End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium. The early approaches for hand gesture recognition used device-based methods. These methods use mechanical or optical sensors attached to a glove or markers, which hinders the natural human-machine communication. On the other hand, vision-based methods are not restrictive and allow for a more spontaneous communication without the need of an intermediary between human and machine. Therefore, vision gesture recognition has been a popular area of research for the past thirty years. Hand gesture recognition finds its application in many areas, particularly the automotive industry where advanced automotive human-machine interface (HMI) designers are using gesture recognition to improve driver and vehicle safety. However, technology advances go beyond active/passive safety and into convenience and comfort. In this context, one of America’s big three automakers has partnered with the Centre of Pattern Analysis and Machine Intelligence (CPAMI) at the University of Waterloo to investigate expanding their product segment through machine learning to provide an increased driver convenience and comfort with the particular application of hand gesture recognition for autonomous car parking. In this thesis, we leverage the state-of-the-art deep learning and optimization techniques to develop a vision-based multiview dynamic hand gesture recognizer for self-parking system. We propose a 3DCNN gesture model architecture that we train on a publicly available hand gesture database. We apply transfer learning methods to fine-tune the pre-trained gesture model on a custom-made data, which significantly improved the proposed system performance in real world environment. We adapt the architecture of the end-to-end solution to expand the state of the art video classifier from a single image as input (fed by monocular camera) to a multiview 360 feed, offered by a six cameras module. Finally, we optimize the proposed solution to work on a limited resources embedded platform (Nvidia Jetson TX2) that is used by automakers for vehicle-based features, without sacrificing the accuracy robustness and real time functionality of the system

Optimized Neural Networks-PID Controller with Wind Rejection Strategy for a Quad-Rotor

In this paper a full approach of modeling and intelligent control of a four rotor unmanned air vehicle (UAV) known as quad-rotor aircraft is presented. In fact, a PID on-line optimized Neural Networks Approach (PID-NN) is developed to be applied to angular trajectories control of a quad-rotor. Whereas, PID classical controllers are dedicated for the positions, altitude and speed control. The goal of this work is to concept a smart Self-Tuning PID controller, for attitude angles control, based on neural networks able to supervise the quad-rotor for an optimized behavior while tracking a desired trajectory.  Many challenges could arise if the quad-rotor is navigating in hostile environments presenting irregular disturbances in the form of wind modeled and applied to the overall system. The quad-rotor has to quickly perform tasks while ensuring stability and accuracy and must behave rapidly with regards to decision making facing disturbances. This technique offers some advantages over conventional control methods such as PID controller. Simulation results are founded on a comparative study between PID and PID-NN controllers based on wind disturbances. These later are applied with several degrees of strength to test the quad-rotor behavior and stability. These simulation results are satisfactory and have demonstrated the effectiveness of the proposed PD-NN approach. In fact, the proposed controller has relatively smaller errors than the PD controller and has a better capability to reject disturbances. In addition, it has proven to be highly robust and efficient face to turbulences in the form of wind disturbances

Parallel Execution of ATL Transformation Rules

International audienceIndustrial environments that make use of Model-Driven Engineering (MDE) are starting to see the appearance of very large models, made by millions of elements. Such models are produced automatically (e.g., by reverse engineering complex systems) or manually by a large number of users (e.g., from social networks). The success of MDE in these application scenarios strongly depends on the scalability of model manipulation tools. While parallelization is one of the traditional ways of making computation systems scalable, developing parallel model transformations in a general-purpose language is a complex and error-prone task. In this paper we show that rule-based languages like ATL have strong parallelization properties. Transformations can be developed without taking into account concurrency concerns, and a transformation engine can automatically parallelize execution. We describe the implementation of a parallel transformation engine for the current version of the ATL language and experimentally evaluate the consequent gain in scalability

A Software Testbed for Assessing Human-Robot Verbal Interaction

Verbal interaction provides a natural and social-style interaction mode by which robots can communicate with general public who is likely unknowledgeable in robotics. This interaction mechanism is also very important for a broad range of users such as hands/eyes-busy users, motor-impaired users, users with vision impairment and users working in hostile environments. Verbal interaction is very popular in robotics especially in personal assistive robots, which are used to help elderly people and in entertainment robots. Several research endeavors have been assigned to endow the robots with verbal interaction as a high-level faculty. However, the language usages of many of them were simple and may not be considered as full speech dialogue systems providing natural language understanding. In this thesis, we investigate a testbed platform that can be deployed to enable human-robot verbal interaction. The proposed approach encompasses a design pattern-based user interface and a user-independent automatic speech recognizer with a modified grammar module in the context of human-robot interaction. The user interface is used to simulate robots response toward multiple users’ voice commands. The performance of the proposed testbed has been evaluated quantitatively using a set of evaluation metrics such as word correct rate, recognition time and success and false action rates. The conducted experiments show the promising features of the system. The results obtained could be refined even further by training the system for more voice commands and the whole system could be ported to real robotic platforms such as Peoplebot to endow it with natural language understanding

Vertex Downgrading to Minimize Connectivity

We consider the problem of interdicting a directed graph by deleting nodes with the goal of minimizing the local edge connectivity of the remaining graph from a given source to a sink. We introduce and study a general downgrading variant of the interdiction problem where the capacity of an arc is a function of the subset of its endpoints that are downgraded, and the goal is to minimize the downgraded capacity of a minimum source-sink cut subject to a node downgrading budget. This models the case when both ends of an arc must be downgraded to remove it, for example. For this generalization, we provide a bicriteria (4,4)-approximation that downgrades nodes with total weight at most 4 times the budget and provides a solution where the downgraded connectivity from the source to the sink is at most 4 times that in an optimal solution. We accomplish this with an LP relaxation and rounding using a ball-growing algorithm based on the LP values. We further generalize the downgrading problem to one where each vertex can be downgraded to one of k levels, and the arc capacities are functions of the pairs of levels to which its ends are downgraded. We generalize our LP rounding to get a (4k,4k)-approximation for this case

Randomized Contractions for Multiobjective Minimum Cuts

We show that Karger\u27s randomized contraction method (SODA 93) can be adapted to multiobjective global minimum cut problems with a constant number of edge or node budget constraints to give efficient algorithms. For global minimum cuts with a single edge-budget constraint, our extension of the randomized contraction method has running time tilde{O}(n^3) in an n-node graph improving upon the best-known randomized algorithm with running time tilde{O}(n^4) due to Armon and Zwick (Algorithmica 2006). Our analysis also gives a new upper bound of O(n^3) for the number of optimal solutions for a single edge-budget min cut problem. For the case of (k-1) edge-budget constraints, the extension of our algorithm saves a logarithmic factor from the best-known randomized running time of O(n^{2k} log^3 n). A main feature of our algorithms is to adaptively choose, at each step, the appropriate cost function used in the random selection of edges to be contracted. For the global min cut problem with a constant number of node budgets, we give a randomized algorithm with running time tilde{O}(n^2), improving the current best determinisitic running time of O(n^3) due to Goemans and Soto (SIAM Journal on Discrete Mathematics 2013). Our method also shows that the total number of distinct optimal solutions is bounded by O(n^2) as in the case of global min-cuts. Our algorithm extends to the node-budget constrained global min cut problem excluding a given sink with the same running time and bound on number of optimal solutions, again improving upon the best-known running time by a factor of O(n). For node-budget constrained problems, our improvements arise from incorporating the idea of merging any infeasible super-nodes that arise during the random contraction process. In contrast to cuts excluding a sink, we note that the node-cardinality constrained min-cut problem containing a given source is strongly NP-hard using a reduction from graph bisection

Organic Geochemistry of the Cenomanian-Turonian Bahloul Formation Petroleum Source Rock, Central and Northern Tunisia

International audienceTotal organic carbon (TOC) determination, Rock-Eval pyrolysis, extractable organic matter content (EOM) fractionation, gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analyses, were carried out on 79 samples from eleven outcrop cross sections of the Bahloul Formation in central and northern Tunisia. The TOC content varied between 0.23 to 35.6%, the highest average values (18.73%, 8.46% and 4.02%) being at the east of the study area (at Ain Zakkar, Oued Bahloul and Dyr Ouled Yahia localities, respectively). The Rock-Eval maximum pyrolysis temperature (Tmax) values in the 424-453°C range delineated a general east-west trend increase in the organic matter (OM) maturity. The disparity in hydrogen index (HI) values, in the range 114-824 mg hydrocarbons (HC) g−1 TOC, is relevant for the discrepancy in the level of OM preservation and maturity among localities and samples. The n-alkane distributions, maximizing in the C17 to C20 range, are typical for a marine planktonic origin, whereas pristine/phytane (Pr/Ph) average values in the 1-2 range indicate an oxic to suboxic depositional environment. Pr/n-C17 and Ph/n-C18 ratios in the 0.38-6.2 and 0.68-3.25 range, respectively, are consistent with other maturity indicators and the contribution of specific bacteria to phytol as a precursor of isoprenoids. The thermal maturity varies between late diagenesis to main-stage of petroleum generation based on the optic and the cis-trans isomerisation of the C29 sterane [20S/(20S+20R) and 14β(H),17β(H)/(14β(H),17β(H)+14α(H),17α(H)), respectively] and the terpane [18α(H)22,29,30-Trisnorneohopane/(18α(H)22,29,30-Trisnorneohopane+17α(H)22,29,30-Trisnorhopane): Ts/(Ts+Tm)] ratios. The Bahloul OM is represented by an open marine to estuarine algal facies with a specific bacterial contribution as revealed by the relative abundance of the ααα-20R C27 (33-44%), C28 (22-28%) and C29 (34-41%) steranes and by the total terpanes/total steranes ratio (1.2-5.33). These results attested that the Bahloul OM richness was controlled both by an oxygen minimum zone induced by high productivity and restricted circulation in narrow half graben structures and around diapirs of the Triassic salt

Protocoles quantiques et relativistes de mise en gage

Dans la vie, on peut avoir besoin de communiquer avec des parties auxquelles on ne fait pas confiance, d'où l'importance de systèmes capables de contrôler ce type de communications. Des systèmes peuvent garantir, par exemple, un ballottage secret, des ventes aux enchères secrètes, des levées d'impôt tout en conservant l'intimité, l'authentification à distance à un ordinateur, l'aide anonyme de la police dans leurs enquêtes, etc. La cryptographie peut aider, au moins, dans quelques cas parmi ceux-ci, par la régularisation du flux d'information de telle manière qu'on n'aura plus besoin de faire confiance à l'autre partie. On fera confiance, seulement, aux systèmes cryptographiques utilisés. Une primitive, appelée mise en gage, est d'une importance suprême dans la cryptographie bipartite, où deux parties qui ne se font pas confiance essayent tout de même d'accomplir un calcul commun sur des données privées (calculer une fonction publique de leurs données secrètes). Cette primitive va être l'objet de ce mémoire. On va expliquer jusqu'à quel point on peut accomplir des taches cryptographiques de façon inconditionnellement sécuritaire, sous la seule hypothèse que la mécanique quantique et la relativité restreinte sont valides. Ce mémoire est largement basé sur les travaux de Mayers [52,53,54,55], Lo et Chau [49,50], Brassard, Crépeau, Mayers et Salvail [15], Spekkens et Rudolph [73], Hardy et Kent [35], Ishizaka [39] et Kent [43,44]. Il fait à la fois une présentation de la cryptographie quantique et une synthèse des travaux essentiels concernant les protocoles de mise en gage quantiques et relativistes. Nous allons donc commencer par une introduction sur l'histoire de la cryptographie\ud classique et son prolongement naturel à ses homologues, quantique et relativiste, qui permettent d'obtenir de meilleurs résultats. Ensuite, nous introduirons un certain nombre\ud d'outils mathématiques utiles à la description de la cryptographie quantique. Nous y présenterons également les preuves de plusieurs résultats à la base de la cryptographie quantique, tels que la décomposition de Schmidt, la purification, le théorème GHJW, le théorème d'Ulmann, le théorème de non-clonage, le théorème de la représentation de Kraus, etc. Nous discuterons aussi des concepts de base de l'informatique quantique, comme la mesure projective et généralisée, l'évolution des systèmes quantiques non isolés, la trace partielle, l'opérateur de densité, etc. Nous aborderons le protocole de la mise en gage proprement dit en exposant en détail la preuve du théorème de l'impossibilité de Mayers, Lo et Chau. Nous y présentons également le travail de Rudolph et Spekkens qui ont calculé les degrés optimaux de lien et de camouflage qui peuvent être obtenus simultanément dans tout protocole de mise en gage quantique non relativiste. Il s'agit-là d'une caractéristique qu'aucun protocole classique non relativiste ne peut assurer. Un autre type de sécurité pour ce protocole est étudié aussi, c'est celui de la mise en gage sensible à la tricherie "cheat sensitive" pour lequel on croyait que le protocole quantique de Hardy et Kent fonctionnait alors que lshizaka a démontré récemment que ce n'est pas le cas. Pire, il a même remis en question toute possibilité de réaliser ce type de sécurité en ce basant sur l'utilisation du protocole du tir à pile ou face comme sous-protocole. La cryptographie relativiste fera l'objet de notre dernier chapitre. Nous commencerons par montrer comment la théorie de la relativité restreinte, et donc l'impossibilité qu'un signal puisse se déplacer à une vitesse supérieur à celle de la lumière, peut être exploitée pour construire un protocole de mise en gage temporairement sécuritaire, c'est celui de Brassard, Crépeau, Mayers et Salvail. Nous présenterons ensuite le premier protocole relativiste d'une mise en gage continuellement sécuritaire, celui de Kent, et la preuve de sa sécurité. Ce protocole ne peut malheureusement pas être implémenté, même s'il est théoriquement sûr. Nous terminerons cette étude par une description d'un deuxième protocole relativiste du même auteur, qui va remédier aux problèmes liés à l'impossibilité pratique du premier protocole. Les preuves de la sécurité de ce dernier contre les attaques classiques et quantiques du type Mayers, Lo et Chau vont être abordées. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Informatique quantique, Mise en gage quantique, Mise en gage quantique sensible à la tricherie, Mise en gage relativiste