691 research outputs found

    Time is of the Essence: Machine Learning-based Intrusion Detection in Industrial Time Series Data

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    The Industrial Internet of Things drastically increases connectivity of devices in industrial applications. In addition to the benefits in efficiency, scalability and ease of use, this creates novel attack surfaces. Historically, industrial networks and protocols do not contain means of security, such as authentication and encryption, that are made necessary by this development. Thus, industrial IT-security is needed. In this work, emulated industrial network data is transformed into a time series and analysed with three different algorithms. The data contains labeled attacks, so the performance can be evaluated. Matrix Profiles perform well with almost no parameterisation needed. Seasonal Autoregressive Integrated Moving Average performs well in the presence of noise, requiring parameterisation effort. Long Short Term Memory-based neural networks perform mediocre while requiring a high training- and parameterisation effort.Comment: Extended version of a publication in the 2018 IEEE International Conference on Data Mining Workshops (ICDMW

    Variability in GRMHD simulations of Sgr A∗^*: Implications for EHT closure phase observations

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    The observable quantities that carry the most information regarding the structures of the images of black holes in the interferometric observations with the Event Horizon Telescope are the closure phases along different baseline triangles. We use long time span, high cadence, GRMHD+radiative transfer models of Sgr A∗^* to investigate the expected variability of closure phases in such observations. We find that, in general, closure phases along small baseline triangles show little variability, except in the cases when one of the triangle vertices crosses one of a small regions of low visibility amplitude. The closure phase variability increases with the size of the baseline triangle, as larger baselines probe the small-scale structures of the images, which are highly variable. On average, the jet-dominated MAD models show less closure phase variability than the disk-dominated SANE models, even in the large baseline triangles, because the images from the latter are more sensitive to the turbulence in the accretion flow. Our results suggest that image reconstruction techniques need to explicitly take into account the closure phase variability, especially if the quality and quantity of data allow for a detailed characterization of the nature of variability. This also implies that, if image reconstruction techniques that rely on the assumption of a static image are utilized, regions of the u−vu-v space that show a high level of variability will need to be identified and excised.Comment: submitted to apj. 12 pages, 12 figure

    GRMHD simulations of visibility amplitude variability for Event Horizon Telescope images of Sgr A*

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    Synthesis imaging of the black hole in the center of the Milky Way, Sgr A*, with the Event Horizon Telescope (EHT) rests on the assumption of a stationary image. We explore the limitations of this assumption using high-cadence GRMHD simulations of Sgr A*. We employ analytic models that capture the basic characteristics of the images to understand the origin of the variability in the simulated visibility amplitudes. We find that, in all simulations, the visibility amplitudes for baselines oriented perpendicular to the spin axis of the black hole typically decrease smoothly over baseline lengths that are comparable to those of the EHT. On the other hand, the visibility amplitudes for baselines oriented parallel to the spin axis show significant structure with one or more minima. This suggests that fitting EHT observations with geometric models will lead to reasonably accurate determination of the orientation of the black-hole on the plane of the sky. However, in the disk-dominated models, the locations and depths of the minima in the visibility amplitudes depend primarily on the width and asymmetry of the crescent-like images and are highly variable. In the jet-dominated models, the locations of the minima are determined by the separation of the two image components but their depths depend primarily on the relative brightness of the two components and are also variable. This suggests that using time-independent models to infer additional black-hole parameters, such as the shadow size or the spin magnitude, will be severely affected by the variability of the accretion flow.Comment: replaced to match published version, new figure added, results unchange

    Linear decoder analysis applied to multineuronal records of retinal ganglion cells

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    Achieving a thorough understanding about the neural code is one of the neuroscientists’ greatest challenges. One way to evaluate our current knowledge about the neural code is trying to reconstruct sensorial stimuli from neuronal responses. In spite of nowadays there are several types of decoding techniques, few of them have been used and analyzed in actual multi neuronal records of retinal ganglion cells. In this work, we had employed and analyzed a linear decoder to reconstruct different visual stimulus, white noise scramble and natural image, from multi neuronal records of retinal ganglion cells. The efficiency of the reconstruction depends on two factors: one the one hand, the type of visual stimulus, if parameters used were calculated since white noise, scramble or natural image , and on the other hand, the numbers of cells employed in the reconstruction.Fil: Soletta, Jorge Humberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Bioingeniería. Laboratorio de Medios e Interfases; ArgentinaFil: Farfan, Fernando Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Bioingeniería. Laboratorio de Medios e Interfases; ArgentinaFil: Albarracin, Ana Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Bioingeniería. Laboratorio de Medios e Interfases; ArgentinaFil: Felice, Carmelo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Bioingeniería. Laboratorio de Medios e Interfases; Argentin

    Analysis of fault bend folding kinematic models and comparison with an analog experiment

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    Analog modeling of a flat-ramp-flat fault system was performed and its geometry and displacement field were compared to those of different kinematic models such as classical fault bend folding, fault parallel flow, incline-shear, curvilinear hinge, and backlimb trishear. To obtain the displacement vectors of the analog experiment, a Particle Image Velocimetry was performed. All analyzed kinematic models could explain the general configuration of the fault bend folding. However, only backlimb trishear could represent the geometry, directions of particle displacements, and relations between the displacements’ vectors. We propose in this paper that the combination of different asymmetry angles and different apical angles of the backlimb trishear model for each bend in a fault bend fold could be a very versatile and general kinematic model for simulating fault bend folds. Backlimb trishear apical angle can be used to control the shape of the hinges of a fold, while the asymmetry can be used to convolve the velocity of the particles above the fault. Both apical angle and asymmetries different from zero imply thickness changes. Fault bend folds with high inclination forelimbs can be reproduced with high positive asymmetries in the anticline bends of the fault.Fil: Plotek, Berenice Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Guzman, Cecilia Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Cristallini, Ernesto Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Yagupsky, Daniel Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentin

    Growing Up Down South: Spatial and Temporal Variability in Early Growth of Fuegian Sprat Sprattus fuegensis From the Southwest Atlantic Ocean

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    The Fuegian sprat Sprattus fuegensis represents one of the most important pelagic resources in the Southwest Atlantic Ocean (SWAO), exerting a crucial ecological role as an intermediary link in Patagonian food webs. Otolith microstructure of 217 age-0 sprats were analyzed aiming to characterize growth patterns and possible environmental effects over them. Samples were gathered during three oceanographic surveys (spring 2014; autumns 2016, 2017) in Tierra del Fuego (TDF) and the Marine Protected Area Namuncurá-Burdwood Bank (MPAN-BB), the first Argentinian open-sea marine protected area. Daily growths (DG) of larvae and post-larvae were estimated by individually modeling size and otolith radius relationships through back-calculation procedures using potential and linear functions, respectively. Increment widths (IW) and DG values and trajectories were assessed for older sprats (i.e., survivors) sampled in the autumn surveys considering the habitat, year sampled and sprats’ hatching seasons, and were additionally evaluated in relation to sea-surface temperature (SST). IW and DG trajectories differed primarily according to the habitat sampled and sprats’ hatching seasons. Overall, strong coupling was detected between IW and DG trajectories with SST in both habitats. However, statistical assessment on particular comparisons showed that this general trend is not strictly invariant. Even though several results pinpointed a positive correlation between IW and DG with SST, the highest DG were estimated for summer- and autumn-born sprats sampled in 2016 in the MPAN-BB, period and habitat with the lowest SST values. These results unveil a complex relationship between spatial and temporal variability during early growth of Fuegian sprats, supplying relevant information that could be used in the creation of adequate ecosystem based management strategies in the SWAO.Fil: García Alonso, Virginia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Brown, Daniel Roberto. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Pájaro, Marcelo. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Capitanio, Fabiana Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

    Juvenile Myoclonic Epilepsy: distinct phenotypes considering aspects neuropsychological, personality traits and variables clinics

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    INTRODUÇÃO: Estudos neuropsicológicos sugerem que indivíduos com EMJ apresentam disfunção executiva além de maior impulsividade, refletindo uma disfunção de lobo frontal. Este estudo teve como objetivos verificar: 1. o desempenho e gravidade de comprometimento das funções executivas; 2. presença de traços de personalidade impulsivos; 3. a correlação entre o desempenho nas funções cognitivas e a expressão de traços de personalidade impulsivos e; 4. se as variáveis da epilepsia se correlacionam com as disfunções executivas e a um pior controle de impulsos. MÉTODOS: Foram avaliados 42 pacientes com EMJ e 42 sujeitos saudáveis pareados por idade, escolaridade e nível socioeconômico, através de bateria compreensiva de testes neuropsicológicos avaliadores de funções executivas e questionário padronizado de avaliação de traços de personalidade (ITC). RESULTADOS: Pacientes com EMJ tiveram pior desempenho nos testes de atenção imediata, seletiva e sustentada; controle mental e inibitório; flexibilidade mental; fluência verbal; formação de conceitos e manutenção de metas. A disfunção executiva foi moderada/grave em 83,33%. Pacientes com EMJ apresentaram maior expressão dos traços de personalidade impulsivos. A disfunção executiva se correlacionou com o pior controle dos impulsos. Pacientes refratários apresentaram pior disfunção executiva e maior expressão de traços impulsivos. CONCLUSÕES: Nosso estudo demonstra a presença de disfunção atencional e executiva nos pacientes com EMJ, além da presença de traços de personalidade impulsivos. Além disso, verificamos a existência de dois grupos distintos de pacientes, sendo que pacientes mais refratários apresentam-se globalmente comprometidos. Estes achados sugerem que há uma necessidade de melhor caracterização fenotípica dos pacientes com EMJ a fim de incluir endofenótipos visto que nossos resultados demonstram uma possível existência de grupos distintos de pacientes com EMJ.INTRODUCTION: Neuropsychological studies suggest that patients with JME have executive dysfunction and impulsiveness, reflecting a possible frontal lobe dysfunction. This study aimed to verify: 1. the performance and severity of attentional and executive functions; 2. presence of impulsive personality traits; 3. correlation between cognitive performance and the expressions of impulsive personality traits; 4. correlation between epilepsy variables and neuropsychological performance as well as worse impulse control. METHODS: We evaluated 42 patients with JME and a group of 42 control subjects, matched for age, education and socioeconomic status with a comprehensive battery of neuropsychological tests of attentional and executive functions and a standardized assessment of personality traits (TCI). RESULTS: Patients with JME showed worse performance than controls on tests of attentional span, working memory, inhibitory control, concept formation, maintenance of goals, and verbal fluency. Executive dysfunction was severe/moderate in 83.33%. Patients with JME showed higher expression of personality traits associated with an impaired impulse control. Attentional/executive dysfunction was correlated with poor impulse control. Refractory patients had worse executive dysfunction with an even a greater presence of impulsive personality traits. CONCLUSIONS: Our study demonstrates the presence of attentional and executive dysfunction in patients with JME, as well as the presence of impulsive personality traits. We also note the existence of two distinct groups of patients, were more refractory patients appear to present broader impairment. These findings suggest that there is a need for better phenotypic characterization of patients with JME to include diverse phenotypes since our results suggest a possible existence of distinct groups of patients with JME

    Optimized design and data analysis of tag-based cytosine methylation assays

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    Genome-wide, tag-based cytosine methylation analysis is optimized
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