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 ...

this paper is devoted to the study of determining optimal process mean in system production with the two markets for the sale of goods. in this paper, we developed an absorbing markov chain model in production systems where all items are inspected %100 for conformance with their specification limits. when the value of the quality characteristic of an item falls below a lower limit, the item is ...

in this research, a new control policy for the acceptance sampling problem is introduced. decision is made based on the number of defectives items in an inspected batch. the objective of the model is to find a constant control level that minimizes the total costs, including the cost of rejecting the batch, the cost of inspection and the cost of defective items. the optimization is performed by ...

ATLAS is a general purpose experiment approved for the LHC collider at CERN. An important component of the detector is the central hadronic calorimeter; for its construction more than 600,000 Wave Length Shifting (WLS) fibres (corresponding to a total length of 1,120 Km) have been used. We have built and put into operation a dedicated instrument for the measurement of light yield and attenuatio...

In this paper, we propose a model based disturbance attenuator (MBDA) with the conventional PD controller for robot manipulators. It is a generalization of MBDA structure in [l] and is .applied to a robot manipulator which is nonlinear. This method does not require an accurate model of a robot manipulator and takes care of disturbances or modeling errors so that the plant output remains relativ...

The velocity and attenuation of ultrasonic stress waves in gabbroic rock samples (San Marcos, California) subjected to shock loading in the 2 GPa range were studied. From P wave velocity measurements we determined the damage parameter Dp and crack density e of the samples and related these to the attenuation coefficient (quality factor) under dynamic strains of 2 x 10 -? and at a frequency of 2...

Introduction: The evaluation of X-ray and light field coincidence in linear accelerators as a quality control test is often performed subjectively, involving the manual marking of films and their visual inspection following the irradiation. Therefore, the present study aimed to develop an objective method for the performance of this test leading to the increased levels...

A nonlinear optimal control method is developed for magnetostrictive actuators used to actively attenuate plate vibration. Significant improvements in vibration control can be achieved when the magnetostrictive actuators are driven at moderate to high field levels. This results in nonlinearity and hysteresis which cannot be effectively compensated using linear control theory. This issue is addr...