2,068 research outputs found

    Social reinforcement in artificial prelinguistic development : a study using intrinsically motivated exploration architectures

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    This work introduces an intrinsically motivated sensorimotor exploration architecture which considers social reinforcement and motor constraint awareness. The main objective is to study the influence of social interactions during artificial early prelinguistic development. We argue that this architecture contributes to explain development from voiceless to sequence of vowels vocalizations. A cognitive developmental perspective is considered emphasizing embodied cognition and sensorimotor exploratory behaviors. For a new-born agent, motor constraints are unknown. However, the agent is endowed with a somatosensory system that indicates if a motor configuration was reached or not. This information is used to model and predict constraint violations. Furthermore, the architecture considers imitative behaviors that constrain the search space during exploration. Interaction occurs when the learner sensory production is similar to a sensory unit relevant to communication. In that case, the instructor perceives this similitude and reformulates with the relevant sensory unit. When the learner perceives an utterance by the instructor, it attempts to imitate it. Two systems are considered for experimentation: A toy example and a simulated vocal tract. In general, our results suggest that constraint awareness and social reinforcement contribute to achieve less redundant exploration, lower exploration and evaluation errors, and a clearer picture of developmental transitions.© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Peer ReviewedPostprint (author's final draft

    SensiCut: Material-Aware Laser Cutting Using Speckle Sensing and Deep Learning

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    Laser cutter users face difficulties distinguishing between visually similar materials. This can lead to problems, such as using the wrong power/speed settings or accidentally cutting hazardous materials. To support users, we present SensiCut, an integrated material sensing platform for laser cutters. SensiCut enables material awareness beyond what users are able to see and reliably differentiates among similar-looking types. It achieves this by detecting materials' surface structures using speckle sensing and deep learning. SensiCut consists of a compact hardware add-on for laser cutters and a user interface that integrates material sensing into the laser cutting workflow. In addition to improving the traditional workflow and its safety1, SensiCut enables new applications, such as automatically partitioning designs when engraving on multi-material objects or adjusting their geometry based on the kerf of the identified material. We evaluate SensiCut's accuracy for different types of materials under different sheet orientations and illumination conditions

    Analysis Of Energy Production With Different Photovoltaic Technologies In The Colombian Geography

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    This research has analyzed the photovoltaic technologies, Polycrystalline silicon, Monocrystalline Silicon, GIS, Cadmium Tellurium and Amorphous Silicon; in eight cities of the Colombian territory, in order to obtain a clear idea of what is the most appropriate for each city or region studied. PVsyst simulation software has been used to study in detail each photovoltaic technology, for an installed capacity of 100kW knowing the specific data of losses by temperature, mismatch, efficiency, wiring, angle inclination of the arrangement, among other

    Scavenger Activity Evaluation of the Clove Bud Essential Oil (Eugenia caryophyllus) and Eugenol Derivatives Employing ABTS+• Decolorization

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    The essential oil (EO) of clove bud dried fruits from Eugenia caryophyllus was obtained by a conventional hydrodistillation process in an excellent yield (11.7 %). Its chemical composition was analyzed by GC-MS, identifying eugenol as a main constituent (60.5%). Four eugenol-like molecules, γ-diisoeugenol, hydroxymethyleugenol, dihydroeugenol and 1,3-dioxanylphenol, were synthesized using eugenol or isoeugenol as initial precursors under green chemistry protocols. To evaluate the possible antioxidant capacity of eugenol compounds including the clove bud EO, the Trolox® Equivalent Antioxidant Capacity value, obtained by the ABTS+• radical-cation discoloration method, was employed. The methodology was performed in a UV-Vis reader of 96-well microplates (dilution methodology), using well-known antioxidant agents (BHA, BHT and vitamin E) as reference compounds. It was found that the prepared eugenol derivatives had a more potent free radical scavenger activity than the reference compounds. In particular, the most active molecules, γ-diisoeugenol and 1,3-dioxanylphenol, were ca. 3-fold more potent than vitamin E

    Graft-Copolymerization of Acrylate Monomers onto Chitosan Induced by Gamma Radiation: Amphiphilic Polymers and Their Behavior at The Air-Water Interface

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    Graft polymerization induced by ionizing radiation is a powerful tool in materials science to modifying the physical properties of polymers. Chitosan is a biocompatible, biodegradable, antibacterial, and highly hydrophilic polysaccharide. In this work, we report the obtaining of amphiphilic polymers through graft polymerization of acrylic monomers (methyl acrylate, t-butyl acrylate, and hexyl acrylate) onto chitosan. The polymerization reaction was carried out by simultaneous irradiation of monomers and chitosan using a gamma radiation source of 60Co. The formation of Langmuir films of amphiphilic polymers was studied at the air-water interface through surface pressure versus main molecular area isotherms (Π-A) and hysteresis cycles of compression and decompression. Finally, it was analyzed the transferring of Langmuir films towards solid substrates to obtaining Langmuir-Blodgett films with potential application as an antibacterial coating. The microstructure of the Langmuir-Blodgett films was characterized by AFM microscopy observing a regular topography with roughness ranging between 0.53 and 0.6 μm

    Starch enzymatic hydrolysis, structural, thermal and rheological properties of pigeon pea (Cajanus cajan) and dolichos bean (Dolichos lab-lab) legume starches

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    ProducciĂłn CientĂ­ficaCajanus CajansandDolichos lab-lablegume starches from Argentine cultivars were investigated under atechnological and nutritional point of view. Their physico-chemical, structural, thermal and the rheologi-cal properties of their gels were evaluated. Rice (RS) and potato (PS) starches were included as references.In vitrodigestibility from Englyst method was also evaluated. Legume starches had the highest amylosecontent and the most stable chemical structure. Their rapidly digestible starch and starch digestibility rateindex were very low, similar to PS, and fivefold lower than RS. They had a much higher slowly digestiblestarch content than PS. Legume starches showed the highest gel stability versus heating and stirring andan intermedium pasting temperature between RS and PS. They formed viscoelastic gels at 6% concentra-tion with stronger elastic-like behaviour and higher yield stress than references. Our results indicate theselegumes represent an efficient starch source to provide tailor-made properties to food/industrial applica-tions.Ministerio de Economia y Competitividad and the European Regional Development Fund (FEDER) (AGL2015-63849-C2-2-R)Junta de Castilla y Leon/FEDER VA072P17Universidad Nacional del Nordeste, Argentina (PI: 16-F017

    Nuevos datos sobre algunas especies de Hemeróbidos de la península Ibérica e islas Canarias, incluyendo una nueva especie invasora de origen neotropical en Portugal (Insecta, Neuroptera, Hemerobiidae)

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    New data on the distribution, biology and phenology of 25 brown lacewings species (Insecta, Neuroptera: Hemerobiidae) of Iberian and Canaries fauna are given. The species Hemerobius bolivari Banks, 1910, widely distributed in the Neotropical Region, is recorded for the first time in Europe as a new invasive species, from specimens collected on Thaumastocoris peregrinus Carpintero & Dellapé, 2006 (Hemiptera: Thaumastocoridae) colonies on Eucalyptus in Lisbon (Portugal). This brown lacewing species, along with Sympherobius gayi Navás, 1910, also known from South America, is the second invasive species of neotropical origin, belonging to this family, that is recorded in the Iberian Peninsula, both from Portugal. We also mention several species that have been seldom recorded in the Iberian Peninsula, and among them Wesmaelius ravus (Withycombe, 1923) is recorded for the second time in the Iberian Peninsula, now from Sierra Nevada (Granada). From samplings made in southern Spain (Malaga, Granada) Micromus angulatus (Stephens, 1836) shows activity as imagoes during winter time (the entire year in the Iberian Peninsula, including this area), and these data seem also to confirm its link to grass vegetation.Se anotan nuevos datos sobre la distribución, biología y fenología de 25 especies de hemeróbidos (Insecta, Neuroptera: Hemerobiidae) de las Faunas Ibérica y Canaria. La especie Hemerobius bolivari Banks, 1910, ampliamente distribuida por la Región Neotropical, se cita por primera vez de Europa como una nueva especie invasora, a partir de ejemplares recolectados en colonias de Thaumastocoris peregrinus Carpintero y Dellapé, 2006 (Hemiptera: Thaumastocoridae:) sobre Eucalyptus en Lisboa (Portugal). Esta especie, junto a Sympherobius gayi Navás, 1910, también originaria de Sudamérica, es la segunda especie invasora de origen neotropical que de esta familia se cita en la Península Ibérica, en este caso también de Portugal. Se mencionan varias especies que han sido muy escasamente citadas en la Península Ibérica, y entre ellas destaca Wesmaelius ravus (Withycombe, 1923), que se cita por segunda vez en la Península Ibérica, en este caso de Sierra Nevada (Granada). A partir de muestreos realizados en el sur de España (Málaga, Granada), se desprende actividad en los imagos de Micromus angulatus (Stephens, 1836) en los meses de invierno (a lo largo de todo el año en la Península Ibérica, incluyendo esta zona ibérica), y estos datos también parecen corroborar su vinculación con la vegetación arvense

    Optical Light Curve of the Type Ia Supernova 1998bu in M96 and the Supernova Calibration of the Hubble Constant

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    We present the UBVRI light curves of the Type Ia supernova SN 1998bu which appeared in the nearby galaxy M96 (NGC 3368). M96 is a spiral galaxy in the Leo I group which has a Cepheid-based distance. Our photometry allows us to calculate the absolute magnitude and reddening of this supernova. These data, when combined with measurements of the four other well-observed supernovae with Cepheid based distances, allow us to calculate the Hubble constant with respect to the Hubble flow defined by the distant Calan/Tololo Type Ia sample. We find a Hubble constant of 64.0 +/- 2.2(internal) +/- 3.5(external) km/s/Mpc, consistent with most previous estimates based on Type Ia supernovae. We note that the two well-observed Type Ia supernovae in Fornax, if placed at the Cepheid distance to the possible Fornax spiral NGC 1365, are apparently too faint with respect to the Calan/Tololo sample calibrated with the five Type Ia supernovae with Cepheid distances to the host galaxies.Comment: AAS LaTeX, 20 pages, 4 figures, 6 tables, accepted for publication in the Astronomical Journal. Figure 1 (finding chart) not include
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