Browsing Institutt for matematiske fag by Title
Now showing items 2449-2468 of 2558
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Ultraprodukter og anvendelser i kommutativ algebra
(Bachelor thesis, 2024)Denne oppgaven gir en introduksjon til ultraprodukter, med sikte for å gjøre algebra med dem. Ultraproduktet, en konstruksjon fra modellteorien, er et slags gjennomsnitt av objektene det tar inn: Et ultraprodukt av ringer ... -
Unbounded HIBE with Tight Security
(Peer reviewed; Journal article, 2020)We propose the first tightly secure and unbounded hierarchical identity-based encryption (HIBE) scheme based on standard assumptions. Our main technical contribution is a novel proof strategy that allows us to tightly ... -
Uncertainty Assessment in Ensemble Kalman Filters
(Doktoravhandlinger ved NTNU, 1503-8181; 2009:246, Doctoral thesis, 2009) -
Uncertainty Measures and Transfer Learning in Active Learning for Text Classification
(Master thesis, 2019)Dyp læring har blitt et fremtredende og populært verktøy i et bredt spekter av applikasjoner som omhandler behandling av komplekse data. For å kunne trene en modell tilstrekkelig, er imidlertid dyp læring avhengig av store ... -
Uncertainty principle via variational calculus on modulation spaces
(Journal article; Peer reviewed, 2022)We approach uncertainty principles of Cowling-Price-Heis-enberg-type as a variational principle on modulation spaces. In our discussion we are naturally led to compact localization operators with symbols in modulation ... -
Uncertainty Principles in Time-Frequency Analysis – Fractals and Schrödinger Evolutions
(Doctoral theses at NTNU;2023:162, Doctoral thesis, 2023)In this thesis we study two uncertainty principles from the perspective of timefrequency analysis. The first part, to which a significant portion is dedicated, is concerned with deriving an analog in the joint time-frequency ... -
Uncertainty propagation through a point model for steady-state two-phase pipe flow
(Peer reviewed; Journal article, 2020)Uncertainty propagation is used to quantify the uncertainty in model predictions in the presence of uncertain input variables. In this study, we analyze a steady-state point-model for two-phase gas-liquid flow. We present ... -
Unconditionally Secure NIZK in the Fine-Grained Setting
(Peer reviewed; Journal article, 2022)Non-interactive zero-knowledge (NIZK) proof systems are often constructed based on cryptographic assumptions. In this paper, we propose the first unconditionally secure NIZK system in the AC0 -fine-grained setting. More ... -
Uncovering the drivers of host-associated microbiota with joint species distribution modelling
(Journal article; Peer reviewed, 2018)In addition to the processes structuring free‐living communities, host‐associated microbiota are directly or indirectly shaped by the host. Therefore, microbiota data have a hierarchical structure where samples are nested ... -
Understanding module categories through triangulated categories using Auslander-Reiten theory
(Doctoral thesis at NTNU;2016:223, Doctoral thesis, 2016) -
Understanding the Population Structure Correction Regression
(Peer reviewed; Journal article, 2022) -
Ungulate population monitoring in an open tundra landscape:distance sampling versus total counts
(Journal article; Peer reviewed, 2017)Researchers and wildlife managers strive for low bias and high precision (i.e. high accuracy) when estimating animal population sizes. Distance sampling is currently one of the most widely used monitoring methods. However, ... -
Uniform tail estimates and Lp(RN)-convergence for finite-difference approximations of nonlinear diffusion equations
(Journal article; Peer reviewed, 2022) -
Uniformt fordelte følger og diskrepans
(Bachelor thesis, 2022) -
Unique factorization in Dedekind domains
(Master thesis, 2016)In this thesis we study ideals in Dedekind domains, which factorize uniquely into a product of prime ideals. As not every Dedekind domain is a unique factorization domain, a general element in these domains does not ... -
Unique Factorization of Ideals
(Master thesis, 2013)We study Dedekind domains, where ideals factorize uniquely into a product ofprime ideals. This subject is of interest as general elements in these rings donot necessarily factorize uniquely. -
Uniqueness and properties of distributional solutions of nonlocal equations of porous medium type
(Journal article; Peer reviewed, 2017)We study the uniqueness, existence, and properties of bounded distributional solutions of the initial value problem for the anomalous diffusion equation ∂tu−Lμ[φ(u)]=0. Here Lμ can be any nonlocal symmetric degenerate ... -
Uniqueness of conservative solutions for the Hunter–Saxton equation
(Peer reviewed; Journal article, 2022)We show that the Hunter–Saxton equation ut+uux=14(∫x−∞dμ(t,z)−∫∞xdμ(t,z)) and μt+(uμ)x=0 has a unique, global, weak, and conservative solution (u,μ) of the Cauchy problem on the line. -
Uniqueness of dissipative solutions for the Camassa-Holm equation
(Peer reviewed; Journal article, 2024)We show that the Cauchy problem for the Camassa–Holm equation has a unique, global, weak, and dissipative solution for any initial data u0 ∈H1(R), such that u0,x is bounded from above almost everywhere. In particular, we ... -
Universal Zero Dynamics: The SISO Case
(Chapter, 2021)Given a single-input, single-output (SISO) system with a Chen-Fliess series representation whose generating series has a well defined relative degree, it is shown that there is a notion of universal zero dynamics that ...