8,257 research outputs found

    Time Geography for Ad-Hoc Shared-Ride Trip Planning

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    CAREER: Data Management for Ad-Hoc Geosensor Networks

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    This project explores data management methods for geosensor networks, i.e. large collections of very small, battery-driven sensor nodes deployed in the geographic environment that measure the temporal and spatial variations of physical quantities such as temperature or ozone levels. An important task of such geosensor networks is to collect, analyze and estimate information about continuous phenomena under observation such as a toxic cloud close to a chemical plant in real-time and in an energy-efficient way. The main thrust of this project is the integration of spatial data analysis techniques with in-network data query execution in sensor networks. The project investigates novel algorithms such as incremental, in-network kriging that redefines a traditional, highly computationally intensive spatial data estimation method for a distributed, collaborative and incremental processing between tiny, energy and bandwidth constrained sensor nodes. This work includes the modeling of location and sensing characteristics of sensor devices with regard to observed phenomena, the support of temporal-spatial estimation queries, and a focus on in-network data aggregation algorithms for complex spatial estimation queries. Combining high-level data query interfaces with advanced spatial analysis methods will allow domain scientists to use sensor networks effectively in environmental observation. The project has a broad impact on the community involving undergraduate and graduate students in spatial database research at the University of Maine as well as being a key component of a current IGERT program in the areas of sensor materials, sensor devices and sensor. More information about this project, publications, simulation software, and empirical studies are available on the project\u27s web site (http://www.spatial.maine.edu/~nittel/career/)

    GIS-based identification and assessment of suitable meeting point locations for ride-sharing

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    Ride-Sharing or carpooling is a common means to utilize available but so far unused vehicle seat capacity. To establish a shared ride, it is necessary that the driver and the passengers agree on a meeting point. In most existing applications, the pickup location of a passenger is assumed to be on his or her doorstep. However, many people are willing to walk a certain distance to meet at a place where a safe and convenient boarding can be established, while at the same time the necessary detour of the driver can be kept acceptable. In this contribution we introduce an assessment scheme for meeting point locations based on results of an online survey retrieving the stated acceptance of meeting point locations and the relevance of the available facilities like parking places, seating, shelter and light. To this end, the infrastructure of a medium-sized European city is assumed to show exemplary how the amount and the distribution of suitable meeting point locations affects the performance and convenience of ride-sharing.DFG/GRK/193

    The Right Tools for the Job: The Case for Spatial Science Tool-Building

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    This paper was presented as the 8th annual Transactions in GIS plenary address at the American Association of Geographers annual meeting in Washington, DC. The spatial sciences have recently seen growing calls for more accessible software and tools that better embody geographic science and theory. Urban spatial network science offers one clear opportunity: from multiple perspectives, tools to model and analyze nonplanar urban spatial networks have traditionally been inaccessible, atheoretical, or otherwise limiting. This paper reflects on this state of the field. Then it discusses the motivation, experience, and outcomes of developing OSMnx, a tool intended to help address this. Next it reviews this tool's use in the recent multidisciplinary spatial network science literature to highlight upstream and downstream benefits of open-source software development. Tool-building is an essential but poorly incentivized component of academic geography and social science more broadly. To conduct better science, we need to build better tools. The paper concludes with paths forward, emphasizing open-source software and reusable computational data science beyond mere reproducibility and replicability

    Dockless micromobility sharing in Calgary: A spatial equity comparison of e-bikes and e-scooters

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    This paper reports on a comparison of the spatial equity dimensions of dockless bike and e-scooter sharing in Calgary, Alberta. Using trip data from the City of Calgary’s Shared Mobility Pilot (between July-September 2019), this study investigates differences in micromobility utilization by dockless mode between areas characterized by different levels of deprivation. ANOVA and linear regression results show that utilization of both dockless modes was spatially inequitable, with e-scooter and dockless bike trips concentrated in the least deprived areas. Dockless bike and e-scooter sharing utilization declined with each increase in deprivation level by 0.138 trips per 1,000 persons per vehicle for dockless e-scooters, and 0.015 trips per 1,000 persons per vehicle for dockless bikes, suggesting that more equity considerations are required to ensure that the benefits of dockless micromobility sharing are available to all areas regardless of the relative advantage or disadvantage.Cet article rend compte d’une comparaison des dimensions d’équité spatiale du partage de vélos et de scooters électriques sans quai à Calgary, en Alberta. À l’aide des données sur les déplacements du projet pilote de ‘mobilité partagée’ de la ville de Calgary (entre juillet et septembre 2019), cette étude examine les différences d’utilisation de la micromobilité en mode sans quai entre les zones caractérisées par différents niveaux de privation. Les résultats de l’ANOVA et de la régression linéaire montrent que l’utilisation des deux modes sans quai était spatialement inéquitable, et de même que spatialement inéquitable, tant les déplacements en scooter électrique et en vélo sans quai étant concentrés dans les zones les moins défavorisées. L’utilisation du partage de vélos et de scooters électriques sans quai diminue à chaque augmentation du niveau de privation de 0,138 trajets pour 1 000 personnes par véhicule pour les scooters électriques sans quai et de 0,015 trajets pour 1 000 personnes par véhicule pour les vélos sans quai. Ce qui suggère que davantage de considérations d’équité sont nécessaires pour garantir que les avantages du partage de la micromobilité sans quai sont disponibles dans toutes les régions, quel que soit l’avantage ou le désavantage relatif

    Transportation for an Aging Population: Promoting Mobility and Equity for Low-Income Seniors

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    This study explores the travel patterns, needs, and mobility problems faced by diverse low-income, inner-city older adults in Los Angeles in order to identify solutions to their mobility challenges. The study draws information from: (1) a systematic literature review of the travel patterns of older adults; (2) a review of municipal policies and services geared toward older adult mobility in six cities; (3) a quantitative analysis of the mobility patterns of older adults in California using the California Household Travel Survey; and (4) empirical work with 81 older adults residing in and around Los Angeles’ inner-city Westlake neighborhood, who participated in focus groups, interviews, and walkabouts around their neighborhood
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