919 research outputs found
The CMS High Level Trigger
The CMS experiment has been designed with a 2-level trigger system: the Level
1 Trigger, implemented on custom-designed electronics, and the High Level
Trigger (HLT), a streamlined version of the CMS offline reconstruction software
running on a computer farm. A software trigger system requires a tradeoff
between the complexity of the algorithms running on the available computing
power, the sustainable output rate, and the selection efficiency. Here we will
present the performance of the main triggers used during the 2012 data taking,
ranging from simpler single-object selections to more complex algorithms
combining different objects, and applying analysis-level reconstruction and
selection. We will discuss the optimisation of the triggers and the specific
techniques to cope with the increasing LHC pile-up, reducing its impact on the
physics performance.Comment: PIC2013 conferenc
Performance of the online track reconstruction and impact on hadronic triggers at the CMS High Level Trigger
The trigger systems of the LHC detectors play a crucial role in determining
the physics capabilities of the experiments. A reduction of several orders of
magnitude of the event rate is needed to reach values compatible with the
detector readout, offline storage and analysis capabilities. The CMS experiment
has been designed with a two-level trigger system: the Level 1 (L1) Trigger,
implemented on custom-designed electronics, and the High Level Trigger (HLT), a
streamlined version of the CMS reconstruction and analysis software running on
a computer farm. The software-base HLT requires a trade-off between the
complexity of the algorithms, the sustainable output rate, and the selection
efficiency. This is going to be even more challenging during Run II, with a
higher centre-of-mass energy, a higher instantaneous luminosity and pileup, and
the impact of out-of-time pileup due to the 25 ns bunch spacing. The online
algorithms need to be optimised for such a complex environment in order to keep
the output rate under control without impacting the physics efficiency of the
online selection. Tracking, for instance, will play an even more important role
in the event reconstruction. In this poster we will present the performance of
the online track and vertex reconstruction algorithms, and their impact on the
hadronic triggers that make use of b-tagging and of jets reconstructed with the
Particle Flow technique. We will show the impact of these triggers on physics
performance of the experiment, and the latest plans for improvements in view of
the Run II data taking in 2015.Comment: arXiv admin note: substantial text overlap with arXiv:1403.150
Search for a high mass Higgs-like boson produced via Vector Boson Fusion, in the decay channel H -> ZZ -> llqq (l=e, mu) with the CMS detector
Urinary Cytology: Potential Role in Canine Urinary Tract Infections
The diagnosis of urinary tract infections (UTIs) requires a concomitant evaluation of clinical signs and urine culture, which is of fundamental to start an appropriate antibiotic treatment. Several factors, such as subclinical bacteriuria or pre-analytical errors, may make the interpretation of urine culture difficult. The aim of the study was to evaluate the association between the finding of neutrophils and bacteria in unstained and stained canine urine sediment and the presence of clinical signs and positive urine culture. Urine samples from 35 dogs with clinical signs of UTI and 55 asymptomatic dogs with risk factors for UTI were prospectively collected by cystocentesis, divided into three aliquots, and submitted for: (1) physical and chemical Dipstick analysis and unstained urinary sediment (casts, crystals, bacteria, leucocytes, cells, parasites); (2) stained urinary sediment (extra/intracellular bacteria, degenerated and non-degenerated neutrophils); (3) qualitative and quantitative urine culture and antimicrobial sensitivity-test. The association between unstained and stained findings of urinary sediment and urine culture was tested. Sensibility, specificity, and positive/negative predictive values in diagnosing positive urine cultures of bacteria at unstained and stained evaluation were compared. Both wet-mount bacteriuria and the cytological presence of intracellular and extracellular bacteria, neutrophils, and degenerated neutrophils were successively associated with positive urine culture (p < 0.001). The presence of intracellular bacteria was the only independent predictor of positive urine culture. Total bacterial count did not differ significantly between symptomatic and asymptomatic dogs. Detection of extracellular and intracellular bacteriuria at stained urinary sediment significantly improved the sensibility of predicting positive urine culture. Cytologic evaluation of urinary sediment may be helpful in detecting signs of active inflammation, thus enhancing the clinical relevance of a positive urine culture
Search for long-lived particles that decay into final states containing two electrons or two muons in proton-proton collisions at sqrt(s) = 8 TeV
Search for stealth supersymmetry in events with jets, either photons or leptons, and low missing transverse momentum in pp collisions at 8 TeV
Retrofitting traditional buildings: a risk-management framework integrating energy and moisture
Traditional buildings constitute a large proportion of the building stock in many countries worldwide; around 40% of the UK’s housing stock was built before 1940 and was primarily made with solid masonry walls. Only 11% of UK solid-walled dwellings had insulation installed, suggesting the high potential of the low-carbon retrofit of traditional buildings. However, there is evidence of the occurrence of unintended consequences, often associated with excess moisture. A method is presented for moisture risk management that includes the development of a process and a framework. These tools are then integrated into a novel framework for the combined energy and moisture performance retrofit of traditional buildings. An example of the framework’s practical application is provided, with a focus on retrofit measures for solid-wall insulation. The proposed systematic approach demonstrates the interconnected nature of energy and moisture. It harmonises the principles needed to support organisations in the delivery of robust retrofit of traditional buildings through the integration of pre-retrofit building assessment and post-retrofit monitoring in the process. The risk-management process and framework presented can be valuable tools to support designers in providing robust and scalable retrofit measures and strategies. 'Practice relevance' An integrated energy and moisture risk-management process is presented to support designers in the retrofit of traditional buildings. This is accompanied by a framework that explains the steps required for moisture risk management at the various stages of the retrofit process. This systematic approach harmonises the principles needed to support organisations in delivering robust low-carbon retrofits and integrates pre- and post-retrofit building assessment in the process. While previous work has addressed energy and moisture management separately, this integrates the two aspects into a framework for risk management. An example illustrates the relevant modes and methods of assessment and monitoring in support of risk management. When combined with practical guidelines and training, the risk-management process and framework can be valuable tools to provide robust and scalable retrofit measures and strategies. The framework was developed within the context of the UK construction industry; it can be adapted to other contexts
Energy calibration and resolution of the CMS electromagnetic calorimeter in pp collisions at √s = 7 TeV
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