1,355,983 research outputs found
A decomposition algorithm for unconstrained optimization problems with partial derivative information
No full textIn this paper we consider the problem of minimizing a nonlinear function using partial derivative knowledge. Namely, the objective function is such that its derivatives with respect to a pre-specified block of variables cannot be computed. To solve the problem we propose a block decomposition method that takes advantage of both derivative-free and derivative-based iterations to account for the features of the objective function. Under standard assumptions, we manage to prove global convergence of the method to stationary points of the problem. © 2010 Springer-Verlag
Drought planning and drought mitigation measures in the Mediterranean region. In “Drought management: Scientific and technological innovation”
No full textDora Liuzzi (a cura di), Maniliofra poesia e scienza
No full textDehon Pierre-Jacques. Dora Liuzzi (a cura di), Maniliofra poesia e scienza. In: L'antiquité classique, Tome 66, 1997. pp. 452-453
Staring at the Abyss: a neurocognitive grounded agent-based model of collective-risk social dilemma under the threat of environmental disaster
No full textIncreasingly visible climate change consequences challenge carbon-based economies worldwide. While expert knowledge on climate change percolates through political initiatives and public awareness, its translation into large-scale policy actions appears limited. Climate change consequences unequally target regions, countries and social classes, a vital issue for social cooperation. When facing an imminent ecological collapse, in which conditions can self-interested agents gain environmental awareness and settle on a sustainable path of actions when their knowledge of the imminent collapse is bounded? This cooperation emerges from the interaction between individuals and the interaction of various cognitive processes within individuals. This article develops an agent-based model for this emergence of cooperation enriched with the Agent Zero neurocognitive grounded cognitive architecture. We investigate when agents endowed with deliberative, affective and social modules can settle on actions that safeguard their environment through numerical simulations. Our results show that cooperation on sustainable actions is the strongest when the system is at the edge of collapse. Policy measures that increase the environment’s resilience become internalized by the agents and undermine awareness of the ecological catastrophe. Depending on the cognitive channels activated, agent behaviors and reactions to specific interventions significantly vary. Our analysis suggests that taking different cognitive channels, deliberative, affective, social, and others into account, significantly impact results. The complexity of agent cognition deserves more attention to assess parameter sensitivity in social simulation models
Dora Liuzzi (a cura di), M. Manilio. Astronomica. Libro IV
No full textDehon Pierre-Jacques. Dora Liuzzi (a cura di), M. Manilio. Astronomica. Libro IV. In: L'antiquité classique, Tome 66, 1997. pp. 451-452
Diritto processuale dell'immigrazione
No full textIl volume costituisce una guida sistematica che raccoglie in un unico corpus le norme di tutela giurisdizionale dei diritti legate al fenomeno migratorio. La legislazione di un settore tradizionalmente ritenuto "di confine" ha avuto, negli ultimi anni, uno sviluppo esponenziale dovuto all'incremento della domanda di giustizia da parte dei migranti che giungono nel nostro paese. L'opera, che affronta in quattro capitoli le questioni relative al diritto al riconoscimento della protezione internazionale, al rilascio delle nuove forme di permesso di soggiorno introdotte dal decreto sicurezza, alla tutela dei minori stranieri non accompagnati che giungono sul territorio italiano e alle procedure finalizzate all'espulsione dello straniero c.d. irregolare, è diretta a professionisti e, grazie approfondimento dottrinario e giurisprudenziale, anche a studiosi
A magnetic resonance device designed via global optimization techniques
No full textIn this paper we are concerned with the design of a small low-cost, low-field multipolar magnet for
Magnetic Resonance Imaging with a high field uniformity. By introducing appropriate variables, the considered
design problem is converted into a global optimization one. This latter problem is solved by means of a
new derivative free global optimization method which is a distributed multi-start type algorithm controlled by
means of a simulated annealing criterion. In particular, the proposed method employs, as local search engine,
a derivative free procedure. Under reasonable assumptions, we prove that this local algorithm is attracted
by global minimum points. Additionally, we show that the simulated annealing strategy is able to produce a
suitable starting point in a finite number of steps with probability one
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