Cooperative Transmission and Radio Resources Management for Wireless Networks

Report for the scientific sojourn at the Multimedia Communications Laboratory, University of Texas at Dallas, USA, from September to December 2005. The cooperative transmission has been analyzed taking a broadcast relay channel which assumes a scenario with one source and multiple destinations. Moreover, in order to improve the performance in terms of mutual information, it has been considered that for each destination there is another nearby terminal (called relay) which will help to improve the performance of the destination. This scheme combines different types of channels considered in the information theory, such as the relay channel, broadcast channel and interference channel (if the relays transmit information intended only to its associated destination). In this work, the author has studied the optimal way to encode the signals for the different users, known as capacity region (i.e. related to radio resources management ), of the broadcast relay channel.

Relay-assisted transmission and radio resource management for wireless networks

The following paper presents an overview of the Ph.D Thesis1 presented in [1], which compiles all the research done during the period of time between 2004-2007. In that dissertation the relay-assisted transmission with half-duplex relays is analyzed from different points of view. This study is motivated by the necessity of finding innovative solutions to cope with the requirements of next generation wireless services, and with current radio technology. The use of relayed communications represents a change of paradigm of conventional communications, and requires the definition and evaluation of protocols to be applied to single or multiple-user relay communication. With the two fold goal of enhancing spectral efficiency and homogenize service in cellular communications, system design is investigated at physical (type of transmissions of the relay, decoding mode, ..) and upper layers (resource allocation, dynamic link control).

Creación de una radio musical participativa con difusión online y FM

Este proyecto propone crear un sistema inteligente y autónomo de emisión conjunta por Internet y FM. A través de una interfaz Web cómoda y sencilla, el oyente podrá interactuar con la emisora e influir en la emisión, exponiendo sus preferencias. El sistema tomará de forma autónoma y dinámica las decisiones pertinentes que garantizarán que la emisión cumple las preferencias definidas.

Comparativa de la publicitat radiofònica entre Espanya i Itàlia. Estudi de les emissores Els 40 Principals y Radio Deejay

El treball final de carrera “Comparativa de la publicitat radiofònica entre Espanya i Itàlia. Estudi de les emissores Els 40 Principals i Radio Deejay”, és un anàlisi que pretén, mitjançant un estudi de cas de dues emissores de radiofórmula privades i nacionals, una espanyola i una italiana, comparar la publicitat radiofònica entre Espanya i Itàlia en cadenes musicals. L’estudi analitza la història, el target, la programació, la publicitat i les tarifes en cada una de les dues emissores per tal de trobar les semblances i diferències entre elles. La recerca es centra amb l’anàlisi dels tipus d’anunciants, l’estructura dels espais i formats publicitaris i l’anàlisi de la publicitat emesa en cada emissora en la franja horària del matí. Se n’extreuen conclusions que utilitzem com a referència per veure si a Espanya i a Itàlia aquest tipus d’emissores de ràdio usen les mateixes estratègies organitzatives i creatives, veure si en el passat i el present han seguit i segueixen un mateix camí o no.

Revisión de resultados en el tratamiento de las fracturas distales de radio

Es presenta un estudi de l’avaluació dels resultats en el tractament de les fractures distals de radi durant el període de temps 2008-2010 a l’Hospital Sant Joan de Reus. A partir del estudi radiogràfic i biomecànic de les fractures i mitjançant la classificació de Fernández s’avalua el tractament realitzat, en termes de funcionalitat i resultat radiogràfic posterior. Els tractament utilitzats van ser: la reducció tancada i immobilització amb guix antebraquiopalmar (ABP), la reducció tancada i fixació percutánia amb agulles de Kirchner, la reducció oberta per abordatge palmar i fixació amb placa volar DVR (Distal Volar Radius). Els resultat s’avaluen amb l’escala de valoració de Gartland modificada. Fent una revisió actualitzada de la literatura i l’evidencia que existeix pel tractament de cada tipus de fractura.

Stream Radio Community : comunitat web per la difusió de radio via streaming

Desenvolupament d'una aplicació web amb projecció a comunitat virtual d’usuaris, que també integra un sistema de transmissió de streaming. Mitjançant aquest sistema els usuaris són capaços d’emetre o d’escoltar un programa radiofònic en temps real o offline.

TwHistory : Sharing History Using Twitter

In light of the fact that several studies indicate that students can benefit from deeper understandings of the processes by which historical accounts are constructed, history educators have increasingly been focused on finding ways to teach students how to read and reason about events in the same manner as professional historians (Wineburg, 2001; Spoehr & Spoehr, 1994; Hynd, Holschuh, & Hubbard, 2004; Wiley & Voss, 1996). One possible resource for supporting this development may come out of emerging web-based technologies. New technologies and increased access to historical records and artifacts posted the Internet may be precisely the tools that can help students (Bass, Rosenzweig, & Mason, 1999). Given the right context, we believe it is possible to combine such resources and tools to create an environment for students that could strengthen their abilities to read and reason about historical events. Moreover, we believe that social media, specifically, microblogging (Nardi, Schiano, Gumbrecht, & Swartz, 2004) could play a key role.

Conversation is the Key : A Short History of Smarthistory.org

Smarthistory.org is a proven, sustainable model for open educational resources in the Humanities. We discuss lessons learned during its agile development. Smarthistory.org is a free, creative-commons licensed, multi-media web-book designed as a dynamic enhancement or substitute for the traditional art history textbook. It uses conversation instead of the impersonal voice of the typical textbook in-order to reveal disagreement, emotion, and the experience of looking. The listener remains engaged with both the content and the interaction of the speakers. These conversations model close looking and a willingness to encounter and engage the unfamiliar. Smarthistory takes the inherent dialogic and multimedia nature of the web and uses it as a pedagogical method. This extendable Humanities framework uses an open-source content management system making Smarthistory inexpensive to create, and easy to manage and update. Its chronological timeline/chapter-based format integrates new contributions into a single historical framework, a structure applicable across the Humanities.

Preserving memories on-line : the exhibition 'Memories of our childhood' and the Catalan Immigration History Museum

Gràcies a la introducció d'Internet, les institucions de la memòria poden anar ara un pas endavant i proporcionar narratives i documentació en línia. La present comunicació intenta descobrir com poden ser utilitzades les memòries en línia basant-se en dues experiències: una exposició de nens de la guerra i un portal d'immigració.

Medium access control messaging scheme for cognitive radio networks

Los sistemas de radio cognitivos son una solución a la deficiente distribución del espectro inalámbrico de frecuencias. Usando acceso dinámico al medio, los usuarios secundarios pueden comunicarse en canales de frecuencia disponibles, mientras los usuarios asignados no están usando dichos canales. Un buen sistema de mensajería de control es necesario para que los usuarios secundarios no interfieran con los usuarios primarios en las redes de radio cognitivas. Para redes en donde los usuarios son heterogéneos en frecuencia, es decir, no poseen los mismos canales de frecuencia para comunicarse, el grupo de canales utilizado para transmitir información de control debe elegirse cuidadosamente. Por esta razón, en esta tesis se estudian las ideas básicas de los esquemas de mensajería de control usados en las redes de radio cognitivas y se presenta un esquema adecuado para un control adecuado para usuarios heterogéneos en canales de frecuencia. Para ello, primero se presenta una nueva taxonomía para clasificar las estrategias de mensajería de control, identificando las principales características que debe cumplir un esquema de control para sistemas heterogéneos en frecuencia. Luego, se revisan diversas técnicas matemáticas para escoger el mínimo número de canales por los cuales se transmite la información de control. Después, se introduce un modelo de un esquema de mensajería de control que use el mínimo número de canales y que utilice las características de los sistemas heterogéneos en frecuencia. Por último, se comparan diversos esquemas de mensajería de control en términos de la eficiencia de transmisión.

The History of the European Union (Chinese version)

Descriu i analitza el procés d'integració europea des dels seus inicis, els anys cinquanta, fins als nostres dies. L'objectiu consisteix a oferir una visió de conjunt d'un procés que va començar modestament amb la integració dels mercats del carbó i de l'acer dels sis membres fundadors i que ha derivat en una Unió Europea de 27 estats membres i més de 500 milions d'habitants, amb polítiques comunes, una cooperació estreta en els àmbits més sensibles de la sobirania estatal i una moneda única en setze estats

Origin and genetic differentiation of Three Mexican Native Groups (Purépechas, Triquis and Mayas): contribution of CODIS-STRs to the history of human populations of Mesoamerica

BACKGROUND: CODIS-STRs in Native Mexican groups have rarely been analysed for human identification and anthropological purposes. AIM:To analyse the genetic relationships and population structure among three Native Mexican groups from Mesoamerica.SUBJECTS AND METHODS: 531 unrelated Native individuals from Mexico were PCR-typed for 15 and 9 autosomal STRs (Identifiler™ and Profiler™ kits, respectively), including five population samples: Purépechas (Mountain, Valley and Lake), Triquis and Yucatec Mayas. Previously published STR data were included in the analyses. RESULTS:Allele frequencies and statistical parameters of forensic importance were estimated by population. The majority of Native groups were not differentiated pairwise, excepting Triquis and Purépechas, which was attributable to their relative geographic and cultural isolation. Although Mayas, Triquis and Purépechas-Mountain presented the highest number of private alleles, suggesting recurrent gene flow, the elevated differentiation of Triquis indicates a different origin of this gene flow. Interestingly, Huastecos and Mayas were not differentiated, which is in agreement with the archaeological hypothesis that Huastecos represent an ancestral Maya group. Interpopulation variability was greater in Natives than in Mestizos, both significant.CONCLUSION: Although results suggest that European admixture has increased the similarity between Native Mexican groups, the differentiation and inconsistent clustering by language or geography stresses the importance of serial founder effect and/or genetic drift in showing their present genetic relationships.

Leaving the labour market: event-history analysis of the female workers' transition to housework in Denmark, Germany, Great Britain and Spain

This paper is aimed at exploring the determinants of female activity from a dynamic perspective. An event-history analysis of the transition form employment to housework has been made resorting to data from the European Household Panel Survey. Four countries representing different welfare regimes and, more specifically, different family policies, have been selected for the analysis: Britain, Denmark, Germany and Spain. The results confirm the importance of individual-level factors, which is consistent with an economic approach to female labour supply. Nonetheless, there are significant cross-national differences in how these factors act over the risk of abandoning the labour market. First, the number of trnasitions is much lower among Danish working women than among British, German or Spanish ones, revealing the relative importance of universal provision of childcare services, vis-à-vis other elements of the family policy, as time or money.

Quantifying quantitative literacy: Age heaping and the history of human capital

Age data frequently display excess frequencies at round or attractive ages, such as even numbers and multiples of five. This phenomenon of age heaping has been viewed as a problem in previous research, especially in demography and epidemiology. We see it as an opportunity and propose its use as a measure of human capital that can yield comparable estimates across a wide range of historical contexts. A simulation study yields methodological guidelines for measuring and interpreting differences in ageheaping, while analysis of contemporary and historical datasets demonstrates the existence of a robust correlation between age heaping and literacy at both the individual and aggregate level. To illustrate the method, we generate estimates of human capital in Europe over the very long run, which support the hypothesis of a major increase in human capital preceding the industrial revolution.

Recreating the South Sea bubble: Lessons from an experiment in financial history

Major bubble episodes are rare events. In this paper, we examine what factors might cause some asset price bubbles to become very large. We recreate, in a laboratory setting, some of the specific institutional features investors in the South Sea Company faced in 1720. Several factors have been proposed as potentially contributing to one of the greatest periods of asset overvaluation in history: an intricate debt-for-equity swap, deferred payment for these shares, and the possibility of default on the deferred payments. We consider which aspect might have had the most impact in creating the South Sea bubble. The results of the experiment suggest that the company?s attempt to exchange its shares for government debt was the single biggest contributor to the stock price explosion, because of the manner in which the swap affected fundamental value. Issuing new shares with only partial payments required, in conjunction with the debt-equity swap, also had a significant effect on the size of the bubble. Limited contract enforcement, on the other hand, does not appear to have contributed significantly.