Grundlagen des Burrows-Wheeler-Kompressionsalgorithmus

Der Burrows-Wheeler-Kompressionsalgorithmus hat als ein universelles Kompressionsverfahren in den letzten Jahren aufgrund seiner hervorragenden Kompressionsraten und hohen Verarbeitungsgeschwindigkeiten eine bemerkenswerte Beachtung erfahren. Das Herzstück des Algorithmus stellt die sogenannte Burrows-Wheeler-Transformation dar. Es handelt sich bei dieser Transformation um eine Permutation der Eingabedaten, welche Zeichen mit ähnlichem Kontext nahe beieinander anordnet. Die Transformation sowie die zugehörige Rücktransformation werden zusammen mit den weiteren Stufen des Algorithmus in einer gegenüber der Standardversion verbesserten Variante vorgestellt und die Ergebnisse mit denen anderer Datenkompressionsalgorithmen verglichen.     

A praxeological perspective for the design and implementation of a digital role-play game

This paper draws on an empirical work dedicated to discussing a theoretical model for design-based research. The context of our study is a research project for the design, the implementation and the analysis of Insectophagia, a digital role-play game implemented in secondary schools. The model presented in this paper aims at conceptualizing researchers’ and practitioners’ relationships with the notion that knowledge development takes place at a meta-didactical level when the participants develop a shared practice and a shared discourse on practice (a common praxeology). This is done through collaboration and teacher-centered design of innovative learning settings. This model emerges from a double approach: (1) a literature review on collaborative research in education and, (2) an analysis of the verbal interactions of practitioners and researchers involved in the project. The study emphasizes the development of knowledge among participants. It also emphasizes the importance of knowledge brokering for filling the gap between research and practice and thus, for the adoption of digital technology by practitioners.     

Invisible and Indispensable: Parttime Teachers in California Community Colleges

Abstract

Although parttime instructors constitute a substantial portion—often a majority—of community college faculties, they are accorded a low status on campus, with less than half the salary and none of the benefits of fulltime faculty members. This study points up a number of misconceptions that administrators have been using to justify discriminatory treatment of parttime teachers.