This study compared reconstruction algorithms [filtered back projection (FBP) and simultaneous iterative reconstruction technique (SIRT)] with respect to radiation doses and image quality and suggested the possibility of decreasing the exposure dose in digital breast tomosynthesis (DBT). These two existing algorithms were implemented using a DBT system and experimentally evaluated using contras...

OBJECTIVE(S) In SPECT, the sinogram contains scatter and lack of attenuated counts that degrade the reconstructed image quality and quantity. Many techniques for attenuation and scatter correction have been proposed. An acceptable method of correction is to incorporate effects into an iterative statistical reconstruction. Here, we propose new Maximum Likelihood Expectation Maximization (MLEM) f...

Large-eddy simulation (LES) has become a widely-used method for computation of field-scale environmental flows; however, challenges remain in determining the optimal turbulence closure method. Recently, the concept of explicit filtering and reconstruction has become recognized as a means to obtain more accurate simulation results (Carati et al. 2001, Winckelmans et al. 2001, Stolz et al. 2001, ...

We compared reconstruction algorithms [filtered back projection (FBP), maximum likelihood expectation maximization (MLEM), and the simultaneous iterative reconstruction technique (SIRT)] in terms of the radiation dose and image quality, for exploring the possibility of decreasing the radiation dose during digital breast tomosynthesis (DBT). The three algorithms were implemented using a DBT syst...

We present a gravitational lensing analysis of the galaxy cluster Abell 1689, incorporating measurements of the weak shear, flexion, and strong lensing induced in background galaxies. This is the first time that a shapelet technique has been used to reconstruct the distribution of mass in this cluster and the first time that a flexion signal has been measured using cluster members as lenses. Fr...

We investigate the impact of line-edge and line-width roughness (LER, LWR) on the measured diffraction intensities in angular resolved extreme ultraviolet (EUV) scatterometry for a periodic line-space structure designed for EUV lithography. LER and LWR with typical amplitudes of a few nanometers were previously neglected in the course of the profile reconstruction. The two-dimensional (2D) rigo...

there is controversy in the literature regarding a number of topics related to anterior cruciate ligament (acl)reconstruction. the purpose of this article is to answer the following questions: 1) bone patellar tendon bone (bptb) reconstruction or hamstring reconstruction (hr); 2) double bundle or single bundle; 3) allograft or authograft; 4) early or late reconstruction; 5) rate of return to sp...

We construct a mid-latitude (30–60 N) reduced temperature-depth profile from a global borehole temperature database compiled for climate reconstruction. This reduced temperature profile is interpreted in terms of past surface ground temperature change and indicates warming on the order of 1C over the past 100 to 200 years. The combination of an initial temperature (the primary free parameter) w...

Fluorescence detectors of the Pierre Auger Observatory have been operating in a stable manner since January 2004. After a brief review of the physical characteristics of the detectors, the associated atmospheric monitoring, the calibration infrastructure and the detector aperture, we will describe the steps required for the reconstruction of fluorescence event data, with emphasis on the shower ...

— There is a strong interest in the development of single shot diagnostics of fs relativistic electron bunches within research areas including THz sources of radiation. The goal of the work presented is to understand the properties of coherent Smith-Purcell radiation to enable the reconstruction of the longitudinal profile of a fs-long electron bunch.