Search results for "online"
showing 10 items of 4526 documents
Identification of stiffness,dissipation and input parameters of randomly excited non-linear systems: Capability of restricted potential models (RPM)
2006
Abstract A dynamic identification technique in the time domain for time invariant systems under random external forces is presented. This technique is based on the use of the class of restricted potential models (RPM), which are characterized by a non-linear stiffness and a special form of damping, that is a product of the input power spectral density (PSD) matrix and the velocity gradient of a non-linear function of the total mechanical energy. By applying It o ^ stochastic differential calculus and by specific analytical manipulations, some algebraic equations, depending on the response statistics and on the mechanic parameters that characterize RPM, are obtained. These equations can be u…
One-dimensional families of projections
2008
Let m and n be integers with 0 < m < n. We consider the question of how much the Hausdorff dimension of a measure may decrease under typical orthogonal projections from onto m-planes provided that the dimension of the parameter space is one. We verify the best possible lower bound for the dimension drop and illustrate the sharpness of our results by examples. The question stems naturally from the study of measures which are invariant under the geodesic flow.
Comparison of discretization strategies for the model-free information-theoretic assessment of short-term physiological interactions
2023
This work presents a comparison between different approaches for the model-free estimation of information-theoretic measures of the dynamic coupling between short realizations of random processes. The measures considered are the mutual information rate (MIR) between two random processes [Formula: see text] and [Formula: see text] and the terms of its decomposition evidencing either the individual entropy rates of [Formula: see text] and [Formula: see text] and their joint entropy rate, or the transfer entropies from [Formula: see text] to [Formula: see text] and from [Formula: see text] to [Formula: see text] and the instantaneous information shared by [Formula: see text] and [Formula: see…
Influence of Active Device Nonlinearities on the Determination of Adler's Injection.Locking Q-Factor
2011
The problem of the correct evaluation of Q-factor appearing in Adler's equation for injection-locking is addressed. Investigation has shown that recent results presented in the literature, while extending applicability of the original method, do not completely account for nonlinear effects occurring when two-port active devices are involved. To overcome such limitation, use can be made of a newly developed theory in the dynamical complex envelope domain, capable of providing first-approximation exact dynamical models of driven quasi-sinusoidal oscillators. Some preliminary results are presented here concerning a class of injection-locked oscillators with single-loop feedback type configurat…
Emotions in E-Learning
2008
This paper presents the results of an educational innovation in Higher Education, whose aim is to design and test a pedagogical model for e-learning. This paper has the main aim to identify and evaluate emotional factors related to e-learning by means of a survey research. The results show emotional well-being scores higher than wrong-being, identifying a range of emotions, which are related to different emotional states in e-learning. In addition, we present features of teachers’ and students’ virtual discourses in forums of discussion starting from types of educational interaction and kind of emotions related to certain settings of learning activity.
Convergence of KAM iterations for counterterm problems
1998
Abstract We analyse two iterative KAM methods for counterterm problems for finite-dimensional matrices. The starting point for these methods is the KAM iteration for Hamiltonians linear in the action variable in classical mechanics. We compare their convergence properties when a perturbation parameter is varied. The first method has no fixed points beyond a critical value of the perturbation parameter. The second one has fixed points for arbitrarily large perturbations. We observe different domains of attraction separated by Julia sets.
Ģeogrāfisko informācijas sistēmu apguve pamatskolā: Arcgis online praktiskie uzdevumi ģeogrāfijā 7.-9. klasēs
2022
Bakalaura darba tēma ir “Ģeogrāfisko informācijas sistēmu apguve pamatskolā: ArcGIS Online praktiskie uzdevumi ģeogrāfijā 7.-9.klasēs”. Ģeogrāfiskā izglītība visā pasaulē mainās, pēdējā laikā skolās aktīvāk sāka pielietot ģeogrāfiskās informācijas sistēmas (ĢIS) ģeogrāfijas stundās. Arī Latvijā kopš kompetenču pieejas ieviešanu visos mācību priekšmetos, par ģeogrāfijas mācību satura neatņemamo daļu kļuva tiešsaistes ĢIS vide ArcGIS Online, kas ļauj skolēniem izmantot interaktīvās kartes. Ņemot vērā to, ka darbs ar interaktīvām kartēm ir jaunums Latvijas skolās un materiālu daudzums nav pietiekams, bakalaura darba ietvaros tika izvirzīts mērķis - izstrādāt praktiskos uzdevumus ArcGIS Online …
Student evaluations of the credibility and argumentation of online sources
2021
This study investigated upper secondary school students’ skills in evaluating the credibility and argumentative content of a blog text and a YouTube video. Both sources concerned child vaccination, the blog text opposing and the YouTube video supporting it. Students rated each source as credible, fairly credible or non-credible, justified their ratings, and analyzed the argumentation of both sources. Their justifications were analyzed for trustworthiness and expertise and their argument analyses for identification of the main position of the source and the reasons supporting it. Students’ justification skills proved fairly weak, and they also struggled with recognizing unbalanced argumentat…
Cardinal invariants of cellular Lindelof spaces
2018
A space X is said to be cellular-Lindelof if for every cellular family $$\mathcal {U}$$ there is a Lindelof subspace L of X which meets every element of $$\mathcal {U}$$ . Cellular-Lindelof spaces generalize both Lindelof spaces and spaces with the countable chain condition. Solving questions of Xuan and Song, we prove that every cellular-Lindelof monotonically normal space is Lindelof and that every cellular-Lindelof space with a regular $$G_\delta $$ -diagonal has cardinality at most $$2^\mathfrak {c}$$ . We also prove that every normal cellular-Lindelof first-countable space has cardinality at most continuum under $$2^{<\mathfrak {c}}=\mathfrak {c}$$ and that every normal cellular-Lindel…
(Bounded) Traveling combustion fronts with degenerate kinetics
2022
Abstract We consider the propagation of a flame front in a solid periodic medium. It is governed by an equation of Hamilton–Jacobi type, whose front’s velocity depends on the temperature via a nonlinear degenerate kinetic rate. The temperature solves a free boundary problem subject to boundary conditions depending on the front’s velocity itself. We show the existence of nonplanar traveling wave solutions which are bounded and global. Previous results by the same authors (cf. Alibaud and Namah, 2017) were obtained for essentially positively lower bounded kinetics or eventually which have some very weak degeneracy. Here we consider very general degenerate kinetics, including for the first tim…