Reconstructibility and forward-observability of behaviors over Z

: The properties of reconstructibility and forward-observability for systems overthe whole time axis Z are introduced and characterized in terms of appropriate rankconditions. A comparison is made with the existing results in the behavioral setting aswell as in the classical state space framewor

Distributed Parameters Dynamic Model of a Solar Fresnel Collector Field

8th World CongressThe International Federation of Automatic ControlMilano (Italy) August 28 - September 2, 2011This paper describes a dynamic model for a linear Fresnel collector field of a solar refrigeration plant. The collector field concentrates solar radiations on a tube that heats up water that is used by an absorption machine to produce chilled air for refrigeration purposes. The model takes into account the solar radiation losses produced by the mirrors and the absorbing tube structure as well as the temperatures in 64 segments of the receiving tube and water. Although the dynamic model is of high dimension and nonlinear, the identification problem can be expressed as a linear problem in model parameters. The least square method was used for identification. The model was validated comparing the simulation results with the plant data for different operating conditions

Directed graphs, 2D state models, and characteristic polynomials of irreducible matrix pairs

AbstractThe definition and main properties of a 2D digraph, namely a directed graph with two kinds of arcs, are introduced. Under the assumption of strong connectedness, the analysis of its paths and cycles is performed, based on an integer matrix whose rows represent the compositions of all circuits, and on the corresponding row module. Natural constraints on the composition of the paths connecting each pair of vertices lead to the definition of a 2D strongly connected digraph. For a 2D digraph of this kind the set of vertices can be partitioned into disjoint 2D-imprimitivity classes, whose number and composition are strictly related to the structure of the row module. Irreducible matrix pairs, i.e. pairs endowed with a 2D strongly connected digraph, are subsequently discussed. Equivalent descriptions of irreducibility, naturally extending those available for a single irreducible matrix, are obtained. These refer to the free evolution of the 2D state models described by the pairs and to their characteristic polynomials. Finally, primitivity is viewed as a special case of irreducibility, and completely characterized in terms of 2D-digraphs, characteristic polynomials, and 2D system dynamics

On the Herdability of Linear Time-Invariant Systems with Special Topological Structures

In this paper, we investigate the herdability property, namely the capability of a system to be driven towards the (interior of the) positive orthant, for linear time-invariant state-space models. Herdability of certain matrix pairs (A,B), where A is the adjacency matrix of a multi-agent network, and B is a selection matrix that singles out a subset of the agents (the "network leaders"), is explored. The cases when the graph associated with A, G(A), is directed and clustering balanced (in particular, structurally balanced), or it has a tree topology and there is a single leader, are investigated.Comment: Provisionally accepted in Automatica, currently under review. arXiv admin note: substantial text overlap with arXiv:2108.0157

Multi-dimensional extensions of the Hegselmann-Krause model

In this paper, we consider two multi-dimensional Hagselmann-Krause (HK) models for opinion dynamics. The two models describe how individuals adjust their opinions on multiple topics, based on the influence of their peers. The models differ in the criterion according to which individuals decide whom they want to be influenced from. In the average-based model, individuals compare their average opinions on the various topics with those of the other individuals and interact only with those individuals whose average opinions lie within a confidence interval. For this model, we provide an alternative proof for the contractivity of the range of opinions and show that the agents' opinions reach consensus/clustering if and only if their average opinions do so. In the uniform affinity model agents compare their opinions on every single topic and influence each other only if, topic-wise, such opinions do not differ more than a given tolerance. We identify conditions under which the uniform affinity model enjoys the order-preservation property topic-wise and we prove that the global range of opinions (and hence the range of opinions on every single topic) are nonincreasing.Comment: Submitted to the 61st Conference on Decision and Control (CDC 2022), Cancun, Mexic

Formal assessment of some properties of Context-Aware Systems

Context-Aware systems are becoming useful components in autonomic and monitoring applications and the assessment of their properties is an important step towards reliable implementation, especially in safety-critical applications. In this paper, using an avalanche/landslide alert system as a running example, we propose a technique, based on Boolean Control Networks, to verify that the system dynamics has stable equilibrium states, corresponding to constant inputs, and hence it does not exhibit oscillatory behaviors, and to establish other useful properties in order to implement a precise and timely alarm system

Modeling the Cooperative Process of Learning a Task

In this paper, we propose a mathematical model for a Transactive Memory System (TMS) involved in the cooperative process of learning a task. The model is based on an intertwined dynamics involving both the individuals level of expertise and the interaction network among the cooperators. The model shows that if all the agents are non-stubborn, then all of them are able to acquire the competence of the most expert members of the group, asymptotically reaching their level of proficiency. Conversely, when dealing with all stubborn agents, the capability to pass on the task depends on the connectedness properties of the interaction graph.Comment: Accepted for presentation at the European Control Conference (ECC 2022