• Journal of agriculture & life science
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• v.45 no.5
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• pp.1-8
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• 2011

In this study, 160 tea tree (Camellia sinensis L.) lines were classified by caffeine content using colorimetric methods. Among them, caffeine-rich lines (HR-78, HR-137, HR-82 and HR-123) and poor lines (HP-85, HP-88, HP-19, and HP-131) were selected. To know the difference in morphological and genetic characters between caffeine-rich and poor lines, we used leaf/shoot growth and RAPD methods. Cluster pattern of morphological characters (leaf width, leaf length, leaf area and shoot length) showed that shoot length was longer in caffein-rich lines than in -poor lines. In genetic analysis, amplified DNA bands having various sizes were detected in RAPD analysis where 30 random primers were used. However, the discriminated primer set that distinguish caffein-rich tree line from -poor lines was not found. These results can be used as the basic data to determine the morphological and genetic differences among caffein-rich and -poor lines.

• Journal of Korea Artificial Intelligence Association
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• v.1 no.2
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• pp.1-6
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• 2023

In this paper, we present a new method for classifying malicious URLs to reduce cases of learning difficulties due to unfamiliar and difficult terms related to information protection. This study plans to extract only visually distinguishable features within the URL structure and compare them through map learning algorithms, and to compare the contribution values of the best map learning algorithm methods to extract features that have the most impact on classifying malicious URLs. As research data, Kaggle used data that classified 7,046 malicious URLs and 7.046 normal URLs. As a result of the study, among the three supervised learning algorithms used (Decision Tree, Support Vector Machine, and Logistic Regression), the Decision Tree algorithm showed the best performance with 83% accuracy, 83.1% F1-score and 83.6% Recall values. It was confirmed that the contribution value of https is the highest among whether to use https, sub domain, and prefix and suffix, which can be visually distinguished through the feature contribution of Decision Tree. Although it has been difficult to learn unfamiliar and difficult terms so far, this study will be able to provide an intuitive judgment method without explanation of the terms and prove its usefulness in the field of malicious URL detection.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.389-395
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• 2012

Stored grain insects appear frequently as grains are harvested, stored, and distributed on the market. Producers mostly depend on chemical fumigants to control and repel insect pests, but this application of chemicals may cause side effects for humans and the environment. Safer control approaches, including the use of natural products are required, and in this study, we assessed the control effect of essential oils on stored grain insects. The essential oils of 8 plant species from 6 families were tested for their fumigant toxicity and repellent effects using a Y-tube Olfactometer against Sitophilus zeamais adults. Pennyroyal and tea tree oil respectively exhibited 97% and 63% mortality at $10{\mu}{\ell}L^{-1}$ air concentration in tested fumigant toxicity. Of particular note, pennyroyal oil ($LT_{50}$, hour=3.87) showed higher adulticidal activities than tea tree oil ($LT_{50}$, hour=4.09). When assessing repellent effects, using a Y-tube Olfactometer at $10{\mu}{\ell}$/filter paper concentration, the cedarwood, cinnamon, cypress, patchouli and pennyroyal essential oils showed potent repellent activities against Sitophilus zeamais adults. Cinnamon, cypress and pennyroyal essential oils showed notably high repellent activities of 82.4%, 80.0% and 86.7%, respectively, at $1{\mu}{\ell}$/filter paper concentration.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.2
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• pp.77-84
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• 2014

The purpose of this research is to identify and develop technology protection plans for small and medium-sized enterprises (SMEs) by analyzing past technology leakage patterns which were experienced by SMEs. We identified factors which affect the technology leakage, and analyzed patterns of the influences using a data mining algorithms. A decision tree analysis showed several significant factors which lead to technology leakage, so we conclude that preemptive actions must be put in place for prevention. We expect that this research will contribute to determining the priority of activities necessary to prevent technology leakage accidents in Korean SMEs. We expect that this research will help SMEs to determine the priority of preemptive actions necessary to prevent technology leakage accidents within their respective companies.

• The Plant Pathology Journal
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• v.27 no.1
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• pp.1-7
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• 2011

Colletotrichum panacicola isolates were obtained from anthracnose lesions of Korean ginseng and compared with four Colletotrichum species in morphology, molecular phylogeny and pathogenicity. Based on morphological characteristics, C. panacicola was easily distinguished from Colletotrichum gloeosporioides but not from Colletotrichum higginsianum, Colletotrichum destructivum and Colletotrichum coccodes. A phylogenetic tree generated from ribosomal DNA-internal transcribed spacer sequences revealed that C. panacicola is remarkably distinguished from C. gloeosporioides and C. coccodes but not from C. higginsianum and C. destructivum. However, molecular sequence analysis of three combined genes (actin + elongation factor-$1{\alpha}$ + glutamine synthatase) provided sufficient variability to distinguish C. panacicola from other Colletotrichum species. Pathogencity tests showed that C. panacicola is pathogenic to Korean ginseng but not to other plants. These results suggest that C. panacicola is an independent taxon distin-zguishable from C. gloeosporioides and other morphologically similar Colletotrichum species.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.4
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• pp.51-56
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• 2016

Old-growth and giant tree is a nonrenewable resource with great value. The purpose of this study is to provide scientific and reasonable evaluations for the preservation and management of the old-growth and giant tree. Until now the research of old-growth and giant tree's value evaluation and authoritative index is so insufficient and imperfection. Combining with the particularity of the old-growth and giant tree, this study analyzed the main value factors of the old-growth and giant tree and objectively selected the evaluation indicators. According to the actual situation value appraisal model of the old-growth and giant tree was builded. The main value factors can be divided into economic value, cultural history, growing place, tree state, tree form, tree vigor, protection level, growth environment, tree species, tree canopy, and so on. The evaluate indicators can be selected and the indicators' weight can be calculate using analytic hierarchy process methods(AHP). Based on economic value and indicators' weight, tree's total value can be revealed. After calculation and analysis, Gyeongju Gyerim Zelkova serrata's value evaluation results is 491,503,300 won. The research results of this study can provide scientific basis and reference to the old-growth and giant trees' value appraisal and loss compensation, and arouse people's environmental awareness.

• The Journal of Society for e-Business Studies
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• v.15 no.3
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• pp.85-98
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• 2010

The prevailing infrastructure of ubiquitous computing paradigm on the one hand making significant development for integrating technology in the daily life but on the other hand raising concerns for privacy and confidentiality. This research presents a new privacy-preserving spatio-temporal query processing technique, in which location based services (LBS) can be serviced without revealing specific locations of private users. Existing location cloaking techniques are based on a grid-based structures such as a Quad-tree and a multi-layered grid. Grid-based approaches can suffer a deterioration of the quality in query results since they are based on pre-defined size of grids which cannot be adapted for variations of data distributions. Instead of using a grid, we propose a location-cloaking algorithm which uses the R-tree, a widely adopted spatio-temporal index structure. The proposed algorithm uses the MBRs of leaf nodes as the cloaked locations of users, since each leaf node guarantees having not less than a certain number of objects. Experimental results show the superiority of the proposed method.

• Journal of Environmental Science International
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• v.25 no.5
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• pp.635-644
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• 2016

Birds play a main role in the formation and change of forest structures as they are seed-dispersal agents. This study aims to identify birds consuming fruits and seeds of the tree and their associated fruits and seeds on Jeju Island in the context on the forest restoration in Korea. We conducted field surveys twice a month from 2013 to 2015 at nine study sites located across Jeju Island and collected available photographic and observation records. A total of 50 species of birds consuming fruits and seeds of the tree were identified and birds belonging to Bombycillidae, Pycnonotidae, Zosteropidae, Sturnidae and Fringillidae were confirmed as major birds consuming fruits and seeds of the tree. Gulping was the dominant type of feeding as well as crushing, but relationship between the size of a bird and the number of fruit and seed species used by the bird was not significant. We also documented that 118 fruit and seed species were consumed by birds and that shrubby fruits and seeds were more consumed by birds than those of other plant types. The relative consumption rate of fruits and seeds ranged from 0.02 to 0.44, but five species were the most important fruits and seeds for birds. Our finding suggest that avian frugivorous gulpers will benefit the seed dispersal, especially of five fruiting plants, providing useful baseline data for forest restoration and urban park design.

• The Plant Pathology Journal
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• v.31 no.4
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• pp.379-387
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• 2015

Melon necrotic spot virus (MNSV) was recently identified on watermelon (Citrullus vulgaris) in Korea, displaying as large necrotic spots and vein necrosis on the leaves and stems. The average occurrence of MNSV on watermelon was found to be 30-65% in Hapcheon and Andong City, respectively. Four isolates of the virus (MNSV-HW, MNSV-AW, MNSV-YW, and MNSV-SW) obtained from watermelon plants in different areas were non-pathogenic on ten general indicator plants, including Chenopodium quinoa, while they infected systemically six varieties of Cucurbitaceae. The virus particles purified by 10-40% sucrose density gradient centrifugation had a typical ultraviolet spectrum, with a minimum at 245 nm and a maximum at 260 nm. The morphology of the virus was spherical with a diameter of 28-30 nm. Virus particles were observed scattered throughout the cytoplasm of watermelon cells, but no crystals were detected. An ELISA was conducted using antiserum against MNSV-HW; the optimum concentrations of IgG and conjugated IgG for the assay were $1{\mu}l/ml$ and a 1:8,000-1:10,000 dilutions, respectively. Antiserum against MNSV-HW could capture specifically both MNSV-MN from melon and MNSV-HW from watermelon by IC/RT-PCR, and they were effectively detected with the same specific primer to produce product of 1,172 bp. The dsRNA of MNSV-HW had the same profile (4.5, 1.8, and 1.6 kb) as that of MNSV-MN from melon. The nucleotide sequence of the coat protein of MNSV-HW gave a different phylogenetic tree, having 17.2% difference in nucleotide sequence compared with MNSV isolates from melon.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.419-427
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• 2013

The insecticidal activity of 124 plant essential oils and control efficacy of six experimental spray formulations (SF) containing 0.25, 0.5, 1, 2.5, 5, and 10% of the selected oils was examined against both nymph and adult of the citrus flatid planthopper, Metcalfa pruinosa using direct contact applications (leaf dipping and spray). Reponses varied according to dose (1,000 and 500 mg/L). When exposed at 1,000 mg/L for 24 h using leaf dipping assay, 19 essential oils showed strong mortality (100%) among 124 essential oils screened. At 500 mg/L, 100% mortality was observed in cinnamon technical, cinnamon green leaf, cinnamon #500, cassia tree, citronella java and pennyroyal followed by origanum, thyme white, grapefruit, savory, fennel sweet, aniseed and cinnamon bark showed considerable mortality (93.3-80%) against nymphs of M. pruinosa. The moderate mortality (73.3-60%) was found in thyme red, tagetes, calamus, lemoneucalptus and geranium. Oils applied as SF-10% sprays provided 100 % mortality against adult M. pruinosa. One hundred mortalities were achieved in cinnamon technical at >SF-0.5 formulation, in cinnamon #500, cinnamon green leaf and penny royal at >SF-2.5. To reduce the level of highly toxic synthetic insecticides in the agricultural environment, the active essential oils as potential larvicides could be provided as an alternative to control M. pruinosa populations.