Search results for "values."
showing 10 items of 1353 documents
Adiabatic evolution for systems with infinitely many eigenvalue crossings
1998
International audience; We formulate an adiabatic theorem adapted to models that present an instantaneous eigenvalue experiencing an infinite number of crossings with the rest of the spectrum. We give an upper bound on the leading correction terms with respect to the adiabatic limit. The result requires only differentiability of the considered projector, and some geometric hypothesis on the local behavior of the eigenvalues at the crossings.
Protecting sensitive patient groups from imaging using ionizing radiation: effects during pregnancy, in fetal life and childhood
2019
The frequency of imaging examinations requiring radiation exposure in children (especially CT) is rapidly increasing. This paper reviews the current evidence in radiation protection in pediatric imaging, focusing on the recent knowledge of the biological risk related to low doses exposure. Even if there are no strictly defined limits for patient radiation exposure, it is recommended to try to keep doses as low as reasonably achievable (the ALARA principle). To achieve ALARA, several techniques to reduce the radiation dose in radiation-sensitive patients groups are reviewed. The most recent recommendations that provide guidance regarding imaging of pregnant women are also summarized, and the…
ANALISI SISTEMATICA DELL'UNIVERSO VALORIALE DEI GIOVANI ATTRAVERSO LO SCHWARTZ VALUES SURVEY (SVS)
2007
The aim of this research is inquiring how the universal human values proposed by Schwartz are applicable to a sample of Sicilian young people. Particularly, our research wants to evaluate how much our value system is afar from the one proposed by Schwartz and to which values our sample gives importance. The results of the research seem to confirm Schwartz’s theory on human values, except some difference.
Socially desirable responding:enhancement and denial in 20 countries
2015
This article investigated the dimensionality, measurement invariance, and cross-cultural variations of social desirability. A total of 3,471 university students from 20 countries completed an adapted version of the Marlowe–Crowne scale. A two-dimensional structure was revealed in the pooled sample, distinguishing enhancement (endorsement of positive self-description) and denial (rejection of negative self-description). The factor structure was supported in most countries; medium-sized item bias was found in two denial items. In a multilevel analysis, we found that (a) there was more cross-cultural variation in denial than enhancement; (b) females tended to score higher on enhancement where…
Invariant Feature Matching for Image Registration Application Based on New Dissimilarity of Spatial Features
2016
An invariant feature matching method is proposed as a spatially invariant feature matching approach. Deformation effects, such as affine and homography, change the local information within the image and can result in ambiguous local information pertaining to image points. New method based on dissimilarity values, which measures the dissimilarity of the features through the path based on Eigenvector properties, is proposed. Evidence shows that existing matching techniques using similarity metrics--such as normalized cross-correlation, squared sum of intensity differences and correlation coefficient--are insufficient for achieving adequate results under different image deformations. Thus, new…
Comparative in vitro study of the accuracy of impression techniques for dental implants: Direct technique with an elastomeric impression material ver…
2019
Background The aim of this study was to compare a conventional technique (elastomeric impression material - EIM) and a digital technique (scanner digital model – SDM) on a six-analog master model (MM) to determine which was the most exact. Material and Methods Twenty impressions were taken of a master model (EIM) and twenty scanned impressions (SDM) (True Definition). A coordinate measuring machine (CMM) was used to measure the distances between adjacent analogues (1-2, 2-3, 3-4, 4-5, 5-6), intermittently positioned analogues (1-4, 3-6) and the most distal (1-6). Reference values were established from the master model, which were compared with the two impression techniques. The significance…
Experimental and Modeling Analyses of Human Motion Across the Static Magnetic Field of an MRI Scanner
2021
It is established that human movements in the vicinity of a permanent static magnetic field, such as those in magnetic resonance imaging (MRI) scanners induce electric fields in the human body; this raises potential severe risks of health to radiographers and cleaners exposed routinely to these fields in MRI rooms. The relevant directives and parameters, however, are based on theoretical models, and accurate studies on the simulation of the effects based on human movement data obtained in real conditions are still lacking. Two radiographers and one cleaner, familiar with MRI room activities and these directives, were gait analyzed during the execution of routine job motor tasks at different…
Problematic aspects of models of culture in European legal culture and selected personal models of people of the road
2016
the aim of the hereby paper is not to present a standpoint related to the term and structure of culture, it is to present the models of culture from a perspective of scientists that undertake this matter. Therefore, the problematic issues of models of culture have been presented, with regard to differentiation of standpoints presented by authors undertaking the matter. Against this background, the problem of placing personal models of culture within changes that take place in culture, seems to outline distinctively. the issue of personal models is related to the sphere of cultural values. These determine the changes that take place in the area of culture: the deeper the alterations in cultu…
Sharp estimates and saturation phenomena for a nonlocal eigenvalue problem
2011
Abstract We determine the shape which minimizes, among domains with given measure, the first eigenvalue of a nonlocal operator consisting of a perturbation of the standard Dirichlet Laplacian by an integral of the unknown function. We show that this problem displays a saturation behaviour in that the corresponding value of the minimal eigenvalue increases with the weight affecting the average up to a (finite) critical value of this weight, and then remains constant. This critical point corresponds to a transition between optimal shapes, from one ball as in the Faber–Krahn inequality to two equal balls.
Distribution of Eigenvalues for Semi-classical Elliptic Operators with Small Random Perturbations, Results and Outline
2019
In this chapter we will state a result asserting that for elliptic semi-classical (pseudo-)differential operators the eigenvalues are distributed according to Weyl’s law “most of the time” in a probabilistic sense. The first three sections are devoted to the formulation of the results and in the last section we give an outline of the proof that will be carried out in Chaps. 16 and 17.