• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1621-1628
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• 2012

The agar-degrading bacterium GNUM-1 was isolated from the brown algal species Sargassum serratifolium, which was obtained from the West Sea of Korea, by using the selective artificial seawater agar plate. The cells were Gram-negative, $0.5-0.6{\mu}m$ wide and $2.0-2.5{\mu}m$ long curved rods with a single polar flagellum, forming nonpigmented, circular, smooth colonies. Cells grew at $20^{\circ}C-37^{\circ}C$, between pH 5.0 and 9.0, and at 1-10% (w/v) NaCl. The DNA G+C content of the GNUM-1 strain was 45.5 mol%. The 16S rRNA sequence of the GNUM-1 was very similar to those of Alteromonas stellipolaris LMG 21861 (99.86% sequence homology) and Alteromonas addita $R10SW13^T$(99.64% sequence homology), which led us to assign it to the genus Alteromonas. It showed positive activities for agarase, amylase, gelatinase, alkaline phosphatase, esterase (C8), lipase (C14), leucine arylamidase, valine arylamidase, ${\alpha}$-chymotrypsin, acid phosphatase, naphthol-AS-BI-phosphohydrolase, ${\alpha}$-galactosidase, ${\beta}$-galactosidase, ${\beta}$-glucosidase, catalase, and urease. It can utilize citrate, malic acid, and trisodium citrate. The major fatty acids were summed feature 3 (21.5%, comprising $C_{16:1}{\omega}7c/iso-C_{15:0}$ 2-OH) and C16:0 (15.04%). On the basis of the variations in many biochemical characteristics, GNUM-1 was considered as unique and thus was named Alteromonas sp. GNUM-1. It produced the highest agarase activity in modified ASW medium containing 0.4% sucrose, but lower activity in rich media despite superior growth, implying that agarase production is tightly regulated and repressed in a rich nutrient condition. The 30 kDa protein with agarase activity was identified by zymography, and this report serves as the very first account of such a protein in the genus Alteromonas.

• Journal of Sericultural and Entomological Science
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• v.44 no.2
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• pp.74-81
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• 2002

The optimal conditions for mycelial growth of P. linteus ASI 26011 were 25-30$^{\circ}C$ and pH 6.0, respectively. The mycelial growth of P. linteus was excellent on MCM medium. In case of carbon sources, the mycelial growth of P. linteus was best on the culture media that were contained with sucrose, mannose and glucose. Potassium nitrate and sodium nitrate were good for the mycelial growth of P. linteus as a nitrogen source. For comparison of the mycelial colonization of P. linteus on logs, several techniques of inoculation were tested; the sterilized short log inoculation, drilling inoculation and log-end sandwich inoculation. The mycelial colonization of P. linteus on logs was good in the treatment of sterilized short log inoculation, but poor in the traditional methods such as drilling inoculation and log-end sandwich. The initial mycelial growth and the full mycelial colonization of P. linteus were the best on 20 cm logs under the condition of 42% of moisture content in log. Also the initial mycelial growth of P. linteus was accelerated over 12 hours of sterilization. Burying method of logs after 5-6 months of incubation was the best for formation of basidiocarp of P. linteus. The formation of fruiting body of P. linteus was quite good in the cultivation house at the 31-35$^{\circ}C$ and over 96% of relative humidity.

• The Korean Journal of Mycology
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• v.29 no.2
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• pp.131-133
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• 2001

A destructive collar rot disease was found on broad bean (Vicia faba) in several farmer's field located in Changseon-myon, Namhae-gun, Gyeongsangnam-do in 2001. The typical symptoms of the disease were stem rot, crown rot, wilt or blight. Upper parts of the infected stems were mostly blighted and white mycelial mats were spread over lesions and the sclerotia were formed on the stems near soil line. The infection rates of the disease in the surveyed area were ranged from 28.6 to 42.8%. The sclerotia of the fungus readily formed in artificial media such as PDA at $30^{\circ}C$ and its shape was globoid or irregular and size was $1.0{\sim}3.7{\times}1.0{\sim}2.8\;mm\;(av.\;1.0{\sim}2.3\;mm)$ and was brown or dark brown in color. The optimum temperature for growth of the fungus was about $30^{\circ}C$. The typical clamp connections were found in the hypha of the fungus grown on PDA. On the basis of mycological characteristics and pathogenecity test on host plants, the fungus was identified as Sclerotium rolfsii. This is the first report on the collar rot of broad bean caused by Sclerotium rolfsii in Korea.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.10a
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• pp.9-18
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• 2003

A method for rapid propagation of mature Jack fruit was developed. Four types of explants (mature embryos, apical meristems of young seedlings, apices from mature plants and nodal segments) were used. It has been found 88% of young apical meristems produced shoots in Campbell and Durzan (CD) medium compared to 60% in Murashige and Skoog (MS) medium. Only 1/3 of them produced multiple shoots. Shoot idtiation from nodal segments was very rare. Mature apices produced callus. Although removed of the sheathing cover around mature buds enhanced the shoot initiation but success rate was low in growth regulator free medium. Embryos respond to the CD medium but not to the MS medium. Embryos from seeds soaked in water for 24 hours produced shoots after 8 weeks of incubation and the success rate was 70% while embryos from dry seeds only produced roots. There was no significant effect of cold storage (refrigeration) for 7 days on shoot initiation from mature embryos (65%) but the ability for shoot induction declines with storage time (55% after 21 days of cold storage). Mature axillary buds were established in Modified Campbell and Durzan (CD) medium supplemented with 0.5mg/1 and IBA. There was a significant difference in the growth performance of shoots according to the period of the year in which explants were collected. Highest (60%) was observed in November-January period. It was only 30% when the explants were collected in February-April or May-July and decreased to 20% in August-October. The shoots produced in November-January showed a higher vigor than those produced in other months. Since Jak fruit show seasonal changes in fruit bearing and shedding of leaves, it can be suggested that the difference in growth performances of tissues cultured in artificial culture media would have been affected by endogenous rhythms.

• Journal of Sericultural and Entomological Science
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• v.45 no.2
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• pp.103-107
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• 2003

Entomopathogenic nematodes were isolated through the investigation in soils collected from cultivated and non-cultivated fields using silkworms (Bombyx mori) and Galleria mellonella trap. The detectable rate of entomopathogenic nematodes of silkworms trap was higher than the G. mellonella trap. This study indicates the detection of entomopathogenic nematodes from soils that silkworms are sensitive superior to the G. mellonella to entomopathogenic nematodes. The steinernema, rhabditidae, and diplogatroidae strains successfully cultured on the silkworms host as well as on artificial media. Reproductivity in the living silkworm larva and pupa was 1.5 to 3.5${\times}$ 10$\^$5/ nematodes per host However, G. mellonella could be multiplied less than 5${\times}$l0$\^$5/ nematodes. The dried pupa of the silkworm following mositurize was cultured 0.5 to 2${\times}$10$\^$5/) nematodes per host. The culture methods of the steinernema, rhabditidae, and diplogatroidae strains, using silkworm powder, extracted chicken intestine, and food waste fertilizer could be applicative, but rate of reproduction was low.

• Journal of Soil and Groundwater Environment
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• v.26 no.6
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• pp.1-17
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• 2021

Self-potential (SP) surveys measure naturally occurring differences in electrical potential in the absence of artificial sources and have been applied to various fields since the first application in mineral explorations. Among various causes of SP occurrences, streaming potential is generated by the flow of groundwater, and makes SP surveys suitable for the exploration of groundwater table fluctuation, fractures, sinkholes and landslide occurrences. Recently, there has been many studies that applied SP surveys to monitor water leakage through dikes and embankments. In this review paper, we first review the characteristics and theoretical backgrounds of streaming potential in saturated or unsaturated porous media to introduce it in the embankment among various application field. After the review of the background theory, we review the past cases of field SP surveys on dikes and embankments and also the characteristics of field streaming potential data in the surveys. Further, by analyzing past studies of qualitative as well as quantitative interpretation of SP survey data, we show the possibility of quantitative interpretation of streaming potential data obtained on dikes and embankments. Consequently, it is hope that this review paper helps researches on SP surveys on dikes and embankments, and provides basis for interpretation methods of the SP data to identify leaked area and further leakage rate (or permeability).

• Research in Plant Disease
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• v.24 no.4
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• pp.342-347
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• 2018

Bacterial canker caused by Clavibacter michiganensis is considered to be one of the most serious diseases, leading to economic damage to tomato worldwide. Diagnosis of the bacterial canker on tomato is known to be difficult because the causal pathogen is slow-growing on artificial media as well as causes latent infection in tomato. In this study, as a less time-consuming method, a specific primer set was newly designed for rapid detection of C. michiganensis. The method presented here is so simple, easy, and fast that it can be useful and practical in direct detection of the bacterial canker pathogen from tomato plants.

• Geophysics and Geophysical Exploration
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• v.21 no.4
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• pp.231-243
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• 2018

Streaming potential (SP) arises from fluid flow through effectively connected pores. From this potential, formation water information as well as fluid flow properties can be estimated. As micro particles being located in boundary between subsurface porous media and fluid are charged to form electrical double layer, fluid flow caused by several reasons generates SP, one of electrokinetic phenomena. Occurrence mechanism of SP is complex and signal strength is relatively weak compared to noise. However, application of self potential survey using SP to monitoring of formation fluid is expanding because of its' convenience of exploration without artificial source and repetitiveness of signal. This paper accounts for the occurrence mechanism of SP studied before, including governing equations and analyzes previous various case studies of SP according to the change of physical properties of materials. It helps to increase understanding about SP and also lays the foundations of the application of SP to fields.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.77-86
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• 2019

This paper proposes using machine-learning technology to analyze and classify historical collected documents based on them. Data is collected based on keywords associated with a specific domain and the non-conceptuals such as special characters are removed. Then, tag each word of the document collected using a Korean-language morpheme analyzer with its nouns, verbs, and sentences. Embedded documents using Doc2Vec model that converts documents into vectors. Measure the similarity between documents through the embedded model and learn the document classifier using the machine running algorithm. The highest performance support vector machine measured 0.83 of F1-score as a result of comparing the classification model learned.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.58-66
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• 2019

Recognition of named entity such as proper nouns in conversation sentences is the most fundamental and important field of study for efficient conversational information prediction. The most important part of a task-oriented dialogue system is to recognize what attributes an object in a conversation has. The named entity recognition model carries out recognition of the named entity through the preprocessing, word embedding, and prediction steps for the dialogue sentence. This study aims at using user - defined dictionary in preprocessing stage and finding optimal parameters at word embedding stage for efficient dialogue information prediction. In order to test the designed object name recognition model, we selected the field of daily chemical products and constructed the named entity recognition model that can be applied in the task-oriented dialogue system in the related domain.