• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.467-475
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• 2009

Existing studies have suggested Universal Curve only for supplemental damping by damper. Therefore net damping has been determined by means of arithmetic summation between intrinsic, aero-damping of cable and supplemental damping of damper. However linear combination approach by means of the arithmetic summation is not enough theoretical background. So validity of this approach should be verified in order to design adequate cable-damper system by engineers. This study establishes governing differential equation which can consider intrinsic, aero-damping and supplemental damping as well. And also analysis method is solved by combination of muller method and successive iteration method. Consequently, this study succeeds in verification for validity of linear combination approach. As a result of this study, linear combination approach is limitedly effective in case of low stiffness and optimum damping coefficient of damper, short distance from support to damper, lower vibration mode, low aero-damping, and normal windy environment. Whereas this study will be effective in case of opposite conditions, and existing studies or linear combination approach occur to further error. Meaning of this study presents exact solution for net damping of cable-damper system, and verifies linear combination approach by means of the analysis method. In the future, if monitoring of optimum damping coefficient of a damper against aero-damping is feasible on time, algorithm of this study will be available for control of cable and semi-active damper system such as magneto-rheological damper.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.282-289
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• 2017

Animal Welfare is spreading throughout the world, but remains weak in Korean swine farms. Therefore, the aim of this study was to identify the effect of floor type and hanging type environmental enrichment on the behavior of growing pigs under the traditional feeding environment. A total of 45 crossbred pigs (Yorkshire${\times}$Landrace${\times}$Duroc; average weight, $33.35{\pm}5.5kg$) were assigned into three treatments consisting of control, hanging type(T1) and floor type(T2) with three replicates in semi-slurry pen. The hanging enrichment was suspended at shoulder height of the pigs, and the floor enrichment was fixed in the center of the pens. Growth and cortisol were estimated at the end of the experimental period. Behaviour patterns were analyzed on the first and eighth days after starting the experiment. Growth was not differed among control and treatments. However, cortisol was decreased in T2 compared to control(25.28 vs. 46.75 ng/mL; p<0.05). On the first day, movement and aggression were lower in both treatments than in control(p<0.01). On the eighth day, time and frequency of playing action were increased in T2 compared to T1(p<0.01) and both treatment groups showed more active behaviour than control(p<0.01). These results suggested that the enrichment may meet the natural action requirement of pigs. Therefore, our data can be utilized as basic information for welfare with environmental enrichments in farm animals.

• Tuberculosis and Respiratory Diseases
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• v.50 no.2
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• pp.182-195
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• 2001

Background : Idiopathic pulmonary fibrosis(IPF) is a devastating illness for which there is little effective treatment. The key cytokines currently implicated in the fibrotic process are the transforming growth factor-${\beta}_1$(TGF-${\beta}_1$), tumor necrosis factor-$\alpha$(TNF-$\alpha$), endothelin-1(ET-1) and interferon-$\gamma$(IFN-$\gamma$). The rat model for paraquat-induced pulmonary fibrosis was chosen to investigate the role of ET-1 in this disease. Both ET-1 and TGF-${\beta}_1$ expression in lung lesions were examined using immunohistochemical staining. After $Bosentan^{(R)}$ administration, an orally active ET-$l_A$ and ET-$1_B$ receptor antagonist, the degree of pulmonary fibrosis and ET-1 and TGF-${\beta}_1$ expression were analyzed. Method : Sprague-Dawley rats were divided into three groups, the control group, the fibrosis group, and the fibrosis-$Bosentan^{(R)}$-treated group. The animals were sacrificed periodically at 1, 3, 5, 7, 10, 14 days after administering saline or paraquat. The effects between groups were compared with the results of light microscopy and immunohistochemical staining for ET-1 and TGF-${\beta}_1$. The degree of fibrosis was evaluated by H&E and Masson's trichrome staining, which were graded by a computerized image analyzer. The degree of immunohistochemical staining was categorized by a semi-quantitative analysis method. Results : The lung collagen content had increased in the paraquat instillated animals by day 3, and continued to increase up to day 14. A daily treatment by gavage with $Bosentan^{(R)}$ (100mg/kg) did not prevent the increase in collagen deposition on the lung that was induced by paraquat instillation. There were increased immunohistochemical stains of ET-1 on the exudate, macrophages, vascular endothelial cells and pneumocytes in the paraquat instillated group. Furthermore, TGF-${\beta}_1$ expression was higher on the exudate, macrophages, some inflammatory cells, pneumocytes( type I, and II), vascular endothelium and the respiratory epithelial cells around the fibrotic area. After Bosentan treatment, there were no definite changes in ET-1 and TGF-${\beta}_1$ expression. Conclusion : Fibrosis of the Paraquat instillated group was more advanced when compared with the control group. In addition, there was increased ET-1 and TGF-${\beta}_1$ expression around the fibrotic area. ET-1 is associated with lung fibrosis but there was little effect of the ET-1 receptor blocker($Bosentan^{(R)}$) on antifibrosis.Background : Idiopathic pulmonary fibrosis(IPF) is a devastating illness for which there is little effective treatment. The key cytokines currently implicated in the fibrotic process are the transforming growth factor-${\beta}_1$(TGF-${\beta}_1$), tumor necrosis factor-$\alpha$(TNF-$\alpha$), endothelin-1(ET-1) and interferon-$\gamma$(IFN-$\gamma$). The rat model for paraquat-induced pulmonary fibrosis was chosen to investigate the role of ET-1 in this disease. Both ET-1 and TGF-${\beta}_1$ expression in lung lesions were examined using immunohistochemical staining. After $Bosentan^{(R)}$ administration, an orally active ET-$1_A$ and ET-$1_B$ receptor antagonist, the degree of pulmonary fibrosis and ET-1 and TGF-${\beta}_1$ expression were analyzed. Method : Sprague-Dawley rats were divided into three groups, the control group, the fibrosis group, and the fibrosis-$Bosentan^{(R)}$-treated group. The animals were sacrificed periodically at 1, 3, 5, 7, 10, 14 days after administering saline or paraquat. The effects between groups were compared with the results of light microscopy and immunohistochemical staining for ET-1 and TGF-${\beta}_1$. The degree of fibrosis was evaluated by H&E and Masson's trichrome staining, which were graded by a computerized image analyzer. The degree of immunohistochemical staining was categorized by a semi-quantitative analysis method. Results : The lung collagen content had increased in the paraquat instillated animals by day 3, and continued to increase up to day 14. A daily treatment by gavage with $Bosentan^{(R)}$ (100mg/kg) did not prevent the increase in collagen deposition on the lung that was induced by paraquat instillation. There were increased immunohistochemical stains of ET-1 on the exudate, macrophages, vascular endothelial cells and pneumocytes in the paraquat instillated group. Furthermore, TGF-${\beta}_1$ expression was higher on the exudate, macrophages, some inflammatory cells, pneumocytes( type I, and II), vascular endothelium and the respiratory epithelial cells around the fibrotic area. After Bosentan treatment, there were no definite changes in ET-1 and TGF-${\beta}_1$ expression. Conclusion : Fibrosis of the Paraquat instillated group was more advanced when compared with the control group. In addition, there was increased ET-1 and TGF-${\beta}_1$ expression around the fibrotic area. ET-1 is associated with lung fibrosis but there was little effect of the ET-1 receptor blocker($Bosentan^{(R)}$) on antifibrosis.