7,098 research outputs found

    Theory of photon coincidence statistics in photon-correlated beams

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    The statistics of photon coincidence counting in photon-correlated beams is thoroughly investigated considering the effect of the finite coincidence resolving time. The correlated beams are assumed to be generated using parametric downconversion, and the photon streams in the correlated beams are modeled by two partially correlated Poisson point processes. An exact expression for the mean rate of coincidence registration is developed using techniques from renewal theory. It is shown that the use of the traditional approximate rate, in certain situations, leads to the overestimation of the actual rate. The error between the exact and approximate coincidence rates increases as the coincidence-noise parameter, defined as the mean number of uncorrelated photons detected per coincidence resolving time, increases. The use of the exact statistics of the coincidence becomes crucial when the background noise is high or in cases when high precision measurement of coincidence is required. Such cases arise whenever the coincidence-noise parameter is even slightly in excess of zero. It is also shown that the probability distribution function of the time between consecutive coincidence registration can be well approximated by an exponential distribution function. The well-known and experimentally verified Poissonian model of the coincidence registration process is therefore theoretically justified. The theory is applied to an on-off keying communication system proposed by Mandel which has been shown to perform well in extremely noisy conditions. It is shown that the bit-error rate (BER) predicted by the approximate coincidence-rate theory can be significantly lower than the actual BER obtained using the exact theory

    Continuous wave laser-induced forward transfer of conductive Ag nanoparticle inks

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    Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2017, Tutor: Pere Serra CorominaThe laser induced forward transfer of silver nanoparticle ink using continuous wave laser is studied in this work. The feasibility of this method for printing well-defined lines is proven. Line formation is studied in the laser intensity - scan speed parameter space, showing satisfactory results for a range of energies and speeds. The conductivity of the lines was measured to be comparable to those obtained with inkjet printing, proving the effectiveness of this technique to produce functional electrical interconnects. High speed photography of the transfer process is performed, revealing the markedly different transfer dynamics compared to the traditional, pulsed laser LIFT process

    Medium-as-meaning: Translation commodities and pragmatic ideologies in Translation Studies

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    RESUMEN: Aunque se ha derramado ríos de tinta sobre el rol de las ideologías de la traducción y sobre la ideología en la traducción (e.g. Venuti 1992; Calzada Pérez 2005), poco se ha dicho acerca de la influencia de las ideologías encubiertas (ideologías pragmáticas) asociadas con los medios-como-sentido en el contexto de los Estudios de Traducción. El resultado de esto es que muchos teóricos de la traducción han confundido la tecnología con la traducción y el soporte de la traducción (medio) con el significado en la así llamada Era de la Traducción (e.g. Cronin 2012). En dicho escenario, la invisibilidad del traductor ha aumentado, mientras que el texto traducido se ha convertido en un producto al servicio de una más rápida y eficiente diseminación de traducciones mercantilizadas dentro de redes de producción (Sturgeon 1984). Lo anterior ha desbancado paulatinamente la noción de Ontología (para la construcción de una realidad de la traducción) en favor de una serie de ontologías de la traducción más en línea con la producción en serie y la validación empírica de conceptos en el marco de las tecno-ciencias. El artículo termina con la propuesta de un cambio paradigmático de la ética de los Estudios de Traducción que tenga en cuenta la dignidad como fuente de desarrollo (Castells y Himanen, 2014) así como las epistemologías de la verdad.ABSTRACT: Although a lot of ink has been spilt about the role of translation ideologies and ideologies in Translation Studies (e.g. Venuti 1992; Calzada Pérez 2005), little has been said about the influence of covert translation ideologies (pragmatic ideologies) associated with localized medium-as-meaning. As a result, the ubiquity of digital technologies has led some translation scholars to conflate technology with translation and medium with meaning in a so-called Translation Age (e.g. Cronin 2012). In such a scenario, translator’s invisibility has increased, as the translated text has become a commodity at the service of a quick and more efficient dissemination of translated products within production networks (Sturgeon 1984). This has progressively debunked the notion of Ontology (for the construction of a translational reality) in favor of translational ontologies, more in tune with the expeditious production and empirical validation of concepts within techno-sciences. I finish the article by suggesting an ethical turn in Translation Studies encompassing concepts such as dignity as development (Castells and Himanen, 2014) and virtue epistemologies

    Semiosic translation : A new theoretical framework for the implementation of pedagogically-oriented subtitling

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    RESUMEN: El presente artículo explora un nuevo tipo de traducción semiótica en el marco de la traducción audiovisual (TA). El estudio se nutre de varias secuencias lexicales llamadas hedging strings. El artículo sugiere que ciertas fórmulas usadas en inglés durante el proceso de construcción del discurso conversacional, pueden incluirse en cursos de inglés como lengua extrajera. El marco teórico de la propuesta parte del concepto de Traducción Semiósica, con especial énfasis en la noción de subtitulación semiósica, la cual se divide a su vez en tres tipos de esenciales de traducción: (i) Traducción metaléptica, (ii) traducción indicial, y (iii) traducción como continuidad dinámica. Dicho marco teórico busca reivindicar la relación del signo lingüístico con otros sistemas de signos.ABSTRATC: In this paper, I explore a new type of semiotic translation in the context of Audiovisual Translation Studies (AVTS). To that end, a set of formulaic sequences bestowed of pragmalinguistic value (hedging strings) is analysed. It is argued that the semiotic analysis of conversational features in English may contribute to facilitate their pedagogical exploitation in English as a Foreign Language (EFL) classrooms. Th is analysis builds theoretically on a semiotic translational framework termed Semiosic Translation (and its subset, Semiosic Subtitling) predicated upon three types of translation: (i) Metaleptic translation; (ii) indexical translation; and (iii) translation as dynamic discontinuity. Th e translational rationale thus arrived at is deemed to account for what it is that binds together linguistic signs with other sign systems

    Information retrieval for children based on the aggregated search paradigm

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    This report presents research to develop information services for children by expanding and adapting current Information retrieval technologies according to the search characteristics and needs of children. Concretely, we will employ the aggregated search paradigm as theoretical framework. The objective is to develop approaches that identify the most appropriate information types and sources given a child's information request and to present this information to ease and improve his/her search experience
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