A USB3.0 FPGA Event-based Filtering and Tracking Framework for Dynamic Vision Sensors

Dynamic vision sensors (DVS) are frame-free sensors with an asynchronous variable-rate output that is ideal for hard real-time dynamic vision applications under power and latency constraints. Post-processing of the digital sensor output can reduce sensor noise, extract low level features, and track objects using simple algorithms that have previously been implemented in software. In this paper we present an FPGA-based framework for event-based processing that allows uncorrelated-event noise removal and real-time tracking of multiple objects, with dynamic capabilities to adapt itself to fast or slow and large or small objects. This framework uses a new hardware platform based on a Lattice FPGA which filters the sensor output and which then transmits the results through a super-speed Cypress FX3 USB microcontroller interface to a host computer. The packets of events and timestamps are transmitted to the host computer at rates of 10 Mega events per second. Experimental results are presented that demonstrate a low latency of 10us for tracking and computing the center of mass of a detected object.Ministerio de Economía y Competitividad TEC2012-37868-C04-0

Psychosocial and psychological factors are not related to low back pain in office-workers who develop pain during standing-paradigm: preliminary study

Poster[Abstract] Background: Low back pain (LBP) is a common and disabling musculoskeletal disorder in the working population. Laboratory studies have indicated that prolonged standing is associated with LBP with the focus to date on understanding the biomechanical source of this pain. An induced-pain protocol (standing-paradigm) has been used to examine psychological factors in back-healthy people in previous studies, but none have examined the association with psychosocial factors in office workers. Purpose: To examine: 1) the relationship between group status (those who did and did not develop LBP during standing) and workplace psychosocial factors (Job Content Questionnaire, Job Satisfaction), and individual psychological factors (Pain Catastrophizing Scale, Mental Component Summary of SF-12); and 2) the relationship between intensity of LBP during standing and workplace psychosocial and individual psychological factors. Methods: A cross-sectional laboratory-based study was conducted. A convenience sample of 32 office-workers, who perform more than 30 hours per week mostly sitting at a computer were recruited. Participants completed their own work and rated their LBP intensity every 15 minutes during the one-hour standing-paradigm. The primary outcomes were: a) group status based on change in LBP score (measured on a 100-mm visual analogue scale (VAS); and b) change in LBP intensity during the standing-paradigm. Secondary outcome measures completed prior to the one-hour standing task were: four dimensions of the Job Content Questionnaire (JCQ); one question on Job Satisfaction; 3 dimensions of Pain Catastrophizing Scale (PCS) and PCS-total score; Mental Component Summary (MCS) of SF12. Demographic, anthropometric, physical activity levels (International Physical Activity Questionnaire), and previous episode of LBP (lifetime and last month) data was collected. Data analysis included independent group t-test (continuous variables) and Chi Square (categorical variables) to test for differences between PDs and NPDs at baseline. Pearson correlation coefficients were calculated for VAS and the scores on JCQ, Satisfaction Job, PCS and MCS. Logistic regression was performed to identify which factors were associated with group membership (PDs or NPDs) with JCQ, PCS and MCS as independent variables controlling for age, sex, BMI and history of LBP. Statistical significance was set at p ≤ 0.05. Results: There were 14 (43.8%) PDs. The mean maximum LBP reported by PDs was 26 mm (range 4 to 59 mm). There were no significant differences at baseline for age, BMI, and physical activity levels between the PDs vs NPDs and nor any significant differences between the groups for any workplace psychosocial or psychological measures. Correlations between VAS and each psychosocial and psychological measures were small and not significant. Regression modelling showed that sex (p=0.01), lifetime episode of LBP (p=0.04) and LBP-last month (p≤0.01) predicted PD status. Conclusion(s): These results suggest that in office-workers baseline psychosocial and psychological status do not differentiate who will develop LBP during standing. LBP intensity was not related to workplace psychosocial nor individual psychological status. Only sex and previous history of LBP identified those who developed LBP during the standing-paradigm

Raman microprobe characterization of electrodeposited S-rich CuIn(S,Se)2 for photovoltaic applications: Microstructural analysis

This article reports a detailed Raman scattering and microstructural characterization of S-rich CuIn(S,Se)2 absorbers produced by electrodeposition of nanocrystalline CuInSe2 precursors and subsequent reactive annealing under sulfurizing conditions. Surface and in-depth resolved Raman microprobe measurements have been correlated with the analysis of the layers by optical and scanning electron microscopy, x-ray diffraction, and in-depth Auger electron spectroscopy. This has allowed corroboration of the high crystalline quality of the sulfurized layers. The sulfurizing conditions used also lead to the formation of a relatively thick MoS2 intermediate layer between the absorber and the Mo back contact. The analysis of the absorbers has also allowed identification of the presence of In-rich secondary phases, which are likely related to the coexistence in the electrodeposited precursors of ordered vacancy compound domains with the main chalcopyrite phase, in spite of the Cu-rich conditions used in the growth. This points out the higher complexity of the electrodeposition and sulfurization processes in relation to those based in vacuum deposition techniques

Spike-based VITE control with Dynamic Vision Sensor applied to an Arm Robot.

Spike-based motor control is very important in the field of robotics and also for the neuromorphic engineering community to bridge the gap between sensing / processing devices and motor control without losing the spike philosophy that enhances speed response and reduces power consumption. This paper shows an accurate neuro-inspired spike-based system composed of a DVS retina, a visual processing system that detects and tracks objects, and a SVITE motor control, where everything follows the spike-based philosophy. The control system is a spike version of the neuroinspired open loop VITE control algorithm implemented in a couple of FPGA boards: the first one runs the algorithm and the second one drives the motors with spikes. The robotic platform is a low cost arm with four degrees of freedom.Ministerio de Ciencia e Innovación TEC2009-10639-C04-02/01Ministerio de Economía y Competitividad TEC2012-37868-C04-02/0

Study on the anomalous quartic W+W-yy couplings of electroweak bosons in e-p collisions at the LHeC and the FCC-he

In this paper, a study is carried out on the e−p --> e−y*p --> pW−ynu_e production to probe quartic W+W−yy couplings at the Large Hadron electron Collider (LHeC) with s= 1.30, 1.98 TeV and at the Future Circular Collider-hadron electron (FCC-he) with s= 3.46, 5.29 TeV. Production cross-sections are determined for both at leptonic and hadronic decay channels of the W-boson. With the data from future e−p colliders, it is possible to obtain sensitivity measures at 95% C.L

The prion 2018 round tables (I): the structure of PrP Sc

Understanding the structure of PrPSc is without doubt a sine qua non to understand not only PrPSc propagation, but also critical features of that process such as the strain phenomenon and transmission barriers. While elucidation of the PrPSc structure has been full of difficulties, we now have a large amount of structural information that allows us to begin to understand it. This commentary article summarizes a round table that took place within the Prion 2018 meeting held in Santiago de Compostela to discuss the state of the art in this matter. Two alternative models of PrPSc exist: the PIRIBS and the 4-rung β-solenoid models. Both of them have relevant features. The 4-rung β-solenoid model agrees with experimental constraints of brain derived PrPSc obtained from cryo-EM and X-ray fiber diffraction studies. Furthermore, it allows facile accommodation of the bulky glycans that decorate brain-derived PrPSc. On the other hand, the infectious PrP23-144 amyloid exhibits a PIRIBS architecture. Perhaps, both types of structure co-exist.Supported by grants BFU2013-48436-C2-1-P and BFU2017- 86692-P from the Spanish Ministries of Economy and Competitiveness and Science, Innovation and Universities, respectively, to JRR and grant 201600029 from the Alberta Prion Research Institute to HW. This work was also supported in part by the Intramural Research Program of the NIAID (BC) and by the National Institute of Health grants R01 NS045585 (IVB), P01 AI106705 (WKS), R01 NS083687 (WKS) and R01 NS103848 (WKS)S

Polarized Raman scattering study of kesterite type Cu2ZnSnS4 single crystals

A non-destructive Raman spectroscopy has been widely used as a complimentary method to X-ray diffraction characterization of Cu2ZnSnS4 (CZTS) thin films, yet our knowledge of the Raman active fundamental modes in this material is far from complete. Focusing on polarized Raman spectroscopy provides important information about the relationship between Raman modes and CZTS crystal structure. In this framework the zone-center optical phonons of CZTS, which is most usually examined in active layers of the CZTS based solar cells, are studied by polarized resonant and non-resonant Raman spectroscopy in the range from 60 to 500 cm(-1) on an oriented single crystal. The phonon mode symmetry of 20 modes from the 27 possible vibrational modes of the kesterite structure is experimentally determined. From in-plane angular dependences of the phonon modes intensities Raman tensor elements are also derived. Whereas a strong intensity enhancement of the polar E and B symmetry modes is induced under resonance conditions, no mode intensity dependence on the incident and scattered light polarization configurations was found in these conditions. Finally, Lyddane-Sachs-Teller relations are applied to estimate the ratios of the static to high-frequency optic dielectric constants parallel and perpendicular to c-optical axis

El nivel mental del estudiante de medicina colombiano

El presente estudio resulta de tomar grupos de datos experimentales que está levantando la Sección de Investigación de la Facultad de Psicología de la  Universidad Nacional; consta de dos partes: la primera, con alumnos de sexto curso de Medicina de la Universidad Nacional, y la segunda, con alumnos también de Medicina, fusionados los Cursos 5° y 6°

Near-Field Interference for the Unidirectional Excitation of Electromagnetic Guided Modes

Wave interference is a fundamental manifestation of the superposition principle with numerous applications. Although in conventional optics, interference occurs between waves undergoing different phase advances during propagation, we show that the vectorial structure of the near field of an emitter is essential for controlling its radiation as it interferes with itself on interaction with a mediating object. We demonstrate that the near-field interference of a circularly polarized dipole results in the unidirectional excitation of guided electromagnetic modes in the near field, with no preferred far-field radiation direction. By mimicking the dipole with a single illuminated slit in a gold film, we measured unidirectional surface-plasmon excitation in a spatially symmetric structure. The surface wave direction is switchable with the polarization.This work has been supported in part by the Engineering and Physical Sciences Research Council (grant EP/H000917/2). 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