Télé-université

About: Télé-université is a education organization based out in Québec, Quebec, Canada. It is known for research contribution in the topics: Ontology (information science) & Context (language use). The organization has 231 authors who have published 608 publications receiving 5413 citations.

Understanding and analysing activity and learning in virtual communities

Abstract: The purpose of this study is to provide a preliminary framework to observe, analyse and evaluate both activity and learning in virtual communities. So various types of virtual communities will be studied by examining their relationship to socialisation and learning. After a presentation of the main ideas of Wenger's social learning theory, the principal components of the social context of the emergence and evolution of virtual communities will be described. It will show how taking this context into account enables the definition of four principal types of virtual communities: community of interest, goal-oriented community of interest, learners' community and community of practice and describe how the activity of these communities develops according to the goals they set for themselves and to the strategies they adopt to reach them. For each type of virtual community, an attempt will be made to determine the process of negotiation of meaning at the base of learning, and to describe the learning performed in terms of participation and reification processes.

Advances in Intelligent Tutoring Systems

Abstract: The idea for this book on Intelligent Tutoring Systems (ITS) was sparked by the success of the ITS08 international conference. The number of presentations and their quality bore witness to the vitality and maturity of the field, and the enthusiasm of the participants held out a promise of sustainability and innovative research. Long life to ITS research! The book is divided into five parts. The introductory chapters to these parts, which summarize foundations, developments, strengths and weaknesses in each of the areas covered, are addressed to all readers. For those who want more in-depth knowledge, we give the floor to researchers who present their work, their results, and their view of what the future holds. It is our hope that all readers will find the book informative and thought-provoking.

Decoding billions of integers per second through vectorization

Abstract: In many important applications-such as search engines and relational database systems-data are stored in the form of arrays of integers. Encoding and, most importantly, decoding of these arrays consumes considerable CPUtime. Therefore, substantial effort has been made to reduce costs associated with compression and decompression. In particular, researchers have exploited the superscalar nature of modern processors and single-instruction, multiple-data SIMD instructions. Nevertheless, we introduce a novel vectorized scheme called SIMD-BP128i¾? that improves over previously proposed vectorized approaches. It is nearly twice as fast as the previously fastest schemes on desktop processors varint-G8IU and PFOR. At the same time, SIMD-BP128i¾? saves up to 2bits/int. For even better compression, we propose another new vectorized scheme SIMD-FastPFOR that has a compression ratio within 10% of a state-of-the-art scheme Simple-8b while being two times faster during decoding. Copyright © 2013 John Wiley & Sons, Ltd.

From management to stewardship: Viewing forests as complex adaptive systems in an uncertain world

Abstract: The world's forests and forestry sector are facing unprecedented biological, political, social, and climatic challenges. The development of appropriate, novel forest management and restoration approaches that adequately consider uncertainty and adaptability are hampered by a continuing focus on production of a few goods or objectives, strong control of forest structure and composition, and most importantly the absence of a global scientific framework and long-term vision. Ecosystem-based approaches represent a step in the right direction, but are limited in their ability to deal with the rapid pace of social, climatic, and environmental changes. We argue here that viewing forest ecosystems as complex adaptive system provides a better alternative for both production- and conservation-oriented forests and forestry. We propose a set of broad principles and changes to increase the adaptive capacity of forests in the face of future uncertainties. These span from expanding the sustained-yield, single-good paradigm to developing policy incentives and interventions that promote self-organization and integrated social-ecological adaptation.

An Improved Petal Heuristic for the Vehicle Routeing Problem

Abstract: Solutions produced by the first generation of heuristics for the vehicle routeing problem are often far from optimal. Recent adaptations of local search improvement heuristics, like tabu search, produce much better solutions but require increased computing time. However there are situations where good solutions must be obtained quickly. The algorithm proposed in this paper yields solutions almost as good as those produced by tabu search adaptations, but at only a small fraction of their computing time. This heuristic can be seen as an improved version of the original petal heuristic. On 14 benchmark test problems, the proposed heuristic yields solutions whose values lie on average within 2.38% of that of the best known solutions.