Showing papers by "Hermann Wagner published in 1997"
TL;DR: In this article, the authors measured the polarization of polyvinyl acetate in terms of a real dielectric relaxation technique by studying the decay of the electric field E(t) for times 10−3 s ≤ t ≤ 106 s under the condition of a constant displacement for t > 0.
76 citations
TL;DR: In this paper, the authors measured the thermally stimulated decay of the dielectric modulus M(T, t) for poly(vinylacetate) by monitoring the electric field E(t) under the condition of a constant voltage for t > 0.
40 citations
TL;DR: The psychophysical, neurological and neurophysiological mechanisms underlying the detection and representation of acoustic motion are quite similar to those underlying the Detection and representation in other modalities, especially in vision.
25 citations
01 Dec 1997
TL;DR: An integrateand-fire model of spike processing in the third order nucleus laminaris of the auditory pathway of the barn owl is presented, showing how neuronal connections are fine tuned during a critical period of development as has been suggested by recent experiments.
Abstract: Binaural coincidence detection is essential for the localization of external sounds and requires auditory signal processing with high temporal precision. We present an integrateand-fire model of spike processing in the third order nucleus laminaris of the auditory pathway of the barn owl. Each input spike generates an excitatory postsynaptic potential with a width of 250 μs. Output spikes occur with a tenfold enhanced temporal precision. This is possible since neuronal connections are fine tuned during a critical period of development as has been suggested by recent experiments. This rule does not only explain the temporal presicion in the output, but causes also a tuning to interaural time difference. The learning rule is of the Hebbian type: A synaptic weight is increased if a presynaptic spike arrives at about the same time as or slightly before postsynaptic firing. A presynaptic spike arriving after postsynaptic firing leads to a decrease of the synaptic efficacy.
11 citations
13 Jun 1997
TL;DR: In this paper, isothermal and thermally stimulated experimental techniques for directly accessing the relaxation M(t) are outlined and discussed as regards their relation to the dielectric retardation (epsilon) (t) and to dc-conductivity(sigma) dc.
Abstract: The common technique of dielectric (epsilon) (t) measurements involves the application of a polarization invariant electric field to a capacitor filled with the material under study and the detection of the temporal evolution of the resulting current or charge flow. The counterpart condition of applying a given dielectric displacement and monitoring the electric field relates to the dielectric modulus M(t) with M((omega) ). Isothermal and thermally stimulated experimental techniques for directly accessing the relaxation M(t) are outlined and discussed as regards their relation to the dielectric retardation (epsilon) (t) and to dc-conductivity(sigma) dc. We also address several microscopic processes which are inherently linked to the dielectric modulus through their common feature of displaying a redistribution of charge.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
2 citations
01 Jan 1997
1 citations