An Analysis of Coalition-Competition Pricing Strategies for Multi-Operator Mobile Traffic Offloading using Bi-objective Heuristics

In a competitive market relationships between telecommuni- cations operators serving simultaneously over a certain geographical area are diverse and motivated by very different business strategies and goals. Such relationships ultimately yield distinct pricing portfolios depending on the contractual affiliation of the user being served. Furthermore a key role in the last decade is the concept of tethering (connection sharing) which, when controlled by the operator, may help alleviating the con- sumption of network resources in densely populated scenarios. In this work we investigate the application of bi-objective heuristics for the de- sign of Pareto-optimal network topologies leading to an optimal Pareto between the revenue of the incumbent operators in the scenario and the quality of service degradation experienced by the end users as a result of tethering. Based on computer simulation this work unveils that such a Pareto-optimal set of topologies is strongly determined by the market relationships between such operators

Evolution of surname distribution under gender-equality measurements

We consider a model for the evolution of the surnames distribution under a gender-equality measurement presently discussed in the Spanish parliament (the children take the surname of the father or the mother according to alphabetical order). We quantify how this would bias the alphabetical distribution of surnames, and analyze its effect on the present distribution of the surnames in Spain

Stability of homogeneous bundles on P^3

We study the stability of some homogeneous bundles on P^3 by using their representations of the quiver associated to the homgeneous bundles on P^3. In particular we show that homogeneous bundles on P^3 whose support of the quiver representation is a parallelepiped are stable, for instance the bundles E whose minimal free resolution is of the kind 0 --> S^{l_1, l_2, l_3} V (t) --> S^{l_1 +s, l_2, l_3} V (t+s) --> E --> 0 are stable.Comment: to appear in Geometriae Dedicata http://www.springer.com/mathematics/geometry/journal/1071

Hydrodynamic analysis of a tidal cross-flow turbine

This study presents a numerical investigation of a generic horizontal axis cross-flow marine turbine. The numerical tool used is the commercial Computational Fluid Dynamics package ANSYS FLUENT 12.0. The numerical model, using the SST k-w turbulence model, is validated against static, dynamic pitching blade and rotating turbine data. The work embodies two main investigations. The first is concerned with the influence of turbine solidity (ratio of net blade chord to circumference) on turbine performance, and the second with the influence of blockage (ratio of device frontal area to channel crosssection area) and free surface deformation on the hydrodynamics of energy extraction in a constrained channel.Turbine solidity was investigated by simulating flows through two-, three- and four-bladed turbines, resulting in solidities of 0.019, 0.029 and 0.038, respectively. The investigation was conducted for two Reynolds numbers, Re = O(10^5) & O(10^6), to reflect laboratory and field scales. Increasing the number of blades from two to four led to an increase in the maximum power coefficient from 0.43 to 0.53 for the lower Re and from 0.49 to 0.56 for the higher Re computations. Furthermore, the power curve was found to shift to a lower range of tip speed ratios when increasing solidity.The effects of flow confinement and free surface deformation were investigated by simulating flows through a three-bladed turbine with solidity 0.125 at Re = O(10^6) for channels that resulted in cross-stream blockages of 12.5% to 50%. Increasing the blockage led to a substantial increase in the power and basin efficiency; when approximating the free surface as a rigid lid, the highest power coefficient and basin efficiency computed were 1.18 and 0.54, respectively. Comparisons between the corresponding rigid lid and free surface simulations, where Froude number, Fr = 0.082, rendered similar results at the lower blockages, but at the highest blockage an increase in power and basin efficiency of up to 7% for the free surface simulations over that achieved with a rigid lid boundary condition. For the free surface simulations with Fr = 0.082, the energy extraction resulted in a drop in water depth of up to 0.7%. An increase in Fr from 0.082 to 0.131 resulted in an increase maximum power of 3%, but a drop in basin efficiency of 21%.This thesis is not currently available via ORA

ON THE SUPERCRITICALITY OF THE FIRST HOPF BIFURCATION IN A DELAY BOUNDARY PROBLEM

The goal of this paper is to analyze the character of the first Hopf bifurcation (subcritical versus supercritical) that appears in a one-dimensional reaction-diffusion equation with nonlinear boundary conditions of logistic type with delay. We showed in the previous work [Arrieta et al., 2010] that if the delay is small, the unique non-negative equilibrium solution is asymptotically stable. We also showed that, as the delay increases and crosses certain critical value, this equilibrium becomes unstable and undergoes a Hopf bifurcation. This bifurcation is the first one of a cascade occurring as the delay goes to infinity. The structure of this cascade will depend on the parameters appearing in the equation. In this paper, we show that the first bifurcation that occurs is supercritical, that is, when the parameter is bigger than the delay bifurcation value, stable periodic orbits branch off from the constant equilibrium

Mitigating Unconscious Bias in Recruitment and Hiring

Unconscious biases in recruitment and hiring can limit the potential for building a diverse academic and private radiology practice. In the private practice environment of radiology, especially in smaller firms, in which a dysfunctional team can lead to a dysfunctional practice overall, it is especially essential to find the best candidates for the team. Many strategies for mitigating these biases can be employed strategically at multiple levels of the hiring process