6,723 research outputs found
ROSA Analyser: An automatized approach to analyse processes of ROSA
In this work we present the first version of ROSA Analyser, a tool designed
to get closer to a fully automatic process of analysing the behaviour of a
system specified as a process of the Markovian Process Algebra ROSA. In this
first development stage, ROSA Analyser is able to generate the Labelled
Transition System, according to ROSA Operational Semantics.
ROSA Analyser performance starts with the Syntactic Analysis so generating a
layered structure, suitable to then, apply the Operational Semantics Transition
rules in the easier way. ROSA Analyser is able to recognize some states
identities deeper than the Syntactic ones. This is the very first step in the
way to reduce the size of the LTS and then to avoid the state explosion
problem, so making this task more tractable.
For the sake of better illustrating the usefulness of ROSA Analyser, a case
study is also provided within this work.Comment: In Proceedings WS-FMDS 2012, arXiv:1207.1841. Formal model's too
Hamiltonian dynamics and spectral theory for spin-oscillators
We study the Hamiltonian dynamics and spectral theory of spin-oscillators.
Because of their rich structure, spin-oscillators display fairly general
properties of integrable systems with two degrees of freedom. Spin-oscillators
have infinitely many transversally elliptic singularities, exactly one
elliptic-elliptic singularity and one focus-focus singularity. The most
interesting dynamical features of integrable systems, and in particular of
spin-oscillators, are encoded in their singularities. In the first part of the
paper we study the symplectic dynamics around the focus-focus singularity. In
the second part of the paper we quantize the coupled spin-oscillators systems
and study their spectral theory. The paper combines techniques from
semiclassical analysis with differential geometric methods.Comment: 32 page
Spatio-temporal variability of bovine tuberculosis eradication in Spain (2006-2011)
A. Garcia-Saenz et al.In this study we analyzed the space–time variation of the risk of bovine tuberculosis (bTB) in cattle between 2006 and 2011. The results indicated that at country level, there were no significant temporal changes between years, but, at county level bTB evolution was more heterogeneous. In some counties, between some years, the prevalence and the incidence of the disease was higher as compared to the global rate in the rest of the counties of Spain. The analysis of potential risk factors indicated that both, a large number of movements from counties with high incidence (>1%), and presence of bullfighting cattle herds increased bTB risk. Red deer abundance, number of goats and number of mixed cattle-goat farms were not significantly associated with the prevalence/incidence of bTB.This research was supported by a Grant from the Ministerio de Ciencia e Innovación of Spain (AGL-2010-21098). PhD studies of Garcia-Saenz A, are funded by a FPI Grant from Ministerio de Ciencia e Innovación of Spain (BES-2011-043628) and PhD studies of Guta S., are funded by Agencia Española de Cooperación Internacional para el Desarrollo (AECID). Acevedo P., was supported by a Beatriu de Pinós fellowship funded by ‘Comissionat per a Universitats i Recerca del Departament d’Innovació, Universitats i Empresa’ of the Generalitat de Catalunya, and the COFUND Programme – Marie Curie Actions under 7th Framework Programme of the European Community. He is currently funded from the SFRH/BPD/90320/2012 post-doctoral Grant by Portuguese Fundação para a Ciência e a Tecnologia (FCT) and European Social Fund.Peer Reviewe
Analysis of the MPEG-2 Encoding Algorithm with ROSA1 1This work has been supported by the CICYT project “Performance Evaluation of Distributed Systems”, TIC2000-0701-C02-02.
AbstractThe authors present both the specification and a performance analysis of the MPEG2 algorithm for video encoding, by using the Stochastic Process Algebra ROSA. This process algebra is a very general framework for describing and analyzing more complex Real Time Systems than the one presented. Some interesting results about the temporal behaviour of the algorithm and an immediate estimation of benefits when having a twin-processors platform have been obtained
Symplectic geometry on moduli spaces of J-holomorphic curves
Let (M,\omega) be a symplectic manifold, and Sigma a compact Riemann surface.
We define a 2-form on the space of immersed symplectic surfaces in M, and show
that the form is closed and non-degenerate, up to reparametrizations. Then we
give conditions on a compatible almost complex structure J on (M,\omega) that
ensure that the restriction of the form to the moduli space of simple immersed
J-holomorphic Sigma-curves in a homology class A in H_2(M,\Z) is a symplectic
form, and show applications and examples. In particular, we deduce sufficient
conditions for the existence of J-holomorphic Sigma-curves in a given homology
class for a generic J.Comment: 16 page
Design and Manufacture of a Large-Bore 10 T Superconducting Dipole for the CERN Cable Test Facility
A large-bore 10 T superconducting dipole magnet was designed and fabricated in close cooperation between CERN and HMA Power Systems. The dipole has a length of about 1.7 m and an aperture of 88 mm and is composed of two two-layer poles wound with NbTi cables cooled to 1.9 K to reach magnetic inductions close to 10 T. This dipole will be installed at the CERN cable test facility and used as a background field magnet to test LHC superconducting cables. In its large aperture up to four cable samples can be tested at the same time. The mechanical design of the magnet is such that coil prestress variations between warm and cold conditions are kept within 20 MPa. A short model was also built and cooled down in order to check and confirm with test results the mechanical behavior of the dipole. Magnetic measurements, at room temperature, were performed upon its arrival at CERN prior to installation in the test facility. The dipole was recently cooled down and tested. This paper will discuss the design, the main manufacturing steps and the initial test results
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