Trajectory Prediction with Event-Based Cameras for Robotics Applications

This thesis presents the study, analysis, and implementation of a framework to perform trajectory prediction using an event-based camera for robotics applications. Event-based perception represents a novel computation paradigm based on unconventional sensing technology that holds promise for data acquisition, transmission, and processing at very low latency and power consumption, crucial in the future of robotics. An event-based camera, in particular, is a sensor that responds to light changes in the scene, producing an asynchronous and sparse output over a wide illumination dynamic range. They only capture relevant spatio-temporal information - mostly driven by motion - at high rate, avoiding the inherent redundancy in static areas of the field of view. For such reasons, this device represents a potential key tool for robots that must function in highly dynamic and/or rapidly changing scenarios, or where the optimisation of the resources is fundamental, like robots with on-board systems. Prediction skills are something humans rely on daily - even unconsciously - for instance when driving, playing sports, or collaborating with other people. In the same way, predicting the trajectory or the end-point of a moving target allows a robot to plan for appropriate actions and their timing in advance, interacting with it in many different manners. Moreover, prediction is also helpful for compensating robot internal delays in the perception-action chain, due for instance to limited sensors and/or actuators. The question I addressed in this work is whether event-based cameras are advantageous or not in trajectory prediction for robotics. In particular, if classical deep learning architecture used for this task can accommodate for event-based data, working asynchronously, and which benefit they can bring with respect to standard cameras. The a priori hypothesis is that being the sampling of the scene driven by motion, such a device would allow for more meaningful information acquisition, improving the prediction accuracy and processing data only when needed - without any information loss or redundant acquisition. To test the hypothesis, experiments are mostly carried out using the neuromorphic iCub, a custom version of the iCub humanoid platform that mounts two event-based cameras in the eyeballs, along with standard RGB cameras. To further motivate the work on iCub, a preliminary step is the evaluation of the robot's internal delays, a value that should be compensated by the prediction to interact in real-time with the object perceived. The first part of this thesis sees the implementation of the event-based framework for prediction, to answer the question if Long Short-Term Memory neural networks, the architecture used in this work, can be combined with event-based cameras. The task considered is the handover Human-Robot Interaction, during which the trajectory of the object in the human's hand must be inferred. Results show that the proposed pipeline can predict both spatial and temporal coordinates of the incoming trajectory with higher accuracy than model-based regression methods. Moreover, fast recovery from failure cases and adaptive prediction horizon behavior are exhibited. Successively, I questioned how much the event-based sampling approach can be convenient with respect to the classical fixed-rate approach. The test case used is the trajectory prediction of a bouncing ball, implemented with the pipeline previously introduced. A comparison between the two sampling methods is analysed in terms of error for different working rates, showing how the spatial sampling of the event-based approach allows to achieve lower error and also to adapt the computational load dynamically, depending on the motion in the scene. Results from both works prove that the merging of event-based data and Long Short-Term Memory networks looks promising for spatio-temporal features prediction in highly dynamic tasks, and paves the way to further studies about the temporal aspect and to a wide range of applications, not only robotics-related. Ongoing work is now focusing on the robot control side, finding the best way to exploit the spatio-temporal information provided by the predictor and defining the optimal robot behavior. Future work will see the shift of the full pipeline - prediction and robot control - to a spiking implementation. First steps in this direction have been already made thanks to a collaboration with a group from the University of Zurich, with which I propose a closed-loop motor controller implemented on a mixed-signal analog/digital neuromorphic processor, emulating a classical PID controller by means of spiking neural networks

Relationship between rainfall and flood frequency curves in high elevation areas

Flood hazard assessment and its relationship with extreme rainfall probabilities is a welladdressed topic in the literature, but not enough in mountain areas, where the climate change effect can hit much more than in other physical contexts. In mountain basins, the lack of systematic data and the complexity of the rain/snow phenomena make investigations even more necessary to figure out the consequences of global warming. This study explores how the partial contributing area effect due to snow accumulation, on the one hand, and the basin runoff coefficient, on the other hand, shape the relationship between rainfall and flood probabilities in high elevation areas. To this aim, the FloodAlp geomorphoclimatic model (Allamano P. et al., 2009) is used. The model is based on the derived distribution approach, producing as a result a simplified flood frequency curve based on the intra-annual variability of the portion of the catchment area covered by snow, according to simple descriptions of the seasonal variation of the freezing elevation and of the hypsographic curve of the basin. To model the basin hypsometric features, we propose the use of a two-parameter Strahler function, which is a more accurate and alternative formulation to the simple one-parameter function originally used in the model. The role of the extreme rainfall frequency analysis is also explicitly analysed, by applying the model using rainfall extremes recorded both in the daily and 24-hours windows. In this application, the only parameter that requires calibration is the runoff coefficient. Considering recordings of annual maximum daily discharges, the runoff coefficients for more than 100 gauged basins in north-western Italy have been calibrated. Comparisons are then possible between the shapes of rainfall and flood frequency distributions within the sample analysed, that also take into account the basin geomorphoclimatic features. Results of this application address the selection of relevant characteristics in relation to the impact of climate change on mountain floods as a result of changes in temperatures and in the statistics of rainfall extremes

A Model for Accomplishing and Managing Dynamic Cloud Federations

Cloud computing is not just a promising approach to the service provisioning: nowadays it represents the reference model in such field. Several cloud service providers have emerged as de facto standards and an increasing number of companies are choosing to migrate their business in the Cloud "ecosystem". Nevertheless, each provider adopts a particular interface to manage its services and uses a proprietary technology. In this paper we present a cloud federation model which is able to provide scalability and flexibility to small clouds. The idea is to benefit of renting seamless resources according to federation agreements among operators. The challenge here is to overcome all the problems raising trying to merge small clouds with heterogeneous administrative domains

Reforma do marco legal do saneamento e o contrato de programa: discussão sobre o protagonismo das empresas estatais na prestação dos serviços

Recentemente esteve em debate a reforma do marco legal do saneamento, sendo um dos pontos de controvérsia a extinção ou continuidade dos contratos de programa, tal como a possibilidade de celebração de novos contratos dessa modalidade. O contrato de programa, ao possibilitar a contratação entre entes da Administração sem a necessidade de realização de licitação, é entendido como causa para o predomínio da prestação dos serviços pelas companhias estaduais, e por isso enfrentou grande oposição por parte do setor privado no debate público, e também do Poder Executivo Federal, encampando uma agenda liberal. Ainda que haja importantes divergências, os argumentos que foram trazidos pelas companhias estaduais em defesa da continuidade do contrato de programa relacionam-se à defesa do papel de protagonista do Estado na direção dos investimentos em infraestrutura, o que representa, em alguma medida, o resgate e a atualização de elementos do pensamento cepalino

Reforma do marco legal do saneamento e o contrato de programa: discussão sobre o protagonismo das empresas estatais na prestação dos serviços

Recentemente esteve em debate a reforma do marco legal do saneamento, sendo um dos pontos de controvérsia a extinção ou continuidade dos contratos de programa, tal como a possibilidade de celebração de novos contratos dessa modalidade. O contrato de programa, ao possibilitar a contratação entre entes da Administração sem a necessidade de realização de licitação, é entendido como causa para o predomínio da prestação dos serviços pelas companhias estaduais, e por isso enfrentou grande oposição por parte do setor privado no debate público, e também do Poder Executivo Federal, encampando uma agenda liberal. Ainda que haja importantes divergências, os argumentos que foram trazidos pelas companhias estaduais em defesa da continuidade do contrato de programa relacionam-se à defesa do papel de protagonista do Estado na direção dos investimentos em infraestrutura, o que representa, em alguma medida, o resgate e a atualização de elementos do pensamento cepalino

Efficacy and safety of reparixin in patients with severe covid-19 Pneumonia. A phase 3, randomized, double-blind placebo-controlled study

Introduction: Polymorphonuclear cell influx into the interstitial and bronchoalveolar spaces is a cardinal feature of severe coronavirus disease 2019 (COVID-19), principally mediated by interleukin-8 (IL-8). We sought to determine whether reparixin, a novel IL-8 pathway inhibitor, could reduce disease progression in patients hospitalized with severe COVID-19 pneumonia. Methods: In this Phase 3, randomized, double-blind, placebo-controlled, multicenter study, hospitalized adult patients with severe COVID-19 pneumonia were randomized 2:1 to receive oral reparixin 1200 mg three times daily or placebo for up to 21 days or until hospital discharge. The primary endpoint was the proportion of patients alive and free of respiratory failure at Day 28, with key secondary endpoints being the proportion of patients free of respiratory failure at Day 60, incidence of intensive care unit (ICU) admission by Day 28 and time to recovery by Day 28. Results: Of 279 patients randomized, 182 received at least one dose of reparixin and 88 received placebo. The proportion of patients alive and free of respiratory failure at Day 28 was similar in the two groups {83.5% versus 80.7%; odds ratio 1.63 [95% confidence interval (CI) 0.75, 3.51]; p = 0.216}. There were no statistically significant differences in the key secondary endpoints, but a numerically higher proportion of patients in the reparixin group were alive and free of respiratory failure at Day 60 (88.7% versus 84.6%; p = 0.195), fewer required ICU admissions by Day 28 (15.8% versus 21.7%; p = 0.168), and a higher proportion recovered by Day 28 compared with placebo (81.6% versus 74.9%; p = 0.167). Fewer patients experienced adverse events with reparixin than placebo (45.6% versus 54.5%), most mild or moderate intensity and not related to study treatment. Conclusions: This trial did not meet the primary efficacy endpoints, yet reparixin showed a trend toward limiting disease progression as an add-on therapy in COVID-19 severe pneumonia and was well tolerated. Trial registration: ClinicalTrials.gov: NCT04878055, EudraCT: 2020-005919-51

Matching microscopic and macroscopic responses in glasses

Primero reproducimos en las computadoras Janus y Janus II un experimento importante que mide la longitud de la coherencia de los hilados de vidrio a través de la reducción de las barreras de energía libre inducidas por el efecto Zeeman. En segundo lugar, determinamos el comportamiento de escala que permite un análisis cuantitativo de un nuevo experimento informado en la Carta complementaria [S. Guchhait y R. Orbach, Phys. Rev. Lett. 118, 157203 (2017)]. El valor de la longitud de coherencia estimada a través del análisis de las funciones de correlación microscópicas resulta ser cuantitativamente consistente con su medición a través de las funciones de respuesta macroscópica. Además, las susceptibilidades no lineales, recientemente medidas en líquidos formadores de vidrio, se escalan como potencias de la misma longitud microscópica.We first reproduce on the Janus and Janus II computers a milestone experiment that measures the spin glass coherence length through the lowering of free-energy barriers induced by the Zeeman effect. Secondly, we determine the scaling behavior that allows a quantitative analysis of a new experiment reported in the companion Letter [S. Guchhait and R. Orbach, Phys. Rev. Lett. 118, 157203 (2017)]. The value of the coherence length estimated through the analysis of microscopic correlation functions turns out to be quantitatively consistent with its measurement through macroscopic response functions. Further, nonlinear susceptibilities, recently measured in glass-forming liquids, scale as powers of the same microscopic length.• European Research Council. Beca No. NPRGGLASS. Ayuda para Marco Baity Jesi • Unión Europea. Marie Skłodowska- Curie. Beca No. 654971 • Consejo Europeo de Investigación (ERC). Subvención 694925 • University of Syracuse. Beca No. NSF-DMR-305184, para David Yllanes Mosquera • Ministerio de Economía y Competitividad. No. FIS2012-35719-C02, No. FIS2013-42840-P (I+D+i), No. FIS2015-65078-C2, No. FIS2016-76359-P (I+D+i), y No. TEC2016-78358-R • Junta de Extremadura y Fondos FEDER. Contrato parcial GRU10158 • Dipùtación General de Aragón y Fondos Social Europeo. AyudapeerReviewe