1,721,322 research outputs found
On the aggregation of self-similar processes
No full textThe problem of aggregating different stochastic process into a unique one that must be characterized based on the statistical knowledge of its components is a key point in the modeling of many complex phenomena such as the merging of traffic flows at network nodes. Depending on the physical intuition on the interaction between the processes, many different aggregation policies can be devised, from averaging to taking the maximum in each time slot. We here address flows averaging and maximum since they are very common modeling options. Then we give a set of axioms defining a general aggregation operator and, based on some advanced results of functional analysis, we investigate how the decay of correlation of the original processes affect the decay of correlation (and thus the self-similar features) of the aggregated process
Peer-to-Peer Distribution on Asymmetric Channels
No full textWe address the problem of incrementally constructing
a peer-to-peer network distributing a content coming from
a unique source by means of asymmetric channels. Criteria and
algorithms to minimize either the source output bandwidth or the
maximum delay suffered by peers are devised and characterized
as far as performance and network features are concerned. We
can also prove that, though we rely on a regular connectivity
based on tiers, the performance of our algorithms is negligibly
different from optimum
On the Nearest Neighbor of the Nearest Neighbor in Multidimensional Continuous and Quantized Space
No full textThe probability that an entity in a set of entities uniformly
distributed in space is the nearest neighbor of its nearest
neighbor is evaluated for generic distances in a multidimensional
environment. Such an expression is then specialized for systems
with norm-based distances and for systems with quantized normbased distance. Examples for scalar products and sup-norm are derived. When applicable, invariances with respect to the underlying distance and entities density are highlighted. Dimensionality effects are investigated
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
Routing Protocol Emulator for Ad Hoc and Sensor networks
No full textThe paper describes the proposal of a general framework
used to emulate network routing protocols for ad
hoc or sensor networks. The emulation is performed using
a cluster of hosts with Linux operating system. The
platform is developed in the user space, without need of
kernel modifications. The emulator can be used to emulate
many different routing protocols, in quite different
wireless environments, such as the mobile scenario of
the ad hoc networks or the static behavior of the sensor
networks. We have tested this approach by porting an
existing routing protocol to our platform
A Flow Cytometric Study of the Propidium Iodide Staining Kinetics of Human-leukocytes and Its Relationship With Chromatin Structure
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