In [15], Kaplansky introduced Baer rings as rings in which every right (left) annihilator ideal is generated by an idempotent. According to Clark [9], a ring R is called quasi-Baer if the right annihilator of every right ideal is generated (as a right ideal) by an idempotent. Further works on quasi-Baer rings appear in [4, 6, 17]. Recently, Birkenmeier et al. [8] called a ring R to be a right (...

A complemented modular lattice L is coordinatizable, if it is isomorphic to the lattice L(R) of principal right ideals of some von Neumann regular ring R. All known sufficient conditions for coordinatizability, due first to J. von Neumann, then to B. Jónsson, are first-order. Nevertheless, we prove that coordinatizability of complemented modular lattices is not firstorder, even for countable 2-...

A new characteristic property of von Neumann regular rings is proposed in terms of annihilators of elements. An ELT fully idempotent ring is a regular ring whose simple left (or right) modules are either injective or projective. Artinian rings are characterized in terms of Noetherian rings. Strongly regular rings and rings whose two-sided ideals are generated by central idempotents are characte...

In diesem Beitrag wird die Berechnung von Differenzen zwischen Prozessmodellen betrachtet. Hierzu werden verschiedene Ansätze und Werkzeuge zur Berechnung von Differenzen beschrieben. Ausgehend von einem konkreten Anwendungsfall – einer EPK-zu-BPEL-Transformation – werden verschieden Testkriterien aufgestellt, die anschließend zur Evaluierung von zwei Differenzbildungswerkzeugen dienen. Abschli...

We introduce the notation Q(1) ∗ · · · ∗ Q(n) ∗L(Fr) for von Neumann algebra II1–factors where r is allowed to be negative. This notation is defined by rescalings of free products of II1–factors, and is proved to be consistent with known results and natural operations. We also give two statements which we prove are equivalent to isomorphism of free group factors.

The term von Neumann computer has two common meanings. Its strictest de nition refers to a speci c type of computer organization, or \architecture," in which instructions and data are stored together in a common memory. This type of architecture is distinguished from the \Harvard" architecture in which separate memories are used to store instructions and data. The term \von Neumann computer" al...

In this article, we present a family of algorithms for linear programming based on an algorithm proposed by von Neumann. The von Neumann algorithm is very attractive due to its simplicity, but is not practical for solving most linear programs to optimality due to its slow convergence. Our algorithms were developed with the objective of improving the practical convergence of the von Neumann algo...

The purpose of this paper is to prove that a completely positive projection on a Hilbert space associated with a standard form of a von Neumann algebra induces the existence of a conditional expectation of the von Neumann algebra with respect to a normal state, and we consider the application to a standard form of an injective von Neumann algebra.