Essays about: "EM-algorithm"

Showing result 1 - 5 of 23 essays containing the word EM-algorithm.

  1. 1. Reconstruction of Fire Spread with a Markov Random Field Mixture Model

    University essay from Lunds universitet/Matematisk statistik

    Author : Marcus Gehrmann; [2023]
    Keywords : Forest fire; fire scars; spatial statistics; Markov random field; EM-algorithm; pseudo-likelihood; Mathematics and Statistics;

    Abstract : This thesis revolves around reconstructing fire sizes for historical fires in Jämtgaveln, Sweden based on data of fire scars in trees. We propose a Hidden Markov Model (HMM), where the domain is divided into quadratic grid cells of 250 $\times$ 250 m and with these grid cells we associate a binary Markov random field taking values 0 or 1 corresponding to no fire and fire respectively. READ MORE

  3. 2. AI based prediction of road users' intents and reactions

    University essay from Linköpings universitet/Statistik och maskininlärning

    Author : Akshay Gurudath; [2022]
    Keywords : Intent prediction; Trajectory prediction; road users; pedestrians; cyclists; autonomous vehicles; LSTM networks; Attention modules; Transformer encoders; Attention based intent prediction; Constant velocity model; EM algorithm; Road user behavior dynamics; social behavior of road users;

    Abstract : Different road users follow different behaviors and intentions in the trajectories that they traverse. Predicting the intent of these road users at intersections would not only help increase the comfort of drive in autonomous vehicles, but also help detect potential accidents. READ MORE

  4. 3. Joint Estimation and Calibration for Motion Sensor

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

    Author : Peng Liu; [2020]
    Keywords : State space model; accelerometer array; parameter estimation; Maximum Likelihood; Expectation Maximization; Gradient Descent; ill-conditioned matrix.; tillståndsmodell; accelerometerarray; parameterskattning; maximimetoden; väntevärdesmaximering; gradientsökning; illakonditionerade matriser.;

    Abstract : In the thesis, a calibration method for positions of each accelerometer in an Inertial Sensor Array (IMU) sensor array is designed and implemented. In order to model the motion of the sensor array in the real world, we build up a state space model. Based on the model we use, the problem is to estimate the parameters within the state space model. READ MORE

  5. 4. Sum-Product Network in the context of missing data

    University essay from KTH/Matematisk statistik

    Author : Pierre Clavier; [2020]
    Keywords : Statistics; Mixture model; Probabilistic Graphical Models; Statistik; Probabilistiska grafiska modeller;

    Abstract : In recent years, the interest in new Deep Learning methods has increased considerably due to their robustness and applications in many fields. However, the lack of interpretability of these models and the lack of theoretical knowledge about them raises many issues. It is in this context that sum product network models have emerged. READ MORE

  6. 5. ON THE PREDICTIVE PERFORMANCE OF THE STOCK RETURNS BY USING THE MARKOV-SWITCHING MODELS

    University essay from Uppsala universitet/Statistiska institutionen

    Author : Yanan Wu; [2020]
    Keywords : stock returns; regime-switching regression; regime identify; EM algorithm; statistical method;

    Abstract : This paper proposes the basic predictive regression and Markov Regime-Switching regression to predict the excess stock returns in both US and Sweden stock markets. The analysis shows that the Markov Regime-Switching regression models out perform the linear ones in out-of-sample forecasting, which is due to the fact that the regime-switching models capture the economic expansion and recession better. READ MORE