From Anecdote to Evidence: Assessing the Status and Condition of Arts Education at the State Level

Without solid evidence about the status and condition of arts education in the nation's public schools, it is difficult to make a convincing case for the arts. This research and policy brief draws on the experiences of five states -- Illinois, Kentucky, New Jersey, Rhode Island, and Washington -- as the basis for a discussion of various approaches and methodologies for conducting statewide arts education research

Tracking analysis of a first order phase- locked loop with two sinewaves modulation

Phase locked-loop tracking with sine wave modulation in Apollo communication system

Firm Capabilities, Competition and Industrial Policies in a History-Friendly Model of the Computer Industry

In this paper, we explore some problems that industrial policy faces in industries characterized by dynamic increasing returns on the basis of a 'history friendly model' of the evolution of the computer industry. How does policy affect industry structure over the course of industry evolution? Is the timing of the intervention important? Do policy interventions have indirect and perhaps unintended consequences on different markets at different times? We focus on two sets of policies: antitrust and interventions aiming at supporting the entry of new forms in the industry. The results of our simulations show that, if strong dynamic increasing returns are operative, both through technological capabilities and through customer tendency to stick with a brand, there is little that antitrust and entry policy could have done to avert the rise of a dominant firm in mainframes. On the other hand, if the customer lock in effect had been smaller, either by chance or through policies that discouraged efforts of firms to lock in their customers, the situation might have been somewhat different. In the first place, even in the absence of antitrust or entry encouraging policies, market concentration would have been lower, albeit a dominant firm would emerge anyhow. Second, antitrust and entry encouraging policies would have been more effective in assuring that concentration would decrease. The leading firm would continue to dominate the market, but its relative power would be reduced. © Elsevier Science B.V

Dynamic Web File Format Transformations with Grace

Web accessible content stored in obscure, unpopular or obsolete formats represents a significant problem for digital preservation. The file formats that encode web content represent the implicit and explicit choices of web site maintainers at a particular point in time. Older file formats that have fallen out of favor are obviously a problem, but so are new file formats that have not yet been fully supported by browsers. Often browsers use plug-in software for displaying old and new formats, but plug-ins can be difficult to find, install and replicate across all environments that one may use. We introduce Grace, an http proxy server that transparently converts browser-incompatible and obsolete web content into web content that a browser is able to display without the use of plug-ins. Grace is configurable on a per user basis and can be expanded to provide an array of conversion services. We illustrate how the Grace prototype transforms several image formats (XBM, PNG with various alpha channels, and JPEG 2000) so they are viewable in Internet Explorer.Comment: 12 pages, 9 figure

On the divine clockwork: the spectral gap for the correspondence limit of the Nelson diffusion generator for the atomic elliptic state

The correspondence limit of the atomic elliptic state in three dimensions is discussed in terms of Nelson's stochastic mechanics. In previous work we have shown that this approach leads to a limiting Nelson diffusion and here we discuss in detail the invariant measure for this process and show that it is concentrated on the Kepler ellipse in the plane z=0. We then show that the limiting Nelson diffusion generator has a spectral gap; thereby proving that in the infinite time limit the density for the limiting Nelson diffusion will converge to its invariant measure. We also include a summary of the Cheeger and Poincare inequalities both of which are used in our proof of the existence of the spectral gap.Comment: 30 pages, 5 figures, submitted to J. Math. Phy

The preparation and evaluation of high-purity, fine-grained tungsten and tungsten alloy castings summary report

High purity, cylindrical castings of high melting point materials such as tungsten and tungsten alloy

Creep fatigue life prediction for engine hot section materials (ISOTROPIC)

The specific activities summarized include: verification experiments (base program); thermomechanical cycling model; multiaxial stress state model; cumulative loading model; screening of potential environmental and protective coating models; and environmental attack model

Clearigate ® Treatments for Control of Giant Salvinia

Results of recent field trials using the chelated copper formulation Clearigate® 4 showed that applying a 20% solution by volume was effective for controlling populations of giant salvinia in irrigation canals. 5 Lower rates may be efficacious, thereby reducing chemical use and cost; however, little is known about the dose-response effects of Clearigate® against giant salvinia. The objective of this study was to determine the effective rate range of chelated copper applied as Clearigate® for control of giant salvinia

Field efficacy evaluation and post-treatment contamination risk assessment of an ultraviolet disinfection and safe storage system.

Inconsistent use of household water treatment and safe storage (HWTS) systems reduces their potential health benefits. Ultraviolet (UV) disinfection is more convenient than some existing HWTS systems, but it does not provide post-treatment residual disinfectant, which could leave drinking water vulnerable to recontamination. In this paper, using as-treated analyses, we report on the field efficacy of a UV disinfection system at improving household drinking water quality in rural Mexico. We further assess the risk of post-treatment contamination from the UV system, and develop a process-based model to better understand household risk factors for recontamination. This study was part of a larger cluster-randomized stepped wedge trial, and the results complement previously published population-level results of the intervention on diarrheal prevalence and water quality. Based on the presence of Escherichia coli (proportion of households with ≥ 1 E. coli/100 mL), we estimated a risk difference of -28.0% (95% confidence interval (CI): -33.9%, -22.1%) when comparing intervention to control households; -38.6% (CI: -48.9%, -28.2%) when comparing post- and pre-intervention results; and -37.1% (CI: -45.2%, -28.9%) when comparing UV disinfected water to alternatives within the household. We found substantial increases in post-treatment E. coli contamination when comparing samples from the UV system effluent (5.0%) to samples taken from the storage container (21.1%) and drinking glasses (26.0%). We found that improved household infrastructure, additional extractions from the storage container, additional time from when the storage container was filled, and increased experience of the UV system operator were associated with reductions in post-treatment contamination. Our results suggest that the UV system is efficacious at improving household water quality when used as intended. Promoting safe storage habits is essential for an effective UV system dissemination. The drinking glass appears to represent a small but significant source of recontamination that is likely to impact all HWTS systems

Polynomial knot and link invariants from the virtual biquandle

The Alexander biquandle of a virtual knot or link is a module over a 2-variable Laurent polynomial ring which is an invariant of virtual knots and links. The elementary ideals of this module are then invariants of virtual isotopy which determine both the generalized Alexander polynomial (also known as the Sawollek polynomial) for virtual knots and the classical Alexander polynomial for classical knots. For a fixed monomial ordering $<$, the Gr\"obner bases for these ideals are computable, comparable invariants which fully determine the elementary ideals and which generalize and unify the classical and generalized Alexander polynomials. We provide examples to illustrate the usefulness of these invariants and propose questions for future work.Comment: 12 pages; version 3 includes corrected figure