Cyberman choosing to fill in gaps in the history of the Cybermen or depict new encounters between them and the Doctor. The species also appeared in the "Doctor Who" TV spin-off "Torchwood", appearing in the fourth episode, "Cyberwoman" (2006). The name "Cyberman" comes from cybernetics, a term used in Norbert Wiener's book "Cybernetics or Control and Communication in the Animal and the Machine" (MIT Press, 1948). Wiener used the term in reference to the control of complex systems in the animal world and in mechanical networks, in particular self-regulating control systems. By 1960, doctors were performing research into surgically or mechanically
Wiener filter criterion of the latter does not rely on cross-correlations or auto-correlations. Its solution converges to the Wiener filter solution. For complex signals, the derivation of the complex Wiener filter is performed by minimizing formula_55 =formula_56. This involves computing partial derivatives with respect to both the real and imaginary parts of formula_32, and requiring them both to be zero. The resulting Wiener-Hopf equations are: which can be rewritten in matrix form: Note here that:formula_60 The Wiener coefficient vector is then computed as:formula_61 The Wiener filter has a variety of applications in signal processing, image processing, control systems, and digital communications. These