Publications (10)
Sparsity constrained split feasibility for dose-volume constraints in inverse planning of intensity-modulated photon or proton therapy
S. Penfold, R. Zalas, M. Casiraghi +3
A split feasibility formulation for the inverse problem of intensity-modulated radiation therapy (IMRT) treatment planning with dose-volume constraints (DVCs) included in the plann…
On the Effectiveness of Projection Methods for Convex Feasibility Problems with Linear Inequality Constraints
Y. Censor, W. Chen, P. L. Combettes +2
The effectiveness of projection methods for solving systems of linear inequalities is investigated. It is shown that they have a computational advantage over some alternatives and…
Perturbation Resilience and Superiorization of Iterative Algorithms
Y. Censor, R. Davidi, G. T. Herman
Iterative algorithms aimed at solving some problems are discussed. For certain problems, such as finding a common point in the intersection of a finite number of convex sets, there…
Bounded perturbation resilience of projected scaled gradient methods
W. Jin, Y. Censor, M. Jiang
We investigate projected scaled gradient (PSG) methods for convex minimization problems. These methods perform a descent step along a diagonally scaled gradient direction followed…
Total variation superiorization schemes in proton computed tomography image reconstruction
S. N. Penfold, R. W. Schulte, Y. Censor +1
Purpose: Iterative projection reconstruction algorithms are currently the preferred reconstruction method in proton computed tomography (pCT). However, due to inconsistencies in th…
String-Averaging Expectation-Maximization for Maximum Likelihood Estimation in Emission Tomography
E. S. Helou, Y. Censor, T. -B. Chen +4
We study the maximum likelihood model in emission tomography and propose a new family of algorithms for its solution, called String-Averaging Expectation-Maximization (SAEM). In th…
Approaches to iterative algorithms for solving nonlinear equations with an application in tomographic absorption spectroscopy
F. J. Aragón-Artacho, W. Cai, Y. Censor +3
In this paper we propose an approach for solving systems of nonlinear equations without computing function derivatives. Motivated by the application area of tomographic absorption…
Superiorization: An optimization heuristic for medical physics
G. T. Herman, E. Garduño, R. Davidi +1
Purpose: To describe and mathematically validate the superiorization methodology, which is a recently-developed heuristic approach to optimization, and to discuss its applicability…
Feasibility-Seeking and Superiorization Algorithms Applied to Inverse Treatment Planning in Radiation Therapy
R. Davidi, Y. Censor, R. W. Schulte +2
We apply the recently proposed superiorization methodology (SM) to the inverse planning problem in radiation therapy. The inverse planning problem is represented here as a constrai…
String-Averaging Projected Subgradient Methods for Constrained Minimization
Y. Censor, A. J. Zaslavski
We consider constrained minimization problems and propose to replace the projection onto the entire feasible region, required in the Projected Subgradient Method (PSM), by projecti…