Parameter Analysis Method Research Articles

Study on impact dynamic characteristics of semi-autogenous mill liner based on improved multivariable method

The impact resistance of semi-autogenous mill liner has an important influence on the reliable operation of the system. The complex dynamic characteristics in the process of collision with abrasive medium are studied by the improved multivariable method proposed in this paper. Firstly, based on manifold element method, the deformation of abrasive medium and lining plate in the contact area is expressed by the coordinates of first-order manifold element basis function, while the deformation of the non-contact region is described by modal coordinates to improve the traditional multivariable method, and the displacement constraint equations as well as the acceleration constraint equations of the collision system are derived, then the Lagrange method is used to establish the impact dynamic equation of abrasive medium and lining plate system. Secondly, a collision test rig between abrasive medium and lining plate was built to verify the correctness and accuracy of the proposed method. Finally, the influence of structural parameters and motion parameters of abrasive medium and lining plate on the dynamic characteristics of collision system is analyzed by parameter analysis method. It is found that when the Poisson’s ratio of abrasive medium to lining plate material exceeds 1.0, the increase amplitude of stress becomes smaller. The increase amplitude of displacement, velocity, acceleration and stress at the collision contact point decreases when the initial velocity of abrasive medium exceeds 3.0 m/s. The stress at the collision contact point changes greatly, and the maximum acceleration occurs in advance when the radius of abrasive medium exceeds 20 mm. When the thickness of liner exceeds 40 mm, the time of maximum acceleration to reach is almost unchanged. The results show that compared with the traditional multivariable method, the improved multivariable method can increase the modeling efficiency and solving accuracy, and lay a theoretical foundation for optimizing the structure of the liner and raising the service life of the system.

ANALYSIS OF ABNORMAL RETURN AND TRADING VOLUME ACTIVITY BEFORE AND AFTER THE LQ45 COMPANY CASH DIVIDEND ANNOUNCEMENT FOR THE 2020 PERIOD

An increase in the trading volume of dividend-declaring shares at a particular moment may indicate that the company is performing well and has promising prospects. The dividend announcement includes crucial information for investors seeking abnormal returns. This study seeks to determine and assess whether there is a difference between AR and TVA before to and following the release of cash dividends. This study's data analysis method is a parametric statistical data analysis method. This method is used to statistically evaluate population parameters, or in other words, to test population size using pre-selected sample data and a significance level () of 0.05 or 5%. A data set is considered regularly distributed if asym.sig is less than 0.05. Sig. 0.277 > 0.05 indicates that there is no change in the average abnormal return before and after the declaration of cash dividends for LQ45 Company 2020. The findings of evaluating the sample data for trading volume activity indicate, with a significance level of 0.000 < 0.05, that there is a difference in trading volume activity before and after the release of cash dividends for LQ45 Company 2020. A significant negative abnormal return value at t-4, t-1, t0, t+3, t+4, and t+5 conveyed bad news, therefore investors overreacted to alter stock prices, resulting in disparities in trading volume activity before to and following the announcement of cash distributions. Indirectly, the declaration of cash dividends can impact the trading volume activities of LQ45 Index-listed businesses.

Parametric analysis of the stress-strain state for the unsupported and supported horizontal underground workings

An analysis of analytical and numerical approaches to the problem of determining the stress-strain state of underground workings has been carried out. A system of parametric analysis of the stress-strain state of unsupported and supported horizontal underground workings has been developed. This system proved that to determine the stress-strain state of horizontal unsupported workings of a certain diameter, it is enough to perform one numerical calculation of a finite-element model with unit parameters, and using simple analytical formulas, extrapolate the stress-strain state of this model to all possible cases of real workings. Finite element models of underground workings were developed to justify the author’s system. A method of parametric analysis of the strained state of a supported working by using models with equivalent bending stiffness has been developed and substantiated. On its basis, it is possible to perform a numerical analysis of a finite-element model with unit parameters of the frame, selecting the equivalent modulus of elasticity.

Analytical modeling of the virtual sound insulation measurement suite and research on sound insulation test methods

With the development of modern industrial technology, it is an essential problem to calculate the noise reduction performance of the flexible partition walls. The sound insulation measurement model is modeled by the Spectral geometry method (SGM). Compared with the traditional ones, it is a method with higher calculation accuracy and faster convergence speed. The displacement of the panel and the sound pressure field inside the rooms are expressed as Fourier series with additional items. In order to simulate the real measurement environment, the sound source room and the receiving room are set as a reverberation chamber and an anechoic chamber with impedance boundaries, respectively. The coupling relationship is established by the Hamilton’s principle. Then the natural frequencies and the sound pressure level are compared with those derived by the finite element method (FEM). The results show that the analytical method has good accuracy and convergence. Moreover, the sound transmission loss (STL) of the partition could be obtained by the sound pressure method. Considering there is no accurate method for measuring the STL, this paper studies some factors affecting the sound insulation performance of the model by the parametric analysis method, such as the thickness of the panel, the length of the receiving room, the impedance of the receiving room and the parameters of medium.

Analysis of Computer Visualized Sound Parameters of Vocal Music Singing Based on Deep Learning

The first impression of the early historical recordings on the contemporary audience is often not ideal; the overall speed is relatively fast, the rhythm is relatively loose and free, and the strings are slippery. In recent years, a large number of research achievements have emerged at home and abroad that apply computer visualization analysis methods to music performance practice. It is feasible and necessary to gradually apply the visual audio parameter analysis method to music research and performance practice teaching. In this study, a prosody hierarchy prediction model based on the CNN (convective neural network) is proposed, and word vectors are added as semantic features. The DL (deep learning) method is applied to vocal music recognition, and a recognition method based on the DL framework is proposed by combining traditional audio signal processing methods. After introducing word vectors as features in the CNN model, the F-score value increased from 77% to 80%. The feasibility of the proposed vocal music recognition algorithm based on DL is verified by experiments.

Improve the Assessment Model of Personnel Develop Level in Higher Education Based on Machine Learning

In order to improve the ability to manage the quality constraint index parameters of higher education talent training, an evaluation model of higher education talent training quality based on improved machine learning is proposed. Combined with the characteristic analysis method of higher education talent training quality constraint index parameters, an autocorrelation feature matching model of higher education talent training quality constraint index parameters is established, and fuzzy association rule scheduling is used to realize the feature extraction and fuzzy clustering of higher education talent training quality constraint index parameters. The mutual information coupling parameter analysis of the quality constraint index parameters of higher education talent training, combined with the generalized association rules and periodic association rules, realizes the feature clustering and global candidate item set analysis of the quality constraint index parameters of higher education talent training and realizes the dynamic evaluation of the quality of higher education talent training according to the machine learning analysis results. The test results show that this method has good clustering of data characteristics, good reliability of the evaluation process, and good convergence of machine learning process, which improves the dynamic and quantitative management ability of talent training quality in higher education.

Assessment of changes in a child's body length during a health-improving shift with consideration of physical development, gender and age differences as an indicator of the effectiveness of health improvement

Methodological evaluation of the effectiveness of recuperation of children at the present time, according to many authors, requires revision and improvement. One of the traditionally used criteria for assessing the effectiveness of recuperation are somatometric indicators. The aim of the study was to assess the dynamics of the body length of the child during the health-improving shift (21 days) taking into account age and gender differences in order to further substantiate the applied criteria for assessing the effectiveness of health improvement. The object of the study was children of 7–17 years old (n = 18 081) who stayed at 52 stationary recreation and health improvement organizations and who got the high recuperation. effect during the change. Assessment of recuperation efficiency was conducted according to the currently existing methodological recommendations for assessing the effectiveness of recuperation in 2018, data collection and primary analysis were carried out by means of the software tool «Assessment of recuperation efficiency» developed by FBSI «Novosibirsk Research Institute of Hygiene» of Rospotrebnadzor. The database was processed using parametric and nonparametric methods of statistical analysis. It was reliably established that children with underweight and deficit had a smaller mean value of growth gain than children in other physical development groups, also in this physical development group the lowest proportion of children who had growth gain was noted. At the same time, no reliable differences were found between the average values of growth gain in children of different age groups. The above identified patterns can be used in adjusting the integral assessment of the effectiveness of health promotion.

Crack classification of fiber-reinforced backfill based on Gaussian mixed moving average filtering method

The crack classification in the rupture process of filling materials is important for predicting rupture instability and identifying rupture precursor features. To investigate fiber-reinforced backfill crack classification, uniaxial compression tests were performed on different fiber-reinforced backfills using a microcomputer-controlled electronic universal testing machine and a Micro-II Express Digital acoustic emission (AE) system. The crack classification model based on the Gaussian mixed moving average filtering method was combined with AE technique under uniaxial compression test, and the crack classification results of the Japanese Construction Materials Standard (JCMS-III B5706) parametric analysis method and the Gaussian mixed model (GMM) were compared and analyzed by comparing changes in the distribution of RA (rise time/maximum amplitude) and AF (average frequency) values. The results revealed that the fiber-reinforced backfill is dominated by tensile cracks in the initial loading stage, tensile cracks transitioned to shear cracks in the intermediate loading stage, and shear cracks dominated in the final loading stage. The fiber-reinforced backfill exhibits an overall distribution of high RA values and low AF values, and the data points are generally close to the RA half-axis, increasing along the RA half-axis in a striped distribution. The percentages of tensile and shear cracks obtained based on the GMM are roughly the same as those obtained by the JCMS-III B5706 parametric analysis method, indicating that the model is feasible to be applied to the crack classification of fiber-reinforced backfills. The results of the study can provide a new method for the crack classification during the rupture of fiber-reinforced filling materials in mines.

Research of Parametric Modeling and Simulation Analysis Methods of Aero-engine’s Rear Variable Area Bypass Injector of Mapping Dispersive Dimension Based on ADAMS

Aiming at the problem of motion accuracy caused by dispersive dispersion in the design of the aero-engine rear variable area bypass injector, a multi-body dynamics model mapping dimension tolerance, part flexibility, and collision contact is established based on multi-body dynamics theory and ADAMS. The simulation results are verified with the theoretical solution, which is calculated in MATLAB to ensure the correctness of the simulation’s results. The effect of key design variables on the motion accuracy of the mechanism is analyzed by the parametric module. The reliability calculation method is studied based on the improved Latin hypercube Monte Carlo method mapping the dimension dispersion. The method provides the relevant basis for the structural design of the RVABI.

Importance of Integrating Traditional Physical Education into Physical Education Teaching Using Big Data

In order to advance the assessment capability of the significance of integrating old-fashioned physical education into school physical education, an evaluation model of the significance of integrating old-fashioned physical education into school physical education founded on big data analysis of influencing factors of physical education quality is put forward. The big data analysis model of the significance of integrating old-fashioned physical education into school physical education was established, and the constraint parameter model was adopted to evaluate the significance of integrating old-fashioned physical education into school physical education by the method of objective elements collection of physical education teaching effect. Combined with the quantitative statistical analysis method of structural parameters of physical education system, the important parameter analysis model of integrating classical physical education into institution physical education was realized, and the inversion feature quantity of the significance evaluation of integrating classical physical education into institution physical education was extracted. Combining the questionnaire analysis method of influencing factors of institution physical education teaching quality, this paper realizes the piecewise linear estimation of the significance of classical physical education in institution physical education teaching, adopts the joint feature analysis method of quantitative rules, combines the quantitative analysis of indicators and the confidence test results of the significance of classical physical education in institution physical education teaching, and therefore realizes the fuzzy assessment of the significance of classical physical education in institution physical education teaching by fuzzy decision method. We realize the comprehensive evaluation decision of the significance of integrating classical sports into institution physical education. According to the big data mining results of the significance evaluation of integrating classical sports into institution physical education, realize the decision evaluation of the significance of integrating classical sports into institution physical education. The test outcomes express that this approach has good adaptability in evaluating the significance of integrating old-fashioned physical education into school physical education, and the confidence level of the evaluation results is higher than the other approaches.

A Self-Adaptive Recommendation Method for Online Ideological and Political Teaching Resources Based on Deep Reinforcement Learning

The online ideological as well as the political teaching resource management system structure is established in the view of information management in colleges and universities. Furthermore, the online ideological as well as the political teaching information level is improved by combining the optimized design of resource recommendation model. In this paper, an online ideological as well as political teaching resource adaptive recommendation system and algorithm, which is designed on deep reinforcement learning, is suggested. The cost relationship model between online ideological as well as the political teaching resources and learning profitability is constructed. Similarly, the multidimensional constraint index parameter analysis method is adopted, and the adaptive matching model of online ideological as well as the political teaching resources is established. According to online ideological as well as the political teaching norms, combined with the analysis of high-quality educational resources of audience groups, the dynamic evaluation of online ideological as well as the political teaching resources and the adaptive matching model of interest preferences are established. Finally, the deep reinforcement learning method is adopted. By analyzing the characteristics of the resource structure model of online ideological as well as the political teaching resources, through benefit evaluation, resource supply and demand balance management analysis and balanced game control, the online ideological as well as the political teaching resources management system can be improved and self-adaptive recommended. The simulation outcomes indicate that this approach has noble adaptability and high correctness in recommending online ideological as well as the political teaching resources.

Survival analysis of the unsafe behaviors leading to urban expressway crashes.

A common cause of vehicle crashes on urban expressways lies in the unsafe behaviors of drivers. This study focused on analyzing the influence of various unsafe behaviors on crash duration. Based on actual video image of vehicle crashes, 14 unsafe behaviors were identified for the analysis of crashes on urban expressways. Using the correspondence analysis method, the correlation among unsafe behaviors and collision types was obtained. Nonparametric survival analysis was then presented to obtain the survival rate curves of sideswipe crashes and rear-end crashes. Finally, parametric survival analysis method can get the influence of unsafe behaviors on crash duration. The survival rate of any time was quantified through the reasoning of key unsafe behaviors for different types of crashes. The results show that there were striking differences in the duration among different types of crashes. The unsafe behaviors had a significant impact on duration for different types of crashes. This study focused on the duration under the influence of unsafe behaviors before the crash, and the results provide valuable information to prevent crashes, which can improve traffic safety.

МЕТОДОЛОГИЧЕСКИЕ АСПЕКТЫ ПРОЕКТИРОВАНИЯ ЦИФРОВОЙ МОДЕЛИ ПРОЦЕССА ДВУСТОРОННЕЙ ТОРЦЕШЛИФОВАЛЬНОЙ ОБРАБОТКИ

The paper is devoted to the development of methodological foundations of digital models of two-sided face grinding treatment. The study objective is further increase in the effectiveness of work preparation of two-sided face grinding in the conditions of automated and digital manufacture. At the present stage of the development of mechanical engineering and computerized manufacture the technological parameters of adjustment and cutting modes of metalworking systems should be determined not by reference data, but as a result of simulation modeling of treatment processes taking into account all actual technological factors of influence. The problem to which the paper is devoted is the search for solutions to the problems of ensuring the correctness of mathematical and computer models being developed, adequate consideration of dominant factors, correct representation in the digital form of treatment process of patterns, relationships and constraints taking place based on the methods of structural parametric analysis and simulation modeling. These problems can be solved only on the basis of a systematic approach to the treatment and the development of methodological foundations for creating its digital model, which is the subject of research in the presented paper in relation to two-sided face treatment (FT). The following things are proposed: an algorithm of structural and parametric FT design, a structural and functional model of workpiece forming, objects and connections of technological interaction in FT, which together are the methodological foundations for the virtual FT presentation and have signs of scientific novelty. The results of virtual FT of cylindrical rollers in production conditions and the technical settings of the machine found on the basis of the stated methodological recommendations show that the required values of the dominant shape errors and the relative position of the treated surfaces are provided within the specified constrains. Conclusions: the provisions given in the paper and the model environment can be used in the development of an automated system for technological FT preparation in the conditions of digital production.

Computer-Visualized Sound Parameter Analysis Method and Its Application in Vocal Music Teaching

In order to improve the quality of vocal music teaching, this paper applies the computer visualization sound parameter analysis method to vocal music teaching and discusses the scheme of parametric coding. Moreover, this paper adopts the transient signal detection mechanism to divide the signal. For frames that have detected a shock signal, frequency-domain parametric differential predictive coding can be used like temporal noise shaping (TNS) techniques. In addition, based on the short-term periodicity and short-term stationarity of speech signals, an analytical synthesis model based on harmonic decomposition is proposed. Through the simulation data analysis, it can be seen that the computer visualization sound parameter analysis method proposed in this paper has a very good application effect in vocal music teaching and can improve the quality of vocal music teaching.

The Effect of Critical Thinking Course Carry Out with Distance Education on Critical Thinking Skills and Dispositions

The purpose of this study is to examine the effects of a distance learning course in critical thinking on the critical thinking skills and dispositions of university students. The diversification model was adopted in the study, which was carried out in line with the mixed research method, which combines the results of the data obtained by collecting both quantitative and qualitative data and allows comparisons to be made. The data of the study conducted with 30 senior university students were obtained with the "California Critical Thinking Disposition Scale" and open-ended questions about "What is critical thinking" and "Why is critical thinking important". Parametric and non-parametric analysis methods were used in the analysis of the quantitative data obtained from the data collection tools that were transferred to the online environment and applied to the participants before and after the critical thinking course. The content analysis method was used to analyze qualitative data gathered via open-ended questions. As a result of the analyses conducted, it was determined that there was a significant difference between the pre-test and post-test in terms of the participants' critical thinking dispositions. It was determined that there were no significant gender or departmental differences in the participants' critical thinking dispositions. As a result of the content analysis carried out within the framework of open-ended questions, it was determined that there were differences in the views of senior university students towards critical thinking before and after the critical thinking course. Within the framework of the results, it was suggested that more activities and practices for critical thinking should be included in undergraduate courses.

Term structure of risk factor premiums: evidence from international equity markets

Subject. Factor models are among the most popular tools for the analysis of stock market risks. For a long time, factor models were developed mainly by the formation of additional risk factors. However, static linear specifications are usually not sufficiently sensitive to structural changes in the market and to changes in the operational regimes of markets and in this regard they have a limited number of functions. The idea of regime switching is natural for markets and is intuitively comprehensible, therefore, in order to take into account the non-linear dependencies in factor models of risk analysis, it is advisable to use the mechanism of Markov regime switching with them. Objectives. Statistical analysis of the dynamic properties of the factor structure of risk premiums for transactions with stock market financial instruments based on a modification of the Fama & MacBeth procedure that takes into account the current market regime. Methods: In our study, we used parametric methods of data analysis and machine learning methods, description, analysis, synthesis, induction, deduction, comparison, and grouping method. An EM algorithm was used for the parametric identification of models with Markov regime switching. Results: The paper provides convincing evidence that the relationship between the excess return of financial instruments and factor loads is influenced by the current regime in the market. The main feature of the low volatility regime is the presence of a positive statistically significant risk-adjusted premium. The change in the current regime in the market is accompanied by the transformation of the factor structure of the risk premium. This fact indicates that it is reasonable to divide risk factors into speculative and protective risk factors. Speculative factors include market risks, the risk related to the size of the issuing company, and the momentum effect risk. They have a positive and significant premium in the low volatility regime. The protective factors include risk factors related to value, capital investment, and return on equity. The protective factors are characterised by a positive and significant premium only during periods of high volatility.

The Role of Circumstances in The Differentiation of Russian Wages

The purpose of this study is to determine the influence of circumstances (opportunities) and efforts on the wages differentiation of Russian citizens. Research objectives: identification of factors of circumstances, quantitative assessment of their contribution to the wages of Russians and their individual income groups. The research is based on the HSE RLMS data for 2004 and 2018 and LITS-III data for 2016. We applied parametric methods of regression analysis, the Morduch-Sicular method of inequality decomposition, as well as the construction of quantile regressions. As a result of the study, we obtained assessments of the contribution of circumstances to wages inequality of the Russian population. We found that income inequality in the Russian labour market was primarily determined by the regional factor, to a lesser extent by the employment sector and the gender of the respondents. The least contribution to inequality was made by the factor of the employment formality. The influence of parents’ education on future earnings of offspring was also negligible – according to the model based on the LITS-III sample. The reduction in the contribution of circumstances to the general wage inequality in Russia in 2004–2018 was mainly due to a decrease in interregional differences in wages, where an active government policy of income redistribution played a significant role. The influence of circumstances on wage inequality was uneven in different quantiles of the distribution scale. In particular, employment in the metropolitan area or in the oil and gas sector has been most beneficial to high-income groups of workers. At the same time, parents’ education had the least and even negative effect on the earnings of the highest-paid people, which can be explained by the peculiarities of the formation of the modern Russian elite. The results of the study are applicable for conducting an effective social policy of the state.

The Choice of Protamine Sulfate Dosing Regimen for Coronary Artery Bypass Graft Surgery

Changes in hemodynamics and coagulation hemostasis during the use of protamine sulfate to neutralize heparin in a ratio of 0.5:1 in coronary artery bypass graft surgery have been studied. A comparative analysis of hemodynamic abnormalities, postoperative blood loss, and the need for blood transfusion in patients receiving protamine sulfate at the above dose has been carried out. The study included 70 patients who were successively operated on at the Shalimov National Institute of Surgery and Transplantation due to coronary heart disease, in whom coronary artery bypass grafting was performed on a working heart. The study group included 30 patients in whom heparin was neutralized with protamine in a ratio of 1:0.5. The comparison group included patients in whom heparin was neutralized with protamine in a ratio of 1:1. Statistical processing of the material was performed using the software StatPlus professional 2007. Both parametric and non-parametric methods of statistical analysis were used. The parametric method (Student’s t-test) was used to test the hypothesis of the equality of the mean values of two samples from different general sets. Pearson’s criterion was used to compare the two sets by qualitative features. Statistically significant differences in the obtained results were considered at p <0.05, which indicated a 95% probability of discrepancies. Changes in blood pressure, central venous pressure, electrocardiogram, cardiac output, cardiac index, coagulogram, complete blood count, biochemical blood test, electrolyte, acid-base and gas composition of blood during surgery and in the postoperative period were analyzed. The results showed that reduction in the dose of protamine to neutralize heparin is effective and safe in patients undergoing coronary artery bypass grafting. However, changes in hemodynamics and coagulogram in patients treated with 50% protamine dose were insignificant and did not increase perioperative blood loss and blood transfusion needs.

Manageable risk factors for progression of HPV-associated cervical intraepithelial neoplasia

Objective: to identify informative markers of the progression of cervical intraepithelial lesions of low degree.Materials and methods: the dynamics of the results of the cytological study of cervical epithelium, genotyping of human papilloma viruses of high carcinogenic risk (HPV) with an assessment of the viral load, an immunocytochemical study of the expression of protein p16 (p16INK4α), serum folic acid in 90 HPV-positive patients of reproductive age was analyzed. 43 of the 90 patients (47.8%) who made up group I had regression of the disease. Group II included 30 of 90 patients (33.3%) with disease persistence - no significant changes in the results of laboratory and instrumental research methods. Group III was 17 out of 90 patients (18.9%) with disease progression. Statistical processing of the results was carried out using parametric and non-parametric analysis methods using IBM SPSS Statistics 28.0.1.1 (developed by IBM Corporation), STATISTICA 13.5.0.17 (developed by StatSoft.Inc) and MedCalc 20.027. Results: factors that significantly distinguish patients with persistence or progression of low grade cervical intraepithelial lesions from women with regression of the disease are: earlier age of sexual onset, detection of atypical changes in low grade cervical epithelium, clinically significant HPV viral load, detection of p16INK4a protein expression, serum folic acid below 3.1 ng/ml. Conclusions: deficiency of serum folic acid in HPV of positive patients should be considered as a pathogenetically significant risk factor for the implementation of infection into the clinical form of the disease, which is confirmed by its correlation with the cytological detection of LSIL, progressive increase in the copy of HPV, and p16INKα expression. The patient management strategy, which provides a personalized assessment of the risk of progression of cervical intraepithelial lesions, expands the monitoring of patients with cervical neoplasias associated with HPV.

Research on the Influence of Tractor Parameters on Shift Quality, Based on Uniform Design

This paper mainly studies the influence of tractor parameters on shift quality. The kinetic theoretical model of the powertrain system was deduced, and then the simulation model was established by using AMESim simulation software. The acceptable jerk and shift time were selected as the evaluation indexes of shift quality. The influence of engine speed, the tractive resistance of the tractor, the clutch oil pressure and the orifice diameter on the above evaluation indexes were quantitatively studied. The simulation test, under the influence of a single parameter, was carried out using the parameter analysis method. After this, the uniform design experimentation method was used to carry out the simulation test, under the influence of combined parameters. The results showed that in order to improve the shift quality, it is necessary to focus on the selection of clutch oil pressure and orifice diameter.