• Mycobiology
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• v.41 no.4
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• pp.245-247
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• 2013

The ambrosia beetle, Platypus koryoensis, is an economically important pest affecting oak trees in Korea. Candida kashinagacola was isolated from galleries of the beetle in oak wood and identified by analyses of morphology, physiological properties, and nucleotide sequence of the large subunit ribosomal DNA. This is the first report on Candida species associated with oak wilt disease vectored by the ambrosia beetle, Platypus koryoensis, in Korea.

• Korean journal of applied entomology
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• v.47 no.2
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• pp.117-126
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• 2008

Nine species of Curculionidae, Pimelocerus elongates (Roelofs, 1873), Phylaitis maculiventris Voss, 1958, Egiona picta (Roelofs, 1875), Cryptorhynchus electus (Roelofs, 1875), Rhadinopus confinis Voss, 1958, R. sulcatostriatus (Roelofs, 1875), 1962, Deiradocranus setosus (Morimoto, 1962), Rhadinomerus annulipes (Roelofs, 1875), and R. maebarai Chujo et Voss, 1960 are recorded for the first time in Korea. And the distribution of the species of Shirahoshizo hiurai Morimoto to Korea which its distribution was unclear is confirmed with this report. Habitus photos and descriptions of the species are given.

• Journal of the Korean Wood Science and Technology
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• v.33 no.5 s.133
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• pp.86-91
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• 2005

Six compounds were isolated from the EtOAc and $Et_2O$ fractions of the bark of Rhus chinensis by repeated column chromatography with $SiO_2$ and Sephadex LH-20. The structures were determined by instrumental analysis using MS and NMR spectrophotometer as: gallic acid (1), methyl gallate (2), 6, 7-dimethoxycoumarin (3), orcinol-${\beta}$-D-glucoside (4), scopoletin (5), semialactone (6). Among these compounds, 6,7-dimethoxycoumarin (3) was isolated from this plant for the first time. To measure the antioxidant activity, the DPPH radical scavenging activity test was performed. Gallic acid (1) showed the strongest activity, while orcinol-${\beta}$-D-glucoside (4), semialactone (5) and scopoletin (6) had the low activities.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.04a
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• pp.26.1-26
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• 1999

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.440-446
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• 2019

Pine wilt disease occurred for the first time in Busan in 1988 and the damage has since been increasing. In 2005, a special law was enacted for pine wilt disease by Korea Forest Service. Incidences relating to the forest pest had been frequent and chemical control as well as physical control techniques had been applied to control it. Therefore, there is a need to reduce the damage caused by the pine wilt disease through intensive management such as continuous monitoring, control, and monitoring based on active control as well as management measures. In this study, the UAV-based monitoring method was proposed as an economical way of monitoring the forest pest. The efficiency of the existing method and UAV method had been analyzed, and as a result the study suggested that UAV can be used for forest pest monitoring and indeed improve efficiency. The UAV-based forest pest monitoring method has a cost reduction of about 50% compared with the conventional method and will also help to reduce the area where the survey was omitted.

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.280-288
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• 2021

Understanding the occurrence characteristics of pine wilt disease (PWD) is essential for determining a suitable strategy to minimize the damage caused by PWD. Thus, in this study, we characterized various environmental conditions, including meteorological factors, geographical factors, and artificial factors influencing the occurrence of PWD. The occurrence data of PWD from May 2016 to April 2018 and spatial data of various environmental factors, including natural and anthropogenic factors, were collected. We evaluated the relative contribution of the environmental variables on the number of dead pine trees by PWD. In this study, among the 17 natural and anthropogenic factors, the factors affecting the occurrence of dead trees by PWD were verified. The results showed that altitude and temperature from May to August, among natural factors, and distance to building and forest road among anthropogenic factors were the most influential factors on the occurrence of PWD.

• Natural Product Sciences
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• v.10 no.5
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• pp.207-210
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• 2004

Three chalcones and a stilbenoid have been isolated from the stem bark of Lindera erythrocarpa. They were elucidated as 2'-hydroxy-3',4',5',6'- tetramethoxychalcone, 2',4'-dihydroxy-3',6'-dimethoxy chalcone, 2',4',5',6'- tetrahydroxy-3'-methoxychalcone, and 5,6-dihydroxy-2,3,4-trimethoxystilbene. Chemical structures were elucidated on the basis of MS, $^1H,\;^{13}C$ and 2D-NMR spectroscopic data. This is the first report on the isolation of these compounds from the L. erythrocarpa.

• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.248-253
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• 1989

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.1058-1062
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• 2008

In clinical decision support system(CDSS), unlike rule-based expert method, appropriate data-driven machine learning method can easily provide the information of individual feature(clinical test) for disease classification. However, currently developed methods focus on the improvement of the classification accuracy for diagnosis. With the analysis of feature importance in classification, one may infer the novel clinical test sets which highly differentiate the specific diseases or disease states. In this background, we introduce a novel CDSS that integrate a classifier and feature selection module together. Random forest algorithm is applied for the classifier and the feature importance measure. The system selects the significant clinical tests discriminating the diseases by examining the classification error during backward elimination of the features. The superior performance of random forest algorithm in clinical classification was assessed against artificial neural network and decision tree algorithm by using breast cancer, diabetes and heart disease data in UCI Machine Learning Repository. The test with the same data sets shows that the proposed system can successfully select the significant clinical test set for each disease.

• The Plant Pathology Journal
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• v.25 no.3
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• pp.241-246
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• 2009

Korean pine (Pinus koraiensis Sieb. et Zucc.), a five-needle pine, has recently been suffering pine wilt disease caused by non-native pinewood nematode, Bursaphelenchus xylophilus. Three-year-old Korean pine seedlings were inoculated with 10,000 pathogenic nematodes in a greenhouse to investigate disease development, water content and the density of nematodes in stems. Needle dehydration, xylem drying and pith browning started 20 days after inoculation (DAI). There were significant differences between seedlings inoculated with nematodes and control seedlings in the relative water content of stems and leaves at 20 and 30 DAI. At 60 DAI, all remaining seedlings inoculated with nematodes had died, but control seedlings all remained alive. The average number of nematodes recovered from stems of Korean pine dramatically increased from 10 to 20 DAI, and then decreased at the end of the experiment at 60 days. This study suggests that the relative water content of stems and leaves in current-year branches could be used as a useful physiological indicator for early diagnosis of pine wilt disease.