Mexicana de Aviación Mexicana de Aviación Compañía Mexicana de Aviación, S.A. de C.V. (commonly known as Mexicana) was Mexico's oldest airline and one of the oldest continuously single-branded airlines (after KLM, Avianca and QANTAS), and Mexico's biggest and flagship airline before ceasing operations on August 28, 2010. The group's closure was announced by the company's recently installed management team a short time after the group filed for Concurso Mercantil (Mexican law equivalent to US Chapter 11) and US Chapter 15. On April 4, 2014, a judge declared Mexicana bankrupt and ordered to start selling off the company's assets to repay the airline's obligations.
S transform S transform S transform as a time–frequency distribution was developed in 1994 for analyzing geophysics data. In this way, the "S" transform is a generalization of the short-time Fourier transform (STFT), extending the continuous wavelet transform and overcoming some of its disadvantages. For one, modulation sinusoids are fixed with respect to the time axis; this localizes the scalable Gaussian window dilations and translations in "S" transform. Moreover, the "S" transform doesn't have a cross-term problem and yields a better signal clarity than Gabor transform. However, the "S" transform has its own disadvantages: the clarity is worse than Wigner distribution function