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Mapping social activities and concepts with social media (Twitter) and web search engines (Yahoo and Bing): a case study in 2012 US Presidential Election / Ming-Hsiang Tsou in Cartography and Geographic Information Science, vol 40 n° 4 (September 2013)
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Titre : Mapping social activities and concepts with social media (Twitter) and web search engines (Yahoo and Bing): a case study in 2012 US Presidential Election Type de document : Article/Communication Auteurs : Ming-Hsiang Tsou, Auteur ; Jiue-An Yang, Auteur ; Brian Spitzberg, Auteur ; Jean Marc Gawron, Auteur ; Dipak Gupta, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : pp 337 - 348 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] analyse diachronique
[Termes IGN] comportement
[Termes IGN] données issues des réseaux sociaux
[Termes IGN] élection
[Termes IGN] estimation par noyau
[Termes IGN] Etats-Unis
[Termes IGN] logiciel de navigation
[Termes IGN] moteur de recherche
[Termes IGN] ontologie
[Termes IGN] TwitterRésumé : (Auteur) We introduce a new research framework for analyzing the spatial distribution of web pages and social media (Twitter) messages with related contents, called Visualizing Information Space in Ontological Networks (VISION). This innovative method can facilitate the tracking of ideas and social events disseminated in cyberspace from a spatial-temporal perspective. Thousands of web pages and millions of tweets associated with the same keywords were converted into visualization maps using commercial web search engines (Yahoo application programming interface (API) and Bing API), a social media search engine (Twitter APIs), Internet Protocol (IP) geolocation methods, and Geographic Information Systems (GIS) functions (e.g., kernel density and raster-based map algebra methods). We found that comparing multiple web information landscapes with different keywords or different dates can reveal important spatial patterns and “geospatial fingerprints” for selected keywords. We used the 2012 US Presidential Election candidates as our case study to validate this method. We noticed that the weekly changes of the geographic probability of hosting “Barack Obama” or “Mitt Romney” web pages are highly related to certain major campaign events. Both attention levels and the content of the tweets were deeply impacted by Hurricane Sandy. This new approach may provide a new research direction for studying human thought, human behaviors, and social activities quantitatively. Numéro de notice : A2013-762 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/15230406.2013.799738 En ligne : https://doi.org/10.1080/15230406.2013.799738 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32898
in Cartography and Geographic Information Science > vol 40 n° 4 (September 2013) . - pp 337 - 348[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 032-2013041 RAB Revue Centre de documentation En réserve L003 Disponible Using hyperspectral reflectance data to assess biocontrol damage of giant salvinia / James H. Everitt in Geocarto international, vol 28 n° 5-6 (August - October 2013)
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Titre : Using hyperspectral reflectance data to assess biocontrol damage of giant salvinia Type de document : Article/Communication Auteurs : James H. Everitt, Auteur ; Chenghai Yang, Auteur ; Julie G. Nachtrieb, Auteur Année de publication : 2013 Article en page(s) : pp 502 - 516 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse diachronique
[Termes IGN] analyse discriminante
[Termes IGN] espèce exotique envahissante
[Termes IGN] Etats-Unis
[Termes IGN] image hyperspectrale
[Termes IGN] lutte biologique
[Termes IGN] milieu naturel
[Termes IGN] plante aquatique d'eau salée
[Termes IGN] réflectance végétale
[Termes IGN] surveillance de la végétationMots-clés libres : Salvinia molesta Résumé : (Auteur) Field hyperspectral reflectance data were studied at 50 wavebands (10-nm bandwidth) over the 400- to 900-nm spectral range to determine their potential for distinguishing among giant salvinia (Salvinia molesta Mitchell) plants subjected to four population levels of salvinia weevils (Cyrtobagous salviniae Calder and Sands) to develop feeding damage to the plants. The four populations included a control with no insects and those with low, medium and high insect populations. The plants were studied in two experiments on each of two dates: 14 October 2010 and 21 July 2011. Two procedures were used to determine the optimum bands for discriminating among treatments: least significant difference (LSD) and stepwise discriminant analysis. The LSD comparison test results for both October and July experiments showed that generally the best bands for separating among treatments occurred in the green (505–595 nm), red (605–635 nm), red-near-infrared (NIR; 695–745 nm) edge and NIR (755–895 nm) regions where three to four treatments could be distinguished. Stepwise discriminant analysis identified four bands in the green, red and red-NIR edge to be significant to discriminate among the four treatments in Experiment 1 in October. For Experiment 2 in October, discriminant analysis identified five bands in the blue, green, red and NIR regions to be significant for distinguishing among the treatments. In Experiment 1 in July, five bands in the blue, green, red-NIR edge and NIR regions were found to be significant to discriminate among the treatments. For Experiment 2 in July, discriminant analysis identified four bands in the blue, green and red-NIR edge regions to be significant to discriminate among the treatments. Numéro de notice : A2013-550 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2012.724454 Date de publication en ligne : 25/09/2012 En ligne : https://doi.org/10.1080/10106049.2012.724454 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=78074
in Geocarto international > vol 28 n° 5-6 (August - October 2013) . - pp 502 - 516[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 059-2013031 RAB Revue Centre de documentation En réserve L003 Disponible Semi-automated analysis of high-resolution aerial images to quantify docks in glacial lakes / Marcus W. Beck in ISPRS Journal of photogrammetry and remote sensing, vol 81 (July 2013)
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Titre : Semi-automated analysis of high-resolution aerial images to quantify docks in glacial lakes Type de document : Article/Communication Auteurs : Marcus W. Beck, Auteur ; Bruce Vondracek, Auteur ; Lorin Hatch, Auteur ; Jason Vinje, Auteur Année de publication : 2013 Article en page(s) : pp 60 - 69 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] détection d'objet
[Termes IGN] image aérienne
[Termes IGN] lac
[Termes IGN] Minnesota (Etats-Unis)
[Termes IGN] pêche
[Termes IGN] ressources aquatiques
[Termes IGN] surveillance écologiqueRésumé : (Auteur) Lake resources can be negatively affected by environmental stressors originating from multiple sources and different spatial scales. Shoreline development, in particular, can negatively affect lake resources through decline in habitat quality, physical disturbance, and impacts on fisheries. The development of remote sensing techniques that efficiently characterize shoreline development in a regional context could greatly improve management approaches for protecting and restoring lake resources. The goal of this study was to develop an approach using high-resolution aerial photographs to quantify and assess docks as indicators of shoreline development. First, we describe a dock analysis workflow that can be used to quantify the spatial extent of docks using aerial images. Our approach incorporates pixel-based classifiers with object-based techniques to effectively analyze high-resolution digital imagery. Second, we apply the analysis workflow to quantify docks for 4261 lakes managed by the Minnesota Department of Natural Resources. Overall accuracy of the analysis results was 98.4% (87.7% based on View the MathML source) after manual post-processing. The analysis workflow was also 74% more efficient than the time required for manual digitization of docks. These analyses have immediate relevance for resource planning in Minnesota, whereas the dock analysis workflow could be used to quantify shoreline development in other regions with comparable imagery. These data can also be used to better understand the effects of shoreline development on aquatic resources and to evaluate the effects of shoreline development relative to other stressors. Numéro de notice : A2013-389 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2013.04.006 En ligne : https://doi.org/10.1016/j.isprsjprs.2013.04.006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32527
in ISPRS Journal of photogrammetry and remote sensing > vol 81 (July 2013) . - pp 60 - 69[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2013071 RAB Revue Centre de documentation En réserve L003 Disponible Utility of the wavelet transform for LAI estimation using hyperspectral data / Asim Banskota in Photogrammetric Engineering & Remote Sensing, PERS, vol 79 n° 7 (July 2013)
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Titre : Utility of the wavelet transform for LAI estimation using hyperspectral data Type de document : Article/Communication Auteurs : Asim Banskota, Auteur ; Randolph H. Wynne, Auteur ; Shawn P. Serbin, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : 662 p. ; pp 653 - 662 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] algorithme génétique
[Termes IGN] forêt tempérée
[Termes IGN] image AVIRIS
[Termes IGN] image hyperspectrale
[Termes IGN] Leaf Area Index
[Termes IGN] transformation en ondelettes
[Termes IGN] Wisconsin (Etats-Unis)Résumé : (Auteur) We employed the discrete wavelet transform to reflectance spectra obtained from hyperspectral data to improve estimation of LAi in temperate forests. We estimated LAl for 32 plots across a range afforest types in Wisconsin using hemispherical photography. Plot spectra were extracted from AVIRIS data and transformed into wavelet features using the Haar wavelet. Separately, subsets of spectral bands and the Haar features selected by a genetic algorithm were used as independent variables in linear regressions. Models using wavelet coefficients explained the most variance for both broadleaf plots (R2 = 0.90 for wavelet features versus R2 = 0.80 for spectral bands) and all plots independent afforest type (R2 = 0.79 for wavelet features vs. R2 = 0.58 for spectral bands). The forest-type specific models were better than the models using all plots combined. Overall, wavelet features appear superior to band reflectances alone for estimating temperate forest LAI using hyperspectral data. Numéro de notice : A2013-394 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.14358/PERS.79.7.653 En ligne : https://doi.org/10.14358/PERS.79.7.653 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32532
in Photogrammetric Engineering & Remote Sensing, PERS > vol 79 n° 7 (July 2013) . - 662 p. ; pp 653 - 662[article]An object-based system for Lidar data fusion and feature extraction / Jarlath P. M. O'Neil-Dunne in Geocarto international, vol 28 n° 3-4 (June - July 2013)
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Titre : An object-based system for Lidar data fusion and feature extraction Type de document : Article/Communication Auteurs : Jarlath P. M. O'Neil-Dunne, Auteur ; Sean W. Macfaden, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : pp 227 - 242 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] carte d'occupation du sol
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] données vectorielles
[Termes IGN] extraction de traits caractéristiques
[Termes IGN] fusion de données
[Termes IGN] image aérienne
[Termes IGN] milieu urbain
[Termes IGN] modèle orienté objet
[Termes IGN] occupation du sol
[Termes IGN] Philadelphie
[Termes IGN] villeRésumé : (Auteur) In urbanized areas of the developed world, light detection and ranging (LiDAR) exists alongside a wealth of other geospatial information. Despite this bounty, high-resolution land cover is still lacking in many urban areas. This can be attributed to the complexity of many landscapes, the volume of available data and the challenges associated with combining data that were acquired over differing time periods using inconsistent standards. Object-based approaches are ideal for overcoming these limitations. We describe the design, development and deployment of an object-based system that incorporated LiDAR, imagery and vector data sets to develop a comprehensive, multibillion-pixel land-cover data set for the City of Philadelphia. A novel approach using parallel processing allowed us to distribute the feature extraction load to multiple cores, providing massive gains in efficiency and permitting continual modification of the expert system until the accuracy goals of the project were achieved. Numéro de notice : A2013-397 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2012.689015 Date de publication en ligne : 29/05/2012 En ligne : https://doi.org/10.1080/10106049.2012.689015 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32535
in Geocarto international > vol 28 n° 3-4 (June - July 2013) . - pp 227 - 242[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 059-2013021 RAB Revue Centre de documentation En réserve L003 Disponible Assessing the effect of data imports on the completeness of OpenStreetMap: a United States case study / Dennis Zielstra in Transactions in GIS, vol 17 n° 3 (June 2013)
PermalinkChallenges and lessons from a wetland LiDAR project: a case study of the Okefenokee Swamp, Georgia, USA / L. Shea Rose in Geocarto international, vol 28 n° 3-4 (June - July 2013)
PermalinkEducating students for the extensive range of surveying activities / Daniel T. Gillins in SaLIS Surveying and land information science, vol 73 n° 1 (May 2013)
PermalinkHistogram curve matching approaches for object-based image classification of land cover and land use / Sory I. Toure in Photogrammetric Engineering & Remote Sensing, PERS, vol 79 n° 5 (May 2013)
PermalinkInfluence of a dense, low-height shrub species on the accuracy of a lidar-derived DEM / Samuel B. Gould in Photogrammetric Engineering & Remote Sensing, PERS, vol 79 n° 5 (May 2013)
PermalinkA GIS-based site identification for the seasonal storage of solar heating: Promises and pitfalls / Timothy J. Dolney in Transactions in GIS, vol 17 n° 2 (April 2013)
PermalinkSeeing the wood for the trees: Opentreemap is helping individuals, organisations and governments to collaborate in mapping, tending and preserving 'urban forest' / Deborah Boyer in GEO: Geoconnexion international, vol 12 n° 4 (april 2013)
PermalinkSegmentation hyperspectrale de forêts tropicales par arbres de partition binaires / Guillaume Tochon in Revue Française de Photogrammétrie et de Télédétection, n° 202 (Avril 2013)
PermalinkUsing GIS to tackle chronic absenteeism / Jim Baumann in GEO: Geoconnexion international, vol 12 n° 4 (april 2013)
PermalinkSpatial, temporal, and socioeconomic patterns in the use of Twitter and Flickr / Linna Li in Cartography and Geographic Information Science, vol 40 n° 2 (March 2013)
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