VPP: Visibility-Based Path Planning Heuristic for Monitoring Large Regions of Complex Terrain Using a UAV Onboard Camera

This work was partially supported by the Spanish Ministry of Science and Technology through the projects TIN2016-80920-R and PID2019-105396RB-I00, the Regional Government of Andalusia through the project A-TIC-458-UGR18 (DeepL-ISCO) within the Andalucia ERDF2014-20 Operational Programme, and the University of Malaga through the I Plan Propio de Investigacion.The use of unmanned aerial vehicles with multiple onboard sensors has grown significantly in tasks involving terrain coverage such as environmental and civil monitoring, disaster management, and forest fire fighting. Many of these tasks require a quick and early response, which makes maximizing the land covered from the flight path a challenging objective, especially when the area to bemonitored is irregular, large and includesmany blind spots. Accordingly, state-of-the-art total viewshed algorithms can be of great help to analyze large areas and find new paths providing maximum visibility. This article shows how the total viewshed computation is a valuable tool for generating paths that provide maximum visibility during a flight. We introduce a new heuristic called visibility-based path planning (VPP) that offers a different solution to the path planning problem. VPP identifies the hidden areas of the target territory to generate a path that provides the highest visual coverage. Simulation results show that VPP can cover up to 98.7% of theMontes deMalaga Natural Park and 94.5% of the Sierra de las Nieves National Park, both located within the province of Malaga (Spain) and chosen as regions of interest. In addition, a real flight test confirmed the high visibility achieved using VPP. Our methodology and analysis can be easily applied to enhance monitoring in other large outdoor areas.Spanish Government TIN2016-80920-R PID2019-105396RB-I00Regional Government of Andalusia within the Andalucia ERDF2014-20 Operational Programme A-TIC-458-UGR18University of Malaga through the I Plan Propio de Investigacio

Economic cycles and environmental crisis in arid southeastern Spain. A historical perspective

The arid southeast region has been one of the areas with the oldest settlement in the Iberian Peninsula. Despite limitations imposed by lack of water and low soil fertility, a great number of dwellers have settled in this land for three thousand years thanks to its easy access to the commercial paths of the Mediter- ranean. The area is currently under great territorial and socioeconomic transformation activated by intensive agriculture through greenhouses and irrigation. The history of this territory offers a series of successful and downward cycles determined, from an ecological and economic point of view, by its integration in different stages of the globalization process. Most recently, in the 19th century an intensive deforestation process took place caused by the mining and iron industry. The deep economic and social crisis which followed the declining of this development model brought also about an ecological crisis. In the second half of the 20th century, negative environmental effects have continued and extended to the next generations with problems such as territorial saturation and aquifer depletion that characterize the new intensive agriculture under plastic. The current debate about the sustainability of this developmental model in such vulnerable environment can take advantage of some ecological lessons from the past

Поверхностные скорости и айсберговый сток ледникового купола Академии Наук на Северной Земле

We have determined the ice-surface velocities of the Academy of Sciences Ice Cap, Severnaya Zemlya, Russian Arctic, during the period November 2016 – November 2017, using intensity offset-tracking of Sentinel-1 synthetic-aperture radar images. We used the average of 54 pairs of weekly velocities (with both images in each pair separated by a12-day period) to estimate the mean annual ice discharge from the ice cap. We got an average ice discharge for 2016–2017 of 1,93±0,12 Gt a−1, which is equivalent to −0,35±0,02 m w.e. a−1 over the whole area of the ice cap. The difference from an estimate of ~1,4 Gt a−1 for 2003–2009 can be attributed to the initiation of ice-stream flow in Basin BC sometime between 2002 and 2016. Since the front position changes between both periods have been negligible, ice discharge is equivalent to calving flux. We compare our results for calving flux with those of previous studies and analyse the possible drivers of the changes observed along the last three decades. Since these changes do not appear to have responded to environmental changes, we conclude that the observed changes are likely driven by the intrinsic characteristics of the ice cap governing tidewater glacier dynamics.По 54 парам космических снимков Sentinel‐1, сделанных с ноября 2016 г. по ноябрь 2017 г., определены скорости движения ледникового купола Академии Наук на Северной Земле. На этой основе оценён среднегодовой расход льда в море этого купола (1,93±0,12 Гт/год), установлены основные пути стока льда, проведено сравнение с прежними оценками

Dynamic control of a reconfigurable stair-climbing mobility system

Electric-powered wheelchairs improve the mobility of people with physical disabilities, but the problem to deal with certain architectural barriers has not been resolved satisfactorily. In order to solve this problem, a stair-climbing mobility system (SCMS) was developed. This paper presents a practical dynamic control system that allows the SCMS to exhibit a successful climbing process when faced with typical architectural barriers such as curbs, ramps, or staircases. The implemented control system depicts high simplicity, computational efficiency, and the possibility of an easy implementation in a microprocessor-/microcontroller-based system. Finally, experiments are included to support theoretical results

G-band Spectral Synthesis in Solar Magnetic Concentrations

Narrow band imaging in the G-band is commonly used to trace the small magnetic field concentrations of the Sun, although the mechanism that makes them bright has remained unclear. We carry out LTE syntheses of the G-band in an assorted set of semi-empirical model magnetic concentrations. The syntheses include all CH lines as well as the main atomic lines within the band-pass. The model atmospheres produce bright G-band spectra having many properties in common with the observed G-band bright points. In particular, the contrast referred to the quiet Sun is about twice the contrast in continuum wavelengths. The agreement with observations does not depend on the specificities of the model atmosphere, rather it holds from single fluxtubes to MIcro-Structured Magnetic Atmospheres. However, the agreement requires that the real G-band bright points are not spatially resolved, even in the best observations. Since the predicted G-band intensities exceed by far the observed values, we foresee a notable increase of contrast of the G-band images upon improvement of the angular resolution. According to the LTE modeling, the G-band spectrum emerges from the deep photosphere that produces the continuum. Our syntheses also predict solar magnetic concentrations showing up in continuum images but not in the G-band . Finally, we have examined the importance of the CH photo-dissociation in setting the amount of G-band absorption. It turns out to play a minor role.Peer reviewe

Systematics and diversity of Neotropical ants.

With a long history of more than 100 million years and about 14,000 described living species, ants are one of the most important and well-known groups of insects in the world. Ants are key elements in the structure and dynamics of terrestrial systems, especially in the tropics, as well as models in studies of evolution, ecology, and monitoring of disturbed ecosystems. For all this, it is essential to know their history and phylogeny, in order among other things, to have a solid base for their systematics and taxonomy. Within Aculeata ants appear to be the sister group of Apoidea, and the ancestor of the Formicidae may have inhabited the northern hemisphere during the early Cretaceous. Since then, and especially since the Eocene, ants have spread throughout the planet, occupying almost all environments from forests to deserts. The Neotropical region has 137 genera and around 3,100 species of ants. The Neotropics seem to have been the “cradle” and “museum” of the groups of ants, which would explain their great diversity and a high degree of endemisms. This review describes the current state of knowledge of ants in the Neotropical region from a systematic point of view, with a synopsis of all supraspecific taxa described to date. Critical genera, problems to be solved, and perspectives for the study of these insects are also presented

‘Omics’ approaches for crop improvement

The growing human population and climate change are imposing unprecedented challenges on the global food supply [1]. To cope with these pressures, crop improvement demands enhancing important agronomical traits beyond yield, such as adaptation, resistance, and nutritional value, by pivoting direct and indirect selection approaches [2]. The development of next-generation high-throughput screening technologies, referred to as ‘omics’, promises to speed up plant trait improvement [3] while producing more sustainable crops. Large-scale techniques, such as genomics, transcriptomics, proteomics, metabolomics, and phenomics, have already provided large datasets for that purpose. Meanwhile, modern bioinformatic and machine-learning approaches are helping us to process this heterogeneous hyper-dimensional data [4] while ultimately understanding the mechanisms behind agronomic features within the contemporary plant breeding triangle (i.e., genomics vs. phenomics vs. enviromics) [5]. ‘Omics’ datasets are also being generated to study macro-scale interactions and deepen our knowledge of crop behavior across the microbial [6] and environmental [7,8] continua. However, despite these massive technological and computational developments [4], systemic efforts to integrate ‘omics’ studies to understand biochemical pathways and cellular networks of crop systems are in their infancy [9], especially in orphan species [10]. Therefore, this Special Issue envisions offering updated emergent views on large-scale ‘omics’-based approaches. Specifically, the compilation explores the conceptual framework of the ‘omics’ paradigm [11], the practical uses of multiple ‘omics’ technologies, and their integration through trans-disciplinary bioinformatics as tools to improve qualitative and quantitative traits in a diverse panel of crop species

WRF hourly evaluation for extreme precipitation events

.Precipitation is one of the most relevant fields in atmospheric modeling because of its environmental, social and economic implications. However, precipitation validation from weather model outputs presents substantial challenges, such as measurement uncertainties, use of gridded datasets vs. direct observations, and the selection of statistical goodness-of-fit measures. The main difficulty of working with precipitation is that it can be spatially irregular, especially in extreme events. High temporal aggregation smooths the field and reduces verification uncertainty. For this reason, validations are usually focused on a daily scale. However, many extreme events occur on shorter periods, for which a sub-daily precipitation assessment is required. In this paper, hourly precipitation verification of the Weather Research and Forecasting (WRF) model is explored for 45 extreme precipitation events (EPEs) recorded in northeastern Spain. For this, stations with recorded EPEs were classified according to the hourly distribution of precipitation. WRF simulations were established considering three microphysics and two planetary boundary layer (PBL) parameterizations. Finally, several statistical goodness-of-fit measures and spatial and temporal precipitation distributions were used for evaluating WRF performance. The results showed that microphysics were more important than PBL parameterizations. Goddard and Thompson together with Mellor-Yamada-Nakanishi and Nino PBL gave better results for most of the analyzed characteristics. However, an optimal combination of parameterizations was not obtained for all EPEs, because event characteristics had important effects on model performance.S

El nuevo reglamento general de desarrollo de la Ley General Tributaria en materia de revisión en vía administrativa

En el presente trabajo se da cuenta de las novedades que supone la aprobación del Real Decreto 520/2005, de 13 de mayo, y de cada uno de los siete procedimientos que desarrolla en cumplimiento de las previsiones de la propia LGT: 1) Procedimiento de revisión de actos nulos de pleno derecho; 2) Procedimiento de declaración de lesividad; 3) Procedimiento de revocación; 4) Procedimiento de rectificación de errores; 5) Procedimiento de devolución de ingresos indebidos; 6) Recurso de reposición; y 7) Reclamación económico-administrativa

Long range absorption in the scattering of 6He on 208Pb and 197Au at 27 MeV

Quasi-elastic scattering of 6He at E_lab=27 MeV from 197Au has been measured in the angular range of 6-72 degrees in the laboratory system employing LEDA and LAMP detection systems. These data, along with previously analysed data of 6He + 208Pb at the same energy, are analyzed using Optical Model calculations. The role of Coulomb dipole polarizability has been investigated. Large imaginary diffuseness parameters are required to fit the data. This result is an evidence for long range absorption mechanisms in 6He induced reactions.Comment: 10 pages, 10 figures, minor corrections. To appear in Nucl. Phys.