Search results for "Linea"
showing 10 items of 7724 documents
Modelling of rotations by using matrix solutions of nonlinear wave equations
2007
A family of matrix solutions of nonlinear wave equations is extended and its application to modelling is given. It is shown that a similarity transformation, induced by the matrix solution, is equivalent to the rotation. Matrix solutions are used for modelling helical motions and vortex rings, simultaneous rotations and particles collision, mapping contraction and pulsating spheres. Geometrical interpretation of the doubling of rotation angle in each step of sequential mapping contraction is given. First Published Online: 14 Oct 2010
The role of physical activity in the link between menopausal status and mental well-being
2020
OBJECTIVE To examine the relationship between menopausal status and mental well-being, and whether this relationship varies as a function of physical activity (PA). METHODS Based on a hormonal analysis and bleeding diary, women aged 47 to 55 were categorized as pre (n = 304), early peri (n = 198), late peri (n = 209), or postmenopausal (n = 387). Mental well-being was assessed using the Centre for Epidemiologic Studies Depression Scale, the International Positive and Negative Affect Schedule Short Form, and the Satisfaction with Life Scale. PA was self-reported and categorized as low, medium, and high. Associations between variables were analyzed using multivariate linear regression adjuste…
The Potentials of Tangible Technologies for Learning Linear Equations
2020
Tangible technologies provide interactive links between the physical and digital worlds, thereby merging the benefits of physical and virtual manipulatives. To explore the potentials of tangible technologies for learning linear equations, a tangible manipulative (TM) was designed and developed. A prototype of the initial TM was implemented and evaluated using mixed methods (i.e., classroom interventions, paper-based tests, thinking aloud sessions, questionnaires, and interviews) in real classroom settings. Six teachers, 24 primary school students, and 65 lower secondary school students participated in the exploratory study. The quantitative and qualitative analysis revealed that the initial…
All-Possible-Couplings Approach to Measuring Probabilistic Context
2013
From behavioral sciences to biology to quantum mechanics, one encounters situations where (i) a system outputs several random variables in response to several inputs, (ii) for each of these responses only some of the inputs may ‘‘directly’’ influence them, but (iii) other inputs provide a ‘‘context’’ for this response by influencing its probabilistic relations to other responses. These contextual influences are very different, say, in classical kinetic theory and in the entanglement paradigm of quantum mechanics, which are traditionally interpreted as representing different forms of physical determinism. One can mathematically construct systems with other types of contextuality, whether or …
Demo 101. Cohete impulsado por agua y aire a presión
2013
Objetivos: Demostrar el principio de conservación del momento lineal de un sistema: el cuerpo del cohete se mueve en un determinado sentido (hacia arriba) debido a que los fluidos propulsores salen despedidos en sentido opuesto.
Demo 17. Coordenadas curvilíneas: cilindro y esfera
2013
Objetivo: Adquirir familiaridad con las coordenadas cilíndricas y esféricas mediante un modelo real o 3D previo a la representación en el plano mediante la perspectiva.
An operatorial approach to stock markets
2009
We propose and discuss some toy models of stock markets using the same operatorial approach adopted in quantum mechanics. Our models are suggested by the discrete nature of the number of shares and of the cash which are exchanged in a real market, and by the existence of conserved quantities, like the total number of shares or some linear combination of cash and shares. The same framework as the one used in the description of a gas of interacting bosons is adopted.
Egg parasitoid attraction toward induced plant volatiles is disrupted by a non-host herbivore attacking above or belowground plant organs.
2014
Plants respond to insect oviposition by emission of oviposition-induced plant volatiles (OIPVs) which can recruit egg parasitoids of the attacking herbivore. To date, studies demonstrating egg parasitoid attraction to OIPVs have been carried out in tritrophic systems consisting of one species each of plant, herbivore host, and the associated egg parasitoid. Less attention has been given to plants experiencing multiple attacks by host and non-host herbivores that potentially could interfere with the recruitment of egg parasitoids as a result of modifications to the OIPV blend. Egg parasitoid attraction could also be influenced by the temporal dynamics of multiple infestations, when the same …
Water polo game-related statistics in women’s international championships as a function of final score differences
2016
The aims of this study were: (i) to compare water polo game-related statistics by context (winning and losing teams) and final score differences (using three categories – “close” games, “unbalanced...
Insights into the derivative-based method for nonlinear mediation models
2022
Associational mediation analysis has generally relied on the linearity of models to estimate the indirect effect as a product of regression coefficients. Very few examples of generalisations to nonlinear settings have been proposed, including a derivative-based method that, however, is far from being widely spread among scholars. In this paper, we clarify some aspects of such an approach to nonlinear mediation models, which have not been addressed by the previous literature. In addition, we run a simulation study to compare confidence intervals for the indirect effect obtained through different approaches.