Essays about: "surrogate model"

Showing result 26 - 30 of 49 essays containing the words surrogate model.

1. 26. Structural optimization of electronic packages using DOE

   University essay from KTH/Hållfasthetslära

   Author : Robin Johansson; [2020]
   Keywords : Design of experiments; DOE; Structural optimization; Electronic packages; DOE; Försöksplanering; Strukturoptimering;

   Abstract : The reliability of a mechanical system containing electronic packages is highly affectedby the environment the system is stationed in. The difference and fluctuationsbetween the ambient temperature and the operating temperature of the electronicpackage cause accumulation of inelastic strains in the package components thusdecreasing the service life. READ MORE

3. 27. Analysis and Simulation Study of Stochastic Time-To-Collision as a Severity Measure in Traffic Security

   University essay from Lunds universitet/Matematisk statistik

   Author : Per Niklas Benzler Waaler; [2020]
   Keywords : time; collision; ttc; stochastic; probability; transform; transformation; traffic; data; under; estimation; post; encroachment; mixture; distribution; simulation; study; encounter; conflict; trajectory; prediction; road; user; safety; severity; surrogate; measure; Mathematics and Statistics;

   Abstract : Traffic accidents are extremely rare, creating the need for surrogate methods for safety analysis that makes efficient use of the information provided by traffic conflicts, which also are limited in availability. The severity measure time-to-collision (TTC) in combination with extreme value theory have so far been one of the primary measures used to infer traffic safety levels, but it relies on unrealistic assumptions that results in severity measures that do not always agree well with observed danger. READ MORE

4. 28. Determining the Sensitivity of Reactor Parameters in a Sodium Cooled Fast Reactor

   University essay from Uppsala universitet/Tillämpad kärnfysik

   Author : Alexander Palfelt; Wilhelm Thunberg; Anders Winka; [2020]
   Keywords : serpent; SFR; sodium cooled fast reactor; generation 4;

   Abstract : The sensitivity of two operational output parameters, criticality and isotopic composition during burnup, to specific design and operational reactor parameters in a Sodium Cooled Fast Reactor, is investigated. The computational simulation tool Serpent is used. READ MORE

5. 29. Statistical Inference for Traffic Safety Analysis Using the Generalized Pareto Distribution

   University essay from Lunds universitet/Matematisk statistik

   Author : Emilsson Sara; Filip Vestin; [2020]
   Keywords : Extreme value theory; traffic safety analysis; surrogate measure of safety; maximum likelihood; delta method; profile likelihood; modified profile likelihood.; Mathematics and Statistics;

   Abstract : This thesis investigates the possibility of computing interval estimates for metrics that pertain to traffic safety based on surrogate measures of safety. A probabilistic model of the (near) crash count is defined using the generalized Pareto distribution and three different methods for calculating confidence intervals for the corresponding intensity parameter are proposed. READ MORE

6. 30. Multitask Convolutional Neural Network Emulators for Global Crop Models - Supervised Deep Learning in Large Hypercubes of Non-IID Data

   University essay from Lunds universitet/Matematisk statistik

   Author : Amanda Nilsson; [2020]
   Keywords : Multitask Learning; Convolutional Neural Network CNN ; Branched Neural Network; Dynamic Global Vegetation Models DGVM ; Automated Feature Extraction; Feature Importance; Supervised Machine Learning; Emulator; Surrogate Model; Response Surface Model; Approximation Model; Metamodeling; Model Composition; Regularization; Robustness; Hyperparameter Optimization; Mathematics and Statistics;

   Abstract : The aim of this thesis is to establish whether a neural network (NN) can be used for emulation of simulated global crop production - retrieved from the computationally demanding dynamic global vegetation model (DGVM) Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS). It has been devoted to elaboration with various types of neural network architectures: Branched NNs capable of processing inputs of mixed data types; Convolutional Neural Network (CNN) architectures able to perform automated temporal feature extraction of the given weather time series; simpler fully connected (FC) structures as well as Multitask NNs. READ MORE