Вычисление дисперсионного сембланса для волнового акустического каротажа
A computer implementation of the method of dispersive semblance for multi-element wave acoustic logging is proposed. The correction matrix for dispersion is constructed in (f-p)-domain using sets of dispersion curves of the flexural wave or Stoneley wave. The matrix is applied in computing scheme of the conventional semblance method in (tau-p)-domain (the Matlab script is given in electronic appendix).
Two realizations of direct and inverse Radon transform were considered for solving the problem of velocity filtering of acoustic logging data, represented as arrays in (t ‑ x)-area (time – linear spatial coordinate): 1) through (τ – p)-area (travel time – slowness ); 2) through (f – p)-area (frequency – slowness). Original MATLAB-functions are outlined, comparison of filtering results for arrays of multielement wave acoustic logging data are adduced.
Semblance or slowness time coherence is a measure of the coherence of energy distribution be-tween recorded signals at antenna array receivers of acoustic wave logging probe in the coordinates "the reduced time of the wave path from the middle of the antenna array” — “interval time". Several semblance filtering methods are proposed to allow for elimination of the effect of aliasing and to separate the wave packet components.
Basic relationships understood as the concept of semblance have been presented. Their classification and comparison are given.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.