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Mikhail Trifonov

Mikhail Trifonov
Sechenov Institute of Evolutionary Physiology and Biochemistry · Laboratory of Comparative Ecological and Physiological Studies

PhD

About

42
Publications
1,476
Reads
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60
Citations
Citations since 2016
21 Research Items
53 Citations
201620172018201920202021202202468101214
201620172018201920202021202202468101214
201620172018201920202021202202468101214
201620172018201920202021202202468101214
Introduction
Skills and Expertise
Additional affiliations
November 1993 - present
Sechenov Institute of Evolutionary Physiology and Biochemistry
Position
  • Researcher
November 1990 - November 1993
IP Pavlov Institute of Physiology
Position
  • Doctorant in Physiology of Vision
Description
  • Human visual perception of images and the mathematical model of an observer in the process of the object visual detection and discrimination.
July 1979 - November 1990
Vavilov State Optical Institute
Position
  • Engineer, Junior Researcher, Senior Researcher
Education
April 1976 - April 1979
Leningrad State University
Field of study
  • Remote sensing of the atmoshere and sea surface temperature
September 1970 - February 1976
Leningrad State University
Field of study
  • Physics and mathematics

Publications

Publications (42)
Preprint
Full-text available
This preprint provides an analytical derivation of several identities of infinite series and their analogues - integral representations involving the modified Bessel functions of the first kind and the Hermite polynomials. These identities are new in the sense of not being found in the existing databases of relevant identities. All proposed identit...
Article
We present here results from analysis of the formation of brain bioelectrical activity in children and adolescents living in the northern region of Russia based on evaluation of integral multichannel EEG parameters. A total of 33 boys and 32 girls aged 7–18 years studying at rural schools took part in the study. The study was run in two stages, eac...
Article
The aim of the work was to assess the stability (intraindividual variability) of two integral parameters of the human EEG, which characterize its spatial and temporal order in a resting state with the eyes closed or open or while performing several types of tasks. A longitudinal dynamic study of the parameters in a healthy male subject was carried...
Article
A new representation for the probability density function (PDF) of a single real sinusoid in additive white Gaussian noise is presented. It has the form of an infinite series of the exponentially scaled modified Bessel functions of the first kind of integer order. The new PDF is an alternative to the classical PDF’s expressed in terms of the deriva...
Article
Development of methods for monitoring the functional state (FS) of people under extreme conditions is of great applied significance. The aim of this study was to investigate the dynamics of integral EEG parameters in individuals with different levels of hypoxia sensitivity and tolerance during their exposure to oxygen deficiency. Acute hypoxia was...
Article
Представлены результаты анализа формирования биоэлектрической активности мозга у детей и подростков, проживающих в северном регионе России, на основе оценки интегральных параметров многоканальной ЭЭГ. В исследованиях приняли участие 33 мальчика и 32 девочки в возрасте от 7 до 18 лет, учащихся сельской школы. Работа проведена в 2 этапа, каждый из ко...
Preprint
Full-text available
A new representation for the probability density function (PDF) of a single real sinusoid in additive white Gaussian noise is presented. It has the form of an infinite series of the exponentially scaled modified Bessel functions of the first kind of integer order. The new PDF is an alternative to the classical PDF's expressed in terms of the deriva...
Conference Paper
Full-text available
The stability of various individual EEG measures over time (from trial to trial) and across tasks (EEG intra-individual variability) at specific scalp locations is now attracting increasing interest from neuroscientists and clinicians studying and monitoring human brain functional state. But, early and reliable identification of its changes is impo...
Article
The purpose of this study was to evaluate the age dynamics of the integral characteristics of spatial (Asf), temporal (Rsf), and spectral (frequency) organization of brain bioelectric activity by analyzing the structure function (SF) of a multichannel EEG. The study consisted of two series, one conducted in autumn and other, four months later in sp...
Article
In this paper, we examine the methodological aspects of correlation analysis of resting state human EEG data. The reasons why the sample Pearson correlation coefficient r between two EEG signals is not the direct indicator of presence or absence of connectivity between relevant brain areas are analyzed. Various examples of relative frequency histog...
Article
Full-text available
The effects of sharp variations in geomagnetic and solar activity at high latitudes on human brain bioelectrical activity were studied using a multichannel EEG structural function. Studies were performed on 10 healthy men aged 19–37 years. EEG recordings were made daily for 25 days. Solar flares of classes C and M occurred during the study period,...
Article
The present study aimed to assess the possible relationship between psychometric and electroencephalographic (EEG) parameters in humans. Normalized parameters of the integrated spatial (pS ) and integrated temporal (pT ) regularities of real resting EEG with the eyes closed were calculated. The algorithm of estimation of these parameters was based...
Article
Full-text available
The first-order temporal structure functions (SFs), i.e., the first-order statistical moment of absolute increments of scaled multichannel resting state EEG signals in healthy children and teenagers over a wide range of temporal separation (time lags) are computed. Our research shows that the sill level (asymptote) of the SF is mainly defined by a...
Article
We investigate the impacts of sharp variations in solar and geomagnetic activity (GMA) at high latitudes on the human brain bioelectrical activity by means of the empirical structure function of multi-channel EEG. Ten healthy men ages 19 to 37 took part in the study. EEG was recor- ded daily over the 25 days test period that was marked by C- and M-...
Article
Full-text available
The probability density functions (pdf’s) and the first order structure functions (SF’s) of the pairwise Euclidean distances between scaled multichannel human EEG signals at different time lags under hypoxia and in resting state at different ages are estimated. It is found that the hyper gamma distribution is a good fit for the empirically derived...
Article
Full-text available
The mechanisms regulating the functional state (FS) of the brain were studied in humans in conditions of dosed acute hypoxia (breathing a mixture of 8% oxygen in nitrogen for 15-25 min). The dynamics of the FS of the brain due to changes in the balance of the activities of brain regulatory structures in hypoxia were reflected in rearrangements of E...
Article
Full-text available
Regulation mechanisms of the brain functional state (FS) were studied in man during acute hypoxic conditions (inhalation of 8% O2 hypoxic air for 15-25 minutes). Changes in balance of the brain regulatory structures activities caused by hypoxia determine FS dynamics that is reflected in the reorganization of the EEG spatial interrelations (by data...
Article
Full-text available
This paper proposes a method for automatically altering image contrast, directed toward enhancing the quality of the visual perception of these images by an observer. The method is a three-step procedure of histogram transformation of the Y component in the YIQ color model. The question is considered of adapting the method to the difference in the...
Conference Paper
Full-text available
We hypothesize that ability of observers to be sensitive to an image noise is based on the presence of a random component of visual filter induced by this noise. The concept of the noisy visual filter was incorporated with the concept of additive and multiplicative internal noise of the observer to predict the visual sensitivity of image noise disc...
Article
Many processes of visual perception may be modelled by nonlinear systems. I here present a novel nonlinear analysis of contrast sensitivity data. My point of departure was the similarity in shape of (i) curves giving threshold contrast as a function of spatial modulation frequency, and (ii) the envelope of bifurcational diagrams obtained from the l...
Article
Full-text available
The orthodox data concerning the contrast sensitivity estimation for sine-wave gratings were formally analyzed. The result of our analysis made feasible a threshold energy value (Delta) E -- energetic equivalent to quantum of perception -- as (Delta) E equals (alpha) (Delta) L(Delta) X2, where (alpha) is a proportionality coefficient, (Delta) L is...
Article
Full-text available
A new mathematical technique is described that makes it possible to find an exact analytical solution of the quadratic optimization problem of maximizing the detectability index d' for visual signal detection on a white noise background. The observer model is assumed to have one channel with a 2D spatial sensitivity function A(x), satisfying limita...
Article
Full-text available
Modeling for amplitude discrimination of visual signals M I Trifonov, Y P. Danilov* (Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 St Petersburg, Russia; *Department of Psychology, University of Wisconsin, Madison, WI 53706, USA) Mathematical aspects of amplitude discrimination of visual signals on a r...
Article
Full-text available
A definition is given for a new two-dimensional unitary transformation of images called radial-angular transformation by the authors. The coefficients of this transformation make it possible to determine the presence of luminance differentials in the fragment of an image being analyzed and to estimate their shape, size and orientation. The processi...
Article
Full-text available
Измерено влияние квазибелого шума на обнаружение тестовых изображений типа элементов Габора. Выдвинуто предположение, что частотно-контрастная (ЧКХ) зрительной системы, полученная в условиях порогового обнаружения при отсутствии внешнего шума, не может быть использована для описания поведения зрительной системы при решении произвольных зрительных з...
Article
On the basis of comparisons (50 cases) between the measured (by the Meteor-28) and calculated spectra of outgoing thermal radiation in the range 400-1300/cm, the precision of a radiative model of the atmosphere is assessed. The model uses water vapor continuum-absorption coefficients and recent data on the parameters describing the fine structure o...
Article
Calculations made with the Gudi (1966) model are compared with experimental values obtained from 15 tests of the transmission spectra of the atmosphere in a column from top to bottom. Allowance is made in the calculations for the attenuation in the water vapor continuum. Through this comparison, spectral intervals are detected in which inaccuracies...
Article
The possibility of using measurements of outgoing radiation along slant paths at the oxygen absorption lines for lambda equals 2.53 mm is analyzed for solving the problem of thermal sounding the atmosphere. The choice of this particular absorption line, based upon the Zeeman effect and the use of instruments of high angular resolution, is discussed...

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