Search results for "Normalization"
showing 10 items of 632 documents
Modified LACIF filtering in background disjoint noise
2011
Abstract This work deals with pattern recognition methods based on correlations for images in the presence of noise. We propose a modification of the nonlinear Locally Adaptive Contrast Invariant Filter (LACIF) that yields correlation peaks that are invariant to linear intensity changes of the target but that has some limitations in the presence low variance nonoverlapping background noise. The modification of the filter implies a normalization by a global variance of several distributions. The estimation of the variance distributions is done locally by means of correlations. Experimental results as well as comparisons with the classical matched filter and the common LACIF are given.
EFFECT OF IMAGE NORMALIZATION ON CAROTID PLAQUE CLASSIFICATION AND THE RISK OF IPSILATERAL HEMISFERIC ISCHEMIC EVENTS. RESULTS FROM THE ASYMPTOMATIC …
2005
The aim of this study was to determine the effect of image normalization on plaque classification and the risk of ipsilateral ischemic neurologic events in patients with asymptomatic carotid stenosis. The first 1,115 patients recruited to the Asymptomatic Carotid Stenosis and Risk of Stroke (ACSRS) study with a follow-up of 6 to 84 months (mean 37.1 months) were included in this study. Duplex ultrasonography was used for grading the degree of internal carotid artery stenosis and for plaque characterization (types 1-5), which was performed before and after image normalization. One hundred sixteen ipsilateral ischemic hemispheric events occurred. Image normalization resulted in 60% of plaques…
Penetrant diffusion in frozen polymer matrices: A finite-size scaling study of free volume percolation
1996
The diffusion of penetrant particles in frozen polymer matrices is investigated by means of Monte Carlo simulations of the bond fluctuation model. By applying finite-size scaling to data obtained from very large systems it is demonstrated that the diffusion process takes place on a percolating free volume cluster describable by a correlated site percolation model which falls into the same universality class as random percolation. The diverging correlation length entails a pronounced dependence of the diffusion constant on the size of the simulated system. It is shown that this dependence is appreciable for a wide range of parameters around the transition. \textcopyright{} 1996 The American …
Low-temperature specific heat of orientational glasses
1992
This review summarizes specific heat data measured at low temperatures (T<1 K) on orientational glasses. Three species of mixed molecular crystals exhibiting orientational disorder are considered, namely (KBr)1−x (KCN) x , (NaCN)1−x (KCN) x (Rb)1−x (NH4) x H2PO4. For intermediate concentrations of the anisotropic components, glass-like excitations have been observed. It is demonstrated that with respect to thermal properties, orientational disorder leads to the same “universal” behaviours than for structural disorder, i.e. a specific heat which varies below 1 K and for times 10−4 s–10 s as:C p(T,t)∞T 1×ln(t). The variation of the glass-like anomaly with compositional disorder is also discus…
Design of a customized pattern for improving color constancy across camera and illumination changes
2010
International audience; This paper adresses the problem of color constancy on a large image database acquired with varying digital cameras and lighting conditions. Automatic white balance control proposed by an available commercial camera is not sufficient to provide reproducible color classification. A device-independent color representation may be obtained by applying a chromatic adaptation transform, from a calibrated color checker pattern included in the field of view. Instead of using the standard Macbeth color checker, we suggest to select judicious colors to design a customized pattern from contextual information. A comparative study demonstrates that this approach insures a stronger…
Quantum effects, anomalies and renormalization in Electrodynamics, Cosmology and Black Holes
2023
La Teoria Quàntica de Camps en Espais Corbats ha demostrat ser una teoria semi-clàssica molt útil per a l'estudi de fenòmens físics que combinen gravetat i efectes quàntics. En particular, prediu que la dinàmica d'un camp gravitacional de fons pot excitar espontàniament partícules a partir del buit quàntic. El procés de producció de partícules té una importància especial en l'estudi de l'univers primerenc en cosmologia i és la base de la radiació de Hawking en la física dels forats negres. Físicament, aquest efecte quàntic és anàleg a l'efecte Schwinger ben conegut en l'electrodinàmica quàntica. L'objectiu d'aquesta Tesi és estudiar aquest fenomen general de producció de partícules, així co…
Complete One-Loop Renormalization of the Higgs-Electroweak Chiral Lagrangian
2018
The electroweak sector of the Standard Model can be formulated in a way similar to Chiral Perturbation Theory (ChPT), but extended by a singlet scalar. The resulting effective field theory (EFT) is called Higgs-Electroweak Chiral Lagrangian (EWCh$\mathcal{L}$) and is the most general approach to new physics in the Higgs sector. It solely assumes the pattern of symmetry breaking leading to the three electroweak Goldstone bosons (i.e. massive $W$ and $Z$) and the existence of a Higgs-like scalar particle. The power counting of the EWCh$\mathcal{L}$ is given by a generalization of the momentum expansion of ChPT. It is connected to a loop expansion, making the theory renormalizable order by ord…
High-energy resummation effects in the production of Mueller-Navelet dijet at the LHC
2016
We study the production of two forward jets with a large interval of rapidity at hadron colliders, which was proposed by Mueller and Navelet as a possible test of the high energy dynamics of QCD, within a complete next-to-leading logarithm framework. We show that using the Brodsky-Lepage-Mackenzie procedure to fix the renormalization scale leads to a very good description of the recent CMS data at the LHC for the azimuthal correlations of the jets. We show that the inclusion of next-to-leading order corrections to the jet vertex significantly reduces the importance of energy-momentum non-conservation which is inherent to the BFKL approach, for an asymmetric jet configuration. Finally, we ar…
LGTBIQfobia audiovisual: La ocultación de colectivos sexualmente diversos en Disney
2021
La LGTBIQfobia supone una barrera para la normalización de colectivos sexualmente diversos. Productos como los audiovisuales Disney dificultan esta tarea ya que la compañía tiende a ocultarlas. De esta manera se frena el desarrollo de una ciudadanía más tolerante y respetuosa con la diferencia desde las primeras edades. En la educación hay una preocupación latente por erradicar el bullying LGTBIQfóbico. Por ello, a través de un posicionamiento queer y de una metodología mixta se analiza la colección “Los clásicos” Disney para manifestar los ataques hacia dicho colectivo y concienciar a quienes la utilizan como recurso en sus aulas con los grupos de menores. También para visibilizar los ejem…
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:…