Essays about: "Motion field"

Showing result 1 - 5 of 271 essays containing the words Motion field.

  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. Prospects for a Free Electron Laser at the FemtoMAX Beamline

    University essay from Lunds universitet/Synkrotronljusfysik; Lunds universitet/Fysiska institutionen

    Author : Johan Holmberg; [2024]
    Keywords : Free Electron Lasers; FEL; synchrotron radiation; MAX IV; FemtoMAX; GENESIS 1.3; XFEL; X-rays; soft X-rays; Physics and Astronomy;

    Abstract : A Free Electron Laser (FEL), is a device that generates extremely coherent and brilliant radiation using electrons accelerated to relativistic velocities in a particle accelerator. The process utilises similar equipment to what is used at a synchrotron source like MAX IV, but in addition there is an interaction between the relativistic electron beam and the generated radiation to achieve an exponential growth in radiation intensity. READ MORE

  4. 3. Preprocessing for intravoxel incoherent motion analysis in the brain - Signal drift correction

    University essay from

    Author : Amina Warsame; [2023-04-17]
    Keywords : Medical physics; Diffusion magnetic resonance imaging; dMRI; Intravoxel incoherent motion; IVIM;

    Abstract : Diffusion magnetic resonance imaging (dMRI) is a diagnostic imaging technique that is sensitized to the movement of water molecules in tissues. Intravoxel incoherent motion (IVIM) analysis can be used to estimate blood flow in capillaries from weakly diffusion-weighted data. READ MORE

  5. 4. Heart rate estimation from wrist-PPG signals in activity by deep learning methods

    University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Author : Marie-Ange Stefanos; [2023]
    Keywords : Deep Learning; Medical Data; Signal Processing; Heart Rate Estimation; Wrist Photoplethysmography; Djup lärning; Medicinska Data; Signalbehandling; Pulsuppskattning; Handledsfotopletysmograf;

    Abstract : In the context of health improving, the measurement of vital parameters such as heart rate (HR) can provide solutions for health monitoring, prevention and screening for certain chronic diseases. Among the different technologies for HR measuring, photoplethysmography (PPG) technique embedded in smart watches is the most commonly used in the field of consumer electronics since it is comfortable and does not require any user intervention. READ MORE

  6. 5. Modulating Depth Map Features to Estimate 3D Human Pose via Multi-Task Variational Autoencoders

    University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Author : Kobe Moerman; [2023]
    Keywords : 3D pose estimation; Joint landmarks; Variational autoencoder; Multi-task model; Loss discrimination; Latent-space modulation; Depth map; 3D-positionsuppskattning; Gemensamma landmärken; Variationell autoencoder; Multitask-modell; Förlustdiskriminering; Latent-space-modulering; Djupkarta;

    Abstract : Human pose estimation (HPE) constitutes a fundamental problem within the domain of computer vision, finding applications in diverse fields like motion analysis and human-computer interaction. This paper introduces innovative methodologies aimed at enhancing the accuracy and robustness of 3D joint estimation. READ MORE