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Wearing a single DNA molecule with an AFM tip

  • Santos Hernández, Sergio
  • Barcons Xixons, Víctor
  • Font Teixidó, Josep
  • Thomson, Neil H.
While the fundamental limit on the resolution achieved in an atomic force microscope (AFM) is clearly related to the tip radius, the fact that the tip can creep and/or wear during an experiment is often ignored. This is mainly due to the difficulty in characterizing the tip, and in particular a lack of reliable methods that can achieve this in situ. Here, we provide an in situ method to characterize the tip radius and monitor tip creep and/or wear and biomolecular sample wear in ambient dynamic AFM. This is achieved by monitoring the dynamics of the cantilever and the critical free amplitude to observe a switch from the attractive to the repulsive regime. The method is exemplified on the mechanically heterogeneous sample of single DNA molecules bound to mica mineral surfaces. Simultaneous monitoring of apparent height and width of single DNA molecules while detecting variations in the tip radius R as small as one nanometer are demonstrated. The yield stress can be readily exceeded for sharp tips (R<10 nm) at typical operating amplitudes (A>10nm). The ability to know the AFM tip radius in situ and in real-time opens up the future for quantitative nanoscale materials properties determination at the highest possible spatial resolution.
Proyecto:


De habitar a morar: el tiempo en la arquitectura, From inhabiting to dwelling: time in architecture

  • Galmés Cerezo, Álvaro
El concepto de “Habitar” sufrió una importante transformación en el transcurso del siglo xx. La arquitectura de la modernidad ha estado muy preocupada por involucrar en su discurso muchos de los aspectos que emanan de este concepto. Aun así, ya bien entrado el siglo XXI, algunos de estos principios han quedado obsoletos.El presente artículo intenta poner al día el significado de habitar, buscando un vocablo que se adecúen mejor a lo que se entiende en la actualidad por esa acción ciudadana que repercute de un modo transcendente en la arquitectura y en especial en la vivienda.A través del vocablo “Morar” se establecen unos nuevos vínculos entre el individuo y su entorno, vínculos que van más allá del espacio y que se manifiestan en la relevancia que tiene el tiempo para la experiencia del morador. Por otro lado, se analizan las transformaciones que se han dado en aspectos relacionados con el “qué”, el “cómo” y el “donde” entre el antiguo termino de “habitar” y está nueva acepción. Por último, se redefine el concepto de “Morar” en para acercarse a las ideas del pensamiento fenomenológico actual., The concept of “inhabiting” has been one of the most influential ideas in the development of Modern Architecture. However, a hundred years after the beginning of that period, the premises that supported that notion have changed, which calls for a necessary revision of the concept. The present article analyzes the main ideas towards which this concept of inhabiting gravitated in the past, and how they have been subsequently replaced by new ones. According to that, it is necessary to redefine its meaning so that it adapts to the current thinking, as well as, in our opinion, to change its designation and replace the old term “inhabiting”, charged with a static and eminently functional connotation, with the term “dwelling”, which, due to its etymology, allows for a more up-to-date comprehension of that idea, by referring to the time factor as well as to diverse experiences of spatial interaction., Peer Reviewed
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Application of the measured equation of invariance to transmission.

  • Prouty, M.D.
  • Pous Andrés, Rafael
  • Mei, K.K.
The MEI (measured equation of invariance) method can easily be applied to static analyses of uniform transmission lines, such as single and coupled microstrip lines. Laplace's equation is solved for the static electric potential, and the total charges on the metal structures are found. Solving the problem with the correct permittivity values for the dielectrics yields the capacitance of the structures, while solving the problem with all permittivities equal to the free-space value yields the inductances. The quasi-static impedance values may then be obtained. Planar microstrip-type structures, where currents are confined to two dimensions are also considered. Results are presented for cases where no dielectric is present. This simplifies the Green's function calculation for the present purposes, but the method may be applied to more general cases., Peer Reviewed
Proyecto:


Channel matrix characterization in MIMO scenario through impedance modulation

  • Monsalve Carcelen, Beatriz
  • Romeu Robert, Jordi
  • Blanch Boris, Sebastián
In this paper a new measurement setup to obtain the characteristic channel matrix of a MIMO radio system is presented using a small and non intrusive device able to characterize two antennas and therefore obtaining the characteristic channel matrix of a MIMO radio system of Nx2 antennas without using a receiver for each port. The extension to a system of more than two output elements can be easily achieved increasing the complexity of the switching device. To validate the new methodology presented here a 2x2 MIMO channel matrix has been characterized comparing the singular value distribution obtained with a traditional measurement procedure., Peer Reviewed
Proyecto:


Bistatic synthetitc aperture radar imaging based on Geostationatry transmitters and Ground-Based receivers

  • Pinar Riasol, Ricard
This thesis belongs to the remote sensing field, particularly on the Geostationary Synthetic Aperture Radar (SAR) imaging systems with on-ground receiver. These systems forms images taking the signals along the orbital track of one satellite while the receiver is placed on the Earth coherently processing the echoes received by the receiver. The study presented in this thesis is centered in an algorithm known as back projection algorithm that presents the main advantage that is possible to permanently acquire images from the same region thanks to the small motion of the platform with respect to the Earth. An introduction to all the important aspects of the GEOSAR mission is presented in order to let the reader known all the important information of why it is important to study the Synthetic Aperture Radars (SAR) mounted on geostationary satellite platforms. Moreover, an introduction to orbits, coordinates systems and Synthetic Aperture Radar (SAR) is essential in order to understand the algorithm developed in this thesis for obtaining SAR images from a geostationary orbit with the receiver placed on ground. So a detailed explanation of all this topics is developed during this thesis. The main section of this thesis presents the development of a back projection algorithm for a GEOSAR satellite with on ground receiver. Detailed explanations on how each block of the algorithm has been developed and which are the main functionalities of each block are explained and analysed. Finally, a test in order to prove that the algorithm works as expected has been performed in order to see if it is possible to obtain SAR images from a geostationary orbit using this geometry.
Proyecto:


Evaluación del registro y transmisión de señales electromiográficas mediante un dispositivo inalámbrico

  • Torres Cebrián, Abel
  • Estévez Piorno, Josep
  • Ràfols de Urquía, Magda
  • Estrada, Luis
  • Jané Campos, Raimon
Los dispositivos vestibles son aquellos dispositivos que se incorporan a piezas de ropa u otros accesorios que se puedan llevar cómodamente en el cuerpo. Estos dispositivos funcionan habitualmente mediante la comunicación inalámbrica. Esta comunicación consiste en la transmisión de información entre dos o más puntos que no están conectados mediante un conductor eléctrico. Shimmer es un dispositivo multisensor vestible con unas prestaciones muy altas que lo diferencian de otros dispositivos y que permite de una forma simple la medida de parámetros cinemáticos y fisiológicos que pueden ser capturados y visualizados en tiempo real. Sin embargo, estos dispositivos pueden presentar pérdidas de datos durante la adquisición de señales biomédicas. En este estudio se ha evaluado la pérdida de datos durante la adquisición de señales cinemáticas y fisiológicas. Se han realizado registros electromiográficos de músculos esqueléticos usando las distintas vías de registro y configuraciones que ofrece el dispositivo. Los registros se han realizado en un sujeto sano. Se ha observado que a medida que se incrementa la frecuencia de muestreo y a un mayor número de canales, la cantidad de pérdidas aumenta. En general, a una frecuencia de muestreo de 512 Hz el dispositivo Shimmer es capaz de obtener señales sin pérdidas sin importar la vía de registro utilizada.
Proyecto:


Measurement-Based Worst-Case Execution Time Estimation Using the Coefficient of Variation

  • Abella Ferrer, Jaume
  • Padilla, Maria
  • del Castillo, Joan
  • Cazorla, Francisco J.
Extreme Value Theory (EVT) has been historically used in domains such as finance and hydrology to model worst-case events (e.g., major stock market incidences). EVT takes as input a sample of the distribution of the variable to model and fits the tail of that sample to either the Generalised Extreme Value (GEV) or the Generalised Pareto Distribution (GPD). Recently, EVT has become popular in real-time systems to derive worst-case execution time (WCET) estimates of programs. However, the application of EVT is not straightforward and requires a detailed analysis of, and customisation for, the particular problem at hand. In this article, we tailor the application of EVT to timing analysis. To that end, (1) we analyse the response time of different hardware resources (e.g., cache memories) and identify those that may lead to radically different types of execution time distributions. (2) We show that one of these distributions, known as mixture distribution, causes problems in the use of EVT. In particular, mixture distributions challenge not only properly selecting GEV/GPD parameters (i.e., location, scale and shape) but also determining the size of the sample to ensure that enough tail values are passed to EVT and that only tail values are used by EVT to fit GEV/GPD. Failing to select these parameters has a negative impact on the quality of the derived WCET estimates. We tackle these problems, by (3) proposing Measurement-Based Probabilistic Timing Analysis using the Coefficient of Variation (MBPTA-CV), a new mixture-distribution aware, WCET-suited MBPTA method that builds on recent EVT developments in other fields (e.g., finance) to automatically select the distribution parameters that best fit the maxima of the observed execution times. Our results on a simulation environment and a real board show that MBPTA-CV produces high-quality WCET estimates., The research leading to these results has received funding from the European Community’s FP7 [FP7/2007- 2013] under the PROXIMA Project (www.proxima-project.eu), grant 611085. This work has also been par- tially supported by the Spanish Ministry of Science and Innovation under grant TIN2015-65316-P and the HiPEAC Network of Excellence. Jaume Abella was partially supported by the Ministry of Economy and Competitiveness under Ramon y Cajal postdoctoral fellowship RYC-2013-14717., Peer Reviewed
Proyecto:


Topos & Khora: territoriality as a cultural creation of human being

  • González Torres, Rolando
Ponència presentada a: Session 4: Etnografìas, fenomenología, fenomenología social y dialogía social / Ethnographies in the studios, phenomenology, social dialogy
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