1,721,500 research outputs found
A study of demand oblivious routing algorithms
No full textNowadays, people make use of communication networks (e.g. Internet) everyday and expect high quality from the offered services. Providing a good quality of service and optimizing the utilization of the network resources are the main objectives in designing a routing. It has always been believed that traffic demands play an important role in this design because the better the traffic demands are known, the more properly they can be allocated. However, understanding and estimating these traffic demands is not a trivial task. In 2002 Räcke asked himself an important question: ``how important is accurate knowledge of traffic demands for obtaining good utilization of the network?" This marked the beginning of a new kind of routing algorithms: the demand oblivious routing algorithms or oblivious routing. These routing algorithms ignore the current status of the network when making routing decisions and they only base their decisions on the source, destination of the flows and, in certain cases, some random values. These kind of algorithms have evolved a lot during the last years in three different directions. Nevertheless, according to the knowledge of the author, there has been no study until now that evaluates the performance of algorithms from these three branches. Firstly, this thesis will present a complete and exhaustive study based on the three papers that originated the different kinds of oblivious routing. Then, a framework will be developed to compare these three algorithms under the same conditions and with a range of metrics from theoretical calculations to more practical ones. Finally, based on the results obtained, possible improvements for these families of algorithms will be suggested.MSc. TelecommunicationsNetwork Architectures and Services GroupElectrical Engineering, Mathematics and Computer Scienc
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Analysis of streaming media systems
No full textMultimedia services have been popping up at tremendous speed in recent years. A large number of these multimedia streaming systems are introduced to the consumer market. Internet Service Providers, Telecommunications Operators, Service/Content Providers, and end users are interested in the mechanisms they use, the Quality-of-Experience they provide (e.g. video/audio quality, audio-video synchronization, communication delay, start-up time, etc.), the resources they need, the system stability, and the service availability. The multimedia streaming systems analyzed in this thesis include IP layer multicast TV (IPTV), Peer-to-Peer TV (P2PTV), Content Delivery Networking (CDN), Peer-to-Peer Video-on-Demand (P2PVoD), Server-to-Client Video Conferencing (IPVC) and Peer-to-Peer Video Conferencing (P2PVC). This thesis aims to study various kinds of popular streaming systems, through analytical models, measurement experiments, and simulations, to reveal their characteristics and performance in different aspects. Based on this research, we can not only better understand the behavior and limitations of existing systems and find out the key parameters that affect their performance, but also investigate the potential problems and predict the system performance for future cases. By comparing the two general streaming content delivery methods (Server-Client and Peer-to-Peer), we gain in-depth insights on “which is better” and “what determines better” for different services and in different scenarios.TelecommunicationsElectrical Engineering, Mathematics and Computer Scienc
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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