We describe a procedure for constructing morphisms in additive categories, combining Auslander’s concept of a morphism determined by an object with the existence of flat covers. Also, we show how flat covers are turned into projective covers, and we interprete these constructions in terms of adjoint functors.

In recent years, variance-reducing stochastic methods have shown great practical performance, exhibiting linear convergence rate when other stochastic methods offered a sub-linear rate. However, as datasets grow ever bigger and clusters become widespread, the need for fast distribution methods is pressing. We propose here a distribution scheme for SAGA which maintains a linear convergence rate,...

Pauschale Nutzungstarife gewinnen seit einigen Jahren kontinuierlich an Bedeutung, wie etwa im Bereich der Telefonie oder bei Internetzugängen. Die Konsumenten wählen jedoch nicht immer den ökonomisch besten Tarif, sondern fällen Ihre Entscheidung auf Basis falscher Annahmen bezüglich ihres tatsächlichen Nutzungsverhaltens. So konnte bereits für unterschiedliche Produkte und Branchen die Existe...

In this paper, we first consider (po-)torsion free and principally weakly (po-)flat $S$-posets, specifically  we discuss when (po-)torsion freeness implies principal weak (po-)flatness. Furthermore, we give a counterexample to show that Theorem 3.22 of Shi is incorrect. Thereby we present a correct version of this theorem. Finally, we characterize pomonoids over which all cyclic $S$-posets are ...

Zusammenfassung: Das multimedia lecture board (mlb) ist ein sogenanntes Shared Whiteboard und ermöglicht die Präsentation und die gemeinsame Bearbeitung von Dokumenten in computergestützten Videokonferenzen. Es wurde im Rahmen des DFN-Projekts “ANETTE” speziell für den Einsatz in TeleteachingVeranstaltungen entwickelt und findet seit dem Sommersemester 2001 Verwendung an verschiedenen Universit...

In order to take panel surveys into the ‘mobile age’, a careful analysis of their characteristics is conducted. Core issues of mobile surveys and panel designs are addressed and contrasted to their respective alternatives. Moreover, the use of mobile technology for carrying out panel surveys is discussed. Thereby, necessary actions and actors involved are identified, which provides a guideline ...

We have solved a σ–model in curved background using the fact that the Poisson–Lie T-duality can transform the curved background into the flat one. For finding solution of the flat model we have used transformation of coordinates that makes the metric constant. The T-duality transform was then explicitly performed.