• 농약과학회지
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• 제9권4호
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• pp.365-373
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• 2005

현재 우리나라 주요 벼 해충은 벼멸구(Nilaparvata lugens), 애멸구(Laodelphax striatellus), 끝동매미충 (Nephotetix cincticeps) 등 멸구류와 벼물바구미(Lissorhoptrus oryzophilus) 등이며, 약제에 대한 위 해충들의 약제 감수성을 모니터링한 결과 이미다클로프리드에 대해서만 일부 지역에서 68배의 높은 저항성을 보이고 있으며, 다른 약제에 대해서는 1979년 이래 지역에 따라 $0{\sim}20$배 정도의 같은 감수성을 보이고 있어 저항성의 계속적인 발달은 없었다. 끝동매미충은 기존 carbamates, organophosphorus, pyrethroid 계통의 살충제에 대해서는 1976년 이래 감수성 저하가 없어 저항성 발달을 인정할 수 없었으나, 벼물바구미의 대표적 약제인 fipronil 과 imidacloprid에 대해서는 두드러진 감수성 저하를 보였다. 벼물바구미는 1999년에서는 조사지역에서 높은 감수성을 보여 carbofuran, ethofenprox, fipronil, imidacloprid 등 시험약제 모두는 지역 계통에 관계없이 기준 약량의 4분의1 농도에서도 높은 살충력을 보였으나, 2002년에는 수원지역 계통이 carbofuran에 대해 현저한 감수성 저하 현상을 보였다.

• 한국측량학회지
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• 제7권2호
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• pp.85-92
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• 1989

본 연구에서는 원격탐사 기법을 이용하여 인공위성 MSS 데이타와 TM 데이타를 몇 가지의 선형변환된 데이타로 변형시킴으로 분류 정확도향상과 특정 대상물에서의 유효 변환데이타 조합을 알아내고자 하는 것이 주된 목적이라 하겠다. LANDSAT 데이타를 처리함에 있어서, 문제점 중의 하나가 자료의 방대함이며, 이 방대한 자료에 대하여 보다 효율적이고 경제적인 분석을 행하기 위한 방법이 선형변환이다. 이 방법은 여러가지 선형적 산술과 통계적 변환을 하여 다파장 데이타들을 변환시킴으로써, (1) 복잡한 데이타에 대해서는 단순함을 제공 (2) 중복 데이타에 대한 선택적 처리 및 불필요한 자료 제거 (3) 연구대상에 대한 강조등을 행한다. 본 연구에서는 Band Ratioing과 PCA를 수행하여 자료를 변환 분석하여 보았다. 분류 결과 Infrared/RED Ratio는 식물의 특성을 확장시켜 다른 분류 항목과 구별하여 분류하는 데 유용하였으며, 주성분 분석 결과 녹색식물역의 분류에 있어서 Band 1,27이 효과적이었다.

• 농업과학연구
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• 제48권4호
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• pp.945-956
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• 2021

The effective growth of pepper seedlings relies on the growing period and tray used, which both aim to minimize seedling damage during the transplantation process. Therefore, the objective of this study was to evaluate the effect of red and green pepper seedling growth in plug and cylindrical paper pot (CPP) trays with different growth periods of the seedlings. Two different seedling growth trays were used for the two varieties of pepper seedlings in the same growing media. The pepper seedling growth rates were investigated at 15, 30, and 45 days for each of variety. Important parameters, e.g., the plant height, fresh weight for the plant and root, number of leaves, leaf length and width, and leaf chlorophyll contents, were measured. During the experiment, the CPP tray maintained uniform seedling growth as compared to the plug tray. CPP trays ensured the height of the seedling, with these results 0.84 to 1.6 times higher than those of the plug tray for all conditions, indicating the good quality of the pepper seedlings. The shoot and root weights were found to be greater with more leaves in the CPP tray seedlings for 45 days compared to the seedlings grown in the plug tray, whereas the green pepper variety showed a greater leaf ratio than the red pepper seedlings. The analysis of pepper seedling growth presented in this study will guide the selection of suitable growth trays and seedling periods for farmers when they undertake automatic pepper transplantation in the field.

• KSBB Journal
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• 제25권4호
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• pp.371-378
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• 2010

For the biodiesel fuel production from microalgae, the lipid from wet and dry samples of green algae Scenedesmus sp. was extracted by using various solvents and pre-treatment methods. Extraction yield of the lyophilized sample was better than that of dry sample. Chloroform/methanol (2:1, v/v) and ultrasonication or homogenization method were also selected as the most effective solvent and pre-treatment methods for lipid extraction, respectively. Under these constraint conditions, optimization experiment of lipid extraction was investigated by Taguchi approach using orthogonal matrix $L_9$ ($3^4$) method. The optimum extraction conditions of lipid extraction was obtained at pre-treatment of homogenization, extraction time of 5 hour, temperature of $35^{\circ}C$, and solvent ratio of 1:20 (w/v). Yield of extraction at optimized condition was 20.55% and it was 96% of total lipid content (21.38%) of Scenedesmus sp.

• ALGAE
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• 제32권2호
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• pp.131-137
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• 2017

Although green algae of the genus Closterium are considered ideal models for testing toxicity in aquatic ecosystems, little data about the effects of toxicity on these algal species is currently available. Here, Closterium ehrenbergii was used to assess the acute toxicity of copper (Cu). The median effective concentration ($EC_{50}$) of copper sulfate based on a dose response curve was $0.202mg\;L^{-1}$, and reductions in photosynthetic efficiency ($F_v/F_m$ ratio) of cells were observed in cultures exposed to Cu for 6 h, with efficiency significantly reduced after 48 h (p < 0.01). In addition, production of reactive oxygen species significantly increased over time (p < 0.01), leading to damage to intracellular organelles. Our results indicate that Cu induces oxidative stress in cellular metabolic processes and causes severe physiological damage within C. ehrenbergii cells, and even cell death; moreover, they clearly suggest that C. ehrenbergii represents a potentially powerful test model for use in aquatic toxicity assessments.

• Tribology and Lubricants
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• 제26권1호
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• pp.73-77
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• 2010

One of the important trends for condition monitoring in the 21st century is the development of smart sensors that will permit the cost-effective continuous monitoring of key machine equipments. In this study, an integrated in-line oil monitoring sensor assigned for continuous in situ monitoring multiple parameters of oil performance is presented. The sensor estimates oil deterioration based on the information about chemical degradation, total contamination, water content of oil and oil temperature. The oil oxidation is estimated by "chromatic ratio", total contamination is measured by the changes in optical density of oil in three optical wave-bands ('Red', 'Green' and 'Blue') and water content is evaluated as relative saturation of oil by water. In order to evaluate the sensor's effectiveness, the sensor was applied to several used oil samples in steel making industry and the results were compared with those measured by standard test methods.

• 한국정밀공학회지
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• 제28권9호
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• pp.1078-1085
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• 2011

Prediction of a minimum crack size for growth, which is defined as a crack size that grows fast enough to keep ahead of its removal by contact wear and periodic grinding, is the most demanding work to prevent rail from fatigue failure and develop cost effective railway maintenance strategy In this study, we investigated the wheel load increment due to a rail defect during a train ran over it, and its effect on the minimum crack size for growth. For this purpose, we developed simulation software based on the Fletcher and Kapoor's "2.5D" model and measured wheel load increment during a train passed over a defect. A maximum contact pressure and contact patch size were calculated by 3D FEM and crack growth analyses were performed by varying two of dominant contact contributors; surface friction coefficient(0.1, 0.2, 0.3 and 0.4) and crack aspect ratio. The minimum crack sizes for growth were calculated from 0.29 to 1.44mm depending on the contact conditions. They were decreasing with increasing surface friction coefficient and decreasing with crack aspect ratio(a/b).

• 한국콘텐츠학회논문지
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• 제11권5호
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• pp.466-473
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• 2011

본 연구는 서울시를 대상으로 건축물 연면적 비율을 이용하여 토지이용 용도 특성이 어떻게 분포하고 있으며, 개발밀도와는 어떠한 상관관계를 가지고 있는지 분석하여 토지이용의 용도 관리가 필요함을 제기 하였다. 건축물 연면적 비율을 이용한 군집분석결과 서울시는 연립주택 등을 위주로 한 저층공동주택지역과 아파트 위주의 고층공동주택지역의 특성을 나타내는 지역이 대부분이며, 업무지역이나 공업지역 등은 극히 일부 지역에 집중되어 있었다. 이 중 도심일대의 업무지역은 강남지역의 업무지역과는 달리 주거면적과 상주인구가 부족하여 도심공동화를 초래할 우려가 있어 용도에 대한 관리가 필요함이 나타났다. 뉴타운사업 등 재개발 재건축으로 인해 서울의 고밀화는 서울시 전역으로 확대될 것으로 예상되어 지역특성을 고려한 개발이 필요함을 제기하였으며, 업무용도가 분포하며 도로여건이 비교적 양호한 공장지역은 주거환경을 개선하여 직주근접을 유도할 수 있을 것으로 분석되었다.

• 한국통신학회논문지
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• 제36권10B호
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• pp.1258-1267
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• 2011

본 논문에서는, 실내에서 Light Emitting Diode-Identification(LED-ID) 통신 시스템을 이용하여 비디오 신호를 전송하는 방법에 대하여 연구하였다. LED-ID 통신 기술은 기존 조명의 기능을 수행하는 LED를 사용하여 통신의 가능까지 동시에 구현할 수 있는 효과적인 방법이다. 본 기술은 LED의 RGB(Red Green Blue)광원을 통하여 신호를 전송하는 방법으로, RGB의 혼합 비율에 따라서 조명의 색이 결정되고, 또한 각 RGB신호의 BER성능이 결정된다. 그러나, 기존의 시스템처럼 비디오 신호를 RGB에 고정적으로 할당 시켜 전송하는 경우, 각 선호의 중요도가 다른 Scalable Video Coding(SVC) 신호에 비해서 비디오의 품질에 한계가 발생한다. 이러한 문제를 해결하기 위해서 이 논문에서는 White LED를 위한 RGB 혼합 비율에 따른 RGB신호의 성능을 분석하고, 분석된 성능을 바탕으로 SVC 신호를 할당 하여 전송함으로써 비디오의 품질을 향상 시킬 수 있는 방법에 대해서 연구하였다.

• 한국농공학회논문집
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• 제65권5호
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• pp.25-35
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• 2023

The estuary reservoir is a major source of agricultural water in Korea; for effective and sustainable water resource management of the estuary reservoir, it is crucial to comprehensively consider various water resource factors, including water supply, flood, and pollutant management, and analyze future runoff changes in consideration of environmental changes such as climate change. The objective of this study is to estimate the impact of future climate change on the runoff characteristics of an estuary reservoir watershed. Climate data on future Shared Socioeconomic Pathway (SSP) scenarios were derived from two Global Climate Models (GCMs) of the Coupled Model Intercomparison Project phase 6 (CMIP6). The Hydrological Simulation Program-Fortran (HSPF) was used to simulate past and future long-term runoff of the Ganwol estuary reservoir watershed. The findings showed that as the impact of climate change intensified, the average annual runoff in the future period was higher in the order of SSP5, SSP3, SSP1, and SSP2, and the ratio of runoff in July decreased while the ratio of runoff in October increased. Moreover, in terms of river flow regime, the SSP2 scenario was found to be the most advantageous and the SSP3 scenario was the most disadvantageous. The findings of this study can be used as basic data for developing sustainable water resource management plans and can be applied to estuary reservoir models to predict future environmental changes in estuary reservoirs.