We give a new proof of a result of Ozawa showing that if a von Neumann subalgebra Q of a free group factor LFn, 2 ≤ n ≤ ∞ has relative commutant diffuse (i.e. without atoms), then Q is amenable.

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Let S be a finite nonabelian simple group, and let H be a subgroup of S . In this work, the dominion (in the sense of Isbell) of H in S in Var(S) is determined, generalizing an example of B.H. Neumann. A necessary and sufficient condition for H to be epimorphically embedded in S is obtained. These results are then extended to a variety generated by a family of finite nonabelian simple groups. S...

We continue the studies of the second author on regulated uniformly k-limited and regulated k-limited ET0L systems. We focus on the permitting and forbidding random context regulation. Especially, we establish some results on (regulated) propagating (uniformly) k-limited ET0L systems which were not solved in 2, 18, 21, 22]. Moreover, relations to recurrent programmed languages introduced by von...

Hybrid Particle Swarm Optimization (PSO) algorithm that combines the idea of global best model with the idea of local best model is presented in this paper. The hybrid PSO mixes the use of the traditional velocity and position update rules of star, ring and Von Neumann topologies all together. The objective of building PSO on multi-models is that, to find a better solution without trapping in l...

This article describes the addition to the von Neumann cellular automaton of the Tom Thumb Algorithm, a mechanism developed for the self-replication of multi-processor systems. Except for the cell construction process, every functionality of the original CA has been preserved in our new system. Moreover, the Tom Thumb Algorithm now allows the replication of any structure within the von Neumann ...

Let $R$ be a ring, $S$ multiplicative subset of $R$. An $R$-module $M$ is said to $u$-$S$-flat ($u$- always abbreviates uniformly) if $\Tor^R_1 (M, N)$ $u$-$S$-torsion for all $R$-modules $N$. In this paper, we introduce and study the concept $S$-cotorsion module which in some way generalization notion cotorsion module. $\Ext^1_R(F,M)=0$ any $F$. This new class modules will used characterize $u...

Die Aussagekraft betrieblicher Daten kann durch die Nutzung von Unternehmensvergleichen wesentlich erhöht werden. An einem Beispiel von Gesundheitsdaten beim Milchrind werden die informationstechnologischen Voraussetzungen zur Umsetzung eines entsprechenden Konzeptes erläutert. Schwerpunkte bilden dabei die Bereitstellung, die Vergleichbarkeit, die Übertragung und die Präsentation der Daten.

First order conditions are given which are necessary for a commutative regular ring to have a prime integrally closed extension. If the ring is countable these conditions are also sufficient. In [8] an example was given of a commutative regular ring with no prime model extension to a commutative integrally closed regular ring. In this paper we give (in §2) first order conditions which are neces...