35,129 research outputs found

    Detection of cochlear hearing loss applying wavelet packets and support vector machines

    Get PDF
    The aim of this paper is to evaluate the application of the wavelet packet transform (WP) and support vector machines (SVM) to transient evoked otoacoustic emissions (TEOAE) in order to achieve a detection of frequency-specific hearing loss. We introduce a system to determine detection rates between groups of persons with normal hearing, high frequency hearing loss, and pantonal hearing loss. The validity and use of our approach is verified on a different patient group

    Biological effects of prolonged exposure of animals to unusual gaseous environments Semiannual report, 1 Sep. 1969 - 28 Feb. 1970

    Get PDF
    Lung weights of rats exposed to hyperoxic gas mixtures with He or no inert gas diluents substituting N

    A parabolic free boundary problem with Bernoulli type condition on the free boundary

    Full text link
    Consider the parabolic free boundary problem Ī”uāˆ’āˆ‚tu=0in{u>0},āˆ£āˆ‡uāˆ£=1onāˆ‚{u>0}. \Delta u - \partial_t u = 0 \textrm{in} \{u>0\}, |\nabla u|=1 \textrm{on} \partial\{u>0\} . For a realistic class of solutions, containing for example {\em all} limits of the singular perturbation problem Ī”uĻµāˆ’āˆ‚tuĻµ=Ī²Ļµ(uĻµ)asĻµā†’0,\Delta u_\epsilon - \partial_t u_\epsilon = \beta_\epsilon(u_\epsilon) \textrm{as} \epsilon\to 0, we prove that one-sided flatness of the free boundary implies regularity. In particular, we show that the topological free boundary āˆ‚{u>0}\partial\{u>0\} can be decomposed into an {\em open} regular set (relative to āˆ‚{u>0}\partial\{u>0\}) which is locally a surface with H\"older-continuous space normal, and a closed singular set. Our result extends the main theorem in the paper by H.W. Alt-L.A. Caffarelli (1981) to more general solutions as well as the time-dependent case. Our proof uses methods developed in H.W. Alt-L.A. Caffarelli (1981), however we replace the core of that paper, which relies on non-positive mean curvature at singular points, by an argument based on scaling discrepancies, which promises to be applicable to more general free boundary or free discontinuity problems

    Biological effects of prolonged expoure of small animals to unusual gaseous environments semiannual report, 1 sep. 1964 - 28 feb. 1965

    Get PDF
    Biological effect of prolonged exposure of man and small animals to pure oxygen and helium - oxygen environmen

    Results of the 1980 NASA/JPL balloon flight solar cell calibration program

    Get PDF
    Thirty-eight modules were carried to an altitude of about 36 kilometers. In addition to the cell calibration program, an experiment to evaluate the calibration error versus altitude was performed. The calibrated cells can be used as reference standards in simulator testing of cells and arrays

    Results of the 1981 NASA/JPL balloon flight solar cell calibration program

    Get PDF
    The calibration of the direct conversion of solar energy through use of solar cells at high altitudes by balloon flight is reported. Twenty seven modules were carried to an altitude of 35.4 kilometers. Silicon cells are stable for long periods of time and can be used as standards. It is demonstrated that the cell mounting cavity may be either black or white with equal validity in setting solar simulators. The calibrated cells can be used as reference standards in simulator testing of cells and arrays

    Results of the 1979 NASA/JPL balloon flight solar cell calibration program

    Get PDF
    Calibration of solar cells to be used as reference standards in simulator testing of cells and arrays was accomplished. Thirty-eight modules were carried to an altitude of about 36 kilometers during the solar cell calibration balloon flight

    Non-Markovian incoherent quantum dynamics of a two-state system

    Full text link
    We present a detailed study of the non-Markovian two-state system dynamics for the regime of incoherent quantum tunneling. Using perturbation theory in the system tunneling amplitude Ī”\Delta, and in the limit of strong system-bath coupling, we determine the short time evolution of the reduced density matrix and thereby find a general equation of motion for the non-Markovian evolution at longer times. We relate the nonlocality in time due to the non-Markovian effects with the environment characteristic response time. In addition, we study the incoherent evolution of a system with a double-well potential, where each well consists several quantized energy levels. We determine the crossover temperature to a regime where many energy levels in the wells participate in the tunneling process, and observe that the required temperature can be much smaller than the one associated with the system plasma frequency. We also discuss experimental implications of our theoretical analysis.Comment: 10 pages, published versio

    Effective target arrangement in a deterministic scale-free graph

    Full text link
    We study the random walk problem on a deterministic scale-free network, in the presence of a set of static, identical targets; due to the strong inhomogeneity of the underlying structure the mean first-passage time (MFPT), meant as a measure of transport efficiency, is expected to depend sensitively on the position of targets. We consider several spatial arrangements for targets and we calculate, mainly rigorously, the related MFPT, where the average is taken over all possible starting points and over all possible paths. For all the cases studied, the MFPT asymptotically scales like N^{theta}, being N the volume of the substrate and theta ranging from (1 - log 2/log3), for central target(s), to 1, for a single peripheral target.Comment: 8 pages, 5 figure
    • ā€¦
    corecore