On the consistency of Fr\'echet means in deformable models for curve and image analysis

A new class of statistical deformable models is introduced to study high-dimensional curves or images. In addition to the standard measurement error term, these deformable models include an extra error term modeling the individual variations in intensity around a mean pattern. It is shown that an appropriate tool for statistical inference in such models is the notion of sample Fr\'echet means, which leads to estimators of the deformation parameters and the mean pattern. The main contribution of this paper is to study how the behavior of these estimators depends on the number n of design points and the number J of observed curves (or images). Numerical experiments are given to illustrate the finite sample performances of the procedure

Measuring Competition between Non-Food and Food Demand on World Grain Markets : Is Biofuel Production Compatible with Pressure for Food Production ?

The flow of agricultural products between countries is conditioned by several factors including domestic and trade policy tools for the main competing exporters countries, and macroeconomic variables (such as real income per capita, rate of population growth,etc). Important structural changes are occurring on world agricultural markets that will have an impact on the long term competitiveness of countries and regions. These changes include developments in biofuels production linked to policy incentives, and the rapid growth in income and population numbers in some developing countries (such as India and China). An important issue is to identify the factors that are going to modify the balance between the supply and demand for agricultural products in the long term. In this paper, we look the example of arable crops. These markets allow an interesting analysis since they are directly concerned with the evolution of biofuels. One important question is to measure the competition between food demand and non food demand. We use a partial equilibrium model that focuses on world arable crop markets, the World Econometric Modeling of Arable Crops. The aim of the model is to produce annual market projections over a medium-term perspective and to simulate the impact of alternative national and international agricultural policy reforms for the main arable crops. The results of the simulations performed show that even if incentives to produce of biofuels have strong impacts on world markets, other factors such as changes in the assumptions of concerning the growth of emerging countries are also of great importance since the world cereal and oilseed markets as much are just bymodeling, econometric, partial equilibrium, land uses, biofuels, Demand and Price Analysis, International Relations/Trade,

What are the long-term drivers of food prices? Investigating improvements in the accuracy of prediction intervals for the forecast of food prices

Over the last few years, the prices of the main agricultural raw materials have been highly volatile. The situation is unprecedented, both in the magnitude of the upward and downward volatility observed, and in the number of agricultural commodities affected. Various factors are contributing to these contrasting shifts: the role of emerging countries, changing dietary habits, an increase in energy demand related to the boom in biofuels, adverse weather conditions and speculation. In this paper we try to capture long-term relationships between crop prices and crude oil price using a partial equilibrium and times series method. The study finds little empirical evidence that the crude oil price have a significant influence on the variation of major vegetable crops pricesPartial equilibrium modeling, Forecasting cointegration, Demand and Price Analysis, Q11, Q13, Q42,

Consistent estimation of a mean planar curve modulo similarities

We consider the problem of estimating a mean planar curve from a set of $J$ random planar curves observed on a $k$-points deterministic design. We study the consistency of a smoothed Procrustean mean curve when the observations obey a deformable model including some nuisance parameters such as random translations, rotations and scaling. The main contribution of the paper is to analyze the influence of the dimension $k$ of the data and of the number $J$ of observed configurations on the convergence of the smoothed Procrustean estimator to the mean curve of the model. Some numerical experiments illustrate these results

Recherche du rôle des intervenants et de leurs interactions pour la structuration de documents audiovisuels

Nous présentons un système de structuration automatique d'enregistrements audiovisuels s'appuyant sur des informations non lexicales caractéristiques des rôles des intervenants et de leurs interactions. Dans une première étape, nous proposons une méthode de détection et de caractérisation de séquences temporelles, nommée « zones d'interaction », susceptibles de correspondre à des conversations. La seconde étape de notre système réalise une reconnaissance du rôle des intervenants : présentateur, journaliste et autre. Notre contribution au domaine de la reconnaissance automatique du rôle se distingue en reposant sur l'hypothèse selon laquelle les rôles des intervenants sont accessibles à travers des paramètres « bas-niveau » inscrits d'une part dans l'organisation temporelle des tours de parole des intervenants, dans les environnements acoustiques dans lesquels ils apparaissent, ainsi que dans plusieurs paramètres prosodiques (intonation et débit). Dans une dernière étape, nous combinons l'information du rôle des intervenants à la connaissance des séquences d'interaction afin de produire deux niveaux de description du contenu des documents. Le premier niveau de description segmente les enregistrements en zones de 4 types : informations, entretiens, transition et intermède. Un second niveau de description classe les zones d'interaction orales en 4 catégories : débat, interview, chronique et relais. Chaque étape du système est validée par une grand nombre d'expériences menées sur le corpus du projet EPAC et celui de la campagne d'évaluation ESTER.We present a system for audiovisual document structuring, based-on speaker role recognition and speech interaction zone detection. The first stage of our system consists in an automatic method for speech interaction zones detection and characterization. Such zones correspond to temporal sequences of documents which potentially contain conversations between speakers. The second stage of our system achieves the recognition of speaker roles : anchorman, journalist and other. Our contribution to this domain is based on the hypothesis that cues about speaker roles are available through low-level features extracted from the temporal organization of turn-takings and from acoustic and prosodic features (speech rate and pitch). In the last stage of our system, we combine speaker roles and speech interaction zones to provide two descriptive layers of the audiovisual document contents. The first descriptive layer gathers segments of 4 types : informations, meeting, transition and interlude. The second descriptive layer consists in a classification of speech interaction zones into 4 categories : debate, interview, chronicle and relay. Each step of the system has been evaluated using a large number of experiments realized using the EPAC project and ESTER campaign corpora

Thermal contact resistance in micromoulding.

yesThis work outlines a novel approach for determining thermal contact resistance (TCR) in micromoulding. The proposed technique aims to produce TCR predictions with known confidence values and combines experimental evidence (temperature fields and contact angle measurements) with various mathematical modelling procedures (parametric representation of surfaces, finite element analysis and stochastic processes). Here, emphasis is made on the mathematical aspects of the project. In particular, we focus on the description of the parametric surface representation technique based on the use of partial differential equations, known as the PDE method, which will be responsible for characterizing and compressing micro features in either moulds or surface tools.EPSR

Factors acting on Mos1 transposition efficiency

<p>Abstract</p> <p>Background</p> <p><it>Mariner-</it>like elements (<it>MLEs</it>) are widespread DNA transposons in animal genomes. Although <it>in vitro </it>transposition reactions require only the transposase, various factors depending on the host, the physico-chemical environment and the transposon sequence can interfere with the <it>MLEs </it>transposition <it>in vivo</it>.</p> <p>Results</p> <p>The transposition of <it>Mos1</it>, first isolated from <it>drosophila mauritiana</it>, depends of both the nucleic acid sequence of the DNA stuffer (in terms of GC content), and its length. We provide the first <it>in vitro </it>experimental demonstration that MITEs of <it>MLE </it>origin, as small as 80 to 120-bp, are able to transpose. Excessive temperature down-regulates <it>Mos1 </it>transposition, yielding excision products unable to re-integrate. Finally, the super-helicity of the DNA transposon donor has a dramatic impact on the transposition efficiency.</p> <p>Conclusion</p> <p>The study highlights how experimental conditions can bias interpretation of <it>mariner </it>excision frequency and quality. <it>In vitro</it>, the auto-integration pathway markedly limits transposition efficiency to new target sites, and this phenomenon may also limit events in the natural host. We propose a model for small transposons transposition that bypasses DNA bending constraints.</p

PERSON NAME RECOGNITION IN ASR OUTPUTS USING CONTINUOUS CONTEXT MODELS

ABSTRACT The detection and characterization, in audiovisual documents, of speech utterances where person names are pronounced, is an important cue for spoken content analysis. This paper tackles the problematic of retrieving spoken person names in the 1-Best ASR outputs of broadcast TV shows. Our assumption is that a person name is a latent variable produced by the lexical context it appears in. Thereby, a spoken name could be derived from ASR outputs even if it has not been proposed by the speech recognition system. A new context modelling is proposed in order to capture lexical and structural information surrounding a spoken name. The fundamental hypothesis of this study has been validated on broadcast TV documents available in the context of the REPERE challenge

Predicting laser powder bed fusion defects through in-process monitoring data and machine learning

Industry application of additive manufacturing demands strict in-process quality control procedures and high product quality. Feedback loop control is a reasonable solution and a necessary tool. This paper demonstrated our preliminary work on the laser powder-bed fusion feedback loop: predict local porosity through in-process monitoring images and machine learning. 3D models were rebuilt from in-situ optical tomography monitoring images and post-build X-ray CT images. They were registered to the original CAD. Dataset for machine learning was assembled from those registered 3D models. The trained machine learning model can precisely predict local porosity caused by lack of fusion and keyhole with multi-layer monitoring images. It also indicates the optimal processing window. It is impossible to be sure about the occurrence of defects in a layer based only on the abnormality of a single layer, and vice versa. Defects in a layer can be caused by improper parameters or anomalies in current layer or subsequent layers; defects in one layer can also be eliminated by proper parameters in the following layers. The work laid the basis for the next step feedback loop control of pore defect

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)