arXiv subjects

S. García

Publications and source records attributed to S. García.

3 recordsLinked to original sources

arXiv2020

Recent Trends in the Use of Statistical Tests for Comparing Swarm and Evolutionary Computing Algorithms: Practical Guidelines and a Critical Review

A key aspect of the design of evolutionary and swarm intelligence algorithms is studying their performance. Statistical comparisons are also a crucial part which allows for reliable conclusions to be drawn. In the present paper we gather and examine the approaches taken from different perspectives to summarise the assumptions made by these statistical tests, the conclusions reached and the steps followed to perform them correctly. In this paper, we conduct a survey on the current trends of the proposals of statistical analyses for the comparison of algorithms of computational intelligence and include a description of the statistical background of these tests. We illustrate the use of the most common tests in the context of the Competition on single-objective real parameter optimisation of the IEEE Congress on Evolutionary Computation (CEC) 2017 and describe the main advantages and drawbacks of the use of each kind of test and put forward some recommendations concerning their use.

cs.NE↗

arXiv2015

JavaNPST: Nonparametric Statistical Tests in Java

Nonparametric statistical tests are useful procedures that can be applied in a wide range of situations, such as testing randomness or goodness of fit, one-sample, two-sample and multiple-sample analysis, association between bivariate samples or count data analysis. Their use is often preferred to parametric tests due to the fact that they require less restrictive assumptions about the population sampled. In this work, JavaNPST, an open source Java library implementing 40 nonparametric statistical tests, is presented. It can be helpful for programmers and practitioners interested in performing nonparametric statistical analyses, providing a quick and easy way of running these tests directly within any Java code. Some examples of use are also shown, highlighting some of the more remarkable capabilities of the library.

stat.CO↗

arXiv2005

Lower critical field and intragrain critical current density in the ruthenate-cuprate RuSr$_{2}$Gd$_{1.5}$Ce$_{0.5}$Cu$_{2}$O$_{10}$

The lower critical field of the grains, $H_{c1}$, and the intragrain critical current density, $J_{c}$, were determined for the superconducting ruthenate-cuprate RuSr$_{2}$Gd$_{1.5}$Ce$_{0.5}$Cu$_{2}$O$_{10-δ}$ [Ru-1222(Gd)] through a systematic study of the hysteresis in magnetoresistance loops. A reliable method, based on the effects of the magnetization of the grains on the net local field at the intergranular junctions is provided, circumventing the problem of the strong masking of the superconducting diamagnetic signal by the ferromagnetic background. The temperature dependency of $H_{c1}$ and $J_{c}$ both exhibit a smooth increase on cooling without saturation down to $T/T_{SC}$ $\cong $ 0.2. The obtained $H_{c1}$ values vary between 150 and 1500 Oe in the 0.2 $\leq $ $% T/T_{SC}$ $\leq $ 0.4 interval, for samples annealed in an oxygen flow; oxygenation under high pressure (50 atm) leads to a further increase. These values are much larger than the previously reported rough assessments (25-50 Oe), using conventional magnetization measurements. High $J_{c}$ values of $% \sim $ 10$^{7}$ A/cm$^{2}$, comparable to the high-T$_{c}$ cuprates, were obtained. The $H_{c1}(T)$ and $J_{c}(T)$ dependencies are explained in the context of a magnetic phase separation scenario.

cond-mat.supr-con↗