computer experiment
Recently Published Documents


TOTAL DOCUMENTS

332
(FIVE YEARS 67)

H-INDEX

23
(FIVE YEARS 2)

Informatics ◽  
2021 ◽  
Vol 18 (4) ◽  
pp. 17-25
Author(s):  
A. N. Markov ◽  
R. O. Ihnatovich ◽  
A. I. Paramonov

Objectives. The authors aimed to demonstrate the need for implementation of video conferencing service into the learning process, to select a video conferencing service, and to conduct a computer experiment with the selected BigBlueButton video conferencing service.Methods. The problems of choosing a video conferencing service from the list of video conferencing and video conferencing software are considered. At the stage of software selection, the features of its operation, requirements for hardware and for integration into internal information systems are indicated. Load testing of the video conferencing service was carried out by the method of volume and stability testing.Results. The load graphs for hardware components of the virtual server in the long term period are presented. The article describes the results of the graphs analysis in order to identify the key features of the video conferencing service during the test and trial operations.Conclusion. Taking into account the cost of licensing, as well as integration into the e-learning system, a choice of video conferencing service was made. A computer experiment was carried out with the selected BigBlueButton video conferencing service. The features of the hardware operation of the virtual server (on which the BigBlueButton system is located) have been determined. The load graphs for the central processing unit, random access memory and local computer network are presented. Problems of service operation at the stage of load increase are formulated.


Author(s):  
Дмитрий Викторович Иванов ◽  
Виталий Александрович Анофриев ◽  
Владимир Александрович Кошелев ◽  
Александр Сергеевич Антонов ◽  
Сергей Александрович Васильев ◽  
...  

В данной работе методом молекулярной динамики с использованием потенциала сильной связи проведено моделирование процесса молекулярно-лучевой эпитаксии с целью определения закономерностей при формировании фрактальных металлических пленок платины на поверхности родия. Установлена возможность формирования фрактальных структур как в островковых пленках платины на поверхности родия, так и в сплошной пленке. Установлены параметры компьютерного эксперимента, определяющие переход от отдельных островковых пленок к сплошной пленке в указанной системе. С использованием различных программных продуктов Gwyddion и Image Analysis, а также собственной разработки FractalSurface проанализирован диапазон изменения фрактальной размерности при различных условиях молекулярно-динамического эксперимента методом подсчета кубов. Полученные значения фрактальной размерности в целом находятся в приемлемом согласии между собой, однако существует ряд исключений, которые обсуждаются более подробно. Сравнительный анализ получаемых результатов позволяет формулировать рекомендации для методики создания, корректировки и прецизионного контроля при «выращивании» структур с заданной морфологией поверхности. In this work, the molecular dynamics method and the tight-binding potential are used to simulate the process of molecular beam epitaxy in order to determine the regularities in the formation of fractal platinum metal films on the rhodium surface. The possibility of formation of fractal structures both in island platinum films on the rhodium surface and in a continuous film has been established. The parameters of the computer experiment, which determine the transition from individual island films to a continuous film in the indicated system, have been established. Using various software products Gwyddion and Image Analysis, as well as our own software FractalSurface, the range of changes in the fractal dimension has been analyzed under various conditions of a molecular dynamics experiment by the method of cube counting. The obtained values of the fractal dimension are generally in acceptable agreement with each other; however, there is a number of exceptions, which are discussed in more detail. A comparative analysis of the results obtained allows one to formulate recommendations for the methodology for creating, adjusting and precision control when «growing» structures with a given surface morphology.


2021 ◽  
Vol 6 (4 (114)) ◽  
pp. 21-27
Author(s):  
Vasyl Lytvyn ◽  
Roman Peleshchak ◽  
Ivan Peleshchak ◽  
Oksana Cherniak ◽  
Lyubomyr Demkiv

Large enough structured neural networks are used for solving the tasks to recognize distorted images involving computer systems. One such neural network that can completely restore a distorted image is a fully connected pseudospin (dipole) neural network that possesses associative memory. When submitting some image to its input, it automatically selects and outputs the image that is closest to the input one. This image is stored in the neural network memory within the Hopfield paradigm. Within this paradigm, it is possible to memorize and reproduce arrays of information that have their own internal structure. In order to reduce learning time, the size of the neural network is minimized by simplifying its structure based on one of the approaches: underlying the first is «regularization» while the second is based on the removal of synaptic connections from the neural network. In this work, the simplification of the structure of a fully connected dipole neural network is based on the dipole-dipole interaction between the nearest adjacent neurons of the network. It is proposed to minimize the size of a neural network through dipole-dipole synaptic connections between the nearest neurons, which reduces the time of the computational resource in the recognition of distorted images. The ratio for weight coefficients of synaptic connections between neurons in dipole approximation has been derived. A training algorithm has been built for a dipole neural network with sparse synaptic connections, which is based on the dipole-dipole interaction between the nearest neurons. A computer experiment was conducted that showed that the neural network with sparse dipole connections recognizes distorted images 3 times faster (numbers from 0 to 9, which are shown at 25 pixels), compared to a fully connected neural network


2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Dongqing Wu ◽  
Yunong Zhang

The time-variant matrix inversion (TVMI) problem solving is the hotspot of current research because of its frequent appearance and application in scientific research and industrial production. The generalized inverse problem of singular square matrix and nonsquare matrix can be related to Penrose equations (PEs). The PEs implicitly define the generalized inverse of a known matrix, which is of fundamental theoretical significance. Therefore, the in-depth study of PEs might enlighten problem solving of TVMI in a foreseeable way. For the first time, we construct three different matrix error-monitoring functions based on PEs and propose the corresponding models for TVMI problem solving by using the substitution technique and ZNN design formula. In order to facilitate computer simulation, the obtained continuous-time models are discretized by using ZTD (Zhang time discretization) formulas. Furthermore, the feasibility and effectiveness of the novel Zhang neural network (ZNN) multiple-multiplication model for matrix inverse (ZMMMI) and the PEs-based Getz–Marsden dynamic system (PGMDS) model in solving the problem of TVMI are investigated and shown via theoretical derivation and computer simulation. Computer experiment results also illustrate that the direct derivative dynamics model for TVMI is less effective and feasible.


2021 ◽  
Vol 2066 (1) ◽  
pp. 012081
Author(s):  
Jianqing Deng

Abstract With the development of the era of big data and the continuous updating of computer technology, the traditional teaching is not satisfied with the current diversified educational development concept, especially for the computer operation class, computer operation has become the mainstream of the current computer experiment class.With the increasing number of computer experiments and the extensive use of computers in open laboratories, how to manage computer experiments reasonably has become an urgent problem. The function of the computer is powerful, and students have different habits of using the computer, and the entertainment function of the computer is also loved by many students. Therefore, in the process of experiment, students often play games and watch movies, which is not easy to manage. In order to solve these problems, this paper studies the computer experiment management system under the virtual environment to help teachers manage the experiment process. This paper studies the function modules of the computer experiment management system, explains the key elements of the analysis of the implementation of the experiment management system, and explains the construction scheme of the virtual experiment teaching environment, and expounds the ant colony algorithm used in the design and management of the course scheduling system. This paper also analyzes the operation and load of computer experiment management through simulation experiment research, and tests and analyzes to prove the rationality of the management system. The experimental research shows that in the daily computer experiment management system, the most commonly used is the experimental teaching, and the conventional office, accounting for 27.35 and 26.33 respectively. The highest utilization rate of the computer experiment system is the daily teaching, accounting for 53.6%.


Author(s):  
С.А. Желтов ◽  
Н.Н. Чупятов

Процесс нанесения покрытий на поверхности является одним из важнейших при нанесении защитных слоев. Особенно актуальным является метод молекулярно-лучевой эпитаксии, который применяют, например, для нанесения покрытий металлов и полимеров на металлические поверхности. Однако при производстве установок необходимо провести много предварительных экспериментов для получения максимально однородных напыленных поверхностей: размеры кювет, уровень расплава в кювете, расстояния до напыляемой поверхности и расположения системы кювет. Упрощением проведения этих реальных экспериментов является метод Монте-Карло. Моделируя компьютерные эксперименты с предполагаемыми параметрами установки, можно быстро получить необходимый результат с высокой точностью. В каждом компьютерном эксперименте разыгрывался вылет N = 108 частиц (атомов, молекул), что обеспечивало получение всех результатов с высокой точностью. Было установлено, что результаты расчетов не зависят от масс частиц. Анализ полученных данных позволил установить, что частицы, испарявшиеся с поверхности расплава по равновероятному закону и по закону косинуса, имеют близкие распределения, отличающиеся не более чем на 10%. Увеличение расстояния от верхнего края пластины до напыляемой плоскости с расстояния G = 0,01 м до расстояния G = 0,05 м приводит к тому, что плотность распределения для первого случая, имеющая значительный максимум около середины кюветы, становится практически равномерным распределением во втором случае. Применение метода Монте-Карло для процессов напыления в вакууме эффективно использовать не только для плоских поверхностей, но и на поверхности произвольных форм, например, цилиндрических. The coating process on surfaces is one of the most important in the application of protective layers. Particularly relevant is the method of molecular beam epitaxy, which is used, for example, for the deposition of coatings of metals and polymers on metal surfaces. However, in the manufacture of installations, it is necessary to carry out many preliminary experiments to obtain the most homogeneous sprayed surfaces: the dimensions of the cuvettes, the level of the melt in the cuvette, the distance to the sprayed surface and the location of the cuvette system. A simplification of these real-world experiments is the Monte Carlo method. By simulating computer experiments with the expected parameters of the installation, it is possible to quickly obtain the required result with high accuracy. In each computer experiment, the emission of N = 108 particles (atoms, molecules) was played, which ensured obtaining all results with high accuracy. It was found that the calculation results do not depend on the particle masses. An analysis of the data obtained made it possible to establish that the particles evaporated from the surface of the melt according to the equiprobable law and according to the cosine law have similar distributions differing by no more than 10%. An increase in the distance from the upper edge of the plate to the sprayed plane from a distance of G = 0.01 m to a distance of G = 0.05 m leads to the fact that the distribution density for the first case, which has a significant maximum near the middle of the cell, becomes an almost uniform distribution in the second case. ... The use of the Monte Carlo method for vacuum deposition processes can be effectively used not only for flat surfaces, but also on surfaces of arbitrary shapes, for example, cylindrical ones.


2021 ◽  
Vol 11 (3) ◽  
pp. 121-129
Author(s):  
Mikhail Drapalyuk ◽  
Leonid Bukhtoyarov ◽  
A. Pridvorova

Brush cutters are used in forestry for the care of forest plantations in operations for cutting unwanted tree and shrub vegetation (TSV). Rotors can be used as working bodies. The rotor we are considering is a flywheel, on the outer sides of which the blades are hinged. When cutting DKR with blades, a cutting moment arises, which is transmitted through the knife to the axis of its rotation and then to the shaft driving the flywheel. When designing a brush cutter structure, the impact from the cutting forces of the DKR is decisive for the choice of drive power and rotor parameters. We designed the brush cutter rotor in CAD Solidworks to study the cutting process of the DKR. Its geometric and mass parameters were set; the kinematic links of the links were established. The input motion characteristics were set in the Motion Solidworks module and the cutting moment was applied to the knives. Virtual sensors were installed on the model to record movement characteristics. As a result of a computer experiment for three options, which differ in cutting force and the presence of a damper, the trajectories of the knives and the power consumption of the drive were established


Author(s):  
Maxim Polyakov ◽  
◽  
Illarion Popov ◽  
Alexander Losev ◽  
Alexander Khoperskov ◽  
...  

This work was done with the aim of developing the fundamental breast cancer early differential diagnosis foundations based on modeling the spacetime temperature distribution using the microwave radiothermometry method and obtained data intelligent analysis. The article deals with the machine learning application in the microwave radiothermometry data analysis. The problems associated with the construction mammary glands temperature fields computer models for patients with various diagnostics classes, are also discussed. With the help of a computer experiment, based on the machine learning algorithms set (logistic regression, naive Bayesian classifier, support vector machine, decision tree, gradient boosting, Knearest neighbors, etc.) usage, the mammary glands temperature fields computer models set adequacy.


Author(s):  
Т.А. Апалько ◽  
М.Х. Най

В статье описана математическая модель проектирования барже-буксирного комплекса с учётом особенности эксплуатации в условиях Республики Союз Мьянма. В статье исследуются особенности ББК как объекта оптимизации, описана математическая модель ББК, отображается его как сложную техническую систему. В рамках модели приведены математические зависимости и алгоритмы для определения элементов теоретического чертежа, мощности главных двигателей, для решения некоторых вопросов общего расположения с учетом расстояния главных водонепроницаемых переборок корпуса, для расчета нагрузки и устойчивости. Метод комплексной оценки эффективности применения барже-буксирного комплекса на стадии технико-экономического обоснования проекта в условиях развивающихся стран, в частности в условиях Республики Союз Мьянмы. В результате работы были полностью определены параметры основных типов барже-буксировочных комплексов для перспективной системы внутреннего водного транспорта Республики Союза Мьянма. На базе методов случайного поиска создан алгоритм оптимизации элементов ББК, решающий задачу математического программирования с процедурным характером функции критерия и функциональных ограничений. Математическая модель и алгоритм оптимизации реализованы в виде программы для обеспечения компьютерного эксперимента. Программа, реализующая математическую модель проектирования ББК, состоит из отдельных программных модулей, что облегчает ее совершенствование в анализе результатов решения задачи. Создан программный комплекс с использованием языка программирования Паскаль в среде Delphi для обеспечения автоматизирования проектирования. Указанные программы могут быть использованы в исследовательском проектировании на начальных стадиях проектирования. The article describes a mathematical models for designing a barge-towing complex, taking into account the peculiarities of operation in the conditions of the Republic of the Union of Myanmar. The article examines the features of the BBK as an object of optimization, describes the mathematical model of the BBK, displays it as a complex technical system. Within the framework of the model, mathematical dependencies and algorithms are given for determining the elements of the theoretical drawing, the power of the main engines, for solving some issues of the general location, taking into account the distance of the main watertight bulkheads of the hull, for calculating the load and stability. The method of comprehensive assessment of the effectiveness of the use of the barge-tow complex at the stage of the feasibility study of the project in the conditions of developing countries, in particular in the conditions of the Republic of the Union of Myanmar. As a result of the work, the parameters of the main types of barge-towing complexes for the prospective inland water transport system of the Republic of the Union of Myanmar were fully determined. On the basis of random search methods, an algorithm for optimizing the BBK elements is created, which solves the problem of mathematical programming with the procedural nature of the criterion function and functional constraints. The mathematical model and the optimization algorithm are implemented as a program to provide a computer experiment. The program that implements the mathematical model of the design of the BBK consists of separate program modules, which facilitates its improvement in the analysis of the results of solving the problem. A software package was created using the Pascal programming language in the Delphi environment to provide design automation. These programs can be used in research design at the initial stages of design.


Author(s):  
Leonid Gorbunov ◽  
Nadiia Larintseva ◽  
Oksana Zviahintseva

When conducting biotechnological field studies using plant objects, there is a problem of taking into account the heterogeneity of the results, the imperfection of methods leads to the need for multiple repetitions of experiments, but the issue of reproducibility and comparability of research results is not resolved, therefore, the use of mathematical models in research makes it possible not only to identify, but also to explain the obtained patterns. The subject of the study in the article is a simulation model for estimating the mass of corn grains taking into account their genotype and growing conditions. The model is based on an analytical expression that reflects the main reasons for the growth of corn seeds after pollination of the plant. The mass of corn grains depends on a number of biological factors (genotype), technological – soil structure (its fertility and methods of cultivation), and climatic conditions (humidity, light intensity). The aim of the study is to create a simulation model to ensure the comparability of the results obtained when growing corn for grain in different conditions. Biological (cultivation) and mathematical (simulation model) methods were used as methods for obtaining and constructing results. The discrepancy in the estimation of the mass of grain of the same genotype grown in different research farms of different climatic zones of Ukraine and obtained by calculation was not more than 18 % and obtained experimentally up to 64 %. A feature of the model is the independence of the heterogeneity of the bioobject (studied lines and hybrids) from the conditions of their cultivation (soil structure and climatic conditions). The application of mathematical modeling makes it possible to reduce the differences in the studied indicators up to 25 times, which were obtained in different experiments, thereby significantly reducing time, money and provide a condition for comparability of results to obtain a reliable result.


Sign in / Sign up

Export Citation Format

Share Document