1,721,089 research outputs found
Design and performance evaluation of a Linux HPC cluster
Full text linkIn this paper after a short theoretical introduction about modern techniques used inparallel computing, we report a case study related to the design and development of the Caliban Linux High Performance Computing cluster, carried out by the author in the High Performance Computing Laboratory of the University of L’Aquila. Finally we report some performance evaluation tests related to the Caliban cluster performed using HPL (High-Performance Linpack) benchmarks
GPU SOFTWARE AND ARCHITECTURE COMPARISONS FOR NUMERICAL SIMULATION OF PARTIAL DIFFERENTIAL EQUATIONS
Full text linkThis paper will show a comparison between the Kepler, Maxwell and Pascal
GPU architectures using CUDA-Fortran, with and without dynamic calls, to efficiently solve partial
differential equations. The target is to show the possibility of using affordable hardware, such as
the GTX 670, GTX 970 and GTX 1080 NVIDIA GPU s, which are commonly found in personal
and portable computers, for scientific applications. For simplicity we consider a standard
wave equation where we use a second order finite difference method for the spatial and time
discretizations to obtain the numerical solution. We found that, as we increase the spatial
resolution of the domain we also increase the performance difference between the
GPU and the Central Processing Unit (CPU)
Fenologia da laranjeira Pera D-9 no Vale do São Francisco.
Full text linkEste trabalho teve como objetivo caracterizar a fenologia da cultivar de Laranja ‘Pera D - 9’ no período de setembro de 2011 a abril de 2012, nas condições do Semiárido Nordestino
Characterizing somatosensory evoked potential sources with dipole models: advantages and limitations
No full textSeveral methods have been developed to investigate the cerebral generators of scalp somatosensory evoked potentials (SEPs), because simple visual inspection of the electroencephalographic signal does not allow for immediate identification of the active brain regions. When the neurons fired by the afferent inputs are closely grouped, as usually occurs in SEP generation, they can be represented as a dipole, that is, as a linear source with two opposite poles. Several techniques for dipolar source modeling, which use different algorithms, have been employed to build source models of early, middle-latency, and late cognitive SEPs. Modifications of SEP dipolar activities after experimental maneuvers or in pathological conditions have also been observed. Although the effectiveness of dipolar source analysis should not be overestimated due to the intrinsic limitations of the approach, dipole modeling provides a means to assess SEPs in terms of cerebral sources and voltage fields that they produce over the head
AN INTEGRATED MONITORING SYSTEM THROUGH 3D LASER SCANNER AND TRADITIONAL INSTRUMENTS FOR LOAD TEST ON ARCH BRIDGE
Full text linkThe experimental campaign represents an example of how the careful design of the different test phases and the choice of the needed
instrumentation are fundamental aspects to obtain a proper interpretation of the results, for future application on the real structures.
Additionally, the present work represents a successful example of a combined monitoring system, integrating the traditional and
innovative technical instrumentation for loading tests and geomatics survey techniques. The monitoring system has been designed
with the aim of defining the load carrying capacity of a masonry arch bridge scaled model and to test the performances of a new
retrofitting method. In particular, two different configuration have been considered: a first one with isolated arch and a second one
with gravel fill on the arch
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
Pain-related modulation of the human motor cortex
No full textPain is a complex multi-dimensional phenomenon that influences a wide variety of nervous system functions, including sensory--discriminative, affective--motivational and cognitive--evaluative components. So far, these components have been studied in both patients with chronic pain and in normal subjects in whom pain was induced experimentally. The interaction between pain and motor function is not fully understood, although from everyday life it is known that pain affects movements. The effects of pain on motor control are typically seen as a limited or impaired ability to perform movements. Most studies have dealt with the effects of pain on the spinal cord reflexes, but in recent years, several lines of evidence suggest that the interaction between motor and pain systems in conditions of pain induced experimentally, rather than a simple spinal reflex, is a more complex process that involves also supraspinal brain areas. Although pain-motor interaction shows different features and time course depending on different pain variables, such as duration (tonic versus phasic pain), submodalities (deep versus superficial pain) and location (distal versus proximal pain), a common finding is that pain is able to inhibit the motor cortex. This motor cortex inhibition may act as a sort of motor 'decerebration' so as to allow the spinal motor system to freely develop protective responses to noxious stimulation. Further studies are required to assess the effects of pain on the motor system in patients suffering from chronic pain, in order to develop innovative rational therapeutic strategies to reduce both pain and motor disability
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