Centre dedocumentation
scientifique

Assessing public transit performance using real-time data: spatiotemporal patterns of bus operation delays in Columbus, Ohio, USA / Yongha Park in International journal of geographical information science IJGIS, vol 34 n° 2 (February 2020)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 34 n° 2 (February 2020) . - pp 367 - 392 Titre : Assessing public transit performance using real-time data: spatiotemporal patterns of bus operation delays in Columbus, Ohio, USA Type de document : Article/Communication Auteurs : Yongha Park, Auteur ; Jerry Mount, Auteur ; Luyu Liu, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 367 - 392 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes descripteurs IGN] base de données spatiotemporelles [Termes descripteurs IGN] COLOMBUS (USA) [Termes descripteurs IGN] diffusion de données [Termes descripteurs IGN] géolocalisation [Termes descripteurs IGN] interface web [Termes descripteurs IGN] mobilité urbaine [Termes descripteurs IGN] réseau de transport [Termes descripteurs IGN] temps réel [Termes descripteurs IGN] trafic routier [Termes descripteurs IGN] transport public Résumé : (auteur) Public transit vehicles such as buses operate within shared transportation networks subject to dynamic conditions and disruptions such as traffic congestion. The operational delays caused by these conditions can propagate downstream through scheduled transit routes, affecting system performance beyond the initial delay. This paper develops an approach to measuring and assessing vehicle delay propagation in public transit systems. We fuse data on scheduled bus service with real-time vehicle location data to measure the originating, cascading and recovery locations of delay events across space with respect to time. We integrate the resulting patterns to construct stop-specific delay propagation networks. We also analyze the spatiotemporal patterns of propagating delays using parameters such as 1) transit line-based network distance, 2) total propagating delay size, and 3) distance decay. We apply our methodology using publicly available schedule and real-time location data from the Central Ohio Transit Authority (COTA) public bus system in Columbus, Ohio, USA. We find that delay initiation is spatially and temporally uneven, concentrating on specific stops in downtown and specific suburban locations. Core stops play a critical role in propagating delays to a wide range of connected stops, eventually having a disproportional impact on the on-time performance of the bus system. Numéro de notice : A2020-030 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2019.1608997 date de publication en ligne : 30/04/2019 En ligne : https://doi.org/10.1080/13658816.2019.1608997 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94485 [article]

Comparative usability of an augmented reality sandtable and 3D GIS for education / Antoni B. Moore in International journal of geographical information science IJGIS, vol 34 n° 2 (February 2020)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 34 n° 2 (February 2020) . - pp 229 - 250 Titre : Comparative usability of an augmented reality sandtable and 3D GIS for education Type de document : Article/Communication Auteurs : Antoni B. Moore, Auteur ; Benjamin Daniel, Auteur ; greg Leonard, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 229 - 250 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique [Termes descripteurs IGN] enseignement supérieur [Termes descripteurs IGN] hydrologie [Termes descripteurs IGN] modèle numérique de terrain [Termes descripteurs IGN] modélisation 3D [Termes descripteurs IGN] Nouvelle-Zélande [Termes descripteurs IGN] réalité augmentée [Termes descripteurs IGN] réalité de terrain [Termes descripteurs IGN] réalité virtuelle [Termes descripteurs IGN] sable [Termes descripteurs IGN] test de performance Résumé : (auteur) Augmented Reality (AR) sandtables facilitate the shaping of sand to form a surface that is transformed into a digital terrain map which is projected back onto the sand. Although a mature technology, there are still few instances of sandtables being used in surface analysis. Fundamentally there has not been any reported formal assessment of how well sandtables perform in an educational context compared to other conventional learning environments. We compared learning outcomes from using an AR sandtable versus a conventional 3D GIS to convey key concepts in terrain and hydrological analyses via usability and knowledge testing. Overall results from students at a research-intensive New Zealand university reveal a faster task performance and more learning satisfaction when using the sandtable to undertake experimental tasks. Effectiveness and knowledge quiz results revealed no significant difference between the technologies though there was a trend for more accurate answers with 3D GIS tasks. Student learning wise, the sandtable integrated core concepts (especially morphometry) more effectively though both technologies were otherwise similar. We conclude that sandtables have high potential in geospatial teaching, fostering accessible and engaging means of introducing terrain and hydrological concepts, prior to undertaking a more accurate and precise surface analysis with 3D GIS. Numéro de notice : A2020-028 Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2019.1656810 date de publication en ligne : 27/08/2019 En ligne : https://doi.org/10.1080/13658816.2019.1656810 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94481 [article]

Real-time mapping of natural disasters using citizen update streams / Iranga Subasinghe in International journal of geographical information science IJGIS, vol 34 n° 2 (February 2020)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 34 n° 2 (February 2020) . - pp 393 - 421 Titre : Real-time mapping of natural disasters using citizen update streams Type de document : Article/Communication Auteurs : Iranga Subasinghe, Auteur ; Silvia Nittel, Auteur ; Michael Cressey, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 393 - 421 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes descripteurs IGN] approche participative [Termes descripteurs IGN] cartographie collaborative [Termes descripteurs IGN] catastrophe naturelle [Termes descripteurs IGN] classification par réseau neuronal [Termes descripteurs IGN] diagramme de Voronoï [Termes descripteurs IGN] données localisées des bénévoles [Termes descripteurs IGN] effondrement de terrain [Termes descripteurs IGN] incendie [Termes descripteurs IGN] inondation [Termes descripteurs IGN] positionnement cinématique en temps réel [Termes descripteurs IGN] système multi-agents [Termes descripteurs IGN] tempête [Termes descripteurs IGN] temps réel [Termes descripteurs IGN] ville intelligente Résumé : (auteur) Natural disasters such as flooding, wildfires, and mudslides are rare events, but they affect citizens at unpredictable times and the impact on human life can be significant. Citizens located close to events can provide detailed, real-time data streams capturing their event response. Instead of visualizing individual updates, an integrated spatiotemporal map yields ‘big picture’ event information. We investigate the question of whether information from affected citizens is sufficient to generate a map of an unfolding natural disaster. We built the Citizen Disaster Reaction Multi-Agent Simulation (CDR-MAS), a multi-agent system that simulates the reaction of citizens to a natural disaster in an urban region. We proposed an rkNN classification algorithm to aggregate the update streams into a series of colored Voronoi event maps. We simulated the 2018 Montecito Creek mudslide and customized the CDR-MAS with the local environment to systematically generate stream data sets. Our experimental evaluation showed that event mapping based on citizen update streams is significantly influenced by the amount of citizen participation and movement. Compared with a baseline of 100% participation, with 40% citizen participation, the event region was predicted with 40% accuracy, showing that citizen update streams can provide timely information in a smart city. Numéro de notice : A2020-031 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2019.1639185 date de publication en ligne : 15/07/2019 En ligne : https://doi.org/10.1080/13658816.2019.1639185 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94486 [article]

A two-step approach for the correction of rolling shutter distortion in UAV photogrammetry / Yilin Zhou in ISPRS Journal of photogrammetry and remote sensing, vol 160 (February 2020)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 160 (February 2020) . - pp 51 - 66 Titre : A two-step approach for the correction of rolling shutter distortion in UAV photogrammetry Type de document : Article/Communication Auteurs : Yilin Zhou, Auteur ; Mehdi Daakir, Auteur ; Ewelina Rupnik , Auteur ; Marc Pierrot-Deseilligny , Auteur Année de publication : 2020 Article en page(s) : pp 51 - 66 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] capteur aérien [Termes descripteurs IGN] compensation par faisceaux [Termes descripteurs IGN] correction [Termes descripteurs IGN] création de zone intermédiaire [Termes descripteurs IGN] distorsion d'image [Termes descripteurs IGN] étalonnage en vol [Termes descripteurs IGN] image de drone [Termes descripteurs IGN] MicMac [Termes descripteurs IGN] obturateur [Termes descripteurs IGN] photogrammétrie aérienne Résumé : (Auteur) The use of consumer grade unmanned aerial vehicles (UAV) is becoming more and more ubiquitous in photogrammetric applications. A large proportion of consumer grade UAVs are equipped with CMOS image sensor and rolling shutter. When imaging with a rolling shutter camera, the image sensor is exposed line by line, which can introduce additional distortions in image space since the UAV navigates at a relatively high speed during aerial acquisitions. In this paper, we propose (1) an approach to calibrate the readout time of rolling shutter camera, (2) a two-step method to correct the image distortion introduced by this effect. The two-step method makes assumption that during exposure, the change of camera orientation is negligible with respect to the change of camera position, which is often the case when camera is fixed on a stabilized mount. Firstly, the camera velocity is estimated from the results of an initial bundle block adjustment; then, one camera pose per scan-line of the image sensor is recovered and image observations are corrected. To evaluate the performance of the proposed method, four datasets of block and corridor configurations are acquired with the DJI Mavic 2 Pro and its original Hasselbald L1D-20c camera. The proposed method is implemented in MicMac, a free, open-source photogrammetric software; comparisons are carried out with other two mainstream software, AgiSoft MetaShape and Pix4D, which also have the functionality of rolling shutter effect correction. For block configuration datasets, the three software give comparable results. AgiSoft Metashape and Pix4D are sensitive to the flight configuration and encounter difficulties when processing datasets in corridor configurations. The proposed method shows good robustness both in block and corridor configurations, and is the only method that works in corridor configuration. After the application of the rolling shutter effect correction, the 3D accuracy is improved by 30–60% in block configuration and 15–25% in corridor configuration. A further improvement can be expected if a precise dating of image is available or if the camera positions can be directly extracted from GNSS data. Numéro de notice : A2020-018 Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2019.11.020 date de publication en ligne : 16/12/2019 En ligne : https://doi.org/10.1016/j.isprsjprs.2019.11.020 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94456 [article]

Artificial neural network models by ALOS PALSAR data for aboveground stand carbon predictions of pure beech stands: a case study from northern of Turkey / Alkan Günlü in Geocarto international, Vol 35 n° 1 ([02/01/2020])  

Public [article]  inGeocarto international > Vol 35 n° 1 [02/01/2020] . - pp 17 - 28 Titre : Artificial neural network models by ALOS PALSAR data for aboveground stand carbon predictions of pure beech stands: a case study from northern of Turkey Type de document : Article/Communication Auteurs : Alkan Günlü, Auteur ; Ilker Erkanli, Auteur Année de publication : 2020 Article en page(s) : pp 17 - 28 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes descripteurs IGN] biomasse aérienne [Termes descripteurs IGN] carbone [Termes descripteurs IGN] Fagus (genre) [Termes descripteurs IGN] image ALOS-PALSAR [Termes descripteurs IGN] peuplement forestier [Termes descripteurs IGN] régression multiple [Termes descripteurs IGN] réseau neuronal artificiel [Termes descripteurs IGN] Turquie Résumé : (auteur) The goal of this study was to estimate aboveground stand carbon (AGSC) of pure beech stands in Turkey with ground measurements as well as topographic information and remote sensing data. For this purpose, 153 sample plots were collected from pure beech stands in study area. The AGSC of each sample plot was computed. Eight texture images (variance, dissimilarity, homogeneity, entropy, contrast, mean, second moment and correlation) with five window sizes (3 × 3, 5 × 5, 7 × 7, 9 × 9 and 11 × 11) generated from ALOS PALSAR L-band satellite image. The AGSC models predicting the relationships between ALOS PALSAR texture values and topographic information, and sample plot AGSC were developed by using multiple linear regressions (MLR). Also, artificial neural networks (ANNs) architectures were trained by comparing various numbers of neurons and activation functions in its network types. Our results revealed the ability of ANNs was better than MLR models to predict AGSC values. Numéro de notice : A2020-017 Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2018.1499817 date de publication en ligne : 20/09/2018 En ligne : https://doi.org/10.1080/10106049.2018.1499817 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94410 [article]

Camera orientation, calibration and inverse perspective with uncertainties: a Bayesian method applied to area estimation from diverse photographs / Grégoire Guillet in ISPRS Journal of photogrammetry and remote sensing, vol 159 (January 2020)  

Permalink

Comparison of multi-seasonal Landsat 8, Sentinel-2 and hyperspectral images for mapping forest alliances in Northern California / Matthew L. Clark in ISPRS Journal of photogrammetry and remote sensing, vol 159 (January 2020)  

Permalink

Complex deformation at shallow depth during the 30 October 2016 Mw6.5 Norcia earthquake: interferencebetween tectonic and gravity processes? / Arthur Delorme in Tectonics, Inconnu (2020)    

Permalink

Context-Aware Convolutional Neural Network for Object Detection in VHR Remote Sensing Imagery / Yiping Gong in IEEE Transactions on geoscience and remote sensing, vol 58 n° 1 (January 2020)  

Permalink

Estimation and representation of regional atmospheric corrections for augmenting real-time single-frequency PPP / Peiyuan Zhou in GPS solutions, vol 24 n° 1 (January 2020)  

Permalink

INS/GNSS integration using recurrent fuzzy wavelet neural networks / Parisa Doostdar in GPS solutions, vol 24 n° 1 (January 2020)  

Permalink

A new cellular automata framework of urban growth modeling by incorporating statistical and heuristic methods / Yongjiu Feng in International journal of geographical information science IJGIS, vol 34 n° 1 (January 2020)  

Permalink

Perspective switch and spatial knowledge acquisition: effects of age, mental rotation ability and visuospatial memory capacity on route learning in virtual environments with different levels of realism / Ismini E. Lokka in Cartography and Geographic Information Science, Vol 47 n° 1 (January 2020)  

Permalink

A polyhedra-based model for moving regions in databases / Florian Heinz in International journal of geographical information science IJGIS, vol 34 n° 1 (January 2020)  

Permalink

Potential of crowdsourced traces for detecting updates in authoritative geographic data / Stefan Ivanovic (2020)  

Permalink