objective: iqspect is an advanced high-speed spect modality for performing myocardial perfusion imaging (mpi), which uses a multi-focus fan beam collimator with resolution recovery reconstruction. the aim of this study was to compare iqspect compared with conventional spect interms of performance based on standard clinical protocols. in addition, we examined the concordance between conventional...

This paper introduces a novel architecture of a multi-beam adaptive beamformer for SDMA (space division multiple access) applications. Combined with a 5.8 GHz eight-element RF front-end, digital beamforming performance using the proposed frequency-domain multi-beam beamformer is demonstrated in post processing. The DOA estimation based on the ESPRIT algorithm and simultaneous dual-beam forming ...

Laser diode beam divergence is the main parameter for beam shaping and fiber optic coupling. Increasing the waveguide layer thickness is the conventional method to decrease the beam divergence. In this paper, the broadened asymmetric waveguide is introduced to decrease the divergence without increasing the optical power. The asymmetric waveguide was used to shift the vertical optical field to n...

In the Spallation Neutron Source (SNS) ring, multi-turn injection is employed to obtain a large transverse beam size which significantly reduces the space-charge tune shift of the accumulated beam. Careful choice of the painting scheme and bump function is required to obtain the desired beam profile together with low beam loss. In this paper we examine, both analytically and numerically, the ef...

Fixed multi-beam base stations can significantly increase the capacity of WCDMA systems. Previous capacity studies have not included important Radio Network Algorithms (RNA) such as Admission Control (AC) which are essential to guarantee an acceptable Quality Of Service (QoS). Some of these RNA may have to be changed to secure the full gains of fixed multi-beam antennas. In this paper two downl...

Due to lack of resources such as transmission power and bandwidth in satellite systems, resource allocation problem is a very important challenge. Nowadays, new heterogeneous network includes one or more satellites besides terrestrial infrastructure, so that it is considered that each satellite has multi-beam to increase capacity. This type of structure is suitable for a new generation of commu...

Multi-point laser ignition (LI) is one of the key potential advantages that LI can offer over conventional spark ignition (SI). Previous research found that multi-point ignition produced more stable and faster combustion. This paper demonstrates a diffractive multi-point LI technology which is experimentally attempted at Liverpool University Laser Group. Sparks with arbitrary geometrical locati...

3.3 Multi-slice CT Acquisition and Reconstruction for Body Imaging 52 3.3.1 Defi nition of the Pitch 52 3.3.2 The Cone-Angle Problem in Multi-slice CT 53 3.3.3 Multi-slice Spiral Reconstruction Neglecting the Cone-Beam Geometry 54 3.3.3.1 180° and 360° Multi-slice Linear Interpolation 54 3.3.3.2 z-Filter Approaches 56 3.3.4 Multi-slice Spiral Reconstruction with Cone-Beam Algorithms 58 3.3.4.1 ...

PURPOSE This phantom study investigated variations of mucosal dose on photon beam energy, beam angle, multi-beam configuration and mucosal thickness, when using small photon fields in head-and-neck radiotherapy. METHODS Cylindrical mucosa phantoms with bone and air heterogeneities were created with mucosal thickness (normal tissue) equal to 1, 2 and 3 mm. For dosimetric comparison, correspond...