An autonomic traffic analysis proposal using Machine Learning techniques

International audienceNetwork analysis has recently become in one of the most challenging tasks to handle due to the rapid growth of communication technologies. For network management, accurate identification and classification of network traffic is a key task. For example, identifying traffic from different applications is critical to manage bandwidth resources and to ensure Quality of Service objectives. Machine learning emerges as a suitable tool for traffic classification; however, it requires several steps that must be followed adequately in order to achieve the goals. In this paper, we proposed an architecture to perform traffic analysis based on Machine Learning techniques and autonomic computing. We analyze the procedures to perform Machine Learning over traffic network classification, and at the same time we give guidelines to introduce all these procedures into the architecture proposed. The main contribution of our proposal is the reconfiguration of the traffic classifier that will change according to the knowledge adquired from the traffic analysis process

Computing commons interval of K permutations, with applications to modular decomposition of graphs

International audienceWe introduce a new way to compute common intervals of K permutations based on a very simple and general notion of generators of common intervals. This formalism leads to simple and efficient algorithms to compute the set of all common intervals of K permutations, that can contain a quadratic number of intervals, as well as a linear space basis of this set of common intervals. Finally, we show how our results on permutations can be used for computing the modular decomposition of graphs in linear time

Force-induced acoustic phonon transport across single-digit nanometre vacuum gaps

Heat transfer between bodies separated by nanoscale vacuum gap distances has been extensively studied for potential applications in thermal management, energy conversion and data storage. For vacuum gap distances down to 20 nm, state-of-the-art experiments demonstrated that heat transport is mediated by near-field thermal radiation, which can exceed Planck's blackbody limit due to the tunneling of evanescent electromagnetic waves. However, at sub-10-nm vacuum gap distances, current measurements are in disagreement on the mechanisms driving thermal transport. While it has been hypothesized that acoustic phonon transport across single-digit nanometre vacuum gaps (or acoustic phonon tunneling) can dominate heat transfer, the underlying physics of this phenomenon and its experimental demonstration are still unexplored. Here, we use a custom-built high-vacuum shear force microscope (HV-SFM) to measure heat transfer between a silicon (Si) tip and a feedback-controlled platinum (Pt) nanoheater in the near-contact, asperity-contact, and bulk-contact regimes. We demonstrate that in the near-contact regime (i.e., single-digit nanometre or smaller vacuum gaps before making asperity contact), heat transfer between Si and Pt surfaces is dominated by force-induced acoustic phonon transport that exceeds near-field thermal radiation predictions by up to three orders of magnitude. The measured thermal conductance shows a gap dependence of $d^{-5.7\pm1.1}$ in the near-contact regime, which is consistent with acoustic phonon transport modelling based on the atomistic Green's function (AGF) framework. Our work suggests the possibility of engineering heat transfer across single-digit nanometre vacuum gaps with external force stimuli, which can make transformative impacts to the development of emerging thermal management technologies.Comment: 9 pages with 4 figures (Main text), 13 pages with 7 figures (Methods), and 13 pages with 6 figures and 1 table (Supplementary Information

Petrology, Geochemistry and Geodynamic Significance of the Mafic and Ultramafic Rocks of the Akou (Okondja Basin, Gabon)

The Akou section (Okondja in the Francevillian Basins, Gabon) has a set of mafic and ultrmafic magmatic rocks with various deposit patterns; interbedded basaltic flows, sills and small intrusive bodies within the formations FB francevillian series. The succession of these rocks pyroxenites, gabbros and basalts characterizes the oceanic crust. These rocks mainly consists of olivine, pyroxene, amphibole and biotite. This mineralogical continuation shows that these rocks result from process of split crystallization of an ultramafic magma. The geochemical analyses reveal the major elemental composition such as Na2O (0.24-3.47) and K2O (0.04-3.95). These values indicate that these series are originated from the alkaline magma, which is associated with within plate oceanic volcanicity

Poster Abstract: Interconnecting Low-Power Wireless and Power-Line Communications using IPv6

Wireless sensor networks for building automation and energy management has made great progress in recent years, but the inherent indoor radio range limitations can make communication unpredictable and system deployments difficult. Low-power radio can be combined with low-power Power-Line Communication (PLC) to extend the range and predictability of indoor communication for building management and automation systems. We take the first steps towards exploring the system implications for integration of low-power wireless and PLC in the same network. We leverage IPv6, which allow networks to exist over multiple physical communication media as well as the RPL routing protocol for low-power lossy networks

2-D materials for ultra-scaled field-effect transistors: hundred candidates under the ab initio microscope

Thanks to their unique properties single-layer 2-D materials appear as excellent candidates to extend Moore's scaling law beyond the currently manufactured silicon FinFETs. However, the known 2-D semiconducting components, essentially transition metal dichalcogenides, are still far from delivering the expected performance. Based on a recent theoretical study that predicts the existence of more than 1,800 exfoliable 2-D materials, we investigate here the 100 most promising contenders for logic applications. Their "current vs. voltage" characteristics are simulated from first-principles, combining density-functional theory and advanced quantum transport calculations. Both n- and p-type configurations are considered, with gate lengths ranging from 15 down to 5 nm. From this unprecedented collection of electronic materials, we identify 13 compounds with electron and hole currents potentially much higher than in future Si FinFETs. The resulting database widely expands the design space of 2-D transistors and provides original guidelines to the materials and device engineering community

PLC sensor IPv6 networking interoperabe with WSN

International audienceTechnology evolution have made possible to connect all kind of devices to IP network. This becomes an evident objective for sensors networks research. In this paper, we investigate the possibility of using IPv6 for sensor networks connected through powerline communication (PLC) non-wireless mediums and demonstrate possible interoperability. Our work is based on the adaptation of the IEEE 802.15.4 standard protocol. It is constrained by the low-power, lossy and low data-rate context of powerline transceiver that uses pulse modulation. Our aim is to provide interoperability features regarding others mediums with a robust and reliable communication stack for smart metering, home control or home area networks applications. This document propose the first adaptation of the IEEE 802.15.4 commons standard on PLC medium. Following this standard interface, we demonstrate the possibility to carry out data on PLC with great reliability, and low power energy requirement using our WPCTMphysical layer (standing for Watt Pulse Communication (WPC)). Relying on this adaptation, we then focus on the convergence of the IPv6 protocol at the network level, with the 6LoWPAN adaptation. We also present our initial implementation of the RPL setup and routing protocol. This allows for a full network layer stack and results in efficient routing in our low power, low data-rate and lossy network context. Thus, we finally demonstrate interoperability with a real testbed between powerline and wireless sensor networks running IEEE 802.15.4/6LoWPAN/IPv6/RPL stacks. We conclude about the interest of such interoperability for the real usage of sensor networks with a feedback from field's applications deployment and our future work

Field-Effect Transistors based on 2-D Materials: a Modeling Perspective

Two-dimensional (2D) materials are particularly attractive to build the channel of next-generation field-effect transistors (FETs) with gate lengths below 10-15 nm. Because the 2D technology has not yet reached the same level of maturity as its Silicon counterpart, device simulation can be of great help to predict the ultimate performance of 2D FETs and provide experimentalists with reliable design guidelines. In this paper, an ab initio modelling approach dedicated to well-known and exotic 2D materials is presented and applied to the simulation of various components, from thermionic to tunnelling transistors based on mono- and multi-layer channels. Moreover, the physics of metal - 2D semiconductor contacts is revealed and the importance of different scattering sources on the mobility of selected 2D materials is discussed. It is expected that modeling frameworks similar to the one described here will not only accompany future developments of 2D devices, but will also enable them