Jiosseu Jean Lambert, Mengounou Ghislain Mengata, Nkouetcha Emeric Tchamdjio, Imano Adolphe Moukengue
Pure Physique Laboratory UFD MIP, University of Douala, Douala, Cameroon.
Laboratory of Technology and Applied Sciences, University of Douala, Douala, Cameroon.
Heliyon. 2023 Jun 1;9(6):e16796. doi: 10.1016/j.heliyon.2023.e16796. eCollection 2023 Jun.
This paper presents a new method for analysing creeping discharges based on information theory as it applies to medical imaging. The analysis of information surface data is used to determine the impact of relaxation time on the characteristic parameters of creeping discharges. The same information is used to make a comparative study of the morphology of discharges propagating in palm kernel oil methyl ester (PKOME) and in mineral oil (MO). Other comparative methods based on fractal analysis and normality hypothesis tests associated with Anderson Darling (AD), Kolmogorov-Smirnoff (KS) and Shapiro-Wilk (SW) statistics are used. The results show that very short relaxation times increase the error on the measurement of the fractal dimension and the maximum extension of the discharges. A growth of the mutual information between 0 and 60% is observed for relaxation times varying between 60s and 420s respectively. For the same time interval, the -value increases from 0.027 to 0.821 according to the AD statistic, from 0.01 to more than 0.150 according to KS and from 0.083 to more than 0.1 according to SW. This result indicates that the data are from a normal distribution. After 420s of relaxation, the error on the maximum extension measurement is reduced by 94% in PKOME and 92% in MO. Similarly, the error on the mean fractal dimension in MO is reduced by 86.7% for a relaxation time between 301s and 420s, and by 84.6% in PKOME for a time between 180s and 420s. These different results imply that the impact of the discharge can be predicted when it is in its initial phase during which the number of discharge occurrences is reduced. On the other hand, the physicochemical characteristics of the insulating liquid used dictate the relaxation time to be allowed for the laboratory measurements.
本文提出了一种基于信息论的用于分析沿面放电的新方法，该方法应用于医学成像领域。通过对信息表面数据进行分析，来确定弛豫时间对沿面放电特征参数的影响。利用相同信息对在棕榈仁油甲酯（PKOME）和矿物油（MO）中传播的放电形态进行比较研究。还使用了基于分形分析以及与安德森 - 达林（AD）、柯尔莫哥洛夫 - 斯米尔诺夫（KS）和夏皮罗 - 威尔克（SW）统计相关的正态性假设检验的其他比较方法。结果表明，非常短的弛豫时间会增加分形维数测量误差以及放电的最大扩展范围。对于分别在60秒至420秒之间变化的弛豫时间，观察到互信息增长了0至60%。在相同的时间间隔内，根据AD统计，p值从0.027增加到0.821，根据KS统计从0.01增加到超过0.150，根据SW统计从0.083增加到超过0.1。该结果表明数据来自正态分布。在弛豫420秒后，PKOME中最大扩展测量的误差降低了94%，MO中降低了92%。同样，对于301秒至420秒之间的弛豫时间，MO中平均分形维数的误差降低了86.7%，对于180秒至420秒之间的时间，PKOME中降低了84.6%。这些不同结果意味着，当放电处于初始阶段（此时放电发生次数减少）时，可以预测放电的影响。另一方面，所使用的绝缘液体的物理化学特性决定了实验室测量所需的弛豫时间。
