Crafting networks to achieve, or not achieve, chaotic states

The influence of networks topology on collective properties of dynamical systems defined upon it is studied in the thermodynamic limit. A network model construction scheme is proposed where the number of links, the average eccentricity and the clustering coefficient are controlled. This is done by rewiring links of a regular one dimensional chain according to a probability $p$ within a specific range $r$, that can depend on the number of vertices $N$. We compute the thermodynamic behavior of a system defined on the network, the $XY-$rotors model, and monitor how it is affected by the topological changes. We identify the network dimension $d$ as a crucial parameter: topologies with d\textless{}2 exhibit no phase transitions while ones with d\textgreater{}2 display a second order phase transition. Topologies with $d=2$ exhibit states characterized by infinite susceptibility and macroscopic chaotic/turbulent dynamical behavior. These features are also captured by $d$ in the finite size context

El ser y la sustancia de Aristóteles ante la razón vital: las cuatro reducciones de la realidad

«Hermeneutic» means interpretation, that is, looking from a point of view. In this study we try to interpret from the vital reason, the method of Ortega y Gasset, his and his disciple Julián Marías, the Aristotelian concept of «substance». If life is the radical reality, as Ortega stresses, and the person its programmatic realization, in Marías’ opinion, a vital reason of the concept of οὐσία, means to discover its capacity to understand human life. We will find, as a matter of fact, that there are four limits, essentially, that distance the philosopher from that comprehension. By them, we will find the core of the greatest contradictions of the Aristotelian thought, that has been subject to intense critics throughout its history. We will concern, especially, on the function of language in the Greek conception of reason, on the interpretations that brought to «being» and «entity» as Aristotle’s thought starting point.«Hermenéutica» significa interpretar, mirar desde un punto de vista. En este estudio buscamos interpretar desde la «razón vital», el método de Ortega y Gasset y su discípulo Julián Marías, el concepto aristotélico de «sustancia». Si la vida es la realidad radical, como afirma Ortega, y la persona es su realización programática, según entiende Marías, una razón vital de la οὐσία significa descubrir su capacidad de comprensión para con la vida humana. Encontraremos, entonces, que hay esencialmente cuatro límites que desvían de esa comprensión; mediante ellos, habremos encontrado el núcleo de importantes contradicciones del pensamiento aristotélico que han sido objeto de encendidos debates a lo largo de la historia. Nos centraremos, sobre todo, en la función del lenguaje en la concepción de la razón griega, en los supuestos interpretativos del «ser» y del «ente» como puntos de partida del pensamiento de Aristóteles

Chinese art museums: organisational models and roles in promoting contemporary art

This article aims to outline a general framework of the most recent development of contemporary art museum in China, in order to answer some questions: which kind of art museum exhibits Chinese contemporary art, and consequently, what is their role in promoting this art? Finally, considering the host of problems in the management and long term curatorial planning, it aims at examining whether it is possible to identify a sustainable way to manage contemporary art museums in China. This analysis has been drawn following field research on Chinese contemporary art museums, focussing on museums observations and interviews held with stakeholders (artists, museum directors and curators) involved in the museum work in some of the major cities of China

The Public Policy Exception: The Need to Reform Florida\u27s At-Will Employment Doctrine After Jarvinen v. HCA Allied Clinical Laboratories andBellamy v. Holcomb

Silence, the King of the Turtles barked back, I\u27m king, and you\u27re only a turtle named Mack

Critical behaviour of the XY -rotors model on regular and small world networks

We study the XY-rotors model on small networks whose number of links scales with the system size $N_{links}\sim N^{\gamma}$, where $1\le\gamma\le2$. We first focus on regular one dimensional rings in the microcanonical ensemble. For $\gamma<1.5$ the model behaves like short-range one and no phase transition occurs. For $\gamma>1.5$, the system equilibrium properties are found to be identical to the mean field, which displays a second order phase transition at a critical energy density $\varepsilon=E/N, \varepsilon_{c}=0.75$. Moreover for $\gamma_{c}\simeq1.5$ we find that a non trivial state emerges, characterized by an infinite susceptibility. We then consider small world networks, using the Watts-Strogatz mechanism on the regular networks parametrized by $\gamma$. We first analyze the topology and find that the small world regime appears for rewiring probabilities which scale as $p_{SW}\propto1/N^{\gamma}$. Then considering the XY-rotors model on these networks, we find that a second order phase transition occurs at a critical energy $\varepsilon_{c}$ which logarithmically depends on the topological parameters $p$ and $\gamma$. We also define a critical probability $p_{MF}$, corresponding to the probability beyond which the mean field is quantitatively recovered, and we analyze its dependence on $\gamma$

Onset of anomalous diffusion from local motion rules

Anomalous diffusion processes, in particular superdiffusive ones, are known to be efficient strategies for searching and navigation by animals and also in human mobility. One way to create such regimes are Lévy flights, where the walkers are allowed to perform jumps, the " flights " , that can eventually be very long as their length distribution is asymptotically power-law distributed. In our work, we present a model in which walkers are allowed to perform, on a 1D lattice, " cascades " of n unitary steps instead of one jump of a randomly generated length, as in the Lévy case, where n is drawn from a cascade distribution pn. We show that this local mechanism may give rise to superdiffusion or normal diffusion when pn is distributed as a power law. We also introduce waiting times that are power-law distributed as well and therefore the probability distribution scaling is steered by the two PDF's power-law exponents. As a perspective, our approach may engender a possible generalization of anomalous diffusion in context where distances are difficult to define, as in the case of complex networks, and also provide an interesting model for diffusion in temporal networks

Persistent Homology analysis of Phase Transitions

Persistent homology analysis, a recently developed computational method in algebraic topology, is applied to the study of the phase transitions undergone by the so-called XY-mean field model and by the phi^4 lattice model, respectively. For both models the relationship between phase transitions and the topological properties of certain submanifolds of configuration space are exactly known. It turns out that these a-priori known facts are clearly retrieved by persistent homology analysis of dynamically sampled submanifolds of configuration space.Comment: 10 pages; 10 figure

El uso de los hornos pachamanca y guayra para la fundición en los Andes

El presente estudio ofrece una reseña sobre la tradición metalúrgica andina, discrimina al horno de pachamanca del horno guayra, así como de otros hornos, y trata sobre su uso para la fundición en los Andes. Se apoya en las descripciones aportadas por los cronistas españoles coloniales, arqueólogos, etc. Haciendo referencia a evidencias arqueológicas pertenecientes a los períodos prehispánicos y colonial que se presentan en los distritos mineros de Morococha (Huancavelica, Perú), Porco (Bolivia) y en algunos sitios del Noroeste de Argentina, etc. Cabe acotar que la temática abordada aporta al conocimiento de los hornos de fundición andinos y constituye una parte apenas divulgada del patrimonio minero