Tuy's cone-beam inversion formula was modified to develop a cone-beam reconstruction algorithm. The algorithm was implemented for a cone-beam vertex orbit consisting of a circle and two orthogonal lines. This orbit geometry satisfies the cone-beam data sufficiency condition and is easy to implement on commercial single photon emission computed tomography (PECT) systems. The algorithm, which con...

In this paper altitude measurement from water surface using laser beam is presented. Research data indicate that the reflection of infrared waves from water surface is about zero and it is less than 2% for visible radiations. Phase-shift and heterodyne technique was used for the measurement, and the laser beam ( mW p nm 10 , 700 = = l ) was modulated by a sine wave having a fixed frequency....

background: physical wedges are still widely used as beam modifiers in external beam radiotherapy. however the presence of them in the beam trace may cause beam hardening which may not be considered in many treatment planning systems. the aim of this study is to investigate the beam hardening effect generated by physical wedges via different beam quality indexes as photon spectrum, half value l...

In this paper, we present a new algorithm designed for a specific data truncation problem in fan-beam CT. We consider a scanning configuration in which the fan-beam projection data are acquired from an asymmetrically positioned half-sized detector. Namely, the asymmetric detector only covers one half of the scanning field of view. Thus, the acquired fan-beam projection data are truncated at eve...

Enhancement of the response of reinforced concrete (RC) beams using fiber-reinforced polymer (FRP) reinforcement bars has become a popular structural technique over the past two decades due to the well-known advantages of FRP composites including their high strength-to-weight ratio and excellent corrosion resistance. Thisstudy presents n...

Bai et al. recently proposed to acquire random fanbeam/cone-beam projections with a linear/planar detector from a circular scanning locus for controlled cardiac computed tomography (CT). After specifying a uniform acquisition geometry required by FBP (filtration-backprojection), we rebin the random fan-beam/cone-beam data via nearest-neighbor, quadrilateral and triangle-based linear interpolati...

a definitive diagnosis of vertical root fracture (vrf) is often a challenging task for clinicians. this is because two dimensional periapical radiographs are usually unable to detect the fracture line due to the direction of the x-ray beam. this report presents a set of 3 cases of endodontically treated teeth that were diagnosed with vrfs based on findings from clinical, radiographic, and cone-...

in this paper, an interference management for multi-beam satellite network to enhance spectral efficiency is studied. first, a two-satellite for future generation satellite network using cognitive radio technology is provided.this network is composed of a secondary satellite and aprimary satellite where the primary satellite system does not suffer from severe destructive interferences coming fr...

the rapid melting of a semi- infinite body due to the absorption of a cw laser beam radiation has been studied. the enthalpy technique for the solution of phase change problems has been used in an explicit finite difference form to calculate the transient temperature distribution in the semi-infinite body and the growth rate of the melt pool. the technique has been modified so that it is not ne...