An in-reachability based classification of invariant synchrony patterns in weighted coupled cell networks

This paper presents an in-reachability based classification of invariant synchrony patterns in Coupled Cell Networks (CCNs). These patterns are encoded through partitions on the set of cells, whose subsets of synchronized cells are called colors. We study the influence of the structure of the network in the qualitative behavior of invariant synchrony sets, in particular, with respect to the different types of (cumulative) in-neighborhoods and the in-reachability sets. This motivates the proposed approach to classify the partitions into the categories of strong, rooted and weak, according to how their colors are related with respect to the connectivity structure of the network. Furthermore, we show how this classification system acts under the partition join ($\vee$) operation, which gives us the synchrony pattern that corresponds to the intersection of synchrony sets.Comment: 48 pages, 19 figures, 3 table

Cartografia e diplomacia: usos geopolíticos da informação toponímica (1750-1850)

O artigo explora dimensões geopolíticas da toponímia, registradas em documentos cartográficos, desde as reformas empreendidas pelo consulado pombalino em meados do século XVIII, até às primeiras décadas do século XIX, em meio ao processo de afirmação do Estado imperial pós-colonial.This paper explores the geopolitical dimensions of toponymy as registered in cartographic documents dating from the reforms pushed through by the consulate of Marquis of Pombal in the mid 18th century to the early decades of the 19th century, as the post-colonial imperial State established itself

Urbs e civitas: a formação dos espaços e territórios urbanos nas minas setecentistas

O presente artigo procura situar a evolução das abordagens acerca da cidade colonial mineira dentro da perspectiva mais ampla dos estudos sobre o urbanismo colonial português. A análise privilegia os trabalhos que, em vez de se aterem aos aspectos ligados à estética urbana, procuraram relacioná-los às questões fundiárias e à constituição das redes e hierarquias urbanas.This article seeks to situate the evolution of approaches to the study of the colonial towns of Minas Gerais placing them in the broader perspective of studies on the Portuguese colonial urbanism. Instead of restricting our approach to questions of urban aesthetics, the analysis focuses on the works that tried to relate these questions to aspects of land ownership and to the establishment of networks and urban hierarchies

Linear Parametrically Varying Systems with Brief Instabilities: An Application to Vision/Inertial Navigation

This paper addresses the problem of nonlinear filter design to estimate the relative position and velocity of an unmanned air vehicle (UAV) with respect to a point on a ship using infrared (IR) vision, inertial, and air data sensors. Sufficient conditions are derived for the existence of a particular type of complementary filters with guaranteed stability and performance in the presence of so-called out-of-frame events that arise when the vision system loses its target temporarily. The results obtained build upon new developments in the theory of linear parametrically varying systems (LPVs) with brief instabilities–also reported in the paper–and provide the proper framework to deal with out-of-frame events. Field tests with a prototype UAV illustrate the performance of the filter and the scope of applications of the new theory developed.Office of Naval Research under Contract N0001497AF00002National Science Foundation under Grants CCR-0311084 and ECS-0093762Portugese FCT POSI program under framework QCA II

Cautious hierarchical switching control of stochastic linear systems

Standard switching control methods are based on the certainty equivalence philosophy in that, at each switching time, the supervisor selects the candidate controller that is better tuned to the currently estimated process model. If the estimated model does not appropriately describe the process, this procedure may result in the selection of a controller that is not appropriate for the actual process. In this paper, we propose a supervisory switching logic that takes into account the uncertainty on the process description when performing the controller selection. Specifically, a probability measure describing the likelihood of the different models is computed on-line based on the collected data and, at each switching time, the supervisor selects the candidate controller that, according to this probability measure, performs the best on the average. If the candidate controller set is hierarchically structured, the supervisor automatically selects the controller that appropriately compromises robustness and performance, given the actual level of uncertainty on the process description. The use of randomized algorithms makes the supervisor implementation computationally tractable