Introduction: Brachytherapy is a type of radiotherapy in which radioactive sources are used in proximity of tumors normally for treatment of malignancies in the head, prostate and cervix. Materials and Methods: The Cs-137 Selectron source is a low-dose-rate (LDR) brachytherapy source used in a remote afterloading system for treatment of different cancers. This system uses active and inactive sp...

In this paper we propose a methodology for localizing acoustic planar reflectors in a 3D geometry, using acoustic measurements acquired by a set of microphones. An acoustic source emitting a known signal is placed close to the wall to be identified, and is used for estimating the source-to-microphone impulse responses. In a preliminary step, such estimates are employed for localizing the source...

A number of recent surveys for gravitational lenses have found examples of double Einstein rings. Here, we investigate analytically the occurence of multiple Einstein rings. We prove, under very general assumptions, that at most one Einstein ring can arise from a mass distribution in a single plane lensing a single background source. Two or more Einstein rings can therefore only occur in multi-...

ABSTRACT Digital tomosynthesis mammography algorithms allow reconstructions of arbitrary planes in the breast from limitedangle series of projection images as the x-ray source moves along an arc above the breast. Though several tomosynthesis algorithms have been proposed, no complete comparison of the methods has previously been conducted. This paper presents an analysis of impulse response for...

We consider visibility and shadow problems in the plane under static and dynamic conditions. We show that several problems in this domain are intimately related and that a careful formulation of the requirements of each problem can lead to a great deal of reuse in the implementation. This is of interest to the practitioner who may find it difficult to implement visibility and shadow algorithms ...

Teleseismic body waveform modeling of the far-field P-and SH-waveforms and spectral analysis of P-waves are used to determine the source parameters of the March 25, 2006 Fin earthquake (mb 5.7). Its epicenter is located at the South of Iran in Hormozgan Province. The waveform modeling results show the earthquake was caused by a thrust motion on a NW-SE striking fault with parameters: Fault plan...

Background: In order to deliver the precise dose to the target in radiotherapy, absorbed dose to water at the reference point should be assessed. When the calibration procedure is performed for a reference dosimeter in the 60Co beam of a Secondary Standard Dosimetry Laboratory (SSDL), the total uncertainty in absorbed dose to water (Dw) is estimated to be approximately 1.5%. This study attempts...

The spectral localization cues contained in the head-related transfer function are known to play a contributory role in the sound source localization abilities of humans. However, existing localization techniques are unable to fully exploit this diversity to accurately localize a sound source. The availability of just two measured signals complicates matters further, and results in front to bac...