Home About us Contact
|
Home About us Contact | ||
|
|
||
Dynamical Systems Theory (dynamical + system_theory)
Selected AbstractsSome Problems and Possibilities in the Study of Dynamical Social ProcessesJOURNAL FOR THE THEORY OF SOCIAL BEHAVIOUR, Issue 1 2000John E. Puddifoot The recent challenge of Dynamical Systems Theory (also known as ComplexityTheory or Chaos Theory) to the social sciences, is based largely on the beliefthat processes in the social arena can be considered as analogous to those of the natural world, and that in consequence general theoretical advances in explaining the latter might with advantage be applied to the former. This paper aims to show that claims for Dynamical Systems Theory with respect to the understanding or measurement of social processes would be premature; the reasons for this lying not only in the unfamiliarity and operational difficulties of Dynamical Systems Theory in itself, but also in the problematic nature and history of our usage of the term ,social process'. Reviewing some examples of such usage from Sociology and Social Psychology, it is concluded that Dynamical Systems Theory might serve as a catalyst for a re-examination of existing orthodoxies and major concepts, but that progress would be retarded by the uncritical application of it's terminology, concepts, and techniques of mathematical modelling, without this prior and demanding first step. [source] Practitioner Review: Approaches to assessment and treatment of children with DCD: an evaluative reviewTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 8 2005Peter H. Wilson Background:, Movement clumsiness (or Developmental Coordination Disorder , DCD) has gained increasing recognition as a significant condition of childhood. However, some uncertainty still exists about diagnosis. Accordingly, approaches to assessment and treatment are varied, each drawing on distinct theoretical assumptions about the aetiology of the condition and its developmental course. Method:, This review evaluates the current status of different approaches to motor assessment and treatment for children with DCD. These approaches are divided according to their broad conceptual origin (or explanatory framework): Normative Functional Skill Approach, General Abilities Approach, Neurodevelopmental Theory, Dynamical Systems Theory, and the Cognitive Neuroscientific Approach. Conclusions:, Each conceptual framework is shown to support assessment and treatment methods with varying degrees of conceptual and psychometric integrity. The normative functional skill approach supports the major screening devices for DCD and cognitive (or top-down) approaches to intervention. The general abilities approach and traditional neurodevelopmental theory are not well supported by recent research. The dynamical systems approach supports promising trends in biomechanical or kinematic analysis of movement, ecological task analysis, and task-specific intervention. Finally, and more recently, the cognitive neuroscientific approach has generated some examples of process-oriented assessment and treatment based on validated (brain,behaviour) models of motor control and learning. A multi-level approach to movement assessment and treatment is recommended for DCD, providing a more complete representation of motor development at different levels of function , behavioural, neurocognitive, and emotional. [source] Nonlinear epigenetic variance: review and simulationsDEVELOPMENTAL SCIENCE, Issue 1 2010Kees-Jan Kan We present a review of empirical evidence that suggests that a substantial portion of phenotypic variance is due to nonlinear (epigenetic) processes during ontogenesis. The role of such processes as a source of phenotypic variance in human behaviour genetic studies is not fully appreciated. In addition to our review, we present simulation studies of nonlinear epigenetic variance using a computational model of neuronal network development. In each simulation study, time series for monozygotic and dizygotic twins were generated and analysed using conventional behaviour genetic modelling. In the results of these analyses, the nonlinear epigenetic variance was subsumed under the non-shared environmental component. As is commonly found in behaviour genetic studies, observed heritabilities and unique environmentabilities increased with time, whereas common environmentabilities decreased. The fact that the phenotypic effects of nonlinear epigenetic processes appear as unsystematic variance in conventional twin analyses complicates the identification and quantification of the ultimate genetic and environmental causes of individual differences. We believe that nonlinear dynamical system theories provide a challenging perspective on the development of individual differences, which may enrich behaviour genetic studies. [source] The dynamical stability of a Kuiper Belt-like regionMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2007A. Celletti ABSTRACT The dynamics of the Kuiper Belt region between 33 and 63 au is investigated just taking into account the gravitational influence of Neptune. Indeed the aim is to analyse the information which can be drawn from the actual exoplanetary systems, where typically physical and orbital data of just one or two planets are available. Under this perspective we start our investigation using the simplest three-body model (with Sun and Neptune as primaries), adding at a later stage the eccentricity of Neptune and the inclinations of the orbital planes to evaluate their effects on the Kuiper Belt dynamics. Afterwards we remove the assumption that the orbit of Neptune is Keplerian by adding the effect of Uranus through the Lagrange,Laplace solution or through a suitable resonant normal form. Finally, different values of the mass ratios of the primary to the host star are considered in order to perform a preliminary analysis of the behaviour of exoplanetary systems. In all cases, the stability is investigated by means of classical tools borrowed from dynamical system theory, like Poincaré mappings and Lyapunov exponents. [source] ON AXISYMMETRIC TRAVELING WAVES AND RADIAL SOLUTIONS OF SEMI-LINEAR ELLIPTIC EQUATIONSNATURAL RESOURCE MODELING, Issue 3 2000THOMAS P. WITELSKI ABSTRACT. Combining analytical techniques from perturbation methods and dynamical systems theory, we present an elementaryapproach to the detailed construction of axisymmetric diffusive interfaces in semi-linear elliptic equations. Solutions of the resulting non-autonomous radial differential equations can be expressed in terms of a slowlyvarying phase plane system. Special analytical results for the phase plane system are used to produce closed-form solutions for the asymptotic forms of the curved front solutions. These axisym-metric solutions are fundamental examples of more general curved fronts that arise in a wide variety of scientific fields, and we extensivelydiscuss a number of them, with a particular emphasis on connections to geometric models for the motion of interfaces. Related classical results for traveling waves in one-dimensional problems are also reviewed briefly. Manyof the results contained in this article are known, and in presenting known results, it is intended that this article be expositoryin nature, providing elementarydemonstrations of some of the central dynamical phenomena and mathematical techniques. It is hoped that the article serves as one possible avenue of entree to the literature on radiallysymmetric solutions of semilinear elliptic problems, especiallyto those articles in which more advanced mathematical theoryis developed. [source] Dynamics of Interpersonal Political Environment and Party Identification: Longitudinal Studies of Voting in Japan and New ZealandPOLITICAL PSYCHOLOGY, Issue 4 2005Ken'ichi Ikeda The dynamical systems theory of groups claims that interpersonal political environment and party identification are dynamically interrelated to provide heuristics under uncertainty. Panel data over the course of a year examined the longitudinal dynamics between social networks, social identifications, and voting behavior among a national sample of registered voters in Japan and a regional sample in Wellington, New Zealand. Respondents with more stable party identification had greater stability in the political preferences of their interpersonal network in both countries; moreover, stability in party identification was predicted by interpersonal political environment and older age in both countries. Stability of party identification predicted voting consistency in both countries, whereas stability of interpersonal political environment made an independent contribution to voting consistency in Japan only. There were cultural differences in levels of interpersonal political environment stability, but the amount of political discussion and ideological stability did not make independent contributions to any of the three main variables. Results provided support for the dynamical systems theory of groups. [source] Continuities and Discontinuities in Children and ScholarshipCHILD DEVELOPMENT, Issue 6 2008Lynn S. Liben This article introduces a collection of essays on continuity and discontinuity in cognitive development. In his lead essay, J. Kagan (2008) argues that limitations in past research (e.g., on number concepts, physical solidarity, and object permanence) render conclusions about continuity premature. Commentaries respectively (1) argue that longitudinal contexts are essential for interpreting developmental data, (2) illustrate the value of converging measures, (3) identify qualitative change via dynamical systems theory, (4) redirect the focus from states to process, and (5) review epistemological premises of alternative research traditions. Following an overview of the essays, this introductory article discusses how the search for developmental structures, continuity, and process differs between mechanistic-contextualist and organismic-contextualist metatheoretical frameworks, and closes by highlighting continuities in Kagan's scholarship over the past half century. [source] | ||||||||||