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Intransitive machines
The intransitive cycle of superiority is characterized by such binary relations between A, B, and C that A is superior to B, B is superior to C, and C is superior to A (i.e., A>B>C>A—in contrast with transitive relations A>B>C). The first part of the article presents a brief review of studies of intransitive cycles in various disciplines (mathematics, biology, sociology, logical games, decision theory, etc.), and their reflections in educational materials. The second part of the article introduces the issue of intransitivity in elementary physics. We present principles of building mechanical intransitive devices in correspondence with the structure of the Condorcet paradox, and describe five intransitive devices: intransitive gears; levers; pulleys, wheels, and axles; wedges; inclined planes. Each of the mechanisms are constructed as compositions of simple machines and show paradoxical intransitivity of relations such as “to rotate faster than”, “to lift”, “to be stronger than” in some geometrical constructions. The article is an invitation to develop teaching materials and problems advancing the understanding of transitivity and intransitivity in various areas, including physics education.
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English
Селянин Ф. И., Journal of Dynamical and Control Systems 2026 Vol. 32 No. 2 P. 1–16
A B-facet is a lattice -dimensional polytope in the positive octant with a positive normal covector, such that every -dimensional simplex with vertices in it is a B-simplex (i.e., a pyramid of height one with base on a coordinate hyperplane). B-facets were introduced in [2] in the context of the monodromy conjecture. In this paper, we complete the ...
Added: May 21, 2026
Denis Seliutskii, Russian Journal of Mathematical Physics 2025 Vol. 32 No. 2 P. 399–407
In this paper, we find an upper bound for the first Steklov eigenvalue for a surface of revolution with boundary consisting of two spheres of different radii. Moreover, we prove that, in some cases, this boundary is sharp. ...
Added: May 19, 2026
Viacheslav K., Русский инженер 2024 № 3 С. 34–37
Analysis of various methods referred to the increasing energy efficiency and movement safety through the use of
control systems which take into account the force factors of interaction of the wheel propeller with the supporting surface. During
the analysis of methods dedicated to energy efficiency rise and were used techniques of logical and statistical analysis. There are
various ...
Added: May 19, 2026
Жакупов О. Б., European Journal of Mathematics 2025 Vol. 11 Article 84
We provide examples of smooth three-dimensional Fano complete intersections of degree 2, 4, 6, and 8 that have absolute coregularity 0. Considering the main theorem of Avilov, Loginov, and Przyjalkowski (CNTP 18:506–577, 2024) on the remaining 101 families of smooth Fano threefolds, our result implies that each family of smooth Fano threefolds has an element of absolute ...
Added: May 18, 2026
Zamkovaya M., Педагогика и психология образования 2026 № 1 С. 57–67
В статье рассматривается процесс становления системы билингвального образования в Республике Сербия с акцентом на его цели, достижения и существующие вызовы. Отмечается, что несмотря на положительные результаты, образовательные учреждения сталкиваются с рядом проблем, среди которых недостаточное финансирование, нехватка квалифицированных специалистов и отсутствие четкой нормативно-правовой базы, регламентирующей процесс билингвального обучения. В статье также анализируются результаты эмпирических исследований, ...
Added: May 18, 2026
Андреева О. С., Просвещение, 2023.
Эта книга о том, как воспитать финансово грамотных детей. Не так важно, какой уровень дохода в вашей семье: умение зарабатывать, сберегать и тратить поможет вашим детям достичь благополучия в будущем. Все необходимые навыки для реальной сложной и порой трудной жизни вы должны вложить в детей сами.
Эта книга – пособие, которое поможет родителям понятно, последовательно и ...
Added: May 18, 2026
Андреева О. С., Росмэн-Пресс, 2026.
«Деньги. Энциклопедия российского школьника» кратко и емко расскажет:
· Чем в древности платили за товары
· Как выглядели первые деньги, из чего их делали и где хранили
· Как найти клад и можно ли выиграть в лотерею
· Как работает банк
· Как дети и подростки могут зарабатывать и распоряжаться личным бюджетом
· И еще сотни интересных научно-обоснованных фактов
Книга поможет мальчикам ...
Added: May 18, 2026
Андреева О. С., Просвещение, 2024.
В книге собраны рекомендации и практические советы приёмным родителям, с помощью которых можно сформировать у детей правильное отношение к денежным средствам, рассказывается, какими словами объяснять понятные взрослым истины относительно личных и семейных финансов ребёнку любого возраста. Одной из задач книги стала необходимость объяснения этого феномена — потребительского отношения приёмных детей к труду замещающих родителей, к ...
Added: May 18, 2026
Pavliuk D., Higher Education 2026
The literature on doctoral students’ experience rarely examines the importance of thesis topic characteristics, even though this is one of the central decisions both at the start and throughout the doctoral journey. Although studies examine how students choose their thesis topics, there is little research on how different topic characteristics are linked to doctoral experience ...
Added: May 16, 2026
Kolachev N., Kovaleva G., Educational Research and Evaluation 2026 P. 1–24
This study investigates the psychometric structure and school-level associations between cognitive abilities of teachers and students. Using a cross-sectional quantitative design, we administered a PISA-based cognitive assessment tool measuring reading, mathematics, science literacy, and global competence to 5,391 eighth-grade students and 2,385 teachers from 84 schools in a Russian region. Bifactor modeling, measurement invariance testing, ...
Added: May 15, 2026
Gonchenko S., Lerman L., Turaev D., Regular and Chaotic Dynamics 2026 Vol. 31 No. 3 P. 349–369
We show that bifurcations of four-dimensional symplectic diffeomorphisms with a quadratic homoclinic tangency to a saddle periodic orbit with real multipliers produce 2-elliptic periodic orbits if the tangency is not partially hyperbolic. We show that a normal form for the rescaled first-return maps near such tangency is given by a four-dimensional symplectic H´enonlike map and study bifurcations of the ...
Added: May 15, 2026
Aleskerov F. T., Khutorskaya O., Stepochkina A. et al., Springer, 2026.
The book contains new models of bibliometric analysis based on centrality measures in network analysis, pattern analysis and stability analysis. A distinctive feature of these centrality measures is that they account for the parameters of vertices and group influence of vertices to a vertex. This reveals specific groups of publications, authors, terms, journals and affiliations ...
Added: May 15, 2026
Kuptsov P., Panyushev A., Stankevich N., Chaos 2026 Vol. 36 No. 5 Article 053138
We develop a machine-learning approach to reproduce the behavior of two versions of the van der Pol oscillator exhibiting a subcritical Andronov–Hopf bifurcation, with or without a codimension-2 Bautin point. We construct a neural-network model that functions as a recur rent map and train it on short segments of oscillator trajectories. The results show that, ...
Added: May 15, 2026
Dorovskiy A., / Series arXiv "math". 2026.
In this paper the structural stability of generic families of vector fields of the PC-HC class on the two-dimensional sphere is proved. A classification of these families up to moderate equivalence in neighborhoods of their large bifurcation supports is presented, based on such invariants as the configuration and the characteristic set. The realization lemma is proved. ...
Added: May 14, 2026
Lebedev V., Journal of Mathematical Analysis and Applications 2026 Vol. 563 No. 2 Article 130787
It is known that for every continuous real-valued
function $f$ on the circle $\mathbb T=\mathbb R/2\pi\mathbb Z$ there exists a
change of variable, i.e., a self-homeomorphism $h$ of $\mathbb T$, such that
the superposition $f\circ h$ is in the Sobolev space $W_2^{1/2}(\mathbb T)$.
We obtain new results on simultaneous improvement of functions by a single
change of variable in relation ...
Added: May 14, 2026
Taletskii D., / Series arXiv "math". 2026.
A vertex subset of a graph is called a \textit{distance-$k$ independent set} if the distance between any two of its distinct vertices is at least $k + 1$. For all $n,k \geq 1$, we determine the minimum possible number of inclusion-wise maximal distance-$k$ independent sets among all $n$-vertex trees. It equals~$n$ if $n \leq k ...
Added: May 1, 2026
Ovcharenko M., / Series arXiv "math". 2026.
We introduce an explicit class of tempered Laurent polynomials in the sense of Villegas and Doran--Kerr in n⩽4 variables including all Landau--Ginzburg models for smooth Fano threefolds with very ample anticanonical class. We check that it contains Landau--Ginzburg models for various Fano fourfolds which are complete intersections in smooth toric varieties and Grassmannians of planes, ...
Added: April 30, 2026
Strizhkova D., / Институт русской литературы (Пушкинский Дом) РАН. Серия B001 "Репозиторий открытых данных по русской литературе и фольклору". 2026.
В базе данных представлена роспись русскоязычных литературных произведений и отрывков, напечатанных в учебниках по словесности, хрестоматиях, книгах для чтения, сборниках стихотворений и рассказов, выходивших во Франции, Германии, Латвии, Эстонии, Болгарии, Сербии в период первой волны русской эмиграции с 1918 по 1939 гг. Датасет представляет интерес для исследователей школьного литературного канона, эмиграции и детского чтения ...
Added: April 22, 2026
Жигунов А. Ю., / Basic Research Programme. Серия HUM "Humanities". 2026. № 1.
The article attempts to describe the features of the educational potential of Russian animation programmes in aspect of the representation of traditional spiritual and moral values. Based on media and semiotic analysis, the method of cultural and historical interpretation, animated Russian projects created from 2000 to the 2025, which were translated on television channels or streaming ...
Added: April 19, 2026
Zlotnik Alexander, / Series arXiv "math". 2026. No. 2602.03481v1.
We deal with the global in time weak solutions to the 1D compressible Navier-Stokes system of equations for large discontinuous initial data and nonhomogeneous boundary conditions of three standard types. We prove the Lipschitz-type continuous dependence of the solution $(\eta,u,\theta)$, in a norm slightly stronger than $L^{2,\infty}(Q)\times L^2(Q)\times L^2(Q)$, on the initial data $(\eta^0,u^0,e^0)$ in a ...
Added: April 18, 2026
Medvedev V., / Series arXiv "math". 2026.
We investigate the interplay between the dimension of the space of static potentials and the geometric and topological structure of the underlying static three-manifold. A partial classification of boundaryless static manifolds is obtained in terms of this dimension. We also treat the case of static manifolds with boundary. In particular, we prove that if a ...
Added: April 3, 2026
Gabdullin N., Androsov I., / Series Computer Science "arxiv.org". 2026.
Label prediction in neural networks (NNs) has O(n) complexity proportional to the number of classes. This holds true for classification using fully connected layers and cosine similarity with some set of class prototypes. In this paper we show that if NN latent space (LS) geometry is known and possesses specific properties, label prediction complexity can ...
Added: April 2, 2026
Kolesnikov A., / Series arXiv "math". 2025.
We study Blaschke--Santal{ó}-type inequalities for N>=2 sets (functions) and a special class of cost functions. In particular, we prove new results about reduction of the maximization problem for the Blaschke--Santal{ó}-type functional to homogeneous case (functional inequalities on the sphere) and extend the symmetrization argument to the case of N>2 sets.
We also discuss links to the ...
Added: February 13, 2026
Sorokin K., Beketov M., Онучин А. et al., / arxiv.org. Серия cs.SI "Social and Information Networks ". 2025.
Community detection in complex networks is a fundamental problem, open to new approaches in various scientific settings. We introduce a novel community detection method, based on Ricci flow on graphs. Our technique iteratively updates edge weights (their metric lengths) according to their (combinatorial) Foster version of Ricci curvature computed from effective resistance distance between the ...
Added: January 15, 2026