• The Korean Journal of Mycology
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• v.45 no.4
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• pp.259-269
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• 2017

In order to investigate the diversity of yeasts from major rivers (the Daejeoncheon, Gapcheon and Yudeungcheon) located in Daejeon city, we isolated wild yeasts by plating diluents of samples collected during the summer and winter of 2016 onto yeast extract-peptone-dextrose (YPD) medium, then identified them using Basic Local Alignment Search Tool (BLAST) analysis to compare the nucleotide sequences of the PCR amplicons for the D1/D2 domain of 26S rDNA. In total, we isolated 191 yeast strains belonging to 104 species from 148 soil or water samples from the rivers and their junctions. Candida spp. (45 strains) including Candida tropicalis (22 strains) were the most abundantly isolated strains from the Daejeoncheon. Candida spp. (16 strains) including Candida vartiovaarae (8 strains) and Candida spp. (18 strains) such as Candida sake (4 strains) were also the dominant isolates from the Gapcheon and Yudeungcheon, respectively. In conclusion, Candida spp. and Cryptococcus spp. were the most dominant strains, corresponding to 42% and 7% of the 191 yeast strains isolated in this study, respectively.

• The Korean Journal of Mycology
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• v.45 no.2
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• pp.153-159
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• 2017

We isolated 120 strains of wild yeasts from the water and riverside soils of Daejeoncheon and Gapcheon in Daejeon, Korea. We identified Debaryomyces udenii JSF601, Kazachstania telluris JSF602, Trichosporon faecale JSF614, Candida infanticola WJSL0039, Candida palmioleophila WJSL0048, Pichia spartinae WJSL0087, and Trichosporon coprophilum WJSL0093 from Daejeoncheon, and Leucosporidium golubevii WJSL0108 and Ustilentyloma graminis WJSL0118 from Gapcheon, as newly recorded yeast strains in Korea and investigated their microbiological characteristics. All of these previously unrecorded yeasts were oval- or ellipsoidal-shaped with ascospores, except C. infanticola WJSL0039, C. palmioleophila WJSL0048, and D. udenii JSF601. L. golubevii WJSL0108 and U. graminis WJSL0118 grew in vitamin-free medium, and C. infanticola WJSL0039 was halotolerant and grew in 10% NaCl-containing YPD broth. K. telluris JSF602 and P. spartinae WJSL0087 were thermophilic yeasts, which grew at $37^{\circ}C$.

• Korean Journal of Agricultural Science
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• v.38 no.1
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• pp.163-172
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• 2011

To provide the operation rule curve for suppling instream flow to urban stream from reservoir, the Soho reservoir with watershed area of 7.4 $km^2$ and total water storage of 2.58 $Mm^3$ was planned at the headwaters of the Daejeoncheon. Daily streamflow was simulated and using the simulated streamflow and desired instream flow, the operation rule curve by Senga method was drawn and evaluated through reservoir operation. Senga method is derived by accumulating the differences between streamflow and desired instream flow adversely. Water storages were simulated on a daily basis to supply urban instream flow from Soho reservoir, but the amount of supplying instream flow to urban stream was not nearly increased comparing with that of normal operation that does not used the rule curve. Thereafter the new simulation-based operation rule curve was derived and applied to supply instream flow from Soho reservoir. In normal operation, the amount of instream flow was shown to 15,000 $m^3$/d, but it was increased to 27,700 $m^3$/d in withdrawal limited operation using the new derived rule curve, in which the applicability of this rule curve was proved. Also comparing with the flow duration curves at station just before urban Daejeoncheon stream without and with upstream Soho reservoir, the 95th flow was decreased from 1.64 mm/d to 1.51 mm/d, and the 355th flow was increased from 0.17 mm/d to 0.30 mm/d. Monthly streamflows during October to March were increased from 10.6~24.1 mm to 24.1~34.0 mm with the increasing rate of 141~227%.

• Journal of Korean Society on Water Environment
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• v.29 no.4
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• pp.504-513
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• 2013

Water quality trends for major tributaries (66 sites) in the Yeongsan River basin of Korea were examined for 12 parameters based on water quality data collected every month over a period of 12 months. The complex data matrix was treated with multivariate analysis such as PCA, FA and CA. PCA/FA identified four factors, which are responsible for the structure explaining 78.2% of the total variance. The first factor accounting 27.3% of the total variance was correlated with BOD, TN, TP, and TOC, and weighting values were allowed to these parameters for grade classification. CA rendered a dendrogram, where monitoring sites were grouped into 5 clusters. Cluster 2 corresponds to high pollution from domestic wastewater, wastewater treatment and run-off from livestock farms. For grade classification of tributaries, scores to 10 indexes were calculated considering the weighting values to 3 parameters as BOD, TN and TP which were categorized as the first factor after FA. The highest-polluted group included 10 tributaries such as Gwangjucheon, Jangsucheon, Daejeoncheon, Gamjungcheon, Yeongsancheon. The results indicate that grade classification method suggested in this study is useful in reliable classification of tributaries in the study area.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.2
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• pp.28-41
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• 2023

The objective of the study was to develop an Urban Windway Forest Creation Planning Technique for the Improvement of the Urban Environment using the case of Daejeon Metropolitan City. Through a spatial analysis of fine dust and heat waves, a basin zone, in which the concentration was relatively serious, was derived, and an area with the potential of cold air flow was selected as the target area for the windway forest development by analyzing the climate and winds in the relevant zone. Extreme fine dust areas included the areas of the Daejeon Industrial Complex Regeneration Business District in Daedeok-gu and Daedeok Techno Valley in Yuseong-gu. Heat wave areas included the areas of Daedeok industrial Complex in Moksang-dong, the Daejeon Industrial Complex Regeneration Business District in Daehwa-dong, and the high-density residential area in Ojeong-dong. As a result of measuring the wind speeds in Daejeon with an Automatic Weather System, the average wind speeds during the day and night were 0.1 to 1.7 m/s,, respectively. So, a plan of for a windway forest that smoothly induces the movement of cold air formed in outer forests at night is required. The fine dust/heat wave intensive management zones of Daejeon Metropolitan City were Daejeoncheon, Yudeungcheon, Gapcheon-Yudeungcheon, and Gapcheon. The windway forest formation plan case involved the old city center of Daejeon Metropolitan City among the four zones, the Gapcheon-Yudeungcheon area, in which the windway formation effect was presumed to be high. The Gapcheon-Yudeungcheon area is a downtown area that benefits from the cold and fresh air generated on Mt. Gyejok and Mt. Wuseong, which are outer forests. Accordingly, the windway forest was planned to spread the cold air to the city center by connecting the cold air generated in the Seosa-myeon forest of Mt. Gyejok and the Namsa-myeon forest of Mt. Wuseong through Gapcheon, Yudeungcheon, and street forests. After selecting the target area for the wind ventilation forest, a climate map and wind formation function evaluation map were prepared for the area, the status of variation wind profiles (night), the status of fine dust generation, and the surface temperature distribution status were grasped in detail. The wind ventilation forest planning concept and detailed target sites by type were identified through this. In addition, a detailed action plan was established according to the direction of creation and setting of the direction of creation for each type of wind ventilation forest.