We have developed an algorithm based on optical flow for the extraction of flow waveforms from dynamic digital x-ray images. The aim of this study was to extend the validation of this technique to blood flow measurement in moving vessels. A pulsatile blood flow circuit was constructed to simulate the human arterial circulation using a length of silicone tubing as a model artery. A computer-prog...

The instantaneous mass flow was measured during the intake and discharge processes of a reciprocating gas compressor (1)*. The purpose of these measurements was to identify the mechanism which caused a loss of adiabatic and volumetric efficiency that could not be accounted for by valve flow losses. The measurements were made wi ·th square-edged orifices and fast response differential pressure t...

Maximal instantaneous codes are characterized by the property that they allow unique parsing of every infinite string. The sequence of codeword lengths of a maximal instantaneous code, sequenced in lexicographic order of the codewords, completely determines the code itself. Any increasing, decreasing or unimodal reordering of such a sequence again corresponds to a maximal instantaneous code. Le...

Esterel is an imperative synchronous programming language for the specification of deterministic concurrent reactive systems. While providing the usual control-flow constructs—sequences, loops, conditionals, and exceptions—its lack of a goto instruction makes the programming of arbitrary finite state machines awkward and hinders the design of source-to-source program transformations. We previou...

A fundamental frequency (F0) estimator named Harvest is described. The unique points of Harvest are that it can obtain a reliable F0 contour and reduce the error that the voiced section is wrongly identified as the unvoiced section. It consists of two steps: estimation of F0 candidates and generation of a reliable F0 contour on the basis of these candidates. In the first step, the algorithm use...

The use of general time-frequency distributions as features for automatic speech recognition (ASR) is discussed in the context of hidden Markov classifiers. Short-time averages of quadratic operators, e.g., energy spectrum, generalized first spectral moments, and short-time averages of the instantaneous frequency, are compared to the standard front end features, and applied to ASR. Theoretical ...

A form of stochastic perturbation theory is described, where the representative stochastic fields are generated instantaneously rather than through a Markov process. The correctness of the procedure is established to all orders of the expansion and for a wide class of field theories that includes all common formulations of lattice QCD.

This paper investigated the use of instantaneous frequency (IF) instead of power amplitude and power spectrum in side-channel analysis. By opposition to the constant frequency used in Fourier Transform, instantaneous frequency reflects local phase differences and allows detecting frequency variations. These variations reflect the processed binary data and are hence cryptanalytically useful. IF ...

Instantaneous frequency (IF) is necessary for understanding the detailed mechanisms for nonlinear and nonstationary processes. Historically, IF was computed from analytic signal (AS) through the Hilbert transform. This paper offers an overview of the difficulties involved in using AS, and two new methods to overcome the difficulties for computing IF. The first approach is to compute the quadrat...