• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.628-636
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• 2018

Because large buoys are mainly made of steel, they are heavy and vulnerable to corrosion by sea water. This makes buoy installation and maintenance difficult. Moreover, vessel collision accidents with buoys and damage to vessels due to the material of buoys (e.g., steel) are reported every year. Recently, light buoys adopting eco-friendly and lightweight materials have come into the spotlight in order to solve the previously-mentioned problems. In Korea, a new lightweight buoy with a 7-Nautical Mile lantern adopting expanded polypropylene (EPP) and aluminum to create a buoyant body and tower structure, respectively, was developed in 2017. When these light buoys are operated in the ocean, the visibility and angle of light from the lantern installed on the light buoys changes, which may cause them to function improperly. Therefore, research on the performance of light buoys is needed since the weight distribution and motion characteristics of these new buoys differ from conventional models. In this study, stability estimation and motion analyses for newly-developed buoys under various environmental conditions considering a mooring line were carried out using ANSYS AQWA. Numerical simulations for the estimation of wind and current loads were performed using commercial CFD software, Siemens STAR-CCM+, to increase the accuracy of motion analysis. By comparing the estimated maximum significant motions of the light buoys, it was found that waves and currents were more influential in the motion of the buoys. And, the estimated motions of the buoys became larger as the sea state became worser, which might be the reason that the peak frequencies of the wave spectra got closer to those of the buoys.

• Journal of Service Research and Studies
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• v.6 no.1
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• pp.83-95
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• 2016

We examine the information transmission between the Service Industrial Production Index and the Service Industrial Wholesale and Retail Index, based on the returns data offered by the Korea Bank. The data includes daily return data from January 2000 to September 2015. Utilizing a dynamic analytical tool-the VAR model, Granger Causality test, Impulse Response Function and Variance Decomposition have been implemented. The results of the analysis are as follows. Firstly, results of Granger Causality test suggests the existence of mutual causality the Service Industrial Production Index precede and have explanatory power the Service Industrial Wholesale and Retail Index However the results also identified a greater causality and explanatory power of the Service Industrial Wholesale and Retail Index over the Service Industrial Production Index. Secondly, the results of impulse response function suggest that the Service Industrial Production Index show immediate response to the Service Industrial Wholesale and Retail Index and are influenced by till time 5 From time 2, the impact gradually disappears. Also the Service Industrial Wholesale and Retail Index show immediate response to the Service Industrial Production Index and are influenced by till time 2.5, the impact gradually disappears. Lastly, the variance decomposition analysis shows that the changes of return of Service Industrial Production Index are dependent on those of the Service Industrial Wholesale and Retail Index. This implies that returns on the Service Industrial Production Index have a significant influence over returns on the Service Industrial Wholesale and Retail Index. It contributes to the understanding of market price formation function through analysis of detached the Service Industrial Production Index and Service Industrial Wholesale and Retail Index. Finally, our results can be used as a guide by the Korea Bank and Republic of Korea and as well as Statistics Korea.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.4 s.59
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• pp.233-239
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• 2006

This study was carried out for the evaluation of the effects of emulsion containing the specific antibodies against S. aureus that secreted staphylococcal toxins in atopy dermatitis (AD). The emulsion was formulated to have basic moisturizing effect and the function to inhibit S. aureus colonization and Staphylococcal toxins. The results were as follows; 1. In 19 subjects, 14 subjects (73.7%) showed improvement in SCORAD the mean SCORAD score was improved by 21.87% at week 4 compared to pre-application (p < 0.05). 2. In 17 subjects with severe lesions, 14 subjects(82.35%) showed improvement in SCORAD; the mean SCORAD score was improved by 25.11% at week 4 compared to pre-application (p < 0.05). 3. In 19 subjects, 15 subjects (79%) showed improvement in TEWL; the mean TEWL was improved by 24.32% at week 4 compared to pre-application (p < 0.05). 4. In 17 subjects with severe lesions, 14 subjects (82.35%) showed improvement in TEWL; the mean TEWL was improved by 25.47% at week 4 compared to pre-application (p < 0.05). 5. In 19 subjects, 15 subjects (79%) showed improvement in keratin capacitance; the mean keratin capacitance was improved by 25.01% at week 4 compared to pre-application (P < 0.05). 6. In 17 subjects with severe lesions, 13 subjects (76.47%) showed improvement in keratin capacitance; the mean keratin capacitance was improved by 20.82% at week 4 compared to pre-application (p < 0.05). Based on above-described results, emulsion containing the specific antibodies against S. aureus that secreted staphylococcal toxins is considered to be helpful in the improvement of atopic dermatitis.

• Food Science and Preservation
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• v.22 no.3
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• pp.399-407
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• 2015

Sumaeyaksuk (Artemisia Argyi H.) is one of the original mugwort spices in Namhae-gun, Korea. This study was conducted to investigate the physicochemical characteristics and biological activities of water extracts from dried and aging Sumaeyaksuk samples during the May-July harvest season. One (SD) was dried under shade for 12 days, while the other (AD) was aged for 7 days at $60^{\circ}C$ and then roasted for 220 minutes at over $90^{\circ}C$. Glucose was solely detected as a free sugar, and its SD and AD content were $0.42{\pm}0.02{\sim}0.43{\pm}0.01g/100g$, and $0.41{\pm}0.02{\sim}0.47{\pm}0.04g/100g$, respectively. The total phenolic contents of SD were $1.85{\pm}0.09{\sim}3.45{\pm}0.14g/100g$, which were higher than those of AD ($1.29{\pm}0.08{\sim}2.90{\pm}0.08g/100g$). The antioxidant activities of the water extract powder from each Sumaeyaksuk were assessed by different in vitro methods, such as the DPPH and ABTS radical scavenging activity, FRAP, and decoloration prevention activity in ${\beta}$-carotene linoleic system. The DPPH and ABTS radical scavenging activity of AD extract were significantly higher than those of the SD extract (p<0.05). Moreover, at the concentrations of 31.25, 62.5, 125, 250, $500{\mu}g/mL$, the FRAP of the SD-May extract showed $1.67{\pm}0.58{\sim}489.90{\pm}7.59{\mu}M$, while the AD-July extract showed $9.70{\pm}1.07{\sim}590.40{\pm}7.45{\mu}M$. The ${\beta}$-carotene decoloration prevention activity of the SD-May and AD-July extracts were $25.53{\pm}2.85{\sim}81.43{\pm}2.56%$, $35.98{\pm}2.22{\sim}79.00{\pm}1.42%$, respectively. Based on these results, the extracts of SD-May and AD-July were promising as a functional food source due to their high antioxidant activites.

• Food Science and Preservation
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• v.19 no.5
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• pp.783-791
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• 2012

The purpose of the study was to provide baseline information that could encourage consumers and establish the direction of development for sprouts and leafy vegetables. A survey on the consumption and preference for sprouts and leafy vegetables of 823 people over 20 years of age in Seoul and Gyeonggi province was conducted. The preference for sprouts was higher in men ($3.75{\pm}0.96$) than in women ($3.64{\pm}0.84$), whereas the preference for leafy vegetables was higher in women ($4.06{\pm}0.74$) than in men ($3.88{\pm}0.90$). Based on age, the respondents in their 40s or above had high preferences for sprouts and leaf vegetables due to the importance that they accorded to health and nutrition (p<0.01). The sprouts and leafy vegetables were purchased mainly for their high nutritional value. The purchase frequency of once a month or more for leafy vegetables (82.7%) was higher than that for sprouts (57.1%). The consumers purchased sprouts and leafy vegetables mainly from a large discount store. The respondents in their 20s showed the highest percentage of purchasing from a local store whereas the older ones showed a high preference for traditional markets. The reason for the choice of the place of purchase was convenience. The freshness and price were important factors in the consumption of sprouts and leafy vegetables. In the case of leafy vegetables, the consumers preferred to buy them using the conventional weight measurement system rather than in small packages. On the other hand, mixed small packages were preferred for sprouts. The purchase frequency was correlated with the preferences, need for improvement and purchase intent for sprouts and leafy vegetables. The aspects that require improvement for producing high-quality sprouts and leafy vegetables were the nutritional and functional properties. To increase the consumption of sprouts and leafy vegetables, there is need for variations and improvement of the quality and safety of the products.

• Food Science and Preservation
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• v.24 no.7
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• pp.1025-1033
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• 2017

In this study, Ledum palustre L. was extracted by 4 different methods (LPW, hot water extraction; LPA, autoclave extraction; LPU, ultrasonification extraction; LPE, 70% ethanol extraction) and LPE was fractionated by using polarity difference of each solvent and used as 4 samples (LPE/H, the n-hexane layer; LPE/E, the EtOAc layer; LPE/B, the n-BuOH layer; LPE/W, the $H_2O$ layer). Antioxidant activities of Ledum palustre L. extracts were measured by DPPH and ABTS. As a result, the DPPH and ABTS radical scavenging showed high activities with LPE (82.3%, 99.8%) and LPE/E (91.8%, 99.6%) at the concentration of $1,000{\mu}g/mL$. The anti-inflammatory activities of LPE and LPE/E were measured by the inhibitory activity against NO, $PGE_2$, TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 production on LPS-stimulated Raw 264.7 macrophages. As a result of MTT assay, cell viabilities of LPE and LPE/E were more than 90% at $25{\mu}g/mL$. NO and $PGE_2$ productions were inhibited by LPE (NO: 50%, $PGE_2$: 70%) and LPE/E (NO: 57%, $PGE_2$: 73%) at the concentration of $25{\mu}g/mL$. The inhibition activities against TNF-${\alpha}$, IL-$1{\beta}$, IL-6 production were 24%, 47% and 40% at the concentration of $25{\mu}g/mL$ of LPE. In particular, LPE/E showed 51%, 57% and 62% inhibition activities at the same concentration, respectively. From the above results, it can be concluded that $1,000{\mu}g/mL$ of LPE and LPE/E have the high antioxidant activities similar with Vitamin C, and $25{\mu}g/mL$, the low concetration of LPE and LPE/E have excellent anti-inflammatory activities. Therefore, if more research about anti-aging, whitening and antimicrobial activity of Ledum palustre L. extracts is carried out in the future, it will be possible to use them as effective materials for the prevention and treatment of inflammatory diseases and in the areas of functional foods and cosmetics.

• The Journal of Society for e-Business Studies
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• v.21 no.3
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• pp.51-78
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• 2016

Online-to-offline (O2O) commerce is the new trend that merges online commerce with traditional industries in various fields. The primary purpose of this paper is to find out which factors influence customers' intention to switch from call-based driver-for-hire services to O2O app-based services. This study used variables and factors based on Theory of Switching Intention, and Extended Unified Theory of Acceptance and Use of Technology in order to design research questions. We surveyed 500 users of call-based driver-for-hire services. According to the result of this study, dissatisfaction with the current call-based driver-for-hire services is estimated to be a significant factor that strengthens customers' intention to switch from the call-based driver-for-hire services to the app-based services. Loyalty to the previous call-based driver-for-hire services was not seen as a crucial motivator that causes customers to switch to the new O2O driver service. Switching cost also did not play a key role in explaining the relationship between dissatisfaction with the current call-based service and the intention to use the new app-based service. Performance expectancy, easiness in use, the level of user's knowledge or available assistance in relation to the use of app-based services, and expectancy for reasonable price was found to have meaningful impacts on customers' intention to switch from the call-based driver-for-hire services to the app-based services. Age, gender and user experience on the new service were found incapable of moderating the relationship between aforementioned factors which influence customers' choice of the app-based driver-for-hire service, and customers' intent to switch to the app-based service.

• Food Science and Preservation
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• v.20 no.3
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• pp.404-418
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• 2013

This study was conducted to investigate changes in the physicochemical properties (proximate compounds, reducing sugar, organic acid, ATP and related compounds, and free amino acid) of beachu kimchi (BK) with octopus, abalone, squid and webfoot octopus added during its storage at $4^{\circ}C$ for 35 days. The crude protein content of the seafood Kimchi, 1.98~3.41%, was higher than that of the BK. The organic acid level did not significantly differ in the four kinds of seafood during their fermentation, and their malate and succinate contents decreased while their lactate content increased. The levels of the ATP and related compound substances of the hypoxanthine contents were high but decreased during their fermentation. However, $3.40{\mu}mol/g$ of IMP was detected in the Kimchi with octopus added; $0.67{\mu}mol/g$ in the Kimchi with abalone added; and $1.80{\mu}mol/g$ in the Kimchi with squid added after they were fermented for 21 days, but the same were not detected in the BK. The taurine and ${\gamma}$-amino-n-butyric acid contents of the free amino acids in the seafood Kimchi were approximately two to 10 times and 1.5 to three times higher than in the BK, respectively.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.233-239
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• 2010

Four genes (yqfR, yfmL, ydbR, deaD) were identified as putative DEAD-box RNA helicase genes in the genomic sequence of Bacillus subtilis by homology search. To understand the function of these genes, each of the genes was deleted and the constructed strains were tested for their growth charateristics at different temperatures. The growth rate of ydbR deletion mutant ($T_d$=53 min) was a little bit reduced at $37^{\circ}C$ as compared to that of wild type strain (CU1065). But the growth rate of other three (yqfR, yfmL, deaD) deletion mutants ($T_d$=30-40 min) is nearly equal to the growth rate of wild type ($T_d$=32 min). On the other hands, the growth rate of deletion mutants were reduced at $22^{\circ}C$ in order of yqfR ($T_d$=151 min), yfmL ($T_d$=214 min), ydbR ($T_d$=343 min), which showed cold-sensitive phenotype. The deletion mutant of deaD ($T_d$=109 min) grew equally as compared to the growth rate ($T_d$=102 min) of the wild type at $22^{\circ}C$ and did not show cold-sensitive growth. Double, triple and quadruple deletion mutants of these genes were constructed, and growth rate of these mutants were measured at various temperature conditions ($22^{\circ}C$, $37^{\circ}C$, $42^{\circ}C$) using LB broth. Multiple deletion mutations showed more severe cold-sensitive growth than single deletion mutations, and double deletion of ydbR and yfmL ($T_d$=984 min) showed most cold-sensitive growth than any other double mutants. Such a cold-sensitive growth of these mutations is quite similar to the result of csdA or srmB deletion in E. coli and suggested that physiological role of ydbR and yfmL is related with ribosome assembly.

• Journal of Life Science
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• v.25 no.3
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• pp.329-335
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• 2015

This study was performed to determine the optimal ratio of Petasites japonicus, Luffa cylindrica, and Houttuynia cordata, all of which are supposed to have anti-respiratory disease effects, such as against rhinitis. The experiment incorporated a mixture design and included 12 experimental points with center replicates for three different independent variables (Petasites japonicus 30~70%; Luffa cylindrica 10~30%; and Houttuynia cordata 10~30%). Based on this design, the mixture was extracted in hot water at 121℃ for 45 min and anti-allergy and anti-microbial activities were observed. The response surface and trace plot described for the anti-allergy activity showed Petasites japonicas was a relatively important factor. The correlation coefficient (R²) value 82.10% for the inhibition effect of degranulation was analyzed by the regression equation. The analysis of variance showed the model fit was statistically significant (p<0.05). The optimal ratio of the mixture was Petasites japonicus 0.75%, Luffa cylindrica 0.11%, and Houttuynia cordata 0.14%. The anti-microbial activity for each extraction of the mixture was valid on gram-positive, such as Staphylococcus aureus (KCCM 40881) and Staphylococcus epidermidis (KCCM 35494), while it was less effective on gram-negative, such as Escherichia coli (KCCM 11234) and Pseudomonas aeruginosa (KCCM 11328).