Reconstruction of UWB Impulse Train by Parallel Sampling of Cascaded Identical RC Filters

1. The purpose of this work was to determine whether computed temporally coded axonal information generated by Poisson process stimulation were modified during long-distance propagation, as originally suggested by S. A. George. Propagated impulses were computed with the use of the Hodgkin-Huxley equations and cable theory to simulate excitation and current spread in 100-microns-diam unmyelinated axons, whose total length was 8.1 cm (25 lambda) or 101.4 cm (312.5 lambda). Differential equations were solved numerically, with the use of trapezoidal integration over small, constant electrotonic and temporal steps (0.125 lambda and 1.0 microsecond, respectively). 2. Using dual-pulse stimulation, we confirmed that for interstimulus intervals between 5 and 11 ms, the conduction velocity of the second of a short-interval pair of impulses was slower than that of the first impulse. Further, with sufficiently long propagation distance, the second impulse's conduction velocity increased steadily and eventually approached that of the first impulse. This effect caused a spatially varying interspike interval: as propagation proceeded, the interspike interval increased and eventually approached stabilization. 3. With Poisson stimulation, the peak amplitude of propagating action potentials varied with interspike interval durations between 5 and 11 ms. Such amplitude attenuation was caused by the incomplete relaxation of parameters n (macroscopic K-conductance activation) and h (macroscopic Na-conductance inactivation) during the interspike period. 4. The stochastic properties of the impulse train became less Poisson-like with propagation distance. In cases of propagation over 99.4 cm, the impulse trains developed marked periodicities in Interevent Interval Distribution and Expectation Density function because of the axially modulated transformation of interspike intervals. 5. Despite these changes in impulse train parameters, the arithmetic value of the mean interspike interval did not change as a function of propagation distance. This work showed that in theory, whereas the pattern of Poisson-like impulse codes was modified during long-distance propagation, their mean rate was conserved.

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Correction to "Probability of error of a binary infinite impulse train signal over a random parallel channel"

IEEE Transactions on Sonics and Ultrasonics ◽

10.1109/t-su.1978.31051 ◽

1978 ◽

Vol 25 (6) ◽

pp. 395-395

Author(s):

R.A. Abotteen

Keyword(s):

Parallel Channel ◽

Probability Of Error ◽

Impulse Train

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Parallel Sampling for Dioxins Using Various Sampling Techniques At a Swedish Municipal Solid Waste Incinerator

Waste Management & Research ◽

10.1177/0734242x9201000104 ◽

1992 ◽

Vol 10 (1) ◽

pp. 21-36 ◽

Cited By ~ 13

Author(s):

Stellan Marklund ◽

Gunilla Söderstrom ◽

Karin Ljung ◽

Christoffer Rappe ◽

Michael Kraft ◽

...

Keyword(s):

Municipal Solid Waste ◽

Solid Waste ◽

Sampling Methods ◽

Sampling Technique ◽

Sampling Techniques ◽

Large Contribution ◽

Waste Incinerator ◽

Emission Data ◽

Chlorinated Dioxins ◽

Parallel Sampling

Parallel sampling was carried out in a Swedish municipal solid waste (MSW) incinerator, on two consecutive days, with five different sampling techniques. The samples were analysed for chlorinated dioxins (PCDDs) and chlorodibenzofurans (PCDFS) at two laboratories, one in Sweden and the other in Germany. Two different spiking protocols were used, both including pre-sampling or clean-up spikes from each homolog group of the tetra to octa CDDs and CDFs. Comparable results were obtained for all five sampling methods for the emission data and the recoveries for all pre-sampling spikes were above 50%. The agreement between the two laboratories was good. The different sampling methods resulted in very similar congener distributions (congener profiles) or isomer distributions (isomer patterns). However, the sampling techniques differ considerably in the distribution of PCDDs/PCDFs in various sampling compartments, The sampling techniques where large contribution of PCDDs and PCDFs could be found in the wash solvent may suffer from losses and/or cross-contamination problems unless the washing is carried out properly. The use of a cooled probe in combination with an adsorption (polyurethane foam plug) or absorption (ethoxyethanol) trap, where the main portion of the PCDDs and PCDFs were found in the condensate, is considered as a convenient and efficient sampling technique.

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