92 research outputs found

    Building Fuzzy Elevation Maps from a Ground-based 3D Laser Scan for Outdoor Mobile Robots

    Get PDF
    Mandow, A; Cantador, T.J.; Reina, A.J.; Martínez, J.L.; Morales, J.; García-Cerezo, A. "Building Fuzzy Elevation Maps from a Ground-based 3D Laser Scan for Outdoor Mobile Robots," Robot2015: Second Iberian Robotics Conference, Advances in Robotics, (2016) Advances in Intelligent Systems and Computing, vol. 418. This is a self-archiving copy of the author’s accepted manuscript. The final publication is available at Springer via http://link.springer.com/book/10.1007/978-3-319-27149-1.The paper addresses terrain modeling for mobile robots with fuzzy elevation maps by improving computational speed and performance over previous work on fuzzy terrain identification from a three-dimensional (3D) scan. To this end, spherical sub-sampling of the raw scan is proposed to select training data that does not filter out salient obstacles. Besides, rule structure is systematically defined by considering triangular sets with an unevenly distributed standard fuzzy partition and zero order Sugeno-type consequents. This structure, which favors a faster training time and reduces the number of rule parameters, also serves to compute a fuzzy reliability mask for the continuous fuzzy surface. The paper offers a case study using a Hokuyo-based 3D rangefinder to model terrain with and without outstanding obstacles. Performance regarding error and model size is compared favorably with respect to a solution that uses quadric-based surface simplification (QSlim).This work was partially supported by the Spanish CICYT project DPI 2011-22443, the Andalusian project PE-2010 TEP-6101, and Universidad de Málaga-Andalucía Tech

    Un estudio comparativo sobre el pensamiento profesional y la "acción docente" de los profesores de ciencias de Educación Secundaria. Parte II

    Get PDF
    Este artículo es la segunda parte de una investigación más amplia sobre el pensamiento del profesor (Martínez et al., 2001). En este caso el estudio gira en torno al análisis de las diferencias y similitudes entre dos muestras de profesores de ciencias de educación secundaria que difieren en sus años de docencia y en su trayectoria profesional, definida por la realización de cursos de formación permanente de alta cualificación científica y didáctica. En un primer apartado se analizan facetas relacionadas con la motivación y la satisfacción en la realización de su tarea, la manera de entender la formación del profesor y sus percepciones sobre diferentes factores profesionales. A continuación se aborda lo que «dicen hacer» en relación a aspectos curriculares referidos a contenidos, metodología y evaluación. A partir del análisis de las respuestas a los cuestionarios elaborados se plantean una serie de reflexiones que buscarían mejorar el «desarrollo profesional» de este colectivo de profesores.This article is a part of a wider research on secondary science teachers' beliefs. Through the use of a questionnaire data were obtained from 103 secondary science teachers in service with different degrees of experience. Analysis of data are discussed in terms of their implication in teacher training in service

    ¿Qué pensamiento profesional y curricular tienen los futuros profesores de ciencias de Secundaria?

    Get PDF
    This article is a part of a wider research on secondary science teachers' beliefs. Through the use of a questionnaire data were obtained from 211 secondary science teacher candidates. Analyses of data are discussed in terms of their implication in science teacher education

    Carnegie Supernova Project-II: Extending the Near-Infrared Hubble Diagram for Type Ia Supernovae to z∼0.1z\sim0.1

    Full text link
    The Carnegie Supernova Project-II (CSP-II) was an NSF-funded, four-year program to obtain optical and near-infrared observations of a "Cosmology" sample of ∼100\sim100 Type Ia supernovae located in the smooth Hubble flow (0.03≲z≲0.100.03 \lesssim z \lesssim 0.10). Light curves were also obtained of a "Physics" sample composed of 90 nearby Type Ia supernovae at z≤0.04z \leq 0.04 selected for near-infrared spectroscopic time-series observations. The primary emphasis of the CSP-II is to use the combination of optical and near-infrared photometry to achieve a distance precision of better than 5%. In this paper, details of the supernova sample, the observational strategy, and the characteristics of the photometric data are provided. In a companion paper, the near-infrared spectroscopy component of the project is presented.Comment: 43 pages, 10 figures, accepted for publication in PAS

    The Carnegie Supernova Project I: photometry data release of low-redshift stripped-envelope supernovae

    Full text link
    The first phase of the Carnegie Supernova Project (CSP-I) was a dedicated supernova follow-up program based at the Las Campanas Observatory that collected science data of young, low-redshift supernovae between 2004 and 2009. Presented in this paper is the CSP-I photometric data release of low-redshift stripped-envelope core-collapse supernovae. The data consist of optical (uBgVri) photometry of 34 objects, with a subset of 26 having near-infrared (YJH) photometry. Twenty objects have optical pre-maximum coverage with a subset of 12 beginning at least five days prior to the epoch of B-band maximum brightness. In the near-infrared, 17 objects have pre-maximum observations with a subset of 14 beginning at least five days prior to the epoch of J-band maximum brightness. Analysis of this photometric data release is presented in companion papers focusing on techniques to estimate host-galaxy extinction (Stritzinger et al., submitted) and the light-curve and progenitor star properties of the sample (Taddia et al., submitted). The analysis of an accompanying visual-wavelength spectroscopy sample of ~150 spectra will be the subject of a future paper.Comment: Updated a couple of small error

    Developing a Complex Understanding of Physical Activity in Cardiometabolic Disease from Low-to-Middle-Income Countries—A Qualitative Systematic Review with Meta-Synthesis

    Get PDF
    Physical activity behaviour is complex, particularly in low-resource settings, while existing behavioural models of physical activity behaviour are often linear and deterministic. The objective of this review was to (i) synthesise the wide scope of factors that affect physical activity and thereby (ii) underpin the complexity of physical activity in low-resource settings through a qualitative meta-synthesis of studies conducted among patients with cardiometabolic disease living in low-to-middle income countries (LMIC). A total of 41 studies were included from 1200 unique citations (up to 15 March 2021). Using a hybrid form of content analysis, unique factors (n = 208) that inform physical activity were identified, and, through qualitative meta-synthesis, these codes were aggregated into categories (n = 61) and synthesised findings (n = 26). An additional five findings were added through deliberation within the review team. Collectively, the 31 synthesised findings highlight the complexity of physical activity behaviour, and the connectedness between person, social context, healthcare system, and built and natural environment. Existing behavioural and ecological models are inadequate in fully understanding physical activity participation in patients with cardiometabolic disease living in LMIC. Future research, building on complexity science and systems thinking, is needed to identify key mechanisms of action applicable to the local context

    The Carnegie Supernova Project II. The shock wave revealed through the fog: The strongly interacting Type IIn SN 2013L

    Full text link
    We present ultra-violet to mid-infrared observations of the long-lasting Type IIn supernova (SN) 2013L obtained by the Carnegie Supernova Project II (CSP-II). The spectra of SN 2013L are dominated by H emission features characterized by three components attributed to different regions. A unique feature of this Type IIn SN is that the blue shifted line profile is dominated by the macroscopic velocity of the expanding shock wave of the SN. We are therefore able to trace the evolution of the shock velocity in the dense and partially opaque circumstellar medium (CSM), from ∼4800 km s−1\sim 4800~km~s^{-1} at +48 d, decreasing as t−0.23t^{-0.23} to ∼2700 km s−1\sim 2700~km~s^{-1} after a year. We perform spectral modeling of both the broad- and intermediate-velocity components of the Hα\alpha line profile. The high-velocity component is consistent with emission from a radially thin, spherical shell located behind the expanding shock with emission wings broadened by electron scattering. We propose that the intermediate component originates from pre-ionized gas from the unshocked dense CSM with the same velocity as the narrow component, ∼100 km s−1\sim 100~km~s^{-1}, but also broadened by electron scattering. The spectral energy distributions (SEDs) of SN 2013L after +132 d are well reproduced by a two-component black-body (BB) model. The circumstellar-interaction model of the bolometric light curve reveals a mass-loss rate history with large values (1.7×10−2−0.15 M⊙ yr−11.7\times 10^{-2} - 0.15~M_\odot~yr^{-1}) over the ∼\sim 25 - 40 years before explosion. The drop in the light curve at ∼350\sim 350 days and presence of electron scattering wings at late epochs indicate an anisotropic CSM. The mass-loss rate values and the unshocked CSM velocity are consistent with the characteristics of a massive star, such as a luminous blue variable (LBV) undergoing strong eruptions, similar to η\eta Carina.Comment: Replaced after language editor corrections, accepted for publication on Astronomy and Astrophysics, 43 pages, 29 figures. Abstract abridge

    Steroid regulation: An overlooked aspect of tolerance and chronic rejection in kidney transplantation.

    Get PDF
    Steroid conversion (HSD11B1, HSD11B2, H6PD) and receptor genes (NR3C1, NR3C2) were examined in kidney-transplant recipients with "operational tolerance" and chronic rejection (CR), independently and within the context of 88 tolerance-associated genes. Associations with cellular types were explored. Peripheral whole-blood gene-expression levels (RT-qPCR-based) and cell counts were adjusted for immunosuppressant drug intake. Tolerant (n = 17), stable (n = 190) and CR patients (n = 37) were compared. Healthy controls (n = 14) were used as reference. The anti-inflammatory glucocorticoid receptor (NR3C1) and the cortisol-activating HSD11B1 and H6PD genes were up-regulated in CR and were lowest in tolerant patients. The pro-inflammatory mineralocorticoid gene (NR3C2) was downregulated in stable and CR patients. NR3C1 was associated with neutrophils and NR3C2 with T-cells. Steroid conversion and receptor genes, alone, enabled classification of tolerant patients and were major contributors to gene-expression signatures of both, tolerance and CR, alongside known tolerance-associated genes, revealing a key role of steroid regulation and response in kidney transplantation

    SN 2012fr: Ultraviolet, Optical, and Near-infrared Light Curves of a Type Ia Supernova Observed within a Day of Explosion

    Get PDF
    We present detailed ultraviolet, optical, and near-infrared light curves of the Type Ia supernova (SN) 2012fr, which exploded in the Fornax cluster member NGC 1365. These precise high-cadence light curves provide a dense coverage of the flux evolution from −12 to +140 days with respect to the epoch of B-band maximum (tBmax). Supplementary imaging at the earliest epochs reveals an initial slow and nearly linear rise in luminosity with a duration of ∼2.5 days, followed by a faster rising phase that is well reproduced by an explosion model with a moderate amount of 56Ni mixing in the ejecta. From our analysis of the light curves, we conclude that: (i) the explosion occurred 1800 Å) luminosity was 16.5 ± 0.6 days, (iii) the supernova suffered little or no host-galaxy dust reddening, (iv) the peak luminosity in both the optical and near-infrared was consistent with the bright end of normal Type Ia diversity, and (v) 0.60 ± 0.15 M⊙ of 56Ni was synthesized in the explosion. Despite its normal luminosity, SN 2012fr displayed unusually prevalent high-velocity Ca II and Si II absorption features, and a nearly constant photospheric velocity of the Si II λ6355 line at ∼12,000 km s-1 that began ∼5 days before tBmax. We also highlight some of the other peculiarities in the early phase photometry and the spectral evolution. SN 2012fr also adds to a growing number of Type Ia supernovae that are hosted by galaxies with direct Cepheid distance measurements.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

    SN 2013ai: a link between Hydrogen-rich and Hydrogen-poor Core-collapse Supernovae

    Get PDF
    We present a study of the optical and near-infrared (NIR) spectra of SN 2013ai along with its light curves. These data range from discovery until 380 days after explosion. SN 2013ai is a fast declining Type II supernova (SN II) with an unusually long rise time, 18.9 2.7 days in the V-band, and a bright V-band peak absolute magnitude of -18.7 0.06 mag. The spectra are dominated by hydrogen features in the optical and NIR. The spectral features of SN 2013ai are unique in their expansion velocities, which, when compared to large samples of SNe II, are more than 1,000 km s-1 faster at 50 days past explosion. In addition, the long rise time of the light curve more closely resembles SNe IIb rather than SNe II. If SN 2013ai is coeval with a nearby compact cluster, we infer a progenitor zero-age main-sequence mass of ∼17 M o˙. After performing light-curve modeling, we find that SN 2013ai could be the result of the explosion of a star with little hydrogen mass, a large amount of synthesized 56Ni, 0.3-0.4 M o˙, and an explosion energy of 2.5-3.0 1051 erg. The density structure and expansion velocities of SN 2013ai are similar to those of the prototypical SN IIb, SN 1993J. However, SN 2013ai shows no strong helium features in the optical, likely due to the presence of a dense core that prevents the majority of γ-rays from escaping to excite helium. Our analysis suggests that SN 2013ai could be a link between SNe II and stripped-envelope SNe.Fil: Davis, Scott. University of California; Estados UnidosFil: Pessi, Priscila Jael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Fraser, M.. University College Dublin; IrlandaFil: Ertini, Keila Yael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Martinez, Veronica Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Hoeflich, Peter. Florida State University; Estados UnidosFil: Hsiao, Eric. Florida State University; Estados UnidosFil: Folatelli, Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Ashall, Chris. University of Hawaii at Manoa; Estados UnidosFil: Phillips, Mark. Carnegie Observatories. Las Campanas Observatory; ChileFil: Anderson, J. P.. European Southern Observatory Chile; ChileFil: Bersten, Melina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Englert, B.. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Fisher, A.. Florida State University; Estados UnidosFil: Benetti, S.. Osservatorio Astronomico di Padova; ItaliaFil: Simaz Bunzel, Adolfo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Burns, Christopher R.. Observatories of the Carnegie Institution for Science; Estados UnidosFil: Chen, T. W.. Stockholm University; SueciaFil: Contreras, Carlos. 9Carnegie Observatories. Las Campanas Observatory; ChileFil: Elias Rosa, N.. Osservatorio Astronomico di Padova; ItaliaFil: Falco, E.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Galbany, Lluís. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Kirshner, Robert. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Kumar, S.. Florida State University; Estados UnidosFil: Lu, J.. Florida State University; Estados UnidosFil: Lyman, D.. University of Warwick; Reino UnidoFil: Marion, G. H.. University of Warwick; Reino UnidoFil: Mattila, S.. University of Turku; FinlandiaFil: Maund, J.. University of Sheffield; Reino UnidoFil: Morrell, Nidia Irene. Carnegie Observatories. Las Campanas Observatory; ChileFil: Serón, J.. University of Sheffield; Reino UnidoFil: Stritzinger, Maximilian. Aarhus University; DinamarcaFil: Shahbandeh, Melissa. Florida State University; Estados UnidosFil: Sullivan, Mark. Aarhus University; DinamarcaFil: Suntzeff, N. B.. Texas A&M University; Estados UnidosFil: Young, D. R.. Texas A&M University; Estados Unido
    • …
    corecore