Results 21 to 30 of about 3,595,948 (318)
Noether's theorem on time scales [PDF]
Journal of Mathematical Analysis and Applications, 2008 We show that for any variational symmetry of the problem of the calculus of variations on time scales there exists a conserved quantity along the respective Euler-Lagrange extremals.
Bartosiewicz, Z., Torres, D.F.M.
openaire +3 more sources
Observable space of the nonlinear control system on a homogeneous time scale; pp. 11–25 [PDF]
Proceedings of the Estonian Academy of Sciences, 2014 The observability property of the nonlinear system, defined on a homogeneous time scale, is studied. The observability condition is provided through the notion of the observable space.
Vadim Kaparin +2 more
doaj +1 more source
The asymptotic properties of the dynamic equation with a delayed argument [PDF]
Opuscula Mathematica, 2006 In this paper, we present some asymptotic results related to the scalar dynamic equation with a delayed argument. Using the time scale calculus we generalize some results known in the differential and difference case to the more general dynamic case.
Jan Čermák, Miroslav Urbánek
doaj
Nabla inequalities and permanence for a logistic integrodifferential equation on time scales
Open Mathematics, 2017 In this paper, by using the theory of calculus on time scales and some mathematical methods, several nabla dynamic inequalities on time scales are established. As an application, we apply the obtained results to a logistic integrodifferential equation on
Hu Meng, Wang Lili
doaj +1 more source
Certain novel estimates within fractional calculus theory on time scales
AIMS Mathematics, 2020 The key purpose of this study is to suggest a delta Riemann-Liouville (RL) fractional integral operators for deriving certain novel refinements of Pólya-Szegö and Čebyšev type inequalities on time scales.
Jian-Mei Shen +4 more
doaj +1 more source
The Time Scale of Evolution [PDF]
, 2018 AbstractFitness is a measure of how quickly alleles change in frequency under natural selection. Time is always implicit in evolutionary models but its units are rarely made explicit. When measuring phenotypes such as absolute growth rate, the units of measurement need to be made explicit.
Passagem-Santos, Diogo, Perfeito, Lilia
openaire +2 more sources
On the Variation of Turbulence in a High-Velocity Tidal Channel
Energies, 2019 This study presents the variation in turbulence parameters derived from site measurements at a tidal energy test site. Measurements were made towards the southern end of the European Marine Energy Centre’s tidal energy test site at the Fall of Warness ...
Charles Greenwood +2 more
doaj +1 more source
Time scales in cognitive neuroscience [PDF]
Frontiers in Physiology, 2013 Cognitive neuroscience boils down to describing the ways in which cognitive function results from brain activity. In turn, brain activity shows complex fluctuations, with structure at many spatio-temporal scales. Exactly how cognitive function inherits the physical dimensions of neural activity, though, is highly non-trivial, and so are generally the ...
openaire +6 more sources
A Hierarchy of Time-Scales and the Brain
PLoS Computational Biology, 2008 In this paper, we suggest that cortical anatomy recapitulates the temporal hierarchy that is inherent in the dynamics of environmental states. Many aspects of brain function can be understood in terms of a hierarchy of temporal scales at which representations of the environment evolve. The lowest level of this hierarchy corresponds to fast fluctuations
Kiebel, SJ, Daunizeau, J, Friston, KJ
openaire +7 more sources
Time‐scale transformations of discrete time processes [PDF]
Journal of Time Series Analysis, 2003 Abstract. This paper investigates the effects of temporal aggregation when the aggregation frequency is variable and possibly stochastic. The results that we report include, as a particular case, the well‐known results on fixed‐interval aggregation, such as when monthly data are aggregated into quarters.
Òscar Jordà +3 more
openaire +6 more sources