As the paper tries to find measured phrasing to describe his seizure of power, it goes for the same word over and over.

The perfect tense is used to talk about something that happened in the past - an action that is completely finished, eg: she watched TV, she has watched TV.

Angular Frequency,Belo Monte,Complex Conjugate,Continuous Wavelet Transform,Damping Factor,Decay Constant,Detection Mode,Fast Fourier Transform,Fundamental Frequency ...