308 research outputs found

    On the Efficiency of Angular Intraprediction

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    Angular intraprediction (AIP) is a coding tool that has been incorporated into the video coding standards H.264/AVC (Advanced Audio Coding) and High Efficient Video Coding. In this paper, we study how the efficiency of AIP depends on its prediction parameters. To carry out this paper, we first theoretically analyze the variance of the error incurred when a perfectly directional signal is predicted in a certain direction. The results of this analysis are then used to study the efficiency of AIP when it is applied to a distribution of directions. To facilitate mathematical derivations, we make several assumptions about the signal and the prediction process, and we use some approximations. This allows us to obtain simple expressions for the variance of the AIP prediction error as a function of signal and prediction parameters. Finally, we compare our theoretical results with the results obtained from the prediction of images containing rectilinear edges. This comparison shows that our theoretical expressions follow the main trends of the experimental results except when AIP is performed with a very high accuracy.Prades Nebot, J. (2014). On the Efficiency of Angular Intraprediction. IEEE Transactions on Image Processing. 23(12):5733-5742. doi:10.1109/TIP.2014.2369954S57335742231

    The imprint of El Escorial in Spanish post-war architecture: some cases of religious reconstructions in the province of Alicante (Spain)

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    Tras las destrucciones de la guerra civil española, se abrió un debate teórico para tratar de establecer qué caminos debería tomar la arquitectura del nuevo régimen. Se analiza aquí la defensa del modelo herreriano-escurialense, símbolo de la pasada gloria imperial, propuesto por las facciones más conservadoras y por la propia Falange, y cómo éste se refleja en algunas reconstrucciones religiosas que tuvieron lugar durante la posguerra a partir de tres casos localizados en la provincia de Alicante. El estudio parte del análisis de los documentos custodiados en el Archivo General de la Administración del Estado correspondientes a la Junta Nacional de Reconstrucción de Templos Parroquiales, incorporando datos sobre sus elementos formales y ciertos rasgos técnicos y presupuestarios, así como referencias a las figuras de sus arquitectos.After the destruction caused by the Spanish civil war, a theoretical debate started to try and determine what direction the new regime should take. This article analyses the model 'herreriano-escurialense', which symbolizes past imperial glory and which was proposed by the most conservative factions and by the Falange itself. It also looks how this model is reflected in some religious reconstruction works that took place during the post-war period based on three cases found in the province of Alicante. The study is based on the analysis of the documents kept in the General Archive of the State Administration belonging to Rebuilding Parochial Churches, incorporating certain data about its formal elements and some technical and budgetary features as well as references to the architects involved

    La gliptografía en la arquitectura medieval. Visión general y estudios en España

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    Se aborda los inicios de la Gliptografía y se plantea el origen y desarrollo de los signos lapidarios, ligados al uso de la piedra sillar en la Edad Media y a la actividad de las logias masónicas, así como su papel en la construcción desde los siglos XI al XV y la utilidad de su estudio en el proceso del análisis arquitectónico de los edificios románicos y góticos. Se presenta asimismo una reseña bibliográfica de los estudios gliptográficos en España.It discusses the beginnings of Glyptography and the origin and development of mason’s marks, linked to the use of ashlar stone and freemasons lodges, as well as its roll in medieval building and the usefulness of its study in the architectural analysis process. It also presents an updated bibliography of glyptographic studies in Spain

    Durkheim, the Sacred and Environmental Crisis in the Contemporary Industrial Society

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    Este artículo presenta una lectura heurística de Las formas elementales de la vida religiosa. Contiene dos partes. La primera trata unos prolegómenos teóricos y metodológicos y la segunda pasa a considerar una aplicación práctica. Los prolegómenos precisan los conceptos de lectura y de lectura heurística, para recordar luego el valor heurístico concreto que damos a una serie de conceptos de base de la obra durkheimiana. La interdependencia y la integración de estos conceptos nos dan una idea concisa del núcleo central del pensamiento de Durkheim en lo que toca a la relación entre lo sagrado y el mundo contemporáneo. La aplicación práctica nos parece más ambiciosa, ya que se refiere directamente al excepcional problema del calentamiento climático y de la degradación constante del medio ambiente que vivimos desde hace unas décadas. Después de indicar en sus grandes líneas las causas societales determinantes de este problema, entramos en la cuestión delicada del remedio que es necesario encontrar para poder sobrevivir, nosotros, nuestros hijos y nuestros nietos. Para entrar de manera concreta en estas causas y remedios, nuestra lectura de FE nos lleva a considerar la importancia suprema del concepto de sagrado que, para expresarlo en términos puramente positivos y naturales, calificamos de valor ético fundamental que orienta el comportamiento de las personas y de los grupos sociales. El artículo termina sometiendo a consideración los elementos de un cambio social alternativo que, siguiendo las posiciones de Durkheim, incluya a la vez, estos valores éticos fundamentales y las condiciones organizativas, económicas y sociales.This paper presents a heuristic reading of The Elementary Forms of the Religious Life. It includes two parts. The first one deals with theoretical and methodological prolegomena and the second, with a practical application. The prolegomena specify previously the notions of reading and of heuristic reading, and later the heuristic value that we attribute to a series of basic durkheimian concepts. The interdependence and integration of these concepts offers a concise idea on the hard core of the sociological theory concerned with sacred and profane throughout The Forms The practical application seems vaster and more ambitious. It refers directly to the exceptional problem of climate change and the constant degradation of natural environment that we are suffering these last decades. After showing broadly the societal determinant causes of climate change, we go into the critical question of the remedies that are necessary to survive, ourselves, our children and our grand children. To study concretely these causes and these remedies, our reading of The Forms leads to consider the major importance of the crucial term of sacred. A term which, in order to employ a positive and neutral vocabulary, will be called as the founding ethical value that guides the behaviour of people and of social groups. This paper ends with an appeal to a kind of social alternative change that, following Durkheim’s insights, includes simultaneously the recognition of these fundamental ethical values and a particular attention to the social and economic conditions that shape the modern lif

    Acerca de la masonería operativa y la gliptografía medieval. Algunos apuntes sobre los primeros estudios

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    Se tratan los primeros estudios sobre Gliptografía en relación a la Masonería y al desarrollo de la Arqueología, la construcción medieval y la definición de los nuevos estilos, románico y gótico. Asimismo se valoran dichas primeras investigaciones como base de la Gliptografía contemporánea, ciencia auxiliar de la Historia del Arte.This article analyses the first studies about Glyptography in relation to Masonry and the development of Archaeology, the mediaeval construction and the definition of the new styles: romanesque and ghotic art. Also these first studies are taken into account as a basis for contemporary Glyptography which is the auxiliary discipline of Art History

    Endorsement, reasons and intentional action

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    Improving scope sensitivity in contingent valuation: joint and separate evaluation of health states

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    We present data of a contingent valuation survey, testing the effect of evaluation mode on the monetary valuation of preventing road accidents. Half of the interviewees was asked to state their willingness to pay (WTP) to reduce the risk of having only 1 type of injury (separate evaluation, SE), and the other half of the sample was asked to state their WTP for 4 types of injuries evaluated simultaneously (joint evaluation, JE). In the SE group, we observed lack of sensitivity to scope while in the JE group WTP increased with the severity of the injury prevented. However, WTP values in this group were subject to context effects. Our results suggest that the traditional explanation of the disparity between SE and JE, namely, the so-called “evaluability,” does not apply here. The paper presents new explanations based on the role of preference imprecision

    Meson-Baryon Effective Chiral Lagrangian at O(q3)O(q^3) Revisited

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    After our work [1] was published, Frink and Meissner [2] pointed out that the O(q^3) three-flavour meson-baryon chiral Lagrangian presented there was not minimal. Here, we critically review their paper and revise ours. Remarkably, we find that the effective meson-baryon chiral Lagrangian at O(q^3) contains 76 monomials, i.e. eight less than in [1] and two less than in [2]

    Generalized PCM coding of Images

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    Pulse-code modulation (PCM) with embedded quantization allows the rate of the PCM bitstream to be reduced by simply removing a fixed number of least significant bits from each codeword. Although this source coding technique is extremely simple, it has poor coding efficiency. In this paper, we present a generalized PCM (GPCM) algorithm for images that simply removes bits from each codeword. In contrast to PCM, however, the number and the specific bits that a GPCM encoder removes in each codeword depends on its position in the bitstream and the statistics of the image. Since GPCM allows the encoding to be performed with different degrees of computational complexity, it can adapt to the computational resources that are available in each application. Experimental results show that GPCM outperforms PCM with a gain that depends on the rate, the computational complexity of the encoding, and the degree of inter-pixel correlation of the image.This work was supported by the Spanish Government CYCIT under Grant TEC2009-09146. The work of M. Morbee was supported by the Special Research Fund of Ghent University. The associate editor coordinating the review of this manuscript and approving it for publication was Prof. Zhou Wang.Prades Nebot, J.; Morbee, M.; Delp, E. (2012). Generalized PCM coding of Images. IEEE Transactions on Image Processing. 21(8):3801-3806. doi:10.1109/TIP.2012.2197015S3801380621

    Modelling Noise and Imprecision in Individual Decisions

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    When individuals take part in decision experiments, their answers are typically subject to some degree of noise / error / imprecision. There are different ways of modelling this stochastic element in the data, and the interpretation of the data can be altered radically, depending on the assumptions made about the stochastic specification. This paper presents the results of an experiment which gathered data of a kind that has until now been in short supply. These data strongly suggest that the 'usual' (Fechnerian) assumptions about errors are inappropriate for individual decision experiments. Moreover, they provide striking evidence that core preferences display systematic departures from transitivity which cannot be attributed to any 'error' story.Error Imprecision Preferences Transitivity
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