111,962 research outputs found
Assessment of dual frequency GNSS observations from a Xiaomi Mi 8 android smartphone and positioning performance analysis
No full textOn May 2018 the world’s first dual-frequency Global Navigation Satellite System (GNSS) smartphone produced by Xiaomi equipped with a Broadcom BCM47755 chip was launched. It is able to receive L1/E1/ and L5/E5 signals from GPS, Galileo, Beidou, and GLONASS (GLObal NAvigation Satellite System) satellites. The main aim of this work is to achieve the phone’s position by using multi-constellation, dual frequency pseudorange and carrier phase raw data collected from the smartphone. Furthermore, the availability of dual frequency raw data allows to assess the multipath performance of the device. The smartphone’s performance is compared with that of a geodetic receiver. The experiments were conducted in two different scenarios to test the smartphone under different multipath conditions. Smartphone measurements showed a lower C/N0 and higher multipath compared with those of the geodetic receiver. This produced negative effects on single-point positioning as showed by high root mean square error (RMS). The best positioning accuracy for single point was obtained with the E5 measurements with a DRMS (horizontal root mean square error) of 4.57 m. For E1/L1 frequency, the 2DRMS was 5.36 m. However, the Xiaomi Mi 8, thanks to the absence of the duty cycle, provided carrier phase measurements used for a static single frequency relative positioning with an achieved 2DRMS of 1.02 and 1.95 m in low and high multipath sites, respectively
Precise point positioning with single and dual-frequency multi-GNSS android smartphones
No full textThe new generation of Android smartphones is equipped with high performance Global Navigation Satellite System (GNSS) chips capable of tracking dual frequency multi-constellation data. Moreover, starting from version 9 of Android users can disable the duty cycle power saving option thus good quality pseudorange and carrier phase raw data are available thus the application of Precise Point Positioning (PPP) algorithm becomes more and more interesting. The main aim of this work is to assess the PPP performance of the first dual-frequency GNSS smartphone produced by Xiaomi equipped with a Broadcom BCM47755. The advantage of acquire dual frequency data is highlighted by comparing the performance obtained by Xiaomi with that of a single frequency smartphone the Samsung S8. The horizontal and vertical accuracy achieved by Xiaomi are of 0.51 m and 6 m respectively while those achieved by Samsung are 5.64 m for 15 m for horizontal and vertical
author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
No full text“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
Optimal operating parameters in the fuzzy-assisted microwave removal of carbon particulate from ceramic filters
No full textThe consequences of pyroclastic fallout on the dynamics of mountain catchments: geomorphic events in the Rivo d’Arco Basin (Sorrento peninsula, Italy) after the Plinian eruption of Vesuvius in 79 AD.
No full textThe consequences of pyroclastic fallout on the dynamics of mountain catchments: geomorphic events in the Rivo d’Arco Basin (Sorrento peninsula, Italy) after the Plinian eruption of Vesuvius in 79 AD.
No full textSociobiologia possibile. Neodarwinismo e scienze dell'uomo: la ricerca di un'alternativa al determinismo biologico
No full textUn confronto interdisciplinare sulla sociobiologia che cerca di individuare una strada per un confronto costruttivo fra evoluzionismo e scienze sociali oltre il determinismo di molte formulazioni
Ghirardi Botanic Garden, “factory” of molecules
No full textBotanic gardens are primarily experienced as environments where the plants often lose their identity to give rise to a whole that welcomes visitors. Adopting a different inquiring approach, it turns out that each plant is different from the other. The presence of several species native of different countries attests that botanic gardens are primarily places devoted to preserve plant biodiversity. Another point of view is to perceive botanic gardens as factories of molecules, that means evaluating their characteristics at an higher level than that visually described. Indeed, each plant communicates with the environment synthesizing and emitting secondary metabolites. The aim of this project is to investigate botanic gardens under this novel perspective, as factories of molecules. In this context, we planned a multidisciplinary research project on a pool of selected medicinal species preserved at the Ghirardi Botanic Garden (Toscolano Maderno, Bs) on the basis of their productivity in volatile compounds (VOCs), essential oils (EOs), epicuticular depositions and substances stored at tissue level. This heterogeneous set of molecules drives multiple functions for the plants themselves, and consequently for the ecosystem and the environment. The project involves multiple-scale analyses: (i) micromorphological description of the secretory structures; (ii) chemical characterization of the secondary metabolites; (iii) ecological study of the biotic interactions mediated by such chemicals; (iii) evaluation of their biological activity to assess their potential application in human nutrition as well as for therapeutic or cosmetic sectors.
As preliminary steps we addressed our attention on the morpho-anatomy of the secretory structure and on the phytochemistry and antibacterial activity of the EOs obtained from the aerial parts of six target-species: Cinnamomun camphora (L.) J.Presl., Laurus nobilis L., Myrtus communis L., Eugenia uniflora L., Santolina chamaecyparissus L. and Citrus japonica Thunb.
The structures responsible for oil production and accumulation were found to be non-differentiated cells (Lauraceae), glandular hairs (Asteraceae) and secretory ducts (schizogenous in Myrtaceae and schizolysigenous in Rutaceae).
The analysis of EO composition allowed the overall identification of 165 different compounds, with the highest number detected in S. chamaecyparissus (72) and the lowest in M. communis (31). Oxygenated sesquiterpenes represented the most abundant chemical class in C. japonica and E. uniflora, whereas oxygenated monoterpenes dominated in the other examined species. Two common compounds were found in all the species: -pinene and myrcene, most abundant in M. communis (39.0%) and in S. chamaecyparissus (3,7%), respectively. As a whole, a high level of chemical variability was found across the EOs, with S. chamaecyparissus exhibiting the most complex profile due to the occurrence of the highest number of exclusive compounds, accounting for 58.3% of the total. The EO antimicrobial activity was evaluated towards Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 15325, Salmonella enterica thiphymurium ATCC 14028, Lysteria monocytogenes ATCC 7644, Enterococcus faecalis V583E and Pseudomonas aeruginosa ATCC 27853. The most active oils resulted S. chamaecyparissus EO against L. monocytogenes (MIC 1:256 v/v) and P. aeruginosa (MIC 1:256 v/v) and C. japonicum EO against S. aureus (MIC 1:256 v/v) and L. monocytogenes (MIC 1:512 v/v). These preliminary results were discussed in the light of the most recent literature contributions
- …
