International Professional University of Technology in Nagoya Repository
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Energy Efficient Scheduling for Delay-Constrained Spectrum Aggregation: A Differentiated Water-Filling Approach
No full textInternational audienceSpectrum aggregation (SA) enables wireless devices to utilize heterogeneous resources, which can potentially fulfill the requirement of broadband services. In this paper, we study the delay-constrained SA, where the characteristics of SA bring various technical challenges. Specifically, the SA capability limitation induces a complicated coupling among the data rate, power and channel allocation, and the total power consumption varies according to the channel aggregation due to the SA circuit structure. Moreover, with these practical considerations, the water-filling power allocation cannot be adopted over all the channels. To overcome these challenges, we design the efficient scheduling for delay-constrained SA (ESSA) scheduling scheme in two steps. First, given the sum data rate and the channel allocation, we minimize the total power consumption for SA, including both the transmit power and the circuit power. Due to the properties of delay-constrained SA, we divide the scheduled users into conforming and nonconforming user sets, and design their water-filling power allocation strategies differentially. Second, based on the differentiated water-filling power control, we optimize the channel allocation and rate control iteratively via Lyapunov optimization to minimize the power consumption under average delay constraint. The proposed ESSA scheme is finally evaluated by simulation
Configuration dynamique et routage pour l'internet des objets
No full textIn recent years, the growing interest of scientific and industrial community has led to the standardization of new protocols that consider the unique requirements of Wireless Sensor Networks (WSN) nodes. At network layer, RPL (IPv6 Routing Protocol for Low-power and Lossy Network) has been proposed by IETF as the routing standard for network that uses LLN nodes, namely, those where both nodes and their interconnects are constrained. They operate on low-power embedded batteries and use lossy links, making communications unreliable and lead to a significant data loss rates. This thesis aims to optimize the routing in WSNs (especially those using TCP/IP protocol stack), as well as their efficient and cost-effective connection to the Internet. First, we have proposed two new RPL objective functions. The first uses as unique routing criterion, the node remaining energy with the goal of maximizing the network lifetime. An energy model that allows the nodes to dynamically estimate their remaining energy at runtime has been implemented and integrate to the protocol. The second objective function uses fuzzy logic reasoning to combine several criteria to take Quality of Service into account. Indeed, this scheme provides a good trade-off on several inputs and requires a low memory footprint. In the last part of this thesis, we designed and implemented an architecture that enable an efficient integration of several RPL based WSNs to the Internet to achieve the Internet of Things visionL’intérêt croissant de la communauté scientifique et industrielle ces dernières années pour les réseaux de capteurs sans fil (RCSF), a conduit à la définition de nouveaux protocoles normalisés prenant en compte les spécificités matérielles des nœuds utilisés. Dans la couche réseau, le protocole RPL (de l’acronyme anglais IPv6 Routing Protocol for Low-power and Lossy Network) a été proposé en 2012 par l’IETF, comme standard de routage pour les réseaux dont les nœuds sont de type "LLN" (Low-power and Lossy Network), i.e. caractérisés par une faible autonomie énergique et transmettant sur des liens radios dotés d’un taux de perte de données élevé. Dans cette thèse, nous nous intéressons à l’optimisation du routage dans ces réseaux (notamment ceux utilisant la pile protocolaire TCP/IP), ainsi qu’à leur interconnexion efficace à Internet à des coûts soutenables. Tout d’abord, nous proposons deux fonctions d’objectif organisant le routage avec RPL. La première se sert de l’unique critère énergétique, avec comme objectif principal la maximisation de la durée de vie du réseau. Pour ce faire, nous avons implémenté un modèle d’estimation d’énergie, intégré par la suite aux nœuds pour leur permettre d’estimer en temps réel leur énergie résiduelle. La deuxième fonction d’objectif proposée, vise à combiner plusieurs critères pour la prise en compte de la qualité de service durant le routage. Nous développons un modèle à base de la logique floue pour mettre en œuvre la combinaison. En effet, elle nous permet d’obtenir un bon compromis entre les différentes entrées et requiert une empreinte mémoire faible. Dans la dernière partie de cette thèse, nous concevons et implémentons une architecture d’activation de passerelles permettant d’assurer une connexion Internet efficace de divers RCSFs utilisant RPL, pour la réalisation de la vision de l’Internet des Objet
Energy Efficiency of Hybrid Unicast-Broadcast Networks for Mobile TV Services
No full textInternational audienceThe increasing popularity of linear services such as mobile TV, broadcasting live and sports events using mobile and portable devices, has led to a dramatic growth of the mobile data traffic. To deal with this traffic explosion, future networks have to increase the capacity offered to mobile communications, while at the same time trying to reduce their energy consumption. Actually, recent studies have shown that network cooperation is a promising candidate to deal with such issues. Based on these facts, this paper addresses the optimization of the energy efficiency of a hybrid network in which a broadcast and a unicast networks cooperate to deliver linear type of services to mobile and portable devices. Two optimization methods have been proposed to analytically find the optimal broadcast coverage area that maximizes the energy efficiency of the hybrid network. Simulation results show that using such a hybrid approach improves the overall energy efficiency
An output sensitive algorithm for maximal clique enumeration in sparse graphs
No full textInternational audienc
Robust observer-based stabilization of Lipschitz nonlinear uncertain systems via LMIs - Discussions and new design procedure
No full textInternational audienceThis paper presents a new observer-based controller design method for Lipschitz nonlinear systems with uncertain parameters and math formula-bounded disturbance inputs. In the presence of uncertain parameters, the separation principle is not applicable even in the case of linear time invariant systems. A state of the art review for uncertain linear systems is first presented to describe the shortcomings and conservatism of existing results for this problem. Then a new LMI-based design technique is developed to solve the problem for both linear and Lipschitz nonlinear systems. The features of the new technique are the use of a new matrix decomposition, the allowance of additional degrees of freedom in design of the observer and controller feedback gains, the elimination of any need to use equality constraints, the allowance of uncertainty in the input matrix and the encompassing of all previous results under one framework. An extensive portfolio of numerical case studies is presented to illustrate the superiority of the developed design technique to existing results for linear systems from literature and to illustrate application to Lipschitz nonlinear systems
Power Modeling for Fast & Early Power Estimation of FPGA-based Communications Systems
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Strong Electro-Optic Effect and Spontaneous Domain Formation in Self-Assembled Peptide Structures
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Constraint-Based Oracles for Timed Distributed Systems
No full textPart 5: Testing Timed and Distributed SystemsInternational audienceThis paper studies the situation in which the system under test and the system model are distributed and have the same structure; they have corresponding remote components that communicate asynchronously. In testing, a component with interface has its own local tester that interacts with and this local tester observes a local trace consisting of inputs, outputs and durations as perceived by . An observation made in testing is thus a multi-trace: a tuple of (timed) local traces, one for each . The conformance relation for such distributed systems combines a classical unitary conformance relation for localised components and the requirement that the communication policy was satisfied. By expressing the communication policy as a constraint satisfaction problem, we were able to implement the computation of test verdicts by orchestrating localised off-line testing algorithms and the verification of constraints defined by message passing between components. Lastly, we illustrate our approach on a telecommunications system
Etudes numérique et expérimentale du refroidissement par bain d’huile d’un système électromagnétique
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A Survey on Deep Learning Based Approaches for Action and Gesture Recognition in Image Sequences
No full textInternational audienceThe interest in action and gesture recognition has grown considerably in the last years. In this paper, we present a survey on current deep learning methodologies for action and gesture recognition in image sequences. We introduce a taxonomy that summarizes important aspects of deep learning for approaching both tasks. We review the details of the proposed architectures, fusion strategies, main datasets, and competitions. We summarize and discuss the main works proposed so far with particular interest on how they treat the temporal dimension of data, discussing their main features and identify opportunities and challenges for future research