Bøger af Thomas (Queen Mary University of London) Muller

Das Buch behandelt die technischen Grundlagen und die Geschichte der Analogrechner auf deutschen U-Booten des Zweiten Weltkrieges. Analoge Rechenhilfsmittel wurden vor allem zur Berechnung des Torpedoschusswinkels und zur Lösung von taktischen Aufgaben sowie zu Navigationszwecken eingesetzt. Mechano-optische Analogrechner wie die Rechenschieber der Hamburger Firma Dennert & Pape ARISTO werden ebenso ausführlich dargestellt, wie die Torpedovorhaltrechner der Firma Siemens Apparate und Maschinen GmbH.

The theory of R-trees is a well-established and important area of geometric group theory and in this book the authors introduce a construction that provides a new perspective on group actions on R-trees. They construct a group RF(G), equipped with an action on an R-tree, whose elements are certain functions from a compact real interval to the group G. They also study the structure of RF(G), including a detailed description of centralizers of elements and an investigation of its subgroups and quotients. Any group acting freely on an R-tree embeds in RF(G) for some choice of G. Much remains to be done to understand RF(G), and the extensive list of open problems included in an appendix could potentially lead to new methods for investigating group actions on R-trees, particularly free actions. This book will interest all geometric group theorists and model theorists whose research involves R-trees.