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Physical interaction is fundamental to the human experience. Our embodiment has been optimised through aeons of evolution for the ability of general purpose physical interaction. Currently, there is a distinct gap between the physical capabilities of humans and those of robots. In robotics, rich contact-based interaction is often minimised due to the complexity that arises from these interactions. The information carried in these interactions is difficult to perceive and to model, leading to a lack of physical skill in robotics. In humans, touch is a fundamental sense for enabling our physical capabilities. This work examines the use of touch in robotics for perception and manipulation, aiming to improve the physical skills of robots. The goal of this work is to combine recent advances in tactile sensing technology with powerful and scalable robot-learning methods. To this end we successfully apply several learning methods to data obtained with a TacTip tactile sensor. We examine the use of deep learning for tactile perception, with both a single sensor and multi-fingered robotic hand. We apply end-to-end deep reinforcement learning, directly from sensory inputs to control outputs, for a complex tactile task requiring sensitive perception and precise action. We provide a scalable and efficient method of simulating tactile data, demonstrating zero-shot sim-to-real transfer of multiple learned tactile polices. Finally, we make progress towards solving a grand challenge of in-hand dexterous manipulation, using a combination of the above approaches. The successful application of these techniques provides evidence that physically interactive tasks can be solved by focussing on them through a tactile lens. The application of general and scalable techniques such as deep reinforcement learning shows potential, as these methods progress many new tasks will become achievable goals. Overall, we make progress towards our overarching aim of endowing general purpose robots with the ability to physically interact in our world.

First Generation (FG) students' pursuit of higher education continues to be initiated at community colleges at high rates; these two-year Higher Education Institutions (HEIs) are critical in bridging the gap for an increase in degree completion at four-year HEIs. The purpose of this study is to explore the institutional barriers, indicators, and participant experiences faced by FG students in preparation of the vertical transfer process from a two-year HEI to a four-year HEI. As literature suggests, there is still a lack of development and implementation of key indicators for an FG student's readiness including institutional transfer processes that may inhibit an efficient transfer to benefit the aforementioned population. This comparative case study analysis of the transfer processes, in preparation of FG students' transfer from a two-year to a four-year HEI, is imperative for professionals in higher education to utilize when developing interventions, but also in assessing adequate student support resources for vertical transfer, development of viable institutional articulation agreements and indicators for preparation and readiness. The analysis of the study found similar answers to previous research findings regarding preparation as it is crucial for the effectiveness of the transfer process and as a main indicator for FG students' successful vertical transfer from a two to a four-year HEI. The finding, preparation, as an indicator of vertical transfer for FG students, enhances the transfer process in higher education, whereby accelerating the rate of college completion. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

This thesis consists of a literature review and a research study. The review used a meta-synthesis to integrate the findings of existing literature on problem construction in initial sessions of psychotherapy. Five main themes were constructed from the studies reviewed: Problems are defined by therapists, Therapists employ rhetorical strategies, Therapists’ use of power and clients’ resistance, Problems are structured and ordered through language, and Problems exist in socio-historical context. A new explanatory model for problem construction in psychotherapy was proposed. Therapists’ problem schemas that were shaped by socio-historical factors and rhetorical strategies involved in realising these schemas were central to the process of problem construction. Epistemological differences in research methodologies generated difficulties in the synthesis of existing research. For the research study, a critical discourse analysis was used to analyse therapist-client problem construction in first sessions of therapy in a trial comparing two psychotherapies for depression. Four stages of analysis were conducted, with the following findings: (1) discursive constructs included how problems were experienced and made sense of; (2) rhetorical strategies were used to pursue agendas by both clients and therapists; (3) subject positions were interactive and could be contradictory for both therapists and clients, they were generally more problem focused for clients and powerful for therapists; (4) therapists and clients reproduced normative discourses from institutions and ideologies shaping their subjectivity. Methodological limitations and recommendations for practice were outlined.

This study is primarily concerned with the ecology of Ribautodelphax imitans (Ribaut.), a seldom recorded, data deficient and rare species of planthopper (Delphacidae: Auchenorrhyncha: Hemiptera) in the UK. Although it dealt with the ecology of this one species, it explored its community, related species and how they respond to habitat, host plants, and each other. Firstly this project looked at the community position of R. imitans over a single season, clarifying its numerical abundance related to other species in its community. The lifecycles of many species could be modelled over the year; delphacids and cicadellids were mostly synchronous within each family. Monitoring the site over the course of several years also highlighted co-abundance patterns with a related planthopper Javesella pellucida (Fab.), which opened up avenues for experiments and comparisons between this species and R. imitans. Host plant associations of R. imitans were investigated, as were the associated host plant networks of the Auchenorrhyncha community. It was determined that R. imitans was monophagous on tall fescue Schedonorus arundinaceus, but the community was dominated by generalist species. It was determined that in this typical grass feeding Auchenorrhyncha community, plant diversity was not the main driver for species richness however it was probably a factor in its stability. As tall fescue was the dominant grass on the study site, Coe Fen, it was determined that structures associated with this grass, tussocks, were important in the Auchenorrhyncha community. Tussocks were investigated using survey and experimental manipulation approaches. Firstly the role of tussocks in grassland appeared to ameliorate the negative effects of declining sward height outside of tussocks - as a result of cutting and grazing - as more insects were found in tussocks surrounded by shorter swards than long. Secondly, there were contrasting responses of different groups to different aspects of tussock structure, it was thought that delphacids prefer denser and more nutrient-rich areas, whereas cicadellids prefer more open and less nutrient-rich areas of sward. These may relate to both their nutritional physiology and their biomechanics. The strong fidelity towards tussocks of its host plant could increase conspecific heterosexual encounters of R. imitans, thus maintaining high local population size and natality. Lastly, interactions between and within species were investigated in a series of lab-based experiments. No effect of conspecific or allospecific density could be attributed to a change in developmental rate. However, there was evidence of host plant shifting in the generalist J. pellucida caused by the presence R. imitans. The combination of host plant specificity, habitat specificity and competitive dominance feed into a model that would explain how rare species, or low-density populations can persist. However without fully understanding the distributions of species, one cannot be fully certain of its real distribution and status. This thesis provides a clear understanding of aspects of the species’ general ecology, thus helping advise on how to collect further national records of this species, unlocking the key to its true status.

Analysis has been made of the amplitudes of the second and third harmonics when pumping a discrete frequency to the Josephson-vortex photonic crystal within the THz range of the electromagnetic spectrum. The results of numerical simulations show that there are certain resonance frequencies for these harmonics where the amplitudes are strongly enhanced. The frequencies at which these resonances occur can be tuned by an applied magnetic field and tilting the material with respect to the incident radiation. For the second harmonic it has been possible to describe these resonances analytically with a resonance approximation which displays good agreement with numerical simulations at and near the resonances. A similar perturbative method has been used to simulate the nonlinear mixing of two discrete THz frequencies in the JV photonic crystal, producing resonances for harmonics at the sum and the difference of these two input frequencies. This method can allow a high degree of control over the harmonic frequencies produced.

Using computer simulation in healthcare is a longstanding endeavor, where alternative scenarios and system configurations can be tested before they are implemented in the real world. One facet of healthcare that has an apparent lack of simulation work is that of emergency transportation, especially that which has a goal to reduce the amount of time a crew works over their designated shift. In collaboration with a Midwest USA Hospital, the researcher sought to model the current system, then experiment by altering crew schedule start times, the number of crews, and policy to reduce the frequency and duration a crew works past their scheduled end time. Therefrom, a framework was developed to help other institutions with similar aims. After the simulation model was verified and validated, experiments varying the start times of the crews, scheduling the crew constituent resources separately, and the number of crews were investigated. With the goal to reduce the time a crew spends working past their scheduled shift without negatively affecting productivity, scenarios that performed similarly in the number of transport requests serviced where there was a decrease in over-shift metrics were identified. The results of the simulation experimentation can be summarized this way: reducing over-shift comes at a cost, likely, either a reduction in productivity or an additional crew. A seven-themed framework for future studies was derived: a sound mission, system understanding, data availability/understanding, respect for process, simulation experience, results analysis and recommendations, and empathy.

This thesis presents a high-efficiency Class-F power amplifier (PA) operating from 30-88 MHz through the use of an electronically tunable resonant network. While conventional Class-F designs are limited to operation over less than an octave, the proposed design utilizes reconfigurable reactive elements in order to cover the entire VHF-FM frequency range. A real circuit implementation using GaN HEMT is designed and simulated, with the notable design considerations examined in detail. A minimum power added efficiency (PAE) of 71.7% is achieved across the band, at output powers = 49.2 dBm. This combination of high output power and high-efficiency operation across a wide frequency range creates opportunities for the design’s use in various commercial and defense applications where power consumption is a major design factor, most notably Unmanned Aerial Vehicle (UAV) systems.

The purpose of this study is to investigate whether scleral lenses have vision performance advantages compared to soft contact lenses in normal eyes. Previous studies reported that rigid contact lenses can increase or decrease optical aberrations of the eye depending on the quantity of aberrations at baseline.1 Soft contact lenses have generally increased optical aberrations compared to baseline. 2 3 Conclusions regarding optical quality with contact lenses have been inconsistent due to variability in study design, variability in contact lens parameters, differing lens fitting protocols, the specific measurements taken and the instruments used to take those measurements. This study will minimize variability due to rigid lens decentration and movement on eye by using a larger, more stable scleral design. The study will also include clinically relevant vision performance testing such as high contrast visual acuity, low contrast visual acuity, and contrast sensitivity. The hypothesis is that scleral lenses improve vision performance compared to soft contact lenses due to a reduction in optical aberrations of the eye. 14 subjects were fit with the Onefit P&A (Blanchard Lab, Manchester, NH) and Air Optix Aqua or Air Optix for Astigmatism (Alcon, Ft. Worth, TX) contact lenses. Measurements were taken at baseline and separate lens evaluation visits scheduled after completion of the contact lens fits. The order the contact lenses were worn was randomized and the lenses were worn for six hours prior to each lens evaluation visit. The primary outcomes were Bailey-Lovie high and low contrast visual acuity (10% Michelson), MARS contrast sensitivity, and higher-order aberrations, measured with the Complete Ophthalmic Analysis System (COAS). Secondary outcomes were scleral lens clearance and sodium fluorescein corneal epithelial staining. The corneal clearance was estimated using images from the Heidelberg Spectralis optical coherence tomographer. There was no difference between the contact lenses in measurements of high contrast visual acuity (p=0.61), low contrast visual acuity (p=0.96), and contrast sensitivity (p=0.30). The Air Optix lenses had significantly reduced coma Z(3,1). The Onefit P&A lenses had significantly reduced trefoil Z(3,3) (p=0.01) and spherical aberration Z(4,0) (p

Fibromyalgia (also known as fibromyalgia syndrome, or FMS) is a condition which causes its victims to suffer a wide range of symptoms, most notably chronic musculoskeletal pain. Although the causes of fibromyalgia remain unknown, recent advances help elucidate the underlying pathophysiologies of this condition, and show that it is likely not a musculoskeletal condition, but rather a pathoneurological condition.

Any alternative crop management strategy will only be adopted by growers if yield is not negatively impacted, fits within a current management practice, is easily implementable with minimal cost, or provides other beneficial features such as weed control or suppression. Corn production that incorporates a cover crop as an alternative weed control strategy and ground cover may support a sustainable system that is less dependent on herbicidal weed control. In addition, the cover crop may be used as a fall forage, act as a slow release fertilizer source the following year, and provide ground cover to reduce soil erosion. In South Dakota, cover crop establishment cannot occur after corn harvest, as the growing season is too short, cold, and often dry. Therefore, interseeding cover crops into standing corn has the potential to establish, suppress late-emerging weeds, and provide late season ground cover. The purpose of this research was to examine if a cover crop mixture could be established in a standing corn crop at V5 growth stage, suppress weeds, and provide ground cover after corn harvest without negatively impacting corn yield. Crimson clover (Trifolium incarnatum), winter wheat (Triticum aestivum) and lentil (Lens culinaris) were planted using broadcast or drill methods, as a mixture at a rate of 5.4, 8.9, and 9.8 kg ha-1, respectively, into V5 corn in field studies from 2010 – 2012. In 2010 - 12, the mix was planted at summit (SMT) and toeslope (TSP) locations in corn fields near Andover, SD. In 2011 – 12 the mix also was planted at SMT and TSP locations near Trail City, and in a flat field near Aurora, SD. Corn and cover crop and weed biomass were collected each fall. Cover crops emerged about 14 d (days) after planting. Winter wheat and crimson clover were the only species that survived until corn harvest. The drill interseeding method had 76% more cover crop biomass than the broadcast method. Cover crops drill seeded reduced grass weed biomass by 38%. Regardless of seeding method, cover crops had no impact on corn grain yield. These results indicate that cover crops could be established in standing corn with no adverse yield impact. These crops provided ground cover during and after the corn growing season and suppressed late-emerging grass weed growth. Therefore, interseeding this cover crop mix into standing corn may be a feasible alternative management strategy for getting a cover crop established, as SD weather is too cold, dry, and season too short for after harvest planting.

The Oxford English Dictionary defines 'omnifarious' as 'comprising or relating to all sorts or varieties', which quite accurately captures the very nature of octocorals and this thesis. The research reported here, aims to describe undocumented communities of coral reef organisms - the octocorals - which are an emergent dominant component within their threatened ecosystem of the Caribbean. Within the last four decades, coral reefs worldwide have experienced a precipitous plunge in many ecosystem services they provide, and most notably in the Caribbean. The foundation to reef resilience is structured on the ecosystem's ability to repair and restructure itself in the face of environmental shifts. These intricately complex strategies of resilience depend on repair mechanisms provided by a source of biodiversity, much of which remains poorly understood. This work explores many facets of the functioning within this potential future coral reef ecosystem. These reports are one of the most significant contributions to documenting and describing octocoral biodiversity (e.g. species, genetic, and community diversity) of the wider ecoregion of the Mesoamerican Barrier Reef System within the last three decades.

This thesis centres around two genera of large peltospirid gastropods (Mollusca: Neomphalina: Peltospiridae) endemic to hydrothermal vent ecosystems. One is the 'scaly-foot gastropod', an emblematic species of the Indian Ocean vents with unique dermal sclerites covering the foot like roof tiles. The other was recently discovered from expeditions to the Southern and Indian oceans, lacks sclerites and possesses large opercula. As both genera and their assigned species remained undescribed, they were formally described herein which forms a basis to understanding their biology. The 'scaly-foot gastropod' from both the Central Indian Ridge (CIR) and the Southwest Indian Ridge (SWIR) were confirmed to represent a single species and is formally named as Chrysomallon squamiferum. Through molecular genetic analyses using the COI gene, genetic differentiation between SWIR and CIR populations was detected for the 'scaly-foot gastropod'. In contrast, the peltospirids with large opercula from the East Scotia Ridge (ESR) and the SWIR proved to be two distinct species within an undescribed genus. The ESR species was formally described as Gigantopelta chessoia and the SWIR species as G. aegis. The molecular genetic analyses of the COI gene, confirmed the genetic isolation of the two and consolidated their status as separate species. A 3D tomographic model of Chrysomallon squamiferum was generated to characterise the soft anatomy and morphology as well as to understand its internal anatomy and adaptation which remained little-studied. Further to the enlarged esophageal gland already known to house chemosynthetic endosymbionts, C. squamiferum was discovered to have a hypertrophied circulatory system with a gigantic, muscular heart and large ctenidium to adapt to life in a hypoxic environment and to supply the endosymbionts with necessary chemicals. Histological examinations of the sclerites and operculum showed that it was unlikely that the sclerites originated from operculum duplication. Comparisons with polyplacophoran scales revealed starkly different secretion mechanisms despite the superficial similarity, which has implications on the placement of sclerite-bearing Cambrian taxa. Overall, the results from this thesis ascertained the systematic positions of these large-sized, enigmatic peltospirids, and led to improved understanding of their ecology and evolution. The important role of larval dispersal in maintaining metapopulations across the distribution of a vent-endemic taxa is highlighted. The adaptations of vent-endemic taxa remains little-known even in well-studied species, warranting future studies on these and other species.

Krivelevich and Patkós conjectured in 2009 that χ(G(n, p)) ∼ χ=(G(n, p)) ∼ χ∗=(G(n, p)) for C/n < p < 1 − ε, where ε > 0. We prove this conjecture for n−1+ε1 < p < 1 − ε2 where ε1, ε2 > 0. We investigate several measures that have been proposed to indicate centrality of nodes in networks, and find examples of networks where they fail to distinguish any of the vertices nodes from one another. We develop a new method to investigate core-periphery structure, which entails identifying densely-connected core nodes and sparsely-connected periphery nodes. Finally, we present an experiment and an analysis of empirical networks, functional human brain networks. We found that reconfiguration patterns of dynamic communities can be used to classify nodes into a stiff core, a flexible periphery, and a bulk. The separation between this stiff core and flexible periphery changes as a person learns a simple motor skill and, importantly, it is a good predictor of how successful the person is at learning the skill. This temporally defined core-periphery organisation corresponds well with the core- periphery detected by the method that we proposed earlier the static networks created by averaging over the subjects dynamic functional brain networks.

Spanning tree congestion was defined by Ostrovskii (2004) as a measure of how well a network can perform if only minimal connection can be maintained. We compute the parameter for several families of graphs. In particular, by partitioning a hypercube into pieces with almost optimal edge-boundaries, we give tight estimates of the parameter thereby disproving a conjecture of Hruska (2008). For a typical random graph, the parameter exhibits a zigzag behaviour reflecting the feature that it is not monotone in the number of edges. This motivates the study of the most congested graphs where we show that any graph is close to a graph with small congestion. Next, we enumerate independent sets. Using the independent set polynomial, we compute the extrema of averages in trees and graphs. Furthermore, we consider inverse problems among trees and resolve a conjecture of Wagner (2009). A result in a more general setting is also proved which answers a question of Alon, Haber and Krivelevich (2011). After briefly considering polynomial invariants of general graphs, we specialize into trees. Three levels of tree distinguishing power are exhibited. We show that polynomials which do not distinguish rooted trees define typically exponentially large equivalence classes. On the other hand, we prove that the rooted Ising polynomial distinguishes rooted trees and that the Negami polynomial determines the subtree polynomial, strengthening results of Bollobás and Riordan (2000) and Martin, Morin and Wagner (2008). The top level consists of the chromatic symmetric function and it is proved to be a complete invariant for caterpillars.

Faraday waves arise on the surface of a liquid in a container that is undergoing vertical periodic oscillations. We investigate two-dimensional Faraday waves in a long rectangular container, both theoretically and experimentally. Hysteresis occurs when both finite amplitude solutions and the flat surface solution are available. We derive a nonlinear model of a standing wave, extending the Lagrangian method of Miles (1976). The model is used to investigate hysteresis. It is found necessary to retain cubic damping, cubic forcing and the fifth-order conservative term in order to achieve agreement with experiments. The fifth-order conservative term was omitted from all previous studies of Faraday waves. Stable limit cycles are found to arise from this single-mode equation. We examine the structure of this new solution in detail, both analytically and numerically. We describe local bifurcations using a multiple time scales analysis and global bifurcations using Melnikov's method. The coefficients of linear and cubic damping are derived for a standing wave in a rectangular container by considering energy dissipation in the main body of the fluid (due to potential flow and streaming) and in boundary layers at the sidewalls and at the surface. Surface contamination, due to the presence of a thin viscoelastic surface film, creates a boundary layer at the surface which causes enhanced dissipation comparable to, or greater than, that caused by the boundary layers at the walls of the container. Three-mode interaction equations are used to model intermittency and complex modulations which are found to arise from a sideband instability mechanism similar to that of Eckhaus (1963) and Benjamin & Feir (1967). The role of cubic and fifth-order nonlinear terms on this instability mechanism is examined. Theoretical results are found to compare quite favourably with experimental data.

Oscillatory fluid flows arise naturally in many systems. Whether or not these systems are stable is an important question and external periodic forcing of the flow may result in rich and complicated behaviours. Here three distinct oscillatory fluid flows are examined in detail, with the stability of each being established using a range of analytical and computational methods. The first system comprises standing surface capillary-gravity waves in second-harmonic resonance subject to Faraday excitation. Using the perturbation technique of multiple scales, the amplitude equations for the system are derived. At exact resonance, and with the absence of damping, the only fixed point of the equations is found to be the origin. A computational approach reveals that the amplitudes of the two waves remain either bounded or grow to infinity depending on initial data. With the introduction of detuning and damping into the system families of fixed points now exist and some special cases are considered. The second class of flows are unbounded time-periodic flows with fixed ellipsoidal stream surfaces, and having spatially uniform but time-periodic strain rates. Using a recently developed method based on theoretical study of the Schrodinger equation with quasi-periodic potential, a computational approach is adopted which determines the stability of the flow to three-dimensional plane wave disturbances. Results for the growth rate and winding number of the disturbance clearly reveal the regions of instability. It is found that almost all these flows are highly unstable. The third class is another set of three-dimensional time-periodic flows with spatially uniform strain rates. These flows are non-axisymmetric and have sinusoidally-fluctuating rates of strain directed along the fixed coordinate axes. The same computational method is employed and it is found that instability increases along with the non-axisymmetric nature of the flow.

This work assesses the importance of nonlinearity in the stability of flows over compliant and rigid walls, and comprises three main parts. The first part considers inviscid flow with a free surface over a flexible boundary. The dispersion relation is obtained, and the conditions for linear instability investigated. The linear dispersion relation is then used to show that the conditions for nonlinear three-wave resonance are often met. In some circumstances, the resonance may be of 'explosive' sort, involving waves of opposite energy sign; but non-explosive resonant configurations are most common. Next, the wave- amplitude evolution equations for three-wave resonance are derived, firstly by a 'direct' approach, and then via a variational (averaged Lagrangian) method. Results agree with those of Case & Chiu (1977) for capillary-gravity waves, and Craik & Adam (1979), for three-layer fluid flow, on taking the appropriate limits. We also consider a nonlinear model for the flexible boundary. In the second part, stability of Blasius flow over a compliant surface is studied. This extension of rigid-wall work of Craik (1971) and Hendriks (appendix to Usher & Craik 1975) determines the quadratic interaction coefficients of three-wave resonance, and complements the linear analysis of Carpenter & Garrad (1985, 1986) and others. First, the linear eigenvalue spectrum is investigated for various values of the wall parameters. Then, resonant triads are located and the quadratic interaction coefficients determined numerically. By way of introduction some rigid-wall results are also presented, extending those of Hendriks.

In Part I of this thesis, steady and time-dependent, natural-convection similarity flows with mass transfer are discussed. Similarity flows for natural convection on families of two-dimensional bodies with closed lower ends are enumerated, when both a temperature distribution and a suction velocity distribution are prescribed at the body surface. For steady similarity flow on a heated vertical flat plate, with mass transfer at the surface, a numerical procedure is introduced for determining the velocity and temperature profiles. These results are presented in Figs. 2 and 3. Other similarity flows may be found by the same method. A simplification, valid for “strong” suction, is discussed. An extension of Mangler's transformation [1948] is given which reduces the equations governing axisymmetric flow to those for two-dimensional flow in steady natural convection. In Part II non-linear resonant instability in parallel shear flows is discussed. A.D.D.Craik's (see Usher and Craik [I]) modified version of Bateman's [1956] variational formulation for viscous flows is employed to derive the second-order interaction equations governing the temporal evolution of a resonant wave triad in a sheer flow. (An extension of Craik's variational formulation to free surface flows is presented but is not required in the subsequent analysis for the resonance problem). This problem was treated previously using a ‘direct' approach (employing the Navier-Stokes equations) by Craik [1971]. The major advantage of the present method over the ‘direct' method is the substantial reduction in algebraic complexity. Also, a justification of the validity of Craik's previous analysis is given. For this same resonance problem, third-order interaction equations are derived by the *direct* method since, to this order of approximation, little advantage is to be gained from the variational formulation. The resonance theory is thereby developed to the same order of approximation as the non-resonant third-order theory of Stuart [1960, 1962]. An asymptotic analysis for large Reynolds numbers reveals that the magnitudes of the third-order interaction coefficients – like certain of those at second-order – are remarkably large. Such results lead to a discussion of the regions of validity of the perturbation analysis. Also some light is shed on the roles played by resonance and three-dimensionality in the non-linear instability of shear flows.

The subject matter of this thesis is concerned with the stability of fluid flows; more particularly , with the stability of liquid films which have an interface with air. We will therefore begin by formulating the basic equations and ideas which pertain to this class of problems. Later in this chapter, a summary will be given of the topics dealt with in this dissertation.