Background: In order to assign appropriate planning target volume (PTV) margins, each centre should measure the patient positioning deviations for their set-up techniques. At the Royal Marsden Hospital, UK, a conformal shell (cast) system is used when a stereotactic frame is not suitable. In this paper, we report on a series of measurements with the aim of obtaining the systematic and random ...

Introduction: The use of panoramic radiography has shown a remarkable expansion over the past 20 years. Accurate positioning and preparation of patients is needed to avoid image distortion. The aim of this study was to evaluate the common errors on panoramic radiographs taken in the radiology department of Rasht dental school. Materials and Methods: The study sample included 390 digital panoram...

Optimal Positioning of Middle Schools within the City of Dehdasht through a Combination of Boolean Logic and FAHP M.A. Firoozi, Ph.D. P. Rahmaani N. Hosseini Shahpariyaan M. Fereydoonnejaad Optimal positioning of schools is of much interest to planners because the rapid increase in population and structural changes within the cities could lead to distribution problems if not fo...

In automotive industry fixtures have a direct effect on product manufacturing quality, productivity and cost, as a result fixtures, particularly welding fixture, play a crucial role in the auto industry. The fixture is a special tool for holding a work piece in proper position during manufacturing operation, so in the phase of the fixture design process positioning pins and surfaces are used to...

Global Positioning System (GPS) is proven to be an accurate positioning sensor. However, there are several sources of errors such as ionosphere and troposphere effects, satellite time errors, errors of orbit data, receivers errors, and errors resulting from multi-path effect which reduce the accuracy of low-cost GPS receivers. These sources of errors also limit the use of single-frequency GPS r...

Introduction: The accuracy of patient positioning plays an important role for radiotherapy tasks. Short and automated Quality Assurance (QA) programs are becoming one of the challenging tasks in Radiotherapy. The current study, investigates the accuracy of treatment couch positioning with four degrees of freedom (4DoF) using a fast and accurate method based on an image acquired...

in this paper a practical method for tropospheric effects on gps derived coordinates in absolute mode is presented. gps observations at the permanent gps stations can be used as source of information for the modeling. the developed model is a time-dependent model and as such differs from usual tropospheric models, which are based on atmospheric parameters, i.e. temperature, pressure and humidit...