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Cartographic symbol design considerations for the space–time cube / Christopher League in Cartographic journal (the), Vol 56 n° 2 (May 2019)  

Public [article]  inCartographic journal (the) > Vol 56 n° 2 (May 2019) . - pp 117 - 133 Titre : Cartographic symbol design considerations for the space–time cube Type de document : Article/Communication Auteurs : Christopher League, Auteur ; Patrick Kennelly, Auteur Année de publication : 2019 Article en page(s) : pp 117 - 133 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] conception cartographique [Termes descripteurs IGN] cube espace-temps [Termes descripteurs IGN] données localisées 2D [Termes descripteurs IGN] données spatiotemporelles [Termes descripteurs IGN] figuré ponctuel [Termes descripteurs IGN] saturation de la couleur [Termes descripteurs IGN] sémiologie graphique [Termes descripteurs IGN] symbole graphique 3D [Vedettes matières IGN] Géovisualisation Résumé : (Auteur) The cartographic representation of geographic phenomena in the space–time cube comes with special challenges and opportunities when compared with two-dimensional maps. While the added dimension allows the display of attributes that vary with time, it is difficult to display rapidly varying temporal data given the limited display height. In this study, we adapt 2D cyclic point symbols to construct 3D surfaces designed along a helical path for the space–time cube. We demonstrate how these complex 3D helical surfaces can display detailed data, including data reported daily over 100 years and data reported in four-hour intervals over a year. To create the point symbols, each value is plotted along the curve of a helix, with each turn of the helix representing one year or week, respectively. The model is modified by varying the radii from the time axis to all points using the attribute value, in these cases maximum daily temperature and four-hourly ridership, and then creating a triangulated surface from the resulting points. Using techniques common to terrain representation, we apply hue and saturation to the surface based on attribute values, and lightness based on relief shading. Multiple surfaces can be displayed in a space–time cube with a consistent time interval facing the viewer, and the surfaces or viewer perspective can be rotated to display synchronized variations. We see this method as one example of how cartographic design can refine or enhance operations in the space–time cube. Numéro de notice : A2019-239 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00087041.2018.1533291 date de publication en ligne : 29/05/2019 En ligne : https://doi.org/10.1080/00087041.2018.1533291 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92931 [article]

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Cartographic design and the space–time cube / Irma Kveladze in Cartographic journal (the), Vol 56 n° 1 (February 2019)  

Public [article]  inCartographic journal (the) > Vol 56 n° 1 (February 2019) . - pp 73 - 90 Titre : Cartographic design and the space–time cube Type de document : Article/Communication Auteurs : Irma Kveladze, Auteur ; Menno-Jan Kraak, Auteur ; Corné P.J.M. Van Elzakker, Auteur Année de publication : 2019 Article en page(s) : pp 73 - 90 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] convivialité [Termes descripteurs IGN] couleur (rédaction cartographique) [Termes descripteurs IGN] cube espace-temps [Termes descripteurs IGN] estompage en fonction de l'éloignement [Termes descripteurs IGN] information complexe [Termes descripteurs IGN] oculométrie [Termes descripteurs IGN] taille (variable visuelle) [Termes descripteurs IGN] variable visuelle [Vedettes matières IGN] Géovisualisation Résumé : (Auteur) This paper reports on the results of an empirical evaluation that aimed to define the effectiveness and efficiency of different visual variables in depicting the Space–Time Cube’s (STC) content. Existing STC applications demonstrate that the most used visual variables are size and colour hue. Less is known, however, about their usability metrics. The research sets design criteria for STC contents, such as space–time paths, based on the cartographic design theory. The visual variables colour hue, colour value, colour saturation, size and orientation have been applied in two different use case studies. Besides, to support the three-dimensional visual environment, depth cues such as shading and transparency were considered too. User tests have been executed based on real-world problems with particular attention for the visualization strategy and data complexity. The outcomes revealed the most efficient and effective visual variables to represent data of various complexities in the STC. Numéro de notice : A2019-449 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00087041.2018.1495898 date de publication en ligne : 13/12/2018 En ligne : https://doi.org/10.1080/00087041.2018.1495898 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92796 [article]

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Feasibility of the space-time cube in temporal cultural landscape visualization / Edyta P. Bogucka in ISPRS International journal of geo-information, vol 7 n° 6 (June 2018)  

Public [article]  inISPRS International journal of geo-information > vol 7 n° 6 (June 2018) Titre : Feasibility of the space-time cube in temporal cultural landscape visualization Type de document : Article/Communication Auteurs : Edyta P. Bogucka, Auteur ; Mathias Jahnke, Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] cube espace-temps [Termes descripteurs IGN] données spatiotemporelles [Termes descripteurs IGN] oculométrie [Termes descripteurs IGN] patrimoine culturel [Termes descripteurs IGN] site historique [Termes descripteurs IGN] système d'information géographique [Termes descripteurs IGN] Varsovie (Pologne) [Termes descripteurs IGN] visualisation de données [Vedettes matières IGN] Géovisualisation Résumé : (Auteur) Change acts as an inherent characteristic of the landscape, and expresses dynamic interactions between its tangible and intangible elements. While the documentation and analysis of spatiotemporal patterns have been broadly discussed, major challenges concern the design of task-oriented, user-friendly landscape visualizations. Geographic information system (GIS) techniques and approaches from visual analytics may bring solutions to those questions. This paper considers the milestone documents for the representation of cultural heritage, and proposes a workflow for assessing the feasibility of the space–time cube concept in landscape representation. The usability of the visualization was examined during the interview with domain experts and potential interdisciplinary users. The evaluation session covered benchmark tasks, feedback, and eye-tracking. The performance of the space–time cube was compared with another spatiotemporal visualization technique and measured in terms of correctness, response time, and satisfaction. The Royal Castle in Warsaw, which was registered in 1980 as a part of Warsaw’s World Heritage Site of United Nations Educational, Scientific and Cultural Organization (UNESCO), served as the case study. The user tests show that the designed space–time cube excels for the completion rate; however, more time is required to provide answers to question tasks focusing on comparisons. Together, the case study and feedback from domain experts and participants demonstrate the benefit of the space–time cube concept in designing landscape visualizations. Numéro de notice : A2018-344 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi7060209 date de publication en ligne : 31/05/2018 En ligne : https://doi.org/10.10.3390/ijgi7060209 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90566 [article]

Vision-based detection of aircrafts and UAVs / Artem Rozantsev (2017)  

Public Titre : Vision-based detection of aircrafts and UAVs Type de document : Thèse/HDR Auteurs : Artem Rozantsev, Auteur ; Pascal Fua, Directeur de thèse ; Vincent Lepetit, Directeur de thèse Editeur : Lausanne : Ecole Polytechnique Fédérale de Lausanne EPFL Année de publication : 2017 Importance : 117 p. Format : 21 x 30 cm Note générale : bibliographie Thèse présentée à l'Ecole Polytechnique Fédérale de Lausanne pour l'obtention du grade de Docteur ès Sciences Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Télédétection [Termes descripteurs IGN] apprentissage automatique [Termes descripteurs IGN] apprentissage profond [Termes descripteurs IGN] classification par réseau neuronal convolutif [Termes descripteurs IGN] cube espace-temps [Termes descripteurs IGN] détection d'objet [Termes descripteurs IGN] drone [Termes descripteurs IGN] image aérienne [Termes descripteurs IGN] objet mobile [Termes descripteurs IGN] régression [Termes descripteurs IGN] vision par ordinateur Résumé : (auteur) Unmanned Aerial Vehicles are becoming increasingly popular for a broad variety of tasks ranging from aerial imagery to objects delivery. With the expansion of the areas, where drones can be efficiently used, the collision risk with other flying objects increases. Avoiding such collisions would be a relatively easy task, if all the aircrafts in the neighboring airspace could communicate with each other and share their location information. However, it is often the case that either location information is unavailable (e.g. flying in GPS-denied environments) or communication is not possible (e.g. different communication channels or non-cooperative flight scenario). To ensure flight safety in this kind of situations drones need a way to autonomously detect other objects that are intruding the neighboring airspace. Visual-based collision avoidance is of particular interest as cameras generally consume less power and are more lightweight than active sensor alternatives such as radars and lasers. We have therefore developed a set of increasingly sophisticated algorithms to provide drones with a visual collision avoidance capability. First, we present a novel method for detecting flying objects such as drones and planes that occupy a small part of the camera field of view, possibly move in front of complex backgrounds, and are filmed by a moving camera. In order to be solved this problem requires combining motion and appearance information, as neither of the two alone is capable of providing reliable enough detections. We therefore propose a machine learning technique that operates on spatiotemporal cubes of image intensities where individual patches are aligned using an object-centric regression-based motion stabilization algorithm. Second, in order to reduce the need to collect a large training dataset and to manual annotate it, we introduce a way to generate realistic synthetic images. Given only a small set of real examples and a coarse 3D model of the object, synthetic data can be generated in arbitrary quantities and further used to supplement real examples for training a detector. The key ingredient of our method is that the synthetically generated images need to be as close as possible to the real ones not in terms of image quality, but according to the features, used by a machine learning algorithm. Third, though the aforementioned approach yields a substantial increase in performance when using Adaboost and DPM detectors, it does not generalize well to Convolutional Neural Networks, which have become the state-of-the-art. This happens because, as we add more and more synthetic data, the CNNs begin to overfit to the synthetic images at the expense of the real ones. We therefore propose a novel deep domain adaptation technique that allows efficiently combining real and synthetic images without overfitting to either of the two. While most of the adaptation techniques aim at learning features that are invariant to the possible difference of the images, coming from different sources (real and synthetic). Unlike those methods, we suggest modeling this difference with a special two-stream architecture. We evaluate our approach on three different datasets and show its effectiveness for various classification and regression tasks. Note de contenu : Introduction 1- Flying Objects Detection 2- Synthetic Data Generation 3- Domain Adaption for Deep Networks 4- Concluding Remarks Numéro de notice : 25870 Thématique : IMAGERIE Nature : Thèse étrangère Note de thèse : Thèse de Doctorat : Sciences : Lausanne : Suisse : 2017 En ligne : https://infoscience.epfl.ch/record/227934?ln=fr Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95538

The space-time cube as part of a GeoVisual analytics environment to support the understanding of movement data / Irma Kveladze in International journal of geographical information science IJGIS, vol 29 n° 11 (November 2015)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 29 n° 11 (November 2015) . - pp 2001 - 2016 Titre : The space-time cube as part of a GeoVisual analytics environment to support the understanding of movement data Type de document : Article/Communication Auteurs : Irma Kveladze, Auteur ; Menno-Jan Kraak, Auteur ; Corné P.J.M. Van Elzakker, Auteur Année de publication : 2015 Article en page(s) : pp 2001 - 2016 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes descripteurs IGN] application informatique [Termes descripteurs IGN] cube espace-temps [Termes descripteurs IGN] mouvement [Termes descripteurs IGN] représentation cartographique Résumé : (Auteur) This paper reports the results of an empirical usability experiment on the performance of the space-time cube in a GeoVisual analytics environment. It was developed to explore movement data based on the requirements of human geographers. The interactive environment consists of multiple coordinated views incorporating three graphical representations. For the experiment, two groups of the user, domain experts and non-domain experts, had to execute several map-use tasks to answers specific question. The data collected during the experiment were analysis resulting in a set of usability metrics related to the effectiveness, efficiency and user satisfaction of developed application. The comparison of both groups showed that domain experts were able to operate the visual analytical environment more effectively and efficiently due to their interest to explore their data. The user feedback derived from the analysis of both experiments was further processed for the improvement of the application. Numéro de notice : A2015-617 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2015.1058386 En ligne : https://doi.org/10.1080/13658816.2015.1058386 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=78086 [article]

Stacked space-time densities: a geovisualisation approach to explore dynamics of space use over time / Urška Demšar in Geoinformatica [en ligne], vol 19 n° 1 (January - March 2015)  

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Exploring eye movement patterns on cartographic animations using projections of a space-time-cube / Alexander Salveson Nossum in Cartographic journal (the), vol 51 n° 3 (August 2014)

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A methodological framework for researching the usability of the space-time cube / Irma Kveladze in Cartographic journal (the), vol 50 n° 3 (August 2013)

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The space-time cube revisited from a geovisualization perspective / Menno-Jan Kraak (2003) 

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