From time series to complex networks: the visibility graph

In this work we present a simple and fast computational method, the visibility algorithm, that converts a time series into a graph. The constructed graph inherits several properties of the series in its structure. Thereby, periodic series convert into regular graphs, and random series do so into random graphs. Moreover, fractal series convert into scale-free networks, enhancing the fact that power law degree distributions are related to fractality, something highly discussed recently. Some remarkable examples and analytical tools are outlined in order to test the method's reliability. Many different measures, recently developed in the complex network theory, could by means of this new approach characterize time series from a new point of view

Evaluación ecográfica del Ligamento Calcáneonavicular (Ligamento de Spring): correlación de hallazgos anatómicos y sonográficos

Programa Oficial de Doutoramento en Saúde e Motricidade Humana. 5002V01[Resumen] Introducción: El ligamento Spring (LS) representa una de las estructuras más importantes en la estabilidad del pie, principalmente en el mantenimiento del arco plantar (AP), evitando así el pie plano adquirido en el adulto (PPAA). Debido a su ubicación, origen e inserción, así como la disposición de sus haces, lo convierten en un elemento estabilizador que está minuciosamente preparado para mejorar la biomecánica del pie. El análisis de dicho ligamento mediante ecografía se presenta ventajoso por su rapidez, facilidad de uso en el ámbito clínico, inocuidad y efectividad. Objetivos: El propósito ha sido evaluar la confiabilidad intra e interobservador entre las imágenes de ultrasonido (US) y las mediciones del calibre para determinar las dimensiones del LS en cadáveres, para poder de esta manera contribuir en la calidad y especificidad diagnóstica de esta estructura. Material y Métodos: Se estudiaron LS de 62 pies humanos de cadáveres embalsamados con formaldehído. La confiabilidad intra e interobservador de la longitud, el ancho y el grosor de LS entre las medidas de US y el calibre se determinó en períodos de sesiones intra e intersesión por los coeficientes de correlación intraclase (ICC) y los coeficientes de correlación de Pearson (r). Resúmenes 18 Resultados: Diferenciando entre los resultados intersesión y los resultados entre examinadores encontramos que la evaluación de LS realizada por US y el calibre entre el primer y el segundo observador entre sesiones mostró una excelente confiabilidad entre examinadores (ICC (1-1) = 0.938-0.994; ICC (1-1) = 0.825-0.998) con una fuerte correlación ( r = 0.893-0.989; r = 0.725-0.998; P <0.001) para todas las medidas (ancho, longitud y grosor), respectivamente, y no hubo diferencias estadísticamente significativas entre los evaluadores (P> 0.05) para todas las dimensiones, aunque para las medidas de ancho por US sí que las hubo (P < 0,05). Al contrastar tanto el US como el calibre, la evaluación de LS entre las mediciones entre el US y el calibre entre sesiones para ambos observadores demostró una excelente confiabilidad entre evaluadores (ICC (1-1) = 0.911-0.966) con una fuerte correlación (r = 0.852-0.937; P <0.001) para todas las medidas, y no hubo diferencias estadísticamente significativas entre sesiones (P> 0.05) entre las medidas de US y el calibre. Conclusión: Tanto el US como el Calibre pueden ser recomendados para las mediciones de las diferentes dimensiones del LS debido a su excelente confiabilidad y fuerte correlación en cadáveres, aunque las mediciones de ancho deben ser tomadas con precaución ya que existen diferencias de repetibilidad en los US.[Resumo] Introducción: O ligamento Spring (LS) representa unha das estruturas máis importantes na estabilidade do pé, principalmente no mantemento do arco plantar (AP), evitando así o pé plano adquirido no adulto (PPAA). Debido á súa localización, orixe e inserción, así como a disposición dos seus feixes de fibras, convérteno nun elemento estabilizador que está minuciosamente preparado para mellorar a biomecánica do pé. A análise deste ligamento mediante a ecografía preséntase vantaxosa pola súa rapidez, facilidade de uso no ámbito clínico, inocuidade e efectividade. Obxectivos: o propósito foi avaliar a fiabilidade intra e interobservador entre as medidas de ultrasóns (US) e as medidas do calibre para determinar as dimensións do LS nos cadáveres, co fin de contribuír deste xeito á calidade e diagnóstico específico desta estrutura. Material e métodos: Estudáronse LS de 62 pés humanos de cadáveres embalsados con formaldehído. A fiabilidade intra e interobservador da lonxitude, ancho e grosor do LS entre as medidas US e calibre determinouse nas sesións intra e intersesión mediante coeficientes de correlación intraclase (ICC) e coeficientes de correlación Pearson (r). Resúmenes 20 Resultados: Diferenciando entre os resultados da intersección e os resultados entre os examinadores descubrimos que a avaliación do LS realizada polos US e do calibre entre o primeiro e o segundo observador entre as sesións mostraron unha excelente fiabilidade inter-examinadores (ICC (1-1) = 0.938-0.994 ; CCI (1-1) = 0,825-0,998) cunha forte correlación (r = 0,893-0,989; r = 0,725-0,998; P <0,001) para todas as medidas (ancho, lonxitude e grosor), respectivamente, e non houbo diferenzas estatísticamente significativas entre os avaliadores (P> 0,05) para tódalas dimensións, aínda que para as medicións de ancho dos US houbo (P <0,05). Ao contrastar tanto os US como o calibre, a avaliación do LS entre as medidas entre os US e calibre entre as sesións de ambos os observadores demostrou unha excelente fiabilidade entre os avaliadores (ICC (1-1) = 0.911-0.966) cunha forte correlación (r = 0,852-0,937; P <0,001) para tódalas medicións, e non houbo diferenzas estadísticamente significativas entre as sesións (P> 0,05) entre as medicións dos US e calibre. Conclusión: Os US e o calibre pódense recomendar para as medicións das diferentes dimensións do LS debido á súa excelente fiabilidade e forte correlación nos cadáveres, aínda que as medidas de ancho deben tomarse con precaución xa que hai diferenzas de repetibilidade nos US.[Abstract] Introduction: The spring ligament (SL) is one of the most important structures responsible for stabilizing the foot, mainly in the plantar arch (PA) maintaining. This ligament is not present or is lax in adults acquired flat foot deformity (AFFD). Due to its location, origin, and insertion in addition to the disposition of its beams, it is a stabilizing element that was meticulously designed to improve the biomechanics of the foot. Ultrasound analysis of this ligament is advantageous due to its speed, ease of use in the clinical field, safety, and efficacy. Objectives: The purpose has been to evaluate intra and inter- rater reliability between ultrasound imaging (US) and caliper measures, to determine Spring ligament (SL) dimensions in cadavers, in order to evaluate the structure’s quality and diagnostic specificity. Material and Methods: SLs were studied from 62 human feet from formaldehyde-embalmed cadavers. Intra and inter-observer reliability of SL length, width and thickness between US and caliper measurements was determined at intra and inter-session by intraclass correlation coefficients (ICC) and Pearson´s correlation coefficients (r). Resúmenes 22 Results: Differentiating between intersession results and results between examiners, we found that SL evaluation by US and caliper between inter-session first and second observer showed excellent inter-rater reliability (ICC(1-1)=0.938-0.994; ICC(1- 1)=0.825-0.998) with a strong correlation (r=0.893-0.989; r=0.725- 0.998; P<0.001) for all dimensions (width, length and thickness), respectively, and there were not inter-rater statistically significant differences (P>0.05) for all measurement even though there were for width measurements by US (P < 0.05). Comparing both US and caliper, SL evaluation between inter-session US and caliper measurements for both observers showed an excellent inter-rater reliability (ICC(1-1)=0.911-0.966) with a strong correlation (r=0.852-0.937; P < 0.001) for all dimensions, and there were not inter-session statistically significant differences (P>0.05) between US and caliper measurements. Conclusion: US and caliper could be recommended for all SL measurements evaluation due to their excellent reliability and strong correlation in cadavers, although width measurements should be taken with caution due to US repeatability difference

Development of Magnetostrictive Transducer Prototype for Blockage Detection on Molten Salt Pipes

In solar thermal power plants molten salt is often used to store and transport the energy that is collected during the day. The external pipe temperature is measured to activate an electric heating system if the temperature approaches the melting point. However, salt solidification cannot be completely excluded from the plant management. Once occurred, the location of a salt blockage is very complex due to the high temperature of the pipe. Therefore, when this problem arises, power plants have to stop production with the consequences in time and cost that this entails. Electro-magnetic acoustic transducers can be used as non-destructive testing systems for this application. A method for salt blockage detection is proposed that is applicable in straight sections of pipes by employing torsional guided waves that are generated with magnetostrictive transducers. The present paper deals with the transducer conception and the design of the power supply to activate it. Two alternatives are proposed and compared to determine the improvement in the amplitude/noise ratio. Finally, the experimental results show the performance of the equipment in a small prototype, thus validating the technique presented

Controversies in Exit Polling: Implementing a Racially Stratified Homogenous Precinct Approach

In November 2000, exit poll interviews with voters in Florida indicated that Al Gore won the state. As a result, many television networks declared Gore the winner of Florida, a pivotal state to winning the presidency in 2000. Only a few hours later, the first vote tallies from the Florida Secretary of State\u27s office revealed that George W. Bush was in fact leading in Florida. After 45 days of recounts and lawsuits, it was clear that the exit polls were wrong; Bush had won the state by the narrowest of margins. As a result of the flawed exit poll the media and pollsters scoured and reanalyzed the methodology used in 2000 to prepare and correct for the 2004 presidential election. The old system, Voter News Service (VNS) was scrapped entirely, and Edison-Mitofsky Research was chosen to implement a new and more accurate national exit poll in 2004 by a consortium of news organizations retained by the Associated Press called the National Election Pool (NEP). What happened? Exit poll results from Edison-Mitofsky showed John Kerry ahead in Ohio, Florida, and New Mexico—all states which he lost to Bush in 2004.

Low-cost port competitiveness index: Implementation in the Spanish port system

Spanish Port Authorities currently face a wide range of complexities in their decision-making processes, as they have to satisfy several port management objectives that may conflict with one another. This paper examines these circumstances by using decision theory methodology with multiple objectives, which, through the Promethee method, makes the design of an index possible. This index combines different decision factors that shape the competitiveness of a port to rank the Spanish Port Authorities. This ranking serves as an alternative to the traditional ranking system by easily providing more information about port traffic. The Promethee method was chosen because it is reliable, the outcomes are easy for decision makers to understand and the parameters can be economically interpreted. To account for any subjectivity in the measures for different criteria, we developed three survey campaigns aimed at the following groups: members of the port community, Port Authority managers and academic researchers

A scalable WebRTC platform based on open technologies

International Conference on Computer, Information and Telecommunication Systems (7th, 2018, Colmar, Francia

Li-Po Battery Charger Based on the Constant Current/Voltage Parallel Resonant Converter Operating in ZVS

Battery requirements for electrical vehicles are continuously becoming more demanding in terms of energy density and reliability. Nowadays, batteries for drones must be able to supply 100 A for 15 min, not to mention the specifications required for batteries in electrical vehicles. These specifications result in more stringent specifications for battery chargers. They are required to be more efficient, flexible, and, as with any another power equipment, to have reduced size and weight. Since the parallel resonant converter can operate as a current source and as a voltage source, this paper presents a battery charger power stage for lithium ion polymer batteries, based on the above topology, operating in zero voltage switching mode, and implementing frequency and duty cycle control

Intra and Inter-rater Reliability between Ultrasound Imaging and Caliper Measures to determine Spring Ligament Dimensions in Cadavers

The purpose was to evaluate intra and inter-rater reliability, repeatability and absolute accuracy between ultrasound imaging (US) and caliper measures to determine Spring ligament (SL) dimensions in cadavers. SLs were identified from 62 human feet from formaldehyde-embalmed cadavers. Intra and inter-observer reliability, repeatability and absolute accuracy of SL width, thickness and length between US and caliper measurements were determined at intra and inter-session by intraclass correlation coefficients, Pearson´s correlation coefficients, Student t tests, standard errors of measurement, minimum detectable changes, values of normality, 95% limits of agreement, and Bland-Altman plots. Excellent inter-session and inter-rater reliability, adequate absolute accuracy, almost perfect agreement and strong correlations were shown for caliper, US and their comparison for all SL dimensions. US measurements presented higher absolute accuracy than caliper measures for SL length and thickness dimensions, while caliper displayed greater absolute accuracy for SL width dimensions. Good repeatability (P > 0.05) was shown for all SL dimensions by US, caliper and their comparison, except for SL width dimension measured with US (P = 0.019). Both US and caliper could be recommended for all SL dimensions evaluation due to their excellent reliability and absolute accuracy in cadavers, although width dimensions should be considered with caution due to US repeatability differences

Prevalencia y factores de riesgo de enfermedad grasa hepática no alcohólica en pacientes con enfermedad inflamatoria intestinal.

Introducción: La patogénesis de la enfermedad hepática grasa no alcohólica (EHGNA) y de laenfermedad inflamatoria intestinal (EII) no son del todo bien conocidas. La EHGNA podría tenersu origen en la resistencia insulínica y en las alteraciones metabólicas ligadas al depósito de grasahepática, junto con una asociación con el síndrome metabólico y la obesidad. A ello, se suma lareciente irrupción de la microbiota intestinal como otra posible causa (teoría “multi-hit”). Elorigen de la EII más aceptado es el de una activación del sistema inmune en relación con ladisbiosis de la microbiota intestinal unida a desencadenantes ambientales en individuosgenéticamente predispuestos. Diferentes estudios han propuesto una relación entre EHGNA y EII,planteando la existencia de dos fenotipos de EHGNA en pacientes con EII: un fenotipo asociadoa factores de riesgo metabólico y un fenotipo asociado a factores inflamatorios de la EII(inmunomediado).Objetivos: 1) Evaluar la prevalencia de EHGNA y fibrosis asociada en pacientes con EII. 2)Identificar factores de riesgo metabólico y no metabólico para el desarrollo de EHGNA enpacientes con EII.Material y métodos: Estudio transversal que incluyó pacientes consecutivos con EII atendidosen Hospital Clínico de Zaragoza a lo largo de febrero de 2020. Para el diagnóstico de EHGNA yfibrosis se realizó: ecografía, elastografía de transición con CAP e índices serológicos.Resultados: Se incluyeron 144 pacientes. La prevalencia de EHGNA y de fibrosis asociada fuede 39,3% y 2,2%, respectivamente. Se identificaron como factores de riesgo metabólico deEHGNA en pacientes con EII: DM-II (OR=12,32), hipercolesterolemia (OR=3,31),hipertrigliceridemia (OR=5,14), IMC elevado (OR=1,44, por cada punto de IMC) y síndromemetabólico (OR=8,43). La dieta mediterránea se halló como posible factor protector (OR=0,437).En lo referente al fenotipo inmunomediado, solo la edad al diagnóstico de la EII se asoció aldesarrollo de EHGNA (OR=1,03).Conclusiones: 1) La prevalencia de EHGNA en pacientes con EII es elevada, siendo laprevalencia de fibrosis similar a la descrita en población general. 2) Se confirma la asociación defactores de riesgo metabólico en el desarrollo de EHGNA en pacientes con EII, 3) La dietamediterránea parece tener un papel protector en el desarrollo de EHGNA en pacientes con EII.<br /