1,721,223 research outputs found
Analysis of phase-detection algorithms for back-EMF-based sensorless strategies through real-time simulations
No full textThe work developed in this paper presents a comparison between three different phase detection algorithms in order to study the benefits of using each of them when they are applied inside a sensorless rotor position estimation technique. In particular we will analyse the various aspects related to the use of each single algorithm when it is applied into a specific model-based sensorless strategy and when we also take into account the typical impairments affecting the implementation of the real setup, such as unwanted harmonic components and measurement offsets.
As a first step a short overview on the phase-detection algorithms under consideration will be given and subsequently the proposed model-based estimation technique is presented, that are suitable for different machines. As a second step the three algorithms are analyzed in detail highlighting their dynamical performances and their robustness properties against implementative knots, in particular through the use of software simulations and real-time simulations reproducing the specific test case of a five-phase motor.The work developed in this paper presents a comparison between three different phase detection algorithms in order to study the benefits of using each of them when they are applied inside a sensorless rotor position estimation technique. In particular we will analyse the various aspects related to the use of each single algorithm when it is applied into a specific model-based sensorless strategy and when we also take into account the typical impairments affecting the implementation of the real setup, such as unwanted harmonic components and measurement offsets. As a first step a short overview on each phase-detection algorithm under consideration will be given and subsequently the proposed model-based estimation technique will be presented. As a second step the three algorithms are analyzed in detail highlighting their dynamical performances and their robustness properties against implementative knots, in particular through the use of software simulations and real-time simulations reproducing the specific test case of a five-phase motor. © 2011 IEEE
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
A new membrane equilibrium solution for masonry railway bridges: The case study of Marsh Lane Bridge
No full textMasonry railways bridges were built and are still in use all over Europe and in many other countries all over the world. Limit analysis is widely adopted to assess the equilibrium of these structures under self and train loads and, mainly, assuming uniaxial stresses only in the span direction. In the last decade, some of these bridges, as our case study, have been subjected to detailed structural health monitoring (SHM) campaigns whose primary outcome is that these structures exhibit biaxial stresses. In this paper, within the framework of the Heyman masonry unilateral model, an application of membrane equilibrium analysis (MEA) is presented. MEA provides an efficient approach to account for biaxial stress states and, thus, taking into account beneficial 3D effects for load capacity analyses. This paper illustrates how various assumptions of the membrane behaviour yield a range of potential equilibrium solutions, all of which demonstrate higher capacity than the traditional 2D assessment methods
A new membrane equilibrium solution for masonry railway bridges: the case study of Marsh Lane Bridge
No full textMasonry railways bridges were built and are still in use all over Europe and in many other countries all over the world. Limit analysis is widely adopted to assess the equilibrium of these structures under self and train loads and, mainly, assuming uniaxial stresses only in the span direction. In the last decade, some of these bridges, as our case study, have been subjected to detailed structural health monitoring (SHM) campaigns whose primary outcome is that these structures exhibit biaxial stresses. In this paper, within the framework of the Heyman masonry unilateral model, an application of membrane equilibrium analysis (MEA) is presented. MEA provides an efficient approach to account for biaxial stress states and, thus, taking into account beneficial 3D effects for load capacity analyses. This paper illustrates how various assumptions of the membrane behaviour yield a range of potential equilibrium solutions, all of which demonstrate higher capacity than the traditional 2D assessment methods
Cytokine modulators in the treatment of sarcoidosis
No full textSarcoidosis is a granulomatous lung disease in which several cytokines play a pivotal pathogenetic role. Steroid-resistant disease can be treated with immunosuppressive drugs, antimalarial therapies and recently with anti-TNFα agents. The use of biological agents for the treatment of sarcoidosis springs from research into the pathogenesis of the disease and also from the experience of rheumatologists with other chronic inflammatory diseases. Rituximab, golimumab and ustekinumab are cytokine modulators, useful in the treatment of immunoinflammatory disorders, for which randomized trials to evaluate safety and efficacy in sarcoidosis are not yet available. Novel anticytokine drugs administered alone or in association may offer a new approach to treatment of the disease. This review focuses on recent advances in anti-TNFα agents and cytokine modulators for the treatment of sarcoidosis and their therapeutic prospects.
PMID: 21644041 [PubMed - indexed for MEDLINE
Physiologic comparison between conventional mechanical ventilation and transtracheal open ventilation in acute traumatic quadriplegic patients
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