• ETRI Journal
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• v.44 no.4
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• pp.588-598
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• 2022

Since multi-access edge computing (MEC) was established as a key enabler of 5G, MEC based on 5G networks (5G MEC) has been perceived as a new business opportunity for many industry players, including telecom operators. Numerous 5G MEC cooperation announcements among companies playing their respective roles in the MEC ecosystem have been recently released. However, because of cooperative and competitive relationships among key players in the MEC ecosystem and the uncertainty of 5G MEC, the announcement of 5G MEC cooperation can negatively affect the telecom operators' firm value. This study investigates the market reaction to announcements of 5G MEC cooperation for telecom operators using an event study methodology. The empirical results show that announcements of 5G MEC cooperation have a negative impact on the telecom operators' firm value. The results also show that the early deployment of 5G networks may reduce the negative impact of 5G MEC cooperation announcements by reducing uncertainty.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.91-91
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• 2018

The Rosa multiflora, a well-known plant belonging to Rosacea, is widely used in orthodox medicine in worldwide. However, its biological activity as a functional ingredient for cosmetic products have not yet been studied. Accordingly, an investigation of the above mentioned atrributes was performed on a 50% ethanol extract of Rosa multiflora. The antioxidant activities were determined by DPPH. Additionally, the contents of total phenols and flavonoids were analyzed. Also, the phenolic compounds were detected using HPLC. The melanogenesis regulatory effect was evaluated using melanin content and cellular tyrosinase activity in B16F10 melanoma cells. The elastase inhibitory activity assay was performed for anti-wrinkle effect. The antimicrobial activity was assessed using the disc diffusion assay. The DPPH radical scavenging ability, denoted by the $SC_{50}$ value was found to be $123.1{\mu}g/ml$, whereas that of positive control (ascorbic acid) was $27.5{\mu}g/mL$. The content of total polyphenol and flavonoid content were 202 mg/g and 86.77 mg/g, respectively. In addition, astragalin and gallic acid were identified in the extract. Also, the ethanol extract significantly inhibited ${\alpha}$-MSH-induced melanogenesis in B16F10 cells. For anti-wrinkle effect, elastase inhibition activity of the ethanol extract was 53.2% at a concentration of $100{\mu}g/ml$. The antimicrobial activity of the extract against S. aureus and E. coli was observed to be 0.5 - 5%, and no significant activity was noted against C. albicans. Therefore, the ethanol extract of Rosa multiflora can be used effectively for development of functional cosmetic materials.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.1
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• pp.97-102
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• 2008

For the use of salmon frame in zero emission, the snack using residues of salmon Gomtang was prepared and investigated on the food component characterization. According to the results of volatile basic nitrogen, water activity and sensory evaluation, the optimal substitution ratio of residues was 15% based on the mix. Total amino acid content was higher in the snack (14.8 g/100 g) with 15% residues than in snack (9.8 g/100 g) without residues. The major amino acids of the residues-added snack were aspartic acid (9.9%), glutamic acid (14.7%) and proline (9.5%). The snack with 15% residues were enriched in the mineral (calcium and phosphorus) and polyunsaturated fatty acid (20:5n-3 and 22:6n-3) compared to those of snack without residues.

• Animal Bioscience
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• v.37 no.4
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• pp.689-696
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• 2024

Objective: Our study examined the impact of propriety blends of Bacillus strain probiotics on the performance, egg quality, and faecal microflora of laying hens. Methods: A total of 183 Institut de selection Animale (ISA) brown laying hens aged 23 weeks with an average body weight of 1,894±72 g were randomly allocated into 3 groups as control (corn-soybean meal based diet, CON), 0.5 g/kg Enterosure probiotics (ET1, 3×10⁸ colony-forming unit [CFU]/kg feed), and 5 g/kg Enterosure probiotics (ET2, 3×10⁹ CFU/kg feed) administered in mashed form. At the completion of each phase hen day egg production (HDEP), average egg weight (AEW), feed intake, and faecal microbiota were evaluated. Results: HDEP and AEW were higher (p<0.05) in the ET2-supplemented diet in phase 3 (week 9 to 12) compared with CON. Egg mass (EM) was higher (p<0.05) in phase 2 at ET2, and also higher (p<0.05) in phase 3 at the ET1 and ET2-supplemented diets compared with CON. Feed conversion ratio was lower (p<0.05) in phase 3 at the ET1 and ET2-supplemented diets, with ET2 being the lowest compared with ET1 and CON. Yolk colour was higher (p<0.05) in the ET-supplemented diets at phase 3 compared with CON. Bifidobacterium spp. was higher (p<0.05) in the ET2- supplemented diet compared with CON in phase 2, while in In phase 3, Lactobacillus spp. and Bifidobacterium spp. were higher (p<0.05) in the ET-supplemented diets compared with CON. Coliforms were lower (p<0.05) in the ET-supplemented diets compared with CON in phase 3. Conclusion: The propriety blends of Bacillus strain probiotics supplements at 0.5 g/kg and 5 g/kg could improve the production and quality of eggs with more significance at 5 g/kg for HDEP, AEW and EM, which was achieved via the increase of beneficial microbiomes such as Lactobacillus spp., Bifidobacterium spp., and the decrease of pathogenic microbiomes like Escherichia coli and Coliforms which was speculated to improve gut barrier function and the reproductive hormone.

• Korean Journal of Ichthyology
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• v.23 no.3
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• pp.225-233
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• 2011

This is the attempt to study the fish assemblages in eelgrass bed of Jeogu on Geoje Island, Korea. Samples were collected by surf net monthly from August 2009 to July 2010. A total 38 species, 2,335 individuals, and 5,289.8g of fishes were collected. The dominant species were Chaenogobius annularis, Gymnogobius heptacanthus, Rudarius ercodes, Siganus fuscescens, Ditrema temminckii, Takifugu niphobles, Aulichthys japonicus, Pseudoblennius cottoides, Syngnathus schlegeli, Sebastes schlegelii, Pterogobius elapoides, Urocampus nanus, Takifugu pardalis, Hypodytes rubripinnis which accounted for 94.2% of total number of individuals of fish collected. Eelgrass biomass showed a peak in August (DW 121.5g/m$^2$), low values in November (DW 74.9 g/m$^2$) to February (DW 49.3g/m$^2$), and started growing from May (DW 112.8g/m$^2$). Gymnogobius heptacanthus, Sebastes schlegeli, Takifugu niphobles, Syngnathus schlegeli, Urocampus nanus were collected year-round with no clear relationship to the biomass of eelgrass bed.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1087-1095
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• 2020

Objective: The present study aimed to evaluate the effects of γ-aminobutyric acid (GABA)-producing bacteria (GPB) on in vitro rumen fermentation and on the growth performance and meat quality of Hanwoo steers. Methods: The effects of GPB (Lactobacillus brevis YM 3-30)-produced and commercially available GABA were investigated using in vitro rumen fermentation. Using soybean meal as a substrate, either GPB-produced or commercially available GABA were added to the in vitro rumen fermentation bottles, as follows: control, no additive; T1, 2 g/L GPB; T2, 5 g/L GPB; T3, 2 g/L autoclaved GPB; T4, 5 g/L autoclaved GPB; T5, 2 g/L GABA; and T6, 5 g/L GABA. In addition, 27 Hanwoo steers (602.06±10.13 kg) were subjected to a 129-day feeding trial, during which they were fed daily with a commercially available total mixed ration that was supplemented with different amounts of GPB-produced GABA (control, no additive; T1, 2 g/L GPB; T2, 5 g/L GPB). The degree of marbling was assessed using the nine-point beef marbling standard while endotoxin was analyzed using a Chromo-Limulus amebocyte lysate test. Results: In regard to in vitro rumen fermentation, the addition of GPB-produced GABA failed to significantly affect pH or total gas production but did increase the ammonia nitrogen (NH₃-N) concentration (p<0.05) and reduce total biogenic amines (p<0.05). Animals fed the GPB-produced GABA diet exhibited significantly lower levels of blood endotoxins than control animals and yielded comparable average daily gain, feed conversion ratio, and beef marbling scores. Conclusion: The addition of GPB improved in vitro fermentation by reducing biogenic amine production and by increasing both antioxidant activity and NH₃-N production. Moreover, it also reduced the blood endotoxin levels of Hanwoo steers.

• Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.12.1-12.8
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• 2016

Roe is the term used to describe fish eggs (oocytes) gathered in skeins and is one of the most valuable food products from fishery sources. Thus, means of processing are required to convert the underutilized yellowfin tuna roes (YTR) into more marketable and acceptable forms as protein concentrate. Roe protein concentrates (RPCs) were prepared by cooking condition (boil-dried concentrate, BDC and steam-dried concentrate, SDC, respectively) and un-cooking condition (freeze-dried concentrate, FDC) from yellowfin tuna roe. The yield of RPCs was in the range from 22.2 to 25.3 g/100 g of roe. RPCs contained protein (72.3-77.3 %), moisture (4.3-5.6 %), lipid (10.6-11.3 %) and ash (4.3-5.7 %) as the major constituents. The prominent amino acids of RPCs were aspartic acid, 8.7-9.2, glutamic acid, 13.1-13.2, and leucine, 8.5-8.6 g/100 g of protein. Major differences were not observed in each of the amino acid. K, S, Na, and P as minerals were the major elements in RPCs. No difference noted in sodium dodecyl sulfate polyacrylamide gel electrophoresis protein band (15-100 K) possibly representing partial hydrolysis of myosin. Therefore, RPCs from YTR could be use potential protein ingredient for human food and animal feeds.

• Journal of Environmental Science International
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• v.18 no.10
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• pp.1135-1141
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• 2009

Carrots (Daucus carota L.) are consumed as an important dietary source of provitamin A including $\beta$-carotene, $\alpha$-carotene and lutein. An HPLC method was applied to determine the content of the carotenoid composition in carrot cutivars cultivated in Korea. HPLC analyses were carried out with five carrot cultivars (Socheon-5-chon, Hongsim-5-chon, Myeongju-5-chon, Seonhongbom-5-chon and Betarich) sown at April, 2007 and six cultivars (Yeoreum-5-chon, Hanyeoreum-5-chon, Sinheukjeon-5-chon, Bibariheukjeon, Manina and Betarich) sown at August of the same year. In general, the former varieties are not used for the sowing at summer because of their bolting (growth of floral axis). The former and the latter carrots were harvested after 110 and 96 days from seeding, respectively, and the carotenoids were extracted with acetone after freeze-drying. The amount of $\alpha$-carotene ($117.7{\sim}205.3\;{\mu}g/g{\cdot}DW$) was similar to that of $\beta$-carotene ($113.1{\sim}189.6\;{\mu}g/g{\cdot}DW$) for the carrot cultivars sown at spring, while the content ($46.2{\sim}71.1\;{\mu}g/g{\cdot}DW$) was about a half of $\beta$-carotene content ($92.5{\sim}140.2\;{\mu}g/g{\cdot}DW$) for the latter cultivars. In addition, the average content of lutein ($25.2\;{\mu}g/g{\cdot}DW$) in the former cultivars was eight times higher than that in the latter cultivars ($3.1\;{\mu}g/g{\cdot}DW$). Among the spring cultivation types, Socheon-5-chon and Myeongju-5-chon showed higher amount of $\alpha$-carotene and $\beta$-carotene, while the higher amount was determined in Yeoreum-5-chon and Sinheukjeon-5-chon among the autumn cultivation types. Validation of the HPLC-DAD method showed good linearity ($r^2$ > 0.997) of the three compounds analyzed in a wide concentration range ($0.025{\sim}20\;{\mu}g/ml$). The R.S.D. values for intra-day and inter-day precision were less than 19.2% and the mean recovery of each compound was 85.4~104.7%.

• Journal of Applied Biological Chemistry
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• v.50 no.4
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• pp.215-220
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• 2007

One of the important functions of skin is protection from harmful environments. Many studies have explored how to prevent skin from wrinkling and the occurrence of pigmentation changes. Skin wrinkling and pigmentation changes could be caused by unusual disruption of connective tissue, the formation of free radicals and ultraviolet radiation. In this study, extracts obtained from 254 different kinds of Jeju medicinal plants were screened for inhibitory effects on tyrosinase and elastase, and for free radical scavenging effects. Four herbs, Phormium tenax, Morus bombycis, Morus alba, and Cudrania tricuspidata, were potent inhibitors of tyrosinase ($IC_{50}$ values 4.62, 5.46, 8.17, and 64.17 ${\mu}g$/mL, respectively). Aleurites fordii [$IC_{50}$: 5.29 ${\mu}g$/mL, 1,1-diphenyl-2-picrylhydrazyl (DPPH)], Distylium racemosum ($IC_{50}$: 6.14 ${\mu}g$/mL), Acer palmatum ($IC_{50}$: 5.44 ${\mu}g$/mL), and Spiraea salicifolia ($IC_{50}$: 5.25 ${\mu}g$/mL) showed good antioxidative effects. Furthermore, Distylium racemosum ($IC_{50}$: 7.51 ${\mu}g$/mL), Diospyros kaki ($IC_{50}$: 15.1 ${\mu}g$/mL), Cornus macrophylla ($IC_{50}:$ 16.59 ${\mu}g$/mL), and Psidium guajava ($IC_{50}$: 40.25 ${\mu}g$/mL) exhibited potent inhibitory effects on elastase. These results suggest that medicinal plants possessing several biological activities may be potent inhibitors of the processes involved in pigmentation increases and aging. Further investigations will focus on in vivo assays and on the chemical identification of the major active components responsible for whitening and anti-aging activity in the screened efficacious extracts.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.2
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• pp.165-173
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• 2020

Fish roe is among the most valuable food resources produced by fisheries. Raw fish roe requires processing for conversion into hygienic, marketable, and consumer-acceptable forms. In this study, to investigate the food compositional characteristics of various types of fish roe, we applied vacuum freeze-drying to prepare fish roe concentrates (FRCs) from roe of Alaska pollack Theragra chlcogramma, bastard halibut Paralichythys olivaceus, and skipjack tuna Katsuwonus pelamis. The FRC yield ranged from 22.7 to 26.7 g/100 g roe. The major constituents of FRCs were protein (65.4-79.6%), moisture (2.8-6.2%), lipids (8.5-18.3%), and ash (4.8-7.2%). Potassium, sulfur, sodium, and phosphorus were the major mineral elements of FRCs, and the major amino acids were aspartic acid (9.0-10.4 g/100 g protein), glutamic acid (13.2-14.5 g/100 g protein), lysine (8.4-8.6 g/100 g protein), and leucine (8.3-9.7 g/100 g protein). Vacuum freeze-dried FRCs differed among fish species in terms of amino acid composition and electrophoresis protein band distribution. Therefore, FRCs are an excellent source of protein nutrition and an appropriate protein fortification material in human foods or animal feed.