1,083 research outputs found

    Traces of hecke operators and refined weight enumerators of reed-solomon codes

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    We study the quadratic residue weight enumerators of the dual projective Reed-Solomon codes of dimensions 5 and q − 4 over the finite field Fq. Our main results are formulas for the coefficients of the the quadratic residue weight enumerators for such codes. If q = p v and we fix v and vary p then our formulas for the coefficients of the dimension q − 4 code involve only polynomials in p and the trace of the q th and (q/p2 ) th Hecke operators acting on spaces of cusp forms for the congruence groups SL2(Z), Γ0(2), and Γ0(4). The main tool we use is the Eichler-Selberg trace formula, which gives along the way a variation of a theorem of Birch on the distribution of rational point counts for elliptic curves with prescribed 2-torsion over a fixed finite field

    A twisted Motohashi formula and Weyl-subconvexity for -functions of weight two cusp forms

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    We derive a Motohashi-type formula for the cubic moment of central values of -functions of level cusp forms twisted by quadratic characters of conductor , previously studied by Conrey and Iwaniec and Young. Corollaries of this formula include Weyl-subconvex bounds for -functions of weight two cusp forms twisted by quadratic characters, and estimates towards the Ramanujan-Petersson conjecture for Fourier coefficients of weight 3/2 cusp forms

    Operational experience with the GEM detector assembly lines for the CMS forward muon upgrade

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    The CMS Collaboration has been developing large-area triple-gas electron multiplier (GEM) detectors to be installed in the muon Endcap regions of the CMS experiment in 2019 to maintain forward muon trigger and tracking performance at the High-Luminosity upgrade of the Large Hadron Collider (LHC); 10 preproduction detectors were built at CERN to commission the first assembly line and the quality controls (QCs). These were installed in the CMS detector in early 2017 and participated in the 2017 LHC run. The collaboration has prepared several additional assembly and QC lines for distributed mass production of 160 GEM detectors at various sites worldwide. In 2017, these additional production sites have optimized construction techniques and QC procedures and validated them against common specifications by constructing additional preproduction detectors. Using the specific experience from one production site as an example, we discuss how the QCs make use of independent hardware and trained personnel to ensure fast and reliable production. Preliminary results on the construction status of CMS GEM detectors are presented with details of the assembly sites involvement

    Floods and health in Gambella region, Ethiopia: a qualitative assessment of the strengths and weaknesses of coping mechanisms

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    BACKGROUND: Floods are the most frequent and devastating type of natural disaster worldwide, causing unprecedented deaths, diseases, and destruction of property and crops. Flooding has a greater impact in developing countries due to lack of sufficient disaster management structures and a lack of economic resources. OBJECTIVE: This study was conducted with the aim of contributing to the knowledge base of development strategies that reduce flood-related health risks in developing countries. The study focused particularly on assessing the flood risks and health-related issues in the Gambella region of Ethiopia; with the intent of producing relevant information to assist with the improvements in the efficacy of the current flood coping strategies in the region. METHODS: Data were gathered through interviews with 14 officers from different government and non-governmental organizations and a questionnaire survey given to 35 flood victims in Itang woreda. A qualitative approach was applied and the data were analyzed using content analysis. RESULTS: It was found that flooding is a common problem in Gambella region. The findings also indicate that the flood frequency and magnitude has increased rapidly during the last decade. The increase in floods was driven mainly by climate change and changes in land use, specifically deforestation. The reported main impacts of flooding on human health in Gambella region were deaths, injuries, and diseases such as malaria and diarrhea. Another notable consequence of flooding was crop destruction and subsequent malnutrition. CONCLUSIONS: Three weaknesses that were identified in the current coping strategies for flood-related health impacts in Gambella region were a lack of flood-specific policy, absence of risk assessment, and weak institutional capacity. This study recommends new policy approaches that will increase the effectiveness of the current flood coping strategies to sustainably address the impact of flooding on human health

    Evaluation of planar silicon pixel sensors with the RD53A readout chip for the Phase-2 Upgrade of the CMS Inner Tracker

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    Shared via Kudos: https://www.growkudos.com/publications/10.1088%25252F1748-0221%25252F18%25252F11%25252Fp11015The Large Hadron Collider at CERN will undergo an upgrade in order to increase its luminosity to 7.5 × 10^34 cm^-2s^-1. The increased luminosity during this High-Luminosity running phase, starting around 2029, means a higher rate of proton-proton interactions, hence a larger ionizing dose and particle fluence for the detectors. The current tracking system of the CMS experiment will be fully replaced in order to cope with the new operating conditions. Prototype planar pixel sensors for the CMS Inner Tracker with square 50 μm × 50 μm and rectangular 100 μm × 25 μm pixels read out by the RD53A chip were characterized in the lab and at the DESY-II testbeam facility in order to identify designs that meet the requirements of CMS during the High-Luminosity running phase. A spatial resolution of approximately 3.4 μm (2 μm) is obtained using the modules with 50 μm × 50 μm (100 μm × 25 μm) pixels at the optimal angle of incidence before irradiation. After irradiation to a 1 MeV neutron equivalent fluence of Φeq = 5.3 × 10^15 cm^-2, a resolution of 9.4 μm is achieved at a bias voltage of 800 V using a module with 50 μm × 50 μm pixel size. All modules retain a hit efficiency in excess of 99% after irradiation to fluences up to 2.1 × 10^16 cm^-2. Further studies of the electrical properties of the modules, especially crosstalk, are also presented in this paper.BMWFWandFWF(Austria);FNRSandFWO(Belgium);CERN;MSEandCSF(Croatia);Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); NKFIA K124850, and Bolyai Fellowship of the Hungarian Academy of Sciences (Hungary); DAE and DST (India); INFN (Italy); PAEC (Pakistan); SEIDI, CPAN, PCTI and FEDER(Spain); Swiss Funding Agencies (Switzerland); MST (Taipei); STFC (United Kingdom); DOEandNSF(U.S.A.). This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 884104 (PSI-FELLOW-III-3i) and project AIDA-2020, GA no. 654168. Individuals have received support from HFRI (Greece)

    Triple-GEM discharge probability studies at CHARM: Simulations and experimental results

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    The CMS muon system in the region with 2.03<|η|<2.82 is characterized by a very harsh radiation environment which can generate hit rates up to 144 kHz/cm2^{2} and an integrated charge of 8 C/cm2^{2} over ten years of operation. In order to increase the detector performance and acceptance for physics events including muons, a new muon station (ME0) has been proposed for installation in that region. The technology proposed is Triple—Gas Electron Multiplier (Triple-GEM), which has already been qualified for the operation in the CMS muon system. However, an additional set of studies focused on the discharge probability is necessary for the ME0 station, because of the large radiation environment mentioned above. A test was carried out in 2017 at the Cern High energy AcceleRator Mixed (CHARM) facility, with the aim of giving an estimation of the discharge probability of Triple-GEM detectors in a very intense radiation field environment, similar to the one of the CMS muon system. A dedicated standalone Geant4 simulation was performed simultaneously, to evaluate the behavior expected in the detector exposed to the CHARM field. The geometry of the detector has been carefully reproduced, as well as the background field present in the facility. This paper presents the results obtained from the Geant4 simulation, in terms of sensitivity of the detector to the CHARM environment, together with the analysis of the energy deposited in the gaps and of the processes developed inside the detector. The discharge probability test performed at CHARM will be presented, with a complete discussion of the results obtained, which turn out to be consistent with measurements performed by other groups

    Benchmarking LHC background particle simulation with the CMS triple-GEM detector

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    In 2018, a system of large-size triple-GEM demonstrator chambers was installed in the CMS experiment at CERN\u27s Large Hadron Collider (LHC). The demonstrator\u27s design mimicks that of the final detector, installed for Run-3. A successful Monte Carlo (MC) simulation of the collision-induced background hit rate in this system in proton-proton collisions at 13 TeV is presented. The MC predictions are compared to CMS measurements recorded at an instantaneous luminosity of 1.5 ×1034^{34} cm2^{-2} s1^{-1}. The simulation framework uses a combination of the FLUKA and GEANT4 packages. FLUKA simulates the radiation environment around the GE1/1 chambers. The particle flux by FLUKA covers energy spectra ranging from 1011^{-11} to 104^{4} MeV for neutrons, 103^{-3} to 104^{4} MeV for γ\u27s, 102^{-2} to 104^{4} MeV for e±^{±}, and 101^{-1} to 104^{4} MeV for charged hadrons. GEANT4 provides an estimate of the detector response (sensitivity) based on an accurate description of the detector geometry, the material composition, and the interaction of particles with the detector layers. The detector hit rate, as obtained from the simulation using FLUKA and GEANT4, is estimated as a function of the perpendicular distance from the beam line and agrees with data within the assigned uncertainties in the range 13.7-14.5%. This simulation framework can be used to obtain a reliable estimate of the background rates expected at the High Luminosity LHC

    Modeling the triple-GEM detector response to background particles for the CMS Experiment

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    An estimate of environmental background hit rate on triple-GEM chambers is performed using Monte Carlo (MC) simulation and compared to data taken by test chambers installed in the CMS experiment (GE1/1) during Run-2 at the Large Hadron Collider (LHC). The hit rate is measured using data collected with proton-proton collisions at 13 TeV and a luminosity of 1.5×1034\times10^{34} cm2^{-2} s1^{-1}. The simulation framework uses a combination of the FLUKA and Geant4 packages to obtain the hit rate. FLUKA provides the radiation environment around the GE1/1 chambers, which is comprised of the particle flux with momentum direction and energy spectra ranging from 101110^{-11} to 10410^{4} MeV for neutrons, 10310^{-3} to 10410^{4} MeV for γ\gamma's, 10210^{-2} to 10410^{4} MeV for e±e^{\pm}, and 10110^{-1} to 10410^{4} MeV for charged hadrons. Geant4 provides an estimate of detector response (sensitivity) based on an accurate description of detector geometry, material composition and interaction of particles with the various detector layers. The MC simulated hit rate is estimated as a function of the perpendicular distance from the beam line and agrees with data within the assigned uncertainties of 10-14.5%. This simulation framework can be used to obtain a reliable estimate of background rates expected at the High Luminosity LHC.Comment: 16 pages, 9 figures, 6 table

    Detector Control System for the GE1/1 slice test

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    Gas Electron Multiplier (GEM) technology, in particular triple-GEM, was selected for the upgrade of the CMS endcap muon system following several years of intense effort on R&D. The triple-GEM chambers (GE1/1) are being installed at station 1 during the second long shutdown with the goal of reducing the Level-1 muon trigger rate and improving the tracking performance in the harsh radiation environment foreseen in the future LHC operation [1]. A first installation of a demonstrator system started at the beginning of 2017: 10 triple-GEM detectors were installed in the CMS muon system with the aim of gaining operational experience and demonstrating the integration of the GE1/1 system into the trigger. In this context, a dedicated Detector Control System (DCS) has been developed, to control and monitor the detectors installed and integrating them into the CMS operation. This paper presents the slice test DCS, describing in detail the different parts of the system and their implementation

    CAD-based computer vision: the automatic generation of recognition stragtegies

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    Journal ArticleThree-dimensional model-based computer vision uses geometric models of objects and sensed data to recognize objects in a scene. Likewise, Computer Aided Design (CAD) systems are used to interactively generate three-dimensional models during these fields. Recently, the unification of CAD and vision systems has become the focus of research in the context of manufacturing automation. This paper explores the connection between CAD and computer vision. A method for the automatic generation of recognition strategies based on the geometric properties of shape has been devised and implemented. This uses a novel technique developed for quantifying the following properties of features which compose models used in computer vision: robustness, completeness, consistency, cost, and uniqueness. By utilizing this information, the automatic synthesis of a specialized recognition scheme, called a Strategy Tree, is accomplished. Strategy Trees describe, in a systematic and robust manner. the search process used for recognition and localization of particular objects in the given scene. They consist of selected features which satisfy system constraints and Corroborating Evidence Subtrees which are used in the formation of hypotheses. Verification techniques, used to substantiate or refute these hypotheses, are explored. Experiments utilizing 3-D data are presented
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