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Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 185-196).

The effects of immersion with respect to information visualization have rarely been explored. In this thesis, we describe a methodology, two information visualization applications that were developed using the CAVE, and three user studies in order to explore, examine and attempt to quantify the effects of immersion. We focus on three major components of immersion: field of regard (FOR), head-based rendering (HBR), and stereoscopic viewing. We hypothesize that a high degree of FOR will result in increased task performance and user satisfaction when visualizing data represented by scatter and surface plots. We also hypothesize that HBR and stereoscopic viewing will result in increased task performance, but the effects of these components would be greater in the scatter plots than surface plots. We have conducted three user studies with the information visualization applications developed for this research. In the first study, an exploratory pilot study, we observed a trend in favor of using high FOR and HBR. In the second exploratory pilot study, we observed a slight trend in favor of high FOR. In the third study, thirty-two subjects performed tasks using both the scatter plots and surface plots with eight test conditions. We observed trends in favor of high levels of FOR, HBR and stereoscopic viewing in scatter plots, a slight trend in favor of HBR for surface plots, and a significant interaction effect between FOR and HBR in scatter plots for a particular task. / Master of Science

This paper describes the "strucplot" framework for the visualization of multi-way contingency tables. Strucplot displays include hierarchical conditional plots such as mosaic, association, and sieve plots, and can be combined into more complex, specialized plots for visualizing conditional independence, GLMs, and the results of independence tests. The framework's modular design allows flexible customization of the plots' graphical appearance, including shading, labeling, spacing, and legend, by means of "graphical appearance control" functions. The framework is provided by the R package vcd.

This paper describes the `strucplot' framework for the visualization of multi-way contingency tables. Strucplot displays include hierarchical conditional plots such as mosaic, association, and sieve plots, and can be combined into more complex, specialized plots for visualizing conditional independence, GLMs, and the results of independence tests. The framework's modular design allows flexible customization of the plots' graphical appearance, including shading, labeling, spacing, and legend, by means of graphical appearance control (`grapcon') functions. The framework is provided by the R package vcd. (author's abstract) / Series: Research Report Series / Department of Statistics and Mathematics

This thesis examines vegetation community change at two temporal scales in the Piedmont of North Carolina. Using long-term plots in the Duke Forest, I examine decadal-scale changes in community composition of the forest understory and shed light on the potential drivers of that change. Using historical data from colonial survey records, I study presettlement forest communities of the Piedmont and attempt to reconstruct Piedmont forests as they may have been in the time before European arrival. The pattern of successional change in southeastern United States Piedmont forests has been assumed from chronosequence studies over the last half century. However, these assumptions for forest understory herb-layer populations and communities have not been tested using long term data sets. Using permanently marked plots in the Duke Forest (Durham, NC, USA) re-censused after a 23 year time step, species richness and community changes at 25m2 and 1000m2 scales are examined. I look at changes across life forms and examine these changes in relation to measured stand and environmental factors. Although total species richness stayed relatively constant through the 23 year step, herb richness declined with a concomitant increase in woody richness. Plot composition change was remarkably consistent and this change was not correlated to any measured stand or environmental factors. These community-level changes are consistent with previously reported changes in the understories of hardwood dominated stands in the Duke Forest, suggesting that landscape scale drivers may be more important than within-stand successional processes in patterning herbaceous communities at this time. Combined with growing evidence from other studies, this work indicates that forests in the temperate region may be experiencing changes different from those predicted by successional chronosequence studies. It indicates that one of the primary drivers of this change is the explosive growth of deer populations in the last two decades. Witness trees recorded in historical surveys have been used to reconstruct presettlement vegetation in many parts of North America, leading to a better understanding of vegetation patterns before the effects of Europeans. For some parts of North America, Government Land Office records make the process of reconstructing vegetation patterns easier - thus more is known about these areas. Because of the unique and unplanned nature of settlement in the southeastern U.S., less is known about the presettlement vegetation in this area of the country. Using a reconstructed cadastral map of a section of the North Carolina Piedmont, I was able to plot the positions of trees on the historical landscape. These data were then used to understand and reconstruct the composition of presettlement forests. Although the vegetation of some areas of the Piedmont is similar to what was expected, I find significant differences with the expected presettlement composition. In particular, pine species were common in some areas and rare in others, indicating that different disturbance regimes were active on the landscape. / Dissertation

Stickiness is a ubiquitous property of dynamical systems. However, recognizing whether an orbit is temporarily `stuck' (and therefore very nearly quasiperiodic) is hard to detect. Outlined in this thesis is an approach to quantifying stickiness in area-preserving maps based on a tool called recurrence plots that is not very commonly used. With the analyses presented herein it is shown that recurrence plot methods can give very close estimates to stickiness exponents that were previously calculated using Poincare recurrence and other methods. To capture the dynamics, RP methods require shorter data series than more conventional methods and are able to represent a more-global analysis of recurrence. A description of stickiness of the standard map for a wide array of parameter strengths is presented and a start at analyzing the standard nontwist map is presented. / text

The development of radiata pine (Pinus radiata D. Don.) clones was compared in monoclonal and clonal mixture plots planted in an experiment established at Dalethorpe, Canterbury, New Zealand with ten radiata pine clones in September 1993. Clones were deployed in a randomised complete block plot design with three replications. Each replication contained ten treatments of monoclonal plots and one in which all the clones were intimately mixed in equal proportions. Clones significantly differed in initial morphologies, survival and stem slenderness. Sturdiness and initial heights were found to be the best predictors of initial survivals. The study revealed that mode of deployment did not affect overall productivity, but individual clones exhibited significantly different productivities between modes of deployment. All clones contributed similarly to overall productivity in the monoclonal mode of deployment, whereas the contribution of clones in the clonal mixture mode of deployment was disproportionate. A minority of the clones contributed a majority of overall productivity in the clonal mixture mode of deployment. The inclusion of competition index as an independent variable in a distance-dependent individual tree diameter increment model explained a significant amount of variability in diameter growth. The use of an inverse-squared distance to neighbouring plants in the competition index provided a slightly superior fit to the data compared to one that employed a simple inverse of distance. Addition of genotype information in the competition index further improved the fit of the model. Clones experienced different levels of competition in monoclonal and clonal mixture modes of deployment. Competition in monoclonal plots remained uniform over time, whereas some clones experienced greater competition in clonal mixture plots which led to greater variability in their tree sizes. This study indicated that single tree plot progeny test selections and early selections may miss out some good genotypes that can grow rapidly if deployed monoclonally. Stand level modelling revealed that clones differed significantly in modeled yield patterns and model asymptotes. Clones formed two distinct groups having significantly different yield models. The study also demonstrated that models developed from an initial few years’ data were biased indicators of their relative future performances. Evaluation of effectiveness of the 3-PG hybrid model using parameter values obtained from destructive sampling and species-specific values from different studies revealed that it is possible to calibrate this model for simulating the productivity of clones, and predictions from this model might inform clonal selections at different sites under differing climatic conditions. Destructive sampling at age 5 years revealed that clones significantly differed in foliage and stem biomass. The differences in productivities of clones were mainly due to differences in biomass partitioning and specific leaf areas. Clones significantly differed in dynamic wood stiffness, stem-slenderness, branch diameter, branch index and branch angle at an initial stocking of 1250 stems/ha. Mode of deployment affected stem slenderness, which is sometimes related to stiffness. Although dynamic stiffness was correlated with stem slenderness and stem slenderness exhibited a significant influence on stiffness, clones did not exhibit statistically significant differences in dynamic stiffness. Increasing initial stocking from 833 stems/ha to 2500 stems/ha resulted in a 56 % decrease in branch diameter and a 17 % increase in branch angle. Trees in the monoclonal mode of deployment exhibited greater uniformity with respect to tree size, stem-slenderness, and competition experienced by clones compared to those in the clonal mixture mode of deployment. Susceptibility of one clone to Woolly aphid suggested that greater risks were associated with large scale deployment of susceptible clones in a monoclonal mode of deployment. This study also indicated that if the plants were to be deployed in a monoclonal mode then block plot selections would have greater potential to enhance productivity.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1965. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 161-175).