Search results for "Subtraction"
showing 10 items of 112 documents
On the importance of background subtraction in the analysis of coronal loops observed with TRACE
2010
In the framework of TRACE coronal observations, we compare the analysis and diagnostics of a loop after subtracting the background with two different and independent methods. The dataset includes sequences of images in the 171 A, 195 A filter bands of TRACE. One background subtraction method consists in taking as background values those obtained from interpolation between concentric strips around the analyzed loop. The other method is a pixel-to-pixel subtraction of the final image when the loop had completely faded out, already used by Reale & Ciaravella 2006. We compare the emission distributions along the loop obtained with the two methods and find that they are considerably differen…
Analysis of a multi-wavelength time-resolved observation of a coronal loop
2005
Several items on the diagnostics and interpretation of coronal loop observations are under debate. In this work, we analyze a well-defined loop system detected in a time-resolved observation in several spectral bands. The dataset includes simultaneous images in the TRACE 171 A, 195 A and 284 A bands, and Yohkoh/SXT, and two rasters taken with SoHO/CDS in twelve relevant lines. The loop is initially best visible in the TRACE 195 A filter band, and later in the 171 A filter band, with correspondence with the CDS raster images at log T \~ 6.0-6.1. We have taken as pixel-by-pixel background the latest TRACE, Yohkoh and CDS images where the loop has faded out. We examine the loop morphology evol…
Dealing with contaminants in Coulomb excitation of radioactive beams
2020
Abstract Data analysis of the Coulomb excitation experiment of the exotic 206Hg nucleus, recently performed at CERN’s HIE-ISOLDE facility, needs to account for the contribution to target excitation due to the strongly-present beam contaminant 130Xe. In this paper, the contamination subtraction procedure is presented.
Vertical ground reaction force measurements and video measurements provide comparable estimates of distance moved by mice during artificial light and…
2011
Video-based measures of spontaneous activity of rodents are of interest in studying, e.g. physiology. However, video-based tracking methods typically require light. The purpose of the present study was to develop a video based method for tracking movements of mice during a dark period. The method was applied in comparing the dark and light period activities of mice. Ten male mice were used in the present study. The activity of the animals was monitored simultaneously with video and ground reaction force (GRF) recordings during consecutive 12h periods of artificial light and dark. Texture based background subtraction method was used to track the mouse from the video recording, while the weig…
Random polarisations of the dipoles
2012
We extend the dipole formalism for massless and massive partons to random polarisations of the external partons. The dipole formalism was originally formulated for spin-summed matrix elements and later extended to individual helicity eigenstates. For efficiency reasons one wants to replace the spin sum by a smooth integration over additional variables. This requires the extension of the dipole formalism to random polarisations. In this paper we derive the modified subtraction terms. We only modify the real subtraction terms, the integrated subtraction terms do not require any modifications.
12C(p,p′) scattering measurement at forward angles
2006
Experimental method of measuring inelastic proton scattering with high-resolution at forward angles including zero degrees has been developed. An energy resolution of 20 keV and a scattering angle resolution of 0.5 degrees have been achieved as well as low background condition and a reliable background subtraction method. The experimental technique was applied to the 12 C (p,p′) reaction for studying the property of the second 0+ state at 7.7 MeV and a broad bump around Ex~10 MeV , where the presence of a 2+ state was reported from the 12 C (α,α′) measurement. Preliminary spectra and angular distributions are shown.
Infrared singularities in one-loop amplitudes
2010
In this talk we discuss a purely numerical approach to next-to-leading order calculations in QCD. We present a simple formula, which provides a local infrared subtraction term for the integrand of a one-loop amplitude. In addition we briefly comment on local ultraviolet subtraction terms and on the required deformation of the contour of integration.
Light Quark Masses from Lattice Quark Propagators at Large Momenta
1999
We compute non-perturbatively the average up-down and strange quark masses from the large momentum (short-distance) behaviour of the quark propagator in the Landau gauge. This method, which has never been applied so far, does not require the explicit calculation of the quark mass renormalization constant. Calculations were performed in the quenched approximation, by using O(a)-improved Wilson fermions. The main results of this study are ml^RI(2GeV)=5.8(6)MeV and ms^RI(2GeV)=136(11)MeV. Using the relations between different schemes, obtained from the available four-loop anomalous dimensions, we also find ml^RGI=7.6(8)MeV and ms^RGI=177(14)MeV, and the MSbar-masses, ml^MS(2GeV)=4.8(5)MeV and …
Superresolved imaging of remote moving targets.
2006
We present a superresolving approach that allows one to exceed the diffraction limit and recover highly resolved contours of moving targets from a sequence of low-resolution images. The presented approach is suitable for remote sensing applications. The resolution decoding algorithm that is used to recover the high-resolution features of the target can be run partially via optical means and that way can be used to reduce the required computational complexity.
Strategies for endovascular aortic repair in aortobronchial and aortoesophageal fistulas.
2013
Objective To report our experience of thoracic endovascular aortic repair (TEVAR) for acute bleeding originating from the thoracic aorta in patients with aortobronchial fistula (ABF) or aortoesophageal fistula (AEF). Patients and Methods A total of nine patients (three woman) were treated from September 1995 to March 2012 by TEVAR for ABF (n = 5) and AEF (n = 4). The implants (N = 14) were introduced with fluoroscopic guidance via the aorta (n = 1), the iliac (n = 2), or femoral (n = 11) artery, respectively. Results All aortic lesions could be sealed successfully. Perioperative morbidity was 0% in the ABF group and 50% (2 of 4) in the AEF group and no procedure-related morbidity was noted …