Efficient reverse k-nearest neighbor estimation     

Elke Achtert  Christian B?hm  Peer Kr?ger  Peter Kunath  Alexey Pryakhin  Matthias Renz 《Informatik - Forschung und Entwicklung》2007,15(3):179-195

The reverse k-nearest neighbor (RkNN) problem, i.e. finding all objects in a data set the k-nearest neighbors of which include a specified query object, has received increasing attention recently. Many industrial and scientific applications call for solutions of the RkNN problem in arbitrary metric spaces where the data objects are not Euclidean and only a metric distance function is given for specifying object similarity. Usually, these applications need a solution for the generalized problem where the value of k is not known in advance and may change from query to query. In addition, many applications require a fast approximate answer of RkNN-queries. For these scenarios, it is important to generate a fast answer with high recall. In this paper, we propose the first approach for efficient approximative RkNN search in arbitrary metric spaces where the value of k is specified at query time. Our approach uses the advantages of existing metric index structures but proposes to use an approximation of the nearest-neighbor-distances in order to prune the search space. We show that our method scales significantly better than existing non-approximative approaches while producing an approximation of the true query result with a high recall.  相似文献   

„Standardisierung,Professionalisierung, Profilierung — Herausforderungen für den Schulsport“     

Elke Grimminger 《Sportwissenschaft》2007,37(1):114-116

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Technological Study of the Decoration on an Erard Harp from 1818     

Panagiotis Poulopoulos  Marisa Pamplona  Luise Richter  Elke Cwiertnia 《文物保护研究》2020,65(2):86-102

ABSTRACT

Historical pedal harps from the early nineteenth century are highly adorned objects, decorated with various techniques such as polychromy, gilding, decoupage, and gilt composition ornaments. Even though a large number of such instruments are kept in private and public collections, until now their decorative features have not been examined systematically. Moreover, little has been written about the motives behind the choice of various decorative techniques by harp makers. This article presents results from the investigation of a double-action harp made in 1818 by Erard, the leading manufacturer of harps in Regency London, focusing on the technological aspects of its decorative features. Various analytical methods, such as visual examination, microscopy, SEM-EDX, FTIR, and Py-GC-MS, were used to identify the inorganic and organic components in the coating of the harp and to analyse its stratigraphy. Inspection with ultraviolet light revealed details of the original layers and of later additions, while radiography made the internal structure as well as damaged areas and repairs visible. The outcome of this object-based examination was complemented by archival research on the Erard firm, providing new insight into Erard’s production and marketing strategies.  相似文献   

The development of computational estimation in the transition from informal to formal mathematics education     

Sekeris  Elke  Empsen  Michaël  Verschaffel  Lieven  Luwel  Koen 《European Journal of Psychology of Education - EJPE》2021,36(3):845-864

European Journal of Psychology of Education - The transition from informal to formal mathematics is an important episode in children’s mathematical development. The current study investigated...  相似文献   

AN APPROACH TO THE EVALUATION OF TEACHING COMPANY PROGRAMMES     

Colin A. Carnall  Ray Wild 《Assessment & Evaluation in Higher Education》1981,6(3):249-262

In this paper we consider the problems associated with the evaluation of Teaching Company Programmes. These programmes involve Universities and Colleges, together with manufacturing companies, in efforts to improve manufacturing methods and to develop graduates for careers in manufacturing industry. We introduce a framework for the evaluation of these programmes and apply it to one in which the authors have been involved. The paper reports a number of results from the Teaching Company Programme involving Molins Ltd., Brunel University and Henley, the Management College.  相似文献   

Framework for Empirical Research on Science Teaching and Learning     

Hans Ernst Fischer  Klaus Klemm  Detlev Leutner  Elke Sumfleth  Rüdiger Tiemann  Joachim Wirth 《Journal of Science Teacher Education》2005,16(4):309-349

In view of the research on education—and subject-related education in particular—that has been conducted in recent years, it would seem useful to describe the current state and future trends of research on science teaching and learning. In the present article, research findings are described, the deficits of science education are analyzed, and medium- and long-term research goals are specified from the perspective of an interdisciplinary cooperative effort between specialists in the fields of empirical educational research; the psychology of learning and instruction; and biology, chemistry, and physics education. Revised and supplemented version of Fischer, H. E., Klemm, K., Leutner, D., Sumfleth, E., Tiemann, R., and Wirth, J. (2003). Naturwissenschaftsdidaktische Lehr-Lernforschung: Defizite und Desiderata [Natural science-didactical learning research: Deficits and desiderata]. Zeitschrift für Didaktik der Naturwissenschaften, 9, 179–208.  相似文献   

Evaluation of the implementation, use and effects of a computerised management information system in English secondary schools     

Adrie Visscher  Phil Wild  Debbie Smith  Len Newton 《British journal of educational technology : journal of the Council for Educational Technology》2003,34(3):357-366

Very little empirical large-scale research has been carried out on the use of IT in the management and administration of schools despite of the fact that schools all over the world have adopted such IT based systems. The move in many countries towards autonomous school management will further require the use of these systems. Sophisticated computerised school information systems (SISs) will have to provide school-based information relevant to the development of policies in areas where schools used merely to follow governmental guidelines. If such systems are to be designed and used to full effect, knowledge is urgently needed on the implementation, use and effects of established computerised SISs. The large-scale research project in England, reported here, goes some way towards filling this gap in our knowledge.  相似文献   

Secondary schools included: a literature review     

Annet De Vroey  Elke Struyf  Katja Petry 《International Journal of Inclusive Education》2016,20(2):109-135

For over a decade, inclusive discourse comprises the development of a school for all, both in primary and in secondary education. Facing long-standing barriers for effective comprehensive education, secondary schools show specific interests, strengths and needs in a school-wide movement towards inclusion. Reviewing literature of recent research in inclusion in secondary schools (2000–2012), current interests represent inclusive culture, policy and practices, although the balance between each of these dimensions is unequal. A large number of studies report on attitudes towards inclusion, followed by inclusive practice. A lower number of studies deal with policy issues. Staff attitudes towards inclusion, access to the general curriculum, peer support, self-determination strategies and collaborative practices in specific subject areas were identified as major topics of investigation. Considerable attention has also been paid to peer attitudes, self-advocacy and student grouping. While the adolescent perspective is emphasised, little room is left for parental involvement. Also, the central role of administrators and professional development of staff has been underexposed in current research on secondary inclusion.  相似文献   

A tale of two mailing lists     

Martyn Wild 《Education and Information Technologies》1999,4(4):369-389

This paper serves to report a research study on the use made of two separate mailing lists or listservs, for professional development—Oz-Teachers and UK-Schools. Both lists were, and still are, used by teachers in Australia and the United Kingdom, as well as by teachers across the globe, to communicate electronically with each other. The practice of this communication is typically characterised by text messages that pose questions or offer answers; by threads of discussion based around single or combined themes; and by statements of information. In this context, two windows are opened in this study: one shows a dynamic picture of teachers at work and play in the technology of listservs, developing skills and practices in asynchronous communications. The other looks into the content of many of the postings, demonstrating the practices, views, ideas and concerns teachers have with using technology in traditional school and classroom environments. Whilst this paper provides a detailed overview of the study, the full report of the research programme, of which this study constitutes one part, can be found elsewhere, in Lankshear et al. (1997) and Wild (1999).  相似文献   

Supporting Cognitive Design: Lessons from Human-computer Interaction and Computer-mediated Learning     

Clark N. Quinn  Martyn Wild 《Education and Information Technologies》1998,3(3-4):175-185

Cognitive engineering has led to a consideration of the capabilities and limitations of users in relation to the products of system design. However, there has not been a similar recognition of human limitations in the process of design. One way to improve the products of system design is by making improvements in the process of design and, in particular, by addressing the limitations of designers through scaffolding with the technology that is the object of design. To do this we need to identify what we know about the process of designing for computer-mediated learning systems, and to build an understanding of how the design process might benefit from cognitive strategies and computer technology. Here we survey various approaches to support the design process, in order to identify approaches and opportunities that may inform both fields. Specific suggestions include heuristics for design, and scaffolding the design process through support tools. © IFIP, published by Kluwer Academic Publishers  相似文献