International Professional University of Technology in Nagoya Repository
Not a member yet
15131 research outputs found
Sort by
From 3D models to 3D prints: an overview of the processing pipeline
No full textInternational audienceDue to the wide diffusion of 3D printing technologies, geometric algorithms for Additive Manufacturing are being invented at an impressive speed. Each single step along the processing pipeline that prepares the 3D model for fabrication can now count on dozens of methods, that analyse and optimize geometry and machine instructions for various objectives. This report provides a classification of this huge state of the art, and elicits the relation between each single algorithm and a list of desirable objectives during model preparation – a process globally refereed to as Process Planning. The objectives themselves are listed and discussed, along with possible needs for tradeoffs. Additive Manufacturing technologies are broadly categorized to explicitly relate classes of devices and supported features. Finally, this report offers an analysis of the state of the art while discussing open and challenging problems from both an academic and an industrial perspective
Désynchronisation bio-inspirée dans les réseaux véhiculaires : quand les véhicules imitent les grenouilles
No full textInternational audienceA priori, on se dit qu’il n’est de chose plus éloignée d’un véhicule qu’une grenouille. Nous allons pourtant montrer dans cet article, que ces joyeuses bêtes ne sont pas seulement de passives victimes de nos routes, souvent réduites à deux dimensions entre gomme et asphalte. Ces créatures peuvent également nous servir de source d’inspirationpour développer des algorithmes permettant, sinon d’arrêter ce génocide batracien, d’au moins limiter le nombre de victimes, bien humaines elles, sur les routes. En effet, la sécurité routière est la principale motivation avancée pour le développement des réseaux véhiculaires. Cependant, de nombreux problèmes restent à résoudre pour que les applications de sécurité routière soient vraiment efficaces. Ces applications sont basées sur des échanges de messages périodiques appelés beacons. Ces beacons permettent aux véhicules d’avoir une vision élargie de leur environnement,et ainsi de pouvoir prévenir les situations dangereuses. Un des problèmes majeurs pour l’échange de beacons est que, dans les réseaux véhiculaires denses, les collisions de ces messages empêchent les véhicules d’avoir une vision à jourde leur environnement. Dans cet article, nous évaluons des algorithmes inspirés des désynchronisations de croassement de grenouilles qui permettent de réduire les collisions de manière distribuée et donc permettent aux véhicules d’avoir une meilleure vision de leur environnement
Realization of flexible piezoelectric thin film on polymer substrate
No full textInternational audienc
Low cost instantly printed silver nano ink flexible dual-band antenna onto paper substrate
No full textInternational audienc
Spikes super-resolution with random Fourier sampling
No full textInternational audienceWe leverage recent results from machine learning to show theoretically and practically that it is possible to stably recover a signal made of few spikes (in the gridless setting) from few random weighted Fourier measurements. Given a free choice of frequencies, a number of measurements lower than with the traditional low-pass filter (uniform sampling of low frequencies) guarantees stable recovery
A relaxed characterization of ISS for periodic systems with multiple invariant sets
No full textInternational audienceA necessary and sufficient criterion to establish input-to-state stability (ISS) of nonlinear dynamical systems, the dynamics of which are periodic with respect to certain state variables and which possess multiple invariant solutions (equilibria, limit cycles, etc.), is provided. Unlike standard Lyapunov approaches, the condition is relaxed and formulated via a sign-indefinite function with sign-definite derivative, and by taking the system's periodicity explicitly into account. The new result is established by using the framework of cell structure and it complements the ISS theory of multistable dynamics for periodic systems. The efficiency of the proposed approach is illustrated via the global analysis of a nonlinear pendulum with constant persistent input
An overview of recent advances on Iterative Physical Optics
No full textInternational audienceThe Radar Cross Section (RCS) of electrically large targets including cavities (such as jet engine inlets) remains a challenging problem in electromagnetic modeling. Rigorous methods are known to provide a good accuracy, since only the approximation due to meshing is considered. Nevertheless, these methods are difficult to use for targets much greater than the wavelength due to the computation time and memory requirements. For electrically large targets, High Frequency asymptotic methods can be used, among which Iterative Physical Optics (IPO) is very efficient. IPO is an asymptotic numerical method based on Physical Optics (PO). This method, first introduced in 1995 by Obelleiro et al, is known to provide a good trade-off between complexity and accuracy.Since 1995, several improvements were published. More recently, some improvements were made to the IPO method by the help of fast numerical techniques, generally inherited from advances made for rigorous methods.Given all these previous studies, the IPO method can be implemented into very various forms depending on the desired application.Thus, the goal of this paper is to provide a complete overview of the recent improvements on Iterative Physical Optics. The advantages and drawbacks of each specific form and acceleration of IPO will be discussed in order to give some advices on the choice of the best IPO form for a given problem
Power-Aware Population Protocols
No full textInternational audienceThe contribution of the paper is twofold. First, it introduces a model for analyzing energy consumption in networks of mobile sensors. Second, it uses this model for studying energy complexity of distributed protocols for the task of data collection. The proposed model is quite general and can be used for other tasks. It can be considered as the first extension of this kind, taking into account energy consumption, of the classical model of population protocols. In population protocols, anonymous and bounded memory agents (sensors) move unpredictably and communicate in pairs when two of them are in proximity. The interest of the extended model is to allow a purely analytical analysis of the energy complexity of a protocol, in the same spirit as for time and space complexity, without appealing to simulations. This approach allows to exhibit energy functions and to draw their curves, from which the optimal values of various parameters can be deduced. In order to illustrate the power and the usefulness of this model, we consider the issue of determining and adjusting the amount of agents' initial energy necessary and sufficient for being able to perform a given task. This issue is crucial for choosing, in practice, a category of sensors (in respect with their power capacities) adapted both to the task and to the number of times it should be repeated (before the sensors are replaced or recharged). In this context, the natural chosen metric is the maximum energy spent by an agent (for accomplishing the overall collaborative task). This metric is directly related to the minimum necessary initial energy (and also to the lifetime of the network). Contrary to most of the energy studies in networks of mobile agents, our approach is completely deterministic. The reason is that due to the nature of the considered problem, the analysis has to be done in the worst case (in particular, such analysis is impossible when the interactions between agents are supposed to be probabilistic). The specific task we consider in this work is data collection, which is known to be fundamental in sensor networks. In this problem, initially, each sensor has an input (a sensed) value, and eventually, every input should be delivered exactly once, to a base station. Transfers of inputs between sensors are possible in order to optimize time and energy metrics. In this context, our first contribution is the energy complexity analysis of an already known time optimal protocol. The second contribution is a new power-aware protocol, which improves the previous one in terms of the maximum energy spent by an agent. Finally, we present a lower bound concerning energy consumption of any possible data collection protocol and we show the cases where this lower bound is reached by the presented protocols
Inhibitor of Fatty Acid Amide Hydrolase - Learning from Tragic Failures
No full textInternational audienceThe authors reply: Anghelescu comments on the mechanism responsible for the acute neurologic disorders observed in the four volunteers described in our article..
A Comparative Study of Calorimetric Methods to Determine theCrosslinking Degree of the Ethylene-Co-Vinyl Acetate Polymer Usedas a Photovoltaic Encapsulant
No full textInternational audienceEVA copolymer foils are widely used as encapsulantsfor photovoltaic (PV) cells in PV modules. These foilsneed to be crosslinked during module manufacturing, toenhance their properties. Accurate and reliable methods for thedetermination of their crosslinking degree are thus very important.In this work, two semi-empirical calorimetric methods areconsidered and compared to a scientifically sound rheologicalmethod used as a reference. The main purpose of this work isto reveal the chemical and physical fundamentals on which thetwo calorimetric methods are based, to allow for a scientificunderstanding of their advantages, and limitations. For one ofthese calorimetric methods, the so-called “Melt-Freeze” method,we have sought for a deeper understanding of the underlyingcrystallization physics through the use of successive selfnucleationand annealing experiments, which give access tothe crystallite size distribution of EVA, and to the influence ofcrosslinking upon it