997 research outputs found

    USE PROSPECTS AND PROBLEMS OF OLD CARTOGRAPHY IN DIGITAL FORMAT

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    La produzione, la documentazione e la pubblicazione di prodotti cartografici ha subito cambiamenti sostanziali. Tali cambiamenti coinvolgono in primo luogo la cartografia creata ex novo, ma impongono l’adozione di particolari procedure anche in fase di acquisizione, documentazione e pubblicazione sul web di cartografia del passato. In particolare la possibilità di acquisire cartografie in formato raster o vettoriale in un GIS consentendone una gestione integrata con altri strati informativi, l’uso di strumenti di analisi spaziale, di rendering e di esposizione sul web rappresenta una grande opportunità e, insieme, una sfida come dimostrano i contributi alla sezione dedicata alla cartografia storica che trattano le problematiche relative all’uso della cartografia storica (Leonardo Rombai); l’accessibilità delle risorse cartografiche in rete (Lamberto Laureti); la progettazione di un geodatabase per la gestione di cartografia non omogenea (Andrea Favretto); la valutazione delle distorsioni geometriche della cartografia storica attraverso l’analisi di alcune cartografie realizzate tra il 1500 ed il 1700 relative al Golfo di Trieste; l’utilizzo di software libero e Open Source (Quantum GIS e gvSIG) per analizzare l’espansione urbana della città di Curtea de Arges (România) attraverso carte topografiche del Novecento (G. Osaci-Costache).Production, documentation and publication of cartographic products has fundamentally changed. These changes involve first of all the newly created maps, but require the adoption of special procedures in the acquisition phase, documentation and web publishing mapping of the past. In particular, the possibility of acquiring maps in raster or vector GIS enabling integrated management with other layers, the use of tools of spatial analysis, rendering and display on the web is a great opportunity and together, a challenge

    Variational theory of confinement effects on cholesteric liquid crystals

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    This thesis is devoted to a theoretical description of the effects of confinement in cholesteric liquid crystals. The project is inspired by recent experimental works on cholesteric droplets based on amyloid fibrils. Particularly, four phase transitions were observed in droplets surrounded by isotropic fluid, at growing volumes. The complete phenomenology has to date not yet been described or predicted from a theoretical perspective. Simple scaling arguments based on bulk terms of the Frank-Oseen (FO) energy-density functional have been found only for the first three phases, so that a more thorough analysis is needed. In this thesis, we will address the issue by means of a variational approach, with particular focus on understanding how confinement affects the various terms of the FO functional, for both bulk and surface terms. This will serve to rationalize the experimental findings observed on amyloid-based systems, as well as provide a basis for more refined theoretical approaches. In this thesis we propose two models to explain the whole phenomenology presented by the system, and introduce scaling laws for the three phase transitions.ope

    A dialogic and democratic journey throughout editing a (very) special journal issue

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    This introductory article to the special issue “Dialogic pedagogy and democratic education” aims to reflect upon the process of putting this special issue together and to pinpoint some of the most relevant aspects of the articles collected within the issue. Therefore, reverberating one of the editors’ perspectives, not only is this paper meant to introduce the DPJ readers to the texts compiled in the volume, as well as it is dedicated to giving you, dear reader, a glimpse of the journey taken by the editors and authors. It also tries and situates the issue in its social and historic chronotope to justify the ever-so-present appeal to reinforce, advocate and share theoretical discussions as well as practical accounts which focus on dialogic and democratic educational efforts – both distant and more recent events – that took place in different contexts, and different parts in the world. It's claimed that the several accounts and discussions highlighted in the papers in this special issue provide DPJ readers with both hints and strong, factual proposals which might foster new ideas and further actions by those who want to consider dialogic/democratic education either as an end or/and as an act of/for social transformation

    Tile2Vec: Unsupervised representation learning for spatially distributed data

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    Geospatial analysis lacks methods like the word vector representations and pre-trained networks that significantly boost performance across a wide range of natural language and computer vision tasks. To fill this gap, we introduce Tile2Vec, an unsupervised representation learning algorithm that extends the distributional hypothesis from natural language -- words appearing in similar contexts tend to have similar meanings -- to spatially distributed data. We demonstrate empirically that Tile2Vec learns semantically meaningful representations on three datasets. Our learned representations significantly improve performance in downstream classification tasks and, similar to word vectors, visual analogies can be obtained via simple arithmetic in the latent space.Comment: 8 pages, 4 figures in main text; 9 pages, 11 figures in appendi

    1 Indirect estimation of signal-dependent noise with non-adaptive heterogeneous samples

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    Abstract—We consider the estimation of signal-dependent noise from a single image. Unlike conventional algorithms that build a scatterplot of local mean-variance pairs from either small or adaptively selected homogeneous data samples, our proposed approach relies on arbitrarily large patches of heterogeneous data extracted at random from the image. We demonstrate the feasibility of our approach through an extensive theoretical analysis based on mixture of Gaussian distributions. A prototype algorithm is also developed in order to validate the approach on simulated data as well as on real camera raw images. Index Terms—Noise estimation, signal-dependent noise, Poisson noise

    GIS in Geography Teaching

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    If it is true that every period of our history is marked by important revolutions which shaped its spirit and nature, today we can claim to live in what has been aptly defined, by a Pennsylvania State University project, as a “Geospatial Revolution”. Understanding the world in which we live, how it has changed and how the ways in which humans interact with it have changed, how people try to know, interpret and represent it, all provide crucial aspects for the planning of curricula, training courses and in the production of appropriate contents for them. GIS represents an effective tool for teaching the understanding of space and place. GIS finds application in various fields from natural science and geology to sociology and anthropology, from political sciences, economics and urban studies to archaeology and history. The use of this tool enables the introduction of research methods in geography teaching, leading, for example, to the acquisition of the ability to create a conceptual model of reality that can be studied as well as to select the most useful data for this purpose, to interpret it independently, and to represent it effectively
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