123 research outputs found

    DeepDeMod: BPSK Demodulation Using Deep Learning Over Software-Defined Radio

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    In wireless communication, signal demodulation under non-ideal conditions is one of the important research topic. In this paper, a novel non-coherent binary phase shift keying demodulator based on deep neural network, namely DeepDeMod, is proposed. The proposed scheme makes use of neural network to decode the symbols from the received sampled signal. The proposed scheme is developed to demodulate signal under fading channel with additive white Gaussian noise along with hardware imperfections, such as phase and frequency offset. The time varying nature of hardware imperfections and channel poses a additional challenge in signal demodulation. In order to address this issue, additionally we propose transfer learning based DeepDeMod scheme. Pilot symbols along with data is transmitted in a packet which is used to learn the time varying parameters from the pilot reception followed by data demodulation. Results show that compared with the conventional demodulators and other machine learning based demodulators, our proposed DeepDeMod provides significantly better performance in term of bit error rate. We also implement the proposed DeepDeMod on software defined radio and present the experimental results

    Many-core and heterogeneous architectures: programming models and compilation toolchains

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    1noL'abstract Ăš presente nell'allegato / the abstract is in the attachmentopen677. INGEGNERIA INFORMATInopartially_openembargoed_20211002Barchi, Francesc

    Aspects of learning within networks of spiking neurons

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    Spiking neural networks have, in recent years, become a popular tool for investigating the properties and computational performance of large massively connected networks of neurons. Equally as interesting is the investigation of the potential computational power of individual spiking neurons. An overview is provided of current and relevant research into the Liquid Sate Machine, biologically inspired artificial STDP learning mechanisms and the investigation of aspects of the computational power of artificial, recurrent networks of spiking neurons. First, it is shown that, using simple structures of spiking Leaky Integrate and Fire (LIF) neurons, a network n(P), can be built to perform any program P that can be performed by a general parallel programming language. Next, a form of STDP learning with normalisation is developed, referred to as STDP + N learning. The effects of applying this STDP + N learning within recurrently connected networks of neurons is then investigated. It is shown experimentally that, in very specific circumstances Anti-Hebbian and Hebbian STDP learning may be considered to be approximately equivalent processes. A metric is then developed that can be used to measure the distance between any two spike trains. The metric is then used, along with the STDP + N learning, in an experiment to examine the capacity of a single spiking neuron that receives multiple input spike trains, to simultaneously learn many temporally precise Input/Output spike train associations. The STDP +N learning is further modified for use in recurrent networks of spiking neurons, to give the STDP + NType2 learning methodology. An experiment is devised which demonstrates that the Type 2 method of applying learning to the synapses of a recurrent network — effectively a randomly shifting locality of learning — can enable the network to learn firing patterns that the typical application of learning is unable to learn. The resulting networks could, in theory, be used to create to simple structures discussed in the first chapter of original work.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Deep learning for time series classification

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    Time series analysis is a field of data science which is interested in analyzing sequences of numerical values ordered in time. Time series are particularly interesting because they allow us to visualize and understand the evolution of a process over time. Their analysis can reveal trends, relationships and similarities across the data. There exists numerous fields containing data in the form of time series: health care (electrocardiogram, blood sugar, etc.), activity recognition, remote sensing, finance (stock market price), industry (sensors), etc. Time series classification consists of constructing algorithms dedicated to automatically label time series data. The sequential aspect of time series data requires the development of algorithms that are able to harness this temporal property, thus making the existing off-the-shelf machine learning models for traditional tabular data suboptimal for solving the underlying task. In this context, deep learning has emerged in recent years as one of the most effective methods for tackling the supervised classification task, particularly in the field of computer vision. The main objective of this thesis was to study and develop deep neural networks specifically constructed for the classification of time series data. We thus carried out the first large scale experimental study allowing us to compare the existing deep methods and to position them compared other non-deep learning based state-of-the-art methods. Subsequently, we made numerous contributions in this area, notably in the context of transfer learning, data augmentation, ensembling and adversarial attacks. Finally, we have also proposed a novel architecture, based on the famous Inception network (Google), which ranks among the most efficient to date.Comment: PhD thesi

    Automated application-specific optimisation of interconnects in multi-core systems

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    In embedded computer systems there are often tasks, implemented as stand-alone devices, that are both application-specific and compute intensive. A recurring problem in this area is to design these application-specific embedded systems as close to the power and efficiency envelope as possible. Work has been done on optimizing singlecore systems and memory organisation, but current methods for achieving system design goals are proving limited as the system capabilities and system size increase in the multi- and many-core era. To address this problem, this thesis investigates machine learning approaches to managing the design space presented in the interconnect design of embedded multi-core systems. The design space presented is large due to the system scale and level of interconnectivity, and also feature inter-dependant parameters, further complicating analysis. The results presented in this thesis demonstrate that machine learning approaches, particularly wkNN and random forest, work well in handling the complexity of the design space. The benefits of this approach are in automation, saving time and effort in the system design phase as well as energy and execution time in the finished system

    SystÚme de détection de mouvements complexes de la main à partir des signaux EMG, pour le contrÎle d'une prothÚse myoélectrique

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    Les avancĂ©es technologiques en ingĂ©nierie biomĂ©dicale Ă  travers le monde permettent le dĂ©veloppement de systĂšmes automatisĂ©s et adaptĂ©s, visant Ă  fournir aux personnes vivant avec un handicap un meilleur confort de vie. Les prothĂšses intelligentes basĂ©es sur l'activitĂ© myoĂ©lectrique permettent aux personnes amputĂ©es d'interagir intuitivement avec leur environnement et d'effectuer des activitĂ©s de la vie quotidienne. Des Ă©lectrodes placĂ©es sur la surface de la peau et une Ă©lectronique embarquĂ©e dĂ©diĂ©e recueillent les signaux musculaires et les traduisent en commandes pour piloter les actionneurs de la prothĂšse. Atteindre une performance accrue tout en diminuant le coĂ»t des prothĂšses myoĂ©lectriques est une Ă©tape importante dans l'ingĂ©nierie de rĂ©adaptation. Les mains prothĂ©tiques, actuellement disponibles Ă  travers le monde, bĂ©nĂ©ficieraient d'un contrĂŽle plus efficace et plus intuitif. Ce mĂ©moire prĂ©sente une approche en temps rĂ©el pour classifier les mouvements des doigts Ă  l’aide des signaux d'Ă©lectromyographie (EMG) de surface. Une plateforme multicanale d'acquisition de signaux, de notre conception, est utilisĂ©e pour enregistrer 7 canaux EMG provenant de l'avant-bras. La classification des signaux EMG est effectuĂ©e en temps rĂ©el, en utilisant une approche d'analyse discriminante linĂ©aire. Treize mouvements de la main peuvent ĂȘtre identifiĂ©s avec une prĂ©cision allant jusqu'Ă  95,8% et de 92,7% en moyenne pour 8 participants, avec une prĂ©diction mise Ă  jour toutes les 192 ms. L'approche a voulu ĂȘtre adaptĂ©e pour crĂ©er un systĂšme embarquĂ© ouvrant de grandes opportunitĂ©s pour le dĂ©veloppement des prothĂšses myoĂ©lectriques lĂ©gĂšres, peu coĂ»teuses et plus intuitives.Technological advances in biomedical engineering worldwide enable the development of automated and patient-friendly systems, aiming at providing the severely disabled a better comfort of life. Intelligent prostheses based on myoelectric activity allow amputees to intuitively interact with their environment and perform daily life activities. Electrodes placed on the surface of the skin, and dedicated embedded electronics allow to collect muscle signals and translate them into commands to drive a prosthesis actuators. Increasing performance while decreasing the cost of surface electromyography (sEMG) prostheses is an important milestone in rehabilitation engineering. The prosthetic hands that are currently available to patients worldwide would benefit from more effective and intuitive control. This memoir presents a real-time approach to classify finger motions based on sEMG signals. A multichannel signal acquisition platform of our design is used to record forearm sEMG signals from 7 channels. sEMG pattern classification is performed in real time, using a Linear Discriminant Analysis (LDA) approach. Thirteen hand motions can be successfully identified with an accuracy of up to 95.8% and of 92.7% on average for 8 participants, with an updated prediction every 192 ms. The approach wanted to be adapted to create an embedded system opening great opportunities for the development of lightweight, inexpensive and more intuitive electromyographic hand prostheses

    Architecture de communication pour les rĂ©seaux d’instrumentation sans fil

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    Aujourd'hui les réseaux de capteurs sont devenus des systÚmes pouvant atteindre un trÚs grand nombre de noeuds, avec une zone de couverture déterminée et déployés d'une maniÚre plus ou moins dense dans un environnement hétérogÚne dont on mesure ainsi son état global. La problématique de cette thÚse consiste à concevoir une architecture pour les objets communicants à faible consommation en utilisant des antennes « intelligentes » pour l'instrumentation et la mesure. Intégrant une approche pluridisciplinaire, cette architecture couvre les services offerts depuis les couches MAC jusqu'à celles de plus haut niveau. Basés sur une partie matérielle complÚtement reconfigurable (amplificateur de puissance et antennes à base de MEMS RF), les services des couches supérieures sont définis en partie sur circuits numériques pour la couche physique (bande de base) et la couche MAC, et de maniÚre logicielle pour les protocoles de routages adaptés et les services innovants. En résumé, le travail consiste à concevoir un systÚme autonome multi capteurs, d'acquisition et de traitement avec mémorisation, communicant à travers un réseau sans fil. Les principaux problÚmes à résoudre seront : le contrÎle de la topologie, la précision de la synchronisation, la consommation d'énergie. ABSTRACT : Researches in the field of sensor networks show the variety and vastness of applications in which these types of systems are used. One of their main features is the large number (up to hundreds of elements) of sensors that must be distributed in different environments. Another concern consists in making routing decisions in order to reduce the energy consumption. Depending on the application requirements, ensuring synchronous network functionality is currently a challenge. The issue addressed in this thesis is to develop an architecture for smart objects using low-power antennas for structural heald monitoring. Integrating a multidisciplinary approach, this architecture includes services from the MAC layer to those of the highest level. In summary, we will develop an autonomous system ofi sensors, for acquisition and information processing, which communicate via a wireless network. The main problems are: the control of topology, the timing accuracy and the energy consumption

    ContrÎle intégré du pilotage d'atelier et de la qualité des produits. : Application à la société ACTA mobilier.

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    Centre de Recherche en Automatique de Nancy. The idea is to take advantage of Product Driven System in an industrial environment disturbed by many loops and a rework rate (non quality) causing significant loss of products, non-compliance deadlines, unstable workloads, etc ... impossible link between the product and identifying infotronic lead to more difficult traceability. Work on scheduling and optimization are hampered by these disturbances on the production line that make them untenable schedules. Priority processing on defective products ensures a service rate that remains outstanding compared to the percentage of products to repair. But it also leads to loss of products that prevent the full delivery of the order. The scientific problem revolves around the control of flow in a production context disturbed by the loops and the quality level by assessing its impact on congestion.The quality-control issue has been addressed by using neural networks that can predict the occurrence of the defect to which they are dedicated from production and environmental parameters. This anticipation allows us to offer a program alternative to use or to plan to postpone the task. The adaptation of the forecasting model to the drift of the physical model with a behavior regarded as nervous is made "on line" using control charts that detect drift and its start date.Despite this simplification of flows, the flow control remains complex due to normal production loops and residual nonqualities. There are different system saturation states for which the most suitable control rule is not always the same. This analysis is presented in a two-dimensional mapping which each axis has a key indicator on non-quality rate and / or disruption of flows.Although, unlike algorithms, the most suitable control rule will not always be highlighted, this mapping has other advantages such as the simplification of the control, the ability for all users to have important information about the workshop state, or the need for homogenization of the global state of the production unit.In this context, the intelligent container offers interesting perspectives with the will to trace a group of products with the same rooting sheet rather than products one by one, to share information such as its delivery date, the urgency degree, to know what paths they should take and what are the possible alternatives or to communicate with other machines and systems including the quality forecasting system and retain information over the manufacture of the products. The proposed system is so interactive where container is at the heart of the decision. It reported his presence to scheduling system only if the quality system requirements are met, and simplify this work while allowing a traditional linear algorithm to achieve this task seen as particularlycomplicated at first. It is however the responsibility of the scheduler to ensure the pilot rule to use and request the relevant information available to the lots. The contribution of this thesis is a methodology to simplify complex problems by a division of work between different subsystems actors applied to the case of a manufacturer of high-finished lacquered panels.Cette thĂšse CIFRE s’inscrit dans le cadre d’une collaboration entre Acta-Mobilier, fabricant de façades laquĂ©es haut de gamme, et le Centre de Recherche en Automatique Nancy. L’idĂ©e est de tirer parti du concept de SystĂšme ContrĂŽlĂ© par le Produit dans un environnement industriel perturbĂ© par de nombreuses boucles de production et par un taux de reprises (non-qualitĂ©s) non nĂ©gligeable engendrant des pertes de piĂšces, le non-respect des dĂ©lais, des charges de travail instables, etc
 le lien impossible entre le produit et un identifiant infotronique rendant en plus la traçabilitĂ© difficile. Les travaux sur l’ordonnancementet son optimisation sont freinĂ©s par ces perturbations sur la chaĂźne de production qui rendent les plannings intenables. Le traitement prioritaire des piĂšces dĂ©fectueuses permet d’assurer un taux de service qui reste remarquable au regard du pourcentage de piĂšces Ă  rĂ©parer. Mais cela engendre aussi des pertes de piĂšces qui empĂȘchent la livraison complĂšte de la commande. La problĂ©matique scientifique s’articule autour du pilotage des flux dans un contexte de production perturbĂ© par les reprises et de la maĂźtrise de la qualitĂ© en Ă©valuant son impact sur l’engorgement. L’enjeu de maĂźtrise de la qualitĂ© a Ă©tĂ© abordĂ© Ă  l’aide de rĂ©seaux de neurones capables de prĂ©voir l’apparition du dĂ©faut auquel ils sont dĂ©diĂ©s en fonction des paramĂštres de production et environnementaux. Cette anticipation permet de proposer une alternative de programme Ă  utiliser ou Ă  reporter la planification de la tĂąche. L’adaptation du modĂšle de prĂ©vision aux dĂ©rives du modĂšle physique au comportement considĂ©rĂ© comme nerveux est rĂ©alisĂ©e « en-ligne » Ă  l’aide de cartes de contrĂŽle qui permettent de dĂ©tecter la dĂ©rive et sa date de dĂ©but.MalgrĂ© cette simplification des flux, le pilotage reste complexe en raison des boucles normales de production et des non qualitĂ©s rĂ©siduelles. Il existe diffĂ©rents Ă©tats de saturation du systĂšme pour lesquels la rĂšgle de pilotage la plus adaptĂ©e n’est pas toujours la mĂȘme. Cette analyse est prĂ©sentĂ©e sous forme de cartographie en deux dimensions dont chacun des axes prĂ©sente un indicateur clĂ© du taux de non-qualitĂ© et/ou de la perturbation des flux. MĂȘme si, contrairement aux algorithmes, la rĂšgle de pilotage la mieux adaptĂ©e ne sera pas toujours mise en Ă©vidence, cette cartographie prĂ©sente d’autres avantages tels que la simplification du pilotage, la possibilitĂ© pour tous les utilisateurs d’avoir l’information importante sur l’état de l’atelier en uncoup d’oeil, ou encore la nĂ©cessitĂ© d’homogĂ©nĂ©isation sur la globalitĂ© de l’unitĂ© de production.Dans ce contexte, le container intelligent offre des perspectives intĂ©ressantes avec la volontĂ© de tracer un groupe de produits ayant la mĂȘme gamme de fabrication plutĂŽt que des produits un Ă  un, de partager des informations telles que sa date de livraison, son degrĂ© d’urgence, de connaĂźtre quels chemins ils doivent emprunter dans l’atelier et quelles sont les alternatives possibles ou encore de communiquer avec les machines et les autres systĂšmes dont celui de prĂ©vision de la qualitĂ© et retenir des informations au fil de la fabrication des produits. Le systĂšme proposĂ© est donc interactif ou le conteneur est au coeur de la dĂ©cision. Il signale sa prĂ©sence au systĂšme d’ordonnancement seulement si les conditions qualitĂ© sont rĂ©unies, permettant ainsi de simplifier sontravail autorisant alors un simple algorithme traditionnel de programmation linĂ©aire Ă  rĂ©aliser cette tĂąche particuliĂšrement compliquĂ©e au premier abord. C’est en revanche Ă  la charge de l’ordonnanceur de s’assurer de la rĂšgle de pilotage Ă  utiliser et de demander les informations correspondantes aux lots disponibles.La contribution de cette thĂšse est donc une mĂ©thodologie de simplification de problĂšmes complexes par une rĂ©partition des tĂąches entre diffĂ©rents sous-systĂšmes acteurs appliquĂ©e au cas d’une entreprise de fabrication de façades de cuisine laquĂ©es haut de gamme

    Fusion multi-sources pour l'interprétation d'un environnement routier

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    Exceeding speed limits is a major cause of road accidents, which could be reduced by the use of robust detection of speed limits that may continuously inform the driver of the proper speed limitation. The work presented in this document relate to the achievement of such a system based on a visual detection of speed limit signs. To make the system robust, it is necessary to merge the results of these detections with information from other sensors to interpret the results of the visual detection. For this aim, two algorithms were developed. First, a specific geographic information system was developed in order to expand the electronic horizon of the vehicle. The fusion process in place addressing these various sources of information is based on model-based rules to overcome the problems inherent to the probabilistic fusion process that can sometimes lead to uncertain situations putting the whole system in global fault. These works are the fruit of collaboration with an automotive supplier and the prototype has been validated experimentally on the road and in real conditions. A ground truth tool has been specially developed to quantify the results. The system shows excellent results with high detection and classification rates for speed limit signs recognition and complex situations analysis.Le dĂ©passement des limitations de vitesse est l'une des causes majeures des accidents de la route, qui pourraient ĂȘtre rĂ©duits par l'utilisation de systĂšme robuste de dĂ©tection des limitations de vitesse pouvant continuellement informer le conducteur de la bonne limitation imposĂ©e. Les travaux prĂ©sentĂ©s dans ce document portent sur la rĂ©alisation d'un tel systĂšme basĂ© sur une dĂ©tection visuelle des panneaux de limitation de vitesse. Afin de rendre le systĂšme robuste, il est nĂ©cessaire de fusionner les rĂ©sultats de ces dĂ©tections avec les informations d'autres capteurs pour interprĂ©ter les rĂ©sultats issus de la dĂ©tection visuelle. C'est ainsi qu'a Ă©tĂ© entre autre spĂ©cialement dĂ©veloppĂ© un capteur cartographique permettant d'avoir une vision plus large sur l'horizon Ă©lectronique du vĂ©hicule, ainsi qu'un systĂšme dĂ©tection des lignes de marquage au sol pour analyser les changements de voie. Le processus de fusion mis en place traitant ces diverses sources d'information est fondĂ© sur des modĂšles Ă  base de rĂšgles permettant de s'affranchir des problĂšmes inhĂ©rents aux processus de fusion probabilistes pouvant parfois mener Ă  des situations de doute mettant le systĂšme global en faute. Ces travaux sont le fruit d'une collaboration avec un industriel et le prototype dĂ©veloppĂ© a Ă©tĂ© validĂ© expĂ©rimentalement sur route. Un outil de vĂ©ritĂ© terrain a Ă©tĂ© spĂ©cialement dĂ©veloppĂ© pour quantifier les rĂ©sultats. Le systĂšme montre d'excellents rĂ©sultats en dĂ©tection et reconnaissance des panneaux de limitation de vitesse ainsi que dans la clarification de situations complexes
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