@article{peplow_verghese_2000, title={Differential sampling applied to mammography image simulation}, volume={135}, ISSN={["0029-5639"]}, DOI={10.13182/NSE00-A2128}, abstractNote={Abstract Differential sampling is a powerful tool that allows Monte Carlo to compute derivatives of responses with respect to certain problem parameters. This capability has been implemented within an in-house Monte Carlo code that simulates detailed mammographic images from two new digital systems. Differential sampling allows for the calculation of the first and all second derivatives of all of the different tallies computed by the code as well as the first and second derivatives of the mammographic image itself with respect to material parameters, such as density and cross sections. The theory behind differential sampling is explained, the methodology for implementation into the imaging code is discussed, and two problems are used to demonstrate the power of differential sampling.}, number={2}, journal={NUCLEAR SCIENCE AND ENGINEERING}, author={Peplow, DE and Verghese, K}, year={2000}, month={Jun}, pages={103–122} } @article{peplow_verghese_2000, title={Differential sampling for the Monte Carlo practitioner}, volume={36}, ISSN={["0149-1970"]}, DOI={10.1016/S0149-1970(99)00024-4}, abstractNote={One of the two methods for performing a perturbation calculation using Monte Carlo simulations is by differential sampling. The fundamental theory of differential sampling in Monte Carlo is well-presented in the literature but algorithms for implementation of the theory are not well-documented. The development of a differential sampling scheme and its implementation from the viewpoint of the Monte Carlo practitioner are presented here. Simplified examples of radiation transport and criticality of a multiplying system are used to illustrate the algorithms for implementation. Notes on applying the same schemes to more complex problems are also discussed.}, number={1}, journal={PROGRESS IN NUCLEAR ENERGY}, author={Peplow, DE and Verghese, K}, year={2000}, pages={39–75} } @article{peplow_verghese_2000, title={Digital mammography image simulation using Monte Carlo}, volume={27}, ISSN={["0094-2405"]}, DOI={10.1118/1.598896}, abstractNote={Monte Carlo simulations of digital images of the contrast detail phantom and the ACR phantom are presented for two different x‐ray digital mammography modalities: a synchrotron mammography system and a next‐generation scanning slot clinical system. A combination of variance reduction methods made it possible to simulate accurate images using real pixel dimensions within reasonable computation times. The complete method of image simulation, including a simple detector response model, a simple noise model, and the incorporation of system effects (MTF), is presented. The simulated images of the phantoms show good agreement with images measured on the two systems.}, number={3}, journal={MEDICAL PHYSICS}, author={Peplow, DE and Verghese, K}, year={2000}, month={Mar}, pages={568–579} } @article{peplow_1999, title={Direction cosines and polarization vectors for Monte Carlo photon scattering}, volume={131}, ISSN={["0029-5639"]}, DOI={10.13182/NSE99-A2024}, abstractNote={New ways to calculate the direction cosines and polarization vectors for Monte Carlo photon scattering are developed and presented. The new approach for direction cosines is more physical, easier to understand, straightforward to implement, and--for simulations involving polarized photons--slightly faster than the traditional approach. The polarization vector after scatter is also presented.}, number={1}, journal={NUCLEAR SCIENCE AND ENGINEERING}, author={Peplow, DE}, year={1999}, month={Jan}, pages={132–136} }