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Trajectory indexing using movement constraints / C.S. Jensen in Geoinformatica, vol 9 n° 2 (June - August 2005)  

Public [article]  inGeoinformatica > vol 9 n° 2 (June - August 2005) . - pp 93 - 115 Titre : Trajectory indexing using movement constraints Type de document : Article/Communication Auteurs : C.S. Jensen, Auteur Année de publication : 2005 Article en page(s) : pp 93 - 115 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique [Termes IGN] base de données d'objets mobiles [Termes IGN] base de données spatiotemporelles [Termes IGN] dimension fractale [Termes IGN] données spatiotemporelles [Termes IGN] indexation spatiale [Termes IGN] objet mobile [Termes IGN] reconstruction d'itinéraire ou de trajectoire [Termes IGN] réduction géométrique [Termes IGN] réseau de transport [Termes IGN] réseau routier [Termes IGN] système de gestion de base de données Résumé : (Auteur) With the proliferation of mobile computing, the ability to index efficiently the movements of mobile objects becomes important. Objects are typically seen as moving in two-dimensional (x, y) space, which means that their movements across time may be embedded in the three-dimensional (x, y, t) space. Further, the movements are typically represented as trajectories, sequences of connected line segments. In certain cases, movement is restricted; specifically, in this paper, we aim at exploiting that movements occur in transportation networks to reduce the dimensionality of the data. Briefly, the idea is to reduce movements to occur in one spatial dimension. As a consequence, the movement occurs in two-dimensional (x, t) space. The advantages of considering such lower-dimensional trajectories are that the overall size of the data is reduced and that lower-dimensional data is to be indexed. Since off-the-shelf database management systems typically do not offer higher-dimensional indexing, this reduction in dimensionality allows us to use existing DBMSes to store and index trajectories. Moreover, we argue that, given the right circumstances, indexing these dimensionality-reduced trajectories can be more efficient than using a three-dimensional index. A decisive factor here is the fractal dimension of the network-the lower, the more efficient is the proposed approach. This hypothesis is verified by an experimental study that incorporates trajectories stemming from real and synthetic road networks. Numéro de notice : A2005-222 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-005-6429-9 En ligne : https://doi.org/10.1007/s10707-005-6429-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27359 [article]

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In-route nearest neighbor queries / J.S. Yoo in Geoinformatica, vol 9 n° 2 (June - August 2005)  

Public [article]  inGeoinformatica > vol 9 n° 2 (June - August 2005) . - pp 117 - 137 Titre : In-route nearest neighbor queries Type de document : Article/Communication Auteurs : J.S. Yoo, Auteur ; Shashi Shekhar, Auteur Année de publication : 2005 Article en page(s) : pp 117 - 137 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] analyse comparative [Termes IGN] base de données routières [Termes IGN] classification barycentrique [Termes IGN] coût [Termes IGN] plus proche voisin, algorithme du [Termes IGN] requête spatiale [Termes IGN] système d'information géographique Résumé : (Auteur) Nearest neighbor query is one of the most important operations in spatial databases and their application domains, such as location-based services and advanced traveler information systems. This paper addresses the problem of finding the in-route nearest neighbor (IRNN) for a query object tuple which consists of a given route with a destination and a current location on it. The IRNN is a facility instance via which the detour from the original route on the way to the destination is smallest. This paper addresses four alternative solution methods Comparisons among them are presented using an experimental framework. Extensive experiments using real road map datasets are conducted to examine the behaviors of the solutions in terms of five parameters affecting the performance. The overall experiments show that our strategy to reduce the expensive path-computations to minimize the response time is reasonable. The spatial distance join-based method always shows better performance with fewer path computations compared to the recursive methods. The computation costs for all methods except the precomputed zone-based method increase with increases in the road map size and the query route length but decrease with increases in the facility density. The precomputed zone-based method shows the most efficiency when there are no updates on the road map. Numéro de notice : A2005-223 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-005-6671-1 En ligne : https://doi.org/10.1007/s10707-005-6671-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27360 [article]

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057-05021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

How to get 3D for the price of 2D: topology and consistency of 3D urban GIS / G. Groger in Geoinformatica, vol 9 n° 2 (June - August 2005)  

Public [article]  inGeoinformatica > vol 9 n° 2 (June - August 2005) . - pp 139 - 158 Titre : How to get 3D for the price of 2D: topology and consistency of 3D urban GIS Type de document : Article/Communication Auteurs : G. Groger, Auteur ; L. Plumer, Auteur Année de publication : 2005 Article en page(s) : pp 139 - 158 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique [Termes IGN] cohérence des données [Termes IGN] intégrité des données [Termes IGN] milieu urbain [Termes IGN] modèle topologique de données [Termes IGN] modélisation 2D [Termes IGN] modélisation 3D [Termes IGN] objet géographique 3D Résumé : (Auteur) This article deals with topological concepts and models which are necessary to represent three-dimensional urban objects in a geographical information system (GIS). Depending on the shape and the representation of features, several classes with increasing topological complexity are identified and described. This complexity has strong impacts on the models and tools which are required to represent, manage and edit the data. One specific model we call '2.8-D map' is identified, which covers many 3-D applications in GIS. It is a slight extension of a 2-D or 2.5-D model and preserves the algorithmic and conceptual simplicity of the 2-D case as much as possible. The model is described in a formal way. Integrity axioms are given, which detect errors in corresponding data sets safely and guarantee the consistency of 2.8-D maps in a mathematically sound and provable way. These axioms are effectively and efficiently checkable by automatic procedures. The model extends digital terrain models (2.5-D) by allowing for vertical walls and projections like balconies or ledges. The conceptual simplicity is due to the two-dimensional topology of the model. Thus bridges and tunnels are special cases; it is shown how to detect and handle these cases efficiently. Based on this model, thematic objects and their aggregation structures are defined in a consistent way. Numéro de notice : A2005-224 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-005-6431-2 En ligne : https://doi.org/10.1007/s10707-005-6431-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27361 [article]

Exemplaires(1)

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057-05021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Visualizing demographic trajectories with self-organizing maps / A. Skupin in Geoinformatica, vol 9 n° 2 (June - August 2005)  

Public [article]  inGeoinformatica > vol 9 n° 2 (June - August 2005) . - pp 159 - 179 Titre : Visualizing demographic trajectories with self-organizing maps Type de document : Article/Communication Auteurs : A. Skupin, Auteur ; R. Hagelman, Auteur Année de publication : 2005 Article en page(s) : pp 159 - 179 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse diachronique [Termes IGN] analyse spatiale [Termes IGN] carte de Kohonen [Termes IGN] données démographiques [Termes IGN] données multidimensionnelles [Termes IGN] données socio-économiques [Termes IGN] graphe [Termes IGN] noeud [Termes IGN] représentation spatiale [Termes IGN] réseau neuronal artificiel [Termes IGN] système d'information géographique [Termes IGN] trajectoire (véhicule non spatial) [Termes IGN] visualisation de données [Vedettes matières IGN] Géovisualisation Résumé : (Auteur) In recent years, the proliferation of multi-temporal census data products and the increased capabilities of geospatial analysis and visualization techniques have encouraged longitudinal analyses of socioeconomic census data. Traditional cartographic methods for illustrating socioeconomic change tend to rely either on comparison of multiple temporal snapshots or on explicit representation of the magnitude of change occurring between different time periods. This paper proposes to add another perspective to the visualization of temporal change, by linking multi-temporal observations to a geometric configuration that is not based on geographic space, but on a spatialized representation of n-dimensional attribute space. The presented methodology aims at providing a cognitively plausible representation of changes occurring inside census areas by representing their attribute space trajectories as line features traversing a two-dimensional display space. First, the self-organizing map (SOM) method is used to transform n-dimensional data such that the resulting two-dimensional configuration can be represented with standard GIS data structures. Then, individual census observations are mapped onto the neural network and linked as temporal vertices to represent attribute space trajectories as directed graphs. This method is demonstrated for a data set containing 254 counties and 32 demographic variables. Various transformations and visual results are presented and discussed in the paper, from the visualization of individual component planes and trajectory clusters to the mapping of different attributes onto temporal trajectories. Numéro de notice : A2005-225 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-005-6670-2 En ligne : https://doi.org/10.1007/s10707-005-6670-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27362 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
057-05021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Construction of the planar partition postal code map based on cadastral registration / F. Penninga in Geoinformatica, vol 9 n° 2 (June - August 2005)  

Public [article]  inGeoinformatica > vol 9 n° 2 (June - August 2005) . - pp 181 - 204 Titre : Construction of the planar partition postal code map based on cadastral registration Type de document : Article/Communication Auteurs : F. Penninga, Auteur ; E. Verbee, Auteur ; et al., Auteur Année de publication : 2005 Article en page(s) : pp 181 - 204 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique [Termes IGN] cadastre étranger [Termes IGN] cadastre numérique [Termes IGN] code postal [Termes IGN] diagramme de Voronoï [Termes IGN] géocodage par adresse postale [Termes IGN] Pays-Bas [Termes IGN] squelettisation [Termes IGN] World Geodetic System 1984 Résumé : (Auteur) Accurate postal code maps have many applications within GIS as the postal code has the potential to link the address description of buildings to their location in a specified global reference system in a more natural way. This relationship is possible in both directions: geocoding and reverse-geocoding. These operators demand a mechanism for translating an exact geometric position (i.e., WGS84 coordinate) into a location indication (town, street, house number) and vice versa. As most built-up parcels are provided with a postal code, this indicator can be used as the linkage. This paper describes the procedure, based on the Dutch cadastral registration, to obtain a reliable 6-position (i.e., 262813X, the highest level of detail possible) planar postal code map for the Netherlands. Problems with existing, Voronoi-diagram based, postal code maps, like intersected houses and arbitrary derived (and thus unrecognizable) boundaries are avoided. The reliability of the derived planar postal code map is discussed and results are illustrated by figures. For a planar coverage, non built-up parcels having no postal code should be assigned a plausible postal code. Furthermore special attention is given to infrastructural parcels. These parcels are divided at their (approximated) skeletons first and then these subdivided infrastructure parcels are piecewise attached to their neighbour parcels. This new approach results in very reliable postal code maps, which are visually attractive too as infrastructure lines can be recognized. The procedure is generic and can be applied to other administrative parcel information as well. The algorithm is implemented using the Computational Geometry Algorithms Library (CGAL), and the possibilities and limitations of this library are addressed as well. Also a number of non-implemented alternatives or improvements are given. Numéro de notice : A2005-226 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-005-6430-3 En ligne : https://doi.org/10.1007/s10707-005-6430-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27363 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
057-05021	RAB	Revue	Centre de documentation	En réserve L003	Disponible