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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.
611

Stroop tasks with visual and auditory stimuli : How different combinations of spoken words, written words, images and natural sounds affect reaction times

Malapetsa, Christina January 2020 (has links)
The Stroop effect is the delay in reaction times due to interference. Since the original experiments of 1935, it has been used primarily in linguistic context. Language is a complex skill unique to humans, which involves a large part of the cerebral cortex and many subcortical regions. It is perceived primarily in auditory form (spoken) and secondarily in visual form (written), but it is also always perceived in representational form (natural sounds, images, smells, etc). Auditory signals are processed much faster than visual signals, and the language processing centres are closer to the primary auditory cortex than the primary visual cortex, but due to the integration of stimuli and the role of the executive functions, we are able to perceive both simultaneously and coherently. However, auditory signals are still processed faster, and this study focused on establishing how auditory and visual, linguistic and representational stimuli interact with each other and affect reaction times in four Stroop tasks with four archetypal mammals (dog, cat, mouse and pig): a written word against an image, a spoken word against an image, a written word against a natural sound and a spoken word against a natural sound. Four hypotheses were tested: in all tasks reaction times would be faster when the stimuli were congruent (Stroop Hypothesis); reaction times would be faster when both stimuli are auditory than when they are visual (Audiovisual Hypothesis); reaction times would be similar in the tasks where one stimulus is auditory and the other visual (Similarity Hypothesis); finally, reaction times would be slower when stimuli come from two sources than when they come from one source (Attention Hypothesis). Twelve native speakers of Swedish between the ages of 22 and 40 participated. The experiment took place in the EEG lab of the Linguistics Department of Stockholm University. The same researcher (the author) and equipment was used for all participants. The results confirmed the Stroop Hypothesis, did not confirm the Audiovisual and Similarity Hypothesis, and the results of the Attention Hypothesis were mixed. The somewhat controversial results were mostly attributed to a false initial assumption, namely that having two different auditory stimuli (one on each ear) was considered one source of stimuli, and possibly the poor quality of some natural sounds. With this additional consideration, the results seemed to be in accord with previous research. Future research could focus on more efficient ways to test the reaction times of Stroop tasks involving auditory and visual stimuli, as well as different populations, especially neurodiverse and bilingual populations.
612

Contributions to the Theory of Piecewise Deterministic Markov Processes and Applications to Generalized Age Processes and Storage Models

Löpker, Andreas 09 January 2006 (has links)
Eine Klasse von Markovprozessen mit deterministischem Pfaden und zufälligen Sprüngen wird unter Zuhilfenahme von Martingalen und des erweiterten infinitesimalen Generators untersucht. Dabei steht die Berechnung des Erwartungswertes und der Laplacetransformierten bestimmter Stoppzeiten im Vordergrund. Des weiteren wird die Frage untersucht, wann die in Frage kommenden Prozesse über stationäre Verteilungen verfügen und wie diese im Existenzfall beschaffen sind. Die Methoden werden am Beispiel eines verallgemeinerten Altersprozesses und eines Lager- bzw. Dammprozesses vorgeführt.
613

Variations temporelles et géographiques des méningites à pneumocoque et effet du vaccin conjugué en France / Temporal and geographic variation of pneumococcal meningitis and effect of conjugate vaccine in France

Alari, Anna 30 November 2018 (has links)
Streptococcus pneumoniae est une bactérie cocci gram positif commensale de la flore oropharyngée qui colonise le rhinopharynx de l’Homme et dont près de 100 sérotypes sont connus. Les nourrissons et les jeunes enfants représentent son réservoir principal. Le pneumocoque peut être à l’origine d’infections graves, telles que la méningite, les bactériémies et la pneumonie, et moins graves mais plus courantes comme la sinusite et l’otite moyenne aiguë. Deux vaccins anti-pneumococciques conjugués ont été introduits en France : le PCV7 (couvrant contre 7 sérotypes) en 2003 et le PCV13 (couvrant contre 6 sérotypes supplémentaires) en 2010. L’objectif général de ce travail de thèse est d’évaluer l’impact des politiques vaccinales sur les infections invasives à pneumocoque en France, en s’intéressant principalement aux évolutions temporelles et géographiques des plus graves : les méningites à pneumocoque (MP). Un premier travail a étudié les dynamiques temporelles des MP sur la période 2001–2014 afin d’identifier l’impact de l’introduction des vaccins conjugués. Des techniques statistiques de modélisations adaptées aux séries temporelles ont été utilisées. Les résultats de ce travail retrouvent des effets rapportés dans la littérature : une réduction des MP à sérotypes vaccinaux mais aussi une augmentation des MP dues aux sérotypes non inclus dans le vaccin (phénomène de « remplacement sérotypique »).Par conséquent, le premier bénéfice, à l’échelle de la population générale, de l’introduction de cette vaccination a été observé seulement onze ans après l’introduction du PCV7, et principalement suite à l’introduction du PCV13 en 2010, avec une diminution de 25% du nombre de MP en 2014. La composante géographique a ensuite été prise en compte afin d’étudier le rôle de la de couverture vaccinale dans la variabilité des MP annuelles entre les départements sur la période 2001-2016. Les résultats confirment l’efficacité des deux formulations du vaccin sur les MP dues aux sérotypes vaccinaux et suggèrent une certaine homogénéité de cet effet entre les différents départements. Inversement, le remplacement sérotypique a été confirmé mais uniquement suite à l’introduction de la première formulation du vaccin et ces effets présentent une répartition géographique hétérogène et variable. La variabilité de la couverture vaccinale entre les départements n’explique pas celle observée dans le nombre de MP, ce qui suggère l’intervention d’autres facteurs tel que la densité géographique. Enfin, une modélisation dynamique, permettant de prendre en compte des aspects fondamentaux des dynamiques de transmission et d’infection du pneumocoque non intégrés dans les méthodes de modélisation statique, a été proposée afin de prédire l’impact de différentes stratégies de vaccination pour les adultes de 65 ans et plus et ainsi évaluer leur rapport coût-utilité. / Streptococcus pneumoniae is a Gram-positive commensal bacterium of the oropharyngeal flora usually colonizing human’s rhino pharynx, of which almost 100 serotypes are known. Infants and young children constitute its main reservoir. Pneumococcus may cause serious infections, such as meningitis, bacteremia and pneumonia, or less serious but more common such as sinusitis and acute otitis media (AOM). Two conjugate pneumococcal vaccines have been introduced in France: PCV7 (covering 7 serotypes) in 2003 and PCV13 (covering 6 additional serotypes) in 2010. The overall objective of this thesis is to assess the impact of vaccination policy on invasive pneumococcal diseases in France, by focusing on temporal and geographical trends of the most serious of them: pneumococcal meningitis (PM). An initial study of PMs temporal dynamics over the 2011-2014 period assessed the impact of conjugate vaccines’ introduction. Statistical modeling techniques were used for time series analysis. The results confirm the effects found in literature: a reduction of vaccine serotypes PMs but at the same time an increase of PMs, due to non-vaccine serotypes (effect of “serotype replacement”). Therefore, the first benefit of vaccine introduction at population scale has been observed no less than 11 years after PCV7 introduction, and then principally after PCV13 was introduced in 2010, with a 25% decrease in PMs in 2014. The geographic component was then implemented to analyze the role of vaccine coverage in annual PM variability between geographic units over the 2001-2016 period. Results confirm the effectiveness of both vaccine compositions on vaccine serotypes PMs and suggest homogeneity of this effect among geographic units. Conversely the serotype replacement has been confirmed only after the first vaccine composition was introduced and presents a variable and heterogeneous geographical repartition. Variability in vaccine coverage among geographic units doesn’t explain the differences in PMs, which could suggest the role of others factors such as demographic density. Finally, a dynamic modeling capable of taking into consideration fundamental aspects of pneumococcus transmission and infection mechanisms not integrated in static modeling has been proposed in order to predict the impacts of different vaccination strategies for 65+ adults and therefore assess their cost-utility ratios.
614

Evaluation of Various Inspiratory Times and Inflation Pressures During Airway Pressure Release Ventilation

Gilmore, Tim 01 January 2017 (has links)
There are few recommendations on how best to apply certain modes of mechanical ventilation. The application of Airway Pressure Release Ventilation (APRV) includes strategic implementation of specific inspiratory times (I-times) and particular mean airway pressures (MAWP) neither of which is standardized. This study utilized a retrospective analysis of archived electronic health record data to evaluate the clinical outcomes of adult patients that had been placed on APRV for at least 8 hours. 68 adult subjects were evaluated as part of a convenient purposive sample. All outcomes of interest (surrogates) for short-term clinical outcomes to include the PaO2/FiO2 (P/F) ratio, Oxygen Index and Oxygen Saturation Index (OI; OSI), and Modified Sequential Organ Failure Assessment (MSOFA) scores showed improvement after at least 8 hours on APRV. Most notably, there was significant improvement in P/F ratio (p = .012) and OSI (p = .000). Results of regression analysis showed P low as a statistically significant negative predictor of pre-APRV P/F ratio with a higher initial P low coinciding with a lower P/F ratio. The regression analysis also showed MAWP as a significant positive predictor of post-APRV OSI and P high and P low as significant negative predictors of post-APRV MSOFA scores. In summary, it was found that settings for P high, Plow, and T low in addition to overall MAWP and Body Mass Index (BMI) had significant correlation to impact at least one of the short-term clinical outcomes measured.
615

Antagonistic Narrative Strategies with Chinese Characteristics : A study of Chinese media narratives during 2021

Westling, Lorenzo January 2022 (has links)
This thesis investigates the usage of antagonistic narrative strategies in Chinese state media narratives about the European Union, thus gaining a greater understanding of the usage of narratives by authoritarian states. Articles published during March 2021 and November 2021 by the English-language Chinese state media organisation Global Times are analysed using a novel framework developed by Wagnsson & Barzanje (2021). This framework identifies three strategies used in antagonistic narration but has thus far only been applied to Russian media. Through the framework, the study found that Chinese state media narratively attacked the political systems of the EU and its member states, undermined their relationship with the United States, while also presenting a deepened EU-China relationship as constructive and necessary for the EU’s pursuit of strategic autonomy. The findings suggest that while the antagonistic narrative strategies used by Chinese and Russian media are the same, Chinese state media use different contexts and juxtapose the EU and its member states with different actors to cast them positively or negatively.
616

Medienarrativ som vapen : En studie om informationspåverkan i kinesisk engelskspråkig statsmedia

Fredlund, Lina January 2021 (has links)
Information influence in its most manipulative form can be equated with an attack that threatens democratic values. In order to be able to identify, respond to, and counteract such an attack, it can be argued that it is fundamental to increase the understanding of information influence as a phenomenon. The Chinese President Xi Jinping has formulated an aim to make China democratic by2049. Despite this ambition, actions taken by Xi indicate the opposite direction. This thesis is motivated by the above paradox and attempts to provide insight to the matter by, based on the theoretical framework of strategic narratives, analyzing, by combining textual and narrative analysis, what patterns can be discerned in how democracy is portrayed in Chinese English-language state media. This study uses Global Times as empirical base. From the identified narrative patterns one can distinguish three strategic narratives; 1) The narrative where Western democracy is described as dysfunctional, 2) The narrative where democracy is described as a tool in the pursuit of more power, 3) The narrative whereChina's definition of democracy is described as superior and one Neutral, non-strategic, narrative. The analysis further demonstrates how these strategic narratives can be understood as information influence, produced to create mistrust between actors with the purpose to shape the receiver's perception about democracy. The thesis concludes that Global Times uses certain strategic narratives in combination to exert information influence. The overall strategy, as previous research already identified, is that China shapes its own definition of democracy by discrediting the Western and the generally accepted variant of the concept of democracy, while emphasizing its own. This study has sought not just to contribute with empirical evidence that they are doing this but to also describe how the systematic of the procedure appears – which the identified narrative patterns describe.
617

Současné působení únavy a creepu u Ni superslitin a slitiny TiAl / Fatigue-creep interaction in Ni superalloys and TiAl alloys

Šmíd, Miroslav January 2013 (has links)
The present doctoral thesis is focused on the effect of dwells on the low cycle fatigue behaviour of advanced high temperature materials. 10 minutes strain holds are introduced into the cyclic straining of cast Ni-based superalloy IN792-5A and cast intermetallic alloy TiAl-7Nb which were chosen as experimental material. Fatigue experiments were conducted in strain control mode with constant total strain amplitude and strain rate. IN792-5A was subjected to continuous cyclic loading test as well as fatigue tests either with tensile peak strain holds or compressive peak strain holds at temperature 800 °C. TiAl-7Nb was experimentally examined by continuous cyclic loading tests and also by fatigue test with tensile peak strain hold times at temperature 750 °C. Cyclic hardening/softening curves, cyclic stress-strain curves, Manson-Coffin curves and Basquin curves were obtained. Stress relaxation data were measured during hold times. Mean stress evolution was observed and documented. Microstructure of both alloys was observed in as-received state and also after cyclic loading by means of SEM and TEM. Surface relief investigation revealed cyclic plastic strain localisation as well as fatigue crack initiation sites. Fatigue crack propagation was described using fracture surface and longitudinal gauge section observations. Dislocation structures developed in the course of fatigue tests were studied and documented.
618

The Wall Still Stands... Or Does It? Collective Memory of the Berlin Wall as Represented in American and German Newspapers

Hiller, Katlin M. 01 October 2018 (has links)
No description available.
619

"The Old White Sportswriters Didn't Know What to Think": Tradition vs. New Journalism in the New York Times's Coverage of Muhammad Ali, 1963-1971

Zidonis, Jeffrey J. January 2018 (has links)
No description available.
620

Effect of Copolymer Sequence on Mechanical Properties of Polymer Nanocomposites from Molecular Dynamics Simulations

Trazkovich, Alex 08 July 2019 (has links)
No description available.

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