1,721,126 research outputs found
Power flow analysis of indeterminate rod/beam systems using a susbstructure method
No full textBased on the concepts of a subsystem structural dynamics approach, a general power flow analysis of an indeterminate vibrating system consisting of three rods is presented and discussed. This is achieved by complementing the normal dynamic equations with geometrical compatibility equations allowing assessment of power flow dynamic characteristics applied to and excited within the system. The method may be classified as a form of substructuring using free–free interface conditions. The displacement contribution of the external and boundary coupling forces is deduced, permitting the power flow between the interfaces of substructures to be determined. The method presented is used in a power flow analysis of a simple rod truss system and in a more complex system as demonstrated
An investigation of power flow characteristics of L-shaped plates adopting a substructure approach
No full textA substructure approach with free–free interface condition is formulated to investigate the power flow characteristics of an L-shaped plate. This is achieved by complementing the normal dynamic equations with geometric compatibility equations allowing the assessment of power flow dynamic characteristics applied to and excited within the system. The displacement contribution of the external and boundary coupling forces is deduced, permitting determination of the power flow between the interfaces of substructures. A power flow density vector is defined and the corresponding power flow lines illustrate the flow of power in the plate. Numerical examples demonstrate the applicability of the method and detailed configurations display the power flow characteristics associated with L-shaped plates. The proposed method can calculate the higher modes easily and efficiently to ensure convergence of solution as well as readily taking into account variations in substructure damping
A study of power flow in a coupled plate-cylindrical shell system
No full textA substructure approach is formulated to investigate the power flow characteristics of a plate–cylindrical shell system subject to both conservative and dissipative coupling conditions. The system is divided into a shell substructure and a plate substructure. The theoretical receptance function of each substructure with a free–free interface condition is formulated by modal analysis to describe the dynamical behaviour of each substructure. The displacement components induced by external forces and the interface coupling forces are deduced, permitting determination of the coupling forces and power flow through the interface between the two substructures. On the basis of the dynamic information of the two substructures and through a synthesis analysis using the geometrical compatibility and force balance conditions on the coupling interfaces, the dynamic characteristics of power flow excited and transmitted within the system are calculated. A power flow density vector and the corresponding energy flow line are defined for this coupled system. The numerical example demonstrates the applicability of the proposed method and illustrates the power flow characteristics associated with the complex coupled plate–cylindrical shell system
A substructure approach to power flow analysis and application to engineering structures
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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
Simulation of the phase diagram of magnetic vortices in two-dimensional superconductors: evidence for vortex chain formation
Full text linkWe study the superconducting vortex states induced by the interplay of long-range Pearl repulsion and short-range intervortex attraction using Langevin dynamics simulations. We show that at low temperatures the vortices form an ordered Abrikosov lattice both in low and high fields. The vortices show distinctive modulated structures at intermediate fields depending on the effective intervortex attraction: ordered vortex chain and kagome-like vortex structures for weak attraction; bubble, stripe and antibubble lattices for strong attraction. Moreover, in the regime of the chain state, the vortices display structural transitions from chain to labyrinthine (or disordered chain) and/or to disordered states depending on the strength of the disorder
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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