Search results for "Jacob"

Kirkonrakentajasuku Rijf : pohjalaisen kirkonrakentajasuvun rakennus- ja tuotanto sekä toiminta kustavilaisen aikakauden Suomessa. [Lektio]

2016

Theory of mind development from adolescence to adulthood: Testing the two-component model

2020

The ability to infer mental and affective states of others is crucial for social functioning. This ability, denoted as Theory of Mind (ToM), develops rapidly during childhood, yet results on its development across adolescence and into young adulthood are rare. In the present study, we tested the two‐component model, measuring age‐related changes in social‐perceptual and social‐cognitive ToM in a sample of 267 participants between 11 and 25 years of age. Additionally, we measured language, reasoning, and inhibitory control as major covariates. Participants inferred mental states from non‐verbal cues in a social‐perceptual task (Eye Test) and from stories with faux pas in a social‐cognitive t…

The Radó–Kneser–Choquet theorem for $p$-harmonic mappings between Riemannian surfaces

2020

In the planar setting the Rad\'o-Kneser-Choquet theorem states that a harmonic map from the unit disk onto a Jordan domain bounded by a convex curve is a diffeomorphism provided that the boundary mapping is a homeomorphism. We prove the injectivity criterion of Rad\'o-Kneser-Choquet for $p$-harmonic mappings between Riemannian surfaces. In our proof of the injecticity criterion we approximate the $p$-harmonic map with auxiliary mappings that solve uniformly elliptic systems. We prove that each auxiliary mapping has a positive Jacobian by a homotopy argument. We keep the maps injective all the way through the homotopy with the help of the minimum principle for a certain subharmonic expressio…

The Two-Jacobian Scheme for Systems of Conservation Laws

2006

Jacobi Fields, Conjugate Points

2001

Let us go back to the action principle as realized by Jacobi, i.e., time is eliminated, so we are dealing with the space trajectory of a particle. In particular, we want to investigate the conditions under which a path is a minimum of the action and those under which it is merely an extremum. For illustrative purposes we consider a particle in two-dimensional real space.

New Types of Jacobian-Free Approximate Riemann Solvers for Hyperbolic Systems

2017

We present recent advances in PVM (Polynomial Viscosity Matrix) methods based on internal approximations to the absolute value function. These solvers only require a bound on the maximum wave speed, so no spectral decomposition is needed. Moreover, they can be written in Jacobian-free form, in which only evaluations of the physical flux are used. This is particularly interesting when considering systems with complex Jacobians, as the relativistic magnetohydrodynamics (RMHD) equations. The proposed solvers have also been extended to the case of approximate DOT (Dumbser-Osher-Toro) methods, which can be regarded as simple and efficient approximations to the classical Osher-Solomon method. Som…

Mappings of finite distortion: Reverse inequalities for the Jacobian

2007

Let f be a nonconstant mapping of finite distortion. We establish integrability results on 1/Jf by studying weights that satisfy a weak reverse Holder inequality where the associated constant can depend on the ball in question. Here Jf is the Jacobian determinant of f.

Computing variations of entropy and redundancy under nonlinear mappings not preserving the signal dimension: quantifying the efficiency of V1 cortex

2021

In computational neuroscience, the Efficient Coding Hypothesis argues that the neural organization comes from the optimization of information-theoretic goals [Barlow Proc.Nat.Phys.Lab.59]. A way to confirm this requires the analysis of the statistical performance of biological systems that have not been statistically optimized [Renart et al. Science10, Malo&Laparra Neur.Comp.10, Foster JOSA18, Gomez-Villa&Malo J.Neurophysiol.19]. However, when analyzing the information-theoretic performance, cortical magnification in the retina-cortex pathway poses a theoretical problem. Cortical magnification stands for the increase the signal dimensionality [Cowey&Rolls Exp. Brain Res.74]. Conventional mo…

Säätöteoria ja Hamilton-Jacobi-yhtälöt

2008

Catalan fiction in the 15th century

2018

Catalan fiction in the 15th century is framed within the context of the expansion of the Crown of Aragon around the Mediterranean, the emergence of Valencia as the cultural capital of the Crown, the crisis in the prevailing mediaeval values, the consolidation of a monetary economy, and fertile contacts between Catalan culture and Castile, France, Burgundy and especially Italy. This is perfectly illustrated by the five most important fictional pieces from that era: Història de Jacob Xalabín, which refers to the Ottoman Empire; Curial e Güelfa, which is set in Italy, France, the German Empire, the eastern Mediterranean and North Africa; Tirant lo Blanc, by Joanot Martorell, which focuses on E…