Design and manufacturing of WAAM parts to consolidate new R+D metal AM capabilities at CIM UPC's pilot plant

La fabricació additiva i la robòtica són dues tecnologies que han experimentat una evolució impressionant en els darrers anys. Quan es combinen, permeten resoldre nombroses tasques industrials en diversos camps com l'aeroespacial, l'automòbil o qualsevol sector que requereixi una fabricació o modificació precisa d'una peça. Proporciona un procés d'implementació ràpid, una programació robòtica fàcil i un ús òptim de la cinemàtica del robot per a un control de moviment superior. La fabricació additiva amb arc de filferro (WAAM) és una de les tècniques d'impressió 3D que s'utilitza per fabricar peces metàl·liques utilitzant un arc elèctric, y està en constant evolució. El tema de la meva investigació és establir una manera d'imprimir una peça de plàstic d'una forma desitjada simulant la tecnologia WAAM i realitzar proves mecàniques en les mostres impreses per comparar-les amb productes fabricats de manera convencional del mateix tipus. Per fer-ho, vaig fer servir un cobot UR10e de Universal Robot, combinat amb una eina d'impressió de filament de plàstic d'una impressora 3D Epsilon W27 de BCN3D. L'ús del filament de plàstic és el punt de partida d'un projecte futur que es centra després en l'ús del filament metàl·lic per imprimir peces. Els experiments han portat a una sèrie d'intents d'impressió, estudiant un paràmetre d'impressió a la vegada. La primera sèrie no va portar a impressió reeixides a causa de la distància entre capes i entre passes eren massa grans, portant a discontinuïtats en la trajectòria d'eina i acabat de superfície pobre. Per a la següent sèrie, les opcions d'impressió van ser optimitzades, i les peces impreses van ser molt més precises.La fabricación aditiva y la robótica son dos tecnologías que han experimentado una evolución impresionante en los últimos años. Cuando se combinan, permiten resolver numerosas tareas industriales en varios campos como el aeroespacial, la automoción o cualquier sector que requiera una fabricación o modificación precisa de una pieza. Proporciona un proceso de implementación rápido, una programación robótica fácil y un uso óptimo de la cinemática del robot para un control de movimiento superior. La fabricación aditiva con arco eléctrico (WAAM) es una de las técnicas de impresión 3D que se utiliza para fabricar piezas metálicas, y está en constante evolución. El tema de mi investigación es establecer una manera de imprimir una pieza de plástico de una forma deseada simulando la tecnología WAAM usando un robot colaborativo y realizar pruebas mecánicas en las muestras impresas para compararlas con productos fabricados de manera convencional del mismo tipo. Para ello, utilicé un cobot UR10e de Universal Robot, combinado con una herramienta de impresión de filamento de plástico de una impresora 3D Epsilon W27 de BCN3D. El uso del filamento de plástico es el punto de partida de un proyecto futuro que se centra luego en el uso del filamento metálico para imprimir piezas. Los experimentos han llevado a una serie de intentos de impresiones, estudiando un parámetro de impresión a la vez. La primera serie no dio lugar a impresiones exitosas debido a que la distancia entre capas y entre pasadas era demasiado grande, lo que causaba discontinuidades en la trayectoria de la herramienta y un acabado superficial pobre. Para la serie siguiente, las configuraciones de impresión se optimizaron y las piezas impresas fueron mucho más precisas.Additive manufacturing and robotics are two technologies which have undergone a dazzling evolution over the last few years. When combined, they allow the resolution of numerous industrial tasks in various fields such as aerospace, automobile, or any sector that requires a precise manufacturing or modification of a workpiece. It provides a fast process implementation, an easy robotic programming, and an optimal use of the robot’s kinematics for superior motion control. Wire arc additive manufacturing (WAAM) is one of the 3D printing techniques that is used to manufacture metallic parts using an electric arc, and it is in constant evolution. The subject of my research is about setting up a way to print a plastic part of a desired shape simulating the WAAM technology with a collaborative robot and perform mechanical tests on the printed samples to compare them with conventional manufactured products of the same kind. To do so, I used a UR10e cobot from Universal Robot, combined with a plastic filament printing toolhead of an Epsilon W27 3D printer from BCN3D. The use of plastic filament is the starting point of a future project focusing then on the use of metallic filament to print parts. The experiments have led to a series of attempts of prints, studying a parameter of impression at a time. The first series did not lead to successful prints because of the distance between layers and between passes were too big, leading to discontinuities in the toolpath and poor surface finish. For the following series, the printing settings were optimized, and the printed pieces were much more accurate.Incomin

On the Degrees of Freedom and Eigenfunctions of Line-of-Sight Holographic MIMO Communications

We consider a line-of-sight communication link between two holographic surfaces (HoloSs). We provide a closed-form expression for the number of effective degrees of freedom (eDoF), i.e., the number of orthogonal communication modes that can be established between the HoloSs. The framework can be applied to general network deployments beyond the widely studied paraxial setting. This is obtained by utilizing a quartic approximation for the wavefront of the electromagnetic waves, and by proving that the number of eDoF corresponds to an instance of Landau's eigenvalue problem applied to a bandlimited kernel determined by the quartic approximation of the wavefront. The proposed approach overcomes the limitations of the widely utilized parabolic approximation for the wavefront, which provides inaccurate estimates in non-paraxial deployments. We specialize the framework to typical network deployments, and provide analytical expressions for the optimal, according to Kolmogorov's $N$-width criterion, basis functions (communication waveforms) for optimal data encoding and decoding. With the aid of numerical analysis, we validate the accuracy of the closed-form expressions for the number of eDoF and waveforms.Comment: Submitted for journal publicatio

Masking Dilithium: Efficient Implementation and Side-Channel Evaluation

Although security against side-channel attacks is not an explicit design criterion of the NIST post-quantum standardization effort, it is certainly a major concern for schemes that are meant for real-world deployment. In view of the numerous physical attacks that have been proposed against post-quantum schemes in recent literature, it is in particular very important to evaluate the cost and effectiveness of side-channel countermeasures in that setting. For lattice-based signatures, this work was initiated by Barthe et al., who showed at EUROCRYPT 2018 how to apply arbitrary order masking to the GLP signature scheme presented at CHES 2012 by Güneysu, Lyubashevsky and Pöppelman. However, although Barthe et al.’s paper provides detailed proofs of security in the probing model of Ishai, Sahai and Wagner, it does not include practical side-channel evaluations, and its proof-of-concept implementation has limited efficiency. Moreover, the GLP scheme has historical significance but is not a NIST candidate, nor is it being considered for concrete deployment. In this paper, we look instead at Dilithium, one of the most promising NIST candidates for postquantum signatures. This scheme, presented at CHES 2018 by Ducas et al. and based on module lattices, can be seen as an updated variant of both GLP and its more efficient sibling BLISS; it comes with an implementation that is both efficient and constant-time. Our analysis of Dilithium from a side-channel perspective is threefold. We first evaluate the side-channel resistance of an ARM Cortex-M3 implementation of Dilithium without masking, and identify exploitable side-channel leakage. We then describe how to securely mask the scheme, and verify that the masked implementation no longer leaks. Finally, we show how a simple tweak to Dilithium (namely, replacing the prime modulus by a power of two) makes it possible to obtain a considerably more efficient masked scheme, by a factor of 7.3 to 9 for the most time-consuming masking operations, without affecting security

International criteria for electrocardiographic interpretation in athletes: Consensus statement.

Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly, advanced by a growing body of scientific data and investigations that both examine proposed criteria sets and establish new evidence to guide refinements. On 26-27 February 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington (USA), to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD

LSST: from Science Drivers to Reference Design and Anticipated Data Products

(Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg$^2$ field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5$\sigma$ point-source depth in a single visit in $r$ will be $\sim 24.5$ (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg$^2$ with $\delta<+34.5^\circ$, and will be imaged multiple times in six bands, $ugrizy$, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg$^2$ region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to $r\sim27.5$. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

Perceptual abstraction and attention

This is a report on the preliminary achievements of WP4 of the IM-CleVeR project on abstraction for cumulative learning, in particular directed to: (1) producing algorithms to develop abstraction features under top-down action influence; (2) algorithms for supporting detection of change in motion pictures; (3) developing attention and vergence control on the basis of locally computed rewards; (4) searching abstract representations suitable for the LCAS framework; (5) developing predictors based on information theory to support novelty detection. The report is organized around these 5 tasks that are part of WP4. We provide a synthetic description of the work done for each task by the partners

Novelty detection and learning drives

This document presents Deliverable 5.1 of the IM-CLeVeR (Intrinsically Motivated Cumulative Learning Versatile Robots) EU FP7 project. It represents one of two deliverables from Workpackage 5 (Novelty Detection and Drives for Autonomous Learning)

Optimized EGFR blockade strategies in <i>EGFR</i> addicted gastroesophageal adenocarcinomas

Purpose: Gastric and gastroesophageal adenocarcinomas represent the third leading cause of cancer mortality worldwide. Despite significant therapeutic improvement, the outcome of patients with advanced gastroesophageal adenocarcinoma is poor. Randomized clinical trials failed to show a significant survival benefit in molecularly unselected patients with advanced gastroesophageal adenocarcinoma treated with anti-EGFR agents.Experimental Design: We performed analyses on four cohorts: IRCC (570 patients), Foundation Medicine, Inc. (9,397 patients), COG (214 patients), and the Fondazione IRCCS Istituto Nazionale dei Tumori (206 patients). Preclinical trials were conducted in patient-derived xenografts (PDX).Results: The analysis of different gastroesophageal adenocarcinoma patient cohorts suggests that EGFR amplification drives aggressive behavior and poor prognosis. We also observed that EGFR inhibitors are active in patients with EGFR copy-number gain and that coamplification of other receptor tyrosine kinases or KRAS is associated with worse response. Preclinical trials performed on EGFR-amplified gastroesophageal adenocarcinoma PDX models revealed that the combination of an EGFR mAb and an EGFR tyrosine kinase inhibitor (TKI) was more effective than each monotherapy and resulted in a deeper and durable response. In a highly EGFR-amplified nonresponding PDX, where resistance to EGFR drugs was due to inactivation of the TSC2 tumor suppressor, cotreatment with the mTOR inhibitor everolimus restored sensitivity to EGFR inhibition.Conclusions: This study underscores EGFR as a potential therapeutic target in gastric cancer and identifies the combination of an EGFR TKI and a mAb as an effective therapeutic approach. Finally, it recognizes mTOR pathway activation as a novel mechanism of primary resistance that can be overcome by the combination of EGFR and mTOR inhibitors

Mislocalization of CDK11/PITSLRE, a regulator of the G2/M phase of the cell cycle, in Alzheimer disease

Post-mitotic neurons are typically terminally differentiated and in a quiescent status. However, in Alzheimer disease (AD), many neurons display ectopic re-expression of cell cycle-related proteins. Cyclin-dependent kinase 11 (CDK11) mRNA produces a 110-kDa protein (CDK11(p110)) throughout the cell cycle, a 58-kDa protein (CDK11(p58)) that is specifically translated from an internal ribosome entry site and expressed only in the G(2)/M phase of the cell cycle, and a 46-kDa protein (CDK11(p46)) that is considered to be apoptosis specific. CDK11 is required for sister chromatid cohesion and the completion of mitosis. In this study, we found that the expression patterns of CDK11 vary such that cytoplasmic CDK11 is increased in AD cellular processes, compared to a pronounced nuclear expression pattern in most controls. We also investigated the effect of amyloid precursor protein (APP) on CDK11 expression in vitro by using M17 cells overexpressing wild-type APP and APP Swedish mutant phenotype and found increased CDK11 expression compared to empty vector. In addition, amyloid-beta(25-35) resulted in increased CDK11 in M17 cells. These data suggest that CDK11 may play a vital role in cell cycle re-entry in AD neurons in an APP-dependent manner, thus presenting an intriguing novel function of the APP signaling pathway in AD