Search results for "Invariance"
showing 10 items of 239 documents
Measurement of the lifetime difference in the B$_s^0$ system
2005
We present a study of the decay B_s^0 -> J/psi phi We obtain the CP-odd fraction in the final state at time zero, R_perp = 0.16 +/- 0.10 (stat) +/- 0.02 (syst), the average lifetime of the (B_s, B_sbar) system, tau (B_s^0) =1.39^{+0.13}_{-0.16} (stat) ^{+0.01}_{-0.02} (syst) ps, and the relative width difference between the heavy and light mass eigenstates, Delta Gamma/Gamma = (Gamma_L - Gamma_H)/Gamma =0.24^{+0.28}_{-0.38} (stat) ^{+0.03}_{-0.04} (syst). With the additional constraint from the world average of the B_s^0$lifetime measurements using semileptonic decays, we find tau (B_s^0)= 1.39 +/- 0.06 ~ps and Delta Gamma/\Gamma = 0.25^{+0.14}_{-0.15}. For the ratio of the B_s^0 and B^0 li…
Improving Harris corner selection strategy
2011
This study describes a corner selection strategy based on the Harris approach. Corners are usually defined as interest points for which intensity variation in the principal directions is locally maximised, as response from a filter given by the linear combination of the determinant and the trace of the autocorrelation matrix. The Harris corner detector, in its original definition, is only rotationally invariant, but scale-invariant and affine-covariant extensions have been developed. As one of the main drawbacks, corner detector performances are influenced by two user-given parameters: the linear combination coefficient and the response filter threshold. The main idea of the authors' approa…
The Italian version of the Cognitive Style Indicator and its association with decision-making preferences
2018
By adopting a more flexible view, Cools and Van den Broeck (2007) developed the Cognitive Style Indicator (CoSI) which includes three cognitive dimensions: Creating (flexible, open-ended and inventive), Knowing (emphasizing facts, details, objectivity, and rationality), and Planning (guided by preferences for certainty and well-structured information). The first aim of this research was to validate the three factor structure of the CoSI within the Italian context, whereas the second was to verify whether cognitive styles, as measured by the CoSI, accounted for individual differences in decision-making processes. Two studies were conducted using two different samples (n = 549 and n = 397). C…
Measurement invariance of the nine-item Internet Gaming Disorder Scale (IGDS9-SF) across Albania, USA, UK, and Italy
2018
The IGDS9-SF, which assesses Internet Gaming Disorder behaviors, has been validated in a number of countries (Portugal, Italy, Iran, Slovenia), although the psychometric equivalence of the instrument has been assessed only across Australia, the USA, the UK, and India. This research aimed at providing further cross-cultural insights into IGD by assessing the factorial structure of the IGDS9-SF in Albania and investigating its measurement invariance across Albanian, Italian, American, and British gamers. Multi-Group Confirmatory Factor Analyses were performed on a sample of 1411 participants from Albania (n = 228), USA (n = 237), the UK (n = 275), and Italy (n = 671). The CFAs confirmed the s…
Measuring dispositional optimism in patients with chronic heart failure and their healthcare providers: The validity of the Life Orientation Test-Rev…
2017
Patrizia Steca,1 Dario Monzani,1 Antonia Pierobon,2 Giulia Avvenuti,2 Andrea Greco,1 Anna Giardini2 1Department of Psychology, University of Milano – Bicocca, Milan, 2Psychology Unit, Istituti Clinici Scientifici Maugeri Spa SB, IRCCS Montescano, Montescano, Italy Abstract: The Life Orientation Test-Revised (LOT-R) measures dispositional optimism (DO) – an individual difference promoting physical and psychological well-being in healthy adults (HAs) as well as in patients with chronic heart failure (CHF) and healthcare providers (HPs). Controversy has arisen regarding the dimensionality of the LOT-R. Whereas DO was originally defined as a one-dimensional construct, empiri…
Form constancy
2020
Form constancy denotes the appearance of the invariant shape of objects in the environment, notwithstanding the variability due to changes of the viewpoint, caused by subjects movement, to objects displacement, to illumination, lightness, color, and texture whose variation can affect the internal and external boundaries of the surfaces that fall in the simultaneous or successive views of solid objects. In early psychology of perception, shape invariance was called form constancy to highlight the perceptual ability to derive something constant from the changing forms of the multiple views of objects. Shape is an attribute of 2D surfaces and 3D objects, which are invariant across the transfor…
Multiple solutions with sign information for a (p,2)-equation with combined nonlinearities
2020
We consider a parametric nonlinear Dirichlet problem driven by the sum of a p-Laplacian and of a Laplacian (a (p,2)-equation) and with a reaction which has the competing effects of two distinct nonlinearities. A parametric term which is (p−1)-superlinear (convex term) and a perturbation which is (p−1)-sublinear (concave term). First we show that for all small values of the parameter the problem has at least five nontrivial smooth solutions, all with sign information. Then by strengthening the regularity of the two nonlinearities we produce two more nodal solutions, for a total of seven nontrivial smooth solutions all with sign informations. Our proofs use critical point theory, critical gro…
The Task and Ego Orientation in Sport Questionnaire: Testing for Measurement Invariance and Latent Mean Differences in Spanish and Portuguese Adolesc…
2010
Within the theoretical framework of achievement goals (Nicholls, 1989), Duda and Nicholls (see Duda, 1989; Duda & Whitehead, 1998) developed the Task and Ego Orientation in Sport Questionnaire (TEOSQ) to assess individual differences in achievement goal orientations. This study searches for validity evidence of the TEOSQ in the case of Spanish (2473) and Portuguese (2486) junior high school. The results showed that factor structure, factor loadings, and intercepts could be considered invariant across groups. Between group differences in latent means showed slightly higher mean scores for the Spanish group for both factors. The results also provide high support for the internal consistency o…
A teacher-report measure of children's task-avoidant behavior: A validation study of the Behavioral Strategy Rating Scale
2011
Abstract This study aims to validate a teacher-report measure of children's task-avoidant behavior, namely the Behavioral Strategy Rating Scale (BSRS), in a sample of 352 Finnish children. In each of the four waves from Kindergarten to Grade 2, teachers rated children's task-avoidant behavior using the BSRS, children completed reading and mathematics tests, and trained testers rated children's task-avoidant and social-dependent behavior after the test situation. Mothers also rated children's task-avoidant behavior in the last two waves. The results showed that a two-factor model including one factor representing task avoidance and one method factor accounting for wording effects among the n…
The Multigroup Ethnic Identity Measure – Revised (MEIM-R): Psychometric evaluation with adolescents from diverse ethnocultural groups in Italy
2017
The Multigroup Ethnic Identity Measure – Revised (MEIM-R) is an extensively used questionnaire assessing ethnic identity. However, studies on its measurement characteristics in the European context are lacking. The current study addressed this gap by investigating the MEIM-R psychometric proprieties across multiple ethnocultural groups in Italy. Participants were 1445 adolescents (13–18 years) of Italian, East European, and North African origin. Results showed that the MEIM-R has good internal consistency. Multigroup confirmatory factor analyses revealed configural and metric invariance, i.e., an equal, correlated two-factor structure (ethnic identity exploration and commitment) and equal f…