668 research outputs found

    Deconstructing Videotaped Instruction for Online Delivery: Instructional Design in Reverse

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    This paper examines a project in which videotaped face-to-face class sessions were converted into interactive instructional modules for Internet delivery. The development of the online class involved the challenge of teaching the advanced Microsoft Office Suite – normally skills learned hands-on – to distance learners. Sixteen interactive modules were eventually produced by using a process the authors describe as the instructional design in reverse. This paper discusses the importance of the proper application of instructional design theory, the actual production processes used for developing the modules, and important lessons learned in working with interactive multimedia course content for online delivery.This paper examines a project in which videotaped face-to-face class sessions were converted into interactive instructional modules for Internet delivery. The development of the online class involved the challenge of teaching the advanced Microsoft Office Suite – normally skills learned hands-on – to distance learners. Sixteen interactive modules were eventually produced by using a process the authors describe as the instructional design in reverse. This paper discusses the importance of the proper application of instructional design theory, the actual production processes used for developing the modules, and important lessons learned in working with interactive multimedia course content for online delivery

    Excitation spectrum of bosons in a finite one-dimensional circular waveguide via the Bethe ansatz

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    The exactly solvable Lieb-Liniger model of interacting bosons in one-dimension has attracted renewed interest as current experiments with ultra-cold atoms begin to probe this regime. Here we numerically solve the equations arising from the Bethe ansatz solution for the exact many-body wave function in a finite-size system of up to twenty particles for attractive interactions. We discuss the novel features of the solutions, and how they deviate from the well-known string solutions [H. B. Thacker, Rev. Mod. Phys.\ \textbf{53}, 253 (1981)] at finite densities. We present excited state string solutions in the limit of strong interactions and discuss their physical interpretation, as well as the characteristics of the quantum phase transition that occurs as a function of interaction strength in the mean-field limit. Finally we compare our results to those of exact diagonalization of the many-body Hamiltonian in a truncated basis. We also present excited state solutions and the excitation spectrum for the repulsive 1D Bose gas on a ring.Comment: 13 pages, 12 figure

    Deconstructing Videotaped Instruction for Online Delivery: Instructional Design in Reverse

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    This paper examines a project in which videotaped face-to-face class sessions were converted into interactive instructional modules for Internet delivery. The development of the online class involved the challenge of teaching the advanced Microsoft Office Suite – normally skills learned hands-on – to distance learners. Sixteen interactive modules were eventually produced by using a process the authors describe as the instructional design in reverse. This paper discusses the importance of the proper application of instructional design theory, the actual production processes used for developing the modules, and important lessons learned in working with interactive multimedia course content for online delivery.This paper examines a project in which videotaped face-to-face class sessions were converted into interactive instructional modules for Internet delivery. The development of the online class involved the challenge of teaching the advanced Microsoft Office Suite – normally skills learned hands-on – to distance learners. Sixteen interactive modules were eventually produced by using a process the authors describe as the instructional design in reverse. This paper discusses the importance of the proper application of instructional design theory, the actual production processes used for developing the modules, and important lessons learned in working with interactive multimedia course content for online delivery

    Spatial and temporal filtering of a 10-W Nd:YAG laser with a Fabry-Perot ring-cavity premode cleaner

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    We report on the use of a fixed-spacer Fabry–Perot ring cavity to filter spatially and temporally a 10-W laser-diode-pumped Nd:YAG master-oscillator power amplifier. The spatial filtering leads to a 7.6-W TEMinfinity beam with 0.1% higher-order transverse mode content. The temporal filtering reduces the relative power fluctuations at 10 MHz to 2.8 x 10^-/sqrtHz, which is 1 dB above the shot-noise limit for 50 mA of detected photocurrent

    Inertial Sensors—Applications and Challenges in a Nutshell

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    This editorial provides a concise introduction to the methods and applications of inertial sensors. We briefly describe the main characteristics of inertial sensors and highlight the broad range of applications as well as the methodological challenges. Finally, for the reader’s guidance, we give a succinct overview of the papers included in this special issue

    Sub-dekahertz ultraviolet spectroscopy of 199Hg+

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    Using a laser that is frequency-locked to a Fabry-Perot etalon of high finesse and stability, we probe the 5d10 6s 2S_1/2 (F=0) - 5d9 6s 2D_5/2 (F=2) Delta-m_F = 0 electric-quadrupole transition of a single laser-cooled 199Hg+ ion stored in a cryogenic radio-frequency ion trap. We observe Fourier-transform limited linewidths as narrow as 6.7 Hz at 282 nm (1.06 X 10^15 Hz), yielding a line Q = 1.6 X 10^14. We perform a preliminary measurement of the 5d9 6s2 2D_5/2 electric-quadrupole shift due to interaction with the static fields of the trap, and discuss the implications for future trapped-ion optical frequency standards.Comment: 4 pages, 4 figures, submitted for publicatio

    Form factor expansion for thermal correlators

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    We consider finite temperature correlation functions in massive integrable Quantum Field Theory. Using a regularization by putting the system in finite volume, we develop a novel approach (based on multi-dimensional residues) to the form factor expansion for thermal correlators. The first few terms are obtained explicitly in theories with diagonal scattering. We also discuss the validity of the LeClair-Mussardo proposal.Comment: 41 pages; v2: minor corrections, v3: minor correction

    Optical cavity tests of Lorentz invariance for the electron

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    A hypothetical violation of Lorentz invariance in the electrons' equation of motion (expressed within the Lorentz-violating extension of the standard model) leads to a change of the geometry of crystals and thus shifts the resonance frequency of an electromagnetic cavity. This allows experimental tests of Lorentz invariance of the electron sector of the standard model. The material dependence of the effect allows to separate it from an additional shift caused by Lorentz violation in electrodynamics, and to place independent limits on both effects. From present experiments, upper limits on Lorentz violation in the electrons' kinetic energy term are deduced.Comment: 17 pages revte
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