Geospatial Semantics

Geospatial semantics is a broad field that involves a variety of research areas. The term semantics refers to the meaning of things, and is in contrast with the term syntactics. Accordingly, studies on geospatial semantics usually focus on understanding the meaning of geographic entities as well as their counterparts in the cognitive and digital world, such as cognitive geographic concepts and digital gazetteers. Geospatial semantics can also facilitate the design of geographic information systems (GIS) by enhancing the interoperability of distributed systems and developing more intelligent interfaces for user interactions. During the past years, a lot of research has been conducted, approaching geospatial semantics from different perspectives, using a variety of methods, and targeting different problems. Meanwhile, the arrival of big geo data, especially the large amount of unstructured text data on the Web, and the fast development of natural language processing methods enable new research directions in geospatial semantics. This chapter, therefore, provides a systematic review on the existing geospatial semantic research. Six major research areas are identified and discussed, including semantic interoperability, digital gazetteers, geographic information retrieval, geospatial Semantic Web, place semantics, and cognitive geographic concepts.Comment: Yingjie Hu (2017). Geospatial Semantics. In Bo Huang, Thomas J. Cova, and Ming-Hsiang Tsou et al. (Eds): Comprehensive Geographic Information Systems, Elsevier. Oxford, U

Comparison of Implicit and Explicit Solvation Models for <i>Iota</i>-Cyclodextrin Conformation Analysis from Replica Exchange Molecular Dynamics

Large ring cyclodextrins have become increasingly important for drug delivery applications. In this work, we have performed replica-exchange molecular dynamics simulations using both implicit and explicit water solvation models to study the conformational diversity of <i>iota</i>-cyclodextrin containing 14 α-1,4 glycosidic linked d-glucopyranose units (CD14). The new quantifiable calculation methods are proposed to analyze the openness, bending, and twisted conformation of CD14 in terms of circularity, biplanar angle, and one-directional conformation (ODC). CD14 in GB implicit water model (Igb5) was found mostly in an opened conformation with average circularity of 0.39 ± 0.16 and a slight bend with average biplanar angle of 145.5 ± 16.0°. In contrast, CD14 in TIP3P explicit water solvation is significantly twisted with average circularity of 0.16 ± 0.10, while 29.1% are ODCs. In addition, classification of CD14 conformations using a Gaussian mixture model (GMM) shows that 85.0% of all CD14 in implicit water at 300 K correspond to the elliptical conformation, in contrast to 82.3% in twisted form in explicit water. GMM clustering also reveals minority conformations of CD14 such as the 8-shape, boat-form, and twisted conformations. This work provides fundamental insights into CD14 conformation, influence of solvation models, and also proposes new quantifiable analysis techniques for molecular conformation studies in the future

Geoparsing and geocoding places in a dynamic space context: The case of hiking descriptions

International audienceThe backbone of the proposal in this chapter is an automatic parser and a formal encoder of information describing places, spatial and verbal relations in textual documents in order to reconstruct and map the textually described itinerary. These tools allow us to show how to combine the information expressed in French texts, referring to places, spatial actions associated with them, and data found in external geographical resources to build a geocoded representation of an itinerary. Our approach focuses on the automatic reconstruction of routes and transcribes them in their geographical setting, identifying locations and routes by interpreting spatial information in a dynamic space context