@TechReport{	  it:2011-019,
  author	= {Qaisar Abbas and Jan Nordstr{\"o}m},
  title		= {A Weak Boundary Procedure for High Order Finite Difference
		  Approximations of Hyperbolic Problems},
  institution	= {Department of Information Technology, Uppsala University},
  department	= {Division of Scientific Computing},
  year		= {2011},
  number	= {2011-019},
  month		= sep,
  abstract	= {We introduce a new weak boundary procedures for high order
		  finite difference operators on summation-by-parts type
		  applied to hyperbolic problems. The boundary procedure is
		  applied in an extended domain where data is known. We show
		  how to raise the order of accuracy for a diagonal norm
		  based approximation and how to modify the spectrum of the
		  resulting operator to get a faster convergence to
		  steady-state. Furthermore, we also show how to construct
		  better non-reflecting properties at the boundaries using
		  the above procedure. Numerical results that corroborate the
		  analysis are presented.}
}