Synchronization in dynamical networks of locally coupled self-propelled oscillators

Systems of mobile physical entities exchanging information with their neighborhood can be found in many different situations. The understanding of their emergent cooperative behaviour has become an important issue across disciplines, requiring a general conceptual framework in order to harvest the potential of these systems. We study the synchronization of coupled oscillators in time-evolving networks defined by the positions of self-propelled agents interacting in real space. In order to understand the impact of mobility in the synchronization process on general grounds, we introduce a simple model of self-propelled hard disks performing persistent random walks in 2$d$ space and carrying an internal Kuramoto phase oscillator. For non-interacting particles, self-propulsion accelerates synchronization. The competition between agent mobility and excluded volume interactions gives rise to a richer scenario, leading to an optimal self-propulsion speed. We identify two extreme dynamic regimes where synchronization can be understood from theoretical considerations. A systematic analysis of our model quantifies the departure from the latter ideal situations and characterizes the different mechanisms leading the evolution of the system. We show that the synchronization of locally coupled mobile oscillators generically proceeds through coarsening verifying dynamic scaling and sharing strong similarities with the phase ordering dynamics of the 2$d$ XY model following a quench. Our results shed light into the generic mechanisms leading the synchronization of mobile agents, providing a efficient way to understand more complex or specific situations involving time-dependent networks where synchronization, mobility and excluded volume are at play

Analysis of tourism competitiveness and the key influencers

The aim of this research is measure and analyse the tourism competitiveness, which has become one of the great challenges of tourism researchers in recent years. We analyze the relationship between tourism competitiveness and major tourist magnitudes, relations with most tourist destinations, and some pillars that measure competitiveness such as sustainability. A methodology for calculating an indicator of tourism competitiveness based on a double reference point is proposed, taking into account a level of aspiration and reserve level for each pillar of competitiveness. They are considered different degrees of offset between the pillars so that a series of synthetic indices are calculated. Later the rankings obtained for each country are analyzed and conducted a series of analyses. This tool provides managers with a useful and accurate tool, an interactive flexible and easy to use multi-criteria decision on their part. Allows simulation of situations, monitoring and control of various indicators. Later statistical tools for analyzing and comparing tourism competitiveness and other quantities are used.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Rapid Non-Destructive Assessment of Southern Yellow Pine Lumber Properties by Near Infrared Spectroscopy

Over the last several years questions about the strength of structural lumber have been raised. The purpose of this study was to examine the relationship between physically measured wood properties using Near Infrared spectroscopy. Physical properties were determined from (2 x 4 x 2 in.) cut samples. Destructive mechanical testing was performed on 744; 8 feet long, No.2 grade 2x4’s. Diffuse reflectance NIR spectra was collected from the cross-sectional face of each block using FOSS NIR Systems Inc. Model 5000 scanning spectrometer. Calibrations were then created between measured properties and NIR estimates. Density, specific gravity, latewood percentage, MOE and MOR had coefficient of determinations of 0.78, 0.56, 0.02, 0.56, and 0.48 respectively. The low correlation is likely caused by the grade of lumber. Because No.2 lumber has considerable knots, they were the determining factor in strength and stiffness; these results would likely not be similar in a higher grade lumber

“Haven’t We Come To Kill the Spaniards?” The Tule Upheaval in Eastern Panama, 1727-1728

Investigates a Tule Indian uprising that took place in eastern Panama in 1727. The Indians\u27 motivations for this uprising were varied and complicated and not simply the result of the instigations of mestizo pirate Luis García (as was alleged by the governor of Darién and historians, who have read his account of the events). The violence that spread across the isthmus was caused by the instability inherent in the Spanish colonial policy of tribalization. This policy relied on the Spanish authorities\u27 co-opting men who claimed to be tribal leaders. These leaders, however, were unable to contain the Indians once they believed that the mestizo colonial officials in whom they placed their trust had ceased to understand, care about, or address their needs to higher authorities. Based on documents in the Archivo General de Indias, Seville, and the Archivo Histórico Nacional de España, Madrid; 30 notes, biblio