• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.161-169
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• 2013

This study was carried out to examine characteristics of physical and chemical current status and problems of Salix spp. communities based on growth characteristics by tree age and height of the tree species in around Namgang Dam reservoir area. Tree density in 4 survey areas was 5,284 trees/ha, but all areas need to control high tree density. Tree crown area in 4 survey areas was 9,786.4 $m^2/ha$ and crown area of Salix spp. was the most dominant among tree species in watershed of the Jinyang lake. Mean soil depth in 4 survey areas was 65.5 cm higher in the sedimental deposit soil (78 cm) than in forest soil (12.5 cm) near the watershed. Soil bulk density was also higher in the sedimental deposit soil than in forest soil because of poor porosity in the sandy sediment. Soil pH was higher in sedimental deposit soil (A, B horizon:pH 6.7) than in forest soil (A horizon:pH 5.3; B horizon:pH 5.2) because of originated from non-point source polution and detergent of domestic sewage. The results suggest that growth of Salix spp. could be poor because of low fertility with low cation exchange capacity in sedimental deposit soil.

• Journal of agriculture & life science
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• v.46 no.6
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• pp.59-65
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• 2012

This study evaluated the baby-leaf growth, leaf red color intensity, and phytochemical compounds, such as total phenols and total flavonoids using domestic Amaranthus accessions, to select promising germplasm for the use of baby-leaf vegetable. The 39 accessions, upper 15% of 262 Amaranthus germplasm collection showing high red color intensity in baby-leaf, measured as Hunter's a value, were primarily selected. The eleven accessions including IT199970, showing stable red color intensity in baby-leaf both in high-temperature and low temperature cultivation, were finally selected as promising germplasm for the use of baby-leaf vegetable Amaranthus. The leaf red color intensities when they were cultivated at low temperature period were generally higher than those at low temperature period, and all the eleven selected germplasm, including four Amaranthus sub-species and five unknown species, showed stable red color expression in baby-leaf. The total phenol and total flavonoid contents were also presented for finally selected germplasm including their baby-leaf fresh weights. These finally selected germplasm could be potentially used as baby-leaf vegetable resources, through fortifying the color balance of salad vegetable.

• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.229-238
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• 2019

Various wood defects occur during tree growing or wood processing. Thus, to use wood practically, it is necessary to objectively assess their quality based on the usage requirement by accurately classifying their defects. However, manual visual grading and species classification may result in differences due to subjective decisions; therefore, computer-vision-based image analysis is required for the objective evaluation of wood quality and the speeding up of wood production. In this study, the SIFT+k-NN and CNN models were used to implement a model that automatically classifies knots and analyze its accuracy. Toward this end, a total of 1,172 knot images in various shapes from five domestic conifers were used for learning and validation. For the SIFT+k-NN model, SIFT technology was used to extract properties from the knot images and k-NN was used for the classification, resulting in the classification with an accuracy of up to 60.53% when k-index was 17. The CNN model comprised 8 convolution layers and 3 hidden layers, and its maximum accuracy was 88.09% after 1205 epoch, which was higher than that of the SIFT+k-NN model. Moreover, if there is a large difference in the number of images by knot types, the SIFT+k-NN tended to show a learning biased toward the knot type with a higher number of images, whereas the CNN model did not show a drastic bias regardless of the difference in the number of images. Therefore, the CNN model showed better performance in knot classification. It is determined that the wood knot classification by the CNN model will show a sufficient accuracy in its practical applicability.

• Journal of Food Hygiene and Safety
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• v.33 no.6
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• pp.488-494
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• 2018

To ensure food-safety of mushrooms from radioactive contamination, edible mushroom samples distributed in Gyeonggi province in Korea were collected according to species and country of origin. A total of 284 mushrooms, belonging to 10 species (Lentinula edodes, Pleurotus ostreatus, Pleurotus eryngii, Agaricus bisporus, Flammulina velutipes, Phellinus linteus, Inonotus Obliquus (Chaga), Auricularia auricula-judae, Ganoderma lucidum and Tricholoma matsutake) were subjected to radioactivity testing. The concentration of artificial radionuclides, 131I, 134Cs, and 137Cs, was analyzed using gamma-ray spectrometry. 131I and 134Cs were not detected more than MDA value from all samples. Among 204 domestic mushrooms, however, 137Cs were detected in 0.21~2.58 Bq/kg from six cases (3 Lentinula edodes, 1 Ganoderma lucidum and 2 Tricholoma matsutake), whereas 137Cs were detected in 0.21~53.79 Bq/kg from 38 cases (22 Inonotus Obliquus(Chaga), 14 Phellinus linteus, 1 Lentinula edodes and 1 Tricholoma matsutake) among 80 imported mushrooms. In addition, average concentration of 137Cs in 10 Chaga mushroom-processed products was more than twice as much as dried Chaga mushroom, and maximum concentration was 123.79 Bq/kg. Results suggest that radioactivity monitoring system for imported mushrooms and mushroom-processed products should be continuously intensified to secure food-safety in Korea.

• Journal of Life Science
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• v.29 no.2
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• pp.248-255
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• 2019

This research confirmed the diversity and characterization of gut microorganisms isolated from the intestinal organs of Muraenesox cinereus, collected on the Samcheonpo Coast and Seocheon Coast in South Korea. To isolate strains, Marine agar medium was basically used and cultivated at $37^{\circ}C$ and pH7 for several days aerobically. After single colony isolation, totally 49 pure single-colonies were isolated and phylogenetic analysis was carried out based on the result of 16S rRNA gene DNA sequencing, indicating that isolated strains were divided into 3 phyla, 13 families, 15 genera, 34 species and 49 strains. Proteobacteria phylum, the main phyletic group, comprised 83.7% with 8 families, 8 genera and 26 species of Aeromonadaceae, Pseudoalteromonadaceae, Shewanellaceae, Enterobacteriaceae, Morganellaceae, Moraxellaceae, Pseudomonadaceae, and Vibrionaceae. To confirm whether isolated strain can produce industrially useful enzyme or not, amylase, lipase, and protease enzyme assays were performed individually, showing that 39 strains possessed at least one enzyme activity. Especially the Aeromonas sp. strains showed all enzyme activity tested. This result indicated that isolated strains have shown the possibility of the industrial application. Therefore, this study has contributed for securing domestic genetic resources and the expansion of scientific knowledge of the gut microbial community in Muraenesox cinereus of South Korea.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.411-416
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• 2020

Whitefly populations found in heated tomato greenhouses were monitored across three locations in Korea (Nonsan and Buyeo, Chungnam Province; Iksan, Jeonbuk Province) from November to May during the 2015 -2018 growing seasons. From May to October, surveys were conducted in Jangsu (Jeonbuk Province), where retarding cultivation was performed. Whitefly populations were classified and quantified by location and year. The dominant species were Trialeurodes vaporariorum (Westwood) and Bemisia tabaci (Gennadius). The species populations were mixed, but the frequency of occurrece of B. tabaci was higher than that of T. vaporariorum. Although whitefly populations started to increase in late March, they sharply increased in May and the highest population density was observed at the end of the harvest season. Therefore, the management of greenhouse tomato whiteflies through monitoring should begin in early March. In the case of retarding cultivation, the management of whitefly populations should be implemented in June, before the density of whitefly populations increases.

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.387-397
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• 2021

This study aims to present reference data necessary for developing evaluation indicators to analyze the actual resilience of purchased land by investigating the factors that affect the restoration of the purchased land in the riparian zone and quantitatively calculating its importance. The main results are as follows. Firstly, this study identified 34 potential resilience factors through a literature review encompassing domestic and overseas studies and derived seven ecological responsiveness factors, six physical responsiveness factors, and four managerial responsiveness factors through the Delphi survey. Secondly, reliability analysis and Analytic Hierarchy Process (AHP) analysis derived the following important factors: structural stability of the vegetation restored in the purchased land, species diversity of wildlife, structural stability of wildlife, the size of restored wetland after purchase, number of plant species, and the land cover status adjacent to the purchased land. The study results are expected to be helpful information for ecological restoration and management plans reflecting reinforcing factors for resilience at each stage of land purchase, restoration, and management.

• Journal of Marine Life Science
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• v.4 no.2
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• pp.96-105
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• 2019

The mugilidae fishes are common euryhaline species that live in coastal marine waters to freshwater areas. The taxonomy and nomenclature of the mugilidae fishes still remain unresolved because of their morphological similarities. Among the mugilidae fishes, most commonly consumed in Korea, are grey mullet (Mugil cephalus) and red lip mullet (Chelon haematocheilus). It is generally called 'mullet' without distinguishing between two mullets. Therefore, the aim of this study is to examine the scientific names and common names of mullet species used in Korea from the domestic journals and Korean old documents. The scientific name of grey mullet is M. cephalus, but that of redlip mullet is C. haematocheilus. But the genus of redlip mullet is still mixed with Chelon, Mugil, and Liza. The standard name of two mullet is not distinguished in the Korean dictionary, but they were clearly distinguished in the Japanese, English, and Chinese dictionaries. In the ancient Korean references, the mullet was called 'Chieo' or 'Sueo'. In most of the old literature, the distinction between grey mullet and redlip mullet is not clear. However, in Jasaneobo, it was written separately from grey mullet and redlip mullet, and attaching "ga" was different from now. The Korean standard name of redlip mullet is 'gasungeo', however, the fishermen in Jeollado and Gyoungsangdo call it 'chamsungeo'. Considering the negative perception of 'ga' character, it is proposed to change 'cham(眞)' instead of 'ga(假)' to improve economic value of red lip mullet.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.51-57
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• 2002

Antimicrobial and antioxidative activites on heartwood extractives of domestic species were investigated to develop a natural fungicide or preservative. One steroid, stilbene derivatives and two flavonoids were isolated from heartwood of Robinia pseudo-acacia which has been selected due to its high antioxidative activity among the tested species. The structures were determinded as: 3-𝛽-stigmast-5-en-3-ol(daucosterol), 3,3'4,5-tetrahydroxystilbene, 3,3'4'5,7-pentahydroxyflavone(robinetin) and 3,3'4'7-tetrahydroxyflavanone(fustin) respectively on the basis of spectroscopic data and chemical correlations. According to the results of free radical scavenging activity, 3,3'4'5,7-pentahydroxyflavone was evaluated as the highest antioxidative compound among the four compounds and showed higher radical scavenging activity than those of 𝛼-tocopherol and butylated hydroxytoluene(BHT), one of the strongest synthetic antioxidants. 3,3'4'5-Tetrahydroxystilbene and 3,3'4'7-tetrahydroxyflavanone showed higher antioxidative activities than that of 𝛼-tocopherol. However, 3-𝛽-stigmast-5-en-3-ol did not show free radical scavenging activity. In this regard, it could inferred that high antioxidative activity of extractives of R. pseudo-acacia was derived from 3,3'4'5'7-pentahydroxyflavone, 3,3'4'5-tetrahydroxystilbene and 3,3'4'7-tetrahydroxyflavanone.

• Korean Journal of Environmental Biology
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• v.41 no.2
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• pp.101-108
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• 2023

Recently, in relation to climate change, many studies have been conducted to predict the potential habitat area and distribution range of tilapia and the suitability of habitat for each species. Most tilapia are tropical fish that cannot survive at water temperatures below 10 to 12℃, although some tilapia can survive at 6 to 8℃. This study predicted habitable areas and the possibility of spreading of habitat ranges of tilapia (Oreochromis niloticus and Oreochromis aureus) known to inhabit domestic streams. Due to climate change, it was found that habitats in the Geum River, Mangyeong River, Dongjin River, Seomjin River, Taehwa River, Hyeongsan River, and the flowing in East Sea were possible by 2050. In addition, it was confirmed that tilapia could inhabit the preferred lentic ecosystem such as Tamjin Lake, Naju Lake, Juam Lake, Sangsa Lake, Jinyang Lake, Junam Reservoir, and Hoedong Reservoir. In particular, in the case of tilapia, which lives in tributaries of the Geumho River, Dalseo Stream, and the Nakdong River, its range of habitat is expected to expand to the middle and lower of the Nakdong River system. Therefore, it is judged that it is necessary to prepare physical and institutional management measures to prevent the spread of the local population where tilapia currently inhabits and to prevent introduction to new habitats.