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Pathak, Prashant, Olivier Guyon, Nemanja Jovanovic, Julien Lozi, F. Martinache, Y. Minowa, T. Kudo, H. Takami, Y. Hayano, and N. Narita. "First on-sky closed loop measurement and correction of atmospheric dispersion." SPIE-INT SOC OPTICAL ENGINEERING, 2016. http://hdl.handle.net/10150/622049.
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In the field of exoplanetary sciences, high contrast imaging is crucial for the direct detection of, and answering questions about habitability of exoplanets. For the direct imaging of habitable exoplanets, it is important to employ low inner working angle (IWA) coronagraphs, which can image exoplanets close to the PSF. To achieve the full performance of such coronagraphs, it is crucial to correct for atmospheric dispersion to the highest degree, as any leakage will limit the contrast. To achieve the highest contrast with the state-of-the-art coronagraphs in the SCExAO instrument, the spread in the point-spread function due to residual atmospheric dispersion should not be more than 1 mas in the science band. In a traditional approach, atmospheric dispersion is compensated by an atmospheric dispersion compensator (ADC), which is simply based on model which only takes into account the elevation of telescope and hence results in imperfect correction of dispersion. In this paper we present the first on-sky closed-loop measurement and correction of residual atmospheric dispersion. Exploiting the elongated nature of chromatic speckles, we can precisely measure the presence of atmospheric dispersion and by driving the ADC, we can do real-time correction. With the above approach, in broadband operation (y-H band) we achieved a residual of 4.2 mas from an initial 18.8 mas and as low as 1.4 mas in H-band only after correction, which is close to our science requirement. This work will be valuable in the field of high contrast imaging of habitable exoplanets in the era of the ELTs.
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Buri´c, Maja, Voja Radovanovi´c, and rvoja@rudjer ff bg ac yu. "Quantum Corrections for (Anti)--Evaporating Black Hole." ESI preprints, 2000. ftp://ftp.esi.ac.at/pub/Preprints/esi917.ps.
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Kaczorowski, Andrzej. "Adaptive aberration correction for holographic projectors." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/270322.
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This work builds up on the greatest minds of Cambridge Holography: Adrian Cable, Edward Buckley, Jonathan Freeman, and Christoph Bay. Cable and Buckley, developed an OSPR algorithm which was the first to provide high-quality real-time hologram generation using general-purpose hardware while Freeman designed a method to correct arbitrary aberrations. As ingenious as the method was, the calculations were extensively lengthy. Addressing this issue, a variant of OSPR suited for correcting spatially-varying aberration is presented. The algorithm combines the approaches of Cable, Buckley and Freeman to provide real-time hologram generation while incorporating various corrections (aberration, distortion, and pixel shape envelope). A high-performance implementation on a mid-range GPU achieved hologram generation up to 12 fps. Following topic studied is an adaptive optical correction. This work attempts to construct a set of methods, forming an automated testbed for holographic projectors. Each model, after exiting the production line is placed on such testbed, having all of its imperfections characterized. Once calibrated, each model is able to display highest-quality image throughout its life-span. An application of this work to industry was carried in collaboration with Dr Phillip Hands (University of Edinburgh) and LumeJET. Three demonstrators are constructed intending for a cost-effective system for holographic lithography. They are characterized using the developed testbed. Using the supersampled Adaptive OSPR algorithm, the diffraction limit was surpassed 2.75 times allowing to increase the patterning area. This combines approaches of Cable, Buckley, Freeman and Bay to achieve a wide field-of-view and high pixel-count replay field using off-the-shelf components. This thesis is finished describing the work on 3D holography carried with Penteract28. It is shown that the 2D hologram in the presence of spatially-varying aberrations is mathematically equivalent to a 3D hologram. The same implementation of the algorithm can be used to provide real-time 3D hologram generation.
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CATANIA, GIOVANNI. "Approximate inference on graphical models: message-passing, loop-corrected methods and applications." Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2917994.
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Paulus, Simon. "Etude et développement d'un ASIC pour le conditionnement et le calibrage de tores de Rogowski." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAD009/document.
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La mesure de courant dans un environnement industriel est une étape indispensable pour garantir la pérennité d'un réseau de distribution électrique. En général, chaque domaine d'applications (mesure, protection, etc...) nécessitent l'utilisation d'un capteur adapté. Ces travaux de thèse proposent d'utiliser un capteur bas coût principalement dédié à la protection, le tore de Rogowski, aussi comme élément de mesure. Afin d'améliorer sa précision intrinsèque souvent insuffisante, nous avons développé une boucle de correction et une électronique de calibrage intégrée (CMOS 0,35µm) permettant d'adapter ce capteur aux standards métrologiques. Nous détaillons dans ce manuscrit les étapes de l'élaboration de cette boucle de correction ainsi que les résultats obtenus à l'aide des différents prototypes. Nous terminons par la présentation du premier démonstrateur technologique, premier pas vers un système de mesure de courant sans contact de classe 0.1, auto-calibré, autonome et bas coûtThe measurement of the current in an industrial environment is a necessary step to ensure the sustainability of an electrical distribution network. Typically, each application domain (measurement, protection, etc ...) requires the use of a suitable sensor. This thesis work proposes the use of the Rogowski coil current transducer, a low cost sensor usually used for protection, as measuring element. In order to improve its often insufficient intrinsic accuracy, we have developed a correction loop as well as an integrated electronics for calibration (CMOS 0,35μm) to adapt the sensor to metrological standards. In this manuscript, we detail the development stages of this correction loop and the results obtained with different prototypes. We conclude with the presentation of the first technology demonstrator, a very first step towards a current measurement system that would be contactless, 0.1 accuracy class, auto-calibrated, autonomous and low cost
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Yundin, Valery. "Massive loop corrections for collider physics." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2012. http://dx.doi.org/10.18452/16469.
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Die Berechnung von Tensorintegralen ist eines der komplizierteren Probleme bei der Berechnung von Einschleifen-Feynmandiagrammen. In dieser Arbeit wird die Computerprogrammbibliothek PJFry entwickelt, mit der Tensorintegrale mit bis zu fünf äusseren Beinen und unter Zugrundelegung beliebiger Kinematik numerisch ausgewertet werden können. Im Programm PJFry sind Algorithmen implementiert, mit denen bei der Reduktion von Pentagon-Tensoren inverse Potenzen der Gramdeterminanten vermieden werden können. Gramdeterminanten der Boxdiagramme werden unter Verwendung von Rekursionsrelationen mit variabler Raum-Zeit-Dimension in einem Satz neuer Basisintegrale isoliert. Die neuen Basisintegrale werden ebenfalls durch Rekursionsrelationen mit variabler Raum-Zeit-Dimension oder durch Entwicklung in kleinen Gramdeterminanten ausgewertet. Die Konvergenz letzterer wird durch Padé-Extrapolation erheblich beschleunigt. Ein Cache-System erlaubt die mehrfache Verwendung von numerischen Bausteinen und erhöht zusätzlich die Effizienz des Programmpakets. Ausser ausführlichen Tests von Struktur und Genauigkeit der Algorithmen wird eine nichtriviale Beispielanwendung ausgearbeitet und mit dem Programm NGluon verglichen: die Berechnung von fünf-Gluon-Helizitätsamplituden. Schließlich werden die virtuellen Einschleifenkorrekturen zur Myonpaarproduktion mit Emission energiereicher ("harter") Photonen berechnet. Die Methode wird erläutert, wie auch Renormierung und Behandlung der Polstruktur in dimensionaler Regularisierung. Numerische Vorhersagen für differentielle Wirkungsquerschnitte werden berechnet, unter Zugrundelegung der kinematischen Situationen, wie sie bei den Detektoren KLOE (DAFNE, Frascati) und BaBar (SLAC) typisch sind.In this thesis we discuss the problem of evaluation of tensor integrals appearing in a typical one-loop Feynman diagram calculation. We present a computer library for the numerical evaluation of tensor integrals with up to 5 legs and arbitrary kinematics. The code implements algorithms based on the formalism which avoids the appearance of inverse Gram determinants in the reduction of pentagon diagrams. The Gram determinants of box integrals are isolated in the set of new basis integrals by using dimensional recurrence relations. These integrals are then evaluated by dimensional recurrence or expansion in small Gram determinant, which is improved by Padé extrapolation. A cache system allows reuse of identical building blocks and increases the efficiency. After describing the cross checks and accuracy tests, we show a sample application to the evaluation of five gluon helicity amplitudes, which is compared with the output of the program NGluon. In the last part the program is applied to the calculation of the one-loop virtual corrections to the muon pair production with hard photon emission. The computation method is explained, followed by a discussion of renormalization and pole structure. Finally, we present numerical results for differential cross sections with kinematics of the KLOE and BaBar detectors.
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Lozi, Julien. "Caractérisation du banc stabilisé d’interférométrie en frange noire PERSÉE." Thesis, Paris 11, 2012. http://www.theses.fr/2012PA112047/document.
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L'observation des exoplanètes pose deux problèmes : le contraste entre la planète et l'étoile et leur très faible séparation. L'une des techniques permettant de résoudre ces difficultés est l'interférométrie en frange noire : deux pupilles sont recombinés pour faire une interférence destructive sur l'étoile, et leur base est réglée pour que l'interférence soit constructive sur la planète. Cependant, pour garantir une extinction suffisante de l'étoile, la différence de trajet optique entre les faisceaux doit être de l'ordre du nanomètre, et le pointage meilleur que le centième de tache d'Airy, malgré les perturbations extérieures.Pour valider les points critiques d'une telle mission spatiale, un démonstrateur de laboratoire, PERSÉE, a été défini par un consortium dirigé par le CNES et incluant l'IAS, le LESIA, l'ONERA, l'OCA et Thales Alenia Space puis intégré à l'Observatoire de Meudon. Ce banc simule une mission spatiale dans son ensemble (interféromètre et cophasage nanométrique). Son objectif est de délivrer et maintenir une extinction de 10^-4 stabilisé à mieux que 10^-5 sur plusieurs heures, en présence de perturbations typiques que l'on injecte.Mon travail de thèse a consisté à intégrer le banc en étapes successives et à développer des procédures d'étalonnage. Ceci m'a aidé à caractériser les différents éléments critiques séparément avant de les regrouper. Après avoir mis en œuvre les boucles de contrôle du cophasage, leur analyse précise m'a permis de réduire à 0,3 nm rms le résidu de différence de marche, et à 0,4 % de la tache d'Airy le résidu de tip/tilt, malgré la présence de perturbations d'une dizaine de nanomètres d'amplitude, constituées de plusieurs dizaines de fréquences vibratoires entre 1 et 100 Hz. Cela a été possible grâce à l'implémentation d'un contrôleur linéaire quadratique gaussien, paramétré par la mesure préalable de la perturbation pour la réduire au maximum. Grâce à ces très bons résultats, j'ai pu obtenir un taux d'extinction record sur la bande [1,65 – 2,45] µm de 8,8x10^-6 stabilisé à 9x10^-7 sur quelques heures, soit une décade meilleure que les spécifications initiales. L'extrapolation de ces résultats au cas d'une mission spatiale montre que les performances attendues sont atteignables si le flux disponible est suffisamment important. Avec des télescopes de 40 cm et une fréquence d'asservissement de l'ordre de 100 Hz, des étoiles de magnitude inférieure à 9 devraient être observablesThere are two problems with the observation of exoplanets: the contrast between the planet and the star and their very low separation. One technique solving these problems is nulling interferometry: two pupils are recombined to make a destructive interference on the star, and their base is adjusted to create a constructive interference on the planet. However, to ensure a sufficient extinction of the star, the optical path difference between the beams must be around the nanometer, and the pointing must be better than one hundredth of Airy disk, despite the external disturbances.To validate the critical points of such a space mission, a laboratory demonstrator, PERSÉE, was defined by a consortium led by CNES, including IAS, LESIA, ONERA, OCA and Thales Alenia Space and integrated in Meudon Observatory. This bench simulates the entire space mission (interferometer and nanometric cophasing system). Its goal is to deliver and maintain an extinction of 10^-4 stable at better than 10^-5 over a few hours in the presence of typical injected disturbances.My thesis work consisted in integrating the bench in successive stages and to develop calibration procedures. This helped me to characterize the critical elements separately before grouping them. After having implemented the control loops of the cophasing system, their precise analysis helped me to reduce down to 0.3 nm rms the residual OPD, and 0.4 % of the Airy disk the residual tip/tilt, despite disturbances of tens of nanometers, consisting of several tens of vibrational frequencies between 1 and 100 Hz. This has been achieved by the implementation of a linear quadratic Gaussian controller, parameterized by the preliminary measurement of the disturbance to minimize. Thanks to these excellent results, I obtained on the band [1.65 – 2.45] µm a record null rate of 8.8x10^-6 stabilized at 9x10^-7 over a few hours, a decade better than the original specifications. An extrapolation of these results to the case of a space mission shows that the expected performance is achievable if the available flux is sufficiently important. With telescopes of 40 cm and a control frequency around 100 Hz, stars brighter than magnitude 9 should be observable
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Lambert, N. D., I. Sachs, and Andreas Cap@esi ac at. "String Loop Corrections to Stable Non--BPS Branes." J. High Energy Phys. 02 (2001), paper 018, 2000. ftp://ftp.esi.ac.at/pub/Preprints/esi954.ps.
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Rodgers, Mark. "Automation of one-loop corrections for multi-particle processes." Thesis, Durham University, 2012. http://etheses.dur.ac.uk/4460/.
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With the advent of the Large Hadron Collider, we are in a new era in Particle Physics, in which unprecedented energy scales can be probed. Although it is a discovery machine, it has already been shown to be able to produce experimental precisions at the percent level, and so our theoretical calculations must match that, which requires (at least) calculations to next-to-leading order (NLO). In this thesis, we explain and develop new techniques for the evaluation of one-loop integrals, which have historically been the bottleneck in NLO calculations. After introducing Quantum Field Theory and NLO calculations, we explain the process of tensor reduction and the golem95 method for avoiding its numerical instabilities. We follow this by discussing the techniques used to improve the stability of a library of scalar integrals (for two- and three-point integrals), and then we discuss the extension of the golem95 library to include complex internal masses, along with the reasons for doing so. We then bring together the GoSam project with the event generator Sherpa, in order to calculate the process pp -> e+e−μ+μ− by diboson production to NLO, including the (formally higher order) loop-induced process with gluons in the initial state.
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Prezeau, Gary Marcel. "One loop corrections to a hadronic model with vector mesons." W&M ScholarWorks, 1999. https://scholarworks.wm.edu/etd/1539623951.
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The linear sigma model and its extension, Quantum Hadro-dynamics 3 (QHD-III) are discussed. QHD-III is a gauge-invariant model of the strong interaction based on the linear sigma model, which is made locally invariant under SU(2)L x SU(2)R. Parity conservation is imposed. The gauge bosons rho and a1 are made massive via a Higgs mechanism as in the standard model. The low-energy symmetries of QCD, the ability to evaluate corrections coming from meson loops and the derivation of unambiguous conserved currents is used to motivate QHD-III. A renormalized pipi scattering amplitude to 1-loop using Feynman diagrams in the linear sigma-model is derived. The renormalized corrections due to vector boson exchange are also calculated in QHD-III and explicitly shown to be negligible when their masses become large. The pion decay constant to 1-loop is also calculated and discussed. The gauge invariance of the theory is analyzed and exploited to identify the physical pion and to considerably simplify the QHD-III lagrangian. The 1-loop effective action of the linear sigma model is derived and its predictions are shown to be identical to the amplitudes calculated using Feynman diagrams. The 1-loop effective action of QHD-III is discussed and shown to provide an explicit proof of the decoupling theorem.
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Macorini, Guido. "One loop electroweak corrections for single top production at LHC." Doctoral thesis, Università degli studi di Trieste, 2008. http://hdl.handle.net/10077/2708.
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2006/2007In this thesis we report and discuss the results for the first complete calcula- tion of the one-loop electroweak corrections for the two dominant processes of single Top production at the Large Hadron Collider: the tW-associated pro- duction and the t-channel process. We calculate the corrections working both in the Standard Model (SM) and in the minimal supersymmetric extension of the Standard Model (MSSM, as- suming a mSUGRA scenario), analysing the effect of the corrections on several observables and trying to understand whether deviations from the Standard Model prediction could be observable. The single Top production is the main source of information about the Top weak interaction, and a privileged laboratory to understand the symmetry breaking in the weak sector. Moreover at the hadronic colliders the single Top processes provide the only known way to measure directly the Vtb element of the CKM matrix, providing a fundamental test of the Standard Model struc- ture. For the tW production process we present the complete calculation of the one- loop electroweak effect, including the effect of the hard real photon emission; we combine our results with the available calculation for the QCD and SUSY QCD corrections, providing a complete one loop description of the process. Our interest has been concentrated on the particular quantities that we have defined as partial rates, with special emphasis on the low (400 GeV) final in- variant mass. In this region with the addition of SUSY QCD one-loop terms, the genuine SUSY contribution reaches an interesting 10% size. The analysis of t-channel process is limited to the pure electroweak componet (adding the soft photon emission only, to cancel the infrared divergences aris- ing from diagrams with virtual photon). The electroweak corrections for the t-channel are less sensitive to the presence of the SUSY particles: this conclusion holds for all the four examined bench- mark points in themSUGRA scheme. In addition, considering the small contri- bution of the known SUSY QCD corrections, we conclude that in themSUGRA scenario it will be probably impossible to detect at the LHC any deviation from the SM predictions. In the SMcontext the size of the electroweak correctionswithout the hard emis- sion seems to be very large, but we expect that the total effect should be con- siderably reduced adding the hard emission part.
Nella tesi vengono riportati e discussi i risultati per il calcolo completo delle correzioni radiative elettrodeboli ad un loop per i due processi dominanti nella produzioe di quark Top singoli al Large Hadron Collider: la produzione associata tW e il processo di "canale t". Le correzioni ad un loop sono calcolate sia nelModello Standard (SM) che nella sua estensione supersimmetrica minimale (MSSM, assumendo uno scenario di mSUGRA); si è quindi analizzato l’effetto delle correzioni su varie osservabili fisiche, tentando di comprendere se siano riscontrabili deviazioni misurabili dalle predizioni del Modello Standard. La produzione di quark Top singoli costituisce la principale fonte di informzioni riguardo le interazioni deboli del Top e per lo studio e la comprensione della rottura della simmetria elettrodebole. Inoltre ai collider adronici la produzione di quark Top singoli costituisce l’unico processo che permette una misura diretta dell’elemento Vtb della matrice CKM, costituendo dunque un test fondamentale per la struttua del Modello Standard. Per la produzione associata tW si presenta il calcolo completo dell’effetto elettrodebole ad un loop, includendo poi l’effetto dell’emissione di fotoni duri; si combinano dunque i nostri risultati con i risultati (noti in letteratura) per le correzioni di QCD e QCD supersimmetrica, fornendo una descrizione completa ad un loop del processo. Abbiamo concentrato il nostro interesse su paticolari osservabili dette "rate parziali", con speciale attenzione alla regione di bassemasse invarianti: in data regione, tenendo conto delle correzioni di QCD supersimmetrica, il contributo genuinamente supersimmetrico dell’effetto ad un loop raggiunge il 10%, costituendo una deviazione potenzialmente osservabile. L’analisi del canale t è limitata alla sola componente elettrodebole (con l’aggiunta dell’emissione di fotini "soft", in modo da ottenere un risultao IR-finito): le correzioni ad un loop elettrodeboli per questo processo si sno rivelate meno sensibili alla presenza di eventuali particelle supersimmetriche; questa conclusione è comune nei quatro scenari mSUGRA analizzati. Considerando inoltre che l’effetto della QCD supersimmetrica è piccolo, si può concludere che sarà verosimilmente impossibile osservare deviazioni dalle predizioni SM. Nel Modello Standard le correzioni dovute alla parte elettrodebole sembrano numericamente molto significative, ma ci può aspettare una drastica riduzione di tale effetto una volta aggiunta l’emissione di fotoni reali "hard".
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Nicoletti, Andrea. "Effect of new string loop corrections on type IIB string inflation." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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This Master thesis is focused on the study of the inflationary dynamics coming from new corrections added to the standard LVS framework used in the context of moduli stabilisation in type IIB string compactifications on Calabi-Yau orientifolds. The closed string sector of the 4D effective supergravity theory features 3 classes of moduli: the dilaton which sets the string coupling, the complex structure moduli which parameterise the shape of the extra dimensions, and the Kaehler moduli whose vacuum expectation value controls the size of the extra dimensions. At tree-level the dilaton and the complex structure moduli are stabilised supersymmetrically in terms of 3-form flux quanta. On the other hand, the Kaehler moduli are flat directions due to the underlying no-scale cancellation. It is therefore important to study which perturbative or non-perturbative correction to the effective action generates the leading order no-scale breaking effect. Several contributions have been studied in the past ranging from ED3 instantons, gaugino condensation, alpha' corrections and string loops. In this Master thesis we will focus in particular on new string loop corrections to the Kaehler potential which have been derived recently by Antoniadis and collaborators. These corrections introduce a Kaehler moduli-depedent logarithmic shift of the Calabi-Yau volume that breaks the no-scale structure. We analyse the effect of these new corrections on known moduli stabilisation scenarios like KKLT and LVS and then study its repercussions on cosmological and inflationary quantities in order to make some realistic predictions and match experimental data.
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Graham, Noah Matthew 1972. "Exact renormalized one-loop quantum corrections to energies of solitonic field configurations." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/84759.
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Lushozi, Mawande. "Two-loop corrections to the rho-propagator in the Kroll-Lee-Zumino theory." Master's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/9217.
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Includes bibliographical referencesThe Abelian Kroll-Lee-Zumino theory is a renormalizable quantum field theory of charged pions and neutral rho-mesons. It provides the quantum field theory platform for the vector meson dominance model, allowing for a systematic computation of quantum corrections in perturbation theory (the ρ-π-π coupling is small enough for perturbation theory to make sense). At one-loop level, the theory makes a prediction for the electromagnetic form factor of the pion in good agreement with experiment, but there is room for improvement. This makes the theory an attractive prospect for filling the gap between chiral perturbation theory (which is valid for low-energy interactions) and perturbative QCD (which is valid at high energies). In this thesis we perform a two-loop calculation of the rho-propagator. This quantity is closely related to the pion’s electromagnetic form factor, and will allow its calculation at this order.
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Jasmani, Fadilah. "Malay ESL learners' error-correction strategies and dictionary look-up processes." Thesis, University of Essex, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416718.
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Schmidt-Sommerfeld, Maximilian. "One-loop and D-instanton corrections to the effective action of open string models." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-103433.
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Yundin, Valery [Verfasser], Jan [Akademischer Betreuer] Plefka, Peter [Akademischer Betreuer] Uwer, and Henryk [Akademischer Betreuer] Czyż. "Massive loop corrections for collider physics / Valery Yundin. Gutachter: Jan Plefka ; Peter Uwer ; Henryk Czyz." Berlin : Humboldt Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2012. http://d-nb.info/1020229977/34.
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Eklund, Robert. "Linearization of Voltage-Controlled Oscillators in Phase-Locked Loops." Thesis, Linköping University, Department of Science and Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-5366.
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This is a thesis report done as part of the Master of Science in Electronics Design Engineering given at Linköping University, Campus Norrköping. The thesis work is done at Ericsson AB in the spring of 2005. The thesis describes a method of removing variations in the tuning sensitivity of voltage-controlled crystal oscillators due to different manufacturing processes. These variations results in unwanted variations in the modulation bandwidth of the phase-locked loop the oscillator is used in. Through examination of the theory of phase-locked loops it is found that the bandwidth of the loop is dependent on the tuning sensitivity of the oscillator.
A method of correcting the oscillator-sensitivity by amplifying or attenuating the control-voltage of the oscillator is developed. The size of the correction depends on the difference in oscillator-sensitivity compared to that of an ideal oscillator. This error is measured and the correct correction constant calculated.
To facilitate the measurements and correction extra circuits are developed and inserted in the loop. The circuits are both analog and digital. The analog circuits are mounted on an extra circuit board and the digital circuits are implemented in VHDL in an external FPGA.
Tests and theoretical calculations show that the method is valid and able to correct both positive and negative variations in oscillator-sensitivity of up to a factor ±2.5 times. The bandwidth of the loop can be adjusted between 2 to 15 Hz (up to ±8 dB, relative an unmodified loop).
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Lundin, Henrik. "Characterization and Correction of Analog-to-Digital Converters." Doctoral thesis, KTH, School of Electrical Engineering (EES), 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-547.
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Denna avhandling behandlar analog-digitalomvandling. I synnerhet behandlas postkorrektion av analog-digitalomvandlare (A/D-omvandlare). A/D-omvandlare är i praktiken behäftade med vissa fel som i sin tur ger upphov till distorsion i omvandlarens utsignal. Om felen har ett systematiskt samband med utsignalen kan de avhjälpas genom att korrigera utsignalen i efterhand. Detta verk behandlar den form av postkorrektion som implementeras med hjälp av en tabell ur vilken korrektionsvärden hämtas.
Innan en A/D-omvandlare kan korrigeras måste felen i den mätas upp. Detta görs genom att estimera omvandlarens överföringsfunktion. I detta arbete behandlas speciellt problemet att skatta kvantiseringsintervallens mittpunkter. Det antas härvid att en referenssignal finns tillgänglig som grund för skattningen. En skattare som baseras på sorterade data visas vara bättre än den vanligtvis använda skattaren baserad på sampelmedelvärde.
Nästa huvudbidrag visar hur resultatet efter korrigering av en A/D-omvandlare kan predikteras. Omvandlaren antas här ha en viss differentiell olinjäritet och insignalen antas påverkad av ett slumpmässigt brus. Ett postkorrektionssystem, implementerat med begränsad precision, korrigerar utsignalen från A/D-omvandlaren. Ett utryck härleds som beskriver signal-brusförhållandet efter postkorrektion. Förhållandet visar sig bero på den differentiella olinjäritetens varians, det slumpmässiga brusets varians, omvandlarens upplösning samt precisionen med vilken korrektionstermerna beskrivs.
Till sist behandlas indexering av korrektionstabeller. Valet av metod för att indexera en korrektionstabell påverkar såväl tabellens storlek som förmågan att beskriva och korrigera dynamiska fel. I avhandlingen behandlas i synnerhet tillståndsmodellbaserade metoder, det vill säga metoder där tabellindex bildas som en funktion utav flera på varandra följande sampel. Allmänt gäller att ju fler sampel som används för att bilda ett tabellindex, desto större blir tabellen, samtidigt som förmågan att beskriva dynamiska fel ökar. En indexeringsmetod som endast använder en delmängd av bitarna i varje sampel föreslås här. Vidare så påvisas hur valet av indexeringsbitar kan göras optimalt, och experimentella utvärderingar åskådliggör att tabellstorleken kan reduceras avsevärt utan att fördenskull minska prestanda mer än marginellt.
De teorier och resultat som framförs här har utvärderats med experimentella A/D-omvandlardata eller genom datorsimuleringar.
Analog-to-digital conversion and quantization constitute the topic of this thesis. Post-correction of analog-to-digital converters (ADCs) is considered in particular. ADCs usually exhibit non-ideal behavior in practice. These non-idealities spawn distortions in the converters output. Whenever the errors are systematic, it is possible to mitigate them by mapping the output into a corrected value. The work herein is focused on problems associated with post-correction using look-up tables. All results presented are supported by experiments or simulations.
The first problem considered is characterization of the ADC. This is in fact an estimation problem, where the transfer function of the converter should be determined. This thesis deals with estimation of quantization region midpoints, aided by a reference signal. A novel estimator based on order statistics is proposed, and is shown to have superior performance compared with the sample mean traditionally used.
The second major area deals with predicting the performance of an ADC after post-correction. A converter with static differential nonlinearities and random input noise is considered. A post-correction is applied, but with limited (fixed-point) resolution in the corrected values. An expression for the signal-to-noise and distortion ratio after post-correction is provided. It is shown that the performance is dependent on the variance of the differential nonlinearity, the variance of the random noise, the resolution of the converter and the precision of the correction values.
Finally, the problem of addressing, or indexing, the correction look-up table is dealt with. The indexing method determines both the memory requirements of the table and the ability to describe and correct dynamically dependent error effects. The work here is devoted to state-space--type indexing schemes, which determine the index from a number of consecutive samples. There is a tradeoff between table size and dynamics: more samples used for indexing gives a higher dependence on dynamic, but also a larger table. An indexing scheme that uses only a subset of the bits in each sample is proposed. It is shown how the selection of bits can be optimized, and the exemplary results show that a substantial reduction in memory size is possible with only marginal reduction of performance.
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Meissner, T., Mathias Schleif, and Rudi Wünsch. "Self-Consistent Pushing and Cranking Corrections to the Meson Fields of the Chiral Quark-Loop Soliton." Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-31209.
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We study translational and spin-isospin symmetry restoration for the two-flavor chiral quark-loop soliton. Instead of a static soliton at rest we consider a boosted and rotating hedgehog soliton. Corrected classical meson fields are obtained by minimizing a corrected energy functional which has been derived by semi-classical methods ('variation after projection'). We evaluate corrected meson fields in the region 300 <= M <= 600 of constituent quark masses M and compare them with the uncorrected fields. We study the effect of the corrections on various expectation values of nuclear observables such as the root-mean square radius, the axial-vector coupling constant, magnetic moments and the delta-nucleon mass splitting.
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Meissner, T., Mathias Schleif, and Rudi Wünsch. "Self-Consistent Pushing and Cranking Corrections to the Meson Fields of the Chiral Quark-Loop Soliton." Forschungszentrum Rossendorf, 1997. https://hzdr.qucosa.de/id/qucosa%3A21947.
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We study translational and spin-isospin symmetry restoration for the two-flavor chiral quark-loop soliton. Instead of a static soliton at rest we consider a boosted and rotating hedgehog soliton. Corrected classical meson fields are obtained by minimizing a corrected energy functional which has been derived by semi-classical methods ('variation after projection'). We evaluate corrected meson fields in the region 300 <= M <= 600 of constituent quark masses M and compare them with the uncorrected fields. We study the effect of the corrections on various expectation values of nuclear observables such as the root-mean square radius, the axial-vector coupling constant, magnetic moments and the delta-nucleon mass splitting.
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Panizzi, Luca. "One loop electroweak analysis for third family scalar quarks production at LHC." Doctoral thesis, Università degli studi di Trieste, 2009. http://hdl.handle.net/10077/3064.
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2007/2008The thesis is devoted to the analysis of electroweak one-loop corrections to processes of production of scalar quarks of the third family at the Large Hadron Collider (LHC) in the context of the minimal supersymmetric extension of the Standard Model (MSSM). Third family squarks are are predicted to be among the lightest supersymmetric particles, hence they could be among the first signals of new physics to be detected at the LHC. Moreover, a very light stop (with a mass of the same order of the top mass) might play a relevant role within a cosmological model of electroweak baryogenesis. A precise analysis of one-loop corrections to processes of production of stop and sbottom particles and the determination of theoretical predictions to be tested against LHC data are therefore mandatory to understand the properties of these particles. The EW NLO corrections to the most meaningful observables related to these processes (differential and total cross sections) have been calculated and the dependence on supersymmetric parameters of the considered observables has been analysed. The considered processes are: 1) PP -> gg -> stop-antistop (sbottom-antisbottom); 2) PP-> bg -> stop-chargino. In both cases the analysis has been performed within various mSUGRA scenarios. For this purpose three C++ codes which exploit Monte Carlo techniques for the integration of cross sections have been developed. For the stop-antistop production case the diagonal production shows a total cross section of the order of 10 picobarns in some scenarios which predict a light stop; electroweak corrections, however, are of the order of few percent for every scenario considered; through the definition of the partial rates it is possible to obtain correction near to 10% in the high invariant mass region. The analysis of the dependence of one-loop corrections on mSUGRA parameters has been performed and it has been verified that the dependence is quite mild (variations up to 4%). In the case of sbottom production the total cross sections are generally smaller than 1pb and the one-loop corrections are not very sizable. As far as the parametric dependence is concerned, for diagonal production of light sbottom an interesting dependence on the parameter tg(beta) has been found in a particular scenario. For the stop-chargino production process the total cross sections are of the order of the picobarn in scenarios where stop and charginos are not too massive. The one-loop corrections are of the order of few percent and, due to the small cross sections in the considered scenarios, they are unfortunaltely quite difficult to observe at the LHC; the analysis through the partial rates predicts higher corrections, though difficult to detect. Due to these results, the parametric analysis has been performed at tree level, where the observables depend on a limited number of supersymmetric parameters: the strongest dependence has been found to be on the stop mixing angle and on the supersymmetric parameter mu. The analysis of stop production processes within scenarios of electroweak baryogenesis has been performed in both cases. For the case of diagonal production of light stop-antistop pairs, the electroweak one-loop effect on the total cross section has been found to be quite mild. Due to the small stop mass the total cross section is however of the order of 10pb. Therefore, through the analysis of partial rate it is possible to predict effects of the order of 10% with a still detectable cross section. In the stop-chargino case, the total cross section has been found to be smaller than 1pb even in the lightest configuration, and the one-loop correction is 2%.
La presente tesi consiste nell'analisi delle correzioni elettrodeboli a 1 loop di alcuni processi di produzione di quark scalari della terza famiglia al Large Hadron Collider nell'ambito dell'estensione supersimmetrica minimale del Modello Standard (MSSM). Gli squark della terza famiglia sono particolarmente importanti perché si prevede che siano fra le particelle supersimmetriche più leggere, e per questo motivo potrebbero essere fra i primi segnali di nuova fisica ad essere osservati all'LHC. Inoltre, uno stop particolarmente leggero (con una massa dello stesso ordine di quella del top) potrebbe giocare un ruolo rilevante nell'ambito di un modello cosmologico di bariogenesi elettrodebole. Una precisa analisi delle correzioni a 1 loop dei processi di produzione di stop e sbottom con la determinazione di previsioni teoriche da verificare sperimentalmente ad LHC è quindi fondamentale per cercare di comprendere le proprietà di queste particelle. In questa tesi vengono calcolate le correzioni sui principali osservabili legati a questi processi (sezioni d'urto differenziali e totali) e viene analizzata la dipendenza dai parametri supersimmetrici degli osservabili considerati. I processi analizzati sono: 1) PP -> gg -> stop-antistop (sbottom-antisbottom); 2) PP -> bg -> stop-chargino. In entrambi i casi l'analisi è stata effettuata nel contesto di diversi scenari mSUGRA. Sono stati sviluppati per questo scopo tre codici in C++ che si avvalgono di tecniche di Monte Carlo per l'integrazione delle sezioni d'urto. Nel caso del processo di produzione di stop, si è verificato che per alcuni scenari che prevedono uno stop leggero, la produzione diagonale ha una sezione d'urto totale dell'ordine della decina di picobarn; le correzioni elettrodeboli però sono dell'ordine di qualche punto percentuale per tutti gli scenari considerati; tramite la definizione delle cosiddette rate parziali è possibile ottenere correzioni vicine al 10% nella regione di alte masse invarianti. E' stata poi eseguita un'analisi di come gli effetti a un loop dipendono dai parametri mSUGRA, verificando che la dipendenza è poco apprezzabile (variazioni del 4%). Nel caso di produzione di sbottom le sezioni d'urto sono generalmente inferiori al picobarn e le correzioni a 1 loop rimangono abbastanza limitate. Per quanto riguarda la dipendenza parametrica, per produzione diagonale di sbottom leggeri c'è una interessante dipendenza dal parametro tg(beta) in un particolare scenario supersimmetrico. Nel caso del processo di produzione di stop-chargino la sezione d'urto è dell'ordine del picobarn nei casi che prevedono stop e chargini non eccessivamente massivi. Anche in questo caso le correzioni a 1 loop sono di qualche punto percentuale, difficilmente visibili a LHC a causa delle basse sezioni d'urto negli scenari considerati; l'analisi delle rate parziale consente di ottenere correzioni maggiori, ma difficilmente osservabili. A causa della scarsa visibilità del processo, l'analisi parametrica è stata effettuata a livello albero, dove gli osservabili dipendono da un numero limitato di parametri supersimmetrici: la dipendenza maggiore risulta essere per l'angolo di mixing dello stop e dal parametro supersimmetrico mu. Per quanto riguarda l'analisi dei processi di produzione di stop nell'ambito di scenari di bariogenesi elettrodebole, nel caso di produzione diagonale di stop leggeri, l'effetto a 1 loop è scarso, ma data la piccola massa dello stop che determina una sezione d'urto dell'ordine della decina di picobarn, l'analisi della rate parziale permette di prevedere effetti dell'ordine del 10%. Nel caso di stop-chargino la sezione d'urto risulta essere inferiore al picobarn anche nella configurazione più leggera e la correzione a 1 loop è del 2%.
XXI Ciclo
1980
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Le, Duc Ninh. "One-loop Yukawa corrections to the process pp → bb̄H in the standard model at the LHC : Landau singularities." Chambéry, 2008. http://www.theses.fr/2008CHAMS022.
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Le sujet de ma thèse recouvre deux aspects. En premier lieu, I'objectif était d'étudier et d'améliorer les méthodes de calcul à une boucle pour les corrections radiatives (CR) dans le cadre des théories de champs perturbatives. En second lieu, I'objectif était d'appliquer ces techniques pour calculer les effets dominants des CR électrofaibles au processus important de production de Higgs associé à deux quarks bottom au LHC du CERN. L'étude concerne Ie Higgs du Modèle Standard (MS). Le premier objectif est d'importance plutôt théorique. Bien que la méthode générale pour Ie calcul à une boucle des CR dans Ie MS soit, en principe, bien compris par Ie biais de la renormalisation, il y a un certain nombre de difficultés techniques. Celles-ci sont liées aux intégrales de boucle. Pour les processus avec plus de 4 particules externes, les expressions d'amplitude obtenues en utilisant la méthode d'analyse sont extrêmement lourdes et très difficiles à manipuler. Dans cette thèse, nous avons étudié ce problème et réalisé que tout Ie calcul peut être facilement optimisé si I'on utilise la méthode des amplitudes d'hélicité. Un autre problème est lié aux propriétés analytiques des intégrales scalaires. Une partie importante de cette thèse est consacrée à ce problème et a I'étude des équations de Landau. Nous avons trouvé des effets significatifs en raison de singularités de Landau dans Ie processus pp → b anti-b Higgs au LHC. Le deuxième objectif est d'ordre pratique avec des conséquences expérimentales. On peut résumer les résultats obtenus dans cette thèse comme suit. Si la masse du Higgs est d'environ 120GeV, la correction au premier ordre dominant est petite de I'ordre d'environ - 4%. Si la masse de Higgs est d'environ 160GeV, seuil de production d'une paire de W par Ie Higgs, les corrections électrofaible bénéficient du couplage fort du Yukawa du top et sont amplifiées par la singularité de Landau conduisant à une importante correction d'environ 50%The aim of this thesis is twofold. First, to study methods to calculate one-loop corrections in the context of perturbative theories. Second, to apply those methods to calculate the leading electroweak (EW) corrections to the important process of Higgs production associated with two bottom quarks at the CERN Large Hadron Collider (LHC). Our study is restricted to the Standard Model (SM). The first aim is of theoretical importance. Though the general method to calculate one- loop corrections in the SM is, in principle, well understood by means of renormalisation, it presents a number of technical difficulties. They are all related to loop integrals. The analytical method making use of various techniques to reduce all the tensorial integrals in terms of a basis of scalar integrals is most widely used nowadays. A problem with this method is that for processes with more than 4 external particles the amplitude expressions are extremely cumbersome and very difficult to handle even with powerful computers. In this thesis, we have studied this problem and realised that the whole calculation can be easily optimised if one uses the helicity amplitude method. Another general problem is related to the analytic properties of the scalar loop integrals. An important part of this thesis is devoted to studying this by using Landau equations. We found significant effects due to Landau singularities in the process pp → b anti-b H at the LHC. The second aim is of experimental importance. This process is important to understand the bottom-Higgs Yukawa coupling. The result obtained in this thesis is the following. If the Higgs mass is about 120GeV then the next-to-leading order correction is small, about - 4%. If the Higgs mass is about 163GeV then the EW correction is strongly enhanced by the Landau singularities, leading to a significant correction of about 50%. This important phenomenon is carefully studied in this thesis
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Riello, Aldo. "Corrections radiatives en gravité quantique à mousse de spins : Une étude du graphe de Self énergie dans le modèle EPRL Lorentzien." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4028/document.
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Je propose la première étude quantitative des corrections radiatives du modèle EPRL en gravité quantique à mousse de spins. Ce modèle est la proposition la plus élaborée de gravité quantique Lorentzienne 4D dite 'indépendante du fond' ('background independent'). C'est une réalisation, par intégrale de chemin, de la quantification de la Relativité Générale comme somme sur les géométries. L'étude se focalise sur les propriétés et les aspects géométriques de l'analogue du graphe de self-énergie du modèle, connu comme le graphe 'melonique'. Je montre que les contributions dominantes à un tel graphe divergent beaucoup moins que celles de modèles similaires en théorie topologique des champs. De plus, je dérive en détails la dépendance des amplitudes aux données de bords, et montre que ce graphe n'induit pas une renormalisation de la fonction d'onde. Ceci est dû à des raisons reliées aux fondements du modèle. Cependant, il se trouve que l'amplitude se réduit à une telle renormalisation dans la limite de nombres quantiques élevés. Ensuite, je montre les conséquences de ces calculs sur une observable physique : la fonction à deux points de la métrique quantique. Ainsi, je montre comment l'insertion du graphe de self-énergie dans l'intérieur de la mousse de spins utilisée a des effets non-triviaux sur la fonction à deux points, modifiant ses contributions à l'ordre dominant. De façon intéressante, ces effets ne disparaissent pas dans la limite des nombres quantiques élevés. Enfin, je discute les conséquences de ces calculs pour le modèle lui-même, et je souligne et commente les traits généraux qui semblent commun à tout modèle de mousse de spins basé sur le schéma présenté iciI present the first quantitative study of radiative corrections within the EPRL model of quantum gravity. This model is the most advanced proposal of Lorentzian 4-dimensional background-independent quantum gravity. It is a realization of the path-integral quantization of general relativity as a sum over geometries. The present study focuses on the properties and geometrical features of the analogue of the self-energy graph within the model, often referred to as the "melon"-graph. Here, I show that the dominating contribution to such a graph is characterized by a degree of divergence much smaller than that of closely related topological quantum field theories. Moreover, I work out in detail the dependence of the amplitude from the boundary data, and find that the self-energy graph does not simply induce a wave function renormaliziation. This happens for reasons deeply related to the model foundations. However, it turns out that the amplitude reduces to a wave function renormalzation in the limit of large quantum numbers. Then, I show the consequences of this calculations on a concrete spinfoam observable: the quantum-metric two-point function. In doing this, I show how the insertion of the self-energy graph in the bulk of the (first-order) spinfoam used in the calculation, has non-trivial effects on the correlation function, modifying its leading order contributions. Most interestingly, this effects do not disappear in the limit of large quantum number. Finally, I discuss the consequences of these calculations for the model itself, and I point out and comment those general features which seem to be common to any spinfoam model based on the present model-building schemes
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Favero, Melissa. "The low-down on America's lock-down: a critical look at the political economy of prisons." Thesis, Boston University, 2001. https://hdl.handle.net/2144/27645.
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Boston University. University Professors Program Senior theses.PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
2031-01-02
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Tokuda, Junsei. "Infrared secular effects on our local universe and the stochastic approach to inflation." Kyoto University, 2020. http://hdl.handle.net/2433/253081.
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Breisel, Jonas. "Evaluering av en Klockkorrigerare av klockpulsbredd." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15791.
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Det här examensarbetet presenterar en evaluering av en Klockkorrigerare av klockpulsbredd. Den består främst av en korrigerare av klockpulsbredd (Duty Cycle Corrector DCC) och även en fördröjningslåst loop (Delayed Locked Loop DLL). Det finns många olika korrigerare av klockpulsbredden designade förut, de två populäraste arkitekturerna då har varit enkel eller dubbel återkopplings loop. Den huvudsakliga skillnaden mellan dem är att enkel återkopplings loop använder sig av en öppen loop medan den dubbla varianten istället har en stängd loop. I det här projektet kommer en ny arkitektur att presenteras. Konceptet i den nya designen är att dela upp korrigeraren av klockpulsbredden i två delar, en korrigerare och en detektor. Detektorn får utsignalen från den fördröjningslåsta loopen som insignal och talar om för korrigeraren via två utsignaler ifall signalen behöver justeras. Detektorn är uppdelad i två likadana fördröjningselement, som båda är klockade av utsignalen och dess invers från den fördröjningslåsande loopen, fast i omvänd ordning. Det här gör det möjligt att avgöra om klockpulsbredden av signalen är över eller under 50 %. Om så är fallet kommer den att justeras av korrigeraren för att sedan skickas som insignal till den fördröjningslåsande loopen.
Abstraktionsnivån för det här projektet har varit systemnivå, detta för att kunna vara riktigt säker på att arkitekturen verkligen fungerar innan ett riktigt chip tillverkas. Tips på framtida projekt är att gå vidare till schemanivå för att slutligen göra en implementering och mätningar på ett riktigt chip av den här Klockkorrigeraren av klockpulsbredd när det är känt att idén fungerar.
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Behring, Arnd [Verfasser], Johannes [Akademischer Betreuer] Blümlein, and Gudrun [Gutachter] Hiller. "Three-loop QCD corrections from massive quarks to deep-inelastic structure functions and operator matrix elements / Arnd Behring. Betreuer: Johannes Blümlein. Gutachter: Gudrun Hiller." Dortmund : Universitätsbibliothek Dortmund, 2016. http://d-nb.info/111256182X/34.
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Dovier, Giacomo Oliviero. "Semi-inclusive associated bottom-Higgs production at LHC: the complete one-loop electroweak in the MSSM." Doctoral thesis, Università degli studi di Trieste, 2011. http://hdl.handle.net/10077/4815.
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2009/2010Il bosone di Higgs il tassello mancante del Modello Standard: predetto da Peter Higgs negli anni sessanta, non ancora stato osservato sperimental- mente. Il Large Hadron Collider stato costruito con questo obiettivo in mente, assieme a molti altri. Uno dei processi pi interessanti per la pro- duzione di Higgs Supersimmetrico bg -> bH0 ( A0, h0). La natura dell'accoppiamento Yukawa nel MSSM lo rende predominate per alti valori di tan(beta) . In questa tesi vengono calcolate le correzioni elettrodeboli ad un loop alla sezione d'urto del processo nel MSSM, e viene mostrato come esse possano essere molto rilevanti per alcune regioni dello spazio dei parametri. Viene anche mostrato come i risultati siano indipendenti dalla scelta dello schema di rinormalizzazione tra DCPR and DR, ed anche come la consueta Improved Born Approximation non riproduca accuratamente i risultati ad un loop, mentre una diversa possibile approssimazione, la Reduced Vertex Approximation, in migliore accordo con il calcolo completo. Viene quindi eff ettuato un confronto con i risultati per un Two Higgs Doublet Modle, e viene mostrato come la di erenza con i risultati nel MSSM sia rilevante ad un loop, rendendo lo studio di questo processo una possibile via per discriminare tra i due modelli.
The Higgs particle is the missing piece of the Standard Model picture: pre- dicted by Peter Higgs in the late sixties, it has yet to be observed in a collider. The Large Hadron Collider has been built with this goal in mind, among many others. A very important channel to look at for SUSY Higgs production is bg -> bH0 (A0, h0). The nature of the MSSM Yukawa couplings make it dominant for high Values of tan(beta) . In my work I calculate the electroweak one loop corrections to the cross section of the process' cross section in the MSSM, and show that they can be very relevant for some regions of the parameters' space. It is also shown how the results obey a nice scheme independence at one loop for the two renormalization schemes DCPR and DR, as well as how the usual Improved Born Approximation fails in this case to reproduce the one loop results accurately, while a di fferent suggested Reduced Vertex Approximation is in better agreement with the full calculation. I then proceed to make a comparison with the results for a Two Higgs Doublets Model, and show that the di fference with the MSSM are big at the one loop level, such that this process could provide a way to discriminate between the two models.
XXIII Ciclo
1983
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Hessenberger, Stephan [Verfasser], Wolfgang F. L. [Akademischer Betreuer] Hollik, Alejandro [Gutachter] Ibarra, and Wolfgang F. L. [Gutachter] Hollik. "Two-Loop Corrections to Electroweak Precision Observables in Two-Higgs-Doublet-Models / Stephan Hessenberger ; Gutachter: Alejandro Ibarra, Wolfgang F. L. Hollik ; Betreuer: Wolfgang F. L. Hollik." München : Universitätsbibliothek der TU München, 2018. http://d-nb.info/1152006819/34.
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Alam, S. (Sher) Carleton University Dissertation Physics. "The one loop radiative corrections to W pair production in electron positron annihilation in the supersymmetric extension of the Salam-Weinberg model of the electroweak interactions." Ottawa, 1992.
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Herren, Florian [Verfasser], and M. [Akademischer Betreuer] Steinhauser. "Precision Calculations for Higgs Boson Physics at the LHC - Four-Loop Corrections to Gluon-Fusion Processes and Higgs Boson Pair-Production at NNLO / Florian Herren ; Betreuer: M. Steinhauser." Karlsruhe : KIT-Bibliothek, 2020. http://d-nb.info/1221186914/34.
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Bischof, Rainer. "Gaussian Critical Line in Anisotropic Mixed Quantum Spin Chains." Doctoral thesis, Universitätsbibliothek Leipzig, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-107225.
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By numerical methods, two models of anisotropic mixed quantum spin chains, consisting of spins of two different sizes, Sa = 1/2 and Sb = 1 as well as Sb = 3/2, are studied with respect to their critical properties at quantum phase transitions in a selected region of parameter space. The quantum spin chains are made up of basecells of four spins, according to the structure Sa − Sa − Sb − Sb. They are described by the XXZ Hamiltonian, that extends the quantum Heisenberg model by a variable anisotropic exchange interaction. As additional control parameter, an alternating exchange constant between nearest-neighbour spins is introduced. Insight gained by complementary application of exact diagonalization and quantum Monte Carlo simulations, as well as appropriate methods of analysis, is embedded in the broad existing knowledge on homogeneous quantum spin chains. In anisotropic homogeneous quantum spin chains, there exist phase boundaries with continuously varying critical exponents, the Gaussian critical lines, along which, in addition to standard scaling relations, further extended scaling relations hold. Reweighting methods, also applied to improved quantum Monte Carlo estimators, and finite-size scaling analysis of simulation data deliver a wealth of numerical results confirming the existence of a Gaussian critical line also in the mixed spin models considered. Extrapolation of exact data offers, apart from confirmation of simulation data, furthermore, insight into the conformal operator content of the model with Sb = 1Mittels numerischer Methoden werden zwei Modelle anisotroper gemischter Quantenspinketten, bestehend aus Spins zweier unterschiedlicher Größen, Sa = 1/2 und Sb = 1 sowie Sb = 3/2, hinsichtlich ihrer kritischen Eigenschaften an Quanten-Phasenübergängen in einem ausgewählten Parameterbereich untersucht. Die Quantenspinketten sind aus Basiszellen zu vier Spins, gemäß der Struktur Sa − Sa − Sb − Sb, aufgebaut. Sie werden durch den XXZ Hamiltonoperator beschrieben, der das isotrope Quanten-Heisenberg Modell um eine variable anistrope Austauschwechselwirkung erweitert. Als zusätzlicher Kontrollparameter wird eine alterniernde Kopplungskonstante zwischen unmittelbar benachbarten Spins eingeführt. Die durch komplementäre Anwendung exakter Diagonalisierung und Quanten-Monte-Carlo Simulationen, sowie entsprechender Analyseverfahren, gewonnenen Erkenntnisse werden in das umfangreiche existierende Wissen über homogene Quantenspinketten eingebettet. Im Speziellen treten in anisotropen homogenen Quantenspinketten Phasengrenzen mit kontinuierlich variierenden kritischen Exponenten auf, die Gaußschen kritischen Linien, auf denen neben den herkömmlichen auch erweiterte Skalenrelationen Gültigkeit besitzen. Umgewichtungsmethoden, speziell auch angewandt auf verbesserte Quanten-Monte-Carlo Schätzer, und Endlichkeitsskalenanalyse von Simulationsdaten liefern eine Fülle von numerischen Ergebnissen, die das Auftreten der Gaußschen kritischen Linie auch in den untersuchten gemischten Quantenspinketten bestätigen. Die Extrapolation exakter Daten bietet, neben der Bestätigung der Simulationsdaten, darüber hinaus Einblick in einen Teil des konformen Operatorinhalts des Modells mit Sb = 1
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Bonilla, Bolanos Andrea. "A step further in the theory of regional economic integration : a look at the Unasur's integration strategy." Thesis, Lyon 2, 2015. http://www.theses.fr/2015LYO22009.
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La nouvelle stratégie d'intégration adoptée en 2000 par les pays Sud-Américains, après trois décennies d'instabilité économique et de crises récurrentes, est un jalon de l'histoire économique de la région. En effet, la volatilité du cycle économique de ces pays s'est réduite significativement à partir de cette date, atteignant son niveau le plus bas depuis 1950. L'analyse d'un tel phénomène est particulièrement intéressante en particulier lorsque l'on se place dans le contexte de turbulences et de crises des années 2000, à savoir, la crise financière mondiale (2008-2009) et, dans son sillage, la crise des dettes souveraines en zone euro. Dans cette thèse, l'objectif est d'étudier le projet d'intégration régionale d'Amérique du Sud, institutionnalisé en 2008 avec la création de l'Union des Nations Sud-Américaines Unasur, en tant que vecteur de stabilisation de ces économies. De ce fait, il s'agit de concentrer l'analyse sur les interactions entre les douze pays du continent Sud-Américain – Argentine, Bolivie, Brésil, Chili, Colombie, Équateur, Guyana, Paraguay, Pérou, Uruguay, Suriname et Venezuela – qui forment un groupe hétérogène autour d'un objectif commun l' "… intégration culturelle, sociale, économique et politique …" et la "… réduction des asymétries de la qualité de vie de ses citoyens … ". La thèse s'intéresse exclusivement aux aspects économiques d'un tel projet d'intégration régionale. À partir d'outils empiriques et théoriques, nous cherchons à évaluer le niveau de convergence et de vulnérabilité des économies concernées. Plus particulièrement une analyse des impacts des politiques d'intégration dans court terme et une étude de leurs performances macroéconomiques de long terme. La thèse se divise en quatre chapitres et s'appuie sur des modèles qui intègrent diverses sources de diffusion des chocs asymétriques. Le premier chapitre présente l'état de l'art de la théorie d'intégration économique régionale en soulignant le cas Sud-Américain. Le deuxième chapitre analyse, à l'aide de modèles vectoriels autorégressifs structurels et de mesures de corrélation, l'impact de chocs externes sur les secteurs réel, monétaire et budgétaire des pays membres de l'Unasur. L'analyse montre que : (i) même les pays les plus fermés (Argentine et Venezuela) et les plus industrialisées (Brésil) présentent une forte vulnérabilité aux perturbations internationales, (ii) cette vulnérabilité individuelle se traduit en une convergence de court terme des trajectoires des principales variables macroéconomiques des pays concernés. Dans le troisième chapitre, on cherche à mesurer le degré de convergence de long terme des niveaux de vie des citoyens Sud-Américains à l’aide de modèles empiriques vectoriels à correction d'erreur et de techniques de cointégration. Les résultats montrent l'existence de tendances stochastiques communes à long terme. Cela signifie que les pays sont engagés dans un processus d'évolution vers un objectif commun, autrement dit, que les conditions de vie des citoyens Sud-Américains ne divergent pas à long terme. En fin, le troisième chapitre vise à analyser l'impact de l'investissement dans la construction de réseaux régionaux de transport, de communication et d'énergie, sur la réduction de l'hétérogénéité structurelle des pays de l'Unasur (projet IIRSA). En effectuant un certain nombre d'expériences de politique dans un cadre théorique, cette analyse constate que : (i) une accroissement d'investissement public en infrastructure suscite une augmentation du commerce intra-intra-régional mais pas forcément une réduction de l'écart de production entre les pays, (ii) l'écart de production à long terme entre l'Argentine et le Brésil diminue, dans un scénario gagnant-gagnant, en termes de croissance économique, seulement si les gouvernements de ces deux pays coordonnent leur augmentation d'investissement en infrastructure, comme proposé par l'IIRSAEconomic integration seems to be a new global trend. The past two decades have witnessed the formation of several economic unions in Asia (ASEAN+3 in 1997), Europe (Eurozone in 1999), Africa, and America (Union of South American Nations, Unasur in 2008). The South American case deserves special attention because, unlike the other blocs, the Unasur emerged as a political alliance and not as an economic one. Furthermore, Unasur is conceived as a strategy for improving the socioeconomic conditions of nations that have a common history of economic instability and external dependence. However, while common concerns and political willingness exist among group members, the question of whether that consensus is sufficient to ensure economic integration remains unanswered. For instance, economic integration as a strategy for macroeconomic stability has seemed to work well in Europe after the euro was launched in 1999 (Sapir, 2011), until the breakdown of the European sovereign debt crisis in recent years has revealed the inherent weaknesses of an economic union that lacks a political union (Fligstein et al., 2012, Issing, 2011). This development suggests that the Unasur project is likely to fail if the concerned economies do not converge economically. This is the reason why, this thesis assesses the Unasur project from an economic integration perspective, thus, complementing the huge body of political literature that has been developed on the issue (Briceño-Ruiz, 2014, Sanahuja, 2012). The first chapter describes the theory of economic integration' state of art focusing on South America. The second chapter examines the reactions of the Unasur economies to external shocks. By using a structural vector autoregression approach, it measures the impact of three external shocks (monetary, commercial, and financial) in the real, monetary, and fiscal economic sectors of Unasur economies and investigates co-movement paths. The results show (i) a non-negligible degree of synchronization across the studied economies, confirming their high external vulnerability, (ii) irrespective of size or integration degree, all Unasur members share mutual weaknesses, which they must fight to overcome. The third chapter evaluates the convergence in real GDP per-capita, as a suitable proxy measure, of the concerned economies for the period 1951-2011. By relying on cointegration techniques and applying Bernard and Durlauf's (1995) stochastic definitions of convergence and common trends, the presented evidence supports the existence of common long-run trends driving output in South America, meaning that the region is involved in a dynamic process of convergence in living standards. Finally, the fourth chapter studies the economic spillovers of the most advanced structural project of the group: the Initiative for the Integration of Regional Infrastructure in South America (IIRSA). A micro-founded two-country general equilibrium model is constructed to evaluate potential gains or losses (in terms of output convergence and trade integration) of raising publicly provided transportation infrastructure in a coordinated and uncoordinated manner. The model is solved using data from Argentina and Brazil. Results show that: (i) rising public investment in infrastructure boost commercial integration but not necessarily generates output converge, (ii) the only way for the Argentina and Brazil to achieve output convergence is to coordinate their increments on public infrastructure as proposed by the IIRSA
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Paßehr, S. [Verfasser], Wolfgang F. L. [Akademischer Betreuer] Hollik, and Nora [Akademischer Betreuer] Brambilla. "Two-Loop Corrections to the Higgs-Boson Masses in the Minimal Supersymmetric Standard Model with CP-Violation / Sebastian Paßehr. Gutachter: Nora Brambilla ; Wolfgang F. L. Hollik. Betreuer: Wolfgang F. L. Hollik." München : Universitätsbibliothek der TU München, 2014. http://d-nb.info/1059221942/34.
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Liao, James Yu-Chang. "Evaluating Multi-Modal Brain-Computer Interfaces for Controlling Arm Movements Using a Simulator of Human Reaching." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1404138858.
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Usovitsch, Johann. "Numerical evaluation of Mellin-Barnes integrals in Minkowskian regions and their application to two-loop bosonic electroweak contributions to the weak mixing angle of the Zbb(bar)-vertex." Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/19484.
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In der Z-Boson-Resonanzphysik sind mehrere Präzisionsobservablen in einem perfekten Zustand, bei dem die theoretische Unsicherheit niedriger ist als die gegenwärtige experimentelle Unsicherheit.
Das Konzept für den zukünftigen Teilchenbeschleuniger Future Circular Collider (FCC), will eine Verbesserung der Messungen für die Präzisionsobservablen um ein bis zwei signifikante Stellen erreichen.
Damit werden die Vorhersagen des elektroschwachen Standardmodells in eine Situation versetzt, in der vollständige Zweischleifenkorrekturen zusammen mit den führenden Dreischleifenkorrekturen obligatorisch werden.
2016 wurden die vollständigen Zweischleifenkorrekturen für den effektiven schwachen Mischungswinkel für die bottom Quarks sin^2/theta/^b_eff berechnet, indem die fehlenden bosonischen Zweischleifenkorrekturen bereitgestellt wurden.
Dabei liegt die Schwierigkeit in der Berechnung der entsprechenden Zwei-Schleifen Vertex-Feynman-Integrale, die mehrere massive Teilchen einschließen.
Gegenwärtig ist die analytische Rechnung der meisten dieser Integrale schwierig und deswegen werden rein numerische Techniken, mittels Sektorzerlegungsansatz und der Integralansatz nach Mellin-Barnes, angewandt.
Es war bis vor kurzem nicht bekannt, wie Mellin-Barnes-Integraldarstellungen in den minkowskischen Integrationsgebieten numerisch behandelt werden können.
Um dieses Problem anzugehen, stellen wir eine Vielzahl von ein- und mehrdimensionaler Techniken vor, die ein Teil des neuen Programms MBnumerics.m sind, welches in dieser Dissertation entwickelt wurde.
Der Sektorzerlegungsansatz und der Integralansatz nach Mellin-Barnes sind zusammen ausreichend, um elektroschwache Zweischleifenkorrekturen für die Präzisionsobservablen der Annihilation von e^+e^- in zwei Fermionen in der Z-Bosonresonanz auszurechnen.
Aktuell führt dies zu der genauesten Vorhersage für den effektiven elektroschwachen Mischungswinkel für bottom Quarks sin^2/theta/^b_eff = 0.232312.In the Z-boson resonance physics several precision observables are in a perfect state, where the theory uncertainty is lower than the present experimental uncertainty. The ambitious concepts for the future collider, Future Circular Collider (FCC), aim for an improvement of measurements for the precision observables by one to two significant digits. This will put the Electroweak Standard Model predictions in a situation where complete two-loop corrections together with the leading three-loop corrections will become mandatory. The complete two-loop corrections for effective weak mixing angle for bottom quarks sin^2/theta/^b_eff were reported recently, by providing the missing bosonic two-loop corrections. The difficult task in this computation is the calculation of the corresponding two-loop vertex Feynman integrals which include several massive particles. At present the analytic evaluation for most of these integrals is out of reach and purely numerical techniques were applied. Only two methods, sector decomposition approach and the Mellin-Barnes integral approach, are known to extract infrared and ultraviolet singularities in a systematic way for a general Feynman integral with fully automatized algorithms. It was not known until recently how to treat Mellin-Barnes integral representations in Minkowskian regions numerically. To address this problem we introduce and discuss in detail a variety of one- and multi-dimensional techniques, which are part of a new program MBnumerics.m developed in this thesis work. Two techniques, sector decomposition and Mellin-Barnes integral approach, are together sufficient to treat electroweak two-loop corrections to the precision observables for the e^+e^- annihilation into two fermions at the Z-boson resonance. This leads to the most precise prediction at present for the effective weak mixing angle for bottom quarks: sin^2/theta/^b_eff=0.232312.
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De, Notariis Kevin. "Light hyperweak new gauge bosons from kinetic mixing in string models." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19491/.
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String theory is at the moment our best candidate for a unified quantum theory of gravity, aiming to reconcile all the known (and unknown) interactions with gravity as well as provide insights for currently mysterious phenomena that the Standard Model and the modern Cosmology are not able to explain. In fact, it is believed that most of the problems associated to the Standard Model can indeed be resolved in string theory. Supersymmetry is supposed to be an elegant solution to the Hierarchy problem (even though more and more stringent bounds in this direction are being placed by the fact that we have been unable to experimentally find supersymmetry yet), while all the axions that compactifications bring into play can be used to resolve the strong CP problem as well as provide good candidates for Dark Matter. Inflationary models can also be constructed in string theory, providing, then, the most diffused solution to the Horizon problem. This work, in particular, is formulated in type IIB string theory compactified on an orientifolded Calabi-Yau three-fold in LARGE Volume Scenario (LVS) and focuses on the stabilisation of all the moduli in play compatible with the construction of a hidden gauge sector whose gauge boson kinetically mixes to the visible sector U(1), acquiring a mass via a completely stringy process resulting in the St{\"u}ckelberg mechanism. The "compatibility" regards the fact that certain experimental bounds should be respected combined with recent data extrapolated by Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS) events at the Spallation Neutron Source at Oak Ridge National Laboratory. We are going to see that in this context we will be able to fix all the moduli as well as present a brane and fluxes set-up reproducing the correct mass and coupling of the hidden gauge boson. We also get a TeV scale supersymmetry, since the gravitino in this model will be of order O(TeV), with an uplifted vacuum to reproduce a de Sitter universe as well.
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Connors, Marianne Dorothy. "The pragmatic particles 'enfin' and 'écoute' in French film and TV dialogue." Thesis, University of Exeter, 2016. http://hdl.handle.net/10871/27764.
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This thesis investigates the use of the pragmatic particles (PPs) 'enfin' and 'écoute' in French film dialogue, and their translations in British English subtitles. Using a corpus of nine films and eight episodes drawn from two television series – all released in the UK between 2005 and 2015, and equating to approximately twenty-two hours – the study identifies tokens across a much wider range of contexts than has previously been possible using traditional corpora. The main contribution is an analysis of PP functions. The results for 'enfin' show a different functional distribution of the particle to other corpora, with corrective 'enfin' occurring significantly less frequently. The relatively large number of tokens of performative and emotional (or affective) 'enfin' allows for an elaboration of these two categories, and a tendency is observed for 'enfin' to appear as an apparent disagreement mitigator in discussions between peers. With regard to 'écoute', it is argued that écoute1 functions as a face-threat mitigator in unequal relationships and écoute2 as an FTA, although the particle is multifunctional and some tokens exhibit characteristics of both categories. Attention is given to combinations of 'enfin' and 'écoute' with other particles: while there is a clear tendency for disagreement-mitigating 'enfin' to co-occur with 'mais', and for the precision and restrictive subcategories of the corrective to co-occur with 'je veux dire', other previously documented combinations ('enfin bon' and 'ben écoute') are not frequently occurring in the present corpus. The thesis also makes a significant contribution to the field of Audiovisual Translation (AVT). The English subtitles show high rates of omission for both particles consistent with previous research, with disagreement-mitigating 'enfin' particularly vulnerable to omission. However, the analysis reveals a surprising pattern regarding 'écoute': a clear division of labour between ‘look’ (used to translate more confrontational tokens) and ‘listen’ (more conciliatory and socially distant). The study includes an experimental analysis of the subtitles relative to their character limits, demonstrating a potential new approach for researchers wishing to investigate the impact of various subtitling constraints.
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CHEN, YU-JHE, and 陳昱喆. "A SAR-based Delay-Locked Loop with Duty-Cycle Correction." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/g2gb3w.
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碩士國立雲林科技大學
電機工程系
107
All-digital delay-locked loops (ADDLLs) have been widely applied in clock synchronization due to the advantage of smaller area, lower power and shorter locking time. The successive approximation register-controlled delay-locked loop (SARDLL) adopts the binary search algorithm to set the digital control codes such that the locking time is proportional to the number of bits in the digital-controlled delay line. A clock with 50% duty-cycle is extremely important in double-rate system. Therefore, the duty-cycle correction circuit is needed to correct the duty-cycle of the clock. The general duty-cycle correction circuit uses two half delay line or three half delay line to sample the cycle time, but the cost of the increase in area and operating time must be paid. The circuit proposed in this thesis solves the problem by using a single control delay line with the multiplexer as a recycle delay line. The chip is designed and simulated in a TSMC 90nm process provided by TSRI. Its operating frequency range is within 80~600MHz. The duty cycle of input clock frequency is within 30~70%. The deviation of the output duty cycle is within 48.9~50.6%. the maximum power consumption is 5.6mW, and the locking time is 48 reference clock cycles. Keywords：Successive Approximation Register(SAR), Delay-Locked Loop(DLL), Duty-Cycle Correction(DCC)
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Bo-Jiun, Chen. "All-Digital Fast-Locking Delay-Locked Loop with Duty Cycle Correction." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1207200620264800.
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Chang, Yun-Hsiang, and 張雲翔. "A Novel Current Loop for DSP-Based Power Factor Correction Circuits." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/6bgke7.
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碩士國立中山大學
電機工程學系研究所
95
This thesis mainly focuses on active power factor correction (PFC) circuit research. Based on DSP, a circuit with a digital controller is developed. Boost converter is used as the power stage. For power factor correction, the control law is realized with DSP and the control strategy of controller adopts the multi-loop method, i.e. voltage-loop and modified PI current-loop. Finally, compared with the circuit using the conventional PI control law, performances of the modified PI current-loop circuit are obviously optimized.
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Chen, Bo-Jiun, and 陳柏均. "All-Digital Fast-Locking Delay-Locked Loop with Duty Cycle Correction." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/60142693822760595477.
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碩士國立臺灣大學
電子工程學研究所
94
With the evolution and continuing scaling of CMOS technologies, the demand of high speed and high integration density VLSI systems have the exponential growth recently. However, the synchronization problem among IC modules is undoubtedly important and becoming one of the bottlenecks for high performance systems. Phase-locked loops (PLLs) and delay-locked loops（DLLs）have been widely employed for the purpose of synchronization. Due to the difference of their configurations, the DLLs are preferred for their unconditional stability and faster locking time than the PLLs. Additionally, a DLL offers better jitter performance than a PLL because noise in the voltage-controlled delay line (VCDL) does not accumulate over many clock cycles. The all-digital design has high portability and scalability across different technology process. Its high integrity, low power, and low jitter performance can be easily incorporated into several systems. A clock with 50% duty-cycle is extremely important in many double-rate systems such as DDR-SDRAMs and analog-to-digital converters. Therefore duty-cycle corrector (DCC) is needed to correct duty cycle as 50%. This thesis contains three design and realization of the all-digital DLL and DCC circuits. First of all, an all-digital 50% DCC is presented. The features of the proposed DCC include a wide operation frequency range, a wide input duty cycle range for the input clock, and a faster correction speed. The acceptable duty cycle and frequency range of the input clock is 25%-75% and 250MHz-600MHz, respectively. The correction time is 8ns at 500MHz. Besides, this DCC can save power consumption by turning off half of the delay cells. Secondly, a fast-locking all-digital DLL with 50% duty cycle is proposed. Based on the proposed architecture, not only the phase alignment of input and output clocks can be achieved, but also the duty cycle of the output clock can be corrected to 50%. It can synchronize in four cycles. Besides, the proposed delay line plays not only delay cells but also a time-to-digital converter (TDC). So it reduces active area and power effectively. The input frequency range can operate within 300MHz-500MHz. The accepted input duty cycle range is 40%-60%. Thirdly, a wide-range anti-reset all-digital DLL is presented. The total system does not need any outside-reset signal to reset the system when the input clock frequency changes a lot, due to the dynamic frequency detector. The proposed binary TDC can reduce effectively hardware compared with a traditional TDC. Besides, the while system is a closed loop and it can track PVT variations. The input frequency range can operate within 62.5MHz-625MHz. It spends four to six cycles to get synchronization.
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Chang, Feng-Chia, and 張峰嘉. "A Wide Range Delay Locked-Loop with Built-in Duty Cycle Correction Circuit." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/98153723799468878945.
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碩士臺灣大學
電子工程學研究所
96
With the demand for high-speed and high integration density VLSI systems has grown tremendously, the evolution and continuing scaling of CMOS technologies enable the designers to implement high performance and complex systems on a single chip with millions of transistors and interconnections. However, the synchronization problem has become the most challenging task in such complex systems. This paper presents a novel delay-locked loop (DLL) with wide-range operation, fixed latency of one cycle and still preserve 50% duty cycle. This DLL uses 1/2n outputs of voltage-controlled delay line (VCDL) (n is an integer) to enlarge the Operating frequency range and eliminate stuck or harmonic problem. Theoretically, the operating frequency range of the proposed DLL can be from 0 to 3*2n*Tref, where Tref is the period of input reference clock. Meanwhile, the duty cycle can be detected and corrected by using the phase information from 1/2 VCDL output signal. This circuit is implemented in a TSMC 0.35-μm CMOS technology. The DLL occupies an active area of 0.9 x 0.8 mm2 , operating frequency range from 300MHz to 650Mhz and consumes a maximum power of 60mW at 500MHz.
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Chen, Yi-Ting, and 陳怡婷. "Adaptive Loop Modulation Technique for Enhanced Transient Response in Power Factor Correction Controller." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/86178958272013459143.
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碩士國立交通大學
電控工程研究所
100
Due to the shortage of energy, high reliability and efficiency has become the focus of current green power systems. Power factor correction (PFC) can shape the input current of off-line power supplies in phase with the input AC voltage in order to increase the real power available from the AC source. Reliability of the Power Factor Correction (PFC) system is improved by fast transient response using the proposed adaptive loop modulation (ALM). Low bandwidth of less than 20 Hz that rejects AC source of 60/120 Hz coupling deteriorated system reliability in case of output load variation. The proposed ALM can automatically adjust bandwidth to rapidly increase or decrease inductor current in order to shorten transient response time. In steady state, system stability can be guaranteed by low-frequency compensation pole without being affected by ALM. The test circuit fabricated in TSMC 500V UHV LDMOS process demonstrated the performance of the highly-integrated PFC controller with the proposed ALM. Experimental results showed that the PFC system with ALM has high PF of 99%, high efficiency of 95%, and high power driving capability of about 90W. The improvement in transient response is faster than conventional PFC design with output load variation from 90 to 20W and vice versa
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SIANG, PEL-LUN, and 向培綸. "All-Digital Delay-Locked Loop with Duty-Cycle Correction using Standard Cell Library." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/2x787v.
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碩士國立雲林科技大學
電機工程系
106
In this thesis, an all-digital delay-locked loop with duty-cycle correction is proposed and implemented with the cell-based design flow. The proposed circuit utilizes the two half-delay line architecture to realize the function of duty cycle correction. After the period acquisition is done, the delay time of the half-delay line is set to be equal to one half of the input clock period, and the duty cycle of the output clock is synthesized to be 50%. The half-delay line comprises a coarse delay line and a fine delay line connected in series so as to obtain higher resolution. In addition, a multi-phase cyclic time-to-digital converter is presented here to generate the control codes with the aid of the oscillator outputs with different phases. And the successive approximation register control mechanism also assists in reducing the phase error to achieve fast-locking capability. A test chip is designed and simulated in UMC CMOS 0.18μm process. The circuit can operate at the input clock frequency from 90 ~ 600 MHz with the duty cycle range of 20% ~ 70%, and the skew is reduced to be within -31.88ps ~ +6.01ps. The deviation of the output duty cycle is within 49.64% ~ 52.23%. The required lock time is less than 40 cycles. The proposed circuit will enter the closed-loop control mode after locking. The output clock can be re-calibrated via the counter if the delay of the input clock is changed.
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Teng, Chun, and 鄧. 鈞. "Development of Phase-Locked-Loop Based Signal Correction Method Applied on Linear Positioning System." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/c9cz8e.
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碩士國立清華大學
動力機械工程學系
105
As industrial automation becomes widely used nowadays, prices of machine tools are natural to be decreasing for higher competitiveness. That is, for one thing, demands of higher accuracy and lower cost parts as feedback system in a machine are rising rapidly in following years. Without some key techniques, domestic suppliers still fall behind in offering such kind of products that are able to improve precision of feedback systems and additionally help suppliers stretch profit margins. In respect of magnetic encoder manufacturing, it has been proved that some domestic encoder-supplier has an ability to minimize the pole pitch deviation and unbalance magnetic field like other foreign manufacturers. Even though the qualities of locally made encoders are almost identical to those products other brands offer, it still exists a huge difference between the local made and the other brand-trusted measuring system in performance of resolution, measuring accuracy and tolerance so that it is limited to let market strategies go further with extended industrial applications. This research focused on the development of real-time signal correcting applied on quadrature signals system such as magnetic and optical encoders. Considering the imperfection of signals in quadrature, amplitude deviation, phase shifts and random noises, which could cause inaccurate interpolation on fine, scale positioning, this approach of signal correction based on phase-lock-loop are designed to extract phases of a pair of input signals and regenerate the corresponding signals to alleviate uncertainty of position analyzing. In a first place, regardless of real-time calculation error, a prototype of signal correction was constructed in Simulink to simulate the transient response of parameters modulation with real phase A and B data sampled from oscilloscope. In this process, optimal parameter self-adjustment mechanism was built to make a trade-off between time lag and noise reduction. Next, the verified construction was implemented in LabVIEW FPGA to test the performance of real-time compensation, system repeatability and noises reduction with different sensors applied. Experimental data indicated that the aim of increasing resolution and keeping nice repeatability as other brands’ products was reached through the proposed method.
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Chen, Chi-Lin, and 陳契霖. "Triple Loop Modulation (TLM) for High Reliability and Efficiency in Power Factor Correction (PFC) System." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/85164771988645998761.
Full textAbstract:
博士國立交通大學
電控工程研究所
100
In general power applications, the power factor correction techniques is the one of key techniques in power saving applications and can make AC power more efficient. The PFC has slow system response because it has low one third or one sixth bandwidth smaller than 20 Hz. The low bandwidth is designed to reject AC interference of 60Hz coupling which could deteriorate system reliability in case of output load transient. This dissertation proposes the triple loop modulation (TLM) in PFC system to improve as fast transient response. When system is in steady state, system stability can be guaranteed by low-frequency compensation pole without being affected by TLM. When output loading changes, the TLM can automatically adjust the bandwidth to increase or decrease inductor current rapidly and reduce transient response time. The mathematical analysis is deduced. This PFC chip is fabricated in VIS 0.5um 500V/40V ultra high voltage LDMOS process. Measurement results show that this PFC system with TLM in transient response is twofold faster than conventional PFC design with output load variation from 20W to 90W and the undershoot voltage is half of traditional PFC. When loading changes from 20W to 90W, the PFC with TLM in transient response is twofold faster than conventional PFC design and the overshoot voltage is about half of traditional PFC.
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Siao, Kun-Cheng, and 蕭琨澄. "Single-phase Bi-directional AC/DC Converter with Power Factor Correction and Phase-Locked Loop." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/14660587232864353104.
Full textAbstract:
碩士國立中山大學
電機工程學系研究所
102
With the development of smart grids, more and more Distributed Generation Systems (DGSs) and Renewable Energy Generation Systems (REGSs) will be interconnected to power grids in the foreseeing future. Most of DGSs and REGSs are DC power sources; therefore, power inverters are used to convert DC power of DGSs and REGSs to AC powers and to interconnect to power grids. In addition, most of REGSs are unstable power sources; they require Energy Storage Systems (ESSs) to stabilize output power. The ESSs can be charged by the REGSs and by power grids if necessary, so the design and development of a bi-directional AC/DC converter is necessary. This thesis develops and implements a single-phase bi-directional AC/DC converter with power factor correction and phase-locked loop. A fully digital controller for the implemented 1kW bi-directional AC/DC converter is designed by Microchip dsPIC33FJj16GS504. Experimental results show that the proposed single-phase bi-directional AC/DC converter can not only has rated power of 1kW but also achieve power factor correction and phase-locked loop.
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Zhong, Deng-Hao, and 鍾登皓. "A Wide-Range All-Digital Delay-Locked Loop Using Three kinds of Fast-Lock Binary Search Algorithms with Duty Cycle Correction." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/66677634045277476397.
Full textAbstract:
碩士國立臺灣科技大學
電機工程系
98
With the progress of the CMOS technologies, the complexity and higher clock signal frequency of memory are increasing day after day. Therefore, the reliability of the clock signal in synchronous system becomes more and more important. How to reduce clock skew will be the most important topic of the clock synchronization circuit. Delay-locked loops (DLLs) are widely used to solve the issue of clock synchronization due to its un-conditionally stable, faster transient response and less jitter accumulation than the phase-locked loops (PLLs). However, the narrow operating frequency range and no supply noise suppression become the major drawbacks for the DLLs. Therefore the variable successive approximation register-controlled (VSAR) algorithm [6] was reported to solve the problems, but the lock time is too long. Thus the subject of this dissertation is to overcome the defects, to break the limitations and to make a flexible use for the conventional DLLs circuit. This paper presents an all-digital implemented delay-locked loop with a fast-lock characteristic using three modified binary search algorithms. First, the phenomenon of repetitive search in the VSAR algorithm is removed by the proposed fast VSAR (FVSAR) algorithm. Second, the recursive SAR (RSAR) algorithm applies the binary search algorithm to the delay length adjustment in the VASR algorithm. However, the phenomenon of repetitive search takes place in the RSAR algorithm as well. Therefore the fast recursive SAR (FRSAR) is proposed to speed up the locking process. Finally, the SAR Algorithm Delay-Lock Loop with Length Detection (LDSAR) resolve the FVSAR and the FRSAR algorithm shortcomings, LDSAR algorithm applies the Length Detection Circuit to speed up the locking time and the wide range phase detector to overcome the Non 50% duty cycle problems.