Combining a hierarchical task network planner with a constraint satisfaction solver for assembly operations involving routing problems in a multi-robot context

This work addresses the combination of a symbolic hierarchical task network planner and a constraint satisfaction solver for the vehicle routing problem in a multi-robot context for structure assembly operations. Each planner has its own problem domain and search space, and the article describes how both planners interact in a loop sharing information in order to improve the cost of the solutions. The vehicle routing problem solver gives an initial assignment of parts to robots, making the distribution based on the distance among parts and robots, trying also to maximize the parallelism of the future assembly operations evaluating during the process the dependencies among the parts assigned to each robot. Then, the hierarchical task network planner computes a scheduling for the given assignment and estimates the cost in terms of time spent on the structure assembly. This cost value is then given back to the vehicle routing problem solver as feedback to compute a better assignment, closing the loop and repeating again the whole process. This interaction scheme has been tested with different constraint satisfaction solvers for the vehicle routing problem. The article presents simulation results in a scenario with a team of aerial robots assembling a structure, comparing the results obtained with different configurations of the vehicle routing problem solver and showing the suitability of using this approach.Unión Europea ARCAS FP7-ICT-287617Unión Europea H2020-ICT-644271Unión europea H2020-ICT-73166

Analysis of inequality in fertility curves fitted by gamma distributions

The aim of this paper is to analyse fertility curves from a novel viewpoint, that of inequality. Through sufficient conditions that can be easily verified, we compare inequality, in the Lorenz and Generalized Lorenz sense, in fertility curves fitted by gamma distributions, thus achieving a useful complementary instrument for demographic analysis. As a practical application, we examine inequality behaviour in the distributions of specific fertility curves in Spain from 1975 to 2009.Peer Reviewe

La educación al descubierto tras la pandemia del COVID-19. Carencias y retos

p. 21-28La llegada inesperada del coronavirus ha supuesto una disección al sistema educativo, permitiéndonos observar los aciertos que existen en su obrar, pero al mismo tiempo los errores y deficiencias que conducen a la larga hacia un empobrecimiento de la sociedad. La evidencia disponible sobre las consecuencias educativas de las pérdidas de clases es abundante y mitigar el impacto educativo por el coronavirus requerirá mucho esfuerzo por parte de todos. En este artículo realizamos una reflexión sobre las carencias y retos que han quedado al descubierto a partir de la llegada del COVID-19 y que han de centrar los esfuerzos de gobiernos y familias para conseguir una educación más adaptada con las demandas de nuestro tiempo.S

Nanosecond Pulsed Laser Irradiation of Titanium Alloy Substrate: E ects of Periodic Patterned Topography on the Optical Properties of Colorizing Surfaces

Most of the current works based on surface treatments of metals by laser marking technology are focused on the modification of the color tonality of flat surfaces, or the development of specific topography features, but the combination of both processes is not usually evaluated, mainly due to the complexity of controlling the optical properties on rough surfaces. This research presents an analysis of the influence of the micro-geometrical characteristics of periodic patterned laser tracks on the chromaticity and reflectance of Ti6Al4V substrates. The samples were irradiated with an infrared nanosecond pulsed laser in air atmosphere, taking as the control parameter the scan speed of the beam. A roughness evaluation, microscopic inspection, and absorption and chromaticity examination were conducted. Although micro-crack growth was detected in an isolated case (10 mm/s), the possibility of adjusting the result color was demonstrated by controlling the heat-a ected zone thickness of the textures. The results of rough/colored combined textures allow new perspectives in industrial design to open, particularly in aesthetic applications with special properties

Microsporidia as a Potential Threat to the Iberian Lynx (Lynx pardinus)

Lynx pardinus is one of the world’s most endangered felines inhabiting the Iberian Peninsula. The present study was performed to identify the presence of microsporidia due to the mortality increase in lynxes. Samples of urine (n = 124), feces (n = 52), and tissues [spleen (n = 13), brain (n = 9), liver (n = 11), and kidney (n = 10)] from 140 lynxes were studied. The determination of microsporidia was evaluated using Weber’s chromotrope stain and Real Time-PCR. Of the lynxes analyzed, stains showed 10.48% and 50% positivity in urine and feces samples, respectively. PCR confirmed that 7.69% and 65.38% belonged to microsporidia species. The imprints of the tissues showed positive results in the spleen (38.46%), brain (22.22%), and liver (27.27%), but negative results in the kidneys. PCR confirmed positive microsporidia results in 61.53%, 55.55%, 45.45%, and 50%, respectively. Seroprevalence against Encephalitozoon cuniculi was also studied in 138 serum samples with a positivity of 55.8%. For the first time, the results presented different species of microsporidia in the urine, feces, and tissue samples of Lynx pardinus. The high titers of anti-E. cuniculi antibodies in lynx sera confirmed the presence of microsporidia in the lynx environment. New studies are needed to establish the impact of microsporidia infection on the survival of the Iberian lynx

Variable binomial métrica

Se estudia una generalización de la variable binomial obtenida al considerar la distancia de hamming sobre el espacio muestral soporte de la binomial. Esta generalización esta incluida en la variable binomial de poisson. por tal motivo se obtienen nuevos resultados sobre la distribución binomial de poisson; en especial se considera el comportamiento de la entropía y la energía informacional de dicha distribuciónUniversidad de Granada, Facultad de Ciencias. Leída el 10-11-198

Coastal Retreat on the Spanish Mediterranean Coast in a Climate Change Context: Effects of the Regulation of the Segura River at Its Mouth and the Coastal Sand Dune in Guardamar del Segura (Alicante, Spain)

Coastal retreat processes are usually associated with many anthropogenic actions, such as the regulation of river basins, the construction of hydraulic storm defence works in coastal areas and the building of housing on the beach. To all of this, we should also add the increase in sea levels due to the effect of climate change. The chosen area of study corresponds to the coastal area of the municipality of Guardamar del Segura, belonging to the Segura River Basin. The methodology applied in this study comprised the gathering of historical information, the extraction of data using GIS, the compiling of data using official organisations and the analysis of all these data from a geographical perspective. The obtained results show the chronology of the regulation works in the Segura Basin and their relationship with the reduction and negative trend in average ordinary flows (1940–2023) and the extraordinary, swelled flows recorded in the period 1994–2023. Furthermore, the coastlines from 1923 to 2023 were mapped, enabling us to determine the evolution of the coastline retreat processes experienced in the dune ridge of Guardamar del Segura and the increase in the frequency of impacts due to storms on Babilonia Beach. Finally, data on wind, waves and marine currents recorded at a gauging station were incorporated, enabling us to understand their impact on this coastal sector. The results obtained are discussed, and they indicate the need to incorporate data on sediment into the study in order to complete it. The conclusions reveal the existence of a relationship between all these anthropogenic elements in the beach erosion processes experienced in the village of Guardamar del Segura

La educación al descubierto tras la pandemia del COVID-19. Carencias y retos

La llegada inesperada del coronavirus ha supuesto una disección al sistema educativo, permitiéndonos observar los aciertos que existen en su obrar, pero al mismo tiempo los errores y deficiencias que conducen a la larga hacia un empobrecimiento de la sociedad. La evidencia disponible sobre las consecuencias educativas de las pérdidas de clases es abundante y mitigar el impacto educativo por el coronavirus requerirá mucho esfuerzo por parte de todos. En este artículo realizamos una reflexión sobre las carencias y retos que han quedado al descubierto a partir de la llegada del COVID-19 y que han de centrar los esfuerzos de gobiernos y familias para conseguir una educación más adaptada con las demandas de nuestro tiempo