Search results for "OPTIMA"
showing 10 items of 735 documents
Optimal control of the inversion of two spins in Nuclear Magnetic Resonance
2012
International audience; We investigate the optimal control of the inversion of two spin 1/2 particles in Nuclear Magnetic Resonance. The two spins, which differ by their resonance offset, are controlled by the same radio frequency magnetic field. Using the Pontryagin Maximum Principle, we compute the optimal control sequence which allows to reach the target state in a given time, while minimizing the energy of the magnetic field. A comparison with the time-optimal solution for bounded control amplitude realizing the same control in the same time is made. An experimental illustration is done using techniques of Nuclear Magnetic Resonance.
Connected and Autonomous Vehicles cooperate with the pedestrian in industrial sites based on trajectory optimization and vehicle signalization system
2020
Connected and autonomous vehicles (CAV) is the development trend in the field of transportation systems. Recent studies show that the resources sharing between pedestrians and CAV is a big challenge. Considering traffic safety and efficiency at that sharing point not only requires a collision avoidance system but also more communicative behaviors of the CAV. More precisely, pedestrian needs to understand the intention of the incoming CAV whether it will cross first or not according to its speed profile. This paper uses the optimal trajectory control to provide CAV with a communicative behavior. A scenario where CAV and pedestrian cooperate together to cross a conflict zone is studied. A com…
Robust control of a Hammerstein model of DC/DC converters
2007
This paper deals with the robust control of a Hammerstein mathematical model of DC/DC converters, consisting of the nonlinear static characteristics of the converter followed by one of a few number of linear time- invariant models which describe the converter in the useful working range. One of these models is assumed as the nominal model of the system and the remaining models are used for describing the model uncertainty. Nominal behaviour is assured using H-2 optimal control method, Robust stability and behaviour are assured by imposing H-infin specifications. The closed loop control system consisting of the converter Hammerstein model and the robust controller is analyzed by means of sim…
Optimal reciprocals in German Sign Language
2003
Unlike most spoken languages, German Sign Language (DGS) does not have a single means of reciprocal marking. Rather, different strategies are used, which crucially depend on phonological (one-handed sign vs. two-handed sign) and morphosyntactic (plain verb vs. agreement verb) properties of the underlying verb. Moreover, with plain verbs DGS shows dialectal variation. Altogether there are four different ways of realizing reciprocal marking in DGS. In this paper, we compare a rule-based analysis for the reciprocal data (based on Brentari’s 1998 feature hierarchy) to an optimality-theoretic analysis. We argue that an OT-account allows for a more straightforward explanation of the facts. In par…
In favour of layered feet: A response to Golston
2021
In this response we argue that the factorial typology predicted in Martínez-Paricio & Kager (2015), which representationally relies on the existence of internally layered ternary feet, is complete and accurate. We demonstrate it does not suffer from the problematic cases of overgeneration pointed out by Golston (this issue). Additionally, we corroborate the idea that the internally layered ternary foot is a metrical representation that is typologically warranted for stress phenomena as well as for segmental and tonal metrically conditioned distributions. We suggest that Golston's claim that "no stress system requires internally layered ternary feet" appears to be too strong and is not empir…
Extremal Problems for Elliptic Systems
1998
The specific properties of optimal control problems for elliptic systems, if compared with the case of a single equation, are described. Within them are: strong closures of sets of feasible states; the relaxability via convexification; the type of necessary optimality conditions.
Hemostatic balance in patients with liver cirrhosis: Report of a consensus conference.
2016
Abstract Patients with cirrhosis present with hemostatic alterations secondary to reduced availability of pro-coagulant and anti-coagulant factors. The net effect of these changes is a rebalanced hemostatic system. The Italian Association of the Study of the Liver (AISF) and the Italian Society of Internal Medicine (SIMI) promoted a consensus conference on the hemostatic balance in patients with cirrhosis. The consensus process started with the review of the literature by a scientific board of experts and ended with a formal consensus meeting in Rome in December 2014. The statements were graded according to quality of evidence and strength of recommendations, and approved by an independent …
Economic evaluation of biogas plant size utilizing giant reed
2015
Abstract Amongst energy crops for the production of biomass feedstock for biogas plants, giant reed (Arundo donax L) has been attracting attention in recent years in Italy. Undoubtedly, this is due to its potentially high yield in terms of biomass, low agronomic inputs, as well as for being eligible for European Union energy crop incentives. The aim of this study was to perform an analysis of plant costs considering three macro-categories (biomass, plant installation and transport). Also, we aimed to describe the economic performances of biogas plants, while progressively altering two key variables. Specifically, we considered electrical power capacity (in the 100–999 kW range) and several …
Coarse-Grained Barrier Trees of Fitness Landscapes
2016
Recent literature suggests that local optima in fitness landscapes are clustered, which offers an explanation of why perturbation-based metaheuristics often fail to find the global optimum: they become trapped in a sub-optimal cluster. We introduce a method to extract and visualize the global organization of these clusters in form of a barrier tree. Barrier trees have been used to visualize the barriers between local optima basins in fitness landscapes. Our method computes a more coarsely grained tree to reveal the barriers between clusters of local optima. The core element is a new variant of the flooding algorithm, applicable to local optima networks, a compressed representation of fitnes…
From First Principles to the Burrows and Wheeler Transform and Beyond, via Combinatorial Optimization
2007
AbstractWe introduce a combinatorial optimization framework that naturally induces a class of optimal word permutations with respect to a suitably defined cost function taking into account various measures of relatedness between words. The Burrows and Wheeler transform (bwt) (cf. [M. Burrows, D. Wheeler, A block sorting lossless data compression algorithm, Technical Report 124, Digital Equipment Corporation, 1994]), and its analog for labelled trees (cf. [P. Ferragina, F. Luccio, G. Manzini, S. Muthukrishnan, Structuring labeled trees for optimal succinctness, and beyond, in: Proc. of the 45th Annual IEEE Symposium on Foundations of Computer Science, 2005, pp. 198–207]), are special cases i…