• Journal of Conservation Science
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• v.29 no.2
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• pp.171-185
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• 2013

The purpose of this study were to interpret making characteristics and clay sources for Proto-Three Kingdoms period potteries which were excavated from Bakjimeure site in Tangjeong, Asan, Korea, on the basis of shape types. The pottery samples of the studied included deep bowl pottery, cylinder shaped pottery, duck shaped pottery and rounded based jar with short neck. And the last jar was dominant among them. This is supported in nearby Yongduri Jinter site, Galmaeri site and Baekseokdong site. They vary in terms of color of clay, absorption ratio and mineral classification. Based on the fact that their absorption ratio range was 4.50 to 25.19% and firing temperature range was 850 to $1,150^{\circ}C$, they were thought to be widely used. The equivalence of cylinder shaped pottery, duck shaped pottery and deep bowl pottery was high in terms of material characteristics and their firing temperature range was 850 to $950^{\circ}C$. However, the deep bowl pottery, compared to other pottery shapes, contained great amount of coarse grained quartz and feldspar, and was different from others in terms of function. For soil sample collected from relative plains (area 3) in the southernmost part of the site, their mineralogical and geochemical characteristics were the most similar to those of the potteries excavated from the Bakjimeure site and even most of the potteries collected from different sites.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.36-42
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• 2015

This study was conducted from 2013 to 2014 to explore the feasibility of the cultivation of warm-season grass as an annual Korean forage crop, while concurrently evaluating the characteristics and forage production of warm-season grass in Korea. The experimental design was a randomized block design (RBD) with three replications. Five bermudagrass [Cynodon dactylon (L.) Pers.] cultivars, two teffgrass (Paspalum notatum Flugge) cultivars, and a Kleingrass [Panicum coloratum L.] cultivar were compared for forage production and quality in the middle region of Korea. After seeding, the numbers of days until seedling emergence for bermudagrass and kleingrass were observed at approximately day 11 and day 12, respectively. The heading dates of teffgrass and kleingrass were on July 12 and July 26, respectively. The dry matter (DM) yield of bermudagrass Tifton 85 was usually greater than the other entries. The crude protein content (CPC) and total digestibility nutrient (TDN) for the teffgrass cultivars were usually greater than the other entries at all study sites. The acid detergent fiber (ADF) and in vitro DM digestibility (IVDMD) were similar across all cultivars.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.288-291
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• 2012

Korean oak wilt disease caused by Raffaelea quercus-mongolicae is vectored by the ambrosia beetle Platypus koryoensis. To prevent the spread of the disease, the beetle infested oak tree had been cut into logs, covered with plastic vinyl, fumigated with a pesticide, and stored for three years on the site where the tree was cut. This study was carried out to get information on the fungi colonizing the fumigated oak wood. Wood disk samples collected from the fumigated oak logs at two locations in the Taejo Mountain, Cheonan city, were used for fungal isolation. A total of 99 filamentous fungal isolates were obtained from the wood disk samples. Hypocrea spp., Trichoderma spp. and Penicillium spp. were identified based on morphological characteristics and nucleotide sequence analysis of translation elongation factor 1-alpha gene and ITS rDNA region. Trichoderma was the major fungal group. R. quercus-mongolicae, and P. koryoensis were not detected from the fumigated oak wood. Our work provided evidence that after three years of storage, the fumigated oak wilt-diseased logs should be no longer harmful source of oak wilt disease transmission.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.4
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• pp.228-233
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• 2007

Pear psylla, Caccopsylla pyricola (Homoptera: Psyllidae), is a serious insect pest in pear orchards. C. pyricola overwinters as adults under rough bark scales of pear trees. When the weather warms up in the spring, the overwintered adults become active, climb up to the tree branches, and inhabit on fruit twigs to lay eggs. This study was conducted to develop a forecasting model for the onset of upward-movement of overwintered C. pyricola adults to control them by timely spraying of petroleum oil. The adult population densities were observed under rough barks (B) and on fruit twigs (T) of pear trees. Relative upward-movement rates (R) were calculated as T/(B+T). Low threshold temperatures for the activation of overwintered C. pyricola adults were selected arbitrarily from 5 to $9^{\circ}C$ at a $1^{\circ}C$ interval. Then, the days (D) when daily maximum air temperatures were above each low threshold temperature were counted from 1 February until to the dates with R $\geq$ 0.8. The same methods were applied for the prediction of the first observation of eggs. The variation of coefficients (CV) for the mean Des were lowest with the low threshold temperature of $6^{\circ}C$. At this selected threshold temperature, the upward movement of C. pyricola adults occurred with 12 D and they started laying eggs with 25 D. In the field validation, the model outputs with the $6^{\circ}C$ threshold temperature reasonably well explained the observed data in Suwon and Cheonan in 2002. Practical usages of the model were also discussed.

• Journal of Korea Water Resources Association
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• v.35 no.2
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• pp.149-159
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• 2002

The monthly water quality data measured at 19 stations located in the Sapkyo reservoir watershed were clustered into 2 to 7 clusters and factor analysis was conducted to characterize the water quality, using the information obtained from cluster analysis. The result of cluster analysis shows that Sapkyo reservoir and each stream (Sapkyo stream, Muhan stream and Kokkyo stream) in Sapkyo reservoir watershed hove their own water quality characteristics. The result of water quality analysis indicates that the concentration of suspended solids from Sapkyo reservoir is much higher than those of other streams, and which is probably because of increment of phytoplankton biomass with rich nutrient flowing Into Sapkyo reservoir from the upper stream of watershed. Furthermore, the concentrations of biochemical oxygen demand and chemical oxygen demand were 3.5 to 4.8 times and 1.7 to 2.5 times those of other streams, respectively. The overall water quality of Sapkyo reservoir watershed was considered to exceed eutrophic condition. Based on factor analysis, the water quality characteristics of Sapkyo stream and Muhan stream were closely related with farm land and residence. The water quality of Kokkyo stream was influenced by superabundant organic matter flowing from Chonan city and district wastewater treatment plant located in the upper stream of Kokkyo stream. The water quality factor influencing Sapkyo reservoir was closely related with water quality factors of other three streams.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.293-300
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• 2012

This experiment was carried out to compare the agronomic characteristics, forage yield and quality of sorghum ${\times}$ sudangrass hybrid at two locations (Sungju and Cheonan) in 2009. The experiment was a randomized complete block design with three replications. The eight recommended hybrids used in this experiment were 'Sordan 79', 'SX17', 'Honey chew', 'Honey grazer', 'G7', 'Jumbo', 'Green star' and 'GT56' hybrids. The heading of four hybrids were headed at both region, Sungju and Cheonan. There are no big differences in general agronomic characteristics among hybrids, but brix scale of heading and BMR (brown mid rib) types were higher than those of other hybrids. Dry matter (DM) and plant height of heading type hybrids were higher than those of headless types. The fresh, DM and TDN (total digestible nutrients) yields of heading type hybrids were also higher than those of headless types, and BMR types were lower than others. The crude protein and crude ash contents of headless hybrids were higher than those of heading hybrids, while its non-fiber carbohydrate (NFC) content showed the opposite results. The acid detergent fiber (ADF) and NFC contents of BMR types were lower than others. The results of this experiment indicates that heading hybrids were more higher than headless hybrids in the agronomics and forage yield of sorghum ${\times}$ sudangrass. However heading types were lower headless types in quality of sorghum ${\times}$ sudangrass. And BMR hybrids were also high quality of sorghum ${\times}$ sudangrass hybrid because of higher brix content and lower ADF content among tested hybrids.

• Journal of Wetlands Research
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• v.20 no.1
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• pp.54-62
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• 2018

Nutrients generated from various land uses lead to eutrophication during the influx of water, and it is necessary to apply the LID techniques to reduce nutrients from nonpoint sources in order to mitigate the occurrence of the algal bloom. This study was carried out to derive the design factors of hybrid artificial wetland (HCW) to increase the removal efficiency of nutrients. HCW system was constructed in the year 2010 for the treatment of rainfall runoffs from parking lots and roads composed of 100% impervious floors in the Cheonan campus of Kongju University. The average nutrients removal efficiency of TN and TP was 74% and 72%, respectively. Both TN and TP removal efficiencies were higher than those of free surface wetlands and subsurface flow wetlands due to activated physical and ecological mechanisms. The critical design parameters for the efficient nutrients removal in the artificial wetlands were the ratio of the surface area to the catchment area (SA/CA), land use, the rainfall runoff, and the rainfall intensity. The optimal carbon to nitrogen (C/N) ratio was estimated at 5: 1 to 10.3: 1. The results of this study can be applied to the efficient design of hybrid artificial wetlands to treat nutrients in urban runoff with high efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.536-543
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• 2017

This study developed a new methodology to evaluate the carbon storage using a Mobile Mapping System according to the life cycle of street trees. The system for calculating the carbon storage of a roadside tree using the MMS developed in this study consisted of a database, memory, processor, user interface, and communication module. The carbon storage was calculated for 261 trees in the Cheonan-Asan New Town (distance: 2.1 km, area: $283,698m^2$). The average biomass and carbon storage of Metasequoia glyptostroboides were highest at 34.5 kg and 17.3 kg C and Chionanthus retusa were lowest at 19.5 kg and 9.8 kg C, respectively. The total biomass and total carbon storage of Ginkgo biloba were highest at 5028.8 kg and 17.3 kg C and Chionanthus retusa were lowest at 780.7 kg and 390.3 kg C, respectively. Based on the roadside tree database, the amount of carbon storage in a given area was converted to Google format and visualized in 3D by GIS analysis.

• FLOWER RESEARCH JOURNAL
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• v.18 no.2
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• pp.98-109
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• 2010

78 Korean native plants, which have not been used in general, were selected to be used as outdoor pot plants for three seasons, from spring to autumn. Plants, which were explored in about 30 places of Korea from 2007 to 2009, were transplanted to or sown in white plastic general pots ($27.5cm({\Phi}){\times}27.5cm(H)$) and hanging pots($28cm({\Phi}){\times}13cm(H)$) and grown in the garden of 36''56' latitude(N) and 127''09' longitude(E). 38 species(13 families and 29 genus) were suitable for outdoor general pots, and 46 species(28 families and 43 genus) for outdoor hanging pots. Among 38 plants for outdoor general pots, the principal species, which were easy to grow and have not been used in general, were 16 species, Metaplexis japonica in Asclepiadaceae, Phyteuma japonicum in Campanulaceae, Artemisia capillaris, Artemisia princeps, and Artemisia selengensis in Compositae, Carex humilis in Cyperaceae, Pennisetum alopecuroides, and Setaria viridis in Gramineae, Agastache rugosa, Glechoma hederacea, Elsholtzia splendens, Isodon inflexus, and Mosla punctulata in Labiatae, Vicia villosa in Leguminosae, Piper kadzura in Piperaceae, and Rosa multiflora var. multiflora in Rosaceae. Among 46 plants for outdoor hanging pots, the principal species, which were easy to grow and have not been used in general, were 17 species, Metaplexis japonica in Asclepiadaceae, Ixeris stonlonifera in Compositae, Calystegia japonica and Quamoclit angulata in Convolvulaceae, Dioscorea batatas in Dioscoreaceae, Glechoma hederacea and Thymus quinquecostatus in Labiatae, Trifolium lupinaster for. alpinus and Vicia villosa in Leguminosae, Menispermum dauricum in Menispermaceae, Piper kadzura in Piperaceae, Clematis mandshurica for. lancifolia in Ranunculoideae, Rosa multiflora var. multiflora and Potentilla fragarioides var. major in Rosaceae, Paederia scandens and Rubia akane in Rubiaceae, and Parthenocissus tricuspidata in Vitaceae.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.476-481
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• 2007

There was no difference between eco-friendly and conventional cultivated soils in the chemical properties. But $Av.P_2O_5$ contents in the eco-friendly cultivated soils were slightly higher than that of conventional cultivated soils. In the conventional cultivated soils, the coefficient of correlation between spore density and soil chemical properties such as pH, EC, OM, $Av.P_2O_5$, K${\surd}$(Ca+Mg) and CEC was $-0.48^*$, -0.05, $0.48^*$, -0.12, -0.13, 0.31 respectively. But, in the eco-friendly cultivated soils was $-0.68^*$, $0.69^*$, $0.96^{**}$, $0.75^*$, $0.63^*$, $0.92^{**}$ respectively. The spore density was 140 spores $30g^{-1}$ in the eco-friendly cultivated soils and 60 spores $30g^{-1}$ in the conventional cultivated soils. Infection ratio of intercellular hypha was higher than that of arbuscular and vesicular among the fungi structures within the root. Suncheon and Cheonan as eco-friendly cultivated soil were higher than GimJe and NamWon in infection ratio.