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Full-Text Articles in Databases and Information Systems

Generating Linear Orders Of Events For Geospatial Domains, Suzannah Hall Dec 2004

Generating Linear Orders Of Events For Geospatial Domains, Suzannah Hall

Electronic Theses and Dissertations

Events in the world do not occur in neat chronological order, but may take place, for example, during or overlapping each other, or as simultaneous events. Efficient summaries of real-world events are important in many disciplines and require events to be modeled in a linear fashion. This thesis focuses on modeling events as intervals and using relations between the events to derive linear orders from more complex partially ordered sets. A method is developed for mapping Allen's thirteen temporal relations to only two relations, before and equals, which allow a linear ordering of all events present in the set. This …


Using Linear Features For Aerial Image Sequence Mosaiking, Caixia Wang Dec 2004

Using Linear Features For Aerial Image Sequence Mosaiking, Caixia Wang

Electronic Theses and Dissertations

With recent advances in sensor technology and digital image processing techniques, automatic image mosaicking has received increased attention in a variety of geospatial applications, ranging from panorama generation and video surveillance to image based rendering. The geometric transformation used to link images in a mosaic is the subject of image orientation, a fundamental photogrammetric task that represents a major research area in digital image analysis. It involves the determination of the parameters that express the location and pose of a camera at the time it captured an image. In aerial applications the typical parameters comprise two translations (along the x …


Context-Specific Preference Learning Of One Dimensional Quantitative Geospatial Attributes Using A Neuro-Fuzzy Approach, Georgios Mountrakis Dec 2004

Context-Specific Preference Learning Of One Dimensional Quantitative Geospatial Attributes Using A Neuro-Fuzzy Approach, Georgios Mountrakis

Electronic Theses and Dissertations

Change detection is a topic of great importance for modern geospatial information systems. Digital aerial imagery provides an excellent medium to capture geospatial information. Rapidly evolving environments, and the availability of increasing amounts of diverse, multiresolutional imagery bring forward the need for frequent updates of these datasets. Analysis and query of spatial data using potentially outdated data may yield results that are sometimes invalid. Due to measurement errors (systematic, random) and incomplete knowledge of information (uncertainty) it is ambiguous if a change in a spatial dataset has really occurred. Therefore we need to develop reliable, fast, and automated procedures that …


Structuring A Wayfinder's Dynamic And Uncertain Environment, Michael D. Hendricks May 2004

Structuring A Wayfinder's Dynamic And Uncertain Environment, Michael D. Hendricks

Electronic Theses and Dissertations

Wayfinders typically travel in dynamic environments where barriers and requirements change over time. In many cases, uncertainty exists about the future state of this changing environment. Current geographic information systems lack tools to assist wayfinders in understanding the travel possibilities and path selection options in these dynamic and uncertain settings. The goal of this research is a better understanding of the impact of dynamic and uncertain environments on wayfinding travel possibilities. An integrated spatio-temporal framework, populated with barriers and requirements, models wayfinding scenarios by generating four travel possibility partitions based on the wayfinder's maximum travel speed. Using these partitions, wayfinders …