Event data from proton-proton collisions at the LHC will be selected by the ATLAS experiment in a three level trigger system, which reduces the initial bunch crossing rate of 40 MHz at its first two ...trigger levels (LVL1+LVL2) to ~3 kHz. At this rate the Event-Builder collects the data from all read-out system PCs (ROSs) and provides fully assembled events to the the event-filter (EF), which is the third level trigger, to achieve a further rate reduction to ~ 200 Hz for permanent storage. The event-builder is based on a farm of O(100) PCs, interconnected via gigabit Ethernet to O(150) ROSs. These PCs run Linux and multi-threaded software applications implemented in C++. All the ROSs and one third of the event-builder PCs are already installed and commissioned. We report on performance tests on this initial system, which show promising results to reach the final data throughput required for the ATLAS experiment.
In the ATLAS experiment at the LHC, the ROD Crate DAQ provides a complete framework to implement data acquisition functionality at the boundary between the detector specific electronics and the ...common part of the data acquisition system. Based on a plugin mechanism, it allows selecting and using common services (like data output and data monitoring channels) and developing simple libraries to control, monitor, acquire and/or emulate detector specific electronics. Providing also event building functionality, the ROD Crate DAQ is intended to be the main data acquisition tool for the first phase of detector commissioning. This paper presents the design, functionality and performance of the ROD Crate DAQ and its usage in the ATLAS DAQ and during detector tests
During 2006 and spring 2007, integration and commissioning of trigger and data acquisition (TDAQ) equipment in the ATLAS experimental area has progressed. Much of the work has focused on a final ...prototype setup consisting of around eighty computers representing a subset of the full TDAQ system. There have been a series of technical runs using this setup. Various tests have been run including ones where around 6k Level-1 pre-selected simulated proton-proton events have been processed in a loop mode through the trigger and dataflow chains. The system included the readout buffers containing the events, event building, second level and third level trigger algorithms. Quantities critical for the final system, such as event processing times, have been studied using different trigger algorithms as well as different dataflow components.
In the ATLAS experiment at the LHC, the output of readout hardware specific to each subdetector will be transmitted to buffers, located on custom made PCI cards ("ROBINs"). The data consist of ...fragments of events accepted by the first-level trigger at a maximum rate of 100 kHz. Groups of four ROBINs will be hosted in about 150 read-out subsystem (ROS) PCs. Event data are forwarded on request via Gigabit Ethernet links and switches to the second-level trigger or to the event builder. In this paper a discussion of the functionality and real-time properties of the ROS is combined with a presentation of measurement and modeling results for a testbed with a size of about 20% of the final DAQ system. Experimental results on strategies for optimizing the system performance, such as utilization of different network architectures and network transfer protocols, are presented for the testbed, together with extrapolations to the full system
Implementing backward evaluation as part of the peer assessment process enables students to react to the feedback they receive on their work within one peer assessment activity cycle. The emergence ...of online peer assessment platforms has brought new opportunities to study the peer assessment process, including backward evaluation, through the digital data that the use of these systems generates. This scoping review provides an overview of peer assessment studies that use backward evaluation data in their analyses, identifies different types of backward evaluation and describes how backward evaluation data have been used to increase understanding of peer assessment processes. The review contributes to a mapping of backward evaluation terminology and shows the potential of backward evaluation data to give new insights on students’ perceptions of what is useful feedback, their reactions to the feedback received and its consequences for feedback implementation.
•Backward evaluation can help detect the tit-for-tat strategy.•Backward evaluation is mostly used to examine mediators of student feedback uptake.•Feedback helpfulness is the most popular metric for backward evaluation.
Nucl.Phys.A706:403-417,2002 The cross section for the $^3$He(e, e$'$d)p reaction has been measured as a
function of the missing momentum $p_m$ in q$\omega$ -constant kinematics at
beam energies of ...370 and 576 MeV for values of the three-momentum transfer $q$
of 412, 504 and 604 \mevc. The L(+TT), T and LT structure functions have been
separated for $q$ = 412 and 504 \mevc. The data are compared to three-body
Faddeev calculations, including meson-exchange currents (MEC), and to
calculations based on a covariant diagrammatic expansion. The influence of
final-state interactions and meson-exchange currents is discussed. The
$p_m$-dependence of the data is reasonably well described by all calculations.
However, the most advanced Faddeev calculations, which employ the AV18
nucleon-nucleon interaction and include MEC, overestimate the measured cross
sections, especially the longitudinal part, and at the larger values of $q$.
The diagrammatic approach gives a fair description of the cross section, but
under(over)estimates the longitudinal (transverse) structure function.
Teaching Polish as a foreign language to refugees from Ukraine is an experience at the intersection of intercultural education and glottodidactics. The specificity of the social ...situation—refugeeism—generates special needs of learners and special learning strategies. The need for integration behind language learning is primarily the ability to communicate in a new language as soon as possible. The record of the experience of working with refugees shows that building on cultural difference and the strategy of developing a “rich point” provides opportunities for motivating work on language learning in a difficult refugee situation.
Peer assessment (PA) is the process of students grading and giving feedback to each other's work. Learning analytics is a field focused on analysing educational data to understand and improve ...learning processes. Using learning analytics on PA data has the potential to gain new insights into the feedback giving/receiving process. This exploratory study focuses on backward evaluation, an under researched aspect of peer assessment, where students react to the feedback that they received on their work. Two aspects are analysed: 1) backward evaluation characteristics depending on student perception of feedback that they receive on their work, and 2) the relationship between rubric characteristics and backward evaluation. A big dataset (N = 7,660 records) from an online platform called Peergrade was analysed using both statistical methods and Epistemic Network Analysis. Students who found feedback useful tended to be more accepting by acknowledging their errors, intending to revise their text, and praising its usefulness, while students who found the feedback less useful tended to be more defensive by expressing that they were confused about its meaning, critical towards its form and focus, and in disagreement with the claims. Moreover, students mostly suggested feedback improvement in terms of feedback specificity, justification and constructivity, rather than kindness. The paper concludes by discussing the potential and limitations of using LA methods to analyse big PA datasets.
•Students perceiving feedback as extremely useful, express more gratitude.•Students request more specific, justified or constructive, rather than kind feedback.•Backward evaluation might be used to determine the usefulness of a rubric.•Large datasets need context data to facilitate interpretation of peer feedback.
The cross section for the \(^3\)He(e, e\('\)d)p reaction has been measured as a function of the missing momentum \(p_m\) in q\(\omega\) -constant kinematics at beam energies of 370 and 576 MeV for ...values of the three-momentum transfer \(q\) of 412, 504 and 604 \mevc. The L(+TT), T and LT structure functions have been separated for \(q\) = 412 and 504 \mevc. The data are compared to three-body Faddeev calculations, including meson-exchange currents (MEC), and to calculations based on a covariant diagrammatic expansion. The influence of final-state interactions and meson-exchange currents is discussed. The \(p_m\)-dependence of the data is reasonably well described by all calculations. However, the most advanced Faddeev calculations, which employ the AV18 nucleon-nucleon interaction and include MEC, overestimate the measured cross sections, especially the longitudinal part, and at the larger values of \(q\). The diagrammatic approach gives a fair description of the cross section, but under(over)estimates the longitudinal (transverse) structure function.
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