2,761 research outputs found
Driver behaviour with adaptive cruise control
No full textThis paper reports on the evaluation of adaptive cruise control (ACC) from a psychological perspective. It was anticipated that ACC would have an effect upon the psychology of driving, i.e. make the driver feel like they have less control, reduce the level of trust in the vehicle, make drivers less situationally aware, but workload might be reduced and driving might be less stressful. Drivers were asked to drive in a driving simulator under manual and ACC conditions. Analysis of variance techniques were used to determine the effects of workload (i.e. amount of traffic) and feedback (i.e. degree of information from the ACC system) on the psychological variables measured (i.e. locus of control, trust, workload, stress, mental models and situation awareness). The results showed that: locus of control and trust were unaffected by ACC, whereas situation awareness, workload and stress were reduced by ACC. Ways of improving situation awareness could include cues to help the driver predict vehicle trajectory and identify conflicts
The effectiveness of police driver training on attitudes, beliefs and skills
No full textThe research undertook an analysis of the effectiveness of police driver training in the
development of appropriate driver attitudes and skills in terms of the objectives of the
training. The research focused upon the Standard/Response course of the Essex
Police. Trainees attitudes and skill, levels were measured at the beginning and after
each phase of training. An assessment of the stability and longevity of attitudes and
skill levels was made 3-10 months after the training. In addition, the influence of
police driving instructors and police recruitment policy on the development of
attitudes was made. From the research, an evaluation has also been made of the
effectiveness of different methods of researching and measuring an individual's
attitude towards a particular behaviour, having used direct, semi-direct, and indirect
methods of attitude measurement
Supplemental_Material – Supplemental material for Health Behavior Change Following Stroke Recommendations for Adapting the Diabetes Prevention Program–Group Lifestyle Balance Program
No full textSupplemental material, Supplemental_Material for Health Behavior Change Following Stroke Recommendations for Adapting the Diabetes Prevention Program–Group Lifestyle Balance Program by Ryan R. Bailey, Jennifer L. Stevenson, Simon Driver and Evan McShan in American Journal of Lifestyle Medicine</p
An In-Vehicle Vision-Based Driver's Drowsiness Detection System
No full text[[abstract]]Many traffic accidents have been reported due to driver’s drowsiness/fatigue. Drowsiness degrades driving performance due to the declinations of visibility, situational awareness and decision-making capability. In this study, a vision-based drowsiness detection and warning system is presented, which attempts to bring to the attention of a driver to his/her own potential drowsiness. The information provided by the system can also be utilized by adaptive systems to manage noncritical operations, such as starting a ventilator, spreading fragrance, turning on a radio, and providing entertainment options. In high drowsiness situation, the system may initiate navigation aids and alert others to the drowsiness of the driver.
The system estimates the fatigue level of a driver based on his/her facial images acquired by a video camera mounted in the front of the vehicle. There are five major steps involved in the system process: preprocessing, facial feature extraction, face tracking, parameter estimation, and reasoning. In the preprocessing step, the input image is sub-sampled for reducing the image size and in turn the processing time. A lighting compensation process is next applied to the reduced image in order to remove the influences of ambient illumination variations. Afterwards, for each image pixel a number of chrominance values are calculated, which are to be used in the next step for detecting facial features.
There are four sub-steps constituting the feature extraction step: skin detection, face localization, eyes and mouth detection, and feature confirmation. To begin, the skin areas are located in the image based on the chrominance values of pixels calculated in the previous step and a predefined skin model. We next search for the face region within the largest skin area. However, the detected face is typically imperfect. Facial feature detection within the imperfect face region is unreliable. We actually look for facial features throughout the entire image. As to the face region, it will later be used to confirm the detected facial features. Once facial features are located, they are tracked over the video sequence until they are missed detecting in a video image. At this moment, the facial feature detection process is revoked again. Although facial feature detection is time consuming, facial feature tracking is fast and reliable.
During facial feature tracking, parameters of facial expression, including percentage of eye closure over time, eye blinking frequency, durations of eye closure, gaze and mouth opening, as well as head orientation, are estimated. The estimated parameters are then utilized in the reasoning step to determine the driver’s drowsiness level. A fuzzy integral technique is employed, which integrates various types of parameter values to arrive at a decision about the drowsiness level of the driver. A number of video sequences of different drivers and illumination conditions have been tested. The results revealed that our system can work reasonably in daytime. We may extend the system in the future work to apply in nighttime. For this, infrared sensors should be included.
Supermassive black holes : the local supermassive black hole mass function
No full textOver recent years there has been an increase of the number of secure supermassive black hole (SMBH) detections. These SMBH measurements have lead astronomers to establish well defined empirical relationships between the SMBH mass and some of the properties of the host galaxy. The number of galaxies with SMBH mass measurements is currently limited to about 100. One approach of expanding the study of the SMBH is to use the empirical relations for estimating M[subscript(bh)] for larger samples of galaxies. The investigation of the SMBH population (or SMBH mass function) for large sample of galaxies in the nearby universe has helped to
constrain the SMBH and the galaxy evolution.
Previous estimates of the SMBH mass function at low redshift were produced mainly by combining the measurements of the galaxy luminosity or velocity function with one of the SMBH scaling relations. In the first part of the thesis I will present an independent construction of the nearby supermassive black hole mass function by applying the optical M[subscript(bh)]–L relation onto the Millennium Galaxy Catalogue (MGC).
Additionally, in the second part I will provide photometric analysis of all UKIDSS galaxies for which SMBH masses have been measured. I will derive composite profiles of brightness, ellipticity and position angles of each galaxy. I will show that the Sérsic function fits the brightness profile of the majority of the elliptical galaxies and the bulge of disk galaxies and I will provide alternative multi-component fits when necessary. Then these photometric parameters will be used for constructing the M[subscript(bh)]–L relation in the near-IR and to investigate the M[subscript(bh)]–n relation.
In the third part I will construct the near-IR SMBH mass function for the Galaxy and Mass Assembly (GAMA) survey. For this purpose I will apply the newly derived M[subscript(bh)]–L relation onto an elliptical subsample of K-band images. The advantage of this SMBH mass function is that during the M[subscript(bh)]–L construction I used the same quality images and techniques used on the GAMA survey. Apart from the M[subscript(bh)]–L relation, the M[subscript(bh)]–sigma relation was used as an alternative approach for a subsample of galaxies for which the velocity dispersions were available. Furthermore, I employed both local SMBH mass functions (MGC & GAMA) for estimating the SMBH mass density at redshift zero and accounted for the dependence of the total SMBH density on the look-back time by comparing with semi-analytic SMBH mass functions. Finally, from the SMBH mass density I estimated the baryon fraction that is locked into SMBHs
THE CREATIVE RATIONALITY AS A KEY DRIVER FOR ENHANCING INNOVATION CAPABILITY
No full textSeveral recent works point out that design is one of the main driver of innovation. Therefore, it is interesting to analyze how design contributes to these last process. The point of view we present in this communication assumes that design is based on a specific rational we called creative rationality. This paper aims at presenting its theoretical roots. Creative rationality derives from Vico's notion of Ingenium. Creative rationality explains the creation of new artifacts and knowledge by knoting in a ingenious way scattered knowledge. It depends on several cognitive, individual and social variables one can identify, measure, and combine in a unified model.Design, creativity, innovation, creative rationality.
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“HEMS” Physical activity health education program for persons with multiple sclerosis
No full textPurpose: To evaluate the effectiveness of Health Education for Persons with Multiple Sclerosis (HEMS) on increasing physical activity (PA) behavior and constructs of Social Cognitive Theory (SCT), such as outcome expectations, self-efficacy, social support, and goal achievement in individuals with Multiple Sclerosis (MS). Results have shown there is little translational research on increasing PA in this population. However, it has been demonstrated that physical activity is linked to improved performance of activities of daily living, reduced severity of secondary conditions related to MS, and overall improvements in quality of life.
Methods: Recruitment for participation in this study was achieved through the existing MS exercise clinic at Oregon State University. 21 participants were initially recruited for the intervention. However, only 13 participants completed the health education program and completed measurable data. The average years of living with MS for participants was 14 years, with 63% displaying relapsing remitting MS, 32% secondary progressive MS, and 5% primary progressive MS. Participants underwent an 8 week baseline assessment, followed by 8 weeks of the intervention, which consisted of health education to increase PA and SCT constructs. To evaluate the effectiveness of the intervention, PA measurements were obtained from pedometers and PA logs while SCT constructs were measured by questionnaires.
Results: Baseline assessment of eighteen participants (15 female; M age 55) showed an average of 4,845 steps completed weekly, moderate self-efficacy (M 6.16/10), moderate to high outcome expectations (M 4.09/5), moderate social support to be active (M 2.99/5), and occasionally set activity goals (M 2.66/5). Post-assessment analysis of the 13 participant’s data showed no significant increases among the SCT constructs. Data showed that individuals completed an average of 3814 steps weekly, reported increased self-efficacy (M 7.98/10; p=0.08), moderate outcome expectations (3.96/5), moderate social support to be active (2.11/5), and occasionally set activity goals (M 2.83/5).
Conclusion: It is believed that providing health education increases the amount of time individuals spend per week participating in PA behavior. At baseline, participants had a low PA and have a margin for improvement in the constructs. We anticipated that participants would increase their time spent participating in PA behavior, setting and achieving goals associated with PA, improve self-efficacy toward PA, and gain social support surrounding PA. However, post-assessment data analysis did not support the expected hypotheses. Evaluation of the current health education material may be required to determine if effective modifications to the curriculum are needed. Potential modifications to consider include; alternative modes of assessment such as new physical activity logs, less frequent assessment to avoid “burn-out” of participants, and an online module for health education delivery in order to reach a larger sample population
Gate Driver Design for 1.2 kV SiC Module with PCB Integrated Rogowski Coil Protection Circuit
No full textWide band-gap materials, e.g., Silicon Carbide (SiC), allow the realization of power semiconductor with superior performance with respect to the traditional Si-based counterparts. On the other hand they require more stringent short-circuit or over-current clearing time to safeguard the device lifetime. This paper focuses on the analysis, design guidelines and practical implementation of a gate drive circuit incorporating fast short-circuit/over-current protection based on the device di/dt measurement through PCB-based auxiliary Rogowski coils. The target power module is a industry standard 62mm packaged 1.2kV SiC MOSFET half-bridge. The gate driver protection features are experimentally tested and the target time for the short circuit clearing was satisfied, with the gate driver effectively turning off the switches within 400 ns during a short-circuit test.Accepted author manuscriptDC systems, Energy conversion & Storag
A Conceptual Model for Persuasive In-Vehicle Technology to Influence Tactical Level Driver Behaviour
No full textPersuasive in-vehicle systems aim to intuitively influence the attitudes and/or behaviour of a driver (i.e. without forcing them). However, the challenge in using these systems in a driving setting, is to maximise the persuasive effect without infringing upon the driver's safety. This paper proposes a conceptual model for driver persuasion at the tactical level (i.e., driver manoeuvring level, such as lane-changing and car-following). The main focus of the conceptual model is to describe how to safely persuade a driver to change his or her behaviour, and how persuasive systems may affect driver behaviour. First, existing conceptual and theoretical models that describe behaviour are discussed, along with their applicability to the driving task. Next, we investigate the persuasive methods used with a focus on the traffic domain. Based on this we develop a conceptual model that incorporates behavioural theories and persuasive methods, and which describes how effective and safe driver persuasion functions. Finally, we apply the model to a case study of a lane-specific advice system that aims to reduce travel time delay and traffic congestion by advising some drivers to change lanes in order to achieve a better distribution of traffic over the motorway lanes.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and PlanningTransport and Plannin
Neural basis for priming of pop-out during visual search revealed with fMRI
No full textMalikovic and Nakayama first showed that visual search efficiency can be influenced by priming effects. Even "pop-out" targets (defined by unique color) are judged quicker if they appear at the same location and/or in the same color as on the preceding trial, in an unpredictable sequence. Here, we studied the potential neural correlates of such priming in human visual search using functional magnetic resonance imaging (fMRI). We found that repeating either the location or the color of a singleton target led to repetition suppression of blood oxygen level-dependent (BOLD) activity in brain regions traditionally linked with attentional control, including bilateral intraparietal sulci. This indicates that the attention system of the human brain can be "primed," in apparent analogy to repetition-suppression effects on activity in other neural systems. For repetition of target color but not location, we also found repetition suppression in inferior temporal areas that may be associated with color processing, whereas repetition of target location led to greater reduction of activation in contralateral inferior parietal and frontal areas, relative to color repetition. The frontal eye fields were also implicated, notably when both target properties (color and location) were repeated together, which also led to further BOLD decreases in anterior fusiform cortex not seen when either property was repeated alone. These findings reveal the neural correlates for priming of pop-out search, including commonalities, differences, and interactions between location and color repetition. fMRI repetition-suppression effects may arise in components of the attention network because these settle into a stable 1. attractor state" more readily when the same target property is repeated than when a different attentional state is required
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