Вестник Санкт-Петербургского университета最新文献

{"title":"Rigid body dynamics from the Euler equations to the spacecraft attitude control in the works of scientists from Saint Petersburg State University. Part 1","authors":"Аleksey А. Tikhonov","doi":"10.21638/spbu01.2023.303","DOIUrl":"https://doi.org/10.21638/spbu01.2023.303","url":null,"abstract":"This survey, which consists of several articles, is dedicated to the 300th anniversary ofSaint Petersburg State University (SPbSU) and is an attempt to analyze the scientific achievements of the Saint Petersburg School of Mathematics and Mechanics in the field achievements of the period from the founding of SPbSU to the mid-1970s. Due to the anniversary nature of this work, the scientific results obtained at SPbSU are considered in the context of events inextricably linked with the founding of the Academy of Sciences, the University and the gymnasium in 1724 and their further development over the next 250 years. Due to the impossibility to cover even briefly all the publications that appeared during this period, attention is focused on the most important general areas of scientific thought and on those outstanding scientists of SPbSU, whose works enriched these areas.","PeriodicalId":477285,"journal":{"name":"Вестник Санкт-Петербургского университета","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135913126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Examining the possibility of insurance contract conclusion based on utility function","authors":"Alexander V. Sachkov","doi":"10.21638/11701/spbu10.2023.305","DOIUrl":"https://doi.org/10.21638/11701/spbu10.2023.305","url":null,"abstract":"The problem of a potential insurance contract conclusion is considered taking into account client’s money utility function. A basic model is employed for practical calculations and a formula is proposed and tried for two utility functions corresponding to polar income decile groups. Conclusions are made with suggested future research directions.","PeriodicalId":477285,"journal":{"name":"Вестник Санкт-Петербургского университета","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135151581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of business culture in modelling the firm’s internal environment","authors":"Igor Arenkov, Vladimir Zyabrikov, Igor Shevazutskii","doi":"10.21638/spbu05.2023.306","DOIUrl":"https://doi.org/10.21638/spbu05.2023.306","url":null,"abstract":"A variety of firm’s internal environment models has been formed for about half a century, starting with S. Gibson triad (strategy — structure — systems), which first formulated the sequence of strategic planning stages, and ending with the PEST-atom model, which reflects not only the composition of the elements of internal environment, but also the relationships between them. The article shows that a modern system, which would reflect the structure of the elements of firm’s internal environment, should be built on the basis of its key element, inextricably linked to the essence of the firm and, at the same time, synchronously changing with it in the course of movement along the trajectory of the life cycle. Such element, which directly determines the degree of maturity of a firm, is its culture. Business culture is the central connecting element of the internal environment of a firm, providing a harmonious combination of all its other elements: strategy, organizational structure, motivation system, etc. and making the firm attractive for investment. At the same time the type of business culture is the main indicator of the stage of the life cycle of a firm, and since the diversity of culture types is limited to four types: the cultures of a professional, leader, bureaucrat andentrepreneur, the process of movement of a firm through the stages of its life cycle can be turned into a manageable one. In order to do this in the second half of the firm’s maturity stage the role of professional should be made dominant, and the decline stage should be transformed into the revival stage. This transition will require the transformation of the internal environment of a firm in accordance with the model of intelligent organization, which is a logical development of the concept of a self-learning organization.The paper shows that in the course of movement along the trajectory of its life cycle a firm, by ensuring innovative attractiveness and reducing operating costs per unit, consistently implements the following “chain of criteria”: innovativeness (introduction stage) — efficiency (start-up stage) — productivity (growth stage) — effectiveness (maturity stage). The possibility of applying the theoretical aspects proposed by the authors is confirmed in practice in the study of the life cycle of Rodnik LLC.","PeriodicalId":477285,"journal":{"name":"Вестник Санкт-Петербургского университета","volume":"301 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135556978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scientific school of non-equilibrium aeromechanics in Saint Petersburg State University","authors":"Yulia N. Voroshilova, Vladimir A. Istomin, Ol’ga V. Kunova, Elena V. Kustova, Ekaterina A. Nagnibeda, Maria A. Rydalevskaya","doi":"10.21638/spbu01.2023.302","DOIUrl":"https://doi.org/10.21638/spbu01.2023.302","url":null,"abstract":"The review is devoted to the foundation and development of the scientific school of S. V. Vallander at the Leningrad (now St Petersburg) State University. The achievements of the scientific school in the development of the kinetic theory methods for modeling nonequilibrium flows, construction of rigorous self-consistent mathematical models of varying complexity for strong and weak deviations from equilibrium, and the use of the developed models in challenging problems of modern aerodynamics are discussed. Particular attention is paid to the study of non-equilibrium kinetics and transport processes in carbon dioxide, identification of key relaxation mechanisms of polyatomic molecules, derivation of physically based reduced hybrid models, and optimization of non-equilibrium flow numerical simulations using modern machine learning methods. Correct description of electronic excitation in the kinetics and transport processes, models of local equilibrium gas flows with multiple ionization, and features of modeling bulk viscosity in polyatomic gases are discussed.","PeriodicalId":477285,"journal":{"name":"Вестник Санкт-Петербургского университета","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135912840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transgression effect in the problem of motion of a rod on a cylinder","authors":"Alexander S. Kuleshov, Nikita M. Vidov","doi":"10.21638/spbu01.2023.310","DOIUrl":"https://doi.org/10.21638/spbu01.2023.310","url":null,"abstract":"The problem of motion of a heavy rigid thin rod on a perfectly rough right circular cylinder is considered. It is assumed that the generatrix of the cylinder has a nonzero angle with the direction of gravity. The equilibrium positions of the rod on a cylinder form the equilibria manifold (for all these equilibria the rod touches the cylinder by its center of mass). The effect of transgression (nontrivial evolution along the equilibria manifold) of the rod on the cylinder is studied by the normal form method.","PeriodicalId":477285,"journal":{"name":"Вестник Санкт-Петербургского университета","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135912850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inequalities for the derivative of rational functions with prescribed poles and restricted zeros","authors":"Uzma M. Ahanger, Wal M. Shah","doi":"10.21638/spbu01.2023.309","DOIUrl":"https://doi.org/10.21638/spbu01.2023.309","url":null,"abstract":"In this paper, instead of assuming that a rational function r(z) with prescribed poles has a zero of order s at origin, we suppose that it has a zero of multiplicity s at any point inside the unit circle, whereas the remaining zeros are within or outside a circle of radius k and prove some results which besides generalizing some inequalities for rational functions include refinements of some polynomial inequalities as special cases.","PeriodicalId":477285,"journal":{"name":"Вестник Санкт-Петербургского университета","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135913406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microgrid control for renewable energy sources based on deep reinforcement learning and numerical optimization approaches","authors":"Anastasia Yu. Zhadan, Haitao Wu, Pavel S. Kudin, Yuyi Zhang, Ovanes L. Petrosian","doi":"10.21638/11701/spbu10.2023.307","DOIUrl":"https://doi.org/10.21638/11701/spbu10.2023.307","url":null,"abstract":"Optimal scheduling of battery energy storage system plays crucial part in dis- tributed energy system. As a data driven method, deep reinforcement learning does not require system knowledge of dynamic system, present optimal solution for nonlinear optimization problem. In this research, financial cost of energy con- sumption reduced by scheduling battery energy using deep reinforcement learning method (RL). Reinforcement learning can adapt to equipment parameter changes and noise in the data, while mixed-integer linear programming (MILP) requires high accuracy in forecasting power generation and demand, accurate equipment parameters to achieve good performance, and high computational cost for large- scale industrial applications. Based on this, it can be assumed that deep RL based solution is capable of outperform classic deterministic optimization model MILP. This study compares four state-of-the-art RL algorithms for the battery power plant control problem: PPO, A2C, SAC, TD3. According to the simulation results, TD3 shows the best results, outperforming MILP by 5% in cost savings, and the time to solve the problem is reduced by about a factor of three.","PeriodicalId":477285,"journal":{"name":"Вестник Санкт-Петербургского университета","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135151836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Matrix representations of endomorphism rings for torsion-free abelian groups","authors":"Ekaterina А. Blagoveshchenskaya, Alexander V. Mikhalev","doi":"10.21638/spbu01.2023.304","DOIUrl":"https://doi.org/10.21638/spbu01.2023.304","url":null,"abstract":"Non-isomorphic direct decompositions of torsion-free abelian groups are reflected in their endomorphism ring decompositions which admit matrix representations. The set of possible direct decompositions of a special kind matrix rings into direct sums of one-sided indecomposable ideals is described. This leads to the combinatorial constructions of isomorphisms between non-commutative differently decomposable ring structures.","PeriodicalId":477285,"journal":{"name":"Вестник Санкт-Петербургского университета","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135913101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On probabilities of large deviations of combinatorial sums of independent random variables satisfying Linnik’s condition","authors":"Аndrei N. Frolov","doi":"10.21638/spbu01.2023.308","DOIUrl":"https://doi.org/10.21638/spbu01.2023.308","url":null,"abstract":"We derive new results on asymptotic behaviour for probabilities of large deviations of combinatorial sums of independent random variables satisfying Linnik’s condition. We find zones in which these probabilities are equivalent to the tail of the standard normal law. The author earlier obtained such results under Bernstein’s condition. The truncations method is applied in proofs of results.","PeriodicalId":477285,"journal":{"name":"Вестник Санкт-Петербургского университета","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135913121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expected effects of projected institutional changes in digital out-of-home advertising","authors":"Andrey Shastitko, Anton Morozov, Anastasia Morosanova","doi":"10.21638/spbu05.2023.303","DOIUrl":"https://doi.org/10.21638/spbu05.2023.303","url":null,"abstract":"During the political, economic instability and uncertainty, both the goals of economic regulation and the methods of decision-making are changing. Against the backdrop of changes in state policy, the need to ensure national security is becoming more acute, while there are still decision-making risks associated with the rent-seeking behavior of the regulatory authority or some market players. This article considers Draft law no. 160605–8 “On Amendments to the Federal Law “On Advertising” in context of regulating relations in the outdoor advertising, both in terms of the legislative innovation effectsand the compliance of these norms with the criteria for “promising trajectories” of institutional changes. After a resonant discussion in the media, the Draft law was rejected by the State Duma in its second reading, which confirms the importance of public discussions on lawmaking and economic analysis of the proposed measures. With the regulatory impact assessment methodology, we get a qualitative and quantitative estimation of organizational and technical measures of the proposed regulation (namely, the emergence of a private single operator of digital advertising structures). We also offer alternative institutional solutions that allow achieving the proclaimed goal of the draft law with greater efficiency: the introduction of business requirements (licensing, accreditation, maintaining a registry) or implementation of market self-organization. We conclude that granting control functions to one of the market players creates risks associated with an unresolved conflict of interest, which can lead to monopolization of digital out-of-home services and budget losses.","PeriodicalId":477285,"journal":{"name":"Вестник Санкт-Петербургского университета","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135556964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}