Entropy rate estimates from mutual information

Abstract:The frequency of ventricular premature beats (VPBs) has been related to the risk of mortality. However, little is known about the temporal pattern of occurrence of VPBs and its relationship to autonomic activity. Hence, we applied a general correlation measure, mutual information, to quantify how VPBs are generated over time. We also used mutual information to determine the correlation between VPB production and heart rate in order to evaluate effects of autonomic activity on VPB production. We examined twenty subjects with more than 3000 VPBs/day and simulated ran-( dom time series of VPB occurrence. We found that mutual information values could be used to characterize quantitatively the temporal patterns of VPB generation. Our data suggest that VPB production is not random and VPBs generated with a higher value of mutual information may be more greatly affected by autonomic activity.

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Data Screening Methods – Application to Differential Diagnosis in Pancreatic Pathology from Radiological Signs

Methods of Information in Medicine ◽

10.1055/s-0038-1636606 ◽

1978 ◽

Vol 17 (01) ◽

pp. 36-40 ◽

Cited By ~ 4

Author(s):

J.-P. Durbec ◽

Jaqueline Cornée ◽

P. Berthezene

Keyword(s):

Differential Diagnosis ◽

Mutual Information ◽

Data Processing ◽

Screening Methods ◽

Automatic Data ◽

Chronic Calcifying Pancreatitis ◽

Number Of Patients ◽

Calcifying Pancreatitis ◽

Pancreatic Pathology ◽

Data Screening

The practice of systematic examinations in hospitals and the increasing development of automatic data processing permits the storing of a great deal of information about a large number of patients belonging to different diagnosis groups.To predict or to characterize these diagnosis groups some descriptors are particularly useful, others carry no information. Data screening based on the properties of mutual information and on the log cross products ratios in contingency tables is developed. The most useful descriptors are selected. For each one the characterized groups are specified.This approach has been performed on a set of binary (presence—absence) radiological variables. Four diagnoses groups are concerned: cancer of pancreas, chronic calcifying pancreatitis, non-calcifying pancreatitis and probable pancreatitis. Only twenty of the three hundred and forty initial radiological variables are selected. The presence of each corresponding sign is associated with one or more diagnosis groups.

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Dependence of the local entropy rate of production from speed of change of temperature in a linear mode of thermodynamics оn an example of nitrides and graphite

Izmeritel`naya Tekhnika ◽

10.32446/0368-1025it.2019-4-48-50 ◽

2019 ◽

pp. 48-50

Author(s):

А. V. Kostanovskiy ◽

M. E. Kostanovskaya

Keyword(s):

Entropy Rate ◽

Local Entropy ◽

Linear Mode

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About definition of the local entropy rate of production in experiment of pulse electric heating

Izmeritel`naya Tekhnika ◽

10.32446/0368-1025it.2020-3-29-34 ◽

2020 ◽

pp. 29-34

Author(s):

Alexandr V. Kostanovskiy ◽

Margarita E. Kostanovskaya

Keyword(s):

Thermal Diffusivity ◽

Electric Heating ◽

Thermal Capacity ◽

Entropy Rate ◽

Initial Time ◽

Local Entropy ◽

Linear Mode ◽

Electric Capacity ◽

Definition Of ◽

Pulse Electric

Work is devoted to studying of a linear mode thermodynamic – a mode which is actively investigated now. One of the main concepts of a linear mode – local entropy rate of production. The purpose of given article consists in expansion of a circle of problems for which it is possible to calculate a local entropy rate of production, namely its definition, using the experimental “time-temperature” curves of heating/cooling. “Time-temperature” curves heating or cooling are widely used in non-stationary thermophysical experiments at studying properties of substances and materials: phase transitions of the first and second sort, a thermal capacity, thermal diffusivity. The quantitative substantiation of the formula for calculation of the local entropy rate of production in which it is used thermogram (change of temperature from time) which is received by a method of pulse electric heating is resulted. Initial time dependences of electric capacity and temperature are measured on the sample of niobium in a microsecond range simultaneously. Conformity of two dependences of the local entropy rate of production from time is shown: one is calculated under the known formula in which the brought electric capacity is used; another is calculated, using the thermogram.

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