Winnerless competition in coupled Lotka-Volterra maps

Winnerless competition is analyzed in coupled maps with discrete temporal evolution of the Lotka-Volterra type of arbitrary dimension. Necessary and sufficient conditions for the appearance of structurally stable heteroclinic cycles as a function of the model parameters are deduced. It is shown that under such conditions winnerless competition dynamics is fully exhibited. Based on these conditions different cases characterizing low, intermediate, and high dimensions are therefore computationally recreated. An analytical expression for the residence times valid in the N-dimensional case is deduced and successfully compared with the simulations.J.L.C. and E.D.G. acknowledge support from IVIC-141, L.A.G.-D. acknowledges support from IVIC-1089 and P.V. acknowledges support from MINECO TIN2012-30883

Strategic Wage Setting and Coordination Frictions with Multiple Applications

We examine wage competition in a model where identical workers choose the number of jobs to apply for and identical firms simultaneously post a wage. The Nash equilibrium of this game exhibits the following properties: (i) an equilibrium where workers apply for just one job exhibits unemployment and absence of wage dispersion; (ii) an equilibrium where workers apply for two or for more (but not for all) jobs always exhibits wage dispersion and, typically, unemployment; (iii) the equilibrium wage distribution with a higher vacancy-to-unemployment ratio first-order stochastically dominates the wage distribution with a lower level of labor market tightness; (iv) the average wage is non-monotonic in the number of applications; (v) the equilibrium number of applications is non-monotonic in the vacancy-to-unemployment ratio; (vi) a minimum wage increase can be welfare improving because it compresses the wage distribution and reduces the congestion effects caused by the socially excessive number of applications; and (vii) the only way to obtain efficiency is to impose a mandatory wage that eliminates wage dispersion altogether.wage setting, unemployment, minimum wage, Nash equilibrium

Topological features of hydrogenated graphene

Hydrogen adatoms are one of the most the promising proposals for the functionalization of graphene. Hydrogen induces narrow resonances near the Dirac energy, which lead to the formation of magnetic moments. Furthermore, they also create local lattice distortions which enhance the spin-orbit coupling. The combination of magnetism and spin-orbit coupling allows for a rich variety of phases, some of which have non trivial topological features. We analyze the interplay between magnetism and spin-orbit coupling in ordered arrays of hydrogen on graphene monolayers, and classify the different phases that may arise. We extend our model to consider arrays of adsorbates in graphene-like crystals with stronger intrinsic spin-orbit couplings.Comment: 6 pages, 4 figure

Air Pollution Convergente and Economic Growth across European Countries

This paper analyses the role of macroeconomic performance in shaping the evolution of air pollutants in a panel of European countries from 1990 to 2000. The analysis is addressed in connection with EU environmental regulation and taking into account macroeconomic performance. We start by documenting the patterns of crosscountry differences among different pollutants. We then interpret these differences within a neoclassical growth model with pollution. Three main pieces of evidence are presented. First, we analyze the existence of convergence of pollution levels within European economies. Second, we rank countries according to its performance in terms of emissions and growth. Third, we evaluate the evolution of emissions in terms of the targets signed for 2010.Economic Growth, Air Pollution, Convergence

Classical emulation of quantum-coherent thermal machines

The performance enhancements observed in various models of continuous quantum thermal machines have been linked to the buildup of coherences in a preferred basis. But, is this connection always an evidence of `quantum-thermodynamic supremacy'? By force of example, we show that this is not the case. In particular, we compare a power-driven three-level continuous quantum refrigerator with a four-level combined cycle, partly driven by power and partly by heat. We focus on the weak driving regime and find the four-level model to be superior since it can operate in parameter regimes in which the three-level model cannot, it may exhibit a larger cooling rate, and, simultaneously, a better coefficient of performance. Furthermore, we find that the improvement in the cooling rate matches the increase in the stationary quantum coherences exactly. Crucially, though, we also show that the thermodynamic variables for both models follow from a classical representation based on graph theory. This implies that we can build incoherent stochastic-thermodynamic models with the same steady-state operation or, equivalently, that both coherent refrigerators can be emulated classically. More generally, we prove this for any N-level weakly driven device with a `cyclic' pattern of transitions. Therefore, even if coherence is present in a specific quantum thermal machine, it is often not essential to replicate the underlying energy conversion process.Comment: 13 pages, 4 figures; references updated; appendix adde

Defining an Air Pollution Sensor Inside the Car

This paper provides the specification and definition of a system capable of reading pollution inside the cabin of an automobile and shows the measurements to all passengers. Requirements elicitation, system requirements analysis, system architectural design, software requirements analysis, software architectural design, software detailed design and unit construction phases from the automotive Spice process reference model will be explained in detail and some examples will be shown. This paper can function as a guide to define and specify a system using different methodologies between these phases. The system design proposed here can be a starting point for future applications related to automobile pollution measurements, for example, reading environmental pollution and monitoring automobile emissions.ITESO, A. C

Voltaje de referencia BandGap y módulo de comunicación serial para SAR ADC 10 bits de baja potencia para aplicaciones biomédicas

The document presents two designs a BandGap Reference Voltage, and a Communication Serial Module for a 10 bits SAR ADC for low-power applications. Designs were implemented using TSMC 0.18 µm CMOS technology with 1.8 V supply voltage. The BandGap Reference Voltage was designed to provide a reference voltage of 900 mV ±500 µV. The bandgap was tested at simulation level under different temperature conditions to ensure constant output in a temperature range from –40 °C to 85 °C. The Communication Serial Module is designed using the hardware description language Verilog. This module receives the 10 bits parallel output of the SAR ADC and retransmits the conversion result into a serial format using the SPI format. The Communication Serial Module was tested under a simulator, where multiple test cases were applied to stimulate in different ways the module. Both circuits were designed to accomplish the SAR ADC requirements in which BandGap supplies the reference voltage to the capacitor array in the SAR ADC and the Serial Module sends the data values after the conversion is finalized.ITESO, A. C