• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.122-123
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• 2003

Apple stem grooving virus (ASGV) belongs to Capillovirus and infects pome fruits. Transmission mode of ASGV is known by grafting and mechanical inoculation into susceptible hosts, not by any other natural vectors. But we have observed the spread of ASGV in the field without mechanical inoculation or grafting. Transmission seems to be occurred from tree-to-tree and tree-to-susceptible herbaceous plants along but not across ditches in the field. In order to ascertain this possibility, various fungi were isolated and cultured from ASGV-infected plants and 69 isolates were characterized. By means of RNA dot-blot hybridization and PCR analysis, 3 isolates were sorted out for further studies. The isolates were identified to Tataromyces sp. and belonged to Phenicillium by morphological characteristics and molecular markers. As an experimental host, 10 kidney beans (Phaseolus vulgaris) were screened and Kyunggi-5 was selected for virus amplification and symptom development. Kyunggj-5 infected by fungi which seemed to carry ASGV showed the typical disease symptoms and viral coat protein genes were detected from all tested plants. To confirm the Koch's rule, fungi cultured from inoculation origins of kidney bean were grown on PDA media and re-inoculated to hosts. The fungi isolated from inoculation origins induced the typical disease symptoms on hosts. However virus free fungi did not induce any symptom on the experimental hosts. This bioassay showed that these typical symptoms were caused by virus, not fungi.

• Journal of Broadcast Engineering
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• v.25 no.3
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• pp.399-404
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• 2020

The Disaster text service is a text-based service for public alert. But, foreigners who are not familiar with korean can not understand exactly the disaster text messages provided. Using multimedia information such as images is expected to solve this problem. However, the current disaster message service method is not suitable for multimedia information delivery. This study proposes a firmware-based disaster character service method for displaying disaster image in a terminal. A device using this method should store images corresponding to the type of disaster and use special characters to inform the presentation of image in a terminal. This approach can be implemented in the new firmware installed device and it can be work with the existing device.

• Journal of Broadcast Engineering
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• v.20 no.4
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• pp.598-605
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• 2015

Effective alerts will drastically mitigate the disaster impacts. One way to enhance the effectiveness is to prepare multiple alert distribution channels. In this paper, we propose a new emergency alert distribution system that will solve the weaknesses of the current distribution systems, such as Cell Broadcasting System and T-DMB Automatic Emergency Alert Service. The weaknesses are: the limitation of message length, small portions of terminals that can receive and display the alert signal, and one-way communication service. To solve these problems, we propose an emergency alert distribution system over the Internet with RSS (Rich Site Summary) format. The system also has the capability of adaptive alert filtering according to the receiver characteristics. We analyzed the characteristics of RSS as an alerting format, and draw functional requirements satisfying use case scenarios. We designed the system only with major requirements and verified it on our test bed. Sending richer message contents through various receiving terminals, the system will achieve more effective emergency alert service.

• 한국균학회소식:학술대회논문집
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• 2014.05a
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• pp.25-25
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• 2014

Koji molds are comprised of yellow, black and white. Black and white koji molds were recently re-visited by this author and it is concluded that they consists of Aspergillus luchuesnsis, A. niger and A. tubingensis, and the most important species for alcoholic beverage production is A. luchuensis. In the case of yellow koji mold, it is comprised of Aspergillus oryzae, A. sojae and A. tamari. In the case of A. sojae, the species is scarcely isolated from nature and rarely used for industry in Korea. Aspergillus tamari is often isolated from traditional Korean Meju, a fermented soybean product, and the classification of the species is clear. However, in the case of A. oryzae, differentiation between A. oryzae and A. flavus is still in controversy. In this study, we collected 415 strains of Aspergillus flavus/oryzae complex from air, rice straw, soybean, corn, peanut, arable soil and Meju in Korea and we examined the aflatoxin producing capacity of the strains. The norB-cypA, omtA and aflR genes in the aflatoxin biosynthesis gene cluster were analyzed. We found that 367 strains (88.4%) belonged to non-aflatoxigenic group (Type I of norB-cypA, IB-L-B-, IC-AO, or IA-L-B- of omtA, and AO type of aflR), and only 48 strains (11.6%) belonged to aflatoxin-producible group (Type II of norB-cypA, IC-L-B+/B- or IC-L-B+ of omtA, and AF type of aflR). In the case of A. flavus/oryzae strains from Meju, almost strains (178/192, 92.7%) belonged to non-aflatoxigenic group and only 14 strains (7.3 %) belonged to aflatoxin-producible group. It is proposed in this study that non-aflatoxigenic strain from Meju is classified as A. oryzae, considering that Meju is food material.

• The Plant Pathology Journal
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• v.16 no.1
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• pp.29-35
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• 2000

The internal transcribed spacer regions (ITS I, 5.8S and ITS II) of the ribosomal DNAs were amplified from Korean isolates of Phytophthora spp. and sequenced to characterize them. Sequences from 33 isolates previously identified as P. boehmeriae, P. cactprum, P. cambivora, P. capsici, P. cinnamomi, P. erythroseptica, P. infestans, P. megasperma, P. melonis, P. nicotianae, P. palmivora and P. sojae were compared with published sequences, and a phylogenetic tree was produced. All isolates belonging to 10 species, P. cactorum, P. cambivora, P. capsici, P. cinnamomi P. citricola, P. infestans, P. nicotianae, P. palmivora and P. sojae were clearly clustered into published isolates of each species above 97% bootstrap value. Cucurbits isolates of Phytophthora previously identified as either P. melonis or P. drechsleri showed distinct evolutionary lineages from the P. megasperma was closely related to isolates of P. cryptogea-P. drechsleri showed distinct evolutionary lineages from the P. cryptogea-P. drechsleri complex group, indicating that P. melonis is a valid species. A Korean isolate of P. megasperma was closely related to isolates of P. erythroseptica showed distant genetic relationship with published isolates of P. erythroseptica (CBS 956.87). It is probable that the two Korean isolates could be genetically different from foreign isolates or misidentified. A grouping of species according to ITS sequence divergence matched, to some degree, the broad classification based on type of papilla. However, a separation of semi-papillate species and papillate species was not wvident in this study.

• Journal of Microbiology and Biotechnology
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• v.18 no.12
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• pp.1915-1918
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• 2008

An entomopathogenic fungus was isolated from an infected aphid. The isolate conformed most closely to Lecanicillium attenuatum CBS 402.78 (AJ292434) based on the internal transcribed spacer (ITS) region of its 18S rDNA, and thus was designated L. attenuatum CNU-23. Laboratory and field evaluations of CNU-23 blastospores were carried out for the control of green peach aphids. The laboratory evaluations of CNU-23 revealed an aphid mortality of about 80% with an estimated $LT_{50}$ of 3.72 days after the application of CNU-23 at $1{\times}10^6$ blastospores/ml. Meanwhile, the field evaluations of CNU-23 performed on greenhouse pepper plants during the rainy season showed an aphid mortality ranging from 72% to 97%. Significant sporulation was observed in the aphids treated with CNU-23. Therefore, the results suggest that L. attenuatum CNU-23 can be used as a biocontrol agent for green peach aphids on greenhouse pepper plants.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.153-161
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• 2008

Agriculture and forest are basis for livelihood in Nepal while both sectors constitute around 40 percent of the national product and over two-thirds of the economically active population is dependent on agriculture. However, radical changes in land use, depletion in crops production and food availability are major threats due to loss of soil fertilityand severe environmental degradation. In this study, we used time series data from 1986/87 to 2005/06 about food crop production and population published by Government of Nepal, Ministry of Agriculture and Cooperatives and Central Bureau of Statistics. Descriptive statistics and ArcGIS were used to assess and map the food security status of Nepalese Terai based on the local food demand and supply system. Food supply to demand ratio(FSDR) was the main idea of assessment. Our results showed that out of 20 districts, only 8 districts were categorised under secured food districts whereas 5 districts were still under food unsecured situation. The analysis further revealed that 7 districts had faced food deficit more than 8-16 times during the last 20 year periods. Data further showed that there was surplus food supply relative to the requirements dictated by FSDR. However, the average FSDR was less than 1.2(less than 20% surplus) exploring fact that most of the districts were not producing sufficient food to cope up the food shock and after 1995 it was relatively stagnant. Our prediction reveals that food supply in Terai even in the future would remain at almost the same level as now, and there will not more than 16-17% surplus by 2021 considering medium vibrant population growth. The findings thus, indicate that Terai may not be a food secure region in the future, even though the region is considered as a food storage house of Nepal. In addition, this paper suggests ways to make future comprehensive case studies more widely comparable in Terai, Nepal.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.839-844
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• 2014

The gas-phase radical-radical reaction $O(^3P)$ + $C_2H_5$ (ethyl) ${\rightarrow}$ $H(^2S)$ + $CH_3CHO$(acetaldehyde) was investigated by applying a combination of vacuum-ultraviolet laser-induced fluorescence spectroscopy in a crossed beam configuration and ab initio calculations. The two radical reactants $O(^3P)$ and $C_2H_5$ were respectively produced by photolysis of $NO_2$ and supersonic flash pyrolysis of the synthesized precursor azoethane. Doppler profile analysis of the nascent H-atom products in the Lyman-${\alpha}$ region revealed that the average translational energy of the products and the average fraction of the total available energy released as translational energy were $5.01{\pm}0.72kcalmol^{-1}$ and 6.1%, respectively. The empirical data combined with CBS-QB3 level ab initio theory and statistical calculations demonstrated that the title exchange reaction is a major channel and proceeds via an addition-elimination mechanism through the formation of a short-lived, dynamical addition complex on the doublet potential energy surface. On the basis of systematic comparison with several exchange reactions of hydrocarbon radicals, the observed small kinetic energy release can be explained in terms of the loose transition state with a product-like geometry and a small reverse activation barrier along the reaction coordinate.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.390-393
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• 2008

We analyzed the landuse change, quantify the area covered by majors food crops (Paddy, Wheat, Barely, Maize, Millet and Potato) and their productivity trends in Terai, Nepal from 1987 to 2006. We used series of area covered by each single crop and production data published by Government of Nepal, Central Bureau of Statistics and Ministry of Agriculture and Cooperatives. Our results indicated that the agriculture land has increased by about 47% while forest has decreased by 32% between 1964 and 2001 in Terai. Whilst the total cropped area has increased by 19% between 1987 and 2006. The highest incremental change has observed in Potato by 234% followed by Wheat 31%, Maize 20% and Paddy 12% and so on. However, data revealed with very low crops productivity and it showed less than half of its potential except in Potato. The average yield of food crops /hectare /year during last 20 year has found only 3.094 metric tons. Only Potato has gained high average yield by 10.34 metric tons. While others crops yielded entirely low. 3 periods moving average depicted that the productivity trend of Barely and Millet has stagnant while others crops showed slightly up and down and increasing steadily over time. Further study is needed to comprehend the linkage of food productivity in the present food supply to demand and food security system in Terai, Nepal.

• Journal of the Korean Wood Science and Technology
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• v.39 no.6
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• pp.490-497
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• 2011

In this study, we determined optimal conditions for simultaneous saccharification and fermentation (SSF) using corncob biomass pretreated with oxalic acid. The effect of SSF temperature ($25.8{\sim}34.2^{\circ}C$) and agitation speed (80~220 rpm) were significant at a 99% confidence level in its effect on ethanol production. The highest ethanol production was expected when SSF was performed at $30^{\circ}C$, 170 rpm (22.5 g/L). The ethanol production was improved by mixture of yeast extract (1.25 g/L) and urea (1.25 g/L) as nitrogen source. However, addition of trace metal components and vitamin for SSF was not affected in the ethanol production. Optimal concentration of $KH_2PO_4$, $MgSO_4{\cdot}7H_2O$ for SSF was 1 g/L, 0.25 g/L respectively.