• Journal of Electrochemical Science and Technology
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• 제8권4호
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• pp.344-355
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• 2017

In this study, a numerical approach is adopted to investigate the effectiveness factors for distributed electrochemical reactions in thin active reaction layers of solid oxide fuel cells (SOFCs), taking into account the Butler-Volmer reaction kinetics. The mathematical equations for the electrochemical reaction and charge conduction process were formulated by assuming that the active reaction layer has a small thickness, homogeneous microstructure, and high effective electronic conductivity. The effectiveness factor is defined as the ratio of the actual reaction rate (or equivalently, current generation rate) in the active reaction layer to the nominal reaction rate. From extensive numerical calculations, the effectiveness factors were obtained for various charge transfer coefficients of 0.3-0.8. These effectiveness data were then fitted to simple correlation equations, and the resulting correlation coefficients are presented along with estimated magnitude of error.

• 동아시아식생활학회지
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• 제18권4호
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• pp.608-617
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• 2008

This study examined the level of reaction towards damage related to health foods and the factors affecting this reaction among the elderly. Data were collected from 269 elderly individuals living in Seoul, Daejeon, Daegu, Gwangju and Busan. Frequencies, chi-square tests, and a multinomial logistic regression analysis were performed using the SPSS v. 14.0 program. When asked about their reaction towards damage related to health foods, approximately 48% of the respondents answered 'no response', 34% answered 'private response', and 18% answered 'public response'. Multinomial logistic regression analysis revealed that education level and awareness of health food price were significant factors influencing 'private response', and concerns about health foods and awareness of damage redemption were significant factors for 'public response'. These results imply that consumer education for elderly to prevent damage derived from the purchase and consumption of health foods is required.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1247-1254
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• 2018

We study the uncertainty stemming from different theoretical models in the spectroscopic factors extracted from experiments. We use three theoretical approaches, the distorted wave Born approximation (DWBA), the adiabatic distorted wave approximation (ADWA) and the continuum discretized coupled-channels method (CDCC), and analyze the $^{12}C(d,p)^{13}C$, $^{14}C(d,p)^{15}C$ reactions. We find that the uncertainty associated with the adopted theoretical models is less than 20%. We also investigate the contribution from the remnant term and observe that it gives less than 10% uncertainty. We finally make an attempt to explain the discrepancy in the spectroscopic factors of $^{17}C(\frac{3}{2}^+)$ between the ones extracted from experiments and from shell model calculations by analyzing the $^{16}C(d,p)^{17}C$ reaction.

• 한국운동역학회지
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• 제12권1호
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• pp.193-204
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• 2002

The purpose of this study was to investigate the effect of martial art type and target height on the ground reaction force factors during Dollyuchagi motion. Data were collected using force plate. Five Taekwondo players and five Hapkido players were tested during Dollyuchagi motion to three different target heights(0.8, 1.2, 1.6 m). After analysis of kinetics using force plate data, maximum vertical ground reaction force was 1.62~2.44 BW, and impulse was $0.66\sim1.01 BW{\cdot}s$. Even though there was no difference for maximum ground reaction forces and impulse between Hapkido and Taekwondo, as target height was higher, impulse increased. Anterior-posterior and vertical ground reaction forces at kicking foot take-off were greater with target height, although there was no difference for medio-lateral force with target height. At impact there was significant difference for anterior-posterior ground reaction force between Hapkido and Taekwondo players. Taekwondo players' force (range, -0.23~-0.26 BW) was greater than Hapkido players's force (range, -0.08~-0.14 BW).

• 한국보육지원학회지
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• 제13권3호
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• pp.39-54
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• 2017

Objective: The purpose of this study was to examine natural groupings of the sub-factors of mother's reaction to children's negative emotions. The natural groupings were as follows; the emotion-coaching-reaction, the emotion-minimizing-reaction and oversensitive reaction. In addition, this paper also investigated individual differences in children's emotion regulation by clusters of sub-factors of mother's reaction to children's negative emotions. Methods: The subjects of this study consisted of 318 children. The data were analyzed using cluster analysis and one-way ANOVA. Results: The results suggested four proper clusters, according to the characteristics of mother's reaction to children's negative emotions. Cluster 1 was categorized as 'child centered-emotion coaching', cluster 2 was categorized as 'oversensitive-emotion coaching comorbid', cluster 3 was categorized as 'acception-emotion minimizing confused' and cluster 4 was categorized as 'emotion minimizing-unsupporting.' Additionally, the differences between Emotion regulations in each cluster showed distinct points of interest. In terms of the maladaptive emotion regulation, cluster 3 showed the highest level followed by cluster 4. And cluster 1 and 2 showed the lowest level. Conclusion/Implications: The results of this study helped to find a deeper understanding of the operation of specific clusters of mother's reaction to children's negative emotion and children's emotion regulation.

• 한국운동역학회지
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• 제26권1호
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• pp.83-92
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• 2016

Objective: This study aimed to compare differences in biomechanical factors according to distance changes in relation to approaches during a round of golf to obtain basic data on golf swings. Methods: The research subjects were 8 KPGA-affiliated professional golfers who performed approach shots that put a ball into a circle of 8 feet in diameter from distances of 30, 50, and 70 m. Data were collected by using six infrared cameras and a ground reaction force device, which were applied to calculate biomechanical factors by using Kwon3D XP. The calculated data were subjected to one-way ANOVA by using SPSS 20.0, with the significance level set at p value of 0.05. Results: Elapsed time, stance width, clubhead position variation, clubhead synthesis speed, and cocking angle significantly differed according to distance change during the approach swing. Clubhead speed was positively related with stance width and clubhead displacement. Ground reaction force significantly differed according to distance change during the approach swing. Factors before and after showed differences in other states, except in the impact state. Conclusion: In the present study, we drew several conclusions regarding biomechanical factors and ground reaction forces according to distance change in the approach swing of professional golfers. According to these conclusions, we suggest that distance control with swing range is more important than power control in maintaining the accuracy and consistency of golf swing and is the most important mechanism of golf swing.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제10권S_4호
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• pp.173-179
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• 2001

The chemical behavior and properties of the redox state of environmental pollutants was investigated using electrochemical methods. The purpose was to measure the variations in the redox reaction of differential pulse polarograms and cyclic voltammograms. The results observed the influences on redox potential and current of various factors including concentration, temperature, salt, and pH. These were established factors as the effect of the redox reaction. It can be clearly recognized that the electrode reaction are from reversible to irreversible processes. Also, it was mixing with reaction current controlled.

• 한국환경과학회지
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• 제11권2호
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• pp.131-137
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• 2002

The chemical behavior and properties on the redox state of environmental pollutant has been investigated by electrochemical methods. We carried out to measure the variations in the redox reaction of differential pulse polarogram and cyclic voltammogram. The results observed the influences on redox potential and current of various factors with temperature and pH. These were established factors as the effect of the redox reaction. It can be clearly recognized that the electrode reaction are from qusi-reversible to irreversible processes. Also, it was mixing with reaction current controlled. The bits-phenol A in the waste water was made to compound with cobalt ion and it take away from the separation into compound. The $Co(BPA)_2$ compound was not found to be dissociation in waste water. However, this compound is avery unstable(K=1.02) and for a while, it was to be a dissociation. Therefore, we believed that it was likely to a toxic substance.

• 환경위생공학
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• 제14권4호
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• pp.1-8
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• 1999

This study was aimed ultimately to develop an adsorption process treating heavy metal wastewater by utilizing activated carbon using flyash. The affecting factors in adsorption process on heavy metal by flyash adhesion-activated carbon are s follows. Factors such as pH, and quality of activated carbon, and reaction time made batch adsorption isotherm described adsorption capacity was made use of the investigation to evaluate adsorptive possibility of heavy metal.As the results of this study, H ion has influence on adsorption of heavy metal if pH is low. As reaction time is transformed, factors such as optimum reaction time is taken into consideration an adsorptive process of heavy metal because an adsorption and a reduction process occur. Adsorption isotherm of adhesion-activated carbon was generally obeyed to Freundlich formular than Langmuir formular and Freundlich constant, l/n were obtained in the range of 0.1~0.5.

• 에너지공학
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• 제7권2호
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• pp.216-222
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• 1998

단양 백운석, 영월 백운석, 단양 석회석, 영월 석회석을 소성하여 얻은 탈황제에 대한 황화 반응 특성 실험을 열중량분석기를 사용하여 등온 방식에서 수행하였다. 입자 직경 0.08mm인 시료를 사용하여 650~85$0^{\circ}C$의 등온 조건, SO2 농도 0.38~1%, 산소농도 1.2~6.7% 변화 조건에서 황화 반응 실험이 행하여졌다. 여기서 활성화에너지는 23.6~36 kJ/mol, SO2 농도차수 0.3~2.2, 산소 농도 차수 0.22~0.51로 구하여졌다. 전체적인 반응 상수를 고려한 백운석에 대한 황화반응 속도 상관 관계식을 제시하였다.