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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Binding of visual features in human perception and memory

Jaswal, Snehlata January 2010 (has links)
The leit motif of this thesis is that binding of visual features is a process that begins with input of stimulation and ends with the emergence of an object in working memory so that it can be further manipulated for higher cognitive processes. The primary focus was on the binding process from 0 to 2500 ms, with stimuli defined by location, colour, and shape. The initial experiments explored the relative role of topdown and bottom-up factors. Task relevance was compared by asking participants to detect swaps in bindings of two features whilst the third was either unchanged, or made irrelevant by randomization from study to test, in a change detection task. The experiments also studied the differences among the three defining features across experiments where each feature was randomized, whilst the binding between the other two was tested. Results showed that though features were processed to different time scales, they were treated in the same way by Visual Working Memory processes. Relevant features were consolidated and irrelevant features were inhibited. Later experiments confirmed that consolidation was aided by iconic memory and the inhibitory process was primarily a post-perceptual active inhibition.
102

Measurement of the W Boson Helicity Fractions in Top/anit-Top Events at 8 TeV in the Lepton + Jets Channel with the ATLAS Detector

Kareem, Mohammad Jawad 20 April 2017 (has links)
No description available.
103

Causal modeling and prediction over event streams

Acharya, Saurav 01 January 2014 (has links)
In recent years, there has been a growing need for causal analysis in many modern stream applications such as web page click monitoring, patient health care monitoring, stock market prediction, electric grid monitoring, and network intrusion detection systems. The detection and prediction of causal relationships help in monitoring, planning, decision making, and prevention of unwanted consequences. An event stream is a continuous unbounded sequence of event instances. The availability of a large amount of continuous data along with high data throughput poses new challenges related to causal modeling over event streams, such as (1) the need for incremental causal inference for the unbounded data, (2) the need for fast causal inference for the high throughput data, and (3) the need for real-time prediction of effects from the events seen so far in the continuous event streams. This dissertation research addresses these three problems by focusing on utilizing temporal precedence information which is readily available in event streams: (1) an incremental causal model to update the causal network incrementally with the arrival of a new batch of events instead of storing the complete set of events seen so far and building the causal network from scratch with those stored events, (2) a fast causal model to speed up the causal network inference time, and (3) a real-time top-k predictive query processing mechanism to find the most probable k effects with the highest scores by proposing a run-time causal inference mechanism which addresses cyclic causal relationships. In this dissertation, the motivation, related work, proposed approaches, and the results are presented in each of the three problems.
104

Phenomenological studies of top quark production in the forward region of phase space at the LHC

Gauld, Rhorry January 2014 (has links)
This thesis contains phenomenological studies of top quark production in the forward region of phase space at the Large Hadron Collider (LHC). The production of highly forward top quarks has so far not been observed in nature. As the LHCb detector at the LHC is instrumented in the forward region, this opens the possibility of studying top quark properties in this yet unexplored region of phase space. This feasibility of performing cross section and charge asymmetry measurements of top quark pairs with available and future LHCb data is studied in detail. In both cases, potential analysis strategies are proposed, and sophisticated theoretical predictions are provided for both signal and background. By studying the expected experimental sensitivity of cross section measurements, the potential constraints on parton distribution functions is quantified. The sensitivity of the proposed charge asymmetry measurements with the full Run II LHCb data is also considered.
105

Tréninková příprava vrcholových karatistů - mužů v disciplíně kata v České republice před vrcholnou soutěží / Training preparation of top karate men in discipline kata in the Czech republic before the top competition

Tesárek, Jakub January 2012 (has links)
The theoretical part of my thesis deals with the sport karate training, its components, improving motor skills which are typical for karate and other factors affecting the results of sport training. In the empirical part I find, based on direct interviews with individual representatives, national coaches, difference or similarity of their preparation for the World Championships or European Championships in Karate (Kata men) in their final part of season.
106

HOW ORGANISATIONAL CULTURE AFFECTS INTERNAL CONTROL EFFECTIVENESS: THE ROLE PLAYED BY TOP MANAGEMENT : Case study: Uganda Revenue Authority

Nakiyaga, Brenda, Dinh Thi Lan, Anh January 2017 (has links)
Purpose – The purpose of this paper is to examine and understand the role played by top management towards aligning an organization’s culture to achieve effective internal controls, particularly for organizations operating in emerging economies prone to corruption. Methodology – The study applies both the empirical research approach and the theoretical research approach to examine and understand the major concepts of organisational culture, effectiveness of internal controls and the role played by top management to align the organisation’s culture to achieve effective internal controls. The empirical approach employs qualitative methods to collect data and the research findings are analysed using the deductive approach. A case study of URA is used to collect primary data through the use of a questionnaire.  Findings – The study considers the role of top management in the context of the organization’s culture orientation and based on a hierarchical organizational culture background illustrated by the case study, the study concludes that managers in such an organizational culture orientation, play an influential role towards aligning an organization’s culture to achieve the desired “internal control” objective. Research limitations – There was limited time within which to conduct the research which limited the sample size for data collection. It was a huge gamble to determine the effectiveness of internal controls based on an organisation operating in an emerging corrupt economy since there is a chance that internal controls in such organisations are superficial in nature and may not be implemented in practice. Little research has been done on the concepts of organisational culture and effectiveness of internal control systems in emerging economies which limited extensive review of relevant research literature on the research problem. Research contribution – The research contributes additional literature on organizational culture in emerging economies since very little has been done in this area. The research provides practical recommendations on how top management can positively influence an organizational culture to aid the achievement of successful internal controls particularly for organizations operating in East Africa.
107

2D concept to 3D game model : Production of 3D models for top down games

Gomez, Abraham January 2017 (has links)
This work goes through the mindset and ways of analyzing the problem of realizing 2D concept art into the 3D game model used in game. Specifically targeted for top down games and the effects the top down view have on the 3D game model. Studies in Principles and design concepts are used to create a 3D game character that works well for the top down view. The method used where an experimental study which resulted in a 3D model and implementation of principles and design concepts.  Based on the results it is concluded that it could be a useful tool. In the discussion a deeper analysis is conducted and it´s concluded that further research are necessary and the purpose and questions were answered.
108

Search for heavy resonances decaying to a top quark and a bottom quark in proton-proton collisions at 13 TeV with the CMS experiment

Rankin, Dylan Sheldon 27 November 2018 (has links)
Searches are presented for narrow heavy resonances decaying to a top quark and a bottom quark using data collected by the CMS experiment at a center-of-mass energy of 13 TeV. Final states that include a single lepton (electron, muon), multiple jets, and missing transverse momentum are analyzed. No evidence is found for the production of a W' boson, and the production of right-handed W' bosons is excluded at 95% confidence level for masses up to 3.6 TeV depending on the scenario considered. Exclusion limits for W' bosons are also presented as a function of their coupling strength to left- and right-handed fermions. These limits on a W' boson decaying via a top and a bottom quark are the most stringent published to date. Projections for future searches with an integrated luminosity of up to 3 inverse attobarns are also presented, and suggest that W' boson masses above 4 TeV could be excluded.
109

Perceptions of the Principal Evaluation Process and Performance Criteria: A Qualitative Study of the Challenge of Principal Evaluation

Casavant, Christopher, Collins, William, Faginski-Stark, Erica Ann, McCandless, Jason, Tencza, Marilyn January 2012 (has links)
Thesis advisor: Robert J. Starratt / Recent federal and state mandates have tasked school systems to move beyond principal evaluation as a bureaucratic function and to re-imagine it as a critical component to improve principal performance and compel school renewal. This qualitative study investigated the district leaders' and principals' perceptions of the performance evaluation process and criteria by which the effectiveness of principals was judged in a small, urban, New England school district. In an effort to assist the New England School District to create a more authentic principal evaluation process, district document analysis, literature review, interview transcripts and survey data were used to make recommendations to district leaders regarding four major themes including fairness, feedback, process and critical aspects. The themes were discussed in the context of schools as complex systems, where trust and distributive leadership drive school renewal. Emerging from the study of principal and superintendent perceptions of the process and criteria for evaluation, recommendations include: make principal evaluation an ongoing process; schedule time in each building; clearly identify criteria and supportive evidence; standardize rubrics and evaluation instrument; use evaluation instrument and feedback mechanisms that recognizes complexity of the principalship; provide meaningful feedback; and base summative evaluation on goals for personal-professional improvement and growth. / Thesis (EdD) — Boston College, 2012. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Administration and Higher Education.
110

Search for single top-quark production via flavour-changing neutral currents in strong interactions using s = 8 TeV ATLAS data

Friedrich, Conrad 21 September 2015 (has links)
In dieser Dissertation werden Resultate einer Suche nach der Produktion von Einzel-Top-Quarks über flavour-verletzende neutrale Ströme (FCNCs) in starken Welchselwirkungen vorgestellt. Hierfür werden Daten aus Proton-Proton-Kollisionen am Large Hadron Collider bei einer Schwerpunktsenergie von 8TeV verwendet. Die Daten wurden mit dem ATLAS-Experiment im Jahr 2012 aufgenommen und entsprechen einer integrierten Luminosität von 14.1 fb−1. In der Analyse werden FCNC-Ereignisse selektiert, in denen ein leichtes Quark (u oder c) mit einem Gluon wechselwirkt, und ein einzelnes Top-Quark und potentiell ein weiterer einzelner Jet produziert wird. Mittels der Forderung nach genau einem Myon oder Elektron, großer fehlender Transversalenergie und exakt einem Bottom-Quark-Jet und eventuellem zusätzlichen Jet im Endzustand werden Kandidaten der gesuchten Ereignisse im leptonischen Zerfallskanal des Top-Quarks selektiert. Zur Unterscheidung zwischen Signal- und Untergrundereignissen werden multivariate Methoden herangezogen. Künstliche neuronale Netze werden verwendet, um diverse kinematische Variablen zu einem einzelnen Klassifikator zu kombinieren. Um die potentielle Produktion von Top-Quarks über FCNCs zu quantifizieren, werden die Ausgaben der neuronalen Netze einer Bayes''schen statistischen Analyse unterzogen. Da kein Überschuss an Signalereignissen festgestellt werden kann und die Ergebnisse den Erwartungen der theoretischen Vorhersagen entsprechen, werden neue obere Schranken auf den FCNC-Produktionswirkungsquerschnitt von Einzel-Top-Quarks ermittelt. Aus diesen werden unter Verwendung von modell-unabhängigen theoretischen Berechnungen neue obere Schranken auf die Kopplungskonstanten sowie auf die entsprechenden Verzweigungsverhältnisse ermittelt. / This thesis presents results of a search for single top-quark production via flavour-changing neutral currents (FCNCs) in strong interactions using data recorded with the ATLAS experiment at the Large Hadron Collider in 2012. A dataset from proton-proton collisions at a centre-of-mass energy of 8TeV and corresponding to an integrated luminosity of 14.1 fb−1 is used. It is searched for FCNC events in which a light quark (u or c) interacts with a gluon to produce a single top quark, either with or without the associated production of another light quark or gluon. Candidate events of leptonically decaying top-quarks are selected by requiring a single electron or muon, a substantial amount of missing transverse energy, and exactly one or two jets of which exactly one has to fulfil a b-tagging criterion. Multivariate techniques are employed in order to distinguish between signal- and background-like events by making use of artificial neural networks that combine multiple kinematic variables into a single classifier output. A Bayesian statistical analysis is performed on the classifier outputs in order to quantify potential signs of FCNC single top-quark production. No excess in signal events is observed and the results are in agreement with the theory predictions. Consequently a new upper limit is set on the FCNC single top-quark production cross-section multiplied by the t->Wb branching fraction. Using theory calculations within a model-independent effective theory framework, this limit is converted into upper limits on the coupling constants of the FCNC interactions as well as into respective upper limits on the branching fractions.

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