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Mobile precise trigonometric levelling system based on land vehicle: an alternative method for precise levelling / J. Zou in Survey review, vol 49 n° 355 (October 2017)  

Public [article]  inSurvey review > vol 49 n° 355 (October 2017) . - pp 249 - 258 Titre : Mobile precise trigonometric levelling system based on land vehicle: an alternative method for precise levelling Type de document : Article/Communication Auteurs : J. Zou, Auteur ; Y. Zhu, Auteur ; Y. Xu, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 249 - 258 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Nivellement [Termes IGN] Chine [Termes IGN] déviation de la verticale [Termes IGN] nivellement direct [Termes IGN] nivellement géométrique motorisé [Termes IGN] nivellement indirect [Termes IGN] réfraction atmosphérique [Termes IGN] tachéomètre électronique robotisé Résumé : (Auteur) The strict mathematical model of the mobile precise trigonometric levelling (MPTL) is deduced and its error sources are analysed in this paper. Some position sensors are added to instruments and observing reciprocal at the same time using two modified measuring robots so as to reduce the influence of atmospheric refraction, curvature of the earth and other factors. It is not necessary to measure the heights of instruments and targets by constructing the even numbers of observed edges to avoid errors of measuring heights. Experimental results indicate that MPTL has greatly increased the working efficiency and reduced the labour intensity compared with precise geometric levelling in the hills and mountains. A large number of experiments have proved that the standard deflection of measurement is less than and with an average speed of more than 7 kilometres per day in mountainous terrain. Numéro de notice : A2017-548 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/00396265.2016.1163877 En ligne : https://doi.org/10.1080/00396265.2016.1163877 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86604 [article]

Extensions of GAP-tree and its implementation based on a non-topological data model / C. Cheng in International journal of geographical information science IJGIS, vol 22 n° 6-7 (june 2008)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 22 n° 6-7 (june 2008) . - pp 657 - 673 Titre : Extensions of GAP-tree and its implementation based on a non-topological data model Type de document : Article/Communication Auteurs : C. Cheng, Auteur ; F. Niu, Auteur ; J. Cai, Auteur ; Y. Zhu, Auteur Année de publication : 2008 Article en page(s) : pp 657 - 673 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] arbre-B [Termes IGN] arbre-R [Termes IGN] données vectorielles [Termes IGN] généralisation automatique de données [Termes IGN] implémentation (informatique) [Termes IGN] index spatial [Termes IGN] modèle sémantique de données [Termes IGN] occupation du sol [Termes IGN] Pékin (Chine) [Termes IGN] PostgreSQL Résumé : (Auteur) This paper discusses extensions of GAP-trees from three aspects and its implementation based on non-topological structure in order to enhance access to large vector data sets. First of all, we apply cartographic generalization rules to build a generalization procedure of the GAP-tree, which makes coarse representations more consistent with human cognition. Second, we replace the three-dimensional (pseudo-) Reactive-tree index with a 2D R-tree index and a B-tree index to improve the system efficiency. Finally, we compress a binary GAP-tree into multi-way GAP-trees in order to reduce data redundancy. The shallower multi-way GAP-trees not only eliminate redundant data but also accelerate the system's response time. The extensions have been successfully implemented in PostgreSQL. A test of Beijing's land-use data at the 1:10 000 scale demonstrates that the extended GAP-trees are efficient, compact, and easy to implement. Copyright Taylor & Francis Numéro de notice : A2008-226 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1080/13658810701602120 En ligne : https://doi.org/10.1080/13658810701602120 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29221 [article]

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Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-08041	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-08042	RAB	Revue	Centre de documentation	En réserve L003	Disponible