• 인터넷정보학회논문지
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• 제11권1호
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• pp.77-84
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• 2010

모국어나 외국어를 습득할 때 언어 처리의 '속도' 및 '정확도'가 적절하지 않으면 언어발달이 지연되거나 외국어 학습에 어려움을 보이게 되며, 실제 이를 통한 의사소통 상황에서 어려움을 겪게 된다. 따라서, 언어 학습 능력을 평가할 때 단순히 언어 처리의 정확도만이 아닌 '속도'와 '정확도'를 동시에 측정하는 것이 중요하며, 학습에 있어서도 이러한 처리의 효율성을 향상 시키는 것이 필요하다. 우리는 음성 및 시각 자극에 대한 '반응속도 측정기 플랫폼'을 개발함으로써 효율적인 언어 수행 능력을 평가하고 학습 향상에 적용하고자 하였다. 이 글에서는 먼저 이 플랫폼의 구성 및 내용 그리고 온라인 컨텐츠 구성 등의 개발 과정에 대하여 제시하였다. 또한, 이 플랫폼의 실제 적용 가능성을 검토하기 위하여 10명의 성인에게 '청각', '시각' 그리고 '시청각'의 3 가지 자극 조건을 제시하고, 각 조건에서 5회 이상 자극에 반응을 보이도록 하였다. 그리고 1회와 5회 반응의 반응 속도 및 정확도를 측정하여 비교하여 보았다. 이러한 결과 이 플랫폼이 정도의 차이는 있으나 자극의 종류에 상관없이 보다 빠르고 정확하게 언어를 처리할 수 있도록 능력을 향상시키는데 도움을 주고 있음을 알 수 있었다.

• 대한한방부인과학회지
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• 제32권1호
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• pp.1-14
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• 2019

Objectives: This study was designed to investigate the effect of Bombycis corpus on reproductive dysfunction caused by aging. Methods: The experimental group was divided into three groups: a control group consisting of 8-week-old male ICR mice without any treatment, An aging-elicited group (AE group) consisting of 50-week-old ICR male mice without any treatment, and a Bombycis corpus treatment group (BC group) consisting of 50-week-old ICR male mice with treatment Bombycis corpus extract (0.78 g/kg/day) for 6 months. After 6 months, histochemistry and immunohistochemistry of the testis were performed to investigate the effects of Bombycis corpus on the reproductive dysfunction caused by aging. Results: In the first step, Bombycis corpus increased spermatogenesis and distribution of sertoli cells in the seminiferous tubule, increased BrdU positive reaction in the spermatogonium at the basal part of the seminiferous tubule, and decreased the apoptosis of Sertoli cells in the seminiferous tubule. In addition, Bombycis corpus increased AR positive in Sertoli cells and $17{\beta}-HSD$ positive in leydig cells. Finally, Bombycis corpus decreased 8-OHdG positivite reaction in the spermatids of the seminiferous lumen, caspase-3 positivity in leydig cells, and HDAC1 positivite reaction in sertoli cells. Conclusions: These results suggest that Bombycis corpus increases spermatogenesis, decreases apoptosis of leydig cells and Sertoli cells, increases the production and action of testosterone in the testis, and inhibits DNA damages and DNA transcripts decrease in the testis, Thereby improving reproductive dysfunction caused by aging.

• 대한한방소아과학회지
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• 제32권4호
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• pp.1-12
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• 2018

Objectives Bangpungtongsungsan is an herbal medicine that treats obesity and dampness-phlegm. The aim of this study was to investigate the efficacy of Bangpungtongsungsan on insulin resistance induced by non-alcoholic fatty liver disease. Methods Male 6-week-old C57BL/6 male mice were divided into four groups: control group (Ctrl), high fat diet group (HFF), high fat diet with Bangpungtongsungsan extract administration group (BT1), and high fat diet with double concentration of Bangpungtongsungsan extract administration group (BT2). Each 10 mice were allocated to each group (total of 40 mice). All mice were allowed to eat fat rich diet freely throughout the experiment. To examine the effect of Bangpungtongsungsan, we observed weight changes, lipid blot distributions, PGC-1, $p-I{\kappa}B$, 8-OHdG, p-JNK, total cholesterol and glucose levels. Results Comparing of body weight measurements between 4 groups, weight gain was significantly lower in BT1 and BT2 group than the HFF group. The distribution of lipid blots and positive reaction of PGC-1 were significantly lower in BT1 and BT2 group. The positive reaction of $p-I{\kappa}B$ and 8-OHdG in hepatic tissues was significantly lower in BT1 and BT2 group. The positive reaction of p-JNK in hepatic tissues was significantly lower in BT1 and BT2 group. Total cholesterol and glucose levels were significantly lower in BT1 and BT2 group. Conclusions Bangpungtongsungsan has the effect of improving non-alcoholic fatty liver induced insulin resistance through regulation of lipid metabolism.

• 한국구조물진단유지관리공학회 논문집
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• 제23권2호
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• pp.20-27
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• 2019

건전자제품의 개발과 생산기술에 비교하여 폐유리의 재활용을 위한 기술개발은 상대적으로 미흡하여 자원낭비와 환경오염이 가속화되고 있다. 해외에서는 이 분야에 대한 기술개발이 활발하게 이루어지고 있으나 국내의 경우, 그 관심도가 부족하여 폐유리를 불법투기 또는 매립으로 처리하고 있는 실정이다. 폐유리는 시멘트와 수화반응시 포졸란 반응가능성이 있는 것으로 확인되어 경화 콘크리트의 물리적 성질을 향상시키고 굳지 않은 콘크리트의 레올로지 특성을 개선하여 블리딩의 저감 및 수화열 발생의 억제 등에 효과적인 것으로 보고되고 있다. 따라서 본 논문에서는 폐유리를 잔골재로 사용한 차폐콘크리트의 알칼리-실리카반응이 팽창에 미치는 영향을 분석하고 폐유리 혼입에 의한 알칼리-실리카반응의 팽창을 억제하기 위한 방안으로 적정 혼화재료를 사용하여 차폐콘크리트의 내구성능을 평가하였다.

• 대한한방소아과학회지
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• 제33권2호
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• pp.12-21
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• 2019

Objectives Coptidis Rhizoma and Glycyrrhiza Uralensis are herbs that treat obesity and dampness-phlegm. The aim of this study is to investigate the efficacy of Coptidis Rhizoma and Glycyrrhiza Uralensis on lipid deposition with nonalcoholic fatty liver disease (NAFLD). Methods Male 6-week-old C57BL/6 male mice were divided into three groups: control group (Ctrl), high fat diet group (HFF), and high fat diet with Coptidis Rhizoma and Glycyrrhiza Uralensis extract administration group (CGT). Each 10 mice were allocated to each group (total of 30 mice). All mice were allowed to eat fat rich diet freely throughout the experiment. To examine the effect of Coptidis Rhizoma and Glycyrrhiza Uralensis, we observed weight changes, total cholesterol and glucose levels, lipid blot distributions, PGC-1, p-$I{\kappa}B$, and p-JNK. Results Body weights for all mice were measured and analyzed the difference between the groups. Weight gain was significantly lower in CGT group than the HFF group. Total cholesterol and glucose levels were significantly lower in CGT group. The distribution of lipid blots and positive reaction of PGC-1 were significantly lower in CGT group. The positive reaction of p-$I{\kappa}B$ in hepatic tissues was significantly lower in CGT group. The positive reaction of p-JNK in hepatic tissues was significantly lower in CGT group. Conclusions Coptidis Rhizoma and Glycyrrhiza Uralensis have the effect of improving non - alcoholic fatty liver induced insulin resistance through regulation of lipid metabolism.

• 한국결정성장학회지
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• 제31권2호
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• pp.96-101
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• 2021

Developing effective and earth-abundant electrocatalyst for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is critical for the commercialization of a water splitting system. In particular, the overpotential of the OER is relatively higher than the HER, and thus, it is considered that one of the important methods to enhance the performance of the electrocatalyst is to reduce the overpotential of the OER. We report effects of incorporation of metalloid into Ni(OH)2 microcrystal on electrocatalytic activities. In this study, Te incorporated Ni(OH)2 (��Te-Ni(OH)2) were grown on three-dimensional porous NF by a facile solvothermal method with �� = 1, 3 and 5. Homogeneous microplate structure on the NF was clearly observed for the Ni(OH)2/NF and ��Te-Ni(OH)2/NF samples. However, irregular and collapsed nanostructures were found on the surface of nickel foam when Te precursor ratio is (��) over 3. Electrocatalytic OER properties were analysed by Linear sweep voltammetry (LSV) and Electrochemical impedance spectroscopy (EIS). The amount of Te incorporation used in the electrocatalytic reaction was found to play a crucial role in improving catalytic activity. The optimum Te amount (��) introduced into the Ni(OH)2/NF was discussed with respect to their OER performance.

• Journal of Electrochemical Science and Technology
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• 제13권1호
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• pp.112-119
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• 2022

Molten carbonate fuel cells (MCFCs) are environmentally friendly, large-capacity power generation devices operated at approximately 650℃. If MCFCs are to be commercialized by improving their competitiveness, their cell life should be increased by operating them at lower temperatures. However, a decrease in the operating temperature causes a reduction in the cell performance because of the reduction in the electrochemical reaction rate. The cell performance can be improved by introducing a coating on the cathode of the cell. A coating with a high surface area expands the triple phase boundaries (TPBs) where the gas and electrolyte meet on the electrode surface. And the expansion of TPBs enhances the oxygen reduction reaction of the cathode. Therefore, the cell performance can be improved by increasing the reaction area, which can be achieved by coating nanosized LiCoO₂ particles on the cathode. However, although a coating improves the cell performance, a thick coating makes gas difficult to diffuse into the pore of the coating and thus reduces the cell performance. In addition, LiCoO₂-coated cathode cell exhibits stable cell performance because the coating layer maintains a uniform thickness under MCFC operating conditions. Therefore, the performance and stability of MCFCs can be improved by applying a LiCoO₂ coating with an appropriate thickness on the cathode.

• Journal of Electrochemical Science and Technology
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• 제14권1호
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• pp.96-104
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• 2023

Synergistically increased oxygen evolution reaction (OER) of manganese oxide (MnO₂) catalyst is introduced with surface-modified halloysite nanotube (Fe₃O₄-HNTs) structure. The flake shaped MnO₂ catalyst is attached on the nanotube template (Fe₃O₄-HNTs) by series of wet chemical and hydrothermal method. The strong interaction between MnO₂ and Fe₃O₄-HNTs maximized active surface area and inter-connectivity for festinate charge transfer reaction for OER. The synergistical effect between Fe₃O₄ layer and MnO₂ catalyst enhance the Mn³⁺/Mn⁴⁺ ratio by partial replacement of Mn ions with Fe. The relatively increased Mn³⁺/Mn⁴⁺ ratio on MnO₂@FHNTs induced 𝜎^* orbital (e_g) occupation close to single electron, improving the OER performances. The MnO₂@FHNTs catalyst exhibited the reduced overpotential of 0.42 V (E vs. RHE) at 10 mA/cm² and Tafel slope of (99 mV/dec), compared with that of MnO₂ with unmodified HNTs (0.65 V, 219 mV/dec) and pristine MnO₂ (0.53 V, 205 mV/dec). The present study provides simple and innovative method to fabricate nano fiberized OER catalyst for a broad application of energy conversion and storage systems.

• 한국건설순환자원학회논문집
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• 제6권4호
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• pp.103-111
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• 2012

압축강도 50 MPa이상의 압출성형 시멘트 패널은 고온고압 증기양생으로 생산된다. 고온고압 증기양생에서 요구 강도를 얻기 위해서는 시멘트에 포함되어 있는 CaO와의 반응에 필요한 적정량의 $SiO_2$를 공급하는 것이 관건이다. $SiO_2$의 공급원으로 가장 널리 사용되는 원료는 규석분인데, 이는 환경파괴를 전제로 하기 때문에 친환경적인 제품 생산을 위하여 본 연구에서는 규석분을 대신하여 폐석분을 활용한 시멘트 2차 제품을 생산하고 이에 대한 압출성과 물리적인 특성비교를 실시하였다. 이를 위하여 화성 석산에서 채취한 폐석분을 건조 파쇄한 후 이를 규석분 사용량의 최대 50%까지 치환하여 압출성 및 물리적 특성 실험을 수행하였다. 실험결과 평균 입경은 폐석분과 규석분의 크기가 유사하였으나 물리적 특성은 규석분을 폐석분으로 단순 치환하였을 경우, 대부분 낮게 발현되었다. 따라서 폐석분을 활용할 경우 수화활성을 위한 첨가제 등의 활용이 필요할 것으로 판단된다.

• 한국수소및신에너지학회논문집
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• 제25권3호
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• pp.219-226
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• 2014

In HI decomposition, $Pt/Al_2O_3$ has been studied by several researchers. However, after HI decomposition, it could be seen that metal dispersion of $Pt/Al_2O_3$ was greatly decreased. This reason was expected of platinum loss and sintering, which platinum was aggregated. Also, this decrease of metal dispersion caused catalytic deactivation. This study was conducted to find the condition to minimize platinum sintering and loss. In particular, heat treatment atmosphere and temperature were examined to improve the activity of HI decomposition reaction. First of all, although $Pt/Al_2O_3$ treated in hydrogen atmosphere had low platinum dispersion between 13 and 18%, it was shown to suitable platinum form that played an important role in improving HI decomposition reaction. Oxygen in the air atmosphere made $Pt/Al_2O_3$ have high platinum dispersion even 61.52% at $500^{\circ}C$. Therefore, in order to get high platinum dispersion and suitable platinum form in HI decomposition reaction, air heat treatment at $500^{\circ}C$ was needed to add before hydrogen heat treatment. In case of 5A3H, it had 51.13% platinum dispersion and improved HI decomposition reaction activity. Also, after HI decomposition reaction it had considerable platinum dispersion of 23.89%.