Abslrczc-The 3-dimensional finite-difference time-domain method in non-orthogonal co-ordinates (non-standard FDTD) is used to calculate the frequencies of resonators. The numerical boundary conditions of the method are presented. The influences of boundary conditions and discrete meshes on the numerical accuracy are investigated. We present the nonstandard FDTD method using the boundary-orthogo...

Recently, Dag Normann and the author have established a connection between higher-order computability theory and Nonstandard Analysis; new results in both fields are obtained by exploiting this connection ([28]). Now, on the side of computability theory, the technique known as Grilliot’s trick constitutes a template for explicitly defining the Turing jump functional (∃) in terms of a given effe...