Structure, dynamics and bifurcations of discrete solitons in trapped ion crystals

We study discrete solitons (kinks) accessible in state-of-the-art trapped ion experiments, considering zigzag crystals and quasi-3D configurations, both theoretically and experimentally. We first extend the theoretical understanding of different phenomena predicted and recently experimentally observed in the structure and dynamics of these topological excitations. Employing tools from topological degree theory, we analyze bifurcations of crystal configurations in dependence on the trapping parameters, and investigate the formation of kink configurations and the transformations of kinks between different structures. This allows us to accurately define and calculate the effective potential experienced by solitons within the Wigner crystal, and study how this (so-called Peierls-Nabarro) potential gets modified to a nonperiodic globally trapping potential in certain parameter regimes. The kinks' rest mass (energy) and spectrum of modes are computed and the dynamics of linear and nonlinear kink oscillations are analyzed. We also present novel, experimentally observed, configurations of kinks incorporating a large-mass defect realized by an embedded molecular ion, and of pairs of interacting kinks stable for long times, offering the perspective for exploring and exploiting complex collective nonlinear excitations, controllable on the quantum level.Comment: 25 pages, 10 figures, v2 corrects Fig. 2 and adds some text and reference

Polling in Impossible Conditions: Pre-election Polling in New Orleans after Hurricane Katrina

Just months after Hurricane Katrina made landfall, New Orleans held a mayoral election. With so many displaced residents, it was difficult to gauge attitudes, but there are perhaps few more important situations in which the public’s attitudes need to be examined. This paper examines the methodological challenges with survey research in the aftermath of a natural disaster. We conducted a traditional survey just days before the election and attempted to correct for our inability to reach particular segments of the population through post-stratification weights. The results of our poll were relatively accurate for all of the candidates but one – the winner. We recommend in the aftermath of a disaster that researchers provide not only a range of possible outcomes, but also that they should consider other methods, such as focus groups, and alter the usual questions to account for the post-disaster context. Given that the opinion environment after a major disaster is marked by indecision and confusion, it is not surprising that respondents were unsure of their vote choice and/or changed their mind just before the election. Our experience should provide some caution to researchers seeking to measure opinion in these circumstances

Dense Motion Estimation for Smoke

Motion estimation for highly dynamic phenomena such as smoke is an open challenge for Computer Vision. Traditional dense motion estimation algorithms have difficulties with non-rigid and large motions, both of which are frequently observed in smoke motion. We propose an algorithm for dense motion estimation of smoke. Our algorithm is robust, fast, and has better performance over different types of smoke compared to other dense motion estimation algorithms, including state of the art and neural network approaches. The key to our contribution is to use skeletal flow, without explicit point matching, to provide a sparse flow. This sparse flow is upgraded to a dense flow. In this paper we describe our algorithm in greater detail, and provide experimental evidence to support our claims.Comment: ACCV201

Controladores difusos adaptativos como módulos de propiedad intelectual para FPGAs

La continua demanda por parte del mercado microelectrónico de aplicaciones novedosas, con elevados niveles de complejidad y tiempos de desarrollo cortos ha motivado el impulso de las técnicas de diseño basadas en el concepto de “reusabilidad” y el desarrollo de elementos de sistemas como módulos de propiedad intelectual o módulos IP. En esta comunicación se describe la implementación de controladores difusos como módulos IP para FPGAs. Los controladores operan como periféricos conectables al bus OPB para los procesadores disponibles en las FPGAs de Xilinx. El empleo de las memorias internas de las FPGAs para almacenar las bases de conocimiento permite definir o ajustar la funcionalidad en tiempo de operación.Ministerio de Educaión y Ciencia TEC2005-04359/MI

Prototipado rápido de sistemas de procesado de vídeo basados en el VFBC de Xilinx

El presente trabajo desarrolla módulos hardware para el prototipado rápido de sistemas de procesado de vídeo basados en el controlador de memoria para fotogramas de vídeo (VFBC) de Xilinx. Esta implementación permite el almacenamiento de los fotogramas en memoria externa al dispositivo programable, así como su correcto manejo para el diseño de sistemas de procesado espacio-temporales utilizando el flujo de diseño basado en modelos de Xilinx System Generator. Los módulos hardware son los encargados de la configuración y control de las interfaces de escritura y lectura del VFBC, además de la manipulación de las señales de sincronismo de vídeo para la interconexión de periféricos de entrada y salida. El artículo incluye además la descripción de los módulos elaborados así como el análisis de los resultados del empleo de los mismos en el desarrollo de un demostrador de procesado temporal de vídeo utilizando un detector de movimiento simple sobre una placa Spartan-6 SP605 Evaluation Platform.This paper develops hardware modules for rapid prototyping of video processing systems based on the Xilinx video frame buffer controller (VFBC). This implementation allows the storage of video frames in memory external to the programmable device, as well as its proper handle for designing spatio-temporal processing systems using the Xilinx System Generator model-based design flow. The hardware modules are responsible for the configuration and control of writing and reading VFBC interfaces, as well as the manipulation of video synchronization signals for interconnecting input and output peripherals. The article also include the description of the elaborated modules and the analysis of the results of its use for the development of a temporal video processing demonstrator using a simple motion detector on a Spartan-6 SP605 Evaluation Platform board.Agencia Española de Cooperación Internacional para el Desarrollo (AECID) PCI D/024124/09, PCI D/030769/10, PCI A1/039607/1

ADQPCI: Data Acquisition Board for Educational purposes

En este trabajo se presenta una de las placas de adquisición de datos que se ha desarrollado con fines docentes para su utilización en prácticas relacionadas con sistemas en tiempo real e informática industrial y se plantean algunas de las ventajas e inconvenientes frente a la utilización de placas comerciales. A lo largo del trabajo se detalla el diseño del hardware, en el que se ha priorizado la facilidad de programación, siendo ésta una de las ventajas frente a las placas comerciales. En estas prácticas es fundamental que el alumno tome conciencia de la importancia de la interfaz hardware-software, si se quiere conseguir un sistema fiable y que explote al máximo las características del hardware. Con el desarrollo de una placa de adquisición de datos se consigue un sistema que el alumno puede utilizar en varias asignaturas de su titulación que están relacionadas con el desarrollo y programación de sistemas empotrados.In this work a data acquisition board developed for educational use in subjects related to real-time systems and industrial computing, is presented. The main advantages and disadvantages of using these boards versus the use of commercial boards are discussed. The hardware design described along this work emphasizes the facility of programming the board, which is one of the main advantages versus the commercial boards. In these practices it is essential that student comprehend the importance of the hardware-software interface in order to obtain a reliable system which exploits in a maximum way the characteristics of the hardware. The development of a data acquisition board allows to obtain a system that the students can use in several course during his university career which are related to the development and programming of embedded system

CAN2PCI: Board with Interface to CAN and PCI Bus for educational purposes

En este trabajo se presenta una placa con interfaz al bus CAN y PCI desarrollada para la utilización en prácticas de las asignaturas relacionadas con redes de control. Se trata de una placa de altas prestaciones pensada para su utilización docente gracias a su facilidad de programación. La placa dispone de dos canales CAN independientes y permite acceso directo a los registros del controlador CAN. Las prácticas tienen como objetivo conocer la red de control en los niveles físico y de enlace y desarrollar un software de conectividad (middleware) que realice la interfaz entre estas capas y la de aplicación de usuario. Se exponen también brevemente las prácticas realizadas en una de las asignaturas donde se imparte redes de control, en la que es fundamental la utilización de un hardware conocido que permita programar las funciones básicas que operan directamente con el controlador de bus CANIn this work the development of a board with interface to the CAN and PCI bus for its use in lab courses related to control networks, is presented. This board has high benefits and advantages and has been implemented for educational purposes due to its programming facility. The board has two independent CAN channels and it allows direct access to the registers of the CAN controller. The objective of the lab experiments is to study the control networks in the physical and link levels and to develop a middleware that performs the interface between these layers and the user application. The experiments done in one of the courses, which includes control networks, are briefly described. In these practical labs it is very important the use of a known hardware that allows programming the basic functions which directly operate with the CAN bus controlle

FPGA implementation of embedded fuzzy controllers for robotic applications

Fuzzy-logic-based inference techniques provide efficient solutions for control problems in classical and emerging applications. However, the lack of specific design tools and systematic approaches for hardware implementation of complex fuzzy controllers limits the applicability of these techniques in modern microelectronics products. This paper discusses a design strategy that eases the implementation of embedded fuzzy controllers as systems on programmable chips. The development of the controllers is carried out by means of a reconfigurable platform based on field-programmable gate arrays. This platform combines specific hardware to implement fuzzy inference modules with a general-purpose processor, thus allowing the realization of hybrid hardware/soffivare solutions. As happens to the components of the processing system, the specific fuzzy elements are conceived as configurable intellectual property modules in order to accelerate the controller design cycle. The design methodology and tool chain presented in this paper have been applied to the realization of a control system for solving the navigation tasks of an autonomous vehicle