Browsing by Subject "modeling"
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Item A new graphical user interface for a 3D topological mesh modeler(Texas A&M University, 2008-10-10) Morris, David VictorIn this thesis, I present a new platform-independent, open source, intuitive graphical user interface for TopMod, an application designed for interacting with 3-dimensional manifold meshes represented by a Doubly Linked Face List (DLFL). This new interface, created using the Trolltech Qt user interface library, enables users to construct and interact with complex manifold meshes much faster and more easily than was previously possible. I also present a method for the rapid creation of a successful online community of users and developers, by integrating a variety of open source web-based software packages. The new website, which includes a discussion forum, a news blog, a collaborative user and developer wiki, and a source code repository and release manager, received an average of 250 unique visits per day during the first two months of its existence, and it continues to be utilized by a variety of users and developers worldwide.Item A scripting interface for doubly linked face list based polygonal meshes(2009-05-15) Tett, Stuart TostenThis thesis presents a scripting language interface for modeling manifold meshes represented by a Doubly Linked Face List (DLFL).With a scripting language users can create procedurally generated meshes that would otherwise be tedious or impractical to create with a graphical user interface. I have implemented a scripting language interface for the user to create stand-alone scripts as well as script interactively within a graphical environment.Item Adsorption of As(V), As(III) and methyl arsenic by calcite and the impact of some groundwater species(2009-05-15) Jones, Robert GarretThe objective of this research was to investigate the retention of arsenate (iAsV), arsenite (iAsIII), monomethyl arsenate (MMAsV) and dimethyl arsenate (DMAsV) by calcite and assess the impact of dissolved Ca2+, Mg2+, phosphate and sulfate on arsenic solubility, adsorption and precipitation phenomena. Adsorption kinetics of iAsV, evaluated at a low and high concentration, was a relatively rapid process, with a fast initial reaction rate within the first few minutes and a subsequent slower reaction rate as equilibrium was approached. The relative adsorption of arsenicals decreased in the following order: iAsV > iAsIII > DMAV > MMAV. In no case was a clear adsorption maximum observed with increasing dissolved arsenic concentration. Dissolved 0.01 M Ca2+ resulted in an increase in iAsV adsorption; however, in the presence of 0.1 M Ca2+ adsorption of iAsV was decreased. The presence of Mg2+ as 0.01 M Mg(NO3)2 resulted in decreased iAsV adsorption probably the result of a lower iAsV affinity for adsorbed Mg2+ as compared to Ca2+. Phosphate and sulfate were highly competitive with iAsV in adsorption to calcite and both resulted in decreased iAsV adsorption. The total prevention of iAsV adsorption at initial equimolar arsenic/phosphate concentrations > 88 ?M each could be from the consumption of available calcite surface sites by the specific adsorption of phosphate. Equilibrium modeling, using the geochemical and mineral speciation of equilibrium model (MINTEQA2), indicated that at low concentrations of arsenate or phosphate solid-phase precipitation was not likely and adsorption processes likely controlled solubility. At high concentrations of arsenate Ca3(AsO4)2 ? 3 2/3 H2O and Ca3(AsO4)2 ? 4 1/4 H2O solid phases could be controlling arsenate solubility. This study indicates that arsenic adsorption response by calcite was different than that of phosphate suggesting that arsenic may not be specifically adsorbed to calcium at the calcite surface. Reduction and biomethylation of arsenic decreased adsorption, suggesting that processes which could affect the speciation of arsenic in the environment, could increase arsenic mobility in environmental systems where calcite and dissolved aqueous calcium play a predominant role in controlling arsenic solubility. Dissolved aqueous concentrations of magnesium, phosphate and sulfate generally reduced the ability of arsenic to be adsorbed to calcite.Item Aerosol-cloud Interactions from Urban, Regional, to Global Scales(2013-07-30) Wang, YuanThe studies in this dissertation aim at advancing our scientific understandings about physical processes involved in the aerosol-cloud-precipitation interaction and quantitatively assessing the impacts of aerosols on the cloud systems with diverse scales over the globe on the basis of the observational data analysis and various modeling studies. Long-term impacts of aerosols on precipitation and lightning over the Pearl River Delta megacity area in China are identified through the analysis of seven-year measurements of precipitation, lightning flashes, and visibility from 2000 to 2006. The cloud resolving - Weather Research and Forecasting (CR-WRF) model with a two- moment bulk microphysical scheme is employed to simulate a mesoscale convective system in the Guangzhou megacity area and to elucidate the effects of aerosols on cloud processes, precipitation, and lightning activity. The responses of hydrometeors and latent heat release to different aerosol loadings reveal the physical mechanism for the precipitation and lightning enhancement in the Guangzhou megacity area, showing more efficient mixed phase processes and intensified convection under the polluted aerosol condition. Sensitivity modeling experiments are performed for maritime warm stratocumulus clouds over the southeast Pacific Ocean to evaluate the microphysical parameterizations for simulations of the aerosol effects in regional and global climate models. The Morrison double-moment bulk microphysical scheme presently implemented in the WRF model is modified by replacing the fixed aerosols in the original bulk scheme with a prognostic double-moment aerosol representation to predict both aerosol number concentration and mass mixing ratio. The impacts of the parameterizations of diffusional growth and autoconversion of cloud droplets and the selection of the embryonic raindrop radius on the performance of the bulk microphysical scheme are also evaluated. The impacts of Asian pollution outflows on the Pacific storm track are assessed utilizing reanalysis data, a hierarchical modeling approach and the multi-scale aerosol- climate modeling frame. Statistical analysis of two sets of reanalysis data suggests a strengthened trend of the storm track intensity over the North Pacific since 1979. The two-month seasonal simulations using a CR-WRF model with a two-moment bulk microphysics are performed to examine the aerosol effects on the Pacific storm track intensity. Subsequently, the anomalies of the diabatic heating rate by the Asian pollution outflow derived from the CR-WRF simulations have been prescribed in the NACR Community Atmosphere Model (CAM5) to provide the aerosol forcing terms. The forced GCM well reproduces an enhancement in the intensity of storm track, compared to the unforced model simulations. Similarly, under the multi-scale aerosol-climate modeling frame, the comparisons of the simulated present day versus pre-industrial climate corresponding to two different aerosol scenarios indicate the increased precipitation and poleward heat transport for the present-day climate reveal invigorated mid-latitude cyclones. The current work illustrates the complexity of the aerosol effects on the cloud systems at the diverse scales with different meteorological conditions. This study also stresses the importance of accurate representation of aerosol forcings in the different types of atmospheric numerical models for future climate projections.Item An Automated System for the Creation of Articulated Mechanical Parts(2010-07-14) Wheeler, Christopher R.Proposes a new method to model the geometric form of articulated mechanical parts while simultaneously testing their range of motion in relation to other nearby parts. Utilizing a database of mechanical parts in virtual three-dimensional form, a software tool assists users in quickly building a complex high-level mechanical object which can be placed directly into a visual effects production pipeline. The tool creates a workflow that allows modeling and rigging problems to be solved concurrently within the same interface. Optimized animation controls are generated automatically to expedite the rigging process. A system of standardization provides a framework for each part?s functionality within the hierarchy of each new assembly, while also guaranteeing reusability and backwards compatibility with all other assemblies created with this tool. A prototype has been developed as a plug-in to existing commercial software to showcase the described methodology. This prototype provides a unique solution to common modeling and rigging problems in the field of visual effects and animation.Item Asphalt Oxidation Kinetics and Pavement Oxidation Modeling(2012-07-16) Jin, XinMost paved roads in the United States are surfaced with asphalt. These asphalt pavements suffer from fatigue cracking and thermal cracking, aggravated by the oxidation and hardening of asphalt. This negative impact of asphalt oxidation on pavement performance has not been considered adequately in pavement design. Part of the reason is that the process of asphalt oxidation in pavement is not well understood. This work focused on understanding the asphalt oxidation kinetics and on developing pavement oxidation model that predicts asphalt oxidation and hardening in pavement under environmental conditions. A number of asphalts were studied in laboratory condition. Based on kinetics data, a fast-rate ? constant-rate asphalt oxidation kinetics model was developed to describe the early nonlinear fast-rate aging period and the later constant-rate period of asphalt oxidation. Furthermore, reaction kinetics parameters for the fast-rate and constant-rate reactions were empirically correlated, leading to a simplified model. And the experimental effort and time to obtain these kinetics parameters were significantly reduced. Furthermore, to investigate the mechanism of asphalt oxidation, two antioxidants were studied on their effectiveness. Asphalt oxidation was not significantly affected. It was found that evaluation of antioxidant effectiveness based on viscosity only is not reliable. The asphalt oxidation kinetics model was incorporated into the pavement oxidation model that predicts asphalt oxidation in pavement. The pavement oxidation model mimics the oxidation process of asphalt in real mixture at pavement temperatures. A new parameter, diffusion depth, defined the oxygen diffusion region in the mastic. A field calibration factor accounted for the factors not considered in the model such as the effect of small aggregate particles on oxygen diffusion. Carbonyl area and viscosity of binders recovered from field cores of three pavements in Texas were measured and were used for model calibration and validation. Results demonstrated that the proposed model estimates carbonyl growth over time in pavement, layer-by-layer, quite well. Finally, this work can be useful for incorporating asphalt oxidation into a pavement design method that can predict pavement performance with time and for making strategic decisions such as optimal time for maintenance treatments.Item Bacterial total maximum daily load (TMDL): development and evaluation of a new classification scheme for impaired waterbodies of Texas(Texas A&M University, 2005-02-17) Paul, SabuUnder the Clean Water Act (CWA) program the Texas Commission on Environmental Quality (TCEQ) listed 110 stream segments with pathogenic bacteria impairment in 2000. The current study was conducted to characterize the watersheds associated with the impaired waterbodies. The main characteristics considered for the classification of waterbodies were designated use of the waterbody, land use distribution, density of stream network, average distance of a land of a particular use to the closest stream, household population, density of on-site sewage facilities (OSSF), bacterial loading due to the presence of different types of farm animals and wildlife, and average climatic conditions. The availability of observed in-stream fecal coliform bacteria concentration data was evaluated to obtain subgroups of data-rich and data-poor watersheds within a group. The climatic data and observed in-stream fecal coliform bacteria concentrations were analyzed to find out seasonal variability of the water quality. The watershed characteristics were analyzed using the multivariate statistical analysis techniques such as factor analysis/principal component analysis, cluster analysis, and discriminant analysis. Six groups of watersheds were formed as result of the statistical analysis. The main factors that differentiate the clusters were found to be bacterial contribution from farm animals and wildlife, density of OSSF, density of households connected to public sewers, and the land use distribution. Two watersheds were selected each from two groups of watersheds. Hydrological Simulation Program-FORTRAN (HSPF) model was calibrated for one watershed within each group and tested for the other watershed in the same group to study the similarity in the parameter sets due to the similarity in watershed characteristics. The study showed that the watersheds within a given cluster formed during the multivariate statistical analysis showed similar watershed characteristics and yielded similar model results for similar model input parameters. The effect of parameter uncertainty on the in-stream bacterial concentration predictions by HSPF was evaluated for the watershed of Salado Creek, in Bexar County. The parameters that control the HSPF model hydrology contributed the most variance in the in-stream fecal coliform bacterial concentrations corresponding to a simulation period between 1 January 1995 and 31 December 2000.Item Brittle Fracture Modeling with a Surface Tension Excess Property(2012-10-30) Ferguson, LaurenThe classical theory of linear elastic fracture mechanics for a quasi-static crack in an infinite linear elastic body has two significant mathematical inconsistencies: it predicts unbounded crack-tip stresses and an elliptical crack opening profile. A new theory of fracture developed by Sendova and Walton, based on extending continuum mechanics to the nanoscale, corrects these erroneous effects. The fundamental attribute of this theory is the use of a dividing surface to describe the material interface. The dividing surface is endowed with an excess property, namely surface tension, which accounts for atomistic effects in the interfacial region. When the surface tension is taken to be a constant, Sendova and Walton show that the theory reduces the crack-tip stress from a square root to a logarithmic singularity and yields a finite angle opening profile. In addition, they show that if the surface tension depends on curvature, the theory completely removes the stress singularity at the crack-tip, for all but countably many values of the two surface tension parameters, and yields a cusp-like opening profile. In this work, we develop a numerical model using the finite element method for the Sendova-Walton fracture theory applied to the classical Griffith crack problem in the case of constant surface tension. We show that the numerical model behaves as predicted by the theory, yielding a reduced crack-tip singularity and a finite opening angle for all nonzero values of the constant surface tension. We also lay the groundwork for the numerical implementation of the curvature-dependent model by constructing an algorithm to determine the appropriate threshold values for the surface tension parameters that guarantee bounded crack-tip stresses. These values can then be directly applied to the forthcoming numerical model.Item Characterization of livestock herds in extensive agricultural settings in southwest Texas(2009-05-15) Dominguez, Brandon JamesBecause of an ever-increasing threat of foreign animal disease outbreaks in the United States, there is a desire to develop strategies to prevent the occurrence of a foreign animal disease and control an outbreak if it does occur. Infectious disease models have been developed and are being used to determine reasonable mitigation strategies. However, little information is available concerning premises characteristics and movement of animals in extensively managed livestock areas. Hence adaptation of these models to areas where there is low livestock density is not easy. We collected empirical data, via mail out surveys, from an extensively managed livestock area. This will aid in improving the results of infectious disease models in these areas. In contrast to the intensively managed livestock that have previously been modeled, this study has shown that in areas of low livestock density, multiple livestock types often are managed on the same premises. Direct contacts, facilitated through the planned movement of animals, appear to have a greater seasonality in extensively managed areas as compared to intensively managed areas. Furthermore, wildlife contacts are likely and of potential importance. The results of this study add to the knowledge base used to model the spread of infectious disease in extensively managed livestock populations. Seasonal changes in animal densities and contact rates may impact the results of the models. Additionally, the effect of multiple livestock types on premises should be considered when the expected spread of disease is modeled in extensive livestock areas.Item Conversion of methanol to light olefins on SAPO-34: kinetic modeling and reactor design(Texas A&M University, 2005-02-17) Al Wahabi, Saeed M. H.In this work, the reaction scheme of the MTO process was written in terms of elementary steps and generated by means of a computer algorithm characterizing the various species by vectors and Boolean relation matrices. The number of rate parameters is very large. To reduce this number the rate parameters related to the steps on the acid sites of the catalyst were modeled in terms of transition state theory and statistical thermodynamics. Use was made of the single event concept to account for the effect of structure of reactant and activated complex on the frequency factor of the rate coefficient of an elementary step. The Evans-Polanyi relation was also utilized to account for the effect of the structure on the change in enthalpy. The structure was determined by means of quantum chemical software. The number of rate parameters of the complete reaction scheme to be determined from experimental data is thus reduced from 726 to 30. Their values were obtained from the experimental data of Abraha by means of a genetic algorithm involving the Levenberg-Marquardt algorithm and combined with sequential quadratic programming. The retained model yields an excellent fit of the experimental data. All the parameters satisfy the statistical tests as well as the rules of carbenium ion chemistry. The kinetic model also reproduces the experimental data of Marchi and Froment, also obtained on SAPO-34. Another set of their data was used to introduce the deactivation of the catalyst into the kinetic equations. This detailed kinetic model was used to investigate the influence of the operating conditions on the product distribution in a multi-bed adiabatic reactor with plug flow. It was further inserted into riser and fluidized bed reactor models to study the conceptual design of an MTO reactor, accounting for the strong exothermicity of the process. Multi-bed adiabatic and fluidized bed technologies show good potential for the industrial process for the conversion of methanol into olefins.Item Development of dynamic models of reactive distillation columns for simulation and determination of control(Texas A&M University, 2005-02-17) Chakrabarty, ArnabDynamic models of a reactive distillation column have been developed and implemented in this work. A model describing the steady state behavior of the system has been built in a first step. The results from this steady state model have been compared to data provided from an industrial collaborator and the reconciled model formed the basis for the development of a dynamic model. Four controlled and four manipulated variables have been determined in a subsequent step and step tests for the manipulated variables were simulated. The data generated by the step responses was used for fitting transfer functions between the manipulated and the controlled variables. RGA analysis was performed to find the optimal pairing for controller design. Feedback controllers of PID type were designed between the paired variables found from RGA and the controllers were implemented on the column model. Both servo and regulatory problems have been considered and tested.Item Discrete fracture modeling for fractured reservoirs using Voronoi grid blocks(Texas A&M University, 2007-09-17) Gross, Matthew EdwardFractured reservoirs are commonly simulated using the Dual Porosity model, but for many major fields, the model does not match field results. For these cases, it is necessary to perform a more complex simulation including either individual fractures or pseudofracture groups modeled in their own grid blocks. Discrete Fracture Modeling (DFN) is still a relatively new field, and most research on it up to this point has been done with Delaunay tessellations. This research investigates an alternative approach using Voronoi diagrams, yet applying the same DFN principles outlined in previous works. Through the careful positioning of node points, a grid of Voronoi polygons can be produced so that block boundaries fall along the fractures, allowing us to use the DFN simulation methods as proposed in the literature. Using Voronoi diagrams allows us to use far fewer polygons than the Delaunay approach, and also allows us to perfectly align flow so as to eliminate grid alignment errors that plagued previous static systems. The nature of the Voronoi polygon further allows us to simplify permeability calculations due to orthogonality and, by extension, is more accurate than the commonly used cornerpoint formulation for non-square grid blocks.Item Effective contact of cattle and feral swine facilitating potential foot-and-mouth disease virus transmission in southern Texas, USA rangeland(2009-05-15) De La Garza, Guadalupe Ray, IIIFor the second study, a web-based survey was developed and distributed to all members of four major health education organizations. A total of 1,925 HEs? completed the survey and 1,607 responses were utilized in the final analysis. This study indicated that participants had deficient knowledge and unfavorable attitudes toward the CDCproposed genomic competencies. In the third study, a theoretical model was developed to predict HEs? likelihood to incorporate genomic competencies into their practice. Using techniques from Structural Equation Modeling (SEM), the model was tested with the same data of the second study. Findings supported the proposed theoretical model. While genomic knowledge, attitudes, and self-efficacy were significantly associated with HEs? likelihood to incorporate genomic competencies into their practice, attitudes was the strongest predictor of likelihood. In summary, these studies indicated that participating HEs had deficient genomic knowledge, unfavorable attitudes toward a set of CDC-proposed genomic competencies, and low likelihood to adopt genomic competencies into health promotion. Relevant training should be developed and advocated. As the SEM analysis results indicated the survey findings supported the proposed theoretical model, which can be utilized to steer future training for HEs. statistics, 2) unadjusted inferential statistics, 3) stratified analysis, and 4) multivariable models. My investigation produced results in accord with generally accepted notions in addition to significant findings that interestingly counter current preconceptions. Intraspecies contact was more common than inter-species, with indirect contact occurring more frequently than direct. Direct contact between species occurred extremely rarely. The most important factors that influenced the rate of contact for both species were water, winter, and cultivated fields. Information regarding probability of infectious agent survival and transfer will be used in the future to advance current epidemiological models, including geographicautomata (Ward et al. 2007: In Press) and cellular automata models (Doran and Laffan 2005) to better understand and manage integrated domestic cattle and free-ranging wildlife populations. Such modeling provides essential and necessary knowledge for developing prevention, detection, response, and recovery strategies ? employed in advance, during, and after a disease outbreak, respectively.Item Efficient Smoothing and Interpolation of Velocity Models for Seismic Wavefront Construction Algorithms(2012-10-19) Chen, BoThe wavefront construction (WFC) method is an effective tool to compute seismic ray fields and has wide applications. This paper applies the WFC method to a heterogeneous earth model represented as a 3-D grid instead of a sequence of smooth layers, as the layered model is insufficient for the regions with complex geological structures. In order to utilize gridded models, highly heterogeneous models must be smoothed for reliable numerical results. A new velocity gradient smoothing method is proposed that is able to control quantitatively the smoothness of the velocity model while preserving the main structural characteristics of the original model. A modified inverse distance weighting method is applied to obtain velocities or densities at an arbitrary point in the model for successive wavefront propagation. A very complex 3-D grid model based on the standard Marmousi reference model is tested to compare the new approach to alternative smoothing schemes, and the first arrival travel times from the WFC method are compared with results from an eikonal solver. These results are obtained more quickly, but the algorithm is restricted to computing only first arrivals. However, comparison helps to establish the accuracy of the WFC solutions and assess the influence of the smoothing schemes. The modeling comparisons verify the effectiveness of the proposed smoothing methods and the enhanced performance of the WFC algorithm with the 3-D grid model.Item Enhancement of the Response Range and Longevity of Microparticle-based Glucose Sensors(2011-08-08) Singh, SaurabhLuminescent microspheres encapsulating glucose oxidase and an oxygensensitive lumophore have recently been reported as potential implantable sensors for in vivo glucose monitoring. However, there are two main issues that must be addressed for enzymatic systems such as these to realize the goal of minimally-invasive glucose monitoring. The first issue is related to the short response range of such sensors, less than 200 mg/dL, which must be extended to cover the full physiological range (0-600 mg/dL) of glucose possible for diabetics. The second issue is concerning the short operating lifetime of these systems due to enzyme degradation (less than 7 days). Two approaches were considered for increasing the range of the sensor response; nanofilm coatings and particle porosity. In the first approach, microparticle sensors were coated with layer-by-layer deposited thin nanofilms to increase the response range. It was observed that, a precise control on the response range of such sensors can be achieved by manipulating different characteristics (e.g., thickness, deposition condition, and the outermost capping layer) of the nanofilms. However, even with 15 bilayers of poly(allylamine hydrochloride)/poly(styrene sulfonate) (PAH/PSS) nanofilm, limited range was achieved (less than 200 mg/dL). By performing extrapolation on the data obtained for the experimentally-determined response range versus the number of PAH/PSS bilayers, it was predicted that a nanofilm coating comprising of more than 60 PAH/PSS bilayers will be needed to achieve a linear response up to 600 mg/dL. Using modeling, it was realized that a more effective method for achieving a linear response up to 600 mg/dL is to employ microparticles with higher porosity. Sensors were prepared from highly porous silica microparticles (diameter = 7 mu m, porosity = 0.6) and their experimental response was determined. Not surprisingly, the experimentally determined response range of such sensors was found to be higher than 600 mg/dL. To improve the longevity of these sensors, two approaches were employed; incorporation of catalase and increasing the loading of glucose oxidase. Catalase was incorporated into microparticles, which protects the enzyme from peroxide-mediated deactivation, and thus improves the stability of such sensors. Sensors incorporating catalase were found to ~5 times more stable than the GOx-only sensors. It was theoretically predicted, that by maximizing the loading of glucose oxidase within the microparticles, the longevity of such sensors can be substantially improved. Based on this understanding, sensors were fabricated using highly porous microparticles; response range did not vary even after one month of continuous operation under normal physiological conditions. Modeling predicts that 1 mM of glucose oxidase and 1 mM of catalase would extend the operating lifetime to more than 90 days.Item Fundamental kinetic modeling of the catalytic reforming process(Texas A&M University, 2007-04-25) Sotelo-Boyas, RogelioIn this work, a fundamental kinetic model for the catalytic reforming process has been developed. The complex network of elementary steps and molecular reactions occurring in catalytic reforming has been generated through a computer algorithm characterizing the various species by vectors and Boolean relation matrices. The algorithm is based on the fundamental chemistry occurring on both acid and metal sites of the catalyst. Rates are expressed for each of the elementary steps involved in the transformation of the intermediates. The Hougen-Watson approach is used to express the rates of the molecular reactions occurring on the metal sites of the catalyst. The single event approach is used to account for the effect of structure of reactant and activated complex on the rate coefficients of the elementary steps occurring on the acid sites. This approach recognizes that even if the number of elementary steps is very large they belong to a very limited number of types, and therefore it is possible to express the kinetics of elementary steps by a reduced number of parameters. In addition, the single event approach leads to rate coefficients that are independent of the feedstock, due to their fundamental chemical nature. The total number of parameters at isothermal conditions is 45. To estimate these parameters, an objective function based upon the sum of squares of the residuals was minimized through the Marquardt algorithm. Intraparticle mass transport limitations and deactivation of the catalyst by coke formation are considered in the model. Both the Wilke and the Stefan-Maxwell approaches were used to calculate the concentration gradients inside of the particle. The heterogeneous kinetic model was applied in the simulation of the process for typical industrial conditions for both axial and radial flow fixed bed reactors. The influence of the main process variables on the octane number and reformate volume was investigated and optimal conditions were obtained. Additional aspects studied with the kinetic model are the reduction of aromatics, mainly benzene. The results from the simulations agree with the typical performance found in the industrial process.Item Futurist sculpting: modeling movement in 3D(Texas A&M University, 2007-04-25) Krawczyk, PiotrFuturist Sculpting is a collection of techniques for representing dynamic motion in a static three-dimensional model. These techniques allow digital artists to use animation as a new modeling tool. The idea of Futurist Sculpting is inspired by the works of the Italian Futurist artists and it aims to achieve the same goal as the one described by Umberto Boccioni, ??????to find a form that would be like a remembered motion, the product of time but permanent in space.?????? However, Futurist Sculpting extends Boccioni??????s idea to the new medium of 3D animation and modeling, introducing the techniques of Motion Snapshot, Surface Differentiation, and Motion Elasticity. Motion Snapshot has evolved from the idea that multiple key poses captured at different stages of motion can successfully portray the idea of movement. Surface Differentiation was developed to remove redundancy of overlaping geometry introduced by snapshots occuring with high spatial frequency. Exploded Snapshot creates a geometric blur effect and extends application of Motion Snapshots to motion of deforming objects. The Motion Elasticity technique stretches the object to represent a partial volume through which it is moving. As a proof of concept all of the Futurist Sculpting techniques were implemented in Maya. The techniques should be viewed as a set of tools for the artists. The user can choose any one of them to apply to any animation, but he needs to understand their applications and limitations too.Item HABITAT SUITABILITY MODELING OF PEROMYSCUS PECTORALIS (WHITE-ANKLED MOUSE) IN VAL VERDE CO., TEXASMorgan, Clint Newman; Dowler, Robert C; Ammerman, Loren K; Negovetich, Nicholas J; Dickison, James WThe goal of this work was to utilize habitat suitability modeling and spool-and-line tracking to delineate habitat use and distribution of the White-ankled mouse (Peromyscus pectoralis), within the Devils River State Natural Area – Big Satan Unit (DRSNA - BSU), in Val Verde County, Texas. Using trapping data from a 21 month period (February 2013 - October 2014), MaxEnt modeling was used to determine which of 7 environmental variables contributed the most to the species distribution at DRSNA - BSU, and a species distribution map was generated. A jackknife test of variable importance determined vegetation series and slope as the highest contributing variables in isolation. Generalized linear modeling was then used to compare trap-line abundance indices to the percentages of individual vegetation series within a buffered area around the trap-line. Positive correlations with higher abundance indices were observed in winter, spring, and fall among a variety of vegetation series. Using spool-and-line tracking, P. pectoralis was determined to be highly mobile indicating that this species is capable of dispersing to areas of greater resource availability. Data suggest that vegetative habitat selection of this species varies seasonally and is likely dependent on the degree of seasonal resource availability within each vegetation type and the trophic ecology of P. pectoralis.Item Imaging and Computational Methods for Exploring Sub-cellular Anatomy(2010-01-16) Mayerich, DavidThe ability to create large-scale high-resolution models of biological tissue provides an excellent opportunity for expanding our understanding of tissue structure and function. This is particularly important for brain tissue, where the majority of function occurs at the cellular and sub-cellular level. However, reconstructing tissue at sub-cellular resolution is a complex problem that requires new methods for imaging and data analysis. In this dissertation, I describe a prototype microscopy technique that can image large volumes of tissue at sub-cellular resolution. This method, known as Knife-Edge Scanning Microscopy (KESM), has an extremely high data rate and can capture large tissue samples in a reasonable time frame. We can therefore image complete systems of cells, such as whole small animal organs, in a matter of days. I then describe algorithms that I have developed to cope with large and complex data sets. These include methods for improving image quality, tracing filament networks, and constructing high-resolution anatomical models. These methods are highly parallel and designed to allow users to segment and visualize structures that are unique to high-throughput microscopy data. The resulting models of large-scale tissue structure provide much more detail than those created using standard imaging and segmentation techniques.Item Initial Waves from Deformable Submarine Landslides: A Study on the Separation Time and Parameter Relationships(2012-07-16) O'Shay, JustinEarthquake and submarine mass failure are the most frequent causes of tsunami waves. While the process of the tsunami generation by earthquakes is reasonably well understood, the generation of tsunami waves during submarine mass failure is not. Estimates of the energy released during a tsunamigenic earthquake and respective tsunami wave draw a clear picture of the efficiency of the tsunami-generating process. However for submarine landslides, this is not as straightforward because the generation process has never been recorded in nature making energy inferences very difficult. Hence the efficiency of submarine landslide as tsunami generators is yet to be conclusively determined. As the result of this uncertainty, different equations, derived from experimental data or theory, result in leading-wave amplitude that vary over 6 orders of magnitude for the same initial slide conditions. To arrive at more robust estimates of the leading-wave characteristics and associated runup, the spatiotemporal dynamics of the coupling between the slide body and water column needs to be investigated. The duration the water surface deformation is coupled with the slide motion is an essential question to shed light on the energy transfer. A parametric study is conducted with the state of-the-art hydrocode iSALE in order to shed light on this complex geophysical event. The mass, viscosity, and depth of submergence are the particular slide parameters varied and their relationship to runup and decoupling time is analyzed.
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