Search results for "equation"

The generalized Kadomtsev-Petviashvili equation I

1997

ENTROPY SOLUTIONS IN THE STUDY OF ANTIPLANE SHEAR DEFORMATIONS FOR ELASTIC SOLIDS

2000

The concept of entropy solution was recently introduced in the study of Dirichlet problems for elliptic equations and extended for parabolic equations with nonlinear boundary conditions. The aim of this paper is to use the method of entropy solutions in the study of a new problem which arise in the theory of elasticity. More precisely, we consider here the infinitesimal antiplane shear deformation of a cylindrical elastic body subjected to given forces and in a frictional contact with a rigid foundation. The elastic constitutive law is physically nonlinear and the friction is described by a static law. We present a variational formulation of the model and prove the existence and the uniquen…

Uniform, Sobolev extension and quasiconformal circle domains

1991

This paper contributes to the theory of uniform domains and Sobolev extension domains. We present new features of these domains and exhibit numerous relations among them. We examine two types of Sobolev extension domains, demonstrate their equivalence for bounded domains and generalize known sufficient geometric conditions for them. We observe that in the plane essentially all of these domains possess the trait that there is a quasiconformal self-homeomorphism of the extended plane which maps a given domain conformally onto a circle domain. We establish a geometric condition enjoyed by these plane domains which characterizes them among all quasicircle domains having no large and no small bo…

An Itô Formula for rough partial differential equations and some applications

2020

AbstractWe investigate existence, uniqueness and regularity for solutions of rough parabolic equations of the form $\partial _{t}u-A_{t}u-f=(\dot X_{t}(x) \cdot \nabla + \dot Y_{t}(x))u$ ∂ t u − A t u − f = ( X ̇ t ( x ) ⋅ ∇ + Y ̇ t ( x ) ) u on $[0,T]\times \mathbb {R}^{d}.$ [ 0 , T ] × ℝ d . To do so, we introduce a concept of “differential rough driver”, which comes with a counterpart of the usual controlled paths spaces in rough paths theory, built on the Sobolev spaces Wk,p. We also define a natural notion of geometricity in this context, and show how it relates to a product formula for controlled paths. In the case of transport noise (i.e. when Y = 0), we use this framework to prove a…

Hölder continuity of Sobolev functions and quasiconformal mappings

1993

Large-scale effects of migration and conflict in pre-agricultural groups: Insights from a dynamic model.

2016

The debate on the causes of conflict in human societies has deep roots. In particular, the extent of conflict in hunter-gatherer groups remains unclear. Some authors suggest that large-scale violence only arose with the spreading of agriculture and the building of complex societies. To shed light on this issue, we developed a model based on operatorial techniques simulating population-resource dynamics within a two-dimensional lattice, with humans and natural resources interacting in each cell of the lattice. The model outcomes under different conditions were compared with recently available demographic data for prehistoric South America. Only under conditions that include migration among c…

The accumulation of problems of social functioning as a long-term process: Women and men compared

2000

Structural equation modelling was used to analyse the developmental processes involved in the accumulation of problems of social functioning from age 8 to age 36 in men ( n = 152) and women ( n = 145). The accumulation of risk factors in childhood and adolescence, including low control of emotions (aggressiveness and anxiety), school problems (poor adjustment, success, and motivation), and problems in the family (parental drinking and low socioeconomic status), predicted career instability, early timing of parenthood, and a sense of failure at age 27 in both sexes. Similarly, the accumulation of problems of social functioning (e.g. poor financial standing, poor intimate relationships, and d…

Resilience and Parental Burnout Among Finnish Parents During the COVID-19 Pandemic: Variable and Person-Oriented Approaches.

2021

During the coronavirus disease 2019 (COVID-19) crisis, different personality characteristics may have influenced parental well-being in different ways. In the present study, we combined variable and person-oriented approaches and examined relationships between resilience, parental burnout, and perfectionism during the lockdown. We first used structural equation modeling to assess the paths between variables. We then used latent profile analysis to examine different profiles of parents based on resilience, perfectionism, and symptoms of parental burnout. Finally, we examined how these profiles differ in terms of relevant background variables. The results showed that resilience predicted par…

The relationship between positive and negative affect in the Positive and Negative Affect Schedule

2002

Abstract The Positive and Negative Affect Schedule (PANAS; Watson, Clark, & Tellegen, 1988 ) is one of the most widely used affect scales. Nevertheless, the relation between its two scales, positive affect (PA) and negative affect (NA), is still controversial. Previous results that suggest independence between NA and PA were limited to manifest variables. In this study, the relation between PA and NA for both state and trait instructions was analyzed by means of structural equation modeling. Two hundred ninety-two participants responded to the PANAS at three occasions of measurement. No association was found between trait PA and NA, but significant negative correlations between state PA and…

Paired associate learning tasks and their contribution to reading skills

2016

Associative learning has been identified as one of several non-linguistic processes involved in reading acquisition. However, it has not been established whether it is an independent process that contributes to reading performance on its own or whether it is a process that is embedded in other linguistic skills (e.g., phonological awareness or phonological memory) and, therefore, contributing to reading performance indirectly. Research has shown that performance on tasks assessing associative learning, e.g., paired-associate learning (PAL) tasks, is lower in children with specific reading difficulties compared to typical readers. We explored the differential associations of two distinct ver…