3.1 Discrete-Time Fourier Transform Definition- The discrete-time Fourier transform (DTFT) X(eio) of a sequence x[n] is given by jae In general,() is a complex function of the real variable and can be written as X(eio) Xre(eio) +j Xim(eio)
Fourier series: Periodic signals and lti Systems ()=∑H(k k= ak一→H(ko)ak “g Soak-→|H(jkco)lkl H(7k)=1H(k0e∠B(ko) or powers of signals get modified through filter/system ncludes both amplitude phase akeJhwon
A VNi atomic model for 3D periodic structure is posed based on T polyhedrons which are introduced. The fourier transform patterns of the atomic model may explain the 12-fold symmetry in electron diffraction patterns of V60Ni40 alloy. This is the first satisfactory explanation since the V60Ni40 alloy has been reported