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Evaluation of a wearable device to determine cardiorespiratory parameters from surface diaphragm electromyography

  • Ràfols de Urquía, Magda
  • Estrada Petrocelli, Luis Carlos
  • Estévez Piorno, Josep
  • Sarlabous, Leonardo
  • Jané Campos, Raimon
  • Torres Cebrián, Abel
Using wearable devices in clinical routines could reduce healthcare costs and improve the quality of assessment in patients with chronic respiratory diseases. The purpose of this study is to evaluate the capability of a Shimmer3 wearable device device to extract reliable cardiorespiratory parameters from surface diaphragm electromyography (EMGdi). Twenty healthy volunteers underwent an incremental load respiratory test whilst EMGdi was recorded with a Shimmer3 wearable device (EMGdiW). Simultaneously, a second EMGdi (EMGdiL), the inspiratory mouth pressure (Pmouth) and the lead-I electrocardiogram (ECG) were recorded via a standard wired laboratory acquisition system. Different cardiorespiratory parameters have been extracted from both EMGdiW and EMGdiL signals.: heart rate, respiratory rate, respiratory muscle activity and mean frequency of EMGdi signals. Alongside these, similar parameters were also extracted from reference signals (Pmouth and ECG). High correlations were found between the data extracted from the EMGdiW and the reference signal data: heart rate (R = 0.947), respiratory rate (R = 0.940), respiratory muscle activity (R = 0.877), and mean frequency (R = 0.895). Moreover, similar increments in EMGdiW and EMGdiL activity were observed when Pmouth was raised, enabling the study of respiratory muscle activation. In summary, the Shimmer3 device is a promising and cost-effective solution for ambulatory monitoring of respiratory muscle function in chronic respiratory diseases.
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Sensitivity study of the implementation of Air-Breathing Electric Propulsion systems as atmospheric drag compensation measures Earth Observation CubeSat missions at Very Low Earth Orbits

  • Nadal Vila, Pau
Placing a CubeSat in Very Low Earth Orbits can prove to be considerably beneficial for satel-lite imagery missions. To consistently benefit from its advantages though, any satellite insuch orbits must compensate the drag force generated by the residual atmosphere or it willde-orbit in a matter of days. Any sort of thruster is therefore required. It can either be a con-ventional propulsion system with on-board stored fuel or an Air-Breathing Electric Propul-sion system, which can collect its own fuel from the residual atmosphere.This project evaluates the performance that both engines would have in a possible VeryLow Earth Orbit Earth Observation scenario and discloses whether the Air-Breathing Elec-tric Propulsion system can be a viable candidate as CubeSat drag compensation system withregards to conventional thrusters.
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Controlling entrainment in the smoke cloud using level set-based front tracking

  • Dietze, Eckhard
  • Schmidt, Heiko
  • Stevens, Bjorn
  • Mellado González, Juan Pedro
Although large-eddy simulation (LES) has been shown to produce a reasonable representation of the turbulent circulations within the stratocumulus-topped boundary layer, it has difficulties to accurately predict cloud-top entrainment rates. In this paper, we present a front-tracking algorithm for LES to untangle the numerical and physical contributions to entrainment. Instead of resolving the cloud-top inversion, we treat it as a discontinuity separating the boundary layer from the free atmosphere and use the level set method to track its location. We apply our method to the smoke cloud test case as presented by Bretherton et al. (1999) which is simpler than stratocumulus in that it is only driven by radiative cooling avoiding evaporative feedbacks on entrainment. We present three-dimensional LES results with and without use of the level set method varying the grid resolution and the flux limiter. With the level set method, we prescribe zero entrainment and use this case to evaluate our method’s ability to maintain a non-entraining smoke-cloud layer. We use an empiricallybased entrainment law to estimate numerical errors. With the level set method, the prescribed entrainment rate was maintained with errors about one order of magnitude smaller than the entrainment errors found in the standard LES. At the same time, the dependence of the entrainment errors on the choice of the limiter was reduced by more than a factor of 10., Peer Reviewed
Proyecto:


Analysis of the spatial structure of Beijing from the point view of Weibo Data, Análisis de la estructura espacial de Beijing desde la perspectiva de la plataforma Weibo, Anàlisi de l'estructura espacial de Beijing des de la perspectiva de la plataforma Weibo

  • Yang, Liya
  • Marmolejo Duarte, Carlos Ramiro
Beijing es la segunda ciudad más grande de China cuya estructura urbana no está libre de controversias. Los métodos tradicionales suelen definir la estructura urbana mediante el análisis espacial del empleo. Esta investigación estudia la estructura espacio-temporal del área metropolitana de Beijing a partir de datos provenientes de redes sociales. Para ello se utiliza la densidad de Weibo (el equivalente chino de Twitter) para describir las actividades de los ciudadanos en Beijing a lo largo de una semana y, mediante un modelo exponencial clásico, se identifican los sub-centros de Weibo. Este método, detecta sub-centros en diferentes períodos de tiempo y los compara con los usos reales del suelo urbano. Además, el área estudiada se extiende a los "distritos periféricos" de Beijing, por lo que permite evaluar el desarrollo urbano de toda el área de Beijing. Los resultados indican que la estructura de Beijing muestra una estructura policéntrica, aunque la mayor densidad se concentra principalmente en el centro metropolitano de Beijing. Los sub-centros identificados son el aeropuerto, las áreas comerciales, las atracciones turísticas, las universidades y las áreas de uso mixto, que tienen flujos intensos de actividades humanas. Los datos de Weibo han demostrado ser una fuente de datos útil para estudiar la estructura urbana y las áreas funcionales urbanas., Beijing és la segona ciutat més gran de la Xina l'estructura urbana no està lliure de controvèrsies. Els mètodes tradicionals solen definir l'estructura urbana mitjançant l'anàlisi espacial de l'ocupació. Aquesta investigació estudia l'estructura espai-temporal de l'àrea metropolitana de Beijing a partir de dades provinents de xarxes socials. Per a això s'utilitza la densitat de Weibo (l'equivalent xinés de Twitter) per descriure les activitats dels ciutadans a Beijing al llarg d'una setmana i, mitjançant un model exponencial clàssic, s'identifiquen els sub-centres de Weibo. Aquest mètode, detecta sub-centres en diferents períodes de temps i els compara amb els usos reals del sòl urbà. A més, l'àrea estudiada s'estén als "districtes perifèrics" de Beijing, de manera que permet avaluar el desenvolupament urbà de tota l'àrea de Beijing. Els resultats indiquen que l'estructura de Beijing mostra una estructura policèntrica, encara que la major densitat es concentra principalment en el centre metropolità de Beijing. Els sub-centres identificats són l'aeroport, les àrees comercials, les atraccions turístiques, les universitats i les àrees d'ús mixt, que tenen fluxos intensos d'activitats humanes. Les dades de Weibo han demostrat ser una font de dades útil per estudiar l'estructura urbana i les àrees funcionals urbanes., Beijing as the second largest city in China has a controversial urban structure. Traditional methods usually identify the urban structure of cities by analyzing the employment distribution. This research studies the temporal-spatial structure of Beijing metropolitan area in terms of social media activities. It proposes to utilize Weibo (the Chinese equivalent of Twitter) density to describe the citizens' activities in Beijing in one week and adopt the classic exponential model to identify Weibo sub-centers. It detects sub-centers in different time periods and compares them with the actual urban land uses. Moreover, the studied area extends to the “peripheral districts” of Beijing, thus it assesses the developmental situation of the whole Beijing area. The results indicate that the structure of Beijing indeed shows a polycentric structure according to the distribution of potential Weibo sub-centers, though the only clear spatial structure of Weibo distribution is confirmed by the model is the period of the weekend. These Weibo sub-centers of weekend are the airport, commercial areas, tourist attractions, universities, and mixed-activity areas, which have intense flows of human activities. Weibo data is proved to be a useful data source to study the urban structure and urban functional areas., his paper is an evolutionof the author’s master thesis –The Analysis of the Spatial Structure of Beijing from The Point View of Weibo Data. It is also related to the research group of CPSV, under the reference MINECO CSO2012-33441., Peer Reviewed
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Baleares 2013 Calibration Campaign for Jason-2 and Saral/AltiKa

  • Martínez Benjamín, Juan José
  • Biancale, Richard
  • Martín Dávila, José
  • Gárate Pasquín, Jorge
  • Pérez Gómez, Begoña
  • Gili Ripoll, José Antonio
  • López Bravo, Rogelio
  • Tapia Gómez, Ana M.
  • Gracia Gómez, Carlos
  • Frappart, Frédéric
  • Roussel, Nicolas
A Baleares calibration campaign in Spanish-French cooperation is being prepared for mid September 2013 for the altimeters of Jason-2 and Saral/AltiKa in the Ibiza island area. A similar Spanish/French experience with Jason-1 was made in June 2003 in this geographical area under IBIZA 2003 campaign. In this local/regional campaign focusing in bias, we foresee to calibrate the altimeter of Jason-2 and Saral satellites by means of GPS buoys. 4 buoys will be used near a node from Jason-2 (September 15 about 9:38 in ascending track) and Saral (September 15 about 7:30 in ascending track) satellites to get the slope of the sea in along track and cross track directions, what is necessary to interpolate the exact nadir point of the satellite. It will be used Argos floating transmitters from CLS to be tied to the buoys with a long rope. We have thought over different configurations. The crossover point between Jason-2 and Saral North of Ibiza (around 40 nm) and West of Mallorca island seems to be optimal in order to have a comparable layout of buoys at the same place for both satellites, of couse at one day interval. This would allow moreover cross calibration between Jason2 and Saral. The GPS receivers will be at 1Hz. It will be used the CGPS at Ibiza harbour from Puertos del Estado. A description of the actual geodetic infrastructure of Ibiza site will be presented. This campaign Baleares 2013 is founded from the Ministerio de Ciencia e Innovacion of Spain under National Project I+D+i ref:CGL2009-13435/CLI.
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Factores dependientes de la motivación de los estudiantes de formación continua en el Principado de Andorra

  • Sabrià-Bernadó, Betlem
  • Llinàs Audet, Francisco Javier
  • Isus-Barado, Sofia
  • Yáñez-Aldecoa, Cristina
El objetivo principal de este estudio se centra en averiguar los factores dependientes de la motivación de la demanda de los usuarios de formación continua, en el caso del Principado de Andorra. La investigación se enmarca en el paradigma positivista utilizando metodología híbrida. El instrumento principal es un cuestionario, diseñado a partir del estudio del marco teórico de referencia y de los resultados de las entrevistas en profundidad y validado mediante un juicio de expertos y una prueba piloto. Este estudio se inició con la recogida de datos y su posterior tratamiento estadístico y los resultados del proceso de validación han sido publicados. El modelo se ha desarrollado en diversas etapas. Para realizarlo se utiliza la técnica de análisis multivariante del análisis factorial y la de modelización con estructuras de covarianza o modelos de ecuaciones estructurales. La primera fase consistió en un análisis factorial exploratorio de primer orden cuyo objetivo fue determinar las variables que contribuyen a medir los factores directamente observables recogidas en el cuestionario. La segunda fase supuso la realización de un análisis factorial confirmatorio. Estudiamos el ajuste global del modelo, la unidimensionalidad y fiabilidad de cada factor; y la consistencia interna del modelo mediante el análisis de la fiabilidad y la validez discriminante. Los resultados obtenidos garantizan nuestro modelo de medida. Posteriormente se introdujo el modelo estructural, mediante una nueva variable latente exógena que aglutina los constructos de primer nivel. Obtuvimos los principales factores determinantes en la motivación de los estudiantes de formación continua, así como sus indicadores de medición estos factores son: el empleo actual, la necesidad de un cambio profesional y la necesidad de una mejora personal.
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Human activity recognition on smartphones for mobile context awareness

  • Anguita, Davide
  • Ghio, Alessandro
  • Oneto, Luca
  • Llanas Parra, Francesc Xavier
  • Reyes Ortiz, Jorge Luis
Activity-Based Computing [1] aims to capture the state of the user and its environment by exploiting heterogeneous sensors in order to provide adaptation to exogenous computing resources. When these sensors are attached to the subject’s body, they permit continuous monitoring of numerous physiological signals. This has appealing use in healthcare applications, e.g. the exploitation of Ambient Intelligence (AmI) in daily activity monitoring for elderly people. In this paper, we present a system for human physical Activity Recognition (AR) using smartphone inertial sensors. As these mobile phones are limited in terms of energy and computing power, we propose a novel hardware-friendly approach for multiclass classification. This method adapts the standard Support Vector Machine (SVM) and exploits fixed-point arithmetic. In addition to the clear computational advantages of fixed-point arithmetic, it is easy to show the regularization effect of the number of bits and then the connections with the Statistical Learning Theory. A comparison with the traditional SVM shows a significant improvement in terms of computational costs while maintaining similar accuracy, which can contribute to develop more sustainable systems for AmI., Peer Reviewed
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Images encryption system based on a fractional joint transform correlator and nonlinear filtering

  • Vilardy Ortiz, Juan Manuel
  • Millán Garcia-Varela, M. Sagrario
  • Pérez Cabré, Elisabet
A new optical security system for image encryption based on a fractional joint transform correlator and nonlinear filtering is proposed. The position of the lens in the proposed optical encryption setup can be chosen, so that an additional key is introduced in the security system. The distributions at the input and output planes of the encryption system are related by a fractional Fourier transform (FrFT) at a given fractional order that is defined, among other parameters, by the focal length and the position of the lens in the setup; this fractional order acts as an additional key of the security system. The optical intensity of the complex distribution in the fractional Fourier domain (output plane) is captured by a CCD camera. The nonlinearity introduced in the last step of the encryption process, maintains the encrypted function as a real-valued function. The security system proposed in this work is an generalization of the encryption system based on a conventional joint transform correlator (JTC), from the Fourier domain to the fractional Fourier domain. Additional advantages of the proposed system are: new degrees of freedom for the optical setup, alleviated alignment requirement, and the introduction of an additional key (the fractional order of the FrFT) that improves security. Numerical simulations verify the validity of this new optical security system
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Detecting invariant manifolds using hyperbolic Lagrangian coherent structures

  • Pérez, Daniel
  • Gómez Muntané, Gerard
  • Masdemont Soler, Josep
Using as reference test model the Planar Circular Restricted Three Body Prob- lem, this paper explores its Lagrangian Coherent Structures, as well as its Hy- perbolic Lagrangian Coherent Structures. The purpose is to identify stable and unstable manifolds acting as separatrices between orbits with different qualitative behaviour and, therefore, relevant to the dynamics of the problem. Particular at- tention is given to the manifolds associated to the collinear libration points and to the practical stability regions around the triangular equilibrium points
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