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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.
711

Analysis and evaluation of the pilot attentional model

Ghaderi, Maryam 08 1900 (has links)
Pendant les opérations de vol, les pilotes sont exposés à une variété de conditions émotionnelles, mentales et physiques qui peuvent affecter leurs performances et leur attention. Par conséquent, il est crucial de surveiller leur charge de travail et leurs niveaux d'attention pour maintenir la sécurité et l'efficacité de l'aviation, notamment dans les situations d'urgence. La charge de travail fait référence aux exigences cognitives et physiques imposées aux pilotes lors d'un vol. Des niveaux élevés de charge de travail peuvent entraîner une fatigue mentale, une attention réduite et une surcharge cognitive, ce qui peut entraver leur capacité à effectuer leurs tâches de manière efficace et efficiente. L'attention est un processus cognitif complexe qui limite la capacité de se concentrer et de comprendre tout en même temps. Dans les tâches de traitement de l'information visuelle, la vision humaine est la principale source du mécanisme d'attention visuelle. Le mode de distribution de l'attention d'un pilote a un impact significatif sur la quantité d'informations qu'il acquiert, car la vision est le canal le plus critique pour l'acquisition d'informations. Une mauvaise allocation des ressources attentionnelles peut amener les pilotes à négliger ou à oublier des paramètres spécifiques, ce qui entraîne des risques graves pour la sécurité des aéronefs. Ainsi, cette étude vise à étudier les niveaux d'attention des pilotes lors d'une procédure de décollage simulée, en mettant l'accent particulièrement sur les périodes critiques telles que les pannes de moteur. Pour ce faire, l'étude examine s'il existe une corrélation entre la dilatation de la pupille, mesurée à l'aide de la technologie de suivi oculaire, et les niveaux d'engagement, mesurés à l'aide de l'EEG. Les résultats indiquent que les changements de taille de la pupille sont effectivement corrélés aux changements d'activité de l'EEG, suggérant que la dilatation de la pupille peut être utilisée comme un indicateur fiable de l'engagement et de l'attention. Sur la base de ces résultats, la dilatation de la pupille et l'EEG peuvent être utilisés en combinaison pour examiner de manière globale le comportement des pilotes, car les deux mesures sont des indicateurs valides de l'engagement et de la charge cognitive. De plus, l'utilisation de ces mesures peut aider à identifier les périodes critiques où les niveaux d'attention des pilotes nécessitent une surveillance étroite pour garantir la sécurité et l'efficacité de l'aviation. Cette étude met en évidence l'importance de surveiller la charge de travail et les niveaux d'attention des pilotes et recommande d'utiliser les mesures de dilatation de la pupille et d'EEG pour évaluer la charge cognitive et l'engagement d'un pilote pendant les opérations de vol, améliorant ainsi la sécurité et l'efficacité de l'aviation. / During flight operations, pilots are exposed to a variety of emotional, mental, and physical conditions that can affect their performance and attention. Therefore, it is crucial to monitor their workload and attention levels to maintain aviation safety and efficiency, particularly in emergency situations. Workload refers to the cognitive and physical demands placed on pilots during a flight. High levels of workload can lead to mental fatigue, reduced attention, and cognitive overload, which can hinder their ability to perform their tasks effectively and efficiently. Attention is a complex cognitive process that limits the ability to focus and comprehend everything simultaneously. In visual information processing tasks, human vision is the primary source of the visual attention mechanism. A pilot's attention distribution mode significantly impacts the amount of information they acquire, as vision is the most critical channel for information acquisition. Improper allocation of attention resources can cause pilots to overlook or forget specific parameters, resulting in severe risks to aircraft safety. Thus, this study aims to investigate pilots' attention levels during a simulated takeoff procedure, with a specific focus on critical periods such as engine failures. To achieve this, the study examines whether there is a correlation between pupil dilation, measured using eye-tracking technology, and engagement levels, measured using EEG. The results indicate that changes in pupil size are indeed correlated with changes in EEG activity, suggesting that pupil dilation can be used as a reliable indicator of engagement and attention. Based on these findings, pupil dilation and EEG can be used in combination to comprehensively examine pilot behavior since both measures are valid indicators of engagement and cognitive workload. Furthermore, using these measures can help identify critical periods where pilots' attention levels require close monitoring to ensure aviation safety and efficiency. This study emphasizes the significance of monitoring pilots' workload and attention levels and recommends using pupil dilation and EEG measures to assess a pilot's cognitive workload and engagement during flight operations, ultimately enhancing aviation safety and efficiency.
712

Confining Mastery: Understanding the Influence of Parental Incarceration on Mastery in Young Adulthood

Shaw-Smith, Unique R. 25 April 2014 (has links)
No description available.
713

Marital biography and well-being in later life: the role of remarriage, disruption pathways, and duration on health, parent-child contact, and ambivalence toward children

Hammersmith, Anna Marie 23 July 2018 (has links)
No description available.
714

Designing for Senior Wellness: An Accuracy Technology System for Home Exercise Programs in Physical Therapy

Lipman, Julianne 20 December 2018 (has links)
No description available.
715

Resident Assistant Training Programs at Member Schools of the Council of Christian Colleges and Universities

Gwaltney, Richard T. January 2000 (has links)
No description available.
716

Auditory Responses in the Amygdala to Social Vocalizations

Gadziola, Marie A. 01 November 2013 (has links)
No description available.
717

Physiological Factors Influencing Labor Length

Neal, Jeremy L. 11 September 2008 (has links)
No description available.
718

The Association of Immigration and Ethnicity with Adherene to Statins and Cardiac Rehabiltation Post-Myocardial Infarction: A sub-study of the ISLAND randomized controlled trial / Immigrants & Secondary Cardiac Prevention Therapy Adherence

Shepherd, Shaun January 2018 (has links)
Adherence to guideline-recommended secondary cardiovascular prevention therapy (statins and cardiac rehabilitation) has been demonstrated to reduce the risk of all-cause mortality (Statins RRR 0.25, 95% CI 0.19-0.30; Cardiac Rehabilitation RRR 0.26, 95% CI 0.14-0.36) and secondary events.1,2 Yet, ≥50% of patients discontinue statin use within 12-month after an initial prescription and completion of cardiac rehabilitation is ≤20% in Ontario.3,4 Low statin adherence and cardiac rehab completion limits patients from realizing the full benefits of therapy. A meta-analysis of randomized controlled trials of adherence to statins for secondary prevention reported that nonadherence to statins was greater in non-white ethnicities compared to white ethnicities (OR 1.28, 95% CI 1.04-1.59) with geographical variation in outcomes.5 In respect to cardiac rehabilitation, the literature suggests that non-white ethnicities are less likely to complete cardiac rehabilitation compared to white participants.6,7 However, a gap remains in our knowledge of cardiac rehabilitation completion among immigrants due to lack of outcome reporting across clinical trials. The literature suggests that immigrants have improved health profiles relative to Canadian-born patients. Specifically, immigrants with ≤10 years of Canadian residency have greater medication adherence than immigrants with >10 of Canadian residency when compared to Canadian-born participants.6-9 This thesis was a planned sub-study of the Interventions Supporting Long-Term Adherence and Decreasing Cardiovascular Events (ISLAND) randomized control trial. The ISLAND study was a pragmatic, randomized controlled trial investigating the effect of educational reminders on adherence to guideline-recommended therapy post-myocardial infarction. Study participants were allocated in a 1:1:1 ratio to one of three groups: i) usual care, ii) educational reminders sent via post, or iii) combination post and interactive voice response educational reminders. Investigators were blinded to the allocation sequence, participant allocation, and outcome assessment. Medication adherence and completion of cardiac rehabilitation were assessed 12-months from baseline. This sub-study of ISLAND focused on participants who completed a 12-month outcome assessment with a recorded response to the following question, “Were you born a Canadian citizen?”. Immigrants experienced greater odds of statin adherence at 7-days (OR 1.36, 95% CI 1.00-1.85) and 30 days (OR 1.36, 95% CI 0.96-1.94) at one-year post-myocardial infarction, after adjusting for age, diabetes, sex, and smoking status. We found no evidence that immigration status was associated with cardiac rehabilitation completion (OR 0.91, 95% CI 0.72-1.14) after adjusting for age, diabetes, sex, smoking status, average neighborhood income quintile, education, and marital status. The odds of statin adherence at 7-days (OR 1.33, 95% CI 0.89-2.18) and 30-days (OR 1.39, 95% CI 0.89-2.18) was greater in visual minorities than white patients, however the difference was not statistically significant. We found no evidence of an association between ethnicity and cardiac rehabilitation completion (OR 0.98, 95% CI 0.75-1.29). Our analysis could not fully evaluate the healthy immigrant effect due to an insufficient sample size of immigrants with <10 years of Canadian residency exposure (n=29). In conclusion, we report a statistically significant 36% increase in the odds of 7-day and 30-day statin adherence in immigrants compared to Canadian-born patients. We also report that the odds of cardiac rehabilitation decreased by 9% in immigrants compared to Canadian-born patients at 12-months post-myocardial infarction but this was not statistically significant. Our findings offer support for the “healthy immigrant effect” continuing in immigrants with >10 years of Canadian residency exposure. We were unable to evaluate outcomes in immigrants with <10 years Canadian residency exposure due to a lack of sample size (n=29). / Thesis / Master of Science (MSc) / The primary purpose of this research project was to assess whether immigrants, individuals who reside in Canada but were born outside of the country, who have experienced a previous heart attack were adhere to heart health therapies better than Canadian-born patients. The heart health therapies of interest to our investigation are two guideline-recommended heart attack prevention therapies, statins and cardiac rehabilitation. The study design of our research project was a cohort sub-study of the ISLAND randomized control trial which investigated adherence to heart health therapies in patients residing in Ontario, Canada. Our major finding was that immigrants who lived in Canada for >10 years were more adherent to statin therapy for a previous heart attack compared to Canadian-born participants. Our findings support the hypothesis that immigrants tend to demonstrate behaviours associated with improved outcomes compared to their Canadian-born counterparts.
719

Inferred Response Properties of the Synaptic Inputs Underlying Duration-Tuned Neurons in the Big Brown Bat / Response Properties of Inputs to Duration-Tuned Neurons

Valdizon-Rodriguez, Roberto January 2019 (has links)
Duration tuning in the mammalian inferior colliculus (IC) is created by the interaction of excitatory and inhibitory synaptic inputs. We used extracellular recording and paired-tone stimulation to measure the strength and time-course of the contralateral inhibition and offset-evoked excitation underlying duration-tuned neurons (DTNs) in the IC of the awake bat. The onset time of a short, best duration (BD), excitatory probe tone was varied relative to the onset of a longer-duration, non-excitatory (NE) suppressor tone. Spikes evoked by the roving BD tone were suppressed or facilitated when the stationary NE tone was varied in frequency or amplitude. When the NE tone frequency was presented away from the cell’s best excitatory frequency (BEF) or at lower SPLs, the onset of inhibition was relatively constant whereas the offset and duration of inhibition decreased. Excitatory and inhibitory frequency response areas were measured and best inhibitory frequencies matched best excitatory frequencies; however, inhibitory bandwidths were broader than excitatory bandwidths. Excitatory rate-level and inhibitory suppression-level functions were also measured and the dynamic ranges and inflection points were similar, which is hypothesized to play a role in the level tolerance of responses measured from DTNs. We compared the latency of offset-locked facilitation to the onset or offset of inhibition as a function of frequency and amplitude; we found that the facilitation was more related to the onset of inhibition. Moreover, facilitation typically preceded the offset of inhibition – suggesting that it is a separate excitatory input to DTNs and not a rebound from inhibition. We conclude that DTNs receive inputs that generate and preserve temporal selectivity. / Dissertation / Doctor of Philosophy (PhD)
720

Jämförelse av metoder för anslutning av GNSS-mätning till referenssystemet SWEREF 99

Hanson, Erik, Öqvist, Joel January 2019 (has links)
GNSS är idag den vanligaste tekniken för positionering och för att ansluta punkter till det nationella referenssystemet SWEREF 99. Systemet realiseras av ett nätverk av permanenta referensstationer, SWEPOS. Nätet består av ett mindre antal stabilt förankrade klass A-stationer och ett större antal, men mindre stabila klass B-stationer. Lantmäteriet erbjuder idag tre tjänster för efterberäkning av GNSS-data som använder SWEPOS-nätet: 1) SWEPOS Beräkningstjänst, som beräknar positioner genom anslutning till klass A-stationer med långa baslinjer som följd, 2) nedladdning av RINEX-data från valfria SWEPOS-stationer, vilket möjliggör medellånga baslinjer och 3) skapande av virtuella referensstationer (VRS), där baslinjerna är mycket korta. Syftet med detta examensarbete är att, genom att använda dessa tjänster, jämföra olika metoder för anslutning av statisk efterberäknad GNSS-mätning till SWEREF 99 och un-dersöka hur mätosäkerheten beror av sessionstid och baslinjelängd. Dessutom undersöks påverkan av mätmiljö och om det finns någon systematisk skillnad mellan de olika metoderna. Fyra s.k. SWEREF-punkter användes som kontrollpunkter. Punkterna mättes i tre 8 h-sessioner. Insamlat mätdata delades in i fönster och skickades till SWEPOS Beräkningstjänst, beräknades i en kommersiell programvara mot klass A-, närmaste stationer och en VRS. För att jämföra de olika metoderna beräknades RMS och standardosäkerheter. Resultaten visar att vid kortare sessionstider har SWEPOS Beräkningstjänst ett högre RMS än övriga metoder, men vid lätt och normal mätmiljö sjunker RMS till samma nivå som övriga metoder redan efter 1 h sessionstid, vilket var 1 cm eller lägre i plan och 2 cm eller lägre i höjd. Vid svår mätmiljö fortsätter RMS att sjunka ända upp till 4 h sessionstid och ligger då något högre än vid lätt och normal mätmiljö. För övriga metoder sjunker RMS inte lika tydligt när sessionstiden ökar. Det framgår att mät-miljön påverkar mätresultatet. Både standardosäkerheter och RMS är högre vid svår mätmiljö jämfört med lätt och normal mätmiljö. Signifikanta skillnader mellan de olika metodernas medelavvikelser kunde påvisas, vilket innebär att det finns systema-tiska avvikelser mellan metoderna, som kan bero på olika troposfärsmodeller och att SWEPOS beräkningstjänst använder referenssystemet ITRF för att sedan göra en transformation till SWEREF 99. / GNSS is at present the most frequently used method for positioning, as well as connecting new points to the Swedish national reference frame, SWEREF 99. The reference frame is realized by a network of permanent reference stations, SWEPOS. The network consists of a small number of rigidly mounted class-A stations and a larger number of less stable class-B stations. Lantmäteriet, the mapping, cadastral and land registration authority of Sweden, cur-rently offers three services for post processing of GNSS data that utilizes the SWEPOS network: 1) SWEPOS Post Processing Service, which computes coordinates by connecting baselines to class-A stations leading to long baselines. 2) Downloading of RINEX data from any SWEPOS stations leading to medium baseline lengths, and 3) creation of virtual reference stations (VRS), leading to very short baselines. The aim of this thesis is, by using these services, to compare different methods for connecting new points to SWEREF 99, using post processing of static GNSS measurements and to investigate the impact of session duration and baseline length on the uncertainty of the measurements. The impact of different measurement environments and systematic effects between the methods are also investigated. Four SWEREF-points were used as test points. The points were measured in three 8 h sessions. The data were divided into windows and sent to SWEPOS post processing service, as well as processed with a commercial software, where baselines were pro-cessed against class-A, class-B stations and a VRS. To compare the different methods RMS and standard uncertainties were calculated. The results indicate that shorter session duration yields higher RMS for SWEPOS post processing service when compared with the other methods, but in easy measurement environments RMS decreases to the same level as the other methods after 1 h session duration, which is 1 cm or less horizontally and 2 cm or less vertically. However, in complex measurement environments RMS continues to decrease up to 4 h session duration and is higher than in easy environments. For the other methods the decrease of RMS is not as pronounced. It is clear that the measurement environment impacts the results. Both standard uncertainty and RMS are higher in complex environments compared with easy and moderate environments. Significant differences of the mean deviation for each method could be detected, which indicates systematic effects between the methods, that could depend on different troposphere models and that SWEPOS Post Processing Service uses the reference system ITRF and then make a transformation to SWEREF 99.

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