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Full-Text Articles in Physical Sciences and Mathematics

Knowledge-Based Task Structure Planning For An Information Gathering Agent, John Phelps Jan 2003

Knowledge-Based Task Structure Planning For An Information Gathering Agent, John Phelps

Electronic Theses and Dissertations

An effective solution to model and apply planning domain knowledge for deliberation and action in probabilistic, agent-oriented control is presented. Specifically, the addition of a task structure planning component and supporting components to an agent-oriented architecture and agent implementation is described. For agent control in risky or uncertain environments, an approach and method of goal reduction to task plan sets and schedules of action is presented. Additionally, some issues related to component-wise, situation-dependent control of a task planning agent that schedules its tasks separately from planning them are motivated and discussed.


Detection And Generalization Of Spatio-Temporal Trajectories For Motion Imagery, Panayotis Partsinevelos Dec 2002

Detection And Generalization Of Spatio-Temporal Trajectories For Motion Imagery, Panayotis Partsinevelos

Electronic Theses and Dissertations

In today's world of vast information availability users often confront large unorganized amounts of data with limited tools for managing them. Motion imagery datasets have become increasingly popular means for exposing and disseminating information. Commonly, moving objects are of primary interest in modeling such datasets. Users may require different levels of detail mainly for visualization and further processing purposes according to the application at hand. In this thesis we exploit the geometric attributes of objects for dataset summarization by using a series of image processing and neural network tools. In order to form data summaries we select representative time instances …


Modeling Multiple Granularities Of Spatial Objects, Chitra Ramalingam Dec 2002

Modeling Multiple Granularities Of Spatial Objects, Chitra Ramalingam

Electronic Theses and Dissertations

People conceptualize objects in an information space over different levels of details or granularities and shift among these granularities as necessary for the task at hand. Shifting among granularities is fundamental for understanding and reasoning about an information space. In general, shifting to a coarser granularity can improve one's understanding of a complex information space, whereas shifting to a more detailed granularity reveals information that is otherwise unknown. To arrive at a coarser granularity. objects must be generalized. There are multiple ways to perform generalization. Several generalization methods have been adopted from the abstraction processes that are intuitively carried out …


Evaluating Conflicts In The Use And Development Of Geographic Information Systems, Amber Bethell Dec 2002

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 …


Sketch-Based Queries In Mobile Gis-Environments, David Caduff Dec 2002

Sketch-Based Queries In Mobile Gis-Environments, David Caduff

Electronic Theses and Dissertations

Recent achievements in the field of mobile computing and wireless communication promise data retrieval anywhere and anytime. This development provided the basis to expand GIs technology to handheld devices, such as personal digital assistants (PDAs). Although traditional GIs technology is well suited for desktop workstations, it needs to be adapted in order to satisfy the requirements of users using handheld computing devices. This adaptation is necessary because the usability of traditional GISs depends on characteristics of desktop computers, such as their relatively large user interfaces (e.g., displays, keyboards, pointing devices), considerable computing resources (i.e., CPU, memory, storage, operating systems), and …


Modeling Boundaries Of Influence Among Positional Uncertainty Fields, Joshua P. King Dec 2002

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 …


Biodiversity And Ecosystem Informatics - Bdei - Planning Workshop On Biodiversity And Ecosystem Informatics For The Indian River Lagoon, Florida, Mohamad T. Musavi Oct 2002

Biodiversity And Ecosystem Informatics - Bdei - Planning Workshop On Biodiversity And Ecosystem Informatics For The Indian River Lagoon, Florida, Mohamad T. Musavi

University of Maine Office of Research Administration: Grant Reports

This proposal solicits funding to organize and conduct a planning workshop that will establish and facilitate research on the informatics needed to address complex issues of biodiversity and ecosystem processes within the Indian River Lagoon. This workshop will provide the opportunity and resources for collaboration and discussion among scientists from diverse fields of biodiversity, ecological sciences, remote sensing, geographic information systems, computer science and intelligent systems. The topics to be discussed will include investigation of novel computational intelligence techniques for modeling, prediction, analysis and database management of the disparate and complex data for the Indian River Lagoon. The explicit products …


Modeling Intersections Of Geospatial Lifelines, Ramaswam Hariharan Dec 2001

Modeling Intersections Of Geospatial Lifelines, Ramaswam Hariharan

Electronic Theses and Dissertations

Modeling moving objects involves spatio-temporal reasoning. The continuous movements of objects in space-time captured as discrete samples form geospatial lifelines. Existing lifeline models can represent the movement of objects between samples from most likely location to all possible locations. This thesis builds on a model called lifeline bead and necklace that captures all the possible locations of moving objects. Beads are 3-dimensional representations of an object's movements and a series of beads form a necklace. The extent of finding the possible locations is constrained by the speed of movement of the objects. Intersections of lifelines occur when two or more …


Access To Geographic Scientific And Technical Data In An Academic Setting, Bastiaan Van Loenen May 2001

Access To Geographic Scientific And Technical Data In An Academic Setting, Bastiaan Van Loenen

Electronic Theses and Dissertations

Data availability is a key issue affecting society's social well being. Information technology has increased the availability of and improved access to data. The academic community that uses spatial data is one of the groups that has taken advantage of fast and inexpensive opportunities to share data and knowledge in a relatively unfettered fashion across digital networks. However, pressure by the private sector to increase protection for databases through database legislation, self-help measures (contracts, licensing and technological methods for limiting access) and movement by some local governments towards revenue generation from sales of data are decreasing or threatening to decrease …


Ontology-Driven Geographic Information Systems, Frederico Torres Fonseca May 2001

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 May 2001

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 …


Asynchronous Validity Resolution In Sequentially Consistent Shared Virtual Memory, Jonathan Thomas Jan 2001

Asynchronous Validity Resolution In Sequentially Consistent Shared Virtual Memory, Jonathan Thomas

Electronic Theses and Dissertations

Shared Virtual Memory (SVM) is an effort to provide a mechanism for a distributed system, such as a cluster, to execute shared memory parallel programs. Unfortunately, SVM has performance problems due to its underlying distributed architecture. Recent developments have increased performance of SVM by reducing communication. Unfortunately this performance gain was only possible by increasing programming complexity and by restricting the types of programs allowed to execute in the system. Validity resolution is the process of resolving the validity of a memory object such as a page. Current SVM systems use synchronous or deferred validity resolution techniques in which user …


Image-Based Change Detection Using An Integrated Spatiotemporal Gazetteer, Georgios Mountrakis Aug 2000

Image-Based Change Detection Using An Integrated Spatiotemporal Gazetteer, Georgios Mountrakis

Electronic Theses and Dissertations

This thesis addresses image-based change detection. Motivation was provided by the lack of algorithms that incorporate in their solution diverse types of pre-existing and complementary information and have the ability to interact with a spatiotemporal environment. The main differentiation with our approach is that we develop our algorithm within an integrated spatiotemporal environment and we make use of all change evidence that might exist within that environment. In addition, a change resolution model is developed that will distinguish meaningful changes based on user requirements. A model for change is proposed that establishes a general framework for the incorporation of image …


Ria: Selecting Information To Include In Cooperative Task — Oriented Dialogues, Elise H. Turner Jun 2000

Ria: Selecting Information To Include In Cooperative Task — Oriented Dialogues, Elise H. Turner

University of Maine Office of Research Administration: Grant Reports

The goal of this project was to delevop a technique for selecting information to volunteer in problem solving dialogues. The technique was to create usefulness ratings for information based on the problem solving of the agent that may communicate the information. Heuristics translate specific problem solving activities into contributions to the overall usefulness rating for the information. To this end, our objectives included determining the type of information that should be included in dialogues and implementing heuristics.


Using Raster Sketches For Digital Image Retrieval, James Carswell May 2000

Using Raster Sketches For Digital Image Retrieval, James Carswell

Electronic Theses and Dissertations

This research addresses the problem of content-based image retrieval using queries on image-object shape, completely in the raster domain. It focuses on the particularities of image databases encountered in typical topographic applications and presents the development of an environment for visual information management that enables such queries. The query consists of a user-provided raster sketch of the shape of an imaged object. The objective of the search is to retrieve images that contain an object sufficiently similar to the one specified in the query. The new contribution of this work combines the design of a comprehensive digital image database on-line …


Concurrency Issues In Programmable Brick Languages, Gilliad E. Munden Jan 2000

Concurrency Issues In Programmable Brick Languages, Gilliad E. Munden

Electronic Theses and Dissertations

Abstract

The programmable brick constitutes a domain for simple, autonomous robotics geared towards novice programmers in a constructionist setting. A large number of languages have been adapted from other domains to serve as a programming platform for this brick. However, there has yet to be an in-depth analysis of how these languages fit this domain. This work provides such an analysis of the existing brick languages in order to identify how they deal with the issue of concurrency as it relates to the brick. First, the brick domain is characterized and the languages involved are described. Second, the different approaches …


An Implementation Of The El Gamal Elliptic Curve Cryptosystem Over A Finite Field Of Characteristic P, Samuel Thomas Arslanian Jan 1998

An Implementation Of The El Gamal Elliptic Curve Cryptosystem Over A Finite Field Of Characteristic P, Samuel Thomas Arslanian

Electronic Theses and Dissertations

Since the earliest times, individuals and groups of individuals have been interested in communicating sensitive information in a manner which would guarantee that such information could not be arbitrarily received. Further, such information was to be received by select recipients and this required that a means of secure information transmission be found and employed. To these ends, methods of information encryption have ever since been sought and employed. The entire study and practice of this activity, cryptology, the science of message encryption and decryption, provides a framework for this thesis. In particular, the development of cryptology has been influenced by …


The Divided Information Superhighway, Robert Kuttner Jan 1995

The Divided Information Superhighway, Robert Kuttner

Maine Policy Review

This issue marks the introduction of the Margaret Chase Smith Essay, which will be a feature in each issue honoring Sen. Smith by focusing on issues related to citizenship, ethics in government, and integrity as a virtue of public leadership. In this first essay, economist Robert Kuttner asks some important ethical questions about the new world of electronic communications. He suggests that who plays and who pays are very important issues that have not been adequately considered in the highly technical and competitive world that will mark the 21st century. [This essay originally appeared as a column in the …