• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2010년도 춘계학술대회 논문집
• /
• pp.37-37
• /
• 2010

In these days $SF_6$ mixtures and alternative gas has been studied because of global warming. so although many studies have been carried out about binary gas mixtures with $SF_6$, few studies were presented about breakdown characteristics of $SF_6/N_2$ mixtures. In this paper, breakdown experiment values and breakdown simulation value are compared. Streamer theory was used for predicting breakdown voltage. For accurate simulation, this simulation apply utilization factor using CST program. AC breakdown experiments in non-uniform field was performed to compare with the breakdown simulation values. But with gap lengths increasing, the breakdown voltage is saturated. So simulation need surface roughness factor.

• Journal of Electrical Engineering and Technology
• /
• 제4권3호
• /
• pp.410-417
• /
• 2009

The objective of this paper is to study the discharge phenomenon for a point-plane air interval using an original fuzzy logic system. Firstly, a physical model based on streamer theory with consideration of the space charge fields due to electrons and positive ions is proposed. To test this model we have calculated the breakdown threshold voltage for a point-plane air interval. The same model is used to determine the discharge steps for different configurations as an inference data base. Secondly, using results obtained by the numerical simulation of the previous model, we have introduced the fuzzy logic technique to predict the breakdown threshold voltage of the same configurations used in the numerical model and make estimation on the insulating state of the air interval. From the comparison of obtained results, we can conclude that they are in accordance with the experimental ones obtained for breakdown discharges in different point-plane air gaps collected from the literature. The proposed study using fuzzy logic technique shows a good performance in the analysis of different discharge steps of the air interval.

• 한국의류학회지
• /
• 제46권4호
• /
• pp.583-599
• /
• 2022

This study aims to clarify the implications of rapidly growing live commerce in China by examining the multifaceted aspects of social presence, in particular to help small commerce operators and platform companies. It examines the effect of cognitive and affective social presence on consumer engagement by evaluating consumption values and trust in streamers. In this survey study, the responses of 221 individuals residing in large cities of China were analyzed using structural equation modeling. The results showed that cognitive social presence had a positive effect on consumer engagement by mediating the utilitarian value and trust in streamers. Furthermore, affective social presence had a positive effect on consumer engagement through the hedonic value and trust in streamers. Thus, our research provides a new perspective to approaching a multidimensional social presence and understanding consumer behavior in live commerce. Moreover, it contributes to the application and expansion of social presence theory in this field.