Generalized low-density codes with BCH constituents for full-diversity near-outage performance

A new graph-based construction of generalized low density codes (GLD-Tanner) with binary BCH constituents is described. The proposed family of GLD codes is optimal on block erasure channels and quasi-optimal on block fading channels. Optimality is considered in the outage probability sense. Aclassical GLD code for ergodic channels (e.g., the AWGN channel,the i.i.d. Rayleigh fading channel, and the i.i.d. binary erasure channel) is built by connecting bitnodes and subcode nodes via a unique random edge permutation. In the proposed construction of full-diversity GLD codes (referred to as root GLD), bitnodes are divided into 4 classes, subcodes are divided into 2 classes, and finally both sides of the Tanner graph are linked via 4 random edge permutations. The study focuses on non-ergodic channels with two states and can be easily extended to channels with 3 states or more.

A systolic array for linear MIMO detection based on an all-swap lattice reduction algorithm

A systolic array to implement lattice-reduction-aided lineardetection is proposed for a MIMO receiver. The lattice reductionalgorithm and the ensuing linear detections are operated in the same array, which can be hardware-efficient. All-swap lattice reduction algorithm (ASLR) is considered for the systolic design.ASLR is a variant of the LLL algorithm, which processes all lattice basis vectors within one iteration. Lattice-reduction-aided linear detection based on ASLR and LLL algorithms have very similarbit-error-rate performance, while ASLR is more time efficient inthe systolic array, especially for systems with a large number ofantennas.

Design and construction of precision heat fluxmeters

InAlAs/InGaAs/InP based high electron mobility transistor devices have been structurally and electrically characterized, using transmission electron microscopy and Raman spectroscopy and measuring Hall mobilities. The InGaAs lattice matched channels, with an In molar fraction of 53%, grown at temperatures lower than 530¿°C exhibit alloy decomposition driving an anisotropic InGaAs surface roughness oriented along [1math0]. Conversely, lattice mismatched channels with an In molar fraction of 75% do not present this lateral decomposition but a strain induced roughness, with higher strength as the channel growth temperature increases beyond 490¿°C. In both cases the presence of the roughness implies low and anisotropic Hall mobilities of the two dimensional electron gas.

Model-based diagnosis system: application to constructed wetlands

Report for the scientific sojourn carried out at the Model-based Systems and Qualitative Reasoning Group (Technical University of Munich), from September until December 2005. Constructed wetlands (CWs), or modified natural wetlands, are used all over the world as wastewater treatment systems for small communities because they can provide high treatment efficiency with low energy consumption and low construction, operation and maintenance costs. Their treatment process is very complex because it includes physical, chemical and biological mechanisms like microorganism oxidation, microorganism reduction, filtration, sedimentation and chemical precipitation. Besides, these processes can be influenced by different factors. In order to guarantee the performance of CWs, an operation and maintenance program must be defined for each Wastewater Treatment Plant (WWTP). The main objective of this project is to provide a computer support to the definition of the most appropriate operation and maintenance protocols to guarantee the correct performance of CWs. To reach them, the definition of models which represent the knowledge about CW has been proposed: components involved in the sanitation process, relation among these units and processes to remove pollutants. Horizontal Subsurface Flow CWs are chosen as a case study and the filtration process is selected as first modelling-process application. However, the goal is to represent the process knowledge in such a way that it can be reused for other types of WWTP.

Systematic Construction of Goal-Oriented COTS Taxonomies

Informe de investigación realizado a partir de una estancia en el Department of Computer and Information Science de la Norwegian University of Science and Technology (NTNU), Noruega, entre setiembre i diciembre de 2006. El uso de componentes de software llamados Commercial-Off-The-Shelf (COTS) en el desarrollo de sistemas basados en componentes implica varios retos. Uno de ellos es la falta de información disponible y adecuada para dar soporte al proceso de selección de componentes a ser integrados. Para lidiar con estos problemas, se esta desarrollando un trabajo de tesis que propone un método llamado GOThIC (Goal-Oriented Taxonomy and reuse Infrastructure Construction). El método está orientado a construir una infrastructura de reuse para facilitar la búsqueda y reuse de componentes COTS. La estancia en la NTNU, reportada en este documento, tuvo como objetivo primordial las mejora del método y la obtención de datos empíricos para darle soporte. Algunos de los principales resultados fueron la obtención de datos empíricos fundamentando la utilización del método en ámbitos industriales de selección de componentes COTS, así como una nueva estrategia para conseguir de forma factible e incremental, la federación y reuso de los diferentes esfuerzos existentes para encontrar, seleccionar y mantener componentes COTS y Open Source (OSS) -comúnmente llamados componentes Off-The-Shelf (OTS) - en forma estructurada.

Diseño de filtros de onda acústica basados en estructuras "half lattice"

En los últimos tiempos la telefonía móvil ha experimentado una reducción de los terminales gracias a la miniaturización de los filtros a frecuencias de microondas. Los filtros pasa banda más utilizados son los basados en la tecnología SAW, sin embargo son incompatibles con tecnologías de silicio y su comportamiento se degrada a frecuencias superiores de 3 GHz, por ello los estudios actuales se centran en la tecnología BAW. Las dos arquitecturas convencionales de filtros basados en resonadores BAW unidos eléctricamente son el ladder y lattice. Sin embargo, en este proyecto se estudiará la topología half lattice, la cual presenta un mejor comportamiento y unas dimensiones más reducidas. Para ello se obtendrán las ecuaciones de diseño del filtro, y con ellas se realizará la implementación a partir de la frecuencia central y el ancho de banda relativo.

Family-based affirmative action? Subversion and resilience strategies of gay father families

The present doctoral dissertation is aimed at analyzing how and with what consequences gay father families and their children’s schools negotiate possible differences in the construction of family and gender at home and in the families’ social milieus. This objective fits in with the broader goal of researching how family-school interactons are influenced by the social context such as hegemonic masculinity (Connell, 2002). The thesis is based on qualitative fieldwork carried out with 18 nonheterosexual parent families in Spain, comprising 30 interviews with 44 people. The principal participant group were 14 de novo (adoptive and surrogacy) gay father families with resident preadolescent children. The findings revealed that all the de novo families assumed open communication strategies at school with inclusive consequences: apart from incidental questions and reactions of surprise, the children did not suffer homophobic bullying. The analisis showed that the necessary condition for inclusion was not the open communication but rather illocutionary orientation (Habermas, 1984; Soler & Flecha, 2010), understood as the parents’ sensitivity to the attitudes of their children and schools. The schools received the families in an inclusive manner, which, however, was only receptive and not proactive, therefore some of the families (reconstituted ones), coerced by the social context, got excluded. Gender relations at home were predominantly androgynous, and outside home predominantly traditional, yet the children negotiated this difference with inclusive consequences. They participated in hegemonic collective practices, thus confirming the thesis on the similarity between homo- and heterosexual-parent families (Golombok, 2006). Consistently, also the families’ identity politics was “assimilationist” and non-queer. Admittedly, the analisis showed that such a politics was increased by social expectations. Still, the findings suggest that educational and other family policies should draw on broad agendas of gender and family diversity rather than on the politics of difference and the unique status of LGB families.

Globally aligned photomosaic of the Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge, 37°18.5’N): Release of georeferenced data, mosaic construction, and viewing software

We present a georeferenced photomosaic of the Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge, 37°18’N). The photomosaic was generated from digital photographs acquired using the ARGO II seafloor imaging system during the 1996 LUSTRE cruise, which surveyed a ~1 km2 zone and provided a coverage of ~20% of the seafloor. The photomosaic has a pixel resolution of 15 mm and encloses the areas with known active hydrothermal venting. The final mosaic is generated after an optimization that includes the automatic detection of the same benthic features across different images (feature-matching), followed by a global alignment of images based on the vehicle navigation. We also provide software to construct mosaics from large sets of images for which georeferencing information exists (location, attitude, and altitude per image), to visualize them, and to extract data. Georeferencing information can be provided by the raw navigation data (collected during the survey) or result from the optimization obtained from imatge matching. Mosaics based solely on navigation can be readily generated by any user but the optimization and global alignment of the mosaic requires a case-by-case approach for which no universally software is available. The Lucky Strike photomosaics (optimized and navigated-only) are publicly available through the Marine Geoscience Data System (MGDS, http://www.marine-geo.org). The mosaic-generating and viewing software is available through the Computer Vision and Robotics Group Web page at the University of Girona (http://eia.udg.es/_rafa/mosaicviewer.html)

Entropy change of martensitic transformations in Cu-based shape-memory alloys

We have investigated the different contributions to the entropy change at the martensitic transition of different families of Cu-based shape-memory alloys. The total entropy change has been obtained through calorimetric measurements. By measuring the evolution of the magnetic susceptibility with temperature, the entropy change associated with conduction electrons has been evaluated. The contribution of the anharmonic vibrations of the lattice has also been estimated using various parameters associated with the anharmonic behavior of these alloys, collected from the literature. The results found in the present work have been compared to values published for the martensitic transition of group-IV metals. For Cu-based alloys, both electron and anharmonic contributions have been shown to be much smaller than the overall entropy change. This finding demonstrates that the harmonic vibrations of the lattice are the most relevant contribution to the stability of the bcc phase in Cu-based alloys.

Vibrational behaviour of bcc Cu-based shape memory alloys close to the martensitic transition

Experimental data from ultrasonic and inelastic neutron scattering measurements are analyzed for different families of Cu-based shape-memory alloys. It is shown that the transition occurs at a value, independent of composition and alloy family, of the ratio between the elastic constants associated with the two shears necessary to accomplish the lattice distortion from the bcc to the close-packed structure. The zone boundary frequency of the TA2[110] branch evaluated at the transition point (TM), weakly depends, for each family, on composition. A linear relationship between this frequency and the inverse of the elastic constant C', both quantities evaluated at TM, has been found, in agreement with the prediction of a Landau model proposed for martensitic transformations.

Spatial behavior in groups: an agent-based approach

We present an agent-based model with the aim of studying how macro-level dynamics of spatial distances among interacting individuals in a closed space emerge from micro-level dyadic and local interactions. Our agents moved on a lattice (referred to as a room) using a model implemented in a computer program called P-Space in order to minimize their dissatisfaction, defined as a function of the discrepancy between the real distance and the ideal, or desired, distance between agents. Ideal distances evolved in accordance with the agent's personal and social space, which changed throughout the dynamics of the interactions among the agents. In the first set of simulations we studied the effects of the parameters of the function that generated ideal distances, and in a second set we explored how group macrolevel behavior depended on model parameters and other variables. We learned that certain parameter values yielded consistent patterns in the agents' personal and social spaces, which in turn led to avoidance and approaching behaviors in the agents. We also found that the spatial behavior of the group of agents as a whole was influenced by the values of the model parameters, as well as by other variables such as the number of agents. Our work demonstrates that the bottom-up approach is a useful way of explaining macro-level spatial behavior. The proposed model is also shown to be a powerful tool for simulating the spatial behavior of groups of interacting individuals.

FAM-MDR: a flexible family-based multifactor dimensionality reduction technique to detect epistasis using related individuals

We propose a novel multifactor dimensionality reduction method for epistasis detection in small or extended pedigrees, FAM-MDR. It combines features of the Genome-wide Rapid Association using Mixed Model And Regression approach (GRAMMAR) with Model-Based MDR (MB-MDR). We focus on continuous traits, although the method is general and can be used for outcomes of any type, including binary and censored traits. When comparing FAM-MDR with Pedigree-based Generalized MDR (PGMDR), which is a generalization of Multifactor Dimensionality Reduction (MDR) to continuous traits and related individuals, FAM-MDR was found to outperform PGMDR in terms of power, in most of the considered simulated scenarios. Additional simulations revealed that PGMDR does not appropriately deal with multiple testing and consequently gives rise to overly optimistic results. FAM-MDR adequately deals with multiple testing in epistasis screens and is in contrast rather conservative, by construction. Furthermore, simulations show that correcting for lower order (main) effects is of utmost importance when claiming epistasis. As Type 2 Diabetes Mellitus (T2DM) is a complex phenotype likely influenced by gene-gene interactions, we applied FAM-MDR to examine data on glucose area-under-the-curve (GAUC), an endophenotype of T2DM for which multiple independent genetic associations have been observed, in the Amish Family Diabetes Study (AFDS). This application reveals that FAM-MDR makes more efficient use of the available data than PGMDR and can deal with multi-generational pedigrees more easily. In conclusion, we have validated FAM-MDR and compared it to PGMDR, the current state-of-the-art MDR method for family data, using both simulations and a practical dataset. FAM-MDR is found to outperform PGMDR in that it handles the multiple testing issue more correctly, has increased power, and efficiently uses all available information.

La construcción narrativa de la identidad en un contexto educativo intercultural = The narrative construction of identity in a intercultural educative setting

En este trabajo se expone e ilustra un modelo teórico para entender las funciones de la identidad, así como los mecanismospsicosociales asociados a su construcción: “Modelo Evolutivo y Funcional de la Identidad Mediada” (MEBIM). La identidad, mediada narrativamente, cumple una función personal orientada a la dirección de la propia vida, así como una función sociocultural vinculada a la búsqueda de reconocimiento de los derechos de los grupos sociales a los que uno se siente apegado. Se ilustran los factores asociados a la construcción de la identidad personal (sí mismos posibles, transiciones vitales, vínculo afectivo) y sociocultural (acción-transformación e identificación simbólica) a partir de 12 historias de vida realizadas con mestizos e indígenasde la Universidad Intercultural de Chiapas (México). Se sugiere que en contextos educativos formales, como la escuela o la Universidad, se deben propiciar narrativas personales y socioculturales con el objetivo de optimizar la identidad en un mundo a la vez globalizado y plural

Construction and performance of network codes

El principal objectiu d'aquest treball és implementar i exposar una descripció teòrica per a diferents esquemes de Physical Layer Network Coding. Utilitzant un esquema bàsic com a punt de partida, el projecte presenta la construcció i l'anàlisis de diferents esquemes de comunicació on la complexitat va augmentant a mesura que anem avançant en el projecte. El treball està estructurat en diferents parts: primer, es presenta una introducció a Physical Layer Network Coding i a Lattice Network Codes. A continuació, s'introdueixen les eines matemàtiques necessàries per entendre el CF System. Després, s'analitza i implementa el primer esquema bàsic. A partir del qual, implementem una versió vectorial del CF System i una versió codificada amb un Hamming q-ari. Finalment, s'estudien i implementen diferents estratègies per millorar la matriu de coeficients A.