Grundlagen des Burrows-Wheeler-Kompressionsalgorithmus     

Jürgen Abel 《Informatik - Forschung und Entwicklung》2004,39(1):80-87

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.  相似文献   

Do cognitive training strategies improve motor and positive psychological skills development in soccer players? Insights from a systematic review     

Maamer Slimani  Nicola Luigi Bragazzi  David Tod  Alexandre Dellal  Olivier Hue  Foued Cheour 《Journal of sports sciences》2016,34(24):2338-2349

ABSTRACT

Soccer players are required to have well-developed physical, technical and cognitive abilities. The present systematic review, adhering to Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines, examined the effects of cognitive training strategies on motor and positive psychological skills development in soccer performance and identified the potential moderators of the “cognitive training–soccer performance” relationship. Thirteen databases were systematically searched using keywords related to psychological or cognitive training in soccer players. The review is based on 18 studies, employing 584 soccer players aged 7–39 years. Cognitive strategies, particularly imagery, appear to improve sports performance in soccer players. Regarding imagery, the combination of two different types of cognitive imagery training (i.e., cognitive general and cognitive specific) has a positive influence on soccer performance during training, whereas motivational imagery (i.e., motivational general-arousal, motivational general-mastery and motivational specific) enhance competition performance. Younger soccer players employ cognitive general and cognitive specific imagery techniques to a greater extent than older soccer players. Combined cognitive training strategies were more beneficial than a single cognitive strategy relative to motor skills enhancement in elite (particularly midfielders) and amateur (i.e., when practising complex and specific soccer skills in precompetitive period) soccer players. In conclusion, it appears that there are differences in cognitive/psychological training interventions, and their efficacy, according to whether they are directed towards training or competition, and the age, standard and playing position of the players.  相似文献   

Centralization and Freedom in EducationNotes and Comments∗     

Alexandre Vexliard 《比较教育学》1970,6(1):37-47

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Metaphors we’re colonised by? The case of data-driven educational technologies in Brazil     

Giselle Martins dos Santos Ferreira  Luiz Alexandre da Silva Rosado  Márcio Silveira Lemgruber  Jaciara de Sá Carvalho 《Learning, Media and Technology》2020,45(1):46-60

ABSTRACT

This article discusses issues concerning the spread of data-driven educational technologies in Brazil. Here, as elsewhere, educational technology continues to be promoted optimistically as the bearer of a panacea for historically-rooted social problems. Whilst some of these technologies have indeed contributed to important widening-participation programmes in the last two decades, widespread advocacy of technological ‘solutionism’, reflected in gradually stronger policy demands for efficiencies to be improved through ‘innovation’, has supported a relentless marketisation of the country’s educational systems. As transnational corporations position themselves to take control of key areas of these systems, threatening to restructure the whole sector, data-driven educational technologies provide the latest example in a series of ‘new’ ideas offered in an ever-expanding market. Based on the notion of ‘conceptual metaphors’, which encapsulate specific ways of perceiving, thinking and relating with the world, this article examines key metaphors underpinning discourses surrounding data-driven educational technologies in Brazil. In particular, the article analyses ways in which these specific metaphors may be promoting perspectives that ignore difference and obscure broader questions concerning education, thus contributing to the reproduction of previously existing problems and supporting new forms of colonisation.  相似文献   

The new player at the table     

Richard Abel 《Publishing Research Quarterly》1998,14(3):67-71

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Bookreviews     

A. D. C. Peterson  Brian Holmes  G. De Landsheere  Helena W. F. Stellwag  Oskar Anweiler  J. O. J. Vanden Bossche  Abraham Robinson  F. I. Calvert  H. H. Stern  J. F. Willatt  Sydney Taylor  M. J. Langeveld  M. A. Brimer  T. N. Postlethwaite  Alexandre Vexliard 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1964,10(1):106-126

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Clarifying coal oils     

F.A. Abel 《Journal of The Franklin Institute》1860,70(2):123-124

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Symbolising the real of mathematics education     

Alexandre Pais 《Educational Studies in Mathematics》2015,89(3):375-391

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Revisiting Cross-document Structure Theory for multi-document discourse parsing     

Erick Galani Maziero  Maria Lucía del Rosário Castro Jorge  Thiago Alexandre Salgueiro Pardo 《Information processing & management》2014

Multi-document discourse parsing aims to automatically identify the relations among textual spans from different texts on the same topic. Recently, with the growing amount of information and the emergence of new technologies that deal with many sources of information, more precise and efficient parsing techniques are required. The most relevant theory to multi-document relationship, Cross-document Structure Theory (CST), has been used for parsing purposes before, though the results had not been satisfactory. CST has received many critics because of its subjectivity, which may lead to low annotation agreement and, consequently, to poor parsing performance. In this work, we propose a refinement of the original CST, which consists in (i) formalizing the relationship definitions, (ii) pruning and combining some relations based on their meaning, and (iii) organizing the relations in a hierarchical structure. The hypothesis for this refinement is that it will lead to better agreement in the annotation and consequently to better parsing results. For this aim, it was built an annotated corpus according to this refinement and it was observed an improvement in the annotation agreement. Based on this corpus, a parser was developed using machine learning techniques and hand-crafted rules. Specifically, hierarchical techniques were used to capture the hierarchical organization of the relations according to the proposed refinement of CST. These two approaches were used to identify the relations among texts spans and to generate multi-document annotation structure. Results outperformed other CST parsers, showing the adequacy of the proposed refinement in the theory.  相似文献   

Some thoughts on the present state of the book world—I     

Richard Abel 《Publishing Research Quarterly》1997,13(4):41-48

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