1,721,519 research outputs found
Derived invariants of irregular varieties and Hochschild homology
Full text linkWe study the behavior of cohomological support loci of the canonical bundle under derived equivalence of smooth projective varieties. This is achieved by investigating the derived invariance of a generalized version of Hochschild homology. Furthermore, using techniques coming from birational geometry, we establish the derived invariance of the Albanese dimension for varieties having nonnegative Kodaira dimension. We apply our machinery to study the derived invariance of the holomorphic Euler characteristic and of certain Hodge numbers for special classes of varieties. Further applications concern the behavior of particular types of fibrations under derived equivalence
The impact of faking on Cronbach’s alpha for dichotomous and ordered rating scores
No full textIn many psychological inventories (i.e., personnel selection surveys and diagnostic tests) the collected samples often include fraudulent records. This confronts the researcher with the crucial problem of biases yielded by the usage of standard statistical models. In this paper we applied a recent probabilistic perturbation procedure, called sample generation by replacement (SGR)—(Lombardi and Pastore, Multivar. Behav. Res 47:519–546, 2012), to study the sensitivity of Cronbach’s alpha index to fake perturbations in dichotomous and ordered data, respectively. We used SGR to perform two distinct SGR simulation studies involving two sample size conditions, three item set sizes, and twenty levels of faking perturbations. Moreover, in the second SGR simulation study we also evaluated an additional factor, type of faking model, to study sample reliability under different modulations of graded faking (uniform faking, average faking, slight faking, and extreme faking). To simulate these more complex faking models we proposed a novel extension of the SGR perturbation procedure based on a discrete version of the generalized beta density distribution. We also applied the new procedure to real behavioral data on emotional instability
Irregular fibrations of derived equivalent varieties
Full text linkWe study the behavior of irregular fibrations of a variety under derived equivalence of its bounded derived category. In particular we prove the derived invariance of the existence of an irregular fibration over a variety of general type, extending the case of irrational pencils onto curves of genus g≥2. We also prove that a derived equivalence of such fibrations induces a derived equivalence between their general fibers
Sensitivity of fit indices to fake perturbation of ordinal data: A sample by replacement approach.
No full textIn many psychological questionnaires the need to analyze empirical data raises the fundamental problem of possible fake or fraudulent observations in the data. This aspect is particularly relevant for researchers working on sensitive topics such as, for example, risky sexual behaviors and drug addictions. Our contribution presents a new probabilistic approach, called Sample Generation by Replacement (SGR), to address the problem of evaluating the sensitivity of 8 commonly used SEM-based fit indices (Goodness of Fit Index, GFI; Adjusted Goodness of Fit Index, AGFI; Expected Cross Validation Index, ECVI; Standardized Root-Mean-Square Residual Index, SRMR; Root-Mean-Square Error of Approximation, RMSEA; Comparative Fit Index, CFI; Nonnormed Fit Index, NNFI; and Normed Fit Index, NFI) to fake-good ordinal data. We used SGR to perform a simulation study involving 3 different SEM models, 2 sample size conditions, and 2 estimation methods: maximum likelihood (ML) and weighted least squares (WLS). Our results show that the incremental fit indices (CFI, NNFI, and NFI) are clearly more sensitive to fake perturbation than the absolute fit indices (GFI, AGFI, and ECVI). Overall, NFI turned out to be the best and most reliable fit index. We also applied SGR to real behavioral data on (non)compliance in liver transplant patients
WMR_SUPPLEMENTARY_FINAL_07-06-2018 – Supplemental material for Waste to energy efficiency improvements: Integration with solar thermal energy
No full textSupplemental material, WMR_SUPPLEMENTARY_FINAL_07-06-2018 for Waste to energy efficiency improvements: Integration with solar thermal energy by B Mendecka, L Lombardi and Pawel Gladysz in Waste Management & Research</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Analisi dei ricoveri ostetrico ginecologici di donne straniere: la realtà della Clinica Mangiagalli
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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