Coordination and Control of Autonomous Mobile Robots Swarms by using Particle Swarm Optimization Algorithm and Consensus Theory

This thesis presents some different techniques designed to drive a swarm of robots in an a-priori unknown environment in order to move the group from a starting area to a final one avoiding obstacles. The presented techniques are based on two different theories used alone or in combination: Swarm Intelligence (SI) and Graph Theory. Both theories are based on the study of interactions between different entities (also called agents or units) in Multi- Agent Systems (MAS). The first one belongs to the Artificial Intelligence context and the second one to the Distributed Systems context. These theories, each one from its own point of view, exploit the emergent behaviour that comes from the interactive work of the entities, in order to achieve a common goal. The features of flexibility and adaptability of the swarm have been exploited with the aim to overcome and to minimize difficulties and problems that can affect one or more units of the group, having minimal impact to the whole group and to the common main target. Another aim of this work is to show the importance of the information shared between the units of the group, such as the communication topology, because it helps to maintain the environmental information, detected by each single agent, updated among the swarm. Swarm Intelligence has been applied to the presented technique, through the Particle Swarm Optimization algorithm (PSO), taking advantage of its features as a navigation system. The Graph Theory has been applied by exploiting Consensus and the application of the agreement protocol with the aim to maintain the units in a desired and controlled formation. This approach has been followed in order to conserve the power of PSO and to control part of its random behaviour with a distributed control algorithm like Consensus.

L’alternativa democratica: Umberto Zanotti Bianco, il sud Italia e il Mediterraneo tra grande guerra e fascismo.

L’impegno civile di Umberto Zanotti Bianco (1889-1963) intrecciandosi ai principali eventi storici della prima metà del Novecento ha concorso a fare del Mezzogiorno d’Italia un laboratorio per una concreta emancipazione delle fasce sociali più umili. In queste coordinate l’azione di Zanotti Bianco è emblematica: supera la visione conservatrice di un sud incapace di fare emergere saperi e capacità organizzative mirando invece attraverso chiari, determinati e moderni progetti di riforma a far crescere il lievito della consapevolezza e della capacità di governarsi. Si può legittimamente sostenere che la complessa azione di Zanotti Bianco, pur partendo dalle migliori e più avanzate forme del pensiero meridionalista di inizio secolo, nella pratica tende a superare anche queste collocando la questione del Mezzogiorno d’Italia non solo nello scenario nazionale, tipico della fondamentale e già innovativa riflessione intorno al sud sviluppatasi da Villari a Salvemini, ma proietta le problematiche del meridione all’interno di un quadro europeo con una spiccata vocazione mediterranea. In sostanza i piani dell’intervento sociale, studiati e messi a punto inizialmente in Calabria e nelle regioni economicamente depresse del nostro Mezzogiorno, per Zanotti Bianco sembrano essere da modello anche per le più complesse questioni sociali di altri popoli del bacino del Mediterraneo i quali (come le popolazioni dell’Italia meridionale in quegli anni) apparivano deficitarii di strumenti per lo sviluppo economico, sociale, politico: è questa la tesi qui proposta.

Models and Algorihtm for the Optimization of Real-World Routing and Logistics Problems

Logistics involves planning, managing, and organizing the flows of goods from the point of origin to the point of destination in order to meet some requirements. Logistics and transportation aspects are very important and represent a relevant costs for producing and shipping companies, but also for public administration and private citizens. The optimization of resources and the improvement in the organization of operations is crucial for all branches of logistics, from the operation management to the transportation. As we will have the chance to see in this work, optimization techniques, models, and algorithms represent important methods to solve the always new and more complex problems arising in different segments of logistics. Many operation management and transportation problems are related to the optimization class of problems called Vehicle Routing Problems (VRPs). In this work, we consider several real-world deterministic and stochastic problems that are included in the wide class of the VRPs, and we solve them by means of exact and heuristic methods. We treat three classes of real-world routing and logistics problems. We deal with one of the most important tactical problems that arises in the managing of the bike sharing systems, that is the Bike sharing Rebalancing Problem (BRP). We propose models and algorithms for real-world earthwork optimization problems. We describe the 3DP process and we highlight several optimization issues in 3DP. Among those, we define the problem related to the tool path definition in the 3DP process, the 3D Routing Problem (3DRP), which is a generalization of the arc routing problem. We present an ILP model and several heuristic algorithms to solve the 3DRP.