• Elastomers and Composites
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• v.48 no.1
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• pp.2-9
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• 2013

We synthesized polyethylene, poly(ethylene-co-1-decene), poly(ethylene-co-p-methylstyrene), and poly(ethylene-ter-1-decene-ter-p-methystyrene) using a rac-$Et(Ind)_2ZrCl_2$ metallocene catalyst and a methylaluminoxane cocatalyst system. The materials were characterized using nuclear magnetic spectroscopy and fourier transform infrared spectroscopy. To identify suitable reaction conditions for terpolymerization, we studied the effects of catalyst content, cocatalyst/catalyst molar ratio, polymerization time, and polymerization temperature. As the catalyst content increased, the catalytic activity and the molecular weight of the terpolymers increased. The catalytic activity sharply increased but little change was observed after a polymerization time of 30 min. The increase in the cocatalyst/catalyst molar ratio resulted in a decrease in the molecular weight of the terpolymers and an increase in the catalytic activity to some degree. The catalytic activity increased with increasing polymerization temperature, while the molecular weight of the terpolymers decreased.

• Journal of Korean Society for Quality Management
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• v.35 no.2
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• pp.1-26
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• 2007

The purpose of this research is to suggest the promotive directions of Quality Circle activity. Since 1975, variety of organizations in Korea have widely the implemented Quality Circle activities for their management systems. Today, Companies are facing the harsh realities of a competitive environment. This is no time for revolutionary change. Instead, Companies are instituting revolutionary change meant to have impact within a very short time frame. The Worker's Quality Circle activity is, essentially, a trouble shooting oriented voluntary small group within their working place to improve the surroundings creatively. The industries have enthusiastically used Quality Circle activities and were influenced from them. The Quality Circle activities can be regarded as a kind of Knowledge Management where new knowledge is created and knowledge is shared in the economy. However, the academics were less interested in this subject, as a result, there were no systematic guidances for Quality Circle activities. Also, the government was less interested in these activities, as a result, there were no systematic policy making for Quality Circle activities. Thus, in this research, the promotive directions for Quality Circle activities were suggested which were based on the results of survey Questionnaires presented to promoters of the domestic companies. As a results of this research, to maximize the effect of TQM(Total Quality Management) in the nationwide, Quality Circle activity as a bottom-up management should be more expanded and revitalized.

• Journal of Korean Society for Quality Management
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• v.45 no.3
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• pp.561-582
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• 2017

Purpose: The purpose of this study is to share the right conception of win-win partnership innovative activity. This study suggests the desirable methodology to Win-win Partnership. Also, through the in-depth analyzing of the existing problems, we intend to exclude such a formal and erroneous direction of the research. Methods: This study systematically analyzes the best cases of the win-win partnership focusing on the proceedings of the companies participating in the field of win-win Partnership at the national quality-circle contest. Results: This study reveals the underlying problems of win-win partnership innovative activity and draws the conclusion in the way of improvement about the win-win partnership innovative activity. This study also suggests the efficient method of the function and improvement of a system for activating win-win partnership innovative activity. Conclusion: Promoting the effective way of boosting win-win partnership innovative activity, we seek to improve the quality of the product among the companies, and let the a rising curve of the mutual growth continue among the companies by strengthening the competitiveness.

• Mycobiology
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• v.35 no.2
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• pp.76-81
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• 2007

Lactobacillus casei KC-324 was tested for its ability to inhibit aflatoxin production and mycelial growth of Aspergillus flavus ATCC 15517 in liquid culture. flatoxin $B_{1}$ biosynthesis and mycelial growth were inhibited in both simultaneous culture and individual antagonism assays, suggesting that the inhibitory activity was due to extracellular metabolites. produced in cell-free supernatant fluids of the cultured broth of L. casei KC-324. In cell-free supernatant fluids of all media tested, deMan, Rogosa and Sharpe broth, potato dextrose broth, and Czapek-Dox broth+1% yeast extract showed higher antiaflatoxigenic activity. In these case, fungal growths, however, was not affected as measured by mycelial dry weight. The antiaflatoxigenic metabolites from L. casei KC-324 were produced over wide range of temperatures between $25^{\circ}C$ and $37^{\circ}C$. However, these metabolites were not thermostable since the inhibitory activity of the supernatant was inactivated within 30 minutes at $100^{\circ}C$ and $121^{\circ}C$. The inhibitory activity was not influenced by changing pH of supernatant between 4 and 10. However, the antiaflatoxigenic activity was slightly reduced at pH 10.

• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.745-752
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• 2007

A $\beta$-glucosidase from the algal lytic bacterium Sinorhizobium kostiense AFK-13, grown in complex media containing cellobiose, was purified to homogeneity by successive ammonium sulfate precipitation, and anion-exchange and gel-filtration chromatographies. The enzyme was shown to be a monomeric protein with an apparent molecular mass of 52 kDa and isoelectric point of approximately 5.4. It was optimally active at pH 6.0 and $40^{\circ}C$ and possessed a specific activity of 260.4 U/mg of protein against $4-nitrophenyl-\beta-D-glucopyranoside$(pNPG). A temperature-stability analysis demonstrated that the enzyme was unstable at $50^{\circ}C$ and above. The enzyme did not require divalent cations for activity, and its activity was significantly suppressed by $Hg^{+2}\;and\;Ag^+$, whereas sodium dodecyl sulfate(SDS) and Triton X-100 moderately inhibited the enzyme to under 70% of its initial activity. In an algal lytic activity analysis, the growth of cyanobacteria, such as Anabaena flos-aquae, A. cylindrica, A. macrospora, Oscillatoria sancta, and Microcystis aeruginosa, was strongly inhibited by a treatment of 20 ppm/disc or 30 ppm/disc concentration of the enzyme.

• International Journal of Quality Innovation
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• v.7 no.2
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• pp.157-172
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• 2006

Due to the advancement of technology and rapidly changing environment of the market, the life cycle of high-tech products is becoming shorter. The enterprise must constantly innovate and select correct development strategy of new product in order to respond to customers' demands for upgrading operational performance of industry. Development of new product is the critical activity for enterprise's survival and growth. This research focuses on the effects of Taiwan high-tech companies' introduction of innovative activity and development strategy of new product on development performance of new product for analysis and exploration. The result findings reveal that: (1) High execution degree of innovative activity has positive effect on the implementation of development strategy of new product; (2) The companies with better implementation of development strategy of new product reveal better development performance; (3) The companies with higher degree of execution of innovative activity and better execution of development strategy of new product reveal better development performance of new product.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4197-4206
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• 2010

The purpose of this study was to examine the effects of regular physical activity program on young children's basic motor skills and daily stress. The outdoor physical activity program was conducted with 40 participants who were divided into two groups(experimental group and control group) for 10 weeks twice a week. Results of the study were as following. The outdoor physical activity program improved young children's basic motor skills in the experiment group compared to the control group. Also it had positive effects on the reduction of daily stress in the experimental group compared to the control group. This result suggests that the physical activity program have positive effects on the development of young children's basic motor skills and the reduction of daily stress.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3616-3624
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• 2014

The aim of this study was to inquire into the perceptions and the needs of parents on their forest experience activity. To achieve this, a survey was carried out on 250 parents of children in a Gyeonggi-based private kindergarten from December 26 to December 31, 2013. The results are as follows. For the perceptions of parents on the forest experience activity, the 'perception on overall effectiveness' was the highest, followed in order by 'perception on educational effectiveness' and 'general perception'. For the needs of parents on their forest experience activity, 58.2% of them recognized the importance of regular forest experience activity. For the necessity of an annual program, 60.7% of them recognized the necessity of a planned annual program. For the recommendation of forest experience activity, 61.1% of them gave a strong recommendation for forest experience activity. As stated above, most parents positively viewed children's forest experience activity in the environment as it is difficult to approach nature in downtown areas, and children also highly viewed the educational effectiveness of it.

• Journal of Preventive Medicine and Public Health
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• v.32 no.1
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• pp.101-107
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• 1999

Objectives. To determine the effects of exposure to hexavalent chromium, 93 male Sprague-Dawley rats were exposed to hexavalent chromium solution. Methods. Rats were divided into 4 groups and exposed to 0.1ml of 0 mM, 0.4 mM, 2.0 mM, and 10.0 mM potassium chromate in the first experiment, and to 0.1 ml of 0 mM, 20 mM, 40 mM, and 80 mM in the second for consecutive 3 days by tracheal instillation. Three and 10 rats were the controls for the first and the second experiments, respectively. Lung tissues were then removed to measure the 8-hydroxydeoxyguanosine (8-OH-dG) level using the HPLC-ECD method, superoxide dismutase (SOD) activity using the cytochrome C method, and 8-hydroxyguanine endonuclease activity using the oligonucleotide nicking assay. Results. The results showed no significant linear relationship between chromium exposure level and 8-OH-dG level or 8-hydroxyguanine endonuclease activity. In the first experiment, 8-OH-dG level and 8-hydroxyguanine endonuclease activity increased in 0.4 mM group, and then decreased in 2.0 mM and 10.0 mM groups. The correlation coefficients between 8-OH-dG level and 8-hydroxyguanine endonuclease activity was statistically significant (P<0.01), and total SOD activity was elevated by chromium exposure in a dose-dependent manner (P<0.05). In contrast, there was no significant dose-response pattern or correlation in the secod experiment. Conclusions. Based on the fact that there was no linear relationship between chromium dose and 8-OH-dG level or activity of the repair enzyme, it seems unlikely that 8-OH-dG formation is the major mechanism of chromium carcinogenesis.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.26-35
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• 2017

The hydrolysis of proteins constitutes an invaluable tool, granting access to a variety of peptide fragments with potentially interesting biological properties. Therefore, a hemoglobin (Hb) hydrolysate of Crocodylus siamensis was generated by digestion under acidic conditions. The antibacterial and antioxidant activities of the Hb hydrolysate were assessed in comparison with intact Hb. A disc diffusion assay revealed that the Hb hydrolysate exhibited antibacterial activity against eight strains of gram-positive bacteria and showed a higher efficacy than intact Hb. Moreover, the antioxidant activity of intact Hb and its hydrolysate was evaluated using ABTS and DPPH radical scavenging assays. The Hb hydrolysate exhibited free radical scavenging rates of 6-32%, whereas intact Hb showed a slightly higher activity. In addition, non-toxicity to human erythrocytes was observed after treatment with quantities of Hb hydrolysate up to $10{\mu}g$. Moreover, active fragmented Hb (P3) was obtained after purifying the Hb hydrolysate by reversed-phase HPLC. Scanning electron microscopy demonstrated the induction of bacterial cell membrane abnormalities after exposure to P3. Antibacterial and antioxidant activities play crucial roles for supporting the wound healing activity. Consequently, an in vivo mice excisional skin wound healing assay was carried out to investigate the effects of intact Hb treatment on wound healing in more detail. The results clearly demonstrate that intact Hb is capable of promoting 75% wound closure within 6 days. These findings imply that intact Hb of C. siamensis and its acid hydrolysate may serve as valuable precursors for food supplementary products benefitting human health.