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Query-By-Pointing: Algorithms And Pointing Error Compensation, Farhan Faisal Dec 2003

Query-By-Pointing: Algorithms And Pointing Error Compensation, Farhan Faisal

Electronic Theses and Dissertations

People typically communicate by pointing, talking, sketching, writing, and typing. Pointing can be used to visualize or exchange information about an object when there is no other mutually understood way of communication. Despite its proven expressiveness, however, it has not yet become a frequently used modality to interact with computer systems. With the rapid move towards the adoption of mobile technologies, geographic information systems (GISs) have a particular need for advanced forms of interaction that enable users to query the geographic world directly. To enable pointing-based query system on a handheld device, a number of fundamental technical challenges have to …


An Egocentric Spatial Data Model For Intelligent Mobile Geographic Information Systems, Christopher E. Frank Dec 2003

An Egocentric Spatial Data Model For Intelligent Mobile Geographic Information Systems, Christopher E. Frank

Electronic Theses and Dissertations

Individuals in unknown locations, such as utility workers in the field, soldiers on a mission, or sightseeing tourists, share the need for an answer to two basic questions: "Where am I?" and "What is in front of me?Because such information is not readily available in foreign locations, aids in the form of paper maps or mobile GISs, which give individuals an all-inclusive view of the environment, are often used. This panoptic view may hinder the positioning and orienteering process, since people perceive their surroundings perspectively from their current position. In this thesis, I describe a novel framework that resolves this …


Perceptual Sketch Interpretation, Markus Wuersch Dec 2003

Perceptual Sketch Interpretation, Markus Wuersch

Electronic Theses and Dissertations

Sketching is a creative form of describing a spatial scene. People perceive such a scene in a straight forward way and build a mental model of the objects contained in a sketch. Whereas these objects might be regions, a sketch only contains lines and, therefore, developing automated sketch interpretation means outlining a rationale to grouping lines according to the objects they belong to. Automated sketch interpretation allows efficient processing of sketches. Labor intensive manual extraction could be brought to a minimum and, therefore, spatial data in form of sketches and spatial information extracted from sketches would be available more readily. …


Public Commons For Geospatial Data: A Conceptual Model, Chakravarthy Namindi Sharad Aug 2003

Public Commons For Geospatial Data: A Conceptual Model, Chakravarthy Namindi Sharad

Electronic Theses and Dissertations

A wide variety of spatial data collection efforts are ongoing throughout local, state and federal agencies, private firms and non-profit organizations. Each effort is established for a different purpose but organizations and individuals often collect and maintain the same or similar information. The United States federal government has undertaken many initiatives such as the National Spatial Data Infrastructure, the National Map and Geospatial One-Stop to reduce duplicative spatial data collection and promote the coordinated use, sharing, and dissemination of spatial data nationwide. A key premise in most of these initiatives is that no national government will be able to gather …


Spatial Aspects Of Metaphors For Information: Implications For Polycentric System Design, Paul Charles Schroeder Aug 2003

Spatial Aspects Of Metaphors For Information: Implications For Polycentric System Design, Paul Charles Schroeder

Electronic Theses and Dissertations

This dissertation presents three innovations that suggest an alternative approach to structuring information systems: a multidimensional heuristic workspace, a resonance metaphor for information, and a question-centered approach to structuring information relations. Motivated by the need for space to establish a question-centered learning environment, a heuristic workspace has been designed. Both the question-centered approach to information system design and the workspace have been conceived with the resonance metaphor in mind. This research stemmed from a set of questions aimed at learning how spatial concepts and related factors including geography may play a role in information sharing and public information access. In …


A Mathematical Model For Simplifying Representations Of Objects In A Geographic Information System, Gabriel Perrow Jan 2003

A Mathematical Model For Simplifying Representations Of Objects In A Geographic Information System, Gabriel Perrow

Electronic Theses and Dissertations

The study of operations on representations of objects is well documented in the realm of spatial engineering. However, the mathematical structure and formal proof of these operational phenomena are not thoroughly explored. Other works have often focused on query-based models that seek to order classes and instances of objects in the form of semantic hierarchies or graphs. In some models, nodes of graphs represent objects and are connected by edges that represent different types of coarsening operators. This work, however, studies how the coarsening operator "simplification" can manipulate partitions of finite sets, independent from objects and their attributes. Partitions that …