The Ammosov North-Eastern Federal University, NEFU, (in Russian: Северо-Восточный федеральный университет имени Максима Кировича Аммосова; in Sakha: М. К. Аммуоhап аатынан Хотугулуу-Илиҥҥи федеральнай университет) previously known as Yakutsk State University (in Russian: Якутский государственный университет имени Максима Кировича Аммосова), is the largest higher education institution in the Russian northeast and it is one of Russia's ten federal universities. NEFU's main campus is in Yakutsk (Sakha Republic), and it has two other campuses in Sakha (one in Mirny and one in Neryungri) as well as one in Anadyr in the Chukotka Autonomous Okrug.The official name is Ammosov North-Eastern Federal University Federal State Autonomous Educational Institution of Higher Education.[clarification needed] The undergraduate student population numbers over 16,000, while more than 500 students are engaged in postgraduate work. 1,600 academic staff are employed at the university. Of these 200 hold doctor’s degree, 800 are candidate of science degree.[citation needed] There are 15 institutes, 9 faculties, and 3 university branches in Mirny, Neryungri and Chukotka, and 5 major research institutes. 119 degree courses are available to students. The university occupies 9 buildings and 12 residence halls located mostly on the campus. 1,500,000 books, periodicals, and other items are held in the library. The university has a Geology Field Station, a Museum of Archeology and Ethnography, a botanical garden and an orangery open to staff and students' research and study. There is a stadium, swimming pool, and social centre. Students and staff have free access to the Ethernet and Wi-Fi in all university buildings and residence halls.
Efficient and structure-preserving decompositions of quaternion matrices are crucial for spectral analysis and canonical representation in multi-component systems. This paper addresses two fundamental problems: the eigen-decomposition of skew-Hermitian quaternion matrices and the Autonne-Takagi decomposition of eta-Hermitian quaternion matrices. Both problems are investigated within the established framework of the quaternion algebra and its real representation. A structure-preserving algorithm transforms the skew-Hermitian problem into the Hermitian case, ensuring spectral consistency and numerical stability, while a computational algorithm for the Autonne-Takagi decomposition produces canonical diagonal forms under unitary congruence and effectively handles quaternion non-commutativity. The proposed algorithms provide practical and stable tools for quaternion-based computations in various applications.
Environmental justice struggles in restrictive institutional contexts remain contentious and sensitive. Current research confirms that the ability of NGOs to influence government policy and corporate behavior is limited due to state suppression in such contexts. There remains no clear understanding of how the work of NGOs can positively impact policy change for environmental justice. This study examines a case of activism and interaction between two types of NGOs in response to an oil pipeline project in Russia. Their efforts contributed to a regional law that regulates assessment and compensation for Indigenous peoples. Through the lens of institutional work and issue salience, the article examines collaborative and confrontational tactics of NGOs and introduces salience work and futuring as conceptual contributions to institutional work on environmental justice.
This paper presents the results of a numerical solution of an initial-boundary value problem for the one-dimensional Kolmogorov–Petrovsky–Piskunov–Fisher (KPP-F) reaction-diffusion equation with a nonlocal integral term. The aim of the study was to demonstrate the effectiveness of an explicit finite-difference scheme for the numerical solution of a nonlocal integro-differential problem on a uniform spatio-temporal grid. The numerical results confirm that the explicit finite-difference scheme maintains stability and computational feasibility while strictly satisfying the Courant criterion. The simulation successfully reproduces characteristic nonlinear effects: propagation of traveling waves, interaction and merging of local maxima, and the formation of stable spatially periodic structures (self-oscillations).
The paper concerns the equilibrium problem for an elastic body containing a thin elastic inclusion with a local defect. The defect is modeled as a junction point between two separate inclusions, characterized by a positive damage parameter. The thin inclusion is described using the theory of thin elastic Timoshenko beam. The problem formulation involves the contact interaction of bodies of different dimensions (a 2D elastic matrix and 1D inclusions) and the junction of multiple inclusions. A variational statement of the problem and the corresponding differential formulation are presented. Delamination of the inclusion from the matrix is modeled as a crack with the inclusion bonded to one face. To prevent non-physical interpenetration of the crack faces, inequality-type boundary conditions (Signorini conditions) are imposed. The problem is formulated and analyzed using the variational inequality method, establishing the equivalence between the differential and variational statements. The main goal of the study is to develop an algorithm for the numerical solution of the problem. For this purpose, a domain decomposition method combined with the Lagrange multipliers approach is employed, reducing the problem to a saddle-point search. A Uzawa-type algorithm is constructed for this purpose. Numerical results for model problems, implemented using the FreeFem++ package, are presented.
This research presents a mixed generalized multiscale finite element method (mixed GMsFEM) algorithm for the Darcy–Forchheimer–Brinkman model in heterogeneous media. This model governs nonlinear Darcy flow with significant inertial effects at high flow velocities. The fine-grid approximation utilizes a mixed finite element method (FEM), with nonlinearity resolved via Picard iteration. The proposed model reduction approach, mixed GMsFEM, employs local spectral decomposition to construct multiscale basis functions within each local domain using a snapshot space. These basis functions effectively capture the influence of high-contrast coefficients. Numerical results for a two-dimensional heterogeneous domain demonstrate the method’s high accuracy for nonlinear problems. The investigation reveals that accuracy is weakly dependent on the magnitude of the nonlinearity.
