Expansive soils are treated with anhydrous or hydrated lime. The use of calcium-based stabilizers such as calcium oxide (lime) in sulfate-bearing clay soils has historically led to distress due to the formation of an expansive mineral called ettringite and possibly another such mineral, thaumasite. Predicting the precipitation of these minerals is a complex problem related not only to soil composition but also construction methods, availability of water, ion migration, and whether the expansive mineral growth can be accommodated by the void structure in the surrounding soil. In trying to control the damage associated with such occurrences, engineers have attempted to determine a threshold value of soluble sulfates, a quantity that is relatively easy and quick to measure, at which significant ettringite growth and, therefore, structural distress occurs. Unfortunately, experience alone and “rules-of-thumb” based on experience are not sufficient to deal with this complex issue. This thesis describes how thermodynamic geochemical models of lime-treated soil can be used as a first step toward establishing problematic threshold levels of soluble sulfates for a specific soil. A foundation for the model development is presented, and two different soils are compared to illustrate their very different sensitivities to ettringite growth upon the addition of hydrated lime. Various soil series along the route of SH 130 between Austin and San Antonio have been identified to contain soluble sulfate that may pose a problem for soil stabilization using lime and cement. Since the model predicts ettringite growth based upon site-specific properties, this thesis also shows how the model can be used to assess the potential amelioration effects of soluble silica. Research was conducted at the Texas Transportation Institute to develop a methodology for identifying areas which are susceptible for ettringite formation. The proposed methodology uses a magnetometer to quickly screen large areas for high sulfate. Application of GIS to identify ettringite formation using soils, topographical, and geological maps is also illustrated in this thesis.

Tabular data is pervasive in the form of spreadsheets and relational databases. Although tables often describe multivariate data without explicit network semantics, it may be advantageous to explore the data modeled as a graph or network for analysis. Even when a given table design conveys some static network semantics, analysts may want to look at multiple networks from different perspectives, at different levels of abstraction, and with different edge semantics. This dissertation is motivated by the observation that a general approach for performing multi-dimensional and multi-level network-based visual analysis on multivariate tabular data is necessary. We present a formal framework based on the relational data model that systematically specifies the construction and transformation of graphs from relational data tables. In the framework, a set of relational operators provide the basis for rich expressive power for network modeling. Powered by this relational algebraic framework, we design and implement a visual analytics system called Ploceus. Ploceus supports flexible construction and transformation of networks through a direct manipulation interface, and integrates dynamic network manipulation with visual exploration for a seamless analytic experience.

<p>Reverse Engineering of software is a complex task. It is supported by various analyses and the computation of certain software quality metrics. To get an overview of the structure of the analysed software it is often necessary to visualize the relations between different components of software.</p><p>The VizzAnalyzer tool was developed for these purposes and allows visualizing the internal structure of software systems as UML2.0 class diagrams. The existing Eclipse-based visualization plug-in does not allow to automatically lay out the computed graph. Applying the layout manually is not feasible for larger graphs. A proper layout is needed to understand the provided information intuitively and the usefulness of the visualization is, on top of that, strongly connected to its layout.</p><p>In this thesis, we first state requirements for the development and implementation process of a suitable layout algorithm. We further describe the development, design, and implementation of the Sugiyama layout algorithm into the existing Eclipse-based visualization plug-in. We add these new functionalities to be able to automatically compute a layout for given UML2.0 class diagrams achieving a proper Sugiyama layout for this type of diagrams.</p><p>At the end of this thesis, we compare the results achieved by the implemented algorithm with the results achieved by yEd given the same diagrams as input.</p>

<p>In this thesis, a 3D approach to visualize software metrics is presented. Software metrics are attributes of a piece of software or its specification. They generally contain a set of multivariate time-series data and can be displayed, for example, as a Kiviat diagram consisting of axes and polylines. The aim of this work is to design a Win32 application that can load multivariate time-series data from a file and visualize it as an interactive 3D Kiviat diagram.</p><p>There has been an approach that can display software metrics by using 2D Kiviat diagrams, but there are still some drawbacks on it. Since a better visualization of software metrics can help the developer to control the quality of software products more easily, this thesis improved the existing approach by extending 2D Kiviat diagram to 3D Kiviat diagram.</p>

In this paper, we examine Fox colorings of virtual knots, and moves called k-swap moves defined for virtual knot diagrams. The k-swap moves induce a one-to-one correspondence between colorings before and after the move, and can be used to reduce the number of virtual crossings. For the study of colorings, we characterize families of alternating virtual knots to generalize (2, n)-torus knots, alternating pretzel knots, and alternating 2-bridge knots. The k-swap moves are then applied to prove a "virtualization" of the Kauffman-Harary conjecture, originally stated for classical knot diagrams, for the above families of virtual pretzel knot diagrams.

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Mobile robots are increasingly being used to perform tasks in unknown environments. The potential of robots to undertake such tasks lies in their ability to intelligently and efficiently locate and interact with objects in their environment. My research focuses on developing algorithms to plan paths for mobile robots in a partially known environment observed by an overhead camera. The environment consists of dynamic obstacles and targets. A new methodology, Extrapolated Artificial Potential Field, is proposed for real time robot path planning. An algorithm for probabilistic collision detection and avoidance is used to enhance the planner. The aim of the robot is to select avoidance maneuvers to avoid the dynamic obstacles. The navigation of a mobile robot in a real-world dynamic environment is a complex and daunting task. Consider the case of a mobile robot working in an office environment. It has to avoid the static obstacles such as desks, chairs and cupboards and it also has to consider dynamic obstacles such as humans. In the presence of dynamic obstacles, the robot has to predict the motion of the obstacles. Humans inherently have an intuitive motion prediction scheme when planning a path in a crowded environment. A technique has been developed which predicts the possible future positions of obstacles. This technique coupled with the generalized Voronoi diagram enables the robot to safely navigate in a given environment.

Sketching is an important part of creativity process and is used in the design disciplines, concerned with making physical form: mechanical and civil engineering, graphic design, and architecture and physical planning. Almost all designers still begin the design process by sketching their ideas before transferring them to the computer. This helps designers to express nascent ideas fast and naturally and to speed up visual problem solving. Moreover, the importance of sketching in design has been recognized emphasizing that initial drawing allows creative freedom. The sketches represent a rough semblance and functionality of the system and can be essential to understanding the reasoning behind a design. Furthermore, sketching activity makes designers to interact with their sketches, examine all alternative possibilities and explore design solutions in their minds during drawing. This important part of design, which supports ambiguity, imprecision and incremental formalization of ideas as well as rapid exploration of alternatives, is still performed by engineers with the help of paper and pencil. Despite praxis and fondness of natural interface provided by paper, sketching on paper has its own limitations. The main disadvantage of sketching on paper is that you can easily draw the sketch, but editing and improving of design is more problematic. If designer wants to make changes in the sketch, usually he has to take another sheet of paper and basically redraw the sketch... [to full text]

The direct sum decomposition of tensor products for SU(3) has many applications in physics, and the problem has been studied extensively. This has resulted in many decomposition methods, each with its advantages and disadvantages. The description given here is geometric in nature and it describes both the constituents of the direct sum and their multiplicities. In addition to providing decompositions of specific tensor products, this approach is very well suited to studying tensor products as the parameters vary, and drawing general conclusions. After a description and proof of the method, several applications are discussed and proved. The decompositions are also studied further for the special cases of tensor products of an irreducible representation with itself or with its conjugate. In particular, questions regarding multiplicities are considered. As an extension of this diagrammatic method, the repeated tensor product of N copies of the fundamental representation is studied, and a method for its decomposition is provided. Again, questions regarding multiplicities are considered.