• Life and Agrochemicals
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• v.29 no.10
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• pp.21-30
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• 2008

한국농약과학회(회장 최운홍)와 한국작물보호협회(회장 염병만)가 고동 주최한 "2008한국농약과학회 추계 학술발표회 및 한국작물보호협회 창립 35주년 기념 심포지엄"이 관계 및 학계, 언론, 업계 관계자 등 400여명이 참석한 가운데 성황리 개최됐다. 지난 10월 9일부터 10일까지 이틀 동안 강원도 용평리조트내 그린피아콘도 그랜드볼룸에서 '애그플fp이션 시대 식량주권과 작물보호제 산업'이란 주제로 열린 이번 행사에서는 최근 의미가 모호한채 만능인 양 확산되어 가는 유기농업의 빛과 그림자를 조명하고, 애그플레이션 시대 세계열강들의 곡물 확보 전쟁 등으로 식량무기화는 가능성이 아니라 목전에 와 있는 현실임을 상기시켜 작물보호제의 중요성과 그 위상을 재정립하며 나아갈 방향을 확립하는 좋은 계기가 된 것으로 분석된다. 농약과학회 최운홍 회장은 개회사를 통해 "전 세계적으로 몰아닥치고 있는 곡물가격 상승과 식량위기는 식량확보의 중요성은 물론 기존 식량의 소중함을 다시 한번 일깨워 주고 우리농업을 새롭게 평가 조명할 수 있는 좋은 기회"라면서 "급변하는 세계 농업흐름 속에서 현실을 적시하고 농업생산의 중요한 축을 담당하고 있는 작물보호제의 중요성과 위상을 재정립 하며 나아갈 방향을 모색하는 의미 있는 행사가 되길 바란다"고 말했다. 한국작물보호협회 염병만 회장은 환영사를 통해 "지구촌은 지금 어느 누구도 소중한 먹을거리로부터 안심하지 못하고 있다"면서 "식량자급이 안정적으로 이루어지지 않는 한 작금의 일시적 풍요는 사상누각에 불과할 뿐"이라고 전제하고 "이제는 먹을거리의 진정한 위해요소가 무엇인지 가려낼 줄 알아야 하며 과학을 보는 소비자의 인식도 공평해져야 한다"고 강조했다. 이날 심포지엄에서는 일본 동경농업대학 Naoki Motoyama 교수의 '일본 유기농업의 허상과 실상'을 비롯, 모두 5편의 주제발표가 있었다. 주요 내용을 요약, 정리해 본다.

• Korea journal of population studies
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• v.32 no.1
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• pp.113-137
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• 2009

This article uses genealogical information to estimate fertility, mortality, and population growth in Korea during the eighteenth and nineteenth centuries. Upper class males' probability of dying as estimated from genealogies was converted into that for the whole male population drawing upon information on colonial mortality and model life tables, which indicated male life expectancy at birth was 23 years. Age-specific marital fertility rates for upper class females as calculated from genealogies were combined with estimates of age at first marriage and information on colonial fertility to derive age-specific fertility rate for the whole female population, which implied a total fertility rate of 6.81. Finally, the estimated indices of mortality and fertility were inserted into equations describing stable populations to find that the Korean population grew 0.62% p.a. during the eighteenth and nineteenth centuries.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.47-60
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• 2020

To assess the characteristics of phytoplankton community structures related to environmental factors, seasonal surveys were conducted in the vicinity of Dokdo. In 2019, phytoplankton of four phyla and 69 species were observed. During winter, unidentified nanoflagellates dominated, with an average of 3.19×10⁴ cells L^-1. In spring, unidentified nanoflagellates occupied about 50% of the composition and a variety of dinoflagellates appeared. The summer phytoplankton population showed very low abundance. In autumn, various species of Chaetoceros appeared, along with diatoms, such as Bacteriastrum spp., Guinardia striata, and Pseudo-nitzschia spp. In addition, tropical species Amphisolenia sp. and Ornithocercus sp. were observed in both 2018 and 2019. The diversity was high in the summer of 2018 and the winter of 2019 and the characteristics of each index varied. Cluster analysis was divided into four groups according to species and population characteristics regardless of the season. The stratification of spring was particularly weak. In the autumn of 2018, the water mass was stabilized in the same way as in the summer, which is considered a suitable condition for phytoplankton growth. However, in 2019, the water masses were mixed, resulting in a low population. In a phytoplankton comparison, the dominant group showed seasonal differences, except for summer when the population was low, and the difference was most pronounced in autumn. Therefore, the waters surrounding Dokdo have different environmental and ecological characteristics from the East Sea, but the seasonal characteristics of each year are considered to be different depending on the topography, various currents, the island effect, and other factors.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.2
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• pp.196-206
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• 2012

AESA radar is able to instantaneously and adaptively position and control the beam, and such adaptive beam pointing of AESA radar enables to remarkably improve the multi-mission capability, compared with mechanically scanned array radar. AESA radar brings a new challenges, radar resource management(RRM), which is a technique efficiently allocating finite resources, such as energy and time to each task in an optimal and intelligent way. Especially radar beam scheduling is the most critical component for the success of RRM. In this paper, we proposed stochastic radar beam scheduling algorithm using simulated annealing(SA), and evaluated the performance on the multi-function radar scenario. As a result, we showed that our proposed algorithm is superior to previous dispatching rule based scheduling algorithm from the viewpoint of beam processing latency and the number of scheduled beams, with real time capability.

• Journal of Korea Water Resources Association
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• v.31 no.4
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• pp.363-373
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• 1998

In this study, random flow field in a nonstationary porous formation is characterized through cross covariances of the velocity with the log conductivity and the head. The hydraulic head and the velocity in saturated aquifers are found through stochastic analysis of a steady, two-dimensional flow field without recharge. Expression for these cross covariances are obtained in quasi-analytic forms all in terms of the parameters which characterize the nonstationary conductivity field and the average head gradient. The cross covariances with a Gaussian correlation function for the log conductivity are presented for two particular cases where the trend is either parallel or perpendicular to the mean head gradient and for separation distances along and across the mean flow direction. The results may be of particular importance in transport predictions and conditioning on field measurements when the log conductivity field is suspected to be nonstationary and also serve as a benchmark for testing nonstationary numerical codes. Keywords : cross covariance, nonstationary conductivity field, saturated aquifer, stochastic analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2B
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• pp.163-171
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• 2009

Classical linear models have been generally used to analyze and forecast hydrologic time series. However, there is growing evidence of nonlinear structure in natural phenomena and hydrologic time series associated with their patterns and fluctuations. Therefore, the classical linear techniques for time series analysis and forecasting may not be appropriate for nonlinear processes. In recent, the BDS (Brock-Dechert-Scheinkman) statistic instead of conventional techniques has been used for detecting nonlinearity of time series. The BDS statistic was derived from the statistical properties of the correlation integral which is used to analyze chaotic system and has been effectively used for distinguishing nonlinear structure in dynamic system from random structures. DVS (Deterministic Versus Stochastic) algorithm has been used for detecting chaos and stochastic systems and for forecasting of chaotic system. This study showed the DVS algorithm can be also used for detecting nonlinearity of the time series. In this study, the stochastic and hydrologic time series are analyzed to detect their nonlinearity. The linear and nonlinear stochastic time series generated from ARMA and TAR (Threshold Auto Regressive) models, a daily streamflow at St. Johns river near Cocoa, Florida, USA and Great Salt Lake Volume (GSL) data, Utah, USA are analyzed, daily inflow series of Soyang dam and the results are compared. The results showed the BDS statistic is a powerful tool for distinguishing between linearity and nonlinearity of the time series and DVS plot can be also effectively used for distinguishing the nonlinearity of the time series.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.225-229
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• 2005

이류모형을 이용한 단기예측 레이더 강우자료와 관측 레이더자료의 비교를 통하여 얻어진 예측오차를 분석하였다. 임의 시점까지의 예측오차 장에 나타나는 확률분포 형태와 공간적 상관성을 분석하여 이들 특성을 반영하는 추후의 예측오차 장을 모의할 수 있었다. 모의된 예측오차 장과 합성된 단기예측 강우 장은 이류모형을 이용한 예측에 따른 불확실성 을 추계학적으로 반영한 예측강우를 제공한다.

• Journal of Environmental Health Sciences
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• v.21 no.1
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• pp.29-38
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• 1995

The purpose of this study is to improve the present methodology-for the estimation of optimal water supply from an impounding reservoir. The stochastic reservoir storage model presented in this paper is believed to be rational in that. the probability of reservoir depletion (return period) is to be calculated for the various monthly demands and storage capacities. The monthly flows are used to derive the reservoir storage capacity-monthly demand-probability curves at Dalcheon damsite and Hongcheon damsite in Han river basin.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.218-221
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• 2011

본 연구에서는 추계학적 해석을 통하여 구한 교량의 동적 변위와 동일한 변위를 발생시키는 등가 정적 버페팅 하중을 구하는 방법을 제시하고, 단순 양단 캔틸레버에 적용하여 타당성을 검증하였다. 모드 형상이 복잡한 사장교의 경우에 2개 이상의 모드를 포함해야 정확도를 높일 수 있는 것으로 나타났다.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.328-334
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• 2003

현재 우리나라 방파제 설계의 주류를 이루는 방법은 Hudson(SPM,1984)공식과 같은 경험식을 이용하는 결정론적 방법이다 이 결정론적 방법은 사용하기에 간편한 장점이 있으나, 그 유도과정을 살펴보면 적용에 한계가 있음을 알 수 있다. 즉, 임의로 선택된 설계파로부터 구조물의 안정여부에 대한 평가만 가능하다. (중략)