1,721,000 research outputs found
Error Correction Of A Triangulation Vision Machine By Optimization
No full textThis paper reports the error model, the identifiability study of its parameters, its software simulation and the experimental validation used to compensate the error of a triangulation vision machine (AVS-Active Vision System) intended for monitoring and diagnosing monuments and other Cultural Heritage. A careful alignment is required but not sufficient to achieve the sought performance. In addition, operation in open air – where temperature fluctuations up to ±15 K are expected - and transportation would require realignment on the spot. As the errors resulting from misalignment are highly repeatable, they are best compensated in software
Compensazione software degli errori di geometria di una macchina di misura senza contatto a triangolazione (SVA)
No full textQuantum model for rf-SQUID-based metamaterials enabling three-wave mixing and four-wave mixing traveling-wave parametric amplification
Full text linkA quantum model for Josephson-based metamaterials working in the three-wave mixing (3WM) and four-wave mixing (4WM) regimes at the single-photon level is presented. The transmission line taken into account, namely Josephson traveling wave parametric amplifier (JTWPA), is a bipole composed of a chain of rf-SQUIDs, which can be biased by a DC current or a magnetic field to activate the 3WM or 4WM nonlinearities. The model exploits a Hamiltonian approach to analytically determine the time evolution of the system both in the Heisenberg and interaction pictures. The former returns the analytic form of the gain of the amplifier, while the latter allows recovering the probability distributions vs time of the photonic populations, for multimodal Fock and coherent input states. The dependence of the metamaterial’s nonlinearities is presented in terms of circuit parameters in a lumped model framework while evaluating the effects of the experimental conditions on the model validity
Experimental Quantum Imaging exploiting multi-mode spatial correlation of twin beams
No full textProperties of quantum states have disclosed new and revolutionary technologies, ranging from quantum information to quantum imaging. This last field is intended to overcome the limits of classical imaging by exploiting specific properties of quantum states of light. One of the most interesting proposed schemes exploits spatial quantum correlations between twin beams for realizing sub-shot-noise imaging of weakly absorbing objects, leading ideally to a noise-free imaging. Here we discuss in detail the experimental realization of this scheme, showing its capability to reach a larger signal-to-noise ratio with respect to classical imaging methods and therefore its potential for future practical application
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
Magneto-optical imaging technique for hostile environments: The ghost imaging approach
Full text linkTraceability and Online Publication of Weather Station Measurements of Temperature, Pressure, and Humidity
No full textA project to enhance the quality of climate data has been running at the Italian Institute of Metrology (INRiM) since 2007. The focus of the project has been the installation and development of a weather station to monitor temperature, air humidity, and pressure; the collection and storage of the measurements; and the provision online to allow open-access. The project aims to improve the traceability of measurement through development of calibration and measurement protocols able to be applied to the wide variety and geographical spread of weather stations. The data collected have a short traceability to the national standards and a well-known uncertainty budget. In this work the project progress in terms of data collection and calibration of the weather station is reported. The instant measured values of the weather parameters have been published online, as is a complete database of the recordings, stored in daily, monthly, and annually collected data archives. This is the first example at the Italian national level of an archive of reliable climate data open to public access. A traceability study was carried out through calibration of the weather station instruments both in situ (over the course of one seven-hour period) and in the laboratory (under the full range of expected temperature, humidity, and pressure conditions). Significant differences in the results of the two calibrations are noted and implications for the provision of traceability 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
- …
