Mastergradsoppgaver i statistikk: Recent submissions
Now showing items 1-20 of 21
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Automatic Building Structure Extraction from Aerial Photographs using Transformers
(Mastergradsoppgave; Master thesis, 2024-06-01)This thesis explores a method for automatically extracting three-dimensional, geolocated building roof structure representations from non-orthorectified aerial photos, with a view to automate time intensive tasks that are currently handled manually. A two stage framework for 3D roof structure inference from aerial photos is proposed. A transformer-based deep learning framework is used to extract ... -
Deep Learning Based Automatic Segmentation of Gas Flares in Single Beam Echo Sounder Data
(Mastergradsoppgave; Master thesis, 2024-01-18)This thesis introduces the first study of instance segmentation applied to gas flares in single beam echo sounder data. We develop a comprehensive dataset consisting of 1,414 images, featuring 5,142 segmented objects identified as gas flare. A key contribution is the adaptation of the Brier score specifically for instance segmentation. Further, we show how to adapt the Weighted Box Fusion (WBF) ... -
Geographical study of the stroke incidence and mortality rates using Bayesian analysis
(Master thesis; Mastergradsoppgave, 2023-09-21)There is large geographical variation in the stroke incidence rate worldwide. In addition, stroke is one of the diseases with highest mortality rate. In this thesis, our main focus is to examine if there are any geographical variation in stroke incidence and mortality rates in Norway. We approach this study using models within the Bayesian framework. Before performing analysis, we first introduce ... -
Personalized optimization of blood glucose regulation: A Diabetes Mellitus case study
(Mastergradsoppgave; Master thesis, 2022-07-13)Type 1 diabetes (T1D) is a chronic autoimmune disease that leads to insulin deficiency. Consequently, the disease will lead to a poor blood glucose (BG) regulation, and in situations of high energy expenditure like exercise, a dysfunctional regulation can cause severe damage or death [5] [14]. Diabetes is responsible for one death every five seconds and financially drains approximately 11% of the ... -
Probabilistic Wind Power and Electricity Load Forecasting with Echo State Networks
(Mastergradsoppgave; Master thesis, 2022-05-15)With the introduction of distributed generation and the establishment of smart grids, several new challenges in energy analytics arose. These challenges can be solved with a specific type of recurrent neural networks called echo state networks, which can handle the combination of both weather and power consumption or production depending on the dataset to make predictions. Echo state networks ... -
Deep learning applied to fish otolith images
(Master thesis; Mastergradsoppgave, 2021-11-14)This thesis is concerned with classification and regression using deep learning applied to fish otolith images. Otoliths (earstones) are calcified structures in the inner ear of vertebrates, and are used, for instance, in fish stock assessment and fish age determination. We use convolutional neural networks – a class of deep learning models - on two specific problems: discrimination between Northeast ... -
Automatic detection of the mental foramen for estimating mandibular cortical width in dental panoramic radiographs
(Mastergradsoppgave; Master thesis, 2021-12-15)Screening tests are vital for detecting diseases, especially at early stages, where efforts can prevent further illness. For example, osteoporosis is a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, resulting in bone fragility and susceptibility to fracture. Dual-energy x-ray absorptiometry is commonly used to diagnose osteoporosis since ... -
Modelling of Viral Disease Risk
(Mastergradsoppgave; Master thesis, 2021-06-19)Covid-19 has had a significant impact on daily life since the initial outbreak of the global pandemic in late 2019. Countries have been affected to varying degrees, depending on government actions and country characteristics such as infrastructure and demographics. Using Norway and Germany as a case study, this thesis aims to determine which factors influence the risk of infection in each country, ... -
Power Flow Optimization with Graph Neural Networks
(Mastergradsoppgave; Master thesis, 2021-06-01)Power flow analysis is an important tool in power engineering for planning and operating power systems. The standard power flow problem consists of a set of non-linear equations, which are traditionally solved using numerical optimization techniques, such as the Newton-Raphson method. However, these methods can become computationally expensive for larger systems, and convergence to the global optimum ... -
Trans-dimensional inference over Bayesian neural networks
(Master thesis; Mastergradsoppgave, 2021-06-03)Trans-dimensional Bayesian inference for multi-layer perceptron architectures of varying size by reversible jump Markov chain Monte Carlo is developed and examined for its theoretical and practical merits and considerations. The algorithm features the No-U-Turn Sampler and Hamiltonian Monte Carlo for within-dimension moves, and makes use of a delayed-rejection sampler while exploring a variety of ... -
A Step Towards Deep Learning-based CADs for Cancer Analysis in Medical Imaging
(Master thesis; Mastergradsoppgave, 2019-06-01)In 2018, cancer was the second leading cause of death worldwide. Early detection can reduce mortality. Screening programs intended for early detection increases the workload for clinicians. To improve efficiency CAD systems would be highly beneficial. We have developed CAD systems using deep learning, for automatic tissue segmentation and prediction of diagnosis in lung and breast cancer. The ... -
Bayesian analysis of the occurrence of myocardial infarction in the LGM framework
(Master thesis; Mastergradsoppgave, 2019-05-21)The goal of this thesis is analyse the incidence rate of the first ever myocardial infarction (MI) and the survival time after the MI. The data used for this purpose is from the Troms\o{} study surveys collected in the period from 1974 to 2008. This thesis provides a general introduction to latent Gaussian models and the methodology of integrated nested Laplace approximation. Specifically, the data ... -
Bayesian analysis of temporal and spatial trends of house prices in Norway
(Master thesis; Mastergradsoppgave, 2018-09-21)The goal of this thesis is to analyse the temporal and spatial trends of house prices in Norway in a Bayesian setting. We will perform regression analysis of the data which will be modelled using structured additive regression models. This choice was made because structured additive regression models can be put into a computational framework of latent Gaussian models that can be analysed using ... -
Dirichlet process cluster kernel
(Master thesis; Mastergradsoppgave, 2017-05-16)This thesis aims to apply the Dirichlet process mixture model to the cluster kernel framework. The probabilistic cluster kernel is extended with a Bayesian nonparametric model to avoid critical parameters within the model. The Dirichlet process cluster kernel demonstrate advantages compared to the probabilistic cluster kernel in both classification and clustering. Additionally, the two dimensional ... -
Modelling and analysis of health care services using regression and Markov models
(Master thesis; Mastergradsoppgave, 2017-05-12)Using data from electronic health records this thesis aims to model and analyse health care services provided to adult patients with chronic conditions. Two aspects of health care services, with unique aims, have been examined. The first aspect is related to the aim of investigating factors affecting the patients' self experienced quality of the health care encounters with regards to satisfaction, ... -
Empirical analysis of time-lagged cross-correlations in the Norwegian Stock Market. A discussion of the Efficient Market Hypothesis
(Master thesis; Mastergradsoppgave, 2016-12-15)In this thesis we challenge the existence of weak efficiency in the Norwegian Stock Marked, by analysing time-lagged cross-correlations between log-return series from 811 stocks listed on the Oslo stock exchange and by creating prediction strategies based on the discovered patterns. We limit the strategies to predicting the direction of the movements of the time series only, i.e. either generating ... -
Separation of fish stocks by otoliths: Image representation, Fourier approximation and discrimination
(Master thesis; Mastergradsoppgave, 2015-05-18)In this thesis the entire process of Fourier Contour Analysis have been investigated for potential sources of bias. No potential biases has been found when creating the contour, however it has been shown there is a slight bias in which otoliths get invalidated by breakage. A probablity based sampling strategy has been suggested instead of the previously used stratification based. It has been shown ... -
A threshold cointegration analysis of Norwegian interest rates
(Master thesis; Mastergradsoppgave, 2012-04)In this thesis we generalize the Hansen and Seo test in the R package tsDyn, which tests a linear cointegration model against a two-regime threshold cointegration model, to the case of three regimes in the alternative hypothesis. As the Lagrange Multiplier test statistic used in the Hansen and Seo test in tsDyn is different from the LM statistic described in Hansen and Seo (2002), we generalize ... -
Applying the ICM algorithm for separating pictures consisting of two main parts, background and object application to fMRI recordings and mole pictures
(Master thesis; Mastergradsoppgave, 2009-05-15)This work concentrates on using the ICM algorithm for image restoration. The algorithm has been applied to fMRI recordings and mole pictures -
Statistical analysis of CGPS time series
(Master thesis; Mastergradsoppgave, 2007)All points on the surface of the Earth are moving. To define the velocity of a given point, we can place a GPS receiver there and measure the coordinates every day. After collecting enough data, we can generate a time series of three coordinates, North, East and Height directions. The most used technique to determine such displacements, is the linear model. The main objective of this thesis ...