1,721,073 research outputs found
Jump from Parallel to Sequential Proofs : Exponentials
No full textIn previous works, by importing ideas from game semantics (notably Faggian-Maurel-Curien’s
ludics nets), we defined a new class of multiplicative/additive polarized proof nets, called J-proof
nets. The distinctive feature of J-proof nets with respect to other proof net syntaxes, is the possibility
of representing proof nets which are partially sequentialized, by using jumps (that is, untyped extra
edges) as sequentiality constraints. Starting from this result, in the present work we extend J-proof
nets to the multiplicative/exponential fragment, in order to take into account structural rules: more
precisely, we replace the familiar linear logic notion of exponential box with a less restricting one
(called cone) defined by means of jumps. As a consequence, we get a syntax for polarized nets where,
instead of a structure of boxes nested one into the other, we have one of cones which can be partially
overlapping. Moreover, we define cut-elimination for exponential J-proof nets, proving, by a variant
of Gandy’s method, that even in case of “superposed” cones, reduction enjoys confluence and strong
normalization
Node fault robustness for heterogeneous dynamic sensor networks
No full textThe paper deals with the problem of computing reference trajectories for a network of mobile sensors in order to maximize the coverage with respect to multiple quantities within a prefixed time interval. A centralized formulation of the problem is given for the case of sensing nodes provided with a different set of sensors (hence heterogeneity). The same formulation is shown to be useful for facing the problem of nodes faults, yielding to a robust coverage problem. Constraints introduced by kinematic and dynamic actuator limits, by communication and by collision avoidance are considered in the formulation. A global solution is proposed and some simiulations are reported to show its effectiveness
Vaccination, Booster Doses and Social Constraints: A Steady State and an Optimal Transient Approaches to Epidemics Containment
No full textThe problem of the definition of control actions to contain epidemic diseases is crucial in case of high infectivity, dangerous or fatal consequences, large inhabited areas involved. Unfortunately, during the last three years, the COVID-19 pandemic has represented a critical situation all over the world. On the basis of the experiences for known diseases and the literature on the epidemic modeling, various strategies have been proposed and applied in different countries, someone using all the possible efforts, some others just maintaining the global health compact within acceptable levels. The effectiveness of the approaches has been always measured on the basis of the reproduction number Rt, which is intrinsically a steady-state evaluation, since it does not takes into account the control variations. In the present paper, with reference to a mathematical model which takes into account the different level of vaccination in the population, an optimal condition based approach is adopted to define the actions of intervention, bringing to a switching optimal control scheme based on the time by time evolution of the disease. The two approaches are developed and compared, showing that the use of partial information can bring to counter-intuitive situations and supporting the necessity of a feedback action to better adapt the containment measure to the situation. Numerical simulations are performed to better show the claimed result
A Multirate Digital Controller for Nonholonomic Mobile Robot Pose Regulation via Visual Feedback
No full textA multirate strategy for the control of a nonholonomic mobile robot using a visual servoing approach is presented. Such a control is based on a mathematical model computed using two virtual image features. The proposed multirate digital control technique guarantees their presence in the camera field of view during all the robot motion. The absence of obstacles in the robot configuration space is assumed. Simulations results are presented to validate the proposed method
Nonlinear Regulation in Halo Orbits Control Design
No full textThe design and simulation of feedback control laws for tracking prescribed quasi-halo orbits around the translunar libration point L 2 in the Earth-Moon system are considered. The nonlinear regulation approach is used to design control laws for asymptotically tracking those trajectories. The eccentricity of the system is considered and modeled by a periodic disturbance. Simulation with saturations on the controls validates the proposed strategies, which also give good results for large orbital maneuver
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