Centre de documentation
scientifique

Dépouillements

Extracting commuter-specific destination hotspots from trip destination data – comparing the boro taxi service with Citi Bike in NYC / Andreas Keler in Geo-spatial Information Science, vol 23 n° 2 (June 2020)  

Public [article]  inGeo-spatial Information Science > vol 23 n° 2 (June 2020) . - pp 141 - 152 Titre : Extracting commuter-specific destination hotspots from trip destination data – comparing the boro taxi service with Citi Bike in NYC Type de document : Article/Communication Auteurs : Andreas Keler, Auteur ; Jukka Mathias Krisp, Auteur ; Linfang Ding, Auteur Année de publication : 2020 Article en page(s) : pp 141 - 152 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] bicyclette [Termes IGN] données spatiotemporelles [Termes IGN] migration pendulaire [Termes IGN] mobilité urbaine [Termes IGN] New York (Etats-Unis ; ville) [Termes IGN] origine - destination [Termes IGN] qualité de service [Termes IGN] taxi [Termes IGN] trajet (mobilité) [Termes IGN] transport urbain Résumé : (auteur) Taxi trajectories from urban environments allow inferring various information about the transport service qualities and commuter dynamics. It is possible to associate starting and end points of taxi trips with requirements of individual groups of people and even social inequalities. Previous research shows that due to service restrictions, boro taxis have typical customer destination locations on selected Saturdays: many drop-off clusters appear near the restricted zone, where it is not allowed to pick up customers and only few drop-off clusters appear at complicated crossing. Detected crossings imply recent infrastructural modifications. We want to follow up on these results and add one additional group of commuters: Citi Bike users. For selected Saturdays in June 2015, we want to compare the destinations of boro taxi and Citi Bike users. This is challenging due to manifold differences between active mobility and motorized road users, and, due to the fact that station-based bike sharing services are restricted to stations. Start and end points of trips, as well as the volumes in between rely on specific numbers of bike sharing stations. Therefore, we introduce a novel spatiotemporal assigning procedure for areas of influence around static bike sharing stations for extending available computational methods. Numéro de notice : A2020-316 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10095020.2019.1621008 Date de publication en ligne : 10/06/2019 En ligne : https://doi.org/10.1080/10095020.2019.1621008 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95175 [article]

Determining the road traffic accident hotspots using GIS-based temporal-spatial statistical analytic techniques in Hanoi, Vietnam / Khanh Giang Le in Geo-spatial Information Science, vol 23 n° 2 (June 2020)  

Public [article]  inGeo-spatial Information Science > vol 23 n° 2 (June 2020) . - pp 153 - 164 Titre : Determining the road traffic accident hotspots using GIS-based temporal-spatial statistical analytic techniques in Hanoi, Vietnam Type de document : Article/Communication Auteurs : Khanh Giang Le, Auteur ; Pei Liu, Auteur ; Liang-Tay Lin, Auteur Année de publication : 2020 Article en page(s) : pp 153 - 164 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG [Termes IGN] accident de la route [Termes IGN] base de données spatiotemporelles [Termes IGN] données météorologiques [Termes IGN] estimation par noyau [Termes IGN] Hanoï [Termes IGN] indice de risque [Termes IGN] nuit [Termes IGN] système d'information géographique [Termes IGN] variation diurne [Termes IGN] variation saisonnière Résumé : (auteur) This study applied GIS-based statistical analytic techniques to investigate the influence of accident Severity Index (SI) on temporal-spatial patterns of accident hotspots related to the specific time intervals of day and seasons. Road Traffic Accident (RTA) data in 3 years (2015 − 2017) in Hanoi, Vietnam were used to analyze and test this approach. Firstly, the RTA data were divided into four seasons in accordance with Hanoi’s weather conditions and the time intervals such as the daytime, nighttime, or peak hours. Then, the Kernel Density Estimation (KDE) method was applied to analyze hotspots according to the time intervals and seasons. Finally, the results were presented by using the comap technique. This study considered both analyses with and without SI. The accident SI measures the seriousness of an accident. The approach method is to give higher weights to the more serious accidents, but not with the extremely high values calculated on a direct rate to the accident expenditures. The results showed that both analyses determined the relatively similar hotspots, but the rankings of some hotspots were quite different due to the integration of SI. It is better to take into account SI in determining RTA hotspots because the gained results are more precise and the rankings of hotspots are more accurate. From there, the traffic authorities can easily understand the causes behind each accident and provide reasonable solutions to solve the most dangerous hotspots in case of limited budget and resources appropriately. This is also the first study about this issue in Vietnam, so the contribution of the article will help the traffic authorities easily solve this problem not only in Hanoi but also in other cities. Numéro de notice : A2020-317 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/10095020.2019.1683437 Date de publication en ligne : 02/12/2019 En ligne : https://doi.org/10.1080/10095020.2019.1683437 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95176 [article]

Accuracy assessment of real-time kinematics (RTK) measurements on unmanned aerial vehicles (UAV) for direct geo-referencing / Desta Ekaso in Geo-spatial Information Science, vol 23 n° 2 (June 2020)  

Public [article]  inGeo-spatial Information Science > vol 23 n° 2 (June 2020) . - pp 165 - 181 Titre : Accuracy assessment of real-time kinematics (RTK) measurements on unmanned aerial vehicles (UAV) for direct geo-referencing Type de document : Article/Communication Auteurs : Desta Ekaso, Auteur ; Francesco Nex, Auteur ; Norman Kerle, Auteur Année de publication : 2020 Article en page(s) : pp 165 - 181 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] aérotriangulation [Termes IGN] centrale inertielle [Termes IGN] géoréférencement direct [Termes IGN] image captée par drone [Termes IGN] instrument embarqué [Termes IGN] positionnement cinématique en temps réel [Termes IGN] précision du positionnement [Termes IGN] récepteur GNSS Résumé : (auteur) Geospatial information acquired with Unmanned Aerial Vehicles (UAV) provides valuable decision-making support in many different domains, and technological advances coincide with a demand for ever more sophisticated data products. One consequence is a research and development focus on more accurately referenced images and derivatives, which has long been a weakness especially of low to medium cost UAV systems equipped with relatively inexpensive inertial measurement unit (IMU) and Global Navigation Satellite System (GNSS) receivers. This research evaluates the positional accuracy of the real-time kinematics (RTK) GNSS on the DJI Matrice 600 Pro, one of the first available and widely used UAVs with potentially surveying-grade performance. Although a very high positional accuracy of the drone itself of 2 to 3 cm is claimed by DJI, the actual accuracy of the drone RTK for positioning the images and for using it for mapping purposes without additional ground control is not known. To begin with, the actual GNSS RTK position of reference center (the physical point on the antenna) on the drone is not indicated, and uncertainty regarding this also exists among the professional user community. In this study the reference center was determined through a set of experiments using the dual frequency static Leica GNSS with RTK capability. The RTK positioning data from the drone were then used for direct georeferencing, and its results were evaluated. Test flights were carried out over a 70 x 70 m area with an altitude of 40 m above the ground, with a ground sampling distance of 1.3 cm. Evaluated against ground control points, the planimetric accuracy of direct georeferencing for the photogrammetric product ranged between 30 and 60 cm. Analysis of direct georeferencing results showed a time delay of up to 0.28 seconds between the drone GNSS RTK and camera image acquisition affecting direct georeferencing results. Numéro de notice : A2020-319 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/10095020.2019.1710437 Date de publication en ligne : 23/01/2020 En ligne : https://doi.org/10.1080/10095020.2019.1710437 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95184 [article]