排序方式： 共有18条查询结果，搜索用时 15 毫秒
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Winston J. Hagborg Gaetano Masella Phillip Palladino Jerry Shepardson 《Psychology in the schools》1991,28(4):310-317
The present study examines high school students with a prior history of grade retention (N = 38) compared to a matched control group of nonretained students. The retained students were lower on a number of scholastic variables (i.e., achievement, intelligence, grades), more often absent from school, and lower on three subscales of a self-esteem measure (the Self-Perception Profile for Adolescents). The authors explored the correlates of grade retained with the measured variables and found that the later a student was retained was associated with lower grades, less-positive school attitudes, less time on homework, lower educational expectations, more discipline problems, lower self-control, and a more external locus of control. 相似文献
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Gaetano Lanza 《Journal of The Franklin Institute》1895,139(2):122-135
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Severe budget cuts in the cultural sectors of many countries have spurred disparate suggestions for alternative sources available to public institutions. Deaccessioning may be an option, although controversial, to guarantee the survival of cultural institutions. This paper addresses the consequences that deaccessioning may have on donations of artworks to museums, by developing a sequential game with incomplete information. We investigate the interactions between donors and museums, when the former is uncertain about the commitment of a museum not to deaccess part of its endowment in the future. Our analysis shows that deaccessioning may reduce art donations to museums. Interestingly, public grants to museums cause a negative externality to a committed museum, which experiences a reduction in donations. Results provide intuitions for the widespread resistance to deaccessioning of museum associations, for their efforts to enforce common regulation restricting the use of proceeds to the acquisition of art, and also for the proliferation of private art museums. 相似文献
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AbstractIn 2009 the Argentine government of Cristina Fernández de Kirchner created Fútbol para Todos (Soccer for All), a programme that led to a policy of direct state intervention in the acquisition of government television rights for the transmission of soccer matches throughout Argentina. Does Fútbol para Todos serve as a tool for the democratization of Argentinean society, a strategy for populist legitimization, or as an embodiment of quasi-authoritarianism? Successive Argentine governments have politicized soccer. Fútbol para Todos has served as a tool for populist legitimization, but also as a strategy designed to legitimize state interference in a historically private domain, promote government propaganda through a new state monopoly, and strengthen governance processes through popular approval under the ambit of the ‘democratization’ slogan. Fútbol para Todos thus aims to use the state as an agent in the construction of better governance processes for all, but it also reinforces the historical union between soccer and establishment political power in Argentina. Fútbol para Todos is populist in tone and appears democratic, but also masks a darker undercurrent of quasi-authoritarian tendencies in Argentina. 相似文献
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The failure analysis of simply supported, isotropic, square plates is addressed. Attention focuses on minimum failure load amplitudes and failure locations, von Mises＇ equivalent stress along the plate thickness is also addressed. Several distributed and localized loading conditions are considered. Loads act on the top of the plate. Bi-sinusoidal and uniform loads are taken into account for distributed loadings, while stepwise constant centric and off-centric loadings are addressed in the case of localized loadings. Analysis is performed considering plates whose length-to-thickness ratio a/h can be as high as 100 （thin plates） and as low as 2 （very thick plates）. Results are obtained via several 2D plate models. Classical theories （CTs） and higher order models are applied. Those theories are based on polynomial approximation of the displacement field. Among the higher order theories （HOTs） HOTsa models account for the transverse shear deformations, while HOTs models account for both transverse shear and transverse normal deformations. LHOTs represent a local application of the higher order theories. A layerwise approach is thus assumed： by means of mathematical interfaces, the plate is considered to be made of several fictitious layers. The exact 3D solution is presented in order to determine the accuracy of the results obtained via the 2D models. In this way a hierarchy among the 2D theories is established. CTs provide highly accurate results for a/h greater than 10 in the case of distributed loadings and greater than 20 for localized loadings. Results obtained via HOTs are highly accurate in the case of very thick plates for bi-sinusoidal and centric loadings. In the case of uniform and off-centric loadings a high gradient is present in the neighborhood of the plate top. In those cases, LHOTs yield results that match the exact solution. 相似文献
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Bruno Calderoni Giuseppe Cecere Emilia Angela Cordasco Luigi Guerriero Pietro Lenza Gaetano Manfredi 《Journal of Cultural Heritage》2010,11(2):163-171
The knowledge of the morphological and mechanical properties of masonry walls is very important for the refurbishment of ancient buildings, particularly when the requirements of both structural safety and historical preservation must be fulfilled. The masonry is not of homogenous material: its mechanical properties depend on stones, mortar, and texture which are very variable due to their dependence on the historical periods and the geographical area of the erection. For this reason, a deep knowledge of masonries built in different sites and historical periods is essential in order to evaluate both the capacities of bearing vertical load and the seismic vulnerability of the masonry structure. Three fundamental typologies of tuff masonry have been defined: they are the characteristics of different historical periods from the XVI to the XX century. The models are in full-scale in order to reproduce the three defined chronotypes. Original tuff stones quarried in the corresponding historical period, mortars similar to the original ones, reproduced according to ancient documents and original constructive techniques have been used for the construction of the specimens. Compression tests performed in displacement control have been carried out on the masonry models in order to determine the maximum resistance of the material and the corresponding strain, the ultimate strain and corresponding residual strength. In this paper, the procedure used for making the specimens and for experimentally evaluating the mechanical properties of post-medieval Neapolitan yellow tuff masonry are illustrated and the obtained results, even in terms of plastic capacity of these kinds of masonry, are reported. 相似文献
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