Cardiac ablation is increasingly used to interdict the complex propagation of excitatory waves during atrial fibrillation. While such procedures are useful, they can often fail. Here we use fluorescence imaging to observe the electrical activity of an ablated porcine heart. We find that, while ablation lines do attenuate cardiac waves, the attenuation is incomplete. A remnant of the incident wa...

The relative importance of interface, volume, and thermal scattering in spin-dependent hot-electron transmission of magnetic trilayers is quantified. While interfaces produce significant attenuation (factor 2.2 per interface), the spin asymmetry is dominated by volume scattering. Extracted thermal attenuation lengths (130 A at 300 K for Ni80Fe20) show that thermal spin-wave scattering is strong...

Constraint programming is the study of system which is based on constraints. The solution of a constraint satisfaction problem is a set of variable value assignments, which satisfies all members of the set of constraints in the CSP. In this paper the application of constraint satisfaction programming is used in predicting the path loss of various indoor propagation models using chronological ba...

A new transmission line structure is presented in this work for advanced CMOS processes. This structure has a high quality factor and low attenuation. It allows slow-waves to propagate which results in low dispersion for a given characteristic impedance. It is also designed to satisfy the stringent density requirements of advanced CMOS processes. A model is developed to characterize this struct...

A relaxation process, with the associated phenomenology of sound attenuation and sound velocity dispersion, is found in a simulated harmonic Lennard-Jones glass. We propose to identify this process with the so-called microscopic (or, instantaneous) relaxation process observed in real glasses and supercooled liquids. A model based on the memory function approach accounts for the observation and ...

Modifications to the transmission line model developed at the High Voltage Research Institute, Tomsk, USSR, are presented and compared between each other and with the modification proposed by the ItalianSwiss research team. The modifications considered differ from each other by the height dependent attenuation factor for the return stroke current pulse intensity. All of the attenuation factors,...

Microwave attenuation in rain at C-band. observed in radar data from Alberta. Canada, has been assessed by means of two different estimators: one employing KDP measured simultaneously by an S-band radar and the other a comparison of synchronised Sand C-band reflectivity measurements. While good agreement between the two has been found in some cases, in others the second method gave a larger est...

This paper illustrates the advantages of using the Discrete Cosine Transform (DCT) as compared to the standard Discrete Fourier Transform (DFT) for the purpose of removing noise embedded in a speech signal. The derivation of the Minimum Mean Square Error (MMSE) ®lter based on the statistical modelling of the DCT coecients is shown. Also shown is the derivation of an over-attenuation factor bas...

Background: Photon attenuation as an inevitable physical phenomenon influences on the diagnostic information of SPECT images and results to errors in accuracy of quantitative measurements. This can be corrected via different physical or mathematical approaches. As the correction equation in mathematical approaches is nonlinear, in this study a new method of linearization called ‘Piece ...

objective(s): the aim of this study was to determine the optimal reconstruction parameters for iterative reconstruction in different devices and collimators for dopamine transporter (dat) single-photon emission computed tomography (spect). the results were compared between filtered back projection (fbp) and different attenuation correction (ac) methods.methods: an anthropomorphic striatal phant...