  In this paper, we propose a new parallel algorithm which could work naturally
on the parallel computer with arbitrary number of processors. This algorithm is
named Virtual Transmission Method (VTM). Its physical backgroud is the lossless
transmission line and microwave network. The basic idea of VTM is to insert
lossless transmission lines into the sparse linear system to achieve
distributed computing.
  VTM is proved to be convergent to solve SPD linear system. Preconditioning
method and performance model are presented. Numerical experiments show that VTM
is efficient, accurate and stable.
  Accompanied with VTM, we bring in a new technique to partition the symmetric
linear system, which is named Generalized Node & Branch Tearing (GNBT). It is
based on Kirchhoff's Current Law from circuit theory. We proved that GNBT is
feasible to partition any SPD linear system.
