Sergii Vakarchuk | Approximation Theory of Function | Best Paper Award

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Prof. Dr. Sergii Vakarchuk | Approximation Theory of Function | Best Paper Award

Professor | Alfred Nobel University | Ukraine

Prof. Dr. Sergii Vakarchuk of Alfred Nobel University, Ukraine, is a specialist in approximation theory, functional analysis, and polynomial approximation in weighted and unweighted L2L_2 spaces. His work focuses on establishing sharp constants, deriving exact values of n-widths, and developing inequalities of Jackson type for various classes of smooth and analytic functions. He has contributed significantly to understanding the relationships between smoothness characteristics and best approximation by algebraic and trigonometric polynomials. Through precise analytical results, including exact widths of functional classes and optimal linear approximation methods, Prof. Vakarchuk has advanced the theoretical foundations of modern approximation theory and functional spaces.

Profiles: Scopus | Orcid | Google Scholar

Featured Publications

Vakarchuk, S. B. (2004). Exact constant in an inequality of Jackson type for L2-approximation on the line and exact values of mean widths of functional classes. East Journal on Approximations, 10(1), 27–39.
Citations: 41
Year: 2004

Vakarchuk, S. B., & Zabutnaya, V. I. (2016). Inequalities between best polynomial approximations and some smoothness characteristics in the space L2 and widths of classes of functions. Mathematical Notes, 99(1), 222–242.
Citations: 39
Year: 2016

Vakarchuk, S. B., & Shvachko, A. V. (2013). On best approximation in the mean by algebraic polynomials with weight and exact values of widths of function classes. Ukrainian Mathematical Journal, 65(12), 1604–1621.
Citations: 39
Year: 2013

Vakarchuk, S. B. (2002). Exact values of widths of classes of analytic functions in the disk and best linear approximation methods. Mathematical Notes, 72(5), 665–669.
Citations: 39
Year: 2002

Vakarchuk, S. B. (2001). On best polynomial approximations in L2 of certain classes of 2π-periodic functions and exact values of their n-widths. Mathematical Notes, 70(3), 300–310.
Citations: 39
Year: 2001

Mustapha Bouallala | Numerical Analysis | Numerical Analysis Research Award

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Prof. Mustapha Bouallala | Numerical Analysis | Numerical Analysis Research Award

Mustapha Bouallala | Cadi Ayyad University | Morocco

Prof. Mustapha Bouallala, from the Polydisciplinary Faculty at Cadi Ayyad University in Safi, Morocco, specializes in applied mathematics with a focus on variational and hemivariational inequalities, contact mechanics, thermo-viscoelasticity, and fractional‐order differential models. His work emphasizes the mathematical analysis, modeling, and numerical simulation of complex physical systems governed by non-smooth dynamics, memory effects, and time-fractional derivatives. He contributes to the development of analytical frameworks for contact problems involving viscoelastic materials, locking materials, and thermo-mechanical interactions. Through rigorous mathematical modeling and approximation techniques, his research advances the understanding of nonlinear evolutionary problems and supports applications in engineering mechanics, material behavior, and thermal–structural interaction systems.

Profiles: Scopus | Orcid 

Featured Publications

Bouallala, M., Essoufi, E.-H., & Ouafik, Y. (2026). Modeling and simulation of time-fractional derivative contact problem in thermo-viscoelasticity. Rendiconti del Circolo Matematico di Palermo Series 2. https://doi.org/10.1007/s12215-025-01318-1
Year: 2026

Ouaanabi, A., Alaoui, M., Bouallala, M., & Essoufi, E.-H. (2025). Continuous dependence result for a class of evolutionary variational-hemivariational inequalities with application to a dynamic thermo-viscoelastic contact problem. Acta Applicandae Mathematicae. https://doi.org/10.1007/s10440-025-00707-z
Year: 2025

Bouallala, M., Bourichi, S., Essoufi, E. H., & Rahnaoui, H. (2025). Approximation of solution for unilateral contact problem with locking materials. Mathematical Methods in the Applied Sciences. https://doi.org/10.1002/mma.70131
Year: 2025

Bouallala, M., Ouafik, Y., & Bendarag, A. (2025). Analysis of a thermo-viscoelastic contact problem with normal damped response, unilateral constraint and memory term. SeMA Journal. https://doi.org/10.1007/s40324-025-00418-3
Year: 2025

Aharrouch, B., & Bouallala, M. (2025). Convergence analysis of Kantorovich-type operators in variable exponent Sobolev spaces. Georgian Mathematical Journal. https://doi.org/10.1515/gmj-2025-2089
Year: 2025