Statistical Homogeneity Research Articles

THE CONCEPT OF UNIFORMITY OF A GROUP IN HUMAN ECOLOGY

Over the past 100-150 years, the selection of homogeneous groups in ecology as a whole has been carried out as part of the calculation of the coefficient of variation V = о / or by the ABC method. However, the Eskov - Zinchenko effect imposes serious restrictions on all statistical methods. The aim of the study was to verify the statistical homogeneity of three groups of Khanty women of different ages. Methods: The technique of repeating measurements of the same parameters of the Khanty women's cardiovascular system (three different ages) was used, for which matrices of all (105) different pairwise comparisons of samples for each such group were constructed (these measurements were repeated). Results. It was established that the same age, gender and living conditions (ethnicity) do not guarantee the selection of physiologically (statistically) homogeneous groups of subjects. The study proves the lack of statistical homogeneity of the three age-tested groups of Khanty women. The proportion of statistical similarity is less than 20 % of all 105 comparison pairs in all three age comparison groups. It is shown that repeated measurement of the same group gives a different picture of the distribution of pairs that can be attributed to one (common) general population. Each new dimension will give other pairs of k coincidences and it will never (from the standpoint of stochastics) be able to select a homogeneous group statistically coincident in the xi samples of the homeostasis parameter. In fact, the Eskov - Zinchenko effect spreads from one subject (in the mode of n iterations of experiments) to a group of different subjects (which cannot be homogeneous). Conclusions. From the standpoint of chaos theory - self-organization, other criteria of group homogeneity are required, in which the parameters of quasi attractors and the ratio of objects of these quasi attractors are already calculated.

Scale and REV analyses for porosity and pore connectivity measures in undisturbed soil

Soil samples with a volume of approximately 100 mL are commonly used for measuring soil properties needed to parameterize continuum models of transport processes in soils. The necessary assumption that the sampled soil volume corresponds to a representative elementary volume (REV) has only been occasionally tested. Furthermore, the few studies so far have focused on bulk properties such as porosity and bulk density and have not investigated the scale-dependence of pore-space connectivity, which is fundamental for transport properties such as the permeability of soil. In this study, we investigated the scale-dependence of morphologic properties of the soil pore-space in 25 undisturbed soil columns sampled from five different depths (8, 23, 33, 53 and 73 cm) from a field site in southern Norway (Skuterud). We conducted the analyses of scale-dependence on regions of interests of 40 × 40 × 40 mm3 from binarized X-ray images with a resolution of 40 µm. We focused our evaluation on imaged porosity and three measures of pore-space connectivity (the connection probability, the Euler-Poincaré number and the critical pore diameter). As pore network connectivity is scale-dependent and because the connectivity of large pores has a very strong impact on the soil permeability, we conducted our analyses considering three contrasting minimum pore diameters, namely 80, 250 and 500 µm.We found that the pore connectivity improved with scale, predominantly due to the presence of pores with diameters of less than 0.25 mm. This stresses the importance of image resolution in scale analyses. We moreover observed that both the mean and the standard deviation of the critical pore diameter increased with scale, which may explain why the mean and standard deviation of the saturated hydraulic conductivity are often found to increase with scale. We detected an REV range for the macroporosity between approximately 15 and 65 mm. This range decreased with an increase in the minimum pore diameter considered. However, we also found evidence contradicting the existence of the detected REV range for the macroporosity due to a lack of statistical homogeneity. No REV range could be found for the three investigated connectivity measures, probably because the evaluated scales were too small. Based on our results we conclude that larger soil samples should be used to measure soil properties and investigate processes that depend on the pore network connectivity, such as permeability or water flow and long-range solute transport. We recommend that future studies should investigate REVs for connectivity measures and investigate which REV criteria are most meaningful in a continuum modelling context. Such studies are needed to evaluate whether REVs for transport properties are common in soils. If not, flow and transport models that explicitly account for heterogeneity are necessary.

Mapping the Future of Cross-Border Mergers and Acquisitions: A Review and Research Agenda

Cross-border mergers and acquisitions (M&A) are considered one of the main strategies employed by firms to maintain a competitive edge and compete in the high-velocity global industry. This research field holds great promise as many facets are underexplored. Taking into consideration the growing interdisciplinary interest in M&A research, in this article, we performed content analysis in combination with the statistical procedure homogeneity analysis by means of alternating least squares (HOMALS) on 933 articles gathered from the Web of Science and Scopus databases. The quantitative analysis of the intellectual structure of cross-border M&A field yielded the six topics of interest for future research: acquisition versus strategic alliance or joint venture, partial purchase, the outbound acquisitions from emerging-market firms, micro-multinationals, the human side of cross-border acquisitions that tie in with the upper echelons research and knowledge management and transfer, in specific, tacit knowledge.

CPT‐Based Probabilistic Characterization of Undrained Shear Strength of Clay

Applying random field theory involves two important issues: the statistical homogeneity (or stationarity) and determination of random field parameters and correlation function. However, the profiles of soil properties are typically assumed to be statistically homogeneous or stationary without rigorous statistical verification. It is also a challenging task to simultaneously determine random field parameters and the correlation function due to a limited amount of direct test data and various uncertainties (e.g., transformation uncertainties) arising during site investigation. This paper presents Bayesian approaches for probabilistic characterization of undrained shear strength using cone penetration test (CPT) data and prior information. Homogeneous soil units are first identified using CPT data and subsequently assessed for weak stationarity by the modified Bartlett test to reject the null hypothesis of stationarity. Then, Bayesian approaches are developed to determine the random field parameters and simultaneously select the most probable correlation function among a pool of candidate correlation functions within the identified statistically homogeneous layers. The proposed approaches are illustrated using CPT data at a clay site in Shanghai, China. It is shown that Bayesian approaches provide a rational tool for proper determination of random field model for probabilistic characterization of undrained shear strength with consideration of transformation uncertainty.

Assessing the Effect of the Stochastic Structure of Inflow into Lake Baikal on the Long-Term Level Regime of the Lake

The statistical homogeneity of the total inflow into Lake Baikal have been analyzed. The periods of 1901–1933 and 1933–2014 have been found not only to show statistically significant difference between the coefficients of autocorrelation of the total inflow, but also changes in its stochastic structure. For the first period, the autocorrelation function of the total inflow into Lake Baikal corresponds to AR(1)-process, that for the second period corresponds to a single-component AR(2)-process or the most adequate two-component AR-process with components in the form of AR(2)-processes. The use of AR(1)-process to describe the total inflow into Lake Baikal in 1933–2014 has been shown to lead to underestimation of the dispersion and autocorrelation coefficient of water level variations in Lake Baikal. The stochastic structure of the long-term variations of the total water inflow into the lake that has formed after 1934 has to be taken into account to obtain more accurate estimates of these characteristics. With the stochastic properties of water inflow into the lake taken into account properly, extremely high water levels in Lake Baikal show higher exceedance probability than those derived from the model based on AR(1)-process used to describe the inflow. For example, the level of 1% exceedance probability that corresponds to AR(1)-model of inflow will become a level with 2% exceedance probability if the inflow is correctly modeled as an AR-process with two components in the form of AR(2)-processes.

Long-term changes in water flow of the Volga basin rivers

The long periods/phases (with a duration of more than 10-15 years) of increased and decreased water flow of rivers in the Volga river basin were identified. The annual and seasonal water flow (over snow-melt flood period, as well as summer–autumn and winter low-water seasons) of six representative rivers over observation periods more than a century in duration, starting from the 1870s–1890s up to 2016, was used. In addition to this, periods with the average runoff close to its normal value were also observed. The boundaries of contrast phases were determined using normalized cumulative deviation curves in combination with Student’s test of the statistical homogeneity of the data series. The duration of the phases varies from 10 to 96 years. The phases of lower runoff were generally longer than those of higher runoff (this is especially typical of the winter and summer–autumn low-water season). The identified contrast phases show a statistically significant difference between the annual and seasonal runoff. The analysis of the data series of alteration of phases with increased and decreased water flow in hydrological seasons of the year allowed the authors to identify three major types of their long-term dynamics within the Volga river basin.

Buccal mucosal graft urethroplasty of the bulbomembranous part of urethra

IntroductionUrethral stricture is a partial or complete narrowing of the urethra, caused by damage to the urethral epithelium. This disease leads to a persistent urination dysfunction, the elimination of which is a difficult task. The aim of this study was to perform a comparative analysis of the immediate and long-term narrowing treatment results of the proximal part of the bulbar and membranous urethral parts using the developed magnifying and anastomotic methods.Material and methodsA total of 102 patients with a confirmed diagnosis of stricture of the bulbomembranous urethral part of the urethra who underwent treatment in the urological hospital in Irkutsk City Clinical Hospital No. 1 during the period 2012–2018 participated in this prospective study. Urethroplasty operations were performed in two ways, using the anastomotic and intra-urethral substitution techniques. Through the assessment of preoperative parameters, statistical homogeneity of comparison groups was established.ResultsThe final data analysis showed relapse for 4 patients from Group I and for 2 patients in Group II. The absence of relapse during the entire observation period was equal in both groups and after 2 years amounted to 83.0 ±7.9% in Group I and 92.5 ±5.1% in Group II.ConclusionsIn both groups, the desired result was achieved – adequate independent urination was restored. The anastomotic method of urethroplasty should be used with caution in patients at risk groups, as well as with the presence of predictors of complications: previous transurethral surgeries on the urethra and prostate, anastomotic urethroplasty, radical prostatectomy. The developed minimally invasive substitution technique has a similar effectiveness with a lower risk of complications.

СТРУКТУРНО – МАТЕМАТИЧЕСКАЯ МОДЕЛЬ ТЕПЛОПРОВОДНОСТИ БЕТОНА

Introduction: The significance of energy saving in residential construction is associated with the reliable determination of design thermal conductivity characteristics of construction materials. The authors describe a concept of the structural and mathematical modeling of concrete thermal conductivity. The concept is based on methods of the structural approach and generalized conductivity theory. Purpose of the study: The study is aimed at developing an adequate structural and mathematical model to determine the thermal conductivity of concrete. Methods: The authors used the statistical method as a representation of the statistical homogeneity of a multi-component composite closely related to thermal homogeneity, which is understood as a medium with effective thermal resistance constant in space. Results: The authors developed a structural and mathematical model to determine the thermal conductivity of concrete. The model accounts for concrete structural factors existing at the time when the structure formation of concrete is, for the most part, complete. The model also accounts for the thermal and physical properties of concrete components as well as macro- and mesostructural features of concrete. The paper presents calculated data for potential macro- and mesostructural factors, which makes it possible to determine the thermal conductivity of concrete characterized by low thermal conductivity and use the results derived for the approximation of prediction trends related to the thermal properties of such concretes in the operation and adaptation period during the use of building envelopes.

МАТЕМАТИЧЕСКАЯ МОДЕЛЬ ЗАВИСИМОСТИ РАСПРЕДЕЛЕНИЯ СУЛЬФИДНЫХ ВКЛЮЧЕНИЙ В ОТЛИВКЕ ИЗ УГЛЕРОДИСТОЙ СТАЛИ ПРИ ГАЗОДИНАМИЧЕСКОМ ВОЗДЕЙСТВИИ НА РАСПЛАВ, ЗАТВЕРДЕВАЮЩИЙ В КОКИЛЕ

Приведены результаты анализа цифровых изображений серных отпечатков темплетов отливок из стали 35Л, полученных литьем в кокиль по традиционной технологии и с применением газодинамического воздействия. Предложена математическая модель для оценки влияния технологических режимов на количество и размеры сульфидных включений.

RISK-ORIENTED APPROACH TO THE QUALITY ASSESSMENT OF WATER SOURCES OF DRINKING WATER SUPPLY

Introduction. Correct control and assessment of compliance of the composition and properties of drinking water sources with the established safety criteria are necessary conditions for ensuring the quality of life and health of the population in a situation of increasing exposure to chemical factors. Therefore, the most important is to increase the reliability of sanitary and hygienic conclusions. Material and methods. To achieve the goal of the work, there was used the Bayesian approach, methods for checking data homogeneity and evaluation of the measure of the statistical homogeneity. It is shown that the evaluation by Bayes method, requiring consideration of limiting factors, provides a correct solution to the problem of the implementation of the established sanitary and hygienic requirements. Representation of Bayesian relations in the form of estimates of the mixture of distributions allows taking into account the degree of statistical homogeneity of the combined samples, which significantly expands the scope of the method. Although the samples selected for consideration in the simple case can be considered homogeneous in the examples of the assessment of hygienic safety of water, it turned out that the transition from the binomial distribution law to a more strict normal one reduces the risk of accidental error of the desired conclusion. This provides the researcher with the opportunity to use, depending on the requirements for the accuracy of the assessment, different algorithms of a risk-based approach to the assessment of hygienic safety. results. On the example of the study of the water quality in the Verkhny Isetsky Vodokanal recreational area and source of water in Northern part of Ekaterinburg the inclusion of the homogeneity of merged data was shown to allow “forgetting” the earlier information (e.g., 2009) and thus to give more weight to recent data (2010). It is also shown that in this case, the combined estimates with the degree of homogeneity of the data series are not worse than the Bayesian estimates. It is concluded that the lower the degree of uniformity, the faster the above “forgetting” occurs. And the risks of violation of hygienic requirements depend on the choice of the law of distribution of controlled indicators. Conclusion. There was established the possibility of increasing the reliability of sanitary and hygienic conclusions by correctly combining the latest measurement information with outdated data, taking into account their gradual “forgetting”. The developed methods of the used for this risk-based approach can be widely applied to assess the hygienic safety of the population under the influence of a wide range of chemical factors.

Evaluation of physical changes (temperature and salinity) in the Persian Gulf waters due to climate change using field data and numerical modeling

Salinity and temperature are two important physical parameters of seawater that determine the life conditions, development of herbal creatures and sea animals and the class of human activity at the sea. They are also important due to their effects on chemical and biochemical processes that are vital to sea organisms. In this study, the effects of climate change on these physical characteristics of the Persian Gulf waters have been evaluated from 1992 to 2018. A one-dimensional numerical oceanic model, called Program for Boundary layer Environment, and some field data were used to determine the long-term changes of these characteristics. The input data of this model include meteorological information obtained from European Center for Medium Range Forecasting. For vertical turbulence simulation, Axell–Liungman, Omstedt, Rodi, Pacanowski and Marchuk schemes were used for some stations located in the Persian Gulf and the results were compared to some measurements of temperature and salinity at three other stations in the Persian Gulf. The results showed that Omstedt scheme was the best at stimulating the vertical turbulence in the Persian Gulf. Statistical homogeneity tests on the predicted time series on temperature and salinity showed that they are homogeneous. The results clearly indicate the annual variations of temperature (ranging between 20 and 36 °C), as well as showing mild increasing trends of about 1–2 °C in 10–30 years which is rather dramatic for this sea.

Representative elementary area of shale at the mesoscopic scale

The Representative Elementary Area (REA) of two shales (Callovo-Oxfordian claystone and Tournemire argillite) that are actively studied in the framework of the deep disposal of radioactive waste have been estimated from two mineral maps by classical methods (i.e., the box-counting and statistical approaches) and by different microstructural descriptors (i.e., the two-point probability function, lineal path function, percolation length, and variogram). The classical box-counting method provides estimates of the REA size of the clay fraction in the range from 129 μm to 441 μm, consistent with estimates obtained from the literature on other shales. However, these estimates show an extreme sensitivity to the chosen ε threshold or error and a wide scatter, thereby bringing the statistical homogeneity of both maps into question. Although the two-point probability function and lineal path function infer lower bounds of the REA size, these microstructural descriptors are relevant to demonstrate the microstructural anisotropy of both shales due to the alignment of nonclay grains parallel to bedding at the study scale. The results from the two-point probability function and variogram undoubtedly confirm that the Tournemire mineral map is not statistically homogeneous with regard to its mineral composition. This aspect it makes difficult to interpret the results and even questions the REA size determination of this particular map. Finally, our set of results allow us to recommend the use of the two-point probability function and variogram to preliminarily validate the statistical homogeneity of maps under study before calculating the REA size using conventional methods, e.g. the box-counting and statistical approaches.

Energy cascades in active-grid-generated turbulent flows

The energy cascade and diverse turbulence properties of active-grid-generated turbulence were studied in a wind tunnel via hot-wire anemometry. To this aim, two active grid protocols were considered. The first protocol is the standard triple-random mode, where the grid motors are driven with random rotation rates and directions, which are changed randomly in time. This protocol has been extensively used due to its capacity to produce higher values of $Re_\lambda$ than its passive counter part, with good statistical homogeneity and isotropy. The second protocol was a static or open grid mode, where all grid blades were completely open, yielding the minimum blockage attainable with our grid. Centreline streamwise profiles were measured for both protocols and several inlet velocities. It was found that the turbulent flow generated with the triple-random protocol evolved in the streamwise direction consistently with an energy dissipation scaling of the form $\varepsilon=C_\varepsilon u^{\prime3}/L$, with $C_\varepsilon$ being a constant, $L$ the longitudinal integral length-scale, and $u^\prime$ the rms of the longitudinal velocity fluctuations. Conversely for the open-static grid, the energy dissipation followed a non-equilibrium turbulence scaling, namely, $C_\varepsilon \sim Re_G/Re_L$, where $Re_G$ is a global Reynolds number based on the inlet conditions of the flow, and $Re_L$ is based on the local properties of the flow downstream the grid. Furthermore, this open-static grid mode scaling exhibits important differences with other grids, as the downstream location of the peak of turbulence intensity is a function of the inlet velocity. It was also found that a rather simple theoretical model can predict the value of $C_\varepsilon$ based on the number density of zero-crossings of the longitudinal velocity fluctuations. This theory is valid for both active grid operating protocols.

Hipnoterapy Toward Improving The Confidence Of Students

The problem of confidence is one of the global phenomena that everyone has. This event does not only occur in Indonesia but also in other countries. From the results of preliminary studies conducted by researchers, more respondents experienced low self-esteem than moderate and high self-esteem. The purpose of this study was to determine the effect of hypnotherapy on increasing the confidence of students in the fourth semester of the S1 undergraduate study program in the learning process at Stikes Panrita Husada Bulukumba. This research method uses a Pre-experimental design with the One group Pretest-Posttest Design approach. Sampling was done by a systematic random sampling technique. The population in this study was 46 people. The sample in this study were 19 people. Data analysis uses the Marginal Homogeneity alt Wilcoxon test. The results of SPSS analysis using the statistical test Marginal Homogeneity alt Wilcoxon obtained the value (p = 0.001) so that it can be concluded that there is a significant influence between hypnotherapy on increasing the confidence of fourth-semester students of a nursing S1 study program in the learning process at Stikes Panrita Husada Bulukumba.

On Exact Laws in Incompressible Hall Magnetohydrodynamic Turbulence

Abstract A comparison is made between several existing exact laws in incompressible Hall magnetohydrodynamic turbulence in order to show their equivalence, despite stemming from different mathematical derivations. Using statistical homogeneity, we revisit the law proposed by Hellinger et al. and show that it can be written, after being corrected by a multiplicative factor, in a more compact form implying only flux terms expressed as increments of the turbulent fields. The Hall contribution of this law is tested and compared to other exact laws derived by Galtier and Banerjee & Galtier using direct numerical simulations of three-dimensional electron MHD turbulence with a moderate mean magnetic field. We show that the studied laws are equivalent in the inertial range, thereby offering several choices on the formulation to use depending on the needs. The expressions that depend explicitly on a mean (guide) field may lead to residual errors in estimating the energy cascade rate; however, we demonstrate that this guide field can be removed from these laws after mathematical manipulation. Therefore, it is recommended to use an expression independent of the mean guide field to analyze numerical or in situ spacecraft data.

Conditional dynamic subfilter modeling

A novel “conditional” variation of the dynamic approach for modeling of large eddy simulation subfilter terms is derived and tested. In contrast to the traditional dynamic closure, which stabilizes “raw” dynamic coefficients by averaging across ensembles of expected statistical homogeneity, the novel variation averages conditionally on some set of scalars whose local values are expected to correlate with the local degree of turbulence. Simulations of a nonpremixed jet flame show that the conditional dynamic model is both tractable and stable and produces predictions which are essentially indistinguishable from the traditional dynamic closure, although both models give suboptimal predictions. Future work could potentially improve the predictions of both models—facilitating a fairer comparison—by considering a more uniform or “pancake-like” grid.

Placenta previa and the risk of intrauterine growth restriction (IUGR): a systematic review and meta-analysis

Background Whether placental location confers specific neonatal risks is controversial. In particular, whether placenta previa is associated with intra-uterine growth restriction (IUGR)/small for gestational age (SGA) remains a matter of debate. Methods We searched Medline, EMBASE, Google Scholar, Scopus, ISI Web of Science and Cochrane database search, as well as PubMed (www.pubmed.gov) until the end of December 2018 to conduct a systematic review and meta-analysis to determine the risk of IUGR/SGA in cases of placenta previa. We defined IUGR/SGA as birth weight below the 10th percentile, regardless of the terminology used in individual studies. Risk of bias was assessed using the Cochrane Handbook for Systematic Reviews of Interventions. We used odds ratios (OR) and a fixed effects (FE) model to calculate weighted estimates in a forest plot. Statistical homogeneity was checked with the I2 statistic using Review Manager 5.3.5 (The Cochrane Collaboration, 2014). Results We obtained 357 records, of which 13 met the inclusion criteria. All study designs were retrospective in nature, and included 11 cohort and two case-control studies. A total of 1,593,226 singleton pregnancies were included, of which 10,575 had a placenta previa. The incidence of growth abnormalities was 8.7/100 births in cases of placenta previa vs. 5.8/100 births among controls. Relative to cases with alternative placental location, pregnancies with placenta previa were associated with a mild increase in the risk of IUGR/SGA, with a pooled OR [95% confidence interval (CI)] of 1.19 (1.10-1.27). Statistical heterogeneity was high with an I2 = 94%. Conclusion Neonates from pregnancies with placenta previa have a mild increase in the risk of IUGR/SGA.

SUN-242 Hypothyroidism and Reduced Kidney Function: A Meta-Analysis

While chronic kidney disease (CKD) patients have a substantially higher prevalence of hypothyroidism compared to their non-CKD counterparts (i.e., 25% vs. 5%, respectively), the mechanistic link between thyroid and kidney disease remains unclear. We thus sought to conduct a meta-analysis of cross-sectional studies examining the association of hypothyroidism and CKD. We searched MEDLINE, EMBASE, Web of Science, CINAHL, Cochrane CENTRAL, and other sources for relevant cross-sectional studies. Three investigators independently selected the studies using predefined criteria. We quantitatively pooled the results of studies with clinical, methodological, and statistical homogeneity and with no overlap in their data sources. We included eight studies that met the stringent qualification criteria (e.g., adult participants, sample size ≥100, thyroid status defined by serum thyrotropin [TSH], CKD defined by estimated glomerular filtration rate), abstracted the data from the included studies, and independently assessed each study's quality using the Newcastle-Ottawa Quality Assessment Scale. Studies restricted to participants with normal thyroid function and/or end-stage renal disease were excluded (total number of participants = 140,361). Our meta-analysis using random effects indicated that compared to euthyroidism, hypothyroidism was associated with higher risk of CKD: OR: 1.66 (1.35-2.04). In this pooled analysis of moderate-sized studies, hypothyroidism was associated with higher risk of CKD. Further studies are needed to determine underlying mechanisms, and whether associations are ameliorated by correction of thyroid status with thyroid hormone supplementation.

On the Importance of Statistical Homogeneity to the Scaling of Rain

AbstractScaling studies of rainfall are important for the conversion of observations and numerical model outputs among all the various scales. Two common approaches for determining scaling relations are the Fourier transform of observations and the Fourier transform of a correlation function using the Wiener–Khintchine (WK) theorem. In both methods, the observations must be wide-sense statistically stationary (WSS) in time or wide-sense statistically spatially homogeneous (WSSH) in space so that the correlation function and power spectrum form a Fourier transform pair. The focus here is on developing an explicit understanding for the requirement. Statistically heterogeneous (either in space or time) data can produce serious scaling errors. This work shows that the effects of statistical heterogeneity appear as contributions from cross correlations among all of the distinct contributing rainfall components using either method so that the correlation function and its FFT do not form a transform pair. Moreover, the transform then also depends upon the time and location of the observations so that the “observed” power spectrum no longer represents a “universal” scaling function beyond the observations. An index of statistical heterogeneity (IXH) defined in previous work provides a way of determining whether or not a set of rain data may be considered to be WSS or WSSH. The greater IXH exceeds the null, the more likely the derived power spectrum should not be used for general scaling. Numerical simulations and some observations are used to demonstrate all of these findings.

Revealing of regularity, processing and prediction of sulfide inclusions distribution in carbon steel that is hardened in a chill mold

Purpose. To develop a mathematical model that describes the dependence of the size and amount of sulfide inclusions for various zones of the cross-section of a casting on the parameters of the gas-dynamic effect.Research methods. A computer program, ASImprints, has been developed for processing digital images of sulfur imprints. Digital images of sulfur imprints of 35Л steel casting templates obtained by traditional die-casting technology and under various gas-dynamic modes were processed. A mathematical description of the nature of sulfide inclusions distribution along the casting template as a power function is proposed.Results. A model of the sulfide inclusions distribution in a cross section of a cylindrical cast of carbon steel with240 mmdiameter, that solidifies in an uncooled chill mold under various gas-dynamic modes, was obtained.Scientific novelty. Analytical dependences are obtained that allow interpolating parameters values of the power distribution and, thus, make a prediction of the sulfide inclusions distribution in selected areas of the cross section of this cast that solidifies in an uncooled mold under a given gas-dynamic effect mode.Practical value. The suggested model makes it possible to interpolate the parameters values of a power distribution for predicting sulfide inclusions distribution in a cross section of a given cylindrical cast that solidifies in an uncooled chill mold, for a given mode of gas dynamic effect. The correlation analysis of the probability density function of the power distribution obtained for each of the considered fragments of selected casting section areas showed the statistical homogeneity of the fragments belonging to one zone and the possibility of conducting a quantitative analysis of the digital image of a sulfur imprint.