TOPS RESPONSIVENESS, STRATEGY-PROOFNESS AND COALITION FORMATION PROBLEMS

This paper introduces a property over agents' preferences, called Tops Responsiveness Condition. Such a property guarantees that the core in Hedonic Coalition Formation games is not empty. It is also shown that a mechanism exists that selects a stable allocation. It turns out that this mechanism, to be called tops covering, is strategy-proof even if the core is not a singleton. Furthermore, we also find out that the tops covering mechanism is the only strategy-proof mechanism that always selects stable allocations.Coalition Formation; Stability; Strategy Proofness.

- THE ROLE OF UNIONS IN HIRING PROCEDURES FOR JOB MARKETS

This paper studies simple hiring procedures for job markets. We show that when agents act strategically only individually rational outcomes should be expected. Moreover, If agents can form unions, thereby gaining the possibility to commit on the decision to be chosen, only stable allocations are implemented.job matching markets, mechanism design

Researching with Whom? Stability and Manipulation

This paper explores the existence of stable research teams, when each agent's preferences depend on the set of researchers collaborating with her. We introduce a property over researchers' preferences, called tops responsiveness guaranteeing the existence of stable research teams configurations. We also provide a stable mechanism, induced by the so-called tops covering algorithm, which is strategy-proof when researchers preferences satisfy tops responsiveness. Furthermore, we also find out that, in this framework the tops covering mechanism is the unique strategy-proof mechanism that always selects stable allocations.Coalition Formation, Research Teams Configurations, Stability, Strategy-Proofness.

Suppressors of selection

Inspired by recent works on evolutionary graph theory, an area of growing interest in mathematical and computational biology, we present the first known examples of undirected structures acting as suppressors of selection for any fitness value $r > 1$. This means that the average fixation probability of an advantageous mutant or invader individual placed at some node is strictly less than that of this individual placed in a well-mixed population. This leads the way to study more robust structures less prone to invasion, contrary to what happens with the amplifiers of selection where the fixation probability is increased on average for advantageous invader individuals. A few families of amplifiers are known, although some effort was required to prove it. Here, we use computer aided techniques to find an exact analytical expression of the fixation probability for some graphs of small order (equal to $6$, $8$ and $10$) proving that selection is effectively reduced for $r > 1$. Some numerical experiments using Monte Carlo methods are also performed for larger graphs.Comment: New title, improved presentation, and further examples. Supporting Information is also include

Silos: catedrales del siglo XX : el patrimonio como herramienta de revitalización urbana

Este trabajo de Fin de Grado se basa en la revitalización urbana, centrándose en el estudio y rehabilitación de un edificio con gran valor patrimonial industrial, concretamente el Silo de Córdoba. Primeramente, se presenta una investigación sobre la contextualización y origen de los silos, que tiene lugar en el siglo XIX en América, y como llega a Europa con el movimiento de Arquitectura Moderna en el siglo XX y posteriormente a España, con la creación de la Red Nacional de Silos y Graneros en 1942.Por otro lado, se estudiará la ciudad de Córdoba y como con las diferentes transformaciones históricas la ciudad y su entorno han ido evolucionando, generando así en varios puntos de la ciudad edificios y espacios con valor patrimonial que, debido a su localización y su mala gestión, han ido perdiendo el uso y en los que se podría intervenir puntualmente para revitalizar el barrio en el que se encuentran. Posteriormente el trabajo se centra en el barrio de Noreña, al oeste de la ciudad de Córdoba, donde encontramos el silo y espacios en desuso en torno a este. Este trabajo pretende analizar el origen y las características de dicho silo, además de presentar las futuras líneas estratégicas a seguir para su rehabilitación, surgiendo así una conexión con otros espacios patrimoniales cercanos y mejorando así el nivel urbano y social del barrio en el que se encuentra y de la propia ciudad.This Final Degree project is based on urban revitalisation, focusing on the study and rehabilitation of a building with great heritage value, specifically the silo of Córdoba. Firstly, research is presented on the contextualisation and origin of silos, which took place in the 19th century in America, and how it arrived in Europe with the Modern Architecture movement in the 20th century and later in Spain, with the creation of the National Network of Silos and Granaries in 1942. On the other hand, the city of Cordoba will be studied and how the city and its surroundings have evolved with the different historical evolutions. This has generated buildings and spaces with heritage value in various parts of the city which, due to their location and poor management, have lost their use and in which it would be possible to intervene to revitalise the neighbourhood in which they are located. I then focus on the neighbourhood of Noreña, in the west of the city of Córdoba, where we find the silo and disused spaces around it. This work aims to analyse the origin and characteristics of this silo, as well as to present the future strategic lines to be followed for its rehabilitation, thus creating a connection with other nearby heritage spaces and improving the urban and social level of the neighbourhood in which it is located and of the city itself.Universidad de Sevilla. Grado en Arquitectur

A method for validating Rent's rule for technological and biological networks

Rent’s rule is empirical power law introduced in an effort to describe and optimize the wiring complexity of computer logic graphs. It is known that brain and neuronal networks also obey Rent’s rule, which is consistent with the idea that wiring costs play a fundamental role in brain evolution and development. Here we propose a method to validate this power law for a certain range of network partitions. This method is based on the bifurcation phenomenon that appears when the network is subjected to random alterations preserving its degree distribution. It has been tested on a set of VLSI circuits and real networks, including biological and technological ones. We also analyzed the effect of different types of random alterations on the Rentian scaling in order to test the influence of the degree distribution. There are network architectures quite sensitive to these randomization procedures with significant increases in the values of the Rent exponents

Exploring the topological sources of robustness against invasion in biological and technological networks

For a network, the accomplishment of its functions despite perturbations is called robustness. Although this property has been extensively studied, in most cases, the network is modified by removing nodes. In our approach, it is no longer perturbed by site percolation, but evolves after site invasion. The process transforming resident/healthy nodes into invader/mutant/diseased nodes is described by the Moran model. We explore the sources of robustness (or its counterpart, the propensity to spread favourable innovations) of the US high-voltage power grid network, the Internet2 academic network, and the C. elegans connectome. We compare them to three modular and non-modular benchmark networks, and samples of one thousand random networks with the same degree distribution. It is found that, contrary to what happens with networks of small order, fixation probability and robustness are poorly correlated with most of standard statistics, but they depend strongly on the degree distribution. While community detection techniques are able to detect the existence of a central core in Internet2, they are not effective in detecting hierarchical structures whose topological complexity arises from the repetition of a few rules. Box counting dimension and Rent’s rule are applied to show a subtle trade-off between topological and wiring complexityThis work was supported by the Spanish Excellence Grant MTM2013-46337-C2-2-P, Galician Grant GPC2015/006 and the European Regional Development Fund. Third author was also supported by the European Social Fund and Government of Aragón (Grant E15), and University of Zaragoza/CUD Grant UZCUD2015-CIE-05S

Análisis de la Repercusión de las ofertas públicas de adquisición en la estructura y composición de los consejos de administración de las empresas españolas.

Este Trabajo de Fin de Grado analiza la repercusión de las Ofertas Públicas de Adquisición (OPA) en la estructura de los órganos de administración en España entre 2008-2019. Para ello he llevado a cabo un estudio de los 44 casos llevados a cabo a lo largo de este horizonte temporal con la intención de identificar tendencias o patrones en los cambios de estos órganos de gobierno tras la ejecución de una OPA. Revela cambios significativos en la composición y roles del consejo tras la OPA, con impacto variado en el rendimiento empresarial. Finalmente, se enfatiza la importancia de una adaptación eficaz para lograr una integración post-OPA exitosa.<br /