Adaptive Sampling For Efficient Online Modelling

This thesis examines methods enabling autonomous systems to make active sampling and planning decisions in real time. Gaussian Process (GP) regression is chosen as a framework for its non-parametric approach allowing flexibility in unknown environments. The first part of the thesis focuses on depth constrained full coverage bathymetric surveys in unknown environments. Algorithms are developed to find and follow a depth contour, modelled with a GP, and produce a depth constrained boundary. An extension to the Boustrophedon Cellular Decomposition, Discrete Monotone Polygonal Partitioning is developed allowing efficient planning for coverage within this boundary. Efficient computational methods such as incremental Cholesky updates are implemented to allow online Hyper Parameter optimisation and fitting of the GP's. This is demonstrated in simulation and the field on a platform built for the purpose. The second part of this thesis focuses on modelling the surface salinity profiles of estuarine tidal fronts. The standard GP model assumes evenly distributed noise, which does not always hold. This can be handled with Heteroscedastic noise. An efficient new method, Parametric Heteroscedastic Gaussian Process regression, is proposed. This is applied to active sample selection on stationary fronts and adaptive planning on moving fronts where a number of information theoretic methods are compared. The use of a mean function is shown to increase the accuracy of predictions whilst reducing optimisation time. These algorithms are validated in simulation. Algorithmic development is focused on efficient methods allowing deployment on platforms with constrained computational resources. Whilst the application of this thesis is Autonomous Surface Vessels, it is hoped the issues discussed and solutions provided have relevance to other applications in robotics and wider fields such as spatial statistics and machine learning in general

A liberal arts education in film production: Instructional assessment of student film projects

This study examined the educational process of instructors teaching film and video production in higher education. Little research has been dedicated to this field of study. As technology advances and the cost of equipment recedes, educational programs in film and video production will experience growth, transformation, and population. Educational leadership and faculty responsible for these programs experience pressure to stay current with trends and technology while building and maintaining these types of programs; thus, the examination of these programs’ structures and practices are worthwhile endeavors. In addition, expanded markets for educated professionals in film and video production are being sought not only by the motion picture industry, but also by locally and globally focused businesses that are also searching for film and video production specialists capable of projecting brands and telling the story of such organizations. Film and video production is a balance of creative collaboration and technical competencies. It has also been suggested that film and video production is built upon complex processes that incorporate higher order thinking skills. An avenue for the attainment and refinement of these types of skills is found in a liberal arts education. Thus, it is important to explore how moving image content producers are educated regarding liberal arts outcomes. This qualitative study focused on how instructors teaching film and video production are embedding the goals of a liberal arts education in their programs. The assessment process was examined by employing a collective case study of participants with experience instructing film and video production while assessing liberal arts outcomes. The unique perspectives that were offered by the participants in this study produced findings that suggest a variety of methods are required to assess the complexities of both the filmmaking process and the projected liberal arts learning outcomes. Three categories of specific inquiry framed the data collection process: foundational information of assessment, assessment of liberal arts domains and assessment of the “4C’s” (Communication, Creativity, Collaboration, Critical Thinking). Themes and categories emerged from the data offered by the participants. Bloom’s Taxonomy Revised (2001) was applied as a theoretical framework to further examine the data. This lens produced discussion and analysis that led to grouping individual liberal arts outcomes with processes, actions and key indicators used to measure these outcomes. The findings highlighted the challenges and successes that participants had with the assessment process. Implications for practice addressed the following themes. First is administrative leadership, which focuses on institutional leadership and the challenges that instructors have with assessment in film and video production education. Strategies are highlighted which suggest specific administrative support is needed to yield more effective and efficient results with assessment in this field. Second is the need to address the formal educational process of instructors teaching in film and video production programs in higher education. Third is classroom instruction, which includes tips, techniques and methods that are used in the assessment process of film and video production. Several recommendations were offered for future studies. One, in particular, addresses the previous concern of the lack of formal research in this field. Foundational evidence and guidance is also provided regarding continued examination of instruction, assessment and student learning in the field of film and video production education

Social Support, Sense of Community, and Psychological Distress Among College Students: Examining the Impact of University Housing Units

Attending college can be a rewarding but stressful time for students. Colleges and universities across the nation are becoming more and more concerned with the mental health of their students. Although past research has explored how social support and sense of community help students make a better transition to college life, less is known about how these factors interact with where students choose to live. This study examines the relationship between social support, psychological sense of community, residence hall capacity, and psychological distress. Participants from three college campuses in the Midwest were administered surveys to assess perceived social support, psychological sense of community, psychological distress, and various identifying variables. Results showed that social support did not vary across differing hall capacities while sense of community did. Furthermore, when social support, sense of community, residence hall capacity, and psychological distress were analyzed together, only social support and sense of community scores showed significant predictive value of psychological distress. Residence hall capacity did not show predictive value related to psychological distress levels

Beyond single modes and media : writing as an ongoing multimodal text production

In this chapter, we focus on new, hybrid forms of text production and their research. We start from the practical example of Wikipedia, and the ways in which articles are developed quickly and then refined over time by Wikipedians (Part 1). This approach illustrates transitions from a narrow to a broader orientation in writing research (2). We then develop a framework for the state-of-the-art analysis of writing as a focused and incidental, by-the-way activity of producing editable and storable multimodal communication offers (3). Within this framework, challenges for and controversial issues of contemporary writing research can be identified (4). This allows us to outline what such research can contribute to Applied Linguistics (5) and to sketch a related research roadmap (6). Finally, in the reference section, we list key publications that explain writing research beyond single modes and media (7)

The Economics of Selling Crop Residue Biomass for Cellulosic Ethanol Production at the Farm Level

A partial budget decision making framework has been developed to assist crop producers in analyzing the profitability of selling cellulosic biomass from their fields for ethanol production. A multidisciplinary approach is taken in assessing the agronomic and economic factors relevant to biomass contract sales decisions – with direct application made to western Great Plains cropping systems and enterprises. Within this framework the benefits of increased revenue from cellulosic biomass contract sales and potential government assistance payments are considered against possible decreased revenue from diminished crop yields resulting from less crop residue cover and subsequent soil moisture evaporation. Increased biomass harvesting and handling are also considered, as is the cost of replacing crop nutrients removed as part of biomass harvest operations. Examples of the profitability of cellulosic biomass contract sales in center pivot irrigated corn and non-irrigated wheat enterprises are shown.Resource /Energy Economics and Policy,

Detecting mistakes in engineering models: the effects of experimental design

This paper presents the results of an experiment with human subjects investigating their ability to discover a mistake in a model used for engineering design. For the purpose of this study, a known mistake was intentionally placed into a model that was to be used by engineers in a design process. The treatment condition was the experimental design that the subjects were asked to use to explore the design alternatives available to them. The engineers in the study were asked to improve the performance of the engineering system and were not informed that there was a mistake intentionally placed in the model. Of the subjects who varied only one-factor-at-a-time, fourteen of the twenty-seven independently identified the mistake during debriefing after the design process. A much lower fraction, one out of twenty-seven engineers, independently identified the mistake during debriefing when they used a fractional factorial experimental design. Regression analysis shows that relevant domain knowledge improved the ability of subjects to discover mistakes in models, but experimental design had a larger effect than domain knowledge in this study. Analysis of video tapes provided additional confirmation as the likelihood of subjects to appear surprised by data from a model was significantly different across the treatment conditions. This experiment suggests that the complexity of factor changes during the design process is a major consideration influencing the ability of engineers to critically assess models.Charles Stark Draper LaboratorySUTD-MIT International Design Centr

Measured reduction in Alfv\'en wave energy propagating through longitudinal gradients scaled to match solar coronal holes

We have explored the effectiveness of a longitudinal gradient in Alfv\'en speed in reducing the energy of propagating Alfv\'en waves under conditions scaled to match solar coronal holes. The experiments were conducted in the Large Plasma Device at the University of California, Los Angeles. Our results show that the energy of the transmitted Alfv\'en wave decreases as the inhomogeneity parameter, $\lambda/L_{\rm A}$, increases. Here, $\lambda$ is the wavelength of the Alfv\'en wave and $L_{\rm A}$ is the scale length of Alfv\'en speed gradient. For gradients similar to those in coronal holes, the waves are observed to lose a factor of $\approx 5$ more energy than they do when propagating through a uniform plasma without a gradient. We have carried out further experiments and analyses to constrain the cause of wave energy reduction in the gradient. The loss of Alfv\'en wave energy from mode coupling is unlikely, as we have not detected any other modes. Contrary to theoretical expectations, the reduction in the energy of the transmitted wave is not accompanied by a detectable reflected wave. Nonlinear effects are ruled out as the amplitude of the initial wave is too small and the wave frequency well below the ion cyclotron frequency. Since the total energy must be conserved, it is possible that the lost wave energy is being deposited in the plasma. Further studies are needed to explore where the energy is going

The effects of sensitization on habituation using the olfactory jump reflex in Drosophila

Abstract only availableMemories can arise from simpler habituation and sensitization training as well as associative classical conditioning. However, in a complex environment, animals receive sensory cues in a fashion that can be more accurately described as having some habituation, sensitization and associative components. The relation between these types of memories at the molecular, systems and behavioral level remain largely unexplored. We can alter the timing of odor and electric shock presentation to induce all three types of memory in a defensive olfactory jump reflex. Habituation is a short-term change in behavior as a response to a repetitive stimulus. Using seven odors, we showed flies habituate their jump reflex to background levels of jump probabilities with ten odor presentations. Interestingly, the seven odors tested can be categorized into three groups based on their habituation rates: a high jump probability, a low jump probability, or a no-jump probability. Also, odors show some specificity as habituation of one odor does not lead to a total loss of jump response (complete cross-habituation) although it is reduced (partial cross-habituation). We chose to use six odors for further analysis. Sensitization is defined as an interference with habituation because of a dishabituating stimulus. Using electric shock as a potential sensitization cue, we presented shock and immediately tested jump probability. Interestingly, we found unpaired electric shock increased the jump probability with all odors tested, even those that do not induce a naïve jump. Classical (Pavlovian) conditioning arises when an animal associates a neutral stimulus with one that induces a reflex. Preliminary tests suggest that the paired presentation of electric shock and odor does not increase the jump probability of subsequent odor presentation. With the establishment of these three behavioral paradigms, the stage is set to investigate the interaction of habituation and sensitization on associate classical conditioning. Future experimentation should determine the relationship of the molecular and neural systems underlying these different forms of memory.Life Sciences Undergraduate Research Opportunity Progra

A century later another surprise: A non-visual behavioral function of the white gene

Abstract only availableDiscovery of the white mutation in Drosophila melanogaster has broadly influenced our understanding of the mechanisms of inheritance. We recently discovered a role of the white gene in memory formation. Thus, the white gene continues to provide insight into basic biological functions. We use two conditioning methods to routinely measure learning and memory in D. melanogaster, the heat-box, and classical olfactory conditioning. In the heat box experiments, white mutant flies' learning performance was notably impaired. However, in olfactory conditioning studies the mutant flies performed the same or better than wild-type flies. This differentiates the molecular mechanisms that support these conditioned behaviors. To better understand the regulatory elements that control white expression, we have initiated a molecular characterization of the white genomic locus. We identified the necessary regulatory elements by defining the deletion in the w1118 null allele. Using PCR methods we found that the deletion is about 7 kb long, and includes 5' regions, exon 1, and part of the first intron. Experiments to determine the sufficient set of regulatory elements for conditioned behavior were initiated. Two results argue that existing genomic transgenes do not contain all regulatory elements. First, mutations that affect eye color have molecular lesions outside a 14 kb genomic transgene. Second, attempted behavioral rescue experiments with this transgene fail. We interpret the failure of the 14 kb transgene to rescue as a consequence of incorrect white expression. Thus, we are creating a genomic construct that is 18 kb long that includes genomic DNA up to the next known gene. These approaches should define the regulatory regions necessary and sufficient for behaviorally important white expression.NSF-REU Program in Biological Sciences & Biochemistr