A new class of symmetric (v,k, λ)-designs

We construct new families of symmetric (v, k, )-designs with parameters

Erratum: “Studies on Gas Purification by a Pulsed Microwave Discharge at 2.46 GHz in Mixtures of N2/NO/O2 at Atmospheric Pressure” [Plasma Chemistry and Plasma Processing,Vol. 21, No. 2, 2001]

Plasma Chemistry and Plasma Processing -     

Cayley Graphs of Diameter Two from Difference Sets

Let and be the largest order of a Cayley graph and a Cayley graph based on an abelian group, respectively, of degree d and diameter k. When , it is well known that with equality if and only if the graph is a Moore graph. In the abelian case, we have . The best currently lower bound on is for all sufficiently large d. In this article, we consider the construction of large graphs of diameter 2 using generalized difference sets. We show that for sufficiently large d and if , and m is odd.     

Strongly regular graphs associated with ternary bent functions

We prove a new characterization of weakly regular ternary bent functions via partial difference sets. Partial difference sets are combinatorial objects corresponding to strongly regular graphs. Using known families of bent functions, we obtain in this way new families of strongly regular graphs, some of which were previously unknown. One of the families includes an example in [N. Hamada, T. Helleseth, A characterization of some {3v₂+v₃,3v₁+v₂,3,3}-minihypers and some [15,4,9;3]-codes with B₂=0, J. Statist. Plann. Inference 56 (1996) 129-146], which was considered to be sporadic; using our results, this strongly regular graph is now a member of an infinite family. Moreover, this paper contains a new proof that the Coulter-Matthews and ternary quadratic bent functions are weakly regular.     

Weighted multiple interpolation and the control of perturbed semigroup systems

In this paper, the controllability and admissibility of perturbed semigroup systems are studied, using tools from the theory of interpolation and Carleson measures. In addition, there are new results on the perturbation of Carleson measures and on the weighted interpolation of functions and their derivatives in Hardy spaces, which are of interest in their own right.     

Ueber den Arsengehalt des Glases und der Alkalien

Ohne Zusammenfassung     

An estimate for weighted Hilbert transform via square functions

We show that the norm of the Hilbert transform as an operator on the weighted space is bounded by a constant multiple of the power of the constant of , in other words by . We also give a short proof for sharp upper and lower bounds for the dyadic square function.

     

On the Linear Complexity of the Sidelnikov-Lempel-Cohn-Eastman Sequences

In [6] and [10], a construction of binary sequences with an (almost) optimal autocorrelation spectrum is suggested. We continue the study of the linear complexity and the linear feedback polynomial of these sequences over $ \mathbb{F} $ ₂, originated in [4].     

Test Function Criteria for Hankel Operators

It is well known that there are classes of test functions such that a Hankel operator is bounded if and only if it is bounded on those functions. Criteria are derived which determine whether a Hankel operator is compact or belongs to a particular Schatten class, in terms of its action on those test functions.