• 한국구조물진단유지관리공학회 논문집
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• 제12권5호
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• pp.179-189
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• 2008

본 연구는 능동텐던을 이용 지진을 받는 구조물의 최적 능동제어 방법에 관한 수치해법 적용 및 프로그램 개발에 목적이 있다. 능동텐던 시스템에 의한 제어이론을 적용하기 위해서 Ricatti 폐회로 알고리즘을 이용하였으며, 시간지연 문제를 고려하였다. 최적제어의 정식화를 위해서 SUMT기법의 최적화에 의해 성능지수를 최소로 하는 최적 가중치행렬을 추정토록 하였다. 구조물에서의 능동텐던의 최적 위치 선정을 위해서 가제어지수에 의한 방법을 소개하였다. 수치 예를 통해, 제어기의 최적 위치선정을 고려한 능동최적제어가 지진하중을 받는 구조물의 성능제어에 우수한 효과를 나타내는 것으로 평가되었다.

• 한국항공운항학회지
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• 제17권1호
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• pp.17-23
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• 2009

The purpose of this study is possibility of the heavy rainfall prediction using instability index. The convective instability index using this study is Convective Available Potential Energy(CAPE) concerned the growth energy of the storm, Bulk Richardson Number(BRN) concerned the type and strength of the storm, and Sotrm Relative Helicity(SRH) concerned maintenance of the storm. To verify the instability index, the simulation of heavy rainfall case experiment by Numerical Weather Prediction(NWP) model(MM5) are designed. The results of this study summarized that the heavy rainfall related to the high instability index and the proper combination of one more instability index made the higher heavy rainfall prediction.

• 한국해양공학회지
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• 제22권2호
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• pp.34-41
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• 2008

As a basic study for developing a forecasting/estimating system that predicts water quality changes when Deep Sea Water (DSW) drains to the ocean after using it, this study was carried out as follows: 1) numerical simulation of the present state at DSW developing region in the East sea using SWEM, 2) numerical prediction of water quality changes by effluent DSW, 3) analysis of influence degree 'With defined DEI (DSW effect index) at F station. On the whole, when DSW drained to the ocean, Chl-a, COD and water-temperature were decreased and DIN, DIP and DO were increased by effluent DSW, and Salinity was steady. According to analysis of influence degree, the influence degree of DIN was the highest and it was high in order of Chl-a, COD, Water-temperature, DO, DIP and Salinity. The influence degree classified by DSW effluent position was predicted that suiface outflow was lower than bottom outflow. Ad When DSW discharge increased 10 times, the influence degree increased about $5{\sim}14$ times.

• 한국해양환경ㆍ에너지학회지
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• 제7권2호
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• pp.70-74
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• 2004

연안 퇴적물의 오염도 개선을 위해 수행되는 준설의 시행 여부 판단을 위해서는 합리적인 준설판단지수(Dredging Index: DI)설정이 필수적이다. 외국에서 사용되는 DI는 국가별 경제수준, 자연환경 특성, 해역의 이용 목적 등이 상이한 까닭에, 국내 환경에 직접 활용하는 것은 비합리적이다. 본 연구에서는 그 동안 축적된 국내 자료를 활용하여 DI를 개발하였고, 이를 오염 우심해역인 마산만의 준설 전·후 환경에 적용하였다. 적용 결과, 개발된 DI는 준설에 따른 퇴적물 환경변화를 잘 지시하는 것으로 판단되며, 준설에 필요한 사회 경제적 여건이 고려된 합리적 DI 값이 도출된다면 특정해역의 준설 범위와 깊이를 결정하는 도구로 사용될 수 있을 것으로 사료된다.

• 충청수학회지
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• 제19권2호
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• pp.123-131
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• 2006

In this paper, a numerical programming for Liapunov index of differential equations with periodic coefficients depending on parameters is given. The associated equations are given at first, then existence of periodic solutions to the associated equations is proved in this paper. And we compute periodic solution u(t) of the associated equations. Finally, we give the error of approximate calculation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.786-790
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• 1987

An optimization problem minimizing n given time-weighted performance index for discrete-time linear multi-input systems is investigated for the prespecified closed-loop eigenvalues. Necessary conditions for an optimality of the controller that satisfies the specified closed-loop eigenvalues are derived. A computational algorithm solving the optimal constant feedback gain is presented and a numerical example is given to show the effect of a time-weighted performance index on the transient responses.

• 전자공학회논문지A
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• 제29A권11호
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• pp.40-48
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• 1992

The wave-kinetic numerical method is used in simulating the irradiance scintillations of optical wave through a two-dimensional random medium containing weak Gaussian fluctuations of the refractive index. The results are compared to existing analytical or numerical results. The wave-kinetic method is a phase-space ray-tracing method for certain key ray trajectories, and the irradiance is calculated by reconstructing the entire beam from these trajectories. The strength of the wave-kinetic method lies in the fact that it can be applied to any type of random media.

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 하계학술발표회 논문집
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• pp.13-14
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• 2007

• 한국산림과학회지
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• 제21권1호
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• pp.47-51
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• 1974

전자계산조직(電子計算組織)과 수치분석(數値分析)에 의(依)하여 참나무 기본종간(基本種間)의 유연관계(類緣關係)를 증명하고자 non-metric coefficient 식(式)을 적용(適用)하며 UNiVAC-1106으로 처리(處理)하였다. 연구결과(硏究結果)는 이창복교수(李昌福敎授)의 논문결과(論文結果)와 일치(一致)하고 있으나, 필자(筆者)의 연구(硏究)에서는 이들 유연관계(類緣關係)가 수량적(數量的)으로 재증명(再證明)된 것이고 수상형분류(樹狀型分類)에 의거하면 참나무 기본종중(基本種中) 떡갈나무는 유연관계(類緣關係)가 가장 멀게 나타나고 있음을 밝혔다.

• 대기
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• 제28권4호
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• pp.403-414
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• 2018

Predictability of Northern Hemisphere blocking in the Korea Meteorological Administration (KMA) Global Data Assimilation and Prediction System (GDAPS) is evaluated for the period of July 2016 to May 2017. Using the operational model output, blocking is defined by a meridional gradient reversal of 500-hPa geopotential height as Tibaldi-Molteni Index. Its predictability is quantified by computing the critical success index and bias score against ERA-Interim data. It turns out that Northwest Pacific blockings, among others, are reasonably well predicted with a forecast lead time of 2~3 days. The highest prediction skill is found in spring with 3.5 lead days, whereas the lowest prediction skill is observed in autumn with 2.25 lead days. Although further analyses are needed with longer dataset, this result suggests that Northern Hemisphere blocking is not well predicted in the operational weather prediction model beyond a short-term weather prediction limit. In the spring, summer, and autumn periods, there was a tendency to overestimate the Western North Pacific blocking.