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First-order Factors (first-order + factor)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Thin-tube vortex simulations for sinusoidal instability in a counter-rotating vortex pair

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 4 2002
Z. C. ZhengArticle first published online: 22 MAY 200
Abstract A thin-tube vortex method is developed to investigate the intrinsic instability within a counter-rotating vortex pair system and the effects from the core size and the wavenumbers (or wavelengths). The numerical accuracy and the advantages of the scheme are theoretically estimated. A nearest-neighbour-image method is employed in this three-dimensional vortex simulation. Agreement with Crow's instability analysis has been achieved numerically for the long-wave cases. A short-wave instability for the zeroth radial mode of bending instability has also been found using the thin-tube vortex simulations. Then, the combinations of long- and short-wave instability are investigated to elucidate the non-linear effects due to the interactions of two different modes. It is shown that instability is enhanced if both long- and short-wave instabilities occur simultaneously. Although the method used in the paper is not capable of including effects such as axial flow, vortex core deformation and other complicated viscous effects, it effectively predicts and clarifies the first-order factor that dominates the sinusoidal instability behaviour in a vortex pair. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Dental beliefs: factor structure of the revised dental beliefs survey in a group of regular dental patients

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 6 2009
Kajsa H. Abrahamsson
The aim of this study was to investigate the factor structure of the revised dental beliefs survey (DBS-R) in a group of regular dental patients. The study group consisted of 278 patients (mean age 54 yr), 61% of whom were women. The DBS-R item mean value was 1.6. Principal component analysis (PCA) and confirmatory factor analysis (CFA) were performed. The initial PCA among the 28 DBS-R items showed four factors with eigenvalues of > 1 explaining 67% of the total variance. Five different CFA models were tested. The final model revealed a four-factor solution with one second-order factor (i.e. a hierarchical CFA). Thus, the latent second-order variable, ,dental beliefs', explains the variance from all DBS-R items through the four first-order factors labeled ,ethics', ,belittlement', ,communication and empathy', and ,control and anxiety'. The results suggest a somewhat different factor structure of DBS-R than previously reported for dental-fear patients. Hence, the underlying factor structure of the DBS-R may differ between different patient groups. The results point towards the use of the original 28-item DBS-R and interpreting the scale as measuring an overall construct of ,dental beliefs' and thus patients' attitudes and feelings related to dentists and dentistry. [source]

Exploratory second-order analyses for components and factors

JAPANESE PSYCHOLOGICAL RESEARCH, Issue 1 2002
Haruhiko Ogasawara
Abstract: Exploratory methods using second-order components and second-order common factors were proposed. The second-order components were obtained from the resolution of the correlation matrix of obliquely rotated first-order principal components. The standard errors of the estimates of the second-order component loadings were derived from an augmented information matrix with restrictions for the loadings and associated parameters. The second-order factor analysis proposed was similar to the classical method in that the factor correlations among the first-order factors were further resolved by the exploratory method of factor analysis. However, in this paper the second-order factor loadings were estimated by the generalized least squares using the asymptotic variance-covariance matrix for the first-order factor correlations. The asymptotic standard errors for the estimates of the second-order factor loadings were also derived. A numerical example was presented with simulated results. [source]

Resources, Staff Beliefs and Organizational Culture: Factors in the Use of Information and Communication Technology for Adults with Intellectual Disabilities

JOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES, Issue 1 2008
Sarah Parsons
Background, Access to, and the use of, information and communication technology (ICT) is increasingly becoming a vital component of mainstream life. First-order (e.g. time and money) and second-order factors (e.g. beliefs of staff members) affect the use of ICT in different contexts. It is timely to investigate what these factors may be in the context of service provision for adults with intellectual disabilities given the role ICT could play in facilitating communication and access to information and opportunities as suggested in Valuing People. Method, Taking a qualitative approach, nine day service sites within one organization were visited over a period of 6 months to observe ICT-related practice and seek the views of staff members working with adults with intellectual disabilities. All day services were equipped with modern ICT equipment including computers, digital cameras, Internet connections and related peripherals. Results, Staff members reported time, training and budget as significant first-order factors. Organizational culture and beliefs about the suitability of technology for older or less able service users were the striking second-order factors mentioned. Despite similar levels of equipment, support and training, ICT use had developed in very different ways across sites. Conclusion, The provision of ICT equipment and training is not sufficient to ensure their use; the beliefs of staff members and organizational culture of sites play a substantial role in how ICT is used with and by service users. Activity theory provides a useful framework for considering how first- and second-order factors are related. Staff members need to be given clear information about the broader purpose of activities in day services, especially in relation to the lifelong learning agenda, in order to see the relevance and usefulness of ICT resources for all service users. [source]