Bloch wave – MoM method the wave numbers in any of the 3 periodic coordinate directions. This can happen for example when the free space wavelength exactly equals the lattice spacing. This is a statistically rare occurrence in computational practice and corresponds to a propagation anomaly similar to a Wood's reflection anomaly for gratings. To compute bands of the crystal (i.e. "k"-"k" diagrams), successive values of frequency ("k") are tried - in conjunction with pre-selected values of propagation constant ("k") and propagation direction (θ & φ) - until a combination is found which drives the determinant of the matrix to zero. Equation (4.2) has been
Constant-weight code threshold. Most line codes use either a constant-weight code, or a nearly-constant-weight paired disparity code. In addition to use as error correction codes, the large space between code words can also be used in the design of asynchronous circuits such as delay insensitive circuits. Constant-weight codes, like Berger codes, can detect all unidirectional errors. The central problem regarding constant-weight codes is the following: what is the maximum number of codewords in a binary constant-weight code with length formula_1, Hamming distance formula_2, and weight formula_3? This number is called formula_4. Apart from some trivial observations, it is generally impossible to compute