This paper concentrates on a class of pseudorandom sequences generated by combining q-ary m-sequences and quadratic characters over finite field odd order, called binary generalized NTU sequences. It is shown that the relationship among sub-sequences can be formulated as combinatorial structures Hadamard designs. As consequence, generalize group structure discovered Kodera et al. (IEICE Trans. ...

An n-ary operation Q : Σ → Σ is called an n-ary quasigroup of order |Σ| if in the equation x0 = Q(x1, . . . , xn) knowledge of any n elements of x0, . . . , xn uniquely specifies the remaining one. Q is permutably reducible if Q(x1, . . . , xn) = P ( R(xσ(1), . . . , xσ(k)), xσ(k+1), . . . , xσ(n) ) where P and R are (n− k+1)-ary and kary quasigroups, σ is a permutation, and 1 < k < n. Anm-ary ...

We count all latin cubes of order n ≤ 6 and latin hypercubes of order n ≤ 5 and dimension d ≤ 5. We classify these (hyper)cubes into isotopy classes and paratopy classes (main classes). For the same values of n and d we classify all d-ary quasigroups of order n into isomorphism classes and also count them according to the number of identity elements they possess (meaning we have counted the d-a...

The growing amount of data available in modern-day datasets makes the need to efficiently search and retrieve information. To make large-scale search feasible, Distance Estimation and Subset Indexing are the main approaches. Although binary coding has been popular for implementing both techniques, n-ary coding (known as Product Quantization) is also very effective for Distance Estimation. Howev...

In this paper we study nearly perfect sequences (NPS) via their connection to direct product difference sets (DPDS). We prove the connection between a p-ary NPS of period n and type γ and a cyclic (n, p, n, n−γ p + γ, 0, n−γ p )-DPDS for an arbitrary integer γ. Next, we present the necessary conditions for the existence of a p-ary NPS of type γ. We apply this result for excluding the existence ...

An algorithm for finding the unequal error protection (UEP) capability of a q-ary image of a low-rate qm-ary cyclic code is presented by combining its concatenated structure with the UEP capability of concatenated codes. The results are independent of a choice of a basis to be used for expanding an element over GF(qm) into GF(q). A table of the UEP capability of binary images of low-rate Reed-S...

We present some exact expressions for the number of paths of a given length in a perfect $m$-ary tree. We first count the paths in perfect rooted $m$-ary trees and then use the results to determine the number of paths in perfect unrooted $m$-ary trees, extending a known result for binary trees.

Together with stars and paths, b-ary trees are one of the most studied acyclic graph structures. As any other structure, a b-ary tree can be seen as containing information. The aim of the present research was to assess through informational entropy the structural information changes in b-ary trees after removal of an arbitrary vertex.

This paper gives two necessary and sufficient conditions of invariants of an m-ary form and one necessary and sufficient condition of covariants of an m-ary form. By these criterions we compute some invariants and covariants of anm-ary form. At last, two examples of computing the syzygies of invairants by the characteristic set method are given.

The family tree of a Galton-Watson branching process may contain N -ary subtrees, i.e. subtrees whose vertices have at least N ≥ 1 children. For family trees without infinite N -ary subtrees, we study how fast N -ary subtrees of height t disappear as t → ∞.