865 research outputs found
An examination of the positive and negative effects of retention
Each year many students are misplaced in grade levels and are unable to meet academic expectations. As a result, school administrators, teachers and parents are faced with finding a solution to these children\u27s educational problems. Retention is one alternative that is often considered. Due to the frequency of this practice along with limited options, it is important to look at the academic effects of retention on students. Using teachers\u27 report cards and standardized test results, the effects of retention were studied in six elementary school students. Using a combination of factors including literature reviews and the results of this study, it was determined that in order to be effective, the decision to retain must be made on an individual basis
Physical Activity and Adiposity Markers at Older Ages: Accelerometer Vs Questionnaire Data
Physical activity is critically important for successful aging, but its effect on adiposity markers at older ages is unclear as much of the evidence comes from self-reported data on physical activity. We assessed the associations of questionnaire-assessed and accelerometer-assessed physical activity with adiposity markers in older adults
Repeated derivatives of hyperbolic trigonometric functions and associated polynomials
Elementary problems as the evaluation of repeated derivatives of ordinary transcendent functionscan usefully be treated with the use of special polynomials and of a formalism borrowed from combinatorial analysis. Motivated by previous researches in this field, we review the results obtained by other authors and develop a complementary point of view for the repeated derivatives of sec(.), tan(.) and for their hyperbolic counterparts
Some properties and generating functions of generalized harmonic numbers
In this paper, we introduce higher-order harmonic numbers and derive their relevant properties and generating functions by using an umbral-type method. We discuss the link with recent works on the subject, and show that the combinations of umbral and other techniques (such as the Laplace and other types of integral transforms) yield a very efficient tool to explore the properties of these numbers
Effects of 2012 Earthquake on the behavior of Ghirlandina tower in Modena
Collapse events, that occurred in the past (such as the Venice Bell Tower in 1902 and the Civic Tower in Pavia in 1989) claimed for the need to assess the long-term behavior of such monuments. A significant effort has been therefore devoted to clarify the reasons for these collapses after many centuries from the construction date. In addition, recent earthquakes in Italy have once again put into evidence the seismic vulnerability of the cultural heritage. To assess this aspect, in many cases the soil-structure interaction cannot be neglected. In this context, a simple but consistent framework for soil-structure interaction analysis is here presented with reference to a case history. It is discussed how the difference in the fundamental frequency observed during seismic events can be associated to non-linearity in soil response, leading to a rotational stiffness of the soil-foundation system consistent with the shear strain level derived from the seismic ground response analysis. Thereafter, the validated soil-structure interaction model has been used to define an equivalent SDOF model of the structure that explains the differential settlements suffered by the Ghirlandina tower in Modena during the 2012 seismic events as well as its behavior since those
events
Experimental evidence and prediction of soil-structure interaction effects for a masonry tower
Remedial actions on historical buildings have to be planned carefully in order to preserve not only the shape and appearance of the monument but also its historical and material integrity. This requires a deep knowledge of the behaviour of the structure, based on
long term observations, and quite often the interaction with soil plays a relevant role. In particular, this interaction cannot be neglected when dealing when assessing both seismic vulnerability and long-term behaviour. Although advanced numerical tools are increasingly
available, simple approaches still play a fundamental role for the understanding of the actual behaviour of complex structural systems in the engineering practice. In this work a rational framework for soil-structure interaction analysis is proposed and validated by using
experimental data from a permanent monitoring system installed on a masonry tower in Italy
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