Essays about: "nonlinear propagation"

Showing result 1 - 5 of 15 essays containing the words nonlinear propagation.

  1. 1. Nonlinear Methods of Aerodynamic Data-driven Reduced Order Modeling

    University essay from Uppsala universitet/Avdelningen för beräkningsvetenskap

    Author : Arvid Forsberg; [2022]
    Keywords : machine learning; aerodynamics; autoencoder; kernel transformation; principal component analysis; nonlinear; regression; modeling; surrogate model; reduced order modeling; neural network;

    Abstract : Being able to accurately approximate outputs of computationally expensive simulations for arbitrary input parameters, also called missing points estimation, is central in many different areas of research and development with applications ranging from uncertainty propagation to control system design to name a few. This project investigates the potential of kernel transformations and nonlinear autoencoders as methods of improving the accuracy of the proper orthogonal decomposition method combined with regression. READ MORE

  2. 2. III-V semiconductor waveguides for application in nonlinear optics.

    University essay from KTH/Tillämpad fysik

    Author : Andreas Charalampous; [2022]
    Keywords : InGaP; optical waveguides; integrated optics; quantum nonlinear optics; SHG; SPDC; InGaP; optiska vågledare; integrerad optik; icke-linjär kvantoptik; SHG; SPDC;

    Abstract : This thesis presents studies on III-V semiconductor waveguides with particular emphasis on second-order optical nonlinearity. The nonlinear processes that were investigated in this thesis are the Second Harmonic Generation (SHG) and the Spontaneous Parametric Down-Conversion (SPDC). READ MORE

  3. 3. Evaluation of Target Tracking Using Multiple Sensors and Non-Causal Algorithms

    University essay from Linköpings universitet/Reglerteknik

    Author : Albin Vestin; Gustav Strandberg; [2019]
    Keywords : evaluation; target tracking; multiple sensors; non-causal; smoother; smoothing; tracking; vehicle tracking; camera; lidar; estimate; estimation; prediction; vehicle dynamics; sensor fusion; real-time tracking; extended kalman filter; filter validation; validation; position estimation; velocity estimation; dynamic model; model complexity; multi object tracking; multiple object; tracking; single object tracking; data association; tracking fundamentals; iterated kalman filter; track management; gnn; global nearest neighbour; mahalanobis; mahalanobis distance; performance evaluation; differential gps; dgps; roi; ego; several sensors; sensors; rmse; root mean square error; invertible motion; anti-causal motion; anti-causal tracking; constant velocity; gnn; imu; tfs; two filter smoother; ekf; rts; radar; inertial measurement unit; nonlinear; nonlinear systems; mono camera; monocular camera; noise model; tracking performance; fixed interval smoothing; m n logic; centralized fusion; non-causal object tracker; car tracking; car dynamics; automotive; active safety; object tracking; automotive industry; thesis; master; reverse dynamics; reverse tracking; reverse sequence; sequence tracking; data propagation; ground truth; estimating ground truth; additional sensors; mounted sensors; true estimates; environment; comparison; algorithm; independent targets; overlapping; measurements; occluded; track switch; improve; lower; uncertainty; more; certain; state; process; noise; covariance; sampling; image; sprt; adas; cnn; cv; pdf; track; target; ego; tracker; tentative track; observatiom; online tracking; offline tracking; online; offline; recorded; sequences; robust; self driving; self-driving; car; traffic; trajectory; true state; scenario; scenarios; future; accurate; output; advanced; driver; assistance; systems; non-linear; complex noise; pedestrian; truck; bus; maneuvering; vehicles; processed; measurement; frame; state; correction; probability; density; function; tuning; likelihood; transition; measurement; motion; model; recursion; gaussian; approximation; distribution; linear; jacobian; multiplicative; noise; ratio; ad; hoc; ad hoc; state; space; approach; backward; auction; euclidean; distance; statistical; threshold; gating; association; margin; normalize; covariance; matrix; fusion; confirmed; rejected; tentative; history; absolute; error; modular; ego motion; parameters; variables; logg; hardware; specification; fused; causal; factorization; independent; uncorrelated; transform; moving; rotation; translation; oncoming; overtaking;

    Abstract : Today, the main research field for the automotive industry is to find solutions for active safety. In order to perceive the surrounding environment, tracking nearby traffic objects plays an important role. READ MORE

  4. 4. Analysis of the Representation of Orbital Errors and Improvement of their Modelling

    University essay from Luleå tekniska universitet/Institutionen för system- och rymdteknik

    Author : Mini Gupta; [2018]
    Keywords : Space debris; space situational awareness; uncertainty characteristics; Gaussianity;

    Abstract : In Space Situational Awareness (SSA), it is crucial to assess the uncertainty related to thestate vector of resident space objects (RSO). This uncertainty plays a fundamental role in, forexample, collision risk assessment and re-entry predictions. A realistic characterization of thisuncertainty is, therefore, necessary. READ MORE

  5. 5. Evaluation of white-light generation as possible seed for a mid-infrared optical parametric chirped pulse amplifier

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

    Author : Chuang Lu; [2017]
    Keywords : nonlinear linear optics; ultrafast optics; Mid-infrared generation; near-infrared; Optical parametric amplification; Optical Parametric Chirped-pulse Amplification; supercontinuum generation; white-light generation; laser induced filamentation; Dispersion-scan; nonlinear propagation; Physics and Astronomy;

    Abstract : White-light spectra of different crystals, based on 1030-nm intense pump pulses have been investigated in order to derive a near-infrared seed for mid-infrared generation. Among ten crystals, YAG (yttrium aluminium garnet), KGW (potassium gadolinium tungstate) and YVO4 (yttrium orthovanadate) exhibit the most suitable properties for supercontinuum generation with high efficiency for spectral broadening as well as high tolerance to optical damage. READ MORE