Piezoelectric actuators are well suited for high precision mechanical and electrical engineering applications. However, its performance in regulator configurations has been limited due to hysteresis. The hysteresis in these actuators means that multiple input states can result in the same output, which introduces a further design variable (initial state) in the regulation problem. It is proposed that certain initial states result in better regulation performance based on the structure of the Preisach model. These initial states are called “neutral states”. In this thesis, hysteresis and piezoelectric actuators are introduced as background information. The Preisach model is used in this work to describe the hysteresis behaviour of a customized shape control unit SS15 due to its convenient general structure and ability to model hysteresis. The representation tests are performed and a Preisach model is subsequently constructed and verified by comparing simulation and experimental results to ensure that the hysteresis inherent in the piezoceramic actuators of the SS15 is suitably described by this model. In order to evaluate the regulation performance for a given desired output, uniformly-distributed noise is injected at the input side of the SS15 in open- and closed-loop tests. It is demonstrated, by both simulation and experimental results, that the system output drifts less when it starts from the neutral state in open-loop tests. A PI regulator is implemented in the closed-loop tests. When the system is driven from the neutral state, both simulation and experimental results demonstrate that the system requires less control effort for closed-loop regulation.

Approximately 80% of pharmaceutical products and the ingredients required for their manufacture are in powder form. The solid dosage form (tablets and capsules) is manufactured by either dry-blending of fine powder ingredients or combining the ingredients in a wet granulation step, followed by drying. Arching, ratholing, caking, segregation and flooding are some of the commonly encountered flow problems in the handling of fine powders. These problems lead to losses worth thousands of dollars at production scale. Poor powder flowability is a consequence of the combined effects of many variables, including improper equipment design, particle size, size distribution, shape, moisture content and surface texture. In the present work, a systematic study has been performed to determine the relationship between the flowability of fine powders and their physical properties of mean size and size distribution, density and shape.<p> Flowability studies were done on six different powders: the NutraSweet® Brand sweetener (aspartame), Respitose ML001, Alpha-D-Lactose monohydrate, the pharmaceutical binder Methocel (R) F50 Premium Hydroxypropyl methylcellulose- HPMC, a placebo pharmaceutical granulate, and common pastry flour. Scanning electron microscopy (SEM) and stereomicroscopy were used for particle shape and size analysis. Particle size distribution was determined using the laser light scattering technique. Powder flowability was measured using shear strength, angle of repose, and tapped-to-bulk density measurements. A novel method of measuring the dynamic angle of repose using electrical capacitance tomography (ECT) was developed. <p> Analysis of the images from microscopy revealed that the particles of aspartame and HPMC powders were elongated, the particles of ML001, pastry flour and lactose monohydrate powders were irregular, and the particles of placebo granulate were nearly spherical. Particle size was found to be the most reliable indicator of powder flowability, with decreasing particle size corresponding to lower flowability; however other parameters such as particle elongation and irregularity, were also found to have an influence on powder flowability. Although HPMC and pastry flour had similar particle sizes, they exhibited differences in flowability. This can be explained by the greater irregularity of the flour particles. Particle irregularity may cause mechanical interlocking between the particles, thus reducing powder flowability. ECT was found to be a promising non-intrusive tool for the measurement of the dynamic angle of repose. Unlike other methods for the measurement of dynamic angle of repose, the results obtained from ECT were not influenced by the effect of end caps. The present technique could be used by pharmaceutical industries in process analytical technology (PAT) for the detection and elimination of potential flow problems early in the manufacturing process.

Objectives<p>The geometric configuration of skull is complex and unique to each individual. The main objectives of this study are two fold: 1) to provide a new technique to define the outline of skull profile and 2) to find the common factors defining the ultimate skull configuration in adult population. The secondary objective was to explore the effect of age and sex on skull shape formation.<p>Materials & Methods <p>Ninety-three lateral skull x-ray from the CT scan films were selected and digitized. The lateral skull surface was divided into 3 regions based on the presumed location of coronal and lambdoid sutures. A software program (Canvas 7) was used to match the outer surface of lateral skull with circular curves. Three main curvatures (frontal, parietal, occipital) were consistently identified to overlap the skull periphery. The radius, cord length and inclination of each curvature were measured.. Factor analysis technique was also used to reduce the number of variables explaining the overall shape of skull. Student t-test and regression analysis was also used to explore the effect of sex and age on skull shape. <p>Results <p>There were total of 93 patients in this study (54% male). The average values for three defined curvatures of the skull profile were recorded. Factor analysis produced 3 factors. The first factor explained 32% of total variance and was related to the overall size of the head as represented by total length and the radius of the curvature in vertex and back of the head. The second factor covered 26% of the variance representing the inverse correlation between the angle of the frontal and parietal curves. The third factor revealed the direct correlation of occipital and parietal angle. In all of these factors, the frontal zone variation was independent or opposite of the parieto-occipital zone. A strong direct association between the total length of skull, occipital curve radius and length with the sex was shown. No age related variable was identified.<p>Conclusions <p>There is a large variation in the values of different part of the skull. The skull profile topography can be defined mathematically by two distinct territories: frontal and parieto-occipital zones. These territories hinge on the coronal suture. Therefore, coronal suture may play a dominant role in final skull configuration.

This study explored the phenomenon that a consumer's preference on color of car body may vary depending on shape of the car body. First, the study attempted to establish a theoretical framework that can account for this phenomenon. This framework is based on the (modern-) Darwinism approach to the so-called evolutionary psychology and aesthetics. It assumes that human's aesthetic sense works like an agent that seeks for environmental patterns that potentially afford to benefit the underlying needs of the agent, and this seeking process is evolutionary fitting. Second, by adopting the framework, a pattern called fundamental aesthetic dimensions was developed for identifying and modeling consumers aesthetic response to car body shape and color. Next, this study developed an effective tool that is capable in capturing and accommodating consumers color preference on a given car body shape. This tool was implemented by incorporating classic color theories and advanced digital technologies; it was named Color-Shape Synthesizer. Finally, an experiment was conducted to verify some of the theoretical developments. This study concluded (1) the fundamental aesthetics dimensions can be used for describing aesthetics in terms of shape and color; (2) the Color-Shape Synthesizer tool can be well applied in practicing car body designs; and (3) mapping between semantic representations of aesthetic response to the fundamental aesthetics dimensions can likely be a multiple-network structure.

This thesis proposes a model of understanding the constraining effect of floorplates on the integration of office layouts. The proposed model is based on the analysis of floorplates and layouts which is simultaneously configurational, global and robust. The study departs from two observations: first, there is a difference between the lifespan of shells and layouts; second, shells influence but do not determine the layouts than can be accommodated in them. The thesis proposes two descriptions of shape which gauge their compactness and convex fragmentation based on configurational relations among modular units of shape. Shapes of actual floorplates are described according to the proposed measures leading to a typology of office buildings. The space syntax research on workspaces has demonstrated that the integration of layout circulation affects the patterns of movement, encounter and interaction, which are linked to organizational performance. Actual layouts are described according to skewness and density of connectivity of linear maps leading to three alternative types of office layouts: sparse grids, dense grids and fishbones. Two ideal layouts of grids and fishbones, extracted from the typology, reflect opposing ways of increasing the layout integration and best represent open-plan layouts. Experiments with hypothetical grids and fishbones generated systematically on theoretical shapes demonstrate strong but differing effects of shape on layout integration. These are subsequently confirmed by the analysis of hypothetical grids and fishbones generated into a large sample of actual office buildings in the US. The relationship between floorplate shape and layout is mediated by the generative principle applied to the generation of layout. There exists an underlying congruence between a morphological typology of layouts (which distinguishes between fishbone and grid as alternative principles for increasing integration) and a morphological typology of shapes (which distinguishes between more compact and convexly unified shapes and shapes with wings). The findings highlight the distinction between constraint and determination. Floorplate shapes exercise underlying constraints upon the layout integration but they do not determine it. The proposed model enhances the evaluation of existing building portfolios for their suitability for different types of office layouts and aids the design and planning of new work environments.

This thesis deals with the problem of tracking highly deformable objects in the presence of noise, clutter and occlusions. The contributions of this thesis are threefold: A novel technique is proposed to perform filtering on an infinite dimensional space of curves for the purpose of tracking deforming objects. The algorithm combines the advantages of particle filter and geometric active contours to track deformable objects in the presence of noise and clutter. Shape information is quite useful in tracking deformable objects, especially if the objects under consideration get partially occluded. A nonlinear technique to perform shape analysis, called kernelized locally linear embedding, is proposed. Furthermore, a new algebraic method is proposed to compute the pre-image of the projection in the context of kernel PCA. This is further utilized in a parametric method to perform segmentation of medical images in the kernel PCA basis. The above mentioned shape learning methods are then incorporated into a generalized tracking algorithm to provide dynamic shape prior for tracking highly deformable objects. The tracker can also model image information like intensity moments or the output of a feature detector and can handle vector-valued (color) images.

A novel active material for controllable, high work density applications was designed, fabricated, analyzed, and tested. This active material uses a lens-shaped element to implement simple shear motion with gas pressure actuation. The lens element is a bladder-filled Kevlar fabric embedded in a polyurethane matrix. The polyurethane’s hyperelastic material parameters were found by experiment and estimated by numerical analysis. The Ogden material constant set found shows good agreement within the shear actuator’s working range. A fabricated, single-element shear actuator reached 34.2% free shear strain when pressurized to 1.03 MPa. A unitary shear actuator was modeled as were single-acting and dual-acting shear actuator arrays so that solitary and multi-cell behaviors were estimated. Actuator work performance and power from nonlinear finite element analysis found conventional work density is 0.2289 MJ/m3 and 0.2482 MJ/m3, for the singleacting and double-acting shear actuator, respectively. Scientific work densities are 0.0758 MJ/m3 and 0.0375 MJ/m3, for single-acting and double-acting shear actuators, respectively. Calculation shows the volumetric power for a single-acting shear actuator is 0.4578 MW/m3 and 0.4964 MW/m3 for the double-acting shear actuator. Finally, a nastic actuator is applied to twist a generic structural beam. The nasticmaterial actuated structure has an advantage over conventional actuator systems. Work per unit volume for nastic materials is 2280~8471% higher than conventional, discrete actuators that use electric motors. When compared by work per unit mass, this nastic actuator is 2592~13900% better than conventional actuator because nastic actuator is made from lighter materials and it distributes the actuation throughout the structure, which eliminates connecting components. The nastic actuator’s volumetric power is 2217~8602% higher than conventional actuators. Finally, the nastic actuator is 2656~14269% higher than conventional actuators for power per unit mass.

The aim of this work is to demonstrate a Helmholtz potential based approach for the development of the constitutive equations for a shape memory polymer undergoing a thermomechanical cycle. The approach is motivated by the use of a simple spring-dashpot type analogy and the resulting equations are classified as state-equations and suitable kinetic equations for the recoverable-energy elements and the dissipative elements in the model respectively. These elements have mechanical properties which vary with temperature. The governing equations of the model are developed starting from the basic conservation laws together with the laws of thermodynamics. The entire set of equations are written in a state-evolution form as a set of ordinary differential equations to be solved using Matlab. It is shown that the results of the simulation in Matlab are in qualitative and quantitative agreement with experiments performed on polyurethane. Subsequently, we study the dependence of the yield-stress on temperature to be similar and different functions of heating or cooling processes.

Shape memory alloys (SMAs) have recently attracted much attention as a smart material that can be used in passive protection systems such as energy dissipating devices and base isolation systems. For the purpose of investigating the potential use of SMAs in seismic engineering applications a soft computing approach, namely a neurofuzzy technique is used to model dynamic behavior of CuAlBe shape memory alloy wires. Experimental data are collected from two test programs that have been performed at the University of Chile. First, in order to evaluate the effect of temperature changes on the behavior of superelastic SMA wires, a large number of cyclic, sinusoidal, tensile tests are conducted at various temperatures. Second, to assess dynamic effects of the material, a series of laboratory experiments are conducted on a scale model of a three story model of a building that is stiffened with SMA wires and given excitation by a shake table. Two fuzzy inference systems (FISes) that can predict hysteretic behavior of CuAlBe wire have been created using these experimental data. Both fuzzy models employ a total of three input variables (strain, strain-rate, and temperature or prestress) and one output variable (predicted stress). Values of the initially assigned membership functions for each input are adjusted using a neural-fuzzy procedure to accurately predict the correct stress level in the wires. Results of the trained FISes are validated using test results from experimental records that had not been previously used in the training procedure. Finally, numerical simulations are conducted to illustrate practical use of these wires in a civil engineering application. In particular, dynamic analysis of a single story frame and a three story benchmark building that are equipped with SMA damping elements are conducted. Then, an isolated bridge that utilizes a linear rubber bearing together with SMA elements is analyzed. Next, in order to show recentering ability of SMAs, nonlinear time history analysis of a chevron like braced frame is implemented. The results reveal the applicability for structural vibration control of CuAlBe wire whose highly nonlinear behavior is modeled by a simple, accurate, and computational efficient FIS.

The transition to parenthood brings a host of changes to new parents; two key areas of change are decreases in relationship functioning and a worsening of women's eating, weight, and shape (EWS) concerns. Past research has suggested that a connection may exist between women's EWS concerns and relationship functioning during this transition. This study explored the impact of women's EWS concerns on both partners' relationship functioning in a sample of 74 couples (148 individuals) having their first baby. The study was part of a larger project exploring interventions during the transition to parenthood; thus, all couples had at least one risk factor for future relationship problems. Participants completed questionnaires approximately seven months into pregnancy and at one and three months postpartum. Results revealed that relationship functioning and women's EWS concerns worsened from pregnancy to three months postpartum, which is consistent with previous literature. Changes in women's EWS concerns from before and during pregnancy to three months postpartum were not generally related to changes in either partner's relationship functioning during the same period. However, the EWS concerns that predicted poorer relationship outcomes, including women's drive for thinness and bulimia symptoms, suggest the possible role of third factors such as negative affect or neuroticism. Also, increases in women's Body Mass Index from pre-pregnancy to three months postpartum predicted increases in relationship functioning, indicating the possibility of a larger construct such as general acceptance of the post-birth process, both in terms of weight changes and relationship changes. Thus, preventive efforts could include an emphasis on helping partners to accept the changes they will experience during this transition. Finally, the significant relations between women's EWS concerns and relationship functioning were often mediated by men's reported frequency of sexual activity, suggesting the importance of sex as a mediator. Although findings were limited, the results should be interpreted in light of previous research and the current study's limitations. Overall, this study indicates the need for future research exploring the relations between women's EWS concerns and the couple relationship during the transition to parenthood.