Output Regulation for Systems on Matrix Lie-group

This paper deals with the problem of output regulation for systems defined on matrix Lie-Groups. Reference trajectories to be tracked are supposed to be generated by an exosystem, defined on the same Lie-Group of the controlled system, and only partial relative error measurements are supposed to be available. These measurements are assumed to be invariant and associated to a group action on a homogeneous space of the state space. In the spirit of the internal model principle the proposed control structure embeds a copy of the exosystem kinematic. This control problem is motivated by many real applications fields in aerospace, robotics, projective geometry, to name a few, in which systems are defined on matrix Lie-groups and references in the associated homogenous spaces

Molecular characterization of human CD4+ IL-10-producing regulatory cells

Previous studies in the group led to the identification of CD4+FOXP3- cells with regulatory functions in human blood that coproduce IL-10 and IFN-gamma. These cells do not belong to the Treg cell lineage since they are Foxp3- but they show some similarities with Th1 cells since they express CCR5, T-bet and produce high levels of IFN-gamma. Thus, they share relevant characteristics with both T regulatory type I cells (Tr1) and Th1 cells and we called them Th1-10 cells. In this study we presented a molecular characterization of Th1-10 cells that includes a gene expression and a microRNA profiling and performed functional studies to assess Th1-10 cells regulatory properties. We demonstrated that Th1-10 cells have a high regulatory potential being able to block the proliferation of activated CD4 naïve T cells to a similar extent as conventional Treg cells, and that this suppression capacity is at least partially mediated by secreted IL10. We showed also that Th1-10 cells are closely related to Th1 effector memory cells and express genes involved in cytotoxicity. In particular, they express the transcription factor EOMES and the cytotoxic effector molecules GZMA and GZMK, and they release cytotoxic granules upon stimulation. Moreover, we found that Eomes regulates cytotoxic functions in CD4+ T cells. We demonstrated that miR-92a, selectively downregulated in Th1-10 cells, directly targets the 3’UTR of EOMES.and this finding identifies miR-92a as a possible mediator of Th1-10 cytotoxicity. Th1-10 cells retain some proliferative capacity when sorted ex vivo and activated in vitro via their TCR, and this effect is markedly enhanced by IL-15, which also had a pro-survival effect on Th-10 cells. Thus, in contrast to conventional cytotoxic T cells, Th1-10 cells have cytotoxic and regulatory functions and are not terminally differentiated, since they retain proliferative capacity

Atmospheric monitoring in the mm and sub-mm bands for cosmological observations: CASPER2

Cosmological observations from ground at millimetre and sub-millimetre wavelengths are affected by atmospheric absorption and consequent emission. The low and high frequency (sky noise) fluctuations of atmospheric performance imply careful observational strategies and/or instrument technical solutions. Measurements of atmospheric emission spectra are necessary for accurate calibration procedures as well as for site testing statistics. CASPER2, an instrument to explore the 90-450 GHz (3-15 1/cm) spectral region, was developed and verified its operation in the Alps. A Martin-Puplett Interferometer (MPI) operates comparing sky radiation, coming from a field of view (fov) of 28 arcminutes (FWHM) collected by a 62-cm in diameter Pressman-Camichel telescope, with a reference source. The two output ports of the interferometer are detected by two bolometers cooled down to 300 mK inside a wet cryostat. Three different and complementary interferometric techniques can be performed with CASPER2: Amplitude Modulation (AM), Fast-Scan (FS) and Phase Modulation (PM). An altazimuthal mount allows the sky pointing, possibly co-alligned to the optical axis of the 2.6-m in diameter telescope of MITO (Millimetre and Infrared Testagrigia Observatory, Italy). Optimal timescale to average acquired spectra is inferred by Allan variance analysis at 5 fiducial frequencies. We present the motivation for and design of the atmospheric spectrometer CASPER2. The adopted procedure to calibrate the instrument and preliminary performance of the instrument are described. Instrument capabilities were checked during the summer observational campaign at MITO in July 2010 by measuring atmospheric emission spectra with the three different procedures.Comment: 11 pages, 9 figures, 2 tables, Accepted for publication in MNRA

Timing with the Galileo Open Service

The article addresses UTC dissemination through Galileo Open Service and describes the Galileo Open Service Key Performance Indicators related to timing

Female preference and predation risk models can explain the maintenance of a Fallow deer (<i>Dama dama</i>) lek and its ‘handy’ location

We tested the predictions of three models (female preference; hotspot; predator avoidance) on lek formation in the fallow deer population of San Rossore, Tuscany. We collected behavioural observations in two leks and radiotracking data on 67 deer over 7 years. Two deer sub-populations were present in the northern and southern sides of the area, respectively, the two sectors being delimited by a river and including one lek each. Predictions were tested for one lek (SG), located in the south-side where we set up our 7-year radiotracking program. Data from a second lek (FO, north-side) were used to test those predictions which imply the occurrence of multiple leks in the same population. We showed that the majority of females made one single visit to one lek, only during the rut. The lek was located outside areas of higher female traffic and home range overlap, and females increased home range sizes during the rut to reach it. Twilight routes of females never crossed the lek; instead, females walked atypical routes and at a faster pace to reach the lek and mate. The distance between the two leks was higher than the average diameter of female home ranges, and only one lek was present within female home ranges. Males reached the lek one month before the arrival of females, corroborating that lekking is a female-initiated process (females moving towards large clumped male aggregations) rather than a male-initiated process (males moving towards female hotspots). Our results supported the female preference model, and rejected the predictions of the hotspot model. Also, leks were located far from areas with higher predation risk, supporting the predator avoidance model. The position of lek SG resulted ‘handy’ at the sub-population level because of the optimal trade-off between travel costs for females to reach it and avoidance of human predators

Modello dinamico di un veicolo cingolato

2012 - 2013L'obiettivo della tesi e la modellazione dinamica di un veicolo cingolato o -road, e lo sviluppo di una legge di controllo che lo renda autonomo. L'obiettivo del controllo, e rendere il veicolo capace di operare in completa sicurezza ed autonomia su terreni con angoli di pendenza massima pari a 20 . Il sistema, denominato UTV (Unmanned Tracked Vehicle), e pensato per il trasporto di merci su terreni sconnessi con forte pendenze e di di cile accesso. La propulsione e data da un motore a combustione interna a quattro tempi e il veicolo ha una geometria pari a 180 mm di larghezza, una carreggiata di 670 mm e una lunghezza di impronta di 580mm. La modellazione e stata sviluppata in ambiente Solidworks che integrato con il software SimMechanics della Mathworks ha permesso la realizzazione di un modello multi-body. Tale modello e stato impiegato per la progettazione di leggi di controllo in open loop e closed loop, avendo de nito un opportuno set di attuatori e di sensori. Le leggi di controllo, de nite in simulazione sono state implementate sulla macchina e, mediante una procedura di identi cazione N4SID si e ottenuto il relativo modello dinamico identi cato. Su tale ultimo modello si e sviluppato una legge di controllo ottima in retroazione al ne di rendere robusto il controllo. [a cura dell'autore]XII n.s

Output regulation for systems with symmetry

The problem of output regulation deals with asymptotic tracking/rejection of a prescribed reference trajectory/disturbance. The main feature of the output regulation is that references/disturbances to be tracked/rejected belong to a family of trajectories generated as solutions of an autonomous system typically referred to as exosystem. Tackling this problem in context of error feedback leads to solutions that embeds a copy of the exosystem properly updated by means of error measurements. The output regulation problem for linear systems has been fully characterized and solved in the mid seven- ties by Davison, Francis and Wonham and then has been generalized to the non-linear context by Isidori and Byrnes. It is worth noting, however, that most of the frameworks considered so far for output regulation deal with systems and exosytems defined on Euclidean real state space and not much efforts have been done to extend the results of output regulation to systems and exosystems whose states live in more general manifolds. The tools available for solutions of the output regulation problem can’t be extented in a straightforward manner to non-linear systems whose states live in more general manifolds due to some restrictive structural assumption. The present thesis focuses on the problem of output regulation for left invariant systems defined on matrix Lie groups. In this framework we extend the idea of internal model-based control to systems defined on matrix Lie-groups taking advantages of the symmetry and invariant structures of the system considered. In particular we propose a general structure of the regulator for left invariant kinematic systems defined on general matrix Lie-group that solves the output regulation problem. Going further we study the output regulation problem for kinematics systems defined on the special orthogonal group and the special Euclidean group