Roberta De Asmundis

Learn More
G. Aielli, M. Alviggi, V. Ammosov, M. Biglietti, P. Camarri, V. Canale, M. Caprio, R. Cardarelli, G. Carlino, G. Cataldi, G. Chiodini, F. Conventi, R. de Asmundis , M. Della Pietra, D. Della Volpe, A. Di Ciaccio, A. Di Simone ∗, L. Di Stante, E. Gorini, F. Grancagnolo, P. Iengo, B. Liberti, A. Nisati, Fr. Pastore, E. Pastori, S. Patricelli, R. Perrino, M.(More)
In recent years it has been made more and more clear that the critical issue in gradient methods is the choice of the step length, whereas using the gradient as search direction may lead to very effective algorithms, whose surprising behaviour has been only partially explained, mostly in terms of the spectrum of the Hessian matrix. On the other hand, the(More)
Preserving connectivity of a network topology is a crucial aspect for multi-robot systems in order to perform almost any collaborative task. This problem turns out to be significantly challenging in the case of a heterogeneous multirobot system equipped with different sensors with limited field of view. Such an interaction scheme, in fact, is described by(More)
We propose a new gradient method for quadratic programming, named SDC, which alternates some SD iterates with some gradient iterates that use a constant steplength computed through the Yuan formula. The SDC method exploits the asymptotic spectral behaviour of the Yuan steplength to foster a selective elimination of the components of the gradient along the(More)
The proton-proton beam crossing at the LHC accelerator at CERN will have a rate of 40 MHz at the project luminosity. The ATLAS Trigger System has been designed in three levels in order to select only interesting physics events reducing from that rate of 40 MHz to the foreseen storage rate of about 200 Hz. The First Level reduces the output rate to about 100(More)
Started in 1994 the L3 experiment has been equipped with a forward}backward muon spectrometer triggered by an RPC system. Made of 192 double-gap RPCs, it has been working for six years in streamer mode and it will continue to run at least one year more. We monitored the behaviour of the system during the L3 run periods and in this paper we report on its(More)
We analyze the regularization properties of two recently proposed gradient methods applied to discrete linear inverse problems. By studying their filter factors, we show that the tendency of these methods to eliminate first the eigencomponents of the gradient corresponding to large singular values allows to reconstruct the most significant part of the(More)
A 15-month ageing test of an ATLAS module ‘‘0’’ RPC has been performed at the GIF X5 CERN irradiation facility. The aged RPC performances largely fulfilled the ATLAS requirements. However, the test showed a significant reduction of the RPC maximum rate capability, from almost 2 kHz cm 2 to a few hundred Hz cm ; due to the total charge integrated during the(More)
We measure the masses, decay widths and relative production rate of orbitally excited B mesons using 1.25 million hadronic Z decays recorded by the L3 detector. B-meson candidates are inclusively reconstructed and combined with charged pions produced at the primary event vertex. An excess of events above the expected background in the Bp mass spectrum in(More)
The RPC chambers in the L3 forward–backward muon spectrometer have been operational from 1994 to the end of LEP running. After dismantling of the L3 detector some of the RPCs modules have been transported to Napoli where their performance has been re-measured with cosmic rays. Results of long-term performance in the LEP environment and of laboratory tests(More)