Search results for "Estimation"

Evaluation of MRI and cannabinoid type 1 receptor PET templates constructed using DARTEL for spatial normalization of rat brains

2015

Purpose: Image registration is one prerequisite for the analysis of brain regions in magnetic-resonance-imaging (MRI) or positron-emission-tomography (PET) studies. Diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL) is a nonlinear, diffeomorphic algorithm for image registration and construction of image templates. The goal of this small animal study was (1) the evaluation of a MRI and calculation of several cannabinoid type 1 (CB1) receptor PET templates constructed using DARTEL and (2) the analysis of the image registration accuracy of MR and PET images to their DARTEL templates with reference to analytical and iterative PET reconstruction algorithms. Methods:…

Information-theoretic assessment of cardiovascular-brain networks during sleep

2015

This study was aimed at detecting the structure of the physiological network underlying the regulation of the cardiovascular and brain systems during normal sleep. To this end, we measured from the polysomnographic recordings of 10 healthy subjects the normalized spectral power of heart rate variability in the high frequency band (HF) and the EEG power in the δ, θ, α, σ, and β bands. Then, the causal statistical dependencies within and between these six time series were assessed in terms of internal information (conditional self entropy, CSE) and information transfer (transfer entropy, TE) computed via a linear method exploiting multiple regression models and a nonlinear method combining ne…

Time perception in depression: a meta-analysis.

2014

Background Depressive patients frequently report to perceive time as going by very slowly. Potential effects of depression on duration judgments have been investigated mostly by means of four different time perception tasks: verbal time estimation, time production, time reproduction, and duration discrimination. Ratings of the subjective flow of time have also been obtained. Methods By means of a classical random-effects meta-regression model and a robust variance estimation model, this meta-analysis aims at evaluating the inconsistent results from 16 previous studies on time perception in depression, representing data of 433 depressive patients and 485 healthy control subjects. Results Dep…

Editorial for the Special Issue “Frontiers in Spectral Imaging and 3D Technologies for Geospatial Solutions”

2019

This Special Issue hosts papers on the integrated use of spectral imaging and 3D technologies in remote sensing, including novel sensors, evolving machine learning technologies for data analysis, and the utilization of these technologies in a variety of geospatial applications. The presented results showed improved results when multimodal data was used in object analysis.

Diet-disease relationships : recent advances in nutritional epidemiology

2020

Nutritional epidemiology currently studies the diet-disease relationships. In order to evaluate these associations, an accurate estimation of nutritional exposure is essential. Traditional dietary questionnaires are being complemented with the measurement of nutritional biomarkers. New methodologies, including the use of new dietary assessments, metabolomics for increasing the quantity and quality of biomarkers, and statistical approaches to combine both techniques, are required to move forward this field. In this review, we have selected five of the more relevant accomplishments in this field as examples of the importance of dietary factors in the prevention of non-communicable diseases. T…

Effects of cigarette smoking on time estimation

1998

Green value and spatial approaches of energy demand management.

2020

Les contraintes économiques et environnementales actuelles impliquent un besoin de maîtrise de la demande d’énergie du secteur résidentiel. Pour parvenir à cette fin, il est nécessaire d’identifier les déterminants de la consommation d’énergie des ménages puis de trouver des solutions pour réduire la demande d’énergie. Les travaux présentés dans la thèse portent sur le rôle des choix de localisation des ménages dans la formation de la demande d’énergie du secteur résidentiel et s’intéresse à la valeur verte comme outil de promotion des biens immobiliers énergétiquement efficaces. Le premier chapitre étudie les choix de localisation résidentielle et de consommation énergétique des ménages da…

A Velocity Estimation Technique for a Monocular Camera Using mmWave FMCW Radars

2021

Perception in terms of object detection, classification, and dynamic estimation (position and velocity) are fundamental functionalities that autonomous agents (unmanned ground vehicles, unmanned aerial vehicles, or robots) have to navigate safely and autonomously. To date, various sensors have been used individually or in combination to achieve this goal. In this paper, we present a novel method for leveraging millimeter wave radar’s (mmW radar’s) ability to accurately measure position and velocity in order to improve and optimize velocity estimation using a monocular camera (using optical flow) and machine learning techniques. The proposed method eliminates ambiguity in optical flow veloci…

Recursion at the crossroads of sequence modeling, random trees, stochastic algorithms and martingales

2013

This monograph synthesizes several studies spanning from dynamical systems in the statistical analysis of sequences, to analysis of algorithms in random trees and discrete stochastic processes. These works find applications in various fields ranging from biological sequences to linear regression models, branching processes, through functional statistics and estimates of risk indicators for insurances. All the established results use, in one way or another, the recursive property of the structure under study, by highlighting invariants such as martingales, which are at the heart of this monograph, as tools as well as objects of study.

On time-harmonic Maxwell equations with nonhomogeneous conductivities : Solvability and FE-approximation

1989

The solvability of time-harmonic Maxwell equations in the 3D-case with non­homogeneous conductivities is considered by adapting Sobolev space technique and variational formulation of the probJem in question. Moreover, a finite element approximation is presented in the 3D·case together with an error estimate in the energy norm. Some remarks are given to the 2D-problem arising from geophysics. peerReviewed