Social and Behavioral Sciences Commons^™

Support Vector Methods For Higher-Level Event Extraction In Point Data, Jon Devine

Electronic Theses and Dissertations

Phenomena occur both in space and time. Correspondingly, ability to model spatiotemporal behavior translates into ability to model phenomena as they occur in reality. Given the complexity inherent when integrating spatial and temporal dimensions, however, the establishment of computational methods for spatiotemporal analysis has proven relatively elusive. Nonetheless, one method, the spatiotemporal helix, has emerged from the field of video processing. Designed to efficiently summarize and query the deformation and movement of spatiotemporal events, the spatiotemporal helix has been demonstrated as capable of describing and differentiating the evolution of hurricanes from sequences of images. Being derived from image data, the …

Specifying And Detecting Topological Changes To An Areal Object, Jixiang Jiang

Electronic Theses and Dissertations

No abstract provided.

An Embedding Graph For 9-Intersection Topological Spatial Relations, Matthew P. Dube

Electronic Theses and Dissertations

In the practice of mapmaking, it is commonplace to represent many spatial phenomena as if they were in a different dimension than they truly are. In this context, it is extremely important to understand the total set of relationships available in a two-dimensional setting. Currently, there exist many sets of relations in two dimensions that have been modeled by the 9-intersection matrix. Many of these sets of relations have defined conceptual neighborhood graphs that show the inherent topological similarities between different types of configurations. Many of these sets of relations, however, do not have established conceptual neighborhood graphs. Furthermore, …

Provenance Tracking In A Commons Of Geographic Data, David B. Mccurry

Electronic Theses and Dissertations

Advancement in digital archiving technologies provides researchers with a multitude of methods for sharing their research and data digitally with others. However, when acquiring data from others directly or indirectly the law often imposes an assumption of copyright in the dataset acquired. This creates a difficult legal situation affecting future use and creation of derivative works from the data. A digital commons may be defined as a shared resource in which creators of contributed materials (data) grant a legal right for all others to use the material under the provisions of an open-access license. This thesis hypothesizes that an approach …

Combining Geospatial And Temporal Ontologies, Kripa Joshi

Electronic Theses and Dissertations

Publicly available ontologies are growing in number at present. These ontologies describe entities in a domain and the relations among these entities. This thesis describes a method to automatically combine a pair of orthogonal ontologies using cross products. A geospatial ontology and a temporal ontology are combined in this work. Computing the cross product of the geospatial and the temporal ontologies gives a complete set of pairwise combination of terms from the two ontologies. This method offers researchers the benefit of using ontologies that are already existing and available rather than building new ontologies for areas outside their scope of …

Semantic Interoperability Of Geospatial Ontologies: A Model-Theoretic Analysis, James A. Farrugia

Electronic Theses and Dissertations

People sometimes misunderstand each other, even when they use the same language to communicate. Often these misunderstandings happen when people use the same words to mean different things, in effect disagreeing about meanings. This thesis investigates such disagreements about meaning, considering them to be issues of semantic interoperability. This thesis explores semantic interoperability via a particular formal framework used to specify people’s conceptualizations of a given domain. This framework is called an ‘ontology,’ which is a collection of data and axioms written in a logical language equipped with a modeltheoretic semantics. The domain under consideration is the geospatial domain. Specifically, …

Derivation Of Change From Sequences Of Snapshots, Dominik Wilmsen

Electronic Theses and Dissertations

Current research in the domain of geographic information science considers possibilities of including another dimension, time, which is generally missing to this point. Users interested in changes have few functions available to compare datasets of spatial configurations at different points in time. Such a comparison of spatial configurations requires large amounts of manual labor. An automatic derivation of changes would decrease amounts of manual labor. The thesis introduces a set of methods that allows for an automatic derivation of changes. These methods analyze identity and topological states of objects in snapshots and derive types of change for the specific configuration …

Semantic Similarity Of Spatial Scenes, Konstantinos A. Nedas

Electronic Theses and Dissertations

The formalization of similarity in spatial information systems can unleash their functionality and contribute technology not only useful, but also desirable by broad groups of users. As a paradigm for information retrieval, similarity supersedes tedious querying techniques and unveils novel ways for user-system interaction by naturally supporting modalities such as speech and sketching. As a tool within the scope of a broader objective, it can facilitate such diverse tasks as data integration, landmark determination, and prediction making. This potential motivated the development of several similarity models within the geospatial and computer science communities. Despite the merit of these studies, their …

Hierarchies For Event-Based Modeling Of Geographic Phenomena, Rui Zhang

Electronic Theses and Dissertations

Modeling the dynamic aspect, or change, of geographic phenomena is essential to explain the evolution of geographic entities and predict their future. Event-based modelling, describing the occurrences rather than states of geographic phenomena, gives an explicit treatment of such change, but currently does not have the support of the mechanisms to enable the shifts among different granularities of events. To account for different tasks, a hierarchical representation of the event space at different granularities is needed.

This thesis presents an event-based model; a general framework for representing events based on precondition and postcondition using Allen's temporal interval logic. It captures …

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 …

A Data Model For Exploration Of Temporal Virtual Reality Geographic Information Systems, Jorge Alberto Prado De Campos

Electronic Theses and Dissertations

Geographic information systems deal with the exploration, analysis, and presentation of geo-referenced data. Virtual reality is a type of human-computer interface that comes close to the way people perceive information in the real world. Thus, virtual reality environments become the natural paradigm for extending and enhancing the presentational and exploratory capability of GIs applications in both the spatial and temporal domains. The main motivation of this thesis is the lack of a framework that properly supports the exploration of geographic information in a multi-dimensional and multi-sensorial environment (i.e., temporal virtual reality geographic information systems). This thesis introduces a model for …

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

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

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

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 …

Evaluating Conflicts In The Use And Development Of Geographic Information Systems, Amber Bethell

Electronic Theses and Dissertations

Use of geographic information systems is increasing in governments, commercial companies, and by individual users. With such pervasive use of GIs there has been surprisingly little investigation of the values that various parties would support in the development of geographic technologies. There are many parties involved in the use of GIs each with opinions of what are good goals for developing and using such systems. This research seeks to determine differences and similarities among parties in the importance placed on supporting specific societal goals germane to the use of geographic technologies and databases. Previous research determined six areas where the …

Modeling Boundaries Of Influence Among Positional Uncertainty Fields, Joshua P. King

Electronic Theses and Dissertations

Within a CIS environment, the proper use of information requires the identification of the uncertainty associated with it. As such, there has been a substantial amount of research dedicated to describing and quantifying spatial data uncertainty. Recent advances in sensor technology and image analysis techniques are making image-derived geospatial data increasingly popular. Along with development in sensor and image analysis technologies have come departures from conventional point-by-point measurements. Current advancements support the transition from traditional point measures to novel techniques that allow the extraction of complex objects as single entities (e.g., road outlines, buildings). As the methods of data extraction …

Ontology-Driven Geographic Information Systems, Frederico Torres Fonseca

Electronic Theses and Dissertations

Information integration is the combination of different types of information in a framework so that it can be queried, retrieved, and manipulated. Integration of geographic data has gained in importance because of the new possibilities arising from the interconnected world and the increasing availability of geographic information. Many times the need for information is so pressing that it does not matter if some details are lost, as long as integration is achieved. To integrate information across computerized information systems it is necessary first to have explicit formalizations of the mental concepts that people have about the real world. Furthermore, these …

Strategies For Handling Spatial Uncertainty Due To Discretization, Thomas Windholz

Electronic Theses and Dissertations

Geographic information systems (GISs) allow users to analyze geographic phenomena within areas of interest that lead to an understanding of their relationships and thus provide a helpful tool in decision-making. Neglecting the inherent uncertainties in spatial representations may result in undesired misinterpretations. There are several sources of uncertainty contributing to the quality of spatial data within a GIS: imperfections (e.g., inaccuracy and imprecision) and effects of discretization. An example for discretization in the thematic domain is the chosen number of classes to represent a spatial phenomenon (e.g., air temperature). In order to improve the utility of a GIS an inclusion …

Integrated Spatial Reasoning In Geographic Information Systems: Combining Topology And Direction, Jayant Sharma

Electronic Theses and Dissertations

As Geographic Information Systems (GISs) have gained wider acceptance and application, the interest in spatial modeling and reasoning has deepened. The purpose of a model and reasoning framework is to permit a user to experiment and study causal relationships in the real world by operating on the model only. Traditionally GISs employ purely quantitative methods to represent and infer spatial information. This approach has serious shortcomings when dealing with qualitative spatial information, which may be incomplete or imprecise and does not contain knowledge of the geometry of the spatial objects, which humans are particularly adept at utilizing in their daily …