CAJ | 학술논문

针对不规则脉冲簇难以判别问题，将多尺度熵应用于不规则先导分析中，探讨闪电信号不规则脉冲分析应用中多尺度熵关键参量的选择方法。在此基础上，将不规则先导与直窜先导及梯级先导闪电信号的多尺度熵进行比较。统计分析表明：不规则先导和直窜先导熵值随尺度先增加后趋于平稳，但熵值有很大差异；梯级先导熵值随尺度变化不明显，整体呈增长趋势，与不规则先导的熵值在大于3的尺度上也有所差异，因此当尺度大于3时可将熵值大于1．5的先导归类为不规则先导，熵值小于1．5的先导归类为梯级先导或直窜先导。不规则先导的特征熵平均值为2．0～2．1，最大值范围为2．6～2．8，最小值范围为1．51～1．59。
침대불규칙맥충족난이판별문제，장다척도적응용우불규칙선도분석중，탐토섬전신호불규칙맥충분석응용중다척도적관건삼량적선택방법。재차기출상，장불규칙선도여직찬선도급제급선도섬전신호적다척도적진행비교。통계분석표명：불규칙선도화직찬선도적치수척도선증가후추우평은，단적치유흔대차이；제급선도적치수척도변화불명현，정체정증장추세，여불규칙선도적적치재대우3적척도상야유소차이，인차당척도대우3시가장적치대우1．5적선도귀류위불규칙선도，적치소우1．5적선도귀류위제급선도혹직찬선도。불규칙선도적특정적평균치위2．0～2．1，최대치범위위2．6～2．8，최소치범위위1．51～1．59。
The chaotic leader is different from stepped leader and dart leader with distinctive features.It has many narrow pulses,causing strong high-frequency radiation.The pulse occurs right at the position of preceding stepped leader and dart leader,but its structure,width and interval all show significant irregu-larities.The chaotic leader is a new and special one with no exact definition of its pulse characterization so far. <br> Multi-scale entropy is applied to the analysis of chaotic leader,and some key parameters applying in the lightning irregular pulse signal analysis are given after detailed analysis.Dart leader signal,stepped leader signal and the chaotic leader signal are analyzed with the given method and the results are compared, and case studies of the three-leader multi-scale entropy features prove the feasibility of this method.It’s found out through statistical analysis that 3 leaders are different in entropy value especially when the scale is greater than 3,and thus they can be clearly distinguished by entropy values.Entropy value greater than 1.5 may indicate chaotic leader,and entropy value less than 1.5 is classified as stepped leader or dart lead-er.Furthermore chaotic leader and dart leader entropy value both increase with scales first and then stabi-lize but stepped leader entropy value doesn’t change much.Characteristic entropy values for the chaotic leader are given:The average is about 2.0-2.1,the maximum is 2.6-2.8,and the minimum is 1.51-1.59.Based on the analysis of multi-scale entropy characteristics of 3 leaders,the physical meaning of the irregularity is also discussed.The irregularity degree of chaotic electric field pulse can be reflected by the entropy value:The greater the entropy value is,the greater the degree of irregularity.The characteristics of the electric field pulse in the waveform is directly related with the development of the discharge process. For the dart leader or stepped leader,the smaller entropy value illustrates that its discharge is regular. The chaotic leader in small scale with larger entropy directly demonstrates that in this range scale its dis-charge,polarity and intensity are irregular.It shows the electric discontinuity somewhere in the leader de-velopment channel during a certain period before the occurrence of subsequent stroke.