1,721,013 research outputs found
La formazione degli studenti di medicina nel campo del "saper essere": esperienza con il metodo dei video-atteggiamenti
No full textLa formazione degli studenti di medicina nel campo del "saper essere": esperienza con il metodo dei video-atteggiamenti
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Design of COTS-based radio-frequency receiver for cubesat applications
No full textNowadays, integrated small size low sensitivity Radio-Frequency (RF) receivers are quite common on the market. However, they are typically designed for terrestrial communication standards. Integrated circuits that have similar performance are not usually conceived for telemetry telecommand (TMTC) satellite applications. Moreover, they are not enough hardy to radiations and strong temperature changes that typically occur in the space. In order to deal with such issues, we present a design methodology for RF systems based on different techniques, such as the use of the Commercial OffThe-Shelf (COTS) components, the system-based modeling and the electromagnetic analysis of the 50 Ω impedance lines. This methodology has been exploited in order to design a satellite receiver that has a very low noise figure (1 dB), which has improved widely its sensitivity (-115 dBm). A 52 dB Adjustable Gain Control (AGC) range has been obtained by cascading two COTS amplifiers with an intrinsic AGC. The receiver has been made compliant to TMTC applications by designing the input filter to have 2025-2110 MHz bandwidth. Moreover, the receiver has been made radiation tolerant up to 20 krad. The excellent performance reported in this paper makes the receiver suitable for the CubeSat satellites
An Optimization Method for The Monopole Antenna Placement of a Low-Orbit Small Satellite
No full textIn this paper an optimization method for the placement of a small satellite antenna is presented. The method compares the radiation pattern of an antenna system of a satellite with a map showing the direction of the ground station as seen by the spacecraft according to its attitude throughout all the mission phases, expressed in azimuth and elevation. The comparison aims to estimate quantitatively the satellite's connectivity with the Earth. Such estimation has allowed to optimize the antenna system of the small-platform developed by Sitael S.p.A. for the mu HETSat mission, improving the connectivity for the monopole downlink antenna. The theoretical background of the method is described and an application example is given showing the benefit in placement of non-directive antennas for low-orbit small satellites
Curriculum Parallelo Sperimentale (CPS) Bari: modalità di costruzione di una unità didattica integrata
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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
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