1,720,992 research outputs found
Filtering and forecasting problems for aggregate traffic in Internet links
No full textAn important problem in bandwidth allocation and reservation over a communication link is to estimate the traffic bit rate in that link. This can be done by using specific tools for measurements of the traffic bit rate. However, the obtained measures are affected by some noise. Moreover, one might be interested in future traffic forecasting, when a prediction is needed. In this paper, an iterative filtering procedure is proposed for updating the traffic estimate upon the arrival of a new measurement. A birth and death stochastic model is assumed for the traffic bit rate to provide dynamical equations for the average behavior in the absence of information carried by measurements. Approximate solutions of the same updating problem are also given under the assumption that the posterior distribution of the traffic bit rate belongs to a specific class (beta or Gaussian distribution). This leads to approximate filtering procedures, which are expected to provide significant computational advantages. Finally, results obtained by processing simulated and real data are presented; stressing that the practical behavior of the approximate filters is quite satisfactory. (C) 2004 Published by Elsevier B.V
Dynamic bandwidth reservation for label switched paths: An on-line predictive approach
No full textManaging the bandwidth allocated to a Label Switched Path in MPLS networks plays a major role for provisioning of Quality of Service and efficient use of resources. In doing so, two main contrasting factors have to be considered: not only the bandwidth should be adapted to the traffic profile but also the effort for bandwidth renegotiation associated with a variation of the allocated bandwidth should be kept at low levels. In this context, we formulate a problem of optimal LSP bandwidth reservation as the one of minimizing a convex combination of the difference between the assigned bandwidth and the estimated future traffic, and of a measure of the frequency of bandwidth variations. The contribution of this paper is to propose a new method to reserve optimally the bandwidth of an LSP, avoiding an excess of bandwidth renegotiations on the basis of prediction of future traffic, assuming a simple birth-and-death model to describe the traffic dynamics. Whenever the prediction is inaccurate due to unpredictable variations in the characteristics of real traffic, a suitable ‘‘emergency procedure’’ is proposed, which performs a new traffic prediction and a consequent modified bandwidth reservation. Numerical results are presented which show the effectiveness of the method and the achieved performance, both for simulated and real data traffic
Temperature prediction using machine learning approaches
No full textWeather prediction is one of the most important research areas due to its applicability in real-world problems like meteorology, agricultural studies, etc. We propose a method for temperature prediction using three machine learning models - Multiple Linear Regression (MLR), Artificial Neural Network (ANN) and Support Vector Machine (SVM), through a comparative analysis using the weather data collected from Central Kerala during the period 2007 to 2015. The experimental results are evaluated using Mean Error (ME), Mean Absolute Error (MAE), Root Mean Square Error (RMSE) and Correlation Coefficients (CC). The error metrics and the CC shows that MLR is a more precise model for temperature prediction than ANN and SVM
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
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
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