• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.227-233
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• 2004

Chronic exposure to solar radiation, particularly ultraviolet (UV) light, causes a variety of adverse reactions on human skin, such as sunburn, photoaging and photocarcinogenesis. Free radicals and reactive oxygen species (ROS) caused by UV exposure or other environmental facts play critical roles in cellular damage. And, repeated-UV irradiation activated the expression of the matrix metalloproteinase (MMP) and induced skin irritation. Therefore, the development of effective and safe photoprotectants that can reduce and improve the skin damage has been required. The purpose of this study was to investigate the photo-protective effect of several chinese medical plants (Juniperus chinensis) on the UV -induced skin cell damages. We tested free radical and superoxide scavenging effect in vitro. Fluorometric assays of the proteolytic activities of MMP-1 (collagenase) were performed using fluorescent collagen substrates. UVA induced MMP-1 synthesis and activity were analyzed by enzyme-linked immunosorbent assay (ELISA) and gelatin-based zymography in skin fibroblasts. We also examined anti-inflammatory effects by the determination test of proinflammatory cytokine, interleukin 6 in HaCaT keratinocytes. Expression of prostaglandin E$_2$ (PGE$_2$) after UVB irradiation was measured by competitive enzyme immunoassay(EIA) using PGE$_2$ monoclonal antibody. In the human skin we tested anti-irritation effect on the SLS-induced damage skin after appling the extract containing emulsion. We found that Juniperus chinensis extract had potent radical scavenging effect by 98% at 100$\mu\textrm{g}$/mL. The extract of Juniperus chinensis showed strong inhibitory effect on MMP-1 activities by 97% at 100 $\mu\textrm{g}$/mL and suppressed the UVA induced expression of MMP-1 by 79% at 25$\mu\textrm{g}$/mL. This extract also showed strong inhibition on MMP-2 activity in UVA irradiated fibroblast by zymography. In the test of proinflammatory cytokines of human keratinocytes Juniperus chinensis extract decreased expression of interleukin 6 about 30%. The amount of PGE$_2$ by HaCaT keratinocytes was significantly increased at the doses of above 10 mJ/$\textrm{cm}^2$ of UVB (p < 0.05). At the concentrations of 3.2-25$\mu\textrm{g}$/mL of this extract, the production of PGE$_2$ by HaCaT keratinocytes (24 h after 10mJ/$\textrm{cm}^2$ UVB irradiation) was significantly inhibited in culture supernatants (p < 0.05). In SLS-induced skin irritation model in vivo, we found to reduce skin erythema and improve barrier recovery after appling Juniperus chinensis extract containing emulsion when compared to irritated non-treated and placebo-treated skin. Our results suggest that Juniperus chinensis extract can be effectively used for the prevention of UV and SLS-induced adverse skin reactions and applied as anti-aging and anti-irritation cosmetics.

• Journal of Technology Innovation
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• v.29 no.3
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• pp.1-31
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• 2021

With the growing importance of technology innovation as a key factor for firms' competitive advantage, 'innovation persistence' became also an important research subject. 'Innovation Persistence' is a concept that indicates whether or not firms' innovation activity or performance continues. However, the data used for innovation studies are carried out as cross-sectional surveys in most countries. For this reason, studies dealing with longitudinal aspect of innovation persistence are rare. In particular, there is almost no research on innovation persistence using Korean innovation survey data. This study reviews the concepts and characteristics of innovation persistence based on extant literature, and perform an empirical analysis on the status and features of Korean firms' technology innovation persistence. Based on the data of the Korean Innovation Survey (KIS) conducted every other year from 2012 to 2018, panel data on 3,379 firms which observed multiple times are constructed. As a result, only part of the firms with persistent innovation were observed (for innovation performance 10~12%, for innovation activity 15~17%), and it was found that the persistence of non-innovation was remarkable(about 52~57%). And it was confirmed that the persistence of innovation activities is stronger than that of innovation performance. Besides, some features by sub-types of innovation appeared. Product innovation showed higher persistence than process innovation, and internal R&D also showed higher persistence than joint/external R&D. As a result of additional logit analysis to identify factors, it was found that radical or gradual product innovation is the most influential factor in persisting innovation in the next period. Since the sample selection bias due to a limitations of raw data might exist in the panel data constructed in this study, it should be noted that faulty generalization of the results are not allowed. Nevertheless, this is the first study to examine the technology innovation persistence targeting Korean firms and is expected to be a starting point for follow-up studies. It is anticipated that advanced research results will be drawn through the establishment of official panel data and improved methodologies.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.12
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• pp.1686-1692
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• 2009

Garlic oil (GAR, Allium sativum L.) has been studied as a feed additive to improve animal production performance and decrease methane emission in ruminants. The present study was designed to determine the possible effect of GAR on fatty acid composition and accumulation in animal fat tissue using a cell model. 3T3-L1 preadipocytes at $2{\times}10^{4}\;mL^{-1}$ were seeded to 24-well plates and allowed to proliferate to reach confluence. The cells were then treated with media containing 0, 2.5, 5, 10, 20 and 40 $\mu{g}$ $mL^{-1}$ of GAR during the differentiation period for 8 days. Media containing dexamethasone, methyl-isobutylxanthine and insulin was applied during the first 2 days of the early differentiation period. On day 8 sub-sets of the wells were stained with oil red-O and the remaining cells were harvested for determination of glycerol-3-phosphate dehydrogenase [EC 1.1.1.8] (GPDH) activity (n = 6) and cellular fatty acid concentration (n = 6). It was found that supplementation of GAR increased (p<0.05) the ratio of monounsaturated fatty acids/saturated fatty acids in the adipocytes and showed inhibitory effect (p<0.05) on the post-confluent proliferation. With relative low dosage, GAR (5-20 $\mu{g}$ $mL^{-1}$) increased (p<0.05) the GPDH activity without affecting the cellular fatty acid concentration, while a high dosage (40 $\mu{g}$ $mL^{-1}$) inhibited (p<0.05) fatty acid accumulation and decreased GPDH activity. Supplementation of GAR had an effect on cell post-confluent proliferation, differentiation and fatty acid accumulation. However, the effect may be diverse and depends on the dose applied.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.4
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• pp.547-553
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• 2008

The principal objective of this study was to prepare watermelon wine with watermelon juice. For the manufacture of watermelon wine, we determined the contents of starting sugar content ($20^{\circ}Brix$, $25^{\circ}Brix$, $30^{\circ}Brix$, $35^{\circ}Brix$) and three different kinds of yeasts (EC-1118, K1-V1116, D-47). The main additives of the watermelon wine included $K_2S_2O_5$, $NH_4H_2PO_4$, bentonite, yeasts, sugar, mixed acid, and $C_6H_8O_2$. The watermelon wine was fermented at $15^{\circ}C$ until the remaining alcohol content was 5%. We assessed customers' preference regarding the manufactured watermelon wine via sensory evaluation. Three yeasts were shown to result in significantly different alcohol fermentation, among which K2-V1116 was selected for the preparation of the watermelon wine. In our sensory evaluation, the preference of the starting sugar contents was highest in the watermelon wine with $25^{\circ}Brix$ of sugar content. The preference of alcohol content was found to be higher in the watermelon wines prepared with sugar contents of 5% and 7%. The preference test between watermelon wines and purchased white wines demonstrated that the watermelon wine with an alcohol content of 5% was the most preferred wine, and the Chilean Late Harvest wine was the second most preferred.

• The Journal of the Korea Contents Association
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• v.8 no.10
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• pp.317-327
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• 2008

Go-Yang city, rural region by the 1980s, had rapidly grown to the big city for only 15 years because of Il-San new town development which was developed during $1990{\sim}1995$. So the population and industrial function were greatly increased too. The change of urban spatial structure was grasped by tracing the distribution of population, household and industries of Go-Yang city during $1990{\sim}2005$. The new urban center had grown to the center of the whole city, while the industries of existing centers were extended to the neighbor areas. The existing centers had been changed into 3 types - (1) changed into a part of new urban center, (2) declined to sub-center with small merchant facilities. (3) continuously grown with the development of whole city. As a result, a new town development had changed the urban structure by creating new functional relationships among the existing and new centers rather the existing centers had declined.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1577-1580
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• 2012

The orientational and dynamic behavior of liquid crystal molecules on the alignment layer surfaces of liquid crystal display (LCD) devices is crucial to their performance, but there are only a few methods of experimentally elucidating the interactions between the liquid crystals and the alignment layers. Inspired by the natural and technical similarities between membrane proteins in lipid bilayers and liquid crystals in LCDs, we employed solid-state NMR methodologies originally developed for the study of membrane proteins in lipid bilayers for the in-situ analysis of liquid crystal display panels. In this article, we present a home-built 500 MHz narrowbore (NB) The orientational and dynamic behavior of liquid crystal molecules on the alignment layer surfaces of liquid crystal display (LCD) devices is crucial to their performance, but there are only a few methods of experimentally elucidating the interactions between the liquid crystals and the alignment layers. Inspired by the natural and technical similarities between membrane proteins in lipid bilayers and liquid crystals in LCDs, we employed solid-state NMR methodologies originally developed for the study of membrane proteins in lipid bilayers for the in-situ analysis of liquid crystal display panels. In this article, we present a home-built 500 MHz narrowbore (NB) $^{19}F-^{13}C$ double resonance solid-state NMR probe with a flat-square coil and the first application of this probe for the in-situ analysis of LCD panel samples. double resonance solid-state NMR probe with a flat-square coil and the first application of this probe for the in-situ analysis of LCD panel samples.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.261-267
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• 2011

The test fit has commonly used for the evaluation of the railbed condition, and indirect methods by using the compressional wave are also studied. the direct evaluation method by penetration test has not been studied. For the measurement of in-situ cone tip resistance of the railbed with minimizing the disturbance of the upper railbed. the cone penetrometer with the helical type outer rod(CPH) was developed. The outer rod, which has helical screw, is penetrated through the gravel layer and provides the reaction force for cone penetration testing. the cone tip resistances are measured by the mini cone penetrometer, where diameter is 15mm. For the developing the mini cone, strain gauge installation, circuit configuration, penetration rates and calibration process are considered. For the easy penetration of the screw rod in the field, the reaction force stepping plate and guide column are arranged. The screw rod are penetrated through the gravel layer. And the mini cone was pushed into the subgrade railbed at the penetration rate of 1mm/sec. The penetration test shows that the cone tip resistance increases along the depth. In addition, the subgrade condition is evaluated. This study demonstrates that the CPH may be effectively used for the evaluation of subgrade method any damage of the gravel layer.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.485-491
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• 2015

This study was conducted to develop stem volume models for the volume estimation of Quercus glauca Thunb. in Jeju Island, Republic of Korea. Furthermore, this study validated the developed stem volume models using an independent dataset. A total of 167 trees were measured for their diameter at breast height (DBH), total height and stem volume using non-destructive sampling methods. Eighty percent of the dataset was used for the initial model development while the remaining 20% was used for model validation. The performance of the different models was evaluated using the following fit statistics: standard error of estimate (SEE), mean bias absolute mean deviation (AMD), coefficient of determination (R²), and root mean square error (RMSE). The AMD of the five models from the different DBH classes were determined using the validation dataset. Model 5 (V = aD^bH^c), which estimates volume using DBH and total height as predicting variables, had the best SEE (0.02745), AMD (0.01538), R² (0.97603) and RMSE (0.02746). Overall, volume models with two independent variables (DBH and total height) performed better than those with only one (DBH) based on the model evaluation and validation. The models developed in this study can provide forest managers with accurate estimations for the stem volumes of Quercus glauca in the subtropical forests of Jeju Island, Korea.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.403-410
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• 2016

Computer game is a result of integration of various academic areas, and the production of computer game requires knowledge and experience from various areas. This study demonstrates a game production process using Scratch. The intent was to experience the game development process and the production principle through actually building the core functions of a game using Scratch. As such, the computer game production principle was understood and it was made possible to learn more easily and more enjoyably the functions of multimedia and programming necessary for the production process. As the result, the learning of game production principles using Scratch was found to enhance the interest of the learner, and help with the understanding of game structure and learning software/programming language.

• School Mathematics
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• v.17 no.2
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• pp.289-308
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• 2015

This study analyzed mathematical processes elaborated in the mathematics curricula of Korea, China, Japan, and the US. Ten mathematical processes were extracted: (a) learning of concepts, principles, laws, and skills; (b) problem solving; (c) reasoning; (d) communication; (e) representation; (f) connections; (g) creativity; (h) character-building; (i) self-directed learning; and (j) positive attitude toward mathematics. This study specified the meaning of such processes and their sub-domains, noticing similarities and differences among the curricula. On the basis of the results, this study includes suggestions for the development of next mathematics curriculum in Korea.