1993 in Korea, and the species has become severe pest in agricultural industry. We used two different SDMs(Species Distribution Model) which have different approaches to analyse potential distribution of the pest species in climate change scenario, MaxEnt and CLIMEX. The MaxEnt model uses historical occurrence records with environmental variables to estimate the realized niche, and CLIMEX model simulates the fundamental niche of the object based on the seasonal phenology. In MaxEnt simulation, we reduced the number of variables to avoid multi-collinearity problem until we had no pairs with an absolute Pearson correlation coefficient higher than 0.8. BIO1(Annual Mean Temperature), BIO2(Mean diurnal range), BIO3(Isothermality), BIO4(Temperature seasonality) were finally selected as predictor, and we used 10 fold cross validation option to replicate. The averaged results were used to index analysis. The CLIMEX results, The Ecoclimate Index(EI), were also normalized in 0 to 1 scale to analysis. Under RCP 8.5 climate change scenario, in 2070s, the distribution of Thrips palmi was predicted to expand their territory overall agricultural area in Korea.
        2.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 미급수지역의 주요 수원인 지하수위 현황을 이용한 가뭄 모니터링 기법을 개발하기 위해 256개의 국가지하수관측망 관측 자료를 이용하여 관측소별, 월별 수위분포를 핵밀도함수로 추정하였다. 추정된 누적분포함수를 이용하여 월별 지하수위의 분위수를 구하고, 분위수를 정규화 하여 표준지하수지수(SGI)를 산정하였다. 관측소별로 산정된 SGI는 티센망을 이용하여 167개 시군별 SGI로 변환하였다. SGI의 범위에 따른 가뭄등급을 설정하여 시군별 지하수 가뭄 정도를 모니터링 할 수 있는 기법을 제시하였다. 이를 통해 계측이 이루어지지 않는 미급수지역의 지하수 가뭄상황을 국가지하수관측망을 활용해 간접적으로 판단할 수 있도록 하였다.
        3.
        2015.04 KCI 등재 서비스 종료(열람 제한)
        In the mountain streams in Jeju Island, strong turbulence and roughness usually made it nearly impossible to utilize most of intrusive instrumentation for streamflow discharge measurements. Instead, a non-intrusive fixed electro-magnetic wave surface velocimetry (fixed EWSV: Kalesto) became alternatively popular in many representative streams to measure stream discharge seamlessly. Currently, Kalesto has shown noteworthy performance with little loss in flood discharge measurements and also has successfully provided discharge for every minute. However, Kalesto has been operated to regard its measured one-point velocity as the representative mean velocity for the given cross-section. Therefore, it could be highly possible to potentially encompass discharge measurements errors. In this study, we analyzed the difference between such Kalesto discharge measurements and other alternative concurrent discharge measurements such as Acoustic Doppler Current Profiler (ADCP) and mobile EWSV which were able to measure velocity in multi-points in the cross-section. Consequently, Kalesto discharge deviated from ADCP discharge in amount of 48% for relatively low flow, and more than 20% difference for high flow compared with mobile EWSV discharge measurements. These results indicated that the one-point velocity measured by Kalesto should be used as a cross-sectional mean velocity, rather it should be accounted for as an index-velocity in conjunction with directly measured cross-sectional mean velocity by using more reliable instrumentations. After inducing Kalesto Discharge Correction Coefficient (KDCC) that actually means relationship between index velocity and cross-sectional mean velocity, the corrected discharge from Kalesto was significantly improved. Therefore, we found that index velocity method should be applied to obtain better accuracy of discharge measurement in case of Kalesto operation.