Electronic property analysis of O-doped Cu3SbS3

The ternary Cu-Sb-S semiconductors are considered to be sustainable and potential alternative absorber materials in thin film photovoltaic applications. In these compounds, several phases may coexist, albeit in different proportions depending on experimental growth conditions. Additionally, the photovoltaic efficiency could be increased with isoelectronic doping. In this work we analyze the electronic properties of O-doped Cu3SbS3 in two structures: the wittichenite and the skinnerite. We use first-principles within the density functional formalism with two different exchange-correlation potentials. In addition, we estimate the potential of these compounds for photovoltaic applications.

Analysis of electronic and telematic voting systems in binding experiences

This paper is about analysis and assess of three experiences on telematic and electronic voting dealing with such aspects as security and achievement of the social requirements. These experiences have been chosen taking into account the deepness of the public documentation and the technological challenge they faces.

Contributions to traditional electronic voting systems in order to reinforce citizen confidence

This document provides a general description of the telematic voting scenario designed by the author?s research group. This scenario reinforces verification procedures as key elements to achieve full acceptance of the system on the part of voters. To frame this work, a general overview of electronic voting is given and the conditions entailed by these systems are specified.

Analysis of electronic and telematic voting systems in binding experiences.

This paper is about analysis and assess of three experiences on telematic and electronic voting dealing with such aspects as security and achievement of the social requirements. These experiences have been chosen taking into account the deepness of the public documentation and the technological challenge they faces.

Study of an electronic steering antenna with a staggered phase shifter configuration

This paper presents a study of three possible solutions that can be taken into account to control the phase shift between elements in an antenna array. Because commercial digital phase shifters have become a strategic element by U.S. Government, these elements have increased their price. For this reason, it is necessary to adopt some solutions that allow us to deal with the design and construction of antenna arrays.

Ion-beam damage induced in SiO2: Excitonic mechanisms under heavy electronic excitation

The Centro de Micro-Análisis de Materiales (CMAM) in the Universidad Autónoma de Madrid is carrying out an extensive research program on the processes induced by high energy heavy mass ions (SHI) on dielectric materials and their photonic applications [1?21]. A significant part of this activity constitutes a relevant contribution to the scientific program associated to the TECHNOFUSION project. It is performed in collaboration with the Instituto de Fusion Nuclear at the UPM, the CIEMAT, the Departamento de Física de Materiales at UAM and several other national institutions (INTA) and international laboratories (GANIL, France), Legnaro Italy, Grenoble?. The program has led to a large number of publications in reputed international journals.

Integrated electronic system for ultrasonic structural health monitoring

A fully integrated on-board electronic system that can perform in-situ structural health monitoring (SHM) of aircraft?s structures using specifically designed equipment for SHM based on guided wave ultrasonic method or Lamb waves? method is introduced. This equipment is called Phased Array Monitoring for Enhanced Life Assessment (PAMELA III) and is an essential part of overall PAMELA SHM? system. PAMELA III can generate any kind of excitation signals, acquire the response signals that propagate throughout the structure being tested, and perform the signal processing for damage detection directly on the structure without need to send the huge amount of raw signals but only the final SHM maps. It monitors the structure by means of an array of integrated Phased Array (PhA) transducers preferably bonded onto the host structure. The PAMELA III hardware for SHM mapping has been designed, built and subjected to laboratory tests, using aluminum and CFRP structures. The 12 channel system has been designed to be low weight (265 grams only), to have a small form factor, to be directly mounted above the integrated PhA transducers without need for cables and to be EMI protected so that the equipment can be taken on board an aircraft to perform required SHM analyses by use of embedded SHM algorithms. Moreover, the autonomous, automatic and on real-time working procedure makes it suitable for the avionic field, sending the corresponding alerts, maps and reports to external equipment.

Caracterización de la impedancia de superficie para el cálculo del acoplo mutuo en un cilindro circular conductor cubierto por una dieléctrico multicapa

A novel formulation for the surface impedance characterization is introduced for the canonical problem of surface fields on a perfect electric conductor (PEC) circular cylinder with a dielectric coating due to a electric current source using the Uniform Theory of Diffraction (UTD) with an Impedance Boundary Condition (IBC). The approach is based on a TE/TM assumption of the surface fields from the original problem. Where this surface impedance fails, an optimization is performed to minimize the error in the SD Green's function between the original problem and the equivalent one with the IBC. This new approach requires small changes in the available UTD based solution with IBC to include the geodesic ray angle and length dependence in the surface impedance formulas. This asymptotic method, accurate for large separations between source and observer points, in combination with spectral domain (SD) Green's functions for multidielectric coatings leads to a new hybrid SD-UTD with IBC to calculate mutual coupling among microstrip patches on a multilayer dielectric-coated PEC circular cylinder. Results are compared with the eigenfunction solution in SD, where a very good agreement is met.

Electronic systems major in the context of integrated language learning lab (ILLLab) proyect = Sistemas electrónicos en el contexto del proyecto Integrated Language Learning Lab (ILLLab)

Este proyecto colabora con la plataforma Integrated Language Learning Lab (ILLLab) aportando una serie de ejercicios de gramática inglesa para una nueva sección de la web basada íntegramente en la especialidad de Sistemas Electrónicos. Complementariamente se adentra en una nueva oportunidad basada en dispositivos móviles inteligentes creando una aplicación para el repaso de los conceptos estudiados en la titulación de Ingeniería Técnica de Telecomunicación en lengua inglesa.

Theoretical Stark broadening parameters for spectral lines arising from the 2p5ns, 2p5np and 2p5nd electronic configurations of MgIII

In the present work we report theoretical Stark widths and shifts calculated using the Griem semi-empirical approach, corresponding to 237 spectral lines of MgIII. Data are presented for an electron density of 1017 cm?3 and temperatures T = 0.5?10.0 (104 K). The matrix elements used in these calculations have been determined from 23 configurations of MgIII: 2s22p6, 2s22p53p, 2s22p54p, 2s22p54f and 2s22p55f for even parity and 2s22p5ns (n = 3?6), 2s22p5nd (n = 3?9), 2s22p55g and 2s2p6np (n = 3?8) for odd parity. For the intermediate coupling (IC) calculations, we use the standard method of least-squares fitting from experimental energy levels by means of the Cowan computer code. Also, in order to test the matrix elements used in our calculations, we present calculated values of 70 transition probabilities of MgIII spectral lines and 14 calculated values of radiative lifetimes of MgIII levels. There is good agreement between our calculations and experimental radiative lifetimes. Spectral lines of MgIII are relevant in astrophysics and also play an important role in the spectral analysis of laboratory plasma. Theoretical trends of the Stark broadening parameter versus the temperature for relevant lines are presented. No values of Stark parameters can be found in the bibliography.

Use of electronic fruits to evaluate fruit damage along the handling process.

Two electronic fruits (SEP-1, Simulated Electronic Product, developed in Scotland, and Techmark IS-100, Instrumented Sphere, developed in USA) have been compared in laboratory tests and then used to evaluate handling operations, in several cooperatives of two areas of Spain: Lérida (pome fruits) and Valencia (stone fruits). Advantages of each device were evaluated. Harvest, mechanical bin unloading, and grading line transfers and sizers were identified as operations causing fruit damage.

Arquitectura de Control para la Conducción Autónoma de Vehículos en Entornos Urbanos y Autovías

Hoy en día, el desarrollo tecnológico en el campo de los sistemas inteligentes de transporte (ITS por sus siglas en inglés) ha permitido dotar a los vehículos con diversos sistemas de ayuda a la conducción (ADAS, del inglés advanced driver assistance system), mejorando la experiencia y seguridad de los pasajeros, en especial del conductor. La mayor parte de estos sistemas están pensados para advertir al conductor sobre ciertas situaciones de riesgo, como la salida involuntaria del carril o la proximidad de obstáculos en el camino. No obstante, también podemos encontrar sistemas que van un paso más allá y son capaces de cooperar con el conductor en el control del vehículo o incluso relegarlos de algunas tareas tediosas. Es en este último grupo donde se encuentran los sistemas de control electrónico de estabilidad (ESP - Electronic Stability Program), el antibloqueo de frenos (ABS - Anti-lock Braking System), el control de crucero (CC - Cruise Control) y los más recientes sistemas de aparcamiento asistido. Continuando con esta línea de desarrollo, el paso siguiente consiste en la supresión del conductor humano, desarrollando sistemas que sean capaces de conducir un vehículo de forma autónoma y con un rendimiento superior al del conductor. En este trabajo se presenta, en primer lugar, una arquitectura de control para la automatización de vehículos. Esta se compone de distintos componentes de hardware y software, agrupados de acuerdo a su función principal. El diseño de la arquitectura parte del trabajo previo desarrollado por el Programa AUTOPIA, aunque introduce notables aportaciones en cuanto a la eficiencia, robustez y escalabilidad del sistema. Ahondando un poco más en detalle, debemos resaltar el desarrollo de un algoritmo de localización basado en enjambres de partículas. Este está planteado como un método de filtrado y fusión de la información obtenida a partir de los distintos sensores embarcados en el vehículo, entre los que encontramos un receptor GPS (Global Positioning System), unidades de medición inercial (IMU – Inertial Measurement Unit) e información tomada directamente de los sensores embarcados por el fabricante, como la velocidad de las ruedas y posición del volante. Gracias a este método se ha conseguido resolver el problema de la localización, indispensable para el desarrollo de sistemas de conducción autónoma. Continuando con el trabajo de investigación, se ha estudiado la viabilidad de la aplicación de técnicas de aprendizaje y adaptación al diseño de controladores para el vehículo. Como punto de partida se emplea el método de Q-learning para la generación de un controlador borroso lateral sin ningún tipo de conocimiento previo. Posteriormente se presenta un método de ajuste on-line para la adaptación del control longitudinal ante perturbaciones impredecibles del entorno, como lo son los cambios en la inclinación del camino, fricción de las ruedas o peso de los ocupantes. Para finalizar, se presentan los resultados obtenidos durante un experimento de conducción autónoma en carreteras reales, el cual se llevó a cabo en el mes de Junio de 2012 desde la población de San Lorenzo de El Escorial hasta las instalaciones del Centro de Automática y Robótica (CAR) en Arganda del Rey. El principal objetivo tras esta demostración fue validar el funcionamiento, robustez y capacidad de la arquitectura propuesta para afrontar el problema de la conducción autónoma, bajo condiciones mucho más reales a las que se pueden alcanzar en las instalaciones de prueba. ABSTRACT Nowadays, the technological advances in the Intelligent Transportation Systems (ITS) field have led the development of several driving assistance systems (ADAS). These solutions are designed to improve the experience and security of all the passengers, especially the driver. For most of these systems, the main goal is to warn drivers about unexpected circumstances leading to risk situations such as involuntary lane departure or proximity to other vehicles. However, other ADAS go a step further, being able to cooperate with the driver in the control of the vehicle, or even overriding it on some tasks. Examples of this kind of systems are the anti-lock braking system (ABS), cruise control (CC) and the recently commercialised assisted parking systems. Within this research line, the next step is the development of systems able to replace the human drivers, improving the control and therefore, the safety and reliability of the vehicles. First of all, this dissertation presents a control architecture design for autonomous driving. It is made up of several hardware and software components, grouped according to their main function. The design of this architecture is based on the previous works carried out by the AUTOPIA Program, although notable improvements have been made regarding the efficiency, robustness and scalability of the system. It is also remarkable the work made on the development of a location algorithm for vehicles. The proposal is based on the emulation of the behaviour of biological swarms and its performance is similar to the well-known particle filters. The developed method combines information obtained from different sensors, including GPS, inertial measurement unit (IMU), and data from the original vehicle’s sensors on-board. Through this filtering algorithm the localization problem is properly managed, which is critical for the development of autonomous driving systems. The work deals also with the fuzzy control tuning system, a very time consuming task when done manually. An analysis of learning and adaptation techniques for the development of different controllers has been made. First, the Q-learning –a reinforcement learning method– has been applied to the generation of a lateral fuzzy controller from scratch. Subsequently, the development of an adaptation method for longitudinal control is presented. With this proposal, a final cruise control controller is able to deal with unpredictable environment disturbances, such as road slope, wheel’s friction or even occupants’ weight. As a testbed for the system, an autonomous driving experiment on real roads is presented. This experiment was carried out on June 2012, driving from San Lorenzo de El Escorial up to the Center for Automation and Robotics (CAR) facilities in Arganda del Rey. The main goal of the demonstration was validating the performance, robustness and viability of the proposed architecture to deal with the problem of autonomous driving under more demanding conditions than those achieved on closed test tracks.

Electronic structure of copper nitrides as a function of nitrogen content

he nitrogen content dependence of the electronic properties for copper nitride thin films with an atomic percentage of nitrogen ranging from 26 ± 2 to 33 ± 2 have been studied by means of optical (spectroscopic ellipsometry), thermoelectric (Seebeck), and electrical resistivity measurements. The optical spectra are consistent with direct optical transitions corresponding to the stoichiometric semiconductor Cu3N plus a free-carrier contribution, essentially independent of temperature, which can be tuned in accordance with the N-excess. Deviation of the N content from stoichiometry drives to significant decreases from − 5 to − 50 μV/K in the Seebeck coefficient and to large enhancements, from 10− 3 up to 10 Ω cm, in the electrical resistivity. Band structure and density of states calculations have been carried out on the basis of the density functional theory to account for the experimental results.

Effect of Sb incorporation on the electronic structure of InAs quantum dots

On the basis of optical characterization experiments and an eight band kp model, we have studied the effect of Sb incorporation on the electronic structure of InAs quantum dots (QDs). We have found that Sb incorporation in InAs QDs shifts the hole wave function to the center of the QD from the edges of the QD where it is otherwise pinned down by the effects of shear stress. The observed changes in the ground-state energy cannot merely be explained by a composition change upon Sb exposure but can be accounted for when the change in lateral size is taken into consideration. The Sb distribution inside the QDs produces distinctive changes in the density of states, particularly, in the separation between excitation shells. We find a 50% increase in the thermal escape activation energy compared with reference InAs quantum dots as well as an increment of the fundamental transition decay time with Sb incorporation. Furthermore, we find that Sb incorporation into quantum dots is strongly nonlinear with coverage, saturating at low doses. This suggests the existence of a solubility limit of the Sb incorporation into the quantum dots during growth.

Electronic properties of doped magnesium thioindate ternary spinel in the normal and in the inverse structure

We present a theoretical study of the structural and electronic properties of the M-doped MgIn2S4 ternary spinel semiconductor with M = V, Cr, and Mn. All substitutions, in the normal and in the inverse structure, are analyzed. Some of these possible substitutions present intermediate-band states in the band gap with a different occupation for a spin component. It increases the possibilities of inter-band transitions and could be interesting for applications in optoelectronic devices. The contribution to, and the electronic configuration of, these intermediate bands for the octahedral and tetrahedral sites is analyzed and discussed. The study of the substitutional energies indicates that these substitutions are favorable. Comparison between the pure and doped hosts absorption coefficients shows that this deeper band opens up more photon absorption channels and could therefore increase the solar-light absorption with respect to the host.