Search results for "statistical"
showing 10 items of 4960 documents
Stochastic analysis of the critical velocity of an axially moving cracked elastic plate
2014
In this study, a probabilistic analysis of the critical velocity for an axially moving cracked elastic and isotropic plate is presented. Axially moving materials are commonly used in modelling of manufacturing processes, like paper making and plastic forming. In such systems, the most serious threats to runnability are instability and material fracture, and finding the critical value of velocity is essential for efficiency. In this paper, a formula for the critical velocity is derived under constraints for the probabilities of instability and fracture. The significance of randomness in different model parameters is investigated for parameter ranges typical of paper material and paper machin…
Physical education teachers in motion: an account of attrition and area transfer
2013
Background: Teacher turnover has been identified as a major problem that represents instability in teaching. Teacher turnover can be divided into three components: attrition means that the teacher is leaving the profession; area transfer means that the teacher is changing his/her subject area and migration means that the teacher is moving from one school to another. The single most important concern is teacher attrition. Attrition is particularly high among teachers in their first five years of service. Although extensive research has been carried out on teacher attrition, no single study exists which comprehensively analyses the attrition of physical education (PE) teachers.Purpose: The pu…
Constant Hierarchic Patterns of Physical Functioning Across Seven Populations in Five Countries
1998
This research was aimed at identifying critical steps in the decline in physical function that often parallels aging. Six basic and nine instrumental activities of daily living (ADLs) were classified into four domains of disability characterized by specific underlying physical impairment. The hierarchical order of this classification was verified in two random samples representative of the older home-dwelling population. The concordance level of disability and results of performance-based measures of physical function were also tested. Finally, the cross-cultural reliability of the model was verified in seven population-based samples of older persons living in five European countries. In ol…
Method Effects: The Problem With Negatively Versus Positively Keyed Items
2012
Using confirmatory factor analyses, we examined method effects on Rosenberg's Self-Esteem Scale (RSES; Rosenberg, 1965) in a sample of older European adults. Nine hundred forty nine community-dwelling adults 60 years of age or older from 5 European countries completed the RSES as well as measures of depression and life satisfaction. The 2 models that had an acceptable fit with the data included method effects. The method effects were associated with both positively and negatively worded items. Method effects models were invariant across gender and age, but not across countries. Both depression and life satisfaction predicted method effects. Individuals with higher depression scores and lowe…
Evaluation of the postural stability of elderly persons using time domain signal analysis
2012
A force platform is widely used in the evaluation of postural stability in man. Although an abundance of parameters are typically retrieved from force platform data, no uniform analysis of the data has been carried out. In general, the signal analysis does not analyze the underlying postural event, i.e., whether the signal consists of several small corrections or large excursions. In the present work, we studied the postural stability of 4589 elderly persons from Iceland on a force platform under visual and non-visual conditions during stance on a solid surface. We analyzed the internal relationship between frequently used time domain variables. In addition, we conducted a factor analysis u…
Predictive signs and indicators of aggressiveness and violence: a comparison between a group of adolescents attending an external penal area, a group…
2006
Aim. We considered the spreading and the increasing of aggressive and violent behaviours. The most of them have two common roots: lack of actual motivation and brutality. Our research intends to detect specific indicators and predictive signs of violent and aggressive behaviours. In order to this, scientific literature shows that the most reliable indicators and predictive signs are linked to structural personality features (e.g. defensive strategies, impulse control). Methods. This cross sectional study compares a group of 26 male adolescents with Conduct Disorder (F91.8), a group of 29 male patients with Borderline Personality Disorder (F60.31) and a group of 33 male prisoners with Antiso…
Development and validation of prediction model to estimate 10-year risk of all-cause mortality using modern statistical learning methods: a large pop…
2021
Abstract Background In increasingly ageing populations, there is an emergent need to develop a robust prediction model for estimating an individual absolute risk for all-cause mortality, so that relevant assessments and interventions can be targeted appropriately. The objective of the study was to derive, evaluate and validate (internally and externally) a risk prediction model allowing rapid estimations of an absolute risk of all-cause mortality in the following 10 years. Methods For the model development, data came from English Longitudinal Study of Ageing study, which comprised 9154 population-representative individuals aged 50–75 years, 1240 (13.5%) of whom died during the 10-year follo…
Peripheral arterial disease and its clinical significance in nonagenarians
2008
The purpose of this study was to characterize the prevalence and clinical features of peripheral arterial disease (PAD) among 90-year-old individuals and to assess its relationship to lower extremity functional status and survival over one year.A prospective, population- based study of all 90-year-old residents of Jyväskylä, Finland. Fifty-eight out of the 79 registered residents were examined for ankle-brachial index (ABI). Lower extremity functional status was assessed as self-reported difficulty in performing specific physical activities of daily living (PADL). In a subgroup of 36 individuals, lower extremity functioning was further assessed by measuring walking endurance and walking vel…
Platelet Reactivity in Hemophilia a. Flow Cytometry Study to Detect the Hemorragic Phenotype
2016
Abstract INTRODUCTION Hemophilia A (HA) is a rare inherited genetic disorder linked to the X chromosome, characterized by joint bleeding in patients with severe disease with <1% of factor VIII (FVIII)(White et al. Thromb Haemost 2001). However, there are cases of severe HA with less bleeding than usual and it has been postulated that there must be other contributors to the hemorrhagic phenotype, including a platelet dysfunction (Van Bladel et al. Haematologica 2011). In this study we analyzed platelet reactivity in a cohort of 16 male patients with severe HA in prophylactic treatment by flow cytometry. The control group was 15 healthy male subjects. METHODS A longitudinal prospective obs…
Rejoinder on: Natural Induction: An Objective Bayesian Approach
2009
Giron and Moreno. We certainly agree with Professors Giron and Moreno on the interest in sensitivity of any Bayesian result to changes in the prior. That said, we also consider of considerable pragmatic importance to be able to single out a unique, particular prior which may reasonably be proposed as the reference prior for the problem under study, in the sense that the corresponding posterior of the quantity of interest could be routinely used in practice when no useful prior information is available or acceptable. This is precisely what we have tried to do for the twin problems of the rule of succession and the law of natural induction. The discussants consider the limiting binomial versi…