Showing papers by "Simon Scheider published in 2017"

Using SPARQL to describe GIS methods in terms of the questions they answer

Abstract: GIS methods consist of computational and analytic tools applied to data in order to answer a specific question. For example, in which way is the social wellbeing of a city different from its surroundings? Or, in how far is the surrounding population affected by road construction? The first question may be answered e.g. by constructing a choropleth map, the second one by an area interpolation. In order to effectively search and reuse such GIS methods over the Web, it is necessary to describe them in terms of the questions they answer, not only in terms of particular software or data types. This requires a way to match requests to methods, where both are described in terms of queries about a geographic subject matter, as envisioned in previous work on Datalog based geoservice chaining. However, to truly cover GIS methods, we argue that a much more expressive interrogative Web language is needed, which allows querying over relations and classes and includes completion statements. In this paper, we explain why and discuss in how far SPARQL query containment might be a suitable approach to this end.

A Model and Framework for Matching Complementary Spatio-Temporal Needs

Abstract: Currently, systems that let people search for opportunities to fulfill their spatio-temporal needs are built according to the conceptual model of service provider and consumer: After the providers make their needs publicly available, consumers use a specifically tailored query engine to find fitting offers. E.g., in carpooling, someone wants to fill an empty seat and to share costs (and publishes this offer), while another person wants to travel the same route. This model prevents the consuming side from making their needs available to the service providers and makes it hard to generalize, as query engines require rigid (often domain-specific) properties. Addressing this problem, we propose a generic model for publishing and processing complementary spatio-temporal needs. Our model uses a simulator to assess how well the collaboration between different entities would approximate their goals. To reuse existing concepts and embed the model into the emerging Semantic Web, everything is modeled in accordance with Linked Data principles.

Translating Verbally Communicated Local Geographic Knowledge Using Semantic Technologies: A Balinese Example

Abstract: Using cognitive linguistic strategies, people can verbally encode and convey their spatial realities with little effort (i.e. “my house is right across the street from the grocery store”). However, to date there are a limited number of ways to transform such spatial information into forms that are useful for computational analysis in a geographic information system (GIS), and for sharing across research communities. This paper uses a case study in the Balinese language to investigate the spatial and linguistic information necessary to compute such transformations. That is, to transform verbally communicated spatial scenes into GIS-suitable data. We propose an ontology which captures reference frames used in certain Balinese locative expressions together with the parameters (ground, direction and template) required for transformation. The approach allows for the sharing of translation methods and the reuse of contextual information on the Web. Based on this model, we identify open research questions on the way to supporting approximate transformations of locative expressions.