• Journal of Korean Society on Water Environment
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• v.18 no.2
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• pp.201-212
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• 2002

The objective of this study was to investigate the treatment efficiency, kinetics, and morphological characteristics of biofilm in upflow $Biobead^{(R)}$ process, a kind of biological aerated filter(BAF). The $Biobead^{(R)}$ system showed high removal rates of $COD_{Mn}$(76~83%), $BOD_5$(67~88%) and SS(71~91%) for food wastewater with high salt concentration ($>4,000mg/{\ell}$) under short reaction times(2~3hrs). Even at aerobic condition, the system had high treatment efficiency for both T-N (51~63%) and T-P(62~81%). The removal kinetics of $COD_{Mn}$, $BOD_5$, T-N, T-P, and $Cl^-$ in the $Biobead^{(R)}$ system showed a plug-flow pattern with reaction rate constants($hr^{-1}$) of 0.58, 0.63, 0,30, 0.48, and 0.38 respectively. A backwashing process to remove excess biomass and filtered solids was needed at least once during 22-hour operation at $0.5kg\;BOD\;m^{-3}{\cdot}d^{-1}$ loading. At the higher loading($1.0kg\;BOD\;m^{-3}{\cdot}d^{-1}$) the backwashing interval was shorten by 8 hours. The COD, BOD, T-N, and T-P were removed from 43 to 66% only by aerobic biodegradation. The SS was removed over 70% by the filtering of $Biobead^{(R)}$ media in the treatment system. The first one of three serial Biobead reactors showed the highest removal values for $COD_{\alpha}$(52.3%), $COD_{Mn}$(38.8%), BOD(62.5%), and T-N(40.0%). The SS and T-P had the highest removal values(47.5% and 29.2%) at the second one of the serial reactors. The biofilm had non-homogeneous spatial distribution and the colonies were embedded in the sunk area of the Biobead. The thickness of the biofilm was very thin ($5.0{\sim}29.4{\mu}m$) compared to the biofilm thickness($200{\sim}300{\mu}m$) used in other BAF systems.

• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.57-65
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• 2014

Spatial and temporal distributions of zooplankton were measured in an oligotrophic pumped storage-type hydroelectric reservoir which was composed of two reservoirs exchanging water daily, with water going up at night and going down during the day. Repetitive diel disturbance of the water column can be a unique feature of this reservoir system. Chl-${\alpha}$ concentration was highest in the early winter season. Phytoplankton density was lower in summer monsoon due to high flushing rate on rainy days. The zooplankton density was higher in the smaller upper reservoir possibly due to lower fish density in the upper reservoir. In the seasonal variation a time gap was observed between the phytoplankton bloom and the zooplankton bloom (particularly a rotifer, Keratella cochlearis). It is likely to that Keratella production is partially supported by heterotrophic food sources than phytoplankton. The dominance of a mixotrophic dinoflagellate (Peridinium bipes f. ocultatum) might have complicated the trophic relationship between phytoplankton and zooplankton. Our results provide some ecological information of zooplankton community in a highly disturbed alpine reservoir ecosystem relying on mostly allochthonous organic matter.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.2
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• pp.129-134
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• 2016

Odor in pig manure affects the distribution of the manure over grass and crop fields as fertilizer. The objective of this study was to investigate the effect of different types of microbes (Saccharomyces cerevisiae, Bacillus subtilis and Rodobacter capsulata) and incubation temperatures ($20^{\circ}C$ and $35^{\circ}C$) on the levels of odorous compounds in pig manure. Pig manure was incubated with 0.03% microbes (v/v) at temperatures of $20^{\circ}C$ or $35^{\circ}C$. At incubation temperature of $20^{\circ}C$, the addition of Rodobacter capsulata significantly (p<0.05) decreased the levels of indoles and volatile fatty acid (VFA). At incubation temperature of $35^{\circ}C$, the addition of any microbes of the three used in this study did not significantly (p>0.05) affect the levels of odorous compounds. When incubation temperature was increased from $20^{\circ}C$ to $35^{\circ}C$, levels of odorous compounds were significantly (p<0.05) increased. Taken together, these results suggest that Rodobacter capsulata could be utilized to reduce odor from pig manure in the spring and fall when the average temperature is around $20^{\circ}C$. However, alternative odor-reducing technology is needed to be developed to apply onto pig manure during the hot summer season ($35^{\circ}C$).

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.369-376
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• 2009

Cowpea might have been introduced from China to Korea and cultivated for several hundred years but it has never been a staple food crop in Korea. In this study, genetic diversity of 492 Korean cowpea landrace accessions that have passport information was estimated using six SSR markers. The mean of Weir's gene diversity was 0.665 from all accessions investigated in the study. Cowpea gene diversity of six local provinces in Korea was ranged from 0.370 in accessions of Gangwon to 0.680 in Jeonra provinces. Low gene diversity of the cowpea genepool of Gangwon province was probably derived from relatively few introductions. Especially SSR markers VM36 and VM39 seem to be good markers to distinguish the Gangwon accessions from others by occurring at a specific locus with higher than 78% of allele frequency. Except for the Gangwon province with the low genetic diversity, gene diversity of cowpea accessions from other provinces was ranged from 0.600 to 0.680 indicating no big differences among provinces. Distribution pattern of the allele frequencies was similar among the other provinces. This may reveal that Korean farmers might exchange cowpea seeds easily with even their neighbors with geographical barriers. A core collection, 100 landraces, ca. 20% of base collection, was developed at the 70% of a similarity coefficient level using random sampling approaches after stratification of the entire landrace collection based on the phenetic dendrogram. The variability of SSR in the base and core collections of Korean cowpea landrace was compared by calculating Weir's gene diversity. The mean of Weir's gene diversity of the core was 0.707 while that of the base collection was 0.665. The higher diversity index in the core collection indicates that it maintains the initial variability and well represents the base collection. The core collection included one of determinate accession (IT 216155) and two of no branching type accessions (IT 103959 and IT 161024). The core collection could be used to guide more efficient management and utilization of the entire collection. This core collection should be revised periodically as additional accessions are collected and further characterization is conducted.

• Animal Systematics, Evolution and Diversity
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• no.nspc2
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• pp.233-241
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• 1988

The crab, Macrophthalmus (Mareotis ) japonicus , collected in 1983 from CHojijin tidal flat, southeastern part of Kangwha Island , Korea, was studied. Its caraace breadth, the carapace length , and body height were checked , and the measured raw data were analysed for the growth ratios by the mode subtraction method from the frequency distribution compared with the probability graphs. The growth rate of the crab rose more in summer than in fall and exceeded 10% during the same period on Chojijin tidal flat in Kangwha Island , Korea. Four size groups of the crab appeared in June, 1983 , but they were put together into only on emixed group by autumn. The rapid growth of the crab in summer in middle latitude comes from the seasonal bio-rhythm and the best conditions for food. But the physiological activities of the crab are reduced from autumn and the growth rate reaches the upper limits in many individuals on this tidal flat. The more the crabs grow, the more the breadth ratios to the carapac length become larger and the slopes of correlation curve get smaller. The measured values from the carapace breadth of the crab are more useful for morphological studies than those values from the carapace length or body height.

• Journal of vocational education research
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• v.29 no.3
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• pp.61-83
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• 2010

The purpose of this study was to analyze high schools' general and special subject required to successfully complete same stream curriculum which is identical to their major from agricultural high school, and to offer basic data on strategies of organizing agricultural high schools' curriculum for improving universities' major basic competencies. Using purposeful sampling technique, the professors of 116 universities professors in 8 agricultural university were analyzed through the survey research. The result was as follows. first, it appeared that for successful completion of major subjects of the same stream university, the basic science subject such as biology and chemistry has high relation with major basic ability, however math and physics are related highly in agricultural machine and agricultural civil engineering department, economics and math are in agricultural produce distribution department. Second, the basic ability such as linguistic competence and foreign language ability are essential to complete major subject. Third, if we look into relation of agriculture and life science industry stream specialized subject with major basic competencies, we can find considerable similarity between major field of university and subject name of specialized high school. Fourth, the main opinion is that basic concept and principle, laws of nature are should be main contents which is able to be practical, however experiment and practice is in food processing department, and academic theory is in biotechnology department.

• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.463-469
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• 2010

Rice is a staple food for more than 50% of the world's population. Embryo comprises only 2 to 3% of the weight distribution of the entire pericarp but has higher concentration of vitamins, proteins, and essential fatty acids than the other parts of grains. Moreover, ${\alpha}$-tocoperol, ${\gamma}$-oryzanol, phytic acid and ${\gamma}$-aminobutric acid that have nutraceutical value are abundant. Increasing the volume of embryo assures the fortification of nutritional value of rice grain. We developed new black waxy giant embryo rice, Milyang 263 by crossing Josaengheugchal, a black waxy rice variety, and $ge^t$, a giant embryo mutant generated by tissue culture. The nutrient contents and physical properties of Milyang 263 were compared with several giant embryo mutants and normal embryo rice varieties. Changes in the nutrient properties after germination were also observed. Results indicated that this new black waxy giant embryo rice, Milyang 263, offers a promising source for improving nutritional quality of rice especially anthocyanin, essential minerals, and GABA.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.190-199
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• 2019

This study was conducted to expand the distribution of new technology efficiently by analyzing the structure relationship based on the innovation resistance model and partial least square structural equation model (PLS-SEM). This study selected innovative propensity, relative advantage, compatibility, complexity, trialability, risk, and extension service consisting of educational, technical, and funding services as factors affecting innovation resistance. This study constructed a questionnaire that measured 11 factors including acceptance intention of new technology using 33 indicators. Data was from April to October, 2017, targeting 180 farmers who did not join in projects to spread new technologies of the Rural Development Administration. Results showed the factors positively and significantly affecting innovation resistance include complexity and risk. Innovative propensity did not have any effect on innovation resistance. However, it positively affected acceptance intention of new technology. The service of the extension organizations had a negative effect on innovation resistance, but did not affect acceptance intention of new technology. This study suggests that extension services should promote activities such as education, consulting, publicity and pilot projects related with new technologies in order to minimize the antipathy toward new agricultural technologies.

• The Journal of the Korea Contents Association
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• v.18 no.12
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• pp.309-318
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• 2018

In this study, we investigated subjective perceptions of one retailer's PB products for large retailers by applying the Q methodology to examine subjective trends of consumers who purchased and experienced PB products at home. In this study, we examine how HMR-type PB products developed and released by large retailers according to the demographically changing social structure represent the meaning and subjective acceptance of PB products in a single licensee through Q methodological studies. The purpose of this paper is to propose various direction and improvement plan of food product development and release for one license of large distribution company in the future. Based on these research problems, five types of type analysis results were derived. Specifically, the first type (N = 5): Brand image trust type, the second type (N = 5): NB product preference type, the third type(N = 2): Easy cooking preference type, and fourth type (N = 2): Pursuing taste for price type and fifth type (N = 2): Quantitative pursuit for price type.

• Journal of Nutrition and Health
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• v.54 no.3
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• pp.262-276
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• 2021

Purpose: Although, the rate of skipping breakfast among adolescents has increased in recent years, there has been an increase in the consumption of home meal replacement (HMR). This study examines the recognition and preference of rice-based Korean style HMR for breakfast among adolescents in located at Jeollabuk-do. Methods: Total of 550 middle- and high-school students of Jeollabuk-do enrolled in this study signing a consent of participation. After conducting a preliminary survey, the questionnaire employed was modified according to the purpose of this study, and the self-recording method was appliedto fill out the questionnaire. Data were analyzed using IBM SPSS Statistics 25. The 𝛘²-test was performed for categorical variables, whereas continuous variables were analyzed by the independent t-test. Results: Results of this study determined that 272 students (54.6%) belonged tobreakfasteating group and 226 (45.4%) were in the breakfast-skipping group. The reasons specified by both groups for eating HMR were 'convenient to cook', 'delicious', and 'time-saving'. The a result of analyzing perception of the importance of HMR by classifying as whether to eat or not to eat breakfast, revealed that compared to the breakfast-skipping group, the breakfast-eating group considered 'hygiene and cleanliness' as important factors (p < 0.001). Considering the gender, school, and breakfast consumption, the most preferred Korean HMR were 'triangular gimbap', 'gimbap', and 'rice balls'. Conclusion: Results of this study indicate, when considering adolescents, there is a necessary for continuous researches to develop convenient breakfast substitutes that are easily consumed. Moreover, we believe that it is essential to impart proper cooking education and recipe distribution of the menu.