• 대한원격탐사학회지
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• 제28권6호
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• pp.597-609
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• 2012

Leaf area index (LAI) is important in explaining the ability of the crop to intercept solar energy for biomass production and in understanding the impact of crop management practices. This paper describes a procedure for estimating LAI as a function of image-derived vegetation indices from temporal series of IKONOS, Landsat TM, and MODIS satellite images using empirical models and demonstrates its use with data collected at Missouri field sites. LAI data were obtained several times during the 2002 growing season at monitoring sites established in two central Missouri experimental fields, one planted to soybean (Glycine max L.) and the other planted to corn (Zea mays L.). Satellite images at varying spatial and spectral resolutions were acquired and the data were extracted to calculate normalized difference vegetation index (NDVI) after geometric and atmospheric correction. Linear, exponential, and expolinear models were developed to relate temporal NDVI to measured LAI data. Models using IKONOS NDVI estimated LAI of both soybean and corn better than those using Landsat TM or MODIS NDVI. Expolinear models provided more accurate results than linear or exponential models.

• 한국토양비료학회지
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• 제46권4호
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• pp.245-252
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• 2013

Leaf area index (LAI) is important in explaining the ability of crops to intercept solar energy for biomass production, amount of plant transpiration, and in understanding the impact of crop management practices on crop growth. This paper describes a procedure for estimating LAI as a function of image-derived vegetation indices from temporal series of RapidEye imagery obtained from 2010 to 2012 using empirical models in a rice plain in Seosan, Chungcheongnam-do. Rice plants were sampled every two weeks to investigate LAI, fresh and dry biomass from late May to early October. RapidEye images were taken from June to September every year and corrected geometrically and atmospherically to calculate normalized difference vegetation index (NDVI). Linear, exponential, and expolinear models were developed to relate temporal satellite NDVIs to measured LAI. The expolinear model provided more accurate results to predict LAI than linear or exponential models based on root mean square error. The LAI distribution was in strong agreement with the field measurements in terms of geographical variation and relative numerical values when RapidEye imagery was applied to expolinear model. The spatial trend of LAI corresponded with the variation in the vegetation growth condition.

• Spatial Information Research
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• 제19권4호
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• pp.45-54
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• 2011

본 논문에서는 기존에 제시된 MR-tree와 SQR-tree의 장점을 결합하여 대용량 공간 데이타를 보다 효율적으로 처리할 수 있는 하이브리드 인덱스 구조인 SQMR-tree(Spatial Quad MR-tree)를 제시한다. MR-tree는 R-tree에 R-tree 리프 노드를 직접 접근해주는 매핑 트리를 적용한 인덱스 구조이고, SQR-tree는 SQ-tree (Spatial Quad-tree)와 SQ-tree의 리프 노드마다 실제로 공간 객체를 저장하는 R-tree가 결합된 인덱스 구조이다. SQMR-tree는 SQR-tree를 기본 구조로 SQR-Tree의 R-tree 마다 매핑 트리가 적용된 형태를 가진다. 따라서, SQMR-tree는 SQR-tree와 같이 공간 객체가 여러 R-tree에 분산 저장되며 질의 영역에 해당하는 R-tree만 접근하면 되기 때문에 공간 질의 처리 비용을 줄일 수 있다. 또한, SQMR-tree는 MR-tree와 같이 매핑 트리를 통해 트리 검색 없이 R-tree 리프 노드의 빠른 접근이 가능하기 때문에 검색 성능을 향상시킬 수 있다. 마지막으로 실험을 통해 SQMR-tree의 우수성을 입증하였다.

• 대한토목학회논문집
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• 제35권4호
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• pp.815-820
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• 2015

제주도의 효율적 수자원 관리 기반을 구축하기 위해서는 지표수의 유출 특성과 증발산량, 지하수 함양량, 지하수 유출량의 상호관계를 정확하게 제시할 필요가 있다. 이 중 식생에 의한 차단(interception)효과는 증발산량에 직결되는 영향 인자임에도 정량적 분석의 어려움 때문에 유역단위로 정량화된 사례는 드물다. Von Hoyningen-Huene (1981)이 엽면적지수와 차단저류량의 관계를 밝혔고, LAI는 차단, 증산의 핵심요소로 다양한 수문모형에 활용되고 있다. 본 연구에서는 Kozak et al. (2007)이 제시한 엽면적 지수(LAI: Leaf Area Index)에 따른 차단저류량의 관계식을 이용하여 한국형 유역수문모형 SWAT-K (Soil and Water Assessment Tool-Korea)내에 식생에 의한 차단량 산정모듈을 개선하였다. 제주도 천미천 유역을 대상으로 적용한 결과 천미천 유역의 차단증발량은 85~104mm로서 전체 증발산량(993~1062mm)의 약 8~11% 만큼 차지하는 것으로 분석되어 전체 물수지 성분에 영향인자로 고려되어야 할 것이다.

• 농업과학연구
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• 제42권4호
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• pp.293-297
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• 2015

This study was conducted to evaluate the influence of feeding leaf positions on the growth, net formation of fruits, and occurrence of leaf yellowing symptoms (LYS) in muskmelon plants. Plants having five or ten more leaves above the fruit-bearing node produced the greater biomass than those of plants having equal or five less leaves above the fruit-bearing node. The number of leaves above the fruit-bearing node also influenced on the occurrence of LYS. The number of plants with LYS decreased as the number of leaves borne on the nodes above the fruit-bearing node increased. The LYS infected ratio of BL-5 treatment were the greatest, while fruit weight of BL+5 treatment were the greatest among all the tested treatments. In addition, the net formation of BL-5 treatment showed the poorest. Results indicated that maintaining the higher number of leaves over the fruit-bearing node might be feasible the practical method for coping physiological damages from yellowing symptoms.

• Natural Product Sciences
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• 제20권4호
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• pp.301-305
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• 2014

The aim of our study is to investigate the anti-nociceptive and anti-inflammatory properties of an ethanol extract of the leaf and stem of Aralia cordata. Writhing responses induced by acetic acid, tail immersion test, and formalin-induced paw pain response for nociception and formalin-induced paw edema for inflammation were evaluated in mice. A. cordata (50 - 200 mg/kg, p.o.) and ibuprofen (100 mg/kg, p.o.), a positive non-steroidal anti-inflammatory drugs (NSAIDs), inhibited the acetic acid-induced writhing response, but they did not protect the thermal nociception in tail immersion test. However, morphine (5 mg/kg, s.c.) used as positive opioid control alleviated both the acetic acid-induced writhing response and thermal nociception in tail immersion test. In the formalin test, A. cordata (50 - 200mg/kg) and ibuprofen (200mg/kg) inhibited the second phase response (peripheral inflammatory response), but not the first phase response (central response), whereas morphine inhibited both phase pain responses. Both A. cordata (100 mg/kg) and ibuprofen (200 mg/kg) significantly alleviated the formalin-induced increase of paw thickness, the index of inflammation. These results show for the first time that the leaf and stem of A. cordata has a significant anti-nociceptive effect that seems to be peripheral, but not central. A. cordata also displays an anti-inflammatory activity in an acute inflammation model. The present study supports a possible use of the leaf and stem of A. cordata to treat pain and inflammation.

• 한국환경복원기술학회지
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• 제7권1호
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• pp.110-115
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• 2004

This experiment was conducted to investigate the effect of light intensities on the growth responses, carbohydrate contents and the characteristics of leaf gas exchange in Miscanthus sinensis and Pennisetum purpurascens. The plant height and leaf length were increased to about 30% in the sun. However, those were reduced severely in the shade, and leaf necrosis was also observed. The representative growth index and the dry weight of 2 species were 50% higher than shade and the rate was reduced according to the decrease of light intensities. Total carbohydrate contents showed very similar changes to that of dry weight. However, any notable influences were observed at above the light intensities of 250~500${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in the half shade. The size of spikes and the earliest spiking appeared in the sun and the spike color was decolorized as decreased in light intensities, irrespective of species. Photosynthetic rate of 2 species was 2 times higher in the sun than those in the shade, and it showed the typical photoresponses of sun plant. Stomatal conductances and intercelluar $CO_2$ concetration showed similar changes to that of photosynthetic rate. On the contrary, vapor pressure deficit was increased more in the shade than in the sun.

• Journal of Plant Biology
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• 제28권1호
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• pp.1-8
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• 1985

부들(Typha$\times$glauca)의 생산성이 높은 원인을 밝히기 위하여 엽면적지수, 비엽면적, 잎의 방위와 경사 및 방사량의 수직분포를 측정하였다. 생육기간 중 잎은 거의 직립하였고 방위는 무작위한 분포를 유지하였다. 이러한 엽층부의 균일한 공간배치는 비엽면적이 지상 100cm 높이를 경계로하여 상.하에 갈수록 커지는 것으로 보아 엽신이 두꺼움으로서 유지된다. 엽층부의 소멸계수 K는 0.12~0.20으로 육상식물군락 중에서 가장 적은 값이었다. 엽층부 최하층에 투입되는 상대방사량은 성숙한 군락에서도 25% 이상이었다. 부들의 연면적지수가 과이 크지 않은데도 생산성이 높은 이유는 햇빛이 효과적으로 투입되는 엽층부 구조의 특징에 기인하였다.

• 한국육종학회지
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• 제41권1호
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• pp.16-24
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• 2009

콩 재래종과 야생종 자원의 엽 형질간의 관계를 분석하여 콩의 엽형 조사를 계량화할 수 있는 기준을 제시함으로써 콩의 초형개량과 재배법 개선을 위하여 필요한 기초자료를 제공하고자 충북대학교 농업생명환경대학 두류유전자원관리실에서 분양받은 콩 재배종 94개와 야생종 91개의 엽형질을 조사한 결과는 다음과 같다. 1. 재배종과 야생종의 엽장은 각각 12.3$\pm$1.25 cm(8.7~15.3 cm)과 평균 6.6$\pm$1.35 cm(3.7~11.3 cm), 엽폭은 각각 6.8$\pm$1.241 cm(3.3~9.58 cm), 엽면적은 각각 55.6$\pm$15.75 $cm^2$ (23.6~106.8 $cm^2$)와 14.3$\pm$7.83 $cm^2$ (4.1~48.9$cm^2$), LSI는 각각 1.9$\pm$0.38(1.3~3.3)와 2.4$\pm$0.53(1.4~4.2)이었다. 2. 재배종과 야생종 모두 LSI $\leq$2.0은 원형엽, 2.1~3.0은 난형엽, 그리고 3.1$\leq$ 이상은 피침형엽으로 구분할 수 있었다. LSI에 따라서 원형엽, 난형엽 및 피침형엽을 가진 비율이 재배종은 각각 78.7%, 17.0% 및 4.3%, 그리고 야생종은 30.8%, 58.2% 및 9.9%였다. 3. 엽장에 따라서는 2 cm 간격으로 단엽, 중간엽 및 장엽을 분류하되 재배종은 각각 $\leq$11.0 cm, 11.1~13.0 cm, 그리고 13.1 cm$\leq$ 로 구분하고, 야생종은 $\leq$5.0 cm, 5.1~7.0 및 7.0~9.0로 구분하고 9.1 cm$\leq$ 이상인 엽은 초장엽으로 구분할 수 있었다. 이렇게 분류하였을 때 재배종은 단엽이 약 1/3, 중엽이 약1/2 그리고 장엽이 약 1/6이었으며, 야생종은 중엽과 장엽이 약 40%로 비슷하였고, 단엽이 15.4%, 그리고 초장엽이 4.4%였다. 4. 재배종과 야생종의 잎 두께는 각각 0.25$\pm$0.054 mm (0.13~0.45 mm)과 0.14$\pm$0.032 mm(0.06~0.26 mm)였고, LAR은 각각 40.1$\pm$8.22(27.1~70.50)와 53.7$\pm$12.02(33.8~81.5)였으며, 엽각은 각각 $37.6{\pm}5.89^{\circ}$(24.1~56.0$^{\circ}$)와 54.6$\pm$$10.77^{\circ}$(30.8~76.0$^{\circ}$)였고, 엽병장은 각각 23.9$\pm$5.89 cm (11.2~36.9 cm)와 5.9$\pm$2.33 cm(2.2~17.7 cm)였다. 5. 재배종과 야생종 모두 엽장은 엽폭과 고도로 유의한 상관이 있고, 엽폭은 LSI와 고도로 유의한 부의상관이 있었으며, 재배종은 엽면적이 엽장이나 엽폭과 정의 상관이 있고 LSI와는 부의 상관이 있었지만, 야생종은 LSI와 엽장, 엽폭 및 엽면적은 유의한 관계가 없었다. 6. 재배종과 야생종 모두 엽형군 간에 엽폭이나 엽 두께의 차이가 있어 LSI가 낮은 엽형이 엽폭이 길고 엽두께가 두꺼웠으며, 재배종은 엽형군에 따라서 엽면적의 차이가 있었고, 야생종은 엽형군에 따라서 엽병장의 차이가 있었다. 엽두께는 재배종과 야생종 모두 원형엽군과 난형엽군 사이 및 난형엽군과 피침형엽군 사이에 차이가 없었다. 재배종은 엽형군 간에 엽병장의 유의한 차이가 없었으나 야생종은 원형엽군이 난형엽군이나 피침형엽군에 비하여 엽병이 길었다.

• Journal of Radiation Protection and Research
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• 제44권1호
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• pp.43-52
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• 2019

Background: The mid-term performance of clinical linear accelerator (LINAC) during volumetric modulated arc therapy (VMAT) treatment period is not performed in clinical practice and usually replaced with one-time plan quality assurance (QA). In this research we aim to monitor daily reproducibility of VMAT delivery from tracking individual leaf movement error and dosimetric error to evaluate the mid-term quality of the machine used. Materials and Methods: First, multileaf collimator (MLC) information was imported into MATLAB program to determine which of the MLC leaves in the leaf bank had the maximum RMS position error (maxRMS). We estimated where the maximum positional errors (maxPE) of the chosen leaf occur along its path length and tracked its daily variations over the entire treatment period. Secondly, picture information of dosimetric error from portal dosimetry was imported into MATLAB where representative high gamma index region (HGR) was determined as HGR with length of > 1 cm and their centers were daily tracked. Results and Discussion: The maxPEs in the brain and tongue cases were distributed broader than in other cases, but all data were found located within ${\pm}0.5mm$. From first day to last day all of five cases show the similar visual pattern of HGRs and Centers of the longest HGRs remained within ${\pm}1mm$ of that in first day. These findings prove excellent mid-term performance of the LINAC used in VMAT treatments over a full course of treatment. Conclusion: Tracking the daily location changes of leaf movement and dosimetric error can be a good indicator of predicting the daily quality like stability and reproducibility of beam delivering in VMAT treatment.