Browsing by Subject "modelling"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
Item A System for Designing Digital Creatures Based on Rules of Vertebrate Skeletal Structure(2013-10-08) Drell, David MConcept Designers are often required to create digital creatures that do not actually exist in real-life. These fantasy creatures are often inspired by animals that do exist, combining component body parts to create new, chimera-like forms. While these forms can look believable in stationary positions, their construction may yield awkward looking performances while in motion. This awkwardness can often be attributed to the different body parts not being connected correctly, making it impossible for the creature to be articulated in a believable way. This paper defines a set of rules, guided by study in comparative anatomy, for achieving more believable connections of body parts. This paper then details the process by which these rules are automated through a Maya script, allowing them to be integrated into a more artistic creature design process. In conclusion, it is found that the defined rules are successful in guiding believable connections. However, the implementation of the automated solution requires additional work to be a useful tool in the creature design process.Item Caricaturing buildings for effective visualization(Texas A&M University, 2006-04-12) Rice, Grant G., IIIThe objective of my research is to identify and analyze the techniques of exaggeration, simplification, and abstraction used by caricature and cartoon artists. I apply these techniques to an expressive 3D modelling process which is used to create building caricatures. This process minimizes the number of unimportant details and increases the recognizability of the buildings. Additionally, the building caricature process decreases the time spent modelling the buildings and reduces their overall file sizes. The building caricature process has been used to create other building caricatures, as well as interactive visualizations and 3D maps of the Texas A&M University campus.Item Characterization of the 3-D Properties of the Fine-Grained Turbidite 8 Sand Reservoir, Green Canyon 18, Gulf of Mexico(Texas A&M University, 2004-09-30) Plantevin, Matthieu FrancoisUnderstanding the internal organization of the Lower Pleistocene 8 Sand reservoir in the Green Canyon 18 field, Gulf of Mexico, helps to increase knowledge of the geology and the petrophysical properties, and hence contribute to production management in the area. Interpretation of log data from 29 wells, core and production data served to detail as much as possible a geological model destined for a future reservoir simulation. Core data showed that the main facies resulting from fine-grained turbidity currents is composed of alternating sand and shale layers, whose extension is assumed to be large. They correspond to levee and overbank deposits that are usually associated to channel systems. The high porosity values, coming from unconsolidated sediment, were associated to high horizontal permeability but generally low kv/kh ratio. The location of channel deposits was not obvious but thickness maps suggested that two main systems, with a northwest-southeast direction, contributed to the 8 Sand formation deposition. These two systems were not active at the same time and one of them was probably eroded by overlying formations. Spatial relationships between them remained unclear. Shingled stacking of the channel deposits resulted from lateral migration of narrow, meandering leveed channels in the mid part of the turbidite system. Then salt tectonics tilted turbidite deposits and led to the actual structure of the reservoir. The sedimentary analysis allowed the discrimination of three facies A, B and E, with given porosity and permeability values, that corresponded to channel, levee and overbank deposits. They were used to populate the reservoir model. Well correlation helped figure out the extension of these facies.Item Mathematical modelling and analysis of calcium oscillations in excitable and non-excitable cell lines(Texas A&M University, 2004-09-30) Hegde, Bharati KrishnaInformation is transmitted from the cell surface to various specific targets in the cell via several cellular signaling pathways. Cytosolic free calcium (Ca2+)is one of the most versatile and ubiquitous intracellular messengers since it is able to regulate diverse number of functions such as proliferation, secretion, fertilization, metabolism, learning and memory. In the last couple of years, evidence has been accumulating that Ca2+ ion is able to integrate information from multiple signaling pathways and convert this information into a code which regulates events ranging from contraction to modification of gene expression (Berridge et al. 1998). It was shown that Ca2+ concentration displays oscillatory behavior in response to agonist stimulation in a variety of cells(Goldbeter 1996) and the frequency of these oscillations increases with the concentration of agonist, a behavior called frequency encoding which has led to the concept that many Ca2+-regulated processes are controlled by these codes(Berridge 1998). Although the presence of Ca2+ oscillations and the sources of Ca2+ pools involved is known in many cell types, it is yet not known how the various frequencies of Ca2+ oscillations are converted into codes that regulate the numerous cellular events. Recently a number of cellular targets that decode Ca2+ signals and are tuned to the frequency of Ca2+ oscillations have been identified. Prominent among them are calcium-calmodulin kinase II (CAM II) and protein kinase C (PKC). The objective of this work is to study and mathematically model the oxytocin and vasopressin-induced Ca2+ oscillations in cells of normal rat liver (Clone 9) and cells of pregnant human myometrium. The proposed model accounts for the receptor-controlled Ca2+ oscillations involving positive feedback leading to activation of phospholipase C (PLC) and negative feedback from PKC onto G-proteins which simulates many of the features of observed intracellular Ca2+. The model also incorporates the concept that coordinated Ca2+ signals in a group of hepatocytes require both effective gap junctions and the presence of agonist at each cell surface. Another objective of this research is to understand the relevance of frequency-encoded signals by performing an analysis of frequencies of Ca2+ oscillations using the Fast Fourier Transform and the Wavelet Transform. The validity of the model was confirmed by using statistical tests to check if the frequencies and amplitudes of the experimental Ca2+ oscillations match with those of the modelled oscillations.Item Nonlinear surface approximation using photogammetry(Texas A&M University, 2006-04-12) Osgood, ElizabethMany satellite applications require a model that represents a surface as it deforms over time. Yet, space applications demand a precise, low-weight, low-volume, and easy to implement solution. A metrology sensing system is presented in this thesis, consisting of a series of cameras and laser dot projectors positioned along the length of the antenna. This system accurately models the geometry of the surface to meet the demands of a space based radar. Each laser dot projector casts a matrix of points onto the antenna surface. The points are then imaged simultaneously by a pair of cameras, each having a different, but overlapping, viewpoint. Given the two overlapping images, a Gaussian nonlinear least squares algorithm solves the stereo-triangulation problem which provides the coordinates of the projected points and thereby maps the surface. There are three different strategies discussed in this thesis. The first strategy assumes the positions and orientations of the cameras are absolutely known. This produces an extremely accurate result; yet it is unrealistic to assume absolute knowledge of cameras locations and orientations for the application. The next strategy assumes the positions and orientations of the cameras are completely unknown in addition to the unknown surface. This program produces a less accurate, but more realistic, result considering the dynamic nature of rigid structures in space. To increase the accuracy and improve the robustness of these results, the third method employs a global metrology sensing system to reduce the uncertainty in the location and orientation of the outboard cameras relative to the center camera. This approach estimates the surface extremely accurately and, although more complex, offers advantages and addresses the desire for a family of designs wherein higher accuracy is achievable by further optimization.