Cysarz, D., H. Bettermann, and P. Van Leeuwen. Entropies of short binary sequences in heart period dynamics. Am J Physiol Heart Circ Physiol 278: H2163–H2172, 2000.— Dynamic aspects of R-R intervals have often been analyzed by means of linear and nonlinear measures. The goal of this study was to analyze binary sequences, in which only the dynamic information is retained, by means of two differe...

The typical difficulty of various NP-hard problems varies with simple parameters describing their structure. This behavior is largely independent of the search algorithm, but depends on the choice of problem ensemble. A given problem instance belongs to many different ensembles, so applying these observations to individual problems requires identifying which ensemble is most appropriate for pre...

A vanishing viscosity method is formulated for two-dimensional transonic steady irrotational compressible fluid flows with adiabatic constant γ ∈ [1, 3). This formulation allows a family of invariant regions in the phase plane for the corresponding viscous problem, which implies an upper bound uniformly away from cavitation for the viscous approximate velocity fields. Mathematical entropy pairs...

Sample Entropy is the most popular definition of entropy and is widely used as a measure of the regularity/complexity of a time series. On the other hand, it is a computationally expensive method which may require a large amount of time when used in long series or with a large number of signals. The computationally intensive part is the similarity check between points in m dimensional space. In...

Real systems are often complex, nonlinear, and noisy in various fields, including mathematics, natural science, and social science. We present the symplectic entropy (SymEn) measure as well as an analysis method based on SymEn to estimate the nonlinearity of a complex system by analyzing the given time series. The SymEn estimation is a kind of entropy based on symplectic principal component ana...

Driver fatigue is an important factor in traffic accidents, and the development of a detection system for driver fatigue is of great significance. To estimate and prevent driver fatigue, various classifiers based on electroencephalogram (EEG) signals have been developed; however, as EEG signals have inherent non-stationary characteristics, their detection performance is often deteriorated by ba...

We introduce a novel method for estimating the partition function and marginals of distributions defined using graphical models. The method uses the entropy chain rule to obtain an upper bound on the entropy of a distribution given marginal distributions of variable subsets. The structure of the bound is determined by a permutation, or elimination order, of the model variables. Optimizing this ...

Andrew Beckwith [email protected], [email protected] PACs: 98.80.Cq, 95.35.+d, 95.30.Sf, 65.40.gd, 11.25.Uv Abstract We begin our inquiry by asking two questions. First, is there an approximate match up between the total entropy of the universe, and the sum total of entropy between super massive black holes at the center of spiral galaxies? Note that Sean Carroll in 2005 presented a black hole ...

Entropy methods (approximate and sample entropy) have been studied to measure the complexity or predictability of finite length time series. The identification of parameters of this entropy family is indispensable task to enable the measure of predictability of time-series data. So far, there have been no general rules to select these parameters; they rather depend on particular problems. In th...