Spatio-temporal Learning with Arrays of Analog Nanosynapses

Emerging nanodevices such as resistive memories are being considered for hardware realizations of a variety of artificial neural networks (ANNs), including highly promising online variants of the learning approaches known as reservoir computing (RC) and the extreme learning machine (ELM). We propose an RC/ELM inspired learning system built with nanosynapses that performs both on-chip projection and regression operations. To address time-dynamic tasks, the hidden neurons of our system perform spatio-temporal integration and can be further enhanced with variable sampling or multiple activation windows. We detail the system and show its use in conjunction with a highly analog nanosynapse device on a standard task with intrinsic timing dynamics- the TI-46 battery of spoken digits. The system achieves nearly perfect (99%) accuracy at sufficient hidden layer size, which compares favorably with software results. In addition, the model is extended to a larger dataset, the MNIST database of handwritten digits. By translating the database into the time domain and using variable integration windows, up to 95% classification accuracy is achieved. In addition to an intrinsically low-power programming style, the proposed architecture learns very quickly and can easily be converted into a spiking system with negligible loss in performance- all features that confer significant energy efficiency.Comment: 6 pages, 3 figures. Presented at 2017 IEEE/ACM Symposium on Nanoscale architectures (NANOARCH

La structure spatiale de l'offre de transport à grande vitesse

Ce papier propose un analyse détaillée de la géographie de l'offre de transport de personnes à grande vitesse en France. Passant en revue l'abondante littérature sur le thème de l'accessibilité interurbaine, il expose d'abord l'intérêt d'une sélection des services pris en compte. Ensuite, il expose de manière détaillée la méthodologie suivie pour construire les indicateurs présentés et pour les cartographier. Dans un troisième temps, les résultats sont analysés. Ils permettent de visualiser deux ensembles d'agglomérations: tout d'abord un groupe de sept métropoles (plus Paris) qui forme un réseau parfaitement maillé, ensuite, les agglomérations moins importantes dont la structure de desserte générale est constituée de liaisons de proximité et d'un lien avec Paris. Pour attendus qu'ils soient, ces résultats méritent d'être rapprochés de ceux concernant l'analyse qualitative de la demande qui faisaient également apparaître une structure spatiale duale entre espace métropolitain et espace banal.Accessibilité ; offre de transport ; avion ; train à grande vitesse ; TGV ; déplacements interurbains ; réseau métropolitain ; France

Le TGV-Atlantique et les évolutions de la mobilité : entre crise et concurrence

Cet article a pour objet de présenter les principales évolutions de mobilité qui ont pu être repérées par comparaisons des données des deux vagues d'enquête. Il débute par un rapide exposé des principales caractéristiques de l'enquête. Ensuite, les résultats sont décomposés en distinguant 3 zones géographiques suivant leur éloignement à Paris. A l'intérieur de chacune d'elle, les trois grands motifs de déplacement (professionnel, domicile-travail et personnel) sont tour à tour envisagés. Enfin, la conclusion rapproche les observations réalisées sur le TGV-Atlantique des connaissances déjà acquises concernant la mobilité à longue distance et les dessertes ferroviaires à grande vitesse. On y trouve la confirmation de l'essentiel des caractéristiques de la " mobilité à grande vitesse " ainsi que la vérification de ce que nombre d'éléments extérieurs à la sphère des transports pèsent d'un poids déterminant sur les dynamiques de la mobilité.TGV-Atlantique ; transport ferroviaire ; transport à grande vitesse ; choix du mode de transport ; déplacement domicile-travail ; mobilité professionnelle ; déplacement personnel ; enquête

An Approach for spatial and temporal data analysis: application for mobility modeling of workers in Luxembourg and its bordering areas

In this paper, we propose a general visual analytic approach to synthesis very large spatial data and discover interesting knowledge and unknown patterns from complex data based on Origin-Destination (OD) matrices. The research studies of Tobler constitute a good basis in this topic. This paper is interested in the proposal of 2 methods entitled respectively ?Weighted Linear Directional Mean: WLDM? and ?DS-WLDM?. The latter incorporates the Dempster-Shafer theory of evidence with WLDM. Both of the developed methods are an extension of ?Linear Directional Mean: LDM? for mobility modeling. With classical techniques such as LDM among others, the results of data mapping are not intelligible and easy to interpret. However with both WLDM and DS-WLDM methods it is easy to discover knowledge without losing a lot of information which is one of the interests of this paper. This proposal is generic and it intends to be applied for data mapping such as for geographical presentation of social and demographic information (e.g. mobility of people, goods and information) according to multiple spatial scales (e.g. locality, district, municipality). It could be applied also in transportation field (e.g. traffic flow). For the application, administrative data is used in order to evaluate spatial and temporal aspects of the daily and the residential mobility of workers in Luxembourg and its bordering areas.Mobility modeling; data mapping; spatial mobility; geographic knowledge discovery; location uncertainty; daily and residential mobility

Du suivi GPS des individus à une approche chronotopique. Premiers apports d'expérimentations et de recherches territorialisées

International audienceThis communication deals with an assessment of the GPS use for analysing complex trips of hypermodern individuals. Based on research conducted since a dozen years in France and Grand Duchy of Luxembourg, it shows the importance of these systems in the analysis of mobility and possible contributions for public transport policies. From a focus on cartographic representations produced as tools for analysis and dialogue with the public and the policy makers, it sets out some pointers for the future.La communication propose de faire un point sur l’utilisation des systèmes de positionnement par satellite pour l’analyse des déplacements complexes des individus hypermodernes. Sur la base de travaux de recherche menés depuis une douzaine d’années en France et au Grand-Duché de Luxembourg, elle montre l’importance de ces systèmes dans l’analyse des mobilités et les apports possibles pour les politiques publiques de mobilité. Elle insiste sur les représentations cartographiques produites comme outil d’analyse et outils de dialogue avec la population et les décideurs et propose quelques pistes pour demain

A method and a tool for geocoding and record linkage

For many years, researchers have presented the geocoding of postal addresses as a challenge. Several research works have been devoted to achieve the geocoding process. This paper presents theoretical and technical aspects for geolocalization, geocoding, and record linkage. It shows possibilities and limitations of existing methods and commercial software identifying areas for further research. In particular, we present a methodology and a computing tool allowing the correction and the geo-coding of mailing addresses. The paper presents two main steps of the methodology. The first preliminary step is addresses correction (addresses matching), while the second caries geocoding of identified addresses. Additionally, we present some results from the processing of real data sets. Finally, in the discussion, areas for further research are identified.addresses correction; geocodage; matching; data management; record linkage

Two-Way Optical Frequency Comparisons Over 100km Telecommunication Network Fibers

By using two-way frequency transfer, we demonstrate ultra-high resolution comparison of optical frequencies over a telecommunication fiber link of 100 km operating simultaneously digital data transfer. We first propose and experiment a bi-directional scheme using a single fiber. We show that the relative stability at 1 s integration time is 7 10^18 and scales down to 5 10^21. The same level of performance is reached when an optical link is implemented with an active compensation of the fiber noise. We also implement a real-time two-way frequency comparison over a uni-directional telecommunication network using a pair of parallel fibers. The relative frequency stability is 10^15 at 1 s integration time and reaches 2 10^17 at 40 000 s. The fractional uncertainty of the frequency comparisons was evaluated for the best case to 2 10^20. These results open the way to accurate and high resolution frequency comparison of optical clocks over intercontinental fiber networks

Complete mapping of the spin-wave spectrum in vortex state nano-disk

We report a study on the complete spin-wave spectrum inside a vortex state nano-disk. Transformation of this spectrum is continuously monitored as the nano-disk becomes gradually magnetized by a perpendicular magnetic field and encouters a second order phase transition to the uniformly magnetized state. This reveals the bijective relationship that exists between the eigen-modes in the vortex state with the ones in the saturated state. It is found that the gyrotropic mode can be continuously viewed as a uniform phase precession, which uniquely softens (its frequency vanishes) at the saturation field to transform above into the Kittel mode. By contrast the other spin-wave modes remain finite as a function of the applied field while their character is altered by level anti-crossing

Bond offerings in China : The role of ownership

Peer reviewedPostprin

A 1° x 1° resolution data set of historical anthropogenic trace gas emissions for the period 1890-1990

An anthropogenic emissions data set has been constructed for CO2, CO, CH4, nonmethane volatile organic compounds, SO2, NOx, N2O, and NH3 spanning the period 1890–1990. The inventory is based on version 2.0 of the Emission Database for Global Atmospheric Research (EDGAR 2.0). In EDGAR the emissions are calculated per country and economic sector using an emission factor approach. Calculations of the emissions with 10 year intervals are based on historical activity statistics and selected emission factors. Historical activity data were derived from the Hundred Year Database for Integrated Environmental Assessments (1890–1990) supplemented with other data and our own estimates. Emission factors account for changes in economical and technological developments in the past. The calculated emissions on a country basis have been interpolated onto a 1°x1° grid. This consistent data set can be used in trend studies of tropospheric trace gases and in environmental assessments, for example, the analysis of historical contributions of regions and countries to environmental forcing like the enhanced greenhouse gas effect, acidification, and eutrofication. The database focuses on energy/industrial and agricultural/waste sources; for completeness, historical biomass-burning estimates where added using a simple and transparent approach. ? 2001 American Geophysical Unio