BACKGROUND Accurate risk-adjustment models are useful for clinical decision making and are important for minimizing any tendency toward risk-averse clinical practice. In cardiac surgery, emergency patients are potentially at greatest risk of inappropriate risk-averse clinical decisions. UK cardiac surgery outcomes are currently risk-adjusted with EuroSCORE models. The objective of this study wa...

background: absolute dosimetry of external beam radiotherapy is carried out by the use of ionization chambers. these chambers must be calibrated at a standard dosimetry laboratory before any use in clinical dosimetry. the secondary standard dosimetry laboratory of iran (ssdl) has the duty of calibrating the ionization chambers used in radiotherapy centers in iran. materials and methods: the pre...

abstract major of hydrological systems are very complicated and it is not possible to understand them completely, therefore simplification is necessary to understand or control of a part of the system behavior such as water balance relationships. hydrological models are simple structure of complicated systems in water cycle in the nature. the first goal of a hydrological model is function predi...

RATIONALE Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is used for the fast qualitative and quantitative analysis of phosphatidylcholines (PC). Fatty acyl chain lengths and the number of double bonds (DB) affect relative responses of PC; hence the determination of correction factors of individual PC is important for the accurate quantitation. The signal intensity in ...

BACKGROUND The extent to which psychosocial and diet behavior factors affect dietary self-report remains unclear. We examine the contribution of these factors to measurement error of self-report. METHODS In 450 postmenopausal women in the Women's Health Initiative Observational Study doubly labeled water and urinary nitrogen were used as biomarkers of objective measures of total energy expend...

We consider the self-calibration problem in the special context of a stereo head, where the two cameras are arranged on a lateral rig with coplanar optical axes, each camera being free to vary its angle of vergence. Under various constraints, we derive explicit forms for the epipolar equation, and show that a static stereo head constitutes a degenerate camera con guration for carrying out self-...

This paper presents an algorithm for calibrating erroneous tri-axis magnetometers in the magnetic field domain. Unlike existing algorithms, no simplification is made on the nature of errors to ease the estimation. A complete error model, including instrumentation errors (scale factors, nonorthogonality, and offsets) and magnetic deviations (soft and hard iron) on the host platform, is elaborate...