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Generation of crowd arrival and destination locations/times in complex transit facilities / Brian Ricks in The Visual Computer, vol 36 n° 8 (August 2020)
Titre : Generation of crowd arrival and destination locations/times in complex transit facilities Type de document : Article/Communication Auteurs : Brian Ricks, Auteur ; Andraw Dobson, Auteur ; Athanasios Krontiris, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 1651 - 1661 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] calcul d'itinéraire
[Termes IGN] données spatiotemporelles
[Termes IGN] origine - destination
[Termes IGN] piéton
[Termes IGN] simulation dynamique
[Termes IGN] spécification
[Termes IGN] transport collectifRésumé : (auteur) In order to simulate virtual agents in the replica of a real facility across a long time span, a crowd simulation engine needs a list of agent arrival and destination locations and times that reflect those seen in the actual facility. Working together with a major metropolitan transportation authority, we propose a specification that can be used to procedurally generate this information. This specification is both uniquely compact and expressive—compact enough to mirror the mental model of building managers and expressive enough to handle the wide variety of crowds seen in real urban environments. We also propose a procedural algorithm for generating tens of thousands of high-level agent paths from this specification. This algorithm allows our specification to be used with traditional crowd simulation obstacle avoidance algorithms while still maintaining the realism required for the complex, real-world simulations of a transit facility. Our evaluation with industry professionals shows that our approach is intuitive and provides controls at the right level of detail to be used in large facilities (200,000+ people/day). Numéro de notice : A2020-416 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s00371-019-01761-z date de publication en ligne : 14/10/2019 En ligne : https://doi.org/10.1007/s00371-019-01761-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95510
in The Visual Computer > vol 36 n° 8 (August 2020) . - pp 1651 - 1661[article]
Titre : Retrieving relevant land cover and land use data to study urban climate change Type de document : Article/Communication Auteurs : Bénédicte Bucher Editeur : Leibniz : Leibniz Institute of Ecological Urban and Regional Development Année de publication : 2019 Projets : URCLIM / Masson, Valéry Conférence : ILUS 2019 International land use symposium 04/12/2019 06/12/2019 Paris France programme sans actes Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web
[Termes IGN] changement climatique
[Termes IGN] climat urbain
[Termes IGN] image Landsat
[Termes IGN] métadonnées géographiques
[Termes IGN] occupation du sol
[Termes IGN] pertinence
[Termes IGN] plateforme collaborative
[Termes IGN] recherche d'information géographique
[Termes IGN] spécification
[Termes IGN] spécification de processus
[Termes IGN] utilisation du solRésumé : (auteur) The study of urban local phenomena related to climate, like heat islands, road icing, streets overflow during high precipitation events or air pollution, is necessary to develop efficient adaptation strategies to climate change. The URCLIM project studies more specifically urban climate knowledge production and services design. It is funded by the "European Research Area for Climate Services" that targets "the user-driven development, translation and transfer of climate knowledge to researchers and decision—makers in policy and business [..] as well as guidance in the use of climate knowledge." Climate scientists model interactions between meteorological phenomena (wind, moisture, temperature) described at a given scale and the surface of earth described at a finer scale in order to calculate finer meteorological phenomena, e.g. temperature variations depending on trees in cities. The climate community designs such generic canopy models adapted for a set of similar places. To obtain land data required to feed these canopy models, instead of each team producing ad hoc land data on his experimental site, this community has developed a joint approach: 1) agree on common formal specifications of such land models, also known as Local climate Zones, 2) design a production procedure of such Local climate zones data affordable by the community itself. The World Urban Database and Access Portal Tools, WUDAPT support collaborative production of Local climate Zones level 0 (resolution from 500m to 1km) based on Landsat satellite imagery. Producing Local climate Zones level 1 (50 to 100 meters), requires other sources related to buildings and vegetation (Masson et al. 2019). This requires discovering and reusing heterogeneous spatial data whereas there is neither one search engine nor a set of well identified catalogues that can be searched with user-oriented query words. This presentation will concentrate firstly on analyzing what are the relevance criteria from the urban climate scientist perspective to retrieve an existing urban land model or to produce it. We consider for example an accessibility criterion as well as an extrapolation criterion. Second we review the contribution of available metadata and ontologies to make proper recommendations to this scientist who wishes to design an urban land model for his specific study. Important metadata are: features catalogues, spatial and temporal coverage, temporal, geometric and semantic resolutions and accuracies. Last we demonstrate a metadata curation process based on the URCLIM infolab, a collaborative metadata platform (Bucher and Van Damme 2018). Numéro de notice : C2019-066 Affiliation des auteurs : LaSTIG COGIT (2012-2019) Thématique : GEOMATIQUE Nature : Communication nature-HAL : ComSansActesPubliés-Unpublished DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97021
Titre : Grouping rules for effective legend design Type de document : Article/Communication Auteurs : Zhe Qin, Auteur ; Zhilin Li, Auteur Année de publication : 2017 Article en page(s) : pp 36 - 47 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Rédaction cartographique
[Termes IGN] conception cartographique
[Termes IGN] légende cartographique
[Termes IGN] spécification de contenu
[Termes IGN] symbole graphiqueRésumé : (auteur) The legend is an important map component. Legend design is one aspect of map design, which forms an important topic in cartography. From the literature, it is found that only one study was dedicated to the building of cartographic rules for effective legend design, and no systematic investigations into the building of grouping rules for proper determination of the grouping of legend features (symbols + text descriptions) had been carried out. This study is therefore devoted to the building of grouping rules based on Gestalt laws. An experimental evaluation of these developed rules was designed and conducted. The results indicate that a legend designed by considering these new rules is significantly more efficient than the others violating these rules. Numéro de notice : A2017-130 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern En ligne : http://dx.doi.org/10.1080/00087041.2016.1148105 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84550
in Cartographic journal (the) > Vol 54 n° 1 (February 2017) . - pp 36 - 47[article]Réservation
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Titre : Level of detail in 3D city models Type de document : Thèse/HDR Auteurs : Filip Biljecki, Auteur ; Jantien E. Stoter, Auteur ; Hugo Ledoux, Auteur Editeur : Delft [Pays-Bas] : Delft University of Technology Année de publication : 2017 Note générale : bibliographie
Doctoral dissertation, Delft university of technologyLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes IGN] analyse de sensibilité
[Termes IGN] bâtiment
[Termes IGN] CityGML
[Termes IGN] erreur en position
[Termes IGN] modèle 3D de l'espace urbain
[Termes IGN] niveau de détail
[Termes IGN] propagation d'erreur
[Termes IGN] SIG 3D
[Termes IGN] spécificationRésumé : (auteur) The concept of level of detail (LOD) describes the content of 3D city models and it plays an essential role during their life cycle. On one hand it comes akin to the concepts of scale in cartography and LOD in computer graphics, on the other hand it is a standalone concept that requires attention. LOD has an influence on tendering and acquisition, and it has a hand in storage, maintenance, and application aspects. However, it has not been significantly researched, and this PhD thesis fills this void. This thesis reviews dozens of current LOD standards, revealing that most practitioners consider the LOD to be comprised solely of the geometric detail of data and there are disparate views on the concept as a whole. However, the research suggests that the LOD encompasses additional metrics, such as semantics and texture. The thesis formalises the concept, enabling integration and comparison of current LOD standards. The established framework may be applied to cartography and to different forms of 3D geoinformation such as point clouds. Following the formalised concept, a new LOD specification is presented improving the LOD concept in the current OGC CityGML 2.0 standard, a prominent norm in the 3D GIS industry. The specification introduces 16 LODs for buildings that are shaped after analysing the capabilities of acquisition techniques and a large number of real-world datasets. The improved LOD specification may be integrated in product portfolios and tenders, preventing misunderstandings between stakeholders, and as a better language for communicating the specifics of a dataset to be acquired. The specification also considers different approaches to realise the data. Such geometric references result in dozens of different variants of the same LOD.3D data according to the LOD specification was generated using a procedural modelling engine that was developed over the course of the research. The engine is capable of producing 3D city models in a large number of different variants and according to the CityGML standard. The thesis also catalogues the many different ways to create 3D city models. A prominent technique for producing data in a different LOD is generalisation, i.e. simplifying a 3D city model. The inverse---augmenting the LOD of a dataset---has not been researched to a great extent, and this thesis gives an overview of the topic. This research demonstrates that it is possible to generate 3D city models without elevation measurements, inherently augmenting the LOD of coarser data (2D footprints). The method relies on machine learning: several attributes found in 2D datasets may hint at the height of a building, thus enabling extrusion and creating 3D city models suited for several applications.Some acquisition techniques may result in multi-LOD datasets, and nowadays there are some regions represented in different, independent datasets. However, it was found that possibilities to link such data are deficient. The lack of linking mechanisms inhibits acquisition, storage, and maintenance of multi-LOD data. Two methods for linking features across two or more LODs have been developed resulting in an increased consistency of multi-LOD datasets. The first method links matching geometries across multiple LODs, while the second method establishes a 4D data structure in which the LOD is modelled as the fourth (spatial) dimension.It is often believed that the more detailed 3D data the better. However, similarly as in computer graphics, dealing with data at fine LODs comes at a cost: such datasets are harder to obtain, their storage footprint is large, and their usage within a spatial analysis may be slow. Scarce research has been dedicated to investigating whether an increase in the LOD of the data brings a comparably significant increase in benefits when the data is used in a spatial analysis.First, an analysis using real-world multi-LOD data was carried out. Different LODs of spatial data covering the Netherlands was used in a spatial analysis to refine population maps, obtaining different results for each LOD. However, several problems are exposed, revealing that using real data for such investigations is not optimal.The remainder of the research focuses on using procedurally generated data for such experiments. Synthetic data in several different LODs has been generated and employed for four spatial analyses (estimation of the building shadow, envelope area, volume, and solar irradiation). The experiments result in different conclusions. Finer LODs usually bring some improvement to the quality of the spatial analysis, but not always and such may be negligible. The results of the experiments ultimately depend on the spatial analysis that is considered. The varying results between different spatial analyses make each of them unique. Furthermore, the benefit a finer LOD brings to a spatial analysis is not always clear and easily measurable. In short, striving to produce data at finer LODs may please the eye, but this is not always counter-balanced in the benefit it brings to a spatial analysis.A further addition to the equation above is that when realised, 3D city models are unavoidably burdened with acquisition errors. An error propagation analysis was performed by disturbing the procedurally generated datasets with a range of simulated positional errors. Comparisons have been made between the intentionally degraded datasets and their error-free counterparts, thus obtaining the magnitude of uncertainty the positional errors cause in a spatial analysis. Based on these experiments, several findings are discovered, most importantly:1. How the LODs are realised (which geometric references are used) has a larger influence than the LOD. A coarse LOD produced with a favourable geometric reference may yield better results than a finer LOD realised with an unfavourable reference.2. Positional errors considerably affect spatial analyses. The effect is comparable across similar LODs. Simpler LODs are sligthly less affected by positional errors, but they may contain a large systematic error.3. Errors induced in the acquisition process generally cancel out the improvement provided by finer LODs. The main conclusion is that in the considered spatial analyses the positional error has a significantly higher impact than the LOD. As a consequence, it is suggested that it is pointless to acquire geoinformation at a fine LOD if the acquisition method is not accurate, and instead it is advised to focus on the improvement of accuracy of the data. The thesis proposes additional research for future work. For example, since this research focuses specifically on 3D building models, it would be worth extending the research to other urban features such as roads and vegetation. Furthermore, quality control in 3D GIS does not encompass the evaluation of the LOD of data. Hence integration of the LOD in quality standards should be a priority for future work. Note de contenu : 1- Introduction
2- Background
3- Formalisation of LOD
4- Designing an LOD specification for buildings
5- Variants of LODs
6- Realisation of the specification
7- Generating 3D city models without elevation data
8- Managing multi-LOD data
9- Influence of LOD on spatial analyses (I)
10- Influence of LOD on spatial analyses (II)
11- Sensitivity of LOD to positional errors
12- Combining LOD and positional errors
13- Conclusions and future prospectsNuméro de notice : 17541 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Thèse étrangère Note de thèse : Doctoral dissertation : : Delft university of technology : 2017 DOI : 10.4233/uuid:f12931b7-5113-47ef-bfd4-688aae3be248 En ligne : https://repository.tudelft.nl/islandora/object/uuid%3Af12931b7-5113-47ef-bfd4-68 [...] Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91250 
Titre : Towards a protocol for the collection of VGI vector data Type de document : Article/Communication Auteurs : Peter Mooney, Auteur ; Marco Minghini, Auteur ; Mari Laasko, Auteur ; Vyron Antoniou, Auteur ; Ana-Maria Olteanu-Raimond Année de publication : 2016 Projets : Mapping and the citizen sensor / Foody, Giles M. Article en page(s) : pp 1 - 23 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes IGN] données localisées des bénévoles
[Termes IGN] données vectorielles
[Termes IGN] intégration de données
[Termes IGN] lever des détails
[Termes IGN] production participative
[Termes IGN] spécification
[Termes IGN] vectorisationRésumé : (Auteur) A protocol for the collection of vector data in Volunteered Geographic Information (VGI) projects is proposed. VGI is a source of crowdsourced geographic data and information which is comparable, and in some cases better, than equivalent data from National Mapping Agencies (NMAs) and Commercial Surveying Companies (CSC). However, there are many differences in how NMAs and CSC collect, analyse, manage and distribute geographic information to that of VGI projects. NMAs and CSC make use of robust and standardised data collection protocols whilst VGI projects often provide guidelines rather than rigorous data collection specifications. The proposed protocol addresses formalising the collection and creation of vector data in VGI projects in three principal ways: by manual vectorisation; field survey; and reuse of existing data sources. This protocol is intended to be generic rather than being linked to any specific VGI project. We believe that this is the first protocol for VGI vector data collection that has been formally described in the literature. Consequently, this paper shall serve as a starting point for on-going development and refinement of the protocol. Numéro de notice : A2016--120 Affiliation des auteurs : LaSTIG COGIT+Ext (2012-2019) Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi5110217 date de publication en ligne : 17/11/2016 En ligne : http://dx.doi.org/10.3390/ijgi5110217 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84789
in ISPRS International journal of geo-information > vol 5 n° 11 (November 2016) . - pp 1 - 23[article]Documents numériques
en open access
A2016--120_.pdfAdobe Acrobat PDFvol 21 n° 4 - juillet - août 2016 - Diffusion d'alarmes, diffusion d'alertes. De nouveaux enjeux pour les SI (Bulletin de Ingénierie des systèmes d'information, ISI : Revue des sciences et technologies de l'information, RSTI) / Florence Sèdes
PermalinkPermalinkPermalinkPermalinkPermalinkPermalinkSpécifications d’intégration d’une station GNSS permanente dans le RGP, version 2 / Sébastien Saur (2016)
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