Multi-scale cross entropy analysis for inclined oil–water two-phase countercurrent flow patterns

Zhu, Li; Jin, Ningde; Gao, Zhong-Ke; Zong, Yanbing

doi:10.1016/j.ces.2011.08.034

Cited by 33 publications

(8 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Monitoring dynamical process of the system generates a multivariate time series. Shannon entropy based concepts, such as mutual entropy [80] , [81] and transfer entropy [82] , multi-scale cross entropy [83] are proposed in literature to reconstruct the relationship network between the elements from the produced time series. One should divide the distribution region of a bivariate series into some rectangles, and reckon the occurring numbers of samples in each rectangle.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

Evaluation of Scaling Invariance Embedded in Short Time Series

et al. 2014

View full text Add to dashboard Cite

Scaling invariance of time series has been making great contributions in diverse research fields. But how to evaluate scaling exponent from a real-world series is still an open problem. Finite length of time series may induce unacceptable fluctuation and bias to statistical quantities and consequent invalidation of currently used standard methods. In this paper a new concept called correlation-dependent balanced estimation of diffusion entropy is developed to evaluate scale-invariance in very short time series with length . Calculations with specified Hurst exponent values of show that by using the standard central moving average de-trending procedure this method can evaluate the scaling exponents for short time series with ignorable bias () and sharp confidential interval (standard deviation ). Considering the stride series from ten volunteers along an approximate oval path of a specified length, we observe that though the averages and deviations of scaling exponents are close, their evolutionary behaviors display rich patterns. It has potential use in analyzing physiological signals, detecting early warning signals, and so on. As an emphasis, the our core contribution is that by means of the proposed method one can estimate precisely shannon entropy from limited records.

show abstract

Section: Conclusion and Discussionmentioning

confidence: 99%

Evaluation of Scaling Invariance Embedded in Short Time Series

et al. 2014

View full text Add to dashboard Cite

show abstract

“…In such cases, the flow regimes tend to be churn and annular flow regimes with higher gas velocities, which is associated with more mixing and more wall and phase interface frictions. The importance of flow regimes on entropy generation is investigated comprehensively before [23,8]. Fig.…”

Section: Resultsmentioning

confidence: 99%

“…He considered a refrigerant flow to be annular, steady and one-dimensional. In some cases, entropy is used as a practical parameter in determining void fraction and other twophase flow variables [7,8].…”

Section: Introductionmentioning

confidence: 99%

Entropy analysis of buoyancy driven gas–liquid two-phase flow: Analytical and experimental approaches

Hanafizadeh

Eshraghi

Amini

2016

European Journal of Mechanics - B/Fluids

View full text Add to dashboard Cite

“…Lee et al (2008) adopted chaotic characteristics of two-phase flow to identify flow pattern and developed a method to identify flow pattern by applying simple classification rules to the density map. Zhu et al (2011) performed multi-scale cross entropy analysis for inclined oil-water two-phase countercurrent flow patterns, and found that the rate of low-scale cross entropy can effectively identify flow patterns, whereas the high-scale cross entropy can represent their long-range dynamics. Rosa et al (2010) applied artificial neural networks and expert systems to determine the flow pattern in vertical ascendant gas-liquid flow.…”

Section: Introductionmentioning

confidence: 99%