1,995 research outputs found

    New basal Odonatoptera (Insecta) from the lower Carboniferous (Serpukhovian) of Argentina

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    Nuevos Odonatoptera basales del Serpukhoviano superior (325-324 Ma) son descriptos de la localidad Guandacol 1, Quebrada de las Libélulas, Formación Guandacol, provincia de La Rioja, centro oeste de la Argentina. Otras dos especies conocidas del Serpukhoviano, Eugeropteron lunatum Riek, 1983 y Geropteron arcuatum Riek, 1983, de Cuestita de La Herradura, Formación Malanzán, provincia de La Rioja, son discutidas. Varios taxones de orden superior nuevos son nominados para incluir estas especies, resultando en una nueva clasificación: 1 Superorden Odonatoptera, 1.1 Eugeroptera ord. nov., 1.1.1 Eugeropteridae, 1.1.1.1 Eugeropteron, 1.1.1.1.1 Eugeropteron lunatum, 1.1.1.1.2 Tupacsala niunamenos gen. nov. et sp. nov., 1.2 Palaeodonatoptera taxon nov., 1.2.1 Kukaloptera ord. nov., 1.2.1.1 Kirchneralidae fam. nov., 1.2.1.1.1 Kirchnerala treintamil gen. nov. et sp. nov., 1.2.2 Plesiodonatoptera taxon nov., 1.2.2.1 Argentinoptera ord. nov., 1.2.2.1.1 Argentinalidae fam. nov., 1.2.2.1.1.1 Argentinala cristinae gen. nov. et sp. nov., 1.2.2.2 Apodonatoptera taxon nov., 1.2.2.2.1 Orden Geroptera, 1.2.2.2.1.1 Geropteridae fam. nov., 1.2.2.2.1.1.1 Geropteron, 1.2.2.2.1.1.1.1 Geropteron arcuatum, 1.2.2.2.2 Neodonatoptera.Three new basal species of Odonatoptera from the upper Serpukhovian (325-324 Ma) of Guandacol 1 locality, Quebrada de las Libélulas, Guandacol Formation, La Rioja province, central West Argentina, are described. Two known species also from the Serpukhovian, Eugeropteron lunatum Riek, 1983 and Geropteron arcuatum Riek, 1983, from Cuestita de La Herradura, Malanzán Formation, La Rioja province, are discussed. Several higher taxa are nominated to include these species, resulting in a new classification: 1 Superorder Odonatoptera, 1.1 Eugeroptera ord. nov., 1.1.1 Eugeropteridae, 1.1.1.1 Eugeropteron, 1.1.1.1.1 Eugeropteron lunatum, 1.1.1.1.2 Tupacsala niunamenos gen. nov. et sp. nov., 1.2 Palaeodonatoptera taxon nov., 1.2.1 Kukaloptera ord. nov., 1.2.1.1 Kirchneralidae fam. nov., 1.2.1.1.1 Kirchnerala treintamil gen. nov. et sp. nov., 1.2.2 Plesiodonatoptera taxon nov., 1.2.2.1 Argentinoptera ord. nov., 1.2.2.1.1 Argentinalidae fam. nov., 1.2.2.1.1.1 Argentinala cristinae gen. nov. et sp. nov., 1.2.2.2 Apodonatoptera taxon nov., 1.2.2.2.1 Order Geroptera, 1.2.2.2.1.1 Geropteridae fam. nov., 1.2.2.2.1.1.1 Geropteron, 1.2.2.2.1.1.1.1 Geropteron arcuatum, 1.2.2.2.2 Neodonatoptera.Fil: Petrulevicius, Julian Fernando. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gutierrez, Pedro Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

    A Verilog HDL digital architecture for delay calculation

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    A method for the calculation of the delay between two digital signals with central frequencies in the range [20, 300] Hz is presented. The method performs a delay calculation in order to determine the bearing angle of a sound source. Computing accuracy is tested against a previous implementation of the Cross Correlation Derivative method. A Verilog RTL model of the method has been tested on a Xilinx® FPGA in order to evaluate the real performance of the method. Simulations of an ASIC design on a standard CMOS technology predict a power saving of about 25 times per delay stage over previous implementations.Fil: Chacón-Rodríguez, A.. Universidad de Mar del Plata. Laboratorio de Componentes Electrónicos; ArgentinaFil: Martín-Pirchio, F. N.. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; ArgentinaFil: Julian, Pedro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; ArgentinaFil: Mandolesi, Pablo Sergio. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; Argentin

    a study on European mature adults in COVID times

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    Introduction: The COVID-19 pandemic has transformed working at home (WAH) into the exclusive mode of working for many European workers. Although WAH will likely remain after COVID-19, its consequences on workers' health are unclear. This study examines the association of WAH and the change of four mental health (MH) domains. Methods: We used data from the last wave of the Survey on Health, Aging, and Retirement in Europe, collected in June and July 2020 on European people aged 50 and older. We restricted our analysis to people aged 50–65 who were working before COVID-19 (N = 7065). We modeled the risk of worsening of depression and anxiety feelings, sleeping trouble, and feelings of loneliness as a function of the working situation (usual setting, at home and usual setting, at home only), using logistic regressions. A first model adjusted for sociodemographic variables, a second one adding country fixed effects, and the last one adding the stringency of COVID-19-related restrictions. Results: WAH was significantly associated with a worsening of all MH symptoms. Nevertheless, when the stringency index was factored in, no significant association of WAH was found with any of the health outcomes except for anxiety feelings (+4.3% points). However, the increased anxiety feelings among people in WAH were not greater than the one observed among nonworkers. Discussion: Our findings show that WAH was not a major cause of mental health deterioration among European mature adults during the first month of the pandemic. Further evidence is needed on WAH under post-COVID-19 “normal” circumstances.publishersversionpublishe

    VLSI implementation of an energy-aware wake-up detector for an acoustic surveillance sensor network

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    We present a low-power VLSI wake-up detector for a sensor network that uses acoustic signals to localize ground-base vehicles. The detection criterion is the degree of low-frequency periodicity in the acoustic signal, and the periodicity is computed from the "bumpiness" of the autocorrelation of a one-bit version of the signal. We then describe a CMOS ASIC that implements the periodicity estimation algorithm. The ASIC is functional and its core consumes 835 nanowatts. It was integrated into an acoustic enclosure and deployed in field tests with synthesized sounds and ground-based vehicles.Fil: Goldberg, David H.. Johns Hopkins University; Estados UnidosFil: Andreou, Andreas. Johns Hopkins University; Estados UnidosFil: Julian, Pedro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; ArgentinaFil: Pouliquen, Philippe O.. Johns Hopkins University; Estados UnidosFil: Riddle, Laurence. Signal Systems Corporation; Estados UnidosFil: Rosasco, Rich. Signal Systems Corporation; Estados Unido

    Potential of I/O aware workflows in climate and weather

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    The efficient, convenient, and robust execution of data-driven workflows and enhanced data management are essential for productivity in scientific computing. In HPC, the concerns of storage and computing are traditionally separated and optimised independently from each other and the needs of the end-to-end user. However, in complex workflows, this is becoming problematic. These problems are particularly acute in climate and weather workflows, which as well as becoming increasingly complex and exploiting deep storage hierarchies, can involve multiple data centres. The key contributions of this paper are: 1) A sketch of a vision for an integrated data-driven approach, with a discussion of the associated challenges and implications, and 2) An architecture and roadmap consistent with this vision that would allow a seamless integration into current climate and weather workflows as it utilises versions of existing tools (ESDM, Cylc, XIOS, and DDN’s IME). The vision proposed here is built on the belief that workflows composed of data, computing, and communication-intensive tasks should drive interfaces and hardware configurations to better support the programming models. When delivered, this work will increase the opportunity for smarter scheduling of computing by considering storage in heterogeneous storage systems. We illustrate the performance-impact on an example workload using a model built on measured performance data using ESDM at DKRZ

    Advanced UAV Trajectory Generation: Planning and Guidance

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    As technology and legislation move forward (JAA & Eurocontrol, 2004) remotely controlled, semi-autonomous or autonomous Unmanned Aerial Systems (UAS) will play a significant role in providing services and enhancing safety and security of the military and civilian community at large (e.g. surveillance and monitoring) (Coifman et al., 2004). The potential market for UAVs is, however, much bigger than just surveillance. UAVs are ideal for risk assessment and neutralization in dangerous areas such as war zones and regions stricken by disaster, including volcanic eruptions, wildfires, floods, and even terrorist acts. As they become more autonomous, UAVs will take on additional roles, such as air-to-air combat and even planetary science exploration (Held et al., 2005). As the operational capabilities of UAVs are developed there is a perceived need for a significant increase in their level of autonomy, performance, reliability and integration with a controlled airspace full of manned vehicles (military and civilian). As a consequence researchers working with advanced UAVs have moved their focus from system modeling and low-level control to mission planning, supervision and collision avoidance, going from vehicle constraints to mission constraints (Barrientos et al., 2006). This mission-based approach is most useful for commercial applications where the vehicle must accomplish tasks with a high level of performance and maneuverability. These tasks require flexible and powerful trajectory-generation and guidance capabilities, features lacking in many of the current commercial UAS. For this reason, the purpose of this work is to extend the capabilities of commercially available autopilots for UAVs. Civil systems typically use basic trajectory-generation algorithms, capable only of linear waypoint navigation (Rysdyk, 2003), with a minimum or non-existent control over the trajectory. These systems are highly constrained when maneuverability is a mission requirement. On the other hand, military researchers have developed algorithms for high-performance 3D path planning and obstacle avoidance (Price, 2006), but these are highly proprietary technologies that operate with different mission constraints (target acquisition, threat avoidance and situational awareness) so they cannot be used in civil scenarios

    La presión fiscal en las cooperativas: una valoración por tamaños, comunidades y sectores para el periodo 2008-2011

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    Las cooperativas son sociedades con unas características especiales tanto en su regulación como en su tributación, tradicionalmente más ventajosa, a las que se les atribuye importantes funciones sociales. En este trabajo realizamos un cálculo del impuesto sobre sociedades pagado con objeto de medir la presión fiscal de las empresas cooperativas y de esta forma valorar si se producen diferencias estadísticamente significativas entre los diferentes tipos de estas empresas, según tamaños, sectores y comunidades autónomas. Para ello partimos de la información adicional de tipo fiscal que ofrecen los balances anuales a partir del año 2008, como consecuencia de la adaptación de la legislación mercantil a las Normas Internacionales de Contabilidad y trabajamos sobre una muestra de empresas cooperativas durante cuatro años
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