The concept of a uniform density of subsets A of the set N of positive integers was introduced in [1] and [2]. Corresponding Iu convergence to the notion of uniform density u can be found in [8]. This paper studies Iu convergence in detail.

• BioGeoChemie des Watts Auf Beschluss der Deutschen Forschungsgemeinschaft wird an der Universität Oldenburg für die Dauer von sechs Jahren eine Forschergruppe "BioGeoChemie des Watts" eingerichtet. In den ersten drei Jahren erhält die Gruppe fast sechs Millionen DM Förderung. Der Antrag wurde federführend vom Institut für Chemie und Biologie des Meeres (ICBM) vorbereitet. Beteiligt sind außer...

The cross section for U+ production from the reaction gp→p+K−U+, which was observed in the CLAS experiment at the Jefferson National Laboratory, is evaluated in a hadronic model that includes couplings of U+ to both KN and K*N. With their coupling constants determined from the empirical pNNs1710d and rNNs1710d coupling constants using the SU(3) symmetry, the cross section for this reaction has ...

We present here a new code-based digital signature scheme. This scheme uses (U |U + V ) codes, where both U and V are random. We prove that the scheme achieves existential unforgeability under adaptive chosen message attacks under two assumptions from coding theory, both strongly related to the hardness of decoding in a random linear code. The proof imposes a uniform distribution on the produce...

In this paper, we study the algebraic structure of Z2[u]Z2[u, v]-additive codes which are Z2[u, v]-submodules where u 2 = v2 = 0 and uv = vu. In particular, we determine a Gray map from Z2[u]Z2[u, v] to Z 2α+8β 2 and study generator and parity check matrices for these codes. Further we study the structure of Z2[u]Z2[u, v]additive cyclic codes and constacyclic codes.

In this work, by employing the Krasnosel'skii fixed point theorem, we study the existence of positive solutions of a three-point boundary value problem for the following fourth-order differential equation begin{eqnarray*} left { begin{array}{ll} u^{(4)}(t) -f(t,u(t),u^{prime prime }(t))=0 hspace{1cm} 0 leq t leq 1, & u(0) = u(1)=0, hspace{1cm} alpha u^{prime prime }(0) - beta u^{prime prime pri...

Valdis Laan in [5] introduced an extension of strong flatness which is called weak pullback flatness. In this paper we introduce a new property of acts over monoids, called U-WPF which is an extension of weak pullback flatness and give a classification of monoids by this property of their acts and also a classification of monoids when this property of acts implies others. We also show that regu...