Search results for "equation"
showing 10 items of 4219 documents
Motivational climate, goal orientation, perceived sport ability, and enjoyment within Finnish junior ice hockey players
2015
The aim of this study was to investigate the relations among situational motivational climate, dispositional approach and avoidance achievement goals, perceived sport ability, and enjoyment in Finnish male junior ice hockey players. The sample comprised 265 junior B-level male players with a mean age of 17.03 years (SD = 0.63). Players filled questionnaires tapping their perceptions of coach motivational climate, achievement goals, perceived sport ability, and enjoyment. For the statistical analysis, players were divided into high and low perceived sport ability groups. Multigroup structural equation modeling (SEM) revealed an indirect path from task-involving motivational climate via task-…
Validez factorial del “cuestionario para la evaluación del síndrome de quemarse por el Trabajo” (CESQT) en una muestra de médicos mexicanos
2010
El objetivo del este estudio fue evaluar la validez factorial y la consistencia interna del “Cuestionario para la Evaluación del Síndrome de Quemarse por el Trabajo” (CESQT). Se hipotetizó un modelo de cuatro factores, similar al del oringinal. La muestra fueron estuvo formada por 1110 médicos del Instituto Mexicano del Seguro Social. El instrumento está formado por 20 items distribuidos en 4 subescalas: Ilusión por el trabajo (5 items), Desgaste psíquico (4 items), Indolencia (6 items), y Culpa (5 items). El modelo fue evaluado con LISREL 8. Según diferentes índices de ajuste global el modelo presentó un ajuste adecuado: Chi2(164) = 225.06 (p < 0.001), GFI = 0.83, RMSEA = 0.061, NNFI = …
A sub-supersolution approach for Neumann boundary value problems with gradient dependence
2020
Abstract Existence and location of solutions to a Neumann problem driven by an nonhomogeneous differential operator and with gradient dependence are established developing a non-variational approach based on an adequate method of sub-supersolution. The abstract theorem is applied to prove the existence of finitely many positive solutions or even infinitely many positive solutions for a class of Neumann problems.
Unified thermodynamic framework for nonlocal/gradient continuum theories
2003
Abstract A thermodynamic framework, equipped with the concept of nonlocality (energy) residual, is utilized to address nonlocal/gradient internal variable material models. A unified procedure is provided for either nonlocal and gradient materials, which makes it possible to determine the thermodynamic restrictions upon the constitutive equations, and in particular the pertinent state equations, the consistent form of the dissipation power and the constitutive expression of the nonlocality residual. Additionally, for gradient models, the associated nonstandard boundary conditions are derived, pointing out their basically constitutive nature and their substantial differences from the standard…
Comparison of analytical methods and AI tools for material characterisation in hot forming
2002
Abstract Hot forming processes probably represent the most ancient of forming operations and what is more they are still today commonly used in modern mechanical industry in order to obtain sound parts, achieving large deformations with a limited required power. Hot metal forming operations are characterised by a large number of physical and thermal phenomena which have to be taken into account in order to model and design the processes themselves. Actually several thermally activated phenomena occur during the forming processes such as recovery, recrystallisation, grain growth, precipitation, allotropic transformations, etc. In this paper the comparison between an analytical method based o…
Curved Edge Routing
2001
We consider the problem of drawing a graph where edges are represented by smooth curves between the associated nodes. Previously curved edges were drawn as splines defined by carefully calculated control points. We present a completely different approach where finding an edge is reduced to solving a differential equation. This approach allows to represent the graph drawing aesthetics directly, even the most complex ones denoting the dependencies among the paths.
Matter, quantum gravity, and adiabatic phase
1990
Based on the observation that particle masses are much smaller than the Planck mass, a framework for the matter-gravity system in which matter follows gravitation adiabatically is examined in a path-integral approach. It is found that the equations that the resulting gravitational wave function satisfies involve, in addition to the expectation value of the matter stress tensor, an adiabatically induced gauge field which can lead to interesting topological structures in superspace. Such a non-trivial geometric contribution modifies the semiclassical quantization condition and can change the conserved quantities associated with the symmetries of the system. © 1990 The American Physical Societ…
Tourism and migration: Identifying the channels with gravity models
2020
As a result of the role played by migrants in supporting host economies, the interest in understanding the impact of migration is growing. However, the literature remains silent on the channels by which migration affects tourism. The present article aims to isolate the effect of migrant networks on tourism by exploring the role of information, travel costs, and demand for visiting friends and relatives. To this end, a theoretical framework that rests upon a structural gravity model is developed. The model allows not only a better understanding of the relationship between tourism and migration but also to overcome several empirical biases like the omission of multilateral resistance in tour…
IST Versus PDE: A Comparative Study
2015
We survey and compare, mainly in the two-dimensional case, various results obtained by IST and PDE techniques for integrable equations. We also comment on what can be predicted from integrable equations on non integrable ones.
Effect of epicentral direction on seismic response of asymmetric buildings
1984
The paper deals with the influence of the epicentral direction on the displacement and stress response of multistorey asymmetric buildings to earthquake horizontal ground motion. A method is given for computing for each plane frame of the complex structure a particular direction of the bidirectional stationary random input for which the horizontal floor displacement of the given frame is maximized. It is shown that this direction can be considered conservative for the corresponding non-stationary process.