We consider regularization methods of Kaczmarz type in connection with the expectation-maximization (EM) algorithm for solving ill-posed equations. For noisy data, our methods are stabilized extensions of the well established ordered-subsets expectation-maximization iteration (OS-EM). We show monotonicity properties of the methods and present a numerical experiment which indicates that the exte...

x f(x, θ) log f(x, θ) exists for all θ and θ. In principle, one can apply the sum-product algorithm in order to find (1), which involves the following two steps [2]: 1. Determine f(θ) by sum-product message passing. 2. Maximization step: compute θmax △ = argmaxθ f(θ). This procedure is often not feasible, since • When the variable x is continuous, the sum-product rule may lead to intractable in...

In studies that compare physical activity between groups of individuals, it is common for to be quantified by step count, which measured accelerometers or other wearable devices. Missing count data often arise in these settings and can lead bias imprecision the estimated effect if handled inappropriately. Replacing each missing value accelerometer with a single using Expectation–Maximization (E...