Search results for "MATHEMATICS"
showing 10 items of 22031 documents
Acoustic wave guides as infinite-dimensional dynamical systems
2015
We prove the unique solvability, passivity/conservativity and some regularity results of two mathematical models for acoustic wave propagation in curved, variable diameter tubular structures of finite length. The first of the models is the generalised Webster's model that includes dissipation and curvature of the 1D waveguide. The second model is the scattering passive, boundary controlled wave equation on 3D waveguides. The two models are treated in an unified fashion so that the results on the wave equation reduce to the corresponding results of approximating Webster's model at the limit of vanishing waveguide intersection.
Regularity and modulus of continuity of space-filling curves
2019
We study critical regularity assumptions on space-filling curves that possess certain modulus of continuity. The bounds we obtain are essentially sharp, as demonstrated by an example. peerReviewed
Envelopes for sets and functions II: generalized polarity and conjugacy
2018
International audience; Let X,Y be two nonempty sets, Φ an extended real-valued bivariate coupling function on X × Y and Γ a subset of X × Y. The present paper provides extensions to the well-known generalized Φ-conjugacy and Γ-polarity of diverse results of our previous work [2] related to φ-conjucacy and Λ-polarity, where Λ is a subset of a vector space E and φ is a function on E defining the particular coupling function (x,y)→φ(x−y) on E × E. A particular attention is devoted to the conjugacy functions (resp. polarity sets) which are mutually generating. Finally, for a superadditive conjugacy function Φ, we obtain a full description of the class of Φ-envelopes.
Engaging with feedback: How do students remediate errors on their weekly quiz
2018
International audience; Maths for Business is a first-year mathematics module for approximately 500 non-mathematics specialists. It has continuous assessment consisting of ten weekly quizzes, worth 40% of the final mark. In 2016/17, students who did not receive the maximum five marks on their weekly quiz were offered the opportunity to resubmit their quiz, with correction(s) and an explanation of their error(s), for one additional mark. We refer to this process as ‘remediation'. In this paper, we examine how students remediate their errors in order to identify features of a ‘good' remediation. These features are identification, description, and correction of errors. By analysing a subset of…
Efectos positivos en la Educación Universitaria del uso de aplicaciones basadas en la Metodología Mobile-Learning
2020
El objetivo de este trabajo es analizar cómo el rendimiento académico del alumnado puede verse influenciado por el uso de diferentes aplicaciones basadas en la metodología Mobile - Learning , el expediente académico, y la asistencia a las aulas. En particular este estudio, se centra en la forma en la cual el uso de la plataforma tecnológica Kahoot! en las aulas universitarias como herramienta complementaria a las clases magistr ales puede afectar al rendimiento académico de la asignatura. La base de datos utilizada para contrastar las hipótesis planteadas ha sido creada utilizando los datos obtenidos de 39 alumnas/os de la asignatura Dirección de Operaciones, una asignatura oblig atoria de …
Mathematical monuments in Finland
2021
With “mathematical monuments” we mean either monuments for famous mathematicians and their achievements or works of art representing mathematical objects in public places. We present a panoply of such monuments in Finland for the purposes of the mathematical tourist visiting our country. As we are interested in symbolic representations of science, we take a broad view of the notion of “monument” and take into account also some minor artefacts, such as portraits, medals and stamps, and other semiotic signs, such as street names and commemorative plates, illustrating some highlights of the history of mathematics in Finland. Peer reviewed
Residual a posteriori error estimation for frictional contact with Nitsche method
2023
We consider frictional contact problems in small strain elasticity discretized with finite elements and Nitsche method. Both bilateral and unilateral contact problems are taken into account, as well as both Tresca and Coulomb models for the friction. We derive residual a posteriori error estimates for each friction model, following [Chouly et al, IMA J. Numer. Anal. (38) 2018, pp. 921-954]. For the incomplete variant of Nitsche, we prove an upper bound for the dual norm of the residual, for Tresca and Coulomb friction, without any extra regularity and without a saturation assumption. Numerical experiments allow to assess the accuracy of the estimates and their interest for adaptive meshing …
Introduction to Mathematical Logic, Edition 2021
2021
Textbook for students in mathematical logic. First order languages. Axioms of constructive and classical logic. Proving formulas in propositional and predicate logic. Glivenko's theorem and constructive embedding. Axiom independence. Interpretations, models and completeness theorems. Normal forms. Tableaux and resolution methods. Herbrand's theorem. Sections 1, 2, 3 represent an extended translation of the corresponding chapters of the book: V. Detlovs, Elements of Mathematical Logic, Riga, University of Latvia, 1964, 252 pp. (in Latvian).
Lake size and fish diversity determine resource use and trophic position of a top predator in high-latitude lakes
2015
Prey preference of top predators and energy flow across habitat boundaries are of fundamental importance for structure and function of aquatic and terrestrial ecosystems, as they may have strong effects on production, species diversity, and food-web stability. In lakes, littoral and pelagic food-web compartments are typically coupled and controlled by generalist fish top predators. However, the extent and determinants of such coupling remains a topical area of ecological research and is largely unknown in oligotrophic high-latitude lakes. We analyzed food-web structure and resource use by a generalist top predator, the Arctic charr Salvelinus alpinus (L.), in 17 oligotrophic subarctic lakes…
Operators in Rigged Hilbert Spaces, Gel’fand Bases and Generalized Eigenvalues
2022
Given a self-adjoint operator A in a Hilbert space H, we analyze its spectral behavior when it is expressed in terms of generalized eigenvectors. Using the formalism of Gel’fand distribution bases, we explore the conditions for the generalized eigenspaces to be one-dimensional, i.e., for A to have a simple spectrum.