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Sample records for driving simulator study

  1. Influence of roadside infrastructure on driving behavior: driving simulator study

    NARCIS (Netherlands)

    Horst, A.R.A. van der; Ridder, S. de

    2007-01-01

    This paper describes the results of a driving simulator study that focused on the influence of roadside infrastructure on speed choice and lateral placement of car drivers. A review of the RISER detailed accident database revealed that lateral positioning and speed of the vehicle were two of the

  2. Can We Study Autonomous Driving Comfort in Moving-Base Driving Simulators? A Validation Study.

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    Bellem, Hanna; Klüver, Malte; Schrauf, Michael; Schöner, Hans-Peter; Hecht, Heiko; Krems, Josef F

    2017-05-01

    To lay the basis of studying autonomous driving comfort using driving simulators, we assessed the behavioral validity of two moving-base simulator configurations by contrasting them with a test-track setting. With increasing level of automation, driving comfort becomes increasingly important. Simulators provide a safe environment to study perceived comfort in autonomous driving. To date, however, no studies were conducted in relation to comfort in autonomous driving to determine the extent to which results from simulator studies can be transferred to on-road driving conditions. Participants ( N = 72) experienced six differently parameterized lane-change and deceleration maneuvers and subsequently rated the comfort of each scenario. One group of participants experienced the maneuvers on a test-track setting, whereas two other groups experienced them in one of two moving-base simulator configurations. We could demonstrate relative and absolute validity for one of the two simulator configurations. Subsequent analyses revealed that the validity of the simulator highly depends on the parameterization of the motion system. Moving-base simulation can be a useful research tool to study driving comfort in autonomous vehicles. However, our results point at a preference for subunity scaling factors for both lateral and longitudinal motion cues, which might be explained by an underestimation of speed in virtual environments. In line with previous studies, we recommend lateral- and longitudinal-motion scaling factors of approximately 50% to 60% in order to obtain valid results for both active and passive driving tasks.

  3. A Study on Guide Sign Validity in Driving Simulator

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    Wei Zhonghua

    2011-12-01

    Full Text Available The role of guide sign to inform road user about the information of network is important. How to design and locate guide sign to increase traffic operation efficiency is a key point for traffic engineers. Driving simulator is useful devised to study guide sign in the process and system control. For the purpose of studying guide signs using the tool of driving simulator, guide sign's validity in driving simulator was studied. Results of this experiment are the foundation of further study on guide sign. Simulator calibration procedure for guide sign was set up in this study. Legibility distance as measure of performance was used to evaluate the validity of guide sign in driving simulator. Thirty two participants were recruited. Results indicated legibility distance and speed were inversely related with the method of data mining. Legibility distance and text height of guide sign were positive related. When speed is 20km/h, 30km/h, 40km/h, magnifying power of text height is 4.3, 4.1, 3.8, while guide signs are absolute validity in driving simulator.

  4. Study on Computer Numerical Simulation of Driving Static Pressure Pile

    Science.gov (United States)

    Hong, Ji; Xueyi, Yu

    The method to study soil compaction effect caused by driving static pressure pile was proposed with the holes expansion principle analysis. It uses FEM (finite element method) computer numerical simulation to research holes expansion commonly. The expansion of holes radius changes from a0 to 2a0 corresponding to original one from zero to R. Comparing with conclusions obtained from other theories, FEM computer numerical simulation is valid for the analysis of holes expansion. Comparing with the traditional holes expansion principle, it expands the application scope and can be extended to analyze other cross-section forms of holes.

  5. Music mood induction and maintenance while driving : A simulator study

    NARCIS (Netherlands)

    Dijksterhuis, Chris; van der Zwaag, Marjolein; de Waard, Dick; Westerink, Joyce; Brookhuis, Karel; Mulder, Ben L. J. M.

    2010-01-01

    It is common knowledge that mood can influence our everyday behaviour and people often seek to reinforce, or to alter their mood, for example by turning on music. Music listening while driving is a common activity. However, the actual impact of music listening while driving on physical state and

  6. Integration of a driving simulator and a traffic simulator case study: Exploring drivers' behavior in response to variable message signs

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    Mansoureh Jeihani

    2017-12-01

    Full Text Available For the first time, a driving simulator has been integrated with a traffic simulator at the network level to allow subjects to drive in a fairly realistic environment with a realistic traffic flow and density. A 10 mi2 (25 km2 network was developed in a driving simulator and then exported to a traffic simulator. About 30 subjects drove the simulator under different traffic and driving conditions and variable message sign (VMS information, both with and without integration. Route guidance was available for the subjects. The challenges of the integration process are explained and its advantages investigated. The study concluded that traffic density, VMS reliability and compliance behavior are higher when driving and traffic simulators are integrated. To find factors affecting route diversion, researchers applied a binary logistic regression model. The results indicated that the original chosen route, displayed VMS information, subjects' attitude toward VMS information helpfulness, and their level of exposure to VMS affect route diversion. In addition, a multinomial logistic regression model was employed to investigate important factors in route choice. The results revealed that there is a significant correlation with driver route choice behavior and their actual travel time, the need for GPS, VMS exposure and also the designed scenarios. It should be noted that the paper was peer-reviewed by TRB and presented at the TRB Annual Meeting, Washington, D.C., January 2016. Keywords: Integration, Variable message sign, Compliance behavior, Driving simulator, Traffic simulator, Discrete choice analysis

  7. CROSS-STUDY RESEARCH ON UTILITY AND VALIDITY OF DRIVING SIMULATOR FOR DRIVER BEHAVIOR ANALYSIS

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    Michal Matowicki

    2017-12-01

    Full Text Available Driving is one of the most ordinary and universal everyday tasks and, at the same time, one of the most complex and dangerous. It requires a full range of sensory, perceptual, cognitive, and motor functions, all of which can be affected by a wide range of stressors and experience levels. Therefore, exploring of human behaviour while controlling a vehicle is a crucial task in improving traffic safety. Experimental studies can always be conducted with on-road tests, however, using a simulator is safer and more cost-effective. The main goal of this paper is to demonstrate if and under what conditions could a driving simulator provide sufficient results required for a proper study of driver behavior. It discusses its limits and advantages. Overall, the research reviewed in this paper indicates that simulator driving behaviour approximates (relative validity of speed and lateral position of vehicle on road, but does not exactly replicate (absolute validity, on-road driving behaviour.

  8. Comparing Expert and Novice Driving Behavior in a Driving Simulator

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    Hiran B. Ekanayake

    2014-02-01

    Full Text Available This paper presents a study focused on comparing driving behavior of expert and novice drivers in a mid-range driving simulator with the intention of evaluating the validity of driving simulators for driver training. For the investigation, measurements of performance, psychophysiological measurements, and self-reported user experience under different conditions of driving tracks and driving sessions were analyzed. We calculated correlations between quantitative and qualitative measures to enhance the reliability of the findings. The experiment was conducted involving 14 experienced drivers and 17 novice drivers. The results indicate that driving behaviors of expert and novice drivers differ from each other in several ways but it heavily depends on the characteristics of the task. Moreover, our belief is that the analytical framework proposed in this paper can be used as a tool for selecting appropriate driving tasks as well as for evaluating driving performance in driving simulators.

  9. Group Study of Simulated Driving fMRI Data by Multiset Canonical Correlation Analysis.

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    Li, Yi-Ou; Adalı, Tulay; Calhoun, Vince D

    2012-07-01

    In this work, we apply a novel statistical method, multiset canonical correlation analysis (M-CCA), to study a group of functional magnetic resonance imaging (fMRI) datasets acquired during simulated driving task. The M-CCA method jointly decomposes fMRI datasets from different subjects/sessions into brain activation maps and their associated time courses, such that the correlation in each group of estimated activation maps across datasets is maximized. Therefore, the functional activations across all datasets are extracted in the order of consistency across different dataset. On the other hand, M-CCA preserves the uniqueness of the functional maps estimated from each dataset by avoiding concatenation of different datasets in the analysis. Hence, the cross-dataset variation of the functional activations can be used to test the hypothesis of functional-behavioral association. In this work, we study 120 simulated driving fMRI datasets and identify parietal-occipital regions and frontal lobe as the most consistently engaged areas across all the subjects and sessions during simulated driving. The functional-behavioral association study indicates that all the estimated brain activations are significantly correlated with the steering operation during the driving task. M-CCA thus provides a new approach to investigate the complex relationship between the brain functions and multiple behavioral variables, especially in naturalistic tasks as demonstrated by the simulated driving study.

  10. Post and during event effect of cell phone talking and texting on driving performance--a driving simulator study.

    Science.gov (United States)

    Thapa, Raju; Codjoe, Julius; Ishak, Sherif; McCarter, Kevin S

    2015-01-01

    A number of studies have been done in the field of driver distraction, specifically on the use of cell phone for either conversation or texting while driving. Researchers have focused on the driving performance of drivers when they were actually engaged in the task; that is, during the texting or phone conversation event. However, it is still unknown whether the impact of cell phone usages ceases immediately after the end of task. The primary objective of this article is to analyze the post-event effect of cell phone usage (texting and conversation) in order to verify whether the distracting effect lingers after the actual event has ceased. This study utilizes a driving simulator study of 36 participants to test whether a significant decrease in driver performance occurs during cell phone usage and after usage. Surrogate measures used to represent lateral and longitudinal control of the vehicle were standard deviation (SD) of lane position and mean velocity, respectively. RESULTS suggest that there was no significant decrease in driver performance (both lateral and longitudinal control) during and after the cell phone conversation. For the texting event, there were significant decreases in driver performance in both the longitudinal and lateral control of the vehicle during the actual texting task. The diminished longitudinal control ceased immediately after the texting event but the diminished lateral control lingered for an average of 3.38 s. The number of text messages exchanged did not affect the magnitude or duration of the diminished lateral control. The result indicates that the distraction and subsequent elevated crash risk of texting while driving linger even after the texting event has ceased. This finding has safety and policy implications in reducing distracted driving.

  11. A study on optimization of hybrid drive train using Advanced Vehicle Simulator (ADVISOR)

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    Same, Adam; Stipe, Alex; Grossman, David; Park, Jae Wan

    This study investigates the advantages and disadvantages of three hybrid drive train configurations: series, parallel, and "through-the-ground" parallel. Power flow simulations are conducted with the MATLAB/Simulink-based software ADVISOR. These simulations are then applied in an application for the UC Davis SAE Formula Hybrid vehicle. ADVISOR performs simulation calculations for vehicle position using a combined backward/forward method. These simulations are used to study how efficiency and agility are affected by the motor, fuel converter, and hybrid configuration. Three different vehicle models are developed to optimize the drive train of a vehicle for three stages of the SAE Formula Hybrid competition: autocross, endurance, and acceleration. Input cycles are created based on rough estimates of track geometry. The output from these ADVISOR simulations is a series of plots of velocity profile and energy storage State of Charge that provide a good estimate of how the Formula Hybrid vehicle will perform on the given course. The most noticeable discrepancy between the input cycle and the actual velocity profile of the vehicle occurs during deceleration. A weighted ranking system is developed to organize the simulation results and to determine the best drive train configuration for the Formula Hybrid vehicle. Results show that the through-the-ground parallel configuration with front-mounted motors achieves an optimal balance of efficiency, simplicity, and cost. ADVISOR is proven to be a useful tool for vehicle power train design for the SAE Formula Hybrid competition. This vehicle model based on ADVISOR simulation is applicable to various studies concerning performance and efficiency of hybrid drive trains.

  12. A simulator study of the combined effects of alcohol and marihuana on driving behavior--phase II

    Science.gov (United States)

    1983-02-01

    Author's abstract: The study described in this report investigated the effects of alcohol and marihuana, alone and in combination, on driver performance and behavior in a fully interactive driving simulator. The simulator provided the driver a comple...

  13. Designing simulator tools for rail research: the case study of a train driving microworld.

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    Naweed, A; Hockey, G R J; Clarke, S D

    2013-05-01

    The microworld simulator paradigm is well established in the areas of ship-navigation and spaceflight, but has yet to be applied to rail. This paper presents a case study aiming to address this research gap, and describes the development of a train driving microworld as a tool to overcome some common research barriers. A theoretical framework for microworld design is tested and used to explore some key methodological issues and characteristics of train driving, enhancing theory development and providing a useful guideline for the designers of other collision-avoidance systems. A detailed description is given of the ATREIDES (Adaptive Train Research Enhanced Information Display & Environment Simulator) microworld, which simulates the work environment of a train driver in a high-speed passenger train. General indications of the testable driving scenarios that may be simulated are given, and an example of an ATREIDES-based study is presented to illustrate its applied research potential. The article concludes with a review of the design process, considers some strengths and limitations, and explores some future initiatives towards enhancing the systematic study of rail research in the human factors community. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  14. A prospective study of loss of consciousness in epilepsy using virtual reality driving simulation and other video games.

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    Yang, Li; Morland, Thomas B; Schmits, Kristen; Rawson, Elizabeth; Narasimhan, Poojitha; Motelow, Joshua E; Purcaro, Michael J; Peng, Kathy; Raouf, Saned; Desalvo, Matthew N; Oh, Taemin; Wilkerson, Jerome; Bod, Jessica; Srinivasan, Aditya; Kurashvili, Pimen; Anaya, Joseph; Manza, Peter; Danielson, Nathan; Ransom, Christopher B; Huh, Linda; Elrich, Susan; Padin-Rosado, Jose; Naidu, Yamini; Detyniecki, Kamil; Hamid, Hamada; Farooque, Pue; Astur, Robert; Xiao, Bo; Duckrow, Robert B; Blumenfeld, Hal

    2010-07-01

    Patients with epilepsy are at risk of traffic accidents when they have seizures while driving. However, driving is an essential part of normal daily life in many communities, and depriving patients of driving privileges can have profound consequences for their economic and social well-being. In the current study, we collected ictal performance data from a driving simulator and two other video games in patients undergoing continuous video/EEG monitoring. We captured 22 seizures in 13 patients and found that driving impairment during seizures differed in terms of both magnitude and character, depending on the seizure type. Our study documents the feasibility of a prospective study of driving and other behaviors during seizures through the use of computer-based tasks. This methodology may be applied to further describe differential driving impairment in specific types of seizures and to gain data on anatomical networks disrupted in seizures that impair consciousness and driving safety. Copyright 2010 Elsevier Inc. All rights reserved.

  15. Driving simulators for robust comparisons: a case study evaluating road safety engineering treatments.

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    Jamson, Samantha; Lai, Frank; Jamson, Hamish

    2010-05-01

    Road authorities considering the implementation of speed management interventions should have access to the results of scientifically robust evaluations on which to base their decisions. However, studies that evaluate a diverse range of interventions with comparable metrics are rare, with most focussing on one type, for example, types of signage, perceptual countermeasures or physical traffic calming. This paper describes a driving simulator study designed to overcome these constraints. Twenty diverse speed-reducing treatments were developed and tested in urban and rural road environments. Forty participants encountered all the treatments allowing a comparison to be made with their driving behaviour when the treatment was not present. A number of speed parameters were developed to encapsulate the range of effects of the treatments. The results suggest that whilst straight sections of road are difficult to treat, speed reductions can be obtained by increasing risk perception. In contrast, alerting treatments had more effect at junctions, particularly in an urban environment; drivers approaching curves demonstrated improved speed adaptation if the curve radius was highlighted (either implicitly or explicitly). The study highlights how driving simulators can be used to overcome methodological constraints encountered in real-world evaluations of this type. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  16. New concept of direct torque neuro-fuzzy control for induction motor drives. Simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Grabowski, P.Z. [Institute of Control and Industrial Electronics, Warsaw University of Technology, Warsaw (Poland)

    1997-12-31

    This paper presents a new control strategy in the discrete Direct Torque Control (DTC) based on neuro-fuzzy structure. Two schemes are proposed: neuro-fuzzy switching times calculator and neuro-fuzzy incremental controller with space vector modulator. These control strategies guarantee very good dynamic and steady-states characteristics, with very low sampling time and constant switching frequency. The proposed techniques are verified by simulation study of the whole drive system and results are compared with conventional discrete Direct Torque Control method. (orig.) 18 refs.

  17. A driving simulator study : evaluation of vehicle mounted attenuator markings in work zones during different times of the day.

    Science.gov (United States)

    2010-09-01

    This report presents a study of driver perceptions using a driving simulator carried out on the : effectiveness of four markings which vary in striping patterns and color combinations used at the : rear of vehicle mounted attenuators (VMAs) in work z...

  18. PERFORMANCE STUDIES OF INTEGRATED FUZZY LOGIC CONTROLLER FOR BRUSHLESS DC MOTOR DRIVES USING ADVANCED SIMULATION MODEL

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    C. Subba Rami Reddy

    2011-07-01

    Full Text Available This paper introduces an Integrated fuzzy logic controller (IFLC for brushless dc (BLDC motor drives using advanced simulation model and presents a comparative study of performances of PID controller and IFLC. The dynamic characteristics of speed and torque are effectively monitored and analyzed using the proposed model. The aim of IFLC is to obtain improved performance in terms of disturbance rejection or parameter variation than obtained using PID controller. The IFLC is constructed by using Fuzzy logic controller (FLC and PID controller. A performance comparison of the controllers is also given based on the integral of the absolute value of the error (IAE, the integral of the squared error (ISE, the integral of the time-weighted absolute error (ITAE and the integral of the time-weighted squared error (ITSE. The results show the effectiveness of the proposed controller.

  19. Study on driver model for hybrid truck based on driving simulator experimental results

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    Dam Hoang Phuc

    2018-04-01

    Full Text Available In this paper, a proposed car-following driver model taking into account some features of both the compensatory and anticipatory model representing the human pedal operation has been verified by driving simulator experiments with several real drivers. The comparison between computer simulations performed by determined model parameters with the experimental results confirm the correctness of this mathematical driver model and identified model parameters. Then the driver model is joined to a hybrid vehicle dynamics model and the moderate car following maneuver simulations with various driver parameters are conducted to investigate influences of driver parameters on vehicle dynamics response and fuel economy. Finally, major driver parameters involved in the longitudinal control of drivers are clarified. Keywords: Driver model, Driver-vehicle closed-loop system, Car Following, Driving simulator/hybrid electric vehicle (B1

  20. Assessing Risk-Taking in a Driving Simulator Study: Modeling Longitudinal Semi-Continuous Driving Data Using a Two-Part Regression Model with Correlated Random Effects.

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    Tran, Van; Liu, Danping; Pradhan, Anuj K; Li, Kaigang; Bingham, C Raymond; Simons-Morton, Bruce G; Albert, Paul S

    2015-01-01

    Signalized intersection management is a common measure of risky driving in simulator studies. In a recent randomized trial, investigators were interested in whether teenage males exposed to a risk-accepting passenger took more intersection risks in a driving simulator compared with those exposed to a risk-averse peer passenger. Analyses in this trial are complicated by the longitudinal or repeated measures that are semi-continuous with clumping at zero. Specifically, the dependent variable in a randomized trial looking at the effect of risk-accepting versus risk-averse peer passengers on teenage simulator driving is comprised of two components. The discrete component measures whether the teen driver stops for a yellow light, and the continuous component measures the time the teen driver, who does not stop, spends in the intersection during a red light. To convey both components of this measure, we apply a two-part regression with correlated random effects model (CREM), consisting of a logistic regression to model whether the driver stops for a yellow light and a linear regression to model the time spent in the intersection during a red light. These two components are related through the correlation of their random effects. Using this novel analysis, we found that those exposed to a risk-averse passenger have a higher proportion of stopping at yellow lights and a longer mean time in the intersection during a red light when they did not stop at the light compared to those exposed to a risk-accepting passenger, consistent with the study hypotheses and previous analyses. Examining the statistical properties of the CREM approach through simulations, we found that in most situations, the CREM achieves greater power than competing approaches. We also examined whether the treatment effect changes across the length of the drive and provided a sample size recommendation for detecting such phenomenon in subsequent trials. Our findings suggest that CREM provides an efficient

  1. Effects of Lane Width, Lane Position and Edge Shoulder Width on Driving Behavior in Underground Urban Expressways: A Driving Simulator Study

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    Shuo Liu

    2016-10-01

    Full Text Available This study tested the effects of lane width, lane position and edge shoulder width on driving behavior for a three-lane underground urban expressway. A driving simulator was used with 24 volunteer test subjects. Five lane widths (2.85, 3.00, 3.25, 3.50, and 3.75 m and three shoulder widths (0.50, 0.75, and 1.00 m were studied. Driving speed, lane deviation and subjective perception of driving behavior were collected as performance measures. The results show that lane and shoulder width have significant effects on driving speed. Average driving speed increases from 60.01 km/h in the narrowest lane to 88.05 km/h in the widest lane. While both narrower lanes and shoulders result in reduced speed and lateral lane deviation, the effect of lane width is greater than that of shoulder width. When the lane and shoulder are narrow, drivers in the left or right lane tend to shy away from the tunnel wall, even encroaching into the neighboring middle lane. As the lane or shoulder gets wider, drivers tend to stay in the middle of the lane. An interesting finding is that although few participants acknowledged that lane position had any great bearing on their driving behaviors, the observed driving speed is statistically higher in the left lane than in the other two lanes when the lane width is narrow (in 2.85, 3 and 3.25 m lanes. These findings provided support for amending the current design specifications of urban underground roads, such as the relationship between design speed and lane width, speed limit, and combination form of lanes.

  2. The Effect of High and Low Antiepileptic Drug Dosage on Simulated Driving Performance in Person's with Seizures: A Pilot Study

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    Alexander M. Crizzle

    2015-10-01

    Full Text Available Background: Prior studies examining driving performance have not examined the effects of antiepileptic drugs (AED’s or their dosages in persons with epilepsy. AED’s are the primary form of treatment to control seizures, but they are shown to affect cognition, attention, and vision, all which may impair driving. The purpose of this study was to describe the characteristics of high and low AED dosages on simulated driving performance in persons with seizures. Method: Patients (N = 11; mean age 42.1 ± 6.3; 55% female; 100% Caucasian were recruited from the Epilepsy Monitoring Unit and had their driving assessed on a simulator. Results: No differences emerged in total or specific types of driving errors between high and low AED dosages. However, high AED drug dosage was significantly associated with errors of lane maintenance (r = .67, p < .05 and gap acceptance (r = .66, p < .05. The findings suggest that higher AED dosages may adversely affect driving performance, irrespective of having a diagnosis of epilepsy, conversion disorder, or other medical conditions. Conclusion: Future studies with larger samples are required to examine whether AED dosage or seizure focus alone can impair driving performance in persons with and without seizures.

  3. Detection of microsleep events in a car driving simulation study using electrocardiographic features

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    Lenis Gustavo

    2016-09-01

    Full Text Available Microsleep events (MSE are short intrusions of sleep under the demand of sustained attention. They can impose a major threat to safety while driving a car and are considered one of the most significant causes of traffic accidents. Driver’s fatigue and MSE account for up to 20% of all car crashes in Europe and at least 100,000 accidents in the US every year. Unfortunately, there is not a standardized test developed to quantify the degree of vigilance of a driver. To account for this problem, different approaches based on biosignal analysis have been studied in the past. In this paper, we investigate an electrocardiographic-based detection of MSE using morphological and rhythmical features. 14 records from a car driving simulation study with a high incidence of MSE were analyzed and the behavior of the ECG features before and after an MSE in relation to reference baseline values (without drowsiness were investigated. The results show that MSE cannot be detected (or predicted using only the ECG. However, in the presence of MSE, the rhythmical and morphological features were observed to be significantly different than the ones calculated for the reference signal without sleepiness. In particular, when MSE were present, the heart rate diminished while the heart rate variability increased. Time distances between P wave and R peak, and R peak and T wave and their dispersion increased also. This demonstrates a noticeable change of the autonomous regulation of the heart. In future, the ECG parameter could be used as a surrogate measure of fatigue.

  4. Simulation Study on Hot Stamping Forming of the Drive Axle Housing of Heavy Truck

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    Dai, Yongqian; Ji, Jianyi; Luo, Lingjiang

    2018-01-01

    Aiming at the national energy-saving and emission reduction requirements, lightweight of the heavy truck is imminent. Several parameters related to hot stamping forming process of heavy truck drive axle housing are studied in this paper. The results show that the existing two-step stamping with air cooling molding process, can be improved into one-step hot stamping process. The initial temperature of the blank, stamping speed and other parameters related to the forming process were optimized. The results provides useful reference for improving the existing forming process of the drive axle housing, and it is also helpful for realizing the lightweight design of drive axle housing.

  5. Driving with Intuition: A Preregistered Study about the EEG Anticipation of Simulated Random Car Accidents.

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    Gian Marco Duma

    Full Text Available The study of neural pre-stimulus or "anticipatory" activity opened a new window for understanding how the brain actively constructs the forthcoming reality. Usually, experimental paradigms designed to study anticipatory activity make use of stimuli. The purpose of the present study is to expand the study of neural anticipatory activity upon the temporal occurrence of dichotomic, statistically unpredictable (random stimuli within an ecological experimental paradigm. To this purpose, we used a simplified driving simulation including two possible, randomly-presented trial types: a car crash end trial and a no car crash end trial. Event Related Potentials (ERP were extracted -3,000 ms before stimulus onset. We identified a fronto-central negativity starting around 1,000 ms before car crash presentation. By contrast, a whole-scalp distributed positivity characterized the anticipatory activity observed before the end of the trial in the no car crash end condition. The present data are in line with the hypothesis that the brain may also anticipate dichotomic, statistically unpredictable stimuli, relaying onto different pre-stimulus ERP activity. Possible integration with car-smart-systems is also suggested.

  6. A pilot study to evaluate simulated driving performance and cognitive function in healthy subjects and patients with restless legs syndrome

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    Chen D

    2013-10-01

    Full Text Available Dan Chen,1 Paula Shaw,2 Daniel M Canafax,1,3 James Catesby Ware4 1XenoPort, Inc., Santa Clara, CA, USA; 2Charles River Northwest, Tacoma, WA, USA; 3Theravance Inc., South San Francisco, CA, USA; 4Division of Sleep Medicine, Eastern Virginia Medical School, Norfolk, VA, USA Objective: Symptoms of restless legs syndrome (RLS usually occur during the evening and night time, resulting in disrupted sleep and subsequent daytime fatigue. This study compared simulated driving performance, alertness, and cognitive function between healthy subjects and patients with a diagnosis of RLS. Methods: Fifteen healthy subjects and 15 untreated RLS subjects were enrolled and completed two driving tests. The first test occurred at 4 PM followed by the second test at 8 AM the next morning. Outcome measures included lane position variability (LPV, speed variability, frequency of simulated crashes (off-road events or collision, and brake reaction time. Other assessments included visual analog scale (VAS of alertness and the Brief Assessment of Cognition (BAC. Results: Overall, RLS patients and healthy subjects performed similarly on driving assessments. Two subjects within each group experienced off-road events. RLS patients had less alertness on the VAS than healthy subjects before and after driving assessments. Both groups scored similarly on the cognitive function assessments. Conclusion: Despite reported diminished alertness, RLS patients did not demonstrate impairment in driving or cognitive performance. Keywords: restless legs syndrome, simulated driving performance, cognitive function

  7. Ambient light based interaction concept for an integrative driver assistance system – a driving simulator study

    OpenAIRE

    Dziennus, Marc; Kelsch, Johann; Schieben, Anna

    2015-01-01

    For today’s vehicles several advanced driver assistance systems are on the market supporting the driver in critical driving situations or automating parts of the driving tasks. In the future there will be even more. Currently, those assistance systems do not use a common and consistent interaction strategy to communicate with the driver. The goal of the present study is to present and to evaluate a concept using ambient light for presenting information of different assistance systems in an in...

  8. Driving Performance Under Alcohol in Simulated Representative Driving Tasks

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    Kenntner-Mabiala, Ramona; Kaussner, Yvonne; Jagiellowicz-Kaufmann, Monika; Hoffmann, Sonja; Krüger, Hans-Peter

    2015-01-01

    Abstract Comparing drug-induced driving impairments with the effects of benchmark blood alcohol concentrations (BACs) is an approved approach to determine the clinical relevance of findings for traffic safety. The present study aimed to collect alcohol calibration data to validate findings of clinical trials that were derived from a representative test course in a dynamic driving simulator. The driving performance of 24 healthy volunteers under placebo and with 0.05% and 0.08% BACs was measured in a double-blind, randomized, crossover design. Trained investigators assessed the subjects’ driving performance and registered their driving errors. Various driving parameters that were recorded during the simulation were also analyzed. Generally, the participants performed worse on the test course (P the investigators’ assessment) under the influence of alcohol. Consistent with the relevant literature, lane-keeping performance parameters were sensitive to the investigated BACs. There were significant differences between the alcohol and placebo conditions in most of the parameters analyzed. However, the total number of errors was the only parameter discriminating significantly between all three BAC conditions. In conclusion, data show that the present experimental setup is suitable for future psychopharmacological research. Thereby, for each drug to be investigated, we recommend to assess a profile of various parameters that address different levels of driving. On the basis of this performance profile, the total number of driving errors is recommended as the primary endpoint. However, this overall endpoint should be completed by a specifically sensitive parameter that is chosen depending on the effect known to be induced by the tested drug. PMID:25689289

  9. Driving Simulator Study of Effect of Inside Shoulder on Vehicle Operation

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    Han Ding

    2015-02-01

    Full Text Available According to the Chinese Design Specification for Highway Alignment (JTG D20-2006, eight-lane expressways should be paved with an inside shoulder of 2.5 m; however, this regulation is rarely obeyed in engineering practice. On the basis of driving simulator experiment, this research examined the impacts of inside shoulder on vehicle operation with and without the speed limitation. A virtual scenario, consisting of five expressways with different inside shoulder widths, was created and displayed in driving simulator, and vehicle operational data—speed and lane position—were recorded. Authors used analysis of variance (ANOVA and contrast analysis to examine whether inside shoulder width had statistically significant effects on travel speed and lane position. Analytical results indicated that there is a kind of quadratic relationship between inside shoulder width and driver's speed choice, while driver's speed choice is not significantly affected by inside shoulder width. What is more, inside shoulder width has statistically significant effects on vehicle's lane positions, and vehicle's lane position is negatively correlated to inside shoulder width. Specifically, the vehicle can be maintained at the center of lane when the inside shoulder width is 2.5 m.

  10. Can Youth with Autism Spectrum Disorder Use Virtual Reality Driving Simulation Training to Evaluate and Improve Driving Performance? An Exploratory Study

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    Cox, Daniel J.; Brown, Timothy; Ross, Veerle; Moncrief, Matthew; Schmitt, Rose; Gaffney, Gary; Reeve, Ron

    2017-01-01

    Investigate how novice drivers with autism spectrum disorder (ASD) differ from experienced drivers and whether virtual reality driving simulation training (VRDST) improves ASD driving performance. 51 novice ASD drivers (mean age 17.96 years, 78% male) were randomized to routine training (RT) or one of three types of VRDST (8-12 sessions). All…

  11. Driving simulators for occupational therapy screening, assessment, and intervention.

    Science.gov (United States)

    Classen, Sherrilene; Brooks, Johnell

    2014-04-01

    Simulation technology provides safe, objective, and repeatable performance measures pertaining to operational (e.g., avoiding a collision) or tactical (e.g., lane maintenance) driver behaviors. Many occupational therapy researchers and others are using driving simulators to test a variety of applications across diverse populations. A growing body of literature provides support for associations between simulated driving and actual on-road driving. One limitation of simulator technology is the occurrence of simulator sickness, but management strategies exist to curtail or mitigate its onset. Based on the literature review and a consensus process, five consensus statements are presented to support the use of driving simulation technology among occupational therapy practitioners. The evidence suggests that by using driving simulators occupational therapy practitioners may detect underlying impairments in driving performance, identify driving errors in at-risk drivers; differentiate between driving performance of impaired and healthy controls groups; show driving errors with absolute and relative validity compared to on-road studies; and mitigate the onset of simulator sickness. Much progress has been made among occupational therapy researchers and practitioners in the use of driving simulation technology; however, empirical support is needed to further justify the use of driving simulators in clinical practice settings as a valid, reliable, clinical useful, and cost effective tool for driving assessment and intervention.

  12. Simulating Study on Drive System Performance for Hybrid Electric Bus Based on ADVISOR

    Directory of Open Access Journals (Sweden)

    Wang Xingxing

    2017-01-01

    Full Text Available Hybrid electric bus has a number of advantages when compared with ordinary passenger cars, but in the dynamic matching and the vehicle performance are difficult to detect, thus limits its development process. In this paper, combined with the actual models, the hybrid electric bus module parameters were modified in the software of ADVISOR (Advanced Vehicle Simulator, main including: module of the vehicle, the wheel module, motor module, a battery module and engine module, three kinds of bus models for A, B and C were established, and the related performance that need to be analyzed was set up, such as acceleration, gradability, emissions and energy utilization and so on, in order to ensure the vehicle running in the same environment and convenient for comparison, a fixed vehicle driving cycles was chose, then the simulation results was analyzed, and the various performance was compared with the dynamic indicators and economic indicators which determined by referencing of traditional city bus standard and each other, and finally, the performance optimal model of B was chose out which can meet the demand, its related performance parameters of the simulation results are as follows: the best gradability is 26%, maximum speed is 72.7km/h, maximum acceleration is 1.7m/s2, 0~50km/h acceleration time is 9.5s and fuel consumption is 25L/km.

  13. Simulation of linear Switched Reluctance Motor drives

    OpenAIRE

    Garcia Amoros, Jordi; Blanqué Molina, Balduino; Andrada Gascón, Pedro

    2011-01-01

    This paper presents a simulation model of linear switched reluctance motor drives. A Matlab-Simulink environment coupled with finite element analysis is used to perform the simulations. Experimental and simulation results for a double sided linear switched motor drive prototype are reported and compared to verify the simulation model.

  14. Effects of platooning on signal-detection performance, workload, and stress: A driving simulator study.

    Science.gov (United States)

    Heikoop, Daniël D; de Winter, Joost C F; van Arem, Bart; Stanton, Neville A

    2017-04-01

    Platooning, whereby automated vehicles travel closely together in a group, is attractive in terms of safety and efficiency. However, concerns exist about the psychological state of the platooning driver, who is exempted from direct control, yet remains responsible for monitoring the outside environment to detect potential threats. By means of a driving simulator experiment, we investigated the effects on recorded and self-reported measures of workload and stress for three task-instruction conditions: (1) No Task, in which participants had to monitor the road, (2) Voluntary Task, in which participants could do whatever they wanted, and (3) Detection Task, in which participants had to detect red cars. Twenty-two participants performed three 40-min runs in a constant-speed platoon, one condition per run in counterbalanced order. Contrary to some classic literature suggesting that humans are poor monitors, in the Detection Task condition participants attained a high mean detection rate (94.7%) and a low mean false alarm rate (0.8%). Results of the Dundee Stress State Questionnaire indicated that automated platooning was less distressing in the Voluntary Task than in the Detection Task and No Task conditions. In terms of heart rate variability, the Voluntary Task condition yielded a lower power in the low-frequency range relative to the high-frequency range (LF/HF ratio) than the Detection Task condition. Moreover, a strong time-on-task effect was found, whereby the mean heart rate dropped from the first to the third run. In conclusion, participants are able to remain attentive for a prolonged platooning drive, and the type of monitoring task has effects on the driver's psychological state. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. How do ankle braces affect braking performance? An experimental driving simulation study with healthy volunteers.

    Science.gov (United States)

    Hofmann, Ulf Krister; Thumm, Stefan; Jordan, Maurice; Mittag, Falk; Rondak, Ina-Christine; Ipach, Ingmar

    2015-11-01

    Fitness to drive a car has been investigated increasingly over recent years. However, most research has focussed on perioperative driving performance, and few data are available on how orthoses influence the ability to perform an emergency stop. This study investigated the effect of 4 common ankle braces (Kallassy, CaligaLoc, Air-Stirrup, ASO) on reaction time, foot transfer time (together: brake response time) and brake force. The hypothesis was that wearing these braces on the right ankle impairs braking performance, specifically by increasing foot transfer time, but also by altering brake force. A car cabin was set up with measurement equipment to register reaction time, foot transfer time, brake response time and brake force under realistic spatial constraints. A crossover repeated measures design was used to test 30 healthy volunteers with and without each of the braces. All 4 braces resulted in statistically significantly increased foot transfer time (p Brake force was not statistically significantly impaired. This study demonstrates that ankle braces lead to impaired braking performance. Depending on the type of brace, a stopping distance increase of more than 1 m at 100 km/h can be expected.

  16. Educational Biofeedback Driving Simulator as a Drink-Driving Prevention Strategy.

    Science.gov (United States)

    Howat, Peter; And Others

    1991-01-01

    Used experimental driving simulator as basis for strategy to encourage a reduction in drunk driving prevalence using adult male subjects (n=36) who participated in a study group and controls (n=36). Results indicated study group subjects significantly decreased their drunk driving compared to the control group. (ABL)

  17. In-car usage-based insurance feedback strategies. A comparative driving simulator study.

    Science.gov (United States)

    Dijksterhuis, Chris; Lewis-Evans, Ben; Jelijs, Bart; Tucha, Oliver; de Waard, Dick; Brookhuis, Karel

    2016-09-01

    Usage-Based Insurances (UBI) enable policyholders to actively reduce the impact of vehicle insurance costs by adopting a safer and more eco-friendly driving style. UBI is especially relevant for younger drivers, who are a high-risk population. The effectiveness of UBI should be enhanced by providing in-car feedback optimised for individual drivers. Thirty young novice drivers were therefore invited to complete six experimental drives with an in-car interface that provided real-time information on rewards gained, their driving behaviour and the speed limit. Reward size was either displayed directly in euro, indirectly as a relatively large amount of credits, or as a percentage of the maximum available bonus. Also, interfaces were investigated that provided partial information to reduce the potential for driver distraction. Compared to a control no-UBI condition, behaviour improved similarly across interfaces, suggesting that interface personalisation after an initial familiarisation period could be feasible without compromising feedback effectiveness. Practitioner Summary: User experiences and effects on driving behaviour of six in-car interfaces were compared. The interface provided information on driving behaviour and rewards in a UBI setting. Results suggest that some personalisation of interfaces may be an option after an initial familiarisation period as driving behaviour improved similarly across interfaces.

  18. Exploring travelers' behavior in response to dynamic message signs (DMS) using a driving simulator.

    Science.gov (United States)

    2013-10-01

    This research studies the effectiveness of a dynamic message sign (DMS) using a driving : simulator. Over 100 subjects from different socio-economic and age groups were recruited to : drive the simulator under different traffic and driving conditions...

  19. Exploring travelers' behavior in response to dynamic message signs (DMS) using a driving simulator : final report.

    Science.gov (United States)

    2013-10-01

    This research studies the effectiveness of a dynamic message sign (DMS) using a driving : simulator. Over 100 subjects from different socio-economic and age groups were recruited to : drive the simulator under different traffic and driving conditions...

  20. The Drive-Wise Project: Driving Simulator Training increases real driving performance in healthy older drivers

    Directory of Open Access Journals (Sweden)

    Gianclaudio eCasutt

    2014-05-01

    Full Text Available Background: Age-related cognitive decline is often associated with unsafe driving behavior. We hypothesized that 10 active training sessions in a driving simulator increase cognitive and on-road driving performance. In addition, driving simulator training should outperform cognitive training.Methods: Ninety-one healthy active drivers (62 – 87 years were randomly assigned to either (1 a driving simulator training group, (2 an attention training group (vigilance and selective attention, or (3 a control group. The main outcome variables were on-road driving and cognitive performance. Seventy-seven participants (85% completed the training and were included in the analyses. Training gains were analyzed using a multiple regression analysis with planned comparisons.Results: The driving simulator training group showed an improvement in on-road driving performance compared to the attention training group. In addition, both training groups increased cognitive performance compared to the control group. Conclusion: Driving simulator training offers the potential to enhance driving skills in older drivers. Compared to the attention training, the simulator training seems to be a more powerful program for increasing older drivers’ safety on the road.

  1. Simulation and Analysis of Chain Drive Systems

    DEFF Research Database (Denmark)

    Pedersen, Sine Leergaard

    The subject of this thesis is simulation and analysis of large roller chain drive systems, such as e.g. used in marine diesel engines. The aim of developing a chain drive simulation program is to analyse dynamic phenomena of chain drive systems and investigate different design changes...... to the systems, in order to remove unwanted phenomena. Such a computer program can, when properly validated, be used as an alternative to or in combination with physical experiments. Prior investigations in this area have been done with a focus on smaller chains in high speed chain drives. For large low speed...... systems other phenomena occur and therefore, a specific model of the marine engine chain drive is of interest. The research objective of the work presented in this thesis is to contribute with a novel theoretical basis for the analysis of chain drive systems, by posing and validating different...

  2. Augmented Reality Head-Up-Display for Advanced Driver Assistance System: A Driving Simulation Study

    OpenAIRE

    HALIT, Lynda; KEMENY, Andras; GARBAYA, Samir; MERIENNE, Frédéric; MICHELIN, Sylvain; ALBAUT, Valentin

    2014-01-01

    Research and technological advance in the field of Augmented Reality (AR) is growing rapidly (Mas, 2011). One of the new application domains is the automobile industry, linked to the necessary men machine aspects of Advanced Driving Assistance Systems (ADAS). Relevant road traffic as well as useful navigation or path planning information may be displayed using partially or totally the windshield surface thanks to these emerging technologies. However, the way road traffic, signs or vehicle inf...

  3. Augmented Reality Head-Up-Display for Advanced Driver Assistance System: A Driving Simulation Study

    OpenAIRE

    HALIT , Lynda; Kemeny , Andras; Mohellebi , Hakim; GARBAYA , Samir; Merienne , Frédéric; Michelin , Sylvain; ALBAUT , Valentin

    2014-01-01

    International audience; Research and technological advance in the field of Augmented Reality (AR) is growing rapidly (Mas, 2011). One of the new application domains is the automobile industry, linked to the necessary men machine aspects of Advanced Driving Assistance Systems (ADAS). Relevant road traffic as well as useful navigation or path planning information may be displayed using partially or totally the windshield surface thanks to these emerging technologies. However, the way road traff...

  4. Immobilisation of the knee and ankle and its impact on drivers' braking times: a driving simulator study.

    Science.gov (United States)

    Waton, A; Kakwani, R; Cooke, N J; Litchfield, D; Kok, D; Middleton, H; Irwin, L

    2011-07-01

    The purpose of this study was to investigate the effects of right leg restriction at the knee, ankle or both, on a driver's braking times. Previous studies have not investigated the effects of knee restriction on braking performance. A total of 23 healthy drivers performed a series of emergency braking tests in a driving simulator in either an above-knee plaster cast, a below-knee cast, or in a knee brace with an increasing range of restriction. The study showed that total braking reaction time was significantly longer when wearing an above-knee plaster cast, a below-knee plaster cast or a knee brace fixed at 0°, compared with braking normally (p brake accounted for some of the increase in the total braking reaction time. Unexpectedly, thinking time also increased with the level of restriction (p braking time with an above-knee plaster cast in this study would increase the stopping distance at 30 miles per hour by almost 3 m. These results suggest that all patients wearing any lower-limb plaster cast or knee brace are significantly impaired in their ability to perform an emergency stop. We suggest changes to the legislation to prevent patients from driving with lower-limb plaster casts or knee braces.

  5. Obstacle avoidance, visual detection performance, and eye-scanning behavior of glaucoma patients in a driving simulator: a preliminary study.

    Directory of Open Access Journals (Sweden)

    Rocío Prado Vega

    Full Text Available The objective of this study was to evaluate differences in driving performance, visual detection performance, and eye-scanning behavior between glaucoma patients and control participants without glaucoma. Glaucoma patients (n = 23 and control participants (n = 12 completed four 5-min driving sessions in a simulator. The participants were instructed to maintain the car in the right lane of a two-lane highway while their speed was automatically maintained at 100 km/h. Additional tasks per session were: Session 1: none, Session 2: verbalization of projected letters, Session 3: avoidance of static obstacles, and Session 4: combined letter verbalization and avoidance of static obstacles. Eye-scanning behavior was recorded with an eye-tracker. Results showed no statistically significant differences between patients and control participants for lane keeping, obstacle avoidance, and eye-scanning behavior. Steering activity, number of missed letters, and letter reaction time were significantly higher for glaucoma patients than for control participants. In conclusion, glaucoma patients were able to avoid objects and maintain a nominal lane keeping performance, but applied more steering input than control participants, and were more likely than control participants to miss peripherally projected stimuli. The eye-tracking results suggest that glaucoma patients did not use extra visual search to compensate for their visual field loss. Limitations of the study, such as small sample size, are discussed.

  6. Determination of pre-impact occupant postures and analysis of consequences on injury outcome. Part I: a driving simulator study.

    Science.gov (United States)

    Hault-Dubrulle, Audrey; Robache, Frederic; Pacaux, Marie-Pierre; Morvan, Herve

    2011-01-01

    This paper considers pre-impact vehicle maneuvers and analyzes the resulting driver motion from their comfort seating position. Part I of this work consists of analyzing the driver behavior during a crash. The study is conducted using the LAMIH driving simulator and involves 76 participants. The emergency situation is created by a truck emerging from behind a tractor on the opposite side of the road and tearing along the participant. The driver positioning throughout the simulation is recorded via five video cameras allowing view of the front scene, the driver face, feet and pedals, hands on the steering wheel and global lateral view. Data related to braking force, seat pressure, muscular activity for major groups of muscles and actions on the steering wheel are also collected. The typical response to this type of emergency event is to brace rearward into the seat and to straighten the arms against the steering wheel, or, to swerve to attempt to avoid the impacting vehicle. While turning the steering wheel, the forearm can be directly positioned on the airbag module at time of crash which represents a potential injurious situation. These positions are used in Part II to determine scenario of positions for numerical simulation of a frontal collision. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Obstacle avoidance, visual detection performance, and eye-scanning behavior of glaucoma patients in a driving simulator : A preliminary study

    NARCIS (Netherlands)

    Prado Vega, R.; Van Leeuwen, P.M.; Rendon Velez, E.; Lemij, H.G.; De Winter, J.C.

    2013-01-01

    The objective of this study was to evaluate differences in driving performance, visual detection performance, and eye-scanning behavior between glaucoma patients and control participants without glaucoma. Glaucoma patients (n = 23) and control participants (n = 12) completed four 5-min driving

  8. Chinese carless young drivers' self-reported driving behavior and simulated driving performance.

    Science.gov (United States)

    Zhang, Qian; Jiang, Zuhua; Zheng, Dongpeng; Man, Dong; Xu, Xunnan

    2013-01-01

    Carless young drivers refers to those drivers aged between 18 and 25 years who have a driver's license but seldom have opportunities to practice their driving skills because they do not have their own cars. Due to China's lower private car ownership, many young drivers become carless young drivers after licensure, and the safety issue associated with them has raised great concern in China. This study aims to provide initial insight into the self-reported driving behaviors and simulated driving performance of Chinese carless young drivers. Thirty-three carless young drivers and 32 young drivers with their own cars (as a comparison group) participated in this study. A modified Driver Behavior Questionnaire (DBQ) with a 4-factor structure (errors, violations, attention lapses, and memory lapses) was used to study carless young drivers' self-reported driving behaviors. A simulated driving experiment using a low-cost, fixed-base driving simulator was conducted to measure their simulated driving performance (errors, violations, attention lapses, driving maintenance, reaction time, and accidents). Self-reported DBQ outcomes showed that carless young drivers reported similar errors, more attention lapses, fewer memory lapses, and significantly fewer violation behaviors relative to young drivers with their own cars, whereas simulated driving results revealed that they committed significantly more errors, attention lapses, and violation behaviors than the comparison group. Carless young drivers had a lower ability to maintain the stability of speed and lane position, drove more cautiously approaching and passing through red traffic lights, and committed more accidents during simulated driving. A tendency to speed was not found among carless young drivers; their average speed and speeding frequency were all much lower than that of the comparison group. Lifetime mileage was the only significant predictor of carless young drivers' self-reported violations, simulated violations

  9. Driving Competence in Mild Dementia with Lewy Bodies: In Search of Cognitive Predictors Using Driving Simulation

    Directory of Open Access Journals (Sweden)

    Stephanie Yamin

    2015-01-01

    Full Text Available Driving is a multifactorial behaviour drawing on multiple cognitive, sensory, and physical systems. Dementia is a progressive and degenerative neurological condition that impacts the cognitive processes necessary for safe driving. While a number of studies have examined driving among individuals with Alzheimer’s disease, less is known about the impact of Dementia with Lewy Bodies (DLB on driving safety. The present study compared simulated driving performance of 15 older drivers with mild DLB with that of 21 neurologically healthy control drivers. DLB drivers showed poorer performance on all indicators of simulated driving including an increased number of collisions in the simulator and poorer composite indicators of overall driving performance. A measure of global cognitive function (i.e., the Mini Mental State Exam was found to be related to the overall driving performance. In addition, measures of attention (i.e., Useful Field of View, UFOV and space processing (Visual Object and Space Perception, VOSP, Test correlated significantly with a rater’s assessment of driving performance.

  10. Assessment of driving-related performance in chronic whiplash using an advanced driving simulator.

    Science.gov (United States)

    Takasaki, Hiroshi; Treleaven, Julia; Johnston, Venerina; Rakotonirainy, Andry; Haines, Andrew; Jull, Gwendolen

    2013-11-01

    Driving is often nominated as problematic by individuals with chronic whiplash associated disorders (WAD), yet driving-related performance has not been evaluated objectively. The purpose of this study was to test driving-related performance in persons with chronic WAD against healthy controls of similar age, gender and driving experience to determine if driving-related performance in the WAD group was sufficiently impaired to recommend fitness to drive assessment. Driving-related performance was assessed using an advanced driving simulator during three driving scenarios; freeway, residential and a central business district (CBD). Total driving duration was approximately 15min. Five driving tasks which could cause a collision (critical events) were included in the scenarios. In addition, the effect of divided attention (identify red dots projected onto side or rear view mirrors) was assessed three times in each scenario. Driving performance was measured using the simulator performance index (SPI) which is calculated from 12 measures. z-Scores for all SPI measures were calculated for each WAD subject based on mean values of the control subjects. The z-scores were then averaged for the WAD group. A z-score of ≤-2 indicated a driving failing grade in the simulator. The number of collisions over the five critical events was compared between the WAD and control groups as was reaction time and missed response ratio in identifying the red dots. Seventeen WAD and 26 control subjects commenced the driving assessment. Demographic data were comparable between the groups. All subjects completed the freeway scenario but four withdrew during the residential and eight during the CBD scenario because of motion sickness. All scenarios were completed by 14 WAD and 17 control subjects. Mean z-scores for the SPI over the three scenarios was statistically lower in the WAD group (-0.3±0.3; P0.05). Assessment of driving in an advanced driving simulator for approximately 15min revealed

  11. In Patients With Cirrhosis, Driving Simulator Performance Is Associated With Real-life Driving.

    Science.gov (United States)

    Lauridsen, Mette M; Thacker, Leroy R; White, Melanie B; Unser, Ariel; Sterling, Richard K; Stravitz, Richard T; Matherly, Scott; Puri, Puneet; Sanyal, Arun J; Gavis, Edith A; Luketic, Velimir; Siddiqui, Muhammad S; Heuman, Douglas M; Fuchs, Michael; Bajaj, Jasmohan S

    2016-05-01

    Minimal hepatic encephalopathy (MHE) has been linked to higher real-life rates of automobile crashes and poor performance in driving simulation studies, but the link between driving simulator performance and real-life automobile crashes has not been clearly established. Furthermore, not all patients with MHE are unsafe drivers, but it is unclear how to distinguish them from unsafe drivers. We investigated the link between performance on driving simulators and real-life automobile accidents and traffic violations. We also aimed to identify features of unsafe drivers with cirrhosis and evaluated changes in simulated driving skills and MHE status after 1 year. We performed a study of outpatients with cirrhosis (n = 205; median 55 years old; median model for end-stage liver disease score, 9.5; none with overt hepatic encephalopathy or alcohol or illicit drug use within previous 6 months) seen at the Virginia Commonwealth University and McGuire Veterans Administration Medical Center, from November 2008 through April 2014. All participants were given paper-pencil tests to diagnose MHE (98 had MHE; 48%), and 163 patients completed a standardized driving simulation. Data were collected on traffic violations and automobile accidents from the Virginia Department of Motor Vehicles and from participants' self-assessments when they entered the study, and from 73 participants 1 year later. Participants also completed a questionnaire about alcohol use and cessation patterns. The driving simulator measured crashes, run-time, road center and edge excursions, and illegal turns during navigation; before and after each driving simulation session, patients were asked to rate their overall driving skills. Drivers were classified as safe or unsafe based on crashes and violations reported on official driving records; simulation results were compared with real-life driving records. Multivariable regression analyses of real-life crashes and violations was performed using data on

  12. Driver's behavioural changes with new intelligent transport system interventions at railway level crossings--A driving simulator study.

    Science.gov (United States)

    Larue, Grégoire S; Kim, Inhi; Rakotonirainy, Andry; Haworth, Narelle L; Ferreira, Luis

    2015-08-01

    Improving safety at railway level crossings is an important issue for the Australian transport system. Governments, the rail industry and road organisations have tried a variety of countermeasures for many years to improve railway level crossing safety. New types of intelligent transport system (ITS) interventions are now emerging due to the availability and the affordability of technology. These interventions target both actively and passively protected railway level crossings and attempt to address drivers' errors at railway crossings, which are mainly a failure to detect the crossing or the train and misjudgement of the train approach speed and distance. This study aims to assess the effectiveness of three emerging ITS that the rail industry considers implementing in Australia: a visual in-vehicle ITS, an audio in-vehicle ITS, as well as an on-road flashing beacons intervention. The evaluation was conducted on an advanced driving simulator with 20 participants per trialled technology, each participant driving once without any technology and once with one of the ITS interventions. Every participant drove through a range of active and passive crossings with and without trains approaching. Their speed approach of the crossing, head movements and stopping compliance were measured. Results showed that driver behaviour was changed with the three ITS interventions at passive crossings, while limited effects were found at active crossings, even with reduced visibility. The on-road intervention trialled was unsuccessful in improving driver behaviour; the audio and visual ITS improved driver behaviour when a train was approaching. A trend toward worsening driver behaviour with the visual ITS was observed when no trains were approaching. This trend was not observed for the audio ITS intervention, which appears to be the ITS intervention with the highest potential for improving safety at passive crossings. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Driver headway choice: a comparison between driving simulator and real-road driving

    NARCIS (Netherlands)

    Risto, Malte; Martens, Marieke Hendrikje

    2014-01-01

    Driving simulators have become an established tool in driver behaviour research by offering a controllable, safe and cost-effective alternative to real world driving. A challenge for using driving simulators as a research tool has been to elicit driving behaviour that equals real world driving. With

  14. Driver headway choice : A comparison between driving simulator and real-road driving

    NARCIS (Netherlands)

    Risto, M.; Martens, M.H.

    2014-01-01

    Driving simulators have become an established tool in driver behaviour research by offering a controllable, safe and cost-effective alternative to real world driving. A challenge for using driving simulators as a research tool has been to elicit driving behaviour that equals real world driving. With

  15. Developing a driving simulator based functional object detection task.

    Science.gov (United States)

    Goodenough, Richard R; Brooks, Johnell O; Crisler, Matthew C; Rosopa, Patrick J

    2012-10-01

    The purpose of this study was to validate a driving simulator-based tool for assessing functional visual scanning while driving (Goodenough, 2010) by replicating a previous study and assessing whether the results of the task are moderated by strategic decisions regarding task prioritization. Participants completed a functional object detection task that includes a peripheral target detection task and a central braking response task. Results indicated that the simulator task can identify differences in older and younger participants' abilities to functionally scan the driving environment and these differences appear unaffected by prioritizing either the scanning or braking task. Implications are discussed.

  16. Motorcyclist's lane position as a factor in right-of-way violation collisions: a driving simulator study.

    Science.gov (United States)

    Sager, Bertrand; Yanko, Matthew R; Spalek, Thomas M; Froc, David J; Bernstein, Daniel M; Dastur, Farhad N

    2014-11-01

    A driver turning left and failing to notice an oncoming motorcyclist until too late is the most common cause of motorcycle collisions. Consequently, much previous research has focused on motorcycle properties, such as size, shape, and color to explain its inconspicuousness. However, collision statistics remain largely unchanged, suggesting that the issue may not be related solely to the motorcycle's static properties. In the present study, we examined a different characteristic of the motorcycle, namely its trajectory of approach. Seventeen participants faced oncoming traffic in a high-fidelity driving simulator and indicated when gaps were safe enough for them to turn left at an intersection. We manipulated the size of the gaps and the type of oncoming vehicle over 135 trials, with gap sizes varying from 3 to 5s, and vehicles consisting of either a car, a motorcycle in the left-of-lane position, or a motorcycle in the right-of-lane position. Our results show that drivers are more likely to turn in front of an oncoming motorcycle when it travels in the left-of-lane position than when it travels in the right-of-lane position. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. In Patients with Cirrhosis, Driving Simulator Performance is Associated With Real-life Driving

    DEFF Research Database (Denmark)

    Lauridsen, Mette Enok Munk; Thacker, Leroy R; White, Melanie B

    2016-01-01

    , not all patients with MHE are unsafe drivers, but it is unclear how to distinguish them from unsafe drivers. We investigated the link between performance on driving simulators and real-life automobile accidents and traffic violations. We also aimed to identify features of unsafe drivers with cirrhosis...... collected on traffic violations and automobile accidents from the Virginia Department of Motor Vehicles and from participants' self-assessments when they entered the study, and from 73 participants 1 year later. Participants also completed a questionnaire about alcohol use and cessation patterns....... The driving simulator measured crashes, run-time, road center and edge excursions, and illegal turns during navigation; before and after each driving simulation session, patients were asked to rate their overall driving skills. Drivers were classified as safe or unsafe based on crashes and violations reported...

  18. Simulating autonomous driving styles: Accelerations for three road profiles

    Directory of Open Access Journals (Sweden)

    Karjanto Juffrizal

    2017-01-01

    Full Text Available This paper presents a new experimental approach to simulate projected autonomous driving styles based on the accelerations at three road profiles. This study was focused on the determination of ranges of accelerations in triaxial direction to simulate the autonomous driving experience. A special device, known as the Automatic Acceleration and Data controller (AUTOAccD, has been developed to guide the designated driver to accomplish the selected accelerations based on the road profiles and the intended driving styles namely assertive, defensive and light rail transit (LRT. Experimental investigations have been carried out at three different road profiles (junction, speed hump, and corner with two designated drivers with five trials on each condition. A driving style with the accelerations of LRT has also been included in this study as it is significant to the present methodology because the autonomous car is predicted to accelerate like an LRT, in such a way that it enables the users to conduct activities such as working on a laptop, using personal devices or eating and drinking while travelling. The results demonstrated that 92 out of 110 trials of the intended accelerations for autonomous driving styles could be achieved and simulated on the real road by the designated drivers. The differences between the two designated drivers were negligible, and the rates of succeeding in realizing the intended accelerations were high. The present approach in simulating autonomous driving styles focusing on accelerations can be used as a tool for experimental setup involving autonomous driving experience and acceptance.

  19. Effects of advertising billboards during simulated driving.

    Science.gov (United States)

    Edquist, Jessica; Horberry, Tim; Hosking, Simon; Johnston, Ian

    2011-05-01

    There is currently a great deal of interest in the problem of driver distraction. Most research focuses on distractions from inside the vehicle, but drivers can also be distracted by objects outside the vehicle. Major roads are increasingly becoming sites for advertising billboards, and there is little research on the potential effects of this advertising on driving performance. The driving simulator experiment presented here examines the effects of billboards on drivers, including older and inexperienced drivers who may be more vulnerable to distractions. The presence of billboards changed drivers' patterns of visual attention, increased the amount of time needed for drivers to respond to road signs, and increased the number of errors in this driving task. Copyright © 2010 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  20. Effects of modafinil on simulator driving and self-assessment of driving following sleep deprivation.

    Science.gov (United States)

    Gurtman, Clint G; Broadbear, Jillian H; Redman, Jennifer R

    2008-12-01

    While it has been suggested that the novel wake promoting drug modafinil may have some utility with respect to drowsy driving in healthy adults, this has not been investigated until now. The present study was designed to assess the effects of modafinil on objective and self-assessed driving simulator performance during an overnight period of sleep loss. Sixteen healthy participants (eight males and eight females) remained awake overnight on two separate occasions during which they ingested either a single 300 mg dose of modafinil or a placebo capsule at either 0230 or 0330 h. Two hours post-treatment, participants were evaluated using measures of driving simulator performance, self-assessed driving performance and subjective alertness. Modafinil treatment reduced lane deviation but had less effect on speed deviation, off-road incidents and reaction time to a concurrent task. Modafinil also improved subjective appraisals of driving performance, although its use may have resulted in overconfidence in driving ability during short trips. Modafinil offers some benefits with respect to objective driving performance under conditions of sleep loss. However it may induce overconfidence, suggesting that its use as a countermeasure to drowsiness when driving requires further examination.

  1. Concurrent audio-visual feedback for supporting drivers at intersections: A study using two linked driving simulators.

    Science.gov (United States)

    Houtenbos, M; de Winter, J C F; Hale, A R; Wieringa, P A; Hagenzieker, M P

    2017-04-01

    A large portion of road traffic crashes occur at intersections for the reason that drivers lack necessary visual information. This research examined the effects of an audio-visual display that provides real-time sonification and visualization of the speed and direction of another car approaching the crossroads on an intersecting road. The location of red blinking lights (left vs. right on the speedometer) and the lateral input direction of beeps (left vs. right ear in headphones) corresponded to the direction from where the other car approached, and the blink and beep rates were a function of the approaching car's speed. Two driving simulators were linked so that the participant and the experimenter drove in the same virtual world. Participants (N = 25) completed four sessions (two with the audio-visual display on, two with the audio-visual display off), each session consisting of 22 intersections at which the experimenter approached from the left or right and either maintained speed or slowed down. Compared to driving with the display off, the audio-visual display resulted in enhanced traffic efficiency (i.e., greater mean speed, less coasting) while not compromising safety (i.e., the time gap between the two vehicles was equivalent). A post-experiment questionnaire showed that the beeps were regarded as more useful than the lights. It is argued that the audio-visual display is a promising means of supporting drivers until fully automated driving is technically feasible. Copyright © 2016. Published by Elsevier Ltd.

  2. Comparing Expert Driving Behavior in Real World and Simulator Contexts

    Directory of Open Access Journals (Sweden)

    Hiran B. Ekanayake

    2013-01-01

    Full Text Available Computer games are increasingly used for purposes beyond mere entertainment, and current hi-tech simulators can provide quite, naturalistic contexts for purposes such as traffic education. One of the critical concerns in this area is the validity or transferability of acquired skills from a simulator to the real world context. In this paper, we present our work in which we compared driving in the real world with that in the simulator at two levels, that is, by using performance measures alone, and by combining psychophysiological measures with performance measures. For our study, we gathered data using questionnaires as well as by logging vehicle dynamics, environmental conditions, video data, and users' psychophysiological measurements. For the analysis, we used several novel approaches such as scatter plots to visualize driving tasks of different contexts and to obtain vigilance estimators from electroencephalographic (EEG data in order to obtain important results about the differences between the driving in the two contexts. Our belief is that both experimental procedures and findings of our experiment are very important to the field of serious games concerning how to evaluate the fitness of driving simulators and measure driving performance.

  3. Comparing treatment effects of oral THC on simulated and on-the-road driving performance: testing the validity of driving simulator drug research.

    Science.gov (United States)

    Veldstra, J L; Bosker, W M; de Waard, D; Ramaekers, J G; Brookhuis, K A

    2015-08-01

    The driving simulator provides a safe and controlled environment for testing driving behaviour efficiently. The question is whether it is sensitive to detect drug-induced effects. The primary aim of the current study was to investigate the sensitivity of the driving simulator for detecting drug effects. As a case in point, we investigated the dose-related effects of oral ∆(9)-tetrahydrocannabinol (THC), i.e. dronabinol, on simulator and on-the-road driving performance in equally demanding driving tasks. Twenty-four experienced driver participants were treated with dronabinol (Marinol®; 10 and 20 mg) and placebo. Dose-related effects of the drug on the ability to keep a vehicle in lane (weaving) and to follow the speed changes of a lead car (car following) were compared within subjects for on-the-road versus in-simulator driving. Additionally, the outcomes of equivalence testing to alcohol-induced effects were investigated. Treatment effects found on weaving when driving in the simulator were comparable to treatment effects found when driving on the road. The effect after 10 mg dronabinol was however less strong in the simulator than on the road and inter-individual variance seemed higher in the simulator. There was, however, a differential treatment effect of dronabinol on reactions to speed changes of a lead car (car following) when driving on the road versus when driving in the simulator. The driving simulator was proven to be sensitive for demonstrating dronabinol-induced effects particularly at higher doses. Treatment effects of dronabinol on weaving were comparable with driving on the road but inter-individual variability seemed higher in the simulator than on the road which may have potential effects on the clinical inferences made from simulator driving. Car following on the road and in the simulator were, however, not comparable.

  4. Cost reduction of the head stack assembly process in the hard disk drive industry with simulation modeling and optimization: A case study

    Directory of Open Access Journals (Sweden)

    Supawan Srithip

    2017-10-01

    Full Text Available This research with the main goal of cost reduction in the hard disk drive industry focused on the head stack assembly process is action research between university research teams and industry. It aims to study the head stack assembly process and to investigate the problems that need to be solved in order to reduce costs by using computer simulations and optimizations. Steps in simulation methodology were applied starting from data collection, model building, model verification, model validation, experimentation, and optimization. Several factors and their effects were investigated that could lead to production improvement of 7.94% increase in numbers of assembled head stack or 7.32% decrease in production cycle time. This paper demonstrates simulation optimization methodology applied to problem solving. Also it illustrates the successful case of using simulation optimization in cost reduction.

  5. Simulation Analysis on Driving Behavior during Traffic Sign Recognition

    Directory of Open Access Journals (Sweden)

    Lishan Sun

    2011-05-01

    Full Text Available The traffic signs transfer trip information to drivers through vectors like words, graphs and numbers. Traffic sign with excessive information often makes the drivers have no time to read and understand, leading to risky driving. It is still a problem of how to clarify the relationship between traffic sign recognition and risky driving behavior. This paper presents a study that is reflective of such an effort. Twenty volunteers participated in the dynamic visual recognition experiment in driving simulator, and the data of several key indicators are obtained, including visual cognition time, vehicle acceleration and the offset distance from middle lane, etc. Correlations between each indicator above are discussed in terms of risky driving. Research findings directly show that drivers' behavior changes a lot during their traffic sign recognition.

  6. A student-adaptive system for driving simulation

    NARCIS (Netherlands)

    Weevers, I.; Weevers, I.; Nijholt, Antinus; van Dijk, Elisabeth M.A.G.; Kuipers, J.; Zwiers, Jakob; Brugman, A.; Lovell, B.C.; Campbell, D.A.; Fookes, C.B.; Maeder, A.J.

    2003-01-01

    Driving simulators have to be student-oriented. We created the Virtual Driving Instructor (VDI), an intelligent tutoring multiagent system, which provides studentadaptivity. The VDI enhances the interaction between the driving simulator and the student. It uses regressive instruction and feedback,

  7. Chain Drive Simulation Using Spatial Multibody Dynamics

    Directory of Open Access Journals (Sweden)

    Mohamed A. Omar

    2014-04-01

    Full Text Available This paper presents an efficient approach for modeling chain derives using multibody dynamics formulation based on the spatial algebra. The recursive nonlinear dynamic equations of motion are formulated using spatial Cartesian coordinates and joint variables to form an augmented set of differential-algebraic equations. The spatial algebra is used to express the kinematic and dynamic equations leading to consistent and compact set of equations. The connectivity graph is used to derive the system connectivity matrix based on the system topological relations. The connectivity matrix is used to eliminate the Cartesian quantities and to project the forces and inertia into the joint subspace. This approach will result in a minimum set of equation and can avoid iteratively solving the system of differential and algebraic equations to satisfy the constraint equations. In order to accurately capture the full dynamics of the chain links, each link in the chain is modeled as rigid body with full 6 degrees of freedom. To avoid singularities in closed loop configurations, the chain drive is considered a kinematically decoupled subsystem and the interaction between the links and other system components is modeled using force elements. The out-of-plane misalignment between the sprockets can be easily modeled using a compliant force element to model the joints between each two adjacent links. The nonlinear three dimensional contact forces between the chain links and the sprockets are modeled using elastic spring-damper element and accounts for the sliding friction. The proposed approach can be used to model complex drive chain, bicycle chain as well as conveyance systems. Results show that realistic behavior of the chain as well as out-of-plane vibration can be easily captured using the presented approach. The proposed approach for chain drive subsystem could be easily appended to any other multibody simulation system.

  8. Shifting from manual to automatic gear when growing old : Good advice? Results from a driving simulator study

    NARCIS (Netherlands)

    Piersma, Dafne; de Waard, Dick; de Waard, D; Brookhuis, K; Wiczorek, R; di Nocera, F; Brouwer, R; Barham, P; Weikert, C; Kluge, A; Gerbino, W; Toffetti, A

    2014-01-01

    Older people may be advised to switch from manual to automatic gear shifting, because they may have difficulties with dividing their attention between gear shifting and other driving tasks such as perceiving other traffic participants. The question is whether older drivers show a better driving

  9. Beam Dynamics Simulation for the CTF3 Drive Beam Accelerator

    CERN Document Server

    Schulte, Daniel

    2000-01-01

    A new CLIC Test Facility (CTF3) at CERN will serve to study the drive beam generation for the Compact Linear Collider (CLIC). CTF3 has to accelerate a 3.5 A electron beam in almost fully-loaded structures. The pulse contains more than 2000 bunches, one in every second RF bucket, and has a length of more than one microsecond. Different options for the lattice of the drive-beam accelerator are presented, based on FODO-cells and triplets as well as solenoids. The transverse stability is simulated, including the effects of beam jitter, alignment and beam-based correction.

  10. Fatigue and voluntary utilization of automation in simulated driving.

    Science.gov (United States)

    Neubauer, Catherine; Matthews, Gerald; Langheim, Lisa; Saxby, Dyani

    2012-10-01

    A driving simulator was used to assess the impact on fatigue, stress, and workload of full vehicle automation that was initiated by the driver. Previous studies have shown that mandatory use of full automation induces a state of "passive fatigue" associated with loss of alertness. By contrast, voluntary use of automation may enhance the driver's perceptions of control and ability to manage fatigue. Participants were assigned to one of two experimental conditions, automation optional (AO) and nonautomation (NA), and then performed a 35 min, monotonous simulated drive. In the last 5 min, automation was unavailable and drivers were required to respond to an emergency event. Subjective state and workload were evaluated before and after the drive. Making automation available to the driver failed to alleviate fatigue and stress states induced by driving in monotonous conditions. Drivers who were fatigued prior to the drive were more likely to choose to use automation, but automation use increased distress, especially in fatigue-prone drivers. Drivers in the AO condition were slower to initiate steering responses to the emergency event, suggesting optional automation may be distracting. Optional, driver-controlled automation appears to pose the same dangers to task engagement and alertness as externally initiated automation. Drivers of automated vehicles may be vulnerable to fatigue that persists when normal vehicle control is restored. It is important to evaluate automated systems' impact on driver fatigue, to seek design solutions to the issue of maintaining driver engagement, and to address the vulnerabilities of fatigue-prone drivers.

  11. Traffic and Driving Simulator Based on Architecture of Interactive Motion

    Science.gov (United States)

    Paz, Alexander; Veeramisti, Naveen; Khaddar, Romesh; de la Fuente-Mella, Hanns; Modorcea, Luiza

    2015-01-01

    This study proposes an architecture for an interactive motion-based traffic simulation environment. In order to enhance modeling realism involving actual human beings, the proposed architecture integrates multiple types of simulation, including: (i) motion-based driving simulation, (ii) pedestrian simulation, (iii) motorcycling and bicycling simulation, and (iv) traffic flow simulation. The architecture has been designed to enable the simulation of the entire network; as a result, the actual driver, pedestrian, and bike rider can navigate anywhere in the system. In addition, the background traffic interacts with the actual human beings. This is accomplished by using a hybrid mesomicroscopic traffic flow simulation modeling approach. The mesoscopic traffic flow simulation model loads the results of a user equilibrium traffic assignment solution and propagates the corresponding traffic through the entire system. The microscopic traffic flow simulation model provides background traffic around the vicinities where actual human beings are navigating the system. The two traffic flow simulation models interact continuously to update system conditions based on the interactions between actual humans and the fully simulated entities. Implementation efforts are currently in progress and some preliminary tests of individual components have been conducted. The implementation of the proposed architecture faces significant challenges ranging from multiplatform and multilanguage integration to multievent communication and coordination. PMID:26491711

  12. Why do drivers maintain short headways in fog? A driving-simulator study evaluating feeling of risk and lateral control during automated and manual car following.

    Science.gov (United States)

    Saffarian, M; Happee, R; Winter, J C F de

    2012-01-01

    Drivers in fog tend to maintain short headways, but the reasons behind this phenomenon are not well understood. This study evaluated the effect of headway on lateral control and feeling of risk in both foggy and clear conditions. Twenty-seven participants completed four sessions in a driving simulator: clear automated (CA), clear manual (CM), fog automated (FA) and fog manual (FM). In CM and FM, the drivers used the steering wheel, throttle and brake pedals. In CA and FA, a controller regulated the distance to the lead car, and the driver only had to steer. Drivers indicated how much risk they felt on a touchscreen. Consistent with our hypothesis, feeling of risk and steering activity were elevated when the lead car was not visible. These results might explain why drivers adopt short headways in fog. Practitioner Summary: Fog poses a serious road safety hazard. Our driving-simulator study provides the first experimental evidence to explain the role of risk-feeling and lateral control in headway reduction. These results are valuable for devising effective driver assistance and support systems.

  13. Automated driving functions giving control back to the driver: a simulator study on driver state dependent strategies

    NARCIS (Netherlands)

    Willemsen, D.M.C.; Stuiver, A.; Hogema, J.

    2015-01-01

    Many car companies and other organisations are working hard to get automated driving on the road. Where some prefer driverless cars, most foresee a future where control of the vehicle will be shared between the driver and automated functions in the coming years. Sharing tasks and responsibilities

  14. EEG potentials predict upcoming emergency brakings during simulated driving.

    Science.gov (United States)

    Haufe, Stefan; Treder, Matthias S; Gugler, Manfred F; Sagebaum, Max; Curio, Gabriel; Blankertz, Benjamin

    2011-10-01

    Emergency braking assistance has the potential to prevent a large number of car crashes. State-of-the-art systems operate in two stages. Basic safety measures are adopted once external sensors indicate a potential upcoming crash. If further activity at the brake pedal is detected, the system automatically performs emergency braking. Here, we present the results of a driving simulator study indicating that the driver's intention to perform emergency braking can be detected based on muscle activation and cerebral activity prior to the behavioural response. Identical levels of predictive accuracy were attained using electroencephalography (EEG), which worked more quickly than electromyography (EMG), and using EMG, which worked more quickly than pedal dynamics. A simulated assistance system using EEG and EMG was found to detect emergency brakings 130 ms earlier than a system relying only on pedal responses. At 100 km h(-1) driving speed, this amounts to reducing the braking distance by 3.66 m. This result motivates a neuroergonomic approach to driving assistance. Our EEG analysis yielded a characteristic event-related potential signature that comprised components related to the sensory registration of a critical traffic situation, mental evaluation of the sensory percept and motor preparation. While all these components should occur often during normal driving, we conjecture that it is their characteristic spatio-temporal superposition in emergency braking situations that leads to the considerable prediction performance we observed.

  15. EEG potentials predict upcoming emergency brakings during simulated driving

    Science.gov (United States)

    Haufe, Stefan; Treder, Matthias S.; Gugler, Manfred F.; Sagebaum, Max; Curio, Gabriel; Blankertz, Benjamin

    2011-10-01

    Emergency braking assistance has the potential to prevent a large number of car crashes. State-of-the-art systems operate in two stages. Basic safety measures are adopted once external sensors indicate a potential upcoming crash. If further activity at the brake pedal is detected, the system automatically performs emergency braking. Here, we present the results of a driving simulator study indicating that the driver's intention to perform emergency braking can be detected based on muscle activation and cerebral activity prior to the behavioural response. Identical levels of predictive accuracy were attained using electroencephalography (EEG), which worked more quickly than electromyography (EMG), and using EMG, which worked more quickly than pedal dynamics. A simulated assistance system using EEG and EMG was found to detect emergency brakings 130 ms earlier than a system relying only on pedal responses. At 100 km h-1 driving speed, this amounts to reducing the braking distance by 3.66 m. This result motivates a neuroergonomic approach to driving assistance. Our EEG analysis yielded a characteristic event-related potential signature that comprised components related to the sensory registration of a critical traffic situation, mental evaluation of the sensory percept and motor preparation. While all these components should occur often during normal driving, we conjecture that it is their characteristic spatio-temporal superposition in emergency braking situations that leads to the considerable prediction performance we observed.

  16. Main drive selection for the Windstorm Simulation Center

    Energy Technology Data Exchange (ETDEWEB)

    Lacy, J.M.; Earl, J.S.

    1998-02-01

    Operated by the Partnership for Natural Disaster Reduction, the Windstorm Simulation Center (WSC) will be a structural test center dedicated to studying the performance of civil structural systems subjected to hurricanes, tornadoes, and other storm winds. Within the WSC, a bank of high-power fans, the main drive, will produce the high velocity wind necessary to reproduce these storms. Several options are available for the main drive, each with advantages and liabilities. This report documents a study to identify and evaluate all candidates available, and to select the most promising system such that the best possible combination of real-world performance attributes is achieved at the best value. Four broad classes of candidate were identified: electric motors, turbofan aircraft engines, turboshaft aircraft engines, and turboshaft industrial engines. Candidate systems were evaluated on a basis of technical feasibility, availability, power, installed cost, and operating cost.

  17. Testing advanced driver assistance systems with the interactive driving simulator; Erprobung von Fahrerassistenzsystemen mit dem Interactive Driving Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Friedrichs, A.; Grosse-Kappenberg, S.; Happe, J. [Zentrum fuer Lern- und Wissensmanagement und Lehrstuhl Informatik im Maschinenbau ZLW/IMA der RWTH Aachen (Germany)

    2005-07-01

    The Centre for Learning and Knowledge Management and Department of Computer Science in Engineering of the Technical University Aachen has developed a truck driving simulator which combines a driving simulation as well as traffic flow calculations to the interactive Driving Simulator (InDriveS). In real-time the effects of the driver's behaviour on the surrounding traffic are considered and vice versa. The integrative part of InDriveS is a software-in-the-loop and hardware-in-the-loop development environment. By means of this tool, all phases of development (Analysis, Design, Modelling, Simulation, Implementation as well as Testing and Evaluation) of new vehicle technologies, e.g. Information and Assistance Systems, can be realised in consideration of the road traffic and the driver's behaviour. (orig.)

  18. Simulation and Analysis of Roller Chain Drive Systems

    DEFF Research Database (Denmark)

    Pedersen, Sine Leergaard

    The subject of this thesis is simulation and analysis of large roller chain drive systems, such as e.g. used in marine diesel engines. The aim of developing a chain drive simulation program is to analyse dynamic phenomena of chain drive systems and investigate different design changes...... to the systems, in order to remove unwanted phenomena. Such a computer program can, when properly validated, be used as an alternative to or in combination with physical experiments. Prior investigations in this area have been done with a focus on smaller chains in high speed chain drives. For large low speed...... systems other phenomena occur and therefore, a specific model of the marine engine chain drive is of interest. The research objective of the work presented in this thesis is to contribute with a novel theoretical basis for the analysis of chain drive systems, by posing and validating different...

  19. Creating pedestrian crash scenarios in a driving simulator environment.

    Science.gov (United States)

    Chrysler, Susan T; Ahmad, Omar; Schwarz, Chris W

    2015-01-01

    In 2012 in the United States, pedestrian injuries accounted for 3.3% of all traffic injuries but, disproportionately, pedestrian fatalities accounted for roughly 14% of traffic-related deaths (NHTSA 2014 ). In many other countries, pedestrians make up more than 50% of those injured and killed in crashes. This research project examined driver response to crash-imminent situations involving pedestrians in a high-fidelity, full-motion driving simulator. This article presents a scenario development method and discusses experimental design and control issues in conducting pedestrian crash research in a simulation environment. Driving simulators offer a safe environment in which to test driver response and offer the advantage of having virtual pedestrian models that move realistically, unlike test track studies, which by nature must use pedestrian dummies on some moving track. An analysis of pedestrian crash trajectories, speeds, roadside features, and pedestrian behavior was used to create 18 unique crash scenarios representative of the most frequent and most costly crash types. For the study reported here, we only considered scenarios where the car is traveling straight because these represent the majority of fatalities. We manipulated driver expectation of a pedestrian both by presenting intersection and mid-block crossing as well as by using features in the scene to direct the driver's visual attention toward or away from the crossing pedestrian. Three visual environments for the scenarios were used to provide a variety of roadside environments and speed: a 20-30 mph residential area, a 55 mph rural undivided highway, and a 40 mph urban area. Many variables of crash situations were considered in selecting and developing the scenarios, including vehicle and pedestrian movements; roadway and roadside features; environmental conditions; and characteristics of the pedestrian, driver, and vehicle. The driving simulator scenarios were subjected to iterative testing to

  20. The impact of therapeutic opioid agonists on driving-related psychomotor skills assessed by a driving simulator or an on-road driving task: A systematic review.

    Science.gov (United States)

    Ferreira, Diana H; Boland, Jason W; Phillips, Jane L; Lam, Lawrence; Currow, David C

    2018-04-01

    Driving cessation is associated with poor health-related outcomes. People with chronic diseases are often prescribed long-term opioid agonists that have the potential to impair driving. Studies evaluating the impact of opioids on driving-related psychomotor skills report contradictory results likely due to heterogeneous designs, assessment tools and study populations. A better understanding of the effects of regular therapeutic opioid agonists on driving can help to inform the balance between individual's independence and community safety. To identify the literature assessing the impact of regular therapeutic opioid agonists on driving-related psychomotor skills for people with chronic pain or chronic breathlessness. Systematic review reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis statement; PROSPERO Registration CRD42017055909. Six electronic databases and grey literature were systematically searched up to January, 2017. Inclusion criteria were as follows: (1) empirical studies reporting data on driving simulation, on-the-road driving tasks or driving outcomes; (2) people with chronic pain or chronic breathlessness; and (3) taking regular therapeutic opioid agonists. Critical appraisal used the National Institutes of Health's quality assessment tools. From 3809 records screened, three studies matched the inclusion criteria. All reported data on people with chronic non-malignant pain. No significant impact of regular therapeutic opioid agonists on people's driving-related psychomotor skills was reported. One study reported more intense pain significantly worsened driving performance. This systematic review does not identify impaired simulated driving performance when people take regular therapeutic opioid agonists for symptom control, although more prospective studies are needed.

  1. Simulation of Automated Vehicles' Drive Cycles

    Science.gov (United States)

    2018-02-28

    This research has two objectives: 1) To develop algorithms for plausible and legally-justifiable freeway car-following and arterial-street gap acceptance driving behavior for AVs 2) To implement these algorithms on a representative road network, in o...

  2. Alcohol consumption for simulated driving performance: A systematic review

    Directory of Open Access Journals (Sweden)

    Mohammad Saeid Rezaee-Zavareh

    2017-06-01

    Conclusion: Alcohol consumption may decrease simulated driving performance in alcohol consumed people compared with non-alcohol consumed people via changes in SDSD, LPSD, speed, MLPD, LC and NA. More well-designed randomized controlled clinical trials are recommended.

  3. Gender differences in alcohol impairment of simulated driving performance and driving-related skills.

    Science.gov (United States)

    Miller, Melissa A; Weafer, Jessica; Fillmore, Mark T

    2009-01-01

    Considerable laboratory research indicates that moderate doses of alcohol impair a broad range of skilled activities related to driving performance in young adults. Although laboratory studies show that the intensity of impairment is generally dependent on the blood alcohol concentration, some reviews of this literature suggest that women might be more sensitive to the impairing effects of alcohol than men. The present study tested this hypothesis. Drawing on data from previous experiments in our laboratory, we compared men and women in terms of the degree to which a challenge dose of alcohol (0.65 g/kg) impaired their simulated driving performance and measures of three separate behavioral and cognitive functions important to driving performance: motor coordination, speed of information processing and information-processing capacity. Alcohol significantly impaired all aspects of performance. Moreover, women displayed greater impairment than men on all behavioral tests and also reported higher levels of subjective intoxication compared with men. Both biological and social-cultural factors have been implicated in gender differences in the behavioral responses to alcohol. The current evidence of heightened sensitivity to alcohol in women highlights the need for better understanding the biological and environmental factors underlying this gender difference.

  4. A SIMULATION ENVIRONMENT FOR AUTOMATIC NIGHT DRIVING AND VISUAL CONTROL

    OpenAIRE

    Arroyo Rubio, Fernando

    2012-01-01

    This project consists on developing an automatic night driving system in a simulation environment. The simulator I have used is TORCS. TORCS is an Open Source car racing simulator written in C++. It is used as an ordinary car racing game, as a IA racing game and as a research platform. The goal of this thesis is to implement an automatic driving system to control the car under night conditions using computer vision. A camera is implemented inside the vehicle and it will detect the reflective ...

  5. Devices using GPS into driving simulators

    OpenAIRE

    ESPIE, S; GANIEUX, D; TOURNIER, N

    2004-01-01

    Cet article présente un nouvel outil utilisant des données SIG pour obtenir une définition analytique des routes afin que la base de données réponde aux besoins des simulateurs de conduite (modèle dynamique du véhicule, simulation de trafic, module sonore, etc.). Le simulateur peut calculer en temps réel les informations GPS simulées (SIL) et les envoyer au calculateur (HIS) qui fonctionne alors comme s'il équipait un véhicule réel sur une vraie route, dans des conditions réelles.

  6. The use of a driving simulator to determine how time pressures impact driver aggressiveness.

    Science.gov (United States)

    2017-06-01

    Speeding greatly contributes to traffic safety with approximately a third of fatal crashes in the United States being speeding-related. Previous research has identified being late as a primary cause of speeding. In this driving simulator study, a vir...

  7. Behavioral reactions to advanced cruise control: results of a driving simulator experiment

    NARCIS (Netherlands)

    Hoedemaeker, D.M.

    2000-01-01

    This chapter describes an experimental study that is conducted in the driving simulator at the Centre for Environmental and Traffic Psychology (COV) of the University of Groningen. In the experiment, two groups of drivers, who differed with respect to reported driving style in terms of speed, drove

  8. Simulation of SU-8 frequency-driven scratch drive actuators

    KAUST Repository

    Conchouso Gonzalez, David

    2013-04-01

    This paper presents the simulation of Scratch Drive Actuators (SDAs) for micro-robotic applications. SDAs use electrostatic forces to generate motion on top of an interdigitated electrode array. The purpose of this investigation is to evaluate several design geometries and micro-actuator configurations using ConventorWare®\\'s finite element analysis module. The study performed investigates the SDAs modal and electrostatic behavior and the effects of linking two or more SDAs together in a microrobot device. In addition, the interdigitated electrode array performance, used for power delivery, was studied by changing the thickness of its dielectric layer. We present our observations based on these studies, which will aid in the understanding and development of future SDA designs. © 2013 IEEE.

  9. Design of an immersive simulator for assisted power wheelchair driving.

    Science.gov (United States)

    Devigne, Louise; Babel, Marie; Nouviale, Florian; Narayanan, Vishnu K; Pasteau, Francois; Gallien, Philippe

    2017-07-01

    Driving a power wheelchair is a difficult and complex visual-cognitive task. As a result, some people with visual and/or cognitive disabilities cannot access the benefits of a power wheelchair because their impairments prevent them from driving safely. In order to improve their access to mobility, we have previously designed a semi-autonomous assistive wheelchair system which progressively corrects the trajectory as the user manually drives the wheelchair and smoothly avoids obstacles. Developing and testing such systems for wheelchair driving assistance requires a significant amount of material resources and clinician time. With Virtual Reality technology, prototypes can be developed and tested in a risk-free and highly flexible Virtual Environment before equipping and testing a physical prototype. Additionally, users can "virtually" test and train more easily during the development process. In this paper, we introduce a power wheelchair driving simulator allowing the user to navigate with a standard wheelchair in an immersive 3D Virtual Environment. The simulation framework is designed to be flexible so that we can use different control inputs. In order to validate the framework, we first performed tests on the simulator with able-bodied participants during which the user's Quality of Experience (QoE) was assessed through a set of questionnaires. Results show that the simulator is a promising tool for future works as it generates a good sense of presence and requires rather low cognitive effort from users.

  10. Simulation modes of movement the drive rollers of suspension of conveyor with suspended belt and distributed drive

    Directory of Open Access Journals (Sweden)

    Lagerev A.V.

    2016-03-01

    Full Text Available Mathematical model of conveyor with suspended belt and distributed drive which allows to simulate the dynamics of suspension at various modes of movement of the drive roller is developed. The modeling results are presented in the article.

  11. Simulating Spatial-Temporal Changes of Land-Use Based on Ecological Redline Restrictions and Landscape Driving Factors: A Case Study in Beijing

    Directory of Open Access Journals (Sweden)

    Zimu Jia

    2018-04-01

    Full Text Available A change in the usage of land is influenced by a variety of driving factors and policies on spatial constraints. On the basis of considering the conventional natural and socio-economic indicators, the landscape pattern indicators were considered as new driving forces in the conversion of land use and its effects at small regional extent (CLUE-S model to simulate spatial and temporal changes of land-use in Beijing. Compared with traditional spatial restrictions characterized by small and isolated areas, such as forest parks and natural reserves, the ecological redline areas increase the spatial integrity and connectivity of ecological and environmental functions at a regional scale, which were used to analyze the distribution patterns and behaviors of land use conversion in the CLUE-S model. The observed results indicate that each simulation scenario has a Kappa coefficient of more than 0.76 beyond the threshold value of 0.6 and represents high agreements between the actual and simulated land use maps. The simulation scenarios including landscape pattern indicators are more accurate than those without consideration of these new driving forces. The simulation results from using ecological redline areas as space constraints have the highest precision compared with the unrestricted and traditionally restricted scenarios. Therefore, the CLUE-S model based on the restriction of ecological redline and the consideration of landscape pattern factors has shown better effectiveness in simulating the future land use change. The conversion of land use types mainly occurred between construction land and cropland during the period from 2010 to 2020. Meanwhile, a large number of grasslands are being changed to construction lands in the mountain towns of northwest Beijing and large quantities of water bodies have disappeared and been replaced by construction lands due to rapid urbanization in the eastern and southern plains. To improve the sustainable use of

  12. The Evaluation of a Motion Base Driving Simulator in a Cave at TACOM

    National Research Council Canada - National Science Library

    Mollenhauer, M. A; Romano, R. A; Brumm, B

    2004-01-01

    .... In the first study, field (FOV), display system, and motion cueing algorithm were evaluate. In the second study, the optimum configuration from the first study was compared to off-road driving performance in TACOM's Ride Motion Simulator (RMS). In addition to performance evaluation, several simulator sickness mitigation techniques were also tested. The important findings from each of these evaluations will be discussed.

  13. Simulation of control drives in a tower crane

    Directory of Open Access Journals (Sweden)

    Wojciech SOLARZ

    2011-01-01

    Full Text Available The design of a control system for a tower crane is investigated. Underlying the controller design is the theory of optimal linear control. Computer models of a crane and the control systems for the crane drives are developed. Simulation data reveals that the motion of the load can be effectively controlled so that it should follow a predetermined trajectory.

  14. High Field Side Lower Hybrid Current Drive Simulations for Off- axis Current Drive in DIII-D

    Science.gov (United States)

    Wukitch, S. J.; Shiraiwa, S.; Wallace, G. M.; Bonoli, P. T.; Holcomb, C.; Pinsker, R. I.

    2017-10-01

    Efficient off-axis current drive scalable to reactors is a key enabling technology for developing economical, steady state tokamak. Previous studies have focussed on high field side (HFS) launch of lower hybrid current drive (LHCD) in double null configurations in reactor grade plasmas and found improved wave penetration and high current drive efficiency with driven current profile peaked near a normalized radius, ρ, of 0.6-0.8, consistent with advanced tokamak scenarios. Further, HFS launch potentially mitigates plasma material interaction and coupling issues. For this work, we sought credible HFS LHCD scenario for DIII-D advanced tokamak discharges through utilizing advanced ray tracing and Fokker Planck simulation tools (GENRAY+CQL3D) constrained by experimental considerations. For a model and existing discharge, HFS LHCD scenarios with excellent wave penetration and current drive were identified. The LHCD is peaked off axis, ρ˜0.6-0.8, with FWHM Δρ=0.2 and driven current up to 0.37 MA/MW coupled. For HFS near mid plane launch, wave penetration is excellent and have access to single pass absorption scenarios for variety of plasmas for n||=2.6-3.4. These DIII-D discharge simulations indicate that HFS LHCD has potential to demonstrate efficient off axis current drive and current profile control in DIII-D existing and model discharge.

  15. Drive Electric Vermont Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Fred [Energetics Incorporated, Columbia, MD (United States); Roberts, Dave [Vermont Energy Investment Corporation (VEIC), Burlington, VT (United States); Francfort, Jim [Idaho National Lab. (INL), Idaho Falls, ID (United States); White, Sera [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-03-01

    Currently in the United States, the heavy majority of plug-in electric vehicle (PEV) sales have been in highly conducive, selected, metropolitan areas; opposed to more broad distribution across the country. The U.S. Department of Energy’s EV Everywhere Grand Challenge is looking carefully at the barriers and opportunities that exist to enable small and midsize communities to partake in the PEV market and benefit from the economic and environmental advantages of PEVs. In order to gain insight into these challenges and barriers, DOE selected a success story (i.e., Drive Electric Vermont) as the subject of this case study, as the state of Vermont is tied with Detroit, Michigan in having the highest percentage of 2014 (most recent complete data) PEV registrations for cold weather U.S. cities and has seen more than a sixfold increase in charging stations over the last three years. The overall objective of this case study was to use the lessons learned from Drive Electric Vermont to determine what activities are most effective at encouraging acquisitions of PEVs and deployment of charging infrastructure in small to midsize communities, prioritizing and sequencing their implementation, identifying robust means for extrapolation, and applying this understanding to other small to midsize communities across the nation. The Drive Electric Vermont Program was formed in 2012 with a goal of increasing the use of electrified transportation in Vermont through policy development, education and outreach, and infrastructure development. The Drive Electric Vermont Program can be broadly broken into four components: (1) strategic planning/leadership, (2) stakeholder/partnership development, (3) education and outreach, and (4) incentives. The early phases of the program focused heavily on strategic planning, and stakeholder and partnership development, followed by a transition to education and outreach activities, charging infrastructure development, and grant and incentive programs

  16. Expectations while car following--the consequences for driving behaviour in a simulated driving task.

    Science.gov (United States)

    Muhrer, Elke; Vollrath, Mark

    2010-11-01

    The purpose of this study was to better understand the causes of driver errors in the context of rear-end crashes. When drivers move in traffic they generate an overall assessment of the driving situation and what will happen in the near future. Certain cues in the traffic environment may create an expectation that some specific action is required. The more relevant cues are present, the more the driver will expect that some kind of intervention may be required. In contrary, if hardly any or no relevant cues are present, the driver does not anticipate that an imminent reaction will be necessary. This idea is supported by results from accident analyses which showed that in many cases, rear-end crashes occur in situations which are usually easy to handle (e.g. straight roads, low traffic density). In these situations, drivers may not anticipate that the driver in front will brake and they are thus following too closely to be able to react in time when the front vehicle suddenly brakes or stops. In order to test this hypothesis experimentally, in a driving simulator experiment different expectations were generated by varying the behaviour of a lead car (different braking behaviour, signalling or not before a turn). Driver behaviour was examined after these variations. The analyses partially confirm the influence of different expectations generated by the lead car's behaviour in the first phase of the scenario. Drivers with a respective expectation reacted faster when the car in front suddenly braked and signalled their manoeuvre before turning right at an intersection. However, during a car following phase, drivers did not adapt their speed or distance depending on this expectation. These results can be used to adapt a driver assistance system in car following situations. This should warn and intervene, especially in cases when drivers do not foresee the need for action and therefore cannot react in time. 2010 Elsevier Ltd. All rights reserved.

  17. The impact of immediate or delayed feedback on driving behaviour in a simulated Pay-As-You-Drive system.

    Science.gov (United States)

    Dijksterhuis, Chris; Lewis-Evans, Ben; Jelijs, Bart; de Waard, Dick; Brookhuis, Karel; Tucha, Oliver

    2015-02-01

    Pay-As-You-Drive (PAYD) insurance links an individual's driving behaviour to the insurance fee that they pay, making car insurance more actuarially accurate. The best known PAYD insurance format is purely mileage based and is estimated to reduce accidents by about 15% (Litman, 2011). However, these benefits could be further enhanced by incorporating a wider range of driving behaviours, such as lateral and longitudinal accelerations and speeding behaviour, thereby stimulating not only a safe but also an eco-friendly driving style. Currently, feedback on rewards and driver behaviour is mostly provided through a web-based interface, which is presented temporally separated from driving. However, providing immediate feedback within the vehicle itself could elicit more effect. To investigate this hypothesis, two groups of 20 participants drove with a behavioural based PAYD system in a driving simulator and were provided with either delayed feedback through a website, or immediate feedback through an in-car interface, allowing them to earn up to €6 extra. To be clear, every participant in the web group did actually view their feedback during the one week between sessions. Results indicate clear driving behaviour improvements for both PAYD groups as compared to baseline rides and an equal sized control group. After both PAYD groups had received feedback, the initial advantage of the in-car group was reduced substantially. Taken together with usability ratings and driving behaviours in specific situations these results show a moderate advantage of using immediate in-car feedback. However, the study also showed that under conditions of feedback certainty, the effectiveness of delayed feedback approaches that of immediate feedback as compared to a naïve control group. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. A pilot study of the effects of atomoxetine on driving performance in adults with ADHD.

    Science.gov (United States)

    Barkley, Russell A; Anderson, Deborah L; Kruesi, Markus

    2007-02-01

    There is a high risk of vehicular crashes, traffic citations, and poorer driving performance in adults with ADHD. This pilot study examines the value of a new nonstimulant (atomoxetine) for improving the driving performance of adults with ADHD. Atomoxetine (1.2 mg/kg daily for 3 weeks) and a placebo are studied on 18 adults with ADHD (M age = 37 years) using ratings of ADHD symptoms, impairment, and safe driving behavior; a virtual reality driving simulator; and ratings of simulator performance. Atomoxetine improves self-ratings of ADHD symptoms, impairments, safe driving behavior, and simulator driving performance. No effects of atomoxetine are evident on others' ratings of driving behavior or on the simulator. Practice effects on the simulator may have obscured those drug effects. The authors find a mixed pattern of results such that atomoxetine warrants further study for its effects on driving in this high-risk population.

  19. Assessing the Driver’s Current Level of Working Memory Load with High Density Functional Near-infrared Spectroscopy: A Realistic Driving Simulator Study

    Directory of Open Access Journals (Sweden)

    Anirudh Unni

    2017-04-01

    Full Text Available Cognitive overload or underload results in a decrease in human performance which may result in fatal incidents while driving. We envision that driver assistive systems which adapt their functionality to the driver’s cognitive state could be a promising approach to reduce road accidents due to human errors. This research attempts to predict variations of cognitive working memory load levels in a natural driving scenario with multiple parallel tasks and to reveal predictive brain areas. We used a modified version of the n-back task to induce five different working memory load levels (from 0-back up to 4-back forcing the participants to continuously update, memorize, and recall the previous ‘n’ speed sequences and adjust their speed accordingly while they drove for approximately 60 min on a highway with concurrent traffic in a virtual reality driving simulator. We measured brain activation using multichannel whole head, high density functional near-infrared spectroscopy (fNIRS and predicted working memory load level from the fNIRS data by combining multivariate lasso regression and cross-validation. This allowed us to predict variations in working memory load in a continuous time-resolved manner with mean Pearson correlations between induced and predicted working memory load over 15 participants of 0.61 [standard error (SE 0.04] and a maximum of 0.8. Restricting the analysis to prefrontal sensors placed over the forehead reduced the mean correlation to 0.38 (SE 0.04, indicating additional information gained through whole head coverage. Moreover, working memory load predictions derived from peripheral heart rate parameters achieved much lower correlations (mean 0.21, SE 0.1. Importantly, whole head fNIRS sampling revealed increasing brain activation in bilateral inferior frontal and bilateral temporo-occipital brain areas with increasing working memory load levels suggesting that these areas are specifically involved in workload

  20. Driving behavior recognition using EEG data from a simulated car-following experiment.

    Science.gov (United States)

    Yang, Liu; Ma, Rui; Zhang, H Michael; Guan, Wei; Jiang, Shixiong

    2017-11-23

    Driving behavior recognition is the foundation of driver assistance systems, with potential applications in automated driving systems. Most prevailing studies have used subjective questionnaire data and objective driving data to classify driving behaviors, while few studies have used physiological signals such as electroencephalography (EEG) to gather data. To bridge this gap, this paper proposes a two-layer learning method for driving behavior recognition using EEG data. A simulated car-following driving experiment was designed and conducted to simultaneously collect data on the driving behaviors and EEG data of drivers. The proposed learning method consists of two layers. In Layer I, two-dimensional driving behavior features representing driving style and stability were selected and extracted from raw driving behavior data using K-means and support vector machine recursive feature elimination. Five groups of driving behaviors were classified based on these two-dimensional driving behavior features. In Layer II, the classification results from Layer I were utilized as inputs to generate a k-Nearest-Neighbor classifier identifying driving behavior groups using EEG data. Using independent component analysis, a fast Fourier transformation, and linear discriminant analysis sequentially, the raw EEG signals were processed to extract two core EEG features. Classifier performance was enhanced using the adaptive synthetic sampling approach. A leave-one-subject-out cross validation was conducted. The results showed that the average classification accuracy for all tested traffic states was 69.5% and the highest accuracy reached 83.5%, suggesting a significant correlation between EEG patterns and car-following behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Implementation of Multi-Body Dynamics Simulation for the Conveyor Chain Drive System

    Directory of Open Access Journals (Sweden)

    Suvanjumrat Chakrit

    2017-01-01

    Full Text Available The conveyor chain drive system which included four sprockets, four flat bars (chain guides and one conveyor chain had been assembled into commercial software, MSC.ADAMS. The conveyor chain was connected with rollers for running on the chain guides. The multi-body dynamics (MBD simulation was implemented to study the large displacement of chain components which happened during rotations of the symmetric model of the conveyor chain drive system. The physical experiment had obtained by construction of the conveyor chain drive system regarding the MBD model. The speeds of chain drive were adjusted by a gear motor with a converter. The trajectory of conveyor chain links which respectively meshed and ran on sprockets and chain guides was recorded by a high speed camera. Furthermore, impact-contact forces by a collision of components in the conveyor chain drive system during rotation were analysis. The comparison between MBD simulation and physical experiment of the conveyor chain drive system was performed for validation of simulation models. The MBD simulation results were in good agreement with the experimental data which obtained an average error of 3.95%.

  2. Simulation research of acousto optic modulator drive based on Multisim

    Science.gov (United States)

    Wang, Shiqian; Guo, Yangkuan; Zhu, Lianqing; Na, Yunxiao; Zhang, Yinmin; Liu, Qianzhe

    2013-10-01

    The acousto optic modulator drive is mainly made with 2 amplitude shift keying (2ASK)circuit, pre-amplifier circuit and power operational amplifier circuit, and the simulation of the acousto optic modulator drive is realized. Firstly, the acousto optic modulator drive works as follows.The modulation function is realized by the analoged switch circuit, and the on-off of the analoged switch chip (CD4066) are controlled by the pulse signal generated by the electronic conversion circuit. The voltage amplification of the modulated signal is achieved by two reverse proportional operation implements voltage amplifier circuit, and the circuit is mainly made with the AD8001 chip. Then the amplified signal is transfered into a two-stage power operational amplifier circuit of class C which is mainly made with the chip of MRF158. Secondly, both of the simulating structures and the union debugging based on the designed system are realized by Multisim. Finally, obtaining the modulation signal of 150(MHz) frequency and 5(μs) pulse width illustrates that a 2ASk modulation of the 150 (MHz)carrier signal and the 20(kHz) modulation signal is achieved. Besides, as the frequency of input signal and amplitude of voltage change, the output power of the power operational amplifier circuit also changes, and the conclusion is drawn that the output power increases when the frequency of input signal decreases and the amplitude of voltage increases. The component selection of the drive's PCB design, the performance parameter and of the actual circuit and the debugging of the actual circuit are based on the simulation results.

  3. Detecting and Quantifying Mind Wandering during Simulated Driving.

    Science.gov (United States)

    Baldwin, Carryl L; Roberts, Daniel M; Barragan, Daniela; Lee, John D; Lerner, Neil; Higgins, James S

    2017-01-01

    Mind wandering is a pervasive threat to transportation safety, potentially accounting for a substantial number of crashes and fatalities. In the current study, mind wandering was induced through completion of the same task for 5 days, consisting of a 20-min monotonous freeway-driving scenario, a cognitive depletion task, and a repetition of the 20-min driving scenario driven in the reverse direction. Participants were periodically probed with auditory tones to self-report whether they were mind wandering or focused on the driving task. Self-reported mind wandering frequency was high, and did not statistically change over days of participation. For measures of driving performance, participant labeled periods of mind wandering were associated with reduced speed and reduced lane variability, in comparison to periods of on task performance. For measures of electrophysiology, periods of mind wandering were associated with increased power in the alpha band of the electroencephalogram (EEG), as well as a reduction in the magnitude of the P3a component of the event related potential (ERP) in response to the auditory probe. Results support that mind wandering has an impact on driving performance and the associated change in driver's attentional state is detectable in underlying brain physiology. Further, results suggest that detecting the internal cognitive state of humans is possible in a continuous task such as automobile driving. Identifying periods of likely mind wandering could serve as a useful research tool for assessment of driver attention, and could potentially lead to future in-vehicle safety countermeasures.

  4. Peer Passenger Norms and Pressure: Experimental Effects on Simulated Driving Among Teenage Males.

    Science.gov (United States)

    Bingham, C Raymond; Simons-Morton, Bruce G; Pradhan, Anuj K; Li, Kaigang; Almani, Farideh; Falk, Emily B; Shope, Jean T; Buckley, Lisa; Ouimet, Marie Claude; Albert, Paul S

    2016-08-01

    Serious crashes are more likely when teenage drivers have teenage passengers. One likely source of this increased risk is social influences on driving performance. This driving simulator study experimentally tested the effects of peer influence (i.e., risk-accepting compared to risk-averse peer norms reinforced by pressure) on the driving risk behavior (i.e., risky driving behavior and inattention to hazards) of male teenagers. It was hypothesized that peer presence would result in greater driving risk behavior (i.e., increased driving risk and reduced latent hazard anticipation), and that the effect would be greater when the peer was risk-accepting. Fifty-three 16- and 17-year-old male participants holding a provisional U.S., State of Michigan driver license were randomized to either a risk-accepting or risk-averse condition. Each participant operated a driving simulator while alone and separately with a confederate peer passenger. The simulator world included scenarios designed to elicit variation in driving risk behavior with a teen passenger present in the vehicle. Significant interactions of passenger presence (passenger present vs. alone) by risk condition (risk-accepting vs. risk-averse) were observed for variables measuring: failure to stop at yellow light intersections (Incident Rate Ratio (IRR)=2.16; 95% Confidence Interval [95CI]=1.06, 4.43); higher probability of overtaking (IRR=10.17; 95CI=1.43, 73.35); shorter left turn latency (IRR=0.43; 95CI=0.31,0.60); and, failure to stop at an intersection with an occluded stop sign (IRR=7.90; 95CI=2.06,30.35). In all cases, greater risky driving by participants was more likely with a risk-accepting passenger versus a risk-averse passenger present and a risk-accepting passenger present versus driving alone. Exposure of male teenagers to a risk-accepting confederate peer passenger who applied peer influence increased simulated risky driving behavior compared with exposure to a risk-averse confederate peer

  5. Cardiac autonomic control during simulated driving with a concurrent verbal working memory task.

    Science.gov (United States)

    Lenneman, John K; Backs, Richard W

    2009-06-01

    The objective of the study was to illustrate sensitivity and diagnosticity differences between cardiac measures and lane-keeping measures of driving performance. Previous research suggests that physiological measures can be sensitive to the effects of driving and side task performance and diagnostic of the source of the attentional demands. We hypothesized that increases in side task difficulty would elicit physiological change without reduction of driving task performance and that the side task demands would elicit patterns ofautonomic activity that map to specific attentional processing resources. Separately and concurrently, thirty-two participants performed a simulated driving task and verbal working memory task (with two levels of difficulty, 0 back and 3 back) separately and concurrently. Attentional demands were assessed through physiological and performance measures. Cardiac measures reflected changes in attentional demand from single- to dual-task driving with an n-back task, whereas lane-keeping measures did not. Furthermore, patterns of autonomic activity elicited by driving, n-back task, and dual-task driving with a 3-back task were consistent with our predictions about autonomic activity. Changes in cardiac measures without changes in lane-keeping measures provide evidence that cardiac measures can be sensitive to hidden costs in attention that do not manifest in coarse measures of driving performance. Furthermore, correct predictions regarding the patterns of autonomic activity elicited suggests that cardiac measures can serve as diagnostic tools for attention assessment. Because of the demonstrated differences in sensitivity and diagnosticity, researchers should consider the use of cardiac measures in addition to driving performance measures when studying attention in a driving simulator environment.

  6. Driving characteristics and adaptive cruise control : A naturalistic driving study

    NARCIS (Netherlands)

    Schakel, W.J.; Gorter, C.M.; de Winter, J.C.F.; van Arem, B.

    2017-01-01

    With the increasing number of vehicles equipped with Adaptive Cruise Control (ACC), it becomes important to assess its impact on traffic flow efficiency, in particular with respect to capacity and queue discharge rate. Simulation studies and surveys suggest that ACC has both positive and negative

  7. Solid-state-drives (SSDs) modeling simulation tools & strategies

    CERN Document Server

    2017-01-01

    This book introduces simulation tools and strategies for complex systems of solid-state-drives (SSDs) which consist of a flash multi-core microcontroller plus NAND flash memories. It provides a broad overview of the most popular simulation tools, with special focus on open source solutions. VSSIM, NANDFlashSim and DiskSim are benchmarked against performances of real SSDs under different traffic workloads. PROs and CONs of each simulator are analyzed, and it is clearly indicated which kind of answers each of them can give and at a what price. It is explained, that speed and precision do not go hand in hand, and it is important to understand when to simulate what, and with which tool. Being able to simulate SSD’s performances is mandatory to meet time-to-market, together with product cost and quality. Over the last few years the authors developed an advanced simulator named “SSDExplorer” which has been used to evaluate multiple phenomena with great accuracy, from QoS (Quality Of Service) to Read Retry, fr...

  8. Safety evaluation model of urban cross-river tunnel based on driving simulation.

    Science.gov (United States)

    Ma, Yingqi; Lu, Linjun; Lu, Jian John

    2017-09-01

    Currently, Shanghai urban cross-river tunnels have three principal characteristics: increased traffic, a high accident rate and rapidly developing construction. Because of their complex geographic and hydrological characteristics, the alignment conditions in urban cross-river tunnels are more complicated than in highway tunnels, so a safety evaluation of urban cross-river tunnels is necessary to suggest follow-up construction and changes in operational management. A driving risk index (DRI) for urban cross-river tunnels was proposed in this study. An index system was also constructed, combining eight factors derived from the output of a driving simulator regarding three aspects of risk due to following, lateral accidents and driver workload. Analytic hierarchy process methods and expert marking and normalization processing were applied to construct a mathematical model for the DRI. The driving simulator was used to simulate 12 Shanghai urban cross-river tunnels and a relationship was obtained between the DRI for the tunnels and the corresponding accident rate (AR) via a regression analysis. The regression analysis results showed that the relationship between the DRI and the AR mapped to an exponential function with a high degree of fit. In the absence of detailed accident data, a safety evaluation model based on factors derived from a driving simulation can effectively assess the driving risk in urban cross-river tunnels constructed or in design.

  9. Detecting and Quantifying Mind Wandering during Simulated Driving

    Directory of Open Access Journals (Sweden)

    Carryl L. Baldwin

    2017-08-01

    Full Text Available Mind wandering is a pervasive threat to transportation safety, potentially accounting for a substantial number of crashes and fatalities. In the current study, mind wandering was induced through completion of the same task for 5 days, consisting of a 20-min monotonous freeway-driving scenario, a cognitive depletion task, and a repetition of the 20-min driving scenario driven in the reverse direction. Participants were periodically probed with auditory tones to self-report whether they were mind wandering or focused on the driving task. Self-reported mind wandering frequency was high, and did not statistically change over days of participation. For measures of driving performance, participant labeled periods of mind wandering were associated with reduced speed and reduced lane variability, in comparison to periods of on task performance. For measures of electrophysiology, periods of mind wandering were associated with increased power in the alpha band of the electroencephalogram (EEG, as well as a reduction in the magnitude of the P3a component of the event related potential (ERP in response to the auditory probe. Results support that mind wandering has an impact on driving performance and the associated change in driver’s attentional state is detectable in underlying brain physiology. Further, results suggest that detecting the internal cognitive state of humans is possible in a continuous task such as automobile driving. Identifying periods of likely mind wandering could serve as a useful research tool for assessment of driver attention, and could potentially lead to future in-vehicle safety countermeasures.

  10. A Novel Assessment of Braking Reaction Time Following THA Using a New Fully Interactive Driving Simulator.

    Science.gov (United States)

    Ruel, Allison V; Lee, Yuo-Yu; Boles, John; Boettner, Friedrich; Su, Edwin; Westrich, Geoffrey H

    2015-07-01

    After total hip replacement surgery, patients are eager to resume the activities of daily life, particularly driving. Most surgeons recommend waiting 6 weeks after surgery to resume driving; however, there is no evidence to indicate that patients cannot resume driving earlier. Our purpose was to evaluate when in the recovery period following THA that patients regain or improve upon their preoperative braking reaction time, allowing them to safely resume driving. We measured and compared pre- and postoperative braking reaction times of 90 patients from 3 different surgeons using a Fully Interactive Driving Simulator (Simulator Systems International, Tulsa, OK). We defined a return to safe braking reaction time as a return to a time value that is either equal to or less than the preoperative braking reaction time. Patients tested at 2 and 3 weeks after surgery had slower braking reaction times than preoperative times by an average of 0.069 and 0.009 s, respectively. At 4 weeks after surgery, however, patients improved their reaction times by 0.035 s (p = 0.0398). In addition, at 2, 3, and 4 weeks postoperatively, the results also demonstrated that patient less than 70 years of age recovered faster. Based upon the results of this study, most patients should be allowed to return to driving 4 weeks following minimally invasive primary total hip arthroplasty.

  11. Engrossed in conversation: the impact of cell phones on simulated driving performance.

    Science.gov (United States)

    Beede, Kristen E; Kass, Steven J

    2006-03-01

    The current study examined the effects of cognitively distracting tasks on various measures of driving performance. Thirty-six college students with a median of 6 years of driving experience completed a driving history questionnaire and four simulated driving scenarios. The distraction tasks consisted of responding to a signal detection task and engaging in a simulated cell phone conversation. Driving performance was measured in terms of four categories of behavior: traffic violations (e.g., speeding, running stop signs), driving maintenance (e.g., standard deviation of lane position), attention lapses (e.g., stops at green lights, failure to visually scan for intersection traffic), and response time (e.g., time to step on brake in response to a pop-up event). Performance was significantly impacted in all four categories when drivers were concurrently talking on a hands-free phone. Performance on the signal detection task was poor and not significantly impacted by the phone task, suggesting that considerably less attention was paid to detecting these peripheral signals. However, the signal detection task did interact with the phone task on measures of average speed, speed variability, attention lapses, and reaction time. The findings lend further empirical support of the dangers of drivers being distracted by cell phone conversations.

  12. Effects of MDMA (ecstasy), and multiple drugs use on (simulated) driving performance and traffic safety

    NARCIS (Netherlands)

    Brookhuis, KA; de Waard, D; Samyn, N

    Rationale. The effects of MDMA on driving behaviour are not clear, since the direct effects of MDMA on cognitive performance are reported as not generally negative. Objectives. To assess in an advanced driving simulator acute effects on simulated driving behaviour and heart rate of MDMA, and effects

  13. [Effect of air-electric fields on driving and reaction patterns. Test subjects in the car driving simulator (author's transl)].

    Science.gov (United States)

    Anselm, D; Danner, M; Kirmaier, N; König, H L; Müller-Limmroth, W; Reis, A; Schauerte, W

    1977-06-10

    In the relevant frequency range of about 10 Hertz cars can be considered very largely as Faraday cages and consequently as screens against air-electric fields. This may have a negative influence on driving and reaction patterns as a result. In an extensive investigation 48 subjects in a driving simulator were exposed to definite artificially produced air-electric fields. The self-rating of the performance and concentration of the subjects, reaction times and driving errors were determined. While the reaction times remained practically constant, the driving behavior of the subjects improved.

  14. Effects of vibration on occupant driving performance under simulated driving conditions.

    Science.gov (United States)

    Azizan, Amzar; Fard, M; Azari, Michael F; Jazar, Reza

    2017-04-01

    Although much research has been devoted to the characterization of the effects of whole-body vibration on seated occupants' comfort, drowsiness induced by vibration has received less attention to date. There are also little validated measurement methods available to quantify whole body vibration-induced drowsiness. Here, the effects of vibration on drowsiness were investigated. Twenty male volunteers were recruited for this experiment. Drowsiness was measured in a driving simulator, before and after 30-min exposure to vibration. Gaussian random vibration, with 1-15 Hz frequency bandwidth was used for excitation. During the driving session, volunteers were required to obey the speed limit of 100 kph and maintain a steady position on the left-hand lane. A deviation in lane position, steering angle variability, and speed deviation were recorded and analysed. Alternatively, volunteers rated their subjective drowsiness by Karolinska Sleepiness Scale (KSS) scores every 5-min. Following 30-min of exposure to vibration, a significant increase of lane deviation, steering angle variability, and KSS scores were observed in all volunteers suggesting the adverse effects of vibration on human alertness level. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Electroencephalogram and electrocardiograph assessment of mental fatigue in a driving simulator.

    Science.gov (United States)

    Zhao, Chunlin; Zhao, Min; Liu, Jianpin; Zheng, Chongxun

    2012-03-01

    Mental fatigue is a contributing factor to some serious transportation crashes. In this study, we measured mental fatigue in drivers using electroencephalogram (EEG) and electrocardiograph (ECG). Together, thirteen healthy subjects performed a continuous simulated driving task for 90 min with simultaneous ECG and multi-channel EEG recording of each subject. Several important physiological parameters were investigated using preprocessed ECG and EEG signals. The results show that the EEG alpha and beta, the relative power, the amplitude of P300 wave of event-related potential (ERP), the approximated entropy of the ECG, and the lower and upper bands of power of heart rate variability (HRV) are significantly different before and after finishing the driving task (p<0.05). These metrics are possible indices for measuring simulated driving mental fatigue. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. A Refined Numerical Simulation on Dynamic Behavior of Roller Chain Drives

    Directory of Open Access Journals (Sweden)

    H. Zheng

    2004-01-01

    Full Text Available A refined numerical analysis of the dynamic behavior of roller chain drives is performed considering the roller assembly as a three-layer structure with mechanical clearance between each two of the mechanical components. Instead of using analytical method, explicit finite element technique is utilized for modeling and simulating the dynamic behavior of chain drives. The complete standard geometry of sprockets and all components of chain links are used in the developed model with minor geometry simplification. A primary goal is to achieve a more complete understanding of the dynamic behavior of chain drives especially in the transient vibration response of the engaging rollers, which is crucial for noise emission calculation. The simulated velocity response of the engaging rollers and roller-sprocket contact forces achieved using the full model are compared with what found by the simple model which has been adopted in analytical study of chain roller dynamics.

  17. Enhanced Computer Aided Simulation of Meshing and Contact With Application for Spiral Bevel Gear Drives

    National Research Council Canada - National Science Library

    Litvin, F

    1999-01-01

    An integrated tooth contact analysis (TCA) computer program for the simulation of meshing and contact of gear drives that calculates transmission errors and shift of hearing contact for misaligned gear drives has been developed...

  18. Automated generation of virtual scenarios in driving simulator from highway design data.

    Science.gov (United States)

    2010-09-01

    In 2008, the Texas Transportation Institute (TTI) began using a desktop driving simulator made by Realtime : Technologies, Inc. This system comes with a library of different roadway segment types that can be pieced : together to create driving scenar...

  19. Behavioral and Cardiovascular Responses to Frustration during Simulated Driving Tasks in Young Adults with and without Attention Disorder Symptoms

    Science.gov (United States)

    Oliver, Michele L.; Nigg, Joel T.; Cassavaugh, Nicholas D.; Backs, Richard W.

    2012-01-01

    Objective: The present study examined the role of negative emotions on driving performance in relation to ADHD, by comparing young adults scoring high on measures of ADHD (n = 20) with a control group (n = 22). Method: The authors used cardiorespiratory physiological measures, simulated driving behavior, and self-report to examine how participants…

  20. Real-Time Human in the Loop MBS Simulation in the Fraunhofer Robot-Based Driving Simulator

    Directory of Open Access Journals (Sweden)

    Kleer Michael

    2014-08-01

    Full Text Available The paper encompasses the overview of hardware architecture and the systems characteristics of the Fraunhofer driving simulator. First, the requirements of the real-time model and the real-time calculation hardware are defined and discussed in detail. Aspects like transport delay and the parallel computation of complex real-time models are presented. In addition, the interfacing of the models with the simulator system is shown. Two simulator driving tests, including a fully interactive rough terrain driving with a wheeled excavator and a test drive with a passenger car, are set to demonstrate system characteristics. Furthermore, the simulator characteristics of practical significance, such as simulator response time delay, simulator acceleration signal bandwidth obtained from artificial excitation and from the simulator driving test, will be presented and discussed.

  1. A study on the effects of fatigue driving and drunk driving on drivers' physical characteristics.

    Science.gov (United States)

    Zhang, Xingjian; Zhao, Xiaohua; Du, Hongji; Rong, Jian

    2014-01-01

    The purpose of this study was to analyze the effects of fatigue driving and drunk driving on drivers' physical characteristics; to analyze the differences in drivers' physical characteristics affected by different kinds of fatigue; and to compare the differences in the effects of the 2 driving states, fatigue driving and drunk driving. Twenty-five participants' physical characteristics were collected under 5 controlled situations: normal, tired driving, drowsy driving, drowsiness + tired driving, and drunk driving. In this article, fatigue driving refers to tiredness and drowsiness and includes 3 situations: tired driving, drowsy driving, and drowsiness + tired driving. The drivers' physical characteristics were measured in terms of 9 parameters: systolic blood pressure (SBP), heart rate (HR), eyesight, dynamic visual acuity (DVA), time for dark adaption (TDA), reaction time to sound (RTS), reaction time to light (RTL), deviation of depth perception (DDP), and time deviation of speed anticipation (TDSA). They were analyzed using analysis of variance (ANOVA) with repeated measures. Binary logistical regression analysis was used to explain the relationship between drivers' physical characteristics and the two driving states. Most of the drivers' physical characteristic parameters were found to be significantly different under the influence of different situations. Four indicators are significantly affected by fatigue driving during deep fatigue (in decreasing order of influence): HR, RTL, SBP and RTS. HR and RTL are significant in the logistical regression model of the drowsiness + tired driving situation and normal situations. Six indicators of the drivers' physical characteristics are significantly affected by drunk driving (in decreasing order of influence): SBP, RTL, DDP, eyesight, RTS, and TDSA. SBP and DDP have a significant effect in the logistical regression model of the drunk driving situation and the normal situation. Both fatigue driving and drunk driving

  2. Mathematical modeling and dynamic simulation of a class of drive systems with permanent magnet synchronous motors

    Directory of Open Access Journals (Sweden)

    Mikhov M.

    2009-12-01

    Full Text Available The performance of a two-coordinate drive system with permanent magnet synchronous motors is analyzed and discussed in this paper. Both motors have been controlled in brushless DC motor mode in accordance with the rotor positions. Detailed study has been carried out by means of mathematical modeling and computer simulation for the respective transient and steady-state regimes at various load and work conditions. The research carried out as well as the results obtained can be used in the design, optimization and tuning of such types of drive systems. They could be also applied in the teaching process.

  3. Dynamic stability of forklift trucks in cornering situations: parametrical analysis using a driving simulator

    Science.gov (United States)

    Lemerle, P.; Höppner, O.; Rebelle, J.

    2011-10-01

    This paper describes the examination of the vehicle dynamics and stability of four-wheeled forklift trucks (FLTs) in cornering situations. Cornering at excessive speed is one major reason for fatal accidents with forklifts caused by lateral tipover. In order to increase the lateral stability of this kind of working machinery, the influence of certain important design properties has been studied using an appropriate vehicle simulation model and a driving simulator. The simulation model is based on a multi-body system approach and includes submodels for the propulsion system and the tyres. The driving behaviour of the operator has not been modelled. Instead, a driving simulator has been built up and a real human driver was employed for ensuring adequate and realistic model input. As there have not been any suitable standardised test manoeuvres available for FLTs, a new driving test has been developed to assess the lateral stability. This test resembles the well-known J turn/Fishhook turn, but includes a more dynamic counter-steering action. Furthermore, the dimensions of the test track are defined. Therefore, the test is better adapted to the driving dynamics of forklifts and reflects the real driver behaviour more closely. Finally, a parametrical study has been performed, examining the influence of certain important technical properties of the truck such as the maximum speed, the position of centre of gravity, rear axle design features and tyre properties. The results of this study may lead to a better understanding of the vehicle dynamics of forklifts and facilitate goal-oriented design improvements.

  4. Application of a driving simulator to the development of in-vehicle human–machine-interfaces

    Directory of Open Access Journals (Sweden)

    David H. Weir

    2010-07-01

    Full Text Available The use of a driving simulator in the development of human–machine-interfaces (HMI such as a navigation, information or entertainment system is discussed. Such use addresses the need to study and evaluate the characteristics of a candidate HMI early in the R&D and design stage to ensure that it is likely to meet various objectives and requirements, and to revise the HMI as may be necessary. Those HMI requirements include such things as usability, driver comfort, and an acceptable level of attentional demand in dual task conditions (driving while using an HMI. Typically, such an HMI involves an information display to the driver, and a means for driver input to the HMI. Corresponding simulator requirements are discussed, along with typical simulator features and components. The latter include a cab, control feel systems, visual image generator, real time scenario control (task definitions, a motion system (if provided, and data acquisition. Both fixed and moving base systems are described, together with associated benefits and tradeoffs. Considerations in the design of the evaluation experiment are discussed, including definition of primary and secondary tasks, and number of driver subjects (experimental participants. Possible response and performance measures for the primary and secondary tasks are noted, together with subjective measures such as task difficulty and ease of using the HMI. The advantages of using a driving simulator to support R&D are summarized. Some typical and example simulator uses are noted.

  5. EMERGENCY BRAKING IN ADULTS VERSUS NOVICE TEEN DRIVERS: RESPONSE TO SIMULATED SUDDEN DRIVING EVENTS.

    Science.gov (United States)

    Loeb, Helen S; Kandadai, Venk; McDonald, Catherine C; Winston, Flaura K

    Motor vehicle crashes remain the leading cause of death in teens in the United States. Newly licensed drivers are the group most at risk for crashes. Their driving skills are very new, still very often untested, so that their ability to properly react in an emergency situation remains a research question. Since it is impossible to expose human subjects to critical life threatening driving scenarios, researchers have been increasingly using driving simulators to assess driving skills. This paper summarizes the results of a driving scenario in a study comparing the driving performance of novice teen drivers (n=21) 16-17 year olds with 90 days of provisional licensure with that of experienced adult drivers (n=17) 25-50 year olds with at least 5 years of PA licensure, at least 100 miles driven per week and no self-reported collisions in the previous 3 years. As part of a 30 to 35 simulated drive that encompassed the most common scenarios that result in serious crashes, participants were exposed to a sudden car event. As the participant drove on a suburban road, a car surged from a driveway hidden by a fence on the right side of the road. To avoid the crash, participants must hard brake, exhibiting dynamic control over both attentional and motor resources. The results showed strong differences between the experienced adult and novice teen drivers in the brake pressure applied. When placed in the same situation, the novice teens decelerated on average 50% less than the experienced adults (p<0.01).

  6. Training driving ability in a traumatic brain-injured individual using a driving simulator: a case report

    Directory of Open Access Journals (Sweden)

    Imhoff S

    2017-02-01

    Full Text Available Sarah Imhoff,1,2 Martin Lavallière,3,4 Mathieu Germain-Robitaille,5 Normand Teasdale,5–7 Philippe Fait,1,2,8 1Department of Human Kinetics, 2Research Group on Neuromusculoskeletal Dysfunctions (GRAN, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada; 3Massachusetts Institute of Technology AgeLab, Cambridge, MA, USA; 4Department of Health Sciences, Program of Kinesiology, Université du Québec à Chicoutimi, Chicoutimi, 5Faculté de Médecine, Département de Kinésiologie, 6Groupe de recherche en analyse du mouvement et ergonomie, Université Laval, 7CHU de Québec – Université Laval, Centre d’excellence sur le vieillissement de Québec, 8Research Center in Neuropsychology and Cognition (CERNEC, Montréal, QC, Canada Background: Traumatic brain injury (TBI causes functional deficits that may significantly interfere with numerous activities of daily living such as driving. We report the case of a 20-year-old woman having lost her driver’s license after sustaining a moderate TBI.Objective: We aimed to evaluate the effectiveness of an in-simulator training program with automated feedback on driving performance in a TBI individual.Methods: The participant underwent an initial and a final in-simulator driving assessment and 11 in-simulator training sessions with driving-specific automated feedbacks. Driving performance (simulation duration, speed regulation and lateral positioning was measured in the driving simulator.Results: Speeding duration decreased during training sessions from 1.50 ± 0.80 min (4.16 ± 2.22% to 0.45 ± 0.15 min (0.44 ± 0.42% but returned to initial duration after removal of feedbacks for the final assessment. Proper lateral positioning improved with training and was maintained at the final assessment. Time spent in an incorrect lateral position decreased from 18.85 min (53.61% in the initial assessment to 1.51 min (4.64% on the final assessment.Conclusion: Driving simulators represent an

  7. Use of a driving simulator to assess performance under adverse weather conditions in adults with albinism.

    Science.gov (United States)

    Hofman, Gwen M; Summers, C Gail; Ward, Nicholas; Bhargava, Esha; Rakauskas, Michael E; Holleschau, Ann M

    2012-04-01

    Participants with albinism have reduced vision and nystagmus with reduced foveation times. This prospective study evaluated driving in 12 participants with albinism and 12 matched controls. Participants drove a vehicle simulator through a virtual rural course in sunny and foggy conditions. Under sunny conditions, participants with albinism showed a narrower preferred minimum safety boundary during car-following tasks than did controls, but there was no difference under foggy conditions. Their driving did not differ significantly from that of controls when approaching a stop sign or when choosing gap size between oncoming vehicles when crossing an intersection. However, when compared to control drivers, participants with albinism had a decreased minimum safety boundary for car-following that should be included in counseling regarding driving safety.

  8. Effects of two doses of alcohol on simulator driving performance in adults with attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Barkley, Russell A; Murphy, Kevin R; O'Connell, Trisha; Anderson, Deborah; Connor, Daniel F

    2006-01-01

    Prior studies have documented greater impairments in driving performance and greater alcohol consumption among adults with attention-deficit/hyperactivity disorder (ADHD). This study examined whether alcohol consumption produces a differentially greater impairment in driving among adults with ADHD in comparison to a community control group. The present study compared 50 adults with ADHD (mean age 33 years) and 40 control adults (mean age 29 years) on the effects of 2 single, acute doses of alcohol (0.04 and 0.08 blood alcohol concentration) and a placebo on their driving performance. The authors used a virtual reality driving simulator, examiner and self-ratings of simulator performance, and a continuous performance test (CPT) to evaluate attention and inhibition. Approximately half of the adults in each group were randomized to either the low or high dose alcohol treatment arms. Alcohol consumption produced a greater impact on the CPT inattention measures of the ADHD than the control group. Similar results were obtained for the behavioral observations taken during the operation of the driving simulator. Driving simulator scores, however, showed mainly a deleterious effect of alcohol on all participants but no differentially greater effect on the ADHD group. The present results demonstrated that alcohol may have a greater detrimental effect on some aspects of driving performance in ADHD than control adults.

  9. CyberTORCS: An Intelligent Vehicles Simulation Platform for Cooperative Driving

    Directory of Open Access Journals (Sweden)

    Ming Yang

    2011-05-01

    Full Text Available Simulation platforms play an important role in helping intelligent vehicle research, especially for the research of cooperative driving due to the high cost and risk of the real experiments. In order to ease and bring more convenience for cooperative driving tests, we introduce an intelligent vehicle simulation platform, called CyberTORCS, for the research in cooperative driving. Details of the simulator modules including vehicle body control, vehicle visualization modeling and track visualization modeling are presented. Two simulation examples are given to validate the feasibility and effectiveness of the proposed simulation platform.

  10. Distractions N' Driving: video game simulation educates young drivers on the dangers of texting while driving.

    Science.gov (United States)

    Saqer, Haneen; de Visser, Ewart; Strohl, Jonathan; Parasuraman, Raja

    2012-01-01

    The proliferation of portable communication and entertainment devices has introduced new dangers to the driving environment, particularly for young and inexperienced drivers. Graduate students from George Mason University illustrate a powerful, practical, and cost-effective program that has been successful in educating these drivers on the dangers of texting while driving, which can easily be adapted and implemented in other communities.

  11. EMERGENCY BRAKING IN ADULTS VERSUS NOVICE TEEN DRIVERS: RESPONSE TO SIMULATED SUDDEN DRIVING EVENTS

    OpenAIRE

    Loeb, Helen S.; Kandadai, Venk; McDonald, Catherine C.; Winston, Flaura K.

    2015-01-01

    Motor vehicle crashes remain the leading cause of death in teens in the United States. Newly licensed drivers are the group most at risk for crashes. Their driving skills are very new, still very often untested, so that their ability to properly react in an emergency situation remains a research question. Since it is impossible to expose human subjects to critical life threatening driving scenarios, researchers have been increasingly using driving simulators to assess driving skills. This pap...

  12. Effects of two doses of methylphenidate on simulator driving performance in adults with attention deficit hyperactivity disorder.

    Science.gov (United States)

    Barkley, Russell A; Murphy, Kevin R; O'Connell, Trisha; Connor, Daniel F

    2005-01-01

    Numerous studies have documented an increased frequency of vehicular crashes, traffic citations, driving performance deficits, and driving-related cognitive impairments in teens and adults with attention deficit hyperactivity disorder. The present study evaluated the effects of two single, acute doses of methylphenidate (10 and 20 mg) and a placebo on the driving performance of 53 adults with ADHD (mean age=37 years, range=18-65) using a virtual reality driving simulator, examiner and self-ratings of simulator performance, and a continuous performance test (CPT) to evaluate attention and inhibition. A double-blind, drug-placebo, within-subjects crossover design was used in which all participants were tested at baseline and then experienced all three drug conditions. A significant beneficial effect for the high dose of medication was observed on impulsiveness on CPT, variability of steering in the standard driving course, and driving speed during the obstacle course. A beneficial effect of the low dose of medication also was evident on turn signal use during the standard driving course. An apparent practice effect was noted on some of the simulator measures between the baseline and subsequent testing sessions that may have interacted with and thereby obscured drug effects on those measures. The results, when placed in the context of prior studies of stimulants on driving performance, continue to recommend their clinical use as one means of reducing the driving risks in ADHD teens and adults. Given the significantly higher risk of adverse driving outcomes associated with ADHD, industry needs to better screen for ADHD among employees who drive as part of employment so as to improve safety and reduce costs. Use of stimulants to treat the adult ADHD driver may reduce safety risks.

  13. Driving simulator performance of veterans from the Iraq and Afghanistan wars.

    Science.gov (United States)

    Amick, Melissa M; Kraft, Melissa; McGlinchey, Regina

    2013-01-01

    Driving simulator performance was examined in Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) Veterans to objectively evaluate driving abilities among this cohort who self-report poorer driving safety postdeployment. OIF/OEF Veterans (n = 25) and age- and education-matched civilian controls (n = 25) participated in a 30 min driving simulator assessment that measured the frequency of minor, moderate, and severe driving errors. Frequency of errors in specific content domains (speed regulation, positioning, and signaling) was also calculated. All participants answered questions about number of lifetime traffic "warnings," moving violation tickets, and accidents. Veterans completed the Posttraumatic Stress Disorder (PTSD) Checklist-Military Version. On the driving simulator assessment, Veterans committed more minor, moderate, severe, and speeding errors and reported poorer lifetime driving records than the civilian control group. Exploratory analyses revealed an association between increasing errors on the driving simulator with increasing symptoms of PTSD, although statistically this correlation did not reach significance. These findings suggest that Veterans perform more poorly on an objective evaluation of driving safety and that the presence of PTSD could be associated with worse performance on this standardized driving simulator assessment.

  14. The impact of Stereotype Threat on the simulated driving performance of older drivers.

    Science.gov (United States)

    Joanisse, Mélanie; Gagnon, Sylvain; Voloaca, Mihnea

    2013-01-01

    Older drivers are perceived as being dangerous and overly cautious by other drivers. We tested the hypothesis that this negative stereotype has a direct influence on the performance of older drivers. Based on the Stereotype Threat literature, we predicted that older driving performance would be altered after exposure to a Stereotype Threat. Sixty-one older drivers aged 65 and above completed a simulated driving assessment course. Prior to testing, half of the participants were told that the objective of the study was to investigate why older adults aged 65 and above were more implicated in on-road accidents (Stereotype Threat condition) and half were showed a neutral statement. Results confirmed that exposure to the threat significantly altered driving performance. Older adults in the Stereotype Threat condition made more driving mistakes than those in the control group. Interestingly, under a Stereotype Threat condition, older adults tended to commit more speeding infractions. We also observed that domain identification (whether driving is deemed important or not) moderated the impact of the threat. Taken together, these results support recent older drivers' performance models suggesting that the interaction between individual and social factors need to be considered when examining older drivers' performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Algebraic software analysis and embedded simulation of a driving robot

    NARCIS (Netherlands)

    Merkx, L.L.F.; Cuijpers, P.J.L.; Duringhof, H.M.

    2007-01-01

    At TNO Automotive the Generic Driving Actuator (GDA) is developed. The GDA is a device capable of driving a vehicle fully automatically using the same interface as a human driverdoes. In this paper, the design of the GDA is discussed. The software and hardware of the GDA and its effect on vehicle

  16. The pattern of the electromagnetic field emitted by mobile phones in motor vehicle driving simulators

    Directory of Open Access Journals (Sweden)

    Piotr Politański

    2013-06-01

    Full Text Available Introduction: The paper reports the results of the determinations of UMTS EMF distributions in the driver's cab of motor vehicle simulators. The results will serve as the basis for future research on the influence of EMF emitted by mobile phones on driver physiology. Materials and Methods: Two motor vehicle driving simulators were monitored, while an EMF source was placed at the driver's head or on the dashboard of the motor vehicle driving simulator. For every applied configuration, the maximal electric field strength was measured, as were the values at 16 points corresponding to chosen locations on a driver's or passenger's body. Results: When the power was set for the maximum (49 mW, a value of 27 V/m was measured in the vicinity of the driver's head when the phone was close to the head. With the same power, when the phone was placed on the dashboard, the measured maximum was 15.2 V/m in the vicinity of the driver's foot. Similar results were obtained for the passenger. Significant perturbations in EMF distribution and an increase in electric field strength values in the motor vehicle driving simulator were also observed in comparison to free space measurements, and the electric field strength was up to 3 times higher inside the simulator. Conclusions: This study can act as the basis of future studies concerning the influence of the EMF emitted by mobile phones on the physiology of the driver. Additionally, the authors postulate that it is advisable to keep mobile phones at a distance from the head, i.e. use, whenever possible, hands-free kits to reduce EMF exposure, both for drivers and passengers.

  17. Brain activity during driving with distraction: an immersive fMRI study

    Directory of Open Access Journals (Sweden)

    Tom A Schweizer

    2013-02-01

    Full Text Available Introduction: Non-invasive measurements of brain activity have an important role to play in understanding driving ability. The current study aimed to identify the neural underpinnings of human driving behavior by visualizing the areas of the brain involved in driving under different levels of demand, such as driving while distracted or making left turns at busy intersections. Methods: To capture brain activity during driving, we placed a driving simulator with a fully functional steering wheel and pedals in a 3.0 Tesla functional magnetic resonance imaging (fMRI system. To identify the brain areas involved while performing different real-world driving maneuvers, participants completed tasks ranging from simple (right turns to more complex (left turns at busy intersections. To assess the effects of driving while distracted, participants were asked to perform an auditory task while driving analogous to speaking on a hands-free device and driving. Results: A widely distributed brain network was identified, especially when making left turns at busy intersections compared to more simple driving tasks. During distracted driving, brain activation shifted dramatically from the posterior, visual and spatial areas to the prefrontal cortex. Conclusions: Our findings suggest that the distracted brain sacrificed areas in the posterior brain important for visual attention and alertness to recruit enough brain resources to perform a secondary, cognitive task. The present findings offer important new insights into the scientific understanding of the neuro-cognitive mechanisms of driving behavior and lay down an important foundation for future clinical research.

  18. Simple gaze-contingent cues guide eye movements in a realistic driving simulator

    Science.gov (United States)

    Pomarjanschi, Laura; Dorr, Michael; Bex, Peter J.; Barth, Erhardt

    2013-03-01

    Looking at the right place at the right time is a critical component of driving skill. Therefore, gaze guidance has the potential to become a valuable driving assistance system. In previous work, we have already shown that complex gaze-contingent stimuli can guide attention and reduce the number of accidents in a simple driving simulator. We here set out to investigate whether cues that are simple enough to be implemented in a real car can also capture gaze during a more realistic driving task in a high-fidelity driving simulator. We used a state-of-the-art, wide-field-of-view driving simulator with an integrated eye tracker. Gaze-contingent warnings were implemented using two arrays of light-emitting diodes horizontally fitted below and above the simulated windshield. Thirteen volunteering subjects drove along predetermined routes in a simulated environment popu­ lated with autonomous traffic. Warnings were triggered during the approach to half of the intersections, cueing either towards the right or to the left. The remaining intersections were not cued, and served as controls. The analysis of the recorded gaze data revealed that the gaze-contingent cues did indeed have a gaze guiding effect, triggering a significant shift in gaze position towards the highlighted direction. This gaze shift was not accompanied by changes in driving behaviour, suggesting that the cues do not interfere with the driving task itself.

  19. Impacts of a Congestion Assistant on driving behaviour and acceptance using a driving simulator

    NARCIS (Netherlands)

    Driel, C.J.G. van; Hoedemaeker, D.M.; Arem, B. van

    2007-01-01

    In-vehicle systems that assist the driver with his driving task are developed and introduced to the market at increasing rate. Drivers may be supported during congested traffic conditions by a so-called Congestion Assistant consisting of a mix of informing, assisting and controlling functions. This

  20. Impacts of a congestion assistant on driving behaviour and acceptance using a driving simulator

    NARCIS (Netherlands)

    van Driel, Cornelie; Hoedemaker, M.; van Arem, Bart

    2007-01-01

    In-vehicle systems that assist the driver with his driving task are developed and introduced to the market at increasing rate. Drivers may be supported during congested traffic conditions by a so-called Congestion Assistant consisting of a mix of informing, assisting and controlling functions. This

  1. Accuracy of Self-Evaluation in Adults with ADHD: Evidence from a Driving Study

    Science.gov (United States)

    Knouse, Laura E.; Bagwell, Catherine L.; Barkley, Russell A.; Murphy, Kevin R.

    2005-01-01

    Research on children with ADHD indicates an association with inaccuracy of self-appraisal. This study examines the accuracy of self-evaluations in clinic-referred adults diagnosed with ADHD. Self-assessments and performance measures of driving in naturalistic settings and on a virtual-reality driving simulator are used to assess accuracy of…

  2. Can Driving-Simulator Training Enhance Visual Attention, Cognition, and Physical Functioning in Older Adults?

    Directory of Open Access Journals (Sweden)

    Mathias Haeger

    2018-01-01

    Full Text Available Virtual reality offers a good possibility for the implementation of real-life tasks in a laboratory-based training or testing scenario. Thus, a computerized training in a driving simulator offers an ecological valid training approach. Visual attention had an influence on driving performance, so we used the reverse approach to test the influence of a driving training on visual attention and executive functions. Thirty-seven healthy older participants (mean age: 71.46 ± 4.09; gender: 17 men and 20 women took part in our controlled experimental study. We examined transfer effects from a four-week driving training (three times per week on visual attention, executive function, and motor skill. Effects were analyzed using an analysis of variance with repeated measurements. Therefore, main factors were group and time to show training-related benefits of our intervention. Results revealed improvements for the intervention group in divided visual attention; however, there were benefits neither in the other cognitive domains nor in the additional motor task. Thus, there are no broad training-induced transfer effects from such an ecologically valid training regime. This lack of findings could be addressed to insufficient training intensities or a participant-induced bias following the cancelled randomization process.

  3. Age differences in the takeover of vehicle control and engagement in non-driving-related activities in simulated driving with conditional automation.

    Science.gov (United States)

    Clark, Hallie; Feng, Jing

    2017-09-01

    High-level vehicle automation has been proposed as a valuable means to enhance the mobility of older drivers, as older drivers experience age-related declines in many cognitive functions that are vital for safe driving. Recent research attempted to examine age differences in how engagement in non-driving-related activities impact driving performance, by instructing drivers to engage in mandatory pre-designed activities. While the mandatory engagement method allows a precise control of the timing and mental workload of the non-driving-related activities, it is different from how a driver would naturally engage in these activities. This study allowed younger (age 18-35, mean age=19.9years) and older drivers (age 62-81, mean age=70.4years) to freely decide when and how to engage in voluntarily chosen non-driving-related activities during simulated driving with conditional automation. We coded video recordings of participants' engagement in non-driving-related activities. We examined the effect of age, level of activity-engagement and takeover notification interval on vehicle control performance during the takeover, by comparing between the high and low engagement groups in younger and older drivers, across two takeover notification interval conditions. We found that both younger and older drivers engaged in various non-driving-related activities during the automated driving portion, with distinct preferences on the type of activity for each age group (i.e., while younger drivers mostly used an electronic device, older drivers tended to converse). There were also significant differences between the two age groups and between the two notification intervals on various driving performance measures. Older drivers benefited more than younger drivers from the longer interval in terms of response time to notifications. Voluntary engagement in non-driving-related activities did not impair takeover performance in general, although there was a trend of older drivers who were

  4. Study of the Effects of Alcohol on Drivers and Driving Performance on Straight Road

    Directory of Open Access Journals (Sweden)

    Xiaohua Zhao

    2014-01-01

    Full Text Available Drinking driving is responsible for a high proportion of traffic accidents. To study the effects of alcohol on drivers and driving performance, 25 drivers’ subjective feelings and driving performance data in different blood-alcohol concentration (BAC levels were collected with simulated driving experiment. The investigation results revealed that alcohol affected drivers in many aspects, including attitude, judgment, vigilance, perception, reaction, and controlling. The analysis of accident rate showed that higher BAC level would lead to higher accident rate. The statistical analysis results of driving performance indicated that average speed, speed standard deviation, and lane position standard deviation were significantly higher under the influence of alcohol. They also had a statistically significant linear trend as the function of BAC level. The discrimination of drinking driving based on driving performance was performed with Fisher discrimination method. The results showed that drinking driving with higher BAC level was easier to discriminate from normal driving. Also, the results indicated that the three significant indicators on straight roadway could be used in the discrimination of drinking driving state. The conclusions can provide references for the study of drinking driving and the identification of driving state and then contribute to traffic safety.

  5. Suitability of Synthetic Driving Profiles from Traffic Micro-Simulation for Real-World Energy Analysis: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Yunfei; Wood, Eric; Burton, Evan; Gonder, Jeffrey

    2015-10-14

    A shift towards increased levels of driving automation is generally expected to result in improved safety and traffic congestion outcomes. However, little empirical data exists to estimate the impact that automated driving could have on energy consumption and greenhouse gas emissions. In the absence of empirical data on differences between drive cycles from present day vehicles (primarily operated by humans) and future vehicles (partially or fully operated by computers) one approach is to model both situations over identical traffic conditions. Such an exercise requires traffic micro-simulation to not only accurately model vehicle operation under high levels of automation, but also (and potentially more challenging) vehicle operation under present day human drivers. This work seeks to quantify the ability of a commercial traffic micro-simulation program to accurately model real-world drive cycles in vehicles operated primarily by humans in terms of driving speed, acceleration, and simulated fuel economy. Synthetic profiles from models of freeway and arterial facilities near Atlanta, Georgia, are compared to empirical data collected from real-world drivers on the same facilities. Empirical and synthetic drive cycles are then simulated in a powertrain efficiency model to enable comparison on the basis of fuel economy. Synthetic profiles from traffic micro-simulation were found to exhibit low levels of transient behavior relative to the empirical data. Even with these differences, the synthetic and empirical data in this study agree well in terms of driving speed and simulated fuel economy. The differences in transient behavior between simulated and empirical data suggest that larger stochastic contributions in traffic micro-simulation (relative to those present in the traffic micro-simulation tool used in this study) are required to fully capture the arbitrary elements of human driving. Interestingly, the lack of stochastic contributions from models of human drivers

  6. Driving context influences drivers' decision to engage in visual-manual phone tasks: Evidence from a naturalistic driving study.

    Science.gov (United States)

    Tivesten, Emma; Dozza, Marco

    2015-06-01

    Visual-manual (VM) phone tasks (i.e., texting, dialing, reading) are associated with an increased crash/near-crash risk. This study investigated how the driving context influences drivers' decisions to engage in VM phone tasks in naturalistic driving. Video-recordings of 1,432 car trips were viewed to identify VM phone tasks and passenger presence. Video, vehicle signals, and map data were used to classify driving context (i.e., curvature, other vehicles) before and during the VM phone tasks (N=374). Vehicle signals (i.e., speed, yaw rate, forward radar) were available for all driving. VM phone tasks were more likely to be initiated while standing still, and less likely while driving at high speeds, or when a passenger was present. Lead vehicle presence did not influence how likely it was that a VM phone task was initiated, but the drivers adjusted their task timing to situations when the lead vehicle was increasing speed, resulting in increasing time headway. The drivers adjusted task timing until after making sharp turns and lane change maneuvers. In contrast to previous driving simulator studies, there was no evidence of drivers reducing speed as a consequence of VM phone task engagement. The results show that experienced drivers use information about current and upcoming driving context to decide when to engage in VM phone tasks. However, drivers may fail to sufficiently increase safety margins to allow time to respond to possible unpredictable events (e.g., lead vehicle braking). Advanced driver assistance systems should facilitate and possibly boost drivers' self-regulating behavior. For instance, they might recognize when appropriate adaptive behavior is missing and advise or alert accordingly. The results from this study could also inspire training programs for novice drivers, or locally classify roads in terms of the risk associated with secondary task engagement while driving. Copyright © 2015. Published by Elsevier Ltd.

  7. Developing a simulation framework for safe and optimal trajectories considering drivers’ driving style

    DEFF Research Database (Denmark)

    Gruber, Thierry; Larue, Grégoire S.; Rakotonirainy, Andry

    2017-01-01

    Advanced driving assistance systems (ADAS) have huge potential for improving road safety and travel times. However, their take-up in the market is very slow; and these systems should consider driver's preferences to increase adoption rates. The aim of this study is to develop a model providing...... drivers with the optimal trajectory considering the motorist's driving style in real time. Travel duration and safety are the main parameters used to find the optimal trajectory. A simulation framework to determine the optimal trajectory was developed in which the ego car travels in a highway environment...... safe and fast trajectories in three tests scenarios: emergency braking, overtaking and a complex situation with multiple vehicles around the ego vehicle. Different driver profiles were then tested in the complex scenario, showing that the proposed approach can adapt to driver preferences and provide...

  8. Measuring listening effort: driving simulator versus simple dual-task paradigm.

    Science.gov (United States)

    Wu, Yu-Hsiang; Aksan, Nazan; Rizzo, Matthew; Stangl, Elizabeth; Zhang, Xuyang; Bentler, Ruth

    2014-01-01

    The dual-task paradigm has been widely used to measure listening effort. The primary objectives of the study were to (1) investigate the effect of hearing aid amplification and a hearing aid directional technology on listening effort measured by a complicated, more real world dual-task paradigm and (2) compare the results obtained with this paradigm to a simpler laboratory-style dual-task paradigm. The listening effort of adults with hearing impairment was measured using two dual-task paradigms, wherein participants performed a speech recognition task simultaneously with either a driving task in a simulator or a visual reaction-time task in a sound-treated booth. The speech materials and road noises for the speech recognition task were recorded in a van traveling on the highway in three hearing aid conditions: unaided, aided with omnidirectional processing (OMNI), and aided with directional processing (DIR). The change in the driving task or the visual reaction-time task performance across the conditions quantified the change in listening effort. Compared to the driving-only condition, driving performance declined significantly with the addition of the speech recognition task. Although the speech recognition score was higher in the OMNI and DIR conditions than in the unaided condition, driving performance was similar across these three conditions, suggesting that listening effort was not affected by amplification and directional processing. Results from the simple dual-task paradigm showed a similar trend: hearing aid technologies improved speech recognition performance, but did not affect performance in the visual reaction-time task (i.e., reduce listening effort). The correlation between listening effort measured using the driving paradigm and the visual reaction-time task paradigm was significant. The finding showing that our older (56 to 85 years old) participants' better speech recognition performance did not result in reduced listening effort was not

  9. Multiphysics simulation by design for electrical machines, power electronics and drives

    CERN Document Server

    Rosu, Marius; Lin, Dingsheng; Ionel, Dan M; Popescu, Mircea; Blaabjerg, Frede; Rallabandi, Vandana; Staton, David

    2018-01-01

    This book combines the knowledge of experts from both academia and the software industry to present theories of multiphysics simulation by design for electrical machines, power electronics, and drives. The comprehensive design approach described within supports new applications required by technologies sustaining high drive efficiency. The highlighted framework considers the electric machine at the heart of the entire electric drive. The book also emphasizes the simulation by design concept--a concept that frames the entire highlighted design methodology, which is described and illustrated by various advanced simulation technologies. Multiphysics Simulation by Design for Electrical Machines, Power Electronics and Drives begins with the basics of electrical machine design and manufacturing tolerances. It also discusses fundamental aspects of the state of the art design process and includes examples from industrial practice. It explains FEM-based analysis techniques for electrical machine design--providing deta...

  10. NIMROD Simulation of multipulsed edge-current drive in SSPX

    Science.gov (United States)

    Lodestro, L. L.; Cohen, B. I.; Hooper, E. B.; McLean, H. S.; Wood, R. D.

    2009-11-01

    Flux amplification (A)---the ratio of poloidal magnetic flux enclosed by a spheromak's toroidal core to an applied edge flux---is a critical parameter for an economic spheromak-based fusion reactor. In [1], measurements of A in SSPX and NIMROD simulations [2] were found to be in good agreement over a range of discharge parameters while Amodular capacitor bank gave some indication that |dIgun/dt| played a role and that increasing it might build magnetic field more efficiently, but were limited by gun discharge circuit inductance. In [3], multipulsed gun injection was investigated numerically and the results compared to SSPX. Here we report the continuation of those simulations to longer times. We find trends on timescales much longer than could be studied in SSPX, negligible effect on A of multipulsed injection at frequencies smaller than the fundamental SSPX reconnection frequency, and small increases in A for large frequencies.[4pt] [1] B. Hudson et al., Phys. Plasmas 15, 056112 (2008).[0pt] [2] E.B. Hooper et al., Nucl. Fusion 47, 1064 (2007).[0pt] [3] L.L. LoDestro et al., 50^th DPP, TP6-93 (2008).

  11. Car Driving Performance in Hemianopia : An On-Road Driving Study

    NARCIS (Netherlands)

    De Haan, Gera A.; Melis-Dankers, Bart J. M.; Brouwer, Wiebo H.; Bredewoud, Ruud A.; Tucha, Oliver; Heutink, Joost

    2014-01-01

    PURPOSE. To study driving performance in people with homonymous hemianopia (HH) assessed in the official on-road test of practical fitness to drive by the Dutch driver's licensing authority (CBR). METHODS. Data were collected from a cohort (January 2010-July 2012) of all people with HH following the

  12. Detection of braking intention in diverse situations during simulated driving based on EEG feature combination.

    Science.gov (United States)

    Kim, Il-Hwa; Kim, Jeong-Woo; Haufe, Stefan; Lee, Seong-Whan

    2015-02-01

    We developed a simulated driving environment for studying neural correlates of emergency braking in diversified driving situations. We further investigated to what extent these neural correlates can be used to detect a participant's braking intention prior to the behavioral response. We measured electroencephalographic (EEG) and electromyographic signals during simulated driving. Fifteen participants drove a virtual vehicle and were exposed to several kinds of traffic situations in a simulator system, while EEG signals were measured. After that, we extracted characteristic features to categorize whether the driver intended to brake or not. Our system shows excellent detection performance in a broad range of possible emergency situations. In particular, we were able to distinguish three different kinds of emergency situations (sudden stop of a preceding vehicle, sudden cutting-in of a vehicle from the side and unexpected appearance of a pedestrian) from non-emergency (soft) braking situations, as well as from situations in which no braking was required, but the sensory stimulation was similar to stimulations inducing an emergency situation (e.g., the sudden stop of a vehicle on a neighboring lane). We proposed a novel feature combination comprising movement-related potentials such as the readiness potential, event-related desynchronization features besides the event-related potentials (ERP) features used in a previous study. The performance of predicting braking intention based on our proposed feature combination was superior compared to using only ERP features. Our study suggests that emergency situations are characterized by specific neural patterns of sensory perception and processing, as well as motor preparation and execution, which can be utilized by neurotechnology based braking assistance systems.

  13. Detection of braking intention in diverse situations during simulated driving based on EEG feature combination

    Science.gov (United States)

    Kim, Il-Hwa; Kim, Jeong-Woo; Haufe, Stefan; Lee, Seong-Whan

    2015-02-01

    Objective. We developed a simulated driving environment for studying neural correlates of emergency braking in diversified driving situations. We further investigated to what extent these neural correlates can be used to detect a participant's braking intention prior to the behavioral response. Approach. We measured electroencephalographic (EEG) and electromyographic signals during simulated driving. Fifteen participants drove a virtual vehicle and were exposed to several kinds of traffic situations in a simulator system, while EEG signals were measured. After that, we extracted characteristic features to categorize whether the driver intended to brake or not. Main results. Our system shows excellent detection performance in a broad range of possible emergency situations. In particular, we were able to distinguish three different kinds of emergency situations (sudden stop of a preceding vehicle, sudden cutting-in of a vehicle from the side and unexpected appearance of a pedestrian) from non-emergency (soft) braking situations, as well as from situations in which no braking was required, but the sensory stimulation was similar to stimulations inducing an emergency situation (e.g., the sudden stop of a vehicle on a neighboring lane). Significance. We proposed a novel feature combination comprising movement-related potentials such as the readiness potential, event-related desynchronization features besides the event-related potentials (ERP) features used in a previous study. The performance of predicting braking intention based on our proposed feature combination was superior compared to using only ERP features. Our study suggests that emergency situations are characterized by specific neural patterns of sensory perception and processing, as well as motor preparation and execution, which can be utilized by neurotechnology based braking assistance systems.

  14. Simulation of three-phase induction motor drives using indirect field oriented control in PSIM environment

    Science.gov (United States)

    Aziri, Hasif; Patakor, Fizatul Aini; Sulaiman, Marizan; Salleh, Zulhisyam

    2017-09-01

    This paper presents the simulation of three-phase induction motor drives using Indirect Field Oriented Control (IFOC) in PSIM environment. The asynchronous machine is well known about natural limitations fact of highly nonlinearity and complexity of motor model. In order to resolve these problems, the IFOC is applied to control the instantaneous electrical quantities such as torque and flux component. As FOC is controlling the stator current that represented by a vector, the torque component is aligned with d coordinate while the flux component is aligned with q coordinate. There are five levels of the incremental system are gradually built up to verify and testing the software module in the system. Indeed, all of system build levels are verified and successfully tested in PSIM environment. Moreover, the corresponding system of five build levels are simulated in PSIM environment which is user-friendly for simulation studies in order to explore the performance of speed responses based on IFOC algorithm for three-phase induction motor drives.

  15. Effects of mood induction via music on cardiovascular measures of negative emotion during simulated driving.

    Science.gov (United States)

    Fairclough, Stephen H; van der Zwaag, Marjolein; Spiridon, Elena; Westerink, Joyce

    2014-04-22

    A study was conducted to investigate the potential of mood induction via music to influence cardiovascular correlates of negative emotions experience during driving behaviour. One hundred participants were randomly assigned to one of five groups, four of whom experienced different categories of music: High activation/positive valence (HA/PV), high activation/negative valence (HA/NV), low activation/positive valence (LA/PV) and low activation/negative valence (LA/NV). Following exposure to their respective categories of music, participants were required to complete a simulated driving journey with a fixed time schedule. Negative emotion was induced via exposure to stationary traffic during the simulated route. Cardiovascular reactivity was measured via blood pressure, heart rate and cardiovascular impedance. Subjective self-assessment of anger and mood was also recorded. Results indicated that low activation music, regardless of valence, reduced systolic reactivity during the simulated journey relative to HA/NV music and the control (no music) condition. Self-reported data indicated that participants were not consciously aware of any influence of music on their subjective mood. It is concluded that cardiovascular reactivity to negative mood may be mediated by the emotional properties of music. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Indicators of Simulated Driving Skills in Adolescents with Attention Deficit Hyperactivity Disorder

    Directory of Open Access Journals (Sweden)

    Sherrilene Classen PhD, MPH, OTR/L, FAOTA

    2014-01-01

    Full Text Available Adolescents with attention deficit hyperactivity disorder (ADHD have an increased risk for committing traffic violations, and they are four times more likely than neurotypical peers to be crash involved, making them a potentially high risk group for driving. We used a two-group design to measure differences in demographics, clinical off-road tests, and fitness to drive abilities in a driving simulator with nine adolescents with ADHD (mean age = 15.00, SD ± 1.00 compared to 22 healthy controls (HC (mean age = 14.32, SD ±..716, as evaluated by an Occupational Therapist Certified Driving Rehabilitation Specialist (OT-CDRS. Despite few demographic differences, the adolescents with ADHD performed worse than the HC on tests of right visual acuity (F = 5.92, p = .036, right peripheral field (F = 6.85, p = .019, selective attention (U = 53.00, p = .046, and motor coordination (U = 53.00, p = .046. The ADHD group made more visual scanning (U = 52.50, p = .041, speed regulation (U = 28.00, p = .001, and total driving errors (U = 32.50, p = .003 on the simulator. Adolescents with ADHD performed worse on tests measuring visual, cognitive, motor, and pre-driving skills, and on a driving simulator. They may require the services of an OT-CDRS to determine their fitness to drive abilities prior to referring them for driver’s education.

  17. Quantum simulation of the general semi-classical Rabi model in regimes of arbitrarily strong driving

    Science.gov (United States)

    Dai, Kunzhe; Wu, Haiteng; Zhao, Peng; Li, Mengmeng; Liu, Qiang; Xue, Guangming; Tan, Xinsheng; Yu, Haifeng; Yu, Yang

    2017-12-01

    We propose and experimentally demonstrate a scheme to simulate the interaction between a two-level system and a classical light field. Under the transversal driving of two microwave tones, the effective Hamiltonian in an appropriate rotating frame is identical to that of the general semi-classical Rabi model. We experimentally realize this Hamiltonian with a superconducting transmon qubit. By tuning the strength, phase, and frequency of the two microwave driving fields, we simulate the quantum dynamics from the weak to extremely strong driving regime. Under these conditions, we observe that, as a function of increased Rabi drive strength, the qubit evolution gradually deviates from the normal sinusoidal Rabi oscillation, in accordance with the predictions of the general semi-classical Rabi model far beyond the weak driving limit. Our scheme provides an effective approach to investigate the extremely strong interaction between a two-level system and a classical light field. Such strong interactions are usually inaccessible in experiments.

  18. Study on dynamic lifting characteristics of control rod drive mechanism

    International Nuclear Information System (INIS)

    Shen Xiaoyao

    2012-01-01

    Based on the equations of the electric circuit and the magnetic circuit and analysis of the dynamic lifting process for the control rod drive mechanism (CRDM), coupled magnetic-electric-mechanical equations both for the static status and the dynamic status are derived. The analytical method is utilized to obtain the current and the time when the lift starts. The numerical simulation method of dynamic analysis recommended by ASME Code is utilized to simulate the dynamic lifting process of CRDM, and the dynamic features of the system with different design gaps are studied. Conclusions are drawn as: (1) the lifting-start time increases with the design gap, and the time for the lifting process is longer with larger gaps; (2) the lifting velocity increases with time; (3) the lifting acceleration increases with time, and with smaller gaps, the impact acceleration is larger. (author)

  19. Examining the usability of a virtual reality driving simulator.

    Science.gov (United States)

    Schultheis, Maria T; Rebimbas, Jose; Mourant, Ronald; Millis, Scott R

    2007-01-01

    The current study examined specific aspects of usability of a newly developed VR driver rehabilitation (VR-DR) system. Measures of user feedback and user comfort were examined among 54 participants: 33 individuals with acquired brain injury (20 with traumatic brain injury and 13 with cerebral vascular accident) and 21 healthy controls. All participants were administered the VR-DR and completed the VR-DR User Feedback Questionnaire. To examine group differences, a one-way analysis of variance was performed, comparing the user feedback total score between the three groups. The results indicated that the two clinical populations (traumatic brain injury and cerebral vascular accident) varied from the nonclinical population (healthy controls). A standard multiple regression analysis revealed that age was the only significant participant factor that contributed to the differences in user feedback ratings. Finally, consistent across the three groups, a distinct relationship was found between the self-reported user rating and the onset of simulation sickness. The current findings indicate that individuals with traumatic brain injury and cerebral vascular accident provided less favorable user feedback ratings than healthy controls in the use of a new VR-DR system. This difference was not accounted for by differences in gender, education, or cognitive status and was only slightly accounted for by age. Delineating these various aspects of user feedback can assist in identifying potential confounds in VR-DR performance and help refine the application of the VR-DR for clinical decision making.

  20. A Forest Structure Dynamics Model for Driving Three-Dimensional Canopy Radiative Transfer Simulations

    Science.gov (United States)

    Yang, W.; Kobayashi, H.; Kondoh, A.

    2016-12-01

    Three-dimensional (3-D) Monte Carlo (MC)-based radiative transfer (RT) models can simulate highly detailed forest environments, and have produced simulations that agree well with observations; thus, they are routinely used for benchmarking in intercomparisons of RT models. However, MC-based RT models have not been widely applied to the development of inversion algorithms for generating global remote sensing products of forests, due mainly to the difficulties in obtaining realistic forest structures for a variety of forest biomes. In this study, we developed a Forest Structure Dynamics Model (FSDM) to facilitate the application of MC-based RT models to global forests. In this model, the tree architectures are determined based on allometric equations, and the tree locations within a study domain are determined by statistical distributions. The performance of the FSDM was evaluated using field measurements of forest landscapes at two sites located at Järvselja, Estonia and the Poker Flat Research Range (PFRR), USA, respectively. The bidirectional reflectance factor (BRF) for the two study sites was simulated by an MC-based RT model, based on the measured forest stands and modeled stands from the FSDM. A comparison of the results demonstrated that the simulated BRF based on the measured forest stands agreed well with the simulated BRF based on the modeled stands from the FSDM for the two study sites. The applicability of the FSDM to a leaf area index (LAI) retrieval algorithm was also verified using simulations from the MC-based RT model. The results indicate that the FSDM can provide reasonable forest structures to drive 3-D canopy RT models, with no loss of simulation accuracy. When combined with several existing field data sets and satellite products, the FSDM can be used to generate a typical stand structure database for global forest biomes.

  1. Measuring working memory load effects on electrophysiological markers of attention orienting during a simulated drive.

    Science.gov (United States)

    Ross, Veerle; Vossen, Alexandra Y; Smulders, Fren T Y; Ruiter, Robert A C; Brijs, Tom; Brijs, Kris; Wets, Geert; Jongen, Ellen M M

    2018-03-01

    Intersection accidents result in a significant proportion of road fatalities, and attention allocation likely plays a role. Attention allocation may depend on (limited) working memory (WM) capacity. Driving is often combined with tasks increasing WM load, consequently impairing attention orienting. This study (n = 22) investigated WM load effects on event-related potentials (ERPs) related to attention orienting. A simulated driving environment allowed continuous lane-keeping measurement. Participants were asked to orient attention covertly towards the side indicated by an arrow, and to respond only to moving cars appearing on the attended side by pressing a button. WM load was manipulated using a concurrent memory task. ERPs showed typical attentional modulation (cue: contralateral negativity, LDAP; car: N1, P1, SN and P3) under low and high load conditions. With increased WM load, lane-keeping performance improved, while dual task performance degraded (memory task: increased error rate; orienting task: increased false alarms, smaller P3). Practitioner Summary: Intersection driver-support systems aim to improve traffic safety and flow. However, in-vehicle systems induce WM load, increasing the tendency to yield. Traffic flow reduces if drivers stop at inappropriate times, reducing the effectiveness of systems. Consequently, driver-support systems could include WM load measurement during driving in the development phase.

  2. Potential benefits and costs of concurrent task engagement to maintain vigilance: a driving simulator investigation.

    Science.gov (United States)

    Atchley, Paul; Chan, Mark

    2011-02-01

    The objective of this study was to investigate the nature of concurrent task interference during a vigilance task and to determine whether a concurrent task improves performance with decreased vigilance. Research has repeatedly shown that engaging in a cell phone conversation while driving increases the risk of getting into crashes. At the same time, it has also been found that task monotony could lead to an increase in crash risk. There is evidence that suggests that engaging in a concurrent task reduces the effects of monotony, leading to an improvement in vigilance task performance. A monotonous drive in a driving simulator was used to investigate the effects of a concurrent verbal task. Three task conditions were used: no verbal task, continuous verbal task, and late verbal task. When engaged in a secondary verbal task, drivers showed improved lane-keeping performance and steering control when vigilance was lowest. A strategically placed concurrent task can improve performance when vigilance is at its lowest. There is potential for the design of a countermeasure system that can be strategically activated by an automated system monitoring driver performance.

  3. A study of dynamics performance improvement by rear right and left independent drive system

    Science.gov (United States)

    Sugano, Takashi; Fukuba, Hitoshi; Suetomi, Takamasa

    2010-11-01

    In this study, methods of motion control on a rear right and left independent electric motor drive vehicle and the benefit for drivers when using this configuration were researched. The system offers direct yaw moment control (DYC) function and it is possible to compensate for the vehicle turning motion. On the other hand, a rear drive vehicle often becomes unstable at a situation of acceleration in a turn. Even if the DYC system controls the vehicle motion, there are performance limits. One of the cause considered is that the characteristics of rear tyres are changed by the driving force. Control methods that focused especially on this point were examined, and the performance of independent drive system was evaluated by a simulation. Moreover, the effects on driver were confirmed with a driving simulator. The effectiveness of the system was confirmed from these results.

  4. Occupant Kinematics in Simulated Autonomous Driving Vehicle Collisions: Influence of Seating Position, Direction and Angle.

    Science.gov (United States)

    Kitagawa, Yuichi; Hayashi, Shigeki; Yamada, Katsunori; Gotoh, Mitsuaki

    2017-11-01

    This two-part study analyzed occupant kinematics in simulated collisions of future automated driving vehicles in terms of seating configuration. In part one, a frontal collision was simulated with four occupants with the front seats reversed. The left front seat occupant was unbelted while the others were belted. In part two of the study, occupant restraint was examined in various seating configurations using a single seat model with a three-point seatbelt. The seat direction with respect to impact was considered as forward, rearward, and lateral facing in 45 degree increments. The effect of seat recline was also studied in the forward-facing and rear-facing cases by assuming three positions: driving position, resting position and relaxed position. Occupants were represented by human body finite element models. The results of part one showed that the front seat (rear-facing) occupants were restrained by the seatback, resulting in T1 forward displacement less than 100 mm; the rear seat occupants were restrained by the seatbelt resulting larger T1 forward displacement more than 500 mm. The results of the part two showed the directional dependence of occupant restraint. Greater T1 displacements were observed when the occupant faced lateral or front oblique. However, the seatbelt provided some restraint in all directions considered. The seatback generated contact force to the occupant when it was in the impact direction, including the lateral directions. The relaxed position allowed increased excursion compared to the driving position when the occupant faced rearward, but the magnitude of this increase was lower with lower impact speed.

  5. Enhancing Entropy and Enthalpy Fluctuations to Drive Crystallization in Atomistic Simulations.

    Science.gov (United States)

    Piaggi, Pablo M; Valsson, Omar; Parrinello, Michele

    2017-07-07

    Crystallization is a process of great practical relevance in which rare but crucial fluctuations lead to the formation of a solid phase starting from the liquid. As in all first order first transitions, there is an interplay between enthalpy and entropy. Based on this idea, in order to drive crystallization in molecular simulations, we introduce two collective variables, one enthalpic and the other entropic. Defined in this way, these collective variables do not prejudge the structure into which the system is going to crystallize. We show the usefulness of this approach by studying the cases of sodium and aluminum that crystallize in the bcc and fcc crystalline structures, respectively. Using these two generic collective variables, we perform variationally enhanced sampling and well tempered metadynamics simulations and find that the systems transform spontaneously and reversibly between the liquid and the solid phases.

  6. Enhancing Entropy and Enthalpy Fluctuations to Drive Crystallization in Atomistic Simulations

    Science.gov (United States)

    Piaggi, Pablo M.; Valsson, Omar; Parrinello, Michele

    2017-07-01

    Crystallization is a process of great practical relevance in which rare but crucial fluctuations lead to the formation of a solid phase starting from the liquid. As in all first order first transitions, there is an interplay between enthalpy and entropy. Based on this idea, in order to drive crystallization in molecular simulations, we introduce two collective variables, one enthalpic and the other entropic. Defined in this way, these collective variables do not prejudge the structure into which the system is going to crystallize. We show the usefulness of this approach by studying the cases of sodium and aluminum that crystallize in the bcc and fcc crystalline structures, respectively. Using these two generic collective variables, we perform variationally enhanced sampling and well tempered metadynamics simulations and find that the systems transform spontaneously and reversibly between the liquid and the solid phases.

  7. Driving Pattern Analysis for Electric Vehicle (EV) Grid Integration Study

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Nielsen, Arne Hejde; Østergaard, Jacob

    2010-01-01

    In order to facilitate the integration of electric vehicles (EVs) into the Danish power system, the driving data in Denmark were analyzed to extract the information of driving distances and driving time periods which were used to represent the driving requirements and the EV unavailability...... from the driving time periods to show how many cars are available for charging and discharging in each time period. The obtained EV availability data are in one hour time periods and one quarter time periods for different study purposes. The EV availability data of one hour time period are to be used...

  8. Bringing Hollywood to the Driving School: Dynamic Scenario Generation in Simulations and Games

    NARCIS (Netherlands)

    Wassink, I.; van Dijk, Elisabeth M.A.G.; Zwiers, Jakob; Nijholt, Antinus; Maybury, M.; Stock, O.; Wahlster, W.

    2005-01-01

    In this paper we discuss a framework for simulation software called the movie metaphor. It is applied to the Dutch Driving Simulator for dynamic control of traffic scenarios. This framework resolves software complexity by the use of agent protocols inspired by the way of working on a movie set. It

  9. Microscopic Car Modeling for Intelligent Traffic and Scenario Generation in the UCF Driving Simulator : Year 2

    Science.gov (United States)

    2000-01-01

    A multi-year project was initiated to introduce autonomous vehicles in the University of Central Florida (UCF) Driving Simulator for real-time interaction with the simulator vehicle. This report describes the progress during the second year. In the f...

  10. Analyzing and Driving Cluster Formation in Atomistic Simulations.

    Science.gov (United States)

    Tribello, Gareth A; Giberti, Federico; Sosso, Gabriele C; Salvalaglio, Matteo; Parrinello, Michele

    2017-03-14

    In this paper a set of computational tools for identifying the phases contained in a system composed of atoms or molecules is introduced. The method is rooted in graph theory and combines atom centered symmetry functions, adjacency matrices, and clustering algorithms to identify regions of space where the properties of the system constituents can be considered uniform. We show how this method can be used to define collective variables and how these collective variables can be used to enhance the sampling of nucleation events. We then show how this method can be used to analyze simulations of crystal nucleation and growth by using it to analyze simulations of the nucleation of the molecular crystal urea and simulations of nucleation in a semiconducting alloy. The semiconducting alloy example we discuss is particular challenging as multiple nucleation centers are formed. We show, however, that our algorithm is able to detect the grain boundaries in the resulting polycrystal.

  11. The impact of sleep disorders on driving safety-findings from the Second Strategic Highway Research Program naturalistic driving study.

    Science.gov (United States)

    Liu, Shu-Yuan; Perez, Miguel A; Lau, Nathan

    2018-04-01

    This study investigated the association between driving safety and seven sleep disorders amongst 3541 participants of the Second Strategic Highway Research Program (SHRP 2) naturalistic driving study. SHRP 2 collected naturalistic driving data from participants between 16 and 98 years old by instrumenting participants' vehicles. The analyses used logistic regression to determine the likelihood of crash or near-crash involvement, Poisson log-linear regression to assess crash or near-crash rate, and ordinal logistic regression to assess driver maneuver appropriateness and crash or near-crash severity. These analyses did not account for any medical treatments for the sleep disorders. Females with restless legs syndrome/Willis-Ekbom disease (RLS/WED), drivers with insomnia or narcolepsy, are associated with significantly higher risk of crash or near-crash. Drivers with shift work sleep disorder (SWSD) are associated with significantly increased crash or near-crash rate. Females with RLS/WED or sleep apnea and drivers with SWSD are associated with less safe driver maneuver and drivers with periodic limb movement disorder are associated with more severe events. The four analyses provide no evidence of safety decrements associated with migraine. This study is the first examination on the association between seven sleep disorders and different measures of driving risk using large-scale naturalistic driving study data. The results corroborate much of the existing simulator and epidemiological research related to sleep-disorder patients and their driving safety, but add ecological validity to those findings. These results contribute to the empirical basis for medical professionals, policy makers, and employers in making decisions to aid individuals with sleep disorders in balancing safety and personal mobility.

  12. Effects of acute alcohol consumption on measures of simulated driving: A systematic review and meta-analysis.

    Science.gov (United States)

    Irwin, Christopher; Iudakhina, Elizaveta; Desbrow, Ben; McCartney, Danielle

    2017-05-01

    Driving simulators are used in a wide range of research settings to help develop an understanding of driver behavior in complex environments. Acute alcohol impairment is an important research topic for traffic safety and a large number of studies have indicated levels of simulated driving impairment imposed by alcohol across a range of performance outcome variables. The aim of the present study was to examine the impact of acute alcohol consumption on simulated driving performance by conducting a systematic review and meta-analysis of the available evidence. The online databases PubMed (MEDLINE), Web of Science (via Thomas Reuters) and Scopus were searched to identify studies that measured simulated car driving performance under control ('no alcohol' or 'placebo alcohol' ingestion) and intervention (acute alcohol ingestion) conditions, using repeated-measures experimental designs. Primary research outcomes were standard deviation of lane position (SDLP) and standard deviation of speed (SDSP); (total number of lane crossings (LC) and average speed (Speed) were secondary research outcomes). Meta-analytic procedures were used to quantify the effect of acute alcohol consumption on vehicle control, and to determine the influence of methodological variables (i.e. the duration of the simulated driving task, the limb of the BAC curve (ascending vs. descending) and the type of driving simulator employed (i.e. car vs. PC-based)) on the magnitude of the performance change due to alcohol consumption. 423 records were screened, and 50 repeated-measures trials (n=962 participants, 62% male) derived from 17 original publications were reviewed. 37 trials (n=721 participants) used a 'placebo alcohol' comparator to determine the effect of alcohol consumption on SDLP (32/37) and SDSP (22/37). Alcohol consumption significantly increased SDLP by 4.0±0.5cm (95% CI: 3.0, 5.1) and SDSP by 0.38±0.10km⋅h -1 (95% CI: 0.19, 0.57). Regression analyses indicate BAC (p=0.004) and driving

  13. The death drive in tourism studies

    NARCIS (Netherlands)

    Buda, Dorina Maria

    2015-01-01

    The psychoanalytical concept of the death drive postulated by Freud and Lacan refers to a constant force at the junction between life and death, which is not understood in a biological sense of physical demise of the body, nor in opposition to life. Tourist experiences in conflict zones can be more

  14. HIL Simulation of Power Electronics and Electric Drives for Automotive Applications

    Directory of Open Access Journals (Sweden)

    Frank Puschmann

    2012-12-01

    Full Text Available Hardware-in-the-loop simulation is today a standard method for testing electronic equipment in the automotive industry. Since electric drives and power electronic devices are more and more important in automotive applications, these kinds of systems have to be integrated into the hardware-in-the-loop simulation. Power converters and electric drives are used in many different applications in vehicles today (hybrid electric or electric powertrain, electric steering systems, DC-DC converters, etc.. The wide range of applications, topologies, and power levels results in various different approaches and solutions for hardware-in-the-loop testing. This paper gives an overview of hardware-in-the-loop simulation of power electronics and electric drives in the automotive industry. The currently available technologies are described and future challenges are outlined.

  15. Driving Ordering Processes in Molecular-Dynamics Simulations

    Science.gov (United States)

    Dittmar, Harro; Kusalik, Peter G.

    2014-05-01

    Self-organized criticality describes the emergence of complexity in dynamical nonequilibrium systems. In this paper we introduce a unique approach whereby a driven energy conversion is utilized as a sampling bias for ordered arrangements in molecular dynamics simulations of atomic and molecular fluids. This approach gives rise to dramatically accelerated nucleation rates, by as much as 30 orders of magnitude, without the need of predefined order parameters, which commonly employed rare-event sampling methods rely on. The measured heat fluxes suggest how the approach can be generalized.

  16. Speech Auditory Alerts Promote Memory for Alerted Events in a Video-Simulated Self-Driving Car Ride.

    Science.gov (United States)

    Nees, Michael A; Helbein, Benji; Porter, Anna

    2016-05-01

    Auditory displays could be essential to helping drivers maintain situation awareness in autonomous vehicles, but to date, few or no studies have examined the effectiveness of different types of auditory displays for this application scenario. Recent advances in the development of autonomous vehicles (i.e., self-driving cars) have suggested that widespread automation of driving may be tenable in the near future. Drivers may be required to monitor the status of automation programs and vehicle conditions as they engage in secondary leisure or work tasks (entertainment, communication, etc.) in autonomous vehicles. An experiment compared memory for alerted events-a component of Level 1 situation awareness-using speech alerts, auditory icons, and a visual control condition during a video-simulated self-driving car ride with a visual secondary task. The alerts gave information about the vehicle's operating status and the driving scenario. Speech alerts resulted in better memory for alerted events. Both auditory display types resulted in less perceived effort devoted toward the study tasks but also greater perceived annoyance with the alerts. Speech auditory displays promoted Level 1 situation awareness during a simulation of a ride in a self-driving vehicle under routine conditions, but annoyance remains a concern with auditory displays. Speech auditory displays showed promise as a means of increasing Level 1 situation awareness of routine scenarios during an autonomous vehicle ride with an unrelated secondary task. © 2016, Human Factors and Ergonomics Society.

  17. Design and Simulation of an Electrothermal Actuator Based Rotational Drive

    Science.gov (United States)

    Beeson, Sterling; Dallas, Tim

    2008-10-01

    As a participant in the Micro and Nano Device Engineering (MANDE) Research Experience for Undergraduates program at Texas Tech University, I learned how MEMS devices operate and the limits of their operation. Using specialized AutoCAD-based design software and the ANSYS simulation program, I learned the MEMS fabrication process used at Sandia National Labs, the design limitations of this process, the abilities and drawbacks of micro devices, and finally, I redesigned a MEMS device called the Chevron Torsional Ratcheting Actuator (CTRA). Motion is achieved through electrothermal actuation. The chevron (bent-beam) actuators cause a ratcheting motion on top of a hub-less gear so that as voltage is applied the CTRA spins. The voltage applied needs to be pulsed and the frequency of the pulses determine the angular frequency of the device. The main objective was to design electromechanical structures capable of transforming the electrical signals into mechanical motion without overheating. The design was optimized using finite element analysis in ANSYS allowing multi-physics simulations of our model system.

  18. Theoretical studies of non inductive current drive in compact toroids

    NARCIS (Netherlands)

    Farengo, R; Lifschitz, AF; Caputi, KI; Arista, NR; Clemente, RA

    Three non inductive current drive methods that can be applied to compact toroids axe studied. The use of neutral beams to drive current in field reversed configurations and spheromaks is studied using a Monte Carlo code that includes a complete ionization package and follows the exact particle

  19. The simulation of emergent dispatch of cars for intelligent driving autos

    Science.gov (United States)

    Zheng, Ziao

    2018-03-01

    It is widely acknowledged that it is important for the development of intelligent cars to be widely accepted by the majority of car users. While most of the intelligent cars have the system of monitoring itself whether it is on the good situation to drive, it is also clear that studies should be performed on the way of cars for the emergent rescue of the intelligent vehicles. In this study, writer focus mainly on how to derive a separate system for the car caring teams to arrive as soon as they get the signal sent out by the intelligent driving autos. This simulation measure the time for the rescuing team to arrive, the cost it spent on arriving on the site of car problem happens, also how long the queue is when the rescuing auto is waiting to cross a road. This can be definitely in great use when there are a team of intelligent cars with one car immediately having problems causing it's not moving and can be helpful in other situations. Through this way, the interconnection of cars can be a safety net for the drivers encountering difficulties in any time.

  20. The comparing analysis of simulation of emergent dispatch of cars for intelligent driving autos in crossroads

    Science.gov (United States)

    Zheng, Ziao

    2018-03-01

    It is widely acknowledged that it is important for the development of intelligent cars to be widely accepted by the majority of car users. While most of the intelligent cars have the system of monitoring itself whether it is on the good situation to drive, it is also clear that studies should be performed on the way of cars for the emergent rescue of the intelligent vehicles. In this study, writer focus mainly on how to derive a separate system for the car caring teams to arrive as soon as they get the signal sent out by the intelligent driving autos. This simulation measure the time for the rescuing team to arrive, the cost it spent on arriving on the site of car problem happens, also how long the queue is when the rescuing auto is waiting to cross a road. This can be definitely in great use when there are a team of intelligent cars with one car immediately having problems causing its not moving and can be helpful in other situations. Through this way, the interconnection of cars can be a safety net for the drivers encountering difficulties in any time.

  1. Study on Driving Performance of the Axial-Flow Blood Pump under the Condition of Large Gap

    Directory of Open Access Journals (Sweden)

    Yan Xu

    2017-01-01

    Full Text Available The paper demonstrates an improvement of the simulation and computational methods for research on the system magnetic field and driving performance of the large gap magnetic drive system, which is used to drive the axial flow blood pump. The operational principle and structure of large gap magnetic drive system are narrated. Ansoft is adopted to simulate a three-dimensional driving torque to improve accuracy of computation. Experiments and theoretical study show that the use of Z10-T25 oriented silicon steel sheets as the electromagnetic core material can remarkably improve the system driving performance as well as optimize the volume and weight of the electromagnets. So the electromagnet made with oriented silicon steel sheets is conducive to improving the driving performance.

  2. Evaluation of blue light exposure to beta brainwaves on simulated night driving

    Science.gov (United States)

    Purawijaya, Dandri Aly; Fitri, Lulu Lusianti; Suprijanto

    2015-09-01

    Numbers of night driving accident in Indonesia since 2010 are exponentially rising each year with total of loss more than 50 billion rupiah. One of the causes that contribute to night driving accident is drowsiness. Drowsiness is affected by circadian rhythm resulted from the difference of blue light quality and quantity between night and day. Blue light may effect on human physiology through non-visual pathway by suppressing melatonin hormone suppression that influence drowsiness. Meanwhile, the production of hormones and other activities in brain generate bioelectrical activity such as brainwaves and can be recorded using Electroencephalograph (EEG). Therefore, this research objective is to evaluate the effect of blue light exposure to beta brainwave emergence during night driving simulation to a driver. This research was conducted to 4 male subjects who are able to drive and have a legitimate car driving license. The driving simulator was done using SCANIA Truck Driving Simulator on freeform driving mode in dark environment. Subjects drove for total 32 minutes. The data collections were taken in 2 days with 16 minutes for each day. The 16 minutes were divided again into 8 minutes adaptation in dark and 8 minutes for driving either in blue light exposure or in total darkness. While driving the simulation, subjects' brainwaves were recorded using EEG EMOTIV 14 Channels, exposed by LED monochromatic blue light with 160 Lux from source and angle 45o and sat 1 m in front of the screen. Channels used on this research were for visual (O1; O2), cognition (F3; F4; P7; P8), and motor (FC5; FC6). EEG brainwave result was filtered with EEGLab to obtain beta waves at 13 - 30 Hz frequencies. Results showed that beta waves response to blue light varied for each subject. Blue light exposure either increased or decreased beta waves in 2 minutes pattern and maintaining beta waves on cognition and motor area in 3 out of 4 subjects. Meanwhile, blue light exposure did not maintain

  3. A brief peripheral motion contrast threshold test predicts older drivers' hazardous behaviors in simulated driving.

    Science.gov (United States)

    Henderson, Steven; Woods-Fry, Heather; Collin, Charles A; Gagnon, Sylvain; Voloaca, Misha; Grant, John; Rosenthal, Ted; Allen, Wade

    2015-05-01

    Our research group has previously demonstrated that the peripheral motion contrast threshold (PMCT) test predicts older drivers' self-report accident risk, as well as simulated driving performance. However, the PMCT is too lengthy to be a part of a battery of tests to assess fitness to drive. Therefore, we have developed a new version of this test, which takes under two minutes to administer. We assessed the motion contrast thresholds of 24 younger drivers (19-32) and 25 older drivers (65-83) with both the PMCT-10min and the PMCT-2min test and investigated if thresholds were associated with measures of simulated driving performance. Younger participants had significantly lower motion contrast thresholds than older participants and there were no significant correlations between younger participants' thresholds and any measures of driving performance. The PMCT-10min and the PMCT-2min thresholds of older drivers' predicted simulated crash risk, as well as the minimum distance of approach to all hazards. This suggests that our tests of motion processing can help predict the risk of collision or near collision in older drivers. Thresholds were also correlated with the total lane deviation time, suggesting a deficiency in processing of peripheral flow and delayed detection of adjacent cars. The PMCT-2min is an improved version of a previously validated test, and it has the potential to help assess older drivers' fitness to drive. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Characterizing luminous efficiency functions for a simulated mesopic night driving task based on reaction time.

    Science.gov (United States)

    Szalmas, Attila; Bodrogi, Peter; Sik-Lanyi, Cecilia

    2006-05-01

    The objective of this study is to test the luminous efficiency functions V(lambda), V'(lambda), V(10)(lambda) and their linear combinations on the basis of a data set gained from a simulated mesopic night-time driving experiment. Another aim is to provide 'real-world' data for the 'X framework' or 'linear combination model', and to find out its limits in a practical situation. Human performance was measured by the reaction time method. Results show that the single parameter of the linear combination of photopic and scotopic luminous efficiency functions can be determined analytically with little variation for a given mesopic background luminance level and a given visual target colour, but the computation leads to considerable deviations comparing all three target colours (red, green and blue) used in the experiment. The conclusion for the given experimental conditions is that the single parameter of the linear combination model has an increasing deviation for lower background luminance levels.

  5. Referential coding of steering-wheel button presses in a simulated driving cockpit.

    Science.gov (United States)

    Xiong, Aiping; Proctor, Robert W

    2015-12-01

    The present study investigated whether left and right pushbuttons on a steering wheel are coded relative to an "infotainment display" in a simulated driving cockpit. Participants performed a go/no-go Simon task in which they responded on trials for which a tone, presented from a left or right speaker, was 1 of 2 pitches (low or high) with a single button press (left in 1 trial block; right in another). Without the infotainment display in Experiment 1, both left and right responses showed Simon effects of similar size. In both Experiments 2 and 3, the infotainment display was located to the right or left, and the Simon effect was smaller for the response that was on the side of the infotainment display than for the response that was on the opposite side. The results indicate that in a driving cockpit environment, the pushbutton responses are coded as left and right with respect not only to the wheel-based frame but also to a salient object like the infotainment display. The general point for application is that the driver's spatial representation of responses, and consequently performance, can be influenced by multiple frames of reference. (c) 2015 APA, all rights reserved).

  6. 'I didn't see that coming': simulated visual fields and driving hazard perception test performance.

    Science.gov (United States)

    Glen, Fiona C; Smith, Nicholas D; Jones, Lee; Crabb, David P

    2016-09-01

    Evidence is limited regarding specific types of visual field loss associated with unsafe driving. We use novel gaze-contingent software to examine the effect of simulated visual field loss on computer-based driving hazard detection with the specific aim of testing the impact of scotomata located to the right and left of fixation. The 'hazard perception test' is a component of the UK driving licence examination, which measures speed of detecting 15 different hazards in a series of real-life driving films. We have developed a novel eye-tracking and computer set up capable of generating a realistic gaze-contingent scotoma simulation (GazeSS) overlaid on film content. Thirty drivers with healthy vision completed three versions of the hazard perception test in a repeated measures experiment. In two versions, GazeSS simulated a scotoma in the binocular field of view to the left or right of fixation. A third version was unmodified to establish baseline performance. Participants' mean baseline hazard perception test score was 51 ± 7 (out of 75). This reduced to 46 ± 9 and 46 ± 11 when completing the task with a binocular visual field defect located to the left and right of fixation, respectively. While the main effect of simulated visual field loss on performance was statistically significant (p = 0.007), there were no average differences in the experimental conditions where a scotoma was located in the binocular visual field to the right or left of fixation. Simulated visual field loss impairs driving hazard detection on a computer-based test. There was no statistically significant difference in average performance when the simulated scotoma was located to the right or left of fixation of the binocular visual field, but certain types of hazard caused more difficulties than others. © 2016 Optometry Australia.

  7. A Prototype System for Real Time Computer Animation of Slow Traffic in a Driving Simulator

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.; Delden, Mattijs J.B. van; Hin, Andrea J.S.; Wolffelaar, Peter C. van

    1997-01-01

    The Traffic Research Centre (TRC) of the University of Groningen in the Netherlands has developed a driving simulator with ‘intelligent’ computer-controlled traffic, consisting at the moment only of saloon cars. The range of possible applications would be greatly enhanced if other traffic

  8. Increasing Following Headway with Prompts, Goal Setting, and Feedback in a Driving Simulator

    Science.gov (United States)

    Arnold, Michelle L.; Van Houten, Ron

    2011-01-01

    We evaluated the effects of prompting, goal setting, and feedback on following headway of young drivers in a simulated driving environment and assessed whether changes produced in following headway were associated with reductions in hard braking when drivers were and were not using cell phones. Participants were 4 university students. During…

  9. Effects of dexamphetamine with and without alcohol on simulated driving

    NARCIS (Netherlands)

    Simons, R.; Martens, Marieke Hendrikje; Ramaekers, J.; Krul, A.; Klöpping-Ketelaars, I.; Skopp, G.

    2012-01-01

    Rationale: In party circuits dexamphetamine is frequently used in combination with alcohol. It is hypothesized that co-administration of dexamphetamine to alcohol might reduce the sedative effects of alcohol, but may potentiate risk-taking behaviour. Objectives: The study was aimed at assessing the

  10. Experimental study and new three-dimensional kinetic modeling of foamy solution-gas drive processes.

    Science.gov (United States)

    Sun, Xiaofei; Zhang, Yanyu; Wang, Shilin; Song, Zhaoyao; Li, Peng; Wang, Changfa

    2018-03-12

    Foamy solution-gas drive processes in heavy oil reservoirs are very complex. The influence of some microscopic factors on this process is not fully understood due to limitations of traditional depletion tests. This study aims to investigate foamy solution-gas drive by experiments and simulations. First, the effects of the pressure depletion rate on critical gas saturation and foamy solution-gas drive processes were investigated by laboratory experiments. Second, a new three-dimensional foamy oil model that captures many important characteristics of foamy solution-gas drive, such as non-equilibrium behavior, gas evolution kinetics, and the effect of viscous forces on gas mobility, was developed. Last, the effects of some important parameters on foamy solution-gas drive were systematically investigated,and a model application was conducted in a typical foamy oil reservoir. The results indicate that the new model is capble of simulating many of the unusual behaviors observed in foamy solution-gas drive on a laboratory and field scales. High oil recoveries were obtained with a high oil viscosity, high depletion rate, long sandpack, and low solution gas-oil ratio. Foamy solution-gas drive processes are sensitive to the depletion rate, length, and critical gas saturation. The oil viscosity, solution GOR and diffusion coefficient are not sensitive factors.

  11. Beam dynamics simulations for linacs driving short-wavelength FELs

    International Nuclear Information System (INIS)

    Ferrario, M.; Tazzioli, F.

    1999-01-01

    The fast code HOMDYN has been recently developed, in the framework of the TTF (Tesla test facility) collaboration, in order to study the beam dynamics of linacs delivering high brightness beams as those needed for short wavelength Fel experiments. These linacs are typically driven by radio-frequency photo-injectors, where correlated time dependent space charge effects are of great relevance: these effects cannot be studied by standard beam optics codes (TRACE3D, etc.) and they have been modeled so far by means of multi-particle (Pic or quasistatic) codes requiring heavy cpu time and memory allocations. HOMDYN is able to describe the beam generation at the photo-cathode and the emittance compensation process in the injector even running on a laptop with very modest running rimes (less than a minute). In this paper it is showed how this capability of the code is exploited so to model a whole linac up to the point where the space charge dominated regime is of relevance (200 MeV)

  12. Naturalistic Teenage Driving Study: Findings and Lessons Learned

    Science.gov (United States)

    Simons-Morton, Bruce G.; Klauer, Sheila G.; Ouimet, Marie Claude; Guo, Feng; Albert, Paul S.; Lee, Suzanne E.; Ehsani, Johnathon P.; Pradhan, Anuj K.; Dingus, Thomas A.

    2015-01-01

    Problem This paper summarizes the findings on novice teenage driving outcomes (e.g., crashes and risky driving behaviors) from the Naturalistic Teenage Driving Study. Method Survey and driving data from a data acquisition system (Global Positioning System, accelerometers, cameras) were collected from 42 newly-licensed teenage drivers and their parents during the first 18 months of teenage licensure; stress responsivity was also measured in teenagers. Result Overall teenage crash and near crash (CNC) rates declined over time, but were >4 times higher among teenagers than adults. Contributing factors to teenage CNC rates included secondary task engagement (e.g., distraction), kinematic risky driving, low stress responsivity, and risky social norms. Conclusion The data support the contention that the high novice teenage CNC risk is due both to inexperience and risky driving behavior, particularly kinematic risky driving and secondary task engagement. Practical Applications Graduated driver licensing policy and other prevention efforts should focus on kinematic risky driving, secondary task engagement, and risky social norms. PMID:26403899

  13. Naturalistic teenage driving study: Findings and lessons learned.

    Science.gov (United States)

    Simons-Morton, Bruce G; Klauer, Sheila G; Ouimet, Marie Claude; Guo, Feng; Albert, Paul S; Lee, Suzanne E; Ehsani, Johnathon P; Pradhan, Anuj K; Dingus, Thomas A

    2015-09-01

    This paper summarizes the findings on novice teenage driving outcomes (e.g., crashes and risky driving behaviors) from the Naturalistic Teenage Driving Study. Survey and driving data from a data acquisition system (global positioning system, accelerometers, cameras) were collected from 42 newly licensed teenage drivers and their parents during the first 18 months of teenage licensure; stress responsivity was also measured in teenagers. Overall teenage crash and near-crash (CNC) rates declined over time, but were >4 times higher among teenagers than adults. Contributing factors to teenage CNC rates included secondary task engagement (e.g., distraction), kinematic risky driving, low stress responsivity, and risky social norms. The data support the contention that the high novice teenage CNC risk is due both to inexperience and risky driving behavior, particularly kinematic risky driving and secondary task engagement. Graduated driver licensing policy and other prevention efforts should focus on kinematic risky driving, secondary task engagement, and risky social norms. Copyright © 2015 Elsevier Ltd and National Safety Council. All rights reserved.

  14. Evaluating the Impact of Road Grade on Simulated Commercial Vehicle Fuel Economy Using Real-World Drive Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Lopp, Sean; Wood, Eric; Duran, Adam

    2015-10-13

    Commercial vehicle fuel economy is known to vary significantly with both positive and negative road grade. Medium- and heavy-duty vehicles operating at highway speeds require incrementally larger amounts of energy to pull heavy payloads up inclines as road grade increases. Non-hybrid vehicles are then unable to recapture energy on descent and lose energy through friction braking. While the on-road effects of road grade are well understood, the majority of standard commercial vehicle drive cycles feature no climb or descent requirements. Additionally, existing literature offers a limited number of sources that attempt to estimate the on-road energy implications of road grade in the medium- and heavy-duty space. This study uses real-world commercial vehicle drive cycles from the National Renewable Energy Laboratory's Fleet DNA database to simulate the effects of road grade on fuel economy across a range of vocations, operating conditions, and locations. Drive-cycles are matched with vocation-specific vehicle models and simulated with and without grade. Fuel use due to grade is presented, and variation in fuel consumption due to drive cycle and vehicle characteristics is explored through graphical and statistical comparison. The results of this study suggest that road grade accounts for 1%-9% of fuel use in commercial vehicles on average and up to 40% on select routes.

  15. Simplified drive system models for power system transient studies in industrial plants

    DEFF Research Database (Denmark)

    Chen, Peiyuan; Sannino, Ambra

    2007-01-01

    In order to simulate industrial plants for different power system transient studies, simplified adjustable speed drive (ASD) models are needed. For power system transient studies such as assessing the voltage dip ride-through capability of ASDs, detailed representation of semiconductor valve...

  16. Energy analysis of electric vehicles using batteries or fuel cells through well-to-wheel driving cycle simulations

    Science.gov (United States)

    Campanari, Stefano; Manzolini, Giampaolo; Garcia de la Iglesia, Fernando

    This work presents a study of the energy and environmental balances for electric vehicles using batteries or fuel cells, through the methodology of the well to wheel (WTW) analysis, applied to ECE-EUDC driving cycle simulations. Well to wheel balances are carried out considering different scenarios for the primary energy supply. The fuel cell electric vehicles (FCEV) are based on the polymer electrolyte membrane (PEM) technology, and it is discussed the possibility to feed the fuel cell with (i) hydrogen directly stored onboard and generated separately by water hydrolysis (using renewable energy sources) or by conversion processes using coal or natural gas as primary energy source (through gasification or reforming), (ii) hydrogen generated onboard with a fuel processor fed by natural gas, ethanol, methanol or gasoline. The battery electric vehicles (BEV) are based on Li-ion batteries charged with electricity generated by central power stations, either based on renewable energy, coal, natural gas or reflecting the average EU power generation feedstock. A further alternative is considered: the integration of a small battery to FCEV, exploiting a hybrid solution that allows recovering energy during decelerations and substantially improves the system energy efficiency. After a preliminary WTW analysis carried out under nominal operating conditions, the work discusses the simulation of the vehicles energy consumption when following standardized ECE-EUDC driving cycle. The analysis is carried out considering different hypothesis about the vehicle driving range, the maximum speed requirements and the possibility to sustain more aggressive driving cycles. The analysis shows interesting conclusions, with best results achieved by BEVs only for very limited driving range requirements, while the fuel cell solutions yield best performances for more extended driving ranges where the battery weight becomes too high. Results are finally compared to those of conventional internal

  17. Simulated driving in obstructive sleep apnoea-hypopnoea : effects of oral appliances and continuous positive airway pressure

    NARCIS (Netherlands)

    Hoekema, Aarnoud; Stegenga, Boudewijn; Bakker, Marije; Brouwer, Wiebo H.; de Bont, Lambert G. M.; Wijkstra, Peter J.; van der Hoeven, Johannes H.

    Impaired simulated driving performance has been demonstrated in obstructive sleep apnoea-hypopnoea syndrome (OSAHS) patients. Although continuous positive airway pressure (CPAP) generally improves simulated driving performance, the effects of oral-appliance (OA) therapy are unknown. The aims of this

  18. Staying Connected on the Road: A Comparison of Different Types of Smart Phone Use in a Driving Simulator.

    Directory of Open Access Journals (Sweden)

    Jaimie McNabb

    Full Text Available Previous research on smart phone use while driving has primarily focused on phone calls and texting. Drivers are now increasingly using their phone for other activities during driving, in particular social media, which have different cognitive demands. The present study compared the effects of four different smart phone tasks on car-following performance in a driving simulator. Phone tasks were chosen that vary across two factors: interaction medium (text vs image and task pacing (self-paced vs experimenter-paced and were as follows: Text messaging with the experimenter (text/other-paced, reading Facebook posts (text/self-paced, exchanging photos with the experimenter via Snapchat (image, experimenter-paced, and viewing updates on Instagram (image, experimenter-paced. Drivers also performed a driving only baseline. Brake reaction times (BRTs were significantly greater in the text-based conditions (Mean = 1.16 s as compared to both the image-based conditions (Mean = 0.92 s and the baseline (0.88 s. There was no significant difference between BRTs in the image-based and baseline conditions and there was no significant effect of task-pacing. Similar results were obtained for Time Headway variability. These results are consistent with the picture superiority effect found in memory research and suggest that image-based interfaces could provide safer ways to "stay connected" while driving than text-based interfaces.

  19. Staying Connected on the Road: A Comparison of Different Types of Smart Phone Use in a Driving Simulator

    Science.gov (United States)

    McNabb, Jaimie; Gray, Rob

    2016-01-01

    Previous research on smart phone use while driving has primarily focused on phone calls and texting. Drivers are now increasingly using their phone for other activities during driving, in particular social media, which have different cognitive demands. The present study compared the effects of four different smart phone tasks on car-following performance in a driving simulator. Phone tasks were chosen that vary across two factors: interaction medium (text vs image) and task pacing (self-paced vs experimenter-paced) and were as follows: Text messaging with the experimenter (text/other-paced), reading Facebook posts (text/self-paced), exchanging photos with the experimenter via Snapchat (image, experimenter -paced), and viewing updates on Instagram (image, experimenter -paced). Drivers also performed a driving only baseline. Brake reaction times (BRTs) were significantly greater in the text-based conditions (Mean = 1.16 s) as compared to both the image-based conditions (Mean = 0.92 s) and the baseline (0.88 s). There was no significant difference between BRTs in the image-based and baseline conditions and there was no significant effect of task-pacing. Similar results were obtained for Time Headway variability. These results are consistent with the picture superiority effect found in memory research and suggest that image-based interfaces could provide safer ways to “stay connected” while driving than text-based interfaces. PMID:26886099

  20. Staying Connected on the Road: A Comparison of Different Types of Smart Phone Use in a Driving Simulator.

    Science.gov (United States)

    McNabb, Jaimie; Gray, Rob

    2016-01-01

    Previous research on smart phone use while driving has primarily focused on phone calls and texting. Drivers are now increasingly using their phone for other activities during driving, in particular social media, which have different cognitive demands. The present study compared the effects of four different smart phone tasks on car-following performance in a driving simulator. Phone tasks were chosen that vary across two factors: interaction medium (text vs image) and task pacing (self-paced vs experimenter-paced) and were as follows: Text messaging with the experimenter (text/other-paced), reading Facebook posts (text/self-paced), exchanging photos with the experimenter via Snapchat (image, experimenter-paced), and viewing updates on Instagram (image, experimenter-paced). Drivers also performed a driving only baseline. Brake reaction times (BRTs) were significantly greater in the text-based conditions (Mean = 1.16 s) as compared to both the image-based conditions (Mean = 0.92 s) and the baseline (0.88 s). There was no significant difference between BRTs in the image-based and baseline conditions and there was no significant effect of task-pacing. Similar results were obtained for Time Headway variability. These results are consistent with the picture superiority effect found in memory research and suggest that image-based interfaces could provide safer ways to "stay connected" while driving than text-based interfaces.

  1. Texting while driving: A study of 1211 U.S. adults with the Distracted Driving Survey

    Directory of Open Access Journals (Sweden)

    Emily Gliklich

    2016-12-01

    Full Text Available Texting and other cell-phone related distracted driving is estimated to account for thousands of motor vehicle collisions each year but studies examining the specific cell phone reading and writing activities of drivers are limited. The objective of this study was to describe the frequency of cell-phone related distracted driving behaviors. A national, representative, anonymous panel of 1211 United States drivers was recruited in 2015 to complete the Distracted Driving Survey (DDS, an 11-item validated questionnaire examining cell phone reading and writing activities and at what speeds they occur. Higher DDS scores reflect more distraction. DDS scores were analyzed by demographic data and self-reported crash rate. Nearly 60% of respondents reported a cell phone reading or writing activity within the prior 30 days, with reading texts (48%, writing texts (33% and viewing maps (43% most frequently reported. Only 4.9% of respondents had enrolled in a program aimed at reducing cell phone related distracted driving. DDS scores were significantly correlated to crash rate (p < 0.0001, with every one point increase associated with an additional 7% risk of a crash (p < 0.0001. DDS scores were inversely correlated to age (p < 0.0001. The DDS demonstrated high internal consistency (Cronbach's alpha = 0.94. High rates of cell phone-related distraction are reported here in a national sample. Distraction is associated with crash rates and occurs across all age groups, but is highest in younger drivers. The DDS can be used to evaluate the impact of public health programs aimed at reducing cell-phone related distracted driving.

  2. Driving with Central Visual Field Loss II: How Scotomas above or below the Preferred Retinal Locus (PRL Affect Hazard Detection in a Driving Simulator.

    Directory of Open Access Journals (Sweden)

    P Matthew Bronstad

    Full Text Available We determined whether binocular central scotomas above or below the preferred retinal locus affect detection of hazards (pedestrians approaching from the side. Seven participants with central field loss (CFL, and seven age-and sex-matched controls with normal vision (NV, each completed two sessions of 5 test drives (each approximately 10 minutes long in a driving simulator. Participants pressed the horn when detecting pedestrians that appeared at one of four eccentricities (-14°, -4°, left, 4°, or 14°, right, relative to car heading. Pedestrians walked or ran towards the travel lane on a collision course with the participant's vehicle, thus remaining in the same area of the visual field, assuming participant's steady forward gaze down the travel lane. Detection rates were nearly 100% for all participants. CFL participant reaction times were longer (median 2.27s, 95% CI 2.13 to 2.47 than NVs (median 1.17s, 95%CI 1.10 to 2.13; difference p<0.01, and CFL participants would have been unable to stop for 21% of pedestrians, compared with 3% for NV, p<0.001. Although the scotomas were not expected to obscure pedestrian hazards, gaze tracking revealed that scotomas did sometimes interfere with detection; late reactions usually occurred when pedestrians were entirely or partially obscured by the scotoma (time obscured correlated with reaction times, r = 0.57, p<0.001. We previously showed that scotomas lateral to the preferred retinal locus delay reaction times to a greater extent; however, taken together, the results of our studies suggest that any binocular CFL might negatively impact timely hazard detection while driving and should be a consideration when evaluating vision for driving.

  3. Dynamic Simulation Research on Chain Drive Mechanism of Corn Seeder Based on ADAMS

    Science.gov (United States)

    Wang, Y. B.; Jia, H. P.

    2017-12-01

    In order to reduce the damage to the chain and improve the seeding quality of the seeding machine, the corn seeder has the characteristics of the seeding quality and some technical indexes in the work of the corn seeding machine. The dynamic analysis of the chain drive mechanism is carried out by using the dynamic virtual prototype. In this paper, the speed of the corn planter is 5km/h, and the speed of the simulated knuckle is 0.1~0.9s. The velocity is 0.12m/s, which is equal to the chain speed when the seeder is running normally. Of the dynamic simulation of the movement and the actual situation is basically consistent with the apparent speed of the drive wheel has changed the acceleration and additional dynamic load, the chain drive has a very serious damage, and the maximum load value of 47.28N, in order to reduce the damage to the chain, As far as possible so that the sowing machine in the work to maintain a reasonable uniform speed, to avoid a greater acceleration, the corn sowing machine drive the design of a certain reference.

  4. A sonification algorithm for developing the off-roads models for driving simulators

    Science.gov (United States)

    Chiroiu, Veturia; Brişan, Cornel; Dumitriu, Dan; Munteanu, Ligia

    2018-01-01

    In this paper, a sonification algorithm for developing the off-road models for driving simulators, is proposed. The aim of this algorithm is to overcome difficulties of heuristics identification which are best suited to a particular off-road profile built by measurements. The sonification algorithm is based on the stochastic polynomial chaos analysis suitable in solving equations with random input data. The fluctuations are generated by incomplete measurements leading to inhomogeneities of the cross-sectional curves of off-roads before and after deformation, the unstable contact between the tire and the road and the unreal distribution of contact and friction forces in the unknown contact domains. The approach is exercised on two particular problems and results compare favorably to existing analytical and numerical solutions. The sonification technique represents a useful multiscale analysis able to build a low-cost virtual reality environment with increased degrees of realism for driving simulators and higher user flexibility.

  5. Tuning and objective performance evaluation of a driving simulator to investigate tyre behaviour in on-centre handling manoeuvres

    Science.gov (United States)

    Baldoni, F.; Galante, F.; Pernetti, M.; Russo, M.; Terzo, M.; Toscano, M.

    2011-09-01

    Driving simulation aims at reproducing, within a safe and controlled environment, sensorial stimuli as close to those perceived during the actual drive as possible, in order to induce driving behaviour similar to the real one. This paper illustrates an activity carried out on the driving simulator Virtual Environment for Road Safety, bound for system performance optimisation while dealing with subjective and objective tyres evaluation in the field of on-centre manoeuvres. Such activity can be divided into two main steps. The first one, described herewith, has been focusing on platform motion algorithms tuning and has led to driving simulator objective validation within the on-centre range. Device capability of reproducing dynamics, worked out by the vehicle model, has been thoroughly examined. Simulator sensitivity to a few tyre parameters influencing vehicle lateral dynamics has been analysed too. The second step - calling for the support of experienced drivers - will pursue subjective validation.

  6. Study on Forced Torsional Vibration of CFRP Drive-Line System with Internal Damping

    Science.gov (United States)

    Yang, Mo; Hu, Yefa; Zhang, Jinguang; Ding, Guoping; Song, Chunsheng

    2017-12-01

    The use of CFRP transmission shaft has positive effect on the weight and flexural vibration reduction of drive-line system. However, the application of CFRP transmission shaft will greatly reduce the torsional stiffness of the drive-line, and may cause strong transient torsional vibration. Which will seriously affect the performance of CFRP drive-line. In this study, the forced torsional vibration of the CFRP drive-line system is carried out using the lumped parameter model. In addition, the effect of rotary inertia, internal damping, coupling due to the composite laminate, and excitation torque are incorporated in the modified transfer matrix model (TMM). Then, the modified TMM is used to predict the torsional frequency and forced torsional vibration of a CFRP drive-line with three-segment drive shafts. The results of modified TMM shown that the rotational speed difference of the CFRP transmission shaft segment is much larger than metal transmission shaft segment under excitation torque. And compared the results from finite element simulation, modified TMM and torsional vibration experiment respectively, and it has shown that the modified TMM can accurately predict forced torsional vibration behaviors of the CFRP drive-line system.

  7. Test Results from a Direct Drive Gas Reactor Simulator Coupled to a Brayton Power Conversion Unit

    Science.gov (United States)

    Hervol, David S.; Briggs, Maxwell H.; Owen, Albert K.; Bragg-Sitton, Shannon M.; Godfroy, Thomas J.

    2010-01-01

    Component level testing of power conversion units proposed for use in fission surface power systems has typically been done using relatively simple electric heaters for thermal input. These heaters do not adequately represent the geometry or response of proposed reactors. As testing of fission surface power systems transitions from the component level to the system level it becomes necessary to more accurately replicate these reactors using reactor simulators. The Direct Drive Gas-Brayton Power Conversion Unit test activity at the NASA Glenn Research Center integrates a reactor simulator with an existing Brayton test rig. The response of the reactor simulator to a change in Brayton shaft speed is shown as well as the response of the Brayton to an insertion of reactivity, corresponding to a drum reconfiguration. The lessons learned from these tests can be used to improve the design of future reactor simulators which can be used in system level fission surface power tests.

  8. Experiments and simulation of thermal behaviors of the dual-drive servo feed system

    Science.gov (United States)

    Yang, Jun; Mei, Xuesong; Feng, Bin; Zhao, Liang; Ma, Chi; Shi, Hu

    2015-01-01

    The machine tool equipped with the dual-drive servo feed system could realize high feed speed as well as sharp precision. Currently, there is no report about the thermal behaviors of the dual-drive machine, and the current research of the thermal characteristics of machines mainly focuses on steady simulation. To explore the influence of thermal characterizations on the precision of a jib boring machine assembled dual-drive feed system, the thermal equilibrium tests and the research on thermal-mechanical transient behaviors are carried out. A laser interferometer, infrared thermography and a temperature-displacement acquisition system are applied to measure the temperature distribution and thermal deformation at different feed speeds. Subsequently, the finite element method (FEM) is used to analyze the transient thermal behaviors of the boring machine. The complex boundary conditions, such as heat sources and convective heat transfer coefficient, are calculated. Finally, transient variances in temperatures and deformations are compared with the measured values, and the errors between the measurement and the simulation of the temperature and the thermal error are 2 °C and 2.5 μm, respectively. The researching results demonstrate that the FEM model can predict the thermal error and temperature distribution very well under specified operating condition. Moreover, the uneven temperature gradient is due to the asynchronous dual-drive structure that results in thermal deformation. Additionally, the positioning accuracy decreases as the measured point became further away from the motor, and the thermal error and equilibrium period both increase with feed speeds. The research proposes a systematical method to measure and simulate the boring machine transient thermal behaviors.

  9. A Study of Torque Vectoring and Traction Control for an All-Wheel Drive Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Maharun Mui’nuddin

    2014-07-01

    Full Text Available Common vehicle always experience energy loss during cornering manoeuver. Thus, to ensure it did not happened especially at high speed, a study of torque vectoring and traction control need to be made since it can increase the traction control of tyres during cornering at high speed. The study of torque vectoring and traction control for an all-wheel drive electric vehicle was conducted by modelling an all-wheel drive electric vehicle (EV in ADAMS/Car software. In addition, an optimal control algorithm will be developed for best performance to minimize energy losses using MATLAB/Simulink software. Furthermore, to prove the effectiveness of the all-wheel drive electric, the torque and traction control simulation of the all-wheel drive electric vehicle will be compared with uncontrolled electric vehicle model. According to the result, torque vectoring and traction control of in-wheel motor in all wheel drive EV can help to increase the performance of the electric vehicle during cornering manoeuver. In conclusion, this study of torque vectoring and traction control for an all-wheel drive electric vehicle will help researchers to improve the design of the future electric vehicle in term of the vehicle performance during cornering manoeuvre.

  10. Effect of audio in-vehicle red light-running warning message on driving behavior based on a driving simulator experiment.

    Science.gov (United States)

    Yan, Xuedong; Liu, Yang; Xu, Yongcun

    2015-01-01

    Drivers' incorrect decisions of crossing signalized intersections at the onset of the yellow change may lead to red light running (RLR), and RLR crashes result in substantial numbers of severe injuries and property damage. In recent years, some Intelligent Transport System (ITS) concepts have focused on reducing RLR by alerting drivers that they are about to violate the signal. The objective of this study is to conduct an experimental investigation on the effectiveness of the red light violation warning system using a voice message. In this study, the prototype concept of the RLR audio warning system was modeled and tested in a high-fidelity driving simulator. According to the concept, when a vehicle is approaching an intersection at the onset of yellow and the time to the intersection is longer than the yellow interval, the in-vehicle warning system can activate the following audio message "The red light is impending. Please decelerate!" The intent of the warning design is to encourage drivers who cannot clear an intersection during the yellow change interval to stop at the intersection. The experimental results showed that the warning message could decrease red light running violations by 84.3 percent. Based on the logistic regression analyses, drivers without a warning were about 86 times more likely to make go decisions at the onset of yellow and about 15 times more likely to run red lights than those with a warning. Additionally, it was found that the audio warning message could significantly reduce RLR severity because the RLR drivers' red-entry times without a warning were longer than those with a warning. This driving simulator study showed a promising effect of the audio in-vehicle warning message on reducing RLR violations and crashes. It is worthwhile to further develop the proposed technology in field applications.

  11. Experimental evaluation of hybrid vehicle fuel economy and pollutant emissions over real-world simulation driving cycles

    Science.gov (United States)

    Fontaras, Georgios; Pistikopoulos, Panayotis; Samaras, Zissis

    2008-06-01

    The reduction of transport-generated CO2 emissions is currently a problem of global interest. Hybrid electric vehicles (HEVs) are considered as one promising technological solution for limiting transport-generated greenhouse gas emissions. Currently, the number of HEVs in the market remains limited, but this picture will change in the years to come as HEVs are expected to pave the way for cleaner technologies in transport. In this paper, results are presented regarding fuel economy and pollutant emissions measurements of two hybrid electric production vehicles. The measurements were conducted on a Prius II and a Honda Civic IMA using both the European legislated driving cycle (New European Driving Cycle, NEDC) and real-world simulation driving cycles (Artemis). In addition to the emissions measurements, other vehicle-operating parameters were studied in an effort to better quantify the maximum CO2 reduction potential. Data from real-world operation of a Prius II vehicle were also used in the evaluation. Results indicate that in most cases both vehicles present improved energy efficiency and pollutant emissions compared to conventional cars. The fuel economy benefit of the two HEVs peaked under urban driving conditions where reductions of 60% and 40% were observed, respectively. Over higher speeds the difference in fuel economy was lower, reaching that of conventional diesel at 95 km h-1. The effect of ambient temperature on fuel consumption was also quantified. It is concluded that urban operation benefits the most of hybrid technology, leading to important fuel savings and urban air quality improvement.

  12. Age differences in visual-auditory self-motion perception during a simulated driving task

    Directory of Open Access Journals (Sweden)

    Robert eRamkhalawansingh

    2016-04-01

    Full Text Available Recent evidence suggests that visual-auditory cue integration may change as a function of age such that integration is heightened among older adults. Our goal was to determine whether these changes in multisensory integration are also observed in the context of self-motion perception under realistic task constraints. Thus, we developed a simulated driving paradigm in which we provided older and younger adults with visual motion cues (i.e. optic flow and systematically manipulated the presence or absence of congruent auditory cues to self-motion (i.e. engine, tire, and wind sounds. Results demonstrated that the presence or absence of congruent auditory input had different effects on older and younger adults. Both age groups demonstrated a reduction in speed variability when auditory cues were present compared to when they were absent, but older adults demonstrated a proportionally greater reduction in speed variability under combined sensory conditions. These results are consistent with evidence indicating that multisensory integration is heightened in older adults. Importantly, this study is the first to provide evidence to suggest that age differences in multisensory integration may generalize from simple stimulus detection tasks to the integration of the more complex and dynamic visual and auditory cues that are experienced during self-motion.

  13. Driving performance while using cell phones: an observational study.

    Science.gov (United States)

    Rosenbloom, Tova

    2006-01-01

    Through spontaneous driving observations, this study sought to examine the impact of using a hands-free cell phone while driving on speed and safe gap keeping behaviors. The study also examined the association between the measure of disturbance created by using a cell phone and the driver's awareness of the disturbance. Twenty-three male adults were observed while driving for an hour and a half each; drivers were unaware of being observed. During the session, each of the participants received a phone call, initiated by an associate of the observer. The experiment was divided into two periods during which the experimental parameters were monitored: 10 minutes during conversation on a cell phone and 10 minutes of non-conversation on a hands-free cell phone. After the experiment, the driver was questioned concerning the extent to which his/her driving was disturbed by the cell phone conversation. T-test for matched samples revealed that the gaps between the drivers' cars and those in front of them diminished when drivers were engaged in the cell phone conversations. Repeated measures ANOVA revealed that drivers that had short conversations did not change their speed, while drivers who were engaged in long (over 16 minutes) conversations drove faster. No effect of drivers' awareness toward cell phone-related disturbance on actual driving behavior monitored in the present study was found.

  14. Study of the deformation-driving $\

    CERN Document Server

    Diriken, J.; Andreyev, A.N.; Antalic, S.; Bildstein, V.; Blazhev, A.; Darby, I.G.; De Witte, H.; Eberth, J.; Elseviers, J.; Fedosseev, V.N.; Flavigny, F.; Fransen, Ch.; Georgiev, G.; Gernhauser, R.; Hess, H.; Huyse, M.; Jolie, J.; Kröll, Th.; Krücken, R.; Lutter, R.; Marsh, B.A.; Mertzimekis, T.; Muecher, D.; Nowacki, F.; Orlandi, R.; Pakou, A.; Raabe, R.; Randisi, G.; Reiter, P.; Roger, T.; Seidlitz, M.; Seliverstov, M.; Sieja, K.; Sotty, C.; Tornqvist, H.; Van De Walle, J.; Van Duppen, P.; Voulot, D.; Warr, N.; Wenander, F.; Wimmer, K.

    2014-01-01

    The $νg_{9/2} , d_{5/2}, s_{1/2}$ orbitals are assumed to be responsible for the swift onset of collectivity observed in the region below $^{68}$Ni. Especially the single-particle energies and strengths of these orbitals are of importance. We studied such properties in the nearby $^{67}$Ni nucleus, by performing a ($d, p$)-experiment in inverse kinematics employing a post-accelerated radioactive ion beam (RIB) at the REX-ISOLDE facility. The experiment was performed at an energy of 2.95 MeV / u using a combination of the T-REX particle detectors, the Miniball $\\gamma$-detection array and a newly-developed delayed-correlation technique as to investigate $\\mu$s-isomers. Angular distributions of the ground state and multiple excited states in $^{67}$Ni were obtained and compared with DWBA cross-section calculations, leading to the identification of positive-parity states with substantial $νg_{9/2}$ (1007 keV) and $νd_{5/2}$ (2207 keV and 3277 keV) single- particle strengths up to an excitation energy of 5.8 M...

  15. Vector Control System Design for Four Degree-of-Freedom Dynamic Flexible Simulation of the Variable-Frequency Drive

    Directory of Open Access Journals (Sweden)

    Kladiev Sergey N.

    2017-01-01

    Full Text Available In the present work we investigate the control system development of the drive simulators to train driver/operator driving skills, taking into account the ever-changing terrain. In order to meet the required response of the four degree-of-freedom motion platform servomotor current studies have been focused on the vector control of the resistance motor angular velocity from the sensor being incremental encoder. In proposed system the standard security of the frequency converter is realized. It leads to overload capacity of two times within minutes determined by servomotor inertia. Further, we represent the algorithms: positional limitation, reliable acceleration and restraint, frequency break. As well as we demonstrate the position switches implement in software. As a result, the control system commands the control of the angular position of the platform in coordinates.

  16. Influence of oil/gas reservoir driving conditions on reserves estimation using computer simulation

    Directory of Open Access Journals (Sweden)

    Stanisław Rychlicki

    2006-10-01

    Full Text Available One of the methods of assessing reserves is a calibration of a numerical model of a field with assumed driving conditions of the field. The influence of various energy systems assumed for the calculation on the calibration results are presented in the paper. A light oil field was selected for verification of resources on the basis of an analysis of driving conditions. At the first stage of calculations, a „Black Oil” type numerical model was used. The results of a classical „Black – Oil” model made the authors search for an alternative description of energy conditions in the reservoir. Therefore, a modified „Black-Oil” model with „vaporized oil” option, assuming that initially, after evaporation, the condensate in the reservoir was in a gaseous phase was used. The obtained simulation results for the analyzed reservoir prove the accuracy of energy conditions in the reservoir.

  17. Quasi-spherical direct drive fusion simulations for the Z machine and future accelerators.

    Energy Technology Data Exchange (ETDEWEB)

    VanDevender, J. Pace; McDaniel, Dillon Heirman; Roderick, Norman Frederick; Nash, Thomas J.

    2007-11-01

    We explored the potential of Quasi-Spherical Direct Drive (QSDD) to reduce the cost and risk of a future fusion driver for Inertial Confinement Fusion (ICF) and to produce megajoule thermonuclear yield on the renovated Z Machine with a pulse shortening Magnetically Insulated Current Amplifier (MICA). Analytic relationships for constant implosion velocity and constant pusher stability have been derived and show that the required current scales as the implosion time. Therefore, a MICA is necessary to drive QSDD capsules with hot-spot ignition on Z. We have optimized the LASNEX parameters for QSDD with realistic walls and mitigated many of the risks. Although the mix-degraded 1D yield is computed to be {approx}30 MJ on Z, unmitigated wall expansion under the > 100 gigabar pressure just before burn prevents ignition in the 2D simulations. A squeezer system of adjacent implosions may mitigate the wall expansion and permit the plasma to burn.

  18. Simulation Model of the Weaving Machine "Camel” and Selection of the Sufficient Driving Motor

    Directory of Open Access Journals (Sweden)

    Ondřej MAREK

    2013-12-01

    Full Text Available The paper deals with the mathematical model of the waving machine CAMEL. This machine consists of many moving parts (rotational and translational movements, belts, flexible elements and therefore it is very complex. CAMEL uses servomotors working in electronic cam regime. It means that the actual angular velocity of the rotor is not constant and therefore it is really important to reduce the moment of inertia of rotating elements. The inertia of the rotor of the drive is very important too. Existing simulation model can help to choose the optimal drive of the machine. It also allows selecting the best displacement laws for different speeds (rpm in order to decrease the effective torque which is proportional to the heating of the servomotor.

  19. The effects of anti-speeding advertisements on the simulated driving behaviour of young drivers.

    Science.gov (United States)

    Plant, Bernice R C; Irwin, Julia D; Chekaluk, Eugene

    2017-03-01

    Recent examinations of road safety communications, including anti-speeding advertisements, have considered the differential effects of positive and negative emotional appeals on driver behaviour. However, empirical evaluations of anti-speeding messages have largely relied on measures of viewers' reported intentions to comply with speed limits and the self-reported driving behaviour of viewers post-exposure, which might not be indicative of the direct effects that these messages have on real-world driving behaviour. The current research constitutes a first empirical evaluation of different real-world anti-speeding advertisements, as measured by their effects on young drivers' speeding behaviour, using a driving simulator. Licensed drivers (N=116) aged 17-25 years completed driving measures prior to, immediately following, and 7-10days after viewing one of four social marketing advertisements. Results indicated that young drivers' average driving speeds were modestly reduced immediately after they viewed an anti-speeding advertisement that depicted social consequences for speeding and employed a positive emotional appeal when compared to an emotion-matched control advertisement; however, this effect was not found for the anti-speeding advertisement depicting a crash. Interestingly, the results based on reported intentions to reduce speeding predicted the opposite pattern of results. However, there was no evidence that the immediate changes to speeding were maintained 7-10days later, and prompts during Phase 2 did not appear to have an effect. The implications of these findings for road safety advertisements targeting young drivers are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Impaired driving simulation in patients with Periodic Limb Movement Disorder and patients with Obstructive Sleep Apnea Syndrome

    NARCIS (Netherlands)

    Gieteling, Esther W.; Bakker, Marije S.; Hoekema, Aarnoud; Maurits, Natasha M.; Brouwer, Wiebo H.; van der Hoeven, Johannes H.

    Background: Excessive daytime sleepiness (EDS) is considered to be responsible for increased collision rate and impaired driving simulator performance in Obstructive Sleep Apnea Syndrome (OSAS) patients. Periodic Limb Movement Disorder (PLMD) patients also frequently report EDS and may also have

  1. Naturalistic driving studies: The effectiveness of the methodology in monitoring driver behaviour

    CSIR Research Space (South Africa)

    Muronga, Khangwelo

    2017-07-01

    Full Text Available Naturalistic Driving Studies (NDS) is a research methodology that has the potential to improve existing approaches for collecting data about driver behaviour and performance in normal driving conditions. Analysis of naturalistic driving data...

  2. Steering Control in a Low-Cost Driving Simulator: A Case for the Role of Virtual Vehicle Cab.

    Science.gov (United States)

    Mecheri, Sami; Lobjois, Régis

    2018-04-01

    The aim of this study was to investigate steering control in a low-cost driving simulator with and without a virtual vehicle cab. In low-cost simulators, the lack of a vehicle cab denies driver access to vehicle width, which could affect steering control, insofar as locomotor adjustments are known to be based on action-scaled visual judgments of the environment. Two experiments were conducted in which steering control with and without a virtual vehicle cab was investigated in a within-subject design, using cornering and straight-lane-keeping tasks. Driving around curves without vehicle cab information made drivers deviate more from the lane center toward the inner edge in right (virtual cab = 4 ± 19 cm; no cab = 42 ± 28 cm; at the apex of the curve, p vehicle width. This produces considerable differences in the steering trajectory. Providing a virtual vehicle cab must be encouraged for more effectively capturing drivers' steering control in low-cost simulators.

  3. Simulation of Induction Traction Drive with Supercapacitor Energy Storage System Test Bench

    Directory of Open Access Journals (Sweden)

    Stana Girts

    2015-12-01

    Full Text Available The paper describes the application of supercapacitor energy storage system for induction traction drive test bench that replaces a real electric public transport for performing testing and researches. The suitability and usage of such bench for research purposes is explained and the importance of the development of software mathematical model for performing simulations to be done before physical implementation measures is reasoned. The working principle of the bench and applied components are described. A virtual model of the bench was built and simulations were performed using Matlab/Simulink software. The basic topology of the virtual bench model is described as well. The calculations of this work show the scaling of supercapacitor energy storage system by setting different limits of working voltage range in order to adjust them to test bench parameters, whereas the modelling compares two simulation cases – the application of less supercapacitors and the application of more supercapacitors with the same common rated voltage. The autonomous mode simulations were also performed. Simulation results are analyzed and recommendations for the application of the supercapacitor energy storage system, with respect to initial supercapacitor circuit voltage, are given.

  4. Driving simulator validation of driver behavior with limited safe vantage points for data collection in work zones.

    Science.gov (United States)

    Bham, Ghulam H; Leu, Ming C; Vallati, Manoj; Mathur, Durga R

    2014-06-01

    This study is aimed at validating a driving simulator (DS) for the study of driver behavior in work zones. A validation study requires field data collection. For studies conducted in highway work zones, the availability of safe vantage points for data collection at critical locations can be a significant challenge. A validation framework is therefore proposed in this paper, demonstrated using a fixed-based DS that addresses the issue by using a global positioning system (GPS). The validation of the DS was conducted using objective and subjective evaluations. The objective validation was divided into qualitative and quantitative evaluations. The DS was validated by comparing the results of simulation with the field data, which were collected using a GPS along the highway and video recordings at specific locations in a work zone. The constructed work zone scenario in the DS was subjectively evaluated with 46 participants. The objective evaluation established the absolute and relative validity of the DS. The mean speeds from the DS data showed excellent agreement with the field data. The subjective evaluation indicated realistic driving experience by the participants. The use of GPS showed that continuous data collected along the highway can overcome the challenges of unavailability of safe vantage points especially at critical locations. Further, a validated DS can be used for examining driver behavior in complex situations by replicating realistic scenarios. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Simulated Fuel Economy and Emissions Performance during City and Interstate Driving for a Heavy-Duty Hybrid Truck

    Energy Technology Data Exchange (ETDEWEB)

    Daw, C. Stuart; Gao, Zhiming; Smith, David E.; Laclair, Tim J.; Pihl, Josh A.; Edwards, K. Dean

    2013-04-08

    We compare simulated fuel economy and emissions for both conventional and hybrid class 8 heavy-duty diesel trucks operating over multiple urban and highway driving cycles. Both light and heavy freight loads were considered, and all simulations included full aftertreatment for NOx and particulate emissions controls. The aftertreatment components included a diesel oxidation catalyst (DOC), urea-selective catalytic NOx reduction (SCR), and a catalyzed diesel particulate filter (DPF). Our simulated hybrid powertrain was configured with a pre-transmission parallel drive, with a single electric motor between the clutch and gearbox. A conventional HD truck with equivalent diesel engine and aftertreatment was also simulated for comparison. Our results indicate that hybridization can significantly increase HD fuel economy and improve emissions control in city driving. However, there is less potential hybridization benefit for HD highway driving. A major factor behind the reduced hybridization benefit for highway driving is that there are fewer opportunities to utilize regenerative breaking. Our aftertreatment simulations indicate that opportunities for passive DPF regeneration are much greater for both hybrid and conventional trucks during highway driving due to higher sustained exhaust temperatures. When passive DPF regeneration is extensively utilized, the fuel penalty for particulate control is virtually eliminated, except for the 0.4%-0.9% fuel penalty associated with the slightly higher exhaust backpressure.

  6. Driving and traffic simulation for the evaluation of electronically coupled truck platoons; Kombinierte Fahr- und Verkehrsfluss-Simulation zur Untersuchung von elektronisch gekoppelten Lkw-Konvois

    Energy Technology Data Exchange (ETDEWEB)

    Friedrichs, A.; Petry, L.; Savelsberg, E. [RWTH Aachen (Germany). Zentrum fuer Lern- und Wissensmanagement]|[RWTH Aachen (Germany). Lehrstuhl Informatik im Maschinenbau

    2005-07-01

    The concept of creating trains on road (truck platoons) supported by advanced driver assistance systems is one possibility to manage the permanent increase of freight transportation and the utilisation of its capacities. An electronic coupling of trucks with short gaps will release the truck driver and therefore will also increase safety. Furthermore, the capacity of road will be used more efficient due to the short gaps between the trucks and the slip stream will save fuel. Regarding former research programs of the same topic, the practical use of such platoons shall be prepared with help of the InDriveS truck driving simulator. InDriveS is a combined driving and traffic flow simulation and gives the possibility to develop the driver assistance system and to investigate the stress of the truck driver during the platoon driving. It also allows an evaluation of the complete system in meaning of traffic flow, safety, environmental impacts and profitability. (orig.)

  7. The effects of using a portable music player on simulated driving performance and task-sharing strategies.

    Science.gov (United States)

    Young, Kristie L; Mitsopoulos-Rubens, Eve; Rudin-Brown, Christina M; Lenné, Michael G

    2012-07-01

    This study examined the effects of performing scrollable music selection tasks using a portable music player (iPod Touch™) on simulated driving performance and task-sharing strategies, as evidenced through eye glance behaviour and secondary task performance. A total of 37 drivers (18-48 yrs) completed the PC-based MUARC Driver Distraction Test (DDT) while performing music selection tasks on an iPod Touch. Drivers' eye glance behaviour was examined using faceLAB eye tracking equipment. Results revealed that performing music search tasks while driving increased the amount of time that drivers spent with their eyes off the roadway and decreased their ability to maintain a constant lane position and time headway from a lead vehicle. There was also evidence, however, that drivers attempted to regulate their behaviour when distracted by decreasing their speed and taking a large number of short glances towards the device. Overall, results suggest that performing music search tasks while driving is problematic and steps to prohibit this activity should be taken. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  8. Advanced Research and Education in Electrical Drives by Using Digital Real-Time Hardware-in-the-Loop Simulation

    DEFF Research Database (Denmark)

    Bojoi, R.; Profumo, F.; Griva, G.

    2002-01-01

    The authors present in this paper a digital real-time hardware-in-the-loop simulation of a three-phase induction motor drive. The main real-time simulation tool is the dSPACE DS1103 PPC Controller Board which simulates the power and signal conditioning parts. The control algorithm of the virtual...... drive has been implemented on the Evaluation Board of TMS320F240 DSP. The experimental results validate this solution as a powerful tool to be used in research and advanced education. Thus, the students can put in practic the theory without spending too much time with details concerning the hardware...

  9. Study of emissions and fuel economy for parallel hybrid versus conventional vehicles on real world and standard driving cycles

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Samari

    2017-12-01

    Full Text Available Parallel hybrid electric vehicles (PHEVs increasing rapidly in the automobile markets. However, the benefits out of using this kind of vehicles are still concerned a lot of costumers. This work investigated the expected benefits (such as decreasing emissions and increasing fuel economy from using the parallel HEV in comparison to the conventional vehicle model of the real-world and standard driving cycles. The software Autonomie used in this study to simulate the parallel HEV and conventional models on these driving cycles.The results show that the fuel economy (FE can be improved significantly up to 68% on real-world driving cycle, which is represented mostly city activities. However, the FE improvement was limited (10% on the highway driving cycle, and this is expected since the using of brake system was infrequent. Moreover, the emissions from parallel HEV decreased about 40% on the real-world driving cycle, and decreased 11% on the highway driving cycle. Finally, the engine efficiency, improved about 12% on the real-world driving cycle, and about 7% on highway driving cycle. Keywords: Emissions, Hybrid electric vehicles, Fuel economy, Real-world driving cycle

  10. Study on Drive System of Hybrid Tree Harvester

    Directory of Open Access Journals (Sweden)

    Shen Rong-feng

    2017-01-01

    Full Text Available Hybrid tree harvester with a 60 kW diesel engine combined with a battery pile could be a “green” forest harvesting and transportation system. With the new design, the diesel engine maintains a constant engine speed, keeping fuel consumption low while charging the batteries that drive the forwarder. As an additional energy saving method, the electric motors work as generators to charge the battery pile when the vehicle moves downhill. The vehicle is equipped with six large wheels providing high clearance over uneven terrain while reducing ground pressure. Each wheel is driven via a hub gear by its own alternating current motor, and each of the three wheel pairs can be steered independently. The combination of the diesel engine and six electric motors provides plenty of power for heavy lifting and pulling. The main component parameters of the drive system are calculated and optimized with a set of dynamics and simulated with AVL Cruise software. The results provide practical insights for the fuel tree harvester and are helpful to reduce the structure and size of the tree harvester. Advantage Environment provides information about existing and future products designed to reduce environmental impacts.

  11. Development of a simple driving simulator and determination of the reference range of normative performance.

    Science.gov (United States)

    Kato, Noriaki; Saeki, Satoru; Okazaki, Tetsuya; Matsunaga, Katsuya; Hachisuka, Kenji

    2018-01-01

    To establish the reference range for assessment items of the 'Simple Driving Simulator' (SiDS) in a normative population and to compare performance of age-matched young adults with a traumatic brain injury (TBI) to this reference data. Normative ranges were calculated from the data of 445 participants in the control group. Three performance ranges were established: 'normal', 'borderline' and 'impaired' defined using standard deviation cutoff values in the control group. The performance of 28 patients with a TBI, aged 18-35 years, was evaluated. The performance score for the TBI group in the 'impaired range' was calculated for each test item and used to make a synthetic judgment regarding the clinical value of the SiDS. In the control group, only 0.6% of the participants exhibited a performance in the impaired range on >2 items, compared to 33.2% for the TBI group. We provide evidence that impaired performance on ≤2 items of the SiDS provides a sensitive criterion of 'driving fitness' in young adults after a TBI.

  12. Dose to drivers during drive-through cargo scanning using GEANT4 Monte Carlo simulation

    International Nuclear Information System (INIS)

    Gomes, Rogerio S.; Gomes, Joana D'Arc R.L.; Costa, Mara Lucia L.

    2013-01-01

    The use of radiation technologies to perform screening for cargo containers has been increased due to security issues, mainly, as a consequence of the United States (US) legislation which requires, from 2013, the scanning of all intermodal cargo containers which arrive at US ports. Currently, systems to cargo inspections, using accelerator-driven high energy X-rays, between 4 and 9 MeV, are available for scanning operations. It is expected that, in the future, the use of these systems will be widely spread on roads, ports and airports in Brazil. However, in order to improve the productivity and reduce the costs of acquisition, operation and maintenance these systems require that the driver drives its vehicle through irradiation area, in a situation where members of the public (the truck drivers) enter in controlled area and are deliberately exposed to high-energy beam. Some manufacturers justifies this procedure arguing that the drivers are exposed briefly, and only to the scattered beam, since there are safety systems in order to avoid that the drivers are exposed to direct beam. In this work, it is presented the preliminary results of Monte Carlo simulations concerning the dose of drivers during scanning operations, including the dose due to a failure of safety system, producing an exposure of drivers to the direct beam, as well as, an analysis of the justification of practice, mainly related to the drive-through operational procedure. (author)

  13. Assessing video games to improve driving skills: a literature review and observational study.

    Science.gov (United States)

    Sue, Damian; Ray, Pradeep; Talaei-Khoei, Amir; Jonnagaddala, Jitendra; Vichitvanichphong, Suchada

    2014-08-07

    For individuals, especially older adults, playing video games is a promising tool for improving their driving skills. The ease of use, wide availability, and interactivity of gaming consoles make them an attractive simulation tool. The objective of this study was to look at the feasibility and effects of installing video game consoles in the homes of individuals looking to improve their driving skills. A systematic literature review was conducted to assess the effect of playing video games on improving driving skills. An observatory study was performed to evaluate the feasibility of using an Xbox 360 Kinect console for improving driving skills. Twenty-nine articles, which discuss the implementation of video games in improving driving skills were found in literature. On our study, it was found the Xbox 360 with Kinect is capable of improving physical and mental activities. Xbox Video games were introduced to engage players in physical, visual and cognitive activities including endurance, postural sway, reaction time, eyesight, eye movement, attention and concentration, difficulties with orientation, and semantic fluency. However, manual dexterity, visuo-spatial perception and binocular vision could not be addressed by these games. It was observed that Xbox Kinect (by incorporating Kinect sensor facilities) combines physical, visual and cognitive engagement of players. These results were consistent with those from the literature review. From the research that has been carried out, we can conclude that video game consoles are a viable solution for improving user's physical and mental state. In future we propose to carry a thorough evaluation of the effects of video games on driving skills in elderly people.

  14. Test Results From a Direct Drive Gas Reactor Simulator Coupled to a Brayton Power Conversion Unit

    Science.gov (United States)

    Hervol, David S.; Briggs, Maxwell H.; Owen, Albert K.; Bragg-Sitton, Shannon M.

    2009-01-01

    The Brayton Power Conversion Unit (BPCU) located at NASA Glenn Research Center (GRC) in Cleveland, OH is a closed cycle system incorporating a turboaltemator, recuperator, and gas cooler connected by gas ducts to an external gas heater. For this series of tests, the BPCU was modified by replacing the gas heater with the Direct Drive Gas heater or DOG. The DOG uses electric resistance heaters to simulate a fast spectrum nuclear reactor similar to those proposed for space power applications. The combined system thermal transient behavior was the focus of these tests. The BPCU was operated at various steady state points. At each point it was subjected to transient changes involving shaft rotational speed or DOG electrical input. This paper outlines the changes made to the test unit and describes the testing that took place along with the test results.

  15. It's not just what you eat but when: The impact of eating a meal during simulated shift work on driving performance.

    Science.gov (United States)

    Gupta, Charlotte C; Dorrian, Jill; Grant, Crystal L; Pajcin, Maja; Coates, Alison M; Kennaway, David J; Wittert, Gary A; Heilbronn, Leonie K; Della Vedova, Chris B; Banks, Siobhan

    2017-01-01

    Shiftworkers have impaired performance when driving at night and they also alter their eating patterns during nightshifts. However, it is unknown whether driving at night is influenced by the timing of eating. This study aims to explore the effects of timing of eating on simulated driving performance across four simulated nightshifts. Healthy, non-shiftworking males aged 18-35 years (n = 10) were allocated to either an eating at night (n = 5) or no eating at night (n = 5) condition. During the simulated nightshifts at 1730, 2030 and 0300 h, participants performed a 40-min driving simulation, 3-min Psychomotor Vigilance Task (PVT-B), and recorded their ratings of sleepiness on a subjective scale. Participants had a 6-h sleep opportunity during the day (1000-1600 h). Total 24-h food intake was consistent across groups; however, those in the eating at night condition ate a large meal (30% of 24-h intake) during the nightshift at 0130 h. It was found that participants in both conditions experienced increased sleepiness and PVT-B impairments at 0300 h compared to 1730 and 2030 h (p eating condition displayed a significant decrease in time spent in the safe zone (p eating condition. Results suggest that, for optimal performance, shiftworkers should consider restricting food intake during the night.

  16. Comprehensive 3D-elastohydrodynamic simulation of hermetic compressor crank drive

    Science.gov (United States)

    Posch, S.; Hopfgartner, J.; Berger, E.; Zuber, B.; Almbauer, R.; Schöllauf, P.

    2017-08-01

    Mechanical, electrical and thermodynamic losses form the major loss mechanisms of hermetic compressors for refrigeration application. The present work deals with the investigation of the mechanical losses of a hermetic compressor crank drive. Focus is on 3d-elastohydrodynamic (EHD) modelling of the journal bearings, piston-liner contact and piston secondary motion in combination with multi-body and structural dynamics of the crank drive elements. A detailed description of the model development within the commercial software AVL EXCITE Power Unit is given in the work. The model is used to create a comprehensive analysis of the mechanical losses of a hermetic compressor. Further on, a parametric study concerning oil viscosity and compressor speed is carried out which shows the possibilities of the usage of the model in the development process of hermetic compressors for refrigeration application. Additionally, the usage of the results in an overall thermal network for the determination of the thermal compressor behaviour is discussed.

  17. Observation of early shell-dopant mix in OMEGA direct-drive implosions and comparisons with radiation-hydrodynamic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Baumgaertel, J. A.; Bradley, P. A.; Hsu, S. C.; Cobble, J. A.; Hakel, P.; Tregillis, I. L.; Krasheninnikova, N. S.; Murphy, T. J.; Schmitt, M. J.; Shah, R. C.; Obrey, K. D.; Batha, S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Johns, H.; Joshi, T.; Mayes, D.; Mancini, R. C.; Nagayama, T. [Physics Department, University of Nevada, Reno, Nevada 89557 (United States)

    2014-05-15

    Temporally, spatially, and spectrally resolved x-ray image data from direct-drive implosions on OMEGA were interpreted with the aid of radiation-hydrodynamic simulations. Neither clean calculations nor those using a turbulent mix model can explain fully the observed migration of shell-dopant material (titanium) into the core. Shell-dopant migration was observed via time-dependent, spatially integrated spectra, and spatially and spectrally resolved x-ray images of capsule implosions and resultant dopant emissions. The titanium emission was centrally peaked in narrowband x-ray images. In post-processed clean simulations, the peak titanium emission forms in a ring in self-emission images as the capsule implodes. Post-processed simulations with mix reproduce trends in time-dependent, spatially integrated spectra, as well having centrally peaked Ti emission in synthetic multiple monochromatic imager. However, mix simulations still do not transport Ti to the core as is observed in the experiment. This suggests that phenomena in addition to the turbulent mix must be responsible for the transport of Ti. Simple diffusion estimates are unable to explain the early Ti mix into the core. Mechanisms suggested for further study are capsule surface roughness, illumination non-uniformity, and shock entrainment.

  18. Dynamic simulation of a fuel cell hybrid vehicle during the federal test procedure-75 driving cycle

    International Nuclear Information System (INIS)

    Kang, Sanggyu; Min, Kyoungdoug

    2016-01-01

    Highlights: • Development of a FCHV dynamic model. • Integration of a PEMFC system dynamic model with the electric vehicle model. • Investigation of the dynamic behavior of the FCEV and PEMFC system during FTP-75. • Capturing the dynamic correlation among components in PEMFC system during FTP-75. - Abstract: The dynamic behavior of a proton exchange membrane fuel cell (PEMFC) system is a crucial factor to ensure the safe and effective operation of fuel cell hybrid vehicles (FCHVs). Specifically, water and thermal management are critical to stabilize the performance of the PEMFC during severe load changes. In the present study, the FCHV dynamic model is developed. The dynamic model of the PEMFC system developed by Matlab–Simulink® is integrated into the electric vehicle model embedded in the Amesim®. The dynamic model of the PEMFC system is composed of a PEMFC stack, an air feeding system, and a thermal management system (TMS). The component models of PEMFC, a shell-and-tube gas-to-gas membrane humidifier, and a heat exchanger are validated via a comparison with the experimental data. The FCHV model is simulated during a federal test procedure (FTP)-75 driving cycle. One system configuration and control strategy is adopted to attain optimal water and thermal management in the PEMFC system. The vehicle speed obtained from the FCHV model aptly tracks the target velocity profile of the FTP-75 cycle within an error of ±0.5%. The dynamic behavior and correlation of each component in the PEMFC system is investigated. The mass and heat transfer in the PEMFC, a humidifier, and a heat exchanger are resolved to determine the species concentration and the temperature more accurately with discretization in the flow’s perpendicular direction. Discretization in the flow parallel direction of humidifier and heat exchanger model makes it possible to capture the distribution of the characteristics. The present model can be used to attain the optimization of the system

  19. Steering the conversation: A linguistic exploration of natural language interactions with a digital assistant during simulated driving.

    Science.gov (United States)

    Large, David R; Clark, Leigh; Quandt, Annie; Burnett, Gary; Skrypchuk, Lee

    2017-09-01

    Given the proliferation of 'intelligent' and 'socially-aware' digital assistants embodying everyday mobile technology - and the undeniable logic that utilising voice-activated controls and interfaces in cars reduces the visual and manual distraction of interacting with in-vehicle devices - it appears inevitable that next generation vehicles will be embodied by digital assistants and utilise spoken language as a method of interaction. From a design perspective, defining the language and interaction style that a digital driving assistant should adopt is contingent on the role that they play within the social fabric and context in which they are situated. We therefore conducted a qualitative, Wizard-of-Oz study to explore how drivers might interact linguistically with a natural language digital driving assistant. Twenty-five participants drove for 10 min in a medium-fidelity driving simulator while interacting with a state-of-the-art, high-functioning, conversational digital driving assistant. All exchanges were transcribed and analysed using recognised linguistic techniques, such as discourse and conversation analysis, normally reserved for interpersonal investigation. Language usage patterns demonstrate that interactions with the digital assistant were fundamentally social in nature, with participants affording the assistant equal social status and high-level cognitive processing capability. For example, participants were polite, actively controlled turn-taking during the conversation, and used back-channelling, fillers and hesitation, as they might in human communication. Furthermore, participants expected the digital assistant to understand and process complex requests mitigated with hedging words and expressions, and peppered with vague language and deictic references requiring shared contextual information and mutual understanding. Findings are presented in six themes which emerged during the analysis - formulating responses; turn-taking; back

  20. Extracting Synthetic Multi-Cluster Platform Configurations from Grid'5000 for Driving Simulation Experiments

    OpenAIRE

    Suter , Frédéric; Casanova , Henri

    2007-01-01

    This report presents a collection of synthetic but realistic distributed computing platform configurations. These configurations are intended for simulation experiments in the study of parallel applications on multi-cluster platforms.

  1. Driving performance on the descending limb of blood alcohol concentration (BAC) in undergraduate students: a pilot study.

    Science.gov (United States)

    Tremblay, Mathieu; Gallant, François; Lavallière, Martin; Chiasson, Martine; Silvey, Dustin; Behm, David; Albert, Wayne J; Johnson, Michel J

    2015-01-01

    Young drivers are overrepresented in collisions resulting in fatalities. It is not uncommon for young drivers to socially binge drink and decide to drive a vehicle a few hours after consumption. To better understand the risks that may be associated with this behaviour, the present study has examined the effects of a social drinking bout followed by a simulated drive in undergraduate students on the descending limb of their BAC (blood alcohol concentration) curve. Two groups of eight undergraduate students (n = 16) took part in this study. Participants in the alcohol group were assessed before drinking, then at moderate and low BAC as well as 24 hours post-acute consumption. This group consumed an average of 5.3 ± 1.4 (mean ± SD) drinks in an hour in a social context and were then submitted to a driving and a predicted crash risk assessment. The control group was assessed at the same time points without alcohol intake or social context.; at 8 a.m., noon, 3 p.m. and 8 a.m. the next morning. These multiple time points were used to measure any potential learning effects from the assessment tools (i.e. driving simulator and useful field of view test (UFOV)). Diminished driving performance at moderate BAC was observed with no increases in predicted crash risk. Moderate correlations between driving variables were observed. No association exists between driving variables and UFOV variables. The control group improved measures of selective attention after the third assessment. No learning effect was observed from multiple sessions with the driving simulator. Our results show that a moderate BAC, although legal, increases the risky behaviour. Effects of alcohol expectancy could have been displayed by the experimental group. UFOV measures and predicted crash risk categories were not sensitive enough to predict crash risk for young drivers, even when intoxicated.

  2. Driving performance on the descending limb of blood alcohol concentration (BAC in undergraduate students: a pilot study.

    Directory of Open Access Journals (Sweden)

    Mathieu Tremblay

    Full Text Available Young drivers are overrepresented in collisions resulting in fatalities. It is not uncommon for young drivers to socially binge drink and decide to drive a vehicle a few hours after consumption. To better understand the risks that may be associated with this behaviour, the present study has examined the effects of a social drinking bout followed by a simulated drive in undergraduate students on the descending limb of their BAC (blood alcohol concentration curve. Two groups of eight undergraduate students (n = 16 took part in this study. Participants in the alcohol group were assessed before drinking, then at moderate and low BAC as well as 24 hours post-acute consumption. This group consumed an average of 5.3 ± 1.4 (mean ± SD drinks in an hour in a social context and were then submitted to a driving and a predicted crash risk assessment. The control group was assessed at the same time points without alcohol intake or social context.; at 8 a.m., noon, 3 p.m. and 8 a.m. the next morning. These multiple time points were used to measure any potential learning effects from the assessment tools (i.e. driving simulator and useful field of view test (UFOV. Diminished driving performance at moderate BAC was observed with no increases in predicted crash risk. Moderate correlations between driving variables were observed. No association exists between driving variables and UFOV variables. The control group improved measures of selective attention after the third assessment. No learning effect was observed from multiple sessions with the driving simulator. Our results show that a moderate BAC, although legal, increases the risky behaviour. Effects of alcohol expectancy could have been displayed by the experimental group. UFOV measures and predicted crash risk categories were not sensitive enough to predict crash risk for young drivers, even when intoxicated.

  3. Fast response Antiwindup PI speed controller of Brushless DC motor drive: Modeling, simulation and implementation on DSP

    Directory of Open Access Journals (Sweden)

    Mohd Tariq

    2016-05-01

    Full Text Available Most of the Brushless DC (BLDC motors drive adopts proportional, integral and derivative (PID controller and pulse width modulation (PWM scheme for speed control. Hence, BLDC motor drive has strong saturation characteristics. The saturation results in a typical windup phenomenon. The paper presents an Antiwindup drive for BLDC motor. An Antiwindup controller (AWC has been used in the paper. AWC has been modeled in MATLAB/Simulink and comparison has been done between conventional PI controller and AWC at different starting loads. Dynamic characteristics of the BLDC motor drive have been examined and results are presented and discussed in detail in this paper. Details of DSP based experimental validation of the simulated results are also presented here.

  4. Modeling and Simulation of Control Actuation System with Fuzzy-PID Logic Controlled Brushless Motor Drives for Missiles Glider Applications.

    Science.gov (United States)

    Muniraj, Murali; Arulmozhiyal, Ramaswamy

    2015-01-01

    A control actuation system has been used extensively in automotive, aerospace, and defense applications. The major challenges in modeling control actuation system are rise time, maximum peak to peak overshoot, and response to nonlinear system with percentage error. This paper addresses the challenges in modeling and real time implementation of control actuation system for missiles glider applications. As an alternative fuzzy-PID controller is proposed in BLDC motor drive followed by linkage mechanism to actuate fins in missiles and gliders. The proposed system will realize better rise time and less overshoot while operating in extreme nonlinear dynamic system conditions. A mathematical model of BLDC motor is derived in state space form. The complete control actuation system is modeled in MATLAB/Simulink environment and verified by performing simulation studies. A real time prototype of the control actuation is developed with dSPACE-1104 hardware controller and a detailed analysis is carried out to confirm the viability of the proposed system.

  5. Principle for the Validation of a Driving Support using a Computer Vision-Based Driver Modelization on a Simulator

    Directory of Open Access Journals (Sweden)

    Baptiste Rouzier

    2015-07-01

    Full Text Available This paper presents a new structure for a driving support designed to compensate for the problems caused by the behaviour of the driver without causing a feeling of unease. This assistance is based on a shared control between the human and an automatic support that computes and applies an assisting torque on the steering wheel. This torque is computed from a representation of the hazards encountered on the road by virtual potentials. However, the equilibrium between the relative influences of the human and the support on the steering wheel are difficult to find and depend upon the situation. This is why this driving support includes a modelization of the driver based on an analysis of several face features using a computer vision algorithm. The goal is to determine whether the driver is drowsy or whether he is paying attention to some specific points in order to adapt the strength of the support. The accuracy of the measurements made on the face features is estimated, and the interest of the proposal as well as the concepts raised by such assistance are studied through simulations.

  6. Medications and impaired driving.

    Science.gov (United States)

    Hetland, Amanda; Carr, David B

    2014-04-01

    To describe the association of specific medication classes with driving outcomes and provide clinical recommendations. The MEDLINE and EMBASE databases were searched for articles published from January 1973 to June 2013 on classes of medications associated with driving impairment. The search included outcome terms such as automobile driving, motor vehicle crash, driving simulator, and road tests. Only English-language articles that contained findings from observational or interventional designs with ≥ 10 participants were included in this review. Cross-sectional studies, case series, and case reports were excluded. Driving is an important task and activity for the majority of adults. Some commonly prescribed medications have been associated with driving impairment measured by road performance, driving simulation, and/or motor vehicle crashes. This review of 30 studies identified findings with barbiturates, benzodiazepines, hypnotics, antidepressants, opioid and nonsteroidal analgesics, anticonvulsants, antipsychotics, antiparkinsonian agents, skeletal muscle relaxants, antihistamines, anticholinergic medications, and hypoglycemic agents. Additional studies of medication impact on sedation, sleep latency, and psychomotor function, as well as the role of alcohol, are also discussed. Psychotropic agents and those with central nervous system side effects were associated with measures of impaired driving performance. It is difficult to determine if such associations are actually a result of medication use or the medical diagnosis itself. Regardless, clinicians should be aware of the increased risk of impaired driving with specific classes of medications, educate their patients, and/or consider safer alternatives.

  7. Predictors of driving outcomes including both crash involvement and driving cessation in a prospective study of Japanese older drivers.

    Science.gov (United States)

    Kosuge, Ritsu; Okamura, Kazuko; Kihira, Makoto; Nakano, Yukako; Fujita, Goro

    2017-09-01

    The first aim of this study was to investigate predictors of future traffic crash involvement, taking into account bias in the handling of data for former drivers. The second aim was to compare characteristics of former drivers and crash-involved drivers in order to gain an understanding of appropriate driving cessation among older drivers. In all, 154 drivers aged 70 years or older participated in the baseline interview and the follow-up survey conducted two years later. In the baseline interview, participants were asked to respond to a questionnaire, take the Useful Field of View test ® (UFOV), and complete the Mini-Mental State Examination. In the follow-up survey, participants were asked by mail or telephone whether they had stopped driving. Participants reporting that they still drove were invited to participate in a subsequent interview. Based on the information obtained in the follow-up survey, participants were classified as follows: driving cessation group (n=26); crash-involved group (n=18); and crash-free group (n=110). A multinomial logistic regression was then used to analyse the data. Contrary to the results of previous studies, we found older age to be associated with crash involvement but not with driving cessation. The cessation group had more decreased cognitive processing speed than the crash-involved and crash-free groups. Crash history was also predictive of crash involvement. Participants who were subject to license renewal between baseline and follow-up had a greater tendency to continue driving. Results suggested that age and crash history could potentially identify high-risk older drivers. The predictive power of cognitive processing speed is reduced under certain conditions. License-renewal procedures may induce Japanese older adults to continue driving. Future studies should use a large national sample to confirm the results of the present study. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Testing alternative designs for a roadside animal detection system using a driving simulator

    Directory of Open Access Journals (Sweden)

    Molly K. Grace

    2015-07-01

    Full Text Available Objectives: A Roadside Animal Detection System (RADS was installed in January 2012 along Highway 41 through Big Cypress National Preserve in Florida, USA in an attempt to reduce wildlife-vehicle collisions. The system uses flashing warning signs to alert drivers when a large animal is near the road. However, we suspected that the RADS warning signs could be ignored by drivers because they resemble other conventional signs. We hypothesized that word-based warning signs (current design are less effective than picture-based signs at catching drivers’ attention. Methods: We used a driving simulator to test (1 the effects of the RADS on collision rate, driver speed, and latency to brake; and (2 whether the RADS would be more effective if warning signs were picture-based. Participants were randomly assigned to one of three treatments: no warning (control, word-based RADS signs (current design, and picture-based RADS signs (proposed design. During the simulations, a deer entered the road in front of the driver, and we recorded whether drivers “crashed” or not. Results: Both the picture-based and word-based RADS signs resulted in significantly lower crash probabilities. The picture-based RADS signs performed better than the word-based signs in reducing speed and latency to brake, although the effect varied between twilight and night. However, the word-based RADS signs still did produce significant reductions in speed and braking latency. Conclusions: We conclude that the word-based RADS in Big Cypress should help prevent dangerous wildlife-vehicle collisions, but that redesigning the warning signs to be picture-based could yield even greater benefits.

  9. Drowsiness discrimination in an overnight driving simulation on the basis of RR and QT intervals

    Directory of Open Access Journals (Sweden)

    Heinze Christian

    2017-09-01

    Full Text Available We examined if ECG-based features are discrimi-native towards drowsiness. Twenty-five volunteers (19–32 years completed 7×40 minutes of monotonous overnight driving simulation, designed to induce drowsiness. ECG (512 s-1 was recorded continuously; subjective ratings of drowsiness on the Karolinska sleepiness scale (KSS were polled every five minutes. ECG recordings were divided into 5-min segments, each associated with the mean of one self- and two observer-KSS ratings. Those mean KSS values were binarized to obtain two classes not drowsy and drowsy. The Q-, R- and T-waves in the recordings were detected; R-peak positions were manually reviewed; the Q- and T-detection method was tested against the manual annotations of Physio-net’s QT database. Power spectral densities of RR intervals (RR-PSD and quantiles of the empirical distribution of heart-rate corrected QTc intervals were estimated. Support-vector machines and random-holdout cross-validation were used for the estimation of the classification error. Using either RR-PSD or QTc features yielded mean test errors of 79.3 ± 0.3 % and 82.7 ± 0.5 %, respectively. Merging RR and QTc features improved the accuracy to 88.3 ± 0.2 %. QTc intervals of the class drowsy were generally prolonged com-pared to not drowsy. Our findings indicate that the inclusion of QT intervals contribute to the discrimination of driver sleepiness.

  10. THE STUDY OF TRANSIENT PROCESSES OF THE FREQUENCY-REGULATED SYNCHRONOUS ELECTRIC DRIVE

    Directory of Open Access Journals (Sweden)

    B. I. Firago

    2016-01-01

    Full Text Available In order to improve the power indices and to simplify the system of frequency speed control the scope of application of synchronous variable-frequency electric drives with independent frequency setting is being expanded. The synchronous motors with electromagnetic excitation and permanent magnet excitation in various industrial settings, including load-lifting machines and mechanisms, are used. As compared with the asynchronous frequency-regulated electric drives the synchronous ones have lower power loss, harder mechanical characteristic without feedback for speed and the simplest law of frequency control, i. e., a proportional one that, however, provides the maximum electromagnetic torque of the motor constant at all frequencies, due to the constant magnetic flux. The article concerns an analytical study of transient processes of synchronous electric drive with consideration of the influence of damping winding when the motor supply voltage frequency varies linearly during the transient time. As a result of the analysis the formulas have been obtained that make it possible to calculate the angular velocity of the rotor and the electromagnetic torque of the motor at start-up, braking, and impingement and discharge of loads, evaluating the quality of the transition process and tracking the maximum value of the electromagnetic torque, that must not exceed the permissible value. Validation of the developed technique of calculation of transient processes of synchronous electric drive has been obtained by comparison of calculations according to the formulas with the simulation results of the electric drive on the basis of the synchronous motor of the SD3 13-34-6 type (power of 500 kW and voltage of 6 kV.

  11. Polyphilic Interactions as Structural Driving Force Investigated by Molecular Dynamics Simulation (Project 7

    Directory of Open Access Journals (Sweden)

    Christopher Peschel

    2017-09-01

    Full Text Available We investigated the effect of fluorinated molecules on dipalmitoylphosphatidylcholine (DPPC bilayers by force-field molecular dynamics simulations. In the first step, we developed all-atom force-field parameters for additive molecules in membranes to enable an accurate description of those systems. On the basis of this force field, we performed extensive simulations of various bilayer systems containing different additives. The additive molecules were chosen to be of different size and shape, and they included small molecules such as perfluorinated alcohols, but also more complex molecules. From these simulations, we investigated the structural and dynamic effects of the additives on the membrane properties, as well as the behavior of the additive molecules themselves. Our results are in good agreement with other theoretical and experimental studies, and they contribute to a microscopic understanding of interactions, which might be used to specifically tune membrane properties by additives in the future.

  12. Drowsy Driving

    Science.gov (United States)

    ... at least 8 hours. 8-9 Develop good sleeping habits such as sticking to a sleep schedule. If ... K, Howard ME. Cognitive components of simulated driving performance: sleep loss effects and predictors. Accid Anal Prev. 2012; ...

  13. Risk-taking behaviors and prefrontal cortex activity of male adolescents in the presence of peer passengers during simulated driving : a functional near-infrared spectroscopy (fNIRS) study.

    Science.gov (United States)

    2015-09-01

    Crash statistics show that adolescent drivers are more likely to be involved in motor-vehicle crashes than adults and that the : presence of peer passengers pose an additional risk factor for crashes. Experimental and observational studies show that ...

  14. Conducting Simulation Studies in Psychometrics

    Science.gov (United States)

    Feinberg, Richard A.; Rubright, Jonathan D.

    2016-01-01

    Simulation studies are fundamental to psychometric discourse and play a crucial role in operational and academic research. Yet, resources for psychometricians interested in conducting simulations are scarce. This Instructional Topics in Educational Measurement Series (ITEMS) module is meant to address this deficiency by providing a comprehensive…

  15. Study on electromagnetism force of CARR control rod drive mechanism experimental machine

    International Nuclear Information System (INIS)

    Zhu Xuewei; Zhen Jianxiao; Wang Yulin; Jia Yueguang; Yang Kun; Yin Haozhe

    2015-01-01

    With the aim of acquiring electromagnetic force and electromagnetic field distributions of control rod drive mechanism (CRDM) in China Advanced Research Reactor (CARR), the force analysis on the CRDM was taken. Manufacturing the experimental machine, the electromagnetic force experiment was taken on it. The electromagnetic field and electromagnetic force simulation analyses of experimental machine were taken, working out distribution data of electromagnetic force and magnetic induction intensity distribution curve, and the effects of permanent magnetic field on electromagnetic field and structure parameters on electromagnetic force. The simulation value is accord with experiment value, the research results provide a reference to electromagnetic force study on CRDM in CARR, and also provide a reference to design of the same type CRDM. (authors)

  16. Effects of slow-release caffeine and a nap on driving simulator performance after partial sleep deprivation.

    Science.gov (United States)

    De Valck, Elke; De Groot, Esther; Cluydts, Raymond

    2003-02-01

    A driving simulator was used to evaluate the effectiveness of a 30-min. nap and 300-mg slow-release caffeine as countermeasures to drivers' sleepiness induced by partial sleep deprivation. 12 participants were allowed 45 hr. time in bed at the laboratory. Driving performance then was measured twice--at 9 a.m. and at 1 p.m.--by a 45-min. driving task on a simulator. Subjective sleepiness/alertness and mood were assessed four times on the Stanford Sleepiness Scale and the Profile of Mood States. Driving performance was assessed as Lane Drifting, Speed Deviation, and Accident Liability. A 30-min. nap opportunity and 300 mg of slow-release caffeine both were successful in counteracting drivers' sleepiness. The remedial effect of slow-release caffeine lasted longer than that of the nap, that is, it was also effective in the afternoon session. This suggests that slow-release caffeine represents a valuable countermeasure that, in the case of partial sleep deprivation, is preferred to a nap when sleepiness has to be counteracted for a longer time.

  17. Simulation in International Studies

    Science.gov (United States)

    Boyer, Mark A.

    2011-01-01

    Social scientists have long worked to replicate real-world phenomena in their research and teaching environments. Unlike our biophysical science colleagues, we are faced with an area of study that is not governed by the laws of physics and other more predictable relationships. As a result, social scientists, and international studies scholars more…

  18. Simulation models of a drive with an asynchronous electric engine for students of electrical engineering faculties

    Directory of Open Access Journals (Sweden)

    Romanenko N. G.

    2017-10-01

    Full Text Available the application of virtual laboratories will allow to show different transition processes, as well as to carry out experiments that are very expensive in real electrical machines’ labs, for example, to calculate the energy costs in electric drives. Models of non-regulation asynchronous drive and frequency-regulated asynchronous electric drive are examined in this article. The author has calculated and compared the energy losses of these systems with various types of loads and this lets us to evaluate work processes of many technical devices.

  19. Deep Physiological Arousal Detection in a Driving Simulator Using Wearable Sensors

    NARCIS (Netherlands)

    Saeed, Aaqib; Trajanovski, Stojan; van Keulen, Maurice; van Erp, Johannes Bernardus Fransiscus

    2017-01-01

    Driving is an activity that requires considerable alertness. Insufficient attention, imperfect perception, inadequate information processing, and sub-optimal arousal are possible causes of poor human performance. Understanding of these causes and the implementation of effective remedies is of key

  20. The general deterrence of driving while intoxicated. Volume 1, System analysis and computer-based simulation

    Science.gov (United States)

    1978-01-01

    A system analysis was completed of the general deterrence of driving while intoxicated (DWI). Elements which influence DWI decisions were identified and interrelated in a system model; then, potential countermeasures which might be employed in DWI ge...

  1. In The Truman Show: Generating Dynamic Scenarios in a Driving Simulator

    NARCIS (Netherlands)

    Wassink, I.; van Dijk, B.; van Dijk, Elisabeth M.A.G.; Zwiers, Jakob; Nijholt, Antinus; Brugman, A.M.

    Using a movie set metaphor, this software framework increases a driving simulator’s effectiveness by dynamically controlling traffic scenarios. It uses agent protocols to make the system extensible, maintainable, and easy to understand.

  2. CLIC Drive Beam Phase Stabilisation

    CERN Document Server

    Gerbershagen, Alexander; Schulte, Daniel

    The thesis presents phase stability studies for the Compact Linear Collider (CLIC) and focuses in particular on CLIC Drive Beam longitudinal phase stabilisation. This topic constitutes one of the main feasibility challenges for CLIC construction and is an essential component of the current CLIC stabilisation campaign. The studies are divided into two large interrelated sections: the simulation studies for the CLIC Drive Beam stability, and measurements, data analysis and simulations of the CLIC Test Facility (CTF3) Drive Beam phase errors. A dedicated software tool has been developed for a step-by-step analysis of the error propagation through the CLIC Drive Beam. It uses realistic RF potential and beam loading amplitude functions for the Drive and Main Beam accelerating structures, complete models of the recombination scheme and compressor chicane as well as of further CLIC Drive Beam modules. The tool has been tested extensively and its functionality has been verified. The phase error propagation at CLIC h...

  3. SIMULATION STUDIES FOR UPQC

    OpenAIRE

    Dr. PRASAD M. JOSHI; Mukul Kumar

    2016-01-01

    Nowadays, widespread use of power electronics based load in house-hold and industry have increased the importance and application of power Quality studies. Power electronic devices having property of non-linearity draw harmonic and reactive power from the source. Unified Power Quality conditioner (UPQC) is the device that mitigates the harmonics and improves the quality of power. This paper presents the working principle of UOQC based on instantaneous p-q theory which compensates the load cur...

  4. Perodua Myvi engine fuel consumption map and fuel economy vehicle simulation on the drive cycles based on Malaysian roads

    Directory of Open Access Journals (Sweden)

    Ramdan Muhammad Iftishah

    2017-01-01

    Full Text Available This paper presents the fuel consumption engine map for a 1.3L Perodua Myvi passenger car. The engine dynamometer and the engine throttle are controlled, to create the operating conditions for the engine map. Interpolation work is done in MATLAB, to create a 3D fuel consumption engine map. The engine map is used in a fuel-economy estimation simulation, using the city and the highway drive cycles based on Malaysian roads. The fuel economy values generated from the simulations are similar to experimental fuel consumption results.

  5. Marketing blood drives to students: a case study.

    Science.gov (United States)

    Leigh, Laurence; Bist, Michael; Alexe, Roxana

    2007-01-01

    The aim of this paper is to motivate blood donation among international students and demonstrate the applicability of marketing techniques in the health care sector. The paper uses a combination of focus groups and a questionnaire-based survey. The paper finds that donors primarily find gratification from their altruistic acts through awareness of their contribution to saving lives. Receiving information on how each individual donation is used is seen as a powerful means of reinforcement. Practical benefits such as receiving free blood test information are also useful motivators, while communicating the professionalism of the blood collection techniques are important for reassuring the minority of prospective donors who expressed fears about possible risks associated with blood donation. Since this was a small-scale study among Hungarian and international students in Budapest, further research is necessary to validate its results among other demographic groups. Findings were reported to the International Federation of Red Cross and Red Crescent Societies in Hungary in order to increase blood donations among students in Hungary. Subject to validation through further research, applying recommended approaches in different countries and other demographic groups is suggested. This is the first research paper on motivation toward blood donation among international students and offers new and practical suggestions for increasing their level of participation in blood drives.

  6. Heart rate variability (HRV and muscular system activity (EMG in cases of crash threat during simulated driving of a passenger car

    Directory of Open Access Journals (Sweden)

    Krystyna Zużewicz

    2013-10-01

    Full Text Available Objectives: The aim of the study was to verify whether simultaneous responses from the muscular and circulatory system occur in the driver's body under simulated conditions of a crash threat. Materials and Methods: The study was carried out in a passenger car driving simulator. The crash was included in the driving test scenario developed in an urban setting. In the group of 22 young male subjects, two physiological signals - ECG and EMG were continuously recorded. The length of the RR interval in the ECG signal was assessed. A HRV analysis was performed in the time and frequency domains for 1-minute record segments at rest (seated position, during undisturbed driving as well as during and several minutes after the crash. For the left and right side muscles: m. trapezius (TR and m. flexor digitorum superficialis (FDS, the EMG signal amplitude was determined. The percentage of maximal voluntary contraction (MVC was compared during driving and during the crash. Results: As for the ECG signal, it was found that in most of the drivers changes occurred in the parameter values reflecting HRV in the time domain. Significant changes were noted in the mean length of RR intervals (mRR. As for the EMG signal, the changes in the amplitude concerned the signal recorded from the FDS muscle. The changes in ECG and EMG were simultaneous in half of the cases. Conclusion: Such parameters as mRR (ECG signal and FDS-L amplitude (EMG signal were the responses to accident risk. Under simulated conditions, responses from the circulatory and musculoskeletal systems are not always simultaneous. The results indicate that a more complete driver's response to a crash in road traffic is obtained based on parallel recording of two physiological signals (ECG and EMG.

  7. A Comparative Study for the Clic Drive Beam Decelerator Optics

    CERN Document Server

    Sterbini, G; Adli, E

    2012-01-01

    The baseline for the CLIC drive beam decelerator optics consists of a 2 m long FODO cell. This solution was adopted to have strong focusing in order to mitigate the effect of the PETS wake fields and to minimize the drive beam envelope. Taking into account the most recent PETS design, we compare the performance of the baseline FODO cell with a proposal that consider twice longer FODO cell. Despite of the expected cost in terms of performance, the reduction of the complexity of the system due to the halving of the number of quadrupoles can be beneficial for the overall optimization of the decelerator design.

  8. Low levels of alcohol impair driving simulator performance and reduce perception of crash risk in partially sleep deprived subjects.

    Science.gov (United States)

    Banks, Siobhan; Catcheside, Peter; Lack, Leon; Grunstein, Ron R; McEvoy, R Doug

    2004-09-15

    Partial sleep deprivation and alcohol consumption are a common combination, particularly among young drivers. We hypothesized that while low blood alcohol concentration (sleep deprivation and low blood alcohol concentration would cause significant performance impairment. Experimental Sleep Disorders Unit Laboratory 20 healthy volunteers (mean age 22.8 years; 9 men). Subjects underwent driving simulator testing at 1 am on 2 nights a week apart. On the night preceding simulator testing, subjects were partially sleep deprived (5 hours in bed). Alcohol consumption (2-3 standard alcohol drinks over 2 hours) was randomized to 1 of the 2 test nights, and blood alcohol concentrations were estimated using a calibrated Breathalyzer. During the driving task subjects were monitored continuously with electroencephalography for sleep episodes and were prompted every 4.5 minutes for answers to 2 perception scales-performance and crash risk. Mean blood alcohol concentration on the alcohol night was 0.035 +/- 0.015 g/dL. Compared with conditions during partial sleep deprivation alone, subjects had more microsleeps, impaired driving simulator performance, and poorer ability to predict crash risk in the combined partial sleep deprivation and alcohol condition. Women predicted crash risk more accurately than did men in the partial sleep deprivation condition, but neither men nor women predicted the risk accurately in the sleep deprivation plus alcohol condition. Alcohol at legal blood alcohol concentrations appears to increase sleepiness and impair performance and the detection of crash risk following partial sleep deprivation. When partially sleep deprived, women appear to be either more perceptive of increased crash risk or more willing to admit to their driving limitations than are men. Alcohol eliminated this behavioral difference.

  9. Impact of Methylphenidate Delivery Profiles on Driving Performance of Adolescents with Attention-Deficit/hyperactivity Disorder: A Pilot Study

    Science.gov (United States)

    Cox, Daniel J.; Merkel, R. Lawrence; Penberthy, Jennifer Kim; Kovatchev, Boris; Hankin, Cheryl S.

    2004-01-01

    Objective: Adolescents with attention-deficit/hyperactivity disorder (ADHD) are at high risk for driving accidents. One dose of methylphenidate (MPH) improves simulator driving performances of ADHD-diagnosed adolescents at 1.5 hours post-dose. However, little is known about the effects of different MPH delivery profiles on driving performance…

  10. Correlation of reaction time and EEG log bandpower from dry frontal electrodes in a passive fatigue driving simulation experiment.

    Science.gov (United States)

    Ruyi Foong; Kai Keng Ang; Chai Quek

    2017-07-01

    Fatigue is one of the causes of falling asleep at the wheel, which can result in fatal accidents. Thus, it is necessary to have practical fatigue detection solutions for drivers. In literature, electroencephalography (EEG) along with the surrogate measure of reaction time (RT) has been used to develop fatigue detection algorithms. However, these solutions are often based upon wet multi-channel EEG electrodes which are not feasible or practical for drivers. Using dry electrodes and headband like designs would be better. Hence, this study aims to investigate the correlation of EEG log bandpower against RT via a Muse headband which has dry frontal EEG electrodes. 31 subjects underwent an hour-long driving simulation experiment with car deviation events. Based on the video and EEG data, 5 `Sleepy' and 5 `Alert' subjects are identified and analyzed. A differential signal between Fp1 and Fp2 is computed so as to remove the effects of eye blinks, and is analyzed for correlation with RT. Significant positive correlation is found for log delta (1-4 Hz) bandpower, and significant negative correlations for log theta (4-8 Hz) and alpha (8-12 Hz) bandpowers, but the positive correlation of log beta (12-30 Hz) bandpower with RT is not significant. This is a good first step towards building a practical fatigue detection solution for drivers in the future.

  11. Modeling and Simulation of Control Actuation System with Fuzzy-PID Logic Controlled Brushless Motor Drives for Missiles Glider Applications

    Directory of Open Access Journals (Sweden)

    Murali Muniraj

    2015-01-01

    Full Text Available A control actuation system has been used extensively in automotive, aerospace, and defense applications. The major challenges in modeling control actuation system are rise time, maximum peak to peak overshoot, and response to nonlinear system with percentage error. This paper addresses the challenges in modeling and real time implementation of control actuation system for missiles glider applications. As an alternative fuzzy-PID controller is proposed in BLDC motor drive followed by linkage mechanism to actuate fins in missiles and gliders. The proposed system will realize better rise time and less overshoot while operating in extreme nonlinear dynamic system conditions. A mathematical model of BLDC motor is derived in state space form. The complete control actuation system is modeled in MATLAB/Simulink environment and verified by performing simulation studies. A real time prototype of the control actuation is developed with dSPACE-1104 hardware controller and a detailed analysis is carried out to confirm the viability of the proposed system.

  12. Modeling and Simulation of Control Actuation System with Fuzzy-PID Logic Controlled Brushless Motor Drives for Missiles Glider Applications

    Science.gov (United States)

    Muniraj, Murali; Arulmozhiyal, Ramaswamy

    2015-01-01

    A control actuation system has been used extensively in automotive, aerospace, and defense applications. The major challenges in modeling control actuation system are rise time, maximum peak to peak overshoot, and response to nonlinear system with percentage error. This paper addresses the challenges in modeling and real time implementation of control actuation system for missiles glider applications. As an alternative fuzzy-PID controller is proposed in BLDC motor drive followed by linkage mechanism to actuate fins in missiles and gliders. The proposed system will realize better rise time and less overshoot while operating in extreme nonlinear dynamic system conditions. A mathematical model of BLDC motor is derived in state space form. The complete control actuation system is modeled in MATLAB/Simulink environment and verified by performing simulation studies. A real time prototype of the control actuation is developed with dSPACE-1104 hardware controller and a detailed analysis is carried out to confirm the viability of the proposed system. PMID:26613102

  13. Modelling and experimental study for automated congestion driving

    NARCIS (Netherlands)

    Urhahne, Joseph; Piastowski, P.; van der Voort, Mascha C.; Bebis, G; Boyle, R.; Parvin, B.; Koracin, D.; Pavlidis, I.; Feris, R.; McGraw, T.; Elendt, M.; Kopper, R.; Ragan, E.; Ye, Z.; Weber, G.

    2015-01-01

    Taking a collaborative approach in automated congestion driving with a Traffic Jam Assist system requires the driver to take over control in certain traffic situations. In order to warn the driver appropriately, warnings are issued (“pay attention” vs. “take action”) due to a control transition

  14. Langmuir probe study in the nonresonant current drive regime of ...

    Indian Academy of Sciences (India)

    Abstract. Characterization of the current drive regime is done for helicon wave- generated plasma in a torus, at a very high operating frequency. A radiofrequency- compensated Langmuir probe is designed and used for the measurement of plasma parameters along with the electron energy distributions in radial scans of the ...

  15. Study of the Advantages of Internal Permanent Magnet Drive Motor with Selectable Windings for Hybrid-Electric Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Otaduy, P.J.; Hsu, J.S.; Adams, D.J.

    2007-11-30

    This report describes research performed on the viability of changing the effectively active number of turns in the stator windings of an internal permanent magnet (IPM) electric motor to strengthen or weaken the magnetic fields in order to optimize the motor's performance at specific operating speeds and loads. Analytical and simulation studies have been complemented with research on switching mechanisms to accomplish the task. The simulation studies conducted examine the power and energy demands on a vehicle following a series of standard driving cycles and the impact on the efficiency and battery size of an electrically propelled vehicle when it uses an IPM motor with turn-switching capabilities. Both full driving cycle electric propulsion and propulsion limited starting from zero to a set speed have been investigated.

  16. Alcohol intoxication effects on simulated driving: exploring alcohol-dose effects on brain activation using functional MRI.

    Science.gov (United States)

    Calhoun, Vince D; Pekar, James J; Pearlson, Godfrey D

    2004-11-01

    Driving while intoxicated is a major public health problem. We investigated impaired driving using a simulated driving skill game that presents an 'in-car' view of a road and a readout of speed. We explored brain activation and behavioral alterations from baseline at two blood alcohol concentrations (BACs). Participants received single-blind individualized doses of beverage alcohol designed to produce blood alcohol content (BAC) of 0.04 and 0.08 or placebo. Scanning occurred on a 1.5 Tesla Philips MRI scanner after training to asymptote performance. Analysis was performed using independent component analysis (ICA) to isolate systematically nonoverlapping 'networks' and their time courses. Imaging results revealed seven separate driving-related brain networks with different time courses. Several significant findings were observed for the imaging data. First, dose-dependent functional magnetic resonance imaging (fMRI) changes were revealed in orbitofrontal (OF) and motor (but not cerebellar) regions; visual and medial frontal regions were unaffected. Second, cerebellar regions were significantly associated with driving behavior in a dose-dependent manner. Finally, a global disruptive effect of alcohol on the ICA time courses was observed with highly significant differences in OF and motor regions. Alcohol thus demonstrated some behavioral effects and unique, disruptive, dose-dependent effects on fMRI signal within several brain circuits. The fMRI data also suggest that the deficits observed in alcohol intoxication may be modulated primarily through OF/anterior cingulate, motor and cerebellar regions as opposed to attentional areas in frontoparietal cortex.

  17. Flux estimation algorithms for electric drives: a comparative study

    OpenAIRE

    Koteich , Mohamad

    2016-01-01

    International audience; This paper reviews the stator flux estimation algorithms applied to the alternating current motor drives. The so-called voltage model estimation, which consists of integrating the back-electromotive force signal, is addressed. However, in practice , the pure integration is prone to drift problems due to noises, measurement error, stator resistance uncertainty and unknown initial conditions. This limitation becomes more restrictive at low speed operation. Several soluti...

  18. Robust Underestimation of Speed During Driving: A Field Study.

    Science.gov (United States)

    Schütz, Alexander C; Billino, Jutta; Bodrogi, Peter; Polin, Dmitrij; Khanh, Tran Q; Gegenfurtner, Karl R

    2015-12-01

    Traffic reports consistently identify speeding as a substantial source of accidents. Adequate driving speeds require reliable speed estimation; however, there is still a lack of understanding how speed perception is biased during driving. Therefore, we ran three experiments measuring speed estimation under controlled driving and lighting conditions. In the first experiment, participants had to produce target speeds as drivers or had to judge driven speed as passengers. Measurements were performed at daylight and at night. In the second experiment, participants were required to produce target speeds at dusk, under rapidly changing lighting conditions. In the third experiment, we let two cars approach and pass each other. Drivers were instructed to produce target speeds as well as to judge the speed of the oncoming vehicle. Here measurements were performed at daylight and at night, with full or dipped headlights. We found that passengers underestimated driven speed by about 20% and drivers went over the instructed speed by roughly the same amount. Interestingly, the underestimation of speed extended to oncoming cars. All of these effects were independent of lighting conditions. The consistent underestimation of speed could lead to potentially fatal situations where drivers go faster than intended and judge oncoming traffic to approach slower than it actually is. © The Author(s) 2015.

  19. Temporal and Spatial Distribution of Respirable Dust After Blasting of Coal Roadway Driving Faces: A Case Study

    Directory of Open Access Journals (Sweden)

    Shengyong Hu

    2015-10-01

    Full Text Available Coal roadway driving is an important part of the underground mining system, and very common in Chinese coal mines. However, the high concentration of respirable dust produced in the blasting operation poses a great hazard to miners’ health as well as the underground environment. In this paper, based on the direct simulation Monte Carlo method, the gas–solid two-phase flow model of particle movement is established to study the respirable dust distribution in blasting driving face. The results show that there is an obvious vortex region in which airflow velocity is lower than that close to the roadway wall and driving face. After blasting, respirable dust in the front of the dust group jet from the driving face cannot be discharged timely, with the result that its concentration is higher than the critical value until it is expelled from the roadway, whereas respirable dust concentration at the back of the dust group is gradually diluted and exhibits an alternate thin dense phase distribution. Meanwhile, respirable dust concentration in the breathing zone is relatively higher than that at the top and bottom of roadway. The accuracy of numerical simulation results is verified by field measurements. The research results are helpful for further understanding the evolution of respirable dust distribution after blasting, and are good for providing guidance for efficient controlling of respirable dust and improving the working environment for underground miners.

  20. Study on Awakening Effect by Fragrance Presentation Against Drowsy Driving and Construction of Fragrance Presentation System

    Science.gov (United States)

    Kakamu, Yuki; Yoshikawa, Masahito; Shimizu, Takayuki; Yanagida, Yasuyuki; Nakano, Tomoaki; Yamamoto, Shin; Yamada, Muneo

    Traffic accidents caused by drowsy driving never disappear and easily result in fatal crash when heavy vehicle is involved. General methods to prevent drowsy driving are caution-advisory indicators and alarm sounds. However visual and auditory information are excessive enough to alert drivers. This study aims to focus on olfactory stimuli, which do not provoke interference with driving actions, and examine the effectiveness in combating drowsiness. Changing type of scent, we performed investigations on the effectiveness of each countermeasure to remain alert against drowsy driving.

  1. Simulation and Implementation of Sensorless Control in Multi-Motors Electric Drives with High Dynamics

    Directory of Open Access Journals (Sweden)

    Marcel Nicola

    2017-05-01

    Full Text Available In this article we’ll tackle the control of multi-motors electric drives with high dynamic, with rapid changes in torque and speed, with rigid or flexible coupling of motors, where the control strategy is FOC (Field Oriented Control for each drives and the distributed control in local network using the CANopen protocol. In the surface mining industry, from which the electric drive application for this article is selected, the general trend is toward using asynchronous motors with short-circuit rotor, due to the advantages of this motor both in terms of design and operation. In order to achieve the variable speed, must be used the static frequency converters with sensorless control, where speed is estimated using a Model References Adaptive Control Estimator. The global control system proposed in this paper contain this type of MRAC estimator together with PI-control based, who ensures a good dynamic performance but in a lower complexity of structure such that are properly to implement in real time in a distributed control system with DSP in local network using the CANopen protocol with advantages in terms of software technology, as well as control cost and flexibility of use. Following these directions a functional application was implemented and tested in practice.

  2. Psychological predictors of college students' cell phone use while driving.

    Science.gov (United States)

    Schlehofer, Michèle M; Thompson, Suzanne C; Ting, Sarah; Ostermann, Sharon; Nierman, Angela; Skenderian, Jessica

    2010-07-01

    Despite the known risk, many people talk on a phone while driving. This study explored psychological predictors of cell phone use while driving. College students (final N=69) completed a survey and predicted their driving performance both with and without a simultaneous phone conversation. Their actual performance on a driving simulator was then assessed. Cell phone use reduced performance on the simulation task. Further, perceiving oneself as good at compensating for driving distractions, overestimating one's performance on the driving simulator, and high illusory control predicted more frequent cell phone use while driving in everyday life. Finally, those who talked more frequently on a phone while driving had poorer real-world driving records. These findings suggest illusory control and positive illusions partly explain driver's decisions of whether to use cell phones while driving. Copyright 2010 Elsevier Ltd. All rights reserved.

  3. Study of Advantages of PM Drive Motor with Selectable Windings for HEVs

    Energy Technology Data Exchange (ETDEWEB)

    Otaduy, Pedro J [ORNL; Hsu, John S [ORNL; Adams, Donald J [ORNL

    2007-11-01

    The gains in efficiency and reduction in battery costs that can be achieved by changing the effective number of stator turns in an electric motor are demonstrated by simulating the performance of an electric vehicle on a set of eight standard driving cycles.

  4. [Study on illegal driving behavior and vehicle road traffic injury in China from 2006 to 2010].

    Science.gov (United States)

    Dai, Jing; Yang, Yunjuan

    2015-06-01

    To study the characteristics and trend of illegal driving behavior in China to provide evidence for related policy enforcement. Using indices as death rate of ten thousand vehicle, death rate per 100 000 population, thousands of road mileage, degree of motorization and death ratio etc. to analyze the current situation, characteristics of illegal vehicle driving behavior related to road traffic injuries, in China. From 2006 to 2010, death ratio on vehicle road traffic injuries related to the top five illegal driving behaviors were as follows: speeding (from 0.33 down to 0.17), on refuse to give way to others (from 0.26 to 0.14), on driving without license (from 0.21 to 0.08), on illegal driving encroachment (from 0.17 to 0.04) and on reverse driving (from 0.11 to 0.07). Death rates related to vehicle road traffic injuries on drunk driving or fatigue driving were 0.04 in 2010 and 0.02 in 2010, respectively. Despite the fact that the number of vehicle road traffic injuries appeared a declining trend, the severity was increasing. Illegal driving behavior was still prevalent in China.

  5. Using Explorative Simulation to Drive User-Centered Design and IT-Development in Healthcare

    DEFF Research Database (Denmark)

    Edwards, Kasper; Thommesen, Jacob; Broberg, Ole

    2012-01-01

    are simulated on iPads with mock-up screens. We describe and exemplify the chief advantages of the explorative simulation method, summarized briefly as follows: - a surprisingly quick way to set up and test a reasonably complex work setting and task environment - an efficient way in which application developers...

  6. An international crowdsourcing study into people's statements on fully automated driving

    NARCIS (Netherlands)

    Bazilinskyy, P.; Kyriakidis, M.; de Winter, J.C.F.; Ahram, Tareq; Karwowski, Waldemar; Schmorrow, Dylan

    2015-01-01

    Fully automated driving can potentially provide enormous benefits to society. However, it has been unclear whether people will appreciate such far-reaching technology. This study investigated anonymous textual comments regarding fully automated driving, based on data extracted from three online

  7. Effects of alcohol (BAC 0.5‰) and ecstasy (MDMA 100 mg) on simulated driving performance and traffic safety

    NARCIS (Netherlands)

    Veldstra, J.L.; Brookhuis, K.A.; De Waard, D.; Molmans, B.H.W.; Verstraete, A.G.; Skopp, G.; Janstos, R.

    2012-01-01

    Rational An increasing number of fatal road-accidents have been reported in which ecstasy was found in the blood of drivers. Although, ecstasy is frequently found to have been used in combination with alcohol, studies on the acute effects of ecstasy co-administered with alcohol on driving

  8. The role of specific visual subfields in collisions with oncoming cars during simulated driving in patients with advanced glaucoma.

    Science.gov (United States)

    Kunimatsu-Sanuki, Shiho; Iwase, Aiko; Araie, Makoto; Aoki, Yuki; Hara, Takeshi; Fukuchi, Takeo; Udagawa, Sachiko; Ohkubo, Shinji; Sugiyama, Kazuhisa; Matsumoto, Chota; Nakazawa, Toru; Yamaguchi, Takuhiro; Ono, Hiroshi

    2017-07-01

    To assess the role of specific visual subfields in collisions with oncoming cars during simulated driving in patients with advanced glaucoma. Normal subjects and patients with glaucoma with mean deviation glaucoma. And, 5 of the 100 patients with advanced glaucoma experienced simulator sickness during the main test and were thus excluded. In total, 95 patients with advanced glaucoma and 43 normal subjects completed the main test of DS. Advanced glaucoma patients had significantly more collisions than normal patients in one or both DS scenarios (pglaucoma who were involved in collisions were older (p=0.050) and had worse visual acuity in the better eye (pglaucoma. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  9. Simulations of current density profile control using lower hybrid current drive in the TdeV tokamak

    International Nuclear Information System (INIS)

    Fuchs, V.; Bonoli, P.T.; Shkarofsky, I.P.; Cote, A.; Demers, Y.; Janicki, C.

    1995-01-01

    The physics basis of a simulation model for lower hybrid current drive (LHCD) is discussed. Issues associated with LH power deposition - wave propagation, mode conversion and cut-offs in toroidal geometry, as well as linear and quasi-linear Landau damping - are analysed. A simulation model (ACCOME) is applied to the LHCD experiment now operating on the Tokamak de Varennes (TdeV). The profiles and values of density and temperature needed as inputs to ACCOME are taken from the experiment. The predictions of current density and loop voltage from ACCOME are then compared with experimental LHCD results. Possible LH current profile control experiments are also analysed for TdeV using composite LH spectra to control the location of RF power deposition. Finally, the relevance of these current profile control results to future devices is discussed and an example is shown for ITER-like parameters. (author). 44 refs, 15 figs, 4 tabs

  10. Simulation of enhanced tokamak performance on DIII-D using fast wave current drive

    International Nuclear Information System (INIS)

    Grassie, J.S. de; Lin-Liu, Y.R.; Petty, C.C.; Pinsker, R.I.; Chan, V.S.; Prater, R.; John, H. St.; Baity, F.W.; Goulding, R.H.; Hoffman, D.H.

    1993-01-01

    The fast magnetosonic wave is now recognized to be a leading candidate for noninductive current drive for the tokamak reactor due to the ability of the wave to penetrate to the hot dense core region. Fast wave current drive (FWCD) experiments on DIII-D have realized up to 120 kA of rf current drive, with up to 40% of the plasma current driven noninductively. The success of these experiments at 60 MHz with a 2 MW transmitter source capability has led to a major upgrade of the FWCD system. Two additional transmitters, 30 to 120 MHz, with a 2 MW source capability each, will be added together with two new four-strap antennas in early 1994. Another major thrust of the DIII-D program is to develop advanced tokamak modes of operation, simultaneously demonstrating improvements in confinement and stability in quasi-steady-state operation. In some of the initial advanced tokamak experiments on DIII-D with neutral beam heated (NBI) discharges it has been demonstrated that energy confinement time can be improved by rapidly elongating the plasma to force the current density profile to be more centrally peaked. However, this high-l i phase of the discharge with the commensurate improvement in confinement is transient as the current density profile relaxes. By applying FWCD to the core of such a κ-ramped discharge it may be possible to sustain the high internal inductance and elevated confinement. Using computational tools validated on the initial DIII-D FWCD experiments we find that such a high-l i advanced tokamak discharge should be capable of sustainment at the 1 MA level with the upgraded capability of the FWCD system. (author) 16 refs., 3 figs., 1 tab

  11. Development of a 3-D simulation analysis system for PWR control rod drive mechanism

    International Nuclear Information System (INIS)

    Tanaka, Akio; Futahashi, Kensuke; Takanabe, Kiyoshi; Kurimura, Chikara; Kato, Jungo; Hara, Hidekiyo

    2008-01-01

    A 3-D virtual analysis system to analyze the motion of control rod drive mechanism (CRDM) was developed. The analysis system consists of a 3-D model established as per the actual dimensions and interfaces of CRDM parts and a routine to calculate the forces acting on the mechanism, and was verified by mock-up test using the same equipment as the actual product. The analysis system is useful for functional evaluation in maintenance or to factor out root causes in the case of malfunction of CRDM

  12. Studying and simulating transformer configuration to improve power quality

    Directory of Open Access Journals (Sweden)

    Oscar J. Peña Huaringa

    2011-06-01

    Full Text Available This paper presents a study and simulation of transformer configurations to improve power quality; it provides theoretical support based on the expansion of the Fourier series and analysis of symmetrical components. A test system was set up in the laboratory, taking measurements and checking configuration effectiveness in reducing the system’s harmonic content. The configurations were modelled with PSCAD / EMTDC software, using two 6 pulse rectifiers as test loads and two variable speed drives.

  13. To continue, modify or relinquish driving: findings from a longitudinal study of healthy ageing.

    Science.gov (United States)

    Unsworth, Carolyn A; Wells, Yvonne; Browning, Colette; Thomas, Shane A; Kendig, Hal

    2007-01-01

    The number and proportion of drivers among people entering later life continues to rise. More information on patterns of driving for older adults is required to improve service provision and traffic planning. To map the changes in driving status for a sample of drivers aged 65 years or older over the period 1994-2000, and to identify factors associated with older people continuing, modifying or relinquishing their status as drivers. The 752 participants were drawn from the Melbourne Longitudinal Studies on Healthy Ageing (MELSHA) program, a longitudinal study of people aged 65 years and older living in the community. Participants were interviewed or contacted for follow-up in 1994, 1996, 1998 and 2000 on a range of topics including their health, functional independence and driving status. Although the number of recent drivers was smaller as participants died or were admitted to nursing homes over the 6-year data collection period, relatively few participants relinquished driving while remaining in the community. Many drivers reported modifying their driving habits over time, including decisions to restrict their driving to their local area during daylight only. Relationships were explored between driving status and the key variables of age, gender, marital status, instrumental activities of daily living (IADL) independence and self-rated measures of income, health, eyesight and hearing. Multivariate analyses indicated that drivers were more likely to modify their driving habits if they were older, dependent in IADL, and rated their eyesight as poor. Similar factors predicted relinquishing driving, but in addition, women were three times more likely to relinquish driving than men (even when health and disability were taken into account) and people who rated their incomes as 'comfortable' were more likely to relinquish driving than those with lower incomes. This study confirmed previous evidence that older drivers self-regulate by modifying their driving behavior as

  14. Experimental Study of Low Speed Sensorless Control of PMSM Drive Using High Frequency Signal Injection

    Directory of Open Access Journals (Sweden)

    Jyoti Agrawal

    2016-01-01

    Full Text Available Conventional techniques for sensorless control of permanent magnet synchronous motor drive (PMSM, which requires information on rotor position, are reviewed, and recent developments in this area are introduced in this paper along with their inherent advantages and drawbacks. The paper presents an improved method for sensorless speed control of PMSM drive with emphasis placed on signal injection method. This signal injection method examines the control performance of sensorless PMSM drive by injecting signal externally and thereby sensing the rotor position. The main objective of this drive system is to have speed control at standstill and low speed regions. Several tests are carried out to demonstrate the ability of proposed models at different operating conditions with the help of simulation results in Matlab/Simulink environment. Simulation results confirm that the proposed sensorless control approach of PMSM can achieve high performance at standstill and low speeds but not at very high speeds. An experimental setup is implemented using a 1HP surface mounted (SM PMSM and DsPICDEM^TM MCHV-2 development board, to check the validity of simulation results.

  15. Knee Pain and Driving Duration: A Secondary Analysis of the Taxi Drivers’ Health Study

    Science.gov (United States)

    Chen, Jiu-Chiaun; Dennerlein, Jack T.; Shih, Tung-Sheng; Chen, Chiou-Jong; Cheng, Yawen; Chang, Wushou P.; Ryan, Louise M.; Christiani, David C.

    2004-01-01

    Objectives. We explored a postulated association between daily driving time and knee pain. Methods. We used data from the Taxi Drivers’ Health Study to estimate 1-year prevalence of knee pain as assessed by the Nordic musculoskeletal questionnaire. Results. Among 1242 drivers, the prevalence of knee pain, stratified by duration of daily driving (≤ 6, > 6 through 8, > 8 through 10, and > 10 hours), was 11%, 17%, 19%, and 22%, respectively. Compared with driving 6 or fewer hours per day, the odds ratio of knee pain prevalence for driving more than 6 hours per day was 2.52 (95% confidence interval = 1.36, 4.65) after we adjusted for socioeconomic, work-related, and personal factors in the multiple logistic regression. Conclusions. The dose-related association between driving duration and knee pain raises concerns about work-related knee joint disorders among professional drivers. PMID:15054008

  16. Mental flexibility impairment in drivers with early Alzheimer's disease: A simulator-based study

    Directory of Open Access Journals (Sweden)

    Virginie Etienne

    2013-07-01

    Full Text Available After memory impairment, one of the most common troubles of early Alzheimer's disease (AD is the impairment of executive functioning. However, it can have major consequences on daily life, notably on the driving activity. The present study focused on one important executive function involved in driving: mental flexibility; and considered how this impairment can affect driving. Ten patients with early AD were matched with 29 healthy older drivers. All participants were given an evaluation of mental flexibility through neuropsychological tests and an experimental test developed on a static driving simulator. The experiment was divided in two conditions; one without mental flexibility and another condition with a mental flexibility demand. AD patients showed impairments in the neuropsychological tests evaluating mental flexibility. These deficits are linked to the deficits they showed in the driving simulator flexibility tests. This study contributes to the understanding of mental flexibility mechanisms and on their role in driving activity. It also confirms that the driving simulator is a suitable tool to explore cognitive disorders and driving ability.

  17. South African novice driver behaviour: findings from a naturalistic driving study

    CSIR Research Space (South Africa)

    Venter, Karien

    2014-07-01

    Full Text Available : FINDINGS FROM A NATURALISTIC DRIVING STUDY VENTER, K. AND SINCLAIR, M* CSIR Built Environment, PO Box 395, Pretoria, Tel: 012 841 3856, E-mail: kventer@csir.co.za. *Department of Civil Engineering Stellenbosch University, Tel: 021 808 3838, E... acquired skill. With practice, skills such as scanning behaviour and handling of the vehicle improve significantly. This study used naturalistic driving study methodology to investigate novice driver behaviour in South Africa. Data acquisition systems...

  18. Directions for next generation microscopic traffic simulation modeling tool under the IntelliDrive environment

    NARCIS (Netherlands)

    Park, Byungkyu "Brian"; van Arem, Bart; van Noort, Martijn; Abadi, A.; Abdel-Rahim, A.; Preuveneers e.a., D.

    2010-01-01

    Microscopic traffic simulation models have been widely accepted in the evaluations of new treatments in the surface transportation system. These include new highway, lane usage (e.g., high occupancy vehicle lane or high occupancy toll lane), speed limits (e.g., variable speed limit, and uniform or

  19. Comparing the demands of destination entry using Google Glass and the Samsung Galaxy S4 during simulated driving.

    Science.gov (United States)

    Beckers, Niek; Schreiner, Sam; Bertrand, Pierre; Mehler, Bruce; Reimer, Bryan

    2017-01-01

    The relative impact of using a Google Glass based voice interface to enter a destination address compared to voice and touch-entry methods using a handheld Samsung Galaxy S4 smartphone was assessed in a driving simulator. Voice entry (Google Glass and Samsung) had lower subjective workload ratings, lower standard deviation of lateral lane position, shorter task durations, faster remote Detection Response Task (DRT) reaction times, lower DRT miss rates, and resulted in less time glancing off-road than the primary visual-manual interaction with the Samsung Touch interface. Comparing voice entry methods, using Google Glass took less time, while glance metrics and reaction time to DRT events responded to were similar. In contrast, DRT miss rate was higher for Google Glass, suggesting that drivers may be under increased distraction levels but for a shorter period of time; whether one or the other equates to an overall safer driving experience is an open question. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Multi-Phase Modular Drive System: A Case Study in Electrical Aircraft Applications

    Directory of Open Access Journals (Sweden)

    Charles Onambele

    2017-12-01

    Full Text Available In this article, an advanced multiphase modular power drive prototype is developed for More Electric Aircraft (MEA. The proposed drive is designed to supply a multi-phase permanent magnet (PM motor rating 120 kW with 24 slots and 11 pole pairs. The power converter of the drive system is based on Silicon Carbide Metal Oxide Semiconductor Field-Effect Transistor (SiC MOSFET technology to operate at high voltage, high frequency and low reverse recovery current. Firstly, an experimental characterization test is performed for the selected SiC power module in harsh conditions to evaluate the switching energy losses. Secondly, a finite element thermal analysis based on Ansys-Icepak is accomplished to validate the selected cooling system for the power converter. Thirdly, a co-simulation model is developed using Matlab-Simulink and LTspice® to evaluate the SiC power module impact on the performance of a multiphase drive system at different operating conditions. The results obtained show that the dynamic performance and efficiency of the power drive are significantly improved, which makes the proposed system an excellent candidate for future aircraft applications.

  1. Expressing Anger Is More Dangerous than Feeling Angry when Driving.

    Directory of Open Access Journals (Sweden)

    Weina Qu

    Full Text Available Anger is an emotion that drivers often feel and express while driving, and it is believed by researchers to be an important cause of dangerous driving behavior. In this study, the relationships between driving trait anger, driving anger expression, and dangerous driving behaviors were analyzed. The Driving Anger Scale (DAS was used to measure driving trait anger, whereas the Driving Anger Expression (DAX Inventory was used to measure expressions of driving anger. A sample of 38 drivers completed the DAS, DAX, and a driving simulation session on a simulator where their driving behaviors were recorded. Correlation analysis showed that the higher scores on the DAS were associated with longer durations of speeding in the simulator. The more participants expressed their anger in verbal and physical ways, the more likely they were to crash the virtual vehicle during the simulation. Regression analyses illustrated the same pattern. The findings suggest that, although trait anger is related to speeding, the passive expression of anger is the real factor underling traffic accidents. This study extends findings about the predictive effects of self-report scales of driving behaviors to behaviors recorded on a simulator. Thus, if in traffic safety propaganda, guiding drivers to use positive ways to cope with driving anger is recommended by our findings.

  2. Expressing Anger Is More Dangerous than Feeling Angry when Driving

    Science.gov (United States)

    Qu, Weina; Dai, Mengnuo; Zhao, Wenguo; Zhang, Kan

    2016-01-01

    Anger is an emotion that drivers often feel and express while driving, and it is believed by researchers to be an important cause of dangerous driving behavior. In this study, the relationships between driving trait anger, driving anger expression, and dangerous driving behaviors were analyzed. The Driving Anger Scale (DAS) was used to measure driving trait anger, whereas the Driving Anger Expression (DAX) Inventory was used to measure expressions of driving anger. A sample of 38 drivers completed the DAS, DAX, and a driving simulation session on a simulator where their driving behaviors were recorded. Correlation analysis showed that the higher scores on the DAS were associated with longer durations of speeding in the simulator. The more participants expressed their anger in verbal and physical ways, the more likely they were to crash the virtual vehicle during the simulation. Regression analyses illustrated the same pattern. The findings suggest that, although trait anger is related to speeding, the passive expression of anger is the real factor underling traffic accidents. This study extends findings about the predictive effects of self-report scales of driving behaviors to behaviors recorded on a simulator. Thus, if in traffic safety propaganda, guiding drivers to use positive ways to cope with driving anger is recommended by our findings. PMID:27258144

  3. Local stability conditions and calibrating procedure for new car-following models used in driving simulators

    CERN Document Server

    Kurtc, Valentina

    2015-01-01

    This book continues the biannual series of conference proceedings, which has become a classical reference resource in traffic and granular research alike, and addresses the latest developments at the intersection of physics, engineering and computational science. These involve complex systems, in which multiple simple agents, be they vehicles or particles, give rise to surprising and fascinating phenomena. The contributions collected in these proceedings cover several research fields, all of which deal with transport. Topics include highway, pedestrian and internet traffic; granular matter; biological transport; transport networks; data acquisition; data analysis and technological applications. Different perspectives, i.e., modeling, simulations, experiments, and phenomenological observations are considered.    

  4. SIMULATION MODELS OF HEAVY TRUCKS TRAFFIC CONTROL WITH ELECTRIC DC DRIVE

    Directory of Open Access Journals (Sweden)

    N. N. Hurski

    2015-01-01

    Full Text Available A model of the straight course of movement of the mobile machine with a traction electric motor DC. Traffic management controller provides a closed classical scheme with feedback. The mathematical model of the electric DC motor with the energy dissipation in the rotor bearings. Design scheme of mobile machines include speed dial controller, traction electric motor, gearbox, transmission and progressively moving mass on the elastic­dissipative wheel. The results of the simulation of the machine in the form of temporary processes of change control signals, voltage and current in the windings of the motor and traction power developed on the wheel.

  5. Study of Axially-Laminated Anisotropic Rotor Reluctance Synchronous Machine and its Drive

    Science.gov (United States)

    Fu, Zhenxing

    1991-02-01

    This dissertation presents a relatively comprehensive study of 2-pole axially-laminated anisotropic (ALA) rotor reluctance synchronous machine in both motoring and generating modes. The theory, analysis techniques, and vector control strategies developed can be applied to other types of reluctance synchronous machines as well, with or without corresponding modifications. Space phasor models of the machine in stator or rotor coordinates are presented. Steady state performance, such as, maximum power factor and efficiency are studied. Transient torque capabilities for constant stator flux, current, and voltage are investigated together with transient state operations. Analytical determinations of d-axis and q -axis magnetic fields, and the corresponding inductances are presented. FEM numerical magnetic field analysis along the d-axis and q-axis is performed for refined design and parameter estimations. To meet the desired performance and high d-axis to q-axis inductances ratio from axially -laminated anisotropic rotor, multi-slot per phase per pole should be used. Experimental tests of the machine in both motoring and generating modes are performed, a high d-axis to q-axis inductances ratio of 21.3 and a maximum power factor of 0.914 and a maximum efficiency of 94% are obtained. Novel current vector control and torque vector control schemes are developed with extensive digital simulations. Sliding mode controller is used and compared with PI controller. Torque vector control principles and stator flux and torque estimation techniques are presented together with the table of optimal voltage vector switchings. A wide controllable speed range of 0.1 rpm to 5000 rpm (for current vector control) and 0.2 rpm to 12000 rpm (for torque vector control) are obtained. The dynamics of the vector controlled drive are fast and relatively robust. A novel fuzzy knowledge-based sensorless dc output voltage control of ALA-rotor reluctance generator is developed and digitally simulated

  6. Regional model simulation of summer rainfall over the Philippines: Effect of choice of driving fields and ocean flux schemes

    Science.gov (United States)

    Francisco, R. V.; Argete, J.; Giorgi, F.; Pal, J.; Bi, X.; Gutowski, W. J.

    2006-09-01

    The latest version of the Abdus Salam International Centre for Theoretical Physics (ICTP) regional model RegCM is used to investigate summer monsoon precipitation over the Philippine archipelago and surrounding ocean waters, a region where regional climate models have not been applied before. The sensitivity of simulated precipitation to driving lateral boundary conditions (NCEP and ERA40 reanalyses) and ocean surface flux scheme (BATS and Zeng) is assessed for 5 monsoon seasons. The ability of the RegCM to simulate the spatial patterns and magnitude of monsoon precipitation is demonstrated, both in response to the prominent large scale circulations over the region and to the local forcing by the physiographical features of the Philippine islands. This provides encouraging indications concerning the development of a regional climate modeling system for the Philippine region. On the other hand, the model shows a substantial sensitivity to the analysis fields used for lateral boundary conditions as well as the ocean surface flux schemes. The use of ERA40 lateral boundary fields consistently yields greater precipitation amounts compared to the use of NCEP fields. Similarly, the BATS scheme consistently produces more precipitation compared to the Zeng scheme. As a result, different combinations of lateral boundary fields and surface ocean flux schemes provide a good simulation of precipitation amounts and spatial structure over the region. The response of simulated precipitation to using different forcing analysis fields is of the same order of magnitude as the response to using different surface flux parameterizations in the model. As a result it is difficult to unambiguously establish which of the model configurations is best performing.

  7. The Alabama VIP older driver study rationale and design: examining the relationship between vision impairment and driving using naturalistic driving techniques.

    Science.gov (United States)

    Owsley, Cynthia; McGwin, Gerald; Antin, Jonathan F; Wood, Joanne M; Elgin, Jennifer

    2018-02-07

    Older drivers aged ≥70 years old have among the highest rates of motor vehicle collisions (MVC) compared to other age groups. Driving is a highly visual task, and older adults have a high prevalence of vision impairment compared to other ages. Most studies addressing visual risk factors for MVCs by older drivers utilize vehicle accident reports as the primary outcome, an approach with several methodological limitations. Naturalistic driving research methods overcome these challenges and involve installing a high-tech, unobtrusive data acquisition system (DAS) in an older driver's own vehicle. The DAS continuously records multi-channel video of driver and roadway, sensor-based kinematics, GPS location, and presence of nearby objects in front of the vehicle, providing an objective measure of driving exposure. In this naturalistic driving study, the purpose is to examine the relationship between vision and crashes and near-crashes, lane-keeping, turning at intersections, driving performance during secondary tasks demands, and the role of front-seat passengers. An additional aim is to compare results of the on-road driving evaluation by a certified driving rehabilitation specialist to objective indicators of driving performance derived from the naturalistic data. Drivers ≥70 years old are recruited from ophthalmology clinics and a previous population-based study of older drivers, with the goal of recruiting persons with wide ranging visual function. Target samples size is 195 drivers. At a baseline visit, the DAS is installed in the participant's vehicle and a battery of health and functional assessments are administered to the driver including visual-sensory and visual-cognitive tests. The DAS remains installed in the vehicle for six months while the participant goes about his/her normal driving with no imposed study restrictions. After six months, the driver returns for DAS de-installation, repeat vision testing, and an on-road driving evaluation by a certified

  8. Modelling how drivers respond to a bicyclist crossing their path at an intersection: How do test track and driving simulator compare?

    Science.gov (United States)

    Boda, Christian-Nils; Dozza, Marco; Bohman, Katarina; Thalya, Prateek; Larsson, Annika; Lubbe, Nils

    2018-02-01

    Bicyclist fatalities are a great concern in the European Union. Most of them are due to crashes between motorized vehicles and bicyclists at unsignalised intersections. Different countermeasures are currently being developed and implemented in order to save lives. One type of countermeasure, active safety systems, requires a deep understanding of driver behaviour to be effective without being annoying. The current study provides new knowledge about driver behaviour which can inform assessment programmes for active safety systems such as Euro NCAP. This study investigated how drivers responded to bicyclists crossing their path at an intersection. The influences of car speed and cyclist speed on the driver response process were assessed for three different crossing configurations. The same experimental protocol was tested in a fixed-base driving simulator and on a test track. A virtual model of the test track was used in the driving simulator to keep the protocol as consistent as possible across testing environments. Results show that neither car speed nor bicycle speed directly influenced the response process. The crossing configuration did not directly influence the braking response process either, but it did influence the strategy chosen by the drivers to approach the intersection. The point in time when the bicycle became visible (which depended on the car speed, the bicycle speed, and the crossing configuration) and the crossing configuration alone had the largest effects on the driver response process. Dissimilarities between test-track and driving-simulator studies were found; however, there were also interesting similarities, especially in relation to the driver braking behaviour. Drivers followed the same strategy to initiate braking, independent of the test environment. On the other hand, the test environment affected participants' strategies for releasing the gas pedal and regulating deceleration. Finally, a mathematical model, based on both experiments

  9. Stressful task increases drive for thinness and bulimia: a laboratory study.

    Directory of Open Access Journals (Sweden)

    Sandra eSassaroli

    2015-05-01

    Full Text Available The scientific literature has suggested that stress undergirds the development of eating disorders (ED. Therefore, this study explored whether laboratory induced stress increases self-reported drive for thinness and bulimic symptoms measured via self-report. The relationship between control, perfectionism, stress, and cognition related to ED was examined using correlational methodology. 86 participants completed an experimental task using a personal computer. All individuals completed a battery of tests before and after the stressful task. Analyses showed a significant statistical increase in average scores on the drive for thinness and bulimia measured before and after a stressful task, and path analysis revealed two different cognitive models for the mechanism leading to drive for thinness and bulimia. These findings suggest that stress is an important factor in the development of the drive for thinness and bulimia.

  10. Simulating solidification in metals at high pressure: The drive to petascale computing

    International Nuclear Information System (INIS)

    Streitz, Frederick H; Glosli, James N; Patel, Mehul V; Chan, Bor; Yates, Robert K; Supinski, Bronis R de; Sexton, James; Gunnels, John A

    2006-01-01

    We investigate solidification in metal systems ranging in size from 64,000 to 524,288,000 atoms on the IBM BlueGene/L computer at LLNL. Using the newly developed ddcMD code, we achieve performance rates as high as 103 TFlops, with a performance of 101.7 TFlop sustained over a 7 hour run on 131,072 cpus. We demonstrate superb strong and weak scaling. Our calculations are significant as they represent the first atomic-scale model of metal solidification to proceed, without finite size effects, from spontaneous nucleation and growth of solid out of the liquid, through the coalescence phase, and into the onset of coarsening. Thus, our simulations represent the first step towards an atomistic model of nucleation and growth that can directly link atomistic to mesoscopic length scales

  11. Driving gas shells with radiation pressure on dust in radiation-hydrodynamic simulations

    Science.gov (United States)

    Costa, Tiago; Rosdahl, Joakim; Sijacki, Debora; Haehnelt, Martin G.

    2018-01-01

    We present radiation-hydrodynamic simulations of radiatively-driven gas shells launched by bright active galactic nuclei (AGN) in isolated dark matter haloes. Our goals are (1) to investigate the ability of AGN radiation pressure on dust to launch galactic outflows and (2) to constrain the efficiency of infrared (IR) multiscattering in boosting outflow acceleration. Our simulations are performed with the radiation-hydrodynamic code RAMSES-RT and include both single- and multiscattered radiation pressure from an AGN, radiative cooling and self-gravity. Since outflowing shells always eventually become transparent to the incident radiation field, outflows that sweep up all intervening gas are likely to remain gravitationally bound to their halo even at high AGN luminosities. The expansion of outflowing shells is well described by simple analytic models as long as the shells are mildly optically thick to IR radiation. In this case, an enhancement in the acceleration of shells through IR multiscattering occurs as predicted, i.e. a force \\dot{P} ≈ τ_IR L/c is exerted on the gas. For high optical depths τIR ≳ 50, however, momentum transfer between outflowing optically thick gas and IR radiation is rapidly suppressed, even if the radiation is efficiently confined. At high τIR, the characteristic flow time becomes shorter than the required trapping time of IR radiation such that the momentum flux \\dot{P} ≪ τ_IR L/c. We argue that while unlikely to unbind massive galactic gaseous haloes, AGN radiation pressure on dust could play an important role in regulating star formation and black hole accretion in the nuclei of massive compact galaxies at high redshift.

  12. Distracted Driving

    Science.gov (United States)

    ... Communities Toolkit Best Practices Guide Publications Motorcycle Safety Bicycle Safety Publications Global Road Safety Get Email Updates ... study. The Insurance Institute for Highway Safety keeps track of distracted driving laws. 7 As of June ...

  13. Focus on Games & Simulations: Trends+Technologies+Case Studies

    Science.gov (United States)

    Weinstein, Margery

    2011-01-01

    A changing mindset combined with changing technology is driving the use of games and simulations. People are becoming more open to using games and simulations for learning, and, at the same time, the technologies are making the development of games and simulations easier and faster than a mere five years ago. Together, the changing mindset and the…

  14. Factors driving behavioural intentions: Study of Serbian mobile operator customers

    Directory of Open Access Journals (Sweden)

    Senić Vladimir

    2016-01-01

    Full Text Available The concept of perceived value is increasingly becoming a subject of interest for authors and researchers in the field of services marketing. Perceived value represents a multi-dimensional concept that consists of a number of components. In the conducted study, four key components were analyzed: emotional value, social value, functional value and monetary value. The objective of the study was to determine the impact of four identified components of value on customer satisfaction, as well as to test impact of customer satisfaction, corporate social responsibility and corporate reputation on behavioural intentions among Serbian mobile operator customers. Research originates from the assumption that to establish long-term relationships with customers, apart from generating customer satisfaction, issues like customer perception of corporate reputation and corporate responsibility are also of great significance.

  15. Diabetic Driving Studies-Part 1: Brake Response Time in Diabetic Drivers With Lower Extremity Neuropathy.

    Science.gov (United States)

    Meyr, Andrew J; Spiess, Kerianne E

    Although the effect of lower extremity pathology and surgical intervention on automobile driving function has been a topic of contemporary interest, we are unaware of any analysis of the effect of lower extremity diabetic sensorimotor neuropathy on driving performance. The objective of the present case-control investigation was to assess the mean brake response time in diabetic drivers with lower extremity neuropathy compared with that of a control group and a brake response safety threshold. The driving performances of participants were evaluated using a computerized driving simulator with specific measurement of the mean brake response time and frequency of abnormally delayed brake responses. We analyzed a control group of 25 active drivers with neither diabetes nor lower extremity neuropathy and an experimental group of 25 active drivers with type 2 diabetes and lower extremity neuropathy. The experimental group demonstrated a 37.89% slower mean brake response time (0.757 ± 0.180 versus 0.549 ± 0.076 second; p < .001), with abnormally delayed responses occurring at a greater frequency (57.5% versus 3.5%; p < .001). Independent of a comparative statistical analysis, the observed mean brake response time in the experimental group was slower than the reported safety brake response threshold of 0.70 second. The results of the present investigation provide original data with respect to abnormally delayed brake responses in diabetic patients with lower extremity neuropathy and might raise the potential for impaired driving function in this population. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  16. Free testosterone drives cancer aggressiveness: evidence from US population studies.

    Directory of Open Access Journals (Sweden)

    Shohreh Shahabi

    Full Text Available Cancer incidence and mortality are higher in males than in females, suggesting that some gender-related factors are behind such a difference. To analyze this phenomenon the most recent Surveillance, Epidemiology and End Results (SEER database served to access cancer survival data for the US population. Patients with gender-specific cancer and with limited information were excluded and this fact limited the sample size to 1,194,490 patients. NHANES III provided the distribution of physiologic variables in US population (n = 29,314. Cox model and Kaplan-Meier method were used to test the impact of gender on survival across age, and to calculate the gender-specific hazard ratio of dying from cancer five years following diagnosis. The distribution of the hazard ratio across age was then compared with the distribution of 65 physiological variables assessed in NHANES III. Spearman and Kolmogorov-Smirnov test assessed the homology. Cancer survival was lower in males than in females in the age range 17 to 61 years. The risk of death from cancer in males was about 30% higher than that of females of the same age. This effect was present only in sarcomas and epithelial solid tumors with distant disease and the effect was more prominent in African-Americans than Caucasians. When compared to the variables assessed in the NHANES III study, the hazard ratio almost exactly matched the distribution of free testosterone in males; none of the other analyzed variables exhibited a similar homology. Our findings suggest that male sex hormones give rise to cancer aggressiveness in patients younger than 61 years.

  17. Usefulness of indirect alcohol biomarkers for predicting recidivism of drunk-driving among previously convicted drunk-driving offenders: results from the recidivism of alcohol-impaired driving (ROAD) study.

    Science.gov (United States)

    Maenhout, Thomas M; Poll, Anneleen; Vermassen, Tijl; De Buyzere, Marc L; Delanghe, Joris R

    2014-01-01

    In several European countries, drivers under the influence (DUI), suspected of chronic alcohol abuse are referred for medical and psychological examination. This study (the ROAD study, or Recidivism Of Alcohol-impaired Driving) investigated the usefulness of indirect alcohol biomarkers for predicting drunk-driving recidivism in previously convicted drunk-driving offenders. The ROAD study is a prospective study (2009-13) that was performed on 517 randomly selected drivers in Belgium. They were convicted for drunk-driving for which their licence was confiscated. The initial post-arrest blood samples were collected and analysed for percentage carbohydrate-deficient transferrin (%CDT), transaminsase activities [alanine amino transferase (ALT), aspartate amino transferase (AST)], gamma-glutamyltransferase (γGT) and red cell mean corpuscular volume (MCV). The observation time for each driver was 3 years and dynamic. A logistic regression analysis revealed that ln(%CDT) (P drunk-driving. The ROAD index (which includes ln(%CDT), ln(γGT), -ln(ALT) and the sex of the driver) was calculated and had a significantly higher area under the receiver operator characteristic curve (0.71) than the individual biomarkers for drunk-driving recidivism. Drivers with a high risk of recidivating (ROAD index ≥ 25%; third tertile) could be distinguished from drivers with an intermediate risk (16% ≤ ROAD index drunk-driving. The association with gamma-glutamyltransferase, alanine amino transferase and the sex of the driver could have additional value for identifying drunk-drivers at intermediate risk of recidivism. Non-specific indirect alcohol markers, such as alanine amino transferase, gamma-glutamyltransferase, aspartate amino transferase and red cell mean corpuscular volume have minimal added value to % carbohydrate-deficient transferrin for distinguishing drunk drivers with a low or high risk of recidivism. © 2013 Society for the Study of Addiction.

  18. Simulation

    DEFF Research Database (Denmark)

    Gould, Derek A; Chalmers, Nicholas; Johnson, Sheena J

    2012-01-01

    Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable...... performance assessments. Human factors research is central to simulator model development that is relevant to real-world imaging-guided interventional tasks and to the credentialing programs in which it would be used....

  19. Plasma simulation by macroscale, electromagnetic particle code and its application to current-drive by relativistic electron beam injection

    International Nuclear Information System (INIS)

    Tanaka, M.; Sato, T.

    1985-01-01

    A new implicit macroscale electromagnetic particle simulation code (MARC) which allows a large scale length and a time step in multi-dimensions is described. Finite mass electrons and ions are used with relativistic version of the equation of motion. The electromagnetic fields are solved by using a complete set of Maxwell equations. For time integration of the field equations, a decentered (backward) finite differencing scheme is employed with the predictor - corrector method for small noise and super-stability. It is shown both in analytical and numerical ways that the present scheme efficiently suppresses high frequency electrostatic and electromagnetic waves in a plasma, and that it accurately reproduces low frequency waves such as ion acoustic waves, Alfven waves and fast magnetosonic waves. The present numerical scheme has currently been coded in three dimensions for application to a new tokamak current-drive method by means of relativistic electron beam injection. Some remarks of the proper macroscale code application is presented in this paper

  20. Analysis of Lunar Highland Regolith Samples from Apollo 16 Drive Core 64001/2 and Lunar Regolith Simulants - An Expanding Comparative Database

    Science.gov (United States)

    Schrader, Christian M.; Rickman, Doug; Stoeser, Doug; Wentworth, Susan J.; Botha, Pieter WSK; Butcher, Alan R.; McKay, David; Horsch, Hanna; Benedictus, Aukje; Gottlieb, Paul

    2008-01-01

    We present modal data from QEMSCAN(registered TradeMark) beam analysis of Apollo 16 samples from drive core 64001/2. The analyzed lunar samples are thin sections 64002,6019 (5.0-8.0 cm depth) and 64001,6031 (50.0-53.1 cm depth) and sieved grain mounts 64002,262 and 64001,374 from depths corresponding to the thin sections, respectively. We also analyzed lunar highland regolith simulants NU-LHT-1M, -2M, and OB-1, low-Ti mare simulants JSC-1, -lA, -1AF, and FJS-1, and high-Ti mare simulant MLS-1. The preliminary results comprise the beginning of an internally consistent database of lunar regolith and regolith simulant mineral and glass information. This database, combined with previous and concurrent studies on phase chemistry, bulk chemistry, and with data on particle shape and size distribution, will serve to guide lunar scientists and engineers in choosing simulants for their applications. These results are modal% by phase rather than by particle type, so they are not directly comparable to most previously published lunar data that report lithic fragments, monomineralic particles, agglutinates, etc. Of the highland simulants, 08-1 has an integrated modal composition closer than NU-LHT-1M to that of the 64001/2 samples, However, this and other studies show that NU-LHT-1M and -2M have minor and trace mineral (e.g., Fe-Ti oxides and phosphates) populations and mineral and glass chemistry closer to these lunar samples. The finest fractions (0-20 microns) in the sieved lunar samples are enriched in glass relative to the integrated compositions by approx.30% for 64002,262 and approx.15% for 64001,374. Plagioclase, pyroxene, and olivine are depleted in these finest fractions. This could be important to lunar dust mitigation efforts and astronaut health - none of the analyzed simulants show this trend. Contrary to previously reported modal analyses of monomineralic grains in lunar regolith, these area% modal analyses do not show a systematic increase in plagiociase

  1. A 1-D Study of the Ignition Space for Magnetic Indirect (X-ray) Drive Targets

    Energy Technology Data Exchange (ETDEWEB)

    Cobble, James Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinars, Daniel Brian [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-06-02

    The ICF program today is investigating three approaches to achieving multi-MJ fusion yields and ignition: (1) laser indirect (x-ray) drive on the National Ignition Facility (NIF), (2) laser direct drive (primarily on the Omega laser facility at the University of Rochester), and (3) magnetic direct drive on the Z pulsed power facility. In this white paper we briefly consider a fourth approach, magnetic indirect drive, in which pulsedpower- driven x-ray sources are used in place of laser driven sources. We first look at some of the x-ray sources studied on Z prior to 2007 before the pulsed power ICF program shifted to magnetic direct drive. We then show results from a series of 1D Helios calculations of double-shell capsules that suggest that these sources, scaled to higher temperatures, could be a promising path to achieving multi-MJ fusion yields and ignition. We advocate here that more detailed design calculations with widely accepted 2D/3D ICF codes should be conducted for a better assessment of the prospects.

  2. Drive for thinness, affect regulation and physical activity in eating disorders: a daily life study.

    Science.gov (United States)

    Vansteelandt, Kristof; Rijmen, Frank; Pieters, Guido; Probst, Michel; Vanderlinden, Johan

    2007-08-01

    Using Ecological Momentary Assessment, the within patient associations between drive for thinness, emotional states, momentary urge to be physically active and physical activity were studied in 32 inpatients with an eating disorder. Participants received an electronic device and had to indicate at nine random times a day during 1 week their momentary drive for thinness, positive and negative emotional states and their urge to be physically active and physical activity. Multilevel analyses indicated that patients with higher mean levels for urge to be physically active were characterized by lower body mass index (BMI) and chronically negative affect whereas patients with higher mean levels for physical activity were characterized by lower BMI and higher dispositions for drive for thinness. In addition, within patient relations between drive for thinness and urge to be physically active were moderated by BMI and chronically negative affect whereas within patient relations between drive for thinness and physical activity were moderated by BMI. Finally, also positive emotional states were significantly associated with physical activity within patients. By using a daily process design, characteristics of physical activity were revealed that have not been identified with assessment methods that have a lower time resolution.

  3. Lower hybrid current drive in shaped tokamaks

    International Nuclear Information System (INIS)

    Kesner, J.

    1993-01-01

    A time dependent lower hybrid current drive tokamak simulation code has been developed. This code combines the BALDUR tokamak simulation code and the Bonoli/Englade lower hybrid current drive code and permits the study of the interaction of lower hybrid current drive with neutral beam heating in shaped cross-section plasmas. The code is time dependent and includes the beam driven and bootstrap currents in addition to the current driven by the lower hybrid system. Examples of simulations are shown for the PBX-M experiment which include the effect of cross section shaping on current drive, ballooning mode stabilization by current profile control and sawtooth stabilization. A critical question in current drive calculations is the radial transport of the energetic electrons. The authors have developed a response function technique to calculate radial transport in the presence of an electric field. The consequences of the combined influences of radial diffusion and electric field acceleration are discussed

  4. Simulation of engine auxiliary drive V-belt slip motion. Part 1. Development of belt slip model; Engine hoki V belt slip kyodo no simulation. 1. Belt slip model no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kurisu, T. [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    V-belts are widely used for driving auxiliary components of an engine. Inadequet design of such belt system sometimes results in troubles such as belt squeak, side rubber separation and/or bottom rubber crack. However, there has been no design tools which can predict belt slip quantitatively. The author developed a motion simulation program of Auxiliary Drive V-Belt System considering belt slip. The program showed good prediction accuracy for belt slip motion. This paper describes the simulation model. 1 ref., 12 figs.

  5. Changes in glance behaviour when using a visual eco-driving system - A field study.

    Science.gov (United States)

    Ahlstrom, Christer; Kircher, Katja

    2017-01-01

    While in-vehicle eco-driving support systems have the potential to reduce greenhouse gas emissions and save fuel, they may also distract drivers, especially if the system makes use of a visual interface. The objective of this study is to investigate the visual behaviour of drivers interacting with such a system, implemented on a five-inch screen mounted above the middle console. Ten drivers participated in a real-world, on-road driving study where they drove a route nine times (2 pre-baseline drives, 5 treatment drives, 2 post-baseline drives). The route was 96 km long and consisted of rural roads, urban roads and a dual-lane motorway. The results show that drivers look at the system for 5-8% of the time, depending on road type, with a glance duration of about 0.6 s, and with 0.05% long glances (>2s) per kilometre. These figures are comparable to what was found for glances to the speedometer in this study. Glance behaviour away from the windscreen is slightly increased in treatment as compared to pre- and post-baseline, mirror glances decreased in treatment and post-baseline compared to pre-baseline, and speedometer glances increased compared to pre-baseline. The eco-driving support system provided continuous information interspersed with additional advice pop-ups (announced by a beep) and feedback pop-ups (no auditory cue). About 20% of sound initiated advice pop-ups were disregarded, and the remaining cases were usually looked at within the first two seconds. About 40% of the feedback pop-ups were disregarded. The amount of glances to the system immediately before the onset of a pop-up was clearly higher for feedback than for advice. All in all, the eco-driving support system under investigation is not likely to have a strong negative impact on glance behaviour. However, there is room for improvements. We recommend that eco-driving information is integrated with the speedometer, that optional activation of sound alerts for intermittent information is made

  6. SIMULATION OF A HIGH-POWERED VARIABLE FREQUENCY AC DRIVE BASED ON A MULTIPULSE CURRENT SOURCE INVERTER

    Directory of Open Access Journals (Sweden)

    G.G. Zhemerov

    2013-10-01

    Full Text Available A computer model building technique for an AC drive system with an autonomous 24-pulse current inverter is introduced. On the basis of the technique developed, a MATLAB variable-frequency drive model capable of working in both quasi-stationary and transient modes is built.

  7. Simulation study of magnetic reconnection

    International Nuclear Information System (INIS)

    Horiuchi, Ritoku

    1998-01-01

    Dynamical process of collisionless driven reconnection is investigated by means of a two-and-one-half-dimensional particle simulation. Magnetic reconnection develops in two steps in accordance with the formation of ion and electron current layers. The dominant triggering mechanism for electron phase changes from electron meandering motion effect to electron inertia effect as a longitudinal magnetic field increases. It is also found that the energy conversion takes place from electrons to ions through the action of an electrostatic field excited in the downstream and thus the average ion temperature becomes about 1.5 of the average electron temperature. (author)

  8. Human Decisions in Moral Dilemmas are Largely Described by Utilitarianism: Virtual Car Driving Study Provides Guidelines for Autonomous Driving Vehicles.

    Science.gov (United States)

    Faulhaber, Anja K; Dittmer, Anke; Blind, Felix; Wächter, Maximilian A; Timm, Silja; Sütfeld, Leon R; Stephan, Achim; Pipa, Gordon; König, Peter

    2018-01-22

    Ethical thought experiments such as the trolley dilemma have been investigated extensively in the past, showing that humans act in utilitarian ways, trying to cause as little overall damage as possible. These trolley dilemmas have gained renewed attention over the past few years, especially due to the necessity of implementing moral decisions in autonomous driving vehicles (ADVs). We conducted a set of experiments in which participants experienced modified trolley dilemmas as drivers in virtual reality environments. Participants had to make decisions between driving in one of two lanes where different obstacles came into view. Eventually, the participants had to decide which of the objects they would crash into. Obstacles included a variety of human-like avatars of different ages and group sizes. Furthermore, the influence of sidewalks as potential safe harbors and a condition implicating self-sacrifice were tested. Results showed that participants, in general, decided in a utilitarian manner, sparing the highest number of avatars possible with a limited influence by the other variables. Derived from these findings, which are in line with the utilitarian approach in moral decision making, it will be argued for an obligatory ethics setting implemented in ADVs.

  9. Eco-driving behavior tendency among Indonesian people: a preliminary study

    Science.gov (United States)

    Zuraida, Rida; Widjaja, Dimitrius

    2017-12-01

    Eco-driving behavior can be triggered by many aspects such as economic and environmental awareness. In Indonesia this issue received less attention from citizen, whereas it has significant roles in reducing greenhouse gas emission. This paper initiated a study about eco-driving tendency behavior among Indonesian people, the objective is to see whether current behavior support or not, and does the differences between gender and age exist. Adopted on-line study method using an online form questionnaire„ 27 questions developed consist of 8 items related to individual data, 19 items related to perception and driving behavior. The respond measures using 5 scale option answers (i.e. strongly disagree, disagree, quite agree, agree, and strongly agree). Based on average respondents’ answers, can be concluded that the tendency of behavior somewhat supports to in line with eco-driving behavior. After Q15 and Q18 omitted based on Pearson-product moment correlation, further analysis results showed that most of respondents categorized into mild tendency behavior (109 respondents). However, a mild tendency among female respondents are higher than male, and the strong tendency of males is higher than female respondents. Based on gender, there are no significant tendency behavior differences between male and female (p-value = 0, 320), and also among age groups (30y, 31-40y, 41-50y, and >50y), even though age >50 have a lower tendency to the behavior compare to other groups.

  10. Behavioural Comparison of Driverswhen Driving a Motorcycle or a Car: A Structural Equation Modelling Study

    Directory of Open Access Journals (Sweden)

    Darja Topolšek

    2015-12-01

    Full Text Available The goal of the study was to investigate if the drivers behave in the same way when they are driving a motorcycle or a car. For this purpose, the Motorcycle Rider Behaviour Questionnaire and Driver Behaviour Questionnaire were conducted among the same drivers population. Items of questionnaires were used to develop a structural equation model with two factors, one for the motorcyclist’s behaviour, and the other for the car driver’s behaviour. Exploratory and confirmatory factor analyses were also applied in this study. Results revealed a certain difference in driving behaviour. The principal reason lies probably in mental consciousness that the risk-taking driving of a motorbike can result in much more catastrophic consequences than when driving a car. The drivers also pointed out this kind of thinking and the developed model has statistically confirmed the behavioural differences. The implications of these findings are also argued in relation to the validation of the appropriateness of the existing traffic regulations.

  11. The effect of competition on heart rate during kart driving: A field study

    Science.gov (United States)

    2011-01-01

    Background Both the act of competing, which can create a kind of mental stress, and participation in motor sports, which induces physical stress from intense g-forces, are known to increase heart rate dramatically. However, little is known about the specific effect of competition on heart rate during motor sports, particularly during four-wheel car driving. The goal of this preliminary study, therefore, was to investigate whether competition increases heart rate under such situations. Findings The participants drove an entry-level formula kart during two competitive races and during solo driving against the clock while heart rate and g-forces were measured. Analyses showed that heart rate values during the races (168.8 beats/min) were significantly higher than those during solo driving (140.9 beats/min) and rest (75.1 beats/min). Conclusions The results of this preliminary study indicate that competition heightens heart rate during four-wheel car driving. Kart drivers should be concerned about maintaining good health and developing physical strength. PMID:21906298

  12. A Driving Simulator Evaluation of Red Arrows and Flashing Yellow Arrows in Right-Turn Applications : Establishing the Foundation for Future Research

    Science.gov (United States)

    2017-11-01

    Driver understanding of flashing yellow arrow (FYA) indications for left turns has been studied extensively; however, the use of FYA for right-turn applications is an area that needs to be better understood through evaluations focused on actual drive...

  13. Community Drive

    DEFF Research Database (Denmark)

    Magnussen, Rikke

    2018-01-01

    opportunity to break boundaries between research institutions and surrounding communities through the involvement of new types of actors, knowledge forms and institutions (OECD, 2011). This paper presents the project Community Drive a three year cross disciplinary community-driven game– and data-based project....... In the paper we present how the project Community Drive initiated in May 2018 is based on results from pilot projects conducted from 2014 – 2017. Overall these studies showed that it is a strong motivational factor for students to be given the task to change their living conditions through redesign...... of living in the area. The paper discusses potentials and pitfalls of designing community-driven science gaming environments and how results from previous studies can form the project Community Drive....

  14. Simulation modeling to understand how selective foraging by beaver can drive the structure and function of a willow community

    Science.gov (United States)

    Peinetti, H.R.; Baker, B.W.; Coughenour, M.B.

    2009-01-01

    Beaver-willow (Castor-Salix) communities are a unique and vital component of healthy wetlands throughout the Holarctic region. Beaver selectively forage willow to provide fresh food, stored winter food, and construction material. The effects of this complex foraging behavior on the structure and function of willow communities is poorly understood. Simulation modeling may help ecologists understand these complex interactions. In this study, a modified version of the SAVANNA ecosystem model was developed to better understand how beaver foraging affects the structure and function of a willow community in a simulated riparian ecosystem in Rocky Mountain National Park, Colorado (RMNP). The model represents willow in terms of plant and stem dynamics and beaver foraging in terms of the quantity and quality of stems cut to meet the energetic and life history requirements of beaver. Given a site where all stems were equally available, the model suggested a simulated beaver family of 2 adults, 2 yearlings, and 2 kits required a minimum of 4 ha of willow (containing about10 stems m-2) to persist in a steady-state condition. Beaver created a willow community where the annual net primary productivity (ANPP) was 2 times higher and plant architecture was more diverse than the willow community without beaver. Beaver foraging created a plant architecture dominated by medium size willow plants, which likely explains how beaver can increase ANPP. Long-term simulations suggested that woody biomass stabilized at similar values even though availability differed greatly at initial condition. Simulations also suggested that willow ANPP increased across a range of beaver densities until beaver became food limited. Thus, selective foraging by beaver increased productivity, decreased biomass, and increased structural heterogeneity in a simulated willow community.

  15. Comparative study of induction motors drive control techniques applied to load hoisting systems; Estudo comparativo de tecnicas de acionamento de motores de inducao aplicados a sistemas de icamento de cargas

    Energy Technology Data Exchange (ETDEWEB)

    Gouvea, M.R. [Acominas S.A., Belo Horizonte, MG (Brazil); Menezes, B.R.; Silva, S.R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Centro de Pesquisa e Desenvolvimento em Engenharia Eletrica

    1996-12-31

    In this work the induction motor drives control techniques are compared in terms of efficiency, controllability, maintenance and installations costs. The slip control and frequency control are studied for ac drives applied to industrial hoist. The studies stress the advantages of power recovery static converter in the way it improves the efficiency of this type of system. The simulations results are presented to make easy the comparison between the techniques. (author) 13 refs., 9 figs.; 2 tabs.

  16. The influence of music on mental effort and driving performance.

    Science.gov (United States)

    Ünal, Ayça Berfu; Steg, Linda; Epstude, Kai

    2012-09-01

    The current research examined the influence of loud music on driving performance, and whether mental effort mediated this effect. Participants (N=69) drove in a driving simulator either with or without listening to music. In order to test whether music would have similar effects on driving performance in different situations, we manipulated the simulated traffic environment such that the driving context consisted of both complex and monotonous driving situations. In addition, we systematically kept track of drivers' mental load by making the participants verbally report their mental effort at certain moments while driving. We found that listening to music increased mental effort while driving, irrespective of the driving situation being complex or monotonous, providing support to the general assumption that music can be a distracting auditory stimulus while driving. However, drivers who listened to music performed as well as the drivers who did not listen to music, indicating that music did not impair their driving performance. Importantly, the increases in mental effort while listening to music pointed out that drivers try to regulate their mental effort as a cognitive compensatory strategy to deal with task demands. Interestingly, we observed significant improvements in driving performance in two of the driving situations. It seems like mental effort might mediate the effect of music on driving performance in situations requiring sustained attention. Other process variables, such as arousal and boredom, should also be incorporated to study designs in order to reveal more on the nature of how music affects driving. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Seat-belt wearing and driving behavior: an instrumented-vehicle study.

    Science.gov (United States)

    Janssen, W

    1994-04-01

    Less-than-expected fatality reductions after seat-belt legislation has been introduced in a jurisdiction may be explained in terms of selective recruitment of parts of the driving population and/or behavioral adaptation by beginning belt users. The present investigation has compared the relative merits of these two hypotheses at the level of individual driver behavior. In the initial study the driving behavior of groups of habitual wearers and nonwearers of the belt was compared. Nonwearers made two trips, one with the belt on and one without the belt. Habitual wearers drove belted only. The main part of the experiment was a 105 km freeway route. Two additional tasks of a somewhat more critical nature, a double lane-change manoeuvre and the performance of a braking manoeuvre in front of a fixed obstacle, were performed after the freeway trips. Factor analysis on 39 variables describing driving behavior on the road and during the additional tasks resulted in five factors. One of these, the factor describing the distribution of driving speed on the freeway, differentiated between nonwearers and wearers (thus yielding support for the selective recruitment hypothesis) as well as between wearing and not wearing the belt by the same drivers (thus yielding support for the behavioral adaptation hypothesis). In the follow-up study the original wearers and nonwearers were assigned to one of four experimental treatments: (i) the promise by the experimenter of a considerable incentive for not having a culpable motor vehicle accident over a period of a year. Half the habitual wearer subjects were assigned to this condition. The expectation was that this group would become more careful in their driving; (ii) a control group, consisting of the remaining habitual wearers; (iii) the agreement between the experimenter and the subject that the latter would buckle up in everyday driving for the year to come--half the habitual nonwearer subjects were assigned to this condition; (iv) a

  18. Indicators of sleepiness in an ambulatory EEG study of night driving.

    Science.gov (United States)

    Papadelis, Christos; Kourtidou-Papadeli, Chrysoula; Bamidis, Panagiotis D; Chouvarda, Ioanna; Koufogiannis, D; Bekiaris, E; Maglaveras, Nikos

    2006-01-01

    Driver sleepiness due to sleep deprivation is a causative factor in 1% to 3% of all motor vehicle crashes. In recent studies, the importance of developing driver fatigue countermeasure devices has been stressed, in order to help prevent driving accidents and errors. Although numerous physiological indicators are available to describe an individual's level of alertness, the EEG signal has been shown to be one of the most predictive and reliable, since it is a direct measure of brain activity. In the present study, multichannel EEG data that were collected from 20 sleep-deprived subjects during real environmental conditions of driving are presented for the first time. EEG data's annotation made by two independent Medical Doctors revealed an increase of slowing activity and an acute increase of the alpha waves 5-10 seconds before driving events. From the EEG data that were collected, the Relative Band Ratio (RBR) of the EEG frequency bands, the Shannon Entropy, and the Kullback-Leibler (KL) Entropy were estimated for each one second segment. The mean values of these measurements were estimated for 5 minutes periods. Analysis revealed a significant increase of alpha waves relevant band ratios (RBR), a decrease of gamma waves RBR, and a significant decrease of KL entropy when the first and the last 5-min periods were compared. A rapid decrease of both Shannon and K-L entropies was observed just before the driving events. Conclusively, EEG can assess effectively the brain activity alterations that occur a few seconds before sleeping/drowsiness events in driving, and its quantitative measurements can be used as potential sleepiness indicators for future development of driver fatigue countermeasure devices.

  19. The value of site-based observations complematary to naturalistic driving observations : a pilot study on the right turn manoeuvre.

    NARCIS (Netherlands)

    Nes, N. van Christoph, M.W.T. Hoedemaeker, M. & Horst, A.R.A. van der

    2013-01-01

    Naturalistic driving studies are increasingly applied in different shapes and sizes. The European project PROLOGUE has investigated the value and feasibility of a large-scale naturalistic driving study in Europe. Within PROLOGUE several pilot studies have been conducted in different countries. The

  20. Does Talking on a Cell Phone, With a Passenger, or Dialing Affect Driving Performance? An Updated Systematic Review and Meta-Analysis of Experimental Studies.

    Science.gov (United States)

    Caird, Jeff K; Simmons, Sarah M; Wiley, Katelyn; Johnston, Kate A; Horrey, William J

    2018-02-01

    Objective An up-to-date meta-analysis of experimental research on talking and driving is needed to provide a comprehensive, empirical, and credible basis for policy, legislation, countermeasures, and future research. Background The effects of cell, mobile, and smart phone use on driving safety continues to be a contentious societal issue. Method All available studies that measured the effects of cell phone use on driving were identified through a variety of search methods and databases. A total of 93 studies containing 106 experiments met the inclusion criteria. Coded independent variables included conversation target (handheld, hands-free, and passenger), setting (laboratory, simulation, or on road), and conversation type (natural, cognitive task, and dialing). Coded dependent variables included reaction time, stimulus detection, lane positioning, speed, headway, eye movements, and collisions. Results The overall sample had 4,382 participants, with driver ages ranging from 14 to 84 years ( M = 25.5, SD = 5.2). Conversation on a handheld or hands-free phone resulted in performance costs when compared with baseline driving for reaction time, stimulus detection, and collisions. Passenger conversation had a similar pattern of effect sizes. Dialing while driving had large performance costs for many variables. Conclusion This meta-analysis found that cell phone and passenger conversation produced moderate performance costs. Drivers minimally compensated while conversing on a cell phone by increasing headway or reducing speed. A number of additional meta-analytic questions are discussed. Application The results can be used to guide legislation, policy, countermeasures, and future research.

  1. Power quality improvement by using multi-pulse AC-DC converters for DC drives: Modeling, simulation and its digital implementation

    Directory of Open Access Journals (Sweden)

    Mohd Tariq

    2014-12-01

    Full Text Available The paper presents the modeling, simulation and digital implementation of power quality improvement of DC drives by using multi pulse AC–DC converter. As it is a well-known fact that power quality determines the fitness of electrical power to consumer devices, hence an effort has been made to improve power quality in this work. Simulation and digital implementation with the help of MATLAB/Simulink has been done and results obtained are discussed in detail to verify the theoretical results. The multipulse converter was connected with DC drives and was run at no load condition to find out the transient and steady state performances. FFT analysis has been performed and Total Harmonic Distortion (THD results obtained at different pulses are shown here.

  2. Driving things

    DEFF Research Database (Denmark)

    Nevile, Maurice Richard

    2015-01-01

    . pp.155 ((http://www.infrastructure.gov.au/roads/safety/publications/2010/pdf/rsgr_2010001.pdf)) Nevile, M., Haddington, P., Heinemann, T., Rauniomaa, M. (Eds.) Interacting with objects: Language, materiality, and social activity. Amsterdam/Philadelphia: John Benjamins. Redshaw, S. (2008....... Interaction with objects reflects the car’s role beyond mere transport as a site of personal, social, and work life (Featherstone et al. 2005; Redshaw 2008). Studies of interaction examine this role as it is actually enacted, understood, and accomplished, in situ through participants’ practices (e.g. Laurier...... of in-car distractions, and how they impact driving activities (Nevile & Haddington 2010). Data are video recordings of ordinary journeys, capturing drivers and passengers in real-world real-time driving situations (27 hours, 90 journeys). For driving and road safety, research and experience has...

  3. Studying Driving Risk Factors using Multi-Source Mobile Computing Data

    Directory of Open Access Journals (Sweden)

    Xianbiao Hu

    2015-09-01

    In this paper, the overall research framework used in this research is presented, which mainly includes data collection, data processing, calibration and analysis methodology. A preliminary case study — including data summary statistics and correlation analysis — is also presented. The results of our study will further existing knowledge about driving exposure factors that are closely linked to crash risk, and provide the foundation for advanced forms of Usage Based Insurance.

  4. Identifying Method of Drunk Driving Based on Driving Behavior

    Directory of Open Access Journals (Sweden)

    Xiaohua Zhao

    2011-05-01

    Full Text Available Drunk driving is one of the leading causes contributing to traffic crashes. There are numerous issues that need to be resolved with the current method of identifying drunk driving. Driving behavior, with the characteristic of real-time, was extensively researched to identify impaired driving behaviors. In this paper, the drives with BACs above 0.05% were defined as drunk driving state. A detailed comparison was made between normal driving and drunk driving. The experiment in driving simulator was designed to collect the driving performance data of the groups. According to the characteristics analysis for the effect of alcohol on driving performance, seven significant indicators were extracted and the drunk driving was identified by the Fisher Discriminant Method. The discriminant function demonstrated a high accuracy of classification. The optimal critical score to differentiate normal from drinking state was found to be 0. The evaluation result verifies the accuracy of classification method.

  5. Road sign recognition during computer testing versus driving simulator performance for stroke and stroke+aphasia groups.

    Science.gov (United States)

    2015-07-01

    Driving is essential to maintaining independence. For most Americans preserving personal mobility is a : key element to retaining jobs, friends, activities and the basic necessities to maintain a household. This : is particularly true for older peopl...

  6. Effect of whole-body vibration on the low back. A study of tractor-driving farmers in north India.

    Science.gov (United States)

    Kumar, A; Varghese, M; Mohan, D; Mahajan, P; Gulati, P; Kale, S

    1999-12-01

    A retrospective cohort study of tractor-driving farmers (study group) and non-tractor-driving farmers (control group) matched for age, gender, generic/ethnic group, land-holding, and work routines. To determine, using magnetic resonance imaging and clinical investigations, the effect of whole-body vibrations on the back in tractor-driving farmers. Low back pain and pathologic changes in the lower backs of tractor drivers have been reported. However, no study with a control group matched for work-related risk factors has been reported. Fifty tractor-driving farmers were compared with 50 non-tractor-driving farmers matched for age, gender, ethnic group, land-holding, and work routine. Both groups were interviewed for details of work routine, assets held, family profile, and vibration exposure to assess the influence of these parameters on signs and symptoms of backache. Magnetic resonance imaging was done to assess the effect of exposure on whole-body vibration and degenerative changes in the back. Vibration measurements also were done on tractors to observe the actual severity of the vibrations. Regular work-related backache was more common among tractor-driving farmers (40%) than among non-tractor-driving farmers (18%, P = 0.015). Anthropometric evaluation showed abdominal girth and weight to be significantly higher in tractor-driving farmers (P = 0.006 and 0.046, respectively), whereas while height and arm span were similar between the two groups. Clinical examination for evidence of disc or facet degeneration showed no difference between the two groups. Evaluation of magnetic resonance images of tractor-driving farmers and non-tractor-driving farmers by an orthopedic surgeon, radiologist, and neurosurgeon showed degenerative changes to be similar between the two groups (P > 0.050). Tractor-driving farmers report backache more often than non-tractor-driving farmers, but no significant objective differences on clinical or magnetic resonance imaging evaluation were

  7. Validation of the finite element simulation to estimate the rolling resistance of a non-driving wheel with experimental tests

    Directory of Open Access Journals (Sweden)

    N Dibagar

    2015-09-01

    Full Text Available Introduction: Encountering soil from the viewpoint of management and product manufacturing has always been considered important, and an attempt is always made hat the tools and contrasting methods of soil be designed in such a way that itself prevents, as much as possible, the destructive consequences or energy waste that include economical or environmental limitations. Enhancing the soil encountering methods, quality reformation, and its related equipment, requires performing reliable tests in actual soil conditions. Considering the complexity and variety of variables in soil and machine contrast, this is a hard task. Hence, the numeral simulations are the key of all optimizations that illustrate efficient models by removing the costly farm tests and reducing research time. Tire is one of the main factors engaged with soil, and it is one of those tools that are discussable in both farms, and software environments. Despite the complexities in soil behavior, and tire geometry, modeling, tire movement on the soil has been the researchers’ objective from the past. Materials and methods: A non-linear finite element (FE model of the interaction of a non-driving tire with soil surface was developed to investigate the influence of the forward speed, tire inflation pressure and vertical load on rolling resistance using ABAQUS/Explicit code. In this research numerical and experimental tests were done under different conditions in order to estimate tire rolling resistance. In numerical tests, the soil part was simulated as a one-layer viscous-elastic material with a Drucker-Prager model by considering realistic soil properties. These properties included elastic and plastic properties which were obtained in the soil laboratory using relevant tests. The soil samples were prepared from the soil which was inside the soil bin. The same soil was utilized in experimental tests. Finite strain hyper elasticity model is developed to model nearly incompressible

  8. A Study of the Effect of the Fringe Fields on the Electrostatic Force in Vertical Comb Drives

    Directory of Open Access Journals (Sweden)

    Else Gallagher

    2014-10-01

    Full Text Available The equation that describes the relationship between the applied voltage and the resulting electrostatic force within comb drives is often used to assist in choosing the dimensions for their design. This paper re-examines how some of these dimensions—particularly the cross-sectional dimensions of the comb teeth—affect this relationship in vertical comb drives. The electrostatic forces in several vertical comb drives fabricated for this study were measured and compared to predictions made with four different mathematical models in order to explore the amount of complexity required within a model to accurately predict the electrostatic forces in the comb drives.

  9. Microcomputer versus mainframe simulations: A case study

    Science.gov (United States)

    Bengtson, Neal M.

    1988-01-01

    The research was conducted to two parts. Part one consisted of a study of the feasibility of running the Space Transportation Model simulation on an office IBM-AT. The second part was to design simulation runs so as to study the effects of certain performance factors on the execution of the simulation model. The results of this research are given in the two reports which follow: Microcomputer vs. Mainframe Simulation: A Case Study and Fractional Factorial Designs of Simulation Runs for the Space Transportation System Operations Model. In the first part, a DOS batch job was written in order to simplify the execution of the simulation model on an office microcomputer. A comparison study was then performed of running the model on NASA-Langley's mainframe computer vs. running on the IBM-AT microcomputer. This was done in order to find the advantages and disadvantages of running the model on each machine with the objective of determining if running of the office PC was practical. The study concluded that it was. The large number of performance parameters in the Space Transportation model precluded running a full factorial design needed to determine the most significant design factors. The second report gives several suggested fractional factorial designs which require far fewer simulation runs in order to determine which factors have significant influence on results.

  10. Dynamic simulation of a beta-type Stirling engine with cam-drive mechanism via the combination of the thermodynamic and dynamic models

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chin-Hsiang; Yu, Ying-Ju [Department of Aeronautics and Astronautics, National Cheng Kung University, No. 1, Ta-Shieh Road, Tainan, Taiwan (China)

    2011-02-15

    Dynamic simulation of a beta-type Stirling engine with cam-drive mechanism used in concentrating solar power system has been performed. A dynamic model of the mechanism is developed and then incorporated with the thermodynamic model so as to predict the transient behavior of the engine in the hot-start period. In this study, the engine is started from an initial rotational speed. The torques exerted by the flywheel of the engine at any time instant can be calculated by the dynamic model as long as the gas pressures in the chambers, the mass inertia, the friction force, and the external load have been evaluated. The instantaneous rotation speed of the engine is then determined by integration of the equation of rotational motion with respect to time, which in return affects the instantaneous variations in pressure and other thermodynamic properties of the gas inside the chambers. Therefore, the transient variations in gas properties inside the engine chambers and the dynamic behavior of the engine mechanism should be handled simultaneously via the coupling of the thermodynamic and dynamic models. An extensive parametric study of the effects of different operating and geometrical parameters has been performed, and results regarding the effects of mass moment of inertia of the flywheel, initial rotational speed, initial charged pressure, heat source temperature, phase angle, gap size, displacer length, and piston stroke on the engine transient behavior are investigated. (author)

  11. Tape edge study in a linear tape drive with single-flanged guides

    Energy Technology Data Exchange (ETDEWEB)

    Goldade, A.V.; Bhushan, Bharat E-mail: bhushan.2@osu.edu

    2004-05-01

    Improved tape guiding and tape dimensional stability are essential for magnetic tape linear recoding formats to take advantage of vastly increased track density and thereby achieve higher storage capacities. Tape guiding is dependent on numerous parameters, such as type of the guides and tape path geometry, quality of virgin tape edge, drive operating parameters (e.g., tape speed and tape tension), mechanical properties of the tape, and tape geometry (e.g., cupping and curvature). The objective of the present study is to evaluate guiding and tribological performance of single-flanged guides with porous air bearings in a linear tape drive. A comparison of guiding performance of the dual flanged stationary guides and single-flanged guides with porous air bearings is performed. The effect of tape path geometry, drive operating conditions (speed and tension) and tape edge quality of factory-slit tapes on tape guiding are evaluated during short-term tests. A lateral force measurement technique is used to measure the force exerted by the tape edge on the guide flange. A technique for the lateral tape motion measurement is used to study the effect of continuous sliding on tape guiding. Wear tests up to 5000 cycles are conducted and coefficient of friction and lateral tape motion are monitored to study the effect of drive operating conditions (speed and tension), edge quality of factory-slit tapes and tape thickness on tape guiding. Optical microscopy, atomic force microscopy and scanning electron microscopy are employed to study and quantify the quality of tape edge.

  12. Design study of a 10 MW MgB2 superconductor direct drive wind turbine generator

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Magnusson, Niklas; Liu, Dong

    2014-01-01

    A design study of a 10 MW direct drive wind turbine generator based on MgB2 superconducting wires is presented and the cost of the active materials of the generator is estimated to be between 226 €/kW and 84 €/kw, which is lower than the threshold values of 300 €/kW of the INNWIND.EU project. A n...

  13. Tape edge study in a linear tape drive with single-flanged guides

    International Nuclear Information System (INIS)

    Goldade, A.V.; Bhushan, Bharat

    2004-01-01

    Improved tape guiding and tape dimensional stability are essential for magnetic tape linear recoding formats to take advantage of vastly increased track density and thereby achieve higher storage capacities. Tape guiding is dependent on numerous parameters, such as type of the guides and tape path geometry, quality of virgin tape edge, drive operating parameters (e.g., tape speed and tape tension), mechanical properties of the tape, and tape geometry (e.g., cupping and curvature). The objective of the present study is to evaluate guiding and tribological performance of single-flanged guides with porous air bearings in a linear tape drive. A comparison of guiding performance of the dual flanged stationary guides and single-flanged guides with porous air bearings is performed. The effect of tape path geometry, drive operating conditions (speed and tension) and tape edge quality of factory-slit tapes on tape guiding are evaluated during short-term tests. A lateral force measurement technique is used to measure the force exerted by the tape edge on the guide flange. A technique for the lateral tape motion measurement is used to study the effect of continuous sliding on tape guiding. Wear tests up to 5000 cycles are conducted and coefficient of friction and lateral tape motion are monitored to study the effect of drive operating conditions (speed and tension), edge quality of factory-slit tapes and tape thickness on tape guiding. Optical microscopy, atomic force microscopy and scanning electron microscopy are employed to study and quantify the quality of tape edge

  14. Driver Behavior During Overtaking Maneuvers from the 100-Car Naturalistic Driving Study.

    Science.gov (United States)

    Chen, Rong; Kusano, Kristofer D; Gabler, Hampton C

    2015-01-01

    Lane changes with the intention to overtake the vehicle in front are especially challenging scenarios for forward collision warning (FCW) designs. These overtaking maneuvers can occur at high relative vehicle speeds and often involve no brake and/or turn signal application. Therefore, overtaking presents the potential of erroneously triggering the FCW. A better understanding of driver behavior during lane change events can improve designs of this human-machine interface and increase driver acceptance of FCW. The objective of this study was to aid FCW design by characterizing driver behavior during lane change events using naturalistic driving study data. The analysis was based on data from the 100-Car Naturalistic Driving Study, collected by the Virginia Tech Transportation Institute. The 100-Car study contains approximately 1.2 million vehicle miles of driving and 43,000 h of data collected from 108 primary drivers. In order to identify overtaking maneuvers from a large sample of driving data, an algorithm to automatically identify overtaking events was developed. The lead vehicle and minimum time to collision (TTC) at the start of lane change events was identified using radar processing techniques developed in a previous study. The lane change identification algorithm was validated against video analysis, which manually identified 1,425 lane change events from approximately 126 full trips. Forty-five drivers with valid time series data were selected from the 100-Car study. From the sample of drivers, our algorithm identified 326,238 lane change events. A total of 90,639 lane change events were found to involve a closing lead vehicle. Lane change events were evenly distributed between left side and right side lane changes. The characterization of lane change frequency and minimum TTC was divided into 10 mph speed bins for vehicle travel speeds between 10 and 90 mph. For all lane change events with a closing lead vehicle, the results showed that drivers change

  15. Alternative Design Study Report: WindPACT Advanced Wind Turbine Drive Train Designs Study; November 1, 2000 -- February 28, 2002

    Energy Technology Data Exchange (ETDEWEB)

    Poore, R.; Lettenmaier, T.

    2003-08-01

    This report presents the Phase I results of the National Renewable Energy Laboratory's (NREL's) WindPACT (Wind Partnership for Advanced Component Technologies) Advanced Wind Turbine Drive Train Designs Study. Global Energy Concepts, LLC performed this work under a subcontract with NREL. The purpose of the WindPACT project is to identify technology improvements that will enable the cost of energy (COE) from wind turbines to be reduced. Other parts of the WindPACT project have examined blade and logistics scaling, balance-of-station costs, and rotor design. This study was designed to investigate innovative drive train designs.

  16. A synthetic approach to compare the large truck crash causation study and naturalistic driving data.

    Science.gov (United States)

    Hickman, Jeffrey S; Hanowski, Richard J; Bocanegra, Joseph

    2018-03-01

    Truck crashes represent a significant problem on our nation's highways. There is a great opportunity to learn about crash causation by analyzing and comparing the Large Truck Crash Causation Study (LTCCS) and naturalistic driving (ND) data. These data sets provide in-depth information, but have contrasting strengths and weaknesses. The LTCCS contains information on high-severity crashes (crashes and fatal crashes), but relied on data collected during crash investigations. The LTCCS identified principal driver errors in the crash, such as the Critical Reason, but not detailed behaviors or scenario sequences. The ND data sets relate primarily to non-crashes that are detectable from dynamic vehicle events, such as hard braking, swerve, etc., provide direct video observations of the driver and the surrounding driving scene and precise information on driver inputs (kinematics) and captured events, and provide certain types of exposure data that cannot easily be obtained using crash reconstruction data. The ND data are collected continuously, thereby capturing both safety-critical events and normative driving (i.e., baseline). The current project evaluated large-truck crash data from the LTCCS and two large-truck ND data sets, the Naturalistic Truck Driving Study and the Drowsy Driver Warning System Field Operational Test. A synthetic risk ratio analysis on the associated factor, Following Too Closely, indicated that truck drivers in the LTCCS were 1.34 times more likely to be involved in a crash, than an ND crash-relevant conflict, if they were following too closely (i.e., tailgating). Given several caveats noted in the paper, this study suggests it's possible to use the ND data set to calculate the exposure of a given behavior and use the LTCCS data set to calculate the crash exposure to the same behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Identification of common features of vehicle motion under drowsy/distracted driving: A case study in Wuhan, China.

    Science.gov (United States)

    Chen, Zhijun; Wu, Chaozhong; Zhong, Ming; Lyu, Nengchao; Huang, Zhen

    2015-08-01

    Drowsy/distracted driving has become one of the leading causes of traffic crash. Only certain particular drowsy/distracted driving behaviors have been studied by previous studies, which are mainly based on dedicated sensor devices such as bio and visual sensors. The objective of this study is to extract the common features for identifying drowsy/distracted driving through a set of common vehicle motion parameters. An intelligent vehicle was used to collect vehicle motion parameters. Fifty licensed drivers (37 males and 13 females, M=32.5 years, SD=6.2) were recruited to carry out road experiments in Wuhan, China and collecting vehicle motion data under four driving scenarios including talking, watching roadside, drinking and under the influence of drowsiness. For the first scenario, the drivers were exposed to a set of questions and asked to repeat a few sentences that had been proved valid in inducing driving distraction. Watching roadside, drinking and driving under drowsiness were assessed by an observer and self-reporting from the drivers. The common features of vehicle motions under four types of drowsy/distracted driving were analyzed using descriptive statistics and then Wilcoxon rank sum test. The results indicated that there was a significant difference of lateral acceleration rates and yaw rate acceleration between "normal driving" and drowsy/distracted driving. Study results also shown that, under drowsy/distracted driving, the lateral acceleration rates and yaw rate acceleration were significantly larger from the normal driving. The lateral acceleration rates were shown to suddenly increase or decrease by more than 2.0m/s(3) and the yaw rate acceleration by more than 2.5°/s(2). The standard deviation of acceleration rate (SDA) and standard deviation of yaw rate acceleration (SDY) were identified to as the common features of vehicle motion for distinguishing the drowsy/distracted driving from the normal driving. In order to identify a time window for

  18. Taxi drivers' views on risky driving behavior in Tehran: a qualitative study using a social marketing approach.

    Science.gov (United States)

    Shams, Mohsen; Shojaeizadeh, Davoud; Majdzadeh, Reza; Rashidian, Arash; Montazeri, Ali

    2011-05-01

    The use of the social marketing approach for public health issues is increasing. This approach uses marketing concepts borrowed from the principles of commercial marketing to promote beneficial health behaviors. In this qualitative study, four focus groups involving 42 participants were used in consumer research to explore taxi drivers' views on the driving situation and the determinants of risky driving behaviors in Tehran, as well as to gather their ideas for developing a social marketing program to reduce risky driving behaviors among taxi drivers in Tehran, Iran. Participants were asked to respond to questions that would guide the development of a marketing mix, or four Ps (product, price, place and promotion). The discussions determined that the program product should involve avoiding risky driving behaviors through increased attention to driving. They pointed out that developing and communicating with a well-designed persuasive message meant to draw their attention to driving could affect their driving behaviors. In addition, participants identified price, place and promotion strategies. They offered suggestions for marketing nonrisky driving to the target audience. The focus group discussions generated important insights into the values and the motivations that affect consumers' decisions to adopt the product. The focus group guided the development of a social marketing program to reduce risky driving behaviors in taxi drivers in Tehran, Iran. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Talking on a Wireless Cellular Device While Driving: Improving the Validity of Crash Odds Ratio Estimates in the SHRP 2 Naturalistic Driving Study

    Directory of Open Access Journals (Sweden)

    Richard A. Young

    2017-12-01

    Full Text Available Dingus and colleagues (Proc. Nat. Acad. Sci. U.S.A. 2016, 113, 2636–2641 reported a crash odds ratio (OR estimate of 2.2 with a 95% confidence interval (CI from 1.6 to 3.1 for hand-held cell phone conversation (hereafter, “Talk” in the SHRP 2 naturalistic driving database. This estimate is substantially higher than the effect sizes near one in prior real-world and naturalistic driving studies of conversation on wireless cellular devices (whether hand-held, hands-free portable, or hands-free integrated. Two upward biases were discovered in the Dingus study. First, it selected many Talk-exposed drivers who simultaneously performed additional secondary tasks besides Talk but selected Talk-unexposed drivers with no secondary tasks. This “selection bias” was removed by: (1 filtering out records with additional tasks from the Talk-exposed group; or (2 adding records with other tasks to the Talk-unexposed group. Second, it included records with driver behavior errors, a confounding bias that was also removed by filtering out such records. After removing both biases, the Talk OR point estimates declined to below 1, now consistent with prior studies. Pooling the adjusted SHRP 2 Talk OR estimates with prior study effect size estimates to improve precision, the population effect size for wireless cellular conversation while driving is estimated as 0.72 (CI 0.60–0.88.

  20. Dementia & Driving

    Science.gov (United States)

    ... find the loss of driving privileges and the inherent loss of independence upsetting. Encourage the individual with ... to modify their driving. This can reduce the risk of an accident if the individual’s driving skills ...

  1. Drive Stands

    Data.gov (United States)

    Federal Laboratory Consortium — The Electrical Systems Laboratory (ESL)houses numerous electrically driven drive stands. A drive stand consists of an electric motor driving a gearbox and a mounting...

  2. Crop micrometeorology : a simulation study

    NARCIS (Netherlands)

    Goudriaan, J.

    1977-01-01

    This monograph presents the results of a detailed study in micrometeorology; one of the sciences that play an important role in production ecology. The purpose is to explain the microweather as a function of the properties of plant and soil, and of the weather conditions prevalent at some

  3. A study of the effect of driving on pre-bored piles

    Science.gov (United States)

    Mabsout, Mounir; Sadek, Salah

    2003-02-01

    A finite element model for pile-driving analysis is developed and used to investigate the behaviour of pre-bored piles, which are then driven the last 1.25 or 2.25 m to their final design depth. The study was conducted for the case of saturated clays. The model traces the penetration of the pile into the soil and accommodates for large deformations. The non-linear behaviour of the clay in this study is predicted using the bounding-surface-plasticity model, as applied to isotropic cohesive soils. The details of the 3-D numerical modelling and computational schemes are presented. A significant difference was observed in the pile displacement during driving, and in the computed soil resistance at the pile tip, particularly at the earliest driving stages. No difference in soil resistance at the soil pile interface along the pile shaft was detected between the pre-bored piles whether driven 1.25 or 2.25 m.

  4. Driving-Simulator-Based Test on the Effectiveness of Auditory Red-Light Running Vehicle Warning System Based on Time-To-Collision Sensor

    Directory of Open Access Journals (Sweden)

    Xuedong Yan

    2014-02-01

    Full Text Available The collision avoidance warning system is an emerging technology designed to assist drivers in avoiding red-light running (RLR collisions at intersections. The aim of this paper is to evaluate the effect of auditory warning information on collision avoidance behaviors in the RLR pre-crash scenarios and further to examine the casual relationships among the relevant factors. A driving-simulator-based experiment was designed and conducted with 50 participants. The data from the experiments were analyzed by approaches of ANOVA and structural equation modeling (SEM. The collisions avoidance related variables were measured in terms of brake reaction time (BRT, maximum deceleration and lane deviation in this study. It was found that the collision avoidance warning system can result in smaller collision rates compared to the without-warning condition and lead to shorter reaction times, larger maximum deceleration and less lane deviation. Furthermore, the SEM analysis illustrate that the audio warning information in fact has both direct and indirect effect on occurrence of collisions, and the indirect effect plays a more important role on collision avoidance than the direct effect. Essentially, the auditory warning information can assist drivers in detecting the RLR vehicles in a timely manner, thus providing drivers more adequate time and space to decelerate to avoid collisions with the conflicting vehicles.

  5. Consequences of simulated car driving at constant high speed on the sensorimotor control of leg muscles and the braking response.

    Science.gov (United States)

    Jammes, Yves; Behr, Michel; Weber, Jean P; Berdah, Stephane

    2017-11-01

    Due to the increase in time spent seated in cars, there is a risk of fatigue of the leg muscles which adjust the force exerted on the accelerator pedal. Any change in their sensorimotor control could lengthen the response to emergency braking. Fourteen healthy male subjects (mean age: 42 ± 4 years) were explored. Before and after a 1-h driving trial at 120 km h -1 , we measured the braking response, the maximal leg extension and foot inversion forces, the tonic vibratory response (TVR) in gastrocnemius medialis (GM) and tibialis anterior (TA) muscles to explore the myotatic reflex, and the Hoffmann reflex (H-reflex). During driving, surface electromyograms (EMGs) of GM and TA were recorded and the ratio between high (H) and low (L) EMG energies allowed to evaluate the recruitment of high- and low-frequency motor unit discharges. During driving, the H/L ratio decreased in TA, whereas modest and often no significant H/L changes occurred in GM muscle. After driving, the maximal foot inversion force decreased (-19%), while the leg extension force did not vary. Reduced TVR amplitude (-29%) was measured in TA, but no H-reflex changes were noted. The braking reaction time was not modified after the driving trial. Driving at constant elevated speed reduced the myotatic reflex and the recruitment of motor units in TA muscle. The corresponding changes were rarely present in the GM muscle that plays a key role in the braking response, and this could explain the absence of a reduced braking reaction time. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  6. Ambulatory heart rate of professional taxi drivers while driving without their typical psychosocial work stressors: a pilot study.

    Science.gov (United States)

    Choi, BongKyoo; Choi, SangJun; Jeong, JeeYeon; Lee, JiWon; Shu, Shi; Yu, Nu; Ko, SangBaek; Zhu, Yifang

    2016-01-01

    Few studies have examined ambulatory cardiovascular physiological parameters of taxi drivers while driving in relation to their occupational hazards. This study aims to investigate and quantify the impact of worksite physical hazards as a whole on ambulatory heart rate of professional taxi drivers while driving without their typical worksite psychosocial stressors. Ambulatory heart rate (HR driving ) of 13 non-smoking male taxi drivers (24 to 67 years old) while driving was continuously assessed on their 6-hour experimental on-road driving in Los Angeles. Percent maximum HR range (PMHR driving ) of the drivers while driving was estimated based on the individual HR driving values and US adult population resting HR (HR rest ) reference data. For analyses, the HR driving and PMHR driving data were split and averaged into 5-min segments. Five physical hazards inside taxi cabs were also monitored while driving. Work stress and work hours on typical work days were self-reported. The means of the ambulatory 5-min HR driving and PMHR driving values of the 13 drivers were 80.5 bpm (11.2 bpm higher than their mean HR rest ) and 10.7 % (range, 5.7 to 19.9 %), respectively. The means were lower than the upper limits of ambulatory HR and PMHR for a sustainable 8-hour work (35 bpm above HR rest and 30 % PMHR), although 15-27 % of the 5-min HR driving and PMHR driving values of one driver were higher than the limits. The levels of the five physical hazards among the drivers were modest: temperature (26.4 ± 3.0 °C), relative humidity (40.7 ± 10.4 %), PM 2.5 (21.5 ± 7.9  μg /m 3 ), CO 2 (1,267.1 ± 580.0 ppm) and noise (69.7 ± 3.0 dBA). The drivers worked, on average, 72 h per week and more than half of them reported that their job were often stressful. The impact of physical worksite hazards alone on ambulatory HR of professional taxi drivers in Los Angeles generally appeared to be minor. Future ambulatory heart rate studies including both

  7. Police custody following driving under the influence of cannabis: a prospective study.

    Science.gov (United States)

    Mahindhoratep, Tiao Saysouda; Lepresle, Aude; Chiadmi, Fouad; Schlatter, Joël; Boraud, Cyril; Chariot, Patrick

    2013-09-10

    Traffic offences are a common cause of detention in police custody. We hypothesized that drug intoxication while driving could correspond to specific medical conditions of the detainees. Our objective was to evaluate medical features and addictive behaviours of suspected drug drivers and to collect data regarding assaults or injuries in these individuals. We conducted a prospective study (April 2010-December 2011) of suspected drug driving arrestees, who were compared to drink drivers or persons aged over 18 detained for other reasons. Data collected concerned persons' characteristics, reported assaults, and observed injuries. A total of 205 drivers were tested positive for drugs in blood, 116 were either positive for drugs in urine or saliva and negative in blood, or negative in urine. Cannabis-only users accounted for 201 of 205 drug drivers (98%). Suspected drug driving arrestees had good overall health rating. Drug drivers were younger than controls and requested more rarely medical examination (12% vs. 44%, Pcustody was better than that of controls and they were considered unconditionally fit for detention more frequently (99% vs. 77%, P<0.0001). We conclude that arrested drug drivers were young, healthy, and infrequently reported assaults or presented traumatic injuries, which does not put them in a high risk medical condition. Medical care could include brief interventions on addictive behaviours. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. HMI ASPECTS OF THE USABILITY OF INTERNET SERVICES WITH AN IN-CAR TERMINAL ON A DRIVING SIMULATOR

    Directory of Open Access Journals (Sweden)

    J-F. KAMP

    2001-01-01

    Based on these criteria, the results showed that browsing while driving seems to remain both complicated and dangerous even when using a simplified browser. However, the results also indicated that, depending on the type of tasks, the different control modes did not have the same efficiency.

  9. Near-term hybrid vehicle program, phase 1. Appendix B: Design trade-off studies. [various hybrid/electric power train configurations and electrical and mechanical drive-line components

    Science.gov (United States)

    1979-01-01

    The relative attractiveness of various hybrid/electric power train configurations and electrical and mechanical drive-line components was studied. The initial screening was concerned primarily with total vehicle weight and economic factors and identified the hybrid power train combinations which warranted detailed evaluation over various driving cycles. This was done using a second-by-second vehicle simulation program which permitted the calculations of fuel economy, electricity usage, and emissions as a function of distance traveled in urban and highway driving. Power train arrangement possibilities were examined in terms of their effect on vehicle handling, safety, serviceability, and passenger comfort. A dc electric drive system utilizing a separately excited motor with field control and battery switching was selected for the near term hybrid vehicle. Hybrid vehicle simulations showed that for the first 30 mi (the electric range of the vehicle) in urban driving, the fuel economy was 80 mpg using a gasoline engine and 100 mpg using a diesel engine. In urban driving the hybrid would save about 75% of the fuel used by the conventional vehicle and in combined urban/highway driving the fuel saving is about 50%.

  10. Driving factors for the regional implementation of renewable energy ‐ A multiple case study on the German energy transition

    International Nuclear Information System (INIS)

    Lutz, Lotte Marie; Fischer, Lisa-Britt; Newig, Jens; Lang, Daniel Johannes

    2017-01-01

    Understanding what drives the regional implementation of renewable energy is a prerequisite for energy transitions toward a post-fossil-based energy economy. This paper presents an empirical analysis of driving factors for the regional implementation and use of renewable energy. We tested literature-derived driving factors in a comparative analysis of 18 selected study regions using Rough Set Analysis and performance analysis. We paid special attention to common combinations of driving factors, which we understand as established practices concerning the use and implementation of renewable energy. Our findings confirm most of the driving factors identified in the literature, for example the existence of key actors, knowledge exchange, or the use of goals and milestones. We also observe differences in key driving factors between highly successful and less successful regions, especially regarding funding opportunities. The results may support policy makers who aim to successfully implement renewable energy at a regional level. - Highlights: • We analyzed driving factors for RE implementation in 18 best-practice regions. • Most driving factors from transition and governance literature were confirmed. • We identified common successful practices concerning RE implementation.

  11. FES-Assisted Walking with Spring Brake Orthosis: Simulation Studies

    Directory of Open Access Journals (Sweden)

    R. Jailani

    2011-01-01

    Full Text Available This paper presents a simulation of bipedal locomotion to generate stimulation pulses for activating muscles for paraplegic walking with wheel walker using functional electrical stimulation (FES with spring brake orthosis (SBO. A new methodology for paraplegic gait, based on exploiting natural dynamics of human gait, is introduced. The work is a first effort towards restoring natural like swing phase in paraplegic gait through a new hybrid orthosis, referred to as spring brake orthosis (SBO. This mechanism simplifies the control task and results in smooth motion and more-natural like trajectory produced by the flexion reflex for gait in spinal cord injured subjects. SBO can eliminate reliance on the withdrawal reflex and foot-ground clearance without extra upper body effort. The stored energy in the spring of SBO is used to replace stimulation pulses in knee flexion and reduce total required torque for the paraplegic walking with wheel walker. The study is carried out with a model of humanoid with wheel walker using the Visual Nastran (Vn4D dynamic simulation software. Stimulated muscle model of quadriceps is developed for knee extension. Fuzzy logic control (FLC is developed in Matlab/Simulink to regulate the muscle stimulation pulse-width required to drive FES-assisted walking gait and the computed motion is visualised in graphic animation from Vn4D. The simulation results show that SBO can be successfully used with FES for paraplegic walking with wheel walker with all the advantages discussed over the current hybrid orthoses available.

  12. An idiographic study into the physiology and selfreported mental workload of learning to drive a car

    NARCIS (Netherlands)

    Noordzij, Matthijs Leendert; Dorrestijn, Serena M.; van den Berg, Irma A.; de Waard, Dick; Toffetti, Antonella; Wiczorek, Rebecca; Sonderegger, Andreas; Rottger, Stefan; Bouchner, Petr; Franke, Thomas; Fairclough, Stephen; Noordzij, Matthijs; Brookhuis, Karel

    2017-01-01

    A driving instructor has to monitor the performance and state (e.g. mental work load) of the pupil who is learning to drive. However, the instructor is also responsible for road safety. Therefore, it might be beneficial when additional monitoring technology would be available to the driving

  13. Environmental Effects of Driving Automobiles in the University of Malaya Campus: A Pilot Study

    Directory of Open Access Journals (Sweden)

    S.Y. Kong

    2009-12-01

    Full Text Available With the increase of human population there has been an evident increase in per capita automobile use and ownership, significantly to a point that almost every urban university campus faces serious challenges from the heavy traffic movement as well as the associated parking shortages. Multiple factors, including lack of land for new parking lots, high cost of building parking structures and the desire to preserve the air quality and campus green spaces are leading many educational institutions towards a new vision based upon expanded transit access, better bicycle and pedestrian facilities and financial incentives for students and staff to drive less. (Toor and Havlick, 2004 This is in stark contrast to the traditional approach to campus transportation planning of the University of Malaya (UM, Kuala Lumpur, Malaysia that allows students, staff and visitors to drive in the campus. The objective of this study is to investigate the related issues and environmental impact of allowing automobile driving in the campus. Studies will also be done to analyse the relationship between university campus planning and traffic condition. Air quality and noise pollution data of 3 selected sites in the campus will be recorded. Subsequently, the air pollutant index and noise pollution level will be identified and data analyses will be done on the data samples. Simultaneously, a survey questionnaire will be conducted to gauge the student’s attitude and degree of awareness with air and noise pollution in the campus. This pilot study reveals that the increasing use of automobiles within the campus has a negative impact on local environment and the quality of life in campus

  14. Sensory Drive Mediated by Climatic Gradients Partially Explains Divergence in Acoustic Signals in Two Horseshoe Bat Species, Rhinolophus swinnyi and Rhinolophus simulator.

    Directory of Open Access Journals (Sweden)

    Gregory L Mutumi

    Full Text Available Geographic variation can be an indicator of still poorly understood evolutionary processes such as adaptation and drift. Sensory systems used in communication play a key role in mate choice and species recognition. Habitat-mediated (i.e. adaptive differences in communication signals may therefore lead to diversification. We investigated geographic variation in echolocation calls of African horseshoe bats, Rhinolophus simulator and R. swinnyi in the context of two adaptive hypotheses: 1 James' Rule and 2 the Sensory Drive Hypothesis. According to James' Rule body-size should vary in response to relative humidity and temperature so that divergence in call frequency may therefore be the result of climate-mediated variation in body size because of the correlation between body size and call frequency. The Sensory Drive Hypothesis proposes that call frequency is a response to climate-induced differences in atmospheric attenuation and predicts that increases in atmospheric attenuation selects for calls of lower frequency. We measured the morphology and resting call frequency (RF of 111 R. simulator and 126 R. swinnyi individuals across their distributional range to test the above hypotheses. Contrary to the prediction of James' Rule, divergence in body size could not explain the variation in RF. Instead, acoustic divergence in RF was best predicted by latitude, geography and climate-induced differences in atmospheric attenuation, as predicted by the Sensory Drive Hypothesis. Although variation in RF was strongly influenced by temperature and humidity, other climatic variables (associated with latitude and altitude as well as drift (as suggested by a positive correlation between call variation and geographic distance, especially in R. simulator may also play an important role.

  15. Digital Simulation Games for Social Studies Classrooms

    Science.gov (United States)

    Devlin-Scherer, Roberta; Sardone, Nancy B.

    2010-01-01

    Data from ten teacher candidates studying teaching methods were analyzed to determine perceptions toward digital simulation games in the area of social studies. This research can be used as a conceptual model of how current teacher candidates react to new methods of instruction and determine how education programs might change existing curricula…

  16. Effects of trait anger, driving anger, and driving experience on dangerous driving behavior: A moderated mediation analysis.

    Science.gov (United States)

    Ge, Yan; Zhang, Qian; Zhao, Wenguo; Zhang, Kan; Qu, Weina

    2017-11-01

    To explore the effect of anger behind the wheel on driving behavior and accident involvement has been the subject of many studies. However, few studies have explored the interaction between anger and driving experience on dangerous driving behavior. This study is a moderated mediation analysis of the effect of trait anger, driving anger, and driving experience on driving behavior. A sample of 303 drivers was tested using the Trait Anger Scale (TAS), the Driving Anger Scale (DAS), and the Dula Dangerous Driving Index (DDDI). The results showed that trait anger and driving anger were positively correlated with dangerous driving behavior. Driving anger partially mediated the effect of trait anger on dangerous driving behavior. Driving experience moderated the relationship between trait anger and driving anger. It also moderated the effect of driving anger on dangerous driving behavior. These results suggest that drivers with more driving experience may be safer as they are not easily irritated during driving. © 2017 Wiley Periodicals, Inc.

  17. Networked simulators: effects on the perceptual validity of traffic in driving simulators [Genetwerkte simulatoren: effecten op de perceptuele kwaliteit van verkeer in rijsimulatoren

    NARCIS (Netherlands)

    Kappé, B.; Vries, S.C. de

    2000-01-01

    Simulators have been used as a tool for training for many decades, and they are still gaining importance. Originally built for stand-alone use, the emergence of (global) network communication allowed these simulators to be connected with other simulators. This introduced the possibility of

  18. Are we using the right fuel to drive hydrological models? A climate impact study in the Upper Blue Nile

    Science.gov (United States)

    Liersch, Stefan; Tecklenburg, Julia; Rust, Henning; Dobler, Andreas; Fischer, Madlen; Kruschke, Tim; Koch, Hagen; Fokko Hattermann, Fred

    2018-04-01

    Climate simulations are the fuel to drive hydrological models that are used to assess the impacts of climate change and variability on hydrological parameters, such as river discharges, soil moisture, and evapotranspiration. Unlike with cars, where we know which fuel the engine requires, we never know in advance what unexpected side effects might be caused by the fuel we feed our models with. Sometimes we increase the fuel's octane number (bias correction) to achieve better performance and find out that the model behaves differently but not always as was expected or desired. This study investigates the impacts of projected climate change on the hydrology of the Upper Blue Nile catchment using two model ensembles consisting of five global CMIP5 Earth system models and 10 regional climate models (CORDEX Africa). WATCH forcing data were used to calibrate an eco-hydrological model and to bias-correct both model ensembles using slightly differing approaches. On the one hand it was found that the bias correction methods considerably improved the performance of average rainfall characteristics in the reference period (1970-1999) in most of the cases. This also holds true for non-extreme discharge conditions between Q20 and Q80. On the other hand, bias-corrected simulations tend to overemphasize magnitudes of projected change signals and extremes. A general weakness of both uncorrected and bias-corrected simulations is the rather poor representation of high and low flows and their extremes, which were often deteriorated by bias correction. This inaccuracy is a crucial deficiency for regional impact studies dealing with water management issues and it is therefore important to analyse model performance and characteristics and the effect of bias correction, and eventually to exclude some climate models from the ensemble. However, the multi-model means of all ensembles project increasing average annual discharges in the Upper Blue Nile catchment and a shift in seasonal

  19. Análisis por medio de la simulación de un accionamiento con motor de reluctancia conmutada; Analysis by Means of Simulation of a Switched Reluctance Machines Drive

    Directory of Open Access Journals (Sweden)

    Javier Muñoz Álvarez

    2011-02-01

    Full Text Available Se presentan los fundamentos teóricos que modelan el comportamiento de los motores de reluctancia conmutaday sus accionamientos. Se exponen las características constructivas generales, las ecuaciones diferencialesque constituyen el modelo matemático del motor y se describen los bloques en Simulink utilizados para lasimulación. El sistema modular se valida comparando el comportamiento de las variables de salida con señalesobtenidas experimentalmente. Es empleado, además, para realizar diversos estudios sobre la instalación. Losresultados obtenidos en cada corrida son reflejados y se exponen las condiciones de operación y la explicaciónteórica de lo obtenido.  This paper presents the theoretical basis that models the behavior of The switched reluctance machines andtheir drives. The general characteristics, the differential equation system that constitutes the mathematicalmodel of the motor and the Simulink's blocks, which have been built for running the simulation, are outlined. Theresults of the simulation have been shown and compared with those obtained experimentally. The Simulinkmodel is used for studying the Switched Reluctance motor drive behavior under some operation conditions andtheoretical explanations for the simulation's results are given in every case.

  20. Study of the impact of a telematics system on safe and fuel-efficient driving in trucks.

    Science.gov (United States)

    2014-04-01

    A telematics system has been successfully demonstrated to be useful for improving motor carrier efficiency. In this : particular field study, the research team demonstrated that telematics can be used to monitor and improve safe : driving behavior as...

  1. Batu Pahat Driving Cycle for Light Duty Gasoline Engine

    Science.gov (United States)

    Zainul Abidin, Zainul Ameerul Ikhsan B.; Faisal Hushim, Mohd; Ahmad, Osman Bin

    2017-08-01

    Driving cycle is a series of data points that represents the vehicle speed versus time. Transient driving cycles involve many changes such as frequent speed changes during typical on-road driving condition [2]. Model driving cycles involve protracted periods at constant speeds. The Batu Pahat Driving Cycle (BPDC) developed to represent the driving pattern of people in a district of Batu Pahat. Based on this driving cycle, it will be a reference to other researchers to study about the gases emission release and fuel consumption by the vehicle on the dynamometer or automotive simulation based on this driving cycle. Existing driving cycles used such as the New European Driving Cycle (NEDC), the Federal Test Procedure (FTP-72/75, and Japan 10-15 Mode Cycle is not appropriate for Batu Pahat district because of different road conditions, driving habits and environmental of developed driving cycle countries are not same [2][14]. Batu Pahat drive cycle was developed for low-capacity gasoline engine under 150 cc and operating on urban roads, rural roads and road around Universiti Tun Hussein Onn. The importance of these driving cycle as the reference for other research to measure and do automotive simulation regarding fuel consumption and gas emission release from the motorcycle for these three type of driving cycle area. Another use for driving cycles is in vehicle simulations [3]. More specifically, they are used in propulsion system simulations to predict the performance of internal combustion engines, transmissions, electric drive systems, batteries, fuel cell systems, and similar components [18]. Data collection methods used in this study is the use of Global Positioning System (GPS). The results obtained are not similar to each other due to differences in congestion on data taken. From the driving cycle graph obtained, such as the average velocity, maximum velocity, the duration and Positive Acceleration Kinetic Energy (PKE) can be determined. In addition, the best

  2. Effects of alcohol (BAC 0.5 parts per thousand) and ecstasy (MDMA 100 mg) on simulated driving performance and traffic safety

    NARCIS (Netherlands)

    Veldstra, J.L.; Brookhuis, K.A.; De Waard, D.; Molmans, B.H.W.; Verstraete, A.G.; Skopp, G.; Jantos, R.

    An increasing number of fatal road-accidents have been reported in which ecstasy was found in the blood of drivers. Although, ecstasy is frequently found to have been used in combination with alcohol, studies on the acute effects of ecstasy co-administered with alcohol on driving performance are

  3. Economic Viability Study of an On-Road Wireless Charging System with a Generic Driving Range Estimation Method

    Directory of Open Access Journals (Sweden)

    Aditya Shekhar

    2016-01-01

    Full Text Available The economic viability of on-road wireless charging of electric vehicles (EVs strongly depends on the choice of the inductive power transfer (IPT system configuration (static or dynamic charging, charging power level and the percentage of road coverage of dynamic charging. In this paper, a case study is carried out to determine the expected investment costs involved in installing the on-road charging infrastructure for an electric bus fleet. Firstly, a generic methodology is described to determine the driving range of any EV (including electric buses with any gross mass and frontal area. A dynamic power consumption model is developed for the EV, taking into account the rolling friction, acceleration, deceleration, aerodynamic drag, regenerative braking and Li-ion battery behavior. Based on the simulation results, the linear dependence of the battery state of charge (SoC on the distance traveled is proven. Further, the impact of different IPT system parameters on driving range is incorporated. Economic implications of a combination of different IPT system parameters are explored for achieving the required driving range of 400 km, and the cost optimized solution is presented for the case study of an electric bus fleet. It is shown that the choice of charging power level and road coverage are interrelated in the economic context. The economic viability of reducing the capacity of the on-board battery as a trade-off between higher transport efficiency and larger on-road charging infrastructure is presented. Finally, important considerations, like the number of average running buses, scheduled stoppage time and on-board battery size, that make on-road charging an attractive option are explored. The cost break-up of various system components of the on-road charging scheme is estimated, and the final project cost and parameters are summarized. The specific cost of the wireless on-road charging system is found to be more expensive than the conventional

  4. Conceptual Design Study on Electromagnets of Control Rod Drive Mechanism of a SFR

    International Nuclear Information System (INIS)

    Lee, Jaehan; Koo, Gyeonghoi

    2013-01-01

    The prototype SFR has six primary control rod assemblies(CRAs) and three secondary shutdown assemblies. The primary control system is used for power control, burnup compensation and reactor shutdown in response to demands from the plant control or protection systems. This paper describes the design concept of primary control rod drive mechanism shortly, and performs the parametric design studies for the electromagnet device of the drive mechanism to maximize CRA gripping force. The electromagnetic core usually confines and guides the magnetic field. The major parameters influenced on the electromagnetic force are the geometry and arrangement of the electromagnet and armature for a given coil specification. A typical equation calculating the electromagnetic force for a solenoid type is represented in equation. The first one is the increasing of the flux cross section area (Α c , Α g ) in magnetic field connecting of air gap, armature and electromagnets. Secondly, the reducing of the path lengths (l c , l g ) of the armature and electromagnet makes the magnetic flux (Β) resistance to be low. An electromagnet field analyses are performed for the initial design values of the electromagnet device. The gripping force is about 3 times of CRA weight when one coil is power on. The parametric studies on air gap, core sizes configuring of the electromagnet cores are performed to maximize the electromagnetic force

  5. Driving behaviours, traffic risk and road safety: comparative study between Malaysia and Singapore.

    Science.gov (United States)

    Khan, Saif ur Rehman; Khalifah, Zainab Binti; Munir, Yasin; Islam, Talat; Nazir, Tahira; Khan, Hashim

    2015-01-01

    The present study aims to investigate differences in road safety attitude, driver behaviour and traffic risk perception between Malaysia and Singapore. A questionnaire-based survey was conducted among a sample of Singaporean (n = 187) and Malaysian (n = 313) road users. The data was analysed using confirmatory factor analysis and structural equation modelling applied to measure comparative fit indices of Malaysian and Singaporean respondents. The results show that the perceived traffic risk of Malaysian respondents is higher than Singaporean counterparts. Moreover, the structural equation modelling has confirmed perceived traffic risk performing the role of full mediation between perceived driving skills and perceived road safety for both the countries, while perceived traffic skills was found to perform the role of partial mediation between aggression and anxiety, on one hand, and road safety, on the other hand, in Malaysia and Singapore. In addition, in both countries, a weak correlation between perceived driving skills, aggression and anxiety with perceived road safety was found, while a strong correlation exists with traffic risk perception. The findings of this study have been discussed in terms of theoretical, practical and conceptual implications for both scholars and policy-makers to better understand the young drivers' attitude and behaviour relationship towards road safety measures with a view to future research.

  6. preliminary multidomain modelling and simulation study

    African Journals Online (AJOL)

    user

    PRELIMINARY MULTIDOMAIN MODELLING AND SIMULATION STUDY OF A. HORIZONTAL AXIS WIND TURBINE (HAWT) TOWER VIBRATION. I. lliyasu1, I. Iliyasu2, I. K. Tanimu3 and D. O Obada4. 1,4 DEPARTMENT OF MECHANICAL ENGINEERING, AHMADU BELLO UNIVERSITY, ZARIA, KADUNA STATE. NIGERIA.

  7. Study of Cardiac Defibrillation Through Numerical Simulations

    Science.gov (United States)

    Bragard, J.; Marin, S.; Cherry, E. M.; Fenton, F. H.

    Three-dimensional numerical simulations of the defibrillation problem are presented. In particular, in this study we use the rabbit ventricular geometry as a realistic model system for evaluating the efficacy of defibrillatory shocks. Statistical data obtained from the simulations were analyzed in term of a dose-response curve. Good quantitative agreement between our numerical results and clinically relevant values is obtained. An electric field strength of about 6.6 V/cm indicates a fifty percent probability of successful defibrillation for a 12-ms monophasic shock. Our validated model will be useful for optimizing defibrillation protocols.

  8. Conceptual framework on the application of biomechanical measurement methods in driving behavior study

    Science.gov (United States)

    Sanjaya, Kadek Heri; Sya'bana, Yukhi Mustaqim Kusuma

    2017-01-01

    Research on eco-friendly vehicle development in Indonesia has largely neglected ergonomic study, despite the fact that traffic accidents have resulted in greater economic cost than fuel subsidy. We have performed a biomechanical experiment on human locomotion earlier. In this article, we describe the importance of implementing the biomechanical measurement methods in transportation ergonomic study. The instruments such as electromyogram (EMG), load cell, pressure sensor, and motion analysis methods as well as cross-correlation function analysis were explained, then the possibility of their application in driving behavior study is described. We describe the potentials and challenges of the biomechanical methods concerning the future vehicle development. The methods provide greater advantages in objective and accurate measurement not only in human task performance but also its correlation with vehicle performance.

  9. A numerical study of the benefits of driving jellyfish bells at their natural frequency.

    Science.gov (United States)

    Hoover, Alexander; Miller, Laura

    2015-06-07

    A current question in swimming and flight is whether or not driving flexible appendages at their resonant frequency results in faster or more efficient locomotion. It has been suggested that jellyfish swim faster when the bell is driven at its resonant frequency. The goal of this study was to determine whether or not driving a jellyfish bell at its resonant frequency results in a significant increase in swimming velocity. To address this question, the immersed boundary method was used to solve the fully coupled fluid structure interaction problem of a flexible bell in a viscous fluid. Free vibration numerical experiments were used to determine the resonant frequency of the jellyfish bell. The jellyfish bells were then driven at frequencies ranging from above and below the resonant frequency. We found that jellyfish do swim fastest for a given amount of applied force when the bells are driven near their resonant frequency. Nonlinear effects were observed for larger deformations, shifting the optimal frequency to higher than the resonant frequency. We also found that the benefit of resonant forcing decreases for lower Reynolds numbers. Published by Elsevier Ltd.

  10. Naturalistic driving study of rear seat child occupants: Quantification of head position using a Kinect™ sensor.

    Science.gov (United States)

    Arbogast, Kristy B; Kim, Jinyong; Loeb, Helen; Kuo, Jonny; Koppel, Sjaan; Bohman, Katarina; Charlton, Judith L

    2016-09-01

    Restraint performance is evaluated using anthropomorphic test devices (ATDs) positioned in prescribed, optimal seating positions. Anecdotally, humans-children in particular-assume a variety of positions that may affect restraint performance. Naturalistic driving studies (NDSs), where cameras and other data acquisition systems are placed in a vehicle used by participants during their regular transportation, offer means to collect these data. To date, these studies have used conventional video and analysis methods and, thus, analyses have largely been qualitative. This article describes a recently completed NDS of child occupants in which their position was monitored using a Kinect sensor to quantify their head position throughout normal, everyday driving trips. A study vehicle was instrumented with a data acquisition system to measure vehicle dynamics, a set of video cameras, and a Kinect sensor providing 3D motion capture at 1 Hz of the rear seat occupants. Participant families used the vehicle for all driving trips over 2 weeks. The child occupants' head position was manually identified via custom software from each Kinect color image. The 3D head position was then extracted and its distribution summarized by seat position (left, rear, center) and restraint type (forward-facing child restraint system [FFCRS], booster seat, seat belt). Data from 18 families (37 child occupants) resulted in 582 trips (with children) for analysis. The average age of the child occupants was 45.6 months and 51% were male. Twenty-five child occupants were restrained in FFCRS, 9 in booster seats, and 3 in seat belts. As restraint type moved from more to less restraint (FFCRS to booster seat to seat belt), the range of fore-aft head position increased: 218, 244, and 340 mm on average, respectively. This observation was also true for left-right movement for every seat position. In general, those in the center seat position demonstrated a smaller range of head positions. For the first

  11. Study on goaf gas control technology of gob-side entry driving

    Science.gov (United States)

    Ren, Qihan; Yuan, Benqing; Li, Qiansi

    2018-01-01

    The 1112 (1) track gate roadway of Gu Qiao coal mine of Huainan mining group adopt the method of gob-side entry driving, the gas emission is large during the driving of the roadway, the gas in the goaf seriously influences the safe driving of the roadway. Equalizing method, drilling drainage method, jet grouting method and other goaf gas controlling measures has been adopted. Finally, it effectively solves the safety threat of gas in goaf to roadway driving, it provides a good reference for the gas control of the gob-side entry.

  12. HHFW Heating and Current Drive Studies of NSTX H-Mode Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    G. Taylor, P.T. Bonoli, D.L. Green, R.W. Harvey, J.C. Hosea, E.F. Jaeger, B.P. LeBlanc, R. Maingi, C.K. Phillips, P.M. Ryan, E.J. Valeo, J.R. Wilson, J.C. Wright, and the NSTX Team

    2011-06-08

    30 MHz high-harmonic fast wave (HHFW) heating and current drive are being developed to assist fully non-inductive plasma current (I{sub p}) ramp-up in NSTX. The initial approach to achieving this goal has been to heat I{sub p} = 300 kA inductive plasmas with current drive antenna phasing in order to generate an HHFW H-mode with significant bootstrap and RF-driven current. Recent experiments, using only 1.4 MW of RF power (P{sub RF}), achieved a noninductive current fraction, f{sub NI} {approx} 0.65. Improved antenna conditioning resulted in the generation of I{sub p} = 650 kA HHFW H-mode plasmas, with f{sub NI} {approx} 0.35, when P{sub RF} {ge} 2.5 MW. These plasmas have little or no edge localized mode (ELM) activity during HHFW heating, a substantial increase in stored energy and a sustained central electron temperature of 5-6 keV. Another focus of NSTX HHFW research is to heat an H-mode generated by 90 keV neutral beam injection (NBI). Improved HHFW coupling to NBI-generated H-modes has resulted in a broad increase in electron temperature profile when HHFW heating is applied. Analysis of a closely matched pair of NBI and HHFW+NBI H-mode plasmas revealed that about half of the antenna power is deposited inside the last closed flux surface (LCFS). Of the power damped inside the LCFS about two-thirds is absorbed directly by electrons and one-third accelerates fast-ions that are mostly promptly lost from the plasma. At longer toroidal launch wavelengths, HHFW+NBI H-mode plasmas can have an RF power flow to the divertor outside the LCFS that significantly reduces RF power deposition to the core. ELMs can also reduce RF power deposition to the core and increase power deposition to the edge. Recent full wave modeling of NSTX HHFW+NBI H-mode plasmas, with the model extended to the vessel wall, predicts a coaxial standing mode between the LCFS and the wall that can have large amplitudes at longer launch wavelengths. These simulation results qualitatively agree with HHFW

  13. Greater Activity in the Frontal Cortex on Left Curves: A Vector-Based fNIRS Study of Left and Right Curve Driving.

    Directory of Open Access Journals (Sweden)

    Noriyuki Oka

    Full Text Available In the brain, the mechanisms of attention to the left and the right are known to be different. It is possible that brain activity when driving also differs with different horizontal road alignments (left or right curves, but little is known about this. We found driver brain activity to be different when driving on left and right curves, in an experiment using a large-scale driving simulator and functional near-infrared spectroscopy (fNIRS.The participants were fifteen healthy adults. We created a course simulating an expressway, comprising straight line driving and gentle left and right curves, and monitored the participants under driving conditions, in which they drove at a constant speed of 100 km/h, and under non-driving conditions, in which they simply watched the screen (visual task. Changes in hemoglobin concentrations were monitored at 48 channels including the prefrontal cortex, the premotor cortex, the primary motor cortex and the parietal cortex. From orthogonal vectors of changes in deoxyhemoglobin and changes in oxyhemoglobin, we calculated changes in cerebral oxygen exchange, reflecting neural activity, and statistically compared the resulting values from the right and left curve sections.Under driving conditions, there were no sites where cerebral oxygen exchange increased significantly more during right curves than during left curves (p > 0.05, but cerebral oxygen exchange increased significantly more during left curves (p < 0.05 in the right premotor cortex, the right frontal eye field and the bilateral prefrontal cortex. Under non-driving conditions, increases were significantly greater during left curves (p < 0.05 only in the right frontal eye field.Left curve driving was thus found to require more brain activity at multiple sites, suggesting that left curve driving may require more visual attention than right curve driving. The right frontal eye field was activated under both driving and non-driving conditions.

  14. Electric drives

    CERN Document Server

    Boldea, Ion

    2005-01-01

    ENERGY CONVERSION IN ELECTRIC DRIVESElectric Drives: A DefinitionApplication Range of Electric DrivesEnergy Savings Pay Off RapidlyGlobal Energy Savings Through PEC DrivesMotor/Mechanical Load MatchMotion/Time Profile MatchLoad Dynamics and StabilityMultiquadrant OperationPerformance IndexesProblemsELECTRIC MOTORS FOR DRIVESElectric Drives: A Typical ConfigurationElectric Motors for DrivesDC Brush MotorsConventional AC MotorsPower Electronic Converter Dependent MotorsEnergy Conversion in Electric Motors/GeneratorsPOWER ELECTRONIC CONVERTERS (PECs) FOR DRIVESPower Electronic Switches (PESs)The

  15. Accuracy of young male drivers’ self-assessments of driving skill

    DEFF Research Database (Denmark)

    Martinussen, Laila Marianne; Møller, Mette; Prato, Carlo Giacomo

    2017-01-01

    Accurate self-assessment of skill is important because it creates an appropriate level of confidence and hence behaviour. Inaccurate self-assessment of driving ability has been linked to reckless driving and accidents. Inaccurate self-assessment of driving skills may be a contributing factor...... to the over-representation of young male drivers in accident statistics. Most previous research on self-assessment of driving skills did not compare self-reported skills to objectively measured driving skills, so the aims of this study were: (1) to test the accuracy of young male drivers’ self-assessments...... of specific driving skills by comparing them with performance in a driving simulator; (2) to test whether self-assessment accuracy varied with driving skill, driving experience and sensation-seeking propensity. We found that young male drivers’ self-assessments were inconsistent with their driving performance...

  16. Study on phase noise induced by 1/f noise of the modulator drive circuit in high-sensitivity fiber optic gyroscope

    Science.gov (United States)

    Teng, Fei; Jin, Jing; Li, Yong; Zhang, Chunxi

    2018-05-01

    The contribution of modulator drive circuit noise as a 1/f noise source to the output noise of the high-sensitivity interferometric fiber optic gyroscope (IFOG) was studied here. A noise model of closed-loop IFOG was built. By applying the simulated 1/f noise sequence into the model, a gyroscope output data series was acquired, and the corresponding power spectrum density (PSD) and the Allan variance curve were calculated to analyze the noise characteristic. The PSD curve was in the spectral shape of 1/f, which verifies that the modulator drive circuit induced a low frequency 1/f phase noise into the gyroscope. The random walk coefficient (RWC), a standard metric to characterize the noise performance of the IFOG, was calculated according to the Allan variance curve. Using an operational amplifier with an input 1/f noise of 520 nV/√Hz at 1 Hz, the RWC induced by this 1/f noise was 2 × 10-4°/√h, which accounts for 63% of the total RWC. To verify the correctness of the noise model we proposed, a high-sensitivity gyroscope prototype was built and tested. The simulated Allan variance curve gave a good rendition of the prototype actual measured curve. The error percentage between the simulated RWC and the measured value was less than 13%. According to the model, a noise reduction method is proposed and the effectiveness is verified by the experiment.

  17. Is partially automated driving a bad idea? Observations from an on-road study.

    Science.gov (United States)

    Banks, Victoria A; Eriksson, Alexander; O'Donoghue, Jim; Stanton, Neville A

    2018-04-01

    The automation of longitudinal and lateral control has enabled drivers to become "hands and feet free" but they are required to remain in an active monitoring state with a requirement to resume manual control if required. This represents the single largest allocation of system function problem with vehicle automation as the literature suggests that humans are notoriously inefficient at completing prolonged monitoring tasks. To further explore whether partially automated driving solutions can appropriately support the driver in completing their new monitoring role, video observations were collected as part of an on-road study using a Tesla Model S being operated in Autopilot mode. A thematic analysis of video data suggests that drivers are not being properly supported in adhering to their new monitoring responsibilities and instead demonstrate behaviour indicative of complacency and over-trust. These attributes may encourage drivers to take more risks whilst out on the road. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Driving with pets and motor vehicle collision involvement among older drivers: A prospective population-based study.

    Science.gov (United States)

    Huisingh, Carrie; Levitan, Emily B; Irvin, Marguerite R; Owsley, Cynthia; McGwin, Gerald

    2016-03-01

    Distracted driving is a major cause of motor vehicle collision (MVC) involvement. Pets have been identified as potential distraction to drivers, particularly in the front. This type of distraction could be worse for those with impairment in the cognitive aspects of visual processing. The purpose of this study is to evaluate the association between driving with pets and rates of motor vehicle collision involvement in a cohort of older drivers. A three-year prospective study was conducted in a population-based sample of 2000 licensed drivers aged 70 years and older. At the baseline visit, a trained interviewer asked participants about pet ownership, whether they drive with pets, how frequently, and where the pet sits in the vehicle. Motor vehicle collision (MVC) involvement during the three-year study period was obtained from the Alabama Department of Public Safety. At-fault status was determined by the police officer who arrived on the scene. Participants were followed until the earliest of death, driving cessation, or end of the study period. Poisson regression was used to calculate crude and adjusted rate ratios (RR) examining the association between pet ownership, presence of a pet in a vehicle, frequency of driving with a pet, and location of the pet inside with vehicle with any and at-fault MVC involvement. We examined whether the associations differed by higher order visual processing impairment status, as measured by Useful Field of View, Trails B, and Motor-free Visual Perception Test. Rates of crash involvement were similar for older adults who have ever driven with a pet compared to those who never drove with their pet (RR=1.15, 95% CI 0.76-1.75). Drivers who reported always or sometimes driving with their pet had higher MVC rates compared to pet owners who never drive with a pet, but this association was not statistically significant (RR=1.39, 95% CI 0.86-2.24). In terms of location, those reporting having a pet frequently ride in the front of the vehicle

  19. College Students Use Cell Phones while Driving More Frequently than Found in Government Study

    Science.gov (United States)

    Cramer, Sheryl; Mayer, Joni; Ryan, Sherry

    2007-01-01

    Objective: Cell phone use while driving is hazardous; it quadruples the risk of a collision and multiplies the risk of a fatality nine-fold. The National Highway Traffic Safety Administration estimates that 8% of young drivers and 5% of all drivers use cell phones while driving. Participants and Methods: The authors trained graduate student…

  20. Granular gases under extreme driving

    Science.gov (United States)

    Kang, W.; Machta, J.; Ben-Naim, E.

    2010-08-01

    We study inelastic gases in two dimensions using event-driven molecular-dynamics simulations. Our focus is the nature of the stationary state attained by rare injection of large amounts of energy to balance the dissipation due to collisions. We find that under such extreme driving, with the injection rate much smaller than the collision rate, the velocity distribution has a power-law high-energy tail. The numerically measured exponent characterizing this tail is in excellent agreement with predictions of kinetic theory over a wide range of system parameters. We conclude that driving by rare but powerful energy injection leads to a well-mixed gas and constitutes an alternative mechanism for agitating granular matter. In this distinct nonequilibrium steady state, energy cascades from large to small scales. Our simulations also show that when the injection rate is comparable with the collision rate, the velocity distribution has a stretched exponential tail.

  1. The influence of music on mood and performance while driving.

    Science.gov (United States)

    van der Zwaag, Marjolein D; Dijksterhuis, Chris; de Waard, Dick; Mulder, Ben L J M; Westerink, Joyce H D M; Brookhuis, Karel A

    2012-01-01

    Mood can influence our everyday behaviour and people often seek to reinforce, or to alter their mood, for example by turning on music. Music listening while driving is a popular activity. However, little is known about the impact of music listening while driving on physiological state and driving performance. In the present experiment, it was investigated whether individually selected music can induce mood and maintain moods during a simulated drive. In addition, effects of positive, negative, and no music on driving behaviour and physiological measures were assessed for normal and high cognitive demanding rides. Subjective mood ratings indicated that music successfully maintained mood while driving. Narrow lane width drives increased task demand as shown in effort ratings and increased swerving. Furthermore, respiration rate was lower during music listening compared to rides without music, while no effects of music were found on heart rate. Overall, the current study demonstrates that music listening in car influences the experienced mood while driving, which in turn can impact driving behaviour. PRACTITIONERS SUMMARY: Even though it is a popular activity, little is known about the impact of music while driving on physiological state and performance. We examined whether music can induce moods during high and low simulated drives. The current study demonstrates that in car music listening influences mood which in turn can impact driving behaviour. The current study shows that listening to music can positively impact mood while driving, which can be used to affect state and safe behaviour. Additionally, driving performance in high demand situations is not negatively affected by music.

  2. The psychosocial impacts of fly-in fly-out and drive-in drive-out mining on mining employees: a qualitative study.

    Science.gov (United States)

    Torkington, Amanda May; Larkins, Sarah; Gupta, Tarun Sen

    2011-06-01

    To explore how fly-in fly-out (FIFO) and drive-in drive-out (DIDO) mining affects the psychosocial well-being of miners resident in a rural north Queensland town as well as the sources of support miners identify and use in managing these effects. A descriptive qualitative study, using semistructured interviews. Charters Towers, a rural town in north Queensland, and a remote north-western Queensland mine. Eleven people, resident in or near Charters Towers, currently or formerly employed in FIFO or DIDO mining. Self-reported effects on psychosocial well-being and sources of support. Participants reported positive and negative psychosocial impacts across domains including family life, relationships, social life, work satisfaction, mood, sleep and financial situation. Concerns about the impact on participants' partners were described. Awareness of onsite support, such as Employee Assistance Programs, varied. Other supports included administration staff and nurses or medics. Trusted friends or colleagues at the mine site were considered a preferred means of support. Some, but not most, had experienced coworkers discussing problems with them. A reluctance to seek support was described, with a number of barriers identified. Those having problems might not recognise their own stress and thus not seek support. This study identifies numerous psychosocial impacts on FIFO/DIDO miners and their partners, and provides insights into preferences regarding support. Employee Assistance Programs cannot be relied upon as the sole means of support. Further studies exploring the impact upon and supports for FIFO/DIDO workers and their partners will assist in better understanding these issues. © 2011 The Authors. Australian Journal of Rural Health © National Rural Health Alliance Inc.

  3. Developing a Research Protocol to Investigate Stress, Workload, and Driving Apprehension during Driving Lessons in Young Adults with an Autism Spectrum Disorder: A Feasibility Study

    NARCIS (Netherlands)

    Ross, Veerle; Cox, Daniel; Noordzij, Matthijs Leendert; Geryl, Kimberly; Spooren, Annemie

    2018-01-01

    Background Autism Spectrum Disorders (ASD) are known to impact quality-of-life (QoL). Driving can increase autonomy and QoL by enabling maintenance of work and social contacts. Research suggests people with ASD experience difficulties in complex driving situations. These difficulties may induce

  4. Engineering model of the electric drives of separation device for simulation of automatic control systems of reactive power compensation by means of serially connected capacitors

    Science.gov (United States)

    Juromskiy, V. M.

    2016-09-01

    It is developed a mathematical model for an electric drive of high-speed separation device in terms of the modeling dynamic systems Simulink, MATLAB. The model is focused on the study of the automatic control systems of the power factor (Cosφ) of an actuator by compensating the reactive component of the total power by switching a capacitor bank in series with the actuator. The model is based on the methodology of the structural modeling of dynamic processes.

  5. Mobile-ip Aeronautical Network Simulation Study

    Science.gov (United States)

    Ivancic, William D.; Tran, Diepchi T.

    2001-01-01

    NASA is interested in applying mobile Internet protocol (mobile-ip) technologies to its space and aeronautics programs. In particular, mobile-ip will play a major role in the Advanced Aeronautic Transportation Technology (AATT), the Weather Information Communication (WINCOMM), and the Small Aircraft Transportation System (SATS) aeronautics programs. This report presents the results of a simulation study of mobile-ip for an aeronautical network. The study was performed to determine the performance of the transmission control protocol (TCP) in a mobile-ip environment and to gain an understanding of how long delays, handoffs, and noisy channels affect mobile-ip performance.

  6. Numerical Simulation Analysis of an Oversteer In-Wheel Small Electric Vehicle Integrated with Four-Wheel Drive and Independent Steering

    Directory of Open Access Journals (Sweden)

    Muhammad Izhar Ishak

    2016-01-01

    Full Text Available Similar to conventional vehicle, most in-wheel small EVs that exist today are designed with understeer (US characteristic. They are safer on the road but possess poor cornering performance. With recent in-wheel motor and steer-by wire technology, high cornering performance vehicle does not limit to sport or racing cars. We believe that oversteer (OS design approach for in-wheel small EV can increase the steering performance of the vehicle. However, one disadvantage is that OS vehicle has a stability limit velocity. In this paper, we proposed a Four-Wheel Drive and Independent Steering (4WDIS for in-wheel small EV with OS characteristic. The aim of implementing 4WDIS is to develop a high steer controllability and stability of the EV at any velocity. This paper analyses the performance of OS in-wheel small EV with 4WDIS by using numerical simulation. Two cornering conditions were simulated which are (1 steady-state cornering at below critical velocity and (2 steady-state cornering over critical velocity. The objective of the simulation is to understand the behavior of OS in-wheel small EV and the advantages of implementing the 4WDIS. The results show that an in-wheel small EV can achieve high cornering performance at low speed while maintaining stability at high speed.

  7. Older driver estimates of driving exposure compared to in-vehicle data in the Candrive II study.

    Science.gov (United States)

    Porter, Michelle M; Smith, Glenys A; Cull, Andrew W; Myers, Anita M; Bédard, Michel; Gélinas, Isabelle; Mazer, Barbara L; Marshall, Shawn C; Naglie, Gary; Rapoport, Mark J; Tuokko, Holly A; Vrkljan, Brenda H

    2015-01-01

    Most studies on older adults' driving practices have relied on self-reported information. With technological advances it is now possible to objectively measure the everyday driving of older adults in their own vehicles over time. The purpose of this study was to examine the ability of older drivers to accurately estimate their kilometers driven over one year relative to objectively measured driving exposure. A subsample (n = 159 of 928; 50.9% male) of Candrive II participants (age ≥ 70 years of age) was used in these analyses based on strict criteria for data collected from questionnaires as well as an OttoView-CD Autonomous Data Logging Device installed in their vehicle, over the first year of the prospective cohort study. Although there was no significant difference overall between the self-reported and objectively measured distance categories, only moderate agreement was found (weighted kappa = 0.57; 95% confidence interval, 0.47-0.67). Almost half (45.3%) chose the wrong distance category, and some people misestimated their distance driven by up to 20,000 km. Those who misjudged in the low mileage group (≤5000 km) consistently underestimated, whereas the reverse was found for those in the high distance categories (≥ 20,000); that is, they always overestimated their driving distance. Although self-reported driving distance categories may be adequate for studies entailing broad group comparisons, caution should be used in interpreting results. Use of self-reported estimates for individual assessments should be discouraged.

  8. DWPF Simulant CPC Studies For SB8

    Energy Technology Data Exchange (ETDEWEB)

    Newell, J. D.

    2013-09-25

    Prior to processing a Sludge Batch (SB) in the Defense Waste Processing Facility (DWPF), flowsheet studies using simulants are performed. Typically, the flowsheet studies are conducted based on projected composition(s). The results from the flowsheet testing are used to 1) guide decisions during sludge batch preparation, 2) serve as a preliminary evaluation of potential processing issues, and 3) provide a basis to support the Shielded Cells qualification runs performed at the Savannah River National Laboratory (SRNL). SB8 was initially projected to be a combination of the Tank 40 heel (Sludge Batch 7b), Tank 13, Tank 12, and the Tank 51 heel. In order to accelerate preparation of SB8, the decision was made to delay the oxalate-rich material from Tank 12 to a future sludge batch. SB8 simulant studies without Tank 12 were reported in a separate report.1 The data presented in this report will be useful when processing future sludge batches containing Tank 12. The wash endpoint target for SB8 was set at a significantly higher sodium concentration to allow acceptable glass compositions at the targeted waste loading. Four non-coupled tests were conducted using simulant representing Tank 40 at 110-146% of the Koopman Minimum Acid requirement. Hydrogen was generated during high acid stoichiometry (146% acid) SRAT testing up to 31% of the DWPF hydrogen limit. SME hydrogen generation reached 48% of of the DWPF limit for the high acid run. Two non-coupled tests were conducted using simulant representing Tank 51 at 110-146% of the Koopman Minimum Acid requirement. Hydrogen was generated during high acid stoichiometry SRAT testing up to 16% of the DWPF limit. SME hydrogen generation reached 49% of the DWPF limit for hydrogen in the SME for the high acid run. Simulant processing was successful using previously established antifoam addition strategy. Foaming during formic acid addition was not observed in any of the runs. Nitrite was destroyed in all runs and no N2O was detected

  9. Social comparison and prosocial behavior: an applied study of social identity theory in community food drives.

    Science.gov (United States)

    Shipley, Andrew

    2008-04-01

    Social Identity Theory and the concept of social comparison have inspired research on individuals, addressing effects of personal and environmental factors in directing social attention. The theory's conceptual origins, however, suggest that social comparison may have behavioral implications as well. Such behaviors may include attempts by an individual to enhance the relative status of his ingroup on a salient dimension of comparison. Such behavior is referred to as "social competition." In two studies, the effects of social comparison and social competition were measured in the real-world environment of community food drives. Participants were aggregated by household; 600 households in upper middle-class neighborhoods in Eugene and Salem, Oregon, were contacted. In Study 1 of 300 households, it was hypothesized that inclusion of a social competition cue in requests for donation would significantly increase the likelihood of donation. This hypothesis was supported. Study 2 was done to clarify the possible role in a social comparison of perceived ingroup inferiority in the prior observed increase in donations. The inclusion of a social comparison cue in the donation request significantly increased donations in households of the second study. The findings suggest that researchers should expand study of the theory's behavioral implications, including the role of social comparison in prosocial behavior.

  10. A protocol for conducting rainfall simulation to study soil runoff.

    Science.gov (United States)

    Kibet, Leonard C; Saporito, Louis S; Allen, Arthur L; May, Eric B; Kleinman, Peter J A; Hashem, Fawzy M; Bryant, Ray B

    2014-04-03

    Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The objective of this study was to characterize the effects of antecedent soil moisture content on the fate and transport of surface applied commercial urea, a common form of nitrogen (N) fertilizer, following a rainfall event that occurs within 24 hr after fertilizer application. Although urea is assumed to be readily hydrolyzed to ammonium and therefore not often available for transport, recent studies suggest that urea can be transported from agricultural soils to coastal waters where it is implicated in harmful algal blooms. A rainfall simulator was used to apply a consistent rate of uniform rainfall across packed soil boxes that had been prewetted to different soil moisture contents. By controlling rainfall and soil physical characteristics, the effects of antecedent soil moisture on urea loss were isolated. Wetter soils exhibited shorter time from rainfall initiation to runoff initiation, greater total volume of runoff, higher urea concentrations in runoff, and greater mass loadings of urea in runoff. These results also demonstrate the importance of controlling for antecedent soil moisture content in studies designed to isolate other variables, such as soil physical or chemical characteristics, slope, soil cover, management, or rainfall characteristics. Because rainfall simulators are designed to deliver raindrops of similar size and velocity as natural rainfall, studies conducted under a standardized protocol can yield valuable data that, in turn, can be used to develop models for predicting the fate and transport of pollutants in runoff.

  11. The Virtual Driving Instructor: A Multi-agent Based System for Driving Instruction

    NARCIS (Netherlands)

    Weevers, I.; Kuipers, J.; Brugman, A.; Zwiers, Jakob; van Dijk, Elisabeth M.A.G.; Nijholt, Antinus

    Driving simulators need an Intelligent Tutoring System (ITS). Simulators provide ways to conduct objective measurements on students' driving behavior and opportunities for creating the best possible learning environment. The generated traffic situations can be influenced directly according to the

  12. Are we using the right fuel to drive hydrological models? A climate impact study in the Upper Blue Nile

    Directory of Open Access Journals (Sweden)

    S. Liersch

    2018-04-01

    Full Text Available Climate simulations are the fuel to drive hydrological models that are used to assess the impacts of climate change and variability on hydrological parameters, such as river discharges, soil moisture, and evapotranspiration. Unlike with cars, where we know which fuel the engine requires, we never know in advance what unexpected side effects might be caused by the fuel we feed our models with. Sometimes we increase the fuel's octane number (bias correction to achieve better performance and find out that the model behaves differently but not always as was expected or desired. This study investigates the impacts of projected climate change on the hydrology of the Upper Blue Nile catchment using two model ensembles consisting of five global CMIP5 Earth system models and 10 regional climate models (CORDEX Africa. WATCH forcing data were used to calibrate an eco-hydrological model and to bias-correct both model ensembles using slightly differing approaches. On the one hand it was found that the bias correction methods considerably improved the performance of average rainfall characteristics in the reference period (1970–1999 in most of the cases. This also holds true for non-extreme discharge conditions between Q20 and Q80. On the other hand, bias-corrected simulations tend to overemphasize magnitudes of projected change signals and extremes. A general weakness of both uncorrected and bias-corrected simulations is the rather poor representation of high and low flows and their extremes, which were often deteriorated by bias correction. This inaccuracy is a crucial deficiency for regional impact studies dealing with water management issues and it is therefore important to analyse model performance and characteristics and the effect of bias correction, and eventually to exclude some climate models from the ensemble. However, the multi-model means of all ensembles project increasing average annual discharges in the Upper Blue Nile catchment and a shift

  13. Studying Interactions by Molecular Dynamics Simulations at High Concentration

    Directory of Open Access Journals (Sweden)

    Federico Fogolari

    2012-01-01

    Full Text Available Molecular dynamics simulations have been used to study molecular encounters and recognition. In recent works, simulations using high concentration of interacting molecules have been performed. In this paper, we consider the practical problems for setting up the simulation and to analyse the results of the simulation. The simulation of beta 2-microglobulin association and the simulation of the binding of hydrogen peroxide by glutathione peroxidase are provided as examples.

  14. Observational Study of Neural Respiratory Drive During Sleep at High Altitude.

    Science.gov (United States)

    Steier, Joerg; Cade, Nic; Walker, Ben; Moxham, John; Jolley, Caroline

    2017-09-01

    Steier, Joerg, Nic Cade, Ben Walker, John Moxham, and Caroline Jolley. Observational study of neural respiratory drive during sleep at high altitude. High Alt Med Biol. 18:242-248, 2017. Ventilation at altitude changes due to altered levels of pO 2 , pCO 2 and the effect on blood pH. Nocturnal ventilation is particularly exposed to these changes. We hypothesized that an increasing neural respiratory drive (NRD) is associated with the severity of sleep-disordered breathing at altitude. Mountaineers were studied at sea level (London, United Kingdom), and at altitude at the Aconcagua (Andes, Argentina). NRD was measured as electromyogram of the diaphragm (EMGdi) overnight by a transesophageal multi-electrode catheter; results were reported for sea level, 3,380 m, 4,370 m, and 5,570 m. Four healthy subjects (3 men, age 31(3)years, body mass index 23.6(0.9)kg/m 2 , neck circumference 37.0(2.7)cm, forced expiratory volume in 1 second 111.8(5.1)%predicted, and forced vital capacity 115.5(6.3)%predicted) were studied. No subject had significant sleep abnormalities at sea level. Time to ascent to 3,380 m was 1 day, to 4,370 m was 5 days, and the total nights at altitude were 21 days. The oxygen desaturation index (4% oxygen desaturation index [ODI] 0.8(0.4), 22.0 (7.2), 61.4 (26.9), 144.9/hour, respectively) and the EMGdi (5.2 (1.9), 12.8 (5.1), 14.1 (3.4), 18.5%, respectively) increased with the development of periodic breathing at altitude, whereas the average SpO 2 declined (97.5 (1.3), 84.8 (0.5), 81.0 (4.1), 68.5%, respectively). The average EMGdi correlated well with the 4%ODI (r = 0.968, p = 0.032). NRD sleep increases at altitude in relation to the severity of periodic breathing.

  15. Safe Driving After Propofol Sedation.

    Science.gov (United States)

    Summerlin-Grady, Lee; Austin, Paul N; Gabaldon, Dion A

    2017-10-01

    Propofol is a short-acting medication with fast cognitive and psychomotor recovery. However, patients are usually instructed not to drive a motor vehicle for 24 hours after receiving propofol. The purpose of this article was to review the evidence examining when it is safe to drive after receiving propofol for sedation for diagnostic and surgical procedures. This is a systematic review of the literature. A search of the literature was conducted using Google Scholar, PubMed, and the Cochrane Library for the time period 1990 to 2015. Two randomized controlled trials and two observational studies met the inclusion criteria. Using a simulator, investigators examined driving ability of subjects who received modest doses (about 100 mg) of propofol for endoscopic procedures and surveyed subjects who drove immediately after discharge. There were methodological concerns with the studies such as small sample sizes, modest doses of propofol, and three of the four studies were done in Japan by the same group of investigators limiting generalizability. This limited research suggests that it may be safe for patients to drive sooner than 24 hours after receiving propofol. However, large multicenter trials using heterogenous samples using a range of propofol doses are needed to support an evidence-based revision to the current discharge guidelines for patients receiving propofol. Copyright © 2016 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

  16. Studies of Cs3Sb cathodes for the CLIC drive beam photo injector option

    CERN Document Server

    Martini, Irene; Doebert, Steffen; Fedosseev, Valentine; Hessler, Christoph; Martyanov, Mikhail

    2013-01-01

    Within the CLIC (Compact Linear Collider) project, feasibility studies of a photo injector option for the drive beam as an alternative to its baseline design using a thermionic electron gun are on-going. This R&D program covers both the laser and the photocathode side. Whereas the available laser pulse energy in ultra-violet (UV) is currently limited by the optical defects in the 4thharmonics frequency conversion crystal induced by the0.14 ms long pulse trains, recent measurements of Cs3Sbphotocathodes sensitive to green light showed their potential to overcome this limitation. Moreover, using visible laser beams leads to better stability of produced electron bunches and one can take advantages of the availability of higher quality optics. The studied Cs3Sbphotocathodes have been produced in the CERN photo emission laboratory using the co-deposition technique and tested in a DC gun set-up. The analysis of data acquired during the cathode production process will be presented in this paper, as well as the r...

  17. Driving performance at lateral system limits during partially automated driving.

    Science.gov (United States)

    Naujoks, Frederik; Purucker, Christian; Wiedemann, Katharina; Neukum, Alexandra; Wolter, Stefan; Steiger, Reid

    2017-11-01

    This study investigated driver performance during system limits of partially automated driving. Using a motion-based driving simulator, drivers encountered different situations in which a partially automated vehicle could no longer safely keep the lateral guidance. Drivers were distracted by a non-driving related task on a touch display or driving without an additional secondary task. While driving in partially automated mode drivers could either take their hands off the steering wheel for only a short period of time (10s, so-called 'Hands-on' variant) or for an extended period of time (120s, so-called 'Hands-off' variant). When the system limit was reached (e.g., when entering a work zone with temporary lines), the lateral vehicle control by the automation was suddenly discontinued and a take-over request was issued to the drivers. Regardless of the hands-off interval and the availability of a secondary task, all drivers managed the transition to manual driving safely. No lane exceedances were observed and the situations were rated as 'harmless' by the drivers. The lack of difference between the hands-off intervals can be partly attributed to the fact that most of the drivers kept contact to the steering wheel, even in the hands-off condition. Although all drivers were able to control the system limits, most of them could not explain why exactly the take-over request was issued. The average helpfulness of the take-over request was rated on an intermediate level. Consequently, providing drivers with information about the reason for a system limit can be recommended. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Monitoring driver fatigue using a single-channel electroencephalographic device: A validation study by gaze-based, driving performance, and subjective data.

    Science.gov (United States)

    Morales, José M; Díaz-Piedra, Carolina; Rieiro, Héctor; Roca-González, Joaquín; Romero, Samuel; Catena, Andrés; Fuentes, Luis J; Di Stasi, Leandro L

    2017-12-01

    Driver fatigue can impair performance as much as alcohol does. It is the most important road safety concern, causing thousands of accidents and fatalities every year. Thanks to technological developments, wearable, single-channel EEG devices are now getting considerable attention as fatigue monitors, as they could help drivers to assess their own levels of fatigue and, therefore, prevent the deterioration of performance. However, the few studies that have used single-channel EEG devices to investigate the physiological effects of driver fatigue have had inconsistent results, and the question of whether we can monitor driver fatigue reliably with these EEG devices remains open. Here, we assessed the validity of a single-channel EEG device (TGAM-based chip) to monitor changes in mental state (from alertness to fatigue). Fifteen drivers performed a 2-h simulated driving task while we recorded, simultaneously, their prefrontal brain activity and saccadic velocity. We used saccadic velocity as the reference index of fatigue. We also collected subjective ratings of alertness and fatigue, as well as driving performance. We found that the power spectra of the delta EEG band showed an inverted U-shaped quadratic trend (EEG power spectra increased for the first hour and half, and decreased during the last thirty minutes), while the power spectra of the beta band linearly increased as the driving session progressed. Coherently, saccadic velocity linearly decreased and speeding time increased, suggesting a clear effect of fatigue. Subjective data corroborated these conclusions. Overall, our results suggest that the TGAM-based chip EEG device is able to detect changes in mental state while performing a complex and dynamic everyday task as driving. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Using music to change mood while driving.

    Science.gov (United States)

    van der Zwaag, Marjolein D; Janssen, Joris H; Nass, Clifford; Westerink, Joyce H D M; Chowdhury, Shrestha; de Waard, Dick

    2013-01-01

    This study investigated whether gradual or abrupt music change towards more calming music is most effective in calming drivers during high-demand driving situations. Twenty-eight participants were subjected to two types of music change (gradual, abrupt) in a within-subject design. First, a relatively happy mood was induced with personally selected music during an eight-minute simulated high-demand drive. The drive then continued and the mood was changed either gradually or abruptly. Subjective results showed successful music mood induction irrespective of gradual or abrupt changes. The results further showed lower skin conductance (less arousal) and more facial corrugator muscle tension (more sadness) during the abrupt music change. Fewer accidents occurred during the abrupt music mood change. To conclude, the results support the abrupt way of changing music type to down-regulate one's mood: during high-demand driving, abrupt changes in music led to more physiological calmness and improved driving performance, and were thus safer and more effective. The current study shows that during high-demand drives, drivers are calmed more effectively using abrupt music changes compared to gradual music changes. This is illustrated by reductions in physiological arousal and improved driving behaviour. Hence, in-car music presentation can be used as a tool to improve driver's mood and behaviour.

  20. The role of self-regulation in the context of driver distraction: A simulator study.

    Science.gov (United States)

    Wandtner, Bernhard; Schumacher, Markus; Schmidt, Eike A

    2016-07-03

    There is considerable evidence for the negative effects of driver distraction on road safety. In many experimental studies, drivers have been primarily viewed as passive receivers of distraction. Thus, there is a lack of research on the mediating role of their self-regulatory behavior. The aim of the current study was to compare drivers' performance when engaged in a system-paced secondary task with a self-paced version of this task and how both differed from baseline driving performance without distraction. Thirty-nine participants drove in a simulator while performing a secondary visual-manual task. One group of drivers had to work on this task in predefined situations under time pressure, whereas the other group was free to decide when to work on the secondary task (self-regulation group). Drivers' performance (e.g., lateral and longitudinal control, brake reaction times) was also compared with a baseline condition without any secondary task. For the system-paced secondary task, distraction was associated with high decrements in driving performance (especially in keeping the lateral position). No effects were found for the number of collisions, probably because of the lower driving speeds while distracted (compensatory behavior). For the self-regulation group, only small impairments in driving performance were found. Drivers engaged less in the secondary task during foreseeable demanding or critical driving situations. Overall, drivers in the self-regulation group were able to anticipate the demands of different traffic situations and to adapt their engagement in the secondary task, so that only small impairments in driving performance occurred. Because in real traffic drivers are mostly free to decide when to engage in secondary tasks, it can be concluded that self-regulation should be considered in driver distraction research to ensure ecological validity.

  1. Design Study for Controllable Electric Motor for Three Wheel Drive, In Wheel Mounting on Professional, Electric, Lawn Mower

    DEFF Research Database (Denmark)

    Lu, Kaiyuan

    focused upon the transverse flux permanent magnet machine, which attracts great interests in electric and hybrid propulsion systems. This thesis deals with modelling, performance analysis, design, test and measurement of permanent magnet transverse flux machines (PMTFM). It is important to understand......Design of a new generation of electric drive motor for professional lawnmowers forms the basic objective of this thesis. Modern drive concepts produces a growing demand for electrical machines featuring high torque density, and suitable for direct drive applications. Much attention is presently...... is another important issue discussed in this thesis. Based on the magnetic and electrical performance analysis, and by studying the influence of the number of poles, width of C-core tooth, and size of magnets on the torque production capability, an improved design of PMTFM was achieved. The improved design...

  2. High-power converters and AC drives

    CERN Document Server

    Wu, Bin

    2017-01-01

    This new edition reflects the recent technological advancements in the MV drive industry, such as advanced multilevel converters and drive configurations. It includes three new chapters, Control of Synchronous Motor Drives, Transformerless MV Drives, and Matrix Converter Fed Drives. In addition, there are extensively revised chapters on Multilevel Voltage Source Inverters and Voltage Source Inverter-Fed Drives. This book includes a systematic analysis on a variety of high-power multilevel converters, illustrates important concepts with simulations and experiments, introduces various megawatt drives produced by world leading drive manufacturers, and addresses practical problems and their mitigations methods.

  3. A performance study on a direct drive hydro turbine for wave energy converter

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Do [Mokpo National University, Muan (Korea, Republic of); Kim, Chang Goo; Kim, You Taek; Lee, Young Ho [Korea Maritime University, Busan (Korea, Republic of); Song, Jung Il [Changwon National University, Changwon (Korea, Republic of)

    2010-11-15

    Clean and renewable energy technologies using ocean energy give us non-polluting alternatives to fossil-fueled power plants as a countermeasure against global warming and growing demand for electrical energy. Among the ocean energy resources, wave power takes a growing interest because of its enormous amount of potential energy in the world. Therefore, various types of wave power systems to capture the energy of ocean waves have been developed. However, a suitable turbine type is not yet normalized because of relatively low efficiency of the turbine systems. The purpose of this study is to investigate the performance of a newly developed direct drive hydro turbine (DDT), which will be built in a caisson for a wave power plant. Experiment and CFD analysis are conducted to clarify the turbine performance and internal flow characteristics. The results show that the DDT obtains fairly good turbine efficiency in cases with and without wave conditions. Most of the output power is generated at the runner passage of Stage 2. Relatively larger amount of the decreased tangential velocity at Stage 2 produces more angular momentum than that at Stage 1 and thus, the larger angular momentum at the Stage 2 makes a greater contribution to the generation of total output power in comparison with that at Stage 1. Large vortex existing in the upper-left region of the runner passage forms a large recirculation region in the runner passage, and the recirculating flow consumes the output power at Region 2

  4. DWPF simulant CPC studies for SB8

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, D. C.; Zamecnik, J. R.

    2013-06-25

    The Savannah River National Laboratory (SRNL) accepted a technical task request (TTR) from Waste Solidification Engineering to perform simulant tests to support the qualification of Sludge Batch 8 (SB8) and to develop the flowsheet for SB8 in the Defense Waste Processing Facility (DWPF). These efforts pertained to the DWPF Chemical Process Cell (CPC). Separate studies were conducted for frit development and glass properties (including REDOX). The SRNL CPC effort had two primary phases divided by the decision to drop Tank 12 from the SB8 constituents. This report focuses on the second phase with SB8 compositions that do not contain the Tank 12 piece. A separate report will document the initial phase of SB8 testing that included Tank 12. The second phase of SB8 studies consisted of two sets of CPC studies. The first study involved CPC testing of an SB8 simulant for Tank 51 to support the CPC demonstration of the washed Tank 51 qualification sample in the SRNL Shielded Cells facility. SB8-Tank 51 was a high iron-low aluminum waste with fairly high mercury and moderate noble metal concentrations. Tank 51 was ultimately washed to about 1.5 M sodium which is the highest wash endpoint since SB3-Tank 51. This study included three simulations of the DWPF Sludge Receipt and Adjustment Tank (SRAT) cycle and Slurry Mix Evaporator (SME) cycle with the sludge-only flowsheet at nominal DWPF processing conditions and three different acid stoichiometries. These runs produced a set of recommendations that were used to guide the successful SRNL qualification SRAT/SME demonstration with actual Tank 51 washed waste. The second study involved five SRAT/SME runs with SB8-Tank 40 simulant. Four of the runs were designed to define the acid requirements for sludge-only processing in DWPF with respect to nitrite destruction and hydrogen generation. The fifth run was an intermediate acid stoichiometry demonstration of the coupled flowsheet for SB8. These runs produced a set of processing

  5. Fiber lubrication: A molecular dynamics simulation study

    Science.gov (United States)

    Liu, Hongyi

    Molecular and mesoscopic level description of friction and lubrication remains a challenge because of difficulties in the phenomenological understanding of to the behaviors of solid-liquid interfaces during sliding. Fortunately, there is the computational simulation approach opens an opportunity to predict and analyze interfacial phenomena, which were studied with molecular dynamics (MD) and mesoscopic dynamics (MesoDyn) simulations. Polypropylene (PP) and cellulose are two of most common polymers in textile fibers. Confined amorphous surface layers of PP and cellulose were built successfully with xenon crystals which were used to compact the polymers. The physical and surface properties of the PP and cellulose surface layers were investigated by MD simulations, including the density, cohesive energy, volumetric thermal expansion, and contact angle with water. The topology method was employed to predict the properties of poly(alkylene glycol) (PAG) diblock copolymers and Pluronic triblock copolymers used as lubricants on surfaces. Density, zero shear viscosity, shear module, cohesive energy and solubility parameter were predicted with each block copolymer. Molecular dynamics simulations were used to study the interaction energy per unit contact area of block copolymer melts with PP and cellulose surfaces. The interaction energy is defined as the ratio of interfacial interaction energy to the contact area. Both poly(proplene oxide) (PPO) and poly(ethylene oxide) (PEO) segments provided a lipophilic character to both PP and cellulose surfaces. The PPO/PEO ratio and the molecular weight were found to impact the interaction energy on both PP and cellulose surfaces. In aqueous solutions, the interaction energy is complicated due to the presence of water and the cross interactions between the multiple molecular components. The polymer-water-surface (PWS) calculation method was proposed to calculate such complex systems. In a contrast with a vacuum condition, the presence

  6. Highly automated driving, secondary task performance, and driver state.

    Science.gov (United States)

    Merat, Natasha; Jamson, A Hamish; Lai, Frank C H; Carsten, Oliver

    2012-10-01

    A driving simulator study compared the effect of changes in workload on performance in manual and highly automated driving. Changes in driver state were also observed by examining variations in blink patterns. With the addition of a greater number of advanced driver assistance systems in vehicles, the driver's role is likely to alter in the future from an operator in manual driving to a supervisor of highly automated cars. Understanding the implications of such advancements on drivers and road safety is important. A total of 50 participants were recruited for this study and drove the simulator in both manual and highly automated mode. As well as comparing the effect of adjustments in driving-related workload on performance, the effect of a secondary Twenty Questions Task was also investigated. In the absence of the secondary task, drivers' response to critical incidents was similar in manual and highly automated driving conditions. The worst performance was observed when drivers were required to regain control of driving in the automated mode while distracted by the secondary task. Blink frequency patterns were more consistent for manual than automated driving but were generally suppressed during conditions of high workload. Highly automated driving did not have a deleterious effect on driver performance, when attention was not diverted to the distracting secondary task. As the number of systems implemented in cars increases, an understanding of the implications of such automation on drivers' situation awareness, workload, and ability to remain engaged with the driving task is important.

  7. Driving in mild cognitive impairment: The role of depressive symptoms.

    Science.gov (United States)

    Beratis, Ion N; Andronas, Nikos; Kontaxopoulou, Dionysia; Fragkiadaki, Stella; Pavlou, Dimosthenis; Papatriantafyllou, John; Economou, Alexandra; Yannis, George; Papageorgiou, Sokratis G

    2017-07-04

    Previous studies indicate a negative association between depression and driving fitness in the general population. Our goal was to cover a gap in the literature and to explore the link between depressive symptoms and driving behavior in individuals with mild cognitive impairment (MCI) through the use of a driving simulator experiment. Twenty-four individuals with MCI (mean age = 67.42, SD = 7.13) and 23 cognitively healthy individuals (mean age = 65.13, SD = 7.21) were introduced in the study. A valid driving license and regular car use served as main inclusion criteria. Data collection included a neurological/neuropsychological assessment and a driving simulator evaluation. Depressive symptomatology was assessed with the Patient Health Questionnaire (PHQ-9). Significant interaction effects indicating a greater negative impact of depressive symptoms in drivers with MCI than in cognitively healthy drivers were observed in the case of various driving indexes, namely, average speed, accident risk, side bar hits, headway distance, headway distance variation, and lateral position variation. The associations between depressive symptoms and driving behavior remained significant after controlling for daytime sleepiness and cognition. Depressive symptoms could be a factor explaining why certain patients with MCI present altered driving skills. Therefore, interventions for treating the depressive symptoms of individuals with MCI could prove to be beneficial regarding their driving performance.

  8. Road rage: an exploratory study on aggressive driving experience on Indian roads.

    Science.gov (United States)

    Sagar, Rajesh; Mehta, Manju; Chugh, Geetanjali

    2013-06-01

    Driving on Indian roads is a stressful experience. A lacuna of research on aggressive driving experiences in the Indian set-up highlights the need to address this growing concern for individuals, society and mental health professionals. To explore and compare driving-related anger triggers and anger expression among high- and low-angry Indian drivers. Two hundred randomly chosen drivers from the city of Delhi were administered a semi-structured questionnaire intended to understand driving-related aggression. Honking, overtaking from the wrong side, loud music in other cars and hot and humid climate significantly increased the risk of experiencing anger among high-angry drivers. High-angry drivers were significantly more likely to engage in direct and aggressive expression of anger, including overtaking, verbal abuse, yelling and arguing, not giving space to other drivers, fighting, and hitting and bumping other cars in protest. Passive anger expressions such as holding grudges against other drivers and eating or drinking something to cool down were significantly more likely to be used by low-angry drivers. Drivers who are high on anger have a significantly higher risk of experiencing anger triggered by a variety of individual and environmental factors on Indian roads and are more susceptible to engage in aggressive driving behaviour.

  9. Development of a polar direct-drive platform for studying inertial confinement fusion implosion mix on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Mark J.; Bradley, Paul A.; Cobble, James A.; Fincke, James R.; Hakel, Peter; Hsu, Scott C.; Krasheninnikova, Natalia S.; Kyrala, George A.; Magelssen, Glenn R.; Montgomery, David S.; Murphy, Thomas J.; Obrey, Kimberly A.; Shah, Rahul C.; Tregillis, Ian L.; Baumgaertel, Jessica A.; Wysocki, Frederick J.; Batha, Steven H. [Los Alamos National Laboratory, MS F699, Los Alamos, New Mexico 87545 (United States); Stephen Craxton, R.; McKenty, Patrick W. [Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623 (United States); Fitzsimmons, Paul [General Atomics, 3550 General Atomics Court, San Diego, California 92121 (United States); and others

    2013-05-15

    Experiments were performed to develop a platform for the simultaneous measurement of mix and its effects on fusion burn. Two polar direct drive implosions of all-plastic capsules were conducted for the first time on the National Ignition Facility (NIF). To measure implosion trajectory and symmetry, area image backlighting of these capsules was also employed for the first time on NIF, an advance over previous 1-D slit imaging experiments, providing detailed symmetry data of the capsules as they imploded. The implosion trajectory and low-mode asymmetry seen in the resultant radiographs agreed with pre-shot predictions even though the 700 kJ drive energy produced laser beam intensities exceeding laser-plasma instability thresholds. Post-shot simulations indicate that the capsule yield was reduced by a factor of two compared to pre-shot predictions owing to as-shot laser drive asymmetries. The pre-shot predictions of bang time agreed within 200 ps with the experimental results. The second shot incorporated a narrow groove encircling the equator of the capsule. A predicted yield reduction factor of three was not observed.

  10. Development of a polar direct-drive platform for studying inertial confinement fusion implosion mix on the National Ignition Facility

    International Nuclear Information System (INIS)

    Schmitt, Mark J.; Bradley, Paul A.; Cobble, James A.; Fincke, James R.; Hakel, Peter; Hsu, Scott C.; Krasheninnikova, Natalia S.; Kyrala, George A.; Magelssen, Glenn R.; Montgomery, David S.; Murphy, Thomas J.; Obrey, Kimberly A.; Shah, Rahul C.; Tregillis, Ian L.; Baumgaertel, Jessica A.; Wysocki, Frederick J.; Batha, Steven H.; Stephen Craxton, R.; McKenty, Patrick W.; Fitzsimmons, Paul

    2013-01-01

    Experiments were performed to develop a platform for the simultaneous measurement of mix and its effects on fusion burn. Two polar direct drive implosions of all-plastic capsules were conducted for the first time on the National Ignition Facility (NIF). To measure implosion trajectory and symmetry, area image backlighting of these capsules was also employed for the first time on NIF, an advance over previous 1-D slit imaging experiments, providing detailed symmetry data of the capsules as they imploded. The implosion trajectory and low-mode asymmetry seen in the resultant radiographs agreed with pre-shot predictions even though the 700 kJ drive energy produced laser beam intensities exceeding laser-plasma instability thresholds. Post-shot simulations indicate that the capsule yield was reduced by a factor of two compared to pre-shot predictions owing to as-shot laser drive asymmetries. The pre-shot predictions of bang time agreed within 200 ps with the experimental results. The second shot incorporated a narrow groove encircling the equator of the capsule. A predicted yield reduction factor of three was not observed

  11. Osmosis : a molecular dynamics computer simulation study

    Science.gov (United States)

    Lion, Thomas

    Osmosis is a phenomenon of critical importance in a variety of processes ranging from the transport of ions across cell membranes and the regulation of blood salt levels by the kidneys to the desalination of water and the production of clean energy using potential osmotic power plants. However, despite its importance and over one hundred years of study, there is an ongoing confusion concerning the nature of the microscopic dynamics of the solvent particles in their transfer across the membrane. In this thesis the microscopic dynamical processes underlying osmotic pressure and concentration gradients are investigated using molecular dynamics (MD) simulations. I first present a new derivation for the local pressure that can be used for determining osmotic pressure gradients. Using this result, the steady-state osmotic pressure is studied in a minimal model for an osmotic system and the steady-state density gradients are explained using a simple mechanistic hopping model for the solvent particles. The simulation setup is then modified, allowing us to explore the timescales involved in the relaxation dynamics of the system in the period preceding the steady state. Further consideration is also given to the relative roles of diffusive and non-diffusive solvent transport in this period. Finally, in a novel modification to the classic osmosis experiment, the solute particles are driven out-of-equilibrium by the input of energy. The effect of this modification on the osmotic pressure and the osmotic ow is studied and we find that active solute particles can cause reverse osmosis to occur. The possibility of defining a new "osmotic effective temperature" is also considered and compared to the results of diffusive and kinetic temperatures..

  12. Investigate moped-car conflicts in China using a naturalistic driving study approach.

    Science.gov (United States)

    Glaser, Yi G; Guo, Feng; Fang, Youjia; Deng, Bing; Hankey, Jonathan

    2017-12-01

    Mopeds are a popular transportation mode in Europe and Asia. Moped-related traffic accidents account for a large proportion of crash fatalities. To develop moped-related crash countermeasures, it is important to understand the characteristics of moped-related conflicts. Naturalistic driving study data were collected in Shanghai, China from 36 car drivers. The data included 2,878h and 78,296km driven from 13,149 trips. Moped-car conflicts were identified and examined from the passenger car driver's perspective using kinematic trigger algorithms and manual video reduction. A total of 119 moped-car conflicts were identified, including 74 high g-force conflicts and 45 low g-force events. These conflicts were classified into 22 on-road configurations where both similarities and differences were found as compared to Western Countries. The majority of the conflicts occurred on secondary main roads and branch roads. Hard braking was the primary response that the car drivers made to these conflicts rather than hard steering. The identified on-road vehicle-moped conflict configurations in Shanghai, China may be attributed to the complicated traffic environment and risky behavior of moped riders. The lower prevalence of hard steering in Shanghai as compared to the United States may be due to the lower speeds at event onsets or less available steering space, e.g., less available shoulder area on Chinese urban roads. The characteristics of moped-car conflicts may impact the design of active safety countermeasures on passenger cars. The pilot data from Shanghai urban areas suggest that countermeasures developed for China may require some modifications to those developed for the United States and European countries, although this recommendation may not be conclusive given the small sample size of the study. Future studies with large samples may help better understand the characteristics of moped-car conflicts. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights

  13. Molecular dynamic simulation study of molten cesium

    Directory of Open Access Journals (Sweden)

    Yeganegi Saeid

    2017-01-01

    Full Text Available Molecular dynamics simulations were performed to study thermodynamics and structural properties of expanded caesium fluid. Internal pressure, radial distribution functions (RDFs, coordination numbers and diffusion coefficients have been calculated at temperature range 700–1600 K and pressure range 100–800 bar. We used the internal pressure to predict the metal–non-metal transition occurrence region. RDFs were calculated at wide ranges of temperature and pressure. The coordination numbers decrease and positions of the first peak of RDFs slightly increase as the temperature increases and pressure decreases. The calculated self-diffusion coefficients at various temperatures and pressures show no distinct boundary between Cs metallic fluid and its expanded fluid where it continuously increases with temperature.

  14. Taxonomy of Spyware and Empirical Study of Network Drive-By-Downloads

    Science.gov (United States)

    2005-09-01

    crashed Sex-archive.biz/ movies / 9.5 38.1 Drive-By-Download m.cpa4.org/reality 17.6 21.6 Drive-By-Download 60 To document infection by each of...pyramid.ok.opole.pl 3 7 (65) 6 (20) 7 (130) Sex-archive.biz/ movies / 3 9 (100) 11 (41) 10 (242) m.cpa4.org/reality 1 3 (26) 2 (2) 1 (4) F. URL...homepages Mortgage company homepages Universities 500 Source: www.utexas.edu/world/univ/state/ Unsafe Sectors Adult Entertainment 418 Free porn

  15. A study on the fundamental mechanism and the evolutionary driving forces behind aerobic fermentation in yeast.

    Science.gov (United States)

    Hagman, Arne; Piškur, Jure

    2015-01-01

    Baker's yeast Saccharomyces cerevisiae rapidly converts sugars to ethanol and carbon dioxide at both anaerobic and aerobic conditions. The later phenomenon is called Crabtree effect and has been described in two forms, long-term and short-term effect. We have previously studied under fully controlled aerobic conditions forty yeast species for their central carbon metabolism and the presence of long-term Crabtree effect. We have also studied ten steady-state yeast cultures, pulsed them with glucose, and followed the central carbon metabolism and the appearance of ethanol at dynamic conditions. In this paper we analyzed those wet laboratory data to elucidate possible mechanisms that determine the fate of glucose in different yeast species that cover approximately 250 million years of evolutionary history. We determine overflow metabolism to be the fundamental mechanism behind both long- and short-term Crabtree effect, which originated approximately 125-150 million years ago in the Saccharomyces lineage. The "invention" of overflow metabolism was the first step in the evolution of aerobic fermentation in yeast. It provides a general strategy to increase energy production rates, which we show is positively correlated to growth. The "invention" of overflow has also simultaneously enabled rapid glucose consumption in yeast, which is a trait that could have been selected for, to "starve" competitors in nature. We also show that glucose repression of respiration is confined mainly among S. cerevisiae and closely related species that diverged after the whole genome duplication event, less than 100 million years ago. Thus, glucose repression of respiration was apparently "invented" as a second step to further increase overflow and ethanol production, to inhibit growth of other microbes. The driving force behind the initial evolutionary steps was most likely competition with other microbes to faster consume and convert sugar into biomass, in niches that were semi-anaerobic.

  16. A study on the fundamental mechanism and the evolutionary driving forces behind aerobic fermentation in yeast.

    Directory of Open Access Journals (Sweden)

    Arne Hagman

    Full Text Available Baker's yeast Saccharomyces cerevisiae rapidly converts sugars to ethanol and carbon dioxide at both anaerobic and aerobic conditions. The later phenomenon is called Crabtree effect and has been described in two forms, long-term and short-term effect. We have previously studied under fully controlled aerobic conditions forty yeast species for their central carbon metabolism and the presence of long-term Crabtree effect. We have also studied ten steady-state yeast cultures, pulsed them with glucose, and followed the central carbon metabolism and the appearance of ethanol at dynamic conditions. In this paper we analyzed those wet laboratory data to elucidate possible mechanisms that determine the fate of glucose in different yeast species that cover approximately 250 million years of evolutionary history. We determine overflow metabolism to be the fundamental mechanism behind both long- and short-term Crabtree effect, which originated approximately 125-150 million years ago in the Saccharomyces lineage. The "invention" of overflow metabolism was the first step in the evolution of aerobic fermentation in yeast. It provides a general strategy to increase energy production rates, which we show is positively correlated to growth. The "invention" of overflow has also simultaneously enabled rapid glucose consumption in yeast, which is a trait that could have been selected for, to "starve" competitors in nature. We also show that glucose repression of respiration is confined mainly among S. cerevisiae and closely related species that diverged after the whole genome duplication event, less than 100 million years ago. Thus, glucose repression of respiration was apparently "invented" as a second step to further increase overflow and ethanol production, to inhibit growth of other microbes. The driving force behind the initial evolutionary steps was most likely competition with other microbes to faster consume and convert sugar into biomass, in niches that

  17. Theoretical model simulations for the global Thermospheric Mapping Study (TMS) periods

    Science.gov (United States)

    Rees, D.; Fuller-Rowell, T. J.

    Theoretical and semiempirical models of the solar UV/EUV and of the geomagnetic driving forces affecting the terrestrial mesosphere and thermosphere have been used to generate a series of representative numerical time-dependent and global models of the thermosphere, for the range of solar and geoamgnetic activity levels which occurred during the three Thermospheric Mapping Study periods. The simulations obtained from these numerical models are compared with observations, and with the results of semiempirical models of the thermosphere. The theoretical models provide a record of the magnitude of the major driving forces which affected the thermosphere during the study periods, and a baseline against which the actual observed structure and dynamics can be compared.

  18. Marijuana and actual driving performance

    Science.gov (United States)

    1993-11-01

    This report concerns the effects of marijuana smoking on actual driving performance. It presents the results of one pilot and three actual driving studies. The pilot study's major purpose was to establish the THC dose current marijuana users smoke to...

  19. Design study of a 10 MW MgB2 superconductor direct drive wind turbine generator

    NARCIS (Netherlands)

    Abrahamsen, A.B.; Magnusson, N.; Liu, D.; Stehouwer, E.; Hendriks, B.; Polinder, H.

    2014-01-01

    A superconducting direct drive generator based on field windings of MgB2 superconducting tape is proposed as a solution by mounting the generator in front of the blades using a king-pin nacelle design for offshore turbines with power ratings larger than 10 MW as investigated in the INNWIND.EU

  20. Design study of a 10 MW MgB2 superconductor direct drive wind turbine generator

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Magnusson, Niklas; Liu, Dong

    2014-01-01

    A superconducting direct drive generator based on field windings of MgB2 superconducting tape is proposed as a solution by mounting the generator in front of the blades using a king-pin nacelle design for offshore turbines with power ratings larger than 10 MW as investigated in the INNWIND.EU pro...

  1. Design study of coated conductor direct drive wind turbine generator for small scale demonstration

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Jensen, Bogi Bech

    2012-01-01

    We have investigated the properties of a superconducting direct drive generator suitable for demonstration in a small scale 11 kW wind turbine. The engineering current density of the superconducting field windings is based on properties of coated conductors wound into coils holding of the order 6...

  2. Factors Driving the Adoption of M-Learning: An Empirical Study

    Science.gov (United States)

    Liu, Yong; Li, Hongxiu; Carlsson, Christer

    2010-01-01

    Even if m-learning is spreading rapidly in many regions of the world, research addressing the driving factors of m-learning adoption is in short supply. Built on the Technology Acceptance Model, this paper proposes a hypothesized model of m-learning adoption. Employing structural equation modeling technology, the model was assessed based on the…

  3. An Empirical Study of Factors Driving the Adoption of Mobile Learning in Omani Higher Education

    Science.gov (United States)

    Sarrab, Mohamed; Al Shibli, Ibtisam; Badursha, Nabeela

    2016-01-01

    Mobile learning (M-learning) provides a new learning channel in which learners can access content and just in time information as required irrespective of the time and location. Even though M-learning is fast evolving in many regions of the world, research addressing the driving factors of M-learning adoption is in short supply. This article…

  4. Fitness to drive in early stage dementia : an instrumented vehicle study.

    Science.gov (United States)

    2009-10-01

    Over 25 percent of people age 80 and older suffer from some form of dementia, with Alzheimers Disease accounting for around 75 percent of all instances. It is estimated that around one-third of people with dementia continue to drive. Compared to t...

  5. Study on mobile phone use while driving in a sample of Iranian drivers.

    Science.gov (United States)

    Arvin, Ramin; Khademi, Mostafa; Razi-Ardakani, Hesamoddin

    2017-06-01

    The use of cell phone is a significant source of driver distraction. Phone use while driving can impair a number of factors critical for safe driving which can cause serious traffic safety problems. The objective of this paper was to investigate the frequency of using cell phones while driving in Iran's roads through an observational survey with a random sample of drivers, to recognize contributing factors to cell phone usage and to understand the magnitude of the problem. A total of 1794 observations were collected from 12 sites at controlled intersections, entrance and exit points of highways. The cell phone use rate among drivers (talking or texting) was estimated at 10% which is significantly higher than that in other countries such as Australia, USA and Canada. Rate of cell phone use among younger drivers (14.15%) was higher in comparison with other groups. In order to identify factors affecting cell phone use while driving, a binary logit model is estimated. Variables which significantly contribute to the rate of using cell phone were found to be the age of driver, number of passengers, presence of kids under the age of 8, time of observation, vehicle price and type of car.

  6. Crop modeling: Studying the effect of water stress on the driving forces governing plant water potential

    Science.gov (United States)

    van Emmerik, T. H. M.; Mirfenderesgi, G.; Bohrer, G.; Steele-Dunne, S. C.; Van De Giesen, N.

    2015-12-01

    Water stress is one of the most important environmental factors that influence plant water dynamics. To prevent excessive water loss and physiological damage, plants can regulate transpiration by adjusting the stomatal aperture. This enhances survival, but also reduced photosynthesis and productivity. During periods of low water availability, stomatal regulation is a trade-off between optimization of either survival or production. Water stress defence mechanisms lead to significant changes in plant dynamics, e.g. leaf and stem water content. Recent research has shown that water content in a corn canopy can change up to 30% diurnally as a result of water stress, which has a considerable influence on radar backscatter from a corn canopy [1]. This highlighted the potential of water stress detection using radar. To fully explore the potential of water stress monitoring using radar, we need to understand the driving forces governing plant water potential. For this study, the recently developed the Finite-Element Tree-Crown Hydrodynamic model version 2 (FETCH2) model is applied to a corn canopy. FETCH2 is developed to resolve the hydrodynamic processes within a plant using the porous media analogy, allowing investigation of the influence of environmental stress factors on plant dynamics such as transpiration, photosynthesis, stomatal conductance, and leaf and stem water content. The model is parameterized and evaluated using a detailed dataset obtained during a three-month field experiment in Flevoland, the Netherlands, on a corn canopy. [1] van Emmerik, T., S. Steele-Dunne, J. Judge and N. van de Giesen: "Impact of Diurnal Variation in Vegetation Water Content on Radar Backscatter of Maize During Water Stress", Geosciences and Remote Sensing, IEEE Transactions on, vol. 52, issue 7, doi: 10.1109/TGRS.2014.2386142, 2015.

  7. Quench Simulation Studies: Program documentation of SPQR

    CERN Document Server

    Sonnemann, F

    2001-01-01

    Quench experiments are being performed on prototypes of the superconducting magnets and busbars to determine the adequate design and protection. Many tests can only be understood correctly with the help of quench simulations that model the thermo-hydraulic and electrodynamic processes during a quench. In some cases simulations are the only method to scale the experimental results of prototype measurements to match the situation of quenching superconducting elements in the LHC. This note introduces the theoretical quench model and the use of the simulation program SPQR (Simulation Program for Quench Research), which has been developed to compute the quench process in superconducting magnets and busbars. The model approximates the heat balance equation with the finite difference method including the temperature dependence of the material parameters. SPQR allows the simulation of longitudinal quench propagation along a superconducting cable, the transverse propagation between adjacent conductors, heat transfer i...

  8. Simulation study of the high intensity S-Band photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiongwei; Nakajima, Kazuhisa [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

    2001-10-01

    In this paper, we report the results of simulation study of the high intensity S-Band photoinjector. The aim of the simulation study is to transport high bunch charge with low emittance evolution. The simulation result shows that 7nC bunch with rms emittance 22.3 {pi} mm mrad can be outputted at the exit of photoinjector. (author)

  9. Active training and driving-specific feedback improve older drivers' visual search prior to lane changes

    Directory of Open Access Journals (Sweden)

    Lavallière Martin

    2012-03-01

    Full Text Available Abstract Background Driving retraining classes may offer an opportunity to attenuate some effects of aging that may alter driving skills. Unfortunately, there is evidence that classroom programs (driving refresher courses do not improve the driving performance of older drivers. The aim of the current study was to evaluate if simulator training sessions with video-based feedback can modify visual search behaviors of older drivers while changing lanes in urban driving. Methods In order to evaluate the effectiveness of the video-based feedback training, 10 older drivers who received a driving refresher course and feedback about their driving performance were tested with an on-road standardized evaluation before and after participating to a simulator training program (Feedback group. Their results were compared to a Control group (12 older drivers who received the same refresher course and in-simulator active practice as the Feedback group without receiving driving-specific feedback. Results After attending the training program, the Control group showed no increase in the frequency of the visual inspection of three regions of interests (rear view and left side mirrors, and blind spot. In contrast, for the Feedback group, combining active training and driving-specific feedbacks increased the frequency of blind spot inspection by 100% (32.3 to 64.9% of verification before changing lanes. Conclusions These results suggest that simulator training combined with driving-specific feedbacks helped older drivers to improve their visual inspection strategies, and that in-simulator training transferred positively to on-road driving. In order to be effective, it is claimed that driving programs should include active practice sessions with driving-specific feedbacks. Simulators offer a unique environment for developing such programs adapted to older drivers' needs.

  10. Active training and driving-specific feedback improve older drivers' visual search prior to lane changes.

    Science.gov (United States)

    Lavallière, Martin; Simoneau, Martin; Tremblay, Mathieu; Laurendeau, Denis; Teasdale, Normand

    2012-03-02

    Driving retraining classes may offer an opportunity to attenuate some effects of aging that may alter driving skills. Unfortunately, there is evidence that classroom programs (driving refresher courses) do not improve the driving performance of older drivers. The aim of the current study was to evaluate if simulator training sessions with video-based feedback can modify visual search behaviors of older drivers while changing lanes in urban driving. In order to evaluate the effectiveness of the video-based feedback training, 10 older drivers who received a driving refresher course and feedback about their driving performance were tested with an on-road standardized evaluation before and after participating to a simulator training program (Feedback group). Their results were compared to a Control group (12 older drivers) who received the same refresher course and in-simulator active practice as the Feedback group without receiving driving-specific feedback. After attending the training program, the Control group showed no increase in the frequency of the visual inspection of three regions of interests (rear view and left side mirrors, and blind spot). In contrast, for the Feedback group, combining active training and driving-specific feedbacks increased the frequency of blind spot inspection by 100% (32.3 to 64.9% of verification before changing lanes). These results suggest that simulator training combined with driving-specific feedbacks helped older drivers to improve their visual inspection strategies, and that in-simulator training transferred positively to on-road driving. In order to be effective, it is claimed that driving programs should include active practice sessions with driving-specific feedbacks. Simulators offer a unique environment for developing such programs adapted to older drivers' needs.

  11. Functional brain mapping of actual car-driving using [18F]FDG-PET

    International Nuclear Information System (INIS)

    Jeong, M.; Tashiro, Manabu; Singh, L.N.

    2006-01-01

    This study aims at identifying the brain activation during actual car-driving on the road, and at comparing the results to those of previous studies on simulated car-driving. Thirty normal volunteers, aged 20 to 56 years, were divided into three subgroups, active driving, passive driving and control groups, for examination by positron emission tomography (PET) and [ 18 F]2-deoxy-2-fluoro-D-glucose (FDG). The active driving subjects (n=10) drove for 30 minutes on quiet normal roads with a few traffic signals. The passive driving subjects (n=10) participated as passengers on the front seat. The control subjects (n=10) remained seated in a lit room with their eyes open. Voxel-based t-statistics were applied using SPM2 to search brain activation among the subgroups mentioned above. Significant brain activation was detected during active driving in the primary and secondary visual cortices, primary sensorimotor areas, premotor area, parietal association area, cingulate gyms, the parahippocampal gyrus as well as in thalamus and cerebellum. The passive driving manifested a similar-looking activation pattern, lacking activations in the premotor area, cingulate and parahippocampal gyri and thalamus. Direct comparison of the active and passive driving conditions revealed activation in the cerebellum. The result of actual driving looked similar to that of simulated driving, suggesting that visual perception and visuomotor coordination were the main brain functions while driving. In terms of attention and autonomic arousal, however, it seems there was a significant difference between simulated and actual driving possibly due to risk of accidents. Autonomic and emotional aspects of driving should be studied using an actual driving study-design. (author)

  12. Numerical Simulations of Electrokinetic Processes Comparing the Use of a Constant Voltage Difference or a Constant Current as Driving Force

    DEFF Research Database (Denmark)

    Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

    materials and the prevention of the reinforced concrete corrosion. The electrical energy applied in an electrokinetic process produces electrochemical reactions at the electrodes. Different electrode processes can occur. When considering inert electrodes in aqueous solutions, the reduction of water...... are transported from the anode to the cathode through the closed electrical circuit of the cell. In the solution, the electrical current is carried by the ions, which move towards the electrode with different charge. Therefore, different authors have studied the system using the circuit theory. Assuming...

  13. Driving and Multitasking: The Good, the Bad, and the Dangerous.

    Science.gov (United States)

    Nijboer, Menno; Borst, Jelmer P; van Rijn, Hedderik; Taatgen, Niels A

    2016-01-01

    Previous research has shown that multitasking can have a positive or a negative influence on driving performance. The aim of this study was to determine how the interaction between driving circumstances and cognitive requirements of secondary tasks affect a driver's ability to control a car. We created a driving simulator paradigm where participants had to perform one of two scenarios: one with no traffic in the driver's lane, and one with substantial traffic in both lanes, some of which had to be overtaken. Four different secondary task conditions were combined with these driving scenarios. In both driving scenarios, using a tablet resulted in the worst, most dangerous, performance, while passively listening to the radio or answering questions for a radio quiz led to the best driving performance. Interestingly, driving as a single task did not produce better performance than driving in combination with one of the radio tasks, and even tended to be slightly worse. These results suggest that drivers switch to internally focused secondary tasks when nothing else is available during monotonous or repetitive driving environments. This mind wandering potentially has a stronger interference effect with driving than non-visual secondary tasks.

  14. Driving and Multitasking: the Good, the Bad, and the Dangerous.

    Directory of Open Access Journals (Sweden)

    Menno Nijboer

    2016-11-01

    Full Text Available Previous research has shown that multitasking can have a positive or a negative influence on driving performance. The aim of this study was to determine how the interaction between driving circumstances and cognitive requirements of secondary tasks affect a driver’s ability to control a car. We created a driving simulator paradigm where participants had to perform one of two scenarios: one with no traffic in the driver’s lane, and one with substantial traffic in both lanes, some of which had to be overtaken. Four different secondary task conditions were combined with these driving scenarios. In both driving scenarios, using a tablet resulted in the worst, most dangerous, performance, while passively listening to the radio or answering questions for a radio quiz led to the best driving performance. Interestingly, driving as a single task did not produce better performance than driving in combination with one of the radio tasks, and even tended to be slightly worse. These results suggest that drivers switch to internally focused secondary tasks when nothing else is available during monotonous or repetitive driving environments. This mind wandering potentially has a stronger interference effect with driving than non-visual secondary tasks.

  15. Adaptive Virtual Tow Bar and Transition of Control : A truck driving simulator study

    NARCIS (Netherlands)

    Wilschut, E.S.; Willemsen, D.M.C.; Hogema, J.H.; Martens, M.H.

    2016-01-01

    Background : Truck platooning, with trucks being virtually connected, is getting more and more attention. Truck platooning offers the potential for substantial fuel savings while allowing the truck driver in the platoon to take a rest. However, at the current state of technology, truck drivers are

  16. Radio tuning effects on visual and driving performance measures : simulator and test track studies.

    Science.gov (United States)

    2013-05-01

    Existing driver distraction guidelines for visual-manual device interface operation specify traditional : manual radio tuning as a reference task. This project evaluated the radio tuning reference task through two activities. : The first activity con...

  17. Design Study of Propulsion and Drive Systems for the Large Civil TiltRotor (LCTR2) Rotorcraft

    Science.gov (United States)

    Robuck, Mark; Wilkerson, Joseph; Zhang, Yiyi; Snyder, Christopher A.; Vonderwell, Daniel

    2013-01-01

    Boeing, Rolls Royce, and NASA have worked together to complete a parametric sizing study for NASA's Large Civil Tilt Rotor (LCTR2) concept 2nd iteration. Vehicle gross weight and fuel usage were evaluated as propulsion and drive system characteristics were varied to maximize the benefit of reduced rotor tip speed during cruise conditions. The study examined different combinations of engine and gearbox variability to achieve rotor cruise tip speed reductions down to 54% of the hover tip speed. Previous NASA studies identified that a 54% rotor speed reduction in cruise minimizes vehicle gross weight and fuel burn. The LCTR2 was the study baseline for initial sizing. This study included rotor tip speed ratios (cruise to hover) of 100%, 77% and 54% at different combinations of engine RPM and gearbox speed reductions, which were analyzed to achieve the lightest overall vehicle gross weight (GW) at the chosen rotor tip speed ratio. Different engine and gearbox technology levels are applied ranging from commercial off-the-shelf (COTS) engines and gearbox technology to entry-in-service (EIS) dates of 2025 and 2035 to assess the benefits of advanced technology on vehicle gross weight and fuel burn. Interim results were previously reported1. This technical paper extends that work and summarizes the final study results including additional engine and drive system study accomplishments. New vehicle sizing data is presented for engine performance at a single operating speed with a multispeed drive system. Modeling details for LCTR2 vehicle sizing and subject engine and drive sub-systems are presented as well. This study was conducted in support of NASA's Fundamental Aeronautics Program, Subsonic Rotary Wing Project.

  18. Exploring the Factors Driving Seasonal Farmland Abandonment: A Case Study at the Regional Level in Hunan Province, Central China

    OpenAIRE

    Yu, Zhonglei; Liu, Lei; Zhang, Hua; Liang, Jinshe

    2017-01-01

    Farmland abandonment, including perennial and seasonal abandonment, is an important process of land use change that matters most to food security. Although there is a great deal of studies on farmland abandonment, seasonal abandonment, which is as serious as perennial abandonment, has attracted little academic attention. This paper takes Hunan Province in central China as its study area and uses a spatial regression model to examine the driving factors of seasonal farmland abandonment at the ...

  19. Learning with a strategic management simulation game: A case study

    OpenAIRE

    Loon, Mark; Evans, Jason; Kerridge, Clive

    2015-01-01

    The use of simulation games as a pedagogic method is well established though its effective use is context-driven. This study adds to the increasing growing body of empirical evidence of the effectiveness of simulation games but more importantly emphasises why by explaining the instructional design implemented reflecting best practices. This multi-method study finds evidence that student learning was enhanced through the use of simulation games, reflected in the two key themes; simulation game...

  20. Cleaner Technology in the Hard Disk Drive Manufacturing Industry: A Case Study

    Science.gov (United States)

    Moolla, Premchai; Chompu-inwai, Rungchat

    2010-10-01

    The objectives of this research are to improve raw material and energy consumption efficiency, as well as reduce defects and the use of chemicals in the arm coil assembly process of hard disk drive manufacturing in the case study company by applying the Cleaner Technology concepts. The four main sequential steps used in this research were: (1) pre-assessment, (2) assessment, (3) feasibility study, and (4) implementation. In the first step, raw data, such as process flows, raw material usage and defects data were collected. In the second step, the loss during production and causes of loss were analyzed. Opportunities to reduce raw material, chemical and energy wastage could then be recommended. The next step was to evaluate the feasibility and potential benefits of a particular Cleaner Technology opportunity. Finally, in the last step, after a thorough evaluation and implementation of the opportunities to apply Cleaner Technology, the results showed that arm coil defects could be reduced by improving the production process using the ECRS technique. ECRS stands for Eliminate, Combine, Rearrange and Simplify. This improvement reduced arm coil defect rates from 0.48% to 0.15%, thus saving approximately 139,638 Thai Baht per month. In addition, production stoppage decision made by workers was used to increase employee involvement in defect detection. Allowing workers to participate in such a decision was an effective way to reduce defect rate and could motivate workers to produce a better quality job. This resulted in arm coil defects reducing from 0.41% to 0.025%, with about 74,562 Thai Baht per month saving. Additionally, an increase in the efficiency of electricity consumption occurred, by increasing the speed of the infrared oven conveyor belt, improving average productivity from 533 pieces/hour to 560 pieces/hour, without adversely affecting product costs and quality, thus producing products of up to the value of 206,242 Thai Baht per month. Furthermore, the new

  1. Sleep inertia associated with a 10-min nap before the commute home following a night shift: A laboratory simulation study.

    Science.gov (United States)

    Hilditch, Cassie J; Dorrian, Jillian; Centofanti, Stephanie A; Van Dongen, Hans P; Banks, Siobhan

    2017-02-01

    Night shift workers are at risk of road accidents due to sleepiness on the commute home. A brief nap at the end of the night shift, before the commute, may serve as a sleepiness countermeasure. However, there is potential for sleep inertia, i.e. transient impairment immediately after awakening from the nap. We investigated whether sleep inertia diminishes the effectiveness of napping as a sleepiness countermeasure before a simulated commute after a simulated night shift. N=21 healthy subjects (aged 21-35 y; 12 females) participated in a 3-day laboratory study. After a baseline night, subjects were kept awake for 27h for a simulated night shift. They were randomised to either receive a 10-min nap ending at 04:00 plus a 10-min pre-drive nap ending at 07:10 (10-NAP) or total sleep deprivation (NO-NAP). A 40-min York highway driving task was performed at 07:15 to simulate the commute. A 3-min psychomotor vigilance test (PVT-B) and the Samn-Perelli Fatigue Scale (SP-Fatigue) were administered at 06:30 (pre-nap), 07:12 (post-nap), and 07:55 (post-drive). In the 10-NAP condition, total pre-drive nap sleep time was 9.1±1.2min (mean±SD), with 1.3±1.9min spent in slow wave sleep, as determined polysomnographically. There was no difference between conditions in PVT-B performance at 06:30 (before the nap). In the 10-NAP condition, PVT-B performance was worse after the nap (07:12) compared to before the nap (06:30); no change across time was found in the NO-NAP condition. There was no significant difference between conditions in PVT-B performance after the drive. SP-Fatigue and driving performance did not differ significantly between conditions. In conclusion, the pre-drive nap showed objective, but not subjective, evidence of sleep inertia immediately after awakening. The 10-min nap did not affect driving performance during the simulated commute home, and was not effective as a sleepiness countermeasure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. LDRD Final Report (08-ERD-037): Important Modes to Drive Protein MD Simulations to the Next Conformational Level

    Energy Technology Data Exchange (ETDEWEB)

    Sadigh, B

    2011-04-07

    Every action in biology is performed by dynamic proteins that convert between multiple states in order to engage their functions. Often binding to various ligands is essential for the rates of desired transitions to be enhanced. The goal of computational biology is to study these transitions and discover the different states to fully understand the protein's normal and diseased function, design drugs to target/bias specific states, and understand all of the interactions in between. We have developed a new methodology that is capable of calculating the absolute free energy of proteins while taking into account all the interactions with the solvent molecules. The efficiency of the new scheme is an order of magnitude greater than any existing technique. This method is now implemented in the massively parallel popular MD program package NAMD. This now makes it possible to calculate the relative stability of different conformational states of biological macromolecules as well as their binding free energies to various ligands.

  3. Plasma simulation studies using multilevel physics models

    International Nuclear Information System (INIS)

    Park, W.; Belova, E.V.; Fu, G.Y.

    2000-01-01

    The question of how to proceed toward ever more realistic plasma simulation studies using ever increasing computing power is addressed. The answer presented here is the M3D (Multilevel 3D) project, which has developed a code package with a hierarchy of physics levels that resolve increasingly complete subsets of phase-spaces and are thus increasingly more realistic. The rationale for the multilevel physics models is given. Each physics level is described and examples of its application are given. The existing physics levels are fluid models (3D configuration space), namely magnetohydrodynamic (MHD) and two-fluids; and hybrid models, namely gyrokinetic-energetic-particle/MHD (5D energetic particle phase-space), gyrokinetic-particle-ion/fluid-electron (5D ion phase-space), and full-kinetic-particle-ion/fluid-electron level (6D ion phase-space). Resolving electron phase-space (5D or 6D) remains a future project. Phase-space-fluid models are not used in favor of delta f particle models. A practical and accurate nonlinear fluid closure for noncollisional plasmas seems not likely in the near future

  4. A Simulation Study of Paced TCP

    Science.gov (United States)

    Kulik, Joanna; Coulter, Robert; Rockwell, Dennis; Partridge, Craig

    2000-01-01

    In this paper, we study the performance of paced TCP, a modified version of TCP designed especially for high delay- bandwidth networks. In typical networks, TCP optimizes its send-rate by transmitting increasingly large bursts, or windows, of packets, one burst per round-trip time, until it reaches a maximum window-size, which corresponds to the full capacity of the network. In a network with a high delay-bandwidth product, however, Transmission Control Protocol's (TCPs) maximum window-size may be larger than the queue size of the intermediate routers, and routers will begin to drop packets as soon as the windows become too large for the router queues. The TCP sender then concludes that the bottleneck capacity of the network has been reached, and it limits its send-rate accordingly. Partridge proposed paced TCP as a means of solving the problem of queueing bottlenecks. A sender using paced TCP would release packets in multiple, small bursts during a round-trip time in which ordinary TCP would release a single, large burst of packets. This approach allows the sender to increase its send-rate to the maximum window size without encountering queueing bottlenecks. This paper describes the performance of paced TCP in a simulated network and discusses implementation details that can affect the performance of paced TCP.

  5. Plasma simulation studies using multilevel physics models

    Energy Technology Data Exchange (ETDEWEB)

    Park, W.; Belova, E.V.; Fu, G.Y. [and others

    2000-01-19

    The question of how to proceed toward ever more realistic plasma simulation studies using ever increasing computing power is addressed. The answer presented here is the M3D (Multilevel 3D) project, which has developed a code package with a hierarchy of physics levels that resolve increasingly complete subsets of phase-spaces and are thus increasingly more realistic. The rationale for the multilevel physics models is given. Each physics level is described and examples of its application are given. The existing physics levels are fluid models (3D configuration space), namely magnetohydrodynamic (MHD) and two-fluids; and hybrid models, namely gyrokinetic-energetic-particle/MHD (5D energetic particle phase-space), gyrokinetic-particle-ion/fluid-electron (5D ion phase-space), and full-kinetic-particle-ion/fluid-electron level (6D ion phase-space). Resolving electron phase-space (5D or 6D) remains a future project. Phase-space-fluid models are not used in favor of delta f particle models. A practical and accurate nonlinear fluid closure for noncollisional plasmas seems not likely in the near future.

  6. Investigation of a novel completely-in-the-canal direct-drive hearing device: a temporal bone study.

    Science.gov (United States)

    Mahboubi, Hossein; Paulick, Peyton; Kiumehr, Saman; Merlo, Mark; Bachman, Mark; Djalilian, Hamid Reza

    2013-01-01

    Whether a prototype direct-drive hearing device (DHD) is effective in driving the tympanic membrane (TM) in a temporal bone specimen to enable it to potentially treat moderate-to-severe hearing loss. Patient satisfaction with air conduction hearing aids has been low because of sound distortion, occlusion effect, and feedback issues. Implantable hearing aids provide a higher quality sound but require surgery for placement. The DHD was designed to combine the ability of driving the ossicular chain with placement in the external auditory canal. DHD is a 3.5-mm wide device that could fit entirely into the bony ear canal and directly drive the TM rather than use a speaker. A cadaveric temporal bone was prepared. The device developed in our laboratory was coupled to the external surface of the TM and against the malleus. Frequency sweeps between 300 Hz to 12 kHz were performed in 2 different coupling methods at 104 and 120 dB, and the DHD was driven with various levels of current. Displacements of the posterior crus of the stapes were measured using a laser Doppler vibrometer. The DHD showed a linear frequency response from 300 Hz to 12 kHz. Placement against the malleus showed higher amplitudes and lower power requirements than when the device was placed on the TM. DHD is a small completely-in-the-canal device that mechanically drives the TM. This novel device has a frequency output wider than most air conduction devices. Findings of the current study demonstrated that the DHD had the potential of being incorporated into a hearing aid in the future.

  7. Artificial intelligence-based speed control of DTC induction motor drives - A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Gadoue, S.M.; Giaouris, D.; Finch, J.W. [School of Electrical, Electronic and Computer Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2009-01-15

    The design of the speed controller greatly affects the performance of an electric drive. A common strategy to control an induction machine is to use direct torque control combined with a PI speed controller. These schemes require proper and continuous tuning and therefore adaptive controllers are proposed to replace conventional PI controllers to improve the drive's performance. This paper presents a comparison between four different speed controller design strategies based on artificial intelligence techniques; two are based on tuning of conventional PI controllers, the third makes use of a fuzzy logic controller and the last is based on hybrid fuzzy sliding mode control theory. To provide a numerical comparison between different controllers, a performance index based on speed error is assigned. All methods are applied to the direct torque control scheme and each control strategy has been tested for its robustness and disturbance rejection ability. (author)

  8. White book Escrime. Climatic simulation studies

    International Nuclear Information System (INIS)

    Terray, L.; Braconnot, P.

    2007-01-01

    The ESCRIME project aims to manage the analysis realized on the climatic simulations on the framework of the fourth report of the GIEC (group of intergovernmental experts on the climate evolution), in particularly the simulations based on french models. This white book is constituted by 8 chapters: the global scenario, the climatic sensibility, the variation modes, the regionalization and the extremes, the hydrological cycle, the polar regions and the cryo-sphere, the carbon cycle, detection and attributions. (A.L.B.)

  9. Driving Down HB-LED Costs. Implementation of Process Simulation Tools and Temperature Control Methods of High Yield MOCVD Growth

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, William [Veeco Process Equipment, Inc., Plainview, NY (United States)

    2012-04-30

    The overall objective of this multi-faceted program is to develop epitaxial growth systems that meet a goal of 75% (4X) cost reduction in the epitaxy phase of HB-LED manufacture. A 75% reduction in yielded epitaxy cost is necessary in order to achieve the cost goals for widespread penetration of HB-LED's into back-lighting units (BLU) for LCD panels and ultimately for solid-state lighting (SSL). To do this, the program will address significant improvements in overall equipment Cost of Ownership, or CoO. CoO is a model that includes all costs associated with the epitaxy portion of production. These aspects include cost of yield, capital cost, operational costs, and maintenance costs. We divide the program into three phases where later phases will incorporate the gains of prior phases. Phase one activities are enabling technologies. In collaboration with Sandia National Laboratories we develop a Fluent-compatible chemistry predictive model and a set of mid-infrared and near-ultraviolet pyrometer monitoring tools. Where previously the modeling of the reactor dynamics were studied within FLUENT alone, here, FLUENT and Chemkin are integrated into a comprehensive model of fluid dynamics and the most advanced transport equations developed for Chemkin. Specifically, the Chemkin model offered the key reaction terms for gas-phase nucleation, a key consideration in the optimization of the MOCVD process. This new predictive model is used to design new MOCVD reactors with optimized growth conditions and the newly developed pyrometers are used monitor and control the MOCVD process temperature to within 0.5°C run-to-run and within each wafer. This portion of the grant is in collaboration with partners at Sandia National Laboratories. Phase two activities are continuous improvement projects which extend the current reactor platform along the lines of improved operational efficiency, improved systems control for throughput, and carrier modifications for increased yield

  10. Theoretical studies of lower hybrid current drive and ion-cyclotron heating in tokamaks

    International Nuclear Information System (INIS)

    Perkins, F.W.; Valeo, E.J.; Eder, D.C.

    1985-02-01

    A computational model for PLT lower hybrid current drive and ramp-up experiments combines a parallel velocity Fokker-Planck treatment of lower hybrid current drive with minor radius flux diffusion and toroidal ray-tracing wave propagation. Computational and experimental results are in good accord. Analytic solutions of the two-dimensional velocity space (v/sub perpendicular/, v/sub parallel/) diffusion problem give values of the current drive parameter J/P/sub d/ which agree with numerical results, both relativistically and nonrelativistically. Turning to ICRF heating, two new all-metal antenna designs will permit power flux up to 10 kW/cm 2 . A full wave solution to the magnetosonic wave equation, based on the parabolic method, yields cylindrical convergence and treats the diffraction limitation on intensity correctly. Mode conversion with energy absorption has been added to the BALDUR ICRF modeling code. A Fokker-Planck treatment of high energy ion tail formation by ICRF finds that enhanced thermonuclear reactivity can occur

  11. Current drive studies for the ARIES steady-state tokamak reactors

    International Nuclear Information System (INIS)

    Mau, T.K.; Ehst, D.A.; Mandrekas, J.

    1994-01-01

    Steady-state plasma operating scenarios are designed for three versions of the ARIES reactor, using non-inductive current drive techniques that have an established database. R.f. waves, including fast and lower hybrid waves, are the reference drivers for the D-T burning ARIES-I and ARIES-II/IV, while neutral beam injection is employed for ARIES-III which burns D- 3 He. Plasma equilibria with a high bootstrap-current component have been used, in order to minimize the recirculating power fraction and cost of electricity. To maintain plasma stability, the driven current profile has been aligned with that of equilibrium by proper choices of the plasma profiles and power launch parameters. Except for ARIES-III, the current-drive power requirements and the relevant technology developments are found to be quite reasonable. The wave-power spectrum and launch requirements are also considered achievable with a modest development effort. Issues such as an improved database for fast-wave current drive, lower-hybrid power coupling to the plasma edge, profile control in the plasma core, and access to the design point of operation remain to be addressed. ((orig.))

  12. Completely-in-the-canal magnet-drive hearing device: a temporal bone study.

    Science.gov (United States)

    Mahboubi, Hossein; Malley, Melinda J D; Paulick, Peyton; Merlo, Mark W; Bachman, Mark; Djalilian, Hamid R

    2013-03-01

    The magnet-drive hearing device (MHD) is a small completely-in-the-canal hearing aid prototype that drives the tympanic membrane (TM) through a magnetic interface. A cadaveric temporal bone was prepared. The MHD was coupled to a nickel-epoxy pellet glued to the umbo. Frequency sweeps between 0.3 and 10 kHz were performed, and the MHD was driven with various levels of current. Displacements of the posterior crus of the stapes were measured using a laser Doppler vibrometer and compared with sound-induced displacements. The MHD had a linear frequency response and low total harmonic distortion. The pellet placement altered the stapes movements; however, the changes were statistically insignificant. Inputs of 100 and 300 mV produced displacements equivalent to those of the natural sound at 70- and 80-dB sound pressure level, respectively. The coupling of this novel device using a magnetic interface to the umbo had a frequency output wider than air conduction devices, and its actuator was effective in driving the TM.

  13. A study on a micro-stepping drive system for space pointing platform

    Science.gov (United States)

    Yang, Shuang; Li, Bao-quan; Zhang, Xin

    2011-08-01

    Along with the continuous development of the research in the space exploration field, the precision rotation control system is widely utilized in a lot of payloads of the satellites. It is stepping motor cooperating with reduction gear wheel to accomplish the precision rotation in some pointing platforms of the camera used in the satellite. By contrast with that, the approach of this paper could precisely control the rotation angle of the stepping motor without using reduction gear wheel. Therefore, the size and the height of the instrument would be reduced base on simplifying the structural design. Moreover, it reduces the cost to some extent. In this paper, it is adopted that the digital signal processor (DSP) controller and bipolar constant current motor drive circuit UC3717 to make a high performance, high subdivision, miniature control system come true, which is used to drive two-phase hybrid stepping motor. The methods are applied by the driver system that sine cosine micro stepping and constant current chopper drive with a fixed chopper period. The driver system also supplies the functions that involve subdivision selection, clockwise rotation or counter clockwise rotation control, and over current or over voltage or under voltage or overload protection, and so on. The description in this paper also includes the total schematic design, the approach to get current table in different subdivision levels, the current control method in hybrid stepping motor, the way to reduce electro- magnetic interference (EMI) of the hybrid stepping motor. And the total schematic design contains the DSP controller, the communication interface of the driver system, the design of power driving circuit, the interface circuit between the electrical sources, the constant current chopper drive circuit for the two-phase hybrid stepping motor. At last, it is verified by some experimental investigations that the control system not only has miniature size, simplified system design

  14. A prospective study to determine the need for physical simulation following virtual simulation

    International Nuclear Information System (INIS)

    Valicenti, R.K.; Waterman, F.M.; Corn, B.W.; Sweet, J.; Curran, W.J.

    1996-01-01

    Purpose: Virtual simulation is CT based planning utilizing computed digitally reconstructed radiographs (DRRs) in a manner similar to conventional fluoroscopic simulation. However, conventional or physical simulation is still widely used to assure precise implementation of the devised plan. To evaluate the need for performing physical simulation, we prospectively studied patients undergoing virtual simulation who either had or did not have a subsequent physical simulation. Materials and Methods: From July, 1995 to February, 1996, 48 patients underwent conformal 4-field radiation therapy for prostate cancer using a commercial grade spiral CT simulator. All patients were immobilized in a foam body cast and positioned by using a fiducial laser marking system. Following prostate and seminal vesicle definition on a slice-by-slice basis, virtual simulation was performed. The isocenter defined by this process was marked on both the patient and the immobilization device before leaving the CT simulator room. The isocenter position of the devised plan was evaluated by three verification methods: physical simulation, first day treatment port filming, and port filming immediately following physical simulation. Simulator radiographs and port films were compared against DRRs for x, y, and z deviations of the isocenter. These deviations were used as a measure of the implementation precision achieved by each verification method. Results: Thirty-seven patients underwent physical simulation and first day port filming. Eleven had first day treatment verification films only and never had a physical simulation. A total of 79 simulator radiographs and 126 first day treatment port films were reviewed. The tabulation of all deviations is as follows: There was significantly more setup error (≥ 5 mm) observed when the devised treatment was implemented in the treatment room as opposed to the physical simulator. The physical simulator did not lead to a significant reduction in setup error

  15. Driving factors of carbon dioxide emissions in China: an empirical study using 2006-2010 provincial data

    Science.gov (United States)

    Liu, Yu; Chen, Zhan-Ming; Xiao, Hongwei; Yang, Wei; Liu, Danhe; Chen, Bin

    2017-03-01

    The rapid urbanization of China has increased pressure on its environmental and ecological well being. In this study, the temporal and spatial profiles of China's carbon dioxide emissions are analyzed by taking heterogeneities into account based on an integration of the extended stochastic impacts using a geographically and temporally weighted regression model on population, affluence, and technology. Population size, urbanization rate, GDP per capita, energy intensity, industrial structure, energy consumption pattern, energy prices, and economy openness are identified as the key driving factors of regional carbon dioxide emissions and examined through the empirical data for 30 provinces during 2006‒2010. The results show the driving factors and their spillover effects have distinct spatial and temporal heterogeneities. Most of the estimated time and space coefficients are consistent with expectation. According to the results of this study, the heterogeneous spatial and temporal effects should be taken into account when designing policies to achieve the goals of carbon dioxide emissions reduction in different regions.

  16. Comparison between young male drivers' self-assessed and objectively measured driving skills

    DEFF Research Database (Denmark)

    Martinussen, Laila Marianne; Møller, Mette; Prato, Carlo Giacomo

    2017-01-01

    Self-assessment of skills is a self-generated feedback process that contributes to confidence in one's skills. The higher one's self-assessed skills, the more likely one is to feel competent a particular domain thereby influencing the related behaviors. Drivers' self-assessed driving skills...... are not always accurate, which may cause serious problems such as underestimation of risk, reckless driving and accidents. Most previous research on self-assessment of driving skills did not compare self-reported skills to objectively measured driving skills, so the aim of this study was to test the accuracy...... of young male drivers' self-assessments of driving skills using a driving simulator, and to examine whether self-assessment accuracy varied with driving skill, experience or sensation-seeking propensity. Results showed that the drivers' self-assessments were inconsistent with their driving performance...

  17. Broadcasting simulation case studies to the didactic classroom.

    Science.gov (United States)

    Kalmakis, Karen A; Cunningham, Helene; Lamoureux, Erin T; Ahmed, Elshaymaa M

    2010-01-01

    To explore the potential of using simulation in new ways, it is time to think "outside the lab." To do this, the authors expanded the use of case-study simulations by broadcasting them to classrooms where didactic content could be reinforced with simulation content. Advantages included students' active classroom engagement, simultaneously sharing simulations with many students, modeling students' thinking in clinical situations, and connecting theory to practice.

  18. Conducting Simulation Studies in the R Programming Environment

    Directory of Open Access Journals (Sweden)

    Kevin A. Hallgren

    2013-10-01

    Full Text Available Simulation studies allow researchers to answer specific questions about data analysis, statistical power, and best-practices for obtainingaccurate results in empirical research. Despite the benefits that simulation research can provide, many researchers are unfamiliar with available tools for conducting their own simulation studies. The use of simulation studies need not be restricted toresearchers with advanced skills in statistics and computer programming, and such methods can be implemented by researchers with a variety of abilities and interests. The present paper provides an introduction to methods used for running simulationstudies using the R statistical programming environment and is written for individuals with minimal experience running simulation studies or using R. The paper describes the rationale and benefits of using simulations and introduces R functions relevant for many simulation studies. Three examples illustrate different applications for simulation studies, including (a the use of simulations to answer a novel question about statistical analysis, (b the use of simulations to estimate statistical power, and (c the use of simulations to obtain confidence intervals of parameter estimates throughbootstrapping. Results and fully annotated syntax from these examples are provided.

  19. A study on the thermal expansion characteristics of simulated spent fuel and simulated DUPIC fuel

    International Nuclear Information System (INIS)

    Kang, Kweon Ho; Ryu, H. J.; Kim, H. S.; Song, K. C.; Yang, M. S.

    2001-10-01

    Thermal expansions of simulated spent PWR fuel and simulated DUPIC fuel were studied using a dilatometer in the temperature range from 298 to 1900 K. The densities of simulated spent PWR fuel and simulated DUPIC fuel used in the measurement were 10.28 g/cm3 (95.35 % of TD) and 10.26 g/cm3 (95.14 % of TD), respectively. Their linear thermal expansions of simulated fuels are higher than that of UO2, and the difference between these fuels and UO2 increases progressively as temperature increases. However, the difference between simulated spent PWR fuel and simulated DUPIC fuel can hardly be observed. For the temperature range from 298 to 1900 K, the values of the average linear thermal expansion coefficients for simulated spent PWR fuel and simulated DUPIC fuel are 1.391 10-5 and 1.393 10-5 K-1, respectively. As temperature increases to 1900 K, the relative densities of simulated spent PWR fuel and simulated DUPIC fuel decrease to 93.81 and 93.76 % of initial densities at 298 K, respectively

  20. Driving following Kava Use and Road Traffic Injuries: A Population-Based Case-Control Study in Fiji (TRIP 14).

    Science.gov (United States)

    Wainiqolo, Iris; Kafoa, Berlin; Kool, Bridget; Robinson, Elizabeth; Herman, Josephine; McCaig, Eddie; Ameratunga, Shanthi

    2016-01-01

    To investigate the association between kava use and the risk of four-wheeled motor vehicle crashes in Fiji. Kava is a traditional beverage commonly consumed in many Pacific Island Countries. Herbal anxiolytics containing smaller doses of kava are more widely available. Data for this population-based case-control study were collected from drivers of 'case' vehicles involved in serious injury-involved crashes (where at least one road user was killed or admitted to hospital for 12 hours or more) and 'control' vehicles representative of 'driving time' in the study base. Structured interviewer administered questionnaires collected self-reported participant data on demographic characteristics and a range of risk factors including kava use and potential confounders. Unconditional logistic regression models estimated odds ratios relating to the association between kava use and injury-involved crash risk. Overall, 23% and 4% of drivers of case and control vehicles, respectively, reported consuming kava in the 12 hours prior to the crash or road survey. After controlling for assessed confounders, driving following kava use was associated with a four-fold increase in the odds of crash involvement (Odds ratio: 4.70; 95% CI: 1.90-11.63). The related population attributable risk was 18.37% (95% CI: 13.77-22.72). Acknowledging limited statistical power, we did not find a significant interaction in this association with concurrent alcohol use. In this study conducted in a setting where recreational kava consumption is common, driving following the use of kava was associated with a significant excess of serious-injury involved road crashes. The precautionary principle would suggest road safety strategies should explicitly recommend avoiding driving following kava use, particularly in communities where recreational use is common.

  1. Drugs and driving

    NARCIS (Netherlands)

    Walsh, J. Michael; De Gier, Johan J.; Christopherson, Asbjørg S.; Verstraete, Alain G.

    The authors present a global overview on the issue of drugs and driving covering four major areas: (1) Epidemiology and Prevalence-which reviews epidemiological research, summarizes available information, discusses the methodological shortcomings of extant studies, and makes recommendations for

  2. Knowledge of Driving Vehicle Licensing Agency guidelines among NHS doctors: a multicentre observational study.

    Science.gov (United States)

    Ng, Ka Y Bonnie; Garnham, Jack; Syed, Usama M; Green, Ben L; Watson, Robert; Gollop, Nicholas D; Shalhoub, Joseph; Maruthappu, Mahiben

    2015-10-01

    Over half of the UK population holds a driver's licence. The DVLA have produced guidelines to ensure drivers with medical conditions drive safely. Doctors should ensure that patients are given appropriate information and advice if they have a medical condition affecting their driving. We sought to evaluate doctors' knowledge of DVLA guidelines. A 25-point questionnaire was designed from DVLA guidelines ('The DVLA Questionnaire'). Five questions were included for each of neurology, cardiology, drug and alcohol abuse, visual, and respiratory disorders. Ealing Hospital, Northwick Park Hospital, Watford General Hospital, Norfolk and Norwich University Hospital and Leeds Teaching Hospitals Trust. 140 UK doctors. Questionnaire scores assessing knowledge of DVLA guidelines in five specialty areas. The median overall questionnaire score was 28%, interquartile range 20-36% and range 0-100% [Watford 28%, Leeds 30%, Norfolk and Norwich 36%, Ealing 30%, Northwick Park 28%]. There were no significant differences between the scores for each centre (p = 0.1332), Mean scores for specialty areas were: neurology 33.1%, standard deviation 22.1; cardiology 35.6%, standard deviation 26.9; drug and alcohol abuse 30.6%, standard deviation 23.8; visual disorders 33.9%, standard deviation 23.5 and respiratory disorders 20.3%, standard deviation 24.8; overall score 30.7%. There was no significant difference between the scores of the specialty areas (p = 0.4060). Knowledge of DVLA guidelines in our cohort was low. There is a need for increased awareness among hospital doctors through focused education on driving restrictions for common medical conditions. Improving physician knowledge in this area may help optimise patient safety.

  3. Assessing phylogenetic accuracy : a simulation study

    NARCIS (Netherlands)

    Heijerman, T.

    1995-01-01

    A simulation model of phylogeny, called GENESIS, was developed to evaluate and to estimate the qualities of various numerical taxonomic procedures. The model produces sets of imaginary species with known character state distributions and with known phylogenies. The model can be made to

  4. Computer Simulation Studies of Trishomocubane Heptapeptide of ...

    African Journals Online (AJOL)

    As part of an extension on the cage peptide chemistry, the present work involves an assessment of the conformational profile of trishomocubane heptapeptide of the type Ac-Ala3-Tris-Ala3-NHMe using molecular dynamics (MD) simulations. All MD protocols were explored within the framework of a molecular mechanics ...

  5. Partnering to Establish and Study Simulation in International Nursing Education.

    Science.gov (United States)

    Garner, Shelby L; Killingsworth, Erin; Raj, Leena

    The purpose of this article was to describe an international partnership to establish and study simulation in India. A pilot study was performed to determine interrater reliability among faculty new to simulation when evaluating nursing student competency performance. Interrater reliability was below the ideal agreement level. Findings in this study underscore the need to obtain baseline interrater reliability data before integrating competency evaluation into a simulation program.

  6. Cloud Based Drive Forensic and DDoS Analysis on Seafile as Case Study

    Science.gov (United States)

    Bahaweres, R. B.; Santo, N. B.; Ningsih, A. S.

    2017-01-01

    The rapid development of Internet due to increasing data rates through both broadband cable networks and 4G wireless mobile, make everyone easily connected to the internet. Storages as Services (StaaS) is more popular and many users want to store their data in one place so that whenever they need they can easily access anywhere, any place and anytime in the cloud. The use of the service makes it vulnerable to use by someone to commit a crime or can do Denial of Service (DoS) on cloud storage services. The criminals can use the cloud storage services to store, upload and download illegal file or document to the cloud storage. In this study, we try to implement a private cloud storage using Seafile on Raspberry Pi and perform simulations in Local Area Network and Wi-Fi environment to analyze forensically to discover or open a criminal act can be traced and proved forensically. Also, we can identify, collect and analyze the artifact of server and client, such as a registry of the desktop client, the file system, the log of seafile, the cache of the browser, and database forensic.

  7. Piecewise nonlinear dynamic characteristics study of the control rod drive mechanism

    International Nuclear Information System (INIS)

    Shen Xiaoyao; Wang Feng

    2011-01-01

    Piecewise nonlinear dynamics of the control rod mechanism (CRDM), one of the critical components in PWR nuclear power plants, are studied for its lifting process in this paper. Firstly, equations of the electric circuit and the magnetic circuit are set up. Then based on the dynamic lifting process analysis of CRDM, its motion procedure is divided into three stages, and the coupled magnetic-electric-mechanical equation for each stage is derived. By combining the analytical solution method and the numerical simulation method, the piecewise nonlinear governing equations are solved. Finally, parameters which can illustrate the dynamic characteristics of CRDM, such as the magnetic force, the coil current, the armature displacement, the armature velocity and the acceleration are obtained and corresponding curves with the time are drawn and analyzed. The analysis results are confirmed by the test which proves the validity of our method. Work in this paper can be used for design and analysis as well as the site fault diagnosis of CRDM. (author)

  8. Aircraft Simulator Data Requirements Study. Volume II

    Science.gov (United States)

    1977-01-01

    the adjustments to ’rrect current problems may mask serious simulator problems that will emerge in later use of the simulator. It was universally...8217 .:U eVlI !t -’k .lct Io t.t 5 ’h ~ re < ’ t h), * I ’t: ’’"njf of ’ -.it .1 t ai’ltO v- oI t Willi I Ik ~i-±a or tIt aIslrc t’it fitIt.r 1v iiC (via1...operable equipment Environment Flight envelope and maneuvers Scanning area 57Awl -4 Instructor stations - emergencies Mission phases (T.O., cruise

  9. Study of CMOS micromachined self-oscillating loop utilizing a phase-locked loop-driving circuit

    International Nuclear Information System (INIS)

    Li, Hsin-Chih; Tseng, Sheng-Hsiang; Lu, Michael S.-C.; Huang, Po-Chiun

    2012-01-01

    This work describes the design and characterization of integrated CMOS (complementary metal oxide semiconductor) oscillators comprising a capacitively transduced micromechanical resonator and a phase-locked loop (PLL) driving circuit. Three oscillator schemes are studied and compared, including direct feedback, direct feedback containing a PLL and hybrid direct feedback plus a PLL. PLL is known for its capability in automatic tuning and tracking of a reference signal. Inclusion of a PLL is beneficial for sustaining oscillations at resonant frequencies within its capture range. The micromechanical resonator has a measured resonant frequency of 117.3 kHz. The CMOS PLL circuit has a closed-loop bandwidth of 1.8 kHz with a capture range between 111 kHz and 118.4 kHz. The start-up times for oscillation are shortened in the two schemes utilizing a PLL, since it provides an initial driving signal at its free-running frequency. The lock-in time is also reduced by increasing the proportion of PLL drive in the hybrid scheme. The measured noises for the three oscillator schemes are similar with a value of −75 dB below the resonant peak at a 10 Hz offset. (paper)

  10. Unit Under Test Simulator Feasibility Study.

    Science.gov (United States)

    1980-06-01

    Source 0 Nonlinear Elements Nonlinear Voltage-Controlled Current Source Diode Bipolar Junction Transistor ( BJT ) Junction Field-Effect Transistor (JFET...circuit element component levels, such as resistor, capacitor, and transistor . As such, it can provide very accurate simulation with regard to signal...Insulated- Gate Field-Effect Transistor (MOSFET) Each model in turn contains many parameters which are used to reflect the individual device

  11. Simulation

    CERN Document Server

    Ross, Sheldon

    2006-01-01

    Ross's Simulation, Fourth Edition introduces aspiring and practicing actuaries, engineers, computer scientists and others to the practical aspects of constructing computerized simulation studies to analyze and interpret real phenomena. Readers learn to apply results of these analyses to problems in a wide variety of fields to obtain effective, accurate solutions and make predictions about future outcomes. This text explains how a computer can be used to generate random numbers, and how to use these random numbers to generate the behavior of a stochastic model over time. It presents the statist

  12. Return to Driving After Hip Arthroscopy.

    Science.gov (United States)

    Momaya, Amit M; Stavrinos, Despina; McManus, Benjamin; Wittig, Shannon M; Emblom, Benton; Estes, Reed

    2017-07-11

    The objective of this study was to evaluate patients' braking performance using a modern driving simulator after undergoing a right hip arthroscopy. This prospective study included 5 total driving sessions at which measurements were taken. The study was conducted at an academic medical center. A total of 14 patients scheduled to undergo a right hip arthroscopy were enrolled and compared with a control group of 17 participants to account for a potential learning phenomenon. Patients drove in the simulator preoperatively to establish a baseline, and then drove again at 2, 4, 6, and 8 weeks postoperatively. The control group did not undergo any type of surgical procedure. The main independent variable was time from surgery. A modern driving simulator was used to measure initial reaction time (IRT), throttle release time (TRT), foot movement time (FMT), and brake travel time (BTT). The braking reaction time (BRT) was calculated as the sum of IRT + TRT + FMT, and the total braking time (TBT) was calculated as the sum of BRT + BTT. The experimental group showed no significant changes in BTT (P = 0.11, ηG = 0.04) nor TBT (P = 0.20, ηG = 0.03) over the duration of 8 weeks. Although the experimental group did exhibit significant improvements in IRT (P = 0.002), TRT (P < 0.0001), FMT (P < 0.0001), and BRT (P = 0.0002) between preoperative and 2 weeks postoperative driving sessions, there were no significant changes thereafter. The mean preoperative TBT and 2 weeks postoperative TBT for the experimental group were 3.07 seconds (SD = 0.50) and 2.97 seconds (SD = 0.57), respectively. No learning phenomenon was observed in the control group. This study's findings suggest that patients may return to driving 2 weeks postoperatively from a right-sided hip arthroscopy procedure.

  13. Examination of drivers' cell phone use behavior at intersections by using naturalistic driving data.

    Science.gov (United States)

    Xiong, Huimin; Bao, Shan; Sayer, James; Kato, Kazuma

    2015-09-01

    Many driving simulator studies have shown that cell phone use while driving greatly degraded driving performance. In terms of safety analysis, many factors including drivers, vehicles, and driving situations need to be considered. Controlled or simulated studies cannot always account for the full effects of these factors, especially situational factors such as road condition, traffic density, and weather and lighting conditions. Naturalistic driving by its nature provides a natural and realistic way to examine drivers' behaviors and associated factors for cell phone use while driving. In this study, driving speed while using a cell phone (conversation or visual/manual tasks) was compared to two baselines (baseline 1: normal driving condition, which only excludes driving while using a cell phone, baseline 2: driving-only condition, which excludes all types of secondary tasks) when traversing an intersection. The outcomes showed that drivers drove slower when using a cell for both conversation and visual/manual (VM) tasks compared to baseline conditions. With regard to cell phone conversations, drivers were more likely to drive faster during the day time compared to night time driving and drive slower under moderate traffic compared to under sparse traffic situations. With regard to VM tasks, there was a significant interaction between traffic and cell phone use conditions. The maximum speed with VM tasks was significantly lower than that with baseline conditions under sparse traffic conditions. In contrast, the maximum speed with VM tasks was slightly higher than that with baseline driving under dense traffic situations. This suggests that drivers might self-regulate their behavior based on the driving situations and demand for secondary tasks, which could provide insights on driver distraction guidelines. With the rapid development of in-vehicle technology, the findings in this research could lead the improvement of human-machine interface (HMI) design as well

  14. Direct-drive high-convergence-ratio implosion studies on the OMEGA laser system

    International Nuclear Information System (INIS)

    Marshall, F. J.; Delettrez, J. A.; Epstein, R.; Glebov, V. Yu.; Harding, D. R.; McKenty, P. W.; Meyerhofer, D. D.; Radha, P. B.; Seka, W.; Skupsky, S.

    2000-01-01

    A series of direct-drive implosion experiments, using room-temperature, gas-filled CH targets, are performed on the University of Rochester's OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The target performance at stagnation and its dependence on beam smoothing and pulse shaping is investigated. Compressed core conditions are diagnosed using x-ray and neutron spectroscopy, and x-ray imaging. The individual beams of OMEGA are smoothed by spectral dispersion in two dimensions (2D SSD) with laser bandwidths up to ∼0.3 THz, with 1 ns square to 2.5 ns shaped pulses. A clear dependence of target performance on pulse shape and beam smoothing is seen, with the target performance (yield, areal density, and shell integrity) improving as SSD bandwidth is applied. (c)

  15. A field study on the effects of digital billboards on glance behavior during highway driving.

    Science.gov (United States)

    Belyusar, Daniel; Reimer, Bryan; Mehler, Bruce; Coughlin, Joseph F

    2016-03-01

    Developments in lighting technologies have allowed more dynamic digital billboards in locations visible from the roadway. Decades of laboratory research have shown that rapidly changing or moving stimuli presented in peripheral vision tends to 'capture' covert attention. We report naturalistic glance and driving behavior of a large sample of drivers who were exposed to two digital billboards on a segment of highway largely free from extraneous signage. Results show a significant shift in the number and length of glances toward the billboards and an increased percentage of time glancing off road in their presence. Findings were particularly evident at the time the billboards transitioned between advertisements. Since rapidly changing stimuli are difficult to ignore, the planned increase in episodically changing digital displays near the roadway may be argued to be a potential safety concern. The impact of digital billboards on driver safety and the need for continued research are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Impact of distracted driving on safety and traffic flow.

    Science.gov (United States)

    Stavrinos, Despina; Jones, Jennifer L; Garner, Annie A; Griffin, Russell; Franklin, Crystal A; Ball, David; Welburn, Sharon C; Ball, Karlene K; Sisiopiku, Virginia P; Fine, Philip R

    2013-12-01

    Studies have documented a link between distracted driving and diminished safety; however, an association between distracted driving and traffic congestion has not been investigated in depth. The present study examined the behavior of teens and young adults operating a driving simulator while engaged in various distractions (i.e., cell phone, texting, and undistracted) and driving conditions (i.e., free flow, stable flow, and oversaturation). Seventy five participants 16-25 years of age (split into 2 groups: novice drivers and young adults) drove a STISIM simulator three times, each time with one of three randomly presented distractions. Each drive was designed to represent daytime scenery on a 4 lane divided roadway and included three equal roadway portions representing Levels of Service (LOS) A, C, and E as defined in the 2000 Highway Capacity Manual. Participants also completed questionnaires documenting demographics and driving history. Both safety and traffic flow related driving outcomes were considered. A Repeated Measures Multivariate Analysis of Variance was employed to analyze continuous outcome variables and a Generalized Estimate Equation (GEE) Poisson model was used to analyze count variables. Results revealed that, in general more lane deviations and crashes occurred during texting. Distraction (in most cases, text messaging) had a significantly negative impact on traffic flow, such that participants exhibited greater fluctuation in speed, changed lanes significantly fewer times, and took longer to complete the scenario. In turn, more simulated vehicles passed the participant drivers while they were texting or talking on a cell phone than while undistracted. The results indicate that distracted driving, particularly texting, may lead to reduced safety and traffic flow, thus having a negative impact on traffic operations. No significant differences were detected between age groups, suggesting that all drivers, regardless of age, may drive in a manner

  17. Simulation studies of the LAMPF proton linac

    International Nuclear Information System (INIS)

    Garnett, R.W.; Gray, E.R.; Rybarcyk, L.J.; Wangler, T.P.

    1995-01-01

    The LAMPF accelerator consists of two 0.75-MeV injectors, one for H + and the other for H - , a separate low-energy beam transport (LEBT) line for each beam species, a 0.75 to 100-MeV drift-tube linac (DTL) operating at 201.25-MHz, a 100-MeV transition region (TR), and a 100 to 800-MeV side-coupled linac (SCL) operating at 805-MHz. Each LEBT line consists of a series of quadrupoles to transport and transversely match the beam. The LEBT also contains a prebuncher, a main buncher, and an electrostatic deflector. The deflector is used to limit the fraction of a macropulse which is seen by the beam diagnostics throughout the linac. The DTL consists of four rf tanks and uses singlet FODO transverse focusing. The focusing period is doubled in the last two tanks by placing a quadrupole only in every other drift-tube. Doublet FDO transverse focusing is used in the SCL. The TR consists of separate transport lines for the H + and H - beams. The pathlengths for the two beams differ, by introducing bends, so as to delay arrival of one beam relative to the other and thereby produce the desired macropulse time structure. Peak beam currents typically range from 12 to 18-mA for varying macropulse lengths which give an average beam current of 1-mA. The number of particles per bunch is of the order 10 8 . The work presented here is an extension of previous work. The authors have attempted to do a more complete simulation by including modeling of the LEBT. No measurements of the longitudinal structure of the beam, except phase-scans, are performed at LAMPF. The authors show that, based on simulation results, the primary causes of beam spill are inefficient longitudinal capture and the lack of longitudinal matching. Measurements to support these claims are not presently made at LAMPF. However, agreement between measurement and simulation for the transverse beam properties and transmissions serve to benchmark the simulations

  18. Mechanisms of the negative synergy effect between electron cyclotron current drive and lower hybrid current drive in tokamak

    International Nuclear Information System (INIS)

    Chen Shaoyong; Hong Binbin; Tang Changjian; Yang Wen; Zhang Xinjun

    2013-01-01

    The synergy current drive by combining electron cyclotron wave (ECW) with lower hybrid wave (LHW) can be used to either increase the noninductive current drive efficiency or shape the plasma current profile. In this paper, the synergy current drive by ECW and LHW is studied with numerical simulation. The nonlinear relationship between the wave powers and the synergy current of ECW and LHW is revealed. When the LHW power is small, the synergy current reduces as the ECW power increases, and the synergy current is even reduced to lower than zero, which is referred as negative synergy in the this context. Research shows that the mechanism of the negative synergy is the peaking effect of LHW power profile and the trapped electrons effect. The present research is helpful for understanding the physics of synergy between electron cyclotron current drive and lower hybrid current drive, it can also instruct the design of experiments. (authors)

  19. Study on a Suspension of a Planetary Exploration Rover to Improve Driving Performance During Overcoming Obstacles

    Directory of Open Access Journals (Sweden)

    We-Sub Eom

    2012-12-01

    Full Text Available The planetary exploration rover executes various missions after moving to the target point in a