Search results for "F.E.M."

Transitive partially hyperbolic diffeomorphisms on 3-manifolds

2005

Abstract The known examples of transitive partially hyperbolic diffeomorphisms on 3-manifolds belong to 3 basic classes: perturbations of skew products over an Anosov map of T 2 , perturbations of the time one map of a transitive Anosov flow, and certain derived from Anosov diffeomorphisms of the torus T 3 . In this work we characterize the two first types by a local hypothesis associated to one closed periodic curve.

Real quadrics in C n , complex manifolds and convex polytopes

2006

In this paper, we investigate the topology of a class of non-Kähler compact complex manifolds generalizing that of Hopf and Calabi-Eckmann manifolds. These manifolds are diffeomorphic to special systems of real quadrics Cn which are invariant with respect to the natural action of the real torus (S1)n onto Cn. The quotient space is a simple convex polytope. The problem reduces thus to the study of the topology of certain real algebraic sets and can be handled using combinatorial results on convex polytopes. We prove that the homology groups of these compact complex manifolds can have arbitrary amount of torsion so that their topology is extremely rich. We also resolve an associated wall-cros…

Baltu filoloģija, 26 (2)

2018

Nutritional screening of older home-dwelling Norwegians: a comparison between two instruments.

2012

Ulrika Söderhamn, Bjørg Dale, Kari Sundsli, Olle SöderhamnCentre for Caring Research-Southern Norway, Faculty of Health and Sport Sciences, University of Agder, Grimstad, NorwayBackground: It is important to obtain knowledge about the prevalence of nutritional risk and associated factors among older home-dwelling people in order to be able to meet nutritional challenges in this group in the future and to plan appropriate interventions. The aim of this survey was to investigate the prevalence of home-dwelling older people at nutritional risk and to identify associated factors using two different nutritional screening instruments as self-report instruments.Methods…

Lived experiences of self-care among older, home-dwelling individuals identified to be at risk of undernutrition

2012

Solveig T Tomstad,1,2 Ulrika Söderhamn,2 Geir Arild Espnes,3 Olle Söderhamn21Department of Social Work and Health Science, Norwegian University of Science and Technology, Trondheim, Norway; 2Centre for Caring Research – Southern Norway, University of Agder, Grimstad, Norway; 3Research Centre for Health Promotion and Resources HiST-NTNU, Department of Social Work and Health Science, Norwegian University of Science and Technology, Trondheim, NorwayIntroduction: In a society where most older people live in their own homes, it may be expected of older individuals to exercise their potential to take care of themselves in daily life. Nutrition is a central aspect of se…

Effect of steel collars on the seismic behaviour of axially-cracked historical stone columns

2014

Granite and heavy stone circular columns could often be found in the cultural heritage among ancient churches and historical buildings in all the Mediterranean area. Their good strength properties allow them to carry big load values, while their bright colours and aesthetical characteristics were used by a lot of architects in the past to achieve structural solutions with great visual impact.Though such materials have great compressive strength values, environmental effects, especially long term effects, can damage the structural members, by cracking them. In this way the slenderness of the column increases, and the presence of an imposed ground motion can be very dangerous, since the colum…

$n$-harmonic coordinates and the regularity of conformal mappings

2014

This article studies the smoothness of conformal mappings between two Riemannian manifolds whose metric tensors have limited regularity. We show that any bi-Lipschitz conformal mapping or $1$-quasiregular mapping between two manifolds with $C^r$ metric tensors ($r > 1$) is a $C^{r+1}$ conformal (local) diffeomorphism. This result was proved in [12, 27, 33], but we give a new proof of this fact. The proof is based on $n$-harmonic coordinates, a generalization of the standard harmonic coordinates that is particularly suited to studying conformal mappings. We establish the existence of a $p$-harmonic coordinate system for $1 < p < \infty$ on any Riemannian manifold.

Free field realization of cylindrically symmetric Einstein gravity

1998

Cylindrically reduced Einstein gravity can be regarded as an $SL(2,R)/SO(2)$ sigma model coupled to 2D dilaton gravity. By using the corresponding 2D diffeomorphism algebra of constraints and the asymptotic behaviour of the Ernst equation we show that the theory can be mapped by a canonical transformation into a set of free fields with a Minkowskian target space. We briefly discuss the quantization in terms of these free-field variables, which is considerably simpler than in the other approaches.

Invariant circles in the Bogdanov-Takens bifurcation for diffeomorphisms

1996

AbstractWe study a generic, real analytic unfolding of a planar diffeomorphism having a fixed point with unipotent linear part. In the analogue for vector fields an open parameter domain is known to exist, with a unique limit cycle. This domain is bounded by curves corresponding to a Hopf bifurcation and to a homoclinic connection. In the present case of analytic diffeomorphisms, a similar domain is shown to exist, with a normally hyperbolic invariant circle. It follows that all the ‘interesting’ dynamics, concerning the destruction of the invariant circle and the transition to trivial dynamics by the creation and death of homoclinic points, takes place in an exponentially small part of the…

WEPP calibration for improved predictions of interrill erosion in semi-arid to arid environments

2013

Abstract Modeling soil erosion contributes to the understanding of the erosion processes and needs to predict accurately the erosion rates under different environmental conditions. Few studies have investigated the WEPP's applicability for arid and semi-arid conditions that differ from those where the model was developed. This research was carried out to evaluate and improve the WEPP model for arid and semiarid regions for interrill erosion using a rainfall simulator at plot scale. The results showed that measured interrill erosion rates ranged from 9.3 × 10− 6 to 89.6 × 10− 6 kg m− 2 s− 1. In comparison, the WEPP-interrill erosion prediction values were on average 14.5 times lower than the…