@TechReport{	  it:2000-028,
  author	= {Bharath Bhikkaji and Torsten S{\"o}derstr{\"o}m},
  title		= {Reduced order models for diffusion systems using singular
		  perturbations},
  institution	= {Department of Information Technology, Uppsala University},
  department	= {Division of Systems and Control},
  year		= {2000},
  number	= {2000-028},
  month		= nov,
  abstract	= {In this paper, we consider a special case of the one
		  dimensional heat diffusion across a homogeneous wall. This
		  physical system is modeled by a linear partial differential
		  equation, which can be thought of as an infinite
		  dimensional dynamic system. To simulate this physical
		  system, one has to approximate the underlying infinite
		  order system by a finite order approximation. In this paper
		  we first construct a simple and straightforward approximate
		  finite order model for the true system. The proposed
		  approximate models may require large model order to
		  approximate the true system dynamics in the high frequency
		  regions. To avoid the usage of higher order models, we use
		  a scheme similar to singular perturbations to further
		  reduce the model order. }
}