Driving can be a stressful task, especially under congestion conditions. Several studies have shown a positive correlation between stress and aggressive behaviour behind the wheel, leading to accidents. One common way to minimize stress while driving is to avoid highly congested roads. However, not all drivers show the same response towards high traffic situations or other road conditions. For instance, some drivers may prefer congested routes to longer ones to minimize travel time. Increasingly, drivers are employing Advanced Traveller Information Systems while commuting to both familiar and unfamiliar destinations, not just to obtain information on how to reach a certain endpoint, but to acquire real-time data on the state of the roads and avoid undesired traffic conditions. In this thesis, we propose an Advanced Traveller Information System that personalizes the driver’s route using their road preferences and measures their physiological signals during the trip to assess mental stress. The system then links road attributes, such as number of lanes, speed limit, and traffic severity, with the driver’s stress levels. Then, it uses machine learning to predict their stress levels on similar roads. Hence, routes that contribute to high-levels of stress can therefore be avoided in future trips. The average accuracy of the proposed stress level prediction model is 76.11%.

Cognition in schizophrenia (SCZ) has been reported to be heterogeneous. Some have ascribed this to the existence of cognitive subtypes, while others have attributed heterogeneity to the types of assessments used and the implications of various research designs. In absence of a uniform standardized battery, The MATRICS (Measurement and Treatment Research to Improve Cognition in Schizophrenia) Consensus Cognitive Battery (MCCB) was developed to measure the effects of pharmacological treatment. Other neuropsychological tasks such as the Attention Network Test (ANT), Change Localization (CL), and Stop Signal Task (SST) have also been heavily researched in this population. The overall aim of this dissertation is to assess not only the participant performance on these tasks, but also the test-rest reliability of these assessments in a relatively short retest interval (14±2 days) in a Healthy Volunteer (HV) and SCZ group. In addition, the relationship between Continuous Performance Test-Identical Pairs (CPT-IP), an attention task (ANT), and working memory task (CL) was explored to examine the potential working memory (WM) component of CPT-IP. Lastly, to better understand the heterogeneity of cognition observed in SCZ, Intraindividual Variability (IIV) in performance of SST was compared in relation to other tasks. The results indicated that the MCCB has fair to excellent test-retest reliability in both groups with minimal practice effect (PE) in SCZ. Most interesting, two distinct cognitive profiles were observed: cognitively-normal and below-normal. The 4-digit condition of CPT-IP was found to be the most difficult in both groups. The primary metrics of CPT-IP lacked an association with the three primary domains of ANT in HV and SCZ. No relationship was observed between WM and CPT-IP in HV, primarily due to CL’s ceiling effect, while in SCZ, moderate to strong associations in these tasks were observed. Lastly, little to no relationship was observed between IIV and MCC domain scores in HV and SCZ. The HV group demonstrated some relationship between IIV and domains of ANT. The SCZ group failed to show similar relationships primarily due to larger inter-individual variability. Taken together, the findings of this dissertation suggest the potential for cognitive heterogeneity unrelated to PE and reliability of tasks. / 2021-10-07T00:00:00Z

Habitual (i.e., average or typical) sleep duration and sleep efficiency vary widely by demographic characteristics, including age, gender, and racial/ethnic identity. Despite a wealth of studies on demographic patterns in habitual sleep, these results are often based on cross-sectional surveys, which ask participants to retrospectively recall their "typical" or "recent" sleep. Yet, sleep is a highly dynamic behavior and may fluctuate substantially from night-to-night. This intraindividual variability (IIV) in sleep/wake patterns can be captured a multitude of ways, most commonly by using formula-based calculations. Although there is growing attention on the importance of IIV in sleep, findings on demographic differences are still inconclusive, and there are no guidelines for typical values of IIV in sleep. The present study quantitatively synthesized 8 international data sets (N = 2847 participants, 29,832 total days of sleep data), focusing on examining age, gender, and racial/ethnic identity differences in IIV in sleep measured via sleep diaries, actigraphy, and electroencephalography. Sleep duration and sleep efficiency varied widely from night-to-night within people (duration: 64-119 minutes; efficiency: 5-8%). Different metrics of IIV were strongly correlated within and across sleep measurement types. Younger adults had more IIV in diary and actigraphy sleep duration. Gender differences in IIV in sleep were inconsistent, and non-Hispanic/Latinx and White adults had less IIV in sleep compared to other racial/ethnic minority groups. Results emphasize the importance of assessing IIV in sleep, and show that even among healthy sleepers, sleep varies from night-to-night. Like mean sleep, there may also be disparities in IIV in sleep by demographic characteristics, highlighting a need for targeted interventions to stabilize sleep and improve health.

No description available.

Emotion regulation is processes by which individuals influence which emotions they have, when they have them, and how they experience and express those emotions. In the field of developmental psychology, there is a large literature on affect regulation focused almost exclusively on infants and young children with a focus on temperamental differences in reactivity, both affective and physiological, and accompanying regulatory strategies. The purpose of the current study was to examine the role of two dimensions of temperament, negative affect (NA) and effortful control (EC), and how these dimensions relate to physiology, self-report of emotion, and behavior during resting and stressor tasks (Stroop, video game, hand cold pressor, and delayed gratification), the latter in which emotion suppression instructions were given. Using the Adult Temperament Questionnaire (ATQ) to screen 656 subjects, 24 males and 53 females were recruited to take part in the second phase of the study, creating four groups with their screening ATQ scores: high NA/high EC, low NA/low EC, high NA/low EC, low NA/high EC. Physiological measures derived from electrocardiogram (ECG) and impedance cardiography were recorded during each task and behaviors were coded using the Emotion Expressive Behavior Coding System. EC Group and NA Group were not significant for the majority of the physiological, self-report, and behavioral variables. However, the EC subscale inhibitory control was predictive of lower resting HRV for females only, and the Extraversion/Surgency subscale Sociability was a significant predictor of cardiac sympathetic activity during the tasks, with low sociability subjects showing a stronger sympathetic response. Neither self-report of emotion nor behavioral variables show a clear group difference in response to the tasks. Future studies will examine the use of other types of regulatory tasks, such as social interactions, as well as the need for a balance between emotion expressivity and emotion regulation. / Ph. D.

The entropy of all systems is supposed to increase with time, this is also observed in the hydroclimatic records as increased variability. The current dissertation is primarily focused on the hydrologic variability of the hydrologic records in the climate regions across Continental United States. The study evaluated the effects of serial correlation in the historical streamflow records on both gradual trend and abrupt shift in streamflow. The study also evaluated the trend before and after the shift occurrence to validate whether the observed changes in streamflow is a result of long-term variability or climate regime shift. Secondly, the current dissertation evaluated the variability within western US hydrology which is highly driven by the oscillation of Pacific Ocean such as El Niño – Southern Oscillation (ENSO). The dissertation evaluated the variability in snow water equivalent (SWE) of western US as the winter snow accumulation of the region drives the spring-summer streamflow in the region which contributes to the major portion of yearly streamflow. The SWE variability during the individual phases of ENSO were analyzed to reveal the detailed influence of ENSO on historic snow accumulations. The study is not solely limited to the hydrologic variability evaluation rather; it also delves into obtaining the time lagged spatiotemporal teleconnections between large scale climate variables and streamflow and forecast the later based on the obtained teleconnections. To accomplish the research goals the current dissertation was subdivided into three research tasks. First task dealt with the streamflow records of 419 unimpaired streamflow records which were grouped into seven climate regions based on National Climate Assessment, to evaluate the regional changes in both seasonal streamflow and yearly streamflow percentiles. Non-parametric Mann-Kendall test and Pettitt’s test were utilized to evaluate the streamflow variability as gradual trend and abrupt shift, respectively. Walker test was performed to test the global significance of the streamflow variability within each climate regions based on local trend and shift significance of each streamflow stations. The task also evaluated the presence of serial correlation in the streamflow records and its effects on both trend and shift within the climate regions of continental United States for the first time. Maximum variability in terms of both trend and shift were observed for summer as compared to other seasons. Similarly, greater number of stations showed streamflow variability for 5th and 50th percentile streamflow as compared to 95th and 100th percentile streamflow. It was also observed that serial correlation affected both trend and step while, accounting for the lag-1 autocorrelation improved shift results. The results indicated that the streamflow variability has more likely occurred as shift as compared to the gradual trend. The outcomes of the current result detailing historic variability may help to envision future changes in streamflow. The second task evaluated the spatiotemporal variability of western US SWE over 58 years (1961–2018) as a trend and a shift. The task tested whether the SWE is consistent during ENSO phases utilizing the Kolmogorov – Smirnov (KS) test. Trend analysis was performed on the SWE data of each ENSO phase. Shift analysis was performed in the entire time series of 58 years. Additionally, the trend in the SWE data was evaluated before and after shift years. Mann- Kendal and Pettit's tests were utilized for the detection of trend and shift, respectively. The serial correlation was considered during the trend evaluation, while Thiel-Sen approach was used for the evaluation of the trend magnitude. The serial correlation in time series which is the potential cause of overestimation and underestimation of the trend evaluation was found to be absent in the SWE data. The results suggested a negative trend and a shift during the study period. The negative trend was absent during neutral years and present during El Niño and La Niña years. The trend magnitudes were maximum during La Niña years followed by those during El Niño years and the entire length of the data. It was also observed that if the presence of negative shift in the SWE was considered, then most of the stations did not show a significant trend before and after the occurrence of a shift. The third task forecasted the streamflow at a regional scale within Sacramento San Joaquin (SSJ) River Basin with largescale climate variables. SSJ is an agricultural watershed located in the drought sensitive region of California. The forecast techniques involved a hybrid statistical framework that eliminates the bias resulting from predefined indices at regional scale. The study was performed for eight unimpaired streamflow stations from 1962 to 2016. First, the Singular Valued Decomposition (SVD) teleconnections of the streamflow corresponding to 500 mbar geopotential height, sea surface temperature, 500 mbar specific humidity (SHUM500), and 500 mbar U-wind (U500) were obtained. Second, the skillful SVD teleconnections were screened non-parametrically. Finally, the screened teleconnections were used as the streamflow predictors in the non-linear regression models (K-nearest neighbor regression and data-driven support vector machine). The SVD results identified new spatial regions that have not been included in existing predefined indices. The nonparametric model indicated the teleconnections of SHUM500 and U500 being better streamflow predictors compared to other climate variables. The regression models were capable to apprehend most of the sustained low flows, proving the model to be effective for drought-affected regions. It was also observed that the forecasting approach showed better forecasting skills with preprocessed large-scale climate variables rather than using the predefined indices. The techniques involved in this task was simple, yet robust in providing qualitative streamflow forecasts that may assist water managers in making policy-related decisions when planning and managing watersheds.

Depuis les années 1950, la pensée divergente est la principale mesure utilisée pour estimer le niveau de créativité d'un individu. si de nombreuses études lui ont été consacrées, peu se sont attachées à la décrire dans sa dimension processuelle. dans la continuité des travaux fondateurs de lubart et de gilhooly, nous développerons avec cette thèse une approche statique et une approche dynamique du processus de pensée divergente. nous proposerons plus spécifiquement une extension du modèle de résonnance émotionnelle de lubart et getz appliquée aux associations originales (pour l'aspect statique), et une modélisation par des chaînes de markov de différentes dimensions de la pensée divergente, comme les stratégies ou les catégories d'idées (pour l'aspect dynamique). / This dissertation is devoted to the study of the variability of creativity evaluations, by focusing ontraining non-experts judges to enhance their expertise. In the theoretical part, various issues related tocreativity, judgment and variability are explored and provide hypotheses for the empirical part. Thefirst series of studies allows justifying the relevance of the application of a simplified model of creativityjudgment inspired by Besemer & O’Quin (1999) to the evaluation by non-experts judges of graphicproducts made by children. The rest of the empirical studies are devoted to the investigation of theeffect of the training on 1) the stability and 2) the expertise of creativity evaluations. The model ofcreative judgments provides the mechanism explaining the effect of the training on the stability andthe expertise of creativity evaluations, by emphasizing the mediating role of stability and expertise ofrelevant predictors evaluation (originality and elaboration) and of the integration function, by which thejudge combines predictors to make a creativity judgment. A final study allows studying the long-termeffect of the training. These results are discussed and future research and applications are suggested.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1986. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Bibliography: leaf 84. / by Robert Gould Gibson. / M.S.

The variety of Kiswahili spoken in Bujumbura (Burundi) is central to the present sociolinguistic and structural analysis. Swahili in Burundi looks back upon a long history: first having been introduced by the German colonial administration, it has turned into a trade language along both the naval and non-naval trade routes between Uvira (DR Congo), Kigoma (Tanzania) and Bujumbura. Initially stigmatized as a language of ruthless urban rioters in the post-conflict era, it has increasingly gained popularity in Bujumbura, and is nowadays considered as one of the languages of Burundi, alongside Kirundi, French and English. Especially in the lively neighborhoods of the big- gest city, where there is a pulsating nightlife, Kiswahili can be heard in many interactions, and of- ten reveals influence from Kirundi, French, English and sometimes even Lingala. Structurally, the Swahili of Bujumbura combines elements from East Coast Swahili (ECS) as spoken in Tanzania and from Congo Swahili regiolects such as Kivu Swahili, and reveals a high degree of variability, depending upon interlocutors, contexts of interaction and communicative purpose. In this contribution, apart from summarizing the sociohistorical background and suggesting sociolinguistic approaches to grasping the high degree of variability in Kiswahili in Burundi, I discuss the most salient phonological and morphosyntactic patterns of variation and explain their situational distribution.

No description available.