A (v, k, λ) difference family ((v, k, λ)-DF in short) over an abelian group G of order v is a collection F = {Bi | i ∈ I} of k-subsets of G, called base blocks, such that each nonzero element of G can be represented in precisely λ ways as a difference of two elements lying in some base blocks in F . A disjoint (v, k, λ)-DF is a difference family with disjoint blocks. In this paper, it is proved...

background: internal barriers are an important group of barriers to blood glucose level control. finding the viewpoints of patients, their families and medical team on these barriers is an important step towards correct planning and effective control of blood glucose. this study aimed to find and compare viewpoints of patients, their families and medical team about internal barriers to control ...

We give two constructions for semi-regular relative difference sets (RDSs) in groups whose order is not a prime power, where the order u of the forbidden subgroup is greater than 2. No such RDSs were previously known. We use examples from the first construction to produce semi-regular RDSs in groups whose order can contain more than two distinct prime factors. For u greater than 2 these are the...

We mainly investigate the global asymptotic stability and exponential convergence of positive solutions to two families of higher-order difference equations, one of which was recently studied in Stević’s paper 2010 . A new concise proof is given to a quite recent result by Stević and analogous parallel result of the other inverse equation, which extend related results of Aloqeili 2009 , Berenha...

Perfect (v,K, 1) difference families ((v,K, 1)-PDF in short, and (v, k, 1)-PDF when K = {k}) were introduced by Ge et al. for their useful application to the construction of properly centered permutations, which can be used to construct new radar arrays. Some works had been done on the existences of (v, k, 1)-PDFs, while little is known when |K| ≥ 2 except for partial results by Ge et al. In 19...