GIS Colloquium – Talks (Summer Term 2015)
Michael Peter – Thu, Apr 23, 2015, 4.15 pm, Hörsaal Berliner Straße 48
In the recent years, an increased interest in indoor positioning and mapping could be noticed, in the scientific community as well as with advertising companies and commercial map providers. Due to the vast amount of unmapped indoor areas, the ease of frequent rearrangements, and the high manual effort of current indoor mapping methods, a transfer of the approaches in use by Volunteered Geographic Information communities to indoor mapping would be preferable. The mapping concept used in OpenStreetMap bases on GPS traces as well as aerial images released to the community by their owners. These two data sources can be replaced for the mapping of interior structures by photographed evacuation plans and pedestrian traces resulting e.g. from a foot-mounted, inertial measurement based positioning system. The talk will give a review of related work in indoor positioning and mapping, before presenting an image processing pipeline developed for the extraction of polygonal models from photographed evacuation plans, including the geo-referencing by automatic mapping to a model of the building's external shell. Furthermore, methods for the accuracy improvement of the pedestrian traces using the coarse model derived from the photographed evacuation plan will be presented. It will be shown how the traces can be employed for the semi-automatic and automatic semantic annotation and geometric refinement of the coarse model, e.g. by combining them with a hand-held low-cost range camera. Lastly, an indoor mapping method solely based on pedestrian traces and supported by a grammar for building interiors will be presented.
Florian Hillen – Thu, May 7, 2015, 4.15 pm, Hörsaal Berliner Straße 48
The Digital Earth vision by Al Gore recently has evolved to a powerful real-time toolbox for various use cases. Nowadays, almost every geo-sensor data can easily be integrated in a Digital Earth application in real-time and near real-time. This can be in-situ sensor data, smartphone sensor data or also high-resolution remote sensing imagery. However, the benefit of combining multiple data sources is only rarely exploited. Remote sensing data, for example, generally cover large areas but do not deliver information for hidden areas (e.g. under bridges, in house) or under cloud cover. In contrast to that, in-situ sensors deliver punctual information only but may provide information for areas that are invisible to remote sensors. Thus, the first idea that comes to mind is to use the advantages of the respective sensor types to eliminate the disadvantages of the other. The real-time aspect is a crucial point in this process, especially for time-critical applications like early warning systems, decision support systems for security issues or precision fertilisation for agricultural areas. To date, there is a lack of usage regarding real-time integration of fused geo-information even though the benefit is obvious.
Alan Kwok Lun Cheung – Wed, May 13, 2015, 2.00 pm, Hörsaal Berliner Straße 48
System behaviours of juxtaposed landscape elements can be revealed by analysing compositional and configurational properties of a landscape. In this research, spatial relationships in the form of spatial topology are exploited to provide insights on the configurational properties of landscape elements through time and space. For this purpose, a graph-based data structure named Spatial Temporal Relational Graph (STRG) is created, and a set of associated graph analytical tools are adapted for STRG. By analysing the relational dynamics of landscape elements through time, the result shows that the combination of graph analytics and spatial statistics provides clear indication on phenomena suggested by landscape ecology theories such as ecotones, land degradation by perforation and evidence of hemeroby.
Ahmed Loai Ali, PhD Student – Tue, May 26, 2015, 4 pm, Seminarraum Berliner Straße 48
Crowd-sourcing, especially in form of Volunteered Geographic Information (VGI) significantly changed the way how geographic data is collected and which products are generated from them. In VGI projects, contributors’ heterogeneity fosters rich data sources, however with problematic quality. In our work, we tackle the quality from Classification perspective. We address two classification problems: Hierarchical classification where the classification of an entity should follow a strict structure and Arbitrary classification where the classification does not follow any strict structure. In VGI projects, classification has some challenges: In some cases, the classification of entities depends on individual conceptualization about the environment. Whereas in other cases, a geographic feature itself might have ambiguous characteristics. These problems lead to inconsistent and inappropriate classifications. To face these challenges, we propose an approach. The approach is mainly based on investigating the geographic context of a specific class of entity. It employs data mining algorithms to develop a classifier. Then, the developed classifier could be used to guide the contributors during the contribution process. The approach acts not only to improve the quality of data, but also it could be used to improve contributors' experience. However, dealing with VGI is tricky and in geographic context there is no universal rule. The empirical studies emphasized the feasibility of the proposed approach, however with some limitations. Currently, towards real evaluations we are working to implement the approach into action phase. During the talk, I would present the ideas beyond the proposed approach and discuss another hot issues related to the quality of VGI.
Dr. Guibo Sun – Thu, Jun 11, 2015, 4.15 pm, Hörsaal Berliner Straße 48
In a recent study we tested associations between different characteristics of the built-environment and their influence on walking behaviour from metro stations to respective destinations. The study focused on the concern that in the planning process of metro stations typically little attention is paid to the walking conditions in the local and regional urban environment. Moreover, the integration of station facilities into the surrounding built-environment is also usually undertaken without bearing such aspects in mind. We collected data (N=493) on walking behaviour and the perception of the built-environment at six different study sites in China. Those localities comprise three distinct physical settings, e.g., modern neighbourhoods (built after 1980) or more classical old town sceneries. We accompanied willing participants to record walking routes from the metro station upon arrival at their particular destinations. Those participants were requested to record their personal impressions regarding attributes like pavement infrastructure, motor traffic and design aesthetics by means of a questionaire. This empirical dataset was then investigated in terms of GIS. We mapped the walking routes and coded built-environment variables. A multivariate linear regression model was employed for testing associations between different collected aspects and their influence on the walking behaviour around the metro stations. The results indicate that pedestrians take shorter walking times when they walk through areas which are characterised by retail or entertainment related facilities. In contrast, the walking time considerable increased as people were walking through a residential setting. Greater visual connectivity predicts a shorter walking time, while less motor traffic predicts a longer walking time. In conclusion, quantitative as well as qualitative aspects of the built-environment around metro stations have influence on the walking time from metro to destination. Visual connectivity and non-residential land uses around the metro station are associated with shorter walking time and thus may attract more metro riders.
Staatl. exam. Geogr. David Jonietz – Thu, Jun 18, 2015, 2 pm, Hörsaal Berliner Straße 48
Human cognition of space involves its structuring and enrichment with complex meaning, in particular related to its action potentials, and thus results in the formation of separate places. Despite its central role, however, work on the representation of place in Geographical Information Systems (GIS) is still at an early stage. Particular challenges arise from place-inherent characteristics, and include vagueness, subjectivity and dynamic variability in terms of location, footprint and semantics. In this talk, the use of agent-based models (ABM) is proposed to localize places in space. For this, it is necessary to simulate the process of place formation of each individual agent. With a strong focus on its action-related dimension, place is conceptualized as a subset of atomic spatial entities, which are bound by a functional unity condition with regards to a complex action. Based on an hierarchical action model, our framework allows agents to evaluate the suitability of individual geo-atoms with regards to these actions, and choose their behavior accordingly. The usefulness of the approach is demonstrated by simulating pedestrian movement in the city centre of Augsburg, Germany.
Falk Zscheile Referent Recht – Tue, Jun 25, 2015, 4.15 pm, Seminarraum Berliner Straße 48
Das Zivilrecht orientierte sich bei der Beurteilung der Eigenschaften von Dingen im Wesentlichen an körperlichen Gegenständen. Dabei haben (geographische) Daten und Informationen gegenüber Sachen deutliche Unterschiede. Aufgrund der Unkörperlichkeit und der Vielfältigkeit fehlt es bei Daten auch an einer allgemeinen Verkehrsanschauung über die typische Eigenart. Entsprechend schwierig ist zu beurteilen, ob gekaufte Daten die Erwartungen erfüllen, welche die Vertragsparteien an sie stellen. Die Behandlung der Frage, wie die Qualitätsmaßstäbe von Geoinformatik und Zivilrecht zusammenpassen, ist Gegenstand des Vortrags, genauso, wie die Folgen einer Mangelhaftigkeit von geographischen Daten und Informationen.
Dr. Matthew W. Wilson – Tue, Jul 14, 2015, 10 am, Hörsaal Berliner Straße 48
Matthew W. Wilson, PhD, is Associate Professor of Geography at the University of Kentucky and Visiting Scholar at the Center for Geographic Analysis at Harvard University. He co-founded and co-directs the New Mappings Collaboratory which studies and facilitates new engagements with geographic representation. His research in critical GIS draws upon STS and urban political geography to understand the development and proliferation of location-based technologies, with particular attention to the consumer electronic sector. He has previously taught at the Harvard Graduate School of Design, and his current research project focuses on the founding of the Laboratory for Computer Graphics at Harvard in 1965, a catalyzing moment in the advent of the digital map. His work has been published in leading journals and collections including, Society & Space, Landscape & Urban Planning, Qualitative GIS (Sage), Geoforum, The Professional Geographer, the Annals of the Association of American Geographers, Cartographica, Social & Cultural Geography, Gender, Place & Culture, and Environment & Planning A.
New devices and techniques have emerged to better quantify an individual’s movement, stasis, and even sleep, while a ‘smart city’ discourse and marketing apparatus applies these principles to analysis, representation, and management of the city. Indeed, as cities are increasingly rethought as organisms and human bodies are quantified as systems, the interactive opportunities and limitations for engagement, representation, and resistance are evermore significant. In this presentation, I draw parallels between the rising consumer-electronic sector associated with personal activity monitors and the rapid visioning of smart urbanism. More specifically, I interrogate these developments in quantification, namely: interoperability and propriety, competition and habit, fashion and surveillance. What are the social-cultural and political implications for this refiguring of spatial thought and action? What capacities are reinforced and developed through the implementation of these technologies and techniques? I address these concerns, through discussion of a continuum of technologies that serve to open and close multi-scalar systems of attention control.
Univ.-Prof. Dipl.-Ing. Dr. Wolfgang Kainz – Thu, Jul 16, 2015, 4.15 pm, Hörsaal Berliner Straße 48
For thousands of years humans have tried to depict the places and lands where they lived. We know cartographic drawings from many advances civilizations dating back far beyond the cultures of Rome or Greece. However, cartography as a science was only established about 100 years ago. This presentation gives an overview of the major highlights of the history of cartography and its path to become a science in its own right. Important changes in the understanding of cartography during the recent decades, current scientific issues and the position of cartography versus neighboring disciplines will be discussed. The talk finishes with an outlook into the future of cartography and the role of cartographers in shaping that future.
Dr. Norman Kerle – Wed, Jul 22, 2015, 4 pm, Hörsaal Berliner Straße 48
Following a disaster event a rapid assessment of its consequences is required, as all stakeholders involved in response and recovery activities rely on situational intelligence. Remote sensing technology has become the principal tool for such mapping, and many types of sensing instruments deployed over the last decades have been used for damage mapping. However, while properties of remote sensing such as rapid availability or synoptic coverage remain strong assets, and despite a host of technical advances, the actual task of damage assessment continues to pose substantial challenges. Those relate to the unique characteristics of individual sensing systems (repeat visit time, incident angle, spatial and spectral image resolution, etc.), but also to the fact that damage is a complex concept with both physical and functional dimensions. In a bid to increase the amount of information that allows a damage assessment beyond obvious rubble piles, increasing use is being made of airborne oblique sensing systems, in particular with the help of unmanned aerial vehicles. The research in our group focuses not on the instrument or engineering side, but rather on image analysis and semantic processing, with object-based image analysis playing an important role. One interesting recent development that is also increasingly influencing the field of damage assessment if crowdsourcing/VGI. This ranges from field-based reporting to collaborative image-based damage mapping. While the potential of such an approach is event, it is far less clear when specifically to make use of volunteers, and how to instruct and engage them.