• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.433-440
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• 1999

To develop Korean-style hot sauce using red pepper powder and/or Kochujang, its physiochemical and microbiological characteristics were investigated during storage at 20 and $30^{\circ}C$ for 56 days. The capsanthin contents and the value of surface color decreased during storage, but pH and titratable acidity were not changed. The sensory quality showed a decreased tendency during storage. Among the microorganisms, viable cell count decreased, but yeast, lactic acid bacteria and E. coli were not detected during storage. From the correlationship between sensory color and capsanthin content, the shelf-lives of hot sauce were predicted to be 221.7 days at $20^{\circ}C$, and 85.3 days at $30^{\circ}C$. While they were 230.0 days at $20^{\circ}C$ and 70.0 days at $30^{\circ}C$ in case of using Kochujang, hot sauce using both materials showed shelf-lives of 204.0 days at $20^{\circ}C$, 67.3 days at $30^{\circ}C$, respectively.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.3
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• pp.11-18
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• 2012

Increasing concern about biodiversity has lead to a rise in demand on the spatial assessment of biological resources such as biodiversity assessment, protected area selection, habitat management and restoration in Korea. The purpose of this study is to create species richness map through data collection and modeling techniques for wildlife habitat assessment. The GAM (Generalized Additive Model) is easy to interpret and shows better relationship between environmental variables and a response variable than an existing overlap analysis and GLM (Generalized Linear Model). The study area delineated by a large watershed contains Jirisan national park, Mt. Baekun and Sumjin river with three kinds of protected areas (a national park, a landscape ecology protected area and an otter protected area). We collected the presence-absence data for wildlife (mammals and birds) using a stratified random sampling based on a land cover in the study area and implemented natural and socio-environmental data affecting wildlife habitats. After doing a habitat use analysis and specifying significant factors for each species, we built habitat suitability models using a presence-absence model and created habitat suitability maps for each species. Biodiversity maps were generated by taxa and all species using habitat suitability maps. Significant factors affecting each species habitat were different according to their habitat selection. Although some species like a water deer or a great tit were distributed at the low elevation, most potential habitats for mammals and birds were found at the edge of a national park boundary or near a forest around the medium elevation of a mountain range. This study will be used for a basis on biodiversity assessment and proected area selection carried out by Ministry of Environment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.2
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• pp.115-122
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• 2012

Frequency distribution of carapace width, relative growth, sex ratio and fecundity of blue crab Portunus trituberculatus in Younggwang adjacent water were investigated. A total number of individuals collected for this study were 658(Males : 305 and females : 353). Water temperature and salinity of the study areas varied from 5.9 to $27.3^{\circ}C$ and 28.1 to 31.6 psu, respectively. The carapace length-width and carapace width-weight relationship was calculated and the equations obtained are; For males; CL = 1.3652CW + 22.495($R^2$=0.741), $TW=0.0068CW^{2.4001}$($R^2$=0.749), For females; CL = 1.3073 CW + 25.684($R^2$=0.791), $TW=0.0061CW^{2.4231}$($R^2$=0.801). The sex ratios(Males : females) for blue crab were 0.86 : 1. The value of correlations coefficient between total weight and fecundity of the blue crabs was higher that of between carapace width and fecundity.

• Korean Journal of Plant Taxonomy
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• v.45 no.4
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• pp.353-361
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• 2015

Spatio-temporal variation in fruit set in orchids would affect long-term population viability and will influence genetic diversity over many generations. The aim of this study was to examine the breeding system of the nectariferous terrestrial orchid Epipactis thunbergii, to specifically determine levels of fruit set in terms of time and space under natural conditions. We examined pollination under natural conditions and conducted hand pollination experiments during a 2-year survey in four populations located along 1.5 km of coastal line in Jinguiri (rual village) [Jeollanam-do (province), southern Korea]. We found that, over a 2-year period, levels of percentage of fruit set were similar within patches of the four populations. By contrast, we detected significant differences in the percentage of fruit set among patches. We also found that plants with larger inflorescence size produced significantly more fruits than plants with fewer flowers. Over a 2-year period, the percentage of fruit set for E. thunbergii was similar but low (14.1%) compared to that averaged for eighty-four rewarding species (37.1%). However, an increase in fruit set was achieved by hand-pollinations: artificial self-pollination (90.5-95.2%), artificial geitonogamy (94.7-95.0%), and cross-pollination (artificial xenogamy, 91.3-91.4%). No emasculated flowers produced fruits and no automatic pollination was found in E. thunbergii. Our findings suggest that E. thunbergii is a self-compatible terrestrial orchid that depends on pollinators (insects) to achieve fruit set in natural habitats, and that local environmental conditions were similar over a period of 2 years in the study area. Our results also highlight the cryptic variation of fruit production in time, but more pronounced variability in space.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.533-538
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• 2015

This study was conducted to examine the effect of salinity on the early embryonic development stage of boreal digging frogs (Kaloula borealis). An experiment was carried out with the eggs of K. borealis mating couples laid along the coastal zone of Jeju Island in June 2013. The salinity was set to 0, 1, 3, 5, and 7 ‰, respectively. The survival and growth of the larvae at various stages from the egg phase to the closing of their external gills phase were observed. In another experiment, tadpoles in internal gill stage were placed in solutions with salinity of 0, 1, 3, 5, and 7 ‰, respectively, and their survival rate and growth rate were observed, and then the results of the two experiments above were compared. The results showed that in egg and external gill stage, there was no significant difference in survival rate in 3 ‰ solution, though there was low survival rate in 5 ‰ solution. Further, all the eggs were dead in 7 ‰ solution, so it appeared that solutions with salinity of 5 ‰ or higher affect the survival of K. borealis in the early embryonic development. Larvae in the internal gill stage showed no significant difference in survival rate from the control group up to a salinity of 5 ‰, but when placed in a solution of over 7 ‰ salinity, the survival rate decreased. The growth rate also slowed down with the higher salinity. It appeared that in both the external gill stage and the internal gill stage in 5 ‰ solution, the growth rate decreased significantly compared to the control group. From this study it is concluded that higher salinity values have a significant impact on the survival and growth of the K. borealis larvae and this finding can be used to conserve K. borealis species that are decreasing in number due to the side effects of development in coastal areas.

• Korean Journal of Environment and Ecology
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• v.25 no.3
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• pp.307-317
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• 2011

Ground beetle fauna of Mt. Bangtaesan in Inje-gun, Gangwon-do was investigated from June to October in 2010. Ground beetles were collected by pitfall trapping. A total of 34 species of 18 genera belonging to 7 families were identified from 1,041 collected ground beetles. Species richness was high in Pterostichinae (15 species, 44.1%), Carabinae (7 species, 20.6%), Harpalinae (4 species, 11.8%), Nebriinae (3 species, 8.8%) and others (5 species, 14.7%). Dominant species were Synuchus spp. (260 individuals, 25.0%), Aulonocarabus semiopacus (218 individuals, 20.9%), and Pterostichus audax (205 individuals, 19.7%) in order. Korean endemic species were collected 564 individuals belonging to 10 species. By principal component analysis (PCA), species distribution and abundance of ground beetles were different depending on habitat characteristics of vegetation, surrounding environment and feeding habitat. Carabinae and Pterostichinae which live in the forest were preferred in hardwoods and coniferous in the Bangtansan Natural Recreation Forest, while Callistinae and Harpalinae were collected in forest adjacent to grasslands. Overall, differences of habitat environments within forest are important factors associated with distribution of ground beetles. This result will provide useful informations with establishment of conservation program and long-term monitoring against environmental change within mountain by using ground beetles.

• Korean Journal of Environment and Ecology
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• v.31 no.5
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• pp.461-471
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• 2017

Population genetic studies of 10 groups of Iksookimia pacifica were conducted to investigate the genetic diversity and population genetic structure across its known range in South Korea. Population DNA sequences of one mitochondrial gene (mtCOI) and three nuclear genes (IRBP, EGR2B, RAG1) were examined in samples collected from ten streams that flow into the East Sea. Both mitochondrial and nuclear sequences exhibited significant differentiation among populations except a few cases. The Bayesian analysis of the multi-locus genotypes inferred from the DNA sequences of nuclear genes clustered the individual fish largely into two geographical groups: a northern group (from Baebong stream to Cheonjin stream) and a southern group (Yangyangnamdae stream to Gangneungnamdae stream). Given that the streams flowing into the East Sea are geographically isolated water systems, such separation of genotypes can be interpreted by the geographical separation of common ancestors into north and south that had colonized South Korea. Since the initial geographical separation of the ancestral population by north and south, the ancestral groups seem to have experienced further differentiation into the current genetic clusters through the physical isolation of streams by the East Sea in each region. It is notable that many individuals in the Jasan stream formed a genetic cluster with those of Yangyangnamdae and Gangneungnamdae streams which are distant from each other. In addition, mitochondrial gene showed low genetic differentiation between some neighboring populations and very low level of genetic diversity in several populations. The present population genetic study will provide valuable information for the conservation and management of the Korean endemic fish species, I. paicifica.

• Korean Journal of Medicinal Crop Science
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• v.16 no.2
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• pp.112-117
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• 2008

This experiment was carried out to obtain the basic information on processing for product of high quality goods in Artemisia capillaris. We investigated antioxidant and antimicrobial activities by harvesting date and plant parts in Artemisia capillaris. Contents of total polyphenol compounds and flavonoids were the highest in leaf, followed by capitulum and stem. Leaf on June 30 contained 76.7 mg/g DW total phenolic compounds and 78.2 mg/g DW flavonoids. As $RC_{50}$ value, that was, the concentration of sample required for 50% reduction of DPPH (2,2-diphenyl-l-picrylhydrazyl) absorbance, was very low as $5.42\;{\mu}g$ in leaf on June 30, antioxidant activity was the highest. In addition, $RC_{50}$ of BHA, BHT and ${\alpha}-tocopherol$ were $3.09\;{\mu}g$, $24.30{\mu}g$ and $2.87{\mu}g$, respectively. And capitulum had antimicrobial activities against Bacillus subtilis, Staphylococcus aureus, Enterobacter aerogenes, Citrobacter freundii, Vibrio vulnificus, Pseudomonas aeruginosa, Saccharomyces cerevisiae. By the way, leaf and stem rarely had antimicrobial activity. Antimicrobial activities of capitulum according to harvesting date were very various. Capitulum on August 30 had the highest antimicrobial activities against Bacillus subtilis, Staphylococcus aureus, Vibrio vulnificus, Saccharomyces cerevisiae and on July 30 against Enterobacter aerogenes, Citrobacter freundii, Pseudomonas aeruginosa.

• Food Science and Preservation
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• v.23 no.1
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• pp.80-88
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• 2016

Seven kinds (acacia, cochineal, catechu, grape peel, persimmon, gallnut and clove) of color powders obtained from natural resources and their mixtures were evaluated for their biological activities, such as antioxidant (ABTS and DPPH radicals scavenging), cholesterol absorption, and COX-2 inhibitory activities. Catechu, gallnut and clove were selected for the further studies due to its the best activities. The cholesterol absorption, COX-2 inhibitory, ${\alpha}$-amylase inhibitory and ${\alpha}$-glucosidase inhibitory activities were measured using the mixtures of catechu, gallnut and clove. The ABTS radical scavenging activity of the seven types of natural color powders were higher than the DPPH radical scavenging activity. The cholesterol absorption activity was significantly higher in cloves. The COX-2 inhibitory activity was significantly lower in acacia. The ${\alpha}$-amylase inhibitory activity was higher in catechu and gallnut, indicating that there were no significant difference between two mixtures. The ${\alpha}$-glucosidase inhibitory activity was the highest in catechu, which was higher than that of the catechu-containing mixtures. From all these results, a synergistic effect could be obtained when utilizing a mixture of powders rather than using only individual type. Since the activity of each powder was different, further studies will be required for clarifying the interactions between mixtures.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.1
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• pp.13-25
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• 2007

The water treatment plants in Seoul Metropolitan Area, which are under Korea Water Resources Corporation(KOWACO)'s management, take water from Paldang Reservoir in Han River System for drinking water supply. There are taste and odor (T&O) problems in the finished water because the conventional treatment processes do not effectively remove the T&O compounds. As part of countermeasures for taste and odor control, KOWACO is planning to introduce advanced water treatment process such as ozone and GAC in near future. This study evaluated the removal characteristics of T&O and dissolved organic matter (DOM) to find design and operation parameters of advanced water treatment processes in a pilot-scale treatment plant. The GAC adsorption capacity for DOC in the two GAC system (GAC and $O_3$-GAC) at an EBCT of 14min was mostly exhausted after 9months. The differency of the removal efficiency of DOC between $O_3$-GAC and GAC increased with increasing operation time because the bioactivity in $O_3$-GAC process was enhanced by post-ozone process. Removal by conventional treatment was unable to reach the target TON(threshold odor number) of 3 but GAC systems at an EBCT(empty bed contact time) of 14 min were able to archive the target with few exception. During the high T&O episodes, PAC as a pretreatment together with GAC could be useful option for T&O control. However, substantial TON removal continued for more than two year (> 90,000 bed volumes). At the spiking of less concentration 26 to 61 ng/L in the influent of GAC systems, GAC absorber and $O_3$-GAC processes could meet the treatment target. The better spike control after 12 and 19 months of operation compared to that after 7 months of operation is a strong indication of biological control. The results presented in this study had shown that $O_3$-GAC process was found to be more effective for T&O control than GAC process. And the main removal mechanism in GAC systems were adsorption capacity and biodegradation.