• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.1
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• pp.9-14
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• 2014

This experiment was carried out to order to determine the forage production and soil characteristics in mixtures of Italian ryegrass (IRG) and annual legumes at the riverbed. The IRG and hairy vetch mixture had the highest in fresh, dry matter (DM) as well as total digestible nutrients (TDN) yields among the forage mixtures. Further IRG and hairy vetch mixture had the highest in DM content. The crude protein (CP) content of IRG and hairy vetch mixture was the highest, Whereas non-fiber carbohydrate (NFC) and TDN contents were lower compared to other mixtures. The total nitrogen (TN) of IRG and hairy vetch mixture was the highest due to high nitrogen fixation in the riverbed soil. The IRG and rape mixture was the highest in organic matter (OM) of soil. Moreover, the available $P_2O_5$ of soil in IRG and crimson clover mixtures was higher compared to other mixtures. Further, the IRG and hairy vetch mixture was the highest in cation exchange capacity (CEC) content. Therefore IRG and hairy vetch mixture is more suitable in forage mixtures due to high forage production and protein as well as high soil CEC content at the riverbed.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.142-146
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• 2010

Relatively large amounts of GABA can be produced by the fermentation of rice bran. Therefore, this study was conducted to investigate the effects of GABA on the secretion of melatonin and serotonin for the development of a sleep inductive compound. The secretion levels of melatonin and serotonin from mice were found to be $3.425{\pm}0.182\;pg/mL$ and $5.37{\pm}0.963\;ng/mL$, respectively, in response to feeding 120 mg/mL of GABA while they were $2.607{\pm}0.41\;pg/mL$ in the control. The secretion of both melatonin and serotonin was increased up to the 13.51% and 34.99%, respectively, when compared to the negative control. However, the feeding of milk alone did not have a great effect on the melatonin and serotonin secretions. Conversely, feeding of milk with GABA enhanced the secretion of serotonin. The amounts of both melatonin and serotonin secreted increased with respect to the increase in GABA concentrations during feeding. Interestingly, the induction level of melatonin was relatively higher than that of serotonin in response to feeding 120 mg/mL of GABA. This is the first study to report that GABA has an ability to induce sleep related hormones in mice; therefore, it has the potential for use as a natural sleep aid.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.147-154
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• 2010

Gulbi, made of fresh yellow corvenia (Psendosciaena manchurica) that has been salted and dried, is one of the most popular traditional marine foods in Korea. The objective of this study was to develop a method to safely manufacture Gulbi with low levels of oxidation and contamination, by a hot air drying method. Changes in total acidity, pH, salt concentration, thiobarbituric acid-reactive substance (TBARS) and volatile basic nitrogen (VBN) were measured during drying at 30, 35 and $40^{\circ}C$ for 15 days in a hot air-dryer using a semi-dried method. Acidity increased with increasing drying time at all drying temperatures. The pH decreased gradually with increasing drying time. Salt concentration was increased as drying time increased at all drying temperatures due to moisture loss. The VBN increased as drying time increased for all drying temperatures. Data indicate that the drying at $35^{\circ}C$ appears to have a significant sensory and physicochemical advantage in Gulbi products.

• Journal for History of Mathematics
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• v.25 no.4
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• pp.53-67
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• 2012

Today, it is necessary to calculate orbits with high accuracy in space flight. The key words of Poincar$\acute{e}$ in celestial mechanics are periodic solutions, invariant integrals, asymptotic solutions, characteristic exponents and the non existence of new single-valued integrals. Poincar$\acute{e}$ define an invariant integral of the system as the form which maintains a constant value at all time $t$, where the integration is taken over the arc of a curve and $Y_i$ are some functions of $x$, and extend 2 dimension and 3 dimension. Eigenvalues are classified as the form of trajectories, as corresponding to nodes, foci, saddle points and center. In periodic solutions, the stability of periodic solutions is dependent on the properties of their characteristic exponents. Poincar$\acute{e}$ called bifurcation that is the possibility of existence of chaotic orbit in planetary motion. Existence of near exceptional trajectories as Hadamard's accounts, says that there are probabilistic orbits. In this context we study the eigenvalue problem in early 20th century in three body problem by analyzing the works of Darwin, Bruns, Gyld$\acute{e}$n, Sundman, Hill, Lyapunov, Birkhoff, Painlev$\acute{e}$ and Hadamard.

• Korean Journal of Food Science and Technology
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• v.50 no.3
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• pp.292-296
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• 2018

Softening effects of enzyme following pre-treatments were examined. Four pre-treatments: raw (R), heat (H), heat and freeze-thawing (HFT), heat and freeze-drying (HFD) were applied to carrot. Subsequently, each treated sample was immersed in 10% celluclast enzyme solution for up to 6 h and then their properties were compared. The minimum and the maximum color change was observed in HFD and H, respectively. R showed no change in hardness after 6 h immersion, indicating that the enzyme did not penetrate the carrot. The number and size of pores were greater in samples undergone HFT or HFD as observed by microstructure analysis using SEM, and HFD caused 99.5% reduction in hardness after 6 h immersion. After 6 h immersion post-HFT or 3 h immersion post-HFD, the hardness was less than $20,000N/m^2$, indicating tongue ingestion was possible, and the samples retained their original shape and easily collapsed by spoon pressing.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.1
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• pp.13-20
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• 1998

The moving behaviour of Yellowtail Seriola quinqueradiata schools in the main-net of a large scale set-net was investigated in relation to the catching function of the funnel-net by a scanning sonar. The investigation was took place in the Kishihata set-net fishing ground located in Nanao city Ishigawa prefecture, Japan from Nov. 9 to Nov. 13, 1992. The obtained results are summarized as follows; 1. Fish schools showed the greatest number at the playground in the morning and at the bag-net in the afternoon. The fish schools remained long time in the main-net. 2. The rate of fish school through the funnel-net was smaller than that of fish school which is though the playground and bag-net. Because the Yellowtail school changed the shape of school in passing the funnel-net. 3. The rate of entering the bag-net was 24%, among the fish school heading to the outer funnel-net. But, the rate of escaping to the playground was 27%, among the fish school heading to the inner funnel-net. It seems that the structure of the outer funnel-net was not enough to lead the fish to the bag-net. However, the structure of the inner funnel-net was very effective at preventing escape. 4. It is appropriate to haul the net in the morning in considering the number of accumulated fish in the bag-net during the survey.

• Journal of Gifted/Talented Education
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• v.22 no.4
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• pp.875-892
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• 2012

The purpose of this study was to investigate the relationship among peer relation disposition, relationship maintenance effort and school adjustment of gifted students and non-gifted students. And then the final purpose of the study is to give suggestions to help improving gifted students' peer relationship and their school adjustment. For the study, 175 gifted students and 179 non-gifted students in grades 4 and 6 of 5 elementary schools in urban areas were assessed on their peer relation disposition, relationship maintenance effort and school adjustment. The results are summarized as follows. First, gifted students were significantly higher than that of the non-gifted students as a whole. Second, in the correlation among peer relation disposition, relationship maintenance effort and school adjustment, peer relation disposition and relationship maintenance effort showed a significantly positive correlation with all the subvariables of school adjustment. Third, Sympathy-Acceptance disposition was the most influential factor for gifted students, and Independence-Responsibility disposition was the most influential factor for non-gifted students. Finally, the cluster analysis results based on the peer relation type of the gifted and the non-gifted suggested four meaningful clusters. And the four clusters showed significantly differences with all the subvariables of school adjustment. Implications of the study were discussed in depth related to the gifted education practices.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.52-58
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• 2006

Characteristics of dough added with up to 4.0% takju powder and resultant bread were studied. Doughs added with takju power spray-dried after fermentation with starter (SDWS) and takju power spray-dried after fermentation without starter (SDOS) showed higher pH decreases than those added with takju power freeze-dried after fermentation with starter (FDWS) and takju power freeze-dried after fermentation without starter (FDOS) even after 1st fermentation. After 1st fermentation, volume of dough added with 1-4% SDWS was high, with 1% SDWS showing highest value of 23.6 mL. Volume of bread added with SDOS showed highest value. At 1-2% SDWS and SDOS addition, doughs showed highest specific volume values, which decreased at higher than 3% addition, while specific volume increased with increasing FDWS and FDOW contents. L values of SDOS- and FDOS-added doughs decreased gradually with increasing SDOS and FDOS contents compared to SDWS and FDWS addition. In loaf bread added with takju powder less than 2%, loaf bread added with spray-dried takju powder had higher appearance, color, texture, taste, and overall acceptability values compared to those added with freeze-dried takju. Although not significantly, loaf bread added with 1% SDWS showed slightly higher values in appearance, color, yeastiness, texture, taste, and overall acceptability, and showed higher flour odor acceptability than non-added loaf bread. These results indicate addition of takju powder improves flavor of bread.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.631-636
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• 2002

Lethality of high intensity light pulse on the pre-determined microbial populations has been investigated. Prior to the treatment, Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc mesenteroides and Pediococcus pentosaceus were cultivated separately onto the surface of Lactobacilli MRS agar. Pre-determined microbial populations were applied to the test media and these sample were exposed to high intense light source with an exposure time ranging from 1 to $2500\;{\mu}s$. Results showed that at least 200 light pulses of $1\;{\mu}s$ duration were required to reduce L. Plantarum cells by 90% at 25 kV, the greater the number of light pulses, the larger the reduction in viable cell numbers. Viable cells of L. plantarum and the others were reduced by more than 5 and 6 log cycles at the upper exposure level of $750\;{\mu}s$, respectively. These study shows that pulsed light emissions can significantly reduce populations of lactic acid bacteria on exposed surface with exposure times. Killing efficiency for L. plantarum significantly increased with decreasing the distance between the lamp and the surface of samples.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1389-1395
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• 2000

Cervical cancer has been one of the leading causes of female death from cancer worldwide with about 500,000 deaths per year. A strong association between certain human papillomaviruses (HPV types 16 and 18) and cervical cancer has been well known. An extract of natural products, Rhus, has been used to investigate whether this agent has the ability of inhibiting the oncogenes E6 and E7 of HPV type 16. This Rhus inhibited the proliferation of human cervical cancer cell lines (C-33A, SiHa, Caski) and HaCaT keratinocytes in a dose response manner. In vitro binding assay and ELISA showed that Rhus inhibited the in vitro binding of E6 and E6AP which are essential for the binding and degradation of the tumor suppressor p53. In addition, Rhus inhibited the in vitro binding of E7 and Rb which essential tumor suppressor for the control of cell cycle. The level of mRNA for E6 was also decreased by Rhus while that of E7 mRNA was not changed. Our data suggested that Rhus inhibited the oncogenecity of E6 and E7 of HPV 16 type, thus can be used as a putative anti-HPV agent for the treatment of cervical carcinomas by HPV.