Twelve Ways to Build CMS Crossings from ROOT Files

The simulation of CMS raw data requires the random selection of one hundred and fifty pileup events from a very large set of files, to be superimposed in memory to the signal event. The use of ROOT I/O for that purpose is quite unusual: the events are not read sequentially but pseudo-randomly, they are not processed one by one in memory but by bunches, and they do not contain orthodox ROOT objects but many foreign objects and templates. In this context, we have compared the performance of ROOT containers versus the STL vectors, and the use of trees versus a direct storage of containers. The strategy with best performances is by far the one using clones within trees, but it stays hard to tune and very dependant on the exact use-case. The use of STL vectors could bring more easily similar performances in a future ROOT release.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 8 pages, LaTeX, 1 eps figures. PSN TUKT00

Strategy for an initial Measurement of the Inclusive Jet Cross Section with the CMS Detector

A strategy for an initial measurement of the inclusive jet cross section is presented and the related dominating systematic uncertainties are discussed. The study of this observable allows a fundamental probe of the theory of the strong interaction at unpreceeded energies. Additionally a method is presented to compare these measurements to calculations performed at next-to-leading order precision. In this context the dominating theoretical uncertainties are compared to the experimental ones

An Examination of Backgrounds to Early-Run Minimum-Bias Events in ATLAS at the LHC

The initial parts of the Large Hadron Collider (LHC) run will be a source of critical information - about the ATLAS detector and about the physics of $pp$ collisions at $sqrt{s} = 14$ TeV, including parton distribution evolution and the cross-sections of $sigma_{pp}$. The accelerator itself will be the source of some detector interest, as we have a first look at what have so far been speculations on the quality of the vacuum in the experimental insertion, and the cleanliness of the beam from the accelerator. The shakedown period, with its low beam squeeze, low luminosity, and undemanding trigger menus, will be of great interest, avoiding the pileup and radiation levels that will arrive with higher luminosity -- making it an important opportunity to investigate minimum-bias events in relative isolation. For the short lifetime of the Minimum Bias Trigger Scintillators (MBTS), which are expected to fail within a few months of running, they will aid in discriminating the minimum bias signal of inelastic non-single-diffractive $pp$ collisions. Using single- or double-coincidence signatures, the MBTS system and other trigger and analysis strategies attempt to avoid triggering on otherwise empty bunch crossings and eliminate the effects of beam-gas collisions and beam-halo effects which would lead these spurious triggers that would reduce the general minimum-bias trigger efficiency. An examination of the effects of beam halo and beam -gas interactions on the minimum-bias trigger response is made. The signatures of the beam halo and beam gas are examined from the standard ATLAS tracking reconstruction

Strategy for an initial Measurement of the Inclusive Jet Cross Section with the CMS Detector

A strategy for an initial measurement of the inclusive jet cross section is presented and the related dominating systematic uncertainties are discussed. The study of this observable allows a fundamental probe of the theory of the strong interaction at unpreceeded energies. Additionally a method is presented to compare these measurements to calculations performed at next-to-leading order precision. In this context the dominating theoretical uncertainties are compared to the experimental ones

An Analysis of the Migration Policies of the European Union and Their Effectiveness in Managing the Current Migration Crisis

The current migration of individuals into the European Union is creating an unparalleled and unprecedented crisis that has completely overwhelmed the EU Member States. Migrants entering the European Union have done so via dangerous and deadly sea and land routes, resulting in a devastating humanitarian crisis throughout Europe. As conflicts and instability around the world continue to evolve and escalate, larger flows of migrants continue to pour into the European Union causing the irregular migration of people across Europe’s borders. To counter this, European Union officials have attempted to create migration policies based on border management and security ideals. However, many authors, researchers, humanitarian groups, non-governmental organizations, and some policymakers have countered this approach and called upon the European Union to expand its policies to include more humanitarian measures. Up to this point, the Union remains thoroughly fragmented and indecisive in its response. With this research on the European Union migration policies, along with case studies of EU Member States such as Germany, Hungary, and Greece, the goal of this thesis is to advance new approaches to this difficult situation and to provide policy recommendations, program advice as well as suggestions for further analysis

Complexity-reduced hardware-based track-trigger for CMS upgrade

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonThe Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) is designed to study the results of proton-proton collisions. The Tracker sub-detector is designed to detect and reconstruct the trajectories of charged particles produced by the collisions. During the lifetime of the CMS detector, there have been several upgrades aimed at increasing the chance of discovering new physics through increased luminosity levels and instrumentation of advanced technology. The High-Luminosity upgrade optimises the LHC to accelerate high-energy particles with an average of 200 proton-proton interactions per bunch crossing. The Level-1 Trigger system promptly analyses and filters collisions using hardware to reduce the data volume in real-time. For the upgrade, the trigger mechanism will use a particle trajectory estimator that discriminates between particles based on their transverse momentum (pT ). Particles with pT ≥ 2 GeV/c will be transmitted to the Level-1 Track-Trigger system for trajectory reconstruction within a fixed 3 μs latency. This thesis presents a novel Hardware-based Multivariate Linear Fitter (MVLF) system focusing on robustness in tracking efficiency and reduction in logic resource usage within the specified latency. The system components are implemented in Field Programmable Gate Arrays (FPGA), targeting 16 nm FinFET UltraScale+ silicon technology. The development was performed using the High-Level Synthesis (HLS) automation tools and the Hardware acceleration platform for Application-Specific Integrated Circuits (ASIC). A firmware demonstrator has been assembled to verify the feasibility and compatibility of the scaled system with the CMS Level-1 Track-Trigger infrastructure. The system’s performance is compared to past and current system developments, and the results are presented accordingly

Intelligent tutoring in virtual reality for highly dynamic pedestrian safety training

This thesis presents the design, implementation, and evaluation of an Intelligent Tutoring System (ITS) with a Virtual Reality (VR) interface for child pedestrian safety training. This system enables children to train practical skills in a safe and realistic virtual environment without the time and space dependencies of traditional roadside training. This system also employs Domain and Student Modelling techniques to analyze user data during training automatically and to provide appropriate instructions and feedback. Thus, the traditional requirement of constant monitoring from teaching personnel is greatly reduced. Compared to previous work, especially the second aspect is a principal novelty for this domain. To achieve this, a novel Domain and Student Modeling method was developed in addition to a modular and extensible virtual environment for the target domain. While the Domain and Student Modeling framework is designed to handle the highly dynamic nature of training in traffic and the ill-defined characteristics of pedestrian tasks, the modular virtual environment supports different interaction methods and a simple and efficient way to create and adapt exercises. The thesis is complemented by two user studies with elementary school children. These studies testify great overall user acceptance and the system’s potential for improving key pedestrian skills through autonomous learning. Last but not least, the thesis presents experiments with different forms of VR input and provides directions for future work.Diese Arbeit behandelt den Entwurf, die Implementierung sowie die Evaluierung eines intelligenten Tutorensystems (ITS) mit einer Virtual Reality (VR) basierten Benutzeroberfläche zum Zwecke von Verkehrssicherheitstraining für Kinder. Dieses System ermöglicht es Kindern praktische Fähigkeiten in einer sicheren und realistischen Umgebung zu trainieren, ohne den örtlichen und zeitlichen Abhängigkeiten des traditionellen, straßenseitigen Trainings unterworfen zu sein. Dieses System macht außerdem von Domain und Student Modelling Techniken gebrauch, um Nutzerdaten während des Trainings zu analysieren und daraufhin automatisiert geeignete Instruktionen und Rückmeldung zu generieren. Dadurch kann die bisher erforderliche, ständige Überwachung durch Lehrpersonal drastisch reduziert werden. Verglichen mit bisherigen Lösungen ist insbesondere der zweite Aspekt eine grundlegende Neuheit für diesen Bereich. Um dies zu erreichen wurde ein neuartiges Framework für Domain und Student Modelling entwickelt, sowie eine modulare und erweiterbare virtuelle Umgebung für diese Art von Training. Während das Domain und Student Modelling Framework so entworfen wurde, um mit der hohen Dynamik des Straßenverkehrs sowie den vage definierten Fußgängeraufgaben zurecht zu kommen, unterstützt die modulare Umgebung unterschiedliche Eingabeformen sowie eine unkomplizierte und effiziente Methode, um Übungen zu erstellen und anzupassen. Die Arbeit beinhaltet außerdem zwei Nutzerstudien mit Grundschulkindern. Diese Studien belegen dem System eine hohe Benutzerakzeptanz und stellt das Potenzial des Systems heraus, wichtige Fähigkeiten für Fußgängersicherheit durch autodidaktisches Training zu verbessern. Nicht zuletzt beschreibt die Arbeit Experimente mit verschiedenen Formen von VR Eingaben und zeigt die Richtung für zukünftige Arbeit auf

Performance of the H -> ZZ* -> 4 mu analysis with the CMS Phase-2 muon detector upgrade

A study of the performance of the Standard Model H(125 GeV) -> ZZ* -> 4 mu analysis with the upgraded CMS muon detector for the high luminosity operation (up to 7.5 x 10^{34} cm^{-2}s^{-1}) at the Large Hadron Collider (HL-LHC) has been carried out. The CMS Phase-2 muon detector upgrade, which will take place from 2024 to 2026, is crucial to efficiently exploit the data that will be collected at the HL-LHC, under very challenging experimental conditions, such as large number of overlapping collisions per event, up to 200 (referred to as pile-up). The H -> ZZ* -> 4 mu analysis essentially relies on the muon system to detect four muons in the final state; it therefore represents an important benchmark for the proposed muon detector upgrade, in particular the extension in pseudorapidity of the muon detector from |eta| < 2.4 to |eta| < 2.8 by introducing the ME0 (Muon Endcap 0) subdetector. The results presented here are obtained using simulated proton-proton collision events at sqrt{s} = 14 TeV with the full simulation of the upgraded CMS detector. The signal and background events are simulated with an average pile-up of 200. The analysis is performed assuming an integrated luminosity of 3000 fb^{-1} (expected in almost ten years of the HL-LHC operation) and follows the analysis of the 2016 data (Run-2). It is found that the signal selection efficiency remains immune to the high pile-up conditions and increases by 17% with the acceptance extension of the muon system