• Preventive Nutrition and Food Science
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• v.20 no.1
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• pp.78-81
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• 2015

1,4-Dihydroxy-2-naphthoic acid (DHNA) is a bifidogenic growth stimulator (BGS) and could be a functional food ingredient since bifidobacteria are beneficial for human health. For that reason, lactic acid bacteria producing DHNA have been screened. A lactic acid bacterium LP1 strain isolated from a natural cheese was confirmed to produce DHNA, analyzed by a HPLC method. The strain was identified as Lactobacillus casei by 16S rRNA gene sequence analysis. The cell-free supernatant of fermented whey produced by L. casei LP1 presented the BGS activity for three bifidobacterial strains such as Bifidobacterium longum subsp. infantis KCTC 3127, Bifidobacterium bifidum KCTC 3202, and Bifidobacterium breve KCTC 3220 which were human-originated. To the best of our knowledge, a L. casei strain which can produce DHNA was firstly identified in this study.

• Management Science and Financial Engineering
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• v.13 no.1
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• pp.55-72
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• 2007

We consider the product differentiation model of online channel competition and examine the strategies of hybrid firms in terms of efficiency. After measuring the social cost of online business strategies, we show that (i) online channel of hybrid firm under blockaded entry may increase the social cost if the firms' delivery cost is sufficiently smaller than the consumer's transportation cost, and (ii) online competition under free entry may increase the social cost if the firms' delivery cost is sufficiently larger than the consumer's transportation cost. Finally, we discuss the strategic incentive of hybrid firms to reduce delivery cost and investigate the effect of the Internet maturity on the social cost.

• The Korean Journal of Food And Nutrition
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• v.37 no.2
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• pp.123-127
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• 2024

The fatty acid composition and free amino acid content of domestic soybean cultivars were analyzed to confirm the quality characteristics of protein and fat contained in soybeans. The saturated fatty acid content of soybeans included palmitic acid at 9.47~11.15%, followed by stearic acid and myristic acid. The total saturated fatty acid content in soybeans was 12.56~14.34%, with Taekwang having the lowest content, followed by Daewon, Seonyu, Cheonga, and Jinpung. The linoleic acid content, an unsaturated fatty acid, was 45.69~58.17%, with Taekwang showing the lowest composition and Jinpung showing the highest composition. Next was oleic acid at 14.69~33.86%. Jinpung had the highest linoleic acid composition, had the lowest and Taekwang which had the least linoleic acid, had the highest. The unsaturated fatty acid content was in the order of linolenic acid, eicosatrienoic acid, eicosadienoic acid, and eicosapentaenoic acid. The total free amino acid content was 217.28~456.66 mg%, with Daewon showing the highest free amino acid content, followed by Seonyu, Taekwang, Cheonga, and Jinpung. The free amino acid content varied depending on the cultivars, but in general, the free amino acids in the soybeans used in the experiment showed higher aspartic acid, glutamic acid, and proline contents than other amino acids.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.81-98
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• 2002

This paper documents the development of a bi-objective(minimizing delays and Queue lengths) cycle-free signal timing length model using Genetic Algorithm. The model was embodied using MATLAB. the language of technical computing. A special feature of this model is its ability to concurrently manage delays and queue lengths of turning movement concurrently. The model produces a cycle-free signal timing(cycles and green times) for each intersection on the cycle basis. Appropriate offsets could be also accomplished by applying cycle-free based signal timings for respective intersections. The model was applied to an example network which consists of four intersections. The result shows that the model produces superior signal timings to the existing signal timing model in terms of managing delays and queue lengths of turning movements.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.16-22
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• 2015

Alkaloids of Vinca minor L. were characterized by HPLC equipped with the photo diode array detector and compared their UV/vis absorption spectra with an index material such as vincamine. UV/vis absorption spectra of more than 9 compounds belong to various classes such as flavonoids were shown and characterized. Extracts with ethanol or hot water were tested against the DPPH (2,2-diphenyl-1-picrylhydrazyl) free-radical to investigate their antioxidant activity. Based on the results, those extracts show about 14-15% of antioxidant activity of quercetine and vitamin C used as standards.

• The Korean Journal of Food And Nutrition
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• v.36 no.1
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• pp.42-49
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• 2023

To enhance the efficacy of Abeliophyllum distichum leaves, extracts were prepared using different solvents for hydrolytic enzyme-treated Abeliophyllum distichum leaves. Physicochemical quality and antioxidant activity were measured. Soluble solids, reducing sugar, ascorbic acid, flavonoids, and polyphenols contents showed the lowest values in the control without enzyme treatment. However, they showed high contents in ethanol extract. In the case of enzyme treatment, their values were higher than those of the control. In particular, verbascoside content increased about 220 times more than that of the control group when treated with enzymes and extracted with 50% ethanol. pH was lowered upon enzymatic treatment. Regarding DPPH radical scavenging activity, for enzyme-free, 25% ethanol extract showed the highest activity among extracts with different solvents. For cellulase and pectinase-treated leaves, water extract showed the highest DPPH radical scavenging activity among extracts with different solvents. For leaves treated with enzyme combination, 50% ethanol extract showed the highest DPPH radical scavenging activity among extracts with different solvents. Regarding ABTS radical scavenging activity, it was generally higher in the 50% ethanol extract than in the water extract and 25% ethanol extract. In particular, verbascoside content was increased when the extract was prepared by co-treatment with enzymes and 50% ethanol.

• Ocean Systems Engineering
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• v.6 no.4
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• pp.363-375
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• 2016

Large numbers of submarine pipelines are laid as the world now is attaching great importance to offshore oil exploitation. Free spanning of submarine pipelines may be caused by seabed unevenness, change of topology, artificial supports, etc. By combining Iwan's wake oscillator model with the differential equation which describes the vibration behavior of free-span submarine pipelines, the pipe-fluid coupling equation is developed and solved in order to study the effect of both internal and external fluid on the vibration behavior of free-span submarine pipelines. Through generalized integral transform technique (GITT), the governing equation describing the transverse displacement is transformed into a system of second-order ordinary differential equations (ODEs) in temporal variable, eliminating the spatial variable. The MATHEMATICA built-in function NDSolve is then used to numerically solve the transformed ODE system. The good convergence of the eigenfunction expansions proved that this method is applicable for predicting the dynamic response of free-span pipelines subjected to both internal flow and external current.

• Membrane Journal
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• v.22 no.5
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• pp.352-358
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• 2012

In this study, we found structure-property relationship for pressure retarded osmosis (PRO) membrane, between BPS-XX and BisA-XX having similar structure but different free volume. And this comparison was subdivided by controlling its sulfonation degree. BPS-XX and BisA-XX were prepared via a polycondensation reaction. The degree of sulfonation were 20 to 60 mol.%. And they were fabricated to membrane. Characteristics were analyzed to verify of free volume. And the results showed that increase of free volume normally lead to increase permeability and decrease selectivity in equivalent molecule structure. Finally, in the permeability-selectivity results, we conclude high permeability and selectivity membrane can be prepared by controlling molecular structure and free volume.

• Journal of the Chungcheong Mathematical Society
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• v.29 no.4
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• pp.643-650
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• 2016

In this paper, we introduce the notion of a semiderivation on near-rings, and we try to generalize some properties of prime rings with derivations to prime near-rings with semiderivations.

• Proceedings of the KOR-KST Conference
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• 2007.11a
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• pp.467-476
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• 2007