• Journal of the Korean GEO-environmental Society
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• v.13 no.11
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• pp.81-91
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• 2012

This paper mainly deals with the analysis of probabilistic characteristics of the disturbed function proposed to predict dynamic behavior of Geosynthetic-soil interface as the lining and cover systems used in waste landfills. Calibration and statistical property estimation of the parameters in the disturbed function model were first performed using many experimental data obtained from a new multi-purpose interface apparatus (M-PIA). In order to analyze the effect due to changes in chemical degradation and normal loads condition, probabilistic properties such as mean, coefficient of variation and distribution type of the disturbed function were evaluated using both the LHS method known to be a very efficient sampling scheme and the estimated statistical property of A and Z. As a result, variation of the disturbed function is found to range approximately from 10~28% according to the level of ${\xi}_D$ and Weibull appears to be the most adequate distribution type at almost all levels of ${\xi}_D$. It is concluded that a probabilistic safety assessment method for Geosynthetic-soil interface considering uncertainty in shear strength can be developed by utilizing probabilistic properties of the disturbed function obtained in this study.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1128-1136
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• 2015

This study investigated the anti-inflammatory effects of ethanol extract from Grateloupia elliptica Holmes (GEHEE) on the lipopolysaccharide-induced inflammatory response. Anti-inflammatory effects were detected by enzyme-linked immunosorbent assay, Western blotting, and immunohistochemistry. There were no cytotoxic effects on proliferation of macrophages treated with GEHEE compared to the control. GEHEE remarkably suppressed NO and pro-inflammatory cytokines (interleukin-6, tumor necrosis $factor-{\alpha}$, and $interleukin-1{\beta}$) production and reduced expression of inducible nitric oxide synthase, cyclooxygenase-2, and nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) proteins in a dose-dependent manner. GEHEE also significantly reduced activation of mitogen-activated protein kinases (MAPKs). The formation of edema in mouse ears was reduced at the highest dose compared to the control. GEHEE also reduced dermal thickness and mast cell numbers based on histological analysis. These results suggest that GEHEE exerts significant anti-inflammatory activity via inhibition of $NF-{\kappa}B$ and MAPKs activation and may be a potential anti-inflammatory therapeutic material.

• Journal of Korea Water Resources Association
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• v.50 no.5
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• pp.303-313
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• 2017

In environmental impact assessments for large urban development projects, the Korean government requires analysis of stormwater runoff before, during and after the projects. Though hydrological models are widely used to analyze and prepare for surface runoff during storm events, accuracy of the predicted results have been in question due to limited amount of field data for model calibrations. Intensive field measurements have been made for storm events between July 2015 and July 2016 at a sub-basin of the Gwanpyung-cheon, Daejeon, Republic of Korea using an automatic monitoring system and also additional manual measurements. Continuous precipitation and surface runoff data used for utilization of SWMM model to predict surface runoff during storm events with improved accuracy. The optimal values for Manning's roughness coefficient and values for depression storage were estimated for pervious and impervious surfaces using three representative infiltration methods; the Curve Number Methods, the Horton's Method and the Green-Ampt Methods. The results of the research is expected to be used more efficiently for urban development projects in Korea.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.5
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• pp.593-604
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• 2007

Although composite construction has more mechanical advantages compared to noncomposite construction, the design of noncomposite construction for skew bridges with large skew angels has been often checked because composite construction may cause large stresses in the bridge deck. In this study, the analytical model considered dynamic behaviors for noncomposite skew bridges was proposed. Using the proposed analytical model, the validity of the application of noncomposite construction to skew bridges was checked. Also, the effects of interactions between the concrete deck and steel girders such as composite construction, partial composite construction, and noncomposite construction on the dynamic characteristics and dynamic behaviors of simply supported skew bridges were investigated. A series of parametric studies for the total 27 skew bridges was conducted with respect to parameters such as girder spacing, skew angle, and deck aspect ratio. Although the slip at the interfaces between the concrete deck and steel girders results in the reduction of seismic total base shear in the transverse direction due to period elongation, it causes an undesirable behavior of skew bridges by the modification in mode shapes and distributions of stiffness. Shear connectors placed by minimum requirements for partial composite action have an effect on reducing the girder stresses and deck stresses; except case of some skew bridges, the magnitude of the girder stresses and deck stresses obtained from partial composite skew bridges is similar to or slightly more than those acquired from composite skew bridges.

• Korean Journal of Social Welfare
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• v.64 no.1
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• pp.225-247
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• 2012

This study aims at exploring an effective way for social welfare in order to promote psychological well-being of a mother having a child with autism. To achieve this purpose, this study examined the related factors of parenting stress, family functioning, social support, and redefinition of family affecting psychological well-being of a mother having a child with austin by way of applying the Double ABCX model. A survey was conducted with a sample of 207 mothers having a child with autism in Daegu. Results from the survey are as follows: First, there were significant impacts of parenting stress on social support, family functioning, the redefinition of family on crisis situation, and psychological well-being. Second, family functioning and social support had no significant effect on mothers' psychological well-being, while the redefinition of family on crisis situation had significant influences on the psychological well-being of mothers having a child with autism. Third, it turned out that family functioning, social support, and the redefinition of family on crisis situation played a mediating role between parenting stress and psychological well-being. Based on these results, this study suggests that family functioning should be strengthened for promoting psychological well-being of mothers having a child with autism. We should construct and provide social supports in multilateral aspects and help mothers having a child with autism positively recognize stressful situations and improve their capacities to overcome them as well.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1907-1914
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• 2013

Textile-type heat exchangers installed on the tunnel walls for facilitating ground source heat pump systems, so called "energy textile", was installed in an abandoned railroad tunnel around Seocheon, South Korea. To evaluate thermal performance of the energy textile, a series of long-term monitoring was performed by artificially applying daily intermittent cooling and heating loads on the energy textile. In the course of the experimental measurement, the inlet and outlet fluid temperatures of the energy textile, pumping rate, temperature distribution in the ground, and air temperature inside the tunnel were continuously measured. From the long-term monitoring, the heat exchange rate was recorded as in the range of 57.6~143.5 W per one unit of the energy textile during heating operation and 362.3~558.4 W per one unit during cooling operation. In addition, the heat exchange rate of energy textile was highly sensitive to a change in air temperature inside the tunnel. The field measurements were verified by a 3D computational fluid dynamics analysis (FLUENT) with the consideration of air temperature variation inside the tunnel. The verified numerical model was used to evaluate parametrically the effect of drainage layer in the energy textile.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.829-834
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• 2006

LP-BM5 murine leukemia retrovirus induces the immune dysfunction by imbalanced secretion of Th1 and Th2 cytokines in the murine AIDS model. In the present study, it was investigated whether pycnogenol (Pyc) administration could deactivate $NF-{\kappa}B$ to regulate the gene expression of Th1 and Th2 cytokines in C57BL/6 mice with murine AIDS. Treatment with Pyc for 12 weeks significantly inhibited the loss of body weight and enlargement of spleen and lymph node usually seen with AIDS. Moreover, Pyc increased the plasma level of Th1 cytokines, IL-2 and $IFN-{\gamma}$, while reducing the plasma level of Th2 cytokines, IL-6, IL-10, and $TNF-{\alpha}$. In primary culture of splenocytes, mRNA expression of Th2 cytokines was suppressed, but that of Th1 cytokines was not affected. The LP-BM5 retrovirus infection stimulated the cytoplasmic activation of $NF-{\kappa}B$ and nuclear translocation of $I-{\kappa}B$, whereas Pyc administration significantly reduced $NF-{\kappa}B$ activation and $I-{\kappa}B$ degradation. These results suggested that the inhibitory effect of Pyc on Th2 cytokines in mice with murine AIDS was dependent on suppression of the $NF-{\kappa}B$ signaling pathway and was not dependent on $INF-{\gamma}$ level, which regulates Th2 cytokines.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.6
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• pp.91-99
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• 2014

The purpose of this study is to analyze the structural relationship among such variables as self-efficacy, entrepreneurial motivation and entrepreneurial intention in the public sector. In order to achieve the purpose, this study had specifically questions as follows: The first was to examine the effect of the self-efficacy on the entrepreneurial motivation in the public sector. The second was to examine the effect of the self-efficacy on the entrepreneurial intention in the public sector. The third was to examine the effect of the self-efficacy on the entrepreneurial intention according to the entrepreneurial motivation in the public sector. The fourth was to examine the effect of entrepreneurial motivation on the entrepreneurial intention in the public sector. A questionnaire was used as the research instrument. A total number of 257 employees in the public sector responded to questionnaire. In order to estimate the hypothesized structural equation model, the collected data were analyzed by AMOS 17.0, a statistical program for structural equation modeling. The major findings of this study were as follows; First, the self-efficacy was found to have a direct effect on the entrepreneurial motivation in the public sector. Second, the self-efficacy was not found to have a direct effect on the entrepreneurial intention in the public sector. Third, the indirect effect of the entrepreneurial motivation between the self-efficacy and the entrepreneurial intention proved positive in the public sector. Fourth, the entrepreneurial motivation was found to have a direct effect on the entrepreneurial intention in the public sector.

• Journal of Korean Society of Steel Construction
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• v.29 no.6
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• pp.487-495
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• 2017

Recently rapid-transit railway systems have been constructed in many developing countries due to its advantages in congestions and environmental problems. Railway bridges show many different aspects compared to road bridges and passenger comfort and traffic safety are one of them. In particular, deflection and acceleration due to repeated vibration characteristics have a structural weakness that can cause undesirable response. Especially steel railway bridges have been known to have weaknesses due to its relatively light weights compared to concrete bridges. The purpose of this study is to analyze the dynamic response of steel box girder bridges due to passing trains then propose the appropriate method to mitigate the level of vibration in terms of accelerations. Three steel railway bridges are tested and the numerical model to analyze the dynamic response of the bridge by passing train are developed. For the verification of the model, the natural frequency extracted using the acceleration data measured in the bridge is compared with the natural frequency of the numerical model. To mitigate the acceleration level of the bridge, parametric studies are performed to find the effectiveness of the method. Based on the analysis, the appropriate method is proposed for decreasing the acceleration of the bridge for passenger comfort and traffic safety.

• Journal of Chest Surgery
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• v.34 no.3
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• pp.203-211
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• 2001

배경: AT$_1$수용체의 길항제가 세포 수준에서 심근을 재관류 손사으로부터 보호할수 있다는 것으로 알려져 있지만, 생체내에서의 효과나 그 기전은 아직 명확히 밝혀지지 않았다. 본 연구에서는 백서 심근 허혈 모델을 이용하여, AT$_1$ 수용체의 길항제들 중 하나인 irbesartan이 심근이 재관휴 손상에 미치는 효과를 알아보고, 재관류 손상을 매개하는 한 각지 기전으로서 세포자멸의 기여에 대하여 연구하고자 하였다. 대상 및 방법: Sprague-Dawley 백서에서 무작용 부형약(10% gum arabic: 1군, 개체수=14관) irbesartan(50mg/kg/day :II 군, 개체수=12)을 각각 3일 동안 24시간마다 경구로 투여하였다. 실험동물의 좌 관상 동맥을 45분간 결찰하였다가, 그 후 2시간 동안 재관류시킨 다음 심장을 적출 하였다. TTC(triphenyltetrazolium chloride) 염색법을 이용하여, 허혈 노출 부위에 대한 심근 경색 부위의 비율을 측정하였다. Agarose gel 전기영동상의 DNa 분절 양상과 TUNEL(TdT-mediated dUCP nick end labeling) 염색을 관찰하여 세포자멸이 일어난 정도를 평가하였다. 세포자멸을 조절하는데 관여하는 것으로 알려진 Bcl-2(B-cell lymphoma 2 gene), Bad 등의 단백과 ERK (extracellular signal-regulated kinase), p-38 등 신호전달체계에 작용하는 MAPKs(mitogen-activated protein kinases)의 발현을 측정하기 위하여 Western blot을 시행하였다. 결과: 허혈 노출부위에 대한 심근 경색부위의 비율은 II군(42$\pm$2.7%)이 I군( 64.1$\pm$4.65)에 비해 유의하게 작았다.(p< 0.05), Agarose gel 전기영동상의 DNA laddering 양상은 I군에서 보다 높게 발현되었다. Bad와 ERK2의 발현은 두 군간에 유의한 차이가 없었다. 결론: AT$_1$수용체 길항제인 irbesartan은 생체에서 심근의 재관류 손상을 줄이는 효과가 있었다. 이 효과는 적어도 부분적으로 나만 심근세포의 세포자멸이 감소한 것에 기인한 것으로 설명할 수 있으며, 이 항-세포 자멸 효과는 Bcl-2의 발현증가와 관련이 있는 것으로 추정되었다.