3,157 research outputs found

    ALALC : el protocolo de Caracas

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    Fil: Barcia Bermúdez, Anselmo H. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Política Económica. Buenos Aires, ArgentinaFil: Barcia Bermúdez, Anselmo H. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Análisis Económico y Financiero. Buenos Aires, ArgentinaFil: Barcia Bermúdez, Anselmo H. Universidad de Belgrano. Facultad de Derecho. Cátedra Economía Política. Buenos Aires, Argentin

    El factor residual de crecimiento económico

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    Fil: Barcia Bermúdez, Anselmo H. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Política Económica. Buenos Aires, ArgentinaFil: Barcia Bermúdez, Anselmo H. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Análisis Económico y Financiero. Buenos Aires, ArgentinaFil: Barcia Bermúdez, Anselmo H. Universidad de Belgrano. Facultad de Derecho. Cátedra Economía Política. Buenos Aires, Argentin

    Expected exponential loss for gaze-based video and volume ground truth annotation

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    Many recent machine learning approaches used in medical imaging are highly reliant on large amounts of image and ground truth data. In the context of object segmentation, pixel-wise annotations are extremely expensive to collect, especially in video and 3D volumes. To reduce this annotation burden, we propose a novel framework to allow annotators to simply observe the object to segment and record where they have looked at with a \$200 eye gaze tracker. Our method then estimates pixel-wise probabilities for the presence of the object throughout the sequence from which we train a classifier in semi-supervised setting using a novel Expected Exponential loss function. We show that our framework provides superior performances on a wide range of medical image settings compared to existing strategies and that our method can be combined with current crowd-sourcing paradigms as well.Comment: 9 pages, 5 figues, MICCAI 2017 - LABELS Worksho

    The water supercooled regime as described by four common water models

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    The temperature scale of simple water models in general does not coincide with the natural one. Therefore, in order to make a meaningful evaluation of different water models a temperature rescaling is necessary. In this paper we introduce a rescaling using the melting temperature and the temperature corresponding to the maximum of the heat capacity to evaluate four common water models (TIP4P-Ew, TIP4P-2005, TIP5P-Ew and Six-Sites) in the supercooled regime. Although all the models show the same general qualitative behavior, the TIP5P-Ew appears as the best representation of the supercooled regime when the rescaled temperature is used. We also analyze, using thermodynamic arguments, the critical nucleus size for ice growth. Finally, we speculate on the possible reasons why atomistic models do not usually crystalize while the coarse grained mW model do crystallize.Comment: 8 pages, 8 figure

    y tú, ¿por qué eres negro?

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    Y tú, ¿por qué eres negro? es un proyecto que nace con vocación de fotolibro y que se encuentra en continua evolución

    Scattering at the Anderson transition: Power--law banded random matrix model

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    We analyze the scattering properties of a periodic one-dimensional system at criticality represented by the so-called power-law banded random matrix model at the metal insulator transition. We focus on the scaling of Wigner delay times τ\tau and resonance widths Γ\Gamma. We found that the typical values of τ\tau and Γ\Gamma (calculated as the geometric mean) scale with the system size LL as τtypLD1\tau^{\tiny typ}\propto L^{D_1} and ΓtypL(2D2)\Gamma^{\tiny typ} \propto L^{-(2-D_2)}, where D1D_1 is the information dimension and D2D_2 is the correlation dimension of eigenfunctions of the corresponding closed system.Comment: 6 pages, 8 figure

    Analysis of Regulated Pollutant Emissions and Aftertreatment Efficiency in a GTDi Engine Using Different SOI Strategies

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    [EN] In order to improve performance and minimize pollutant emissions in gasoline turbocharged direct-injection (GTDi) engines, different injection strategies and technologies are being investigated. The inclusion of exhaust gas recirculation (EGR) and the variation of the start of injection (SOI) are some of these strategies that can influence the air-to-fuel (AF) mixture formation and consequently in the combustion process and pollutant emissions. This article presents a complete study of the engine performance, pollutant emissions and aftertreatment efficiency that produces the SOI variation with a fixed EGR rate in a 4-cylinder, turbocharged, gasoline direct-injection engine with 2.0 L displacement. The equipment used in this study are TSI-EEPS for particle measurement and HORIBA MEXA 1230-PM for soot measurement being HORIBA MEXA 7100-DEGR with a heated line selector the system employed for regulated gaseous emission measurement and aftertreatment evaluation. The experimental results confirm how the use of an adequate SOI strategy is indispensable to obtain low exhaust emissions values and a balance between the different pollutants. There was found a slight reduction in brake specific fuel consumption (BSFC) with the SOI advance. The experiments showed a decrease in CO, a non-sensible variation of THC and an increase in NOx emissions with SOI delay. Additionally, a significant increase in particle emissions was observed with early SOIs. Finally, with the SOI delay the aftertreatment performance revealed an increase in the oxidation of CO and a decrease in the reduction of NOx.The equipment used in this work has been partially supported by FEDER project funds "Dotacion de infraestructuras cientifico tecnicas para el Centro Integral de Mejora Energetica y Medioambiental de Sistemas de Transporte (CiMeT), (FEDER-ICTS-2012-06)", framed in the operational program of singular scientific and technical infrastructure of the Ministry of Science and Innovation of Spain.Bermúdez, V.; Luján, JM.; Climent, H.; Soto-Izquierdo, L.; Campos-Navarro, D. (2018). Analysis of Regulated Pollutant Emissions and Aftertreatment Efficiency in a GTDi Engine Using Different SOI Strategies. SAE International Journal of Engines. 11(3):363-382. https://doi.org/10.4271/03-11-03-0025S36338211

    Laboratory Characterization and Astrophysical Detection of Vibrationally Excited States of Vinyl Cyanide in Orion-KL

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    New laboratory data of CH2_2CHCN (vinyl cyanide) in its ground and vibrationally excited states at the microwave to THz domain allow searching for these excited state transitions in the Orion-KL line survey. Frequency-modulated spectrometers combined into a single broadband 50-1900 GHz spectrum provided measurements of CH2_2CHCN covering a spectral range of 18-1893 GHz, whose assignments was confirmed by Stark modulation spectra in the 18-40 GHz region and by ab-initio anharmonic force field calculations. For analyzing the emission lines of CH2_2CHCN species detected in Orion-KL we used the excitation and radiative transfer code (MADEX) at LTE conditions. The rotational transitions of the ground state of this molecule emerge from four cloud components of hot core nature which trace the physical and chemical conditions of high mass star forming regions in the Orion-KL Nebula. The total column density of CH2_2CHCN in the ground state is (3.0±\pm0.9)x1015^{15} cm2^{-2}. We report on the first interstellar detection of transitions in the v10=1/(v11=1,v15=1) dyad in space, and in the v11=2 and v11=3 states in Orion-KL. The lowest energy vibrationally excited states of vinyl cyanide such as v11=1 (at 328.5 K), v15=1 (at 478.6 K), v11=2 (at 657.8 K), the v10=1/(v11=1,v15=1) dyad (at 806.4/809.9 K), and v11=3 (at 987.9 K) are populated under warm and dense conditions, so they probe the hottest parts of the Orion-KL source. Column density and rotational and vibrational temperatures for CH2_2CHCN in their ground and excited states, as well as for the isotopologues, have been constrained by means of a sample of more than 1000 lines in this survey. Moreover, we present the detection of methyl isocyanide (CH3_3NC) for the first time in Orion-KL and a tentative detection of vinyl isocyanide (CH2_2CHNC) and give column density ratios between the cyanide and isocyanide isomers.Comment: 46 pages, 22 figures, 14 tables, 9 online table
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