There is a growing interest in the use of megavoltage cone-beam computed tomography (MV CBCT) data for radiotherapy treatment planning. To calculate accurate dose distributions, knowledge of the electron density (ED) of the tissues being irradiated is required. In the case of MV CBCT, it is necessary to determine a calibration-relating CT number to ED, utilizing the photon beam produced for MV ...

In this paper, we show that the optimization of density forecasting models for regression in machine learning can be formulated as a multi-objective problem. We describe the two objectives of sharpness and calibration and suggest suitable scoring metrics for both. We use the popular negative log-likelihood as a measure of sharpness and the probability integral transform as a measure of calibrat...

Animal models have been widely used to correlate in vivo changes in bone mineral density (BMD) with changes in disease state of bone. In small animal models, e.g. the hindlimb suspension model of bone loss, a non-invasive assessment of BMD is required. X-ray radiography has been surpassed in some cases by quantitative computed tomography (QCT) and dual X-ray absorptiometry (DEXA) quantitation. ...

background: ebt and ebt3 radiochromic films have been used in radiotherapy dosimetry for years. objective: the aim of the current study is to compare ebt and ebt3 radiochromic films in dosimetry of radiotherapy fields for treatment of parotid cancer. methods: calibrations of ebt and ebt3 films were performed with identical setups using a 6 mv photon beam of a siemens primus linac. skin dose was...

Regression calibration using biomarkers provides an attractive approach to strengthening nutritional epidemiology. We consider this approach to assessing the relationship of fat and total energy consumption with postmenopausal breast cancer. In analyses that included fat density data, biomarker-calibrated total energy was positively associated with postmenopausal breast cancer incidence in coho...

A new nonparametric approach for statistical calibration with functional data is studied. The practical motivation comes from calibration problems in chemometrics in which a scalar random variable Y needs to be predicted from a functional random variable X. The proposed predictor takes the form of a weighted average of the observed values of Y in the training data set, where the weights are det...

An explicit algebraic model (EARSM) for variable denstiy turbulent flow developed by Grigoriev et al. [Phys. Fluids (2015)] is revisited here. We apply it to a quasi one-dimensional nozzle flow, a wall-jet flow with combustion and large density variation and a supercritical flow of carbon dioxide with heat transfer and buoyancy. It is confirmed that the coupling between strong mean density grad...

In this paper the calibration of a traffic microsimulation model based on speed-density relationships is presented. Hypothesis test was applied in the calibration process to measure the closeness between empirical data and simulation outputs and determine whether the difference between (observed and simulated) speeddensity relationships was statistically significant. Statistical regressions bet...

Process control of wood density with near infrared spectroscopy (NIR) would be useful for pulp mills that need to maximize pulp yield without compromising paper strength properties. If models developed from the absorbance at wavelengths in the NIR region could provide density histograms, fiber supply personnel could monitor chip density variation as the chips enter the mill. The objectives of t...

Weproposeanewdefinitionof excessadsorption foruse inmolecularmodels of adsorption. Thisdefinition implies the calibration of theoreticalmodels inamannermimicking the experimental calibrationprocedure. The method of theoretical calibration is developed on the example of helium calibration. The notions of the He calibrated pore volume and the He calibrated pore size are introduced, and the He cal...