1,720,973 research outputs found
Analisi del comportamento sismico di Palazzo Camponeschi: modelli rappresentativi dello scenario di danno
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Studio del comportamento dinamico della massa sismica isolata per la realizzazione di una tavola vibrante a 6 gradi di libertà
No full text"Seismic protection of frame structures through semi-active dissipative braces"
No full textThe paper illustrates different aspects inherent to the multifaceted task of semi-actively controlling the threedimensional dynamics of a frame structure through interstorey chevron braces embedding smart dampers. The control strategy is finalized to mitigate the latero-torsional motion of a large-scaled laboratory prototype, which experimentally simulates the seismic response of a two-storey building. A synthetic discrete model is purposely formulated in the reduced space of a few significant dynamical variables, and consistently updated to match the modal properties identified from the experimental response of the uncontrolled prototype. The potential occurrence of a significant eccentricity in the storey mass distribution, breaking the global structural symmetry, is considered. The control action is introduced by two magneto-rheological dampers, whose dissipative properties can be modified in real-time, supplying an opportune magnetic field. The suited adjustment of the damper characteristic is governed by a clipped-optimal control law, which entails the instantaneous comparison of the actual force with the active force evaluated through a non-collocated acceleration feedback, designed according to the LQG criterion. Since the dampers are positioned purposely to deliver two eccentric and independent forces, acting on the first-storey displacements, the set-up allows the mitigation of the three-dimensional motion arising when monodirectional ground motion is imposed on the non-symmetric structure. Numerical investigations on the model controlled response to different natural accelerograms are presented. The effectiveness of the control strategy is discussed through synthetic performance indexes. Comments on the real effectiveness of the control strategy in mitigating the experimental response of the prototype are drawn, based on the promising results of a test campaign. Qualitative considerations are finally pointed out for future developments regarding the need of further experimental tests and optimization analyse
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
Variations 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
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