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81.
在量子场论范围内,讨论了规范不变性与电荷守恒的关系,得出了电荷守恒是带电场具有U(1)整体规范不变性的结果,电磁场是自然界具有U(1)局域规范不变相互作用的体现。  相似文献   
82.
Discrete-scale invariance (DSI) is a phenomenon featuring intriguing log-periodicity that can be rarely observed in quantum systems. Here, we report the log-periodic quantum oscillations in the longitudinal magnetoresistivity (ρxx) and the Hall traces (ρyx) of HfTe5 crystals, which reveal the DSI in the transport-coefficients matrix. The oscillations in ρxx and ρyx show the consistent logB-periodicity with a phase shift. The finding of the logB oscillations in the Hall resistance supports the physical mechanism as a general quantum effect originating from the resonant scattering. Combined with theoretical simulations, we further clarify the origin of the log-periodic oscillations and the DSI in the topological materials. This work evidences the universality of the DSI in the Dirac materials and provides indispensable information for a full understanding of this novel phenomenon.  相似文献   
83.
Measurement invariance of the five-factor Servant Leadership Questionnaire between female and male K-12 principals was tested using multi-group confirmatory factor analysis. A sample of 956 principals (56.9% were females and 43.1% were males) was analysed in this study. The hierarchical multi-step measurement invariance test supported the measurement invariance of the five-factor model across gender. Latent factor means were compared between females and males when measurement invariance was established. Results showed that females were significantly higher than males on emotional healing, wisdom, persuasive mapping and organisational stewardship, and they were not statistically different on altruistic calling.  相似文献   
84.
This study compared 5 scoring methods in terms of their statistical assumptions. They were then used to score the Teacher Observation of Classroom Adaptation Checklist, a measure consisting of 3 subscales and 21 Likert-type items. The 5 methods used were (a) sum/average scores of items, (b) latent factor scores with continuous indicators, (c) latent factor scores with ordered categorical indicators using the mean- and variance-adjusted weighted least squares estimation method, (d) latent factor scores with ordered categorical indicators using the full information maximum likelihood estimation method, and (e) multidimensional graded response model using the Bock-Aitkin expectation-maximization estimation procedure. Measurement invariance between gender groups and between free/reduced-price lunch status groups was evaluated with the second, third, fourth, and fifth methods. Group mean differences based on the 5 methods were calculated and compared.  相似文献   
85.
ABSTRACT

We investigate whether Anchoring Vignettes (AV) improve intercultural comparability of non-cognitive student-directed factors (e.g., procrastination). So far, correlation analyses for anchored and non-anchored scores with a criterion have been used to demonstrate the effectiveness of AV in improving data quality. However, correlation analyses are often used to investigate external validity of a scale. Nonetheless, before testing for validity, the reliability of the measurement of a construct should be examined. In the present study, we tested for measurement invariance across countries and languages and compared anchored and non-anchored student-directed self-reports that are highly relevant for the students’ self and their behaviour and performance. In addition, we apply further criteria for testing reliability. The results indicate that the data quality for some of the constructs can – in fact – be improved slightly by anchoring; whereas, for other self-reports, anchoring is less successful than was hoped. We discuss with regard to possible consequences for research methodology.  相似文献   
86.
Abstract

Building on the work of Terry and colleagues (Terry, P. C., Lane, A. M., Lane, H. J., & Keohane, L. (1999). Development and validation of a mood measure for adolescents. Journal of Sports Sciences, 17, 861–872; Terry, P. C., Lane, A. M., & Fogarty, G. J. (2003). Construct validity of the Profile of Mood States-Adolescents for use with adults. Psychology of Sport & Exercise, 4, 125–139.), the present study examined the validity and internal consistency reliability of the Chinese version of the Brunel Mood Scale (BRUMS-C) among 2,548 participants, comprising adolescent athletes (n = 520), adult athletes (n = 434), adolescent students (n = 673), and adult students (n = 921). Both adolescent and adult athletes completed the BRUMS-C before, during, or after regular training and both adolescent and adult students completed the BRUMS-C in a classroom setting. Confirmatory factor analyses (CFAs) provided support for the factorial validity of a 23-item six-factor model, with one item removed from the hypothesised measurement model. Internal consistency reliabilities were satisfactory for all subscales across each of the four samples. Criterion validity was supported with strong relationships between the BRUMS-C, abbreviated POMS, and Chinese Affect Scale consistent with theoretical predictions. Multi-sample CFAs showed the BRUMS-C to be invariant at the configural, metric, strong, and structural levels for all samples. Furthermore, latent mean difference analyses showed that athletes reported significantly higher levels of fatigue than students while maintaining almost the same levels of vigour, and adolescent students reported significantly higher levels of depressed mood than the other three samples.  相似文献   
87.
A Monte Carlo simulation study was conducted to evaluate the sensitivities of the likelihood ratio test and five commonly used delta goodness-of-fit (ΔGOF) indices (i.e., ΔGamma, ΔMcDonald’s, ΔCFI, ΔRMSEA, and ΔSRMR) to detect a lack of metric invariance in a bifactor model. Experimental conditions included factor loading differences, location and number of noninvariant items, and sample size. The results indicated all ΔGOF indices held Type I error to a minimum and overall had adequate power for the study. For detecting the violation of metric invariance, only ΔGamma and ΔCFI, in addition to Δχ2, are recommended to use in the bifactor model with values of ?.016 to ?.023 and ?.003 to ?.004, respectively. Moreover, in the variance component analysis, the magnitude of the factor loading differences contributed the most variation to all ΔGOF indices, whereas sample size affected Δχ2 the most.  相似文献   
88.
The computerization of reading assessments has presented a set of new challenges to test designers. From the vantage point of measurement invariance, test designers must investigate whether the traditionally recognized causes for violating invariance are still a concern in computer-mediated assessments. In addition, it is necessary to understand the technology-related causes of measurement invariance among test-taking populations. In this study, we used the available data (n = 800) from the previous administrations of the Pearson Test of English Academic (PTE Academic) reading, an international test of English comprising 10 test items, to investigate measurement invariance across gender and the Information and Communication Technology Development index (IDI). We conducted a multi-group confirmatory factor analysis (CFA) to assess invariance at four levels: configural, metric, scalar, and structural. Overall, we were able to confirm structural invariance for the PTE Academic, which is a necessary condition for conducting fair assessments. Implications for computer-based education and the assessment of reading are discussed.  相似文献   
89.
“不变性”是线性代数中的重要思想方法,它主要反映矩阵在某种条件下的秩数不变、特征值不变及正定性不变等方面。以初等变换为首选的变换方法能够充分认识矩阵或线性方程组相关变换的本质。  相似文献   
90.
To infer longitudinal relationships among latent factors, traditional analyses assume that the measurement model is invariant across measurement occasions. Alternative to placing cross-occasion equality constraints on parameters, approximate measurement invariance (MI) can be analyzed by specifying informative priors on parameter differences between occasions. This study evaluated the estimation of structural coefficients in multiple-indicator autoregressive cross-lagged models under various conditions of approximate MI using Bayesian structural equation modeling. Design factors included factor structures, conditions of non-invariance, sizes of structural coefficients, and sample sizes. Models were analyzed using two sets of small-variance priors on select model parameters. Results showed that autoregressive coefficient estimates were more accurate for the mixed pattern than the decreasing pattern of non-invariance. When a model included cross-loadings, an interaction was found between the cross-lagged estimates and the non-invariance conditions. Implications of findings and future research directions are discussed.  相似文献   
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