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О применении K-средних для определения распределения масс гантелеобразных небесных тел
Нелинейная динамика. 2018. Т. 14. № 1. С. 45–52.
Burov A. A., Герман А. Д., Распопова Е. А., Nikonov V.
It is well known that several small celestial objects are of irregular shape. In particular, there exist asteroids of the so-called “dog-bone” shape. It turns out that approximation of these bodies by dumb-bells, as proposed by V.V. Beletsky, provides an effective tool for analytical investigation of dynamics in vicinities of such bodies. There remains the question of how to divide reasonably a “dogbone” body into two parts using available measurement data.
In this paper we introduce an approach based on the so-called KK-mean algorithm proposed by the prominent Polish mathematician H. Steinhaus.
Language:
Russian
Блудов М. В., Journal of Fixed Point Theory and Applications 2026 No. 28 Article 73
In this paper, we study a construction of homotopy invariants of open or closed covers, where the homotopy class is defined relative to a pair (V, r), with V a finite set of points in and r a point in the interior of their convex hull. We show that the simplicial complex of non-balanced subsets associated with (V, r) has the homotopy ...
Added: August 25, 2026
L.I. Kuzmina, Osipov , Y. V., Kolokoltseva, T. N., Advances in Water Resources 2026 Vol. 213 Article 105335
We study 1D transport of mobilized particles, detached from the solid matrix, in porous media (so-called fines migration). Three types of colloidal-suspension flow models are considered: (i) averaged model for multicomponent colloids with distributed properties; (ii) flow of binary colloids with interacting particles; (iii) discrete system for multicomponent low-concentration colloid. These models account for distributed ...
Added: August 25, 2026
Liudmila I. Kuzmina, Osipov, Y. V., International Journal for Computational Civil and Structural Engineering 2026 Vol. 22 No. 2 P. 138–148
Modeling the transport and sedimentation of small particles of suspensions and colloids in porous rocks is an important problem in subsurface hydromechanics. Particles entrained in fluid are transported and retained in the rock pores. The filtration process is determined by the number and size of pores and is characterized by porosity—the ratio of the void ...
Added: August 25, 2026
L.I.Kuzmina, Osipov Y. V., Mathematical notes, ISSN 0001-4346 2025 Vol. 116 No. 6 P. 1251–1261
We consider the displacement of oil by water with active chemical reagents in porous media. A one-dimensional model of reagent transport and deposition is defined by a hyperbolic system of first-order equations. The purpose of the article is to find the conditions for the existence of a continuous solution with discontinuous boundary and initial conditions. ...
Added: August 25, 2026
Shabanov N., Kuricheva O., Kurbatova J. et al., / Series Working Papers SSRN "Department of Economics Ca’ Foscari University of Venice". 2026.
The carbon balance of an ecosystem is the difference between Gross Primary Productivity (GPP) and Ecosystem Respiration (Reco) as expressed by Net Ecosystem Exchange (NEE). While remote sensing retrievals of GPP have reached maturity, Reco estimation remains underexplored and ultimately cast bias on NEE. Here we present an end-to-end multi-scale analysis of the mechanism of ...
Added: August 21, 2026
Лукьяненко Д. В., Ragimova A., Мухорина А. et al., European Physical Journal: Special Topics 2026 P. 1–24
Electronic health records (EHRs) contain vast volumes of clinical information that encode complex relationships between diseases. Traditional approaches to the analysis of interrelated or co-occurring diseases have focused on pairwise associations between diagnoses, missing the higher-order structures that characterise multimorbid patients. The present paper offers a narrative review of existing statistical, machine-learning, and artificial intelligence ...
Added: August 20, 2026
Mazur D., Brandyshev P., Doronin S. V. et al., Electrochimica Acta 2026 Vol. 577 Article 149729
The electric double layer (EDL) at a single-crystal metal surface is controlled not only by the electrolyte composition and the electrode potential, but also by the atomic structure of the surface itself. This makes the Ag(hkl)/NaF interface a stringent test for continuum theories of the EDL. In the third part of our series, we examine ...
Added: August 20, 2026
Chernov A., European Journal of Mathematics 2026 Vol. 12 Article 48
An induced additive action on a projective variety is a regular action of the group G_a^n on X in P^n with an open orbit that can be extended to a regular action on P^n. Such actions are known to correspond to pairs (A, U), where A is a local algebra and U is a generating subspace lying in the maximal ideal. This paper ...
Added: August 19, 2026
IEEE Advancing Technology for Humanity, 2025.
Dynamics of Systems, Mechanisms and Machines (Dynamics) ...
Added: August 19, 2026
Gimaev R., Karpenkov A., Shelkovyi F. et al., Journal of Alloys and Compounds 2026 No. 1080 Article 190307
The magnetothermal properties of the quaternary Fe49Rh46.1Pd3.1Ir1.8 alloy are investigated by a combination of first-principles calculations, structural characterization, magnetometry, calorimetry, and direct measurements of the adiabatic temperature change. An exceptional magnetocaloric response is obtained, with ΔTad reaching −11.9 K in a field of 1.85 T under the discontinuous protocol and −8.6 K under the continuous ...
Added: August 18, 2026
Vlasenko D., Saranskaia I., Zakharov D., European Physical Journal: Special Topics 2026 P. 1–16
Hypergraphs provide a natural framework for representing neurophysiological interactions distributed across sets of sensors. A key methodological question is how hyperedges should be defined from frequency-resolved electroencephalography/magnetoencephalography (EEG/MEG) data. We demonstrate a construction strategy in which hyperedges are obtained from canonical coherence (caCOH), an extension of coherence that estimates coupling between multidimensional signal spaces. To ...
Added: August 18, 2026
Borisov D., Katzarkov Ludmil, Sheshmani A. et al., American Journal of Mathematics 2026 Vol. 148 No. 4 P. 1075–1101
It is shown that there are globally defined Lagrangian distributions on the stable loci of derived \mathrm{Quot}-stacks of coherent sheaves on Calabi--Yau four-folds. Dividing by these distributions produces perfectly obstructed smooth stacks with globally defined -1-shifted potentials, whose derived critical loci give back the stable loci of smooth stacks of sheaves in global Darboux form. ...
Added: August 18, 2026
Богатырев А. Б., Математический сборник 2023 Т. 214 № 3 С. 106–119
Рассматривается клеточное разбиение пространства модулей вещественных кривых рода 2 с отмеченной точкой на единственном вещественном овале. Клетки перечисляются определенными графами, веса которых описывают комплексную структуру на кривой. Показано, что стягивание ребра графа приводит к корневой особенности естественного отображения из весов графа в пространство модулей кривых. ...
Added: August 14, 2026
Богатырев А. Б., Gendron Q., Успехи математических наук 2023 Т. 78 № 1 С. 209–210
Уравнение Пелля-Абеля — это функциональное уравнение вида P²-DQ² = 1, с заданным многочленом D, свободным от квадратов, и неизвестными многочленами P и Q. Мы показываем, что пространство уравнений Пелля-Абеля с фиксированными степенями D и примитивным решением P является комплексным многообразием. Мы описываем его связные компоненты с помощью эффективно вычислимого инварианта. ...
Added: August 14, 2026
Богатырев А. Б., Transactions of the Moscow Mathematical Society 2024 Vol. 85 No. 2 P. 323–337
The best uniform rational approximation of the Sign function on two intervals separated by zero was explicitly found by E. I. Zolotarëv in 1877. The natural extension of this problem to three bands was solved by E. Stiefel in 1961. We indicate the solutions overlooked by the prominent geometer and study their properties. ...
Added: August 14, 2026
Богатырев А. Б., Успехи математических наук 2026 Т. 81 № 3(489) С. 159–160
Предложена простая и эффективно реализуемая формула для изменения абелевых интегралов (включая их периоды) при вариации образующих классической группы Шоттки, представляющей риманову поврехность. ...
Added: August 14, 2026
Gendron Q., Compositio Mathematica 2025 Vol. 161 No. 7 P. 1483–1511
A Pell–Abel equation is a functional equation of the form P^2-DQ^2=1 , with a given polynomial D free of squares and unknown polynomials P and Q. We show that the space of Pell–Abel equations with the degrees of D and of the primitive solution P fixed is a complex manifold. We describe its connected components ...
Added: August 14, 2026
Khorunzheva K., Postnikov E., Zakharov D., Chaos, Solitons and Fractals 2026 Vol. 212 No. 2 P. 1–12
Identification of coherent states of spiking neural networks is a fundamental problem of
synchronization theory but conventional methods are computationally expensive. We apply
the crystallographic ideas of processing periodic structures to the analysis of various
states of spiking neuronal networks. In particular, the introduced approach is based on
the application of two-dimensional Fourier transform to rasterplots. By the position ...
Added: August 13, 2026
Beck M. E., Seidov S., Mukhin S., Physical Review A: Atomic, Molecular, and Optical physics 2026
Quantum dissipation is studied in the superradiant phase of the extended Dicke model. It is demonstrated analytically by quantum mechanical derivation of the Lindblad equation for the Dicke model in the superradiant state coupled to Caldeira-Leggett thermal bath that the effective viscosity appearing in the semiclassical equations of motion of polaritonic condensate survives in the zero-temperature limit ...
Added: August 13, 2026
Seidov S., Pugach N., Physical Review B: Condensed Matter and Materials Physics 2026
In this manuscript we consider a superconducting film in the vicinity of the critical temperature and presence of the proximity effect. We analytically solve the corresponding linearized Usadel equation and the self-consistency equation, defining the critical temperature. This is a system of coupled differential and integral equations for the anomalous Green's function and the order parameter of ...
Added: August 13, 2026
Yu Z., Wang J., Wang Z. et al., Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 2026 Vol. 384 P. 1–16
The integration of data-driven and knowledge-driven approaches in generative geospatial modelling (GGM) is often hindered by their mathematical incompatibilities. Here, we propose a geometric algebra (GA)-based framework that employs a unified multi-vector representation to fuse heterogeneous data and diverse knowledge. The framework facilitates structured reasoning and hypothesis generation through a task-adaptable, five-stage cycle: representation, reasoning, ...
Added: August 13, 2026
Ievlev E., Marshakov A., Sumbatian G. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2026 Vol. 114 Article 046006
We continue the study of non-Abelian vortex string in 4D N =2 supersymmetric QCD (SQCD) as
critical superstring, and extend this analysis to UðNÞ gauge theory with arbitrary even N and Nf = 2N
number of quarks. We introduce a special mass deformation and show that the SQCD hadron spectrum is
still given by the string spectrum on the ...
Added: August 13, 2026
Ratnikov F., Bocharnikov V., Journal of High Energy Physics 2026 Vol. 2026 P. 1–21
The BM@N experiment (Baryonic Matter at the Nuclotron) is the first fixed-target experiment at the JINR NICA accelerator complex. In this work, data on the interactions of a carbon-ion beam with kinetic energies of 4.0A GeV and 4.5A GeV with C, Al, Cu, and Pb targets are used to measure transverse momentum spectra and rapidity ...
Added: August 12, 2026
Budkov Y., Kalikin N., Journal of Chemical Physics 2026 Vol. 165 Article 064506
A self-consistent statistical-mechanical theory of the Hall effect in electrolyte solutions is developed by extending the self-consistent Debye–Hückel–Onsager (SCDHO) framework to crossed electric and magnetic fields. The theory incorporates non-local ionic charge distributions via Slater-type form factors, regularizing the Coulomb interaction at short range, and accounts for dielectric friction through ion-specific coefficients, employing experimental values ...
Added: August 12, 2026