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1
Kaul, M., J. Burger, and H. Hasse. "Hierarchical design of extraction-distillation processes using short-cut apparatus models with piece-wise linearized thermodynamics." Chemical Engineering Science 192 (December 2018): 422–33. http://dx.doi.org/10.1016/j.ces.2018.07.030.
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Frolkova, A. V., M. S. Peshekhontseva, and I. S. Gaganov. "SHARP DISTILLATION FOR QUATERNARY SYSTEMS." Fine Chemical Technologies 13, no. 3 (2018): 41–48. http://dx.doi.org/10.32362/24106593-2018-13-3-41-48.
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Conditions of sharp distillation were considered for zeotropic quaternary system (two pairs of components are characterized by relative volatility close to 1) and systems with one (with minimum or maximum boiling point) and two (with minimum and maximum boiling point) binary azeotropes. Regions of compositions for which sharp distillation is effective (distillate and bottom flows don't contain common components) were determined on the basis of analyzing diagrams of unit manifolds of distribution coefficients (distribution coefficients of two components are higher than one, and those of another two components - lower than one). This kind of separation can be recommended if it doesn’t cause an increase in the number of apparatuses in the separation flowsheet. If the system contains azeotropes of saddle type that can generate separatric manifolds, the possibility and expedience of sharp separation decreases. The conclusions were confirmed by simulation of the distillation process in AspenPlus V.10.0 for real and industrially important quaternary systems: ethyl acetate - benzene - toluene - butyl acetate; acetone - methanol - ethanol - propanol-2; methyl acetate - methanol - acetic acid - acetic anhydride and cyclohexene - cyclohexane - cyclohexanone - phenol. Mathematical modeling was carried out using local compositions models Wilson and NRTL-HOC. The relative error of vapor-liquid equilibrium description is less than 4%. The vapor-liquid equilibrium was simulated, a phase diagram was constructed and analyzed, the parameters of sharp distillation column operation (the number of stages, the feed-stage and reflux ratio) were determined for all systems. The effectiveness of using sharp distillation for the system with phenol was confirmed for a wide range of compositions.
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Richardson, W. C., M. K. Beladi, and C. H. Wu. "Steam Distillation Studies for the Kern River Field." SPE Reservoir Evaluation & Engineering 3, no. 01 (2000): 13–22. http://dx.doi.org/10.2118/60909-pa.
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Summary The interactions of heavy oil and injected steam in the mature steamflood at the Kern River Field have been extensively studied to gain insight into the effect of steam on compositional changes of oil during the recovery process and to provide input for compositional thermal simulation. Steam distillation behavior of this 13°API California oil between 300 and 467°F under a variety of process conditions, along with extensive analysis of distilled hydrocarbons were incorporated to give a more in-depth description of what is happening to the oil and what changes are occurring in the distillates or produced oil. This information was further integrated with analysis of the field distillate, "casing blow," to infer what is happening in the field. The results show that steam distillation is temperature dependent and more important than originally thought. The data developed in this study are a basis for improvement of numerical thermal models with potential for better designed steamfloods and reservoir management. The results may also impact certain logging techniques used in steamfloods and possible heavy oil upgrading techniques. Kern River oil is more than 10% distillable at 300°F and 15% distillable at 400°F in dynamic laboratory steam distillation tests at steam throughputs of four times the initial volume of oil. Distillate physical properties of density, viscosity, molecular weight, and hydrocarbon composition of the distillates changed significantly. Distillate properties increased in value with increasing steam throughput, and at higher temperatures. This information is important in the tuning of equations of state, including hydrocarbon-water interaction parameters for compositional thermal simulation. Analysis of the field distillate, "casing blow," showed properties similar to laboratory distillates at low steam throughputs. The observation of a light field distillate production in a mature steamflood compared to laboratory measurements implies that the casing system temperature is a major controlling factor in "casing blow" composition and quantity. Background The phase equilibrium behavior of reservoir fluids is an important phenomenon in petroleum production, particularly in enhanced oil recovery processes. However, phase behavior for heavy oils (<15°API) under steamflood has generally been felt to be unimportant or a minimal effect to be neglected.1 A major question exists about whether the phases and fluids in a steamflood are in equilibrium or not. Proper modeling of a reservoir production process would be expected to include knowledge of the phases and their equilibrium compositions. In heavy oil, devoid of significant C1 to C6 composition, it has been sufficient to treat the oil as a dead oil or a nonvolatile phase for steamflood modeling purposes. A history match numerical study2 of steamflood performance in the Kern River Field treated the oil as nonvolatile, and was conducted without the inclusion of hydrocarbon compositional effects. Through the classic works of Willman et al.,3 Volek and Pryor,4 and Closmann and Seba,5 steam distillation has been shown to be an important component mechanism in the overall steamflooding process.6–10 The practical limit of how much of a reservoir fluid can be distilled, is obtained in dynamic steam distillation experiments developed by Brown and Wu,11,12 extended by Hseuh, Hong, and Duerksen,13,14 and refined by Wu and co-workers.15,16 This body of work demonstrates that steam distillation is an operative mechanism in laboratory models, but it has been difficult to translate this to a quantitative contribution to the field recovery process of steamflooding. Laboratory steam distillation experiments have generally been conducted as dynamic tests, that may or may not be near equilibrium. Experiments near equilibrium with extensive analysis of the phases will yield values for the vapor-liquid equilibrium (VLE) ratios (K values), another way of assessing the importance of compositional changes in steamflooding. A major recent steam distillation study by Northrup and Venkatesan17 has been completed on the South Belridge oil. Compositional data from simple distillation and laboratory steamfloods of oils in the range 13 to 33°API, including Kern River oil, has recently been reported.18 The current report is an extension of that work to include analyses of produced field samples for the Kern River steamflood. Compositional reservoir simulators demand greater emphasis on obtaining more crude oil compositional data, which would be used as input into an equation of state (EOS) or to calculate equilibrium ratios, K values. An appreciable amount of incremental oil19,20 could be recovered by steamflooding due to steam distillation depending on the composition of the crude oil. The present work establishes laboratory data to facilitate such efforts. The EOS approach and table look-up for two-phase K values are applied in thermal numerical simulation models, even though they do not fully represent three-phase separation (steam distillation). A three-component system approximation was used by Coats and Smart21 to incorporate steam distillation effects by adding water as a component in the vapor phase. The compositional variations due to steam distillation cannot be fully described by Coats' model. A difficulty in this model is the lack of three-phase laboratory steam distillation data for high-temperature and high-pressure conditions. A future goal of this research is to obtain three-phase laboratory steam distillation data to better understand the effects of water and its vapor on the hydrocarbon separation processes at high-temperature and high-pressure conditions. This includes the investigation on both the pure hydrocarbon component/water systems and crude oil/water systems. The three-phase equilibrium ratios or K values determined from these laboratory investigations are necessary to accurately describe the effects of steam distillation in mathematical reservoir simulation. Experiment Steam Distillation Cell and Procedures. In order to describe the existing laboratory procedures, Fig. 1 is presented. This experimental setup is used to perform three different types of tests:Static system pressure test (SPT).Dynamic distillation test (DDT).Stagewise isochoric distillation test (SWID). The experimental apparatus is composed of the injection assembly (Ruska pumps and the gas bottles), the distillation cell assembly, the withdrawal assembly (condenser, separator) and the automation/data acquisition assembly. The steam distillation apparatus has been extensively described elsewhere.22
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Zotov, N. I., S. V. Popov, and O. V. Khabibrakhmanov. "Increasing the efficiency of the partial oil removal column." Proceedings of the Voronezh State University of Engineering Technologies 83, no. 1 (2021): 284–89. http://dx.doi.org/10.20914/2310-1202-2021-1-284-289.
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The operation of the primary oil refining unit is considered. An analysis of the operation of the operating column K-1 showed that there are noticeable fluctuations in the operating mode of the apparatus in the summer and cold season, as a result, a change in the temperature of the column top and a deterioration in the clarity of fraction rectification were observed. To study the methods of adjusting the parameters of the K-1 topping column, a computational experiment was carried out using the UniSim Design modeling system, in which the models of the apparatus and the installation model as a whole were formed. The Peng-Robinson method was used as a mathematical package for calculating the thermodynamic properties of the mixture components. Comparison of the calculated performance of the two options for the equipment of the column K-1. According to the first version, the operation of the K-1 column was simulated, in which the raw material enters the 19 tray, the hot stream is fed to the bottom of the column to the 24 tray, oil reflux to the 5 tray, acute irrigation and a partial condenser are used. Unstable technological regimes of the column top were observed in this variant in industrial conditions. To assess the fundamental possibility of changing the hardware design of the K-1 column, another option was chosen, in which there is no acute irrigation and oil irrigation, at the same time, upper circulating irrigation was introduced from the 5th to the 1st tray with cooling the flow and the technological scheme of forming and feeding the hot jet was preserved. Comparison of the fractional compositions of the topped oil showed that for the considered options, there are practically similar calculated estimates, while the use of upper circulating irrigation allows not only to unload the upper part of the distillation column from the heat load, but also to use a significant heat flow of the cooler of the upper circulating irrigation for preheating oil , which will also reduce the consumption of liquid fuel for furnaces.
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Li, Jianwei, Zhigang Lei, Zhongwei Ding, Chengyue Li, and Biaohua Chen. "Azeotropic Distillation: A Review of Mathematical Models." Separation & Purification Reviews 34, no. 1 (2005): 87–129. http://dx.doi.org/10.1081/spm-200054984.
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Guseynov, Sharif E., and Jekaterina V. Aleksejeva. "Mathematical Modelling of Aquatic Ecosystem." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 3 (June 16, 2015): 92. http://dx.doi.org/10.17770/etr2015vol3.192.
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<p class="R-AbstractKeywords"><span lang="EN-US">In present paper we consider the complete statements of initial-boundary problems for the modelling of various aspects of aqueous systems in Latvia. All the proposed models are the evolutionary models: all they are nonstationary and continuous qualitative models having the dynamic parameters and aimed at analysis, evaluation and forecast of aqueous systems (reservoirs, lakes and seas). In constructing these mathematical models as research tools classic apparatus of differential equations (both ODE and PDE) as well as apparatus of mathematical physics were used</span><span lang="EN-US">. </span></p>
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A. Shirkin, L., O. G. Selivanov, T. A. Trifonova, S. I. Roshchina, and M. E. Ilina. "Mathematical Model of Vacuum Evaporation Using Apparatus with Mechanical Water Vapor Recompression." International Journal of Engineering & Technology 7, no. 4.38 (2018): 1222. http://dx.doi.org/10.14419/ijet.v7i4.38.27768.
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This article presents mathematical model of evaporation of aqueous solutions of mineral salts on apparatus with mechanical recompression of water vapor and process intensification upon vacuuming. The developed mathematical model is an engineering prediction where all calculations are associated with technological flowchart of evaporator. Predictions according to the mathematical model for evaporator are exemplified for the case of 2% aqueous solution of sodium chloride evaporated to 15 wt % at distillation capacity of 30 kg/h. Engineering predictions were performed consecutively in 5 stages including material calculation of evaporator; estimation of evaporator temperature mode; hydrodynamic and thermal predictions; estimation of heat transfer coefficient. The developed mathematical model was applied to stationary direct flow evaporation using Mathcad Prime software. In order to perform high quality analysis and to verify adequacy of the mathematical model, 12 criteria were selected characterizing evaporation efficiency in evaporator. Advantages of the developed mathematical model were highlighted and substantiated, practical recommendations on its application were given upon efficiency estimation of vacuum evaporation with mechanical recompression of water vapor.
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Calderale, P. M., and G. Scelfo. "A Mathematical Model of the Locomotor Apparatus." Engineering in Medicine 16, no. 3 (1987): 147–61. http://dx.doi.org/10.1243/emed_jour_1987_016_033_02.
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This study presents a mathematical model for the musculo-skeletal system of the locomotor apparatus. Muscle forces and joint reactions are calculated for the static problem of leaning and squatting and for the dynamic problem of walking on a level surface. Muscle forces thus calculated are compared with electromyographic (EMG) patterns. The model follows previous statically indeterminate mathematical models, from which it differs chiefly in introducing intermediate constraints (in addition to the points of insertion) for the muscles, and in setting bounds on muscle tensile stress depending on system geometry, kinematics, and loading.
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Henry, B. D. "The use of mathematical models in the prediction of optimum distillation sequences." Chemical Engineering Journal 37, no. 2 (1988): 115–21. http://dx.doi.org/10.1016/0300-9467(88)80036-4.
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Li, Rui Duan, and Wei Ping Gao. "Applied Expert System Design for Energy-Efficient Distillation." Applied Mechanics and Materials 278-280 (January 2013): 531–34. http://dx.doi.org/10.4028/www.scientific.net/amm.278-280.531.
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There are so many energy-efficient distillation processes that it is difficult to select the best distillation process and achieve optimal design for a mixture of separation. Studying on different energy-efficient distillation processes, and we finally extracted 30 typical energy-efficient distillation processes, and established mathematical models of these processes to optimize and design. The characters and applicable conditions of every flow were obtained. According to the summary, we build a knowledge base for the expert systems. This was main content of the knowledge base of the system software. This expert system software ，based on windows XP system, was installed with Prolog and. Net.
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Kovtun, I. I., and G. S. Romanenko. "Mathematical models, numerical methods and complexes of programs for efficiency improvement of multiproduct production." Informatization and communication, no. 1 (March 31, 2020): 48–54. http://dx.doi.org/10.34219/2078-8320-2020-11-1-48-54.
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The problems of analysis and planning of diversified production, including the lack of effective methods for search, systematization and primary processing of initial data for mathematical programming methods used in the process of its optimization are considered. Methodology IDEF0 is proposed as a data collection system. For the purpose of practical implementation of the proposed solution, the conceptual apparatus of this methodology is put in accordance with the formal apparatus of these methods and, for its effective realization by computer, relational data model as metamodel is used.
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Sokolovskyy, Yaroslav, and Maryana Levkovych. "Two-Dimensional Mathematical Models of Visco-Elastic Deformation Using a Fractional Differentiation Apparatus." International Journal of Modern Education and Computer Science 10, no. 4 (2018): 1–9. http://dx.doi.org/10.5815/ijmecs.2018.04.01.
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Kochkin, Dmitry, and Aleksei Sukonschicov. "Fuzzy output system on the basis of the modified fuzzy Petri nets." E3S Web of Conferences 161 (2020): 01033. http://dx.doi.org/10.1051/e3sconf/202016101033.
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The development of information technologies requires improvement of simulation methods and mathematical apparatus. The mathematical apparatus of Petri nets is used for simulation of parallel asynchronous systems and has a broad scope. The modified fuzzy Petri nets expand the modeling capabilities of Petri nets by combining the properties of different extensions. Modified extension can serve for construction of models with a complex structure and logic of operation with the use of fuzzy logic apparatus for control on the basis of the system of production rules.
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Bartoszek, Krzysztof, Wojciech Bartoszek, and Michał Krzemiński. "Simple SIR models with Markovian control." Japanese Journal of Statistics and Data Science 4, no. 1 (2021): 731–62. http://dx.doi.org/10.1007/s42081-021-00107-1.
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AbstractWe consider a random dynamical system, where the deterministic dynamics are driven by a finite-state space Markov chain. We provide a comprehensive introduction to the required mathematical apparatus and then turn to a special focus on the susceptible-infected-recovered epidemiological model with random steering. Through simulations we visualize the behaviour of the system and the effect of the high-frequency limit of the driving Markov chain. We formulate some questions and conjectures of a purely theoretical nature.
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Stentsel, Yo I., and K. A. Litvinov. "Mathematical Models of Conservative Objects of Control." Metrology and instruments, no. 1 (March 2, 2020): 30–36. http://dx.doi.org/10.33955/2307-2180(1)2020.30-36.
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Trend analysis and record charts different technological parameter in the heat power, chemical and oil refining industry showed, that most of them are oscillatory in nature. In order to reduce the amplitude of the oscillations, filters are used, and for the actual value of the measured quantity — their average value. Research has found, that the oscillatory-pulse nature of trends and diagrams of measured values is observed in multi-parameter technological objects of control, which have valve valve strapping on both input and output material, heat or energy flows. It is shown that valve-type regulating organs, which are used in automatic control systems, together with the technological apparatus create partial objects, which work on a conservative type. This creates new dynamic objects with three or more private conservative systems, which together create a complex multi-parameter technological control object with the oscillatory-pulse nature of the measured parameters. It was found that in many cases for such complex objects of control the average value of the measured parameter, defined with the trend, can differ significantly from its actual value. This leads to the appearance of significant measurement errors, and consequently, to an incorrect assessment of the quality of manufactured products. The task is to study the causes of the appearance of such vibrational-pulse systems, their properties, deviations of average readings along the trend from the actual value of the measured parameter, and also develop methods for reducing measurement errors. The paper presents mathematical and physical models of such conservative control systems, obtained on the basis of the theory of rheological transformations, as well as the results of their research. It is shown that the vibrational-pulse trends of the measurement parameters are a set of angular frequencies of private objects, the sum of which creates an oscillatory-pulse form of the signals of the measuring parameters.
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BENDIB, Riad, Noual BATOUT, and Abdelmajid KHELASSI. "Design of Effective Control Schemes for Binary Distillation Columns." Algerian Journal of Signals and Systems 2, no. 4 (2017): 248–54. http://dx.doi.org/10.51485/ajss.v2i4.50.
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Distillation column is very important and high consuming energy equipment in oil refineries, such that 3% of the energy consumption in the world is allocated in distillation column. The fact that let controlling the distillation column an attractive field for researcher, and hence different control schemes are proposed by researchers. In this paper we will provide a comparative study between different control schemes for a binary distillation column two simple configurations (the most known ones) (LV&DV) and two more complicated ones ((L/D,V/B) & Ryskamp’s) we compare them in the basis of interactions and disturbance propagation. The mathematical models for the material balance configurations for the considered configurations are deduced using mathematical transformations (in the paper the general case of transformation between any two configurations is presented), taking the conventional configuration (LV) as a based configuration, the Dynamic Relative Magnitude Criterion (DRMC) is used to assess the interactions and disturbance propagation. The results show that the ratios control schemes are less sensitive to interactions compared with energy balance configuration LV. The same was noticed with DV configuration however other process drawbacks let it not recommended in industrial field.
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Sycheva, Oksana I., Yuri A. Pisarenko, and Ivan P. Semenov. "DEVELOPMENT AND MODELING OF REACTIVE DISTILLATION PROCESS OF OBTAINING ETHYLACETATE BY DEHYDROGENATION OF ETHANOL." Bulletin of the Saint Petersburg State Institute of Technology (Technical University) 56 (2021): 101–7. http://dx.doi.org/10.36807/1998-9849-2020-56-82-101-107.
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A promising direction in processes of general organic synthesis is use of bioethanol as a raw material for production of ethylacetate. The article is devoted to the development and modeling of the reaction-rectification process to produce ethyl acetate by dehydrogenation of ethanol, which will allow combining in one apparatus the chemical conversion and separation of the resulting reaction mixture by rectification, reducing the cost of carrying out the process and increasing the main parameters of the process. As part of the work, the collection and processing of physicochemical information about the components of the reaction mixture was carried out, a mathematical model of the process was developed, based on which the development and modeling of the technological scheme were carried out, the parameters and indicators of the process were determined
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Ivanov, Aleksandr K., Aleksandr L. Savkin, and Ilia V. Chernyshev. "THE MATHEMATICAL MODELS OF INFORMATION DECISIONS IN OPERATIONS CONTROLS." АВТОМАТИЗАЦИЯ ПРОЦЕССОВ УПРАВЛЕНИЯ 63, no. 1 (2021): 56–73. http://dx.doi.org/10.35752/1991-2927-2021-1-63-56-73.
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The article proves the relevance of developing decision-support systems that ensure an automation of intellectual activity of operation controls officers. It gives a brief review of scientific researches in terms of psychology of behavior, perception and thinking; and shows the viability of mathematical models for decision-making based on the analogue ones in other science and technology domains having a corresponding mathematical apparatus. The authors create the scheme of information decisions made by operation controls, which includes several stages of initial data conversion and gradient distribution of information resources in a one-dimensional space of structural units. The complex of mathematical models for information decision making for three stages of conversion and for various modes of initial data entry has been developed. The first model describes the gradient distribution of initial data in the form of a partial differential equation, while converting stages are given as an ordinary differential one. The second model includes the gradient distribution of initial data and subsequently converted data in the space of operating controls. It is represented as a partial differential system. The third and fourth models additionally incorporate convective terms of partial differential equations. The article gives the analytical solutions of all models and the estimated structures of information resources allocation
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Zakharov, M. K., A. V. Egorov, and A. A. Podmetenny. "Liquid mixtures separation and heat consumption in the process of distillation." Fine Chemical Technologies 16, no. 1 (2021): 7–15. http://dx.doi.org/10.32362/2410-6593-2021-16-1-7-15.
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Objectives. The aim of this study is to investigate different distillation modes of a binary ideal mixture and determine how various factors affect heat consumption in the column boilers. In addition, it intends to assess the difficulty of separating mixtures. Our research is based on analyzing the characteristics of vapor-liquid equilibrium.Methods. To conduct our study, we used a graphic-analytical tool to calculate the distillation process of a binary mixture and mathematical models based on the Aspen Plus software package along with DSTWU, RadFrac, and the Sensitivity module. We also used the Peng-Robinson equation (PENG-ROB) to determine the liquid-vapor equilibrium.Results. We employed the graphical method and mathematical models to obtain the operation parameters of two column variants for the distillation of binary ideal benzene-toluene mixtures. In each variant the initial mixture contained the same amount of the low- and high-boiling component. The number of plates in the column sections, reflux ratio, energy consumption, and indicators of internal energy saving were determined.Conclusions. Study results show that using the coefficient of the component distribution between the vapor and liquid phases is a promising method for preliminary assessments of the separation difficulty and measurements of the expected heat consumption in the boilers of columns. Comparison studies showed that the heat consumption in the boiler decreases as the internal energy saving in the columns increases.
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Abramov, D. O., T. N. Shvetsova, and D. I. Nazarenko. "Development of mathematical models of test systems as objects with lumped parameters." Proceedings of the Voronezh State University of Engineering Technologies 82, no. 2 (2020): 42–48. http://dx.doi.org/10.20914/2310-1202-2020-2-42-48.
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This paper deals with the problem of constructing a mathematical model for studying the thermal regime of a test system at the design stage. The test system is presented as a complex chemical-technological system, which includes a large number of elements, components and devices, characterized by a variety of functional and thermal relationships. The block-hierarchical method is used for designing the system under consideration. A thermal block diagram of the system has been developed, which includes six interconnected blocks: a thermostat; coolant; heat exchanger; cubic apparatus, medium in apparatus and environment. A mathematical model has been created to estimate the average temperatures in the system, which allows you to calculate the integral characteristics of heat exchange processes (the values average intake temperatures and the values surface average temperatures, average heat fluxes) taking into account the interaction between all blocks of the system. It was assumed that each element of the system under consideration can have thermal connections, both with the environment and with other elements of the system. It was assumed that the element can dissipate its own power, as well as the power supplied for thermal control of the element, which depends on its temperature. The calculation of the temperature fields of bodies and flows of heat carriers was carried out on the basis of models with concentrated parameters, with the assumption that there are no temperature gradients in all directions. The model is represented by a system of ordinary differential equations. The dependences of temperature on time change for two non-stationary modes of a thermostatic system consisting of a hollow device of cubic shape with a volume 3 m3 filled with gas and equipped with a heat exchanger are shown. The developed mathematical model allows solving the problems of temperature stabilization of the test system.
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Kazaryan, Ruben, Peraskovya Andreeva, and Natalya Galaeva. "Organization of planning in transport construction." E3S Web of Conferences 157 (2020): 04006. http://dx.doi.org/10.1051/e3sconf/202015704006.
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Purpose. Development of methods and models of economic efficiency of the integrated use of various modes of transport in the interests of ensuring national security of the state. Methods. System analysis, logical-mathematical modeling, systems theory, economic-visual modeling, research methods of operations, economic and mathematical methods. Results. The paper discusses the need for the application of economic and mathematical models in the design of transport construction (model of “moving the earth masses”, linear programming model, design of the “red line” on the longitudinal profile, dynamic programming model). Conclusion. The difficult stage of the transition of economic and mathematical analysis from the verbal description of the system process to the elemental base of the mathematical apparatus. Most research models of operations are designed for single criteria. Economic and mathematical modeling allows the effect of “private optimization”.
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Roussev, Roumen. "Mathematical apparatus used in “Method of models” for the study of slider-crank mechanism (RRRP)." Applied Researches in Technics, Technologies and Education 4, no. 3 (2016): 181–85. http://dx.doi.org/10.15547/artte.2016.03.003.
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Dashko, Yuri, Olga Vitchenko, and Maxim Kadomtsev. "Soft models of competence assessment in professional education." E3S Web of Conferences 210 (2020): 18011. http://dx.doi.org/10.1051/e3sconf/202021018011.
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The article presents the results of research on the problem of finding new models for assessing students ' competencies in the context of global trends in modern professional education – the merger of competence and project approaches, the development of e-learning, and the introduction of digital technologies to support expert systems. An original development of one of the soft models of fuzzy multiparametric assessment of competencies is proposed, and the mathematical apparatus of the model is described taking into account the requirements of fuzzy logic.
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Igbagara, Princewill. "DESIGN ADAPTATION OF BATCH CRUDE OIL BOILER FOR CONTINUOUS DISTILLATION OPERATIONS." European Journal of Physical Sciences 4, no. 1 (2021): 49–62. http://dx.doi.org/10.47672/ejps.754.
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Purpose: Boilers are some of the most critical equipment in many production process especially in refinery operations, as it is used in generating steam for different applications. Different types of boilers are available commercially and have comparative advantages over one another. The pot or kettle boiler is the foremost of these equipment and consists of an empty vessel with a secure lid and a burner that is the source of heating. Though overtaken in industrial applications by more modern designs, these simple boilers which are often batch process equipment are still useful for small production processes at low pressures. The work here developed design adaptation of these batch boilers for continuous vaporization of crude oil for artesian refining of the oil.
 Methodology: Physical and assay data of Bonnylight Crude Oil (BLCO) was used for the work from the library of ASPEN Technologies. Simple mathematical models were developed from interpretation of implicit phenomena of the boiler transformation process. The models were validated using ASPEN HYSYS process simulation software Version 10.
 Findings: Computational results of the models and simulation results gave good convergence except for the heat transfer parameter of the model which had almost 100% of the simulation value. Nevertheless, the models have good predictive capabilities
 Recommendation: The design adaption models herein developed can be deployed with reasonable accuracy for the heating of crude oil especially for small artesian operations. However, the study space of the subject matter can be expanded for better accuracy and reliability.
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Neustroev, S. S., V. I. Serdyukov, N. A. Serdyukova, and S. I. Shishkina. "Using Mathematical Models in Event Analysis from Military History." Mathematics and Mathematical Modeling, no. 4 (October 23, 2018): 12–26. http://dx.doi.org/10.24108/mathm.0418.0000134.
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One of the ways of knowing the events of military history is to reproduce them using mathematical models. Based on the analysis of the fighting operations of the 4th Panzer Brigade of the Red Army in the vicinity of the city of Mtsensk in early October 1941, the capability to provide mathematical modeling of the fragments of these combat operations and the application of the apparatus of Markov random processes for these purposes is substantiated.The effectiveness of tanks depends not only on their technical properties, but also on the ways they are used on the battlefield. At the same time, combat effectiveness of tanks is commonly understood as their effectiveness in conditions when the methods of conducting combat operations by each of the opposing sides are the best.The battle outcome is probabilistic. It has certain regularity, depending on the combat tactics. The battle can be imagined as a multitude of randomly dueling fights between tanks, differing in their location and range of fire. A study of the probability of a system transition from each transient state to the next leads to the construction of mathematical models that allow calculating the ratio of losses of opposing sides.Based on the facts of military history and discovered regularities, the mathematical models are constructed to allow reproducing various fragments of combat according to the scheme of the Markov random process, and on their basis calculations are performed. The dependence of the ratio of the losses of the opposing sides depending on the number of firing positions used by the ambush tanks was established, provided that the change of these positions was made imperceptibly for the enemy.The obtained results can be used to develop tactical methods of using tanks in antiterrorist operations.
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Manusov, Vadim, and Javod Ahyoev. "Technical Diagnostics of Electric Equipment with the Use of Fuzzy Logic Models." Applied Mechanics and Materials 792 (September 2015): 324–29. http://dx.doi.org/10.4028/www.scientific.net/amm.792.324.
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The possible technical diagnostics method of electrical power systems (EPS) has been considered, in particular, the electric equipment of substations and electric networks by means of using mathematical apparatus of indistinct sets and fuzzy logic theory. It is shown that on the basis of indistinct expert estimates it is possible to do a prediction for possible causes of failures if preliminary estimates of the failures signs available are known.
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Denny, Mark W., and Ben B. Hale. "Cyberkelp: an integrative approach to the modelling of flexible organisms." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 358, no. 1437 (2003): 1535–42. http://dx.doi.org/10.1098/rstb.2003.1341.
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Biomechanical models come in a variety of forms: conceptual models; physical models; and mathematical models (both of the sort written down on paper and the sort carried out on computers). There are model structures (such as insect flight muscle and the tendons of rats' tails), model organisms (such as the flying insect, Manduca sexta ), even model systems of organisms (such as the communities that live on wave–swept rocky shores). These different types of models are typically employed separately, but their value often can be enhanced if their insights are integrated. In this brief report we explore a particular example of such integration among models, as applied to flexible marine algae. A conceptual model serves as a template for the construction of a mathematical model of a model species of giant kelp, and the validity of this numerical model is tested using physical models. The validated mathematical model is then used in conjunction with a computer–controlled tensile testing apparatus to simulate the loading regime placed on algal materials. The resulting information can be used to create a more precise mathematical model.
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YEZHOV, M. B., and S. B. KOLODINSKYI. "NETWORK MODELS OF REGIONAL ECONOMIC SYSTEMS." Economic innovations 22, no. 2(75) (2020): 34–39. http://dx.doi.org/10.31520/ei.2020.22.2(75).34-39.
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Topicality. Modeling the development of regional economic systems is an urgent task in connection with the decentralization reform of the management system and administrative-territorial structure in Ukraine, which creates new opportunities for the economic development of territories.Aim and tasks. The aim of the article is to model regional economic systems to identify their optimal structure and factors that would most contribute to their development, as well as to study the possibility of applying the mathematical apparatus of graph theory.Research results. The factors contributing to the development of regional economic systems and the link between decentralization and the network structure of the modern economy are identified. The concept of a quasi-fractal economic system is introduced. The possibility of using the apparatus of graph theory to study regional economic systems is shown. Examples of problems associated with the functioning of economic systems that can be formulated and solved in terms of graph theory are given. The role of the population as a link in regional economic systems is investigated. The main parameters characterizing the development of regional economic systems are identified: qualitative complexity and the presence of closed cycles. The role of topological sorting in the study of the structure of economic systems is revealed. The relationship between the territorial-administrative units and the structure of regional economic systems is indicated.Conclusion In the study of regional economic systems, a structural approach using the graph theory apparatus is quite effective. It allows to formulate and solve problems associated with the modeling of these systems.The study of the structural properties of economic systems will reveal the patterns of development of socio-economic systems and predict this development.
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Nicolae, Marilena, and Costin Sorin Bîldea. "Isobaric Vapor Liquid Equilibrium Determination for 1,3,5-Trimethylbenzene + Ethanol and 1,3,5-Trimethylbenzene + n-Butanol Binary Systems." Periodica Polytechnica Chemical Engineering 64, no. 4 (2019): 446–56. http://dx.doi.org/10.3311/ppch.14526.
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The vapor-liquid equilibrium data are necessary for the design of the distillation columns which separate the mixture mesitylene – ABE components resulting from the liquid-liquid extraction of butanol from the ABE using 1,3,5-trimethylbenzene as solvent. In this work, the vapor - liquid equilibrium data is determined for the binary systems: ethanol + 1,3,5-trimethylbenzene and n-butanol + 1,3,5-trimethylbenzene at constant pressure of 93.325 KPa using a double phase circulation apparatus. Thus, P-T-x-y data is determined, which is further processed by regression to determine the binary interaction parameters of the NRTL and UNIQUAC models. Furthermore, the T-x-y diagrams are calculated using the completed thermodynamic models (NRTL and UNIQUAC) and the UNIFAC predictive model, and compared with the experimental diagrams.
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Roussev, Roumen. "Mathematical apparatus used in “Method of models” for the study of four-bar linkage mechanism (RRRR)." Applied Researches in Technics, Technologies and Education 4, no. 3 (2016): 186–90. http://dx.doi.org/10.15547/artte.2016.03.004.
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Al-Hotmani, Omer Mohamed Abubaker, Mudhar Abdul Alwahab Al-Obaidi, Yakubu Mandafiya John, Raj Patel, and Iqbal M. Mujtaba. "Scope and Limitations of the Mathematical Models Developed for the Forward Feed Multi-Effect Distillation Process—A Review." Processes 8, no. 9 (2020): 1174. http://dx.doi.org/10.3390/pr8091174.
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Desalination has become one of the obvious solutions for the global water crisis due to affording high-quality water from seawater and brackish water resources. As a result, there are continuing efforts being made to improve desalination technologies, especially the one producing high-quantity freshwater, i.e., thermal desalination. This improvement must be accomplished via enhancement of process design through optimization which is implicitly dependent on providing a generic process model. Due to the scarcity of a comprehensive review paper for modeling multi-effect distillation (MED) process, this topic is becoming more important. Therefore, this paper intends to capture the evolution of modeling the forward feed MED (most common type) and shed a light on its branches of steady-state and dynamic modeling. The maturity of the models developed for MED will be thoroughly reviewed to clarify the general efforts made highlighting the advantages and disadvantages. Depending on the outputs of this review, the requirements of process development and emerging challengeable matters of modeling will be specified. This, in turn, would afford a possible improvement strategy to gain a reliable and sustainable thermal desalination process.
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Al-Ma’aitah, Mohammed, Aldosary Saad, and Ayed Alwadain. "Modeling of the Schemes for Organizing a Session of Person–System Interactions in the Information System for Critical Use Which Operates in a Wireless Communication Environment." Symmetry 13, no. 3 (2021): 391. http://dx.doi.org/10.3390/sym13030391.
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In this article, for the first time, a new mathematical model of the schemes for organizing a session of person–system interactions between the registration center server of the information system for critical use (ISCU) and the terminal of the person-user in a wireless communication environment are presented. In contrast to the existing literature, this article uses the mathematical apparatus of queuing systems to describe the schemes of organizing the stochastic process of a session of person–system interaction in discrete or continuous time, namely, models of the type Geo/Geo/1 with group arrival and ordinary service for the case of discrete representation of time and models of the type M/G/1 for the case of continuous time representation. The use of the mathematical apparatus of queuing systems in the studies made it possible to obtain analytical expressions for comparing formalized schemes for organizing the person–system interaction according to such functional characteristics as the average time of downloading a finite number of data blocks into the terminal of the target person-user (average time that the request spent the server of the information system).
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Vasylieva, Natalia, and John R. Kruse. "Models on providing food security: case of Ukraine." Problems and Perspectives in Management 16, no. 4 (2018): 344–52. http://dx.doi.org/10.21511/ppm.16(4).2018.28.
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Providing food security is a top issue of agricultural economics in a global scale. Although Ukraine helps other countries become more food secure through its exports of wheat, corn, barley, and sunflower, low per capita income levels create challenges for Ukrainians to keep their diet nutrition balance in animal food basket. The research objective supposed applying mathematical apparatus to support solving this problem. The offered consumption optimization model has been developed to ensure inelastic customers’ food preferences by animal products subject to income and calories constraints. The proposed econometric models have been designed to project broiler, pork, eggs, milk, and beef productions. Complex implementation of the set mathematical models maintained the tool to analyze scenarios by expected export/import and demands for grain and oilseed crops used for feed in animal husbandry. The results of this research provide state authorities, livestock and poultry producers, Ukrainian consumers and other interested parties with management guidance focused on developing animal husbandry in the presence of income, as well as animal product price variability.
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KUPRIKOV, Mikhail Yu, and Leonid V. MARKIN. "Method of formalizing the layout of the internal compartments of aircraft." INCAS BULLETIN 11, S (2019): 143–52. http://dx.doi.org/10.13111/2066-8201.2019.11.s.14.
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The mathematical formulation of the aircraft’s internal layout problem is described as an optimization problem, with an indication of its objective function, constraints, and performance criteria. The approach (receptor methods and apparatus of normal equations) is justified, which makes it possible to move from enumeration method of placing added objects to intelligent algorithms of automated placement when creating geometric models of automated layout. It was shown that preparing the aircraft for layout automation complicates the mathematical description of geometric models of added objects, increases the complexity of their visualization in modern computer graphics systems and makes the need to create an additional interface between new geometric models and common CAD systems (SolidWorks, AutoCAD, COMPAS, etc.).
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Velychko, Oleh, and Oleh Hrabovskyi. "The mathematical model of the system-oriented measuring instrument." Ukrainian Metrological Journal, no. 2 (July 2, 2021): 15–19. http://dx.doi.org/10.24027/2306-7039.2.2021.236057.
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Modern measuring instruments (MIs) are designed to obtain complete and reliable measuring information. To perform this important function, MIs must be of appropriate quality and must be reliably assessed. Using mathematical models simulate the operation of technical systems in order to decide on the optimization of its characteristics. As a result of the analysis of the model, the specific features of the studied processes and certain quantitative regularities are established. This allows to predict the processes in the system over time and determine their quantitative characteristics.
 The article presents the results of mathematical modeling of system-oriented measuring instruments as a system and its software as a subsystem using the apparatus of general systems theory. Such models with its graphical interpretation allow obtaining the necessary and useful information about the properties of the MIs as a technical system. The performed modeling makes it possible to describe the functioning of the MIs and to obtain a certain assessment of quality indicators.
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Lewiński, Andrzej, and Tomasz Perzyński. "Telematics as a future method for improving the safety of rail transport." Transportation Overview - Przeglad Komunikacyjny 2019, no. 9 (2019): 1–9. http://dx.doi.org/10.35117/a_eng_19_09_01.
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The paper shows how the development of telematics systems affects the field of railway traffic management and control. It presents current and future solutions that can significantly improve safety. A mathematical apparatus in the form of Markov processes was proposed for analysis. Keywords: Rail systems; Safety; Models of the systems
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Grigorov, Otto, Evgenij Druzhynin, Galina Anishchenko, Marjana Strizhak, and Vsevolod Strizhak. "Analysis of Various Approaches to Modeling of Dynamics of Lifting-Transport Vehicles." International Journal of Engineering & Technology 7, no. 4.3 (2018): 64. http://dx.doi.org/10.14419/ijet.v7i4.3.19553.
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The results of analytical and numerical modeling of dynamic characteristics of linear and non-linear mathematical models of the “trolley-load” system of bridge and container cranes are presented. KiDyM software complex is used for numerical modeling, which, based on the use of the apparatus of structural matrices and the built-in computer algebra system, allows the construction of ordinary differential equations of motion of the class of systems under consideration at the analytical level. Recommendations on the possible use of the considered mathematical models of the “trolley-load” system in various regular and forced operation modes of bridge and container cranes are given on the basis of the analysis. The ratio of the results of calculations for various design models of regular and forced operation of the bridge crane has been established. The magnitude of the distribution of the maximum values of the dynamic characteristics of motion of the container crane has been designed by calculating the forced operation mode using various mathematical models.
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Diaby, Abdullatif Lacina, Lee Luong, Amer Yousef, and Jonas Addai Mensah. "A Review of Optimal Scheduling Cleaning of Refinery Crude Preheat Trains Subject to Fouling and Ageing." Applied Mechanics and Materials 148-149 (December 2011): 643–51. http://dx.doi.org/10.4028/www.scientific.net/amm.148-149.643.
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Refinery crude preheat train (CPHT) is prone to fouling and ageing effects due to the complexity of processed crude feedstock preheated prior to distillation. This has serious implications on the thermal and hydraulic performance of the CPHT. As a result, efficient performance of crude preheat trains is compromised and as such, optimal scheduling cleaning operations are required to restore performance. In this paper, we attempt to review the subject of fouling/ageing control and mitigation in crude preheat train network by optimal scheduling cleaning approach. Three prominent optimisation techniques/models namely Mathematical Models (Mixed integer linear programming (MILP) and Mixed integer non-linear programming (MINLP) models); Artificial Intelligence (AI) Models; and Heuristic Techniques used for achieving optimal cleaning are outlined.
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Petukhov, Alexandr. "Modeling Cognitive Activity of the Human Brain by the Mathematical Apparatus of Quantum Mechanics." EPJ Web of Conferences 248 (2021): 01024. http://dx.doi.org/10.1051/epjconf/202124801024.
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This paper discusses the possible approaches to modeling the cognitive activity of the human brain using the mathematical apparatus of quantum mechanics (primarily – potential wells and virtual particles) in terms of the theory of information representations. The article briefly describes the proposed theory of information representations, draws analogies, and identifies common features of information representations of the human mind and Feynman’s virtual particles. The human mind is represented as a one-dimensional potential well with finite walls of different sizes and internal potential barrier simulating the boundary between consciousness and subconsciousness. This creates a foundation for a mathematical apparatus that can make it possible to forecast particular cognitive functions of the human brain. The results of these studies can be used to create predictive models of various cognitive disorders (diseases) and to be used in diagnostics.
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Yakovenko, Irina. "Fuzzy Stochastic Automation Model for Decision Support in the Process Inter-Budgetary Regulation." Mathematics 9, no. 1 (2020): 67. http://dx.doi.org/10.3390/math9010067.
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The purpose of this article is to study the theoretical foundations of the concept of fiscal decentralization, as the main path of self-development of the national economy of any country, and to develop mathematical tools that support decision-making in the aspect of “hard” budget constraints. The study of the problems of fiscal policy formation in foreign countries presented in modern scientific literature has revealed that the degree of application of the concepts of “soft” and “hard” budget restrictions is an actual topic in the theory of fiscal federalism. It has been substantiated that decision-making within the framework of “soft” budget constraints (financial assistance) leads to low tax autonomy of territories and limited liability of regional and municipal authorities for the results of their financial policy. As a research hypothesis, we put forward the thesis that it is necessary to create conditions for encouraging subnational authorities to support the territorial economy by granting them the possibility to use part of the taxes collected in the respective territories. The implementation of this thesis has given rise to the problem of quantifying decisions made regarding the establishment of standards for the distribution of tax revenues between budgets of different levels of the hierarchy of the country’s budget system. In terms of solving this problem, the author has constructed mathematical models based on the use of synthesis of mathematical apparatus of the theory of stochastic automata, fuzzy algebra, and simulation. In terms of solving this problem, the author proposed the use of mathematical modeling methods. The article presents the results of constructing economic and mathematical models to support decision-making in the vertical distribution of tax revenues between budgets. The models include stochastic automata, as mathematical abstractions, describing the expedient behavior of an economic agent when choosing management alternatives for territories of different levels of economic development. The transition functions of automaton models are formally described on the basis of the synthesis of mathematical apparatus of the theories of stochastic automata operating in random environments and fuzzy sets. The expediency property of the behavior of automaton models is justified by proving the corresponding theorems. The random environment in which stochastic automata are immersed is formed by a simulation model. The article demonstrates the results of experiments carried out on models, as well as a conceptual scheme of interaction between the automaton and simulation models.
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Vukobratović, M. K., V. F. Filaretov, and A. I. Korzun. "A unified approach to mathematical modelling of robotic manipulator dynamics." Robotica 12, no. 5 (1994): 411–20. http://dx.doi.org/10.1017/s0263574700017963.
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SUMMARYA new method for computer forming of dynamic equations of open-chain mechanical robot configurations is presented. The algorithm used is of a numeric-iterative type, based on mathematical apparatus of screw theory, which has enabled elimination of the unnecessary computations in the process of dynamic model derivation. In addition to conventional kinematic schemes of robotic manipulators, the branched kinematic chains which have recently found their application in the locomotion of robotic mechanisms were also treated. Both the inverse and direct problems of dynamics were addressed. A comparative analysis was carried out of the numerical complexity of various existing algorithms of numeric-iterative type dealing with the problems of spatial active mechanisms dynamics. It has been shown that the proposed method regardless of its generality, approaches by its models complexity symbolic models, which are valid for particular robotic mechanisms only where they achieve a high degree of efficiency.
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Bottiglione, F., and G. Mantriota. "Field tests and validation of dynamical models of tank vehicles Part I: mathematical model and experimental apparatus." International Journal of Heavy Vehicle Systems 19, no. 1 (2012): 1. http://dx.doi.org/10.1504/ijhvs.2012.045757.
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Paulin, Michael G., and Larry F. Hoffman. "Models of vestibular semicircular canal afferent neuron firing activity." Journal of Neurophysiology 122, no. 6 (2019): 2548–67. http://dx.doi.org/10.1152/jn.00087.2019.
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Semicircular canal afferent neurons transmit information about head rotation to the brain. Mathematical models of how they do this have coevolved with concepts of how brains perceive the world. A 19th-century “camera” metaphor, in which sensory neurons project an image of the world captured by sense organs into the brain, gave way to a 20th-century view of sensory nerves as communication channels providing inputs to dynamical control systems. Now, in the 21st century, brains are being modeled as Bayesian observers who infer what is happening in the world given noisy, incomplete, and distorted sense data. The semicircular canals of the vestibular apparatus provide an experimentally accessible, low-dimensional system for developing and testing dynamical Bayesian generative models of sense data. In this review, we summarize advances in mathematical modeling of information transmission by semicircular canal afferent sensory neurons since the first such model was proposed nearly a century ago. Models of information transmission by vestibular afferent neurons may provide a foundation for developing realistic models of how brains perceive the world by inferring the causes of sense data.
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Khabarov, I. А., V. V. Zhurov, А. N. Zhabayeva, and S. М. Adekenov. "Modeling the extraction process of medicinal raw materials." Bulletin of the Karaganda University. "Chemistry" series 100, no. 4 (2020): 135–44. http://dx.doi.org/10.31489/2020ch4/135-144.
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The review considers 26 mathematical models of the process of biologically active substances extraction from medicinal plant raw materials, taking into account factors affecting the extraction process: diffusion coefficient, particle size, layer porosity, extractant feed rate, raw material grinding method, pressure, temperature and duration of extraction, individual characteristics of raw materials (content of the target component) and technological equipment. In general, these models fall into four important groups: empirical models, models based on heat transfer analogies, a shrinking core model, and models based on differential mass bal-ance. Here were described problems that occur in the selection of mathematical models, first of all, associated with the imperfect behavior of the flows of extraction liquids, and the inhomogeneous cross-section of the extraction apparatus. It was shown that first of all the extraction process modeling requires mathematical models to describe the mass transfer inside solid particles. It is also important to take into account the solubility of the target substances when simulating. It is shown that for describing the extraction processes, the optimal models are Naik and Lentz, Esquivel, diffusion, H. Sovová mass transfer, damaged and undamaged cells for calculating the main factors of extraction processes.
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Rubio, Eduardo, José Luis Fernández-Zayas, and Miguel A. Porta-Gándara. "Current Status of Theoretical and Practical Research of Seawater Single-Effect Passive Solar Distillation in Mexico." Journal of Marine Science and Engineering 8, no. 2 (2020): 94. http://dx.doi.org/10.3390/jmse8020094.
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Solar distillation is a practical alternative for freshwater production in arid zones where seawater is abundant. The attractiveness of this approach resides in the simplicity of the solar still, equipment used to produce saline-free water for drinking, intensive agriculture, domestic use and other purposes. A solar still is an apparatus exposed to solar radiation that consists essentially of a basin with a solar collector where saline water is deposited and covered with a transparent inclined glass plate. The system operates as a greenhouse where the heated seawater evaporates and condensates on the inner surface of the cover. The distillate yield is collected in an external container. A research group in Mexico has been working for years doing research on the process of freshwater production with solar stills. Various research aspects have been addressed, among which are mathematical modeling of the physical phenomenon, practical research by building solar stills with different geometries and sizes, and the proposal of a process for mass-production manufacturing of solar stills with technology innovations. This paper is an overview of some of the most relevant results obtained by these research efforts.
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Zhani, Khalifa, and Khaled Ali Abuhasel. "Modeling, Simulation, and Optimization of a Solar-Based System of Desalination Using Humidification and Dehumidification." Applied Sciences 10, no. 10 (2020): 3361. http://dx.doi.org/10.3390/app10103361.
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Solar desalination systems are characterized by low freshwater production compared with the usual techniques of mineral and salt removal from water. The usual methods include, but are not limited to, multi-stage flash distillation, multiple-effect distillation, vapor-compression desalination, and reverse osmosis. Solar desalination requires various modifications to make it more productive than the usual methods. The method is suitable for energy and environmental protection, making it the most effective system. The adjustments involve using the humidification and dehumidification principle (HD). The three configurations of the HD solar desalination system in this project are designed to accommodate variations in climate conditions and seasonal changes. Mathematical models are designed to test the workability of the system in an ideal environment. The models are based on universal fluid equations that regulate the functioning of each component of the system. After the model is designed, a regulation algorithm is designed based on the model. The simulation results show that the gain in freshwater production using a regulation algorithm is in the order of 33%.
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El-Saify, M. H., A. M. El-Garhy, and G. A. El-Sheikh. "Brain Emotional Learning Based Intelligent Decoupler for Nonlinear Multi-Input Multi-Output Distillation Columns." Mathematical Problems in Engineering 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/8760351.
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The distillation process is vital in many fields of chemical industries, such as the two-coupled distillation columns that are usually highly nonlinear Multi-Input Multi-Output (MIMO) coupled processes. The control of MIMO process is usually implemented via a decentralized approach using a set of Single-Input Single-Output (SISO) loop controllers. Decoupling the MIMO process into group of single loops requires proper input-output pairing and development of decoupling compensator unit. This paper proposes a novel intelligent decoupling approach for MIMO processes based on new MIMO brain emotional learning architecture. A MIMO architecture of Brain Emotional Learning Based Intelligent Controller (BELBIC) is developed and applied as a decoupler for 4 input/4 output highly nonlinear coupled distillation columns process. Moreover, the performance of the proposed Brain Emotional Learning Based Intelligent Decoupler (BELBID) is enhanced using Particle Swarm Optimization (PSO) technique. The performance is compared with the PSO optimized steady state decoupling compensation matrix. Mathematical models of the distillation columns and the decouplers are built and tested in simulation environment by applying the same inputs. The results prove remarkable success of the BELBID in minimizing the loops interactions without degrading the output that every input has been paired with.
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Yarygina, I. Z., V. B. Gisin, and B. A. Putko. "Fractal Asset Pricing Models for Financial Risk Management." Finance: Theory and Practice 23, no. 6 (2019): 117–30. http://dx.doi.org/10.26794/2587-5671-2019-23-6-117-130.
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The article presents the analysis findings of the problems and prospects of using the fractal markets theory to mathematically predict the price dynamics of assets as part of a financial risk management strategy. The aim of the article is to find out the features of value of bank assets and to develop recommendations for assessing financial risks based on mathematical methods for forecasting economic processes. Theoretical and empirical research methods were used to achieve the aim. The article reveals the features of mathematical modeling of economic processes related to asset pricing in a volatile market. It was proved that using financial mathematics in banking contributes to the stable development of the economy. Mathematical modeling of the price dynamics of financial assets is based on a substantive hypothesis and supported by an adequate apparatus of fractal pair pricing models in order to reveal specific market relations of business entities. According to the authors, the prospects of using forecast models to minimize the financial risks of derivative financial instruments are positive. The authors concluded that the considered methods contribute to managing financial risks and improving forecasts, including operations with derivatives. Besides, the studied fractal volatility parameters proved the predictive power regarding extreme events in financial markets, such as the bankruptcy of Lehman Brothers investment bank in 2008. The relevance of the article is due to the fact that the favorable investment climate and the use of modern financing methods largely depend on the effective financial risk management.
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Grzywacz, Robert. "Continuous mathematical models of airlift bioreactors: Families, affinity, diversity and modelling for single-substrate kinetics." Chemical and Process Engineering 33, no. 2 (2012): 291–309. http://dx.doi.org/10.2478/v10176-012-0027-9.
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Continuous mathematical models of airlift bioreactors: Families, affinity, diversity and modelling for single-substrate kinetics This paper presents a method of describing an airlift bioreactor, in which biodegradation of a carbonaceous substrate described by single-substrate kinetics takes place. Eight mathematical models based on the assumption of liquid plug flow and axial dispersion flow through the riser and the downcomer in the reactor were proposed. Additionally, the impact of degassing zone with assumed complete mixing on the obtained results was analyzed. Calculations were performed for two representative hydrodynamic regimes of reactor operation, i.e. with the presence of gas bubbles only within the riser and for complete gas circulation. The conclusions related to the apparatus design and process performance under sufficient aeration of the reaction mixture were drawn on the basis of the obtained results.
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Saito, Tatsunori, Masanari Asano, Takashi Matsuoka, and Masanori Ohya. "Separability Conditions for a Subclass of Circulant States in Two-Qutrit System and Quasi-Distillation of Entanglement." Open Systems & Information Dynamics 20, no. 03 (2013): 1340006. http://dx.doi.org/10.1142/s1230161213400064.
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We will show the necessary and sufficient condition of separability for a sub-class of circulant states in the ℂ3 ⊗ ℂ3 system. This sub-class includes the models proposed by several authors as special cases. Moreover, it will be proved that our separability condition equals to the failure condition of quasi-distillation of entanglement.