2,080 research outputs found

    ITALICA at PAN 2013: An Ensemble Learning Approach to Author Profiling Notebook for PAN at CLEF 2013

    Get PDF
    This notebook discusses the approach to the Author Profiling task developed by the Italica group for PAN 2013. This system implements two different sets of classifiers which are combined later in order to build a final classifier that takes into account the decisions of the previous ones. The initial classifiers are focused on vector space representations of the documents as a bag of words and n-grams of POS tags and also on a set of stylistic features of the texts. The final classifier consists of a stacking schema that combines the other ones. This approach has obtained better results for the Spanish dataset than for the English dataset, probably due to the use of more detailed POS tagset in the forme

    An extended version of average Markov decision processes on discrete spaces under fuzzy environment

    Get PDF
    summary:The article presents an extension of the theory of standard Markov decision processes on discrete spaces and with the average cost as the objective function which permits to take into account a fuzzy average cost of a trapezoidal type. In this context, the fuzzy optimal control problem is considered with respect to two cases: the max-order of the fuzzy numbers and the average ranking order of the trapezoidal fuzzy numbers. Each of these cases extends the standard optimal control problem, and for each of them the optimal solution is related to a suitable standard optimal control problem, and it is obtained that (i) the optimal policy coincides with the optimal policy of this suitable standard control problem, and (ii) the fuzzy optimal value function is of a trapezoidal shape. Two models: a queueing system and a machine replacement problem are provided in order to examplify the theory given

    Health impact assessment and federal trails policy: equity in public land access.

    Get PDF
    Presented at: New Mexico Public Health Association and New Mexico Center for the Advancement of Research, Engagement & Science on Health Disparities National Health Disparities 2014 Joint Conference; April 1-2, 2014; Albuquerque, NM.https://digitalrepository.unm.edu/prc-posters-presentations/1053/thumbnail.jp

    Accurate and Wide-Field-of-View MEMS-Based Sun Sensor for Industrial Applications

    Get PDF
    This paper describes the design, fabrication, sim- ulation, and experimental results of an improved miniaturized two-axis sun sensor for industrial applications, created by adapt- ing a technology used previously in satellite applications. The sensor for each axis is composed of six photodiodes integrated in a crystalline-silicon substrate and a layer of cover glass, which is used to protect the silicon and to hold the windows. The high precision is obtained by the subdivision of the field of view, which is ± 60 ◦ , with a resolution of 0.1 ◦ . Each region is controlled by an independent high-precision solar sensor. The sensor can be used for sun-tracking applications in a photovoltaic system, heliostat concentration plants, and lighting applications.Gobierno de España. AYA2009- 07188-E, ACI2010-1094, AIC-B-2011-0702 (Sensosol project)Junta de Andalucía (España) P08-TIC-03590 (Satsol project

    Calcium magneto-optical trap loaded from a decelerated atomic beam

    Get PDF
    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOWe describe a new system for laser cooling and trapping of neutral Calcium atoms employing the ¹S0 -¹ P1 resonant transition at 423 nm. An on-axis magneto-optical trap (MOT) is loaded from a Zeeman decelerated atomic beam. When a single laser is used, in order to avoid perturbation of the trap by the deceleration laser beam, this one has been tightly focused near the MOT center, with a waist size much smaller than the atomic cloud. In order to test the efficiency of this novel technique, we have then employed a second, independent decelerating laser, with a profile mode matched to the atomic beam. For an oven temperature of 580±C this system can load 1.2 (2) x 10(7) atoms in 16 (1) ms. By the spatial extension of the atomic cloud the one dimension rms velocity was estimated to be 136 (12) cm/s, corresponding to a temperature of 9 (2) mK. The variation of the number of trapped atoms as a function of laser detuning and intensity, trap magnetic field gradient and oven temperature is analyzed. Spatial structures of the trapped atoms, like stable rings created by vortex forces, have been observed. This is the first time that these structures, already observed in alkali-metal elements, are reported in MOTs of alkaline-earth elements.We describe a new system for laser cooling and trapping of neutral Calcium atoms employing the ¹S0 -¹ P1 resonant transition at 423 nm. An on-axis magneto-optical trap (MOT) is loaded from a Zeeman decelerated atomic beam. When a single laser is used, in order to avoid perturbation of the trap by the deceleration laser beam, this one has been tightly focused near the MOT center, with a waist size much smaller than the atomic cloud. In order to test the efficiency of this novel technique, we have then employed a second, independent decelerating laser, with a profile mode matched to the atomic beam. For an oven temperature of 580±C this system can load 1.2 (2) x 10(7) atoms in 16 (1) ms. By the spatial extension of the atomic cloud the one dimension rms velocity was estimated to be 136 (12) cm/s, corresponding to a temperature of 9 (2) mK. The variation of the number of trapped atoms as a function of laser detuning and intensity, trap magnetic field gradient and oven temperature is analyzed. Spatial structures of the trapped atoms, like stable rings created by vortex forces, have been observed. This is the first time that these structures, already observed in alkali-metal elements, are reported in MOTs of alkaline-earth elements.We describe a new system for laser cooling and trapping of neutral Calcium atoms employing the ¹S0 -¹ P1 resonant transition at 423 nm. An on-axis magneto-optical trap (MOT) is loaded from a Zeeman decelerated atomic beam. When a single laser is used, in order to avoid perturbation of the trap by the deceleration laser beam, this one has been tightly focused near the MOT center, with a waist size much smaller than the atomic cloud. In order to test the efficiency of this novel technique, we have then employed a second, independent decelerating laser, with a profile mode matched to the atomic beam. For an oven temperature of 580±C this system can load 1.2 (2) x 10(7) atoms in 16 (1) ms. By the spatial extension of the atomic cloud the one dimension rms velocity was estimated to be 136 (12) cm/s, corresponding to a temperature of 9 (2) mK. The variation of the number of trapped atoms as a function of laser detuning and intensity, trap magnetic field gradient and oven temperature is analyzed. Spatial structures of the trapped atoms, like stable rings created by vortex forces, have been observed. This is the first time that these structures, already observed in alkali-metal elements, are reported in MOTs of alkaline-earth elements.332355362FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOSem informaçãoSem informaçãoSem informaçãoWe would like to acknowledge the glass shop of the UNICAMP Physics Institute for the very well done work in the construction of the atomic beam and MOT glass chamber. We also would like to thank the machine shop and J.B.Rodrigues for the mechanical parts. This work was supported by FAPESP, CAPES and CNPq and FAEPUNICAMP, Brazilian government agencies. Support for RLCF was through CAPES graduate research scholarship and for DAM and DRO through FAPESP graduate and undergraduate scholarships respectively

    Estudio por primeros principios de las propiedades estructurales y electrónicas de la multicapa CrN/GaN

    Get PDF
    In this work we perform first-principles calculations to investigate the structural and electronic properties of the 1x1 CrN/GaN multilayer. The calculations were executed in zincblende and wurtzite phase, since they are the ground states of chromium nitride CrN and gallium nitride GaN, respectively. However, we study the stability of the multilayer in the NaCl phase, in order to predict possible phase transitions. We found that the most favorable phase for the multilayer is the hexagonal wurtzite type, with possibility of passing to the NaCl phase by applying an external pressure. Our calculations indicate that the pressure of transition is 13,5 GPa. From the density of states, we found that the multilayer present a metallic behavior produced by the hybrid orbitals d-Cr and N-p that cross level Fermi.En este trabajo realizamos cálculos de primeros principios para investigar las propiedades estructurales y electrónicas de la multicapa 1x1 CrN / GaN. Los cálculos se ejecutaron en fase de zincblende y wurtzita, ya que son los estados fundamentales del nitruro de cromo CrN y el nitruro de galio GaN, respectivamente. Sin embargo, estudiamos la estabilidad de la multicapa en la fase de NaCl, para predecir posibles transiciones de fase. Descubrimos que la fase más favorable para la multicapa es el tipo de wurtzita hexagonal, con posibilidad de pasar a la fase de NaCl aplicando una presión externa. Nuestros cálculos indican que la presión de transición es de 13,5 GPa. A partir de la densidad de estados, encontramos que la multicapa presenta un comportamiento metálico producido por los orbitales híbridos d-Cr y N-p que cruzan el nivel de Fermi

    Evaluation of Functional Capacity by Six- Minute Walk Test in Pediatric Asthma Patients

    Get PDF
    Los pacientes con asma muestran menor tolerancia al ejercicio. La prueba de caminata de 6 minutos (6MWD) evalúa la capacidad funcional (CF). La actividad física eleva los puntajes en el Cuestionario de autopercepción física (PSPQ)

    Proper motions of field L and T dwarfs -II

    Full text link
    By using images taken with WFCAM on UKIRT and SofI on the NTT and combining them with 2MASS we have measured proper motions for 126 L and T dwarfs in the dwarf archive. Two of these L dwarfs appear to have M dwarf common proper motion companions, and 2 also appear to be high velocity dwarfs, indicating possible membership of the thick disc. We have also compared the motion of these 126 objects to that of numerous moving groups, and have identified new members of the Hyades, Ursa Major and Pleiades moving groups. These new objects, as well as those identified in Jameson et al. (2008) have allowed us to refine the L dwarf sequence for Ursa Major that was defined by Jameson et al. (2008).Comment: Accepted for publication in MNRAS. 10 pages, 3 figure
    corecore