Essays about: "numerical solution"

Showing result 1 - 5 of 303 essays containing the words numerical solution.

  1. 1. Gravitational Collapse of a Massless Scalar Field in a Theory of Minimally Modified Gravity

    University essay from KTH/Fysik

    Author : Atabak Fathe Jalali; [2024]
    Keywords : Theoretical physics; astrophysics; modified gravity; minimally modified gravity; gravitational collapse; VCDM; scalar collapse; apparent horizon; numerical relativity; Teoretisk fysik; astrofysik; modifierad gravitation; minimalt modifierad gravitation; gravitationskollaps; VCDM; skalär kollaps; uppenbar horisont; numerisk relativitet;

    Abstract : This thesis explores the spherically symmetric gravitational collapse of a massless scalar field in a minimally modified gravity theory denoted VCDM (V replaces $\Lambda$ in the $\Lambda$CDM abbreviation), a class of theories propagating the same degrees of freedom as general relativity at the expense of broken 4D diffeomorphism invariance. Numerical evolution of the equations of motion reveals that for small initial scalar profile amplitudes, no black hole forms from the collapse. READ MORE

  3. 2. Robust Aircraft Positioning using Signals of Opportunity with Direction of Arrival

    University essay from Linköpings universitet/Reglerteknik

    Author : Erik Axelsson; Sebastian Fagerstedt; [2023]
    Keywords : Simultaneous localisation and mapping; direction of arrival; signals of opportunity; extended Kalman filter; positioning;

    Abstract : This thesis considers the problem of using signals of opportunity (SOO) with known direction of arrival (DOA) for aircraft positioning. SOO is a collective name for a wide range of signals not intended for navigation but which can be intercepted by the radar warning system on an aircraft. READ MORE

  4. 3. SECOND-ORDER DIVERGENCE-FREE FEM FOR MAGNETOHYDRODYNAMICS USING LAGRANGE POLYNOMIALS

    University essay from Uppsala universitet/Institutionen för informationsteknologi

    Author : Erik Björklund; Peter Mårtensson; Noah Waltman; [2023]
    Keywords : ;

    Abstract : AbstractMaxwell’s laws state that the divergence of a magnetic field always remains zero. In thecontinuous setting this is true for the magnetohydrodynamics equations. However, in thediscrete setting, the solution does not always remain divergence-free. READ MORE

  5. 4. Virtual Sensing for Cluster Vacuum Control

    University essay from KTH/Skolan för industriell teknik och management (ITM)

    Author : Carl Egenäs; Axel Sacilotto; [2023]
    Keywords : ;

    Abstract : The purpose of this project was to develop a virtual sensing model in order to estimate the vacuum level in the milking cluster with data collected further along the milk tube. Measuring the cluster vacuum level is desirable for many applications, such as control and monitoring, but due to the cow's tendency to kick, chew and stomp on anything within reach, placing a sensor in or close to the cluster is both difficult and impractical. READ MORE

  6. 5. Multiple-Emitter Super-resolution Imaging using the Alternating Descent Conditional Gradient Method

    University essay from Lunds universitet/Beräkningsbiologi och biologisk fysik - Genomgår omorganisation; Lunds universitet/Institutionen för astronomi och teoretisk fysik - Genomgår omorganisation

    Author : Dolev Illouz; [2023]
    Keywords : super-resolution; alternating descent conditional gradient method; ADCG; multiple-emitter localization; nanoscale imaging; single molecule tracking; Physics and Astronomy;

    Abstract : This thesis examines the state-of-the-art 2D super-resolution technique alternating descent conditional gradient (ADCG) method's ability to accurately localize fluorophores in diffraction-limited single molecule images (SMI) and analyze the impact of pre-processing and post-processing modules on ADCG's fluorophore localization. A synthetic dataset obtained from the 2013 Grand Challenge localization microscopy and a temporally linked dataset obtained from an unpublished set of Optical DNA mapping experiments performed by Jonathan Jeffet at the NanoBioPhotonix Lab at Tel-Aviv University were initially segmented to extract their noise parameters. READ MORE