Результаты поиска по 'distribution function':
Найдено статей: 83
  1. Temlyakova E.A., Sorokin A.A.
    Detection of promoter and non-promoter E.coli sequences by analysis of their electrostatic profiles
    Computer Research and Modeling, 2015, v. 7, no. 2, pp. 347-359

    The article is devoted to the idea of using physical properties of DNA instead of sequence along for the aspect of accurate search and annotation of various prokaryotic genomic regions. Particulary, the possibility to use electrostatic potential distribution around DNA sequence as a classifier for identification of a few functional DNA regions was demonstrated. A number of classification models was built providing discrimination of promoters and non-promoter regions (random sequences, coding regions and promoter-like sequences) with accuracy value about 83–85%. The most valueable regions for the discrimination were determined and expected to play a certain role in the process of DNA-recognition by RNA-polymerase.

    Views (last year): 3.
  2. Sairanov A.S., Kasatkina E.V., Nefedov D.G., Rusyak I.G.
    The application of genetic algorithms for organizational systems’ management in case of emergency
    Computer Research and Modeling, 2019, v. 11, no. 3, pp. 533-556

    Optimal management of fuel supply system boils down to choosing an energy development strategy which provides consumers with the most efficient and reliable fuel and energy supply. As a part of the program on switching the heat supply distributed management system of the Udmurt Republic to renewable energy sources, an “Information-analytical system of regional alternative fuel supply management” was developed. The paper presents the mathematical model of optimal management of fuel supply logistic system consisting of three interconnected levels: raw material accumulation points, fuel preparation points and fuel consumption points, which are heat sources. In order to increase effective the performance of regional fuel supply system a modification of information-analytical system and extension of its set of functions using the methods of quick responding when emergency occurs are required. Emergencies which occur on any one of these levels demand the management of the whole system to reconfigure. The paper demonstrates models and algorithms of optimal management in case of emergency involving break down of such production links of logistic system as raw material accumulation points and fuel preparation points. In mathematical models, the target criterion is minimization of costs associated with the functioning of logistic system in case of emergency. The implementation of the developed algorithms is based on the usage of genetic optimization algorithms, which made it possible to obtain a more accurate solution in less time. The developed models and algorithms are integrated into the information-analytical system that enables to provide effective management of alternative fuel supply of the Udmurt Republic in case of emergency.

    Views (last year): 31.
  3. Serkov L.A., Krasnykh S.S.
    Combining the agent approach and the general equilibrium approach to analyze the influence of the shadow sector on the Russian economy
    Computer Research and Modeling, 2020, v. 12, no. 3, pp. 669-684

    This article discusses the influence of the shadow, informal and household sectors on the dynamics of a stochastic model with heterogeneous (heterogeneous) agents. The study uses the integration of the general equilibrium approach to explain the behavior of demand, supply and prices in an economy with several interacting markets, and a multi-agent approach. The analyzed model describes an economy with aggregated uncertainty and with an infinite number of heterogeneous agents (households). The source of heterogeneity is the idiosyncratic income shocks of agents in the legal and shadow sectors of the economy. In the analysis, an algorithm is used to approximate the dynamics of the distribution function of the capital stocks of individual agents — the dynamics of its first and second moments. The synthesis of the agent approach and the general equilibrium approach is carried out using computer implementation of the recursive feedback between microagents and macroenvironment. The behavior of the impulse response functions of the main variables of the model confirms the positive influence of the shadow economy (below a certain limit) on minimizing the rate of decline in economic indicators during recessions, especially for developing economies. The scientific novelty of the study is the combination of a multi-agent approach and a general equilibrium approach for modeling macroeconomic processes at the regional and national levels. Further research prospects may be associated with the use of more detailed general equilibrium models, which allow, in particular, to describe the behavior of heterogeneous groups of agents in the entrepreneurial sector of the economy.

  4. Popov A.B.
    Nonextensive Tsallis statistics of contract system of prime contractors and subcontractors in defense industry
    Computer Research and Modeling, 2022, v. 14, no. 5, pp. 1163-1183

    In this work, we analyze the system of contracts made by Russian defense enterprises in the process of state defense order execution. We conclude that methods of statistical mechanics can be applied to the description of the given system. Following the original grand-canonical ensemble approach, we can create the statistical ensemble under investigation as a set of instant snapshots of indistinguishable contracts having individual values. We show that due to government regulations of contract prices the contract system can be described in terms of nonextensive Tsallis statistics. We have found that probability distributions of contract prices correspond to deformed Bose – Einstein distributions obtained using nonextensive Tsallis entropy. This conclusion is true both in the case of the whole set of contracts and in the case of the contracts made by an individual defense company as a seller.

    In order to analyze how deformed Bose – Einstein distributions fit the empirical contract price distributions we compare the corresponding cumulative distribution functions. We conclude that annual distributions of individual sales which correspond to each company’s contract (order) can be used as relevant data for contract price distributions analysis. The empirical cumulative distribution functions for the individual sales ranking of Concern CSRI Elektropribor, one of the leading Russian defense companies, are analyzed for the period 2007–2021. The theoretical cumulative distribution functions, obtained using deformed Bose – Einstein distributions in the case of «rare contract gas» limit, fit well to the empirical cumulative distribution functions. The fitted values for the entropic index show that the degree of nonextensivity of the system under investigations is rather high. It is shown that the characteristic prices of distributions can be estimated by weighing the values of annual individual sales with the escort probabilities. Given that the fitted values of chemical potential are equal to zero, we suggest that «gas of contracts» can be compared to photon gas in which the number of particles is not conserved.

  5. Shumov V.V., Korepanov V.O.
    Mathematical models of combat and military operations
    Computer Research and Modeling, 2020, v. 12, no. 1, pp. 217-242

    Simulation of combat and military operations is the most important scientific and practical task aimed at providing the command of quantitative bases for decision-making. The first models of combat were developed during the First World War (M. Osipov, F. Lanchester), and now they are widely used in connection with the massive introduction of automation tools. At the same time, the models of combat and war do not fully take into account the moral potentials of the parties to the conflict, which motivates and motivates the further development of models of battle and war. A probabilistic model of combat is considered, in which the parameter of combat superiority is determined through the parameter of moral (the ratio of the percentages of the losses sustained by the parties) and the parameter of technological superiority. To assess the latter, the following is taken into account: command experience (ability to organize coordinated actions), reconnaissance, fire and maneuverability capabilities of the parties and operational (combat) support capabilities. A game-based offensive-defense model has been developed, taking into account the actions of the first and second echelons (reserves) of the parties. The target function of the attackers in the model is the product of the probability of a breakthrough by the first echelon of one of the defense points by the probability of the second echelon of the counterattack repelling the reserve of the defenders. Solved the private task of managing the breakthrough of defense points and found the optimal distribution of combat units between the trains. The share of troops allocated by the parties to the second echelon (reserve) increases with an increase in the value of the aggregate combat superiority parameter of those advancing and decreases with an increase in the value of the combat superiority parameter when repelling a counterattack. When planning a battle (battles, operations) and the distribution of its troops between echelons, it is important to know not the exact number of enemy troops, but their capabilities and capabilities, as well as the degree of preparedness of the defense, which does not contradict the experience of warfare. Depending on the conditions of the situation, the goal of an offensive may be to defeat the enemy, quickly capture an important area in the depth of the enemy’s defense, minimize their losses, etc. For scaling the offensive-defense model for targets, the dependencies of the losses and the onset rate on the initial ratio of the combat potentials of the parties were found. The influence of social costs on the course and outcome of wars is taken into account. A theoretical explanation is given of a loss in a military company with a technologically weak adversary and with a goal of war that is unclear to society. To account for the influence of psychological operations and information wars on the moral potential of individuals, a model of social and information influence was used.

  6. Skvortsova D.A., Chuvilgin E.L., Smirnov A.V., Romanov N.O.
    Development of a hybrid simulation model of the assembly shop
    Computer Research and Modeling, 2023, v. 15, no. 5, pp. 1359-1379

    In the presented work, a hybrid optimal simulation model of an assembly shop in the AnyLogic environment has been developed, which allows you to select the parameters of production systems. To build a hybrid model of the investigative approach, discrete-event modeling and aggressive modeling are combined into a single model with an integrating interaction. Within the framework of this work, a mechanism for the development of a production system consisting of several participants-agents is described. An obvious agent corresponds to a class in which a set of agent parameters is specified. In the simulation model, three main groups of operations performed sequentially were taken into account, and the logic for working with rejected sets was determined. The product assembly process is a process that occurs in a multi-phase open-loop system of redundant service with waiting. There are also signs of a closed system — scrap flows for reprocessing. When creating a distribution system in the segment, it is mandatory to use control over the execution of requests in a FIFO queue. For the functional assessment of the production system, the simulation model includes several functional functions that describe the number of finished products, the average time of preparation of products, the number and percentage of rejects, the simulation result for the study, as well as functional variables in which the calculated utilization factors will be used. A series of modeling experiments were carried out in order to study the behavior of the agents of the system in terms of the overall performance indicators of the production system. During the experiment, it was found that the indicator of the average preparation time of the product is greatly influenced by such parameters as: the average speed of the set of products, the average time to complete operations. At a given limitation interval, we managed to select a set of parameters that managed to achieve the largest possible operation of the assembly line. This experiment implements the basic principle of agent-based modeling — decentralized agents make a personal contribution and affect the operation of the entire simulated system as a whole. As a result of the experiments, thanks to the selection of a large set of parameters, it was possible to achieve high performance indicators of the assembly shop, namely: to increase the productivity indicator by 60%; reduce the average assembly time of products by 38%.

  7. Mitin N.A., Orlov Y.N.
    Statistical analysis of bigrams of specialized texts
    Computer Research and Modeling, 2020, v. 12, no. 1, pp. 243-254

    The method of the stochastic matrix spectrum analysis is used to build an indicator that allows to determine the subject of scientific texts without keywords usage. This matrix is a matrix of conditional probabilities of bigrams, built on the statistics of the alphabet characters in the text without spaces, numbers and punctuation marks. Scientific texts are classified according to the mutual arrangement of invariant subspaces of the matrix of conditional probabilities of pairs of letter combinations. The separation indicator is the value of the cosine of the angle between the right and left eigenvectors corresponding to the maximum and minimum eigenvalues. The computational algorithm uses a special representation of the dichotomy parameter, which is the integral of the square norm of the resolvent of the stochastic matrix of bigrams along the circumference of a given radius in the complex plane. The tendency of the integral to infinity testifies to the approximation of the integration circuit to the eigenvalue of the matrix. The paper presents the typical distribution of the indicator of identification of specialties. For statistical analysis were analyzed dissertations on the main 19 specialties without taking into account the classification within the specialty, 20 texts for the specialty. It was found that the empirical distributions of the cosine of the angle for the mathematical and Humanities specialties do not have a common domain, so they can be formally divided by the value of this indicator without errors. Although the body of texts was not particularly large, nevertheless, in the case of arbitrary selection of dissertations, the identification error at the level of 2 % seems to be a very good result compared to the methods based on semantic analysis. It was also found that it is possible to make a text pattern for each of the specialties in the form of a reference matrix of bigrams, in the vicinity of which in the norm of summable functions it is possible to accurately identify the theme of the written scientific work, without using keywords. The proposed method can be used as a comparative indicator of greater or lesser severity of the scientific text or as an indicator of compliance of the text to a certain scientific level.

  8. Chen J., Lobanov A.V., Rogozin A.V.
    Nonsmooth Distributed Min-Max Optimization Using the Smoothing Technique
    Computer Research and Modeling, 2023, v. 15, no. 2, pp. 469-480

    Distributed saddle point problems (SPPs) have numerous applications in optimization, matrix games and machine learning. For example, the training of generated adversarial networks is represented as a min-max optimization problem, and training regularized linear models can be reformulated as an SPP as well. This paper studies distributed nonsmooth SPPs with Lipschitz-continuous objective functions. The objective function is represented as a sum of several components that are distributed between groups of computational nodes. The nodes, or agents, exchange information through some communication network that may be centralized or decentralized. A centralized network has a universal information aggregator (a server, or master node) that directly communicates to each of the agents and therefore can coordinate the optimization process. In a decentralized network, all the nodes are equal, the server node is not present, and each agent only communicates to its immediate neighbors.

    We assume that each of the nodes locally holds its objective and can compute its value at given points, i. e. has access to zero-order oracle. Zero-order information is used when the gradient of the function is costly, not possible to compute or when the function is not differentiable. For example, in reinforcement learning one needs to generate a trajectory to evaluate the current policy. This policy evaluation process can be interpreted as the computation of the function value. We propose an approach that uses a smoothing technique, i. e., applies a first-order method to the smoothed version of the initial function. It can be shown that the stochastic gradient of the smoothed function can be viewed as a random two-point gradient approximation of the initial function. Smoothing approaches have been studied for distributed zero-order minimization, and our paper generalizes the smoothing technique on SPPs.

  9. Makhov S.A.
    Forecasting demographic and macroeconomic indicators in a distributed global model
    Computer Research and Modeling, 2023, v. 15, no. 3, pp. 757-779

    The paper present a dynamic macro model of world dynamics. The world is divided into 19 geographic regions in the model. The internal development of the regions is described by regression equations for demographic and economic indicators (Population, Gross Domestic Product, Gross Capital Formation). The bilateral trade flows from region to region describes interregional interactions and represented the trade submodel. Time, the gross product of the exporter and the gross product of the importer were used as regressors. Four types were considered: time pair regression — dependence of trade flow on time, export function — dependence of the share of trade flow in the gross product of the exporter on the gross product of the importer, import function — dependence of the share of trade flow in the gross product of the importer on the gross product of the exporter, multiple regression — dependence of trade flow on the gross products of the exporter and importer. Two types of functional dependence were used for each type: linear and log-linear, in total eight variants of the trading equation were studied. The quality of regression models is compared by the coefficient of determination. By calculations the model satisfactorily approximates the dynamics of monotonically changing indicators. The dynamics of non-monotonic trade flows is analyzed, three types of functional dependence on time are proposed for their approximation. It is shown that the number of foreign trade series can be approximated by the space of seven main components with a 10% error. The forecast of regional development and global dynamics up to 2040 is constructed.

  10. Kholodkov K.I., Aleshin I.M.
    Exact calculation of a posteriori probability distribution with distributed computing systems
    Computer Research and Modeling, 2015, v. 7, no. 3, pp. 539-542

    We'd like to present a specific grid infrastructure and web application development and deployment. The purpose of infrastructure and web application is to solve particular geophysical problems that require heavy computational resources. Here we cover technology overview and connector framework internals. The connector framework links problem-specific routines with middleware in a manner that developer of application doesn't have to be aware of any particular grid software. That is, the web application built with this framework acts as an interface between the user 's web browser and Grid's (often very) own middleware.

    Our distributed computing system is built around Gridway metascheduler. The metascheduler is connected to TORQUE resource managers of virtual compute nodes that are being run atop of compute cluster utilizing the virtualization technology. Such approach offers several notable features that are unavailable to bare-metal compute clusters.

    The first application we've integrated with our framework is seismic anisotropic parameters determination by inversion of SKS and converted phases. We've used probabilistic approach to inverse problem solution based on a posteriory probability distribution function (APDF) formalism. To get the exact solution of the problem we have to compute the values of multidimensional function. Within our implementation we used brute-force APDF calculation on rectangular grid across parameter space.

    The result of computation is stored in relational DBMS and then represented in familiar human-readable form. Application provides several instruments to allow analysis of function's shape by computational results: maximum value distribution, 2D cross-sections of APDF, 2D marginals and a few other tools. During the tests we've run the application against both synthetic and observed data.

    Views (last year): 3.
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