‎Let $G$ be a finite group and $nu(G)$ denote the number of conjugacy classes of non-normal subgroups of $G$‎. ‎In this paper‎, ‎all nilpotent groups $G$ with $nu(G)=3$ are classified‎.  

Original scientific paper From the view of time sequence, a petroleum pipeline leak detection and location method is proposed based on intuitionistic fuzzy set theory. The method uses wavelet decomposition and semi-hard-and-soft thresholding method to remove the noise of signal. Secondly, selecting fixed-length normal dynamic pressure wave signal sequences as the template sequence, and the same...

This paper presents a fuzzy optimization method based on the inclusion degrees of intuitionistic fuzzy sets to solve multi-criteria decision making problems under fuzzy environments. First, the inclusion degree of intuitionistic fuzzy sets is defined and a series of specific formulas of inclusion degree are presented by means of the normal implication operators. Some formulas of inclusion degre...