1,720,956 research outputs found
Actuator with a non-contact position sensor
No full textAn actuator having a fixed part, a movable part movable with respect to the fixed part in a travelling direction, and a non-contact position sensor connected to the movable part to read the position of the movable part. The position sensor has a reading device connected to the fixed part and having a ferromagnetic core; and a magnetic cursor, which is integrated in the movable part, is defined by a magnetized portion of the movable part, and is so magnetized as to locally saturate the ferromagnetic core at the magnetic cursor
Actuator with a non-contact position sensor
No full textAn actuator having a fixed part, a movable part movable with respect to the fixed part in a travelling direction, and a non-contact position sensor connected to the movable part to read the position of the movable part. The position sensor has a reading device connected to the fixed part and having a ferromagnetic core; and a magnetic cursor, which is integrated in the movable part, is defined by a magnetized portion of the movable part, and is so magnetized as to locally saturate the ferromagnetic core at the magnetic cursor
Fuel pump operated by means of a shape memory material
No full textA fuel pump for an internal combustion engine; the fuel pump is equipped with at least one pumping chamber with variable volume; with at least one inlet valve communicating with the pumping chamber; with at least one outlet valve communicating with the pumping chamber; with at least one flexible membrane that delimits the pumping chamber; and with an actuating device that acts on the flexible membrane to cyclically vary the volume of the pumping chamber; the actuating device presents at least one shape memory material thet modifies its geometry upon application of an external influence of a physical nature and is mechanically coupled with the flexible membrane, and a piloting device to cyclically apply an external influence of a physical nature to the shape memory material
Mechatronic Design of a shape memory alloy actuator for automotive tumble flaps: a case study
No full textThe continuous advance in mechatronics has long attracted researchers toward the development of new highly integrated actuators for automotive applications where reduced space and low weight are common constraints. In this context, Shape Memory Alloys (SMAs) offer many peculiar characteristics that make this technology very attractive for the construction of miniature mechatronic actuators. This paper presents the design, the prototype fabrication, and the functional testing of a case study, where an SMA binary actuator is used for automotive tumble flaps. The innovative solid-state actuation system is proposed as an alternative to electromagnetic and pneumatic effectors, traditionally used to drive the tumble shaft of an air intake manifold for internal combustion engines. Original features of the linear actuator involve the mechanical architecture and the control structure. On the mechanical side, two contrasting sets of SMA springs are used to actively generate the net actuating force during both outstroke and instroke. On the control side, a current feedback is exploited for sensorless real-time monitoring of the working temperature of the SMA springs during electrical supply. Major shortcomings of the proposed solution are a low response time and a power consumption higher than pneumatic and electromagnetic counterparts
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
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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