4,299 research outputs found

    On the potential contribution of rooftop PV to a sustainable electricity mix: the case of Spain

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    This work evaluates the potential contribution of rooftop PV to the future electricity mix. Several sustainable scenarios are considered, each comprising different shares of centralized renewables, rooftop PV and storage. For each generation scenario, the storage capacity that balances the net hourly demand is determined, and the portfolio combination that minimizes the cost of supplying electricity is obtained. The analysis is applied to mainland Spain, using public information and detailed granular models, both in time (hourly resolution) and space (municipal level). For the Spanish case, when the flexibility of hydro and biomass generation is taken into account, the least-cost portfolio involves rather modest storage capacities, in the order of daily rather than seasonal values. This shows that a sustainable, almost emissions-free electricity system for Spain is possible, at a cost that can be even lower than current wholesale market prices.Comment: 7 tables & 11 figures in the main body (24 pages), and 13 pages for the supplementary material, wit

    3D Segmentation Method for Natural Environments based on a Geometric-Featured Voxel Map

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    This work proposes a new segmentation algorithm for three-dimensional dense point clouds and has been specially designed for natural environments where the ground is unstructured and may include big slopes, non-flat areas and isolated areas. This technique is based on a Geometric-Featured Voxel map (GFV) where the scene is discretized in constant size cubes or voxels which are classified in flat surface, linear or tubular structures and scattered or undefined shapes, usually corresponding to vegetation. Since this is not a point-based technique the computational cost is significantly reduced, hence it may be compatible with Real-Time applications. The ground is extracted in order to obtain more accurate results in the posterior segmentation process. The scene is split into objects and a second segmentation in regions inside each object is performed based on the voxel’s geometric class. The work here evaluates the proposed algorithm in various versions and several voxel sizes and compares the results with other methods from the literature. For the segmentation evaluation the algorithms are tested on several differently challenging hand-labeled data sets using two metrics, one of which is novel.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Methodology for the metric restoration of the historical cartography applied to Francisco Coello's cartografic series of the Royal Site of Aranjuez

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    Hojas Kilométricas (Kilometric Sheets). Specifically, the study focuses on those sheets referring to the city centre and surrounding area of the Royal Site of Aranjuez, a town in the south of the Province of Madrid. The aim of this study is to restore the actual size and measurements of scanned images of the Hojas Kilométricas. This would allow us, among other things, to reestablish both the format and scale of the original plans. To achieve this goal it is necessary to rectify and then georeference these images, i.e. assign them a geographic reference system. This procedure is essential in the overlaying and comparison of the Hojas Kilométricas of the Royal Site with other historical cartography as well as other sources related to the same area from different time periods. Subsequent research would allow us, for example, to reconstruct the time-evolution of the urban area, to spot new construction and to pinpoint the locations of any altered or missing buildings or architectural features. In addition, this would allow us to develop and integrate databases for GIS models applicable to the management of our cultural heritage

    Optimizing Scan Homogeneity for Building Full-3D Lidars based on Rotating a Multi-Beam Velodyne Rangefinder

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    Multi-beam lidar (MBL) scanners are compact, light, and accessible 3D sensors with high data rates, but they offer limited vertical resolution and field of view (FOV). Some recent robotics research has profited from the addition of a degree-of-freedom (DOF) to an MBL to build rotating multi-beam lidars (RMBL) that can achieve high-resolution scans with full spherical FOV. In a previous work, we offered a methodology to analyze the complex 3D scan measurement distributions produced by RMBLs with a rolling DOF and no pitching. In this paper, we investigate the effect of introducing constant pitch angles in the construction of the RMBLs with the purpose of finding a kinematic configuration that optimizes scan homogeneity with a spherical FOV. To this end, we propose a scalar index of 3D sensor homogeneity that is based on the spherical formulation of Ripley's K function. The optimization is performed for the widely used Puck (VLP-16) and HDL-32 sensors by Velodyne.This work was partially funded by the Spanish project {DPI2015-65186-R}. The publication has received support from Universidad de Málaga, Campus de Excelencia Andalucía Tech

    Robustness of electricity systems with nearly 100% share of renewables: a worst-case study

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    Several research studies have shown that future sustainable electricity systems, mostly based on renewable generation and storage, are feasible with current technologies and costs. However, recent episodes of extreme weather conditions, probably associated with climate change, cast shades of doubt on whether the resulting generation portfolios are sufficiently robust to assure, at all times, a suitable balance between generation and demand, when adverse conditions are faced. To address this issue, this work elaborates a methodology intended to determine a sustainable electricity system that can endure extreme weather conditions, which are likely to occur. First, using hourly production and demand data from the last decade, along with estimates of new uses of electricity, a worst-case scenario is constructed, including the storage capacity and additional photovoltaic power which are needed to serve the demand on an hourly basis. Next, several key parameters which may have a significant influence on the LCOE are considered, and a sensitivity analysis is carried out to determine their real impact, significance and potential trends. The proposed methodology is then applied to the Spanish system. The results show that, under the hypotheses and conditions considered in this paper, it is possible to design a decarbonized electricity system that, taking advantage of existing sustainable assets, satisfies the long-term needs by providing a reliable supply at an average cost significantly lower than current market prices.Comment: 33 pages, 13 figures, 10 table

    Mortalidad por lesiones de tránsito en adultos mayores en la República de Ecuador entre los años 1990 y 2018: estudio descriptivo

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    The present study aimed to estimate the trend in road traffic injury mortality in older adults (60 years of age or older) and comparison with those <60 years of age in Ecuador (1990-2018). Official death records and population projections were used to calculate mortality rates per 100,000 population, rate ratios, years of potential life lost (YPLL), and trends. Those under 60 years of age had mortality rates of 16.7 (per 100,000) compared to 36.2 (per 100,000) for older adults, with an increasing trend in YPLL. Older adults recorded fewer deaths than the younger population. However, it is necessary to develop road safety strategies oriented to the progressive aging of the Ecuadorian population. Keywords: older adults, traffic accidents, mortality, trends, Ecuador. References [1]World Health Organization (2018, May 17). Global Status Report on Road Safety 2018 [Online]. Available: https://www.who.int/violence_injury_prevention/road_safety_status/2018/en/ [2]A. F. Algora-Buenafé, M. Russo-Puga, P. R. Suasnavas-Bermúdez, P. Merino-Salazar and A. R. Gómez-García,"Tendencias de los accidentes de tránsito en Ecuador: 2000-2015", Gerencia y Políticas de Salud, vol. 16, n.º 33, pp. 52–58, noviembre de 2017. [Online]. Available: https://doi.org/10.11144/javeriana.rgps16-33.tate. [Last Access: September 2nd, 2021 ]. [3]Pan American Health Organization (2019, June 22). Status of Road Safety in the Region of the Americas [Online]. Available: http://iris.paho.org/xmlui/handle/123456789/51088. [4]S. J. Eun, "Trends in mortality from road traffic injuries in South Korea, 1983–2017: Joinpoint regression and age-period-cohort analyses", Accident Analysis &Prevention, vol. 134, p. 105325, January 2020. [Online]. Available: https://doi.org/10.1016/j.aap.2019.105325. [Last Access: September 2nd, 2021 ]. [5]S. Azami-Aghdash, M. H. Aghaei, and H. Sadeghi-Bazarghani, "Epidemiology of Road Traffic Injuries among Elderly People; A Systematic Review and Meta-Analysis", Bulletin of Emergency and Trauma, vol. 6, n.º 4, pp. 279–291, October 2018. [Online]. Available: https://doi.org/10.29252/beat-060403. [Last Access: September 7th, 2021 ]. [6]Y. Abolfathi Momtaz, R. Kargar, R. Hosseiny, and R. Sahaf, "Rate and pattern of road traffic accidents among older and younger drivers", Healthy Aging Research, vol. 7, n.º 2, June 2018, art. n.º e18. [Online]. Available: https://doi.org/10.1097/hxr.0000000000000018. [Last Access: October 13th, 2021 ]. [7]P. Martínez, D. Contreras and M. Moreno, "Safe mobility, socioeconomic inequalities, and aging: A 12-year multilevel interrupted time-series analysis of road traffic death rates in a Latin American country", PLOS ONE, vol. 15, n.º 1, enero de 2020, art. n.º e0224545. [Online]. Available: https://doi.org/10.1371/journal.pone.0224545. [Last Access: October 10th, 2021 ]. [8]G. Bergen et al., "How do older adult drivers self-regulate? Characteristics of self-regulation classes defined by latent class analysis", Journal of Safety Research, vol. 61, pp. 205–210, June 2017. [Online]. Available: https://doi.org/10.1016/j.jsr.2017.01.002. [Last Access: October 9th, 2021 ] [9]Instituto Nacional de Estadística y Censos (2018, February 2). Registros Estadísticos de Nacidos Vivos, Defunciones Fetales y Defunciones Generales [Online]. Available: https://www.ecuadorencifras.gob.ec/nacimientos_y_defunciones. [10]Instituto Nacional de Estadística y Censos (2017, August 2). Proyecciones Demográficas, 2010 – 2020. [Online]. Available: https://sni.gob.ec/proyecciones-y-estudios-demograficos. [11]W. Y. Yee, "Road traffic injuries in the elderly", Emergency Medicine Journal, vol. 23, n.º 1, pp. 42–46, January 2006. [Online]. Available: https://doi.org/10.1136/emj.2005.023754. [Last Access: October 21st, 2021] [12]L. McElroy, J. Juern, A. Bertleson, Q. Xiang, A. Szabo and J. Weigelt, "A single urban center experience with adult pedestrians struck by motor vehicles", WMJ:official publication of the State Medical Society of Wisconsin, vol. 112(3), pp. 117-122, 2013. [13]K. Bhalla, M. Naghavi, S. Shahraz, D. Bartels and C. J. L. Murray, "Building national estimates of the burden of road traffic injuries in developing countries from all available data sources: Iran", Injury Prevention, vol. 15, n.º 3, pp. 150–156, June 2009. [Online]. Available: https://doi.org/10.1136/ip.2008.020826. [Last Access: October 1st, 2021]. [14]D. Bartels, K. Bhalla, S. Shahraz, J. Abraham, R. Lozano and C. J. L. Murray, "Incidence of road injuries in Mexico: country report", International Journal of Injury Control and Safety Promotion, vol. 17, n.º 3, pp. 169–176, September 2010. [Online]. Available: https://doi.org/10.1080/17457300903564553. [Last Access: November 16th, 2021]. [15]W. R. Boot, C. Stothart and N. Charness, "Improving the Safety of Aging Road Users: A Mini-Review", Gerontology, vol. 60, n.º 1, pp. 90–96, 2014. [Online]. Available: https://doi.org/10.1159/000354212.  [Last Access: November 6th, 2021] [16]Y. L. Michael, E. P. Whitlock, J. S. Lin, R. Fu, E. A. O'Connor and R. Gold, "Primary Care–Relevant Interventions to Prevent Falling in Older Adults: A Systematic Evidence Review for the U.S. Preventive Services Task Force", Annals of Internal Medicine, vol. 153, n.º 12, p. 815, December 2010. [Online]. Available: https://doi.org/10.7326/0003-4819-153-12-201012210-00008.[Last Access: November 29th, 2021] [17]H. Etehad, S. Yousefzadeh-Chabok, A. Davoudi-Kiakalaye, D. A. Moghadam, H. Hemati and Z. Mohtasham-Amiri, "Impact of road traffic accidents on the elderly", Archives of Gerontology and Geriatrics, vol. 61, n.º 3, pp. 489–493, November de 2015. [Online]. Available: https://doi.org/10.1016/j.archger.2015.08.008. [Last Access: November 3th, 2021]. [18]B. H. Ang, W. S. Chen and S. W. H. Lee, "Global burden of road traffic accidents in older adults: A systematic review and meta-regression analysis", Archives of Gerontology and Geriatrics, vol. 72, pp. 32–38, September 2017. [Online]. Available: https://doi.org/10.1016/j.archger.2017.05.004. [Last Access: December 19th, 2021] [19]J. P. Thompson, M. R. J. Baldock and J. K. Dutschke, "Trends in the crash involvement of older drivers in Australia", Accident Analysis & Prevention, vol. 117, pp. 262–269, August 2018. [Online]. Available: https://doi.org/10.1016/j.aap.2018.04.027. [Last Access: December 16th, 2021].El presente estudio tuvo como objetivo estimar la tendencia de mortalidad por lesiones de tránsito en adultos mayores (igual o mayor a 60 años edad) y la comparación con los menores a 60 años edad en el Ecuador (1990-2018). Se emplearon los registros de defunción y proyecciones demográficas oficiales para el cálculo de tasas de mortalidad por 100 mil habitantes, razón de tasas, años de vida potencialmente perdidos (AVPP) y tendencias. Los menores a 60 años edad registraron tasas de mortalidad de 16,7 (por 100 mil) frente a 36,2 (por 100 mil) en los adultos mayores, con tendencia al aumento en los AVPP. Los adultos mayores registraron menor número de casos de fallecimientos con relación a la población más joven. Sin embargo, es necesario elaborar estrategias en seguridad vial orientadas al progresivo envejecimiento de la población ecuatoriana. Palabras Clave: Anciano, accidentes de tránsito, mortalidad, tendencias, Ecuador. Referencias [1]World Health Organization (2018, May 17). Global Status Report on Road Safety 2018 [Online]. Available: https://www.who.int/violence_injury_prevention/road_safety_status/2018/en/ [2]A. F. Algora-Buenafé, M. Russo-Puga, P. R. Suasnavas-Bermúdez, P. Merino-Salazar y A. R. Gómez-García,"Tendencias de los accidentes de tránsito en Ecuador: 2000-2015", Gerencia y Políticas de Salud, vol. 16, n.º 33, pp. 52–58, noviembre de 2017. Accedido el 2 deseptiembre de 2021. [En línea]. Disponible: https://doi.org/10.11144/javeriana.rgps16-33.tate [3]Pan American Health Organization (2019, June 22). Status of Road Safety in the Region of the Americas [Online]. Available: http://iris.paho.org/xmlui/handle/123456789/51088. [4]S. J. Eun, "Trends in mortality from road traffic injuries in South Korea, 1983–2017: Joinpoint regression and age-period-cohort analyses", Accident Analysis &Prevention, vol. 134, p. 105325, enero de 2020. Accedido el 2 de septiembre de 2021. [En línea]. Disponible: https://doi.org/10.1016/j.aap.2019.105325. [5]S. Azami-Aghdash, M. H. Aghaei y H. Sadeghi-Bazarghani, "Epidemiology of Road Traffic Injuries among Elderly People; A Systematic Review and Meta-Analysis", Bulletin of Emergency and Trauma, vol. 6, n.º 4, pp. 279–291, octubre de 2018. Accedido el 7 deseptiembre de 2021. [En línea]. Disponible: https://doi.org/10.29252/beat-060403 [6]Y. Abolfathi Momtaz, R. Kargar, R. Hosseiny y R. Sahaf, "Rate and pattern of road traffic accidents among older and younger drivers", Healthy Aging Research, vol. 7, n.º 2, junio de 2018, art. n.º e18. Accedido el 13 de octubre de 2021. [En línea]. Disponible: https://doi.org/10.1097/hxr.0000000000000018. [7]P. Martínez, D. Contreras y M. Moreno, "Safe mobility, socioeconomic inequalities, and aging: A 12-year multilevel interrupted time-series analysis of road traffic death rates in a Latin American country", PLOS ONE, vol. 15, n.º 1, enero de 2020, art. n.º e0224545. Accedido el 10 de octubre de 2021. [En línea]. Disponible: https://doi.org/10.1371/journal.pone.0224545 [8]G. Bergen et al., "How do older adult drivers self-regulate? Characteristics of self-regulation classes defined by latent class analysis", Journal of Safety Research, vol. 61, pp. 205–210, junio de 2017. Accedido el 9 de octubre de 2021. [En línea]. Disponible: https://doi.org/10.1016/j.jsr.2017.01.002. [9]Instituto Nacional de Estadística y Censos (2018, February 2). Registros Estadísticos de Nacidos Vivos, Defunciones Fetales y Defunciones Generales [Online].Available: https://www.ecuadorencifras.gob.ec/nacimientos_y_defunciones. [10]Instituto Nacional de Estadística y Censos (2017, August 2). Proyecciones Demográficas, 2010 – 2020. [Online]. Available: https://sni.gob.ec/proyecciones-y-estudios-demograficos. [11]W. Y. Yee, "Road traffic injuries in the elderly", Emergency Medicine Journal, vol. 23, n.º 1, pp. 42–46, enero de 2006. Accedido el 21 de octubre de2021. [En línea]. Disponible: https://doi.org/10.1136/emj.2005.023754. [12]L. McElroy, J. Juern, A. Bertleson, Q. Xiang, A. Szabo and J. Weigelt, "A single urban center experience with adult pedestrians struck by motor vehicles", WMJ:official publication of the State Medical Society of Wisconsin, vol. 112(3), pp. 117-122, 2013. [13]K. Bhalla, M. Naghavi, S. Shahraz, D. Bartels y C. J. L. Murray, "Building national estimates of the burden of road traffic injuries in developing countries from all available data sources: Iran", Injury Prevention, vol. 15, n.º 3, pp. 150–156, junio de 2009. Accedido el 1 de octubre de 2021. [En línea]. Disponible: https://doi.org/10.1136/ip.2008.020826. [14]D. Bartels, K. Bhalla, S. Shahraz, J. Abraham, R. Lozano y C. J. L. Murray, "Incidence of road injuries in Mexico: country report", International Journal of Injury Control and Safety Promotion, vol. 17, n.º 3, pp. 169–176, septiembre de 2010. Accedido el 16 de noviembre de 2021. [En línea]. Disponible: https://doi.org/10.1080/17457300903564553. [15]W. R. Boot, C. Stothart y N. Charness, "Improving the Safety of Aging Road Users: A Mini-Review", Gerontology, vol. 60, n.º 1, pp. 90–96, 2014. Accedido el 6 de noviembre de 2021. [En línea]. Disponible: https://doi.org/10.1159/000354212. [16]Y. L. Michael, E. P. Whitlock, J. S. Lin, R. Fu, E. A. O'Connor y R. Gold, "Primary Care–Relevant Interventions to Prevent Falling in Older Adults: A Systematic Evidence Review for the U.S. Preventive Services Task Force", Annals of Internal Medicine, vol. 153, n.º 12, p. 815, diciembre de 2010. Accedido el 29 de noviembre de 2021. [En línea]. Disponible: https://doi.org/10.7326/0003-4819-153-12-201012210-00008. [17]H. Etehad, S. Yousefzadeh-Chabok, A. Davoudi-Kiakalaye, D. A. Moghadam, H. Hemati y Z. Mohtasham-Amiri, "Impact of road traffic accidents on the elderly", Archives of Gerontology and Geriatrics, vol. 61, n.º 3, pp. 489–493, noviembre de 2015. Accedido el 3 de noviembre de 2021. [En línea]. Disponible: https://doi.org/10.1016/j.archger.2015.08.008. [18]B. H. Ang, W. S. Chen y S. W. H. Lee, "Global burden of road traffic accidents in older adults: A systematic review and meta-regression analysis", Archives of Gerontology and Geriatrics, vol. 72, pp. 32–38, septiembre de 2017. Accedido el 19 de diciembre de 2021. [En línea]. Disponible: https://doi.org/10.1016/j.archger.2017.05.004. [19]J. P. Thompson, M. R. J. Baldock y J. K. Dutschke, "Trends in the crash involvement of older drivers in Australia", Accident Analysis & Prevention, vol. 117, pp. 262–269, agosto de 2018. Accedido el 16 de diciembre de 2021. [En línea]. Disponible: https://doi.org/10.1016/j.aap.2018.04.027

    New design parameters for biparabolic beach profiles (SW Cadiz, Spain)

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    165 profiles of seventy-one beaches along the Gulf of Cadiz (SW, Spain) were studied to improve the formulation of the beach profile in tidal seas. Maritime climate, degree of energy exposure and size of the sand grains were taken into account to study the two sections of the biparabolic profile. The objective of the study was the determination of more accurate formulations of the design parameters for the equilibrium profile that involves tidal seas. These formulations were modelled and validated based on existing profiles to quantify the error existing between the real profile and the modelling. This comparative analysis was extended by considering the formulations proposed by other authors. The best results were obtained with the proposal presented herein

    Integration of a Canine Agent in a Wireless Sensor Network for Information Gathering in Search and Rescue Missions

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    Search and rescue operations in the context of emergency response to human or natural disasters have the major goal of finding potential victims in the shortest possible time. Multi-agent teams, which can include specialized human respondents, robots and canine units, complement the strengths and weaknesses of each agent, like all-terrain mobility or capability to locate human beings. However, efficient coordination of heterogeneous agents requires specific means to locate the agents, and to provide them with the information they require to complete their mission. The major contribution of this work is an application of Wireless Sensor Networks (WSN) to gather information from a multi-agent team and to make it available to the rest of the agents while keeping coverage. In particular, a canine agent has been equipped with a mobile node installed on a harness, providing information about the dog’s location as well as gas levels. The configuration of the mobile node allows for flexible arrangement of the system, being able to integrate static as well as mobile nodes. The gathered information is available at an external database, so that the rest of the agents and the control center can use it in real time. The proposed scheme has been tested in realistic scenarios during search and rescue exercises

    Improving deep learning performance with missing values via deletion and compensation

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    Proceedings of: International Work conference on the Interplay between Natural and Artificial Computation (IWINAC 2015)Missing values in a dataset is one of the most common difficulties in real applications. Many different techniques based on machine learning have been proposed in the literature to face this problem. In this work, the great representation capability of the stacked denoising auto-encoders is used to obtain a new method of imputating missing values based on two ideas: deletion and compensation. This method improves imputation performance by artificially deleting values in the input features and using them as targets in the training process. Nevertheless, although the deletion of samples is demonstrated to be really efficient, it may cause an imbalance between the distributions of the training and the test sets. In order to solve this issue, a compensation mechanism is proposed based on a slight modification of the error function to be optimized. Experiments over several datasets show that the deletion and compensation not only involve improvements in imputation but also in classification in comparison with other classical techniques.The work of A. R. Figueiras-Vidal has been partly supported by Grant Macro-ADOBE (TEC 2015-67719-P, MINECO/FEDER&FSE). The work of J.L. Sancho-Gómez has been partly supported by Grant AES 2017 (PI17/00771, MINECO/FEDER)
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