In this paper, we propose a novel approach to automatically building Informed Virtual Geographic Environments (IVGE) using data provided by Geographic Information Systems (GIS). The obtained IVGE provides 2D and 3D ge...In this paper, we propose a novel approach to automatically building Informed Virtual Geographic Environments (IVGE) using data provided by Geographic Information Systems (GIS). The obtained IVGE provides 2D and 3D geographic information for visualization and simulation purposes. Conventional VGE approaches are generally built upon a grid-based representation, raising the well-known problems of the lack of accuracy of the localized data and the difficulty to merge data with multiple semantics. On the contrary, our approach uses a topological model and provides an exact representation of GIS data, allowing an accurate geometrical exploitation. Moreover, our model can merge semantic information, even if spatially overlapping. In addition, the proposed IVGE contains spatial information which can be enhanced thanks to a geometric abstraction method. We illustrate this model with an application which automatically extracts the required data from standard GIS files and allows a user to navigate and retrieve information from the computed IVGE.展开更多
Three new triterpenoid saponins, escins IVg (1), IVh (2) and VIb (3) were isolatedfrom the seeds of Aesculus chinensis along with two known saponins, escin IIIa (4) anddesacylescin I (5). Their structures were elucida...Three new triterpenoid saponins, escins IVg (1), IVh (2) and VIb (3) were isolatedfrom the seeds of Aesculus chinensis along with two known saponins, escin IIIa (4) anddesacylescin I (5). Their structures were elucidated by spectroscopic analysis and chemicalhydrolysis.展开更多
We propose a novel method for the automated generation of virtual geographic environments that allows using geographic information system data to build what we call informed virtual geographic environment(IVGE).The de...We propose a novel method for the automated generation of virtual geographic environments that allows using geographic information system data to build what we call informed virtual geographic environment(IVGE).The description of an IVGE integrates semantic information expressed using conceptual graphs,a standard knowledge representation technique.In addition,we propose an abstraction process that uses geometric,topologic,and semantic characteristics of geographic features to build a hierarchical graph-based structure describing this IVGE.Our IVGE model enables the support of large-scale and complex geographic environment modeling for multiagent geo-simulations in which the agents are situated and with which they interact.展开更多
文摘In this paper, we propose a novel approach to automatically building Informed Virtual Geographic Environments (IVGE) using data provided by Geographic Information Systems (GIS). The obtained IVGE provides 2D and 3D geographic information for visualization and simulation purposes. Conventional VGE approaches are generally built upon a grid-based representation, raising the well-known problems of the lack of accuracy of the localized data and the difficulty to merge data with multiple semantics. On the contrary, our approach uses a topological model and provides an exact representation of GIS data, allowing an accurate geometrical exploitation. Moreover, our model can merge semantic information, even if spatially overlapping. In addition, the proposed IVGE contains spatial information which can be enhanced thanks to a geometric abstraction method. We illustrate this model with an application which automatically extracts the required data from standard GIS files and allows a user to navigate and retrieve information from the computed IVGE.
文摘Three new triterpenoid saponins, escins IVg (1), IVh (2) and VIb (3) were isolatedfrom the seeds of Aesculus chinensis along with two known saponins, escin IIIa (4) anddesacylescin I (5). Their structures were elucidated by spectroscopic analysis and chemicalhydrolysis.
基金The author thanks Dr Bernard Moulin,Laval University,Dr Phil Graniero,University of Windsor,and Dr Normand Bergeron,Institute for their advice during this research.Supported by the Canadian Network of Centers of Excellence in Geomatics(GEOIDE)the Natural Sciences and Engineering Research Council(NSERC)of Canadaand the Fonds Québécois de la Recherche sur la Nature et les Technologies(FQRNT).
文摘We propose a novel method for the automated generation of virtual geographic environments that allows using geographic information system data to build what we call informed virtual geographic environment(IVGE).The description of an IVGE integrates semantic information expressed using conceptual graphs,a standard knowledge representation technique.In addition,we propose an abstraction process that uses geometric,topologic,and semantic characteristics of geographic features to build a hierarchical graph-based structure describing this IVGE.Our IVGE model enables the support of large-scale and complex geographic environment modeling for multiagent geo-simulations in which the agents are situated and with which they interact.
