Método para la comparación y caracterización del ruido de paso en trenes de alta velocidad

El ferrocarril está llamado a ser uno de los modos de transporte del futuro tanto para mercancías como para viajeros. Esto conduce a la necesidad de reducir los efectos negativos que la explotación ferroviaria produce, y entre ellos los más relevantes son el ruido y las vibraciones, que causan molestias a usuarios y habitantes cercanos y perturbaciones en infraestructuras propias de la red o cercanas a la misma. En el trabajo de investigación que aquí se resume, se ha realizado un estudio teórico exhaustivo de los fenómenos de emisión de ruido ferroviario analizando sus causas y parámetros de influencia. A partir de este estudio, se ha elaborado una metodología completa y sencilla para la caracterización del ruido de paso que cubre todas las fases necesarias, desde la adquisición de datos de ruido, hasta la obtención de resultados numéricos y de forma gráfica a través de una herramienta software desarrollada a tal efecto. De las distintas metodologías de caracterización se escogió, por ser la más representativa para el estudio, la caracterización del ruido de paso de vehículos (a velocidad constante). La herramienta informática, la metodología en sí y sus resultados han sido comprobados y ratificados con ensayos reales en las instalaciones de Alta Velocidad de la red española, registrándose el paso de diferentes composiciones. Además se puede afirmar que cumplen con las especificaciones y restricciones establecidas por la normativa vigente en España y Europa. Este trabajo ha sido desarrollado en el Centro de Investigación en Tecnologías Ferroviarias (CITEF), centro ligado a la Escuela Técnica Superior de Ingenieros Industriales de la Universidad Politécnica de Madrid

Adverse aerodynamics effects of a high speed train under the influence of cross winds, analysis and optimization of wind fence

The research work that here is summarized, it is classed on the area of dynamics and measures of railway safety, specifically in the study of the influence of the cross wind on the high-speed trains as well as the study of new mitigation measures like wind breaking structures or wind fences, with optimized shapes. The work has been developed in the Research Center in Rail Technology (CITEF), and supported by the Universidad Politécnica de Madrid, Spain

Conservadurismo del resultado bajo las normas internacionales de contabilidad: un estudio comparado

El presente trabajo muestra que la adopción de la normativa del IASB en los países europeos ha contribuido a aumentar el conservadurismo del resultado de las empresas que las implantaron antes de ser obligatorias en 2005, acercando las medidas de conservadurismo a los niveles estadounidenses. Este no es el caso de las empresas de países menos desarrollados que han adoptado la normativa internacional. Para estas empresas, pese a la adopción de las NIC, el conservadurismo no ha aumentado. De hecho, no hay indicios de asimetría en el reconocimiento de noticias en el resultado. Además, parte del aumento en el conservadurismo observado en las empresas europeas desaparece si se controla de manera adecuada por sus características específicas

Conservadurismo del resultado contable bajo las Normas Internacionales de Contabilidad: Un estudio comparativo.

In this study we analyse whether the use of IASB standards affects the conservatism of earnings of the firms that adopt them. We compare the conservatism of firms by groups of firms/countries using or not IAS. Our results show that 1) Earnings conservatism is, as pointed out in prior research, more pronounced in common-law-based developed economies; 2) The voluntary use of IASB standards in Europe (prior to 2005) has significantly increased the measures of earnings conservatism in adopting firms, and 3) The use of IAS fails to improve the relevance and reliability of accounting information in emerging/developing countries, where enforcement and investor protection is lowEn este trabajo se analiza si el uso de las normas del IASB afecta al conservadurismo del resultado de las empresas que las adoptan. Para ello comparamos el conservadurismo por grupos de empresas/países que usan o no las normas internacionales (NIC). Nuestros resultados muestran que: 1) El conservadurismo del resultado es, tal y como pone de manifiesto la literatura previa, más pronunciado en los países desarrollados basados en el derecho común, 2) La adopción voluntaria de las normas del IASB en Europa (antes de 2005) aumentó significativamente las medidas de conservadurismo del resultado de las empresas que las adoptaron, y 3) El uso de las NIC no logró mejorar la relevancia/fiabilidad de la información contable en los países emergentes o en vías de desarrollo, donde la protección de los intereses de los inversores es escasa

Magnetic-Field Feature Reduction for Indoor Location Estimation Applying Multivariate Models

In the context of a magnetic field-based indoor location system, this paper proposes a feature extraction process that uses magnetic-field temporal and spectral features in order to develop a classification model of indoor places, using only a magnetometer included in popular smartphones. We initially propose 46 features, 26 derived from the spectral evolution and 20 from the temporal one, chosen because of the statistical potential to summarize the behavior of the signal. Nevertheless, in order to simplify the classification model, a genetic algorithm approach, combined with forward selection and back elimination strategies was applied. Our results show that is possible to reduce the magnetic-field signal features from 46 to only 6 features, and estimating the user's location with even better precision

Magnetic Field Feature Extraction and Selection for Indoor Location Estimation

User indoor positioning has been under constant improvement especially with the availability of new sensors integrated into the modern mobile devices, which allows us to exploit not only infrastructures made for everyday use, such as WiFi, but also natural infrastructure, as is the case of natural magnetic field. In this paper we present an extension and improvement of our current indoor localization model based on the feature extraction of 46 magnetic field signal features. The extension adds a feature selection phase to our methodology, which is performed through Genetic Algorithm (GA) with the aim of optimizing the fitness of our current model. In addition, we present an evaluation of the final model in two different scenarios: home and office building. The results indicate that performing a feature selection process allows us to reduce the number of signal features of the model from 46 to 5 regardless the scenario and room location distribution. Further, we verified that reducing the number of features increases the probability of our estimator correctly detecting the user’s location (sensitivity) and its capacity to detect false positives (specificity) in both scenarios.User indoor positioning has been under constant improvement especially with the availability of new sensors integrated into the modern mobile devices, which allows us to exploit not only infrastructures made for everyday use, such as WiFi, but also natural infrastructure, as is the case of natural magnetic field. In this paper we present an extension and improvement of our current indoor localization model based on the feature extraction of 46 magnetic field signal features. The extension adds a feature selection phase to our methodology, which is performed through Genetic Algorithm (GA) with the aim of optimizing the fitness of our current model. In addition, we present an evaluation of the final model in two different scenarios: home and office building. The results indicate that performing a feature selection process allows us to reduce the number of signal features of the model from 46 to 5 regardless the scenario and room location distribution. Further, we verified that reducing the number of features increases the probability of our estimator correctly detecting the user’s location (sensitivity) and its capacity to detect false positives (specificity) in both scenarios

Mipymes distribuidoras turísticas: recomendaciones SEO a partir del análisis de palabras claves

En las prácticas del comercio electrónico, las acciones desempeñadas a través del reconocimiento de palabras claves contribuyen una ventaja competitiva para las empresas, dado que la costumbre del turista por buscar información y gestionar sus viajes, provoca para las marcas, la necesidad de mostrarse y visibilizarse a través de las plataformas web. En dicho sentido, con el propósito de reconocer la realidad en cuanto a la explotación de las palabras claves en los portales web de empresas distribuidoras turísticas cuencanas, la investigación aplicó procedimientos de exploración y análisis cuantitativos y cualitativos desarrollados tanto en SPSS como en Nvivo. Estudios que permitieron descubrir que la gestión de palabras claves en las agencias de viaje, parecería aún no ser una prioridad, o que termina por ser ineficiente. Hallazgo que ha contribuido a deducir que la recomendación básica, con la cual se pueda aportar al contexto social, es la influencia sobre la importancia del uso de palabras claves y su impacto, tanto en la promoción de destinos turísticos, como en la generación de valor orientada a la personalización o individualización de productos.In the practices of electronic commerce, the actions carried out through the recognition of keywords contribute a competitive advantage for companies, given that the custom of tourists to seek information and manage their trips, causes for brands, the need to show and visualize through web platforms. In this sense, with the purpose of recognizing the reality regarding the exploitation of the keywords in the web portals of tourism distributing companies in Cuenca, the research applied quantitative and qualitative exploration and analysis procedures developed in both SPSS and Nvivo. Studies that allowed us to discover that the management of keywords in travel agencies, would seem not yet to be a priority, or that ends up being inefficient. Finding that has helped to deduce that the basic recommendation, with which it can contribute to the social context, is the influence on the importance of the use of keywords and their impact, both in the promotion of tourist destinations, and in the generation of value oriented to the customization or individualization of products

Femtosecond infrared intrastromal ablation and backscattering-mode adaptive-optics multiphoton microscopy in chicken corneas

The performance of femtosecond (fs) laser intrastromal ablation was evaluated with backscattering-mode adaptive-optics multiphoton microscopy in ex vivo chicken corneas. The pulse energy of the fs source used for ablation was set to generate two different ablation patterns within the corneal stroma at a certain depth. Intrastromal patterns were imaged with a custom adaptive-optics multiphoton microscope to determine the accuracy of the procedure and verify the outcomes. This study demonstrates the potential of using fs pulses as surgical and monitoring techniques to systematically investigate intratissue ablation. Further refinement of the experimental system by combining both functions into a single fs laser system would be the basis to establish new techniques capable of monitoring corneal surgery without labeling in real-time. Since the backscattering configuration has also been optimized, future in vivo implementations would also be of interest in clinical environments involving corneal ablation procedures

The causes, consequences, and treatment of left or right heart failure

Chronic heart failure (HF) is a cardiovascular disease of cardinal importance because of several factors: a) an increasing occurrence due to the aging of the population, primary and secondary prevention of cardiovascular events, and modern advances in therapy, b) a bad prognosis: around 65% of patients are dead within 5 years of diagnosis, c) a high economic cost: HF accounts for 1% to 2% of total health care expenditure. This review focuses on the main causes, consequences in terms of morbidity, mortality and costs and treatment of HF

Infrastructure-Less Indoor Localization Using the Microphone, Magnetometer and Light Sensor of a Smartphone

In this paper, we present the development of an infrastructure-less indoor location system (ILS), which relies on the use of a microphone, a magnetometer and a light sensor of a smartphone, all three of which are essentially passive sensors, relying on signals available practically in any building in the world, no matter how developed the region is. In our work, we merge the information from those sensors to estimate the user’s location in an indoor environment. A multivariate model is applied to find the user’s location, and we evaluate the quality of the resulting model in terms of sensitivity and specificity. Our experiments were carried out in an office environment during summer and winter, to take into account changes in light patterns, as well as changes in the Earth’s magnetic field irregularities. The experimental results clearly show the benefits of using the information fusion of multiple sensors when contrasted with the use of a single source of informationIn this paper, we present the development of an infrastructure-less indoor location system (ILS), which relies on the use of a microphone, a magnetometer and a light sensor of a smartphone, all three of which are essentially passive sensors, relying on signals available practically in any building in the world, no matter how developed the region is. In our work, we merge the information from those sensors to estimate the user’s location in an indoor environment. A multivariate model is applied to find the user’s location, and we evaluate the quality of the resulting model in terms of sensitivity and specificity. Our experiments were carried out in an office environment during summer and winter, to take into account changes in light patterns, as well as changes in the Earth’s magnetic field irregularities. The experimental results clearly show the benefits of using the information fusion of multiple sensors when contrasted with the use of a single source of informatio