Results 281 to 290 of about 15,751 (313)

A comparative study between flattening filter-free beams and flattening filter beams in radiotherapy treatment

Oncology and Translational Medicine, 2017
AbstractFlattening filter-free (FFF) beams generated by medical linear particle accelerators (linacs) have recently been used in radiotherapy clinical practice. FFF beams have fundamental physical parameter differences with respect to standard flattening filter (FF) beams, such that the generally used dosimetric parameters and definitions are not ...
Ali Wagdy, Khaled EI Shahat, Huda Ashry, Amaal El Shershaby, Ehab Abdo   +4 more
openaire   +1 more source

Design of the filter with flattening spectral transmittance

SPIE Proceedings, 2002
A new method to produce flattening spectral transmittance for birefringent chain filter based on the interference of polarized light is presented. In previous publications, each birefringent crystal must be of equal thickness and only one group of azimuth angles of the crystals was obtained.
Juan Zhang, Liren Liu, Yu Zhou, Changhe Zhou   +3 more
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A new design for gain flattening filter

Optical Interference Coatings, 2001
A new design for gain flattening filter by using stack of filters has been described. The filter has advantages of less number of layer and all the layers are quarter wave.
Cheng-Chung Lee Lee, Ya-Ping Li, Sheng-Hui Chen   +2 more
openaire   +1 more source

131 Performance analysis of new Delta4 Phantom+ using Flattening-Filter and Flattening Filter-Free beams

Physica Medica, 2018
Abstract Purpose There is a recent increase in the use of Flattening Filter-Free (FFF) beams with the aim of reducing treatment time and consequently intrafractional motions. The goal of this study was to evaluate the performances of the new pre-treatment system Delta4 Phantom+ (Scandidos) in terms of a stable and sensitive tool for achieving a ...
C. Capomolla, A. Zagari, S. Quarta, D. De Luca, A. Carlà, M. Cazzato, E. Martinucci   +6 more
openaire   +1 more source

Gain flattening filter design for EDFA

SPIE Proceedings, 2004
In this paper we report the experimental study of gain of telecommunication Erbium Doped Fiber Amplifier (EDFA). For particular pump power, the gain of Erbium Doped Fiber Amplifier for the wavelength range of 1529 nm - 1559 nm was measured and found that the gain of the Erbium Doped Fiber Amplifier is very uneven exhibiting peaks with different widths ...
Anubhuti Shrivastava, R. P. Singh
openaire   +1 more source

Monte Carlo comparison of superficial dose between flattening filter free and flattened beams

Physica Medica, 2014
This study investigates the superficial dose from FFF beams in comparison with the conventional flattened ones using a Monte Carlo (MC) method. Published phase-space files which incorporated real geometry of a TrueBeam accelerator were used for the dose calculation in phantom and clinical cases. The photon fluence on the central axis is 3 times that of
Khosrow, Javedan, Vladimir, Feygelman, Ray R, Zhang, Eduardo G, Moros, Candace R, Correa, Andy, Trotti, Weiqi, Li, Geoffrey G, Zhang   +7 more
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Data filtering techniques for manifold flattening anchorless localization

2012 International Symposium on Communications and Information Technologies (ISCIT), 2012
Anchorless localization, in which nodes in a wireless network are located without the use of reference nodes, is valuable for applications such as public safety where rapid setup is required. The distances between nodes form a Euclidean distance matrix (EDM), and as distance is not directly measured between all pairs of nodes the EDM needs to be ...
Dan C. Popescu, Mark Hedley, Thuraiappah Sathyan   +2 more
openaire   +1 more source

Optimal flattening filter shape of a surface brachytherapy applicator

Physics in Medicine and Biology, 2002
As an alternative to standard treatment of superficial lesions with surgery and/or superficial/orthovoltage x-ray irradiation, radioactive moulds can be used. However, close proximity of the source to the treatment region leads to significant dose inhomogeneities in the tissue.
Robert, Jeraj, Attila, Sarvary, Tomas, Kron   +2 more
openaire   +2 more sources

FIR digital filter implementation using flattened coefficient

2000 IEEE International Symposium on Circuits and Systems. Emerging Technologies for the 21st Century. Proceedings (IEEE Cat No.00CH36353), 2002
In this paper, we present a new method to reduce the number of adders and registers in FIR digital filters. Few efforts have been taken for reducing the number of registers in filters, while a lot of methods have been developed to decrease the number of adders in the past decade.
Sang-Hun Yoon, Jong-Wha Chong
openaire   +1 more source

Flattening the Gain in 16 Channel EDFA-WDM System by Gain Flattening Filter

2014 International Conference on Computational Intelligence and Communication Networks, 2014
In EDFA (Erbium Doped Fiber Amplifier) the gain flattening is a very important issue. EDFA plays a very important role in WDM optical applications. EDFA is very compatible with WDM applications because of its high gain, high bandwidth, low noise. The uneven gain characteristic is the main drawback of EDFA. In this paper we optimize the flatness of gain
Deepika Verma, Santosh Meena
openaire   +1 more source