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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Förbättring av flödet mellanlager och produktion

Brandsjö, Erik January 2012 (has links)
Atlas Copco Craelius har vid årsskiftet 2011-2012 genomfört en flytt av större delar avlagret då en ökad produktion med tiden har medfört att lagret blivit för litet.Hanteringen av ankommande gods och plock av artiklar till monteringen har inteutvecklats i samma takt som företaget och är därför i behov av modernisering. Idagsläget placeras allt ankommande gods på gården och registrerades sedan i turordningi affärssystemet Movex. Detta sätt att arbeta medför att då det kommer stora volymerankommande gods tar det lång tid innan allt registreras. Atlas Copco Craelius har pgaav detta arbetssätt ingen möjlighet att veta vilka artiklar som finns bland det gods somblir stående i väntan på att läggas in i lager och registreras. Därför vill Atlas CopcoCraelius ta fram ett nytt arbetssätt som gör det möjligt att veta vad som har kommit såfort som möjligt för att sedan kunna lagerlägga och registrera i turordning.På grund av sättet som lagret har arbetat har det inte funnits några möjligheter att mätahur lång tid det tar att lägga in ankommande gods eller hur lång tid det tar från att ettplock kommer ut till lagret tills det att plocket levereras till monteringen. Atlas CopcoCraelius är därför i behov av att implementera nya arbetssätt som gör det möjligt attinför KPI:er (Key Performance Indicator) .Arbetet är fokuserat på att förbättra flödet genom lagret till produktionen genom att tafram nya arbetssätt och KPI:er för godsmottagningen och produktionsteknikerna somansvarar för plocken samt för plockarna. Arbetet har delats in i tre faser för att skapa entydlig struktur. Dessa faser är dokumentation av nuläget, benchmarking med andraföretag samt framtagning av nya arbetssätt och KPI:er.När dokumentationen i första fasen blivit klar och därmed kan fungera som en bas förbenchmarking utfördes studiebesök och dokumentering på två andra företag för attkunna undersöka vilka områden som var i behov av förbättring genom benchmarking.Denna benchmarking ligger sedan tillsammans med idéer och önskemål från anställdatill grund för utformandet av de nya arbetsrutinerna som denna rapport presenterar.
252

Generating Radiosity Maps on the GPU

Moreno-Fortuny, Gabriel January 2005 (has links)
Global illumination algorithms are used to render photorealistic images of 3D scenes taking into account both direct lighting from the light source and light reflected from other surfaces in the scene. Algorithms based on computing radiosity were among the first to be used to calculate indirect lighting, although they make assumptions that work only for diffusely reflecting surfaces. The classic radiosity approach divides a scene into multiple patches and generates a linear system of equations which, when solved, gives the values for the radiosity leaving each patch. This process can require extensive calculations and is therefore very slow. An alternative to solving a large system of equations is to use a Monte Carlo method of random sampling. In this approach, a large number of rays are shot from each patch into its surroundings and the irradiance values obtained from these rays are averaged to obtain a close approximation to the real value. <br /><br /> This thesis proposes the use of a Monte Carlo method to generate radiosity texture maps on graphics hardware. By storing the radiosity values in textures, they are immediately available for rendering, making this algorithm useful for interactive implementations. We have built a framework to run this algorithm and using current graphics cards (NV6800 or higher) it is possible to execute it almost interactively for simple scenes and within relatively low times for more complex scenes.
253

Expatriaten - En agent för kunskapsöverföring : Hur ett multinationellt företag uppnår en effektiv kunskapsöverföring genom expatriater

Wiksten, Sofia, Andersson, Sanna January 2008 (has links)
No description available.
254

Phase and Intensity Monitoring of the Particle Beams at the ATLAS Experiment

Ohm, Christian January 2007 (has links)
At the ATLAS experiment at CERN’s Large Hadron Collider, bunches of protons will cross paths at a rate of 40 MHz, resulting in 14 TeV head-on collisions. During these interactions, calorimeters, spectrometers and tracking detectors will look for evidence that can confirm or disprove theories about the smallest constituents of matter and the forces that hold them together. In order for these sub-detectors to sample the signals from exotic particles correctly, they rely on a constant phase between a clock signal and the bunch crossings in the experiment. On each side of the detector, 175 m away from the interaction point, electrostatic button pick-up detectors are installed along the accelerator ring to monitor the beam. A model describing how these detectors function as beam information transducers is constructed and analyzed in order to understand the signal. The focus of this thesis is the design, implementation and testing of a system that uses this signal to monitor the phase between the clock signal and the arrival time of the bunches in the center of the detector. In addition, the system extracts information about the proton beam structure as well as the individual bunches. Given the interaction rate and the complexity of the processes the experiment wants to study, vast amounts of data will be generated by ATLAS. To filter out well-understood phenomena, a trigger system selects only the most interesting events to be saved for further offline analysis. A proposal for how the signals from the button pick-ups can be used as input to the trigger system is therefore also presented.
255

Préparation de l'expérience ATLAS auprès du futur grand collisionneur de protons LHC : performances du calorimètre électromagnétique et potentiels pour la physique du quark top

Hubaut, F. 29 March 2007 (has links) (PDF)
Ce mémoire présente une synthèse des travaux que j'ai effectués depuis 7 ans pour la préparation de l'expérience ATLAS, devant fonctionner auprès du futur grand collisionneur de hadrons du CERN, le LHC, qui entrera en service en 2008.
256

Measurement of the Cross-Section for W Boson Production in Association with b-Jets in Proton-Proton Collisions at \(\sqrt s = 7\) TeV at the LHC using the ATLAS detector

Zevi Della Porta, Giovanni 21 August 2013 (has links)
This dissertation presents a measurement of the W+b-jets \((pp → W + b(\bar{b}) + X)\) production cross-section in proton–proton collisions at a center-of-mass energy of 7 TeV at the LHC. The results are based on data corresponding to an integrated luminosity of \(4.6 fb^{−1}\), collected with the ATLAS detector. The measurement probes the QCD sector of the Standard Model at high energy, in a region where b-quark mass and double parton scattering play an important role. In addition, the measurement is relevant for searches for physics beyond the Standard Model in final states with a W boson and b-jets. The measurement relies on the leptonic decay modes of the W, and on the iden- tification of b-jets. The backgrounds to the W+b-jets process are estimated using Monte Carlo simulation and data-driven techniques. Cross-sections, corrected for all known detector effects and quoted in a limited kinematic range, are presented as a function of jet multiplicity and of the transverse momentum of the leading b-jet for both the muon and electron decay modes of the W boson. / Physics
257

Search for Vector-Like Quarks using Trilepton and Same-Sign Dilepton Events in 20.3 fb⁻¹ of Proton-Proton Collisions at √S = 8 TeV with the ATLAS Detector

O'Grady, Fionnbarr Timothy January 2015 (has links)
A search is presented for vector-like quarks using 20.3 fb⁻¹ of proton-proton collisions at a center-of-mass energy of √S = 8 TeV collected with the ATLAS detector in 2012 at the CERN Large Hadron Collider. Vector-like quarks are predicted to exist in many theories beyond the Standard Model of particle physics that attempt to resolve the hierarchy problem. Events are selected containing jets including at least one b-jet, sizable missing transverse momentum, large scalar sum of the jet and lepton transverse momenta, and either three leptons or two leptons with the same electric charge. Standard Model processes rarely produce this final state and production of vector-like quarks would lead to an enhanced rate of such events. The data are interpreted in the context of a variety of models including pair production of vector-like quarks T and B, which have the same electric charge as the corresponding Standard Model quarks and can appear in either SU(2) weak isospin singlets, doublets or triplets. In addition single and pair production of the vector-like quark T₅/₃ which appears in an SU(2) weak isospin doublet or triplet and has electric charge 5/3, is considered. A moderate excess of data above the SM background expectation is observed with a significance of less than two standard deviations. The data are used to set limits at 95% Confidence Level (CL) on the new heavy quark mass for the various VLQ models considered using the CL_S method. The vector-like quarks T and B in the singlet model are excluded at 95% CL below a mass of 0.59 TeV and 0.62 TeV respectively. The T₅/₃ is excluded at 95% CL below a mass of 0.74 TeV when only pair production is considered and below 0.75 TeV when both pair and single production are considered.
258

The geology of the Atlas Mine area, Pima County, Arizona

Agenbroad, Larry D. January 1962 (has links)
No description available.
259

'Etudes des états finals diphoton dans l'expérience ATLAS au LHC : mesure de section efficace différentielle, découverte d'une nouvelle résonance dans la recherche du boson de Higgs et étude de ses propriétés'

Schwoerer, Maud 27 September 2013 (has links) (PDF)
Cette thèse sera centrée sur les analyses des événements diphotons dans le détecteur ATLAS. L'activité évoluera au cours du temps et couvrira différents aspects: compréhension de la réponse du détecteur, participation a la prise de données, analyse physique et recherche de signaux de physique au-delà du modèle standard.
260

Hunting the Charged Higgs Boson with Lepton Signatures in the ATLAS Experiment

Madsen, Alexander January 2015 (has links)
This thesis presents searches for a charged Higgs boson (H±) in proton-proton collisions with center-of-mass energies of 7 TeV and 8 TeV, using data collected by the ATLAS experiment at the Large Hadron Collider at CERN. Multiple search channels are used with the common characteristic of at least one charged lepton (electron or muon) that effectively reduces the multi-jet background and is used for efficient triggering. Charged Higgs bosons decaying to a tau lepton and a neutrino are searched for using final states with two charged leptons, or one charged lepton and a hadronically decaying tau. A significant background originates from quark- or gluon-initiated jets that may be misidentified as hadronic tau decays. Methods to estimate this background are presented, including a largely data-driven matrix method. Signal processes with a charged Higgs boson mass below or above that of the top quark are considered. With the dataset collected at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3 fb-1, upper limits at 95% confidence level are placed on the branching fraction B(t→bH±)×B(H±→τν) in the range 1.1–0.3% for charged Higgs boson masses between 80 GeV and 160 GeV, and on the top-quark associated H± production cross section in the range 0.93 to 0.03 pb for charged Higgs boson masses between 180 GeV and 1 TeV.

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