About the Infinite Repetition of Histories in Space

This paper analyzes two different proposals, one by Ellis and Brundrit, based on classical relativistic cosmology, the other by Garriga and Vilenkin, based on the DH interpretation of quantum mechanics, both of which conclude that, in an infinite universe, planets and living beings must be repeated an infinite number of times. We point to some possible shortcomings in the arguments of these authors. We conclude that the idea of an infinite repetition of histories in space cannot be considered strictly speaking a consequence of current physics and cosmology. Such ideas should be seen rather as examples of {\guillemotleft}ironic science{\guillemotright} in the terminology of John Horgan.Comment: 14 pages, no figures. Accepted for publication in slightly different form at THEORIA (http://www.ehu.es/ojs/index.php/THEORIA

The "Names Game": Harnessing Inventors' Patent Data for Economic Research

The goal of this paper is to lay out a methodology and corresponding computer algorithms, that allow us to extract the detailed data on inventors contained in patents, and harness it for economic research. Patent data has long been used in empirical research in economics, and yet the information on the identity (i.e. the names and location) of the patents’ inventors has seldom been deployed in a large scale, primarily because of the “who is who” problem: the name of a given inventor may be spelled differently across her/his patents, and the exact same name may correspond to different inventors (i.e. the “John Smith” problem). Given that there are over 2 million patents with 2 inventors per patent on average, the “who is who” problem applies to over 4 million “records”, which is obviously too large to tackle manually. We have thus developed an elaborate methodology and computerized procedure to address this problem in a comprehensive way. The end result is a list of 1.6 million unique inventors from all over the world, with detailed data on their patenting histories, their employers, co-inventors, etc. Forty percent of them have more than one patent, and 70,000 have more than 10 patents. We can trace those multiple inventors across time and space, and thus study the causes and consequences of their mobility across countries, regions, and employers. Given the increasing availability of large computerized data sets on individuals, there may be plenty of opportunities to deploy this methodology to other areas of economic research as well.

Ideology and the possibility of African political theory: African socialism and “ubuntu” compared

This article explores the lack of investigation into African political theory in the postcolonial period. After discussing the epistemological problems in the study of African political thought, the paper then adopts Michael Freeden’s methodology for the analysis of political ideologies. Through this approach a comparison is made between African Socialism and ubuntu. African Socialism – as developed by Cabral, Nkrumah, Nyerere and Senghor – is defined by its core commitment to freedom from colonialism, to African culture, its promotion of communitarian equality and a belief in the transformative power of the state. Ubuntu – in the political version developed in post-apartheid South Africa, and promoted by Thabo Mbeki and Desmond Tutu – instead emphasises the collective and spiritual character of African society and the distinctively African character of ubuntu ideology. By comparing these two examples, we seek to explore the possibilities and problems which the discipline of African political theory faces in the postcolonial period

Evolutionary Algorithms for Community Detection in Continental-Scale High-Voltage Transmission Grids

Symmetry is a key concept in the study of power systems, not only because the admittance and Jacobian matrices used in power flow analysis are symmetrical, but because some previous studies have shown that in some real-world power grids there are complex symmetries. In order to investigate the topological characteristics of power grids, this paper proposes the use of evolutionary algorithms for community detection using modularity density measures on networks representing supergrids in order to discover densely connected structures. Two evolutionary approaches (generational genetic algorithm, GGA+, and modularity and improved genetic algorithm, MIGA) were applied. The results obtained in two large networks representing supergrids (European grid and North American grid) provide insights on both the structure of the supergrid and the topological differences between different regions. Numerical and graphical results show how these evolutionary approaches clearly outperform to the well-known Louvain modularity method. In particular, the average value of modularity obtained by GGA+ in the European grid was 0.815, while an average of 0.827 was reached in the North American grid. These results outperform those obtained by MIGA and Louvain methods (0.801 and 0.766 in the European grid and 0.813 and 0.798 in the North American grid, respectively)

Compararse para mejorar: los círculos de comparación intermunicipal de eficiencia energética en alumbrado público. Resultados para la provincia de Barcelona

El objetivo de este artículo es presentar el Círculo de Comparación Intermuncipal sobre Eficiencia Energética en el Alumbrado Público, destacando los principales indicadores y su potencialidad de extrapolación al resto de municipios del EstadoPostprint (author's final draft

Tunable ring resonator filter for OFDM Transmission systems

A novel tunable filter is theoretically demonstrated. It is based on a ring resonator with an amplifier and a noise filter in the loop. This optoelectronic device has potential as a high-sensitivity receiver and as a tunable demultiplexer in OFDM transmission systems.Publicad

Infrarrojo para el estudio de la D egeneración Macular Asociada a la Edad

La obtención de imágenes mediante I nfrarrojo junto al Oftalmoscopio de Láser de Barrido (SLO) resulta un método eficaz para el estudio de la Degeneración Macular Asociada a la Edad (DMAE), ya que debido a su longitud de onda penetra con mayor facilidad en los tejidos de la retina. Los signos que se ven con mayor calidad con la luz infrarroja son las drusas y pseudodrusas reticulares. Las drusas de pequeño y mediano tamaño (menores de 125 micras) vistas a través de luz infrarroja se observan con una mayor hiperreflectividad. Sin embargo, las de mayores tamaños (mayores de 125 micras) pueden aparecer como hiperreflectivas o hiporrefle ctivas. Usando radiación infrarroja mediante una abertura hacia la derecha se aprecian con mayor calidad y en mayor número que con otros métodos. Con respecto a las pseudodrusas reticulares, con la reflexión con luz infrarroja se observan hiporreflectivas o hiperreflectivas rodeadas de un halo de hiporreflexión al ser lesiones de mayor tamaño y con mayor riesgo para padecer una fase tardía de la DMAE. Con este método, l as pseudod rusas pueden diferenciar se de las drusas e incluso se pueden clasificar. L a Tomografía de Coherencia Óptica ( OCT ) es una técnica más precisa para el estudio de la Atrofia G eográfica (AG) y la Neovascularización Coroidea (NVC) . No obstante, las técnic as basadas en el I nfrarrojo ofrecen una información bastante aceptable. Así en la AG, que es propia de la fase tardía de la DMAE, con la luz infrarroja se muestra con bastante precisión si la zona atrófica afecta o no a la fóvea y cual es su extensión. La NVC se observa como una zona de hiporreflexión rodeada de un anillo con una mayor reflexión, gracias al cuál es más fácil de apreciar y delimitar este signo que con otros métodos como la fotografía a color. E n la actualidad el método con luz infrar roja junto con SLO tiene un papel importante en el estudio y diagnóstico de la DMAE pero debe combinar se con otras técnicas de imagen . Es de esperar que el resultado de las investigaciones que se están llevando a cabo permita establecer la técnica de Infra rrojo como referencia consolidada e independiente para el estudio de la DMAE.Universidad de Sevilla. Grado en Óptica y Optometrí

Dos veces Laura en el Colibeto de Francesco Galeota.

Sin resume

Modelo dinámico de procesos de lodos activos

Una Estación Depuradora de Aguas Residudes (E.D.A.R.) urbanas consta de una serie variable de etapas de proceso, cuyo objetivo es liberar de estas aguas negras la mayor cantidad de substancias, ya disueltas o en suspensión. En este artículo nos centraremos en el Tratamiento Secundario, etapa en la que se eliminan las materias disueltas biodegradables de las aguas residuaies, por acción de los ~nicroorganis~nos presentes en los lodos activos. La configuración a estudiar comprende al digestor aerobio y sedimentador. Se exponen las ecuaciones que describen este sistema.A domestic wastewater, treament plant is composed of variable elements of process, their target is remove of these black waters the biggest ammount of dissolved and susended inaterials. In this paper we are concerned with secundary treatement. This step reinoves biodegradable dissolved materials currently in these waters. The microorganisnis action of activated sludge remove biodegradable dissolved compounds presents in these waters. An aerobic digestor and clarifier is modeled.Peer Reviewe