Evolution of neural networks, or neuroevolution, has been a successful approach to many low-level control problems such as pole balancing, vehicle control, and collision warning. However, certain types of problems — such as those involving strategic decision-making — have remained difficult to solve. This dissertation proposes the hypothesis that such problems are difficult because they are fractured: The correct action varies discontinuously as the agent moves from state to state. To evaluate this hypothesis, a method for measuring fracture using the concept of function variation of optimal policies is proposed. This metric is used to evaluate a popular neuroevolution algorithm, NEAT, empirically on a set of fractured problems. The results show that (1) NEAT does not usually perform well on such problems, and (2) the reason is that NEAT does not usually generate local decision regions, which would be useful in constructing a fractured decision boundary. To address this issue, two neuroevolution algorithms that model local decision regions are proposed: RBF-NEAT, which biases structural search by adding basis-function nodes, and Cascade-NEAT, which constrains structural search by constructing cascaded topologies. These algorithms are compared to NEAT on a set of fractured problems, demonstrating that this approach can improve performance significantly. A meta-level algorithm, SNAP-NEAT, is then developed to combine the strengths of NEAT, RBF-NEAT, and Cascade-NEAT. An evaluation in a set of benchmark problems shows that it is possible to achieve good performance even when it is not known a priori whether a problem is fractured or not. A final empirical comparison of these methods demonstrates that they can scale up to real-world tasks like keepaway and half-field soccer. These results shed new light on why constructive neuroevolution algorithms have difficulty in certain domains and illustrate how bias and constraint can be used to improve performance. Thus, this dissertation shows how neuroevolution can be scaled up from learning low-level control to learning strategic decision-making problems. / text

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Dark matter and dark energy clearly emerged from recent cosmological surveys as key ingredients of the Universe. Understanding their physical nature might be a way to unlock some of the mysteries in particle physics and General Relativity. In this talk I will discuss how gravitational lensing will have a unique contribution in this endeavor. I will also discuss how future weak lensing surveys, primarily designed to study dark matter and dark energy, will enable the detailed analysis of the physical processes underlying structure formation such as galaxies and clusters of galaxies. Presented on April 10, 2008.

Food insecurity and diet quality are concerns in low-income populations, contributing to high rates of obesity. Food management skills may enable low-income populations to obtain a healthy food supply rather than relying on less expensive and less nutritious foods to fill their diets. The purpose of this study was to assess the relationship between food management practices and diet quality in SNAP-ED/EFNEP participants. This study examines the association between food management behaviors and dietary outcomes (Healthy Eating Index totals, total calories, carbohydrates, protein, fat, and fiber, and servings of fruits, vegetables, milk, and meats/beans) as measured by the Behavior Checklist and diet information collected by Extension Program assistants for 1,585 participants in Kentucky counties (n=57) during 2010-2011. The results of the cross-sectional analysis suggest that food management practices can help low-income SNAP-ED and EFNEP participants obtain more food for their families. However, diet quality was only improved for the variable ‘healthy foods,’ (participants who responded that they thought about healthy foods when deciding what to feed their families). It was concluded that an integrated approach of food management practices and nutrition education is needed to improve diet quality for low-income populations.

Standardization, flexibility and transparency had been the eminent keywords of Modern Architecture that have also provided material for the re-interpretation and re-production of several discussions on concepts like &lsquo / form&rsquo / and &lsquo / function&rsquo / in architecture. This study is an inquiry into a number of different interpretations that scrutinize the intricate relationship between architectural form and function in the 20th century with respect to the concepts defined above. The conceptualization of this thesis will be based on the assumption that function is an inadequate and weak concept for the generation of architectural form. It is in this context that form is accepted as an architectural &ldquo / fragment&rdquo / that attains its autonomy not from the strictures imposed by other architectural fragment like &lsquo / function&rsquo / , &lsquo / structure&rsquo / , &lsquo / program&rsquo / and &lsquo / site / but from an infinite number of internal relationships or &lsquo / design tools&rsquo / as we call. The aim of this study is to propose a project for &ldquo / A Multi &ndash / Functional Hall at METU&rdquo / which has the capability of expanding its limits in future, both physically and conceptually / and investigate the &lsquo / design tools&rsquo / that will direct the steps of transformations in the process of architectural production. Within this framework, the investigation is concerned with the production of a flexible, unstable and indeterminant building, focused on the concepts of &lsquo / transformation of space&rsquo / and &lsquo / constant change&rsquo / , that could be re-designed and re-generated in respect to possible future transformations in the program. Thus, architectural production is defined merely as a &lsquo / step&rsquo / or a &lsquo / snap-shot&rsquo / , controlled by the design tools suggesting the solutions for an ever-lasting transformation as the conditions change.

<p>The primary focus of this dissertation is the characterization of snap-through buckling of discrete and continuous systems. Snap-through buckling occurs as the consequence of two factors, first the destabilization, or more often the disappearance of, an equilibrium position under the change of a system parameter, and second the existence of another stable equilibrium configuration at a remote location in state space. In this sense snap-through buckling is a global dynamic transition as the result of a local static instability.</p><p> </p><p>In order to better understand the static instabilities that lead to snap-through buckling, the behavior of mechanical systems in the vicinity of various local bifurcations is first investigated. Oscillators with saddle-node, pitchfork, and transcritical bifurcations are shown analytically to exhibit several interesting characteristics, particularly in relation to the system damping ratio. A simple mechanical oscillator with a transcritical bifurcation is used to experimentally verify the analytical results. The transcritical bifurcation was selected since it may be used to represent generic bifurcation behavior. It is shown that the damping ratio may be used to predict changes in stability with respect to changing system parameters.</p><p>Another useful indicator of snap-through is the presence of chaos in the dynamic response of a system. Chaos is usually associated snap-through, as in many systems large amplitude responses are typically necessary to sufficiently engage the nonlinearities that induce chaos. Thus, a pragmatic approach for identifying chaos in experimental (and hence noisy) systems is also developed. The method is applied to multiple experimental systems showing good agreement with identification via Lyapunov exponents.</p><p>Under dynamic loading, systems with the requisite condition for snap-through buckling, that is co-existing equilibria, typically exhibit either small amplitude response about a single equilibrium configuration, or large amplitude response that transits between the static equilibria. Dynamic snap-through is the name given to the large amplitude response, which, in the context of structural systems, is obviously undesirable. This phenomenon is investigated using experimental, numerical, and analytical means and the boundaries separating safe (non-snap-through) from unsafe (snap-through) dynamic response in forcing parameter space are obtained for both a discrete and a continuous arch. Arches present an ideal avenue for the investigation of snap-through as they typically have multiple, often tunable, stable and unstable equilibria. They also have many direct applications in both civil engineering, where arches are a canonical structural element, and mechanical engineering, where arches may be used to approximate the behavior of curved plates and panels such as those used on aircraft.</p> / Dissertation

Thesis (Ph.D.) -- University of Rhode Island, 2009. / Typescript. Includes bibliographical references (leaves 128-137).

Giardia intestinalis is the most common parasite found in dogs and cats. It is traditionally diagnosed using a microscope. These methods include direct immunofluorescence, DIF, and zinc sulphate centrifugal flotation, ZnSO4 C-flotation. However, there are commercially available SNAP tests such as the FASTest® GIARDIA strip that is often used by dogs and cats owner to detect Giardia. The aim of this study was to compare the sensitivity, cost and labor intensity of these three methods for detection of Giardia. To investigate this, 150 samples from dogs and cats were examined at the National Veterinary Institute in Sweden. The samples were a mixture of diarrheic and non-diarrheic stool. Of the 150 stool samples 100 samples were examined with FASTest® GIARDIA strip while 150 samples were examined with DIF and ZnSO4 C-flotation. The results indicated that FASTest® GIARDIA strip had a sensitivity of 66.18 %, a cost of 100 Swedish crowns (SEK) per sample and was the easiest test to use. ZnSO4 C-flotation had a sensitivity of 89.90 %, cost 418.75 SEK and took about 15 minutes to perform. DIF had 100 % sensitivity and specificity and due to that it was used as a standard reference method. The cost for DIF was 300 SEK and took more than an hour to perform per sample. The conclusion from this study is that, FASTest® GIARDIA strip is not a recommended test for detection of Giardia despite their low cost and easiness to use. DIF and ZnSO4 C-flotation remain a better diagnostic option for detection of Giardia.

Low consumption of fruits and vegetables due to various barriers among food insecure populations presents a significant health risk across all ages. Nutrition education is available to low-income populations, but due to the complexity and variety of influences that determine dietary behavior, increasing nutrition knowledge as a singular approach does not successfully result in behavior change. This may be supported by low Supplemental Nutrition Assistance Program (SNAP) redemption rates at farmers markets. There is a lack of data using the Theory of Planned Behavior to assess intentions to purchase fruits and vegetables by SNAP-Ed participants at farmers markets in Southern Illinois. There is also a lack of research on the interest in using social media for nutrition education on fruit and vegetable consumption in low-income populations throughout Southern Illinois. A cross-sectional survey was used to understand SNAP-Ed participants’ intentions to purchase fruits and vegetables at farmers markets, as well as their interest in receiving and using online nutrition education through various social media applications. A survey instrument was distributed to low-income participants of various SNAP-Ed nutrition classes hosted by the University of Illinois-Extension throughout the 16 southernmost counties of Illinois. The survey analyzed constructs of the Theory of Planned Behavior and relationships with intentions using regression analysis. Additionally, questions regarding social media usage were used to determine what technologies and social media applications are most commonly used among the sample, and any interest in receiving nutrition education through such applications. A total sample of n=189 SNAP-Ed participants completed the survey. The study found that attitude regarding fresh fruits and vegetables at farmers markets was the strongest predictor of intent to purchase fruits and vegetables for SNAP-Ed participants who receive SNAP benefits. Second, online nutrition education focused on fruit and vegetable purchases at farmers markets may be more generalizable regarding certain socio-demographic factors for SNAP-Ed participants who receive SNAP benefits. Third, results from the study demonstrate that 76.9% of respondents had Internet access, which is higher than current national rates for Internet accessibility in rural areas. Therefore, it is important to consider an increased Internet accessibility beyond at-home broadband coverage, which may include public libraries, work, school, or on a Smartphone. The most important socio-demographic characteristic to consider regarding social media use was age in the context of generations (Millennials, Working Adults, Seniors). Overall, SNAP-Ed participants were most likely to exhibit interest in nutrition education from text messages, email, or on Facebook. SNAP-Ed participants would like to receive online nutrition education via email (30.1%), Facebook (24.7%), and text messaging (21.0%). Online nutrition education in the form of email, Facebook, and text messaging would be the most successful in terms of recruitment and interaction for SNAP-Ed participants. Therefore, using social media to deliver nutrition education may be an effective supplement to reinforce the current classroom curriculum used in SNAP-Ed programming. Findings from this study support the use of online nutrition education through social media applications as an avenue to increase fruit and vegetable purchases at farmers markets in the Southern Illinois Mississippi Delta Region.

abstract: In the delivery of a public service, meeting the needs of its users through cocreation has generated considerable research. Service users are encouraged to engage with public services through dialogue, sustained interaction, and equal partnership, wherein the role of the user changes from passive to active. As the relationship between service provider and service user evolves, researchers have sought to explain how resources, time, accessibility, and bandwidth may affect such relationships, specifically concerning the economically disadvantaged. While many researchers have focused on the logistical barriers that inhibit cocreation among the economically disadvantaged presented by such factors as cost and transportation, limited research has examined the relationship between the service provider and economically disadvantaged service user. Combining previous research, this study examines what economically disadvantaged service users actually do when they cocreate value with a public service by conducting 12 in-depth interviews with participants of SNAP-Ed, nutrition education for persons eligible for government assistance. The study's findings suggest that cocreation exists through relational characteristics of collaboration, isolation, acceptance, connection, and guidance that help in the development and maintenance of relationships, and that a relationship between service provider and user could be further typified by equality. This finding suggests that equality is an independent construct not necessary in the process of cocreation--a departure from previous research--but rather a way to approach the service provider/user relationship. This study is intended as a step toward examining cocreation through the development of organization-public relationships. / Dissertation/Thesis / Doctoral Dissertation Journalism and Mass Communication 2014