A tomographic reconstruction method based on Monte Carlo random searching guided by the information contained in the projections of radiographed objects is presented. In order to solve the optimization problem, a multiscale algorithm is proposed to reduce computation. The reconstruction is performed in a coarse-tofine multigrid scale that initializes each resolution level with the reconstructio...

We propose a multivariate quantile regression framework that exploits the factor structure in multivariate conditional quantiles through nuclear norm regularization. Because the incurred optimization problem can only be solved approximately, we develop a non-asymptotic upper bound for the estimation error that takes into account the optimization error. We specify an algorithm to compute an appr...

A procedure for selecting an optimal NDI (non-destructive inspection) technique and associated schedule for fracture-critical member inspections on a specific steel bridge is presented. Information related to the probability of detection (POD) function (a measure of inspection quality) of alternative NDI techniques is utilized. Calculations based on use of the POD function together with Monte C...

A new voltage controlled oscillator (VCO) in a 0.18 μm CMOS process is offered in this paper. This paper's argument is to provide an innovative approach to improve the phase noise which is one of the most controversial issues in VCOs. Contrary to most ideas that have been put forward to decrease phase noise which are based on higher current dissipation to increase output voltage swing, this new...

Most criticality safety calculations are performed using Monte Carlo techniques because of Monte Carlo’s ability to handle complex three-dimensional geometries. For Monte Carlo calculations, the more histories sampled, the lower the standard deviation of the resulting estimates. The common intuition is, therefore, that the mo re histories, the better; as a result, analysts tend to run Monte Car...

This article presents an approach to the optimization of helical involute gears for geometrical feasibility, contact ratio, teeth sliding velocity, stresses and static transmission error (STE). The teeth shape is subject to random perturbations due to wear (a randomized Archard’s wear). The consequences of shape inaccuracies are statistically expressed as a 90% percentile of the STE variation, ...

abstract background: accurate methods of radiation therapy dose calculation. there are different monte carlo codesfor simulation of photons, electrons and the coupled transport of electrons and photons. mcnpis a general purpose monte carlo code that can be used for electron, photon and coupledphoton-electron transport.monte carlo simulation of radiation transport is considered to be one of the ...

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. Tolerancing decisions can profoundly impact the quality and cost of the mechanism. To evaluate the impact of tolerance on mechanism quality, designers need to simulate the influences of tolerances with respect to the functional requirements. Thi...

A novel robust optimization algorithm is demonstrated, which attempts to account for expected coating errors. Monte Carlo simulations show the robust approach improves manufacturing yields relative to conventional optimization. c © 2010 Optical Society of America OCIS codes: (310.6805) Theory and design; (310.4165) Multilayer design

This paper surveys the use of Monte Carlo sampling-based methods for stochastic optimization problems. Such methods are required when—as it often happens in practice—the model involves quantities such as expectations and probabilities that cannot be evaluated exactly. While estimation procedures via sampling are well studied in statistics, the use of such methods in an optimization context crea...