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Representing complex geographic phenomena in GIS / M. Yuan in Cartography and Geographic Information Science, vol 28 n° 2 (April 2001)  

Public [article]  inCartography and Geographic Information Science > vol 28 n° 2 (April 2001) . - pp 83 - 96 Titre : Representing complex geographic phenomena in GIS Type de document : Article/Communication Auteurs : M. Yuan, Auteur Année de publication : 2001 Article en page(s) : pp 83 - 96 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] données spatiotemporelles [Termes IGN] modèle conceptuel de données [Termes IGN] modèle orienté objet [Termes IGN] Oklahoma (Etats-Unis) [Termes IGN] phénomène météorologique [Termes IGN] précipitation [Termes IGN] processus [Termes IGN] représentation géographique [Termes IGN] requête spatiotemporelle [Termes IGN] système d'information géographique Résumé : (Auteur) Conventionally, spatial data models have been designed according to object- or field-based conceptualizations of reality. Conceptualization of complex geographic phenomena that have both object and field-like properties, such as wildfire and precipitation, has not yet been incorporated into GIS data models. To this end, a new conceptual framework is proposed in this research for organizing data about such complex geographic phenomena in a GIS as a hierarchy of events, processes, and states. In this framework, discrete objects are used to show how events and processes progress in space and time, and fields are used to model how states of geographic themes vary in a space-time frame. Precipitation is used to demonstrate the construction and application of the proposed framework with digital precipitation data from April 15 to May 22, 1998, for the state of Oklahoma, U.S.A. With the proposed framework, two sets of algorithms have been developed. One set automatically assembles precipitation events and processes from the data and stores the precipitation data in the hierarchy of events, processes, and states, so that attributes about events, processes, and states are readily available for information query. The other set of algorithms computes information about the spatio-temporal behavior and interaction of events and processes. The proposed approach greatly enhances support for complex spatio-temporal queries on the behavior and relationships of events and processes. Numéro de notice : A2001-098 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1559/152304001782173718 En ligne : https://doi.org/10.1559/152304001782173718 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=21798 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
032-01021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Improving the quality of mass produced maps / J. Simley in Cartography and Geographic Information Science, vol 28 n° 2 (April 2001)  

Public [article]  inCartography and Geographic Information Science > vol 28 n° 2 (April 2001) . - pp 97 - 110 Titre : Improving the quality of mass produced maps Type de document : Article/Communication Auteurs : J. Simley, Auteur Année de publication : 2001 Article en page(s) : pp 97 - 110 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie [Termes IGN] données localisées numériques [Termes IGN] gestion de la qualité [Termes IGN] ingénierie [Termes IGN] norme ISO 9000 [Termes IGN] production cartographique [Termes IGN] produit cartographique [Termes IGN] qualité cartographique Résumé : (Auteur) Quality is critical in cartography because key decisions are often made based on the information the map communicates. The mass production of digital cartographic information to support geographic information science has now added a new dimension to the problem of cartographic quality, as problems once limited to small volumes can now proliferate in mass production programs.These problems can also affect the economics of map production by diverting a sizeable portion of production cost to pay for rework on maps with poor quality. Such problems are common to general industry - in response, the quality engineering profession has developed a number of successful methods to overcome these problems. Two important methods are the reduction of error through statistical analysis and addressing the quality environment in which people work. Once initial and obvious quality problems have been solved, outside influences periodically, appear that cause adverse variations in quality and consequently increase production costs. Such errors can be difficult to detect before the customer is affected. However, a number of statistical techniques can be employed to detect variation so that the problem is eliminated before significant damage is caused. Additionally, the environment in which the workforce operates must be conducive to quality. Managers have a powerful responsibility to create this environment. Two sets of guidelines, known as Deming's Fourteen Points and ISO-9000, provide models for this environment. Numéro de notice : A2001-099 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1559/152304001782173745 En ligne : https://doi.org/10.1559/152304001782173745 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=21799 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
032-01021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Modifications of Tanaka's illuminated contour method / Patrick Kennelly in Cartography and Geographic Information Science, vol 28 n° 2 (April 2001)  

Public [article]  inCartography and Geographic Information Science > vol 28 n° 2 (April 2001) . - pp 111 - 123 Titre : Modifications of Tanaka's illuminated contour method Type de document : Article/Communication Auteurs : Patrick Kennelly, Auteur ; A.J. Kimerling, Auteur Année de publication : 2001 Article en page(s) : pp 111 - 123 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie numérique [Termes IGN] carte des pentes [Termes IGN] contour [Termes IGN] éclairement lumineux [Termes IGN] niveau de gris (image) [Termes IGN] représentation du relief [Termes IGN] visualisation cartographique Résumé : (Auteur) Visualization of topography can be greatly facilitated by the illuminated contour method. This method, popularized in a hand-drafted map byTanaka, uses a gray background with black and white contours. A direction of illumination is assumed, and white contours represent illuminated topography, while black contours represent non-illuminated or shaded areas. Additionally, thickness of contours varies with the cosine of the angle between the azimuth of maximum slope (i.e., aspect) and the azimuth of illumination. We modified Tanaka's method by basing thickness of contour lines on twice the cosine of the angle between the surface normal and the illumination vector. The cosine of this angle is most commonly used in analytical bill shading. In addition, we present maps with changes in other visual variables and offer our evaluations. Lines with gray tones instead of black and white lines do not improve the illumination effect. We believe variations in the colors of contours and background with elevation can visually enforce information regarding topography. Our use of colors for aspect and variations in the width of contours for slope adds information to the map but does not assist with visualization of topography. Numéro de notice : A2001-100 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1559/152304001782173709 En ligne : https://doi.org/10.1559/152304001782173709 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=21800 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
032-01021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Dasymetric mapping and areal interpolation: implementation and evaluation / C.L. Eicher in Cartography and Geographic Information Science, vol 28 n° 2 (April 2001)  

Public [article]  inCartography and Geographic Information Science > vol 28 n° 2 (April 2001) . - pp 125 - 138 Titre : Dasymetric mapping and areal interpolation: implementation and evaluation Type de document : Article/Communication Auteurs : C.L. Eicher, Auteur ; Cynthia A. Brewer, Auteur Année de publication : 2001 Article en page(s) : pp 125 - 138 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie numérique [Termes IGN] carte choroplèthe [Termes IGN] démographie [Termes IGN] données statistiques [Termes IGN] erreur [Termes IGN] figuration de la densité [Termes IGN] implémentation (informatique) [Termes IGN] interpolation spatiale Résumé : (Auteur) Dasymetric maps display statistical data in meaningful spatial zones. Such maps can be preferable to choropleth maps that show data by enumeration zones, because dasymetric zones more accurately represent underlying data distributions. Though dasymetric mapping has existed for well over a century, the methods for producing these maps have not been thoroughly examined. In contrast, research on areal interpolation has been more thorough and has examined methods of transferring data from one set of map zones to another, an issue that is applicable to dasymetric mapping. Inspired by this work, we tested five dasymetric mapping methods, including methods derived from work on areal interpolation. Dasymetric maps of six socio-economic variables were produced for a study area of 159 counties in the eastern US rising county choropleth data and ancillary land-use data. Both polygonal (vector) and grid (raster) dasymetric methods were tested. We evaluated map accuracy using both statistical analyses and visual presentations of error. A repeated-measures analysis of variance showed that the traditional limiting variable method had significantly lower error than the other four methods. In addition, polygon methods had lower error than their grid-based counterparts, though the difference was not statistically significant. Error maps largely supported the conclusions from the statistical analysis, while also presenting patterns of error that were not obvious from the statistics. Numéro de notice : A2001-101 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1559/152304001782173727 En ligne : https://doi.org/10.1559/152304001782173727 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=21801 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
032-01021	RAB	Revue	Centre de documentation	En réserve L003	Disponible