1,892 research outputs found

    Noncontingent Reinforcement and Decreasing Problem Behaviors with Students with Special Needs and Its Effect on Teacher Behavior

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    A pilot study of noncontingent reinforcement (NCR) was conducted using NCR statements to (a) decrease target behaviors, (b) increase unprompted praise statements from the teacher and decrease reprimands, and (c) increase proximity to the participants by the teacher implementing NCR. Data were collected using a single-subject research design on two participants and one teacher. The target behaviors were physical and verbal aggression and inappropriate gestures. Teacher behaviors targeted with this study were praise statements, reprimands, and proximity to students. The participants included were one 16-year-old student with an emotional behavior disability, one 18-year-old student identified with autism spectrum disorder (ASD) and an undergraduate student who was the teacher in this setting. The results were inconclusive regarding the students’ behavior due to confounding variables. However, regarding teacher behavior, the results demonstrated an increase in proximity and praise statements and a decrease in reprimands. This single-subject study provided empirical support that the NCR intervention positively altered teacher behavior

    Animal Disease Economic Impacts: A Survey of Literature and Typology of Research Approaches

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    Animal diseases such as bovine spongiform encephalopathy (BSE) are a threat to the animal product marketing sector and the broader economy. Policy makers and industry stakeholders seek a means of assessing a disease threat's economic impacts when evaluating prevention and mitigation measures. But, differences in the focus of the impact analysis (production level, market prices, welfare), level of analysis (geographically, marketing phase) and proposed policy alternatives all influence the analytical approach. This paper surveys previous research, focusing on methodological approaches and results. Drawing from past research and future economic data needs, a typology is developed to guide researchers when defining the scope and policy alternatives of various research approaches.Animal disease economics, Literature review, Marketing channel, Livestock Production/Industries, Marketing,

    Consumer Responses to Recent BSE Events

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    Recent bovine spongiform encephalopathy (BSE, a.k.a. mad cow disease) discoveries in Canadian and U.S. beef cattle have garnered significant media attention, which may have changed consumers’ meat-purchasing behavior. Consumer response is hypothesized and tested within a meat demand system in which response is measured using single-period dummy variables, longer-term dummy variables, and media indices that count positive and negative meat-industry articles. Parameters are estimated using retail scanner data, and cross-species price elasticities are calculated. Results suggest that the BSE events negatively impacted ground beef and chuck roasts, while positively impacting center-cut pork chop demand. Dummy variables explained the variation in meat-budget shares better than did media indices.Consumer/Household Economics,

    Dependence of CMI Growth Rates on Electron Velocity Distributions and Perturbation by Solitary Waves

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    We calculate growth rates and corresponding gains for RX and LO mode radiation associated with the cyclotron maser instability for parameterized horseshoe electron velocity distributions. The velocity distribution function was modeled to closely fit the electron distribution functions observed in the auroral cavity. We systematically varied the model parameters as well as the propagation direction to study the dependence of growth rates on model parameters. The growth rate depends strongly on loss cone opening angle, which must be less than 90o90^{o} for significant CMI growth. The growth rate is sharply peaked for perpendicular radiation (k=0k_{\parallel} = 0), with a full-width at half-maximum 1.7o1.7^{o}, in good agreement with observed k-vector orientations and numerical simulations. The fractional bandwidth varied between 104^{-4} and 102^{-2}, depending most strongly on propagation direction. This range encompasses nearly all observed fractional AKR burst bandwidths. We find excellent agreement between the computed RX mode emergent intensities and observed AKR intensities assuming convective growth length LcL_c\approx20-40 km and group speed 0.15cc. The only computed LO mode growth rates compatible observed LO mode radiation levels occurred for number densities more than 100 times the average energetic electron densities measured in auroral cavities. This implies that LO mode radiation is not produced directly by the CMI mechanism but more likely results from mode conversion of RX mode radiation. We find that perturbation of the model velocity distribution by large ion solitary waves (ion holes) can enhance the growth rate by a factor of 2-4. This will result in a gain enhancement more than 40 dB depending on the convective growth length within the structure. Similar enhancements may be caused by EMIC waves.Comment: 21 pages, 11 figures. J. Geophys. Res. 2007 (accepted

    September 2003 Livestock and wildlife disease report, no. 9

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    September 2003

    Design, ancillary testing, analysis and fabrication data for the advanced composite stabilizer for Boeing 737 aircraft. Volume 1: Technical summary

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    The horizontal stabilizer of the 737 transport was redesigned. Five shipsets were fabricated using composite materials. Weight reduction greater than the 20% goal was achieved. Parts and assemblies were readily produced on production-type tooling. Quality assurance methods were demonstrated. Repair methods were developed and demonstrated. Strength and stiffness analytical methods were substantiated by comparison with test results. Cost data was accumulated in a semiproduction environment. FAA certification was obtained

    Dynamic structure selection and instabilities of driven Josephson lattice in high-temperature superconductors

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    We investigate the dynamics of the Josephson vortex lattice in layered high-Tc_{c} superconductors at high magnetic fields. Starting from coupled equations for superconducting phases and magnetic field we derive equations for the relative displacements [phase shifts] between the planar Josephson arrays in the layers. These equations reveal two families of steady-state solutions: lattices with constant phase shifts between neighboring layers, starting from zero for a rectangular configuration to π\pi for a triangular configuration, and double-periodic lattices. We find that the excess Josephson current is resonantly enhanced when the Josephson frequency matches the frequency of the plasma mode at the wave vector selected by the lattice structure. The regular lattices exhibit several kinds of instabilities. We find stability regions of the moving lattice in the plane lattice structure - Josephson frequency. A specific lattice structure at given velocity is selected uniquely by boundary conditions, which are determined by the reflection properties of electromagnetic waves generated by the moving lattice. With increase of velocity the moving configuration experiences several qualitative transformations. At small velocities the regular lattice is stable and the phase shift between neighboring layers smoothly decreases with increase of velocity, starting from π\pi for a static lattice. At the critical velocity the lattice becomes unstable. At even higher velocity a regular lattice is restored again with the phase shift smaller than π/2\pi/2. With increase of velocity, the structure evolves towards a rectangular configuration.Comment: 28 pages, 12 figures, submitted to Phys. Rev.

    Full-scale testing, production and cost analysis data for the advanced composite stabilizer for Boeing 737 aircraft, volume 2

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    The development, testing, production activities, and associated costs that were required to produce five-and-one-half advanced-composite stabilizer shipsets for Boeing 737 aircraft are defined and discussed

    A Microservice Infrastructure for Distributed Communities of Practice

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    Non-formal learning in Communities of Practice (CoPs) makes up a significant portion of today’s knowledge gain. However, only little technological support is tailored specifically towards CoPs and their particular strengths and challenges. Even worse, CoPs often do not possess the resources to host or even develop a software ecosystem to support their activities. In this paper, we describe a distributed, microservice-based Web infrastructure for non-formal learning in CoPs. It mitigates the need for central infrastructures, coordination or facilitation and takes into account the constant change of these communities. As a real use case, we implement an inquiry-based learning application on-top of our infrastructure. Our evaluation results indicate the usefulness of this learning application, which shows promise for future work in the domain of community-hosted, microservice-based Web infrastructures for learning outside of formal settings
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