689 research outputs found

    Examining the Impact of Acquiring the ESL Endorsement on Teacher Knowledge, Dispositions, and English Language Learner Performance on a Standardized Mathematics Test

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    Rising immigration to the United States has changed the demographic make-up of students in general education classrooms. Data from the 2000 Census establish that more than 14 million immigrants entered the United States during the 1990s. The percentage of English language learners (ELLs) in U.S. public schools increased from 8% (3.8 million students) in the year 2000 to 10% (5.0 million students) in 2017. Given this change, classroom teachers are expected to meet the needs of students in mainstream classrooms who are non-native speakers of English. The purpose of this study was to examine the impact of teachers acquiring the ESL endorsement on the ESL outcomes of the ELL populations in elementary school and to compare classroom teachers with and without the ESL endorsement in terms of their ELL-related knowledge, pedagogical skills, and dispositions toward the ELL students in their classrooms. A t-test, a questionnaire, and interviews were the three tools utilized to collect data to compare teachers’ dispositions and level of knowledge in second-language-acquisition with and without the ESL endorsement. The findings showed that ESL-endorsed classroom teachers acquired better knowledge, pedagogical skills, and dispositions toward ELL populations

    An analysis of prop-fan/airframe aerodynamic integration

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    An approach to aerodynamic integration of turboprops and airframes, with emphasis placed upon wing mounted installations is addressed. Potential flow analytical techniques were employed to study aerodynamic integration of the prop fan propulsion concept with advanced, subsonic, commercial transport airframes. Three basic configurations were defined and analyzed: wing mounted prop fan at a cruise Mach number of 0.8, wing mounted prop fan in a low speed configuration, and aft mounted prop fan at a cruise Mach number of 0.8

    Spectrally encoded photoacoustic microscopy using a digital mirror device

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    We have developed spectrally encoded photoacoustic microscopy using a digital mirror device for multi-wavelength tomography, which enables fast spectral imaging of optical absorption. The optical illumination wavelengths are multiplexed at a laser pulse repetition rate of ∼2  kHz. Liquid samples, whole blood, and blood vessels in mouse ears were imaged. Compared with internal wavelength tuning of a narrow-band laser, external wavelength tuning based on a digital mirror device improves the data acquisition speed of spectral photoacoustic microscopy. Compared with external wavelength scanning of a wide-band laser with the same pulse energy, spectral encoding improves the signal-to-noise ratio

    Speckle Detection in Echocardiographic Images

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    Generation-recombination noise of junction-gate field-effect transistors

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    The generation-recombination noise of junction-gate field-effect transistors is calculated taking into account the variable mobility. The field dependence of mobility suggested by Trofimenkoff is used, and the resultant spectral intensity of the drain-noise fluctuations shows no signs of a logarithmic singularity at saturation. The need for any cutoff procedure to remove the logarithmic singularity at saturation is therefore removed, and it is thus an improvement over earlier methods

    Automatic Search for Photoacoustic Marker Using Automated Transrectal Ultrasound

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    Real-time transrectal ultrasound (TRUS) image guidance during robot-assisted laparoscopic radical prostatectomy has the potential to enhance surgery outcomes. Whether conventional or photoacoustic TRUS is used, the robotic system and the TRUS must be registered to each other. Accurate registration can be performed using photoacoustic (PA markers). However, this requires a manual search by an assistant [19]. This paper introduces the first automatic search for PA markers using a transrectal ultrasound robot. This effectively reduces the challenges associated with the da Vinci-TRUS registration. This paper investigated the performance of three search algorithms in simulation and experiment: Weighted Average (WA), Golden Section Search (GSS), and Ternary Search (TS). For validation, a surgical prostate scenario was mimicked and various ex vivo tissues were tested. As a result, the WA algorithm can achieve 0.53 degree average error after 9 data acquisitions, while the TS and GSS algorithm can achieve 0.29 degree and 0.48 degree average errors after 28 data acquisitions.Comment: 13 pages, 9 figure
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