• Journal of Wetlands Research
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• v.14 no.1
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• pp.59-73
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• 2012

The importance of rice paddy wetland has been raised since the 10th Ramsar Convention in 2010. However, there is shortage of study on the evaluation of rice paddy wetland and also of the study on the effect of organic agriculture on the vegetation characteristics. Accordingly, this study examined the vegetation characteristics of organic rice paddy for the basic resources of evaluating value of rice paddy wetland. 6 places of organic rice paddy and conventional rice paddy were chosen as research targets. It analyzed the function of 'Floral Diversity and Wildlife Habitat' among the revised RAM, an existing wetland evaluation system. As to the factor affecting the analysis result, simple land-use result was proved to determine the evaluation. As a result of vegetation investigation total 176 taxa, 53 families, 146 generics, 148 species, 26 varieties and 1 forma. When the difference of appearance of life form between organic area and conventional area was examined, organic paddy had higher appearance of life form in Therophyte and Megaphanerophyte. For the distribution of Naturalized plants, organic rice paddy had lower naturalized rate and urbanization index than conventional rice paddy. As to the Pearson correlation analysis between growing condition and vegetation characteristics, variety of rice paddy vegetation showed it was not heavily influenced by the land use. However, the organic rice paddy area had more variety in vegetation than conventional rice paddy. There was about 1% correlation with types of Cyperaceae, which means that the classification group of Cyperaceae can be utilized in evaluating rice paddy wetland later on. It is determined that the wetland evaluation has been widely influenced by soil environment, water environment and surrounding natural and artificial landscape as well as vegetation characteristics. Accordingly, further research seems to be required with minute investigation to an extensive area.

• The Korean Journal of Mycology
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• v.32 no.2
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• pp.101-104
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• 2004

For artificial cultivation of Phellinus baumii, we have conducted a study on cultural characteristics and condition of fruitbody formation in sawdust cultivation. Mycelial density and incubation rate were higher in oak sawdust+rice bran (4 : 1) medium than oak sawdust 100% medium. However, primordia and fruitbody formation were higher in oak sawdust 100% medium than rice bran added medium. Bigger bottle capacity (1,100 ml) resulted in a little higher yield and more biological efficiency than 850 ml bottle.

• The Plant Pathology Journal
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• v.16 no.1
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• pp.19-24
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• 2000

The direct effects of acute $\textrm{O}_3$ on the growth, sporulation and infection of Pyricularia grisea, rece blast pathogen, were investigated to understand the interactions between ozone and the pathogen. Acute exposure of 200 nl $\textrm{l}^{-1}$ ozone for 8 h significantly reduced conidia germination on water atar. Ozone exposure of 200 nl $\textrm{l}^{-1}$ for 8h per day for 5 days had no effect on increase in colony diameter, but severely damaged actively growing aerial mycelia. However, the damage to mycalia was recovered during the following 16 h exposure of unpolluted air. Conidial production was also stimulated by the acute ozone exposure for 5 days. The conidia exposed to the acute ozone for 5 days normally germinates but slightly reduce appressoria formation on rice leaf. However, the conidia produced by artificial stimulation under the same ozone concentration for 10 days showed significant reduction in appressorea for mation on a hydrophobic film. This study suggests that the acute ozone could ingibit appressoria formation as well as vegetative growth of the pathogen, resulting in decrease in rece blast development in the field during summer when high ozone episodes could occur occasionally.

• Korean Journal of Remote Sensing
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• v.33 no.5_2
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• pp.631-640
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• 2017

The estimation of rice yield affects the income of farmers as well as the fields related to agriculture. Moreover, it has an important effect on the government's policy making including the control of supply demand and the price estimation. Thus, it is necessary to build the crop yield estimation model and from the past, many studies utilizing empirical statistical models or artificial neural network algorithms have been conducted through climatic and satellite data. Presently, scientists have achieved successful results with deep learning algorithms in the field of pattern recognition, computer vision, speech recognition, etc. Among deep learning algorithms, the SSAE (Stacked Sparse AutoEncoder) algorithm has been confirmed to be applicable in the field of forecasting through time series data and in this study, SSAE was utilized to estimate the rice yield in South Korea. The climatic and satellite data were used as the input variables and different types of input data were constructed according to the period of rice growth in South Korea. As a result, the combination of the satellite data from May to September and the climatic data using the 16 day average value showed the best performance with showing average annual %RMSE (percent Root Mean Square Error) and region %RMSE of 7.43% and 7.16% that the applicability of the SSAE algorithm could be proved in the field of rice yield estimation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.241-248
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• 2009

Varietal differences on viviparous germination of newly released rice varieties were investigated to provide selection criteria for the high quality rice production. Laboratory and field tests were conducted on 20 different rice varieties in 2007. Varieties which showed below 10% of viviparous germination at the laboratory test were Odaebyo, Hitomebore, Koshihikari, Hwasungbyo, Hopyongbyo, Ilpumbyo, Chuchungbyo when they were treated 35 days after heading (DAH) at the temperature of 25/$15^{\circ}C$ (day/night) for 8 days, and were Hitomebore, Koshihikari, Hwasungbyo, Hopyongbyo under diurnal temperature of 30/$20^{\circ}C$ (day/night). At the field test with artificial lodging, there were 12 varieties including Hopyongbyo, Hitomebore that showed lower viviparous germination below 10% when they were treated at 35DAH and measured 8 days after lodging treatment but there was only four varieties (Ilpumbyo, Hwasungbyo, Chuchungbyo, Hopyongbyo) when lodging treatment was made at the 45DAH. Among newly released rice varieties, viviparous germination rate of Hopyongbyo was below 10% and was 11 to 20% at Hithomebore and Samgwangbyo, 21 to 40% at Koshihikari, Odae-No.1, Josaengheukchalbyo, Chonghobyo, 41 and 60% at Suean-No.1, Whongwangbyo, Bosukchalbyo, and 61 to 90% at Gopumbyo when it was examined 8 days after lodging treatment at 45DAH.

• Korean journal of applied entomology
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• v.12 no.1
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• pp.29-32
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• 1973

This experiment has been carried out to establish the most effective rearing method of rice stemborer, Chilo suppressalis (Walker) on artificial diets under the aseptic condition. The results obtained were summarized as follows: 1. Semi·synthetic diet was giving better results in the weight of matured larvae (96.4mg), emerging rate$(96.7\%)$ and number of egg masses (2.6) than other diets studied. 2. Number of egg masses and hatching rate were significantly increased on the semi-synthetic diet and chemically defned diet, and it may be due to the choline chloride in the diets, 3. Rice seedling was used as a convenient food material. However, it requires more labours and causes more damages of larvae in replacement of fresh seedlings. 4. A different result in larval weight and pupation rate was observed between simplified diet no. 1 and diet added with chlorella. 5. Simplified diet resulted in low hatchability in the second generation, which may be due to the mulnutrition of the diet for adults. 6. The pupation rate was significantly decreased by infection of microorganisms on matured larvae.

• Journal of Biosystems Engineering
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• v.43 no.2
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• pp.148-159
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• 2018

Purpose: Unmanned air vehicle (UAV) remote sensing was applied to test various vegetation indices and make prediction models of protein content of rice for monitoring grain quality and proper management practice. Methods: Image acquisition was carried out by using NIR (Green, Red, NIR), RGB and RE (Blue, Green, Red-edge) camera mounted on UAV. Sampling was done synchronously at the geo-referenced points and GPS locations were recorded. Paddy samples were air-dried to 15% moisture content, and then dehulled and milled to 92% milling yield and measured the protein content by near-infrared spectroscopy. Results: Artificial neural network showed the better performance with $R^2$ (coefficient of determination) of 0.740, NSE (Nash-Sutcliffe model efficiency coefficient) of 0.733 and RMSE (root mean square error) of 0.187% considering all 54 samples than the models developed by PR (polynomial regression), SLR (simple linear regression), and PLSR (partial least square regression). PLSR calibration models showed almost similar result with PR as 0.663 ($R^2$) and 0.169% (RMSE) for cloud-free samples and 0.491 ($R^2$) and 0.217% (RMSE) for cloud-shadowed samples. However, the validation models performed poorly. This study revealed that there is a highly significant correlation between NDVI (normalized difference vegetation index) and protein content in rice. For the cloud-free samples, the SLR models showed $R^2=0.553$ and RMSE = 0.210%, and for cloud-shadowed samples showed 0.479 as $R^2$ and 0.225% as RMSE respectively. Conclusion: There is a significant correlation between spectral bands and grain protein content. Artificial neural networks have the strong advantages to fit the nonlinear problem when a sigmoid activation function is used in the hidden layer. Quantitatively, the neural network model obtained a higher precision result with a mean absolute relative error (MARE) of 2.18% and root mean square error (RMSE) of 0.187%.

• Microbiology and Biotechnology Letters
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• v.45 no.4
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• pp.277-283
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• 2017

To produce sweet liquor without artificial sweeteners, 8 traditional rice pre-treatment methods (juk, beombeok, seolgitteok, gumeongtteok, mulsongpyeon, injeolmi, gaetteok, and godubap) were analyzed in this study. The formation of sugars with the help of ${\alpha}$-amylase, ${\beta}$-amylase, and glucoamylase using nuruk as a substrate has been previously confirmed. During the early stages of the pre-treatment processes, the amount of maltose produced (in descending order of its concentration) by ${\alpha}$-amylase was observed to be as follows: gaetteok > seolgitteok > beombeok > mulsongpyeon > juk > injeolmi > gumeongtteok > godubap. However, changes in maltose concentrations with respect to the pre-treatment processes after 48 hours were observed to be as follows: injeolmi > beombeok = godubap > gumeongtteok > gaetteok = mulsongpyeon > seolgitteok > juk. Maltose produced using either ${\alpha}$-amylase or ${\beta}$-amylase showed similar results. Glucoamylase produced 10 mg/ml of glucose during the godubap process, which was the highest amount of glucose among all the methods. Moreover, when ${\alpha}$-amylase, ${\beta}$-amylase, and glucoamylase were used concurrently, glucoamylase increased glucose production in the later stages. Therefore, the possibility of producing sweet liquor without employing artificial sweeteners was confirmed, even if the amount of sugar in the liquor varied with the pre-treatment process.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.203-203
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• 2017

The Earth's climate is rapidly changing because of increasing carbon dioxide content in atmosphere so, climate prediction models anticipate that earth surface temperature will rise by 3 to $5^{\circ}C$ in next 50 to 100 years. Therefore, frequency of un-expected weather events such as drought, salinity, low or high temperature and flooding etc. will be increasing worldwide. Furthermore, increased atmosphere temperature can influence pests and pathogens spread as well. Therefore, to protect enormous grain loss from unexpected weather conditions, studies related with combine stress conditions like abiotic plus biotic stress condition are really required. Thus, our research focused on physiological responses under combined abiotic and biotic stress condition in rice plant. To induce uniform stress condition, we used NaCl (100 mM) and salicylic acid (0.5 and 1.0 mM SA) as each stress a stimulator. Each artificial abiotic and biotic stress inducer was applied to hydroponically grown rice seedlings alone or together for four day. The data were collected in a time-dependent manner [1, 2, 3 and 4 day(s) after treatment (DAT)] and were matched with our anticipation that shoot length and shoot fresh weight was decreased in solo and combined abiotic and biotic stress condition. The lipid peroxidation content was significantly increased ($1.5{\pm}0.2$ to $2.7{\pm}0.1mg$ mg of $MDA\;g^{-1}FW$) in the first two days in both stress exposed plants, and showed the opposite trend ($0.5{\pm}0.01$ to $0.1{\pm}0.001mg$ of $MDA\;g^{-1}FW$) in last two days under multi stress condition. Superoxide dismutase (SOD) activity did not showed difference in only biotic stress condition (alone 0.5 and 1.0 mM SA) as compared to control however, it was significantly increased in multi stress condition or solo abiotic stress condition whereas, catalase (CAT), and ascorbate peroxidase (APX) activities were significantly decreased in solo biotic and combined abiotic and biotic condition. In particular, both enzymes activities were more decreased in multi stress condition as compared to solo biotic stress condition. The results for relative mRNA expression level of CAT and APX enzymes were in agreement with results of spectrophotometric values. Correlation value between each stress condition and phenotypic data showed that biotic stress condition showed high correlation with activity of CAT and APX whilst, abiotic stress condition revealed significant correlation with SOD activity.

• The Korean Journal of Mycology
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• v.27 no.4 s.91
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• pp.243-248
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• 1999

To compare the morphological and cultural characteristics of Cordyceps militaris, forming conditions of artificial fruiting body production were investigated in this experiment. The stroma shapes of artificial fruiting body were confirmed to club and/or stick. However, both shapes were same color as a orange. Perithecia of stroma was semi-egg shape and was ranged from $30{\sim}90{\times}90{\sim}130\;{\mu}m$ and it's asci was narrowly cylindric. Ascospore of perithecia was belong to filiform and multiseptate. The conidia of C. militaris was centurally grown and shaped with globose, long clavate type, floccose, centrally raised during anamorph stage. When it was cultured between glass and PP bottle, production of artificial fruiting body, pinheading ratio and total yield were higher in PP bottle. The optimum illumination was 1,000 lx for the those production. The culture medium of barley, wheat and hulled rice showed higher artificial fruiting body compared to that of silkworm. Pinheading and yield of it's isolates was decreased at more than three subsequent transculture.