On the calculation of derivatives of eigenvalues and eigenvectors in the simultaneous design and control of structures

Independent Modal Space Control (IMSC) is a technique that is often used for the control of large order structural systems. The pertinent optimization problem in the simultaneous design and control of structures is a min - min problem that minimizes with respect to the structural design variables, the minimum value of the performance index with respect to the control forces obtained using the IMSC technique. The minimization process requires derivatives of eigenvalues and eigenvectors with respect to the design variables. These derivatives can be computed by a rather involved analytical procedure or a relatively simple finite difference procedure. The computer cost effectiveness of these two procedures for the derivative calculations is examined

Go global or go home: comparing the regional vs. global engagement of Brazil and South Africa at the UN General Assembly

Brazil and South Africa have long been regarded as archetypical regional powers, commanding more resources than their neighbours, spearheading regional projects and pursuing high-profile global status. Yet, recent years have also evidenced how the engagement with their regions and acceptance as leading players is often ambiguous and incomplete. How does one ascertain that a regional power privileges either the regional or the global stage? Through an original dataset of Brazilian and South African output at the UN General Assembly between 1994 and 2013, we monitor sponsorship patterns and thematic preferences in order to verify whether these countries indulged their regional partners and topics. Our findings suggest that Brazil and South Africa favoured their immediate neighbourhoods but have gradually engaged their regions in different ways: while Brazilian emphasis on regional peers and themes declined over the years, South Africa developed an increasingly more regionalised UNGA agenda.info:eu-repo/semantics/acceptedVersio

Severity, salience, and selectivity: understanding the varying responses to regional crises by Brazil and South Africa

Political, military and humanitarian crises endanger regional order. But even though regional powers are expected to act as stabilizers in these cases, their responses to dire demands vary in intensity and loci. Reactions go from zealous engagement to prolonged indifference and reluctance, often leaning on global multilateral institutions as well as regional or ad hoc mechanisms. This study explores the variation in the provision of stability by regional powers via a mixed-methods approach. By contrasting the intensity of regional crises with issue salience at the UN General Assembly, we select crises that drew varying attention from regional powers, despite similar severity. Focusing on Brazil and South Africa as potential regional stabilizers, we compare responses to regional crises that displayed high (Haiti and Somalia) and low (Colombia and Congo-Brazzaville) salience. We find that domestic support, concerns with status and potential competition with other stabilizers tend to play a large part in calibrating regional power responses.info:eu-repo/semantics/acceptedVersio

Teachers representations about students' misbehaviours in physical education related with subjects, class moments and their targets

FCT (Fundação para a Ciência e a Tecnologia), IDP (Instituto do Desporto de Portugal), AIESEP World Congres

An exercise program improves health-related quality of life of workers

Low back problems are associated with decreased quality of life. Specific exercises can improve quality of life, resulting in better professional performance and functionality. The purpose of this study was to evaluate the effect of following a 21-month exercise program on the quality of life of warehouse workers. The population included 557 male warehouse workers from a food distribution company in Oporto, Portugal. Upon application of the selection criteria, 249 workers were deemed eligible, which were randomized into two groups (125 in the intervention group and 124 in the control group). Then, subjects were asked to volunteer for the study, the sample being formed by 229 workers (112 in the intervention group and 117 in the control group). All subjects completed the SF-36 questionnaire prior to beginning the program and on the 11th and 21st months following it. The exercises were executed in the company facilities once a day for 8 min. Data were analyzed using SPSS® 17.0 for Windows®. After 11 months of following the exercise program, there was an increase in all scores for the experimental group, with statistically significant differences in the dimensions physical functioning (0.019), bodily pain (0.010), general health (0.004), and rolephysical (0.037). The results obtained at the end of the study (21 months) showed significant improvements in the dimensions physical functioning (p = 0.002), rolephysical (p = 0.007), bodily pain (p = 0.001), social functioning (p = 0.015), role-emotional (p = 0.011), and mental health (p = 0.001). In the control group all dimensions showed a decrease in mean scores. It can be concluded that the implementation of a low back specific exercise program has changed positively the quality of life of warehouse workers