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Towards the automated large-scale reconstruction of past road networks from historical maps / Johannes H. Uhl in Computers, Environment and Urban Systems, vol 94 (June 2022)  

Public [article]  inComputers, Environment and Urban Systems > vol 94 (June 2022) . - n° 101794 Titre : Towards the automated large-scale reconstruction of past road networks from historical maps Type de document : Article/Communication Auteurs : Johannes H. Uhl, Auteur ; Stefan Leyk, Auteur ; Yao-Yi Chiang, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 101794 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] analyse de groupement [Termes IGN] analyse de sensibilité [Termes IGN] carte ancienne [Termes IGN] carte routière [Termes IGN] carte topographique [Termes IGN] classification par nuées dynamiques [Termes IGN] données multitemporelles [Termes IGN] Etats-Unis [Termes IGN] extraction du réseau routier [Termes IGN] histoire [Termes IGN] paysage [Termes IGN] réseau routier [Termes IGN] transport routier [Termes IGN] urbanisation Résumé : (auteur) Transportation infrastructure, such as road or railroad networks, represent a fundamental component of our civilization. For sustainable planning and informed decision making, a thorough understanding of the long-term evolution of transportation infrastructure such as road networks is crucial. However, spatially explicit, multi-temporal road network data covering large spatial extents are scarce and rarely available prior to the 2000s. Herein, we propose a framework that employs increasingly available scanned and georeferenced historical map series to reconstruct past road networks, by integrating abundant, contemporary road network data and color information extracted from historical maps. Specifically, our method uses contemporary road segments as analytical units and extracts historical roads by inferring their existence in historical map series based on image processing and clustering techniques. We tested our method on over 300,000 road segments representing more than 50,000 km of the road network in the United States, extending across three study areas that cover 42 historical topographic map sheets dated between 1890 and 1950. We evaluated our approach by comparison to other historical datasets and against manually created reference data, achieving F-1 scores of up to 0.95, and showed that the extracted road network statistics are highly plausible over time, i.e., following general growth patterns. We demonstrated that contemporary geospatial data integrated with information extracted from historical map series open up new avenues for the quantitative analysis of long-term urbanization processes and landscape changes far beyond the era of operational remote sensing and digital cartography. Numéro de notice : A2022-947 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1016/j.compenvurbsys.2022.101794 Date de publication en ligne : 18/03/2022 En ligne : https://doi.org/10.1016/j.compenvurbsys.2022.101794 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100182 [article]

Dasymetric mapping for an improved modeling of diseases / Gianluca Boo in Géomatique suisse, vol 114 n° 4 (avril 2016)

Public [article]  inGéomatique suisse > vol 114 n° 4 (avril 2016) . - pp 100 - 101 Titre : Dasymetric mapping for an improved modeling of diseases Type de document : Article/Communication Auteurs : Gianluca Boo, Auteur ; Stefan Leyk, Auteur Année de publication : 2016 Article en page(s) : pp 100 - 101 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] carte thématique [Termes IGN] figuration de la densité [Termes IGN] géolocalisation [Termes IGN] géopositionnement [Termes IGN] habitat collectif [Termes IGN] habitat individuel [Termes IGN] protection de la vie privée [Termes IGN] représentation des données [Termes IGN] santé [Termes IGN] vallée Résumé : (auteur) La recherche de maladies est soumise à de très strictes dispositions légales concernant la protection des données. Celles-ci stipulent l'anonymisation de l'identité des personnes interrogées. Les informations concernant le lieu de stockage des résultats des maladies ne sont donc disponibles que sous forme de résumés. De cette façon on évitera de divulguer l'adresse des personnes interrogées. Les cartes thématiques qui se basent sur des données de maladies agrégées suggèrent faussement que les résultats des maladies sont réparties de façon homogène à l'intérieur des limites administratives. Mais les résultats des maladies se trouvent typiquement aux endroits où vivent des gens. En Suisse par exemple la population et par conséquent les maladies sont réparties dans les lieux d'habitation des communes. Numéro de notice : A2016-278 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80838 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
136-2016041	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Understanding the combined impacts of aggregation and spatial non-stationarity: The case of migration-environment associations in rural South Africa / Galen McLaurin in Transactions in GIS, vol 19 n° 6 (December 2015)  

Public [article]  inTransactions in GIS > vol 19 n° 6 (December 2015) . - pp 877 – 895 Titre : Understanding the combined impacts of aggregation and spatial non-stationarity: The case of migration-environment associations in rural South Africa Type de document : Article/Communication Auteurs : Galen McLaurin, Auteur ; Stefan Leyk, Auteur ; Lori Hunter, Auteur Année de publication : 2015 Article en page(s) : pp 877 – 895 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] Afrique du sud (état) [Termes IGN] agrégation spatiale [Termes IGN] analyse de sensibilité [Termes IGN] données socio-économiques [Termes IGN] données statistiques [Termes IGN] indicateur démographique [Termes IGN] migration humaine [Termes IGN] milieu rural [Termes IGN] relation topologique Résumé : (auteur) Socio-demographic data are typically collected at various levels of aggregation, leading to the modifiable areal unit problem. Spatial non-stationarity of statistical associations between variables further influences the demographic analyses. This study investigates the implications of these two phenomena within the context of migration-environment associations. Global and local statistical models are fit across increasing levels of aggregation using household level survey data from rural South Africa. We raise the issue of operational scale sensitivity, which describes how the explanatory power of certain variables depends on the aggregation level. We find that as units of analysis (households) are aggregated, some variables become non-significant in the global models, while others are less sensitive to aggregation. Local model results show that aggregation reduces spatial variation in migration-related local associations but also affects variables differently. Spatial non-stationarity appears to be the driving force behind this phenomenon as the results from the global model mask this relationship. Operational scale sensitivity appears related to the underlying spatial autocorrelation of the non-aggregated variables but also to the way a variable is constructed. Understanding operational scale sensitivity can help to refine the process of selecting variables related to the scale of analysis and better understand the effects of spatial non-stationarity on statistical relationships. Numéro de notice : A2016-436 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/tgis.12134 En ligne : http://dx.doi.org/10.1111/tgis.12134 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81344 [article]

Exploring the impact of dasymetric refinement on spatiotemporal small area estimates / Barbara P. Buttenfield in Cartography and Geographic Information Science, Vol 42 n° 5 (November 2015)  

Public [article]  inCartography and Geographic Information Science > Vol 42 n° 5 (November 2015) . - pp 449 - 459 Titre : Exploring the impact of dasymetric refinement on spatiotemporal small area estimates Type de document : Article/Communication Auteurs : Barbara P. Buttenfield, Auteur ; Matt Ruther, Auteur ; Stefan Leyk, Auteur Année de publication : 2015 Article en page(s) : pp 449 - 459 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] analyse comparative [Termes IGN] analyse diachronique [Termes IGN] démographie [Termes IGN] données spatiotemporelles [Termes IGN] figuration de la densité [Termes IGN] interpolation [Termes IGN] méthodologie Résumé : (Auteur) Comparing demographic small area estimates across multiple time periods is hindered by boundary changes in census enumeration units. Areal interpolation can resolve temporal incompatibilities, but underlying assumptions of uniform population density within units is sometimes flawed and results in distorted estimates. Dasymetric modeling refines spatial precision by limiting areal interpolation to the most likely residential areas. Here, a systematic examination of the impacts of dasymetric refinement on temporal interpolation accuracy compares errors that emerge as a consequence of differing time spans. This paper compares the accuracy of three commonly utilized methods of areal interpolation for temporal analysis of population data over the 1990–2010 decades. It examines whether multi-temporal dasymetric refinement prior to areal interpolation improves the accuracy of small area estimates, comparing two different demographic contexts. Data sets include tract-level demography exhibiting dramatic growth (Las Vegas, Nevada), and relative stability (Pittsburgh, Pennsylvania). Areal interpolation with and without the dasymetric refinement is validated using block level data. The dasymetrically refined target density weighting (TDW) provides the overall best performance for the 2000 source data and the expectation maximization (EM) method gives the overall best performance for the 1990 source data; effects of refinement are more prominent in areas of faster population change. Numéro de notice : A2015-561 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/15230406.2015.1065206 En ligne : https://doi.org/10.1080/15230406.2015.1065206 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77604 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
032-2015051	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Modeling ambiguity in census microdata allocations to improve demographic small area estimates / Stefan Leyk in Transactions in GIS, vol 17 n° 3 (June 2013)  

Public [article]  inTransactions in GIS > vol 17 n° 3 (June 2013) . - pp 406 - 425 Titre : Modeling ambiguity in census microdata allocations to improve demographic small area estimates Type de document : Article/Communication Auteurs : Stefan Leyk, Auteur ; Barbara P. Buttenfield, Auteur ; Nicholas N. Nagle, Auteur Année de publication : 2013 Article en page(s) : pp 406 - 425 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] allocation [Termes IGN] données démographiques [Termes IGN] estimation statistique [Termes IGN] recensement démographique [Termes IGN] résolution d'ambiguïté [Termes IGN] spatial metrics Résumé : (Auteur) This article describes a methodology for allocating demographic microdata to small enumeration areas such as census tracts, in the presence of underlying ambiguities. Maximum Entropy methods impute population weights that are constrained to match a set of census tract-level summary statistics. Once allocated, the household characteristics are summarized to revise estimates of tract-level demographic summary statistics, and to derive measures of ambiguity. The revised summary statistics are compared with original tract summaries within a context of expected variation. Allocation ambiguity is quantified for each household as a function of the distribution of imputed sample weights over all census tracts, and by computed metrics of confusion and variety of allocation to any census tract. The process reported here allows differentiation of households with regard to inherent ambiguity in the allocation decision. Ambiguity assessment represents an important component that has been neglected in spatial allocation work to date but can be seen as important additional knowledge for demographers and users of small area estimates. For the majority of tested variables, the revised tract level summaries correlate highly with original tract summary statistics. In addition to assessments for individual households, it is also possible to compute average allocation ambiguity for individual tracts, and to associate this with demographic characteristics not utilized in the allocation process. Numéro de notice : A2013-291 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01366.x Date de publication en ligne : 07/01/2013 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01366.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32429 [article]