15 documents found, page 1 of 2

Effects of a music-based intervention on psychophysiological outcomes of patien...

Introduction: Musical intervention (MI) is a valuable strategy for addressing the psychological and emotional challenges faced by patients undergoing imaging procedures. This study explores MI's impact on psychophysiological outcomes during imaging procedures, detailing the sound repertoire and technical characteristics employed in MI. Methods: A systematic review (SR) and meta-analysis (MA) were conducted. Ele...

Evaluation of SPECT imaging: a multi-center and multi-vendor phantom study

Background: Single-photon emission computed tomography (SPECT) is a nuclear medicine (NM) imaging method sensitive to the evaluation and quantification of physiological processes in patients. However, there are different factors that affect qualitatively and quantitatively the SPECT images and, consequently, the reliability of the data. There is a degree of variability underlying the intrinsic performance of sy...

EVOLUTION OF THE NUMBER OF STUDENTS IN ELEMENTARY AND SECONDARY SCHOOL IN PORTU...

In this work, we present an application of a mathematical model structured in classes (see [1]) for the study of the influence of population ageing in the evolution of the number of students in elementary school and in secondary school in Portugal, from 1995/96 to 2014/15 (see [2]). Based on historical data, some scenarios of projection are presented, with the aim of quantifying the young student population and...

Classes of Commuting Matrices

A deflation method for regular matrix pencils

A generalization of the concept of eigenvalue is introduced for a matrix pencil and it is called eigenpencil; an eigenpencil is a pencil itself and it contains part of the spectral information of the matri pencil. A Wielandt type deflation procedure for regular matrix pencils is developed, using eigenpencils and supposing that they can have both finite and infinite eigenvalues. A numerical example illustrates t...

A method for Construct Sets of Commuting Matrices

A method for constructing sets of matrices that pairwise commute is presented. The sets are defined such that each matrix is a combination of basic matrices. An iterative algorithm is given, where the construction approach aims to obtain appropriate basic matrices. A numerical example illustrate the proposed method.

A Model Structured in Classes for the Study of Student Population Evolution

This paper presents an application of a metapopulation model structured in classes for the study of population evolution of a network of schools. The global dynamics are considered in two parts, the local, where the evolution for each grade in a cycle is accounted, and the metapopulation or the movement of students between schools. Simulation of the model is presented.

Evolution of the Number of Students in Elementary and Secondary School in Portu...

In this work, we present an application of a mathematical model structured in classes (see [1]) for the study of the influence of population ageing in the evolution of the number of students in elementary school and in secondary school in Portugal, from 1995/96 to 2014/15 (see [2]). Based on historical data, some scenarios of projection are presented, with the aim of quantifying the young student population and...

A fixed point method to compute solvents of matrix polynomials

Matrix polynomials play an important role in the theory of matrix differential equations. We develop a fixed point method to compute solutions of matrix polynomials equations, where the matricial elements of the matrix polynomial are considered separately as complex polynomials. Numerical examples illustrate the method presented.

Radiopharmaceuticals for myocardial perfusion imaging: SPECT & PET

Myocardial perfusion imaging (MPI) is used on a daily basis to access coronary blood flow in patients that are suspected or have known Coronary Artery Disease (CAD). A Single Photon Emission Computed Tomography (SPECT) or and Positron Emission Tomography (PET) scan are used to access regional blood flow quantification either at rest or stress, the imaging acquisition is connected to an Electrocardiogram (ECG) a...