background: photon attenuation as an inevitable physical phenomenon influences on the diagnostic information of spect images and results to errors in accuracy of quantitative measurements. this can be corrected via different physical or mathematical approaches. as the correction equation in mathematical approaches is nonlinear, in this study a new method of linearization called ‘piece wise line...

An experimental determination has been made of the perturbation correction to be applied to a graphite cylindrical (thimble type) ionization chamber. The results indicate that the magnitude of this correction increases with depth and is closely related to the size of the cavity. This makes possible the use of such a chamber as an' excellent standard of absorbed dose in graphite for 60Co gamma r...

A many-body theory approach to the calculation of gamma spectra of positron annihilation on many-electron atoms is developed. We evaluate the first-order correlation correction to the annihilation vertex and perform numerical calculations for the noble gas atoms. Extrapolation with respect to the maximal orbital momentum of the intermediate electron and positron states is used to achieve conver...

It is well-known that maximum likelihood (ML) estimators of the two parameters in a Gamma distribution do not have closed forms. This poses difficulties in some applications such as real-time signal processing using low-grade processors. The Gamma distribution is a special case of a generalized Gamma distribution. Surprisingly, two out of the three likelihood equations of the generalized Gamma ...

This paper presents an efficient and robust method for performing non-rigid image registration and relative gamma estimation in a simultaneous manner. The proposed method identifies regions of interest within the target image and determines the optimal correspondence and relative gamma between each region of interest and the reference image. The problem of finding the optimal correspondence and...

Background: To determine the basic physical and dosimetric properties of a new synthetic single-crystal diamond detector and its application for relative small field dosimetry. Materials and Methods: The pre-irradiation dose required to stabilize detector response, dose rate dependence, photon and electron energy dependence, temperature dependence and angular dependence of MicroDiamond detector...

Background: Photon attenuation as an inevitable physical phenomenon influences on the diagnostic information of SPECT images and results to errors in accuracy of quantitative measurements. This can be corrected via different physical or mathematical approaches. As the correction equation in mathematical approaches is nonlinear, in this study a new method of linearization called ‘Piece ...

Features • Low-power CMOS image sensor with integrated image flow processor (IFP) and video encoder • 1/4-inch optical format, VGA resolution (640H x 480V) • ±2.5% additional columns and rows to compensate for lens alignment tolerances • Integrated lens distortion correction • Overlay generator for dynamic bitmap overlay • Integrated video encoder for NTSC/PAL with overlay capability and 10-bit...

This paper presents the conditions for robustness to the nonnormality on three test statistics for a general multivariate linear hypothesis, which were proposed under the normal assumption in a generalized multivariate analysis of variance (GMANOVA) model. The proposed conditions require the cumulants of an unknown population’s distribution to vanish in the second terms of the asymptotic expans...