Browsing by Author "Yang, Jing"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    GTMapLens: Interactive Lens for Geo-Text Data Browsing on Map
    (The Eurographics Association and John Wiley & Sons Ltd., 2020) Ma, Chao; Zhao, Ye; AL-Dohuki, Shamal; Yang, Jing; Ye, Xinyue; Kamw, Farah; Amiruzzaman, Md; Viola, Ivan and Gleicher, Michael and Landesberger von Antburg, Tatiana
    Data containing geospatial semantics, such as geotagged tweets, travel blogs, and crime reports, associates natural language texts with geographical locations. This paper presents a lens-based visual interaction technique, GTMapLens, to flexibly browse the geo-text data on a map. It allows users to perform dynamic focus+context exploration by using movable lenses to browse geographical regions, find locations of interest, and perform comparative and drill-down studies. Geo-text data is visualized in a way that users can easily perceive the underlying geospatial semantics along with lens moving. Based on a requirement analysis with a cohort of multidisciplinary domain experts, a set of lens interaction techniques are developed including keywords control, path management, context visualization, and snapshot anchors. They allow users to achieve a guided and controllable exploration of geo-text data. A hierarchical data model enables the interactive lens operations by accelerated data retrieval from a geo-text database. Evaluation with real-world datasets is presented to show the usability and effectiveness of GTMapLens.
  • Thumbnail Image
    Item
    Visually Analyzing Latent Accessibility Clusters of Urban POIs
    (The Eurographics Association, 2019) Kamw, Farah; AL-Dohuki, Shamal; Zhao, Ye; Yang, Jing; Ye, Xinyue; Chen, Wei; Landesberger, Tatiana von and Turkay, Cagatay
    Accessibility of urban POIs (Points of Interest) is a key topic in a variety of urban sciences and applications as it reflects inherent city design, transportation, and population flow features. Isochrone maps and other techniques have been used to identify and display reachable regions from given POIs. In addition, domain experts further want to study the distribution effects of accessibility in the urban space such as finding spatial regions that have different accessibility patterns. Such patterns can be manifested by clustering POIs based on their accessibility of different time periods under different traffic conditions. In this paper, we present a visualization system that helps users to find and visualize Latent Accessibility Clusters (LACs) of POIs. The LACs discover temporally changing urban sub-regions (including nearby POIs) with disparate accessibilities at different times. LACs are computed by a POIGraph which connects POIs into a graph structure by extending the dual road network of the corresponding city. The LAC computation is facilitated by graph traversal over the POIGraph. By visualizing the LAC regions on the map, users can visually study the hidden patterns of spatial accessibility. It can contribute to urban transportation, planning, business, and related social sciences.