scholarly journals DISCREPANCY PARAMETERS OF APPROXIMATIONS OF DISCRETELY SPECIFIED DEPENDENCIES BY ANALYTICAL FUNCTIONS AND SEARCH CRITERIA FOR OPTIMAL VALUES OF THEIR COEFFICIENTS

Author(s):  
S.M. Zakharchenko ◽  
◽  
N.A. Shydlovska ◽  
I.L. Mazurenko ◽  
◽  
...  

Universal discrepancy parameters of approximations of discretely specified dependencies by analytical functions and search criteria for optimal values of their coefficients, as well as analysis of features of their application are described. Discrepancy parameters of approximations, which do not depend on the ranges of variation of the values of functions and the number of points of a discretely specified dependence, are proposed. They can be effective for objectively comparing the quality of approximations of any dependencies by any functions. Approximations of a discretely specified dependence of the mathematical expectation of the equivalent electrical resistance of a layer of aluminum granules during spark-erosion dispersion in water on the instantaneous values of the discharge current are carried out. As approximating functions, we chose a power function with an exponent factor –1 and a function based on exponential. Using the criteria of the least approximation error, the optimal values of the coefficients of both approximating functions are founded. It is shown in which cases it is advisable to use the combined search criteria for the optimal values of the coefficients of the approximating functions, and in which are enough simple one-component ones. Ref. 27, fig. 2, tables 2.

2021 ◽  
Vol 2021 (5) ◽  
pp. 3-10
Author(s):  
S.M. Zakharchenko ◽  
◽  
N.A. Shydlovska ◽  

As a result of processing the experimental data, an analytical continuous nonlinear-probabilistic model of the equivalent electrical resistance of a layer of metal granules in the working liquid was created. It is described by four equations: the modified Gaussian distribution and the dependences on the instantaneous values of the discharge current in the layer of metal granules of the mathematical expectation, dispersion and correction coefficient of the range of its equivalent electrical resistance. Based on the form of the dependences obtained during the experiments and the physics of the processes that occur in this case, two main groups of analytical functions are considered that approximate the obtained dependences. Criteria and methods for finding the optimal values of their coefficients are described. The adequacy of the approximation of each of the three obtained dependences by several analytical functions was investigated, the optimal values of the coefficients of which were found by the described method. Analytical functions was compared, which approximate the dependence of the mathematical expectation of the equivalent electrical resistance of a layer of metal granules on the instantaneous values of the discharge current in it with the known nonlinear models of the resistance of such a medium. References 33, figures 3, tables 3.


2021 ◽  
Vol 2021 (2) ◽  
pp. 3-12
Author(s):  
N.A. Shidlovska ◽  
◽  
S.M. Zakharchenko ◽  

Two strategies for constructing nonlinear-probabilistic models of the equivalent electrical resistance of a layer of metal granules at their spark-erosion and plasma-erosion treatment and algorithms for their implementation are presented. A method for taking into account the parametric properties of such loads in their nonlinear and nonlinear-probabilistic models is described. Based on the data of direct experiments, the distributions of the electrical resistance of a layer of aluminum granules in tap water were obtained for eleven fixed values of the discharge current in it for both the leading and trailing edges of its pulses. The features of these distributions are described for different edges of the discharge current pulses. It has been proved that the obtained distributions can be adequately described by the normal law. The parameters of the normal law for each distribution obtained as a result of direct experiments are founded by the method of moments. A nonlinear-probabilistic model of the equivalent electrical resistance of a layer of aluminum granules in tap water is created, taking into account the main hysteresis of the dependence of resistance on current. It is shown that at large values of discharge currents, the nonlinear-probabilistic model of the equivalent electrical resistance of the layers of metal granules tends to degenerate into a nonlinear model. References 27, figures 4


2020 ◽  
Vol 7 (2) ◽  
pp. 34-41
Author(s):  
VLADIMIR NIKONOV ◽  
◽  
ANTON ZOBOV ◽  

The construction and selection of a suitable bijective function, that is, substitution, is now becoming an important applied task, particularly for building block encryption systems. Many articles have suggested using different approaches to determining the quality of substitution, but most of them are highly computationally complex. The solution of this problem will significantly expand the range of methods for constructing and analyzing scheme in information protection systems. The purpose of research is to find easily measurable characteristics of substitutions, allowing to evaluate their quality, and also measures of the proximity of a particular substitutions to a random one, or its distance from it. For this purpose, several characteristics were proposed in this work: difference and polynomial, and their mathematical expectation was found, as well as variance for the difference characteristic. This allows us to make a conclusion about its quality by comparing the result of calculating the characteristic for a particular substitution with the calculated mathematical expectation. From a computational point of view, the thesises of the article are of exceptional interest due to the simplicity of the algorithm for quantifying the quality of bijective function substitutions. By its nature, the operation of calculating the difference characteristic carries out a simple summation of integer terms in a fixed and small range. Such an operation, both in the modern and in the prospective element base, is embedded in the logic of a wide range of functional elements, especially when implementing computational actions in the optical range, or on other carriers related to the field of nanotechnology.


2018 ◽  
pp. 53-57 ◽  
Author(s):  
G. G. Savenkov ◽  
V. P. Razinkin ◽  
A. D. Mekhtiev

Applications of modern terminal loads and its relevant disadvantages are described in this paper. The decomposing method of wideband microwave high power microstrip loads design is proposed in this paper with purpose of matching quality improving. Multiple extension of multistage load bandwidth is provided by using of external matching circuit and internal matching inductive elements. The maximum reachable bandwidth of multistage load is estimated and optimal values of mathing circuit elements are founded on basis of equivalent lumped scheme. The topology of microstrip two-stage high power microwave load is developed and its frequency response, calculated via numeric electrodynamic modelling method is outlined in the paper. Modelling results show good matching quality of considered load at the frequency band below 3,5 GHz.


Author(s):  
Е.И. ПОНОМАРЕВА ◽  
С.И. ЛУКИНА ◽  
А.А. ЖУРАВЛЕВ ◽  
С.М. ПАВЛОВСКАЯ

Исследовано влияние сочетания нетрадиционных видов сырья – жидкого виноградного сахара и куркумы на качество хлеба из пшеничной муки. Проведена оптимизация дозировок этих рецептурных компонентов по выходным параметрам – удельному объему и формоустойчивости готового изделия. Оптимизацию рецептурного состава хлеба проводили с использованием методов математической статистики и дифференциального исчисления. Построены математические модели в виде регрессионных уравнений. Обработку экспериментальных данных выполняли по статистическим критериям Стьюдента, Кохрена и Фишера при доверительной вероятности 0,95. Дана графическая интерпретация регрессионных уравнений. Оптимизацию рецептурного состава хлеба проводили методом свертывания частных критериев в обобщенный аддитивный критерий. Определены оптимальные значения факторов: дозировка, % к массе муки, жидкого виноградного сахара – 2,50, куркумы – 2,75, обеспечивающие получение изделий с наилучшим сочетанием значений удельного объема и формоустойчивости. На основе полученных данных разработана рецептура и способ производства хлеба «Мерита» профилактической направленности (ТУ 9110–515–02068108–2019), характеризующегося улучшенным качеством и повышенной пищевой ценностью за счет дополнительного внесения биологически активных нутриентов. The influence of a combination of non-traditional raw materials – liquid grape sugar and turmeric on the quality of wheat flour bread has been studied. Optimization of the dosages of these prescription components according to the output parameters – specific volume and dimensional stability of the finished product was carried out with using methods of mathematical statistics and differential calculus. Mathematical models in the form of regression equations are constructed. The experimental data were processed according to the statistical criteria of Student, Cochran, and Fisher with a confidence probability of 0,95. Optimization of the formulation composition of bread was carried out by the method of folding partial criteria into a generalized additive criterion. The optimal values of the factors are determined: dosage, % by weight of flour, liquid grape sugar –2,50, turmeric – 2,75, ensuring the production of products with the best combination of specific volume and dimensional stability. On the basis of the obtained data, the formulation and method of production of bread «Merita» of a preventive orientation (Technical specifications 9110–515–02068108–2019) were developed. The product has improved quality and increased nutritional value due to the additional introduction of biologically active nutrients.


Algorithms ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 130 ◽  
Author(s):  
Dinh Trieu Duong ◽  
Huy Phi Cong ◽  
Xiem Hoang Van

Distributed video coding (DVC) is an attractive and promising solution for low complexity constrained video applications, such as wireless sensor networks or wireless surveillance systems. In DVC, visual quality consistency is one of the most important issues to evaluate the performance of a DVC codec. However, it is the fact that the quality of the decoded frames that is achieved in most recent DVC codecs is not consistent and it is varied with high quality fluctuation. In this paper, we propose a novel DVC solution named Joint exploration model based DVC (JEM-DVC) to solve the problem, which can provide not only higher performance as compared to the traditional DVC solutions, but also an effective scheme for the quality consistency control. We first employ several advanced techniques that are provided in the Joint exploration model (JEM) of the future video coding standard (FVC) in the proposed JEM-DVC solution to effectively improve the performance of JEM-DVC codec. Subsequently, for consistent quality control, we propose two novel methods, named key frame quantization (KF-Q) and Wyner-Zip frame quantization (WZF-Q), which determine the optimal values of the quantization parameter (QP) and quantization matrix (QM) applied for the key and WZ frame coding, respectively. The optimal values of QP and QM are adaptively controlled and updated for every key and WZ frames to guarantee the consistent video quality for the proposed codec unlike the conventional approaches. Our proposed JEM-DVC is the first DVC codec in literature that employs the JEM coding technique, and then all of the results that are presented in this paper are new. The experimental results show that the proposed JEM-DVC significantly outperforms the relevant DVC benchmarks, notably the DISCOVER DVC and the recent H.265/HEVC based DVC, in terms of both Peak signal-to-noise ratio (PSNR) performance and consistent visual quality.


2016 ◽  
Vol 61 (2) ◽  
pp. 671-676
Author(s):  
Н. Dyja ◽  
А.А. Тukibay ◽  
S.A. Mashekov

Abstract To create a rational technology of cogging process and to determinate the optimal values of the angles of tilt and single reduction the stress-strain state (SSS) of the blank during cogging in the flat dies was analyzed. By using the finite element method and program MSC.SuperForge quantitative data are obtained and the basic patterns of distribution of SSS, the temperature during the simulation of tilting in flat dies with different angles of tilting and the amount of reduction were established. Sustainable experimental-industrial technology of forging of two-phase titanium alloys was developed and tested.


Author(s):  
V. Onishchuk ◽  
S. Ageeva ◽  
E. Doroganov

The article presents the results of studies aimed at establishing the possibility of obtaining low-melting nephritized glazes for majolica with a glass transition temperature of not more than 1000 ° C in the system of materials "quartz sand - ulexite - soda - feldspar concentrate". A rational choice of raw materials will ensure the production of slips that are able to maintain their design chemical composition during the application of majolica to the shard, therefore, provide the specified chemical composition of the glaze and contribute to obtaining the required physical, mechanical and chemical properties of the glaze layer. The design of the material compositions of the charges and the chemical compositions of the glaze coatings was carried out using the mathematical planning of the experiment, which significantly reduced the time and material costs for research. The parameters that determine the quality of slips and glaze coatings have been established, their most optimal values have been identified, which ensure the production of acceptable glaze coatings, and the ways to optimize work in the studied direction have been determined. As a result, the fundamental possibility of obtaining low-melting nephritized glazes in the system of materials "quartz sand - ulexite - soda - feldspar concentrate, capable of transforming into a glassy state at temperatures not exceeding 1000 ºC, has been proved.


2021 ◽  
Author(s):  
Ashkan Sedigh ◽  
Mohammad-R. Akbarzadeh-T ◽  
Ryan E. Tomlinson

ABSTRACTBioprinting is an emerging tissue engineering method used to generate cell-laden scaffolds with high spatial resolution. Bioprinting parameters, such as pressure, nozzle size, and speed, have a large influence on the quality of the bioprinted construct. Moreover, cell suspension density, cell culture period, and other critical biological parameters directly impact the biological function of the final product. Therefore, an approximation model that can be used to find the values of bioprinting parameters that will result in optimal bioprinted constructs is highly desired. Here, we propose type-1 and type-2 fuzzy systems to handle the uncertainty and imprecision in optimizing the input values. Specifically, we focus on the biological parameters, such as culture period, that can be used to maximize the output value (mineralization volume). To achieve a more accurate approximation, we have compared a type-2 fuzzy system with a type-1 fuzzy system using two levels of uncertainty. We hypothesized that type-2 fuzzy systems may be preferred in biological systems, due to the inherent vagueness and imprecision of the input data. Here, our results demonstrate that the type-2 fuzzy system with a high uncertainty boundary (30%) is superior to type-1 and type-2 with low uncertainty boundary fuzzy systems in the overall output approximation error for bone bioprinting inputs.


2020 ◽  
Vol 998 ◽  
pp. 185-190
Author(s):  
Ladawan Chotirat ◽  
Sutham Niyomwas ◽  
Sitthisuntorn Supothina ◽  
Witthawat Wongpisan ◽  
Kirati Waree

Thin films of vanadium oxide were synthesized by DC magnetron sputtering on a glass slide. Process parameters including temperature, argon and oxygen ratio (Ar:O2) and base pressure were investigated. It was found that the control of sputtering base pressure is very important in realizing the pure VO2 (M) thin films. These thin films have grown at low base pressure of 5x10-6 mbar. The results of the valence electron analysis show the outstanding phase of VO2 and a small amount of V2O5 and V2O3 phases. The hysteresis loop of electrical resistance property of the VO2 thin films illustrated the quality of film, which is related to metal-insulator transition phase (MIT) at the transition temperature (Tc) of approximately 63°C. The sample was tested for its electrical properties by a four-probe setup with a temperature controller during heating and cooling cycles.


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