Chair: Jr-Jen Huang, Purdue University, USA
Yasuo Nomura, Kansai University (Japan)
Yoshinobu Kajikawa, Kansai University (Japan)
There are two types of distortion of the loudspeaker system, the linear and the nonlinear distortions. We have tried to eliminate the linear distortion by digital filters. However, the more quantity of the elimination of the linear distortion, results in the more quantity of the nonlinear distortion. Therefore in order to make a high quality audio system we need to eliminate both the linear and the nonlinear distortions at the same time. First, we have identified the loudspeaker system by the Volterra expansion which expresses the relationship between input and output signals, and then proposed the design method of the inverse system. The result of simulation shows that a decrease of the nonlinear distortion of about lOOdB can be obtained by using the design method proposed here.
Adriaan van den Bos, Delft University of Technology (The Netherlands)
For the transmission electron microscope, the transfer of the complex specimen exit wave to observed intensities is modelled as a Volterra system function. This system function includes the effect of microscope fluctuations and is used in a parameter estimation based reconstruction of the exit wave. The numerical optimization employed in the parameter estimation procedure is carried out directly with respect to both the real and the complex valued parameters.