The Georgia Old-Time Fiddlers Conventions Revisited

This presentation provides the listener with a basic historical background for the understanding of the nature, and the impact on the South and the nation, of the annual Georgia Old-Time Fiddlers Conventions held in Atlanta from 1913 to 1935. The presenter describes a typical example of the conventions, and highlights some of the atypical activities that took place during many of the fiddlers’ gatherings. The listener becomes acquainted with how the conventions played an important role in the evolution of the musical genre that is now called country. The presenter speaks of the careers of some of the conventions’ performers who, as successful radio and recording artists, are now heralded as pioneers in this fledgling phase of country music. Presentation guest Barbara Panter-Connah, a local fiddler, discusses how the convention contestants, who originally were all males, bowed to the dismantling of the gender barrier that had so long prevailed. The result was the two-time crowning of a female Georgia Old-Time Fiddle Champion. Video footage of the presentation

Matters of fact: reading nonfiction over the edge

(print) x, 224 p. ; 23 cmAcknowledgments -- 1. Nonfictional narrative and the problem of truth. p.1 -- 2. Writing inside out: the nonfiction narrator in scripted and conscripted history. p.40 -- 3. Writing outside in: implicating the author in the narratives of Tom Wolfe and John Reed. p.76 -- 4. Reading inside out: rupture and control in the construction of reader. p.115 -- 5. Reading outside in: over the edge of genre in the case of Private O'Brien. p.164 -- Notes. p.195 -- Works cited. p.205 -- Index. p.21

Can Baryonic Features Produce the Observed 100 Mpc Clustering?

We assess the possibility that baryonic acoustic oscillations in adiabatic models may explain the observations of excess power in large-scale structure on 100h^-1 Mpc scales. The observed location restricts models to two extreme areas of parameter space. In either case, the baryon fraction must be large (Omega_b/Omega_0 > 0.3) to yield significant features. The first region requires Omega_0 < 0.2h to match the location, implying large blue tilts (n>1.4) to satisfy cluster abundance constraints. The power spectrum also continues to rise toward larger scales in these models. The second region requires Omega_0 near 1, implying Omega_b well out of the range of big bang nucleosynthesis constraints; moreover, the peak is noticeably wider than the observations suggest. Testable features of both solutions are that they require moderate reionization and thereby generate potentially observable (about 1 uK) large-angle polarization, as well as sub-arc-minute temperature fluctuations. In short, baryonic features in adiabatic models may explain the observed excess only if currently favored determinations of cosmological parameters are in substantial error or if present surveys do not represent a fair sample of 100h^-1 Mpc structures.Comment: LaTeX, 7 pages, 5 Postscript figures, submitted to ApJ Letter

Uncertainty-Aware Mixed-Variable Machine Learning for Materials Design

Data-driven design shows the promise of accelerating materials discovery but is challenging due to the prohibitive cost of searching the vast design space of chemistry, structure, and synthesis methods. Bayesian Optimization (BO) employs uncertainty-aware machine learning models to select promising designs to evaluate, hence reducing the cost. However, BO with mixed numerical and categorical variables, which is of particular interest in materials design, has not been well studied. In this work, we survey frequentist and Bayesian approaches to uncertainty quantification of machine learning with mixed variables. We then conduct a systematic comparative study of their performances in BO using a popular representative model from each group, the random forest-based Lolo model (frequentist) and the latent variable Gaussian process model (Bayesian). We examine the efficacy of the two models in the optimization of mathematical functions, as well as properties of structural and functional materials, where we observe performance differences as related to problem dimensionality and complexity. By investigating the machine learning models' predictive and uncertainty estimation capabilities, we provide interpretations of the observed performance differences. Our results provide practical guidance on choosing between frequentist and Bayesian uncertainty-aware machine learning models for mixed-variable BO in materials design

AMCIS 2002 Panels and Workshops III: How Will Media Technology Evolve as an Academic Discipline?

Media Technology (MT) is a new, multidisciplinary field that integrates the knowledge, expertise, resources, and creativity of diverse, established, fertile artistic disciplines (visual design, art, music, radio, television) with new technological disciplines (digital media, information systems, information technology, computer science, network engineering) through rapidly-evolving technologies. Its application in electronic commerce into what will become a full synthesis of information technology and sensory interaction will be made possible by approaches to presenting and exchanging information visually, aurally--and eventually in combination with all of the senses. This article reports on a panel held at AMCIS 2002 in Dallas TX. The panel discussed the need to develop a literacy and understanding in the IT discipline of the MT and its importance in keeping IT research relevant. The panel also discussed strategies for attaining MT literacy, integrating MT into the IT curriculum, and discussed two universities where it is being done

It Takes Two to Tango: When and Where Dual Nutrient (N & P) Reductions Are Needed to Protect Lakes and Downstream Ecosystems

Preventing harmful algal blooms (HABs) is needed to protect lakes and downstream ecosystems. Traditionally, reducing phosphorus (P) inputs was the prescribed solution for lakes, based on the assumption that P universally limits HAB formation. Reduction of P inputs has decreased HABs in many lakes, but was not successful in others. Thus, the "P-only" paradigm is overgeneralized. Whole-lake experiments indicate that HABs are often stimulated more by combined P and nitrogen (N) enrichment rather than N or P alone, indicating that the dynamics of both nutrients are important for HAB control. The changing paradigm from P-only to consideration of dual nutrient control is supported by studies indicating that (1) biological N fixation cannot always meet lake ecosystem N needs, and (2) that anthropogenic N and P loading has increased dramatically in recent decades. Sediment P accumulation supports long-term internal loading, while N may escape via denitrification, leading to perpetual N deficits. Hence, controlling both N and P inputs will help control HABs in some lakes and also reduce N export to downstream N-sensitive ecosystems. Managers should consider whether balanced control of N and P will most effectively reduce HABs along the freshwater-marine continuum

CFD analysis of turbopump volutes

An effort is underway to develop a procedure for the regular use of CFD analysis in the design of turbopump volutes. Airflow data to be taken at NASA Marshall will be used to validate the CFD code and overall procedure. Initial focus has been on preprocessing (geometry creation, translation, and grid generation). Volute geometries have been acquired electronically and imported into the CATIA CAD system and RAGGS (Rockwell Automated Grid Generation System) via the IGES standard. An initial grid topology has been identified and grids have been constructed for turbine inlet and discharge volutes. For CFD analysis of volutes to be used regularly, a procedure must be defined to meet engineering design needs in a timely manner. Thus, a compromise must be established between making geometric approximations, the selection of grid topologies, and possible CFD code enhancements. While the initial grid developed approximated the volute tongue with a zero thickness, final computations should more accurately account for the geometry in this region. Additionally, grid topologies will be explored to minimize skewness and high aspect ratio cells that can affect solution accuracy and slow code convergence. Finally, as appropriate, code modifications will be made to allow for new grid topologies in an effort to expedite the overall CFD analysis process