Introduction: In order to properly diagnose and treatment plan, an orthodontist needs to be knowledgeable about the changes that occur to the maxillary and mandibular dental arches throughout growth. The purpose of this study is to provide an analysis of morphological shape differences seen in the maxillary and mandibular dental arches individually, as well as together, from birth to 3 years of age. Methods: Dental casts from the Iowa Infant Growth study ranging from 2 months to age 4 were photographed in the occlusal plane. The images were landmarked with 3 standard landmarks and 10 sliding semi-landmarks along the curvature of the maxillary and mandibular arches. TpsRelW was used to slide the semi-landmarks and superimpose the date to facilitate shape analysis. MorphoJ was used to determine the degree to which size influences dental arch shape. Once the effects of allometry had been removed, a principal component analysis was run on the residuals to display major features of shape variation in the dataset. Finally, a two block partial least squares analysis was run to determine the degree to which the maxillary and mandibular arches were integrated throughout early growth. Results: Allometry accounts for 9.63% of symmetric shape variation in the maxilla, while it accounts for 56% of symmetric shape variation in the mandible. Asymmetric shape variation is independent of allometry as it only affects 0.34% of the maxillary and 1.46% of the mandibular shape variation. Principal component one accounts for over 60% of all shape variation seen in maxillary and mandibular residuals. Principal component one of symmetric residuals results in a longer, wider dental arch or a shorter, narrower one. Principal component one of asymmetric residuals results in a dental arch with one posterior side being longer and wider while the contralateral side is shorter and narrower. The first three time points (2 months- 1 year) do not display significant integration between the maxillary and mandibular arches. Integration increases with age, displaying significant integration at the last three time points, with the most integration being displayed at 2.5 years. Conclusions: Allometry affects some of the symmetric shape variation in the maxilla, but over half of the symmetric shape variation in the mandible. The asymmetric components are independent of allometry. Integration of the maxillary and mandibular arches increase with age from 2 months to 3 years, peaking at a time point of 2.5 years.

Shape reconstruction of different three dimensional objects using multiple range images has evolved recently within the recent past. In this research shape reconstruction of a three dimensional object using multiple range image views is investigated. Range images were captured using the Waikato Range Imager. This range images camera is novel in that it uses heterodyne imaging and is capable of acquiring range images with precision less than a millimeter simultaneously over a full field. Multiple views of small objects were taken and the FastRBF was explored as a mean of registration and surface rendering. For comparison to the real range data, simulated range data under noise free condition were also generated and reconstructed with the FastRBF tool box. The registration and reconstruction of simple object was performed using different views with the FastRBF toolbox. Analysis of the registration process showed that the translation error produced due to distortion during registration of different views hinders the process of reconstructing a complete surface. While analyzing the shape reconstruction using the FastRBF tool it is also determined that a small change in accuracy values can affect the interpolation drastically. Results of reconstruction of a real 3D object from multiple views are shown.

In this thesis, we study the shape analysis problem and propose new methods for shape description, similarity and recognition. Firstly, we introduce a new shape descriptor in a two-step method. In the first step, the 2-D shape information is mapped into a set of 1-D functions. The mapping is based on the beams, which are originated from a boundary point, connecting that point with the rest of the points on the boundary. At each point, the angle between a pair of beams is taken as a random variable to define the statistics of the topological structure of the boundary. The third order statistics of all the beam angles is used to construct 1-D Beam Angle Statistics (BAS) functions. In the second step, we apply a set of feature extraction methods on BAS functions in order to describe it in a more compact form. BAS functions eliminate the context-dependency of the representation to the data set. BAS function is invariant to translation, rotation and scale. It is insensitive to distortions. No predefined resolution or threshold is required to define the BAS functions. Secondly, we adopt three different similarity distance methods defined on the BAS feature space, namely, Optimal Correspondence of String Subsequences, Dynamic Warping and Cyclic Sequence Matching algorithms. Main goal in these algorithms is to minimize the distance between two BAS features by allowing deformations. Thirdly, we propose a new Hidden Markov Model (HMM)topology for boundary based shape recognition. The proposed topology called Circular HMM is both ergodic and temporal. Therefore, the states can be revisited in finite time intervals while keeping the sequential information in the string, which represents the shape. It is insensitive to size changes. Since it has no starting and terminating state, it is insensitive to the starting point of the shape boundary. Experiments are done on the dataset of MPEG 7 Core Experiments Shape-1. It is observed that BAS descriptor outperforms all the methods in the literature. The Circular HMM gives higher recognition rates than the classical topologies in shape analysis applications.

In previous studies, the thermal performance of ribbed channels was studied for Reynolds numbers up to 100,000 with different rib shapes. In more recent studies, the thermal performance of ribbed channels was studied up to Reynolds numbers of 400,000 for angled ribs to cover the range of internal cooling inside land-based gas turbines. Previous studies also show that the thermal performance of V-shaped ribs is better than the angled ribs. In this study, the Reynolds number from 30,000 to 400,000 is studied with V-shaped ribs. The blockage ratio e/D is 0.1, 0.15, and 0.18 and spacing ratio P/e is 5, 7.5, and 10. The results show that the Nusselt number enhancement decreases when the Reynolds number increases. The friction factor is found to be independent of The Reynolds number. The thermal performance decreases when the Reynolds number increases. Correlations for the Nusselt number and the friction factor as function of Re, e/D, and P/e are developed.

The objective of this study is to design and manufacture a tube hydroforming test machine with axial feeding, which includes a forming apparatus¡Bhydraulic system and control system. Using feedback control and fuzzy control criterion to conduct T-Shape hydraulic bulging experiments. Using annealed AA6063-T5 aluminum alloy tubes, experiments are carried out with different working path and different feeding distance, analyze the influences of these parameters on the formability of the tubes.

The fatigue-induced solder joint failure of surface mounted electronic devices has become one of the most critical reliability issues in electronic packaging industry. Prediction of the shape of solder joints has drawn special attention to the related development and engineering applications. Numerous solder joint models, based on energy minimization principle and analytical methods, have been proposed and developed. The methods are extensively utilized to the shape design of solder joint. However, it is important to find a suitable method to real applications. Herein, a series of experiments with different geometric parameters of SAC405 solder joints were carried out and the results were compared with the prediction by Surface Evolver Program. The changes of geometric shape with respect to different parameters of solder joint were also discussed. The influence of the geometric parameters, such as volume of solder joint, package weight, solder surface tension, and gravity force to the shape of solder joint were investigated. Two experiments with SAC405 solder balls were carried out. One is to observe the different reflowed geometry shape of solder balls with various volumes, and another is to observe the different reflowed geometry shape of solder balls with various loadings on them. The results show that the models made by Surface Evolver program are very similar to the real shapes observed by experiments, and the differences are between -3% ~ 6.5%. Thus, the results show that the predicted shapes are satisfactorily suitable. Finally, the predicted models by Surface Evolver program were also put into the ANSYS program, and preceded the fatigue life prediction due to thermal cycling tests. The comparison of the effect on fatigue life with respect to different geometry shapes is illustrated. The results show the shape of solder ball due to high loadings is better than that in thermal cycling tests.

This study examines shape language when used in figures representing humanoid creatures and how a viewer can be manipulated by shape language to feel a certain way about a figure. The study focuses on good versus evil expression and how one can utilise shape to knowingly give cues about a figures alignment or how to mislead the viewer if so desired. Focus is on visceral emotion connected to sharp and soft shapes and asymmetrical or symmetrical features, but it is revealed that its use in character design may be a cultural convention rather than something hard-wired in our brains from years of natural selection and experiences tied to our subconscious visceral response.

An electro-mechanical device was developed to provide mechanical stimulation to cell populations for the purpose of studying how mechanical signals affect cell activity. The system can dynamically deform cubes of hydrogel seeded with cells by applying combinations of normal and shear forces to the faces of the hydrogel cube using plastic pads attached to the cube. The compact device was fabricated using rapid prototyping methods with ABS plastic and uses shape memory alloy actuator wires to generate the necessary forces. The actuator wires can be independently activated in sequence to create stimulation routines involving compression, tension and shear forces. All of the components can be sterilized and are corrosion resistant so they are not affected by the high humidity environment of a tissue incubator where cell stimulation studies are performed. The system fits inside a standard plastic lab container measuring 7 cm tall by 4 cm in diameter to maintain sterile conditions and hold the liquid culture medium required by the cells. During operation the hydrogel cube and the contact pads are submerged in the culture medium. The shape memory alloy actuators have been modeled in a two step process: 1) the electrothermal model, relating input electrical current to the wire temperature due to resistive heating and 2) the thermomechanical model relating the wire temperature to the wire strain and actuator stroke due to the shape memory effect. Testing was completed to validate the models and calibrate the shape memory alloy actuators. There was good agreement between the model predictions and the experimental results. For experiments with a hydrogel cube with sides measuring 1 cm, the system was capable of compressing the hydrogel cube up to 8 %, and generating shear strains of up to 7%. Tensile strains were much smaller at 0.9%. The dynamic deformations were applied at a frequency of 0.5 Hz. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2008-08-12 10:23:15.672

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Discrete shapes can be described and analyzed using Lie groups, which are mathematical structures having both algebraic and geometrical properties. These structures, borrowed from mathematical physics, are both algebraic groups and smooth manifolds. A key property of a Lie group is that a curved space can be studied, using linear algebra, by local linearization with an exponential map. Here, a discrete shape was a Euclidean-invariant computer representation of an object. Highly variable shapes are known to exist in non-linear spaces where linear analysis tools, such as Pearson's decomposition of principal components, are inadequate. The novel method proposed herein represented a shape as an ensemble of homogenous matrix transforms. The Lie group of homogenous transforms has elements that both represented a local shape and acted as matrix operators on other local shapes. For the manifold, a matrix transform was found to be equivalent to a vector transform in a linear space. This combination of representation and linearization gave a simple implementation for solving a computationally expensive problem. Two medical datasets were analyzed: 2D contours of femoral head-neck cross-sections and 3D surfaces of proximal femurs. The Lie-group method outperformed the established principal-component analysis by capturing higher variability with fewer components. Lie groups are promising tools for medical imaging and data analysis. / Thesis (Ph.D, Computing) -- Queen's University, 2014-01-30 09:49:03.293