scholarly journals Conditions DataHandling in the Multithreaded ATLAS Framework

2019 ◽  
Vol 214 ◽  
pp. 05031 ◽  
Author(s):  
Charles Leggett ◽  
Illya Shapoval ◽  
Scott Snyder ◽  
Vakho Tsulaia

In preparation for Run 3 of the LHC, the ATLAS experiment is migrating its offline software to use a multithreaded framework, which will allow multiple events to be processed simultaneously. This implies that the handling of non-event, time-dependent (conditions) data, such as calibrations and geometry, must also be extended to allow for multiple versions of such data to exist simultaneously. This has now been implemented as part of the new ATLAS framework. The detector geometry is included in this scheme by having sets of time-dependent displacements on top of a static base geometry.

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  

AbstractThe performance of the ATLAS Inner Detector alignment has been studied using pp collision data at $$\sqrt{s} = 13\,\hbox {TeV}$$ s = 13 TeV collected by the ATLAS experiment during Run 2 (2015–2018) of the Large Hadron Collider (LHC). The goal of the detector alignment is to determine the detector geometry as accurately as possible and correct for time-dependent movements. The Inner Detector alignment is based on the minimization of track-hit residuals in a sequence of hierarchical levels, from global mechanical assembly structures to local sensors. Subsequent levels have increasing numbers of degrees of freedom; in total there are almost 750,000. The alignment determines detector geometry on both short and long timescales, where short timescales describe movements within an LHC fill. The performance and possible track parameter biases originating from systematic detector deformations are evaluated. Momentum biases are studied using resonances decaying to muons or to electrons. The residual sagitta bias and momentum scale bias after alignment are reduced to less than $$\sim 0.1\hbox { TeV}^{-1}$$ ∼ 0.1 TeV - 1 and $$0.9\times 10^{-3}$$ 0.9 × 10 - 3 , respectively. Impact parameter biases are also evaluated using tracks within jets.


2016 ◽  
Vol 27 (6) ◽  
pp. 1909-1924 ◽  
Author(s):  
Ruwanthi Kolamunnage-Dona ◽  
Paula R Williamson

Joint modelling of longitudinal biomarker and event-time processes has gained its popularity in recent years as they yield more accurate and precise estimates. Considering this modelling framework, a new methodology for evaluating the time-dependent efficacy of a longitudinal biomarker for clinical endpoint is proposed in this article. In particular, the proposed model assesses how well longitudinally repeated measurements of a biomarker over various time periods (0,t) distinguish between individuals who developed the disease by time t and individuals who remain disease-free beyond time t. The receiver operating characteristic curve is used to provide the corresponding efficacy summaries at various t based on the association between longitudinal biomarker trajectory and risk of clinical endpoint prior to each time point. The model also allows detecting the time period over which a biomarker should be monitored for its best discriminatory value. The proposed approach is evaluated through simulation and illustrated on the motivating dataset from a prospective observational study of biomarkers to diagnose the onset of sepsis.


2019 ◽  
Vol 214 ◽  
pp. 05017
Author(s):  
Jack Cranshaw ◽  
David Malon ◽  
Marcin Nowak ◽  
Peter Van Gemmeren

Scalable multithreading poses challenges to I/O for the ATLAS experiment. The performance of a thread-safe I/O strategy may depend upon many factors, including I/O latencies, whether tasks are CPU- or I/O-intensive, and thread count. In a multithreaded framework, an I/O infrastructure must efficiently supply event data to and collect it from many threads processing multiple events in flight. In particular, on-demand reading from multiple threads may challenge caching strategies that were developed for serial processing and may need to be enhanced. This I/O infrastructure must also address how to read, make available, and propagate in-file metadata and other non-event data needed as context for event processing. We describe the design and scheduling of I/O components in the ATLAS multithreaded control framework, AthenaMT, for both event and non-event I/O. We discuss issues associated with exploiting the multithreading capabilities of our underlying persistence technology, ROOT, in a manner harmonious with the ATLAS framework?s own approach to thread management. Finally, we discuss opportunities for evolution and simplification of I/O components that have successfully supported ATLAS event processing for many years from their serial incarnations to their thread-safe counterparts.


2021 ◽  
Author(s):  
Antonella Peresan ◽  
Anastasia Nekrasova

<p>The space concept of the Unified Scaling Law for Earthquakes (USLE), which generalizes the Gutenberg-Richter relationship making use of the fractal distribution of earthquake sources in a seismic region, has been applied to seismicity in Northeastern Italy. In particular, the temporal variations of USLE coefficients have been investigated, with the aim to get new insights in the evolving dynamics of seismicity within different tectonic domains of Friuli-Venezia Giulia region (FVG) and its surroundings.</p><p>For this purpose, we resorted to the catalog compiled at the National Institute of Oceanography and Applied Geophysics (OGS), considering earthquakes occurred in the period 1995 – 2019, with epicenters within three sub-regions of the territory under investigation, delimited based on main geological and tectonic features (Bressan et al. 2018,  J. Seismol. 22, 1563–1578). To quantify the observed variability of seismic dynamics, a multi-parametric analysis has been carried out for each sub-region by means of several moving averages, including: the inter-event time, τ; the cumulative Benioff strain release, Σ; the USLE control parameter, η and the USLE coefficients, estimated for moving six-years time intervals. The analysis evidenced that the USLE coefficients in FVG region are time-dependent and show up correlated (Nekrasova and Peresan 2021, Frontiers in Earth Science, 8, 624). Moreover, the dynamical features of the considered parameters in the three sub-regions highlighted a number of different seismic regimes; in particular, major changes in the parameters are associated to occurrence of the 12 April 1998 (M5.6) and the 12 July 2004 (M5.1) Kobarid (Slovenia) earthquakes within the corresponding sub-region.</p><p>The results obtained for seismicity in Northeastern Italy and surrounding areas confirm similar analysis performed on a global scale, in advance and after the largest earthquakes worldwide. In addition, the analysis evidenced the spatially heterogeneous and non-stationary features of seismicity, in agreement with results from independent analysis of background seismicity within the investigated territory (Benali et al. 2020, Stoch. Environ. Res. Risk. Assess. 34, 775–791), thus suggesting the opportunity of resorting to time-dependent models of earthquakes occurrence for improving local seismic hazard assessment.</p>


Author(s):  
Y. Sato ◽  
T. Hashimoto ◽  
M. Ichihashi ◽  
Y. Ueki ◽  
K. Hirose ◽  
...  

Analytical TEMs have two variations in x-ray detector geometry, high and low angle take off. The high take off angle is advantageous for accuracy of quantitative analysis, because the x rays are less absorbed when they go through the sample. The low take off angle geometry enables better sensitivity because of larger detector solid angle.Hitachi HF-2000 cold field emission TEM has two versions; high angle take off and low angle take off. The former allows an energy dispersive x-ray detector above the objective lens. The latter allows the detector beside the objective lens. The x-ray take off angle is 68° for the high take off angle with the specimen held at right angles to the beam, and 22° for the low angle take off. The solid angle is 0.037 sr for the high angle take off, and 0.12 sr for the low angle take off, using a 30 mm2 detector.


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