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Найдено статей: 371
  1. Salenek I.A., Seliverstov Y.A., Seliverstov S.A., Sofronova E.A.
    Improving the quality of route generation in SUMO based on data from detectors using reinforcement learning
    Computer Research and Modeling, 2024, v. 16, no. 1, pp. 137-146

    This work provides a new approach for constructing high-precision routes based on data from transport detectors inside the SUMO traffic modeling package. Existing tools such as flowrouter and routeSampler have a number of disadvantages, such as the lack of interaction with the network in the process of building routes. Our rlRouter uses multi-agent reinforcement learning (MARL), where the agents are incoming lanes and the environment is the road network. By performing actions to launch vehicles, agents receive a reward for matching data from transport detectors. Parameter Sharing DQN with the LSTM backbone of the Q-function was used as an algorithm for multi-agent reinforcement learning.

    Since the rlRouter is trained inside the SUMO simulation, it can restore routes better by taking into account the interaction of vehicles within the network with each other and with the network infrastructure. We have modeled diverse traffic situations on three different junctions in order to compare the performance of SUMO’s routers with the rlRouter. We used Mean Absoluter Error (MAE) as the measure of the deviation from both cumulative detectors and routes data. The rlRouter achieved the highest compliance with the data from the detectors. We also found that by maximizing the reward for matching detectors, the resulting routes also get closer to the real ones. Despite the fact that the routes recovered using rlRouter are superior to the routes obtained using SUMO tools, they do not fully correspond to the real ones, due to the natural limitations of induction-loop detectors. To achieve more plausible routes, it is necessary to equip junctions with other types of transport counters, for example, camera detectors.

  2. Lukyantsev D.S., Afanasiev N.T., Tanaev A.B., Chudaev S.O.
    Numerical-analytical modeling of gravitational lensing of the electromagnetic waves in random-inhomogeneous space plasma
    Computer Research and Modeling, 2024, v. 16, no. 2, pp. 433-443

    Instrument of numerical-analytical modeling of characteristics of propagation of electromagnetic waves in chaotic space plasma with taking into account effects of gravitation is developed for interpretation of data of measurements of astrophysical precision instruments of new education. The task of propagation of waves in curved (Riemann’s) space is solved in Euclid’s space by introducing of the effective index of refraction of vacuum. The gravitational potential can be calculated for various model of distribution of mass of astrophysical objects and at solution of Poisson’s equation. As a result the effective index of refraction of vacuum can be evaluated. Approximate model of the effective index of refraction is suggested with condition that various objects additively contribute in total gravitational field. Calculation of the characteristics of electromagnetic waves in the gravitational field of astrophysical objects is performed by the approximation of geometrical optics with condition that spatial scales of index of refraction a lot more wavelength. Light differential equations in Euler’s form are formed the basis of numerical-analytical instrument of modeling of trajectory characteristic of waves. Chaotic inhomogeneities of space plasma are introduced by model of spatial correlation function of index of refraction. Calculations of refraction scattering of waves are performed by the approximation of geometrical optics. Integral equations for statistic moments of lateral deviations of beams in picture plane of observer are obtained. Integrals for moments are reduced to system of ordinary differential equations the firsts order with using analytical transformations for cooperative numerical calculation of arrange and meansquare deviations of light. Results of numerical-analytical modeling of trajectory picture of propagation of electromagnetic waves in interstellar space with taking into account impact of gravitational fields of space objects and refractive scattering of waves on inhomogeneities of index of refraction of surrounding plasma are shown. Based on the results of modeling quantitative estimation of conditions of stochastic blurring of the effect of gravitational lensing of electromagnetic waves at various frequency ranges is performed. It’s shown that operating frequencies of meter range of wavelengths represent conditional low-frequency limit for observational of the effect of gravitational lensing in stochastic space plasma. The offered instrument of numerical-analytical modeling can be used for analyze of structure of electromagnetic radiation of quasar propagating through group of galactic.

  3. Panteleev M.A., Bershadsky E.S., Shibeko A.M., Nechipurenko D.Y.
    Current issues in computational modeling of thrombosis, fibrinolysis, and thrombolysis
    Computer Research and Modeling, 2024, v. 16, no. 4, pp. 975-995

    Hemostasis system is one of the key body’s defense systems, which is presented in all the liquid tissues and especially important in blood. Hemostatic response is triggered as a result of the vessel injury. The interaction between specialized cells and humoral systems leads to the formation of the initial hemostatic clot, which stops bleeding. After that the slow process of clot dissolution occurs. The formation of hemostatic plug is a unique physiological process, because during several minutes the hemostatic system generates complex structures on a scale ranging from microns for microvessel injury or damaged endothelial cell-cell contacts, to centimeters for damaged systemic arteries. Hemostatic response depends on the numerous coordinated processes, which include platelet adhesion and aggregation, granule secretion, platelet shape change, modification of the chemical composition of the lipid bilayer, clot contraction, and formation of the fibrin mesh due to activation of blood coagulation cascade. Computer modeling is a powerful tool, which is used to study this complex system at different levels of organization. This includes study of intracellular signaling in platelets, modelling humoral systems of blood coagulation and fibrinolysis, and development of the multiscale models of thrombus growth. There are two key issues of the computer modeling in biology: absence of the adequate physico-mathematical description of the existing experimental data due to the complexity of the biological processes, and high computational complexity of the models, which doesn’t allow to use them to test physiologically relevant scenarios. Here we discuss some key unresolved problems in the field, as well as the current progress in experimental research of hemostasis and thrombosis. New findings lead to reevaluation of the existing concepts and development of the novel computer models. We focus on the arterial thrombosis, venous thrombosis, thrombosis in microcirculation and the problems of fibrinolysis and thrombolysis. We also briefly discuss basic types of the existing mathematical models, their computational complexity, and principal issues in simulation of thrombus growth in arteries.

  4. Okonicha O., Sadovykh A.
    NLP-based automated compliance checking of data processing agreements against General Data Protection Regulation
    Computer Research and Modeling, 2024, v. 16, no. 7, pp. 1667-1685

    As it stands in the contemporary world, compliance with regulations concerning data protection such as GDPR is central to organizations. Another important issue analysis identified is the fact that compliance is hampered by the fact that legal documents are often complex and that regulations are ever changing. This paper aims to describe the ways in which NLP aids in keeping GDPR compliance effortless through automated scanning for compliance, evaluating privacy policies, and increasing the level of transparency. The work does not only limit to exploring the application of NLP for dealing with the privacy policies and facilitate better understanding of the third-party data sharing but also proceed to perform the preliminary studies to evaluate the difference of several NLP models. They implement and execute the models to distinguish the one that performs the best based on the efficiency and speed at which it automates the process of compliance verification and analyzing the privacy policy. Moreover, some of the topics discussed in the research deal with the possibility of using automatic tools and data analysis to GDPR, for instance, generation of the machine readable models that assist in evaluation of compliance. Among the evaluated models from our studies, SBERT performed best at the policy level with an accuracy of 0.57, precision of 0.78, recall of 0.83, and F1-score of 0.80. BERT showed the highest performance at the sentence level, achieving an accuracy of 0.63, precision of 0.70, recall of 0.50, and F1-score of 0.55. Therefore, this paper emphasizes the importance of NLP to help organizations overcome the difficulties of GDPR compliance, create a roadmap to a more client-oriented data protection regime. In this regard, by comparing preliminary studies done in the test and showing the performance of the better model, it helps enhance the measures taken in compliance and fosters the defense of individual rights in the cyberspace.

  5. Revutskaya O.L., Neverova G.P., Frisman E.Y.
    A minimal model of density-dependent population dynamics incorporating sex structure: simulation and application
    Computer Research and Modeling, 2025, v. 17, no. 5, pp. 941-961

    This study proposes and analyzes a discrete-time mathematical model of population dynamics with seasonal reproduction, taking into account the density-dependent regulation and sex structure. In the model, population birth rate depends on the number of females, while density is regulated through juvenile survival, which decreases exponentially with increasing total population size. Analytical and numerical investigations of the model demonstrate that when more than half of both females and males survive, the population exhibits stable dynamics even at relatively high birth rates. Oscillations arise when the limitation of female survival exceeds that of male survival. Increasing the intensity of male survival limitation can stabilize population dynamics, an effect particularly evident when the proportion of female offspring is low. Depending on parameter values, the model exhibits stable, periodic, or irregular dynamics, including multistability, where changes in current population size driven by external factors can shift the system between coexisting dynamic modes. To apply the model to real populations, we propose an approach for estimating demographic parameters based on total abundance data. The key idea is to reduce the two-component discrete model with sex structure to a delay equation dependent only on total population size. In this formulation, the initial sex structure is expressed through total abundance and depends on demographic parameters. The resulting one-dimensional equation was applied to describe and estimate demographic characteristics of ungulate populations in the Jewish Autonomous Region. The delay equation provides a good fit to the observed dynamics of ungulate populations, capturing long-term trends in abundance. Point estimates of parameters fall within biologically meaningful ranges and produce population dynamics consistent with field observations. For moose, roe deer, and musk deer, the model suggests predominantly stable dynamics, while annual fluctuations are primarily driven by external factors and represent deviations from equilibrium. Overall, these estimates enable the analysis of structured population dynamics alongside short-term forecasting based on total abundance data.

  6. Tikunova K.V., Golyshev G.G., Sokolovski S.G., Rafailov E.U., Goltsov A.N.
    Mathematical modeling of near-infrared laser irradiation effects on cancer cells
    Computer Research and Modeling, 2025, v. 17, no. 6, pp. 1205-1218

    In recent decades, the introduction of biophotonics and quantum electronics advance into medical practice led to the development of new diagnostic and therapeutic approaches for many diseases. In the field of oncology, photodynamic therapy (PDT) is successfully used today in the treatment of various types of cancer. Along with further improvement of PDT, the development of direct laser therapy is currently underway, in which the generation of singlet oxygen molecules ($^{1}$О$_2^{}$) in cancer cells occurs under NIR laser irradiation with a wavelength of $\lambda=1267$ nm without the need to introduce photosensitizers into the patient's body. For the purpose of a~theoretical investigation of the direct effect of NIR laser irradiation on cancer cells and the description of a~large set of experimental data, a mathematical model has been developed. The model includes the main cellular processes activated in cancer cells by NIR laser irradiation that determine the effectiveness of its cytotoxic effect on cancer cells. As a result of modeling, the rate of $^{1}$О$_2^{}$ generation under NIR laser irradiation was estimated, and the kinetics of active oxygen species (ROS) molecules was described. The ROS degradation due to the action of the antioxidant system of cell protection was taken into account in the model. It was shown that NIR laser irradiation induces lipid peroxidation that leads to cellular membrane damage and cell death through ferroptosis. As a result of modeling, it was established that a cascade of free-radical and enzymatic reactions of ROS transformation and accumulation leads to a prolonged response of cervical adenocarcinoma cells HeLa to the action of laser irradiation with $\lambda=1267$ nm, during which oxidative stress develops, causing cancer cell death through apoptosis and ferroptosis.

  7. Khoraskina Y.S., Komarov A.S., Bezrukova M.G., Zhiyanski M.K.
    Modeling of calcium dynamics in soil organic layers
    Computer Research and Modeling, 2010, v. 2, no. 1, pp. 103-110

    Calcium is a major nutrient regulating metabolism in a plant. Deficiency of calcium results in a growth decline of plant tissues. Ca may be lost from forest soils due to acidic atmospheric deposition and tree harvesting. Plant-available calcium compounds are in the soil cation exchange complex and soil waters. Model of soil calcium dynamics linking it with the model of soil organic matter dynamics ROMUL in forest ecosystems is developed. ROMUL describes the mineralization and humification of the fraction of fresh litter which is further transformed into complex of partially humified substance (CHS) and then to stable humus (H) in dependence on temperature, soil moisture and chemical composition of the fraction (nitrogen, lignin and ash contents, pH). Rates of decomposition and humification being coefficients in the system of ordinary differential equations are evaluated using laboratory experiments and verified on a set of field experiments. Model of soil calcium dynamics describes calcium flows between pools of soil organic matter. Outputs are plant nutrition, leaching, synthesis of secondary minerals. The model describes transformation and mineralization of forest floor in detail. Experimental data for calibration model was used from spruсe forest of Bulgaria.

    Views (last year): 1.
  8. Bratsun D.A., Zyuzgin A.V.
    Effect of subcritical excitation of oscillations in stochastic systems with time delay. Part II. Control of fluid equilibrium
    Computer Research and Modeling, 2012, v. 4, no. 2, pp. 369-389

    The problem of active control of the mechanical equilibrium of an inhomogeneously heated fluid in a thermosyphon is studied theoretically and experimentally. The control is performed by using a feedback subsystem which inhibits convection by changing the orientation of thermosyphon in space. It is shown that excess feedback leads to the excitation of oscillations which are related to a delay in the controller work. In the presense of noise, the oscillations arise even when deterministic description predicts stationary behaviour. The experimental data and theory are in good agreement.

    Views (last year): 1. Citations: 6 (RSCI).
  9. Koganov A.V., Krechet V.G.
    The introduction of baryon string in the model of spiral galaxies structure
    Computer Research and Modeling, 2012, v. 4, no. 3, pp. 597-612

    It proposes a new alternative approach to explain the flat spectrum of the velocity for stars orbital motion on the periphery of spiral galaxies. In particular, that velocity significant excess of speed calculated according to the virial theorem. The concept is the assumption of the existence for gravitational field of the Central body of the galaxy cylindrical, and not spherical, symmetry. The configuration of this field can be explained by the presence on galaxy axis the cosmic string, the length of which covers the diameter of the disk of the galaxy. This model will be subjected to comparison with the more traditional concept of the availability of the spiral galaxy ball halo of dark matter. For this approach it will also be offered a kinematic model, and the hypothesis about the nature of dark matter. It examines the data of astronomical observations about the presence of cosmic strings in the zones adjacent to galaxies.

    Views (last year): 2. Citations: 1 (RSCI).
  10. Platonov D.V., Minakov A.V., Dekterev A.A., Sentyabov A.V.
    Numerical modeling of flows with flow swirling
    Computer Research and Modeling, 2013, v. 5, no. 4, pp. 635-648

    This paper is devoted to investigation of the swirl flows. Such flows are widely used in various industrial processes. Swirl flows can be accompanied by time-dependent effects, for example, precession of the vortex core. In turn, the large-scale fluctuations due to the precession of the vortex can cause damage of structures and reduce of equipment reliability. Thus, for engineering calculations approaches that sufficiently well described such flows are required. This paper presents the technique of swirl flows calculation, tested for CFD packages Fluent and SigmaFlow. A numerical simulation of several swirl flow test problems was carried out. Obtained results are compared with each other and with the experimental data.

    Views (last year): 4. Citations: 2 (RSCI).
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International Interdisciplinary Conference "Mathematics. Computing. Education"