Spin-helical Dirac states in graphene induced by polar-substrate surfaces with giant spin-orbit interaction: a new platform for spintronics

Spintronics, or spin electronics, is aimed at efficient control and manipulation of spin degrees of freedom in electron systems. To comply with demands of nowaday spintronics, the studies of electron systems hosting giant spin-orbit-split electron states have become one of the most important problems providing us with a basis for desirable spintronics devices. In construction of such devices, it is also tempting to involve graphene, which has attracted great attention because of its unique and remarkable electronic properties and was recognized as a viable replacement for silicon in electronics. In this case, a challenging goal is to lift spin degeneracy of graphene Dirac states. Here, we propose a novel pathway to achieve this goal by means of coupling of graphene and polar-substrate surface states with giant Rashba-type spin-splitting. We theoretically demonstrate it by constructing the graphene@BiTeCl system, which appears to possess spin-helical graphene Dirac states caused by the strong interaction of Dirac and Rashba electrons. We anticipate that our findings will stimulate rapid growth in theoretical and experimental investigations of graphene Dirac states with real spin-momentum locking, which can revolutionize the graphene spintronics and become a reliable base for prospective spintronics applications.

Outdoor robot mugikor baten eraikuntza eta kontrola Arduino bitartez

Proiektu honetan robot mugikor bat eraiki eta arduino bitartez kontrolatu da. Robota edozein smartphone erabiliz kontrolatu daiteke Bluetooth RC Car aplikazioa erabiliz. Ultrasoinu sentsorea du talkak ekiditeko eta GPSaren bidez uneko posizioaren berri ematen du. Honetaz gain, wifi bidez mezuak ere bidal ditzake proiektuan bertan garatu den echo zerbitzarira.

Feature Selection for Speech Emotion Recognition in Spanish and Basque: On the Use of Machine Learning to Improve Human-Computer Interaction

Study of emotions in human-computer interaction is a growing research area. This paper shows an attempt to select the most significant features for emotion recognition in spoken Basque and Spanish Languages using different methods for feature selection. RekEmozio database was used as the experimental data set. Several Machine Learning paradigms were used for the emotion classification task. Experiments were executed in three phases, using different sets of features as classification variables in each phase. Moreover, feature subset selection was applied at each phase in order to seek for the most relevant feature subset. The three phases approach was selected to check the validity of the proposed approach. Achieved results show that an instance-based learning algorithm using feature subset selection techniques based on evolutionary algorithms is the best Machine Learning paradigm in automatic emotion recognition, with all different feature sets, obtaining a mean of 80,05% emotion recognition rate in Basque and a 74,82% in Spanish. In order to check the goodness of the proposed process, a greedy searching approach (FSS-Forward) has been applied and a comparison between them is provided. Based on achieved results, a set of most relevant non-speaker dependent features is proposed for both languages and new perspectives are suggested.

Self-Organized Criticality, Plasticity and Sensorimotor Coupling. Explorations with a Neurorobotic Model in a Behavioural Preference Task

During the last two decades, analysis of 1/f noise in cognitive science has led to a considerable progress in the way we understand the organization of our mental life. However, there is still a lack of specific models providing explanations of how 1/f noise is generated in coupled brain-body-environment systems, since existing models and experiments typically target either externally observable behaviour or isolated neuronal systems but do not address the interplay between neuronal mechanisms and sensorimotor dynamics. We present a conceptual model of a minimal neurorobotic agent solving a behavioural task that makes it possible to relate mechanistic (neurodynamic) and behavioural levels of description. The model consists of a simulated robot controlled by a network of Kuramoto oscillators with homeostatic plasticity and the ability to develop behavioural preferences mediated by sensorimotor patterns. With only three oscillators, this simple model displays self-organized criticality in the form of robust 1/f noise and a wide multifractal spectrum. We show that the emergence of self-organized criticality and 1/f noise in our model is the result of three simultaneous conditions: a) non-linear interaction dynamics capable of generating stable collective patterns, b) internal plastic mechanisms modulating the sensorimotor flows, and c) strong sensorimotor coupling with the environment that induces transient metastable neurodynamic regimes. We carry out a number of experiments to show that both synaptic plasticity and strong sensorimotor coupling play a necessary role, as constituents of self-organized criticality, in the generation of 1/f noise. The experiments also shown to be useful to test the robustness of 1/f scaling comparing the results of different techniques. We finally discuss the role of conceptual models as mediators between nomothetic and mechanistic models and how they can inform future experimental research where self-organized critically includes sensorimotor coupling among the essential interaction-dominant process giving rise to 1/f noise.

Ultrastrong light-matter interaction in quantum technologies

120 p.

Interacción y programación de trayectorias de robot industrial tipo SCARA.

[ES]En el desarrollo de este Trabajo de Fin De Grado (TFG) en el curso 2014-2015 se ha trabajado con un robot de tipo SCARA, muy utilizado en la industria. El objetivo era analizar su cinemática y programar trayectorias que el robot pudiera realizar. En primer lugar se ha llevado a cabo un estudio del Estado del Arte, en el que se describe la robótica industrial y su desarrollo histórico hasta nuestros días, desarrollo que presenta un futuro prometedor. Además, se han descrito las particularidades que atañen al SCARA: sus características, su relevancia y su historia. En cuanto al robot, previamente se ha realizado un análisis cinemático del SCARA. Mediante métodos matriciales se han resuelto los problemas de posiciones y velocidades, para luego programarlas en MATLAB. Una vez comprendida su cinemática, se ha interactuado con él en el taller para poder entender su funcionamiento, sus componentes y su control. Después, con los conocimientos que se han adquirido, se han programado varias trayectorias usando el lenguaje del robot, el lenguaje V+, para finalmente ejecutar esos movimientos. El Trabajo se completa con la descripción de las tareas mediante un diagrama de Gantt, el presupuesto, la declaración de gastos y el análisis de riesgos.

Specific Interaction with Cardiolipin Triggers Functional Activation of Dynamin-Related Protein 1

Dynamin-Related Protein 1 (Drp1), a large GTPase of the dynamin superfamily, is required for mitochondrial fission in healthy and apoptotic cells. Drp1 activation is a complex process that involves translocation from the cytosol to the mitochondrial outer membrane (MOM) and assembly into rings/spirals at the MOM, leading to membrane constriction/division. Similar to dynamins, Drp1 contains GTPase (G), bundle signaling element (BSE) and stalk domains. However, instead of the lipid-interacting Pleckstrin Homology (PH) domain present in the dynamins, Drp1 contains the so-called B insert or variable domain that has been suggested to play an important role in Drp1 regulation. Different proteins have been implicated in Drp1 recruitment to the MOM, although how MOM-localized Drp1 acquires its fully functional status remains poorly understood. We found that Drp1 can interact with pure lipid bilayers enriched in the mitochondrion-specific phospholipid cardiolipin (CL). Building on our previous study, we now explore the specificity and functional consequences of this interaction. We show that a four lysine module located within the B insert of Drp1 interacts preferentially with CL over other anionic lipids. This interaction dramatically enhances Drp1 oligomerization and assembly-stimulated GTP hydrolysis. Our results add significantly to a growing body of evidence indicating that CL is an important regulator of many essential mitochondrial functions.

Diseño e implementación software de un robot humanoide.

[ES]Este documento tiene la intención de presentar un Trabajo de Fin de Grado (TFG). Este proyecto consiste en una serie de herramientas que permitan el diseño, implementación y desarrollo del software de control de un robot humanoide. El proyecto se centra en la mejora de la efectividad, robustez, rendimiento y fiabilidad del software. Los cambios propuestos introducen mejoras sobre el robot comercial robo nova. En concreto la capacidad de ser modular, permitiendo de esta forma el uso total o parcial de las soluciones escogidas, ahorrando tiempo y dinero en futuros desarrollos de esta plataforma

Implementación hardware de un robot humanoide.

[ES]Este trabajo describe una serie de mejoras aplicables a un kit comercial de robot humanoide Robonova, con el fin de que este reproduzca el comportamiento cinemático del ser humano con mayor autonomía. Entre ellas destacan la implementación de sensores infrarrojos, sensores de posición, cámaras de visión y conexiones en serie de servomotores. Todo ello controlado desde un ordenador de placa reducida Raspberry Pi.