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Geometric Transformations on Null Curves in the Anti-de Sitter 3-Space
No full textWe provide a geometric transformation of null curves in anti-de Sitter 3-space (AdS) that induces the Bäcklund transformation for the KdV equation. In addition, we show that this geometric transformation satisfies a suitable permutability theorem. We also illustrate how to implement it when the original null curve has constant bending.Authors partially supported by PRIN 2017 and PRIN 2022 “Real and Complex Manifolds: Topology, Geometry and Holomorphic Dynamics” (prott. 2017JZ2SW5-004 and 2022AP8HZ9003); and by the GNSAGA of INdAM. The authors gratefully acknowledge the warm hospitality of the Department of Mathematics at the Politecnico di Torino and of the Texas Tech University Center in Sevilla. The authors would like to thank the referees for their careful review of the paper
Application of the migrated seismic images resolution capacity increasing technology for 2D- and 3D-surveying
No full textДля проведення геологорозвідувальних робіт важливо мати якомога якісніші результати обробки сейсмічних даних. У цьому контексті особливого значення набувають процедури міграції, що використовуються для сейсмічного матеріалу, на базі якого буде виконано геологічне моделювання та зроблено прогноз розповсюдження колекторів. Для покращення робіт із сейсмічної інтерпретації за допомогою мігрованих сейсмічних даних розроблено і програмно реалізовано математичну модель машинного навчання на базі нейронної мережі архітектури U-Net для збільшення роздільної здатності і співвідношення сигнал / завада для полів сейсмічної 2D- і 3D-зйомки.The quality of geological exploration works is directly proportional to the quality of seismic data processing, in particular the migration procedures that will be used for modeling and forecasting the distribution of reservoirs. To increase the quality of seismic interpretation workflow, a mathematical model of machine learning based on the neural network of the U-net architecture was developed and software implemented to increase the resolution and increase the signal / noise ratio for 2D and 3D seismic survey fields
Determination of human resources of enterprises in the prospects of post-war reconstruction of the economy of Ukraine
No full textСтаття присвячена уточненню сутності людських ресурсів підприємств, визначенню взаємозв’язку між поняттями «людські ресурси» і «людський капітал». Встановлено, що людські ресурси підприємства – це сукупність працівників підприємства та потенційно залучених осіб, що характеризуються кількісними (структура, чисельність) та якісними (професійні знання, навички, досвід, інтелектуальні напрацювання, здоров’я, здібності, соціальні зв’язки, мотивація) характеристиками, які у разі потреби можуть бути використані для досягнення виробничих, управлінських, інноваційних та інших цілей підприємства. Виділено цілі управління людськими ресурсами підприємств.The article is devoted to clarifying the essence of human resources of enterprises. Despite a significant number of deep and meaningful studies on human resources management, the problem of lack of human resources in Ukraine requires intensification of scientific research in this direction, in particular in the prospects of post-war reconstruction of the economy of Ukraine.
The relationship between the concepts of «human resources» and «human capital» is determined.
Based on the research conducted, it was established that human resources are one of the main forms of resources, encompassing a set of individuals, their quantitative characteristics (number, demographic structure) and qualitative characteristics (knowledge, abilities, skills, health, motivation, i.e. human capital), which, if necessary, can be involved in economic, social or other productive activities. The features of this definition are the understanding that: human resources are a certain potential for participation (the ability to use the human capital of people); human capital is an internal characteristic of a person for participation; real participation is labor activity, economic, social employment, etc.
It is substantiated that at the micro level, human resources characterize people working in enterprises, non-commercial organizations or are self-employed. Let us formulate a definition. Human resources of an enterprise are a set of employees of an enterprise and potentially involved persons, characterized by quantitative (structure, number) and qualitative (professional knowledge, skills, experience, intellectual achievements, health, abilities, social ties, motivation) characteristics, which, if necessary, can be used to achieve production, management, innovation and other goals of the enterprise.
The goals of human resources management of enterprises are highlighted
Modular Exercises for Four-Point Blocks - I
No full textThe well-known modular property of the torus characters and torus partition functions of (rational) vertex operator algebras (VOAs) and 2d conformal field theories (CFTs) has been an invaluable tool for studying this class of theories. In this work, we prove that sphere four-point chiral blocks of rational VOAs are vector-valued modular forms for the groups Γ(2), Γ₀(2), or SL₂(ℤ). Moreover, we prove that the four-point correlators, combining the holomorphic and anti-holomorphic chiral blocks, are modular invariant. In particular, in this language, the crossing symmetries are simply modular. This gives the possibility of exploiting the available techniques and knowledge about modular forms to determine or constrain the physically interesting quantities, such as chiral blocks and fusion coefficients, which we illustrate with a few examples. We also highlight the existence of a sphere-torus correspondence equating the sphere quantities of certain theories ₛ with the torus quantities of another family of theories ₜ. A companion paper will delve into more examples and explore this sphere-torus duality.We thank Vassilis Anagiannis, Christopher Beem, Francesca Ferrari, Alex Maloney, Greg Moore, and Gim Seng Ng for useful conversations. We are also grateful to the anonymous referees for their helpful suggestions. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curiegrantagreement No 708045. The work of M.C. and G.L. is supported by an ERC starting grant H2020 #640159. The work of M.C. has also received support from an NWO Vidi grant (number 016. Vidi. 189.182). The work of T.G. is supported by an NSERC Discovery grant
Fermionic Basis in Conformal Field Theory and Thermodynamic Bethe Ansatz for Excited States II
No full textWe consider the XXZ spin chain in the scaling limit in the Matsubara direction. The main result of this paper is new representations for the functions Ψ(, κ) and Θ(, ; κ, α) associated with the function ω(ζ, ξ; κ, κ) found in the expression for the correlation function of the generators of the fermionic basis for the XXZ spin chain. The final result incorporates the case of particle-hole excitations, which is needed for the relation of the fermionic basis to the Virasoro basis of the CFT descendants.SA and HB acknowledge financial support from the DFG in the framework of the research unit FOR 2316 and through project BO 3401/8-1. The authors would like to thank F. Smirnov for explaining his result for the case of different parameters κ and κ′ at the free fermion point. The authors would also like to thank the anonymous referees for their valuable contributions in improving the paper. HB would also like to thank S. Lukyanov for stimulating discussions
Practices of using urban public space during the Russian war in Ukraine (cases of Mykhailivska square and Maidan Nezalezhnosti)
No full textМіський публічний простір має дві основні функції – місце для політичного висловлення та для взаємодії між собою різних категорій людей. Через це він набуває критично важливого значення в процесі демократичної суспільної розбудови, і цим зумовлена пильна увага до його функціонування. Під час найгострішої форми політичної кризи – війни – у публічному просторі неуникно актуалізуються одні практики й відходять на задній план інші. Ідентифікація та аналіз таких змін може стати ключем до розуміння семантики простору та способів співіснування смислів, породжених новими контекстами. Оскільки міський публічний простір є своєрідним дзеркалом суспільно-політичних процесів, які відбуваються в країні (надто, якщо йдеться про центральні площі великих міст), таке розуміння може виявитися помічним у відстеженні ширшого суспільно-політичного курсу країни.
Етнографічне дослідження, на базі якого написана ця стаття, зосереджується на кейсах двох центральних київських площ – Михайлівської та Майдану Незалежності. Воно покликане здійснити розвідку в окреслене дослідницьке поле, а також розпочати ширшу дискусію щодо впливу війни на міський публічний простір в Україні, з одного боку, та щодо ролі простору як наратора, співтворця і транслятора смислів – з іншого.Urban public space has two main functions – it’s a place for political expression and for interactions between different categories of people. Thus, it becomes critically important in the process of building democracy, which is the reason for close attention to its functioning. During the most acute form of a political crisis – war – some practices are inevitably actualized, while other fade. Identifying and analysing such changes can be key to understanding the semantics of space and the way of coexistence of meanings generated by new contexts. Since urban public space is a mirror of the sociopolitical processes taking place in the country (especially when it comes to central squares of large cities), such an understanding can be helpful in tracking the country’s broader sociopolitical course.
The ethnographic research, on which this article is based, focuses on the cases of two central Kyiv squares, Mykhailivska and Maidan Nezalezhnosti. It aims to provide an exploration into the outlined research field, as well as to open, on the one hand, a broader discussion on the impact of the war on urban public space in Ukraine, and, on the other hand, on the role of space as a narrator, co-creator and translator of meanings
Adaptive Strategies for the Economic Development of Industrial Enterprises under Climate Crisis and Innovative Business Model Transformations
No full textУ статті розглядаються теоретичні засади формування адаптаційних стратегій економічного розвитку промислових підприємств в умовах загострення кліматичної кризи. Узагальнено світовий досвід інноваційної трансформації бізнес-моделей у промисловості та визначено механізми перетворення кліматичних ризиків на драйвери сталого розвитку. Проаналізовано ключові бар’єри та стимули трансформації бізнес-моделі в капіталомістких галузях, а також роль динамічних та абсорбційних організаційних здатностей у формуванні проактивних адаптаційних стратегій. Отримані результати можуть бути використані для планування стратегій декарбонізації та інтеграції принципів сталості у систему стратегічного управління підприємством.The article examines the theoretical foundations and practical mechanisms of adaptive strategies for the economic development of industrial enterprises under the intensifying climate crisis. The study systematizes international experience in transforming business models in capital-intensive industries and demonstrates how climate risks reshape the architecture of value creation. The research highlights that the adaptation of industrial enterprises is not limited to technological modernization but is achieved through the innovation-driven reconfiguration of business models, allowing firms to convert regulatory pressure and market shifts into sources of sustainable growth. The author identifies the key drivers and barriers of business model transformation, including decarbonization policies, new standards in global supply chains, investor expectations regarding environmental performance, as well as internal organizational constraints such as low absorptive capacity and inertia of corporate culture. Special attention is given to the role of dynamic and absorptive organizational capabilities, which determine the firm’s ability to integrate external knowledge, adopt sustainable practices, and form proactive strategies of adaptation. Based on the synthesis of global research, the article proposes a conceptual understanding of business model innovation as a core mechanism for transforming climate challenges into strategic opportunities. The results obtained can be applied by industrial enterprises in designing strategic programs of decarbonization, integrating sustainability principles into strategic management, and enhancing competitive resilience in global value chains
Deformation Families of Quasi-Projective Varieties and Symmetric Projective K3 Surfaces
No full textThe main aim of this paper is to construct a complex analytic family of symmetric projective K3 surfaces through a compactifiable deformation family of complete quasi-projective varieties from CP² #9CP¯². Firstly, for an elliptic curve ₀ embedded in CP², let ≅ CP² #9CP¯² be the blow up of CP² at nine points on the image of ₀, and be the strict transform of the image. Then, if the normal bundle satisfies the Diophantine condition, a tubular neighborhood of the elliptic curve can be identified through a toroidal group. Fixing the Diophantine condition, a smooth compactifiable deformation of ∖ over a 9-dimensional complex manifold is constructed. Moreover, with an ample line bundle fixed on , complete Kähler metrics can be constructed on the quasi-projective variety ∖. So, complete Kähler metrics are constructed on each quasi-projective variety fiber of the smooth compactifiable deformation family. Then, a complex analytic family of symmetric projective K3 surfaces over a 10-dimensional complex manifold is constructed through the smooth compactifiable deformation family of complete quasi-projective varieties and an analogous deformation family.Thanks, Professor Zhou Zhang, for his course on algebraic geometry. Thanks, Professor Sho Tanimoto, for providing some useful materials. In particular, thanks to Professor Ryoichi Kobayashi for introducing this topic and giving invaluable comments. I would also like to thank the anonymous referees for their suggestions and comments
On Extended Associative Semigroups
No full textWe study extended associative semigroups (briefly, EAS), an algebraic structure used to define generalizations of the operad of associative algebras, and the subclass of commutative extended diassociative semigroups (briefly, CEDS), which are used to define generalizations of the operad of pre-Lie algebras. We give families of examples based on semigroups or on groups, as well as a classification of EAS of cardinality two. We then define linear extended associative semigroups as linear maps satisfying a variation of the braid equation. We explore links between linear EAS and bialgebras and Hopf algebras. We also study the structure of non-degenerate finite CEDS and show that they are obtained by semi-direct and direct products involving two groups.The author thanks the anonymous referees for their useful and constructive comments on the first version of this text. The author acknowledges support from the grant ANR-20-CE40-0007 Combinatoire Algébrique, Résurgence, Probabilités Libres et Opérades