• Journal of Bio-Environment Control
• /
• v.28 no.4
• /
• pp.279-285
• /
• 2019

To estimate daily canopy photosynthesis, accurate estimation of canopy light interception according to a daily solar position is needed. However, this process needs a lot of cost, time, manpower, and difficulty when measuring manually. Various modeling approaches have been applied so far, but it was difficult to accurately estimate light interception by conventional methods. The objective of this study is to estimate the spatial distributions of light interception and photosynthetic rate of paprika with time by using 3D-scanned plant models and optical simulation. Structural models of greenhouse paprika were constructed with a portable 3D scanner. To investigate the change in canopy light interception by surrounding plants, the 3D paprika models were arranged at $1{\times}1$ and $9{\times}9$ isotropic forms with a distance of 60 cm between plants. The light interception was obtained by optical simulation, and the photosynthetic rate was calculated by a rectangular hyperbola model. The spatial distributions of canopy light interception of the 3D paprika model showed different patterns with solar altitude at 9:00, 12:00, and 15:00. The total canopy light interception decreased with an increase of surrounding plants like an arrangement of $9{\times}9$, and the decreasing rate was lowest at 12:00. The canopy photosynthetic rate showed a similar tendency with the canopy light interception, but its decreasing rate was lower than that of the light interception due to the saturation of photosynthetic rate of upper leaves of the plants. In this study, by using the 3D-scanned plant model and optical simulation, it was possible to analyze the light interception and photosynthesis of plant canopy under various conditions, and it can be an effective way to estimate accurate light interception and photosynthesis of plants.

• Journal of Bio-Environment Control
• /
• v.28 no.4
• /
• pp.286-292
• /
• 2019

This study aimed to investigate the suitable of layer on growth of six baby leaf vegetables using existing facilities and equipment in rice seedling nursery. Three kinds of Lactuca(lettuce 'Jinppallola' and 'Romain white', and indian lettuce), two of Brassica(tatsoi and red tatsoi) and amaranth were used as the materials. After sowing, the rice seedling tray was placed in multi bench system($L120{\times}W60{\times}H195cm$, 10th floor), which were low(1st) layer above 15cm, middle(4th) layer above 115cm and high(7th) layer above 175cm apart from ground. Irrigation was sprayed 2~3 times a day using a automatic irrigation system. The growth characteristics and leaf color were investigated when leaf vegetables were reached the optimum size(within 10cm of plant height). During the culture periods(29th Jun.~31th Jul. 2017), daytime average temperature was $27.4{\sim}28.3^{\circ}C$ regardless of layers but solar irradiance was higher in the high-layer than low and middle-layer of 37% and 22%, respectively. The leaf length, leaf width and number of leaves in middle and high-layer have a tendency to increase but, fresh weight was different according to the layer. When the correlation between accumulation radiation and growth was analyzed, all of growth factor of Amaranth showed a high correlation and other cultivars showed correlation with each growth factors. As a result, It is suitable that amaranth and red tatsoi for high-layer, Indian lettuce and tatsoi for middle and high-layer and 'Romain white' for middle-layer. The growth of red lettuce 'Jinppallola' was good at low layer, but leaf color expression was poor. So the high layer is suitable for 'Jinppallola'.

• Korean Journal of Soil Science and Fertilizer
• /
• v.43 no.6
• /
• pp.954-961
• /
• 2010

Ground-based remote sensing can be used as one of the non-destructive, fast, and real-time diagnostic tools for quantifying yield, biomass, and nitrogen (N) stress during growing season. This study was conducted to assess biomass and nitrogen (N) status of paddy rice (Oryza sativa L.) plants under N stress using passive and active ground-based remote sensors. Nitrogen application rates were 0, 70, 100, and 130 kg N $ha^{-1}$. At each growth stage, reflectance indices measured with active sensor showed higher correlation with DW, N uptake and N concentration than those with the passive sensor. NIR/Red and NIR/Amber indices measured with Crop Circle active sensors generally had a better correlation with dry weight (DW), N uptake and N content than vegetation indices from Crop Circle passive sensor and NDVIs from active sensors. Especially NIR/Red and NIR/amber ratios at the panicle initiation stage were most closely correlated with DW, N content, and N uptake. Rice grain yield, DW, N content and N uptake at harvest were highly positively correlated with canopy reflectance indices measured with active sensors at all sampling dates. N application rate explains about 91~92% of the variability in the SI calculated from NIR/Red or NIR/Amber indices measured with Crop Circle active sensors on 12 July. Therefore, the in-season sufficiency index (SI) by NIR/Red or NIR/Amber index from Crop Circle active sensors can be used for determination of N application rate.

• The Journal of Engineering Geology
• /
• v.32 no.4
• /
• pp.697-723
• /
• 2022

Data-driven models to predict groundwater levels 30 days in advance were developed for 12 groundwater monitoring stations in the middle-Jeju watershed, Jeju Island. Stacked long short-term memory (stacked-LSTM), a deep learning technique suitable for time series forecasting, was used for model development. Daily time series data from 2001 to 2022 for precipitation, groundwater usage amount, and groundwater level were considered. Various models were proposed that used different combinations of the input data types and varying lengths of previous time series data for each input variable. A general procedure for deep-learning-based model development is suggested based on consideration of the comparative validation results of the tested models. A model using precipitation, groundwater usage amount, and previous groundwater level data as input variables outperformed any model neglecting one or more of these data categories. Using extended sequences of these past data improved the predictions, possibly owing to the long delay time between precipitation and groundwater recharge, which results from the deep groundwater level in Jeju Island. However, limiting the range of considered groundwater usage data that significantly affected the groundwater level fluctuation (rather than using all the groundwater usage data) improved the performance of the predictive model. The developed models can predict the future groundwater level based on the current amount of precipitation and groundwater use. Therefore, the models provide information on the soundness of the aquifer system, which will help to prepare management plans to maintain appropriate groundwater quantities.

• Journal of Environmental Impact Assessment
• /
• v.32 no.6
• /
• pp.437-449
• /
• 2023

This study measured PM₁₀ concentrations and wind speeds in buffer green spaces and neighborhood parks located along the road, and compared them with roadside measurementresults to understand the effect of mitigating PM₁₀ concentrations by type of green space and the influence of wind speeds on it. As a result of the analysis, the effect of mitigating PM₁₀ concentration was different depending on the type of roadside green space, and an increase in wind speed had a significant effect on reducing PM₁₀ concentration. In buffer green areas with high planting density, wind speed was low and PM₁₀ stagnated inside, resulting in the highest concentration. On the other hand, green areas in neighborhood parks with relatively low planting density had high wind speeds and the lowest PM₁₀ concentration. The non-green area within the neighborhood park recorded the highest wind speed, which was advantageous for the spread of PM₁₀, but the concentration was higherthan that of the green area. Therefore, in orderto reduce PM₁₀ concentration in roadside green space, it is necessary to create green space with good ventilation, and the combined effect of green space and wind speed seems to be more advantageous in reducing PM₁₀ concentration. Green spaces capture and remove PM inside, contributing to reducing the concentration of PM outside. In order to manage PM in the entire city and on roads, it is necessary to increase planting density and leaf area in roadside green spaces, such as buffer green spaces, so that PM can be removed within the green spaces. However, in green spaces such as neighborhood parks that are actively used by city residents, in orderto minimize damage to users due to PM, it is desirable to create green spaces with a structure that allows PM to spread to the outside rather than stagnate inside.

• Tuberculosis and Respiratory Diseases
• /
• v.46 no.5
• /
• pp.674-684
• /
• 1999

Background : It has been generally known that the incidence of lung cancer is higher in the patients with idopathic pumonary fibrosis (IPF) than those in general population. The reported incidence was variable from 4.8 to 43.2%. There were controversies on the most frequent cell type (squamous cell carcinoma vs. adenocarcinoma) and no study was done about the real concordance of cancer and the fibrotic lesion. And the pulmonary fibrosis may influence not only the development of cancer but also the treatment and prognosis of the cancer, but there was no report on that point. Method : Total 63 patients ($66.8{\pm}7.8$ year, M : F=61 : 2) were diagnosed as IPF combined with lung cancer (IFF-CA) at Asan Medical Center. A retrospective analysis was done about the risk factors of the lung cancer, pulmonary function test, the site of cancer(especially the relationship of the cancer with the fibrotic lesion), the histologic types, and the stage of cancer. The histologic types were compared with those of 2,660 patients with lung cancer who were diagnosed at the same institute for the same period. The effect of IPF on the treatment of the cancer was evaluated with the survival time after the detection of lung cancer. Results : The lung cancer was found in 63(22.9%) out of 281 patients with IPF. But in most of them(45 patients), lung cancer was detected at the same time with IPF and only in 18 patients, the cancer was diagnosed during the follow-up($25.2{\pm}17.7$ months) of IPF. So in our study, 6.7% of patients with IPF developed lung cancer during the course of the disease. The age ($66.8{\pm}7.84$ vs. $63.4{\pm}11.1$ years), percentage of smoker (88.9 vs. 67.2%), and the male gender (96.8 vs. 67.6%) were significantly higher in IPF-CA compared with lone IPF (p<0.05). The odds ratio of smoking was 4.7 compared with non smoking IPF controls. The lung cancer was located more frequently in the upper lobe and 55.5% was in the periphery of lung. The cancer was developed in the fibrotic lesion in 23 patients (35.9%), and in the majority of the patients, the cancer was separated from the fibrosis. The cell type of the lung cancer in IPF-CA was squamous cell carcinoma 34.9%, adenocarcinoma 30.2%, small cell carcinoma 19.0%, large cell undifferenciated carcinoma 6.3%, and others 9.5%. No significant difference in the distribution of histologic type of the lung cancer was found between IPF-CA and lone lung cancer. There was no significant difference in demographic features, cell types, location and the stage of the cancer between the group with concurrent IPF-CA and the group with cancer diagnosed during the follow up of IPF. There was a tendency (but statistically not significant : p=0.081) of higher incidence of adenocarcinoma among the cancers developed in the fibrotic area(43.5%) (F-CA) than in the cancers in non-fibrotic area (22.5%) (NF-CA). The prognosis of the patients with F-CA was poor (median survival : 4 months) compared with the patients with NF-CA (7 months, p=0.013), partly because the prevalence of severe IPF (the extent of fibrosis in HRCT 50%) was higher in F-CA group. Conclusion : These data suggest that the lung cancer in the patients with IPF has similar features to the ordinary lung cancer.

• Journal of Korean Society of Forest Science
• /
• v.52 no.1
• /
• pp.1-30
• /
• 1981

The origin and development of adventitious roots was studied using hypocotyl and epicotyl cuttings of 34 species, 24 genus of woody plants. These cuttings obtained from young seedlings cultured in vials containing distilled water only. The several characteristics of cuttings materials studied are shown in Table 1. The results are summerized as follows: 1. The circumference shapes of cross-sections of hypocotyl and epicotyl cuttings can be divided into six categories, namely, round, irregular round, ellipse, irregular ellipse, square, and triangle. Species differences within a genus did not show any difference of hypocotyl and epicotyl cross-sections shape, however, a noticeable variation among genus or higher taxa. 2. The arrangements of vascular bundles in the cross-sections of hypocotyls or epicotyls were almost all collateral types and generally showed generic characteristics differing one to the other. However, there were some variations between species within the genus. Six models of vascular bundle arrangement were proposed for all the above speices. 3. The rooting portions of hypocotyl and epicotyl cuttings in this experimental materials can be grouped as follows: (1) Interfascicular parenchyma; (Thuja orientalis. T. orientalis for. sieboldii, Acer microsieboldianum, A. palmatum, A. saccharinum, Cercis chinensis, Lespedeza bicolor, Magnolia obovata, M. sieboldii, Mallotus japonicus, Staphylea bumalda) (2) Cambial and phloem parenchyma: (Chamaecyparis obtusa, C. pisifera, Albizzia julibrissin, Buxus microphylla var. Koreana, Cereis chinensis, Euonymus japonica, Firmiana platanifolia, Lagerstroemia indica, Ligustrum salicinum, L. obtusifolium, Magnolia kobus, M. obovata, Mallotus japonicus, Morus alba, Poncirus trifoliata, Quercus myrsinaefolia, Rosa polyantha, Styrax japonica, Styrax obassia) (3) Primary ray tissues; (Euonymus japonica, Styrax japonica) (4) Leaf traces; (Quercus acutissima, Q. aliena) (5) Cortex parenchyma; (Ailanthus altissima) (6) Callus tissues; (Castanea crenata, Quercus aliena, Q. myrsinaefolia, Q. serrata) 4. As a general tendency throughout the species studied, in hypocotyl cuttings, the adventitious root primordia were originated from the interfascicular parenchyma tissue, however, leaf traces and callus tissues were contributed to the root primordia formation in epicotyl cuttings. The hypocotyl cuttings of Ailanthus altissima exhibited a special performance in the root primordia formation, this means that cortex parenchyma was participated to the origin tissue. And in Firmiana platanifolia, differening from the other most species, the root primordia were formed at the phloem parenchyma adjacent outwardly to xylem tissue of vascular bundle system as shown photo. 48. 5. All the easy-to, or difficult-to root species developed adventitious roots in vials filled with distilled water. In the difficult-to-root species, however, root formations seemed to be delayed because they almost all had selerenchyma or phloem fiber which gave some mechanical hindrance to protrusion of root primordia. On the other hand, in the easy-to-root species they seemed to form them more easily because they did not have the said tissues. The rooting portions between easy-to-root and difficult-to-root species have not clearly been distinguished, and they have multitudinous variations. 6. The species structured with the more vascular bundles in number compared with the less vascular bundles exhibited delayed rooting. In the cuttings preparation, the proximal end of cuttings was closer to root-to-stem transition region, the adventitious root formation showed easier. 7. A different case occured however with the mature stem cuttings, in both the needle-leaved and the broad-leaved species. In the hypocotyl cuttings, parenchymatous tissues sited near the vascular bundles become the most frequent root forming portions in general and relevant distinctions between both species were hardly recognizable. 8. In the epicotyl cuttings, root primordia originated mainly in leaf traces in connection with cambial and phloems or callus tissues itself. In the hypocotyl cuttings, interfascicular parenchyma was the most frequent portion of the root primordia formation. The portions of root primordia had more connection with vascular cambium system, as the tissues were continuing to be developed.

• The Journal of Korean Society for Radiation Therapy
• /
• v.24 no.1
• /
• pp.1-10
• /
• 2012

Purpose: To evaluate dose distribution differences when the dose rates are randomly changed in intensity-modulated radiation therapy using a dynamic multileafcollimator. Materials and Methods: Two IMRT treatment plans including small-field and large-field plans were made using a commercial treatment planning system (Eclipse, Varian, Palo Alto, CA). Each plan had three sub-plans according to various dose rates of 100, 400, and 600 MU/min. A chamber array (2D-Array Seven729, PTW-Freiburg) was positioned between solid water phantom slabs to give measurement depth of 5 cm and backscattering depth of 5 cm. Beam deliveries were performed on the array detector using a 6 MV beam of a linear accelerator (Clinac 21EX, Varian, Palo Alto, CA) equipped with 120-leaf MLC (Millenium 120, Varian). At first, the beam was delivered with same dose rates as planned to obtain reference values. After the standard measurements, dose rates were then changed as follows: 1) for plans with 100 MU/min, dose rate was varied to 200, 300, 400, 500 and 600 MU/min, 2) for plans with 400 MU/min, dose rate was varied to 100, 200, 300, 500 and 600 MU/min, 3) for plans with 600 MU/min, dose rate was varied to 100, 200, 300, 400 and 500 MU/min. Finally, using an analysis software (Verisoft 3.1, PTW-Freiburg), the dose difference and distribution between the reference and dose-rate-varied measurements was evaluated. Results: For the small field plan, the local dose differences were -0.8, -1.1, -1.3, -1.5, and -1.6% for the dose rate of 200, 300, 400, 500, 600 MU/min, respectively (for 100 MU/min reference), +0.9, +0.3, +0.1, -0.2, and -0.2% for the dose rate of 100, 200, 300, 500, 600 MU/min, respectively (for 400 MU/min reference) and +1.4, +0.8, +0.5, +0.3, and +0.2% for the dose rate of 100, 200, 300, 400, 500 MU/min, respectively (for 600 MU/min reference). On the other hand, for the large field plan, the pass-rate differences were -1.3, -1.6, -1.8, -2.0, and -2.4% for the dose rate of 200, 300, 400, 500, 600 MU/min, respectively (for 100 MU/min reference), +2.0, +1.8, +0.5, -1.2, and -1.6% for the dose rate of 100, 200, 300, 500, 600 MU/min, respectively (for 400 MU/min reference) and +1.5, +1.9, +1.7, +1.9, and +1.2% for the dose rate of 100, 200, 300, 400, 500 MU/min, respectively (for 600 MU/min reference). In short, the dose difference of dose-rate variation was measured to the -2.4~+2.0%. Conclusion: Using the Varian linear accelerator with 120 MLC, the IMRT dose distribution is differed a little <(${\pm}3%$) even though the dose-rate is changed.

• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.1
• /
• pp.46-52
• /
• 2009

Deposition of atmospheric N that is depleted in $^{15}N$ has shown to decrease N isotope ratio ($^{15}N/^{14}N$,expressed as ${\delta}^{15}N$) of forest samples such as tree rings, foliage, and total soil-N. However, its effect on ${\delta}^{15}N$ of mineral soil-N which is biologically active N pool has never been tested. In this study, ${\delta}^{15}N$ of mineral N($NH{_4}^+$ and $NO_3{^-}$) in forest soils from organic and two depths of mineral soil layers (0 to 20 cm and 20 to 40cm depth) of Pinus densiflora stands located at two distinct areas (rural and industrial areas) in southern Korea was analyzed to investigate if there is any difference in ${\delta}^{15}N$ of mineral N between these areas. We also evaluated potential N loss of the study sites using ${\delta}^{15}N$ of mineral N. Across the soil layers, the ${\delta}^{15}N$ of $NH{_4}^+$ ranged from +8.9 to +24.8‰ in the rural area and from +4.4 to +13.8‰ in the industrial area. Soils from organic layer (+4.4‰) and mineral layer between 0 and 20 cm (+13.8‰) of industrial area showed significantly lower ${\delta}^{15}N$ of $NH{_4}^+$ than those of rural area (+8.9 and +24.3‰, respectively), probably indicating the greater contribution of $^{15}N$-depleted $NH{_4}^+$ from atmospheric deposition to forest in the industrial area than in the rural area. Meanwhile, ${\delta}^{15}N$ of $NO_3{^-}$ was not different between the rural and industrial areas, probably because ${\delta}^{15}N$ of $NO_3{^-}$ is more likely to be altered by the N loss that causes $^{15}N$ enrichment of the remaining soil N pool. Compared with the ${\delta}^{15}N$ of soil mineral N reported by other studies (from -10.9 to +15.6‰ for $NH{_4}^+$ and -14.8 to +5.6‰ for $NO_3{^-}$), the ${\delta}^{15}N$ observed in our study was substantially high, suggesting that the study sites are more subject to the N loss. It was concluded that $NH{_4}^+$ rather than $NO_3{^-}$ can conserve the ${\delta}^{15}N$ signature of atmospheric N deposition in forest ecosystems.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.23 no.4
• /
• pp.329-339
• /
• 2021

Soybeans (Glycine max), one of major upland crops, require precise management of environmental conditions, such as temperature, water, and soil, during cultivation since they are sensitive to environmental changes. Application of spectral technologies that measure the physiological state of crops remotely has great potential for improving quality and productivity of the soybean by estimating yields, physiological stresses, and diseases. In this study, we developed and validated a soybean growth prediction model using multispectral imagery. We conducted a linear regression analysis between vegetation indices and soybean growth data (fresh weight and LAI) obtained at Miryang fields. The linear regression model was validated at Goesan fields. It was found that the model based on green ratio vegetation index (GRVI) had the greatest performance in prediction of fresh weight at the calibration stage (R²=0.74, RMSE=246 g/m², RE=34.2%). In the validation stage, RMSE and RE of the model were 392 g/m² and 32%, respectively. The errors of the model differed by cropping system, For example, RMSE and RE of model in single crop fields were 315 g/m² and 26%, respectively. On the other hand, the model had greater values of RMSE (381 g/m²) and RE (31%) in double crop fields. As a result of developing models for predicting a fresh weight into two years (2018+2020) with similar accumulated temperature (AT) in three years and a single year (2019) that was different from that AT, the prediction performance of a single year model was better than a two years model. Consequently, compared with those models divided by AT and a three years model, RMSE of a single crop fields were improved by about 29.1%. However, those of double crop fields decreased by about 19.6%. When environmental factors are used along with, spectral data, the reliability of soybean growth prediction can be achieved various environmental conditions.