• 한국해양공학회지
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• 제22권1호
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• pp.75-82
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• 2008

A vibration-based damage-monitoring scheme is proposed that would generate an alarm showing the occurrence and location of damage under temperature-induced uncertainty conditions. Experiments on a model plate-girder bridge are described, for which a set of modal parameters was measured under uncertain temperature conditions. A damage-alarming model is formulated to statistically identify the occurrence of damage by recognizing the patterns of damage-driven changes in the natural frequencies of the test structure and by distinguishing temperature-induced off-limits. A damage index method based on the concept of modal strain energy is implemented in the test structure to predict the location of damage. In order to adjust for the temperature-induced changes in the natural frequencies that are used for damage detection, a set of empirical frequency correction formulas is analyzed from the relationship between the temperature and frequency ratio.

• 한국응용곤충학회지
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• 제48권4호
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• pp.553-556
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• 2009

낙엽송의 새로운 해충인 낙엽송잎벌의 천적 종류, 발생량 및 생활사를 강원도 철원과 태백에서 2006년부터 2007년까지 2년간 조사하였다. 주요 천적으로는 낙엽송잎벌살이뾰족맵시벌로 동정되었다. 낙엽송잎벌살이뾰족맵시벌의 1화기 낙엽송잎벌에의 기생률은 우화상 조사에서 42%로 높은 기생률을 보였다. 출현 시기는 5월부터 9월 사이였으며, 최성기는 5월 21일부터 6월 20일 사이였다. 낙엽송잎벌살이뾰족맵시벌의 발생 수와 시기는 기주인 낙엽송잎벌과 매우 밀접한 관계가 있었다.

• 한국조경학회지
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• 제36권1호
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• pp.38-48
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• 2008

This study examines the characteristics of the herbaceous vegetation structure of Haneul Park District in World Cup Park, which had previously been used as a landfill for 15 years. The survey was carried out through actual vegetation and vegetation structures from 2003 to 2006, biannually. Firstly, as a result of analysis of actual vegetation, the autumn season changed more quickly over the 2 year span than did the spring season in terms of actual vegetation area. Annual plants increased for the initial $3{\sim}4$ years and then perennial plants increased. Secondly, the results of analysis in vegetation structure are as follows: 1. The number of planted species gradually decreased. 2. Miscanthus sinensis var. purpurascens of the control region was maintained but Imperata cylindrica var. koenigii of the non-control region was invaded by Miscanthus sacchariflorus, Glycine soja and Phragmites communis etc. 3. Planted species in the control region were maintained in superior state, but the non-control region was changed by natural occurrence plants until 2006, the fourth year. 4. Physostegia virginiana and Aster koraiensis which were planted in the non-control region were maintained but most of planted species weakened and changed by natural occurrence plants including Erigeron annuus, Artemisia princeps, Setaria faberii and Phragmites communis etc. Based on the results, we suggested the management method of herbaceous vegetation in the Haneul Park District.

• 농약과학회지
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• 제17권4호
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• pp.448-453
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• 2013

배 과원에 심겨진 헤어리베치가 배의 주요해충인 4종 나방류(복숭아순나방, 복숭아심식나방, 사과무늬잎말이나방, 애모무늬잎말이나방), 조팝나무진딧물 및 점박이응애의 발생과 천적인 기생봉류의 발생에 미치는 영향을 평가하기 위하여 수행하였다. 헤어리베치가 심겨진 배 과원과 바랭이가 주요 초종인 일반과원에서 4종 나방류의 발생에는 다소 차이를 보였으나, 조팝나무진딧물은 6월 20일 헤어리베치구에서 신초 당 95마리가 1회 확인되었을 뿐 전체적으로 발생되지 않았다. 배 잎의 점박이응애 밀도는 헤어리베치가 심겨진 배 과원에서 월등히 낮았다. 2012년과 2013년에 조사된 기생봉류의 발생은 헤어리베치의 개화시기에 각각 398마리와 798마리로 일반초생구의 9마리와 22마리보다 월등히 높았고, 하고시기에도 헤어리베치구가 114, 172마리로 일반초생구 8, 5마리보다 월등히 많았다. 헤어리베치는 4종 나방류, 조팝나무진딧물, 점박이응애 발생에 영향을 주지 않으며 오히려 천적인 기생봉류에 유리하게 작용하여 배 과원의 피복 및 녹비작물로써 이용가능성이 높으므로, 천적에 저독성 농약선발을 통해 농약방제 체계를 개선한다면 보다 효과적인 해충관리가 가능할 것이다.

• 한국산림과학회지
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• 제109권4호
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• pp.400-412
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• 2020

본 연구는 일본잎갈나무 천연갱신 치수의 생장특성을 분석하여 현장 적용 가능한 갱신 방법을 제안하기 위해 수행되었다. 이를 위해 경기도 가평과 경상북도 봉화에 모수작업과 개벌작업을 실시하여 시험지를 조성하고, 종자 유입, 천연치수의 발생과 생장 특성을 분석하였다. 그 결과 갱신유형별 종자 낙하량은 보잔목작업, 모수작업, 개벌작업 순으로 많았고, 치수 발생율은 처리구(벌채, 지면긁기)가 평균 2.4%, 무처리구 0.3%로 처리구가 무처리구에 비해 8.0배 많았다. 처리구의 갱신 1년차 6월의 치수량은 약 47만본/ha이었고 갱신 3년차 10월의 치수량은 약 78천본/ha이었으며, 치수의 평균 크기는 근원경 6.5 mm, 수고 50.4 cm이었다. 이에 따라 천연갱신에 의한 일본잎갈나무 후계림 조성은 종자결실과 낙하 시기에 맞추어 벌채와 지면긁기를 실시하면 성공 가능성이 크고, 일본잎갈나무의 빠른 생장을 고려하면 효과적인 갱신기술이 될 것으로 판단된다.

• Journal of Information Technology Applications and Management
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• 제15권2호
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• pp.67-82
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• 2008

Risk that breed large size disaster is happening variously for cause at social. natural a management. Incidence and damage scale are trend that increase rapidly than past. In these circumstance, to keep operational continuity of organization, area, society, risk management action that establish systematic counter measure estimating and analyze occurrence possibility and expectation damage of risk is essential indispensable issue and the best countermeasure. Risk management action does by main purpose establish optimum disaster reduction countermeasure. To deduce various countermeasure, process that estimate and analyze occurrence possibility and expectation damage of risk is essential indispensable issue. Therefore, this paper studies process design that can presume risk occurrence frequency and damage scale through distribution of probability.

• Animal cells and systems
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• 제2권2호
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• pp.209-216
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• 1998

The invasion of Ambrosia artemisiifolia in the Ukrainian Carpathians Mts. and the Transcarpathian Plain in Central Europe was reconstructed on the basis of floristic records. The first spontaneous occurrence was dated from the beginning of the 1940s. Within the next 55 year period, the distributional spread speed of the species was of 67.6 $km^2/y$ (by the average data). The occupied area by A. artemisiifolia in the range of the studied areas is about $3716.5km^2$ now. The features of behavior of the invader and the habitat preference were determined. The frequency of occurrence by sociologic-ecological classification was carried out. The generalized model of correlations among the gravitation, the active temperature sum and the disturbance gradients and the frequency of occurrence of the species was presented. The scheme of the invasion stages of A. artemisiifolia is reflected in the population status changes of the species during the areal dynamics.

• 대한지리학회:학술대회논문집
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• 대한지리학회 2003년도 춘계학술대회
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• pp.75-78
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• 2003

A recent rise in mean global temperatures suggests a shift in the temporal cycles of natural seasons. The impacts of warming trends can alter the temporal and spatial distribution of flora and fauna. Especially, phenological cycles are very sensitive to the occurrence of alternation of hot and cold seasons. Phenological calendars reflect the natural seasonality. In more detail, phenological cycles affects agriculture and human health (i.e. the amount of fruit production and allergies), as well as tourism industries like flower fairs or festivals. (omitted)

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2011년도 학술대회 및 정기총회
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• pp.33-36
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• 2011

• International Journal of Naval Architecture and Ocean Engineering
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• 제3권1호
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• pp.53-64
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• 2011

The present study considers multi-level approach for the analysis of parametric roll phenomena. Three kinds of computation method, GM variation, impulse response function (IRF), and Rankine panel method, are applied for the multi-level approach. IRF and Rankine panel method are based on the weakly nonlinear formulation which includes nonlinear Froude-Krylov and restoring forces. In the computation result of parametric roll occurrence test in regular waves, IRF and Rankine panel method show similar tendency. Although the GM variation approach predicts the occurrence of parametric roll at twice roll natural frequency, its frequency criteria shows a little difference. Nonlinear roll motion in bichromatic wave is also considered in this study. To prove the unstable roll motion in bichromatic waves, theoretical and numerical approaches are applied. The occurrence of parametric roll is theoretically examined by introducing the quasi-periodic Mathieu equation. Instability criteria are well predicted from stability analysis in theoretical approach. From the Fourier analysis, it has been verified that difference-frequency effects create the unstable roll motion. The occurrence of unstable roll motion in bichromatic wave is also observed in the experiment.