The BDD preconditioner involves the solution of Neumann problems on all subdomain .
It is a member of the Neumann - Neumann class of methods , so named because they solve a Neumann problem on both sides of the interface between subdomains .
Since the BDD preconditioner involves the solution of Neumann problems on all subdomain , it is a member of the Neumann - Neumann class of methods , so named because they solve a Neumann problem on both sides of the interface between subdomains .