Anomaly Detection in the Molecular Structure of Gallium Arsenide Using Convolutional Neural Networks

This paper concerns the development of a machine learning tool to detect anomalies in the molecular structure of Gallium Arsenide. We employ a combination of a CNN and a PCA reconstruction to create the model, using real images taken with an electron microscope in training and testing. The methodology developed allows for the creation of a defect detection model, without any labeled images of defects being required for training. The model performed well on all tests under the established assumptions, allowing for reliable anomaly detection. To the best of our knowledge, such methods are not currently available in the open literature; thus, this work fills a gap in current capabilities

Selected Studies of the Efficacy of Direct Instruction Mathematics Programs

18 pagesThis study examined the impact of the Direct Instruction program, Connecting Math Concepts, on mathematics achievement over six consecutive school years, 2007-2008 through 2012-2013. Math skills were measured with the Stanford Achievement Test for students in grades kindergarten and higher and the Oregon Assessment of Knowledge and Skills for students in grades three to five

The Threshold and Inclusive Approaches to Determining ‘‘Best Available Evidence’’: An Empirical Analysis

22 pagesMost evaluators have embraced the goal of evidence-based practice (EBP). Yet, many have criticized EBP review systems that prioritize randomized control trials and use various criteria to limit the studies examined. They suggest this could produce policy recommendations based on small, unrepresentative segments of the literature and recommend a more traditional, inclusive approach. This article reports two empirical studies assessing this criticism, focusing on the What Works Clearinghouse (WWC). An examination of outcomes of 252 WWC reports on literacy interventions found that 6% or fewer of the available studies were selected for review. Half of all intervention reports were based on only one study of a program. Data from 131 studies of a reading curriculum were used to compare conclusions using WWC procedures and more inclusive procedures. Effect estimates from the inclusive approach were more precise and closer to those of other reviews. Implications are discussed

Reading Mastery and Students with Learning Disabilities: A Comment on the What Works Clearinghouse Review

32 pagesA recent report by the What Works Clearinghouse (2012) examined two studies of the use of Reading Mastery with learning disabled students and concluded that it had “no discernible effects on reading comprehension and potentially negative effects on alphabetics, reading fluency, and writing.” This conclusion is in stark contrast to dozens of studies of Reading Mastery and other elements of the Direct Instruction (DI) corpus of material. This research has consistently found strong positive effects of the programs on academic achievement for students of all ability levels

The WWC Review Process: An Analysis of Errors in Two Recent Reports

18 pagesThe What Works Clearinghouse (WWC) is a federally funded program established in 2002 that evaluates educational interventions and publishes reports and summary ratings. The reports have received extensive criticism, including concerns such as examining only a small proportion of the available evidence, errors in the review process, and a lack of peer review and comparisons of results to related literature. Two WWC reports issued in July 2013 illustrate the severe problems that can permeate the process and result in the dissemination of erroneous conclusions. In one case, the WWC’s errors resulted in a positive rating for a program that has been determined, by more inclusive and careful reviews, to be ineffective and inefficient. In the other case the WWC’s errors resulted in a negative conclusion regarding a program that has been judged, by more inclusive and careful reviews, to be highly effective. In other words, the errors in the recent WWC reports result in ratings that promote a program found in the established literature to be ineffective and denigrate a program found in all other reviews to be highly effective. These errors illuminate an enormous waste of the nation’s resources. But, the true losers are the nation’s children, as their schools and educational policy makers are deprived of accurate information on which they can make decisions

Reading Mastery and Learning Disabled Students: A Comment on the What Works Clearinghouse Review

32 pagesA recent report by the What Works Clearinghouse (2012) examined two studies of the use of Reading Mastery with learning disabled students and concluded that it had “no discernible effects on reading comprehension and potentially negative effects on alphabetics, reading fluency, and writing.” This conclusion is in stark contrast to dozens of studies of Reading Mastery and other elements of the Direct Instruction (DI) corpus of material. This research has consistently found strong positive effects of the programs on academic achievement for students of all ability levels

Does the What Works Clearinghouse Work?

18 pagesThe What Works Clearinghouse (WWC) is a federally funded program established in 2002 to evaluate educational interventions and provide reliable and trustworthy summary ratings and reports of their effectiveness. Yet, some of their reports directly contradict the conclusions of the research literature, giving positive ratings to a program that scholars have found to be ineffective (Reading Recovery) and failing to give positive ratings to programs the research literature has found to be highly effective (Direct Instruction). This article uses a comparative case study approach to examine how these contradictory conclusions developed. We contrast the methods used by the scholarly world and the WWC to summarize literature and their conclusions about the two curricula. We then examine errors in the three major steps of the WWC review process: 1) compiling lists of studies to examine, 2) applying WWC criteria to select studies for further analysis, and 3) interpreting and reporting the results of the studies. Extensive problems are documented at each step, systematically favoring RR and not favoring DI. Implications of the results are briefly discussed

Hydrogeology and Hydrochemistry of the Falls City Uranium Mine Tailings Remedial Action Project, Karnes County, Texas

Oxidized uranium ore deposits were discovered in the Deweesville sandstone (also referred to as the Stones Switch; Bunker and MacKallor [1973]) in the Falls City region in the 1950s. Uranium was mined and milled in the small community of Deweesville by Susquehanna-Western, Inc. (SWI) from April 1961 to August 1973. Tailings composed of sediment residue from the sulfuric acid milling process and residual sulfuric acid solutions were disposed of in six ponds on the outcrop of the Deweesville, within the mined-out uranium pits in the Deweesville, and on the outcrop of the Conquista, creating a set of large tailings impoundments (figs. 1.1 and 1.2). From 1978 to 1982 Solution Engineering, Inc. (SEI) conducted a secondary recovery of the remaining uranium in the tailings piles by in situ leaching. In 1984, the ponds on top of two of the tailings piles were spray evaporated and a clay cap was placed over the piles to prevent additional percolation of water through the piles and into the underlying aquifers. Acidic tailings solutions have been recharging the underlying aquifers since initial tailings disposal and may still be leaking into these aquifers. Several hydrogeologic investigations have been conducted to assess whether there has been groundwater contamination from the tailings. Early studies were conducted by Turk, Kehle and Associates (1976), and Ford, Bacon & Davis Utah (1978, 1981). Each of these studies included only minor investigations of the hydrogeology and hydrochemistry of the site and, in general, underestimated the extent of contamination from the site. Investigations conducted by the U.S. Department of Energy (DOE) from 1985 to 1991 have since revealed the true extent of contamination (U.S. Department of Energy, 1991).Bureau of Economic Geolog

The effect of relative plasma plume delay on the properties of complex oxide films grown by multi-laser multi-target combinatorial pulsed laser deposition

We report the effects of relative time delay of plasma plumes on thin garnet crystal films fabricated by dual-beam, combinatorial pulsed laser deposition. Relative plume delay was found to affect both the lattice constant and elemental composition of mixed Gd3Ga5O12 (GGG) and Gd3Sc2Ga5O12 (GSGG) films. Further analysis of the plasmas was undertaken using a Langmuir probe, which revealed that for relative plume delays shorter than ~200 µs, the second plume travels through a partial vacuum created by the first plume, leading to higher energy ion bombardment of the growing film. The resulting in-plane stresses are consistent with the transition to a higher value of lattice constant normal to the film plane that was observed around this delay value. At delays shorter than ~10 µs, plume propagation was found to overlap, leading to scattering of lighter ions from the plume and a change in stoichiometry of the resultant films

Hipparcos period-luminosity relations for Miras and semiregular variables

We present period-luminosity diagrams for nearby Miras and semiregulars, selecting stars with parallaxes better than 20 per cent and well-determined periods. Using K-band magnitudes, we find two well-defined P-L sequences, one corresponding to the standard Mira P-L relation and the second shifted to shorter periods by a factor of about 1.9. The second sequence only contains semiregular variables, while the Mira sequence contains both Miras and semiregulars. Several semiregular stars show double periods in agreement with both relations. The Whitelock evolutionary track is shown to fit the data, indicating that the semiregulars are Mira progenitors. The transition between the two sequences may correspond to a change in pulsation mode or to a change in the stellar structure. Large amplitude pulsations leading to classical Mira classification occur mainly near the tip of the local AGB luminosity function.Comment: 10 pages with figures, accepted by ApJ Letter