Results 31 to 40 of about 2,165,172 (354)

Evaluation of intrafraction couch shifts for proton treatment delivery in head‐and‐neck cancer patients: Toward optimal imaging frequency

Journal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Purpose Treatment planning for head‐and‐neck (H&N) cancer, in particular oropharynx, nasopharynx, and paranasal sinus cases, at our center requires noncoplanar proton beams due to the complexity of the anatomy and target location. Targeting accuracy for all beams is carefully evaluated by using image guidance before delivering proton beam ...
Nrusingh C. Biswal, Dario B. Rodrigues, Weiguang Yao, Jason K. Molitoris, Matthew E. Witek, Shifeng Chen   +5 more
wiley   +1 more source

The geometry of degenerations of Hilbert schemes of points [PDF]

Journal of Algebraic Geometry, 2020
Given a strict simple degenerationf:X→Cf \colon X\to Cthe first three authors previously constructed a degenerationIX/Cn→CI^n_{X/C} \to Cof the relative degreennHilbert scheme of00-dimensional subschemes. In this paper we investigate the geometry of this degeneration, in particular when the fibre dimension offfis at most22.
Lars Halvard Halle, Ziyu Zhang, Ziyu Zhang, Klaus Hulek, Martin G. Gulbrandsen   +4 more
openaire   +6 more sources

Treatment planning with a 2.5 MV photon beam for radiation therapy

Journal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Purpose The shallow depth of maximum dose and higher dose fall‐off gradient of a 2.5 MV beam along the central axis that is available for imaging on linear accelerators is investigated for treatment of shallow tumors and sparing the organs at risk (OARs) beyond it.
Navid Khaledi, Chris Hayes, Louise Belshaw, Mark Grattan, Rao Khan, James L. Gräfe   +5 more
wiley   +1 more source

Pairwise transitive 2-designs [PDF]

, 2015
We classify the pairwise transitive 2-designs, that is, 2-designs such that a group of automorphisms is transitive on the following five sets of ordered pairs: point-pairs, incident point-block pairs, non-incident point-block pairs, intersecting block ...
Devillers, Alice, Praeger, Cheryl E.
core   +1 more source

Effect of different noise reduction techniques and template matching parameters on markerless tumor tracking using dual‐energy imaging

Journal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Purpose To evaluate the impact of various noise reduction algorithms and template matching parameters on the accuracy of markerless tumor tracking (MTT) using dual‐energy (DE) imaging. Methods A Varian TrueBeam linear accelerator was used to acquire a series of alternating 60 and 120 kVp images (over a 180° arc) using fast kV switching, on ...
Mandeep Kaur, Peter Wagstaff, Hassan Mostafavi, Mathias Lehmann, Daniel Morf, Liangjia Zhu, Hyejoo Kang, Michal Walczak, Matthew M. Harkenrider, John C. Roeske   +9 more
wiley   +1 more source

Digital radiography image quality evaluation using various phantoms and software

Journal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Purpose To investigate the effect of the exposure parameters on image quality (IQ) metrics of phantom images, obtained automatically using software or from visual evaluation. Methods Three commercial phantoms and a homemade phantom constructed according to the instructions given in the IAEA Human Health Series No.
Ioannis A. Tsalafoutas, Shady AlKhazzam, Virginia Tsapaki, Huda AlNaemi, Mohammed Hassan Kharita   +4 more
wiley   +1 more source

Dynamic Point Cloud Compression Based on Projections, Surface Reconstruction and Video Compression

Sensors, 2021
In this paper we will present a new dynamic point cloud compression based on different projection types and bit depth, combined with the surface reconstruction algorithm and video compression for obtained geometry and texture maps. Texture maps have been
Emil Dumic, Anamaria Bjelopera, Andreas Nüchter   +2 more
doaj   +1 more source

Is the electrostatic force between a point charge and a neutral metallic object always attractive? [PDF]

, 2010
We give an example of a geometry in which the electrostatic force between a point charge and a neutral metallic object is repulsive. The example consists of a point charge centered above a thin metallic hemisphere, positioned concave up.
Griffiths D. J., Jackson J. D., Landau L. D., Marsden J. E., Maxwell J. C., Michael Levin, Purcell E. M., Saslow W. M., Steven G. Johnson   +8 more
core   +2 more sources

Automatic Geometry Generation from Point Clouds for BIM

Remote Sensing, 2015
The need for better 3D documentation of the built environment has come to the fore in recent years, led primarily by city modelling at the large scale and Building Information Modelling (BIM) at the smaller scale.
Charles Thomson, Jan Boehm
doaj   +1 more source

Is there a Jordan geometry underlying quantum physics? [PDF]

, 2008
There have been several propositions for a geometric and essentially non-linear formulation of quantum mechanics. From a purely mathematical point of view, the point of view of Jordan algebra theory might give new strength to such approaches: there is a `
A. Ashtekar, A.I. Nesterov, D.C. Brody, E. Alfsen, H. Upmeier, H. Upmeier, J.R. Faulkner, J.S. Bell, K. McCrimmon, L. Castell, O. Loos, O. Loos, O. Loos, P. Jordan, R. Cirelli, R. Iordanescu, R. Omnès, R. Penrose, R. Penrose, R.J. Baston, R.W. Sharpe, S. Helgason, T.W.B. Kibble, V.S. Varadarajan, W. Bertram, W. Bertram, W. Bertram, W. Bertram, W. Bertram, W. Bertram, W. Bertram, W. Bertram, W. Bertram, W. Kaup, W. Kaup, Wolfgang Bertram, Y. Friedman   +36 more
core   +4 more sources