• Journal of Environmental Health Sciences
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• v.31 no.5 s.86
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• pp.398-403
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• 2005

This study is undertaken to find the optimal method to make the decision on the degree of water pollution by comparison of K-WQI, KOE-WQI that is made for index with the water quality index and water quality environment standard of the Frame Act on Environment Policy as the result of survey for water quality reality on the major point of the Yeongsan river from 2002 to 2004. The water quality of major rivers has some differences depending on seasons. however, under the water quality standard by the $BOD_5$ density, most of rivers displayed the water quality level of $II{\sim}III$ grading, and on K-WQI that is classified by indexing for 10 categories of pH, DO, $BOD_5,\;COD,\;SS,\;T-N,\;NH_3-N,\;NO_{3^-}$ N, T-P, and E-Coli and classified into 5 groups from 100 points to 40 points, they displayed the score distribution of the first grade in water quality for $85{\sim}100$ points to the second grade in water quality for $70{\sim}84$ points. On KOE-WQI that is classified by indexing for 5 categories of pH, DO, $BOD_5$, COD and T-coli and classified into 5 groups from 90 points or above for outstanding and 29 points or below for very bad, and the water quality distribution is made ranged from the first grade in water quality for 90 points or more to the third grade in water quality for $69{\sim}50$ points. In addition, for the contribution of the water quality decline, the Environmental standard has significant dependency on the $BOD_5$ density, with K-WQI contributing in various water quality decline depending on the environment around the river area of $BOD_5,\;T-N,\;NH_3-N,\;NO_3-N,\;T-P$, and E-Coli, and KOE-WQI acting os the factor contributing to lower the water quality decline by $BOD_5$, COD, and T-coli. As such, the current water quality environment standard has high dependency on $BOD_5$ and KOE-WQI excludes some nitrogen and phosphorus that considers the river environment that the grade in water quality is set by some category, and K-WQI reflected well of the ecology environment of rivers with the diversity of the assessment factor as well as to have the low dependency of specific factor to be objective.

• Korean Journal of Organic Agriculture
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• v.32 no.1
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• pp.107-125
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• 2024

Three types of veterinary antibiotics, including oxytetracycline (OTC) and chlortetracycline (CTC) of tetracycline class and amoxicillin (AMX) of penicilline class, were artificially introduced into the irrigation water. The residue of veterinary antibiotics in the soil, the absorption-translocation of veterinary antibiotics into the red lettuce and young radish plant, and crops yield were investigated according to the agricultural water irrigation method (surface drip irrigation, underground drip irrigation, and sprinkler irrigation). There was no significant difference in the residue and translocation of veterinary antibiotics in the soils and crops according to the irrigation method and type of veterinary antibiotics (p>0.05). For the edible parts of red lettuce and young radish, all three types of veterinary antibiotics were found to be below the detection limit, indicating that the safety of the crops was secured. The translocation factor of red lettuce and young radish were found to be less than 0.3 and 0.2, respectively. However, continuous introduction of veterinary antibiotics in agricultural arable lands may have negative effects by affecting soil microbial activity and soil microbe species diversity, so continuous management is deemed necessary.

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.348-361
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• 2012

Altitude is a factor that plays an important role in the diversity, richness and composition of species. Recently, much attention has been paid to the distribution of butterflies and insects according to altitude. The purpose of this article is to propose a method to preserve and manage species efficiently by reviewing the distribution of butterflies according to different altitudes in Mt. Gyeryong National Park. This study found that the number of species and individuals decreased as the altitude increased, possibly due to the increased amount of shade caused by the crown density. When analyzing the factors influencing the distribution of species other than altitude, it was found that the slope, vegetative colonies and hydrosphere distance were correlated with the change in species distribution. As these species are closely related to food plants, it may save time and reduce the cost as well as allow an efficient evaluation of the bio-diversity if these species are selected as biological indicator species suitable for detecting the changes in the forest. It is judged to be a more efficient means of species preservation to accumulate and quantify the materials regarding environmental elements such as the climate, microclimate and food plants, as this would allow the butterfly distribution to be estimated.

• The Korean Journal of Mycology
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• v.43 no.3
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• pp.158-164
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• 2015

A total of 509 rice panicle samples were collected at harvest time from fields in 8 provinces from 2010 to 2014. One hundred five grains per sample were plated on potato dextrose agar and 6,658 Fusarium isolates were obtained; among them, 67 were identified as Fusarium armeniacum by sequencing the translation elongation factor $1{\alpha}$ ($EF-1{\alpha}$) and confirmed by their morphological and cultural characteristics. Considerable variation in conidial size, colony color and $EF-1{\alpha}$ sequences was observed among the fungal isolates. The ability of 24 F. armeniacum isolates to produce T-2 and HT-2 toxin in potato sucrose agar was determined using liquid chromatography-mass spectrometry. Twenty one isolates produced T-2 and HT-2 toxin, resulting in varying toxin levels among the isolates. The results show that Korean isolates of F. armeniacum have diversity with respect to morphological, cultural, genetic, and toxigenic properties.

• Korean journal of food and cookery science
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• v.29 no.4
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• pp.367-376
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• 2013

The objectives of this study are to provide the food market of internet shopping malls with effective marketing data, to provide basic data for the development of related fields of the study, and ultimately to increase the satisfaction of food consumers of internet shopping malls. To achieve the object of this research, a cluster analysis of the research subjects was carried out based on the following 5 factors of food purchasing attribute that had been deduced by a factor analysis by the types of food purchasers: quality characteristics, informativity, convenience, price and diversity. According to the result of the cluster analysis, the research subjects were classified into the 2 clusters of diversity and informativity. The deduced 2 clusters, together with age and occupation among general characteristics, were used as independent variables to find out food purchasing behaviors and satisfaction at internet shopping malls. The results are as follows: Regarding the frequency of food purchasing experiences at internet shopping malls according to occupation, the highest frequency was shown by those involved in service, sales and self-employed businesses; whereas regarding the frequency according to age, those in their 30s and 40s showed the highest frequency. The total amount of money spent on food purchasing for 1 year at internet shopping malls was shown to increase as age increased. The frequency of the purchasing experiences of agricultural products and fish products was shown to be higher as age increased. However, overall purchase satisfaction was highest among those in their 30s, while lowest among those in their 40s. Regarding satisfaction by the types of food purchased via internet shopping malls, satisfaction was relatively higher with common foods and functional foods, while lower with fish products. Taken together, it was concluded that purchasing behaviors at internet food shopping malls, such as the frequency of purchasing experiences and purchase amount, varied depending on age rather than purchasing attribute. Accordingly, in order to vitalize internet food shopping malls, it would be necessary to provide customized food shopping information for individual age groups.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.3
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• pp.151-157
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• 2003

This research was conducted to investigate about structural characteristics of vegetation by change of the environmental factors for prolific open-pollinated progeny forest in Pinus koraiensis stands. Stand slope of Kapyung area was slower than Youngdong area. On the other hand, contents rate of the soil chemical properties in Kapyung was lower than Youngdong area. And relative intensity of light was higher Youngdong than Kapyung area. On the whole, growth of the Pinus koraiensis was more dominant Kapyung area than Youngdong. Analysis result of the relative density, - frequency, - coverage and importance value to shrub layer in each local stands, Quercus mongolica and Quercus acutissima were dominant species in Kapyung area. Dominant species In Youngdong area was Quercus acutissima. In Kapyung area, appearance species of the vegetation layer was consisted that live in moist soil and shaded lot. Youngdong area showed fewer species than Kpyung area. Species diversity of shrub and vegetation layer in Kapyung and Youngdong area was higher than Youngdong. This result was judged by slope difference between each areas. Kapyung area need enforce thinning and Youngdong area conduct tending management on shrub layer.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1883-1895
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• 2018

Alcohol dependence is a global public health problem, yet the mechanisms of alcohol dependence are incompletely understood. The traditional view has been that ethanol alters various neurotransmitters and their receptors in the brain and causes the addiction. However, an increasing amount of experimental evidence suggests that gut microbiota also influence brain functions via gut-to-brain interactions, and may therefore induce the development of alcohol use disorders. In this study, a rat model of alcohol dependence and withdrawal was employed, the gut microbiota composition was analyzed by high-throughput 16S rRNA gene sequencing, and the metagenome function was predicted by PICRUSt software. The results suggested that chronic alcohol consumption did not significantly alter the diversity and richness of gut microbiota in the jejunum and colon, but rather markedly changed the microbiota composition structure in the colon. The phyla Bacteroidetes and eight genera including Bacteroidales S24-7, Ruminococcaceae, Parabacteroides, Butyricimonas, et al were drastically increased, however the genus Lactobacillus and gauvreauii in the colon were significantly decreased in the alcohol dependence group compared with the withdrawal and control groups. The microbial functional prediction analysis revealed that the proportions of amino acid metabolism, polyketide sugar unit biosynthesis and peroxisome were significantly increased in the AD group. This study demonstrated that chronic alcohol consumption has a dramatic effect on the microbiota composition structure in the colon but few effects on the jejunum. Inducement of colonic microbiota dysbiosis due to alcohol abuse seems to be a factor of alcohol dependence, which suggests that modulating colonic microbiota composition might be a potentially new target for treating alcohol addiction.

• Research in Plant Disease
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• v.17 no.2
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• pp.169-176
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• 2011

Phytophthora katsurae is the fungus responsible for chestnut ink disease. The objectives of this study were to determine if a single-strand conformation polymorphism (SSCP) analysis of rDNA-ITS region, elongation factor 1 alpha gene and ${\beta}$-tubulin gene could be used for rapid identification and genetic diversity of P. katsurae, and to assess the potential use of the SSCP technique as a diagnostic tool for P. katsurae. Each regions amplified by PCR using primers designed to overlap the genus Phytophthora were characterized for the Phytophthora species. PCR products were denatured and electrophoresed for SSCP analysis. P. katsurae isolates showed an unique pattern in SSCP analysis and were easily distinguished from other Phytophthora species used as the control. This indicates that SSCP analysis is an useful technique for distinguishing Phytophthora species from genetically close relatives, and show that the SSCP analysis of each region is an efficient detection tool for P. katsurae. But PCR-SSCP analysis of single-gene may have difficulty in distinguishing P. katsurae from other Phytophthora species. Therefore, PCR-SSCP analysis of multi-genes can be useful for rapid and effective identification of P. katsurae.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.3 s.345
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• pp.39-48
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• 2006

In this paper, we analyze the spectral efficiency of multicarrier-code division multiple access (MC-CDMA) scheme. First, we derive a generalized formula for the spectral efficiency according to the number of subcarriers involved in, code division multiplexing and the number of codes used (i.e., loading factor), under a given set of channel coefficients. Also, we derive a generalized formula for spectral efficiency of various reduced-complexity systems that divide the full sets of subcarriers into several groups of subcarriers for code division multiplexing. Then, through these derivations, we establish an inter-relationship between the frequency selectivity and diversity order according to the number of multipaths. From the results, we choose the smallest code length while maximizing the diversity effect, provide an optimum subcarrier allocation strategy, and finally suggest a system structure for capacity-maximizing under the smallest code length. Through numerical analyses under simulated environments, we analyze the properties of spectral efficiency of various systems with reduced complexity and choose a major contributing factors to system design and a better system design methodology. Finally, we compare the spectral efficiency of the MC-CDMA scheme and orthogonal frequency division multiplexing (OFDM) scheme to make a relationship between both schemes.

• Korean Journal of Environment and Ecology
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• v.5 no.1
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• pp.79-90
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• 1991

This study was conducted to investigate seasonal avifauna and to suggest a proper way how to manage and protect wild birds in Chirisan National Park. The survey was carried over 3 main trail districts by line transect method to figure out influence factor of inhabitation of wild birds from February to November in 1991. The study results are as follows : The observed birds were belong to 6 orders 24 families 49 species and 981 individuals and Falco tinnunculus(Natural monument No. 323). These birds also classified into 24 species for residents, 12 species for summer visitor. 9 species for winter visitor, 4 species for passage migrant, respectively. The observed average frequeney of birds was 2.09e.a./ha, and main dominant species were Parus varius, Parus major, Emberiza elegans, Garrolus glandarius, Sitta europaea, Hypsipetes amaurotis, Parus palustris in order. Cheoneun-sa trail route showed relatively decreasing trend of wild birds during spring and fall season because of the highest trail use of visitors. Maximum frequency of species and individuals appeared at Hwaum-sa route in spring and at Piagol route in fall. respectively. Those regions well explained the advantageous inhabitation area of birds in both regions. The diversity index of birds in winter showed little difference of similarity index due to balanced use of trails. Seasonal low similarity index in those 3 main trail district indicate a dissimilarity of environmental factors. Trail use restriction as a provision of proper management and protection of wild birds have to be made at Hwaum-sa route where propagation of birds actively occurred in spring and at Piagol route where birds wintering were observed will contribute to enhance species diversity in the future.