• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.295-303
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• 2006

The pulp yield was improved by about 4.5-5% when polysulfide (PS) and anthraquinone (AQ) were added to the kraft cooking liquor (white liquor). The exchange of the black liquor with fresh white liquor further increased the yield. The highest pulp yield was obtained when the PS cooking liquor containing 70% of total active alkali (AA) and 100% of AQ was used from the beginning of the reaction and the black liquor was exchanged with fresh white liquor containing the residual 30% of AA just after temperature reached $135^{\circ}C$. There was a good correlation between kraft pulp yields of a hardwood species and the ratios of the amount of xylose to glucose (X/G ratio), liberated by an acid hydrolysis of the pulps. However, the correlation was dependent on raw material wood species. Therefore, it is required in advance to establish a correlation between the yields and X/G ratios for raw material wood species of a target pulp in order to estimate pulp yield using X/G ratio. The X/G ratios of relatively high yield pulps showed higher values than those expected from the correlation. In a mill trial, the superiority of the PS-AQ isothermal cooking (ITC) process over the kraft ITC process was confirmed by examining X/G ratio of pulps obtained. The pulp yield in the PS-AQ ITC process was estimated at about 57.0%. This yield is very high, which indicates that reaction conditions of the PS-AQ ITC process are optimal.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.3
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• pp.284-292
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• 2012

Species composition and abundance of larval fishes in the coastal waters off Gori in the southeastern Korea were investigated from January to December in 2006. During the study period, 32 larvae species belonging to 20 families were collected. The dominant species were Engraulis japonicius, Hexagrammos agrammus, Sillago japonicus, Acropoma japonicum, Apogon lineatus, and Konosirus punctatus. These six species accounted for 87.0% of the total number of individuals collected. The number of species, number of individuals, and species diversity indices fluctuated by season. The peak numbers of species and individuals occurred in July and May, respectively. Correlation analysis showed that monthly variations in water temperature and salinity could act as an indicators of seasonal variations in the larval fish community structure and abundance of the dominant species; in particular, the abundance of S. japonicus, A. japonicum, and A. lineatus were significantly corrected with the water temperature.

• 한국석유지질학회:학술대회논문집
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• autumn
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• pp.50-67
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• 1999

Biostratigraphic and paleoenvironmental analyses are carried out on cutting samples from the Dolgorae wells drilled in the Ulleung basin. The clayey, silty, and sandy sediments of the wells yield various microfossil assemblages of relatively good preservation, among which five fossil groups are reported; a total of 97 foraminiferal species of 66 genera, 19 nannofossil species of 12 genera, 86 ostracod species of 41 genera, 107 diatom species of 44 genera, and 124 dinoflagellate cysts species of 45 genera. Based on microfossils the geologic ages of the Dolgorae wells are dated to be from late Early Miocene to Early Pleistocene. Several biohorizons are defined in Neogene successions by the LOD (Last Ocurrence Datum) and FOD (First Ocurrence Datum) of marker species including G. truncatulinoides (LOD: 1.9 Ma) of foraminifera; C. macintyeri (LOD: 1.64-1.60), G. oceanica (FOD: 1.65 Ma), G. caribbeanica (1.72 Ma), D. brouweri (LOD: 2 Ma), R. pseudoumbilica (LOD: 3.66 Ma), P. lacunosa (FOD: 4.2 Ma) of nannofossils; S. ellipsoideus (LOD: 4 Ma), S. palcacantha (LOD: 10.2), C. giusepei (LOD: 14 Ma) of dinocysts; D. seminae v. fossilis (FOD: 3.7 Ma), T. antiqua (LOD: 1.7 Ma), T. convexa (LOD: 2.4 Ma), N. kamtschatica (LOD: 2.58 Ma), T. oestrupii(FOD: 5.1 Ma) of diatoms. Abundance patterns of microfossils throughout the wells reflect changes in paleoenvironmental and sedimentological settings of the basin in relation to sea-level variations. According to these data the large-cycle and small-cycle changes of transgression and regression phases are observed in terrestrial to marine sediments. This high-resolution sequence biostratigraphy established by various fossil groups enabled more reliable correlation between strata and refined interpretation on deposition systems of the basin. It also proved to provide fundamental and precise informations regarding stratigraphic correlation, tectonic events, basin, and depositional history for hydrocarbon explorations, especially in collaboration with seismic-stratigrahic analyses.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.529-538
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• 2019

This study examined the changes in plant phenology of 12 woody species in Daegu University Forest, Gyeongsan-si, Gyeongsanbuk-do in 2007 and 2018. The Hobo was installed at a height of 1.2 meters to measure the microclimate such as air temperature and relative humidity to identify its effects on the changes in plant phenology. The number of trees surveyed were 42 individuals that included 12 species in 9 families, all of which are deciduous broad-leaved trees. The trends in temperature change in 2018 were similar to that in 2007, except for the temperatures in the warmest and coldest month. Compared to 2007, the average temperature of the warmest month in 2018 was $2.5^{\circ}C$ higher, and the coldest month was $3.3^{\circ}C$ lower. The lowest temperature from February to April in 2018 had the highest correlation with the blooming dates of the trees (r = 0.692) in 2018, and the highest temperature showed the lowest correlation (r = 0.392). The blooming date by species was significantly different (p < 0.05). The blooming date of 8 species (75%), including Prunus padus, was earlier by 1 to 16 days, while 4 species, such as Prunus armeniaca var. ansu, was later by 1 to 7 days in 2018 than that in 2007. However, the flowering duration did not have a significant effect on the plant phenology. The results can be used as basic data for long-term monitoring of plant phenology in the future, and follow-up studies on other environmental factors and physiological factors are needed.

• Journal of People, Plants, and Environment
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• v.24 no.3
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• pp.267-275
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• 2021

Background and objective: Particulate matter (PM) has a fatal effect on health. There have been many studies on the use of plants such as trees and shrubs as eco-friendly and sustainable biofilter for the removal of PM. In forming more green space, ground cover plants play an important role in multi-layered planting. This study was conducted to investigate the ability of plants to reduce PM, targeting Korean native ground cover plants with high availability in urban green spaces. Methods: For 4 species of Asteraceae, 4 species of Liliaceae, and 3 species of Rosaceae, one species of plants at a time were placed in an acrylic chamber (800 × 800 × 1000 mm, L × W × H) modeling an indoor space. After the injection of PM, the amount of PM remaining in the chamber over time was investigated. Results: For all three types of PM (PM10, PM2.5, PM1), significant difference occurred in the amount of PM remaining between plant species after 1 hour in the Liliaceae chamber, 3 hours in the Asteraceae chamber, and 5 hours in the Rosaceae chamber. With Liliaceae, the leaf area and the amount of PM remaining in the chamber showed a negative (-) correlation. With the Asteraceae and Rosaceae, there was a weak negative correlation between the leaf area and the amount of PM remaining in the chamber. Conclusion: When using ground cover plants as a biofilter to remove PM, it is considered effective to select a species with a large total leaf area, especially for Liliaceae.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.314-325
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• 2014

We studied fish fauna at 10 study sites in Ungcheon stream for 4 times from April to October, 2011 to investigate the influence of artificial structures such as dam (with fish-way) and weir (without fish-way), and abandoned mine on fish community. A total of 12 families, 36 species of fishes were collected. Dominant species was Zacco platypus (23.4%) and subdominant species was Zacco koreanus (20.5%). Ten species (27.8%) of Korean endemic species and Micropterus salmoides, exotic species, were observed during the study period. Endangered species of Korea such as Pseudopungtungia nigra and Liobagrus obesus, and Korean endemic species, Coreoperca herzi, which are vulnurable for water quality and had been observed in previous study, were not identified in this study. According to the cluster analysis, Ungcheon stream were divided into three groups consisting upstream (St.1, St.2, St.3), midstream (St.4, St.5, St.6, St.7), downstream (St.8, St.9, St.10). Community structure similarity between upper and lower site of Boryeong dam with fish-way (St.6-St.7) was high, whereas that of weir, lack of fish-way (St.7-St.8) showed little similarity indicating that fish-way was required. According to the canonical correlation analysis, high level of conductivity and salinity at upstream was detected and Misgurnus mizolepis, and endemic species of Korea such as Silurus microdorsalis, Coreoleuciscus splendidus and Iksookimia koreensis were observed at this part of the stream. Since Korean endemic species, Squalidus gracilis majimae cohabit with exotic species, M. Salmoides at downstream whose width is wide and water velocity is low, protection was needed for these endemic species.

• Korean Journal of Environment and Ecology
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• v.32 no.5
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• pp.497-506
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• 2018

The purpose of this study was to investigate the proper minimum viable population of a seed bank for the ecological restoration of pine forest using a seed bank. It examined the germinated soil seed bank from August 2010 to November 2011. The results of the correlation analysis showed that the area and the number of herbaceous species were the highest at 0.686. The results of the regression analysis of four variables including the number of woody species, the number of woody individuals, the number of herbaceous species, and the number of herbaceous individuals using the theory of island biogeography to the minimum viable population in studied plots showed that all four variables were significant with area at the level of 0.05, and R square was 0.583. One function was selected between the number of species and the number of individuals from the canonical correlation analysis, and the function square was 0.824. Both canonical function and squared canonical correlation showed significant at the level of 0.01. The result of study recommended the area size of the minimum viable population in pine forest applied by seed bank to be larger than $64m^2$, the number of species to be over 21, and the number of population to be over 120. It also found that the number of herbaceous species determined the cluster size of the seed bank. Therefore, it is necessary to consider herbaceous species that appear in the seed bank.

• Journal of Microbiology and Biotechnology
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• v.26 no.10
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• pp.1723-1735
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• 2016

Pyrosequencing analysis of intestinal microflora from healthy Thai vegetarians and non-vegetarians exhibited 893 OTUs covering 189 species. The strong species indicators of vegetarians and non-vegetarians were Prevotella copri and Bacteroides vulgatus as well as bacteria close to Escherichia hermanii with % relative abundance of 16.9 and 4.5-4.7, respectively. Core gut microbiota of the vegetarian and non-vegetarian groups consisted of 11 and 20 different bacterial species, respectively, belonging to Actinobacteria, Firmicutes, and Proteobacteria commonly found in both groups. Two species, Faecalibacterium prausnitzii and Gemmiger formicilis, had a prevalence of 100% in both groups. Three species, Clostridium nexile, Eubacterium eligens, and P. copri, showed up in most vegetarians, whereas more diversity of Collinsella aerofaciens, Ruminococcus torques, various species of Bacteroides, Parabacteroides, Escherichia, and different species of Clostridium and Eubacterium were found in most non-vegetarians. Considering the correlation of personal characters, consumption behavior, and microbial groups, the age of non-vegetarians showed a strong positive correlation coefficient of 0.54 (p = 0.001) to Bacteroides uniformis but exhibited a moderate one to Alistipes finegoldii and B. vulgatus. Only a positive moderate correlation of body mass index and Parabacteroides distasonis appeared. Based on the significant abundance of potential pathogens, the microbiota of the non-vegetarian group showed an abundance of potential pathogen varieties of Bilophila wadsworthia, Escherichia coli, and E. hermannii, whereas that of the vegetarian group served for only Klebsiella pneumoniae. These results implied that the microbiota of vegetarians with high abundance of P. copri and low potential pathogen variety would be a way to maintain good health in Thais.

• Korean Journal of Environment and Ecology
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• v.12 no.2
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• pp.147-155
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• 1998

This study was conducted from March to August 1997 to decide the size of plant community in fragmentary habitats. The thirty one sites and one hundred and eighteen plots were plotted in the areas including Yangpyong, Yoju, Pyongtaek and Ansong in Kyonggi-do, Chomchon and Sangju in Kyongsangbuk-do, Nonsan in Chungchongnam-do and Iksan in Chollapuk-do. The area and number of woody species by correlation analysis were recorded as the highest value as 0.716. In order to apply the theory of island biogeography to the fragmented habitats in Korea, the four variables were calculated by regression model. The four variables such as number of woody species, number of woody individuals, number of herbaceous species and number of herbaceous individuals were recorded as significant with area at the level of 0.05 and R square was 0.71. The one function was selected between number of species and number of individuals from the canonical correlation analysis, and the function square was 0.8876. Both canonical function and squared canonical correlation showed significant at the level of 0.01. The number of species and individuals were not increased from the condition that was the size of plant community of 400$m^2$, 30 for number of species and 4,000 for number of individuals. This results of this study can be widely used as a basic information for the conservation management, especially the fragmented ecosystems or the biotop creation in the landscaping.

• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.21-29
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• 2005

This study was done to obtain their morphological traits to analyse genetic diversity and intraspecific relationship of 47 Polygonatum species collected from Gyeongnam province. Plant height was the highest in P. thunbergii but the shortest in P. involucratum. Growth habit and its colors were classified to 3 groups, respectively. Leaf shapes were sorted to 5 groups including lanceolate with petiole or none, petiole colors were done to 3 groups including a species having dark green leaves of purple colored margin. Flower shapes were divided as 3 groups of urceolate, tubular and gourd shapes, and its colors were white, greenish white and light green, especially light green in a species with gourd shape. Filament shapes were two types of flatness and cylinder. Peduncle color and bract attached below it showed 4 types, respectively. Fruit shapes were sorted to 3 groups. In 100-fruit weights P. ordoratum var. pluriflorum showed the greatest but P. involucratum did the least. Two species were completely resistant to leaf brightness although 7 species showed less than 7 % infection rates. Rhizome yields ranged from 4.4 g to 94.8 g per plant, showing their significant variation. In correlation analysis between 9 major characters, rhizome yield per plant was positively correlated with plant height, stalk diameter, leaf number, leaf length and width, and rhizome diameter but leaf brightness was negatively done with plant height, stalk diameter, leaf number and length, 100-seed weight, rhizome yield per plan and rhizome diameter.