1000 resultados para Comunicación digital


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In many European countries, image quality for digital x-ray systems used in screening mammography is currently specified using a threshold-detail detectability method. This is a two-part study that proposes an alternative method based on calculated detectability for a model observer: the first part of the work presents a characterization of the systems. Eleven digital mammography systems were included in the study; four computed radiography (CR) systems, and a group of seven digital radiography (DR) detectors, composed of three amorphous selenium-based detectors, three caesium iodide scintillator systems and a silicon wafer-based photon counting system. The technical parameters assessed included the system response curve, detector uniformity error, pre-sampling modulation transfer function (MTF), normalized noise power spectrum (NNPS) and detective quantum efficiency (DQE). Approximate quantum noise limited exposure range was examined using a separation of noise sources based upon standard deviation. Noise separation showed that electronic noise was the dominant noise at low detector air kerma for three systems; the remaining systems showed quantum noise limited behaviour between 12.5 and 380 µGy. Greater variation in detector MTF was found for the DR group compared to the CR systems; MTF at 5 mm(-1) varied from 0.08 to 0.23 for the CR detectors against a range of 0.16-0.64 for the DR units. The needle CR detector had a higher MTF, lower NNPS and higher DQE at 5 mm(-1) than the powder CR phosphors. DQE at 5 mm(-1) ranged from 0.02 to 0.20 for the CR systems, while DQE at 5 mm(-1) for the DR group ranged from 0.04 to 0.41, indicating higher DQE for the DR detectors and needle CR system than for the powder CR phosphor systems. The technical evaluation section of the study showed that the digital mammography systems were well set up and exhibiting typical performance for the detector technology employed in the respective systems.

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Se propone un modelode análisis para cibermedios(periodismo digital) con elfin de determinar su calidad enrelación con un conjunto de parámetrosgenerales y, en especial,respecto a la adopción dela web 2.0. Este modelo se hatestado con el análisis de ochodiarios digitales cuyos resultadosse presentan también. Presentaun carácter modular quepermite por un lado su extensión,y por otro, su aplicacióntotal o parcial en contextos deanálisis diferentes.

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La creciente adaptación de los medios de comunicación al entorno digital hace conveniente la utilización de metodologías de análisis que permitan determinar la calidad de sus sitios web. En este artículo, a partir del estudio de las características de las webs de algunos de los medios de comunicación más importantes a nivel internacional, se propone una metodología para la evaluación específica de este tipo de sitios web. El modelo propuesto se compone de treinta y seis indicadores, organizados en torno a ocho parámetros que permiten valorar, especialmente, la adaptación del medio de comunicación a la interacción de la Web 2.0. Otros aspectos a los que también se presta atención, pero en menor medida, son la arquitectura de la información, la usabilidad, la accesibilidad o las herramientas de interacción y comunicación que éste pone a disposición de sus usuarios.

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BACKGROUND AND STUDY AIMS: The current gold standard in Barrett's esophagus monitoring consists of four-quadrant biopsies every 1-2 cm in accordance with the Seattle protocol. Adding brush cytology processed by digital image cytometry (DICM) may further increase the detection of patients with Barrett's esophagus who are at risk of neoplasia. The aim of the present study was to assess the additional diagnostic value and accuracy of DICM when added to the standard histological analysis in a cross-sectional multicenter study of patients with Barrett's esophagus in Switzerland. METHODS: One hundred sixty-four patients with Barrett's esophagus underwent 239 endoscopies with biopsy and brush cytology. DICM was carried out on 239 cytology specimens. Measures of the test accuracy of DICM (relative risk, sensitivity, specificity, likelihood ratios) were obtained by dichotomizing the histopathology results (high-grade dysplasia or adenocarcinoma vs. all others) and DICM results (aneuploidy/intermediate pattern vs. diploidy). RESULTS: DICM revealed diploidy in 83% of 239 endoscopies, an intermediate pattern in 8.8%, and aneuploidy in 8.4%. An intermediate DICM result carried a relative risk (RR) of 12 and aneuploidy a RR of 27 for high-grade dysplasia/adenocarcinoma. Adding DICM to the standard biopsy protocol, a pathological cytometry result (aneuploid or intermediate) was found in 25 of 239 endoscopies (11%; 18 patients) with low-risk histology (no high-grade dysplasia or adenocarcinoma). During follow-up of 14 of these 18 patients, histological deterioration was seen in 3 (21%). CONCLUSION: DICM from brush cytology may add important information to a standard biopsy protocol by identifying a subgroup of BE-patients with high-risk cellular abnormalities.

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Las administracionespúblicas de los países avanzadosestán llevando a caboiniciativas para gestionar lainformación y la comunicaciónde riesgo y emergencias mediantesitios web concebidos ydiseñados para ello. Estos sitiosestán pensados para facilitarinformación a los ciudadanosen caso de emergencias, perotambién contienen informaciónútil para los expertos y las autoridades.En este trabajo, y ala luz de la legislación españolasobre emergencias, se comparanlos sitios de la administraciónautonómica catalana y delgobierno de España con lossitios de tres países de referencia:Estados Unidos, Francia yReino Unido. Al mismo tiempose propone una metodologíasimple para llevar a cabo unacomparación que permita extraerconclusiones y plantearrecomendaciones en un aspectode la gestión de la información que puede resultar clave para salvar bienes materiales y vidas humanas.

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In this paper we present the theoretical and methodologicalfoundations for the development of a multi-agentSelective Dissemination of Information (SDI) servicemodel that applies Semantic Web technologies for specializeddigital libraries. These technologies make possibleachieving more efficient information management,improving agent–user communication processes, andfacilitating accurate access to relevant resources. Othertools used are fuzzy linguistic modelling techniques(which make possible easing the interaction betweenusers and system) and natural language processing(NLP) techniques for semiautomatic thesaurus generation.Also, RSS feeds are used as “current awareness bulletins”to generate personalized bibliographic alerts.

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This paper initially identifies the main transformations of the television system that are caused by digitalization. Its development in several broadcasting platforms is analyzed as well as the particular obstacles and requirements that are detected for each of them. Due to its technical characteristics and its historical link to the public services, the terrestrial network requires migration strategies different from those strictly commercial, and public intervention might be needed. The paper focuses on such migration strategies towards DTT and identifies the main issues for public intervention in the areas of the digital scenario: technology, business and market transformation and the reception field. Moreover, it describes and classifies the challenges that public broadcasters should confront due to digitalization. This paper finally concludes that the leadership of the public broadcasters during the migration towards DTT is an interesting tool for public policy. The need for foster the digitalization of the terrestrial platform and to achieve certain social and public goal besides the market interest brings an opportunity for public institutions and public broadcasters to work together. That leading role could also be positive for the public service to face its necessary redefinition and reallocation within the digital context.

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In the past, sensors networks in cities have been limited to fixed sensors, embedded in particular locations, under centralised control. Today, new applications can leverage wireless devices and use them as sensors to create aggregated information. In this paper, we show that the emerging patterns unveiled through the analysis of large sets of aggregated digital footprints can provide novel insights into how people experience the city and into some of the drivers behind these emerging patterns. We particularly explore the capacity to quantify the evolution of the attractiveness of urban space with a case study of in the area of the New York City Waterfalls, a public art project of four man-made waterfalls rising from the New York Harbor. Methods to study the impact of an event of this nature are traditionally based on the collection of static information such as surveys and ticket-based people counts, which allow to generate estimates about visitors’ presence in specific areas over time. In contrast, our contribution makes use of the dynamic data that visitors generate, such as the density and distribution of aggregate phone calls and photos taken in different areas of interest and over time. Our analysis provides novel ways to quantify the impact of a public event on the distribution of visitors and on the evolution of the attractiveness of the points of interest in proximity. This information has potential uses for local authorities, researchers, as well as service providers such as mobile network operators.

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El propósito de esta comunicación es analizar el estado actual de los periódicos digitales, prestandoespecial atención a la adaptación de éstos al entorno de la Web 2.0. Para llevar a cabo este trabajo sehan estudiado, entre otras, las siguientes variables: el tipo de herramientas propias de la Web 2.0que los periódicos digitales han incorporado a sus sitios web, la forma en que éstas ha cambiado elproceso de creación de los productos periodísticos, la respuesta que los periódicos digitales hanrecibido por parte de la audiencia y el nuevo tipo de interacción creado con los usuarios.

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“Magic for a Pixeloscope” is a one hour show conceived to berepresented in a theater scenario that merges mixed and augmented reality (MR/AR) and full-body interaction with classical magic to create new tricks. The show was conceived by an interdisciplinary team composed by a magician, twointeraction designers, a theater director and a stage designer. Themagician uses custom based hardware and software to createnew illusions which are a starting point to explore new languagefor magical expression. In this paper we introduce a conceptualframework used to inform the design of different tricks; weexplore the design and production of some tricks included in theshow and we describe the feedback received on the world premiere and some of the conclusions obtained.

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This research report concerns about the post-doctoral activities, conducted betweenSeptember 2010 and March 2011 at the University Pompeu Fabra, Barcelona. It comes to identify the consequences of the convergence phenomenon on photojournalism.Thus, in a more general approach, the effort is to to recovery the structural elements of the convergence concept in journalism. It aims to map, as well, the current debates about the repositioning of photographic practices linked to the news produced in a widespread adoption of digital devices in contemporary workflow. It is also specified,the analysis of photographic collectives as a result of the convergence frameworkapplied to photojournalism; the debate on ways of funding; alternatives facing thealleged crisis of press photography and, finally, proposes to create qualifying stages ofdevelopment of photojournalism in the digital age as well as the proposition of hypotheses concerning the structure of the productive routines. In addition, we present three cases to be analyzed in order to explore and verify the occurrence ofcharacteristics that may identify the object of research in the state of practice. Finally,we work in a series of conclusions, revisiting the main hypotheses. With this strategy, ispossible to define an sequence of analysis capable of addressing the characteristics present in the studied cases and other ones in future, thus, be able to affirm this stage as a step, in the continuous historical course of photojournalism.

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O objetivo do estudo foi caracterizar o perfil de licenciandos de enfermagem, identificar a fluência digital, o conhecimento, a habilidade e o interesse no uso de ambientes virtuais de aprendizagem. Trata-se de uma pesquisa quantitativa, exploratório-descritiva realizada com 51 licenciandos de enfermagem por meio de questionário. Dos participantes do estudo 51 (100%) afirmam ter conhecimento em informática, sendo que 26 (49%) indicam um nível intermediário; 47 (92%) fazem uso diário da Internet; 51 (100%) navegam em redes sociais e possuem e-mail; 51(100%) utilizam MSN e 32 (62,7%) Skype; 41 (82%) acessam Chats, 33 (64,7%) Fóruns de discussão e 22 (43%) Blogs; 33 (64,7%) utilizam frequentemente o Moodle e 26 (51%) o COL; e a grande maioria (45- 88,2%) relatou interesse no uso de ambientes virtuais de aprendizagem. Os alunos foram considerados fluentes digitais e apresentaram conhecimento, habilidade e expressivo interesse no uso de ambientes virtuais de aprendizagem em sua formação acadêmica.

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Este trabajo estudia la evolución de la teoría de los efectos de los medios decomunicación de masas desde su origen, a principios del siglo XX en el contextonorteamericano de la Mass Communication Research, hasta la fecha. Para ello, repasalos diferentes paradigmas en el análisis de la comunicación y sus teorías, haciendo unespecial énfasis en el contexto histórico en que se dan, así como los paradigmassociológicos y psicológicos simultáneos. El trabajo se centra en la teoría de la espiraldel silencio de Noelle-Neumann, como consecuencia de la construcción social de larealidad a partir de los medios de comunicación, y analiza los efectos psicosociales de dicha teoría, principalmente el miedo al aislamiento, la percepción del clima de opinióny la voluntad de expresar opiniones en público.

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El fenómeno de la globalización es cada vez más presente en la vida cotidiana. Juntocon este proceso, se han desarrollado las compañías multinacionales. El reto de estas compañías es de sobrevivir en medios distintos y de adaptarse a cada público, que tiene sus especificidades.Las estrategias de comunicación se crean conforme con las exigencias de cada mercado local.¿Cuál es el papel de la cultura en el proceso de creación de las campañas de comunicación de las compañías multinacionales? ¿Qué indicios nos dan los eslóganes publicitarios sobre la relaciónque se establece entre la identidad del producto y las influencias culturales

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Esta investigación se inserta en el debate sobre el estatuto disciplinario de laComunicación desde el análisis de su campo educativo, es decir, desde la aproximación al quehacer docente de los centros dedicados a su enseñanza universitaria, espacios donde se forman de manera preferente –aunque no exclusiva- los futuros investigadores de la disciplina. La investigación se centrará en la enseñanza de las asignaturas correspondientes a la formación en teoría de la comunicación, en las titulaciones de grado vinculadas al área de la Comunicación en España (Grado en Periodismo, ComunicaciónAudiovisual, y Publicidad y Relaciones Públicas), con el fin de identificar ycaracterizar los discursos que sobre el estatuto disciplinario de este campo deconocimiento reproducen y legitiman las Facultades de Comunicación españolas,como representantes de una comunidad académica. De manera operativa, la aproximación a este discurso disciplinar se realizará a través del análisis de dos de sus dimensiones: el discurso institucional de la comunidad académica: entendido como aquellos documentos oficiales de losestudios de grado donde puedan encontrarse elementos de su concepción disciplinaria del campo de la Comunicación; y el discurso experto: entendido como las opiniones particulares de académicos que participan en esa enseñanza disciplinaria en los centros formativos seleccionados. Este trabajo final correspondiente al Máster en Estudios Avanzados en Comunicación, se ha desarrollado de acuerdo a la modalidad de propuesta de proyecto para la elaboración de tesis doctoral, la que será realizada en el programa de Doctorado en Comunicación Social de esta universidad.