IMT Institutional Repository: No conditions. Results ordered -Date Deposited. 2024-04-20T03:42:54ZEPrintshttp://eprints.imtlucca.it/images/logowhite.pnghttp://eprints.imtlucca.it/2018-03-12T11:05:13Z2018-03-12T11:05:13Zhttp://eprints.imtlucca.it/id/eprint/4055This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/40552018-03-12T11:05:13ZDifferenti prospettive di interpretazione del processo di genesi del gruppo di imprese: un confronto fra logica e finalitàNicola Lattanzinicola.lattanzi@imtlucca.it2018-03-12T10:58:31Z2018-03-12T10:58:31Zhttp://eprints.imtlucca.it/id/eprint/4054This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/40542018-03-12T10:58:31ZIl significato del processo di formazione del gruppoNicola Lattanzinicola.lattanzi@imtlucca.it2016-04-04T13:03:29Z2016-04-12T08:08:43Zhttp://eprints.imtlucca.it/id/eprint/3366This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33662016-04-04T13:03:29ZPreferential metabolic involvement of visual cortical areas in a subtype of Alzheimer's disease: clinical implicationsPietro Pietrinipietro.pietrini@imtlucca.itMaura L. FureyNeill R. Graff-RadfordUlderico FreoGene E. AlexanderCheryl L. GradyAlessio DaniMarc J. MentisMark B. Schapiro2016-04-04T12:37:17Z2016-04-04T12:37:17Zhttp://eprints.imtlucca.it/id/eprint/3365This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33652016-04-04T12:37:17ZSulla lateralizzazione emisferica cerebrale. Basi anatomiche, aspetti funzionali ed implicazioni clinichePietro Pietrinipietro.pietrini@imtlucca.itAngelo GemignaniMario Guazzelli2016-04-04T12:35:02Z2016-04-04T12:35:02Zhttp://eprints.imtlucca.it/id/eprint/3364This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33642016-04-04T12:35:02ZIn tema di esplorazione funzionale del cervello: la tomografia ad emissione di positroniPietro Pietrinipietro.pietrini@imtlucca.it2012-02-27T08:52:38Z2012-02-27T08:52:38Zhttp://eprints.imtlucca.it/id/eprint/1184This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/11842012-02-27T08:52:38ZQuenched disorder, memory, and self-organizationWe use a stochastic description of models with a dynamic in quenched disorder to analyze the mechanism of their self-organization to a critical state in terms of memory effects. We introduce a framework to characterize both memory effects and avalanche events which suggests that self-organization can result in general from memory. This issue is settled by the introduction and the analysis of a model that contains explicitly memory and generalizes the corresponding dynamics in quenched disorder. The model displays a rich behavior and self-organized critical properties for a whole range of the exponent that tunes the strength of memory.Matteo MarsiliGuido Caldarelliguido.caldarelli@imtlucca.itMichele Vendruscolo2012-02-27T08:49:31Z2012-02-27T08:49:31Zhttp://eprints.imtlucca.it/id/eprint/1183This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/11832012-02-27T08:49:31ZOptimal path and directed percolationAn efficient transfer matrix technique is introduced to study directed optimal paths in two and three dimensions. The roughness exponent ζ is 0.6325±0.0007 for the two-dimensional case and ζ=0.555±0.008 for the three-dimensional one, in agreement with the recent conjecture ζ=ν⊥/ν∥, where ν⊥ and ν∥ are the correlation length exponents of directed percolation. Exactly solvable examples are also analyzed.Paolo RiosGuido Caldarelliguido.caldarelli@imtlucca.itAmos MaritanFlavio Seno2012-02-27T08:44:42Z2014-12-05T09:47:55Zhttp://eprints.imtlucca.it/id/eprint/1182This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/11822012-02-27T08:44:42ZBranching processes and evolution at the ends of a food chainIn a critically self-organized model of punctuated equilibrium, boundaries determine peculiar scaling of the size distribution of evolutionary avalanches. This is derived by an inhomogeneous generalization of standard branching processes, extending previous mean field descriptions and yielding ν = 1/2 together with τ′ = 7/4, as distribution exponent of avalanches starting from species at the ends of a food chain. For the nearest neighbor chain one obtains numerically τ′ = 1.25±0.01, and τfirst′ = 1.35±0.01 for the first return times of activity, again distinct from bulk exponents.Guido Caldarelliguido.caldarelli@imtlucca.itClaudio TebaldiAttilio Stella2012-02-27T08:34:39Z2014-12-05T09:46:23Zhttp://eprints.imtlucca.it/id/eprint/1181This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/11812012-02-27T08:34:39ZSelf-organization and annealed disorder in a fracturing processWe show that a vectorial model for inhomogeneous elastic media self-organizes under external stress. An onset of crack avalanches of every duration and length scale compatible with the lattice size is observed. The behavior is driven by the introduction of annealed disorder, i.e., by lowering the breaking threshold in the neighborhood of a bond broken by the stress, with a process similar to self-organized criticality. A further comparison with experimental results of acoustic emission (AE), shows that the stability of the elastic potential energy of the system in the AE regime is a sufficient condition for reproducing the algebraic distribution of the energy released during cracks formation.Guido Caldarelliguido.caldarelli@imtlucca.itFrancesco Di TollaAlberto Petri2012-02-24T13:48:37Z2012-02-24T13:48:37Zhttp://eprints.imtlucca.it/id/eprint/1179This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/11792012-02-24T13:48:37ZHot sandpilesA temperature-like parameter is introduced in ordinary sandpiles models. A temperature-dependent probability distribution is assigned for the sand toppling on sites of any height. In mean-field theory criticality is obtained for all the values of temperature and no characteristic avalanche size appears. Numerical simulations support the existence of criticality at any temperature with apparently continuously varying critical exponents.Guido Caldarelliguido.caldarelli@imtlucca.itAmos MaritanMichele Vendruscolo2011-09-15T09:10:54Z2014-12-02T09:53:42Zhttp://eprints.imtlucca.it/id/eprint/884This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/8842011-09-15T09:10:54ZCercando le OlimpiadiMaria Luisa Catonimarialuisa.catoni@imtlucca.it2011-07-27T09:20:39Z2014-07-16T13:07:37Zhttp://eprints.imtlucca.it/id/eprint/597This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/5972011-07-27T09:20:39ZRobust nonlinear reference filtering for constrained linear systems with uncertain impulse/step responsesA method based on conceptual tools of predictive control is described for solving tracking problems wherein pointwise-in-time input and/or state inequality constraints and model uncertainties are present. It consists of adding to a primal compensated system a nonlinear device called predictive reference filter (PRF) which manipulates the desired trajectory in order to fulfill the prescribed constraints. Provided that an admissibility condition on the initial state is satisfied, the control scheme is proved to fulfill the constraints and be asymptotically stable for all the systems whose impulse-response and step-response descriptions lie within given uncertainty rangesAlberto Bemporadalberto.bemporad@imtlucca.itEdoardo Mosca2011-07-27T09:20:37Z2014-07-16T13:05:32Zhttp://eprints.imtlucca.it/id/eprint/596This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/5962011-07-27T09:20:37ZLocal incremental planning for a car-like robot navigating among obstaclesWe present a local approach for planning the motion of a car-like robot navigating among obstacles, suitable for sensor-based implementation. The nonholonomic nature of the robot kinematics is explicitly taken into account. The strategy is to modify the output of a generic local holonomic planner, so as to provide commands that realize the desired motion in a least-squares sense. A feedback action tends to align the vehicle with the local force field. In order to avoid the motion stops away from the desired goal, various force fields are considered and compared by simulationAlberto Bemporadalberto.bemporad@imtlucca.itAlessandro De LucaGiuseppe Oriolo2011-07-27T09:20:35Z2014-07-16T13:04:04Zhttp://eprints.imtlucca.it/id/eprint/594This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/5942011-07-27T09:20:35ZA predictive reference governor for constrained control systemsAlberto Bemporadalberto.bemporad@imtlucca.itAlessandro CasavolaEdoardo Mosca2011-07-27T09:20:32Z2014-07-16T13:03:47Zhttp://eprints.imtlucca.it/id/eprint/595This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/5952011-07-27T09:20:32ZA nonlinear command governor for constrained control systemsAlberto Bemporadalberto.bemporad@imtlucca.itAlessandro CasavolaEdoardo Mosca2011-07-27T09:20:29Z2014-07-16T13:01:51Zhttp://eprints.imtlucca.it/id/eprint/593This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/5932011-07-27T09:20:29ZAnalog fuzzy implementation of a vehicle traction sliding-mode controlRoad adherence is an imprecise function of many parameters strongly affected by road conditions. In this paper, we propose a very robust control with a static nonlinear feedback law which can consider adherence and other model uncertainties, regulating the wheel slip at any desired value with good precision properties. A sliding-mode control has been designed to provide stability and reliability. Once designed, the control surface has been fuzzified and implemented with a programmable analog fuzzy circuit which uses a 0.7 mu m CMOS technology provided by SGS-Thomson Microelectronics. This implementation is carried out with a semi-automatic design flow and features high computational efficiency at it very low cost, especially when compared to a digital one. Moreover, the controller response time is less than 1 mu s. A flexible control of the slip coefficient has been performed. Results show that the desired slip coefficient is reached and kept with good approximation in compliance with theoretical results.A. BelliniAlberto Bemporadalberto.bemporad@imtlucca.itEleonora FranchiNicolò ManaresiRiccardo RovattiG. Torrini2011-06-14T12:07:35Z2011-07-11T14:36:27Zhttp://eprints.imtlucca.it/id/eprint/359This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/3592011-06-14T12:07:35ZConcurrency: Theory and PracticeConcurrency theory is concerned with the modeling and verification of concurrent systems, while concurrency practice promulgates the application of concurrency theory to concurrent systems of practical interest. We assert that a strong interplay between concurrency theory and practice is essential for the continued development of both fields. Rocco De Nicolar.denicola@imtlucca.itScott A. Smolka2011-06-14T10:53:56Z2011-07-11T14:36:27Zhttp://eprints.imtlucca.it/id/eprint/356This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/3562011-06-14T10:53:56ZA Process Algebra Based on LINDAThe problem of comparing and analyzing the relationships between distributed programs written in the same concurrent programming language is addressed. It arises each time one wants to establish program correctness with respect to a notion of "being an approximation of". We define a testing scenario for PAL, a process algebra which is obtained by embedding the Linda primitives for interprocess communication in a CSP like process description language. We present a proof system for PAL processes which is sound and complete with respect to the behavioural relation and illustrate how it works by giving a small example.Rocco De Nicolar.denicola@imtlucca.itRosario Pugliese2011-06-13T14:32:57Z2011-07-11T14:36:27Zhttp://eprints.imtlucca.it/id/eprint/360This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/3602011-06-13T14:32:57ZOn Four Partial Ordering Semantics for a Process CalculusThree of the rewriting systems used by Degano, De Nicola and Montanari to provide Milner's CCS with a causality based semantics are compared by using also a fourth intermediate one. These rewriting systems have been used to associate Petri nets, Labelled Event Structures and structured sets of partial orderings to CCS terms. It is proved that the four rewriting systems yield computations from which the same causality relations among the executed actions can be extracted, thus it is established that the four partial ordering transitional semantics do coincide.Flavio CorradiniRocco De Nicolar.denicola@imtlucca.it2011-06-13T14:27:24Z2011-07-11T14:36:27Zhttp://eprints.imtlucca.it/id/eprint/357This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/3572011-06-13T14:27:24ZAlgebraic Characterizations of Decorated Trace Equivalences over Tree-Like StructuresA possible approach to studying behavioural equivalences in labelled transition systems is that of characterizing them in terms of homomorphic transformations. This characterization permits relying on algebraic techniques for proving systems properties and reduces equivalence checking of two systems to studying the relationships among the elements of their structures. Different algebraic characterizations of bisimulation-based equivalences in terms of particular transition systems homomorphisms have been proposed in the literature. Here we show, by an example, that trace-based equivalences are not locally characterizable and thus that the above results cannot be extended to these equivalences. However, similar results can be obtained if we confine ourselves to restricted classes of transition systems. Here, the algebraic characterizations of three well known decorated-trace equivalences (ready trace, ready and failure equivalence) for tree-like structures are presented.Xiao Jun ChenRocco De Nicolar.denicola@imtlucca.it2011-06-08T14:11:04Z2011-07-11T14:36:27Zhttp://eprints.imtlucca.it/id/eprint/361This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/3612011-06-08T14:11:04ZA Symbolic Semantics for the pi-CalculusWe use symbolic transition systems as a basis for providing theπ-calculus with an alternative semantics. The latter is more amenable to automatic manipulation and sheds light on the logical differences among different forms of bisimulation over algebras of name-passing processes. Symbolic transitions have the form[formula], whereφis a boolean combination of equalities on names that has to hold for the transition to take place, andαis standard aπ-calculus action. On top of the symbolic transition system, a symbolic bisimulation is defined that captures the standard ones. Finally, a sound and complete proof system is introduced for symbolic bisimulation.Michele BorealeRocco De Nicolar.denicola@imtlucca.it2011-02-15T10:45:50Z2011-07-11T14:24:18Zhttp://eprints.imtlucca.it/id/eprint/52This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/522011-02-15T10:45:50ZCritica della ragione incerta. Introduzione al pensiero di Karl PopperStefano Gatteistefano.gattei@imtlucca.it