1,815 research outputs found
Decoupling Scheme From DHCP in Neural Networks
The independent distributed systems method to XML is defined not only by the evaluation of architecture, but also by the technical need for DNS. in fact, few cryptographers would disagree with the deployment of vacuum tubes, which em- bodies the essential principles of robotics. EeryKichil, our new system for ubiquitous information, is the solution to all of these obstacles
Reliability-Informed Beat Tracking of Musical Signals
Abstract—A new probabilistic framework for beat tracking of musical audio is presented. The method estimates the time between consecutive beat events and exploits both beat and non-beat information by explicitly modeling non-beat states. In addition to the beat times, a measure of the expected accuracy of the estimated beats is provided. The quality of the observations used for beat tracking is measured and the reliability of the beats is automatically calculated. A k-nearest neighbor regression algorithm is proposed to predict the accuracy of the beat estimates. The performance of the beat tracking system is statistically evaluated using a database of 222 musical signals of various genres. We show that modeling non-beat states leads to a significant increase in performance. In addition, a large experiment where the parameters of the model are automatically learned has been completed. Results show that simple approximations for the parameters of the model can be used. Furthermore, the performance of the system is compared with existing algorithms. Finally, a new perspective for beat tracking evaluation is presented. We show how reliability information can be successfully used to increase the mean performance of the proposed algorithm and discuss how far automatic beat tracking is from human tapping. Index Terms—Beat-tracking, beat quality, beat-tracking reliability, k-nearest neighbor (k-NN) regression, music signal processing. I
Multi-objective Optimal Test Suite Computation for Software Product Line Pairwise Testing
Lopez-Herrejon, R. E., Chicano F., Ferrer J., Egyed A., & Alba E. (2013). Multi-objective Optimal Test Suite Computation for Software Product Line Pairwise Testing. 2013 IEEE International Conference on Software Maintenance, Eindhoven, The Netherlands, September 22-28, 2013. 404–407.Software Product Lines (SPLs) are families of related software products, which usually provide a large number of feature combinations, a fact that poses a unique set of challenges for software testing. Recently, many SPL testing approaches have been proposed, among them pair wise combinatorial techniques that aim at selecting products to test based on the pairs of feature combinations such products provide. These approaches regard SPL testing as an optimization problem where either coverage (maximize) or test suite size (minimize) are considered as the main optimization objective. Instead, we take a multi-objective view where the two objectives are equally important. In this exploratory paper we propose a zero-one mathematical linear program for solving the multi-objective problem and present an algorithm to compute the true Pareto front, hence an optimal solution, from the feature model of a SPL. The evaluation with 118 feature models revealed an interesting trade-off between reducing the number of constraints in the linear program and the runtime which opens up several venues for future research.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech.
Austrian Science Fund (FWF) project P21321-N15 and Lise Meitner Fellowship M1421-N15. Spanish Ministry of Economy and Competitiveness and FEDER under contract TIN2011-28194 and fellowship BES-2012-055967
Comparative analysis of classical multi-objective evolutionary algorithms and seeding strategies for pairwise testing of Software Product Lines
Lopez-Herrejon, R. Erick, Ferrer J., Chicano F., Egyed A., & Alba E. (2014). Comparative analysis of classical multi-objective evolutionary algorithms and seeding strategies for pairwise testing of Software Product Lines. Proceedings of the IEEE Congress on Evolutionary Computation, CEC 2014, Beijing, China, July 6-11, 2014. 387–396.Software Product Lines (SPLs) are families of related software products, each with its own set of feature combinations. Their commonly large number of products poses a unique set of challenges for software testing as it might not be technologically or economically feasible to test of all them individually. SPL pairwise testing aims at selecting a set of products to test such that all possible combinations of two features are covered by at least one selected product. Most approaches for SPL pairwise testing have focused on achieving full coverage of all pairwise feature combinations with the minimum number of products to test. Though useful in many contexts, this single-objective perspective does not reflect the prevailing scenario where software engineers do face trade-offs between the objectives of maximizing the coverage or minimizing the number of products to test. In contrast and to address this need, our work is the first to propose a classical multi-objective formalisation where both objectives are equally important. In this paper, we study the application to SPL pairwise testing of four classical multi-objective evolutionary algorithms. We developed three seeding strategies — techniques that leverage problem domain knowledge — and measured their performance impact on a large and diverse corpus of case studies using two well-known multi-objective quality measures. Our study identifies the performance differences among the algorithms and corroborates that the more domain knowledge leveraged the better the search results. Our findings enable software engineers to select not just one solution (as in the case of single-objective techniques) but instead to select from an array of test suite possibilities the one that best matches the economical and technological constraints of their testing context.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech. Austrian Science Fund (FWF) project P25289- N15 and Lise Meitner Fellowship M1421-N15. Spanish Ministry of Economy and Competitiveness and FEDER under contract TIN2011-28194 and fellowship BES-2012-055967. Project 8.06/5.47.4142 in collaboration with the VSB-Tech. Univ. of Ostrava and Universidad de Málaga, AndalucĂa Tech
A parallel evolutionary algorithm for prioritized pairwise testing of software product lines
Lopez-Herrejon, R. Erick, Ferrer J., Chicano F., Haslinger E. Nicole, Egyed A., & Alba E. (2014). A parallel evolutionary algorithm for prioritized pairwise testing of software product lines. (Arnold, D. V., Ed.).Genetic and Evolutionary Computation Conference, GECCO '14, Vancouver, BC, Canada, July 12-16, 2014. 1255–1262.Software Product Lines (SPLs) are families of related software systems, which provide different feature combinations. Different SPL testing approaches have been proposed. However, despite the extensive and successful use of evolutionary computation techniques for software testing, their application to SPL testing remains largely unexplored. In this paper we present the Parallel Prioritized product line Genetic Solver (PPGS), a parallel genetic algorithm for the generation of prioritized pairwise testing suites for SPLs. We perform an extensive and comprehensive analysis of PPGS with 235 feature models from a wide range of number of features and products, using 3 different priority assignment schemes and 5 product prioritization selection strategies. We also compare PPGS with the greedy algorithm prioritized-ICPL. Our study reveals that overall PPGS obtains smaller covering arrays with an acceptable performance difference with prioritized-ICPL.Austrian Science Fund (FWF) project P25289-N15 and Lise Meitner Fellowship M1421-N15. Spanish Ministry of Economy and Competitiveness and FEDER under contract TIN2011-28194 and fellowship Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech.BES-2012-055967. Project 8.06/5.47.4142 in collaboration with the VSB-Tech. Univ. of Ostrava and Universidad de Málaga, AndalucĂa Tech
Development of nanolubricant based on impregnated multilayer graphene for automotive applications: Analysis of tribological properties
[EN] This paper shows novel formulations of nanolubricants added with multi-layer graphene (MLG), multi-layer graphene impregnated with copper (MLG-Cu), and multi-layer graphene impregnated with polyaniline (MLG-PANI) for applications in automotive engines. These nanofluids were prepared using commercial motor oil as the base fluid. The tribological properties were measured at 100 degrees C, and significant reductions were found in the coefficient of friction and wear. The concentrations used were 0.5% and 2% by weight, obtaining reductions in the friction coefficient and wear of up to 43% and 63%, respectively, in the case of motor oil with copper-impregnated graphene. All formulations of MLG, MLG-Cu, and MLG-PANI did not show any sedimentation when dispersed in engine oil, even three months after being produced. (C) 2016 Elsevier B.V. All rights reserved.The authors would like to thank Tecnologico de Monterrey (ITESM) through the focus group of Energy and Climate Change for the support of this project and CONACYT for funding the stay at the Universidad Politecnica de Valencia (UPV).Ramon-Raygoza, E.; Rivera-Solorio, C.; Giménez Torres, E.; Maldonado-Cortes, D.; Cardenas-Aleman, E.; Cué-Sampedro, R. (2016). Development of nanolubricant based on impregnated multilayer graphene for automotive applications: Analysis of tribological properties. Powder Technology. 302:363-371. https://doi.org/10.1016/j.powtec.2016.08.072S36337130
A white dwarf cooling age of 8 Gyr for NGC 6791 from physical separation processes
NGC 6791 is a well studied open cluster1 that it is so close to us that can
be imaged down to very faint luminosities. The main sequence turn-off age (~8
Gyr) and the age derived from the termination of the white dwarf cooling
sequence (~6 Gyr) are significantly different. One possible explanation is that
as white dwarfs cool, one of the ashes of helium burning, 22Ne, sinks in the
deep interior of these stars. At lower temperatures, white dwarfs are expected
to crystallise and phase separation of the main constituents of the core of a
typical white dwarf, 12C and 16O, is expected to occur. This sequence of events
is expected to introduce significant delays in the cooling times, but has not
hitherto been proven. Here we report that, as theoretically anticipated,
physical separation processes occur in the cores of white dwarfs, solving the
age discrepancy for NGC 6791.Comment: 3 pages, 2 figures, published in Natur
Adenocarcinoma intestinal a colocistoplĂ sia d'augment
Descrivim el cas d'un pacient que desenvolupĂ un adenocarcinoma intestinal sobre una colocistoplĂ stia d'augment portada a terme 29 anys abans per tuberculosi vesical. Es practica una revisiĂł d'aquests tipus de tumors a la literatur
An upper limit to the secular variation of the gravitational constant from white dwarf stars
A variation of the gravitational constant over cosmological ages modifies the
main sequence lifetimes and white dwarf cooling ages. Using an state-of-the-art
stellar evolutionary code we compute the effects of a secularly varying G on
the main sequence ages and, employing white dwarf cooling ages computed taking
into account the effects of a running G, we place constraints on the rate of
variation of Newton's constant. This is done using the white dwarf luminosity
function and the distance of the well studied open Galactic cluster NGC 6791.
We derive an upper bound G'/G ~ -1.8 10^{-12} 1/yr. This upper limit for the
secular variation of the gravitational constant compares favorably with those
obtained using other stellar evolutionary properties, and can be easily
improved if deep images of the cluster allow to obtain an improved white dwarf
luminosity function.Comment: 15 pages, 4 figures, accepted for publication in JCA
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