• KIEAE Journal
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• v.14 no.5
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• pp.49-57
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• 2014

This research is about analysis and evaluation of biodiversity of Suwon's street tree, then understanding the problem of it and finally finding a solution. Because the increasing damage of the street trees by disease and insects, insecticide is applied to prevent further damage. However, this insecticide is found to be cancer genic and causing hygienic threat to civilians. Therefore, by gathering Suwon's internal statistics about Suwon's street tree, the trees are divided into three categories, tall evergreen trees, deciduous trees, shrubs following Frank's 30-20-10 theory(1990). Also, according to species diversity index, the problem of disease and insect is researched in terms of biodiversity, and here we suggests solutions to counter such problems. According to the results, the trees planted in Suwon was found to be 31 families, 43 genus and 58 species. The most used kinds, almost 85% of the whole species, are found to be Rhododendron indicum (L.) Sweet, Buxus koreana Nakai ex Chung & al, Euonymus japonicus Thunb, Ligustrum obtusifolium Siebold & Zucc. Besides these, the rest of 15% of street trees had little variety. Therefore, it is necessary to plant tree variously and equally in terms of biodiversity. If this Frank's 10-20-30 solution is not enough to completely solve coulure problem, then further research will be done on soil properties, and local features for improvement of Suwon street tress.

• Journal of Korea Multimedia Society
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• v.16 no.3
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• pp.269-280
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• 2013

In this paper, we suggested the possibility of using an efficient classifier for the dependency analysis of retinal disease. First, we analyzed the classification performance and the prediction accuracy of GBN (General Bayesian Network), GBN with reduced features by Markov Blanket and TAN (Tree-Augmented Naive Bayesian Network) among the various bayesian networks. And then, for the first time, we applied TAN showing high performance to the dependency analysis of the clinical data of retinal disease. As a result of this analysis, it showed applicability in the diagnosis and the prediction of prognosis of retinal disease.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.139-144
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• 2006

Chestnut trees have been severely damaged by the various cankers in Korea. Field surveys for elucidating the relationships between disease occurrence and environmental factors, i.e., tree age, temperature, rainfall precipitation, direction, degree of slope, chemical properties of soils, and so on, were carried out in the chestnut tree plantations located at Gyeongnam, Jeonnam, Chungnam, and Gyeonggi-Do Province. Totally, one thousand and one hundred thirty seven trees from 36 experiment plots were investigated. Trees infected by at least one of the canker fungi were estimated up to 66%. The most severely infested area was Sunchon in Jeonnam Province with the rate of 80%, while the most lightly infested area was Kongju in Chungnam Province with 39%. Disease occurrence was found to be highly correlated with tree age. The disease occurred most frequently on trees ranged from 7 to 12 years old, while it was relatively low on trees below 5 years old or above 25 years old. Canker positions on the tree formed by the pathogenic fungi were most often at 1.6-2.0m above the ground. Over five hundreds bark samples from the canker area on the tree were collected and the pathogenic fungi were isolated. The most commonly isolated fungus was identified as Cryphonectria parasitica, the chestnut blight fungus.

• Journal of Forest and Environmental Science
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• v.33 no.4
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• pp.342-347
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• 2017

Since the first report of the oak wilt disease at 2004 in Korea, the disease distributed over Korean peninsula and are still giving severe damages. The management of oak wilt disease in Korea has mainly focused on the control of insect vector, Platypus koryoensis. Neverthless the effective method for evaluating the pathogenicity of the pathogen, Raffaelea quercus-mongolicae (Rqm), and for screening chemical or biological agents with strong inhibitory activity against the pathogen, is absolutely necessary, an reliable method is not available so far. This study was conducted to develop the effective method for evaluating the pathogenicity of Rqm in oak trees. The culture suspensions of Rqm were artificially injected to the saplings of Quercus acutissima by using ChemJet tree injector. Three months after treatments, the treated saplings were cut and dipped into 1% fuchsin acid solution. There were significant differences in non-conductive area (%), discoloration area (%) and vertical discoloration length between the pathogen-injected and distilled water-injected control treatments. These results indicated that the pathogen is the causal agent for the dysfunction of water conductive tissue, which will finally result in wilt symptom. Re-isolation of the pathogen and PCR detection using specific primers for the pathogen also confirmed the presence of Rqm in the sapwood chips of the pathogen-injected saplings. These observations would be greatly applied to other related researches for evaluating the pathogenicity of tree wilt pathogens and biocontrol efficacy of the selected antagonistic microorganisms, in case that the wilt symptom is not easily shown by artificial inoculation of the causal agent.

• Mycobiology
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• v.48 no.6
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• pp.484-494
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• 2020

Oak wilt disease caused by Raffaelea quercus-mongolicae has emerged obviously in Korea. We selected antifungal isolates against R. quercus-mongolicae among 368 endophytic fungal isolates from different parts of oak and pine trees. The experiment was conducted in the primary and secondary screenings by dual culture test. The antifungal activity of the selected isolates was assessed in culture filtrate test based on the inhibition rates in mycelial growth, sporulation, and spore germination of oak wilt fungus. Five isolates, E089, E199, E282, E409 and E415, showed strong antifungal activity in culture filtrate test, and their antifungal activity decreased on the culture media supplemented with heated culture filtrate. Higher mycelial growth inhibitions on the unheated media were recorded in E409 (Colletotrichum acutatum), E089 (Daldinia childiae), E415 (Alternaria alternata) and E199 (Daldinia childiae) with the inhibition rates of 79.0%, 70.1%, 68.9% and 64.5%, respectively. These isolates also had the higher sporulation inhibitions on unheated media with the rates of 96.8%, 84.2%, 82.8% and 80.5%, respectively. The spore germination of the oak wilt fungus was completely inhibited by E282 (Nectria balsamea) on both unheated and heated media. These results showed that a higher number of potent antifungal isolates against oak wilt fungus was isolated from the petiole compared to the other parts. This study could contribute to the development of biological control approaches for the management of oak wilt disease caused by R. quercus-mongolicae.

• Journal of Sasang Constitutional Medicine
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• v.13 no.2
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• pp.144-155
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• 2001

By the increasing concern about Sasang Constitution Medicine, its practical use is considered very important in disease prevention and medical treatment. However, the method of constitution classification is depending on the doctor's clinical trials because of the lack of the objective test criteria. This study is trying to improve the objectiveness of diagnosis using a new statistical method, decision tree. Decision tree method-a classification technique in the statistical analysis- was used to analyze the result of QSCCII instead of using discriminant analysis. As a result, 16 among 121 QSCCII questions was selected as important questions and 21 terminal nodes was built to classify the constitution. Using only 16 questions shown in the result of decision tree, we can diagnose and interpret the constitution easily and effectively.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.69.2-70
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• 2003

For the selection and breeding of chestnut varieties resistant to the chestnut blight fungus Cryphonectria parasitica, disease resistance and susceptibility of 28 varieties widely planted and growing in Korea were evaluated by artificial inoculation of a pathogenic fungus. For this experiment, a typical virulent strain (KCPC-19) was selected. Artificial inoculation was conducted into all varieties by using two different materials and methods, i.e., bark and wood tissue sections in the laboratory and living trees in the field. In the bark and wood tissue section method, the size of necrotic area and canker development on chestnut varieties were examined and compared 4 days after inoculation. There were wide variations of chestnut varieties in disease resistance and susceptibility against chestnut blight fungus, but 3 varieties, Daebo！, Ishizuchi, and Sandae, were shown to be relatively resistant to the disease with the necrotic area of 0.95-1.03 cm2, while Arima was the most susceptible with the size of 2.0 cm2. In the living tree inoculation examined 5 weeks after inoculation, 3 varieties, Daebo, Ishizuchi, and Riheiguri, showed the higher resistance, but Tono 2 did the highest susceptibility among tested varieties.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1071-1081
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• 2020

Essential oils (EOs) have been shown to be plant-extracted antimicrobial agents. However, there are limited studies investigating the efficacy of EOs against pathogens. Among them, tea tree oil (TTO) is extracted from Melaleuca alternifolia, which is also used as an antifungal agent. In this study, the effect of TTO was investigated on the suppression of melon powdery mildew caused by Podosphaera xanthii and tomato leaf mold disease caused by Passalora fulva. Both powdery mildew and leaf mold diseases were significantly suppressed by a spray of TTO. Eighty percent of powdery mildew and 81% of leaf mold disease of the control value were suppressed by 0.5% TTO liquid, when sprayed 3 times every 7 days on the melon and tomato leaves. Inhibition of mycelial growth was also greatly affected by different concentrations of TTO against four different fungal pathogens. Ninety-eight percent of Pseudocercospora fuligena, 97% of P. fulva, 95% of Botrytis cinerea, and 94% of Phytophthora infestans mycelial growth were inhibited by 0.2% to 1.0% of TTO contained in plate media, respectively. However, phytotoxicity in plants by the TTO treatments was revealed when melon and tomato leaves were sprayed with a 1% and 2% concentration of TTO, respectively. Therefore, our findings show that TTO has high antifungal effects against various plant pathogens that occur during crop cultivation. We also suggest that when applying TTO to plant leaves, it is necessary to establish an accurate treatment concentration for different crops.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.6
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• pp.86-95
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• 2003

The object of this paper is to correct check the tree situation and quantity around highway. Also, those data utilize in order to establish plan about how to the long and short term landscape construction and maintain program. The result of this study can be summarized as follows; 1. Tree decrease rates for 8 branch offices were Jongbu(5.62%), Gangwon(4.32%), Chungcheong (3.35%), Honam(5.62%), Gyeongbuk(3.06%), Gyeongnam(5.60%), Seorak training center(0.31%), Headquarter(1.54%). Also decrease causes were traffic accidents(1.8%), air po11ution(4.7%), humid damage(0.9%), insect and disease(1.2%), wind and rainfall(3.4%), dry damage(3.5%), cold damage (1.0%), fire(3.1%), damage of the man and anima1(4.1%), remove bad tree(13.1%), bad rooting(9.5%) and etc.(53.7%). 2. Improve methods of tree death problems were regulation management(ferti1ize, irrigation and pesticide work), improvement of draining system, Pull out the weeds, Plant native plants, utilize organic matter fertilize and plant environment trees.

• Korean Journal of Oriental Medicine
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• v.17 no.2
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• pp.121-127
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• 2011

Objectives : In the clinical field, it is important to understand the factors that have effects on a certain disease or symptom. For this, many researchers apply Data Mining method to the clinical data that they have collected. One of the efficient methods for Data Mining is decision tree induction. Many researchers have studied to find the best split criteria of decision tree; however, various split criteria coexist. Methods : In this paper, we applied several split criteria(Information Gain, Gini Index, Chi-Square) to Sasang constitutional clinical information and compared each decision tree in order to find optimal split criteria. Results & Conclusion : We found BMI and body measurement factors are important factors to Sasang constitution by analyzing produced decision trees with different split measures. And the decision tree using information gain had the highest accuracy. However, the decision tree that produced highest accuracy is changed depending on given data. So, researcher have to try to find proper split criteria for given data by understanding attribute of the given data.