• Composites Research
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• v.13 no.5
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• pp.10-17
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• 2000

The fatigue properties of short nylon66 fiber reinforced Chloroprene rubber have been investigated as functions of interphase conditions and fiber content. The spring constant of rubber decreased about 21% after the fatigue test. On the contrary, that of reinforced rubber increased in all cases. The changing rate of spring constant for reinforced rubber decreased with increasing fiber content. This means that the better interphase condition, the smaller changing rate of spring constant. Temperature of matrix increased about 2.5 times and one of reinforced rubber showed 1.7∼2 times up after the test. The changing rate of temperature for reinforced rubber during fatigue test decreased with increasing fiber content. It is found that the better interphase condition, the smaller changing rate of specimen temperature at the same fiber content. Double coatings of bonding agent 402 and rubber solution became the best interphase model in this study. And, we have investigated the possibility of applying short-fiber reinforced rubber to automotive engine mount rubber, bush and stopper.

• The Journal of the Korea Contents Association
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• v.16 no.4
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• pp.114-122
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• 2016

Concrete is cost-benefit and high-durable construction material, however durability problem can be caused due to steel corrosion under chloride attack. Recently deicing salt has been widely spread in snowing season, which accelerates micro-cracks and scaling in surface concrete and the melted deicing salt causes corrosion in embedded steel. The previous governing equation of Fick's 2nd Law cannot evaluate the deteriorated surface concrete so that another technique is needed for the surface effect. This paper presents chloride penetration analysis technique for concrete subjected to deicing salt utilizing multi-layer diffusion model and time-dependent diffusion behavior. For the work, field investigation results of concrete pavement exposed deicing salt for 18 years are adopted. Through reverse analysis, deteriorated depth and increased diffusion coefficient in the depth are evaluated, which shows 12.5~15.0mm of deteriorated depth and increased diffusion coefficient by 2.0 times. The proposed technique can be effectively applied to concrete with two different diffusion coefficients considering enhanced or deteriorated surface conditions.

• Herbal Formula Science
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• v.19 no.2
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• pp.11-22
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• 2011

Objectives : Hwangyeonhaedok-tang(HHDT) has been traditionally used for various clinical symptoms associated with gastrointestinal disorder, cardiovascular diseases, and inflammation in the Oriental medicine. However, little is known for antioxidant and anti-inflammatory effects of HHDT on dextran-sulfate sodium(DSS)-induced colitis in mice. Methods : In this study, we investigated an antioxidant and anti-inflammatory effects of HHDT on DSS-induced colitis in mice. An experimental colitis was induced by daily treatment with 5% DSS. HHDT was orally administrated the various concentrations(25-100 mg/kg, body weight/day) for 7 days with one time per day. Results : HHDT reduced significantly clinical sign of DSS-induced colitis, including body weight loss, shorten colon length, disease activity index(DAI), and histological colon injury. HHDT also inhibited significantly serum NO and prostaglandine $E_2(PGE_2)$ productions in DSS-induced colitis mice. Furthermore, HDDT increased significantly an superoxide anion(SOD), catalase, and glutathione peroxidase(GPx) activity of the colon tissue in DSS-induced colitis mice. Conclusions : These results suggest that HHDT administration could reduce significantly the clinical signs and inflammatory mediators, and increase antioxidant activity in DSS-induced colitis model mice and is a good candidate for further evaluation as an effective anti-ulcerative agent.

• Herbal Formula Science
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• v.17 no.2
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• pp.85-98
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• 2009

The fruits of Schisandra chinensis and Prunus mume have been traditionally used in the Oriental countries as an astringent against diarrhea and abdominal pain, a protectant for liver disease, an antimicrobial, and a blood tonic. However, little is known about the extract of Schizandrae Fructus and Mume Fructus (SMF-Ex) on dextran-sulfate sodium (DSS)-induced colitis in mice. In this study, we investigated the protective effects of SMF-Ex on DSS-induced colitis in mice. An experimental colitis was induced by daily treatment with 5% DSS. SMF-Ex was orally administrated the single dose (80 mg/kg, body weight/day) for 7 days with one time per day. SMF-Ex reduced significantly clinical sign of DSS-induced colitis, including body weight loss, shorten colon length, increased disease activity index (DAI), and histological colon injury. SMF-Ex also inhibited significantly nitric oxide (NO) and prostaglandine $E_2$ ($PGE_2$) productions in DSS-induced colitis mice. Furthermore, SMF-Ex increased significantly an superoxide anion (SOD), catalase, and glutathione peroxidase (Gpx) activity of the colon tissue in DSS-induced colitis mice. These results suggest that SMF-Ex administration could reduce significantly the clinical signs and inflammatory mediators, and increase antioxidant activity in DSS-induced colitis model mice and is a good candidate for further evaluation as an effective anti-ulcerative agent.

• Herbal Formula Science
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• v.17 no.2
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• pp.123-132
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• 2009

Acetaminophen (AP) is widely used as an over-the-counter analgesic and antipyretic drug. AP-induced hepatotoxicity is a common consequence of AP overdose and may lead to acute liver failure. In this study, we investigated the liver damage in mice using single dose (300 mg/kg) of AP and the possible protective effects of administration (50-200 mg/kg body weight) of Joo-Juk on acetaminophen-induced liver damage in mice. The alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activities were determined in the plasma of mice. The effect of Joo-Juk on lipid peroxidation product thiobarbituric reacting substances (TBARS) and some antioxidant enzymes superoxide dismutase (SOD), catalase, d-aminolevulinate dehydratase ($\sigma$-ALA-D) activities, and gluthathione peroxidase (GPx), were also evaluated in the mouse liver homogenate. AP caused liver damage as evident by statistically significant increased in plasma activities of AST and ALT. There were statistically significant losses in the activities of SOD, catalase, $\sigma$-ALA-D, and GPx and an increase in TBARS in the liver of AP-treated group compared with the control group. However, Joo-Juk was able to counteract these effects. These results suggest that Joo-juk can act as hepato-protectant against AP toxicity and is a good candidate for further evaluation as an effective chemotherapeutic agent.

• Herbal Formula Science
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• v.16 no.2
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• pp.183-191
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• 2008

Acetaminophen (N-acety1-p-aminophenol, paracetamol) is widely used as an over-the-counter analgesic and antipyretic drug. Intake of a over dose of acetaminophen may result in severe hepatic necrosis. In this study, we investigated the liver damage in mice using single dose (300 mg/kg) of acetaminophen and the possible protective effects of administration (50-200 mg/kg body weight) of SB-Ex on acetaminophen-induced liver damage in mice. The alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activities were determined in the plasma of mice. The effect of SB-Ex on lipid peroxidation product thiobarbituric reacting substances (TBARS) and some antioxidant enzymes superoxide dismutase (SOD), catalase, d-aminolevulinate dehydratase (${\sigma}$-ALA-D) activities, and gluthathione peroxidase (GPx), were also evaluated in the mouse liver homogenate. Acetaminophen caused liver damage as evident by statistically significant increased in plasma activities of AST and ALT. There were general statistically significant losses in the activities of SOD, catalase, ${\sigma}$-ALA-D, and GPx and an increase in TBARS in the liver of acetaminophen-treated group compared with the control group. However, SB-Ex was able to counteract these effects. These results suggest that SB-Ex can act as hepatoprotectives against acetaminophen toxicity and is a good candidate for further evaluation as an effective chemotherapeutic agent.

• Preventive Nutrition and Food Science
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• v.7 no.2
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• pp.113-118
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• 2002

Alpha-lipoic acid is a known hypoglycemic agent that may be useful in the treatment of diabetes. The objective of this study was to investigate the fate of glucose in isolated muscles incubated with lipoic acid by determining its direct effects on specific metabolic and signaling pathways. Soleus muscles from healthy rats were incubated with lipoic acid in the absence or presence of insulin. Glucose transport, glycogen synthesis, glucose oxidation and lipid synthesis were determined and affects on major pathways associated with insulin signaling were evaluated. Glucose transport was not significantly altered by the addition of lipoic acid to the incubation medium. However, lipoic acid decreased glycogen synthesis in comparison to controls. Glucose oxidation was moderately increased while de-novo lipid synthesis from glucose was inhibited. Wortmannin repressed insulin stimulation of glucose incorporation into glycogen, an effect that was augmented by the combined treatment of wortmannin and lipoic acid. Basal and insulin-stimulated serine phosphorylation of Akt was not changed by the addition of lipoic acid to the incubation medium. These data show that in this in vitro model, lipoic acid did not significantly affect glucose uptake but dramatically modified pathways of glucose metabolism within muscle tissue.

• Proceedings of the Korean Association for Survey Research Conference
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• 2000.06a
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• pp.59-87
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• 2000

The hypothesis of this study is that change acceptance and work adaptation of change agents are influenced by positive self-image and risk tolerance. In order to examine the hypothesis, this study was performed with 305 change agents from six branches of a conglomerate company. Specifically, self-image was measured by locus of control, self-efficacy, self-esteem, and positive affectivity; risk tolerance was measured by tolerance for ambiguity, risk aversion, and openness to experience. The result of this study indicated that self-image and risk tolerance significantly predicted change acceptance and work adaptation. Especially, the results of structural model revealed that change acceptance mediated the relationship between characteristic variables (such as self image and risk tolerance in this study) and work adaptation. Based on the results, we suggest that change agents keep developing positive self-image and risk tolerance in order to play the key role in leading organizational change.

• Journal of Microbiology and Biotechnology
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• v.28 no.10
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• pp.1626-1634
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• 2018

Ginseng (the root of Panax ginseng Meyer) fermented by Lactobacillus plantarum has been found to attenuate allergic responses in in vitro and in vivo experimental models. Ginseng has been reported to also possess various biological functions including anti-inflammatory activity. The present study was aimed at comparing the anti-allergic effect of ginseng and fermented ginseng extracts on IgE-mediated passive cutaneous anaphylaxis in vitro in a murine cell line and in vivo in mice. Fermented ginseng extract (FPG) showed higher inhibitory effect against in vitro and in vivo allergic responses when compared with ginseng extract (PG). The secretion of ${\beta}$-hexosaminidase and interleukin (IL)-4 from the IgE-DNP-stimulated RBH-2H3 mast cells were significantly (p < 0.05) inhibited by FPG treatment, and this effect was concentration-dependent. Further, MKK4 activation and subsequent JNK phosphorylation were attenuated by FPG treatment. The inhibitory effect of FPG on the in vitro allergic response was verified in vivo against IgE-DNP-induced passive cutaneous anaphylaxis in a mouse model. These data indicated that the fermentation of ginseng with L. plantarum enhanced its anti-allergic effects both in vitro and in vivo. We predict that compositional changes in the ginsenosides caused by the fermentation may contribute to the change in the anti-allergic effects of ginseng. The results of our study highlight the potential of the use of FPG as a potential anti-allergic agent.

• Journal of the Korea Computer Industry Society
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• v.3 no.2
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• pp.209-216
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• 2002

World Wide Web has potential possibility of infrastructure for parallel computing environment connecting massive computing resources, not just platform to provide and share information via browser. The approach of Web-based parallel computing has many advantages of the ease of accessibility, scalability, cost-effectiveness, and utilization of existing networks. Applet has the possibility of decomposing the independent/parallel task, moving over network, and executing in computers connected in Web, but it lacks in the flexibility due to strict security semantic model. Therefore, in this paper, Web-based parallel computing environment using mobile agent, Aglet (Agile applet) was designed and possible implementation technologies and architecture were analyzed. And simple simulation and analysis was done compared with applet-based approach.