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Design of radio-acoustic sensors for leakage detection in underground water pipes
No full textThe interest in the exploitation of wireless sensor networks in dissipative media (other than the free space) is nowadays growing in importance, thanks to the identification of ever newer fields of applications. This paper introduces an efficient design methodology for an easy definition of the characteristics of mobile sensors inserted in pipes filled with fluids. The proposed procedure takes into account all the physical parameters of the systems such as: the performance range of the acoustic transducer, the acoustic and electromagnetic coupling mechanism among different media, and the electromagnetic interaction within the sensor and among the electronic and metallic components. Results obtained for the design of mobile sensor networks floating in underground water conduits confirm the adequacy of the proposed metho
Wireless sensors as an efficient way to improve sustainability in water management by a significant reduction of water wasting
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A system for remote leak detection and/or path tracking for underground fluid transportation pipelines
No full textThe system comprises a detection module (11), adapted to be conveyed by the fluid flow (F) in a pipeline (20) and comprising an outer envelope (12) transparent to electromagnetic waves, within which there are provided a sensing device (13) for generating detection signals representative in particular of sound waves detected in the pipeline (20); at least one wireless transceiver unit (17, 41; 18, 42; 43) comprising transceiver circuits (37; 38) and an antenna arrangement (41; 42; 43) comprising at least one loop or frame (41a, 41b; 42a, 42b; 43), and a signal processing and control unit (15) for processing the detection signals provided by the sensing device (13) and controlling the transmission of corresponding communication signals through the transceiver units (17, 41; 18, 42; 43) according to a predetermined protocol; the system comprising further at least one remote receiving station (30) adapted to receive the communication signals transmitted by the wireless transceiver unit (17, 41; 18, 42; 43) of the detection module (11
A system for remote leak detection and/or path tracking for underground fluid transportation pipelines
No full textAdvanced experimental setup for the reliability characterization of radio-acoustic sensors in water pipes
No full textThe paper presents the design and construction of a test bench for the analysis and certification of radio-acoustic sensors inside conduits filled with liquids. It is a brand new test-set that integrates the capability to validate and calibrate (separately and together) the electromagnetic and acoustic front-ends of mobile nodes belonging to wireless sensor networks deployed inside conduits. The test bed consists of a pipeline that has been configured in order to host fixed and mobile wireless sensors, which can be connected by cabled and/or radio links towards the external part of the conduit. Inserting the sensor in a real scenario, with exact working conditions, parameters like the efficiency, the gain, the radiation pattern, the reflection coefficient of the radiofrequency component, the sensitivity of the acoustic component, the precision tracking can be efficiently evaluated and consequently a precise calibration is possible. The speed and pressure of the liquid, as well as the speed of the sensor, can be controlled remotely. A de-embedding procedure has been introduced, in order to eliminate the effect of the external nois
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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