We present a method for direction field design on surface and volumetric meshes supporting non-orthogonality. Our approach is generalization of the representation 3D cross fields in spherical harmonic basis. As such it induces geometrically meaningful measure smoothness, allows orthogonality control by simple parameter enables orientation constraints single direction. To best our knowledge this...

In this paper, we prove existence of optimal complementary dual codes (LCD codes) over large finite fields. We also give methods to generate orthogonal matrices over finite fields and then apply them to construct LCD codes. Construction methods include random sampling in the orthogonal group, code extension, matrix product codes and projection over a self-dual basis.

In this paper, we give algorithms and methods of construction of self-dual codes over finite fields using orthogonal matrices. Randomization in the orthogonal group, and code extension are the main tools. Some optimal, almost MDS, and MDS self-dual codes over both small and large prime fields are constructed.

The projective orthogonal and symplectic groups POn(F ) and PSpn(F ) have a natural action on the F vector space V ′ = Mn(F ) ⊕ . . . ⊕ Mn(F ). Here we assume F is an infinite field of characteristic not 2. If we assume there is more than one summand in V , then the invariant fields F (V )n and F (V )n are natural objects. They are, for example, the centers of generic algebras with the appropri...