197,011 research outputs found
Muon trigger with fast Neural Networks on FPGA, a demonstrator
No full textThe online reconstruction of muon tracks in High Energy Physics experiments is a highly demanding task, typically performed on reconfigurable digital circuits, such as FPGAs. Complex analytical algorithms are executed in a quasi-real-time environment to identify, select, and reconstruct local tracks in often noise-rich environments. A novel approach to the generation of local triggers based on a hybrid combination of Artificial Neural Networks and analytical methods is proposed, targeting the muon reconstruction for drift tube detectors. The proposed algorithm exploits Neural Networks to solve otherwise computationally expensive analytical tasks for the unique identification of coherent signals and the removal of geometrical ambiguities. The proposed approach is deployed on state-of-the-art FPGA and its performances are evaluated on simulation and on data collected from cosmic rays
A horizontally scalable online processing system for trigger-less data acquisition
No full textThe vast majority of high energy physics experiments rely on data acquisition and hardware-based trigger systems performing a number of stringent selections before storing data for offline analysis. The online reconstruction and selection performed at the trigger level are bound to the synchronous nature of the data acquisition system, resulting in a trade-off between the amount of data collected and the complexity of the online reconstruction performed. Exotic physics processes, such as long-lived and slow-moving particles, are rarely targeted by online triggers as they require complex and nonstandard online reconstruction, usually incompatible with the time constraints of most data acquisition systems. The online trigger selection can thus impact as one of the main limiting factors to the experimental reach for exotic signatures. Alternative data acquisition solutions based on the continuous and asynchronous processing of the stream of data from the detectors are therefore foreseeable as a way to extend the experimental physics reach. Trigger-less data readout systems, paired with efficient streaming data processing solutions, can provide a viable alternative. In this document, an end-to-end implementation of a fully trigger-less data acquisition and online data processing system is discussed. An easily scalable and deployable implementation of such an architecture is proposed, based on open-source distributed computing frameworks capable of performing asynchronous online processing of streaming data. The proposed schema can be suitable for deployment as a fully integrated data acquisition system for small-scale experimental apparatus, or to complement the trigger-based data acquisition systems of larger experiments. A muon telescope setup consisting of a set of gaseous detectors is used as the experimental development testbed in this work, and a fully integrated online processing pipeline deployed on cloud computing resources is implemented and described
Trigger-less readout and unbiased data quality monitoring of the CMS drift tubes muon detector
No full textThe CMS experiment 40 MHz data scouting project is aimed at intercepting the data produced at the level of the detectors' front-end without the filters induced by hardware-based triggers. A first implementation is realized by the trigger-less reading and processing of a fraction of the Drift Tube (DT) muon detector, equipped with a preliminary version of the so-called Phase-2 Upgrade on-detector electronics boards. The data are transferred via high-speed optical links to back-end boards independently from the central experiment data acquisition (DAQ), permitting real-time detector status monitoring via receiving all the signals produced at the front-end level, and providing an unbiased estimate of the CMS DT hit-rate under various data-taking conditions
40 MHz triggerless readout of the CMS Drift Tube muon detector
No full textThe Level -1 trigger scouting system of the CMS experiment aims at intercepting the intermediate data produced by the L1 trigger processors before the final trigger decision. This system can be complemented by adding the raw stream of data collected from the detector front-end, whenever the throughput is manageable. In this work, the triggerless readout of the CMS Drift Tubes (DT) detector is presented. This is realized by reading a sector of the DT which has been equipped with the preproduction of Phase -2 upgrade front-end boards. A Xilinx VCU118 acts as a concentrator of the Phase -2 demonstrator lpGBT links and transmits data to a server via 100G TCP/IP. First results coming from a test -stand mimicking the sector demonstrator are shown
Gonochorism and planula brooding in the Mediterranean endemic orange coral Astroides calycularis (Scleractinia: Dendrophylliidae). Morphological aspects of gametogenesis and ontogenesis.
No full textInformation on reproduction in temperate scleractinian corals is notably scant. Astroides calycularis is an azooxanthellate coral that inhabits the South-Western Mediterranean Sea, in shaded habitats from 0 to 50 m depth. Recently, it has been observed along the coast of the Adriatic Sea. This study is the first in-depth investigation of A. calycularis reproductive biology. Observations from the nineteenth century described A. calycularis as hermaphroditic; in contrast, we demonstrated gonochorism (male and female colonies) and brooding (planula releasing) as the reproductive mode, consistent with other members of the family Dendrophylliidae. Undifferentiated germ cells arose in the gastrodermis and subsequently migrated to the mesoglea, where they completed gametogenesis. During spermatogenesis, spermary diameter increased from 20 to 940 mu m. During oogenesis, a conspicuous presence of lipid vesicles of exogenous origin (phagocytes) was observed in the ooplasma. As oogenesis progressed, the synthesis of yolk gradually reduced the nucleus to cytoplasm ratio. In the final stages of oogenesis, the nucleus migrated to the extreme periphery of the oocyte adhering to the oolemma, and became indented. Nuclear migration and shape change may facilitate fertilization and determine the future embryonic axis. During oogenesis, the oocyte diameter increased from 25 to 1590 mu m. Embryogenesis took place in the coelenteron. Formation of a blastocoel was not observed, and development proceeded via stereoblastulae with superficial cleavage. Gastrulation took place by delamination. Embryo diameter ranged from 550 to 1140 mu m. Released larvae (length 1700 to 2000 mu m) were observed in the field during summer, along the bentho
Sporadic generalized lentiginosis without systemic involvement
No full textA 42-year old Caucasian man with generalized, acquired lentiginosis and no other associated diseases is described. A brief discussion about the significance of the term lentiginoses, the problems of their classification and nomenclature is also presented. The presence at the histopathologic examination, of some junctional nests of melanocytes provides the basis for a discussion of the relationship of the case presented, as well as other lentiginoses, with melanocytic naevi
Video-Based Analysis of a Smart Lighting Warning System for Pedestrian Safety at Crosswalks
No full textHighlights: What are the main findings? The presence of an integrated lighting warning system near crosswalks significantly increases yielding compliance and allows drivers to respect the stopping distance before a pedestrian crossing. Five-month continuous monitoring of different warning lighting systems proved that the combination of lighting with in-curb fixed LED strips, orange flashing beacons, and dedicated LED lighting reduces drivers’ speed compared to standard street lighting systems. What are the implications of the main findings? Smart lighting systems detecting pedestrians at night, both in urban and suburban areas, are a valid solution to increase safety near pedestrian crossings. These smart systems improve drivers’ vision and significantly reduce the risk of accidents between vehicles and pedestrians. In-curb fixed LED strips and flashing beacons increase driver attention towards pedestrians, thus making drivers stop vehicles at crosswalks, yielding to pedestrians. This study analyses five months of continuous monitoring of different lighting warning systems at a pedestrian crosswalk through video surveillance cameras during nighttime. Three different light signalling systems were installed near a pedestrian crossing to improve the visibility and safety of vulnerable road users: in-curb LED strips, orange flashing beacons, and asymmetric enhanced LED lighting. Seven different lighting configurations of the three systems were studied and compared with standard street lighting. The speed of vehicles for each pedestrian–driver interaction was also evaluated. This was then compared to the speed that vehicles should maintain in order to stop in time and allow pedestrians to cross the road safely. In all of the conditions studied, speeds were lower than those maintained in the five-month presence of standard street lighting (42.96 km/h). The results show that in conditions with dedicated flashing LED lighting, in-curb LED strips, and orange flashing beacons, most drivers (72%) drove at a speed that allowed the vehicle to stop safely compared to standard street lighting (10%). In addition, with this lighting configuration, the majority of vehicles (85%) stopped at pedestrian crossings, while in standard street lighting conditions only 26% of the users stopped to give way to pedestrians
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
Toward electron self-localization in H2 gas: Multiple scattering effects on the electron drift mobility at low temperature and intermediate densities
No full textWe report here the first measurements of the electron drift mobility μ in gaseous H2 in the intermediate density range 0.5 × 1026 m−3 ≤ N ≤ 5 × 1026 m−3, at low temperature, T = 49.7 K and T = 29.7 K. In this range, the density is small enough to make the presence of electron states self-localized in bubbles negligible but, at the same time, is large enough for multiple scattering effects to alter the prediction of the classical kinetic theory for the mobility of quasi-free electrons. The analysis of the present data confirms the validity of the model we have developed to describe the quasi-free electron mobility in dense noble gases, which is based on the heuristic inclusion of multiple scattering effects in the classical kinetic theory
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