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The Hybrid Glider/AUV Folaga
No full textThe paper describes the current evolution of the class of Folaga underwater vehicles, whose actuation mechanism is a hybrid between oceanographic gliders and standard, self-propelled autonomous underwater vehicles (AUVs). The Folaga vehicles have been designed for coastal oceanography and environmental sampling; the application-oriented design approach has resulted in light-weight, low-cost, low-maintenance vehicles. A description of the vehicles' design and guidance, navigation and control capabilities is given, together with data from recent experimental trials
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Folaga: a low cost autonomous underwater vehicle combining glider and auv capabilities
No full textThe paper describes the current developments of a class of low-cost, light-weight autonomous
underwater vehicles for coastal oceanographic applications; the vehicle class is named Fo`laga, the
Italian name of an aquatic bird that swims on the water surface and dives to catch fish. The main design
characteristics of the most recent vehicle of the class, the Fo` laga III, are reviewed. Navigation and
control system design are discussed, with particular attention to the diving phase, which is
accomplished as in oceanographic gliders by varying the vehicle buoyancy and attitude. Experimental
results show that the PID robust controllers implemented are effective in the diving control phase.
Finally, a distributed cooperation algorithm to be applied by a team of Fo` laga-like vehicles in adaptive
oceanographic sampling applications is described. The algorithm optimizes area coverage while taking
into account the accuracy in the reconstruction of the oceanographic field and inter-vehicle
communication through a range constraint. The resulting dynamic programming algorithm can be
implemented in a distributed fashion among the team components
Design and realization of a very low-cost prototypal autonomous vehicle for coastal oceanographic missions
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Variations on the Author
Get PDF“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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