• Journal of Information Technology Applications and Management
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• v.20 no.1
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• pp.173-195
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• 2013

This study is to analyze the impact of the absorptive capacity and information technology (IT) on firms' innovation. The absorptive capacity is measured by R&D investment intensity, R&D manpower concentration, and the firm's size. We try to see the interaction effects between the absorptive capacity and IT usage on firms' innovation. We also look into the differences of the impacts between manufacturing industry and service industry as well as IT industry and service industry. We found that IT and R&D intensity have stronger interaction effect on innovation in manufacturing industry than in service industry, which shows that IT plays a more important role in the accumulation of knowledge in R&D activity in manufacturing industry. Contrarily, in service industry, IT and R&D manpower concentration has significant interaction effects on innovation. This means that the role of IT in service industry is sharing knowledge and experiences among employees in service industry. The interaction effect between firm's size and IT has positive impact on innovation in manufacturing industry, while it has negative impact on innovation in service industry. Finally, we found that the interaction effect is statistically significant in non-IT industry, while it is not statistically significant in IT industry.

• Korean Journal of Pharmacognosy
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• v.36 no.4 s.143
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• pp.273-277
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• 2005

In mammalian melanocytes, melanin synthesis is controlled by tyrosinase, the key enzyme in the pigment synthesis. In this study, to develop a new whitening agent, we have investigated the antioxidant and the inhibitory effect of Artemisia anomala extract on tyrosinase activity and melanigenesis in the B16/F1 melanoma cells. The inhibition ratio of tyrosinase activity of butanol fraction from A. anomala was higher than that of arbutin ($97.5{\pm}0.5%$ at the concentration of 2 mg/ml). The butanol fraction was shown scavenging activities of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and superoxide anion radicals in a dose dependent manner. The highest inhibitory activity of melanogenesis was also butanol fraction ($25.0{\pm}3%$ at the concentration of $200\;{\mu}g/ml$). From these results, we suggest that the A. anomala extract might be used to be a potential agent for skin whitening.

• Special Issue of the Society of Naval Architects of Korea
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• 2015.09a
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• pp.63-68
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• 2015

This paper presents fatigue analysis of helideck structures located in FPSO. After FPSO is moved to the target position where production of resource is performed, FPSO stays at the target position and performs production of resource, storage and off-loading during the design life. Helideck structure is located in FPSO essentially for the movement of personnel and life rescue at emergency situations by using helicopters. Because inertial load induced by FPSO motion and landing and taking-off load of helicopter occur at helideck structures cyclically, helideck structures should be designed to withstand fatigue loads. Therefore, The fatigue assessment of helideck structures should be performed with fatigue loads. Effect of stress concentration due to misalignment between welded plates is considered in fatigue assessment additionally.

• Natural Product Sciences
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• v.5 no.1
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• pp.12-19
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• 1999

Eleven out of 118 herbal medicines which are frequently used in Korean traditional prescriptions for inflammatory diseases exhibited more than 50% of inhibition on $TNF-{\alpha}$ production in LPS-stimulated RAW264.7 cells by their total ethanol extracts with 0.1 mg/ml as a final concentration. The active 11 total extracts were prepared from Angelica koreana, Coptis japonica, Cynanchum paniculatum, Magnolia frgesii, Magnolia officinalis, Panax ginseng, Patrinia scabiosaefolia, Pterocarpus santalius, Rhapontica uniflora, Saussurea lappa. Of them, Coptis japonica, Magnolia fargesii and Saussurea lappa also significantly inhibited $TNF-{\alpha}$ production in vivo. These total extracts were sequentially fractionated with n-hexane, methylene chloride, ethyl acetate, n-butanol and water. Among the solvent-fractionated extracts with 0.05 mg/ml as a final concentration, inhibitory effects of Angelica koreana, Magnolia fargesii, Magnolia officinalis, Pterocarpus santalinus, Rhapontica uniflora and Saussurea lappa markedly showed in one or two solvent fractions suggesting that the principles may be concentrated by subfractionation as the main compounds.

• Journal of odor and indoor environment
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• v.17 no.4
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• pp.346-354
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• 2018

In this study, the condition of the hazardous materials in the bus was monitored according to the ventilation mode of the air conditioning system during bus service. The bus was surveyed using the indoor air quality measurement method of public transportation vehicles within one year of delivery. We evaluate the $CO_2$ and $PM_{10}$, which are the controlled parameters in buses by the Ministry of Environment, and VOCs and HCHO, the non-controlled parameters. The $PM_{10}$ concentration increased due to outdoor air intake; however the $CO_2$ concentration was found to decrease. In addition, the concentration of VOCs and HCHO was found to decrease due to the forced ventilation system and the outdoor air intake. These results show that the concentration of the other materials except $PM_{10}$ can be changed due to the outside air concentration and forced ventilation system. Therefore, through indoor air quality characteristics of the bus according to air condition system are intended to be used as the basis of an operation manual.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.557-561
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• 2014

The aim of the present study was to improve dosing of lacosamide, a functionalized amino acid used as an antiepileptic agent, from twice daily to once daily for the convenience of patients. A sustained-release lacosamide tablet was developed and dissolution testing was employed to determine in vitro release behavior using water or buffer solutions at pH 1.2, 4.0, or 6.8. Lacosamide was released for 12 h from the sustainedrelease (SR) tablet, as compared to complete release within 1 h from an immediate-release $Vimpat^{(R)}$ tablet. Each formulation (100 mg) was orally administered to six beagle dogs and six mini-pigs under fasted conditions, and pharmacokinetic parameters such as the area under the concentration time curve ($AUC_t$), the maximum plasma concentration ($C_{max}$), and the time at which this occurred ($T_{max}$) were calculated. These results showed similar values for $AUC_t$, $C_{max}$, and $T_{max}$ following oral administration of immediate-release ($Vimpat^{(R)}$) and SR lacosamide tablets.

• Journal of the Korean Institute of Gas
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• v.5 no.3 s.15
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• pp.36-44
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• 2001

In case of low odor level, accident probabilities are very high Otherwise, when the odorant concentration is too high, the deterioration of pipeline and governor facilities and the environmental problems may occur. Odorants fade in the pipeline and other equipment due to physical and chemical adsorption and reactions with odorant and materials. So, it is very important to maintain odorant concentration properly In this study, the current status of odorization technologies has been reviewed. And the characteristics of small odorant system have been analyzed. In case that the small odorant system Is introduced in our country, this paper is proposed the feasible management plan and showed feasibility results through the analysis of current available technology.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.2
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• pp.19-31
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• 1999

Most breakthrough tests are conducted at higher concentration levels compared to those in the field of air-purifying respirator applications. For example, typical challenge concentrations for breakthrough tests agains tcarbon tetrachloride are ranged between 250-1000 ppm although applicable concentrations range for air-purifying cartridge is 5-50 ppm for carbon tetrachloride. However, no guarantee has been made that isotherms derived from the experiment at high challenge concentrations could estimate adsorption capacity at the lower concentration range where workers wear usually air-purifying respirators. Three models of adsorption isotherms (Freundlich, Langmuir and Dubinin/Radushkevich(D/R) isotherms) that have been commonly applied for respirator cartridge testing were evaluated. Adsorption capacity at each challenge concentration was calculated from the Reaction Kinetic equation fitted for the breakthrough data. These data were used for derivation of three isotherms. In general, the D/R isotherm has given the best agreement between estimated adsorption capacities and experimentally measured. If the challenge concentration of 100 ppm is included for derivation of models, Freundlich and D/R models could succes sfully produced good estimations for adsorption capacities at 50 ppm level. Estimated adsorption capacities by both models ranged in 94 - 109 % of the experimentally measured. However, Langmuir model gives underes timation in all cases.

• Archives of Pharmacal Research
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• v.28 no.2
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• pp.195-202
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• 2005

Free radicals and reactive oxygen species (ROS) caused by UV exposure or other environmental factors are critical players in cellular damage and aging. In order to develop a new antiphotoaging agent, this work focused on the antioxidant effects of the extract of tinged autumnal leaves of Acer palmatum. One compound was isolated from an ethyl acetate soluble fraction of the A. palmatum extract using silica gel column chromatography. The chemical structure was identified as apigenin-8-C-beta-D-glucopyranoside, more commonly known as vitexin, by spectral analysis including LC-MS, FT-IR, UV, $^{1}H-$, and $^{13}C-NMR$. The biological activities of vitexin were investigated for the potential application of its anti-aging effects in the cosmetic field. Vitexin inhibited superoxide radicals by about $70\%$ at a concentration of $100\;{\mu}g/mL$ and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals by about $60\%$ at a concentration of $100\;{\mu}g/mL$. Intracellular ROS scavenging activity was indicated by increases in dichlorofluorescein (DCF) fluorescence upon exposure to UVB $20\;mJ/cm^2$ in cultured human dermal fibroblasts (HDFs) after the treatment of vitexin. The results show that oxidation of 5-(6-)chloromethyl-2',7'-dichlo-rodihydrofluorescein diacetate ($CM-H_{2}DCFDA$) is inhibited by vitexin effectively and that vitexin has a potent free radical scavenging activity in UVB-irradiated HDFs. In ROS imaging using a confocal microscope we visualized DCF fluorescence in HDFs directly. In conclusion, our findings suggest that vitexin can be effectively used for the prevention of UV-induced adverse skin reactions such as free radical production and skin cell damage.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.1
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• pp.80-85
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• 2006

Ninety six crossbred pigs (Landrace${\times}$Yorkshire${\times}$Duroc) were used to determine the effects of essential oils (Fresta F $Conc^{(R)}$) supplementation on growth performance, immune response and fecal noxious gas of weaned pigs. Treatments were 1) NC (negative control; basal diet without antibiotics), 2) PC [positive control; basal diet+CSP (CTC+Sulfathiazole+Penicillin) 0.1%], 3) NCF (basal diet+Fresta F $Conc^{(R)}$ 0.03%) and 4) PCF [basal diet+CSP (CTC+Sulfathiazole+Penicillin) 0.1%+Fresta F $Conc^{(R)}$ 0.02%]. From d 0 to 14, ADFI was increased in pigs fed PCF diet (p<0.05). From d 14 to 28, pigs fed PCF diet had greater ADG and ADFI than pigs fed NC diet (p<0.05). From d 28 to 49, ADG and ADFI in pigs fed PCF diet were higher than in pigs fed NC diet (p<0.05). Through the entire experimental period, ADG and ADFI in pigs fed PCF diet were the highest compared to pigs fed NC and PC diets (p<0.05). There was no significant difference in fecal consistency score among the treatments (p>0.05). No statistical differences (p>0.05) were found in red blood cells (RBC) counts, white blood cells (WBC) counts, lymphocyte counts, total protein and albumin. Serum IgG concentration of PCF treatment was greater than that of other treatments (p<0.05). From d 0 to 14, there was no significant difference in digestibility of dry matter and nitrogen among the treatments (p>0.05). From d 14 to 28, digestibility of dry matter in pigs fed PC, NCF and PCF diets was higher than that of pigs fed NC diet (p<0.05) and treatments with added essential oils were higher than other diets on digestibility of nitrogen (p<0.05). Also, from d 28 to 49, digestibility of nitrogen in pigs fed PCF diet was the highest among others (p<0.05). On d 14 and 28, no statistical differences (p>0.05) were found in volatile fatty acid (VFA), ammonia nitrogen ($NH_3$-N) and hydrogen sulfide ($H_2S$) concentrations among treatments. On d 49, there was no significant difference in VFA concentration among the treatments (p>0.05). $NH_3$-N concentration in pigs fed PCF diet was lower than in pigs fed other diets (p<0.05). $H_2S$ concentration in pigs fed diets with added essential oils was lower than others. In conclusion, the results suggest that the dietary addition of essential oils and antibiotics into diets for weanling pigs improved growth performance, IgG concentration and nitrogen digestibility and decreased noxious gas concentration. Essential oils can be used to partly replace antibiotics in diets for weaned pigs without negative affects on growth performance.