Operational results on the fully automatic LHC collimator alignment

The Large Hadron Collider has a complex collimation system installed to protect its sensitive equipment from normal and abnormal beam losses. The collimators are set around the beam following a multistage transverse setting hierarchy. The insertion position of each collimator is established using beam-based alignment techniques to determine the local beam position and rms beam size at each collimator. During previous years, collimator alignments were performed semiautomatically, with collimation experts present to oversee and control the alignment. During run II, a new fully automatic alignment tool was developed and used for collimator alignments throughout 2018. This paper discusses the improvements on the alignment software to automate it using machine learning, whilst focusing on the operational results obtained when testing the new software in the LHC. The alignment tests were conducted with both proton and ion beams, and angular alignments were performed with proton beams. This upgraded software successfully decreased the alignment time by a factor of 3 and made the results more reproducible, which is particularly important when performing angular alignments.peer-reviewe

Software architecture for automatic LHC collimator alignment using machine learning

The Large Hadron Collider at CERN relies on a collimation system to absorb unavoidable beam losses before they reach the superconducting magnets. The collimators are positioned close to the beam in a transverse setting hierarchy achieved by aligning each collimator with a precision of a few tens of micrometres. In previous years, collimator alignments were performed semi-automatically, requiring collimation experts to be present to oversee and control the entire process. In 2018, expert control of the alignment procedure was replaced by dedicated machine learning algorithms, and this new software was used for collimator alignments throughout the year. This paper gives an overview of the software re-design required to achieve fully automatic collimator alignments, describing in detail the software architecture and controls systems involved. Following this successful deployment, this software will be used in the future as the default alignment software for the LHC.peer-reviewe

Effects of a Randomized Home-Based Quality of Movement Protocol on Function, Posture and Strength in Outpatients with Obesity

The aim of this study was to determine the effects of two different home-based training interventions on functional parameters and body composition in obese patients. Significant interactions and main effects of time (p < 0.0001) were found in MQ compared to CT in the functional parameters, while muscular strength and body composition variables improved similarly in both groups with a main effect of time (p < 0.05). These findings suggest that a home-based movement quality training is effective in ameliorating postural control and movement efficiency with similar improvements in muscular strength and body composition compared with a mere traditional resistance training

Automatic beam loss threshold selection for LHC collimator alignment

The collimation system used in the Large Hadron Collider at CERN is positioned around the beam with a hierarchy that protects sensitive equipment from unavoidable beam losses. The collimator settings are determined using a beam-based alignment technique, where collimator jaws are moved towards the beam until the beam losses exceed a predefined threshold. This threshold needs to be updated dynamically, corresponding to the changes in the beam losses. The current method for aligning collimators is semi-automated requiring a collimation expert to monitor the loss signals and continuously select and update the threshold accordingly. The human element in this procedure is a major bottleneck for speeding up the alignment. This paper therefore proposes a method to fully automate this threshold selection. A data set was formed from previous alignment campaigns and analysed to define an algorithm that produced results consistent with the user selections. In over 90% of the cases the difference between the two was negligible and the algorithm presented in this study was used for collimator alignments throughout 2018.peer-reviewe

Vortioxetine as adjunctive therapy in the treatment of schizophrenia

Background: The evidence for safe and effective interventions to treat the negative and cognitive symptoms of schizophrenia is lacking. Objectives: Vortioxetine is a novel antidepressant that has been used as adjunctive therapy for the treatment of psychosis; however, its effectiveness in clinical practice is relatively unknown. In this study, we aimed to determine the potential clinical effectiveness and safety and tolerability of vortioxetine in psychosis. Design: This is a non-interventional, retrospective study on the add-on use of vortioxetine in a group of people with schizophrenia-spectrum disorders in a large UK NHS mental health trust. Methods: Clinical effectiveness of vortioxetine was retrospectively assessed through the Clinical Global Impression – Severity (CGI-S) scale at 3 months. Safety and tolerability were evaluated through treatment discontinuation rates at 3, 6, and 12 months, and clinical reasons were evaluated at the primary endpoint of 3 months. Results: Data were available for 40 subjects with a diagnosis of schizophrenia or schizoaffective disorder–prescribed vortioxetine treatment; 30 (75%) remained on treatment at 3 months. At CGI-S assessment, 15 of the 35 evaluated subjects reported at least a 1-point improvement, from 5 at baseline to 4 after 3 months of treatment. Twenty-six (65%) remained on treatment at 1-year follow-up. The main reasons for those discontinuing treatment were inadequate response (10%) and manic switch (7.5%), while one subject refused treatment. Tolerability to treatment was good, and 36 subjects (90%) reported no adverse events specific to vortioxetine treatment. Conclusion: Schizophrenia is a complex illness, and there is insufficient treatment response in many individuals. A significant proportion of whom may require adjunctive treatments depending on the nature of the residual symptoms. Vortioxetine could be a potentially safe and effective option in such people, but further controlled studies are required

Prospects to apply machine learning to optimize the operation of the crystal collimation system at the LHC

Crystal collimation relies on the use of bent crystals to coherently deflect halo particles onto dedicated collimator absorbers. This scheme is planned to be used at the LHC to improve the betatron cleaning efficiency with high-intensity ion beams. Only particles with impinging angles below 2.5 urad relative to the crystalline planes can be efficiently channeled at the LHC nominal top energy of 7 Z TeV. For this reason, crystals must be kept in optimal alignment with respect to the circulating beam envelope to maximize the efficiency of the channeling process. Given the small angular acceptance, achieving optimal channeling conditions is particularly challenging. Furthermore, the different phases of the LHC operational cycle involve important dynamic changes of the local orbit and optics, requiring an optimized control of position and angle of the crystals relative to the beam. To this end, the possibility to apply machine learning to the alignment of the crystals, in a dedicated setup and in standard operation, is considered. In this paper, possible solutions for automatic adaptation to the changing beam parameters are highlighted and plans for the LHC ion runs starting in 2022 are discussed.peer-reviewe

Application of machine learning techniques at the CERN Large Hadron Collider

Machine learning techniques have been used extensively in several domains of Science and Engineering for decades. These powerful tools have been applied also to the domain of high-energy physics, in the analysis of the data from particle collisions, for years already. Accelerator physics, however, has not started exploiting machine learning until very recently. Several activities are flourishing in this domain, in view of providing new insights to beam dynamics in circular accelerators, in different laboratories worldwide. This is, for instance, the case for the CERN Large Hadron Collider, where since a few years exploratory studies are being carried out. A broad range of topics have been addressed, such as anomaly detection of beam position monitors, analysis of optimal correction tools for linear optics, optimisation of the collimation system, lifetime and performance optimisation, and detection of hidden correlations in the huge data set of beam dynamics observables collected during the LHC Run 2. Furthermore, very recently, machine learning techniques are being scrutinised for the advanced analysis of numerical simulations data, in view of improving our models of dynamic aperture evolution.peer-reviewe

Magnetization on rough ferromagnetic surfaces

Journal ArticleUsing Ising-model Monte Carlo simulations, we show a strong dependence of surface magnetization on surface roughness. On ferromagnetic surfaces with spin-exchange coupling larger than that of the bulk, the surface magnetic ordering temperature decreases toward the bulk Curie temperature with increasing roughness. For surfaces with spin-exchange coupling smaller than that of the bulk, a crossover behavior occurs: at low temperature, the surface magnetization decreases with increasing roughness; at high temperature, the reverse is true

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good