5,138 research outputs found

    Universal scaling behavior of the single electron box in the strong tunneling limit

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    We perform a numerical analysis of recently proposed scaling functions for the single electron box. Specifically, we study the ``magnetic'' susceptibility as a function of tunneling conductance and gate charge, and the effective charging energy at zero gate charge as a function of tunneling conductance in the strong tunneling limit. Our Monte Carlo results confirm the accuracy of the theoretical predictions.Comment: Published versio

    Anthropology Takes Control of Morphometrics

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    There has been a startling change over the last decade in the intellectual context of morphometrics. In the 1990’s, this field, which has not altered its focus upon the quantitative analysis of biomedical shape variation and shape change, was principally centered around concerns of medical image analysis; but now it is driven mainly by the demands of researchers in human variability, physical anthropology, primatology, and paleoanthropology instead. This essay celebrates that change and tries to account for it by reference to cognitive and intellectual aspects of the new home

    Adaptive synchronization in delay-coupled networks of Stuart-Landau oscillators

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    We consider networks of delay-coupled Stuart-Landau oscillators. In these systems, the coupling phase has been found to be a crucial control parameter. By proper choice of this parameter one can switch between different synchronous oscillatory states of the network. Applying the speed-gradient method, we derive an adaptive algorithm for an automatic adjustment of the coupling phase such that a desired state can be selected from an otherwise multistable regime. We propose goal functions based on both the difference of the oscillators and a generalized order parameter and demonstrate that the speed-gradient method allows one to find appropriate coupling phases with which different states of synchronization, e.g., in-phase oscillation, splay or various cluster states, can be selected.Comment: 8 pages, 7 figure

    Direct Wolf summation of a polarizable force field for silica

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    We extend the Wolf direct, pairwise r^(-1) summation method with spherical truncation to dipolar interactions in silica. The Tangney-Scandolo interatomic force field for silica takes regard of polarizable oxygen atoms whose dipole moments are determined by iteration to a self-consistent solution. With Wolf summation, the computational effort scales linearly in the system size and can easily be distributed among many processors, thus making large-scale simulations of dipoles possible. The details of the implementation are explained. The approach is validated by estimations of the error term and simulations of microstructural and thermodynamic properties of silica.Comment: See http://link.aip.org/link/?JCP/132/194109 - 8 pages, 6 figures. Changes in v3: Copyright notice added, minor typographical changes. Changes in v2: 1. Inserted Paragraph in Sec. IV B describing the limitations of the TS potential. 2. We corrected transcription errors in Tab. II, and adjusted the deviation percentages mentioned in Sec. IV B, first paragraph, accordingl

    The MASSIVE Survey XIII -- Spatially Resolved Stellar Kinematics in the Central 1 kpc of 20 Massive Elliptical Galaxies with the GMOS-North Integral-Field Spectrograph

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    We use observations from the GEMINI-N/GMOS integral-field spectrograph (IFS) to obtain spatially resolved stellar kinematics of the central ∌1\sim 1 kpc of 20 early-type galaxies (ETGs) with stellar masses greater than 1011.7M⊙10^{11.7} M_\odot in the MASSIVE survey. Together with observations from the wide-field Mitchell IFS at McDonald Observatory in our earlier work, we obtain unprecedentedly detailed kinematic maps of local massive ETGs, covering a scale of ∌0.1−30\sim 0.1-30 kpc. The high (∌120\sim 120) signal-to-noise of the GMOS spectra enable us to obtain two-dimensional maps of the line-of-sight velocity, velocity dispersion σ\sigma, as well as the skewness h3h_3 and kurtosis h4h_4 of the stellar velocity distributions. All but one galaxy in the sample have σ(R)\sigma(R) profiles that increase towards the center, whereas the slope of σ(R)\sigma(R) at one effective radius (ReR_e) can be of either sign. The h4h_4 is generally positive, with 14 of the 20 galaxies having positive h4h_4 within the GMOS aperture and 18 having positive h4h_4 within 1Re1 R_e. The positive h4h_4 and rising σ(R)\sigma(R) towards small radii are indicative of a central black hole and velocity anisotropy. We demonstrate the constraining power of the data on the mass distributions in ETGs by applying Jeans anisotropic modeling (JAM) to NGC~1453, the most regular fast rotator in the sample. Despite the limitations of JAM, we obtain a clear χ2\chi^2 minimum in black hole mass, stellar mass-to-light ratio, velocity anisotropy parameters, and the circular velocity of the dark matter halo.Comment: Accepted to Ap

    QUANTIFICATION OF DROP JUMPS FOR TRAINING IMPLICATION

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    Peak vertical ground reaction force (F1peak), duration on force plate, flight time, and the eccentric loading rate (ELR) were examined during seven drop jumps (DJ) from 22.9 to 68.6 cm and a counter movement jump (CMJ). Thirty-four volunteers performed 16 jumps (14 DJs and 2 CMJs). Subjects were instructed to drop without changing the vertical component of the center of mass. They jumped maximally each jump using any technique and a rest period of 3+min between each jump was implemented. The data were gathered via force plate. Results indicated a significant F1peak difference between trials. There was a significant flight time difference between CMJ and DJs in a given trial, but no differences between DJs in a given trial. No significant differences were present for time spent on the plate between jumps, however; the ELR was different for DJs at the extremes

    Detailed Radio Spectra of Selected Compact Sources in the Nucleus of M82

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    We have determined detailed radio spectra for 26 compact sources in the starburst nucleus of M82, between 74 and 1.3 cm. Seventeen show low-frequency turnovers. One other has a thermal emission spectrum, and we identify it as an HII region. The low frequency turnovers are due to absorption by the interstellar gas in M82. New information on the AGN candidate 44.01+595, shows it to have a non-thermal falling powerlaw spectrum at the highest frequencies, and that it is strongly absorbed below 2 GHz. We derive large magnetic fields in the supernova remnants, of order 1-2 milliGauss, hence large pressures in the sources suggest that the brightest ones are either expanding or are strongly confined by a dense interstellar medium. From the largest source in our sample, we derive a supernova rate of 0.016 SN/yr.Comment: 19 pages, 7 tables, 29 figures, LaTeX, requires AAS macros v. 4.0. To appear in ApJ July 20, 199

    Multiple scaling regimes in simple aging models

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    We investigate aging in glassy systems based on a simple model, where a point in configuration space performs thermally activated jumps between the minima of a random energy landscape. The model allows us to show explicitly a subaging behavior and multiple scaling regimes for the correlation function. Both the exponents characterizing the scaling of the different relaxation times with the waiting time and those characterizing the asymptotic decay of the scaling functions are obtained analytically by invoking a `partial equilibrium' concept.Comment: 4 pages, 3 figure

    THE EFFECTS OF BACKPACK LOADING STYLES ON ENERGY EXPENDITURE AND MOVEMENT IN THE SAGITTAL PLANE DURING TREADMILL WALKING

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    Backpacking is physically demanding on the body. Although much of the load is carried securely inside the pack, non-secure attachment of provisions is commonly practiced. The purpose of this study was to analyze the effects of a non-secure loading style as compared to a secure loading style of a backpack. Fifteen male subjects walked on a treadmill for 10 minutes in four conditions: 2% grade secure and non-secure and 15% grade secure and non-secure. Expired air analysis and movement in the sagittal plane were analyzed. A two-way (pack by grade) ANOVA for energy expenditure yielded significant differences for grade: one minute averages (p < .001), over the each condition (p < .001), and over an estimated 60 minute interval (p = .675). No other energy expenditure differences and no sagittal plane movement differences were found
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