187 research outputs found

    Secuencias inferopaleolíticas en la cuenca media del Duero

    Get PDF
    Síntesis de posibles secuencias de terrazas fluviales pleistocénicas, en la cuenca del Duero, con industrias líticas datables en el Paleolítico Inferior.Synthesis of the presumed sequences of pleistocaenic fluvial terraces in theDuero basin (Spain) with lithic industries dated from lower Paleolithic

    Prevention of Falls from Heights in Construction Using an IoT System Based on Fuzzy Markup Language and JFML

    Get PDF
    The main cause of fatal accidents in the construction sector are falls from height (FFH) and the inappropriate use of a harness is commonly associated with these fatalities. Traditional methods, such as onsite inspections, safety communication, or safety training, are not enough to mitigate accidents caused by FFH associated with a poor management in the use of a harness. Although some technological solutions for the automated monitoring of workers could improve safety conditions, their use is not frequent due to the particularities of construction sites: complexity, dynamic environments, outdoor workplaces, etc. Then, the integration of expert knowledge with technology is a key issue. Fuzzy logic systems (FLS) and Internet of Things (IoT) present many potential benefits, such as real-time decisions being made based on FLS and data from sensors. In the current research, the development and test of an IoT system integrated with the Java Fuzzy Markup Language Library for FLS, to support experts’ decision making in FFH, is proposed. The proposal was checked in four construction scenarios based on working conditions with different levels of risk of FFH and obtained promising results.Universidad de Malaga Plan Propio-Universidad de MalagaSpanish GovernmentEuropean Commission RTI2018-098371-B-I0

    Prevention of Falls from Heights in Construction Using an IoT System Based on Fuzzy Markup Language and JFML

    Get PDF
    The main cause of fatal accidents in the construction sector are falls from height (FFH) and the inappropriate use of a harness is commonly associated with these fatalities. Traditional methods, such as onsite inspections, safety communication, or safety training, are not enough to mitigate accidents caused by FFH associated with a poor management in the use of a harness. Although some technological solutions for the automated monitoring of workers could improve safety conditions, their use is not frequent due to the particularities of construction sites: complexity, dynamic environments, outdoor workplaces, etc. Then, the integration of expert knowledge with technology is a key issue. Fuzzy logic systems (FLS) and Internet of Things (IoT) present many potential benefits, such as real-time decisions being made based on FLS and data from sensors. In the current research, the development and test of an IoT system integrated with the Java Fuzzy Markup Language Library for FLS, to support experts’ decision making in FFH, is proposed. The proposal was checked in four construction scenarios based on working conditions with different levels of risk of FFH and obtained promising results

    "La Cruz del tío Ignacio", yacimiento Achelense, en Belver de los Montes, Zamora

    Get PDF
    [ES] En este artículo se estudia una colección de artefactos líticos recogidos en el yacimiento de «La Cruz del tío Ignacio-, en Belver de los Montes (Zamora). Dichos objetos son analizados, aquí, bajo los aspectos tecnológicos y tipológicos, principalmente los núcleos, las lascas y la macroindustria (cantos tallados, triedros, hendidores y bifaces). Estos últimos útiles constituyen la parte mejor representada de la industria. El conjunto de artefactos analizados puede atribuirse, por sus características técnicas y tipológicas, al Achelense medio, que se encuentra, abundante, en toda la zona de la cuenca media occidental del Duero, y que está uniformado por la forma y el tamaño de la materia prima (el canto rodado de cuarcita), por la técnica y por la tipología.[EN] We try to analyse in this article a collection of stone artifacts gathered in the site of «La Cruz del Tío ignacio» (Belver de los Montes, Zamora, Spain). We analyse these objects under two perspectives, taking into account both the technological and the typological aspects and we concéntrate on core-tools, flake-tools and the macroindustry of pebble-tools, trihedral picks, cleavers and handaxex. These latter artifacts represent the best part of the industry. All these objects as a wole could be ascribed tot he Middle Acheulian if we take into consideration their technical and topological characteristics. Abundante samples of this period can be found all over the western middle basin of the River Duero. All these samples are standardized both by the form/size of the raw material (pebble of quartzite) and by technological and typological elements

    DVB-T Receiver Independent of Channel Allocation, with Frequency Offset Compensation for Improving Resolution in Low Cost Passive Radar.

    Get PDF
    In this article, a commercial low cost solution for increasing DVB-T based passive radar (also referred to as passive coherentlocation)robustnesswith respectto channel allocation and range resolution, is designed. IDEPAR demonstrator is updated to include a new recording system in charge of DVB-T channels reallocation. The use of commercial hardware introduces frequency mismatching between acquired channels that compromises system operation. To face channel frequency alignment, fulfilling the requirements imposed by the high Doppler resolution typical of passive radars, a novel compensation algorithm is proposed, based on the minimization of signal dispersion in the Cross-Ambiguity Function domain. The well-known cyclic prefix van de Beek method is used as reference. Results show an increase in target signal to interference ratio and detection performances, as well as a reduction of clutter dispersion when the novel proposed algorithm is applied. The low cost solution is also compared to a high performance one capable of acquiring a wide bandwidth of sparse DVB-T channels, and performing channel reallocation by digital signal processing. Results show that both systems reached similar performances in terms of range resolution and SNR improvement

    Valuation models for holiday rentals’ daily rates: price composition based on Booking.com

    Get PDF
    In recent years, the number of sharing economy accommodations has grown exponentially due to the Internet and peer-to-peer networks, which has made researchers increasingly interested in analysing this new type of lodging. This study sought to develop models that determine the significant variables for the daily price of staying in holiday rentals based on data extracted from Booking.com and other sources. The hedonic pricing method (HPM) was selected to conduct the research as this methodology has been widely used in real estate valuation and hotel daily rate determination; however, the HPM is still rarely used for holiday rentals. The study focused on the city of Seville, where a notable increase in holiday rentals has been observed in recent years. Variables related to the accommodation typology, including location, size and equipment, as well as seasonality, are the most influential factors in the proposed models. These results are of interest to both owners and users of holiday rentals and can help these individuals to determine if the price of a stay is what would commonly be offered in the market under normal circumstances.info:eu-repo/semantics/publishedVersio

    Tribological Behavior of Nanolubricants Based on Coated Magnetic Nanoparticles and Trimethylolpropane Trioleate Base Oil

    Get PDF
    The main task of this work is to study the tribological performance of nanolubricants formed by trimethylolpropane trioleate (TMPTO) base oil with magnetic nanoparticles coated with oleic acid: Fe3O4 of two sizes 6.3 nm and 10 nm, and Nd alloy compound of 19 nm. Coated nanoparticles (NPs) were synthesized via chemical co-precipitation or thermal decomposition by adsorption with oleic acid in the same step. Three nanodispersions of TMPTO of 0.015 wt% of each NP were prepared, which were stable for at least 11 months. Two different types of tribological tests were carried out: pure sliding conditions and rolling conditions (5% slide to roll ratio). With the aim of analyzing the wear by means of the wear scar diameter (WSD), the wear track depth and the volume of the wear track produced after the first type of the tribological tests, a 3D optical profiler was used. The best tribological performance was found for the Nd alloy compound nanodispersion, with reductions of 29% and 67% in friction and WSD, respectively, in comparison with TMPTO. On the other hand, rolling conditions tests were utilized to study friction and film thickness of nanolubricants, determining that Fe3O4 (6.3 nm) nanolubricant reduces friction in comparison to TMPTOThis research was supported by the Spanish Ministry of Economy and Competitiveness and the ERDF programme through the ENE2017-86425-C2-2-R project. Moreover, this work was funded by the Xunta de Galicia (ED431E 2018/08, GRC ED431C 2017/22 and GRC ED431C 2016/001). These three funders also financed the acquisition of the 3D Optical Profile Sensofar S Neox (UNST15-DE-3156)S

    Immature Blood Vessels in Rheumatoid Synovium Are Selectively Depleted in Response to Anti-TNF Therapy

    Get PDF
    BACKGROUND:Angiogenesis is considered an important factor in the pathogenesis of Rheumatoid Arthritis (RA) where it has been proposed as a therapeutic target. In other settings, active angiogenesis is characterized by pathologic, immature vessels that lack periendothelial cells. We searched for the presence of immature vessels in RA synovium and analyzed the dynamics of synovial vasculature along the course of the disease, particularly after therapeutic response to TNF antagonists. METHODOLOGY/PRINCIPAL FINDINGS:Synovial arthroscopic biopsies from RA, osteoarthritis (OA) and normal controls were analyzed by double labeling of endothelium and pericytes/smooth muscle mural cells to identify and quantify mature/immature blood vessels. To analyze clinicopathological correlations, a cross-sectional study on 82 synovial biopsies from RA patients with variable disease duration and severity was performed. A longitudinal analysis was performed in 25 patients with active disease rebiopsied after anti-TNF-alpha therapy. We found that most RA synovial tissues contained a significant fraction of immature blood vessels lacking periendothelial coverage, whereas they were rare in OA, and inexistent in normal synovial tissues. Immature vessels were observed from the earliest phases of the disease but their presence or density was significantly increased in patients with longer disease duration, higher activity and severity, and stronger inflammatory cell infiltration. In patients that responded to anti-TNF-alpha therapy, immature vessels were selectively depleted. The mature vasculature was similarly expanded in early or late disease and unchanged by therapy. CONCLUSION/SIGNIFICANCE:RA synovium contains a significant fraction of neoangiogenic, immature blood vessels. Progression of the disease increases the presence and density of immature but not mature vessels and only immature vessels are depleted in response to anti-TNFalpha therapy. The different dynamics of the mature and immature vascular fractions has important implications for the development of anti-angiogenic interventions in RA
    corecore