Formal Probabilistic Analysis of a Wireless Sensor Network for Forest Fire Detection

Wireless Sensor Networks (WSNs) have been widely explored for forest fire detection, which is considered a fatal threat throughout the world. Energy conservation of sensor nodes is one of the biggest challenges in this context and random scheduling is frequently applied to overcome that. The performance analysis of these random scheduling approaches is traditionally done by paper-and-pencil proof methods or simulation. These traditional techniques cannot ascertain 100% accuracy, and thus are not suitable for analyzing a safety-critical application like forest fire detection using WSNs. In this paper, we propose to overcome this limitation by applying formal probabilistic analysis using theorem proving to verify scheduling performance of a real-world WSN for forest fire detection using a k-set randomized algorithm as an energy saving mechanism. In particular, we formally verify the expected values of coverage intensity, the upper bound on the total number of disjoint subsets, for a given coverage intensity, and the lower bound on the total number of nodes.Comment: In Proceedings SCSS 2012, arXiv:1307.802

Integrating identity-based cryptography in IMS service authentication

Nowadays, the IP Multimedia Subsystem (IMS) is a promising research field. Many ongoing works related to the security and the performances of its employment are presented to the research community. Although, the security and data privacy aspects are very important in the IMS global objectives, they observe little attention so far. Secure access to multimedia services is based on SIP and HTTP digest on top of IMS architecture. The standard deploys AKA-MD5 for the terminal authentication. The third Generation Partnership Project (3GPP) provided Generic Bootstrapping Architecture (GBA) to authenticate the subscriber before accessing multimedia services over HTTP. In this paper, we propose a new IMS Service Authentication scheme using Identity Based cryptography (IBC). This new scheme will lead to better performances when there are simultaneous authentication requests using Identity-based Batch Verification. We analyzed the security of our new protocol and we presented a performance evaluation of its cryptographic operationsComment: 13Page

Diverse Image Generation with Very Low Resolution Conditioning

Traditionnellement, lorsqu’il s’agit de générer des images à haute résolution (HR) à partir d’images à basse résolution (LR), les méthodes proposées jusqu’à maintenant se sont principalement concentrées sur les techniques de super-résolution qui visent à récupérer l’image la plus probable à partir d’une image de basse qualité. En procédant de cette manière, on ignore le fait qu’il existe généralement de nombreuses versions valides d’images HR qui correspondent à une image LR donnée. L’objectif de ce travail est d’obtenir différentes versions d’images HR à partir d’une même image LR en utilisant un modèle adversarial génératif. On aborde ce problème sous deux angles différents. D’abord, on utilise des méthodes de super résolution, où en plus de l’image LR, le générateur peut être paramétré par une variable latente afin de produire différentes variations potentielles de l’image. Un tel conditionnement permet de moduler le générateur entre la récupération de l’image la plus proche de la vérité terrain et de variété d’images possibles. Les résultats démontrent notre supériorité en termes de reconstruction et de variété d’images hallucinées plausible par rapport à d’autres méthodes de l’état de l’art. La deuxième approche s’appuie sur les travaux de traduction d’image à image, en proposant une nouvelle approche où le modèle est conditionné sur une version LR du cible. Plus précisément, notre approche vise à transférer les détails fins d’une image source HR pour les adapter la structure générale, selon la version LR de celle-ci. On génère donc des images HR qui partagent les caractéristiques distinctives de l’image HR et qui correspond à l’image LR de la cible lors de la réduction d’échelle. Cette méthode diffère des méthodes précédentes qui se concentrent plutôt sur la traduction d’un style d’image donné en un contenu cible. Les résultats qualitatifs et quantitatifs démontrent des améliorations en termes de qualité visuelle, de diversité et de couverture par rapport aux méthodes de pointe telles que Stargan-v2.Traditionally, when it comes to generating high-resolution (HR) images from a low-resolution(LR) images, the methods proposed so far have mainly focused on super-resolution techniques that aim at recovering the most probable image from low-quality image. Doing so ignores the fact that there are usually many valid versions of HR images that match a given LR image. The objective of this work is to obtain different versions of HR images from the same LR imageusing a generative adversarial model. We approach this problem from two different angles. First, we use super-resolution methods, where in addition to the LR image, the generator can be parameterized by a latent variable to produce different potential variations of the image. Such a conditioning allows to modulate the generator between retrieving the closest image to the ground truth and a variety of possible images. The results demonstrate our superiority in terms of reconstruction and variety of plausible hallucinated images compared to other state-of-the-art methods. The second approach builds on the work of image-to-image translation, by proposing a new approach where the model is conditioned on a LR version of the target. More precisely, our approach aims at transferring the fine details of an HR source image to fit the general structure, according to the LR version of it. We therefore generate HR images that share the distinctive features of the HR image and match the LR image of the target duringdownscaling. This method differs from previous methods that focus instead on translatinga given image style into target content. Qualitative and quantitative results demonstrate improvements in visual quality, diversity, and coverage over state-of-the-art methods such asStargan-v2

Proposition pour l’intégration des réseaux petits mondes en recherche d’information

International audienceWe propose in this paper an approach for document clustering. It consists of representing the corpus as a document graph, where the links are defined by some criteria. These links are quantified by simialrity measures. We aim join this context into the approach of classification to constitute small-worlds networks of homogeneous documents. The homogeneity of the clusters is measured according to the properties of small worlds. The clusters, as well as their proprietes, allow to rerank search results. Some experiments were done on a corpus provided by TREC and the obtained results show the contribution of small-worlds networks in information retrieval.Nous proposons dans ce papier une approche de classification d’un corpus de documents. Elle consiste en une représentation du corpus sous forme de graphe, où les liens sont définis par certains critères. Ces liens sont quantifiés par des mesures de similarité. Nous visons à intégrer ce contexte dans l’approche de classification afin de constituer des réseaux petits mondes de documents homogènes. L’homogénéité des classes est valuée suivant les propriétés des réseaux petits mondes. Les classes, ainsi que leurs propriétés, nous servent au ré-ordonnancement de documents résultats de recherche. Quelques expérimentations ont été menées sur un corpus issu de TREC 1 et les résultats obtenus montrent l’apport des réseaux petits mondes en recherche d’information

Multi-Softcore Architecture on FPGA

To meet the high performance demands of embedded multimedia applications, embedded systems are integrating multiple processing units. However, they are mostly based on custom-logic design methodology. Designing parallel multicore systems using available standards intellectual properties yet maintaining high performance is also a challenging issue. Softcore processors and field programmable gate arrays (FPGAs) are a cheap and fast option to develop and test such systems. This paper describes a FPGA-based design methodology to implement a rapid prototype of parametric multicore systems. A study of the viability of making the SoC using the NIOS II soft-processor core from Altera is also presented. The NIOS II features a general-purpose RISC CPU architecture designed to address a wide range of applications. The performance of the implemented architecture is discussed, and also some parallel applications are used for testing speedup and efficiency of the system. Experimental results demonstrate the performance of the proposed multicore system, which achieves better speedup than the GPU (29.5% faster for the FIR filter and 23.6% faster for the matrix-matrix multiplication)

XML Retrieval

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System level synthesis of dataflow programs: HEVC decoder case study

International audienceWhile dealing with increasing complexity of signal processing algorithms, the primary motivation for the development of High-Level Synthesis (HLS) tools for the automatic generation of Register Transfer Level (RTL) description from high-level description language is the reduction of time-to-market. However, most existing HLS tools operate at the component level, thus the entire system is not taken into consideration. We provide an original technique that raises the level of abstraction to the system level in order to obtain RTL description from a dataflow description. First, we design image processing algorithms using an actor oriented language under the Reconfigurable Video Coding (RVC) standard. Once the design is achieved, we use a dataflow compilation infrastructure called Open RVC-CAL Compiler (Orcc) to generate a C-based code. Afterward, a Xilinx HLS tool called Vivado is used for an automatic generation of synthesizable hardware implementation. In this paper, we show that a simulated hardware code generation of High Efficiency Video Coding (HEVC) under the RVC specifications is rapidly obtained with promising preliminary results

Ouverture commerciale et migration : Un modèle d’équilibre général calculable pour le Maroc

Cet article étudie quantitativement l’impact macroéconomique de la constitution d’une zone de libre-échange entre le Maroc et l’Union européenne, tout en soulignant les effets en matière de flux migratoires. Le cadre d’analyse est un modèle d’équilibre général calculable statique avec des hypothèses de la nouvelle théorie du commerce international : rendements d’échelle croissants et différenciation des produits. Le modèle, comportant neuf secteurs économiques marocains, analyse les effets macroéconomiques en matière d’émigration et de constitution d’une zone de libre-échange entre le Maroc et l’Europe. Les résultats montrent que, dans les conditions actuelles de compétitivité de l’économie marocaine, le libre-échange induirait une forte dépression industrielle et un déficit extérieur croissant. Il s’ensuivrait une chute de l’emploi particulièrement dans l’industrie. Par conséquent, les flux migratoires marocains se maintiendront et s’amplifieront en direction de l’Europe.This article quantitatively studies the macroeconomic impact of creating a free trade area between Morocco and the European Union, while underlining its effects regarding migratory flow. The analysis framework is a computable general equilibrium model which assumes the following new international trade theory hypothesis: increasing scale outputs and products differentiation. The model, which comprises nine Moroccan economic sectors, analyzes the macroeconomic effects on emigration and the creation of a free trade area between Morocco and Europe. Results show that, under current conditions of competitiveness of the Moroccan economy, free trade would induce a strong industrial depression and a growing external deficit. It would lead to a fall in employment, particularly in industry. Consequently, Moroccan migratory flows will be maintained and developed towards Europe