• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.82-82
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• 2022

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.1
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• pp.9-15
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• 2000

The objective of this study is to evaluate the use of RADARSAT and Landsat TM data for the monitoring of rice growth. The relationships between backscatter coefficients($\sigma$$^{0}$ ) of RADARSAT data and digital numbers (DN) of Landsat TM and rice growth parameters were investigated. Radar backscatter coefficients were calculated by calibration process and then compared with rice growth parameters; plant height, leaf area index (LAI), and fresh and dry biomass. When radar backscatter coefficient ($\sigma$$^{0}$ ) of rice was expressed as a function of time, it is shown that the increasing trend ranged from -22--20dB to -9--8dB as growth advances. The temporal variation of backscatter coefficient was significant to interpret rice growth. According to the relationship between leaf area index and backscatter coefficient, backscatter coefficient underestimated leaf area index at the beginning of life history and overestimated, at the reproductive stage. The same increasing trend between biomass and backscatter coefficient was shown. From these results, RADARSAT data appear positive to the monitoring of rice growth. Each band of time-series Landsat TM data had a significant trend as a rice crop grows during its life cycle. Spectral indices, NDVI[(TM4-TM3)/(TM4+TM3)] and RVI(TM4/TM2), derived from Landsat TM equivalent bands had the same trend as leaf area index.

• KDI Journal of Economic Policy
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• v.42 no.3
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• pp.1-32
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• 2020

This paper studies urban growth in Korean cities. First, I document that population growth patterns change over time and that the current population distribution supports random urban growth. I confirm two empirical laws-Zipf's law and Gibrat's law-both of which hold in the period of 1995-2015, but do not hold in the earlier period of 1975-1995. Second, I find a systematic employment growth pattern of Korean cities in spite of the random population growth. I examine market access effects on employment growth. Market access, a geographical advantage, has a significant influence on urban employment growth. The market access effect is higher in the Seoul metropolitan area than in the rest of the country. This effect is stronger on employment growth in the manufacturing industry compared to employment growth in the service industry. These results are robust with various checks (e.g., different definitions of urban areas). The results here suggest that policymakers should consider geographical characteristics when they make policy decisions with respect to regional development.

• Ocean and Polar Research
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• v.30 no.4
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• pp.509-518
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• 2008

Distribution of bacterial abundance and production was investigated in seawater around Saemangeum dike 7 times during March, $2007{\sim}July$, 2008. In the inner area of the dike, salinity variation was great due to river runoff from Mangyung and Dongjin Rivers and high chlorophyll a (chl a) concentrations up to $124.3{\mu}g\;l^{-1}$ was found. In the outer area of the dike, salinity was higher than in the inner area of the dike, and chl a was lower up to 10 times than in the inner area of the dike. Thus, the area of Saemangeum showed meso- to hypereutrophic conditions. Bacterial abundance and production ranged from 0.3 to $4.3{\times}10^9\;cells\;l^{-1}$ and from 5.2 to $570 pmol\;l^{-1}h^{-1}$ in outer area of the dike, respectively, while in the inner area of the dike bacterial abundance and production was 3 to 4 times higher ($0.4{\sim}12.7{\times}10^9\;cells\;l^{-1}$ and $12.3{\sim}1309\;pmol\;l^{-1}h^{-1}$, respectively) than those in the outer area. In both areas, bacterial abudance and production was highest in summer and lowest in winter. However, the variations of bacterial parameters was very large in each season. These large variations seemed to be related with the supply of organic matter. Bacterial abundance and production showed significant negative correlations with salinity in the inner area, suggesting that allochthonous organic matter input by river runoff could be an important factor in regulating the distribution of bacterial abundance and production. In addition, bacterial production also correlated positively with chl a in the inner area, suggesting that autochthonous substrate might be another regulating factor of bacterial growth in the area. These results suggest that the supply of both allochthonous organic substrates introduced by river runoff and autochthonous substrates produced by phytoplankon could be important in regulating bacterial growth and utilization of organic matter in the area. Thus, to manage water quality in the inner area of dike, it seems to be important to lower the load of both organic and inorganic nutrients from adjacent rivers.

• Korean Journal of Environmental Biology
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• v.20 no.4
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• pp.378-385
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• 2002

Growth of Pacific oystey, Crassostrea gigas, in Kamak Bay, Korea was modeled using Von Bertalanffy growth function, seasonal Von Bertalanffy growth function and generalized growth equation of Schnute and Richards' growth model, based on shell length and wet weight frequency data of 9208 oysters. Carrying capacity in the oyster culture ground was also estimated using Schaefer's and Fox's surplus production model. The present results suggest that the generalized growth equation of Schnute and Richards' model is fitter to describe the length growth pattern of C. gigas than Von Bertalanffy growth functions. This results also suggest that the current number of culture facility per unit area in 2000 is similar to the number of facility that produces the maximum production of oyster per unit area.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.469-479
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• 2016

Kimchi cabbage is one of the most important vegetables in Korea and a target crop for market stabilization as well. In particular Kimchi cabbages in a highland area are very sensitive to the fluctuations in supply and demand. Yield variability due to growth conditions dictates the market fluctuations of Kimchi cabbage price. This study was carried out to understand the distribution of the highland Kimchi cabbage growth status in Anbandeok. Anbandeok area in Gangneung, Gangwon-do, Korea is one of the main producing districts of highland Kimchi cabbage. The highland Kimchi cabbage status map of each growth factor was obtained from unmanned aerial vehicle (UAV) imagery and field survey data. Six status maps include UAVRGB image map, normalized difference vegetation index (NDVI) distribution/anomaly map, Crop distribution map, Planting/Harvest distribution map, Growth parameter map and Growth disorder map. As a result, the highland Kimchi cabbage status maps from May 31 to Sep. 6 in 2016 were presented to show spatial variability in the field. The benefits of the highland Kimchi cabbage status map can be summarized as follows: crop growth monitoring, reference for field observations and survey, the relative comparison of the growth condition in field scale, evaluation of growth in comparison of average year, change detection of annual crops or planting areas, abandoned fields monitoring, prediction of harvest season etc.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.208-208
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• 2017

No-tillage practices are expected to provide several benefits such as increasing soil organic matter, reducing labor time and saving energy cost compared with conventional tillage practices. This study was conducted to investigate the effects of no-tillage dry-seeding on rice growth and soil properties in comparison with other rice cultivation methods, machine transplanting and wet-hill-seeding on puddled paddy. Rice seedling establishment was slightly higher in no-tillage dry-seeding treatment ($145seedling\;m^{-2}$) than wet-hill-seeding on puddled paddy treatment ($111seedling\;m^{-2}$), but the seedling establishment in both treatments fell within the optimum range for direct seeding rice cultivation. Plant height, number of tillers and chlorophyll content (SPAD value) of rice in no-tillage dry-seeding treatment were higher than those of the other treatments. However, no significant differences in grain yield was observed among three cultivation methods, and the yield ranged 5.8 to $5.9ton\;ha^{-1}$. The heading date from seeding under no-tillage dry-seeding treatment was on average 109 days, which was similar to that under machine transplanting treatment (112 days), but 10 days later than that under wet-hill-seeding on puddled paddy treatment (99 days). Grain quality characteristics grown in no-tillage dry-seeding were similar to those grown in the other cultivation methods. These results indicate that no-tillage dry-seeding practice is comparable to conventional tillage system in terms of seedling establishment, growth, yields and grain quality.

• Korean Journal of Head & Neck Oncology
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• v.14 no.1
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• pp.70-75
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• 1998

Tumor growth and metastasis depends on angiogenesis. Vascular endothelial growth factor (VEGF) is a potent mitogen for vascular endothelial cells in vitro and promotes neoangiogenesis in vivo. Objective: Follicular thyroid cancers(FTC) are a vascular tumor and traditionally metastasize via blood vessels. Likely other cancers, angiogenesis may playa important role in FTC. We, therefore, investigated the expression of VEGF and microvascular density by immunohistochemistry in FTC and follicular adenoma(FA). Materials and Methods: Findings of immunohistochemical stainings for VEGF and CD31 were measured by grading scale from +1 to 4+(strongest) and by counting the stained microvessels in 14 FTCs and 14 FAs. Results: 1) Expression of VEGF. a) FTCs have stronger expression than FAs in areas of tumor adjacent to capsule($mean{\pm}SD\:\;3.2{\pm}0.9\;vs\;2.0{\pm}0.9$, p<0.01) and in central area($2.3{\pm}0.7\;vs\;1.3{\pm}0.6$, p<0.01). b) The VEGF expression of capsular area in FTCs are higher than that of central area(p<0.05). 2) Microvascular density by CD31. a) FTCs have more microvessels than FAs in areas of adjacent to capsule($78.9{\pm}27.3\;vs\;38.7{\pm}15.6$, p<0.01) and in central area($75.5{\pm}23.3\;vs\;27.8{\pm}10.7$, p<0.01). b) In FTCs, the number of microvessels of capsular area are more than that of central tumor area, but not significant statistically(p>0.05). Conclusion: The higher expression of VEGF and microvascular density in FTC suggests angiogenesis plays an important role in progression of FTC.

• Journal of Ginseng Research
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• v.15 no.1
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• pp.31-35
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• 1991

In order to know the optimum planting density under shading structures at different light intensity, We investigated the growth status, distribution of ginseng leaf area, correlation between planting density and root weight per plant and yield, correlation between leaf area index and root weight per plant and yield. According to the increase of planting density the leaf area per plant was decreased, but leaf area index (L.A.I) was increased. Ginseng leaf population at different lines under common straw shading were distributed mainly in frost lines but polyethylene net shading at 10fo light intensity were distributed equally in all lines. Optimum planting density in common straw shading at 5% light intensity was 55 plant per tan (90 cmX180 cm) and polyethylene net shading 81 10% light intensity was 60 plant per tan, in consideration of root weight and yield. Optimum leaf area index was 2.4 under common straw shading at 5% light intensity but was 2.7 under polyethylene net shading at 10% light intensity.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.463-470
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• 2019

Wild-simulated ginseng is requires standard establishment on location environment for long-term and eco-friendly cultivation. The this study was carried out to investigate the correlation between growth characteristics and location environment of wild-simulated ginseng for selection of suitable cultivation area. Samples were collected from a 9 site of wild-simulated cultivation area and examined growth characteristics and location environment. Correlation coefficient between growth characteristics and location environment was analyzed using Spearman's rank correlation. The growth of wild-simulated ginseng was shown significantly higher in Geochang and Hamyang cultivation area. The results of correlation analysis was shown significantly correlation with percentage of conifer, total diameter at breast height, soil pH, K, Ca and Mg. The results of this study was clearly investigated the correlation between growth characteristics and location environment of wild-simulated ginseng, which is considered to will provide understanding for selection suitable cultivation area of wild-simulated ginseng.