scholarly journals Mathematical statistics for measurement of steel temperature in steel-pouring ladle and tundish at steel continuous casting

2021 ◽  
Vol 64 (7) ◽  
pp. 510-518
Author(s):  
S. K. Vil’danov ◽  
G. S. Podgorodetskii
Keyword(s):  
Continuous Casting ◽  
Steel Casting ◽  
Goodness Of Fit ◽  
Stable State ◽  
Sequential Data ◽  
Steel Temperature ◽  
Steel Continuous Casting ◽  
Steel Grades ◽  
Kolmogorov Smirnov ◽  
The Relationship

The article considers the temperature distribution in steel during its continuous casting. Temperatures were measured sequentially in the steelpouring ladle (one measurement) and in the tundish (two measurements) using a platinum-platinum-rhodium thermocouple with an accuracy of ±4 °C. We have analyzed the results of 170 casts of two steel grades: 5SP and 35GS. The type of temperatures set distribution was verified on the basis of three goodness-of-fit criteria: Pearson’s χ-square criterion, λ Kolmogorov-Smirnov criterion and W Shapiro-Wilk criterion. The results obtained are consistent with the physical picture of steel casting. The metal in steel-pouring ladle is practically in a stable state and is subject only to natural cooling through the lining, top and ladle body. In the variant of analyzing a sample of temperature values in tundish at the first and second measurements, the hypothesis of normal distribution should be rejected. Here, the steel temperature depends on a number of parameters, including the feed rate and casting rate, feed time and composition of slag-forming and heat-insulating mixtures, etc. Attempts to establish the relationship between the steel temperatures of in steel-pouring ladle and tundish were unsuccessful. Considering the temperature measurement in tundish as two sequential data arrays, the first of which is an argument, and the second is a function, a linear relationship between these arrays was established. This relationship between the first and second temperature measurements in the tundish can be used to estimate the steel final temperature at thermocouple readout, including in the event of a failure. The results of the work can be used in development of a mathematical model of steel casting.

Thermo-Mechanical Model of Steel Continuous Casting Process

2012 ◽  
Vol 57 (1) ◽  
pp. 355-361 ◽  
Author(s):  
K. Sołek ◽  
L. Trębacz
Keyword(s):  
Continuous Casting ◽  
Mechanical Model ◽  
Low Carbon Steel ◽  
Casting Process ◽  
Low Carbon ◽  
Continuous Casting Process ◽  
Casting Technology ◽  
Steel Continuous Casting ◽  
Simulation Of Casting Processes ◽  
Steel Grades

Thermo-Mechanical Model of Steel Continuous Casting Process In the paper a numerical model of heat and mass transfer in the mould zone in the steel continuous casting technology was presented. The model has been developed using ProCAST software designed for simulation of casting processes. It allows to determine temperature and stress distribution in continuous castings in order to optimize the most important process parameters. In this work calculations were executed for low carbon steel grades casted in the industry. In the simulations the real rheological properties measured in the experimental work and the boundary conditions determined on the basis of the industrial data were used.

Development of steel continuous casting at the Nizhny Tagil steel-works

2020 ◽  
Vol 76 (6) ◽  
pp. 550-555
Author(s):  
М. V. Saveliev ◽  
А. V. Chiglintsev ◽  
D. V. Sushnikov ◽  
P. V. Ekkert ◽  
V. Yu. Elin
Keyword(s):  
Continuous Casting ◽  
Steel Continuous Casting ◽  
Wide Range ◽  
Steel Grades ◽  
The One ◽  
Supporting Rollers ◽  
Work Done ◽  
The Impact ◽  
Ingot Solidification ◽  
Steel Works

Steel continuous casting is one of fundamentals of modern steel industry. Specialists of Nizhny Tagil steel-works (NTMK) made an important contribution to the process perfection. The one-strand slab CCM of curvilinear type with radial mold and slab straightening by multipoint curve, designed and manufactured at Uralmashzavod, became a prototype for many machines, which were later manufactured at domestic and foreign steel-works in the end of 60th of the previous century. In the process of mastering of CCMs, which were put into operation within the programs of the plant modernization and transferring to BOF production with steel continuous casting, the CCMs were significantly modernized and technology of casting was perfected. To bring down the impact on the solidifying billet peel and decrease a billet swell, the scheme of the supporting rollers location was changed, which enabled to increase the length of the supported zone. A principally new scheme of billets cooling was implemented, which ensured a softer and uniform secondary cooling due to water-air “fog”. To create optimal conditions of axis zone forming during production of round billets of 430 mm diameter, a technology of protective heat screens application was used. The protective screens were installed in the end of ingot solidification zone. A large work was done on determination of optimal technological casting parameters – temperature and speed modes, types of slag forming mixtures, types of heat-insulating mixtures, methods of metal protection in the process of casting. As a result of the work done, at EVRAZ NTMK a complex of steel continuous casting was created, which enables to be flexible depending on the varying situation at the market and to produce continuously casted billets of various dimensions and wide range of steel grades.

scholarly journals Early Education Care from Its Practitioners to Achieve Sustainability

2021 ◽  
Vol 13 (6) ◽  
pp. 3396
Author(s):  
Óscar Gavín-Chocano ◽  
David Molero ◽  
Inmaculada García-Martínez
Keyword(s):  
Early Intervention ◽  
Structural Equation ◽  
Goodness Of Fit ◽  
Satisfaction With Life ◽  
Well Being ◽  
Satisfaction With Life Scale ◽  
Life Scale ◽  
Fit Index ◽  
The Relationship ◽  
Early Intervention Professionals

(1) Background: Early intervention professionals are involved in the reconceptualisation of their service due to the exceptional situation caused by the COVID-19 epidemic, within the family context and aware of the children’s needs, with an impact on their emotional well-being to ensure sustainability. An analysis of their socio–emotional profile and training is increasingly needed to face their professional development effectively; (2) Methods: In this study, 209 early intervention professionals participated (n = 209), with an average age of 37.62 (±9.02). The following instruments were used: Satisfaction with Life Scale (SWLS), Wong Law Emotional Intelligence Scale (WLEIS-S) and the Utrecht Work Engagement Scale (UWES-9). The purpose of the study was to examine the relationship between early intervention (EI) and engagement as predictors of greater life satisfaction using Structural Equation Modelling (SEM). (3) Results: There exists a relationship between some dimensions of the instruments used (p < 0.01). The model obtained good structural validity (χ² = 3.264; Root Mean Square Error of Approximation (RMSEA) =.021; Goodness-of-Fit Index (GFI) = 0.991; Comparative Goodness of Fit Index (CFI) = 0.999; Incremental Fit Index (IFI) = 0.999). Subsequently, the results described above were verified through Bayesian statistics, thereby reinforcing the evidence provided; (4) Conclusions: Findings highlight the importance of providing professionals with emotional tools and strategies, from the educational context, in order to carry out their activity effectively and ensure the sustainability within the current situation, while remaining fully engaged.

scholarly journals A Hypothesis Test for the Goodness-of-Fit of the Marginal Distribution of a Time Series with Application to Stablecoin Data

2021 ◽  
Vol 5 (1) ◽  
pp. 10
Author(s):  
Mark Levene
Keyword(s):  
Time Series ◽  
Goodness Of Fit ◽  
Marginal Distribution ◽  
Hypothesis Test ◽  
Data Sets ◽  
Test Statistic ◽  
Sample Test ◽  
Kolmogorov Smirnov ◽  
Heavy Tailed ◽  
Jensen Shannon Divergence

A bootstrap-based hypothesis test of the goodness-of-fit for the marginal distribution of a time series is presented. Two metrics, the empirical survival Jensen–Shannon divergence (ESJS) and the Kolmogorov–Smirnov two-sample test statistic (KS2), are compared on four data sets—three stablecoin time series and a Bitcoin time series. We demonstrate that, after applying first-order differencing, all the data sets fit heavy-tailed α-stable distributions with 1<α<2 at the 95% confidence level. Moreover, ESJS is more powerful than KS2 on these data sets, since the widths of the derived confidence intervals for KS2 are, proportionately, much larger than those of ESJS.

Evolutionary game analysis of information sharing by institutional investors

2021 ◽  
pp. 1-9
Author(s):  
Hua Li ◽  
Qingqing Lou ◽  
Qiubai Sun ◽  
Bowen Li
Keyword(s):  
Information Sharing ◽  
Institutional Investors ◽  
Information Exchange ◽  
Evolutionary Game ◽  
Stable State ◽  
Point Of View ◽  
Game Model ◽  
Game Analysis ◽  
Relationship Network ◽  
The Relationship

In order to solve the conflict of interests of institutional investors, this paper uses evolutionary game model. From the point of view of information sharing, this paper discusses four different situations. Only when the sum of risk and cost is less than the penalty of free riding, the evolution of institutional investors will eventually incline to the stable state of information sharing. That is, the phenomenon of hugging. The research shows that the institutional investors are not independent of each other, but the relationship network of institutional investors for the purpose of information exchange. The content of this paper enriches the research on information sharing of institutional investors.

Process monitoring using causal graphical models, with application to clogging detection in steel continuous casting

2021 ◽  
Vol 105 ◽  
pp. 259-266
Author(s):  
Shu Yang ◽  
Andreas Rebmann ◽  
Ming Tang ◽  
Rudolf Moravec ◽  
Dylan Behrmann ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Process Monitoring ◽  
Graphical Models ◽  
Steel Continuous Casting

Simulation factors of steel continuous casting

2010 ◽  
Vol 17 (3) ◽  
pp. 267-275 ◽  
Author(s):  
A. Ramírez-López ◽  
R. Aguilar-López ◽  
A. Kunold-Bello ◽  
J. González-Trejo ◽  
M. Palomar-Pardavé
Keyword(s):  
Continuous Casting ◽  
Steel Continuous Casting

Beyond the heuristic approach to Kolmogorov-Smirnov theorems

1982 ◽  
Vol 19 (A) ◽  
pp. 359-365 ◽  
Author(s):  
David Pollard
Keyword(s):  
Weak Convergence ◽  
Goodness Of Fit ◽  
Empirical Distribution ◽  
Distribution Functions ◽  
Heuristic Approach ◽  
Convergence Theory ◽  
Simple Method ◽  
Starting Point ◽  
Kolmogorov Smirnov ◽  
The Subject

The theory of weak convergence has developed into an extensive and useful, but technical, subject. One of its most important applications is in the study of empirical distribution functions: the explication of the asymptotic behavior of the Kolmogorov goodness-of-fit statistic is one of its greatest successes. In this article a simple method for understanding this aspect of the subject is sketched. The starting point is Doob's heuristic approach to the Kolmogorov-Smirnov theorems, and the rigorous justification of that approach offered by Donsker. The ideas can be carried over to other applications of weak convergence theory.

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