850 research outputs found
Prototipado de un sistema WiMAX MIMO 2X2 (I)
Este proyecto surgió como respuesta al creciente interés que se ha generado en el mundo de las telecomunicaciones alrededor de las comunicaciones inalámbricas de alta capacidad, las técnicas de diversidad MIMO (Múltiples Entradas Múltiples Salidas) y las plataformas de desarrollo basadas en FPGA (Matrices de Puertas Programables). El desarrollo de las comunicaciones inalámbricas de alta capacidad se ha producido, principalmente y según la cobertura de las redes, debido a la evolución de la familia de estándares IEEE 802.11 (Wi-Fi, es decir, Fidelidad Inalámbrica) y los sistemas HSDPA (Acceso Descendente de Paquetes a Alta Velocidad) introducidos por el 3GPP (Proyecto Conjunto de Tercera Generación). Sin embargo, la incipiente revolución en estas comunicaciones de alta capacidad viene dada por la existencia de dos familias de estándares inalámbricos diseñados para tal fin: IEEE 802.16e-2005 (WiMAX Móvil, donde WiMAX significa Interoperabilidad Mundial para Acceso por Microondas) e IEEE 802.20 (Mobile-Fi, es decir, Fidelidad Móvil). Ambos cuentan con características similares, si bien WiMAX Móvil posee la ventaja de una mayor experiencia en el mercado y apoyo de la industria. Las técnicas MIMO proporcionan una gran mejora en el canal de comunicación, esto es, incremento del radio de la celda y mayor capacidad. Por esta razón, cada vez juega un papel más importante en los últimos estándares de comunicación inalámbricos (IEEE 802.11n, IEEE 802.16e-2005, etc.) siendo unas técnicas fundamentales en los proyectados a futuro. Las plataformas de desarrollo basadas en FPGA han experimentado una gran evolución en los últimos años gracias la mejora de la velocidad de proceso y capacidad de almacenamiento de dichas FPGA. Estos factores, unido a la posibilidad de reprogramación y a la existencia de entornos de desarrollo cada vez más sencillos y flexibles, han permitido su incursión en campos de aplicación típicos de los ASIC (Circuitos Integrados para Aplicaciones Específicas). Este proyecto cuenta con el objetivo principal de aunar los tres puntos anteriores: comunicaciones inalámbricas de alta capacidad, técnicas MIMO y desarrollo sobre FPGA. Para ello, se ha diseñado un receptor para el estándar IEEE 802.16d-2004 (WiMAX Fijo) utilizando MIMO 2x2, OFDM (Multiplexado por División en Frecuencias Ortogonales) en la capa física y BPSK (Modulación Binaria por Salto de Fase) para la modulación de datos. El desarrollo de dicho receptor se ha realizado empleando una plataforma de desarrollo sobre FPGA basada en Simulink®, la cual proporciona un alto nivel de abstracción en el diseño de los modelos. -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------This project arose in response to the growing interest generated in the telecommunications industry around high-capacity wireless communications, MIMO (Multiple Input Multiple Output) diversity techniques and development platforms based on FPGA (Field Programmable Gate Array). The development of high-capacity wireless communications has occurred, mainly and depending on networks coverage, due to the evolution of the family of standards IEEE 802.11 (Wi-Fi, i.e., Wireless Fidelity) and HSDPA (High Speed Downlink Packet Access) systems introduced by the 3GPP (3rd Generation Partnership Project). Nevertheless, the incipient revolution in these high-capacity communications comes from the existence of two families of wireless standards designed for such purpose: IEEE 802.16e-2005 (Mobile WIMAX, where WIMAX stands for Worldwide Interoperability for Microwave Access) and IEEE 802.20 (Mobile-Fi, that is, Mobile Fidelity). Both standards have similar features, although Mobile WIMAX has the advantage of greater market experience and industry support. MIMO techniques provide a great improvement in the communication channel, that is to say, an increase in cell radius and capacity. For this reason, they play a more and more important role in the latest wireless communications standards (IEEE 802.11n, IEEE 802.16e-2005), being key techniques for future projected standards to come. Development platforms based on FPGA have in recent years due to improvements in process and storage capacities of the FPGA. These factors, coupled with the possibility of reprogramming and the appearance of ever simpler and more flexible development environments have allowed FPGA their incursion in application fields typical of ASIC (Application Specific Integrated Circuit). This project has the main objective of joining the above three points: high-capacity wireless communications, MIMO techniques and development on FPGA. With such aim, a receiver has been designed for IEEE 802.16d-2004 standard (Fixed WiMAX), using 2x2 MIMO, OFDM (Orthogonal Frequency Division Multiplexing) in the physical layer and BPSK (Binary Phase Shift Keying) for data modulation. This receiver has been developed using a development platform on FPGA based in Simulink®, which provides a high level of abstraction in model designing.Ingeniería de Telecomunicació
Nuevos instrumentos para la investigación en el laboratorio de farmacología y fisiología. Diseño e implementación
El análisis farmacológico de las sustancias químicas con tejidos vivos de animales es fundamental para valorar sus posibles efectos terapéuticos antes de probarlos en seres humanos. Sin embargo, en la actualidad, estos estudios han sido relegados a las últimas etapas en el cribado masivo de nuevos fármacos. La razón se debe, principalmente, a que las técnicas de experimentación para ensayar sustancias químicas directamente en tejidos vivos son muy lentas y no tienen capacidad de análisis suficiente para afrontar el ritmo de las investigaciones modernas, llegando incluso a no ser rentables desde un punto de vista económico. En este sentido, el proyecto científico-técnico de esta Tesis Doctoral consiste en el diseño e implementación de dos nuevos instrumentos de laboratorio con los que se pretende modernizar las técnicas de estudio con tejidos vivos, permitiendo experimentar con mayor rapidez y eficiencia. Esos instrumentos son: a) Multi-Well Organ Bath (MuWOB): consiste en un innovador instrumento para medir la respuesta contráctil que provocan las sustancias químicas en porciones pequeñas de tejido vivo. A diferencia de los sistemas que se utilizan hoy en día, donde las muestras se incuban en copas de vidrio y las contracciones se miden con sensores electromecánicos, el MuWOB utiliza una placa multipocillos como soporte biológico para los tejidos y una técnica de medida basada en algoritmos de visión por ordenador y fotogrametría. Esto le aporta ventajas que no ofrecen los instrumentos convencionales. Principalmente, el MuWOB se distingue por su capacidad para analizar múltiples sustancias con hasta 96 muestras en paralelo y permite trasladar la experimentación con tejidos vivos a las plataformas de trabajo robotizadas que emplean los grandes laboratorios para el cribado masivo de nuevos fármacos. Además, con MuWOB se consigue ahorrar en el coste económico por experimento, ya que permite un mejor aprovechamiento de las soluciones, fármacos y animales. Se trata de un aparato que ocupa muy poco espacio de poyata y que, económicamente, está al alcance de pequeños y medianos laboratorios. b) CANStim-8: es un equipo de electroestimulación multicanal y reprogramable que permite excitar hasta ocho porciones de tejido al mismo tiempo y de forma independiente. Está especialmente ideado para estimular preparaciones biológicas de muy baja impedancia mediante impulsos eléctricos de alta potencia. Su diseño incorpora mejoras y añade prestaciones adicionales con respecto a sus predecesores en el mercado, convirtiéndolo en un instrumento único para el desarrollo de nuevas técnicas de experimentación en Farmacología y Fisiología.
Los dos instrumentos alcanzan un grado de desarrollo equivalente al nivel TRL-6 de la escala Technology Readiness Level, lo que implica haber demostrado el funcionamiento de un prototipo en un entorno relevante. Para ello, ambos aparatos fueron validados con la realización de múltiples experimentos farmacológicos publicados con anterioridad por diferentes autores, quienes emplearon los sistemas convencionales en sus estudios. La comparación de los resultados demostró que los dos instrumentos desarrollados constituyen nuevas herramientas de experimentación para el estudio farmacológico de nuevas sustancias de forma rápida, eficiente y directamente con tejidos vivos de animales
Governing transnational innovation policy: the case of the blue bioeconomy in the Mediterranean
Recent developments in regional innovation policy have challenged the assumptions of smart specialisation strategies (S3). Initially aimed at governing innovation for growth, S3 need to tackle societal, sustainable development challenges. To this end, reformed S3 approaches are being implemented. The present study sets out to propose an extension of one such approach, the shared agendas led by the Catalan government. Through a literature review, the study will propose an extended shared agendas governance model –the governance arrangements set in place to coordinate innovation projects towards a common goal– suitable to the blue bioeconomy, that is those economic activities related to the living resources at sea. In addition, the shared agendas will be extended to coordinate innovation projects across regions and countries in the Mediterranean. The resulting governance model will be useful to initiatives coordinating food-related innovation, transnationally
Spatiotemporal Analysis of Urban Thermal Effects Caused by HeatWaves through Remote Sensing
In recent years there has been an increase in the number of extreme weather events that lead to higher mortality, such as heat waves. This study carries out a new investigation that integrates the environmental quality parameters-the Surface Urban Heat Island (SUHI) and the Terrestrial Surface Temperature (LST)-during these periods of high temperatures and compares them with normal periods. The study of the relationship between these variables will allow improving the quality of life through new mitigation measures that will minimize the effects of climate change in urban areas. This study analyzes eight cities in the south of Spain (Andalusia) to assess environmental quality through gases SO2, NO2, CO, O-3 and aerosols, obtained through Sentinel-5P satellite images, and the LST and SUHI obtained through Sentinel-3 images. Next, the results of periods of heat waves are compared with periods of normal environmental conditions during the summers of the years 2020 and 2021. The objective is to determine the possible impact of heat waves on environmental quality, as well as on the LST and SUHI of the investigated cities, which are located in an area identified as highly vulnerable to the effects of global warming. During the period of the heat wave and compared to the periods without a heat wave, a variety of environmental pollutants was found: SO2 (+165%), NO2 (+24%), CO (+8%), O-3 (-4%) and aerosols (+193%). Both the LST and the SUHI suffered an average increase of 2.8 K. The results of this document can help to establish pollutant reduction mechanisms in periods prior to heat waves. This could minimize major effects on the population and provide sustainable development
Preparing for generation Z:how can technology enhanced learning be firmly embedded in our students' learning experience? A case study from Abertay University
Abertay is a relatively small, modern university (undergraduate population of around 4000) with a wide portfolio and a diverse student population. Around 35% of our students are direct entry from local partner colleges to years 2 and 3 of our programmes and a significant number are first generation higher education within their families. As such, partnership working with colleges and support to aid student transitions are key aspects of Abertay’s provision. Since 2013/14, the university has developed and implemented a new Teaching and Learning Enhancement strategy that has catalysed wholescale transformation across the institution. This paper provides an overview of technology enhanced learning at the university with the drivers for change being to the quality of our students' learning experience, improve student retention and progression and enhance learners’ engagement
On the Soundness of XAI in Prognostics and Health Management (PHM)
The aim of Predictive Maintenance, within the field of Prognostics and Health
Management (PHM), is to identify and anticipate potential issues in the
equipment before these become critical. The main challenge to be addressed is
to assess the amount of time a piece of equipment will function effectively
before it fails, which is known as Remaining Useful Life (RUL). Deep Learning
(DL) models, such as Deep Convolutional Neural Networks (DCNN) and Long
Short-Term Memory (LSTM) networks, have been widely adopted to address the
task, with great success. However, it is well known that this kind of black box
models are opaque decision systems, and it may be hard to explain its outputs
to stakeholders (experts in the industrial equipment). Due to the large number
of parameters that determine the behavior of these complex models,
understanding the reasoning behind the predictions is challenging. This work
presents a critical and comparative revision on a number of XAI methods applied
on time series regression model for PM. The aim is to explore XAI methods
within time series regression, which have been less studied than those for time
series classification. The model used during the experimentation is a DCNN
trained to predict the RUL of an aircraft engine. The methods are reviewed and
compared using a set of metrics that quantifies a number of desirable
properties that any XAI method should fulfill. The results show that GRAD-CAM
is the most robust method, and that the best layer is not the bottom one, as is
commonly seen within the context of Image Processing
The effects of perceived satisfaction with service recovery efforts: a study in a hotel setting
In the service industry, the importance of achieving the satisfaction of all involved agents is widely
recognized. It is important to note that within the service sector, the hospitality sector involves
a high degree of personal contact between hotel staff and customers, during which various
misunderstandings can result in service failures. Therefore, instruments that enable learning
about and solving problems emerging from customers now serve as one of the most important
elements of the hospitality industry. In this context, the objective of answering the call for more
studies investigating the effectiveness of recovery efforts and discovering their effects to perceived
customer satisfaction, following a service recovery process, and customer behavior outcomes
towards a hotel which had dropped the ball but later offered a solution. A structural equation model
using a sample of 274 valid questionnaires, obtained from hotel establishment customers who had
experienced failed service provisions and who had shown their discontent with these services, was
used to examine these issues. The results confi rm a signifi cant and positive effect between the
analyzed relations and also reinforce the importance of recovery efforts on satisfaction in service
recovery and also determine the impact of that perceived satisfaction on behavioral outcomes of the
affected consumers. Additionally, the empirical results show that communication and explanation
are the dimensions of importance to consumers when they report a service failure to a service
fi rm. Based on these results, this study recommends designing recovery process in such a way to
get maximum advantage of this phenomenon. Therefore, organizations should offer dissatisfi ed
customers with the option to choose among various recovery options
iaBastos: An Intelligent Marketplace for Agricultural Products
In this paper we present a multi-agent platform designed to
support p2p auctions on agricultural products. Experiments show that
it could be feasible to integrate a platform, which is de-centralized by
nature, into the current socioeconomic environment. The reason is that
this market is managed by hard-centralized ecosystem, and experiments
with our system show a significant reduction in marketing margins for
the benefit of consumers and producers
Fuzzy reasoning spiking neural P systems revisited: A formalization
Research interest within membrane computing is becoming increasingly interdisciplinary.In particular, one of the latest applications is fault diagnosis. The underlying mechanismwas conceived by bridging spiking neural P systems with fuzzy rule-based reasoning systems. Despite having a number of publications associated with it, this research line stilllacks a proper formalization of the foundations.National Natural Science Foundation of China No 61320106005National Natural Science Foundation of China No 6147232
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