199 research outputs found
Interference coupling mechanisms in Silicon Strip Detectors - CMS tracker "wings": A learned lesson for SLHC
The identification of coupling mechanisms between noise sources and sensitive areas of the front-end electronics (FEE) in the previous CMS tracker sub-system is critical to optimize the design and integration of integrated circuits, sensors and power distribution circuitry for the proposed SLHC Silicon Strip Tracker systems. This paper presents a validated model of the noise sensitivity observed in the Silicon Strip Detector-FEE of the CMS tracker that allows quantifying both the impact of the noise coupling mechanisms and the system immunity against electromagnetic interferences. This model has been validated based on simulations using finite element models and immunity tests conducted on prototypes of the Silicon Tracker End-Caps (TEC) and Outer Barrel (TOB) systems. The results of these studies show important recommendations and criteria to be applied in the design of future detectors to increase the immunity against electromagnetic noise
EMI Filter Design and Stability Assessment of DC Voltage Distribution based on Switching Converters
Global noise studies for CMS Tracker upgrade
7 páginas, 6 figuras.-- Trabajo presentado al "Topical Workshop on Electronics for Particle Physics 2010 (TWEPP-10)" celebrado en Alemania.-- Open Access.-- et al.The characterization of the noise emissions of DC-DC converters at system level is critical to optimize the design of the detector and define rules for the integration strategy. This paper presents the impedance effects on the noise emissions of DC-DC converters at system level. Conducted and radiated noise emissions at the input and at the output from DC-DC converters have been simulated for different types of power network and FEE impedances. System aspects as granularity, stray capacitances of the system and different working conditions of the DC-DC converters are presented too. This study has been carried out using simulation models of noise emissions of DC-DC converters in the real scenario. The results of these studies show important recommendations and criteria to be applied to integrate the DC-DC converters and decrease the system noise level.C.R. wants to thank to US DOE, under contract DE-AC02-76SF00515,
for the support of this work.Peer reviewe
DC-DC switching converter based power distribution vs serial power distribution: EMC strategies
This paper presents a detailed and comparative analysis from the electromagnetic compatibility point of view of the proposed power distributions for the SLHC tracker up-grade. The main idea is to identify and quantify the noise sources, noise distribution at the system level and the sensitive areas in the front-end electronics corresponding to both proposed topologies: The DC-DC converter based power distribution and the serial power distribution. These studies will be used to define critical points on both systems to be studied and prototyped to ensure the correct integration of the system taking critically into account the electromagnetic compatibility. This analysis at the system level is crucial to ensure the final performance of the detector using non conventional power distributions, avoiding interference problems and excessive losses that can lead to catastrophic failures or expensive and un-practical solutions
Status of the LHC Short Dipole Model Programme
The 1-m model program for the main LHC dipoles is now mainly focussed on double-aperture magnets. In the past years an intensive program based on single-aperture dipoles allowed to select the series-design features among several variants for the coil cross section, the material of the collars and of the coil end spacers, the coil pre-stress and the cable insulation. The recent double-aperture models are dedicated to the fine-tuning of the baseline design and the manufacture of the coil ends. This paper reports about the fabrication and testing of these magnets and the results relevant for the series production of the 15-m long full-size dipole cold masses
The impact of a medication review with follow-up service on hospital admissions in aged polypharmacy patients
© 2016 The British Pharmacological Society Aims: The aims were to assess the impact of a medication review with follow-up (MRF) service provided in community pharmacy to aged polypharmacy patients on the number of medication-related hospital admissions and to estimate the effect on hospital costs. Methods: This was a sub-analysis of a cluster randomized controlled trials carried out in 178 community pharmacies in Spain. Pharmacies in the intervention group (IG) provided a comprehensive medication review during 6 months. Pharmacists in the comparison group (CG) delivered usual care. For the purposes of this sub-analysis, an expert panel of three internal medicine specialists screened the hospitalizations occurring during the main study, in order to identify medication-related hospitalizations. Inter-rater reliability was measured using Fleiss's kappa. Hospital costs were calculated using diagnosis related groups. Results: One thousand four hundred and three patients were included in the main study and they had 83 hospitalizations. Forty-two hospitalizations (50.6%) were medicine-related, with a substantial level of agreement among the experts (kappa = 0.65, 95% CI 0.52, 0.78, P < 0.01). The number of medication-related hospitalizations was significantly lower in patients receiving MRF (IG 11, GC 31, P = 0.042). The probability of being hospitalized was 3.7 times higher in the CG (odds ratio 3.7, 95% CI 1.2, 11.3, P = 0.021). Costs for a medicine-related hospitalization were €6672. Medication-related hospitalization costs were lower for patients receiving MRF [IG: €94 (SD 917); CG: €301 (SD 2102); 95% CI 35.9, 378.0, P = 0.018]. Conclusion: MRF provided by community pharmacists might be an effective strategy to balance the assurance of the benefit from medications and the avoidance of medication-related hospitalizations in aged patients using polypharmacy
Local Whittle estimation in time-varying long memory series
The memory parameter is usually assumed to be constant in traditional long memory time series. We relax this restriction by considering the memory a time-varying function that depends on a finite number of parameters. A time-varying Local Whittle estimator of these parameters, and hence of the memory function, is proposed. Its consistency and asymptotic normality are shown for locally stationary and locally non-stationary long memory processes, where the spectral behaviour is restricted only at frequencies close to the origin. Its good finite sample performance is shown in a Monte Carlo exercise and in two empirical applications, highlighting its benefits over the fully parametric Whittle estimator proposed by Palma and Olea (2010). Standard inference techniques for the constancy of the memory are also proposed based on this estimator.info:eu-repo/semantics/publishedVersio
- …
