• Journal of Korea Multimedia Society
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• v.24 no.6
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• pp.745-752
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• 2021

In this paper, we propose a system that recognizes weed images using a classifier based on ResNeXt model. On the server of the proposed system, the ResNeXt model extracts the fine features of the weed images sent from the user and classifies it as one of the most similar weeds out of 21 species. And the classification result is delivered to the client and displayed on the smartphone screen through the application. The experimental results show that the proposed weed recognition system based on ResNeXt model is superior to existing methods and can be effectively applied in the real-world agriculture field.

• Korean Journal of Environment and Ecology
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• v.22 no.2
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• pp.83-97
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• 2008

This study was carried out to investigate the actual vegetation and Degree of Green Naturality(DGN) and distribution of exotic plants replanted in Bukhansan National Park. The actual vegetation of the surveyed site was classified into eight plant communities and crop land, etc. Substitutional forest were classified into five plant communities; Quercus mongolica community, Q. mongolica-Pinus densiflora community, Deciduous broadleaf forest, etc. Reforested lands were classified into three forest types: P. koraiensis forest, Robinia pseudoacacia forest, P. rigida forest, etc. The area of DGN 8 consisted of 92.80% in Bukhansan National Park. The replanted plants in Bukhansan National Park was enlisted as 212 taxa, 71 families. The indigenous native among the replanted species were enlisted as 67 taxa(31.6%), 37 families. The exotic plants were enlisted as 145 taxa(68.4%), 58 families. The exotic plants needs to management that for recovery of natural environment, improvement about maintenance of multiplicity and a site of scenery about natural plants in Bukhansan National Park.

• Weed & Turfgrass Science
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• v.5 no.3
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• pp.126-135
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• 2016

The surveys of weed species in pastures were conducted in Jeju Island, Pyeongchang Gangwon, and Seosan Chungnam throughout 2013, 2014, and 2015 in order to understand the current status of the weed flora in Korean pastures and to utilize the survey data for basic measure of them. From the surveys, 275 species of 52 families including 83 exotic species were identified and classified into 77 species of annuals, 55 species of biennials and 143 species of perennials. Looking regionally, 207 species of 49 families, 62 species of 14 families, and 136 species of 36 families were occurred in Jeju, Pyeongchang and Seosan, respectively. Based on the importance values, the most dominant species was Rumex obtusifolius followed by Artemisia princeps, Trifolium repens, Digitaria ciliaris, Rumex acetosella etc. in order. The dominance of exotic species was the highest in Rumex obtusifolius followed by Trifolium repens, Rumex acetosella, Erigeron annuus etc. According to the surveys of past and present a pasture weed community has been changed, i.e., Erigeron annuus, Artemisia princeps, and Potentilla fragarioides var. major were dominant in 1990 and Artemisia princeps, Trifolium repens and Rumex acetosella were dominant in 2004. On the other hand, the dominant species at the pastures were changed into Rumex obtusifolius, Artemisia princeps, and Trifolium repens in 2015.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.103-115
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• 2013

The purpose of this study was to analyze fish fauna and species compositions along with trophic guilds, tolerance indicators, and fish community conditions before weir construction (BWC) and after weir construction (AWC) in the Yeongsan River watershed. Total 45 and 44 fish species were sampled in BWC and AWC, respectively without any distinct differences through weir constructions. Fish fauna analysis revealed that the dominant species was the same, Zacco platypus with 24.3% and 20.8% in BWC and AWC, respectively. However, the subdominant species were Carassius auratus with 8.9% in BWC but Opsarichthys uncirostris amurensis with 20.3%, almost identical that of the dominant species AWC. This phenomenon showed the distinct modification of species composition in the watershed. We sampled the $1^{st}$ class endangered species, Liobagrus obesus in tributary stream as previously reported. Also Culter brevicauda was sampled in the mainstream of Yeongsan River watershed and this was the first sampled record in this watershed. One of the most important features were an increase of exotic species, such as Micropterus salmoides and Lepomis macrochirus, with 3.2% BWC vs. 10.2% AWC as well as the increase in tolerant species with 49.2% BWC vs. 73.7% AWC, indicating ecological degradation through weir construction. Overall, our results indicated that fish fauna and composition analyses showed distinct ecological degradations related to increases of exotic and tolerant species AWC. Further long-term studies of fish monitoring should be conducted in the future to configure existent status of river conditions and to provide key information in order to conserve the healthy ecosystem.

• Korean Journal of Ecology and Environment
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• v.54 no.1
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• pp.1-11
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• 2021

Fish community characteristics was investigated in Namyang Lake and tributaries in Han River basin, Korea from April to October 2015. During the period, there were 5,672 individuals of 20 species appeared from tributaries (St. 1~St. 6) and dominant species were Pseudorasbora parva (33.5%). Also 5,672 individuals of 20 species appeared in Namyang Lake (St. 7~St. 9) and dominant species were Carassius auratus (32.2%). There were 5 species of endemic species with Rhodeus uyekii, Acanthorhodeus gracilis, Squalidus japonicus coreanus, Abbottina springeri and Odontobutis interrupta from Namyang Lake watershed. The frequency of endemic species were higher tributaries (18.5%) than Namyang Lake (15%). Exotic species were 3 species with Carassius cuvieri, Lepomis macrochirus, and Micropterus salmoides. there were appeared more frequently Namyang Lake (15.0%) than tributaries(7.4%).

• Journal of Forest and Environmental Science
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• v.28 no.2
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• pp.75-83
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• 2012

An explanatory survey was conducted to assess preference and consumption pattern of horticultural species, their sources, location-wise planting preferences and diversity of these species in the rural homestead forest of the offshore island of Bangladesh. Assessment was done through multistage random sampling. Based on homestead size respondents were categorized into small (<0.05 ha), medium (0.05-0.25 ha) and large (>0.25 ha) and twenty from each category were selected randomly for the study. The study revealed that most of the farmer (75.5%) preferred to plant fruit tree species for future plantation followed by timber species (62.2%). But fruit-bearing plants were being gradually replaced by some exotic timber species such as Swietenia mahagoni, Acacia auriculiformis, Tectona grandis, Eucalyptus spp., etc. Diversity and abundance of fruit species was found higher in almost all homestead. A total of 41 horticultural species were identified and seven horticultural species among them were recognized as the most preferred ones in the study area. Consumption pattern was chiefly to meet the nutritional demand and to gain a quick monetary benefit. Average annual income from horticultural species was 7,183.33 Taka (US$102).

• Journal of the Korea Furniture Society
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• v.20 no.1
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• pp.52-60
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• 2009

Joyangru, which is located in Woodo mountain in Chuncheon, Korea, was a gate tower of Monsogak. There are little historical records about Joyangru except of the 20th-century records. To study about Joyangru history, a dendrochronological analysis was conducted. We identified also the species of woods, We took 87 samples of wood elements for the species analysis and 13 samples for the dendrochronological analysis. We found 78 hard pines(Diploxylon), 4 Douglass-fir, 3 exotic hard pines(Pinus ponderosa type) and 1 Shorea sp.(Dipterocarpaceae). In the dendrochronological analysis, 2 floor flames were dated in 1887 (with complete sapwood) and 2 beams in 1884. We concluded that Joyangru was reconstructed just after 1888, most likely in 1890 together with Monsogak.

• Journal of Environmental Science International
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• v.22 no.12
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• pp.1611-1614
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• 2013

Corythucha marmorata Uhler was newly recorded in Korea as a invasive species at Pohang-si, Gyeongsangbuk-do, Korea in 2011 and at Changwon-si, Gyeongsangnam-do, Korea in 2012. Adults of this species show reticular forewings with a lot of transparent membranes and also show pterigoid process of paranotum with strong processes. This invasive species was originated from North America, and then intruded into Europe and Japan. This species is presumed became an epidemic horticultural pest at present and it is injuring almost of Asteraceae leaves. It was presumed that the invasion of Corythucha marmorata into Korea was prior to September of 2011.

• Journal of Ecology and Environment
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• v.30 no.1
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• pp.39-47
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• 2007

The relationships between the cover of herbaceous species and 15 soil chemical properties (organic carbon contents, total N, available P, exchangeable K, Na, Ca and Mg, HCl-extractable Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in nine poorly controlled waste landfill sites in Korea were examined by correlation analysis and multiple regression equations. Species showed different patterns of correlation between their cover values and soil chemical properties. The cover of Ambrosia artemisiifolia var. elatior, Aster subulatus var. sandwicensis and Erechtites hieracifolia were negatively correlated with the contents of Fe, Mn and Ni within landfill soils. Total cover of all species in quadrats was positively correlated with the contents of Cd and negatively correlated with the contents of Mn and Fe from stepwise regression analysis with 15 soil properties. Canonical correspondence analysis demonstrated that the distribution of native and exotic plants on poorly controlled landfills was significantly influenced by the contents of Na and Ca in soils, respectively.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.301-310
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• 2008

This study was to analyze characteristics of fish compositions and longitudinal distribution, based on trophic and tolerance guild at 22 sampling sites of Yeongsan River watershed during 2003$\sim$2006, and also to compare before and after the estuary dam construction. The collected fishes, based on catch per unit effort (CPUE), were 44 species in the watershed and dominant fishes were Zacco platypus, Acheilognathus macropeterus, Zacco temminckii and Carassius auratus. According to comparative analysis of fish in the non polluted sites (NPS) vs. polluted sites (PS), the number of species and individuals was lower by 70% in the PS than the NPS, indicating ecological degradations by chemical pollutions or/and habitat modifications. The relative abundance of sensitive and insectivore species decreased as the stream order increases, while tolerant and omnivore species increased with the stream order. In this survey, largemouth bass (Micropterus salmoides), which is a top-carnivore and exotic species, may influence trophic guild system throughout active predations on endemic species, resulting in modifications of ecological functions. The construction of estuary dam on Yeongsan River in 1981 resulted in wider lacustrine zone and desalinated through limitation of seawater input. These physical changes have caused increases of lentic dwelling species and limited fish migrations (i.e., eel). Overall, fish fauna and composition analyses showed that the number of species and individuals in this water body may be reduced due to inputs of pollutants from the watershed, habitat modifications, and increases of exotic species (largemouth bass). For these reasons, effective lake management strategies are required for the ecosystem conservation.