t-Exponential Memory Networks for Question-Answering Machines

Recent advances in deep learning have brought to the fore models that can make multiple computational steps in the service of completing a task; these are capable of describ- ing long-term dependencies in sequential data. Novel recurrent attention models over possibly large external memory modules constitute the core mechanisms that enable these capabilities. Our work addresses learning subtler and more complex underlying temporal dynamics in language modeling tasks that deal with sparse sequential data. To this end, we improve upon these recent advances, by adopting concepts from the field of Bayesian statistics, namely variational inference. Our proposed approach consists in treating the network parameters as latent variables with a prior distribution imposed over them. Our statistical assumptions go beyond the standard practice of postulating Gaussian priors. Indeed, to allow for handling outliers, which are prevalent in long observed sequences of multivariate data, multivariate t-exponential distributions are imposed. On this basis, we proceed to infer corresponding posteriors; these can be used for inference and prediction at test time, in a way that accounts for the uncertainty in the available sparse training data. Specifically, to allow for our approach to best exploit the merits of the t-exponential family, our method considers a new t-divergence measure, which generalizes the concept of the Kullback-Leibler divergence. We perform an extensive experimental evaluation of our approach, using challenging language modeling benchmarks, and illustrate its superiority over existing state-of-the-art techniques

Multimodal decision-level fusion for person authentication

In this paper, the use of clustering algorithms for decision-level data fusion is proposed. Person authentication results coming from several modalities (e.g., still image, speech), are combined by using fuzzy k-means (FKM), fuzzy vector quantization (FVQ) algorithms, and median radial basis function (MRBF) network. The quality measure of the modalities data is used for fuzzification. Two modifications of the FKM and FVQ algorithms, based on a novel fuzzy vector distance definition, are proposed to handle the fuzzy data and utilize the quality measure. Simulations show that fuzzy clustering algorithms have better performance compared to the classical clustering algorithms and other known fusion algorithms. MRBF has better performance especially when two modalities are combined. Moreover, the use of the quality via the proposed modified algorithms increases the performance of the fusion system

Forecasting Urban Traffic in France, 1950s to 2000s: The Nation-State, private engineering firms and the globalization of an area of expertise

Despite of its impact on urban transportation policies after the World War II, urban travel demand modeling (UTDM) - an array of mathematical tools and practices geared towards predicting flows in urban transportation networks, such as urban highways and mass transit systems - has received scant attention from humanities and social sciences scholars. This working paper offers a first long-term analysis - from the 1950s to the 2000s - of the trajectory of this kind of modeling in France. To do so, it makes use of an analytical framework which envisages modeling practices as a production process: aside from the "product" itself, i.e. the main characteristics of the model under study, the analysis is interested in the different actors involved in producing the model (individuals and institutions), as well as the "raw materials" (for example, data from surveys of household travel) and the "means of production", such as computer facilities (hardware and software), which are necessary for its production and implementation. Based on this analytical framework, this paper highlights a process characterized by two main developments. From 1950-1980, State French engineers along with private consulting firms, after having familiarized themselves with American modeling practices, succeeded in creating a national expertise in this domain, which the central French state normalized, disseminated, and implemented on a large scale throughout the national territory in the 1970s. The post 1980 period clearly contrasts with what went before. Indeed, evidence shows that the French state progressively withdrew from UTDM, and, therefore, prepared the way for the rise to dominance of private (and more often that not foreign) engineering consulting firms, which became the main repositories of expertise concerning urban traffic forecasting in France.En dépit de l'importance de la modélisation des déplacements urbains en matière de politiques de transports, force est de constater la quasi-absence d'intérêt dont les historiens et autres chercheurs en sciences sociales ont fait montre à son égard jusqu'à présent. Ce document propose une première analyse de la modélisation des déplacements urbains en France, des années 1950 au début des années 2010. Pour ce faire, nous avons adopté une perspective particulière, qui envisage la modélisation comme un processus de production : outre le " produit " lui-même (la structure des modèles), nous nous sommes intéressés à la fois aux différents acteurs (individus et institutions) qui ont produit ce type de modélisation, aux " matières premières " (enquêtes sur la mobilité...) et aux " moyens de production " (logiciels et machines informatiques) nécessaires à sa production et sa mise en œuvre. Regardée à travers cette grille d'analyse, la trajectoire de la modélisation des déplacements urbains en France met en évidence deux grandes périodes distinctes, aux caractéristiques contrastées. Après avoir commencé par se familiariser, à partir des années 1950, avec la modélisation américaine, les acteurs français, publics et privés, construisent, sous l'égide de la puissance publique, durant la décennie suivante et le début des années 1970, une expertise nationale que l'Administration centrale va ensuite " normaliser " et diffuser massivement à travers le territoire. Comme pour le cas nord-américain, la période " 1980-présent " est en revanche marquée par la domination progressive de ce champ de modélisation par le secteur privé, représenté souvent par des bureaux d'études étrangers et des entreprises productrices de logiciels originaires de pays autres que la France. Ce sont ces acteurs privés qui deviennent le vecteur principal du changement dans les pratiques en matière de modélisation des déplacements urbains en France après 1980

Le service des eaux de Paris (1810-1914), exemple (ignoré) de la grande entreprise moderne

Consultable en ligne : http://mtpf.mlab-innovation.net/fr/assets/ressources/PDF%20OK/Chatzis%20VF.pd

Stability of Wilson Loops and Other Observables in Various Type IIB Backgrounds

This work involves the stability study of various observables (Wilson loop, 't Hooft loop and Entanglement Entropy) under linear fluctuations of the coordinates for certain ten-dimensional solutions of type IIB Supergravity that have appeared in the literature recently. These backgrounds are defined using intersecting and wrapped D5 branes, their holographically dual field theories are speculated to confine and they have a non-local UV completion that is governed by Little String Theory. The present study confirms previous claims on the stability of the solutions made using the concavity condition for the energy of the probe strings, by studying the eigenvalue problem for each case and also providing a numerical analysis