Batteryless magneto-driven portable radiac

DOEpatents

Waechter, David A.; Bjarke, George O.; Trujillo, Faustin; Wolf, Michael A.; Umbarger, C. John

1986-01-01

A hand-powered alternator for generating an alternating voltage provides same through a rectifier to a high capacity capacitor which stores the resultant dc voltage and drives a voltage regulator to provide a constant low voltage output for a portable radiation detection instrument. The instrument includes a Geiger-Muller detector tube whose output is fed to a pulse detector and then through an event counter and LCD driver circuit to an LCD bar graph for visual display. An audio driver and an audio output is also provided. All circuitry used is low power so that the capacitor can be readily charged to a sufficient level to provide power for at least 30 minutes. A low voltage indicator is provided on the LCD display to indicate the need for manual recharging.

The case for driver science in motorsport: a review and recommendations.

PubMed

Potkanowicz, Edward S; Mendel, Ronald W

2013-07-01

When discussing sports and the athletes who participate in them, it has long been recognized that fitness is a prerequisite for optimal performance. The goal of training to improve fitness levels in athletes is ultimately to minimize the stress that the body experiences during competition. When it comes to the topic of racecar drivers, however, drivers and their trainers have largely been left to their own devices to figure out the stressors and the areas of specific training focus. Unfortunately, racecar drivers have battled the stereotype that they are not athletes, and with little regard for them as athletes, drivers are seldom the focus of scientific research related to their performance. Like the cars they drive, driver-athletes are complex, but from a physiological perspective. However, unlike the cars they drive, driver-athletes have not been examined, evaluated, and tweaked to the same degree. The purpose of this review is two-fold: first, by examining the available literature, to make the case for new research into the driver's role in the driver-car system (i.e. driver science) and the stresses experienced; second, to make the case for more extensive use of microtechnology in the real-time monitoring of driver-athletes. With the miniaturization of sensors and the advent of portable data storage devices, the prospect of quantifying the stresses unique to the driver are no longer as daunting, and the relative impossibility and difficulties associated with measuring the driver-athlete in real-time no longer need to be as challenging. Using microtechnology in the assessment of the driver-athlete and with a more public discussion and dissemination of information on the topic of driver science, the scientific community has the opportunity to quantify that which has been largely assumed and speculated. The current article will offer the following recommendations: first, rather than examining a singular physiological stressor, to examine the interaction of stressors; second, to examine variables/stressors that are more representative of the changing driver demographics; third, to measure drivers in real-time during actual race events; lastly, to work to develop training programs that more accurately apply to the driver and the stresses experienced. In uncovering this information, there is an opportunity to contribute to racing becoming that much safer, that much more competitive, and that much more comprehensive for the driver, the team, and the sport.

Ten-kilogram vehicle autonomous operations

NASA Astrophysics Data System (ADS)

Rogers, John R.; Korpela, Christopher; Quigley, Kevin

2009-05-01

A low-cost unmanned ground vehicle designed to benchmark high-speed performance is presented. The E-Maxx four-wheel-drive radio-controlled vehicle equipped with a Robostix controller is proposed as a low-cost, high-speed robotic platform useful for military operations. The vehicle weighs less than ten kilograms making it easily portable by one person. Keeping cost low is a major consideration in the design with the aim of providing a disposable military robot. The suitability of the platform was evaluated and results are presented. Commercial-Off-The-Shelf (COTS) upgrades to the basic vehicle are recommended for durability. A procedure was established for bird's-eye-view video recording to document vehicle dynamics. Driver/vehicle performance is quantified by entry velocity, exit velocity and total time through a 90° turn on low-friction terrain. A setup for measuring these values is presented. Expert drivers use controlled skidding to minimize time through turns and the long term goal of the project is to automate such expert behaviors. Results of vehicle performance under human control are presented and stand as a reference for future autonomy.

Portable Diagnostic Devices for Identifying Obstructive Sleep Apnea among Commercial Motor Vehicle Drivers: Considerations and Unanswered Questions

PubMed Central

Zhang, Chunbai; Berger, Mark; Malhotra, Atul; Kales, Stefanos N.

2012-01-01

Obstructive sleep apnea (OSA), a syndrome defined by breathing abnormalities during sleep, can lead to fatigue and excessive daytime sleepiness (EDS) with an increased risk of motor vehicle crashes. Identifying commercial motor vehicle operators with unrecognized OSA is a major public health priority. Portable monitors (PMs) are being actively marketed to trucking firms as potentially lower-cost and more accessible alternatives to the reference standard of in-laboratory polysomnography (PSG) in the diagnosis of OSA among commercial motor vehicle operators. Several factors regarding PMs remain uncertain in this unique patient population: their sensitivity and specificity; the cost-benefit ratio of the PMs versus PSG; potential barriers from human factors; and evolving technologic advancement. Human factors that alter test accuracy are a major concern among commercial drivers motivated to gain/maintain employment. Current available data using PMs as a diagnostic tool among CMV operators indicate relatively high data loss and high loss to follow-up. Loss to follow-up has also been an issue using PSG in commercial motor vehicle operators. Furthermore, PM testing and PM results interpretation protocols may have no sleep specialist oversight, and sometimes minimal physician oversight and involvement. Additional studies comparing unattended and unmonitored PMs directly against full in-laboratory PSG are needed to provide evidence for their efficacy among commercial motor vehicle operators. Citation: Zhang C; Berger M; Malhotra A; Kales SN. Portable diagnostic devices for identifying obstructive sleep apnea among commercial motor vehicle drivers: considerations and unanswered questions. SLEEP 2012;35(11):1481-1489. PMID:23115397

Biomedical engineering tasks. [electrode development for electrocardiography and electroencephalography

NASA Technical Reports Server (NTRS)

1972-01-01

Electrocardiographic and vectorcardiographic bioinstrumentation work centered on the development of a new electrode system harness for Project Skylab. Evaluation of several silver electrode configurations proved superior impedance voltage performance for silver/silver chloride electrodes mounted flush by using a paste adhesive. A portable ECG processor has been designed and a breadboard unit has been built to sample ECG input data at a rate of 500 samples per second for arrhythmia detection. A small real time display driver program has been developed for statistical analysis on selected QPS features. Engineering work on a sleep monitoring cap assembly continued.

Driver electronics design and control for a total artificial heart linear motor.

PubMed

Unthan, Kristin; Cuenca-Navalon, Elena; Pelletier, Benedikt; Finocchiaro, Thomas; Steinseifer, Ulrich

2018-01-27

For any implantable device size and efficiency are critical properties. Thus, a linear motor for a Total Artificial Heart was optimized with focus on driver electronics and control strategies. Hardware requirements were defined from power supply and motor setup. Four full bridges were chosen for the power electronics. Shunt resistors were set up for current measurement. Unipolar and bipolar switching for power electronics control were compared regarding current ripple and power losses. Here, unipolar switching showed smaller current ripple and required less power to create the necessary motor forces. Based on calculations for minimal power losses Lorentz force was distributed to the actor's four coils. The distribution was determined as ratio of effective magnetic flux through each coil, which was captured by a force test rig. Static and dynamic measurements under physiological conditions analyzed interaction of control and hardware and all efficiencies were over 89%. In conclusion, the designed electronics, optimized control strategy and applied current distribution create the required motor force and perform optimal under physiological conditions. The developed driver electronics and control offer optimized size and efficiency for any implantable or portable device with multiple independent motor coils. Graphical Abstract ᅟ.

Novel concept for driving the linear compressor of a micro-miniature split Stirling cryogenic cooler

NASA Astrophysics Data System (ADS)

Maron, V.; Veprik, A.; Finkelstein, L.; Vilenchik, H.; Ziv, I.; Pundak, N.

2009-05-01

New methods of carrying out homeland security and antiterrorist operations call for the development of a new generation of mechanically cooled, portable, battery powered infrared imagers, relying on micro-miniature Stirling cryogenic coolers of rotary or linear types. Since split Stirling linearly driven micro-miniature cryogenic coolers have inherently longer life spans, low vibration export and better aural stealth as compared to their rotary driven rivals, they are more suitable for the above applications. The performance of such cryogenic coolers depends strongly on the efficacy of their electronic drivers. In a traditional approach, the PWM power electronics produce the fixed frequency tonal driving voltage/current, the magnitude of which is modulated via a PID control law so as to maintain the desired focal plane array temperature. The disadvantage of such drivers is that they draw high ripple current from the system's power bus. This results in the need for an oversized DC power supply (battery packs) and power electronic components, low efficiency due to excessive conductive losses and high residual electromagnetic interference which in turn degrades the performance of other systems connected to the same power bus. Without either an active line filter or large and heavy passive filtering, other electronics can not be powered from the same power bus, unless they incorporate heavy filtering at their inputs. The authors present the results of a feasibility study towards developing a novel "pumping" driver consuming essentially constant instant battery power/current without making use of an active or passive filter. In the tested setup, the driver relies on a bidirectional controllable bridge, invertible with the driving frequency, and a fast regulated DC/DC converter which maintains a constant level of current consumed from the DC power supply and thus operates in input current control mode. From the experimental results, the steady-state power consumed by the linear compressor remains the same as compared with the traditional sine wave driver, the voltage and current drawn from the battery pack is essentially free of low frequency ripple (this without use of any kind of filtering) and the overall coefficient of performance of the driver is in excess of 94% over the entire working range of supply voltages. Such a driver free of sine forming PWM stage and have reduced power peaks in all power conversion components.

Optimal pressure regulation of the pneumatic ventricular assist device with bellows-type driver.

PubMed

Lee, Jung Joo; Kim, Bum Soo; Choi, Jaesoon; Choi, Hyuk; Ahn, Chi Bum; Nam, Kyoung Won; Jeong, Gi Seok; Lim, Choon Hak; Son, Ho Sung; Sun, Kyung

2009-08-01

The bellows-type pneumatic ventricular assist device (VAD) generates pneumatic pressure with compression of bellows instead of using an air compressor. This VAD driver has a small volume that is suitable for portable devices. However, improper pneumatic pressure setup can not only cause a lack of adequate flow generation, but also cause durability problems. In this study, a pneumatic pressure regulation system for optimal operation of the bellows-type VAD has been developed. The optimal pneumatic pressure conditions according to various afterload conditions aiming for optimal flow rates were investigated, and an afterload estimation algorithm was developed. The developed regulation system, which consists of a pressure sensor and a two-way solenoid valve, estimates the current afterload and regulates the pneumatic pressure to the optimal point for the current afterload condition. Experiments were performed in a mock circulation system. The afterload estimation algorithm showed sufficient performance with the standard deviation of error, 8.8 mm Hg. The flow rate could be stably regulated with a developed system under various afterload conditions. The shortcoming of a bellows-type VAD could be handled with this simple pressure regulation system.

A linear motor and compact cylinder-piston driver for left ventricular bypass.

PubMed

Qian, K X

1990-01-01

A simple, portable, reliable and noise-free pneumatic driver has been developed. It consists of a linear motor attached to a cylinder piston, in one unit. The motor coil is directly wound on the cylinder, and the permanent magnet is fixed to the piston. As a continuous voltage square wave is applied to the coil, the cylinder reciprocates on the piston periodically, producing air pressure and vacuum alternately. In conjunction with a locally made diaphragm pump, the driver was tested in vitro and in vivo. Results demonstrated that the device could drive the diaphragm pump and so support the circulation of an experimental animal. The driver weighs 12 kg. For 200 mmHg air pressure and -80 mmHg vacuum the power consumed is 30 W. Its noise is about 30 dB, less than that of an artificial valve and pump.

Detection of illicit drugs in impaired driver saliva by a field-usable SERS analyzer

NASA Astrophysics Data System (ADS)

Shende, Chetan; Huang, Hermes; Farquharson, Stuart

2014-05-01

One of the greatest dangers of drug use is in combination with driving. According to the most recent National Highway Traffic Safety Administration (NHTSA) studies, more than 11% of drivers tested positive for illicit drugs, while 18% of drivers killed in accidents tested positive for illicit, prescription or over-the-counter drugs. Consequently, there is a need for a rapid, noninvasive, roadside drug testing device, similar to the breathalyzers used by law enforcement officials to estimate blood alcohol levels of impaired drivers. In an effort to satisfy this need we have been developing a sampling kit that allows extraction of drugs from 1 mL of saliva and detection by surfaceenhanced Raman spectroscopy using a portable Raman analyzer. Here we describe the development of the sampling kit and present measurements of diazepam at sub μg/mL concentrations measured in ~15 minutes.

Cross-Sectional Study of Obstructive Sleep Apnea Syndrome in Japanese Public Transportation Drivers: Its Prevalence and Association With Pathological Objective Daytime Sleepiness.

PubMed

Sasai-Sakuma, Taeko; Kikuchi, Katsunori; Inoue, Yuichi

2016-05-01

This study investigates obstructive sleep apnea syndrome (OSAS) prevalence among Japanese occupational drivers and factors associated with a pathological level of objective daytime sleepiness. Portable monitoring device (PMD) screening was applied to 2389 Japanese male public transportation traffic drivers. Nocturnal polysomnography (n-PSG) and multiple sleep latency tests (MSLT) were administered to subjects with apnea-hypopnea index (AHI) at least 15 on PMD. In all, 235 subjects were diagnosed as having OSAS (9.8%). AHI on n-PSG at least 40 and Epworth Sleepiness Scale score at least 11 were extracted as factors associated with mean sleep latency on MSLT less than 5 minutes. Prevalence of OSAS in male Japanese public transportation traffic drivers was 9.8% or greater. Individuals aware of excessive daytime sleepiness and with severe OSAS were inferred as exhibiting a pathological level of objective daytime sleepiness.

Design of robotic leg and physiotherapy (ROLEP) assist with interactive game

NASA Astrophysics Data System (ADS)

Hasan, A. F.; Husin, M. F. Che; Hashim, M. N.; Rosli, K. A.; Roslim, F. R. A.; Abidin, A. F. Z.

2017-09-01

Injuries in certain parts of the feet can cause a person to have difficulty in walking or running if it is not treated through physiotherapy. In Malaysia, therapy centers only provide a service or the use of basic tools that are not efficient as more sophisticated equipment requires a high cost. In fact, exercise requiring close monitoring physiotherapist are also at a high cost. Therefore, using robot therapy is a new technology that can provide an alternative way to solve this problem. The implementation of this project has produced a robotic physiotherapy which has one degree of freedom, portable and inexpensive way to help the movement of the patient's leg. It covers basic electrical circuits, mechanical components, programming and has been combined with an interactive game as the main driver. ROLEP (Robotic-Leg-Physiotherapy) is able to help patients through the therapy process. It was built using CT-UNO as its microprocessor connected to MD10-C which acted as the motor driver. The interactive game produced by using Unity game software is a key driver in getting rid of boredom and reduce pain. As a result, ROLEP designed can operate well within its range of the patient's weight. It has the advantage of portability and easy to use by the patients. ROLEP expected to help patients undergoing therapy process more efficient and interesting in the process of recovery.

S-Band POSIX Device Drivers for RTEMS

NASA Technical Reports Server (NTRS)

Lux, James P.; Lang, Minh; Peters, Kenneth J.; Taylor, Gregory H.

2011-01-01

This is a set of POSIX device driver level abstractions in the RTEMS RTOS (Real-Time Executive for Multiprocessor Systems real-time operating system) to SBand radio hardware devices that have been instantiated in an FPGA (field-programmable gate array). These include A/D (analog-to-digital) sample capture, D/A (digital-to-analog) sample playback, PLL (phase-locked-loop) tuning, and PWM (pulse-width-modulation)-controlled gain. This software interfaces to Sband radio hardware in an attached Xilinx Virtex-2 FPGA. It uses plug-and-play device discovery to map memory to device IDs. Instead of interacting with hardware devices directly, using direct-memory mapped access at the application level, this driver provides an application programming interface (API) offering that easily uses standard POSIX function calls. This simplifies application programming, enables portability, and offers an additional level of protection to the hardware. There are three separate device drivers included in this package: sband_device (ADC capture and DAC playback), pll_device (RF front end PLL tuning), and pwm_device (RF front end AGC control).

Wireless alerting system using vibration for vehicles dashboard

NASA Astrophysics Data System (ADS)

Raj, Sweta; Rai, Shweta; Magaramagara, Wilbert; Sivacoumar, R.

2017-11-01

This paper aims at improving the engine life of any vehicle through a continuous measurement and monitoring of vital engine operational parameters and providing an effective alerting to drivers for any abnormality. Vehicles currently are using audio and visible alerting signals through alarms and light as a warning to the driver but these are not effective in noisy environments and during daylight. Through the use of the sense of feeling a driver can be alerted effectively. The need to no other vehicle parameter needs to be aided through the mobile display (phone).Thus a system is designed and implements to measure engine temperature, RPM, Oil level and Coolant level using appropriate sensors and a wireless communication (Bluetooth) is established to actuate a portable vibration control device and to read the different vehicle sensor readings through an android application for display and diagnosis.

Teens' distracted driving behavior: Prevalence and predictors.

PubMed

Gershon, Pnina; Zhu, Chunming; Klauer, Sheila G; Dingus, Tom; Simons-Morton, Bruce

2017-12-01

Teen drivers' over-involvement in crashes has been attributed to a variety of factors, including distracted driving. With the rapid development of in-vehicle systems and portable electronic devices, the burden associated with distracted driving is expected to increase. The current study identifies predictors of secondary task engagement among teenage drivers and provides basis for interventions to reduce distracted driving behavior. We described the prevalence of secondary tasks by type and driving conditions and evaluated the associations between the prevalence of secondary task engagement, driving conditions, and selected psychosocial factors. The private vehicles of 83 newly-licensed teenage drivers were equipped with Data Acquisition Systems (DAS), which documented driving performance measures, including secondary task engagement and driving environment characteristics. Surveys administered at licensure provided psychosocial measures. Overall, teens engaged in a potentially distracting secondary task in 58% of sampled road clips. The most prevalent types of secondary tasks were interaction with a passenger, talking/singing (no passenger), external distraction, and texting/dialing the cell phone. Secondary task engagement was more prevalent among those with primary vehicle access and when driving alone. Social norms, friends' risky driving behaviors, and parental limitations were significantly associated with secondary task prevalence. In contrast, environmental attributes, including lighting and road surface conditions, were not associated with teens' engagement in secondary tasks. Our findings indicated that teens engaged in secondary tasks frequently and poorly regulate their driving behavior relative to environmental conditions. Practical applications: Peer and parent influences on secondary task engagement provide valuable objectives for countermeasures to reduce distracted driving among teenage drivers. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

Portable microcontroller-based instrument for near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Giardini, Mario E.; Corti, Mario; Lago, Paolo; Gelmetti, Andrea

2000-05-01

Near IR Spectroscopy (NIRS) can be employed to noninvasively and continuously measure in-vivo local changes in haemodynamics and oxygenation of human tissues. In particular, the technique can be particularly useful for muscular functional monitoring. We present a portable NIRS research-grade acquisition system prototype, strictly dedicate to low-noise measurements during muscular exercise. The prototype is able to control four LED sources and a detector. Such a number of sources allows for multipoint measurements or for multi-wavelength spectroscopy of tissue constituents other than oxygen, such as cytochrome aa3 oxidation. The LEDs and the detector are mounted on separate probes, which carry also the relevant drivers and preamplifiers. By employing surface-mount technologies, probe size and weight are kept to a minimum. A single-chip mixed-signal RISC microcontroller performs source-to- detector multiplexing with a digital correlation technique. The acquired data are stored on an on-board 64 K EEPROM bank, and can be subsequently uploaded to a personal computer via serial port for further analysis. The resulting instrument is compact and lightweight. Preliminary test of the prototype on oxygen consumption during tourniquet- induced forearm ischaemia show adequate detectivity and time response.

UV LED-based lightweight fixed-wavelength detector: for the development of a miniaturized high-performance liquid chromatography (HPLC) system (Erratum)

NASA Astrophysics Data System (ADS)

Guan, Wen Yin; Lee, Wei Yan; Liew, Mervyn Wing On; Tan, Soo Choon; Lim, Jit Kang

2018-02-01

Publisher's Note: This paper, originally published on 14 February, 2018, was replaced with a corrected/revised version on 30 March, 2018. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance. General discussion on the development of portable and miniaturized instrumentation for High Performance Liquid Chromatography (HPLC) is given, specifically the design of UV absorbance detector for field applications. UV/Vis absorption detectors are the most commonly used detector in HPLC for the identification of organic compounds, detection of peptides, proteins and nucleic acids. Opportunities for miniaturization arise from trends which focus on ease of use, portability, and application-specific instruments for example in environmental applications - detection of phenols (water pollutant) and contaminants. Further usage is such as detection of polycyclic aromatic hydrocarbons (PAHs) and carcinogens in edible oils and growth promoter residues in meat. Significant improvement in size and complexity were realized using a simplified optical configuration, efficient low-power LED driver circuit and detector electronics. Firstly, the detector's optical configuration is discussed as an essential part of the miniature fixed-wavelength design. UV-LED with different wavelengths can be installed interchangeably without the need for complicated assembly and precise alignment process. In the second part, each functional block of the detector hardware design are also discussed. The electronics consist of mainly sample photodiode and reference photodiode, Log-ratio amplifier and signal conditioning electronics built with precision analog design techniques and low-noise electronic components. Finally, baseline noise and drift measurements and chromatography performance are presented and the results are compared with conventional detector under identical conditions as benchmark. The advantages of miniaturized HPLC system are portability for onsite analysis, increased efficiency, lower solvent requirements and fully integrated separation and detection system.

Statistical evaluation of PACSTAT random number generation capabilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piepel, G.F.; Toland, M.R.; Harty, H.

1988-05-01

This report summarizes the work performed in verifying the general purpose Monte Carlo driver-program PACSTAT. The main objective of the work was to verify the performance of PACSTAT's random number generation capabilities. Secondary objectives were to document (using controlled configuration management procedures) changes made in PACSTAT at Pacific Northwest Laboratory, and to assure that PACSTAT input and output files satisfy quality assurance traceability constraints. Upon receipt of the PRIME version of the PACSTAT code from the Basalt Waste Isolation Project, Pacific Northwest Laboratory staff converted the code to run on Digital Equipment Corporation (DEC) VAXs. The modifications to PACSTAT weremore » implemented using the WITNESS configuration management system, with the modifications themselves intended to make the code as portable as possible. Certain modifications were made to make the PACSTAT input and output files conform to quality assurance traceability constraints. 10 refs., 17 figs., 6 tabs.« less

Development of a data acquisition system using a RISC/UNIX TM workstation

NASA Astrophysics Data System (ADS)

Takeuchi, Y.; Tanimori, T.; Yasu, Y.

1993-05-01

We have developed a compact data acquisition system on RISC/UNIX workstations. A SUN TM SPARCstation TM IPC was used, in which an extension bus "SBus TM" was linked to a VMEbus. The transfer rate achieved was better than 7 Mbyte/s between the VMEbus and the SUN. A device driver for CAMAC was developed in order to realize an interruptive feature in UNIX. In addition, list processing has been incorporated in order to keep the high priority of the data handling process in UNIX. The successful developments of both device driver and list processing have made it possible to realize the good real-time feature on the RISC/UNIX system. Based on this architecture, a portable and versatile data taking system has been developed, which consists of a graphical user interface, I/O handler, user analysis process, process manager and a CAMAC device driver.

Combat Service Support Enabler Functional Assessment (CEFA). Volume 2: Individual (65) Mini-CEFA Assessments

DTIC Science & Technology

1997-12-01

SLOT) 356 57. Sensor Artificial Intelligence Communications Interactive Maintenance System (SACIMS) 361 58. Soldier’s Portable On- System Repair...increased mobility ; NBC overpressure, environmental control; and situational awareness.] 19. Related changes in CSS effectiveness. Increase The AMEV...to paragraph 17 above.] 19. Related changes in CSS effectiveness. Increase. Driver Minder alerts the maintainer about equipment and operator faults

Surgical resident evaluations of portable laparoscopic box trainers incorporated into a simulation-based minimally invasive surgery curriculum.

PubMed

Zapf, Matthew A C; Ujiki, Michael B

2015-02-01

Box trainers have been shown to be an effective tool for teaching laparoscopic skills; however, residents are challenged to find practice time. Portable trainers theoretically allow for extended hands on practice out of the hospital. We aimed to report resident experience with laparoscopic home box trainers. Over 2 years, all residents rotating through a minimally invasive service were given a portable trainer and access to a surgical simulation lab for practice. Each trainer contained a collapsible frame, a webcam with USB port, trocars, and laparoscopic instruments (needle driver, shears, Maryland and straight dissecting graspers) as well as Fundamentals of Laparoscopic Surgery skills testing materials. Residents were asked to log hours, usages, and their experience anonymously. Twenty-three residents received a portable trainer. Fifty percent of the participants found the trainer useful or very useful, 25% said it was not useful, and 25% did not access the trainer. Those that used the trainer during their rotation did so 3.1 ± 3.0 times for 2.9 ± 3.0 hours/week. After completing their rotation, 5 of 12 residents used their trainer for an average of 10.2 ± 9.4 hours. Forty-two percent of the responders liked the accessibility of the home box trainers, while 25% criticized the camera-computer interface. Portable box trainers are useful and can effectively supplement a laboratory-based surgical simulation curriculum; however, personal possession of a portable simulator does not result in voluntarily long-term practice. © The Author(s) 2014.

The research of digital circuit system for high accuracy CCD of portable Raman spectrometer

NASA Astrophysics Data System (ADS)

Yin, Yu; Cui, Yongsheng; Zhang, Xiuda; Yan, Huimin

2013-08-01

The Raman spectrum technology is widely used for it can identify various types of molecular structure and material. The portable Raman spectrometer has become a hot direction of the spectrometer development nowadays for its convenience in handheld operation and real-time detection which is superior to traditional Raman spectrometer with heavy weight and bulky size. But there is still a gap for its measurement sensitivity between portable and traditional devices. However, portable Raman Spectrometer with Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy (SHINERS) technology can enhance the Raman signal significantly by several orders of magnitude, giving consideration in both measurement sensitivity and mobility. This paper proposed a design and implementation of driver and digital circuit for high accuracy CCD sensor, which is core part of portable spectrometer. The main target of the whole design is to reduce the dark current generation rate and increase signal sensitivity during the long integration time, and in the weak signal environment. In this case, we use back-thinned CCD image sensor from Hamamatsu Corporation with high sensitivity, low noise and large dynamic range. In order to maximize this CCD sensor's performance and minimize the whole size of the device simultaneously to achieve the project indicators, we delicately designed a peripheral circuit for the CCD sensor. The design is mainly composed with multi-voltage circuit, sequential generation circuit, driving circuit and A/D transition parts. As the most important power supply circuit, the multi-voltage circuits with 12 independent voltages are designed with reference power supply IC and set to specified voltage value by the amplifier making up the low-pass filter, which allows the user to obtain a highly stable and accurate voltage with low noise. What's more, to make our design easy to debug, CPLD is selected to generate sequential signal. The A/D converter chip consists of a correlated double sampler; a digitally controlled variable gain amplifier and a 16-bit A/D converter which can help improve the data quality. And the acquired digital signals are transmitted into the computer via USB 2.0 data port. Our spectrometer with SHINERS technology can acquire the Raman spectrum signals efficiently in long time integration and weak signal environment, and the size of our system is well controlled for portable application.

Should we Google it? Resource use by internal medicine residents for point-of-care clinical decision making.

PubMed

Duran-Nelson, Alisa; Gladding, Sophia; Beattie, Jim; Nixon, L James

2013-06-01

To determine which resources residents use at the point-of-care (POC) for decision making, the drivers for selection of these resources, and how residents use Google/Google Scholar to answer clinical questions at the POC. In January 2012, 299 residents from three internal medicine residencies were sent an electronic survey regarding resources used for POC decision making. Resource use frequency and factors influencing choice were determined using descriptive statistics. Binary logistic regression analysis was performed to determine relationships between the independent variables. A total of 167 residents (56%) responded; similar numbers responded at each level of training. Residents most frequently reported using UpToDate and Google at the POC at least daily (85% and 63%, respectively), with speed and trust in the quality of information being the primary drivers of selection. Google, used by 68% of residents, was used primarily to locate Web sites and general information about diseases, whereas Google Scholar, used by 30% of residents, tended to be used for treatment and management decisions or locating a journal article. The findings suggest that internal medicine residents use UpToDate most frequently, followed by consultation with faculty and the search engines Google and Google Scholar; speed, trust, and portability are the biggest drivers for resource selection; and time and information overload appear to be the biggest barriers to resources such as Ovid MEDLINE. Residents frequently used Google and may benefit from further training in information management skills.

A USB-2 based portable data acquisition system for detector development and nuclear research

NASA Astrophysics Data System (ADS)

Jiang, Hao; Ojaruega, M.; Becchetti, F. D.; Griffin, H. C.; Torres-Isea, R. O.

2011-10-01

A highly portable high-speed CAMAC data acquisition system has been developed using Kmax software (Sparrow, Inc.) for Macintosh laptop and tower computers. It uses a USB-2 interface to the CAMAC crate controller with custom-written software drivers. Kmax permits 2D parameter gating and specific algorithms have been developed to facilitate the rapid evaluation of various multi-element nuclear detectors for energy and time-of-flight measurements. This includes tests using neutrons from 252Cf and a 2.5 MeV neutron generator as well as standard gamma calibration sources such as 60Co and 137Cs. In addition, the system has been used to measure gamma-gamma coincidences over extended time periods using radioactive sources (e.g., Ra-228, Pa-233, Np-237, and Am-243).

SVGA and XGA active matrix microdisplays for head-mounted applications

NASA Astrophysics Data System (ADS)

Alvelda, Phillip; Bolotski, Michael; Brown, Imani L.

2000-03-01

The MicroDisplay Corporation's liquid crystal on silicon (LCOS) display devices are based on the union of several technologies with the extreme integration capability of conventionally fabricated CMOS substrates. The fast liquid crystal operation modes and new scalable high-performance pixel addressing architectures presented in this paper enable substantially improved color, contrast, and brightness while still satisfying the optical, packaging, and power requirements of portable applications. The entire suite of MicroDisplay's technologies was devised to create a line of mixed-signal application-specific integrated circuits (ASICs) in single-chip display systems. Mixed-signal circuits can integrate computing, memory, and communication circuitry on the same substrate as the display drivers and pixel array for a multifunctional complete system-on-a-chip. System-on-a-chip benefits also include reduced head supported weight requirements through the elimination of off-chip drive electronics.

A Fast Pulse, High Intensity Neutron Source Based Upon The Dense Plasma Focus

NASA Astrophysics Data System (ADS)

Krishnan, M.; Bures, B.; Madden, R.; Blobner, F.; Elliott, K. Wilson

2009-12-01

Alameda Applied Sciences Corporation (AASC) has built a bench-top source of fast neutrons (˜10-30 ns, 2.45 MeV), that is portable and can be scaled to operate at ˜100 Hz. The source is a Dense Plasma Focus driven by three different capacitor banks: a 40 J/30 kA/100 Hz driver; a 500 J/130 kA/2 Hz driver and a 3 kJ/350 kA/0.5 Hz driver. At currents of ˜130 kA, this source produces ˜1×107 (DD) n/pulse. The neutron pulse widths are ˜10-30 ns and may be controlled by adjusting the DPF electrode geometry and operating parameters. This paper describes the scaling of the fast neutron output with current from such a Dense Plasma Focus source. For each current and driver, different DPF head designs are required to match to the current rise-time, as the operating pressure and anode radius/shape are varied. Doping of the pure D2 gas fill with Ar or Kr was shown earlier to increase the neutron output. Results are discussed in the light of scaling laws suggested by prior literature.

Electronic System for Preventing Airport Runway Incursions

NASA Technical Reports Server (NTRS)

Dabney, Richard; Elrod, Susan

2009-01-01

A proposed system of portable illuminated signs, electronic monitoring equipment, and radio-communication equipment for preventing (or taking corrective action in response to) improper entry of aircraft, pedestrians, or ground vehicles onto active airport runways is described. The main overall functions of the proposed system would be to automatically monitor aircraft ground traffic on or approaching runways and to generate visible and/or audible warnings to affected pilots, ground-vehicle drivers, and control-tower personnel when runway incursions take place.

Portable diagnostic devices for identifying obstructive sleep apnea among commercial motor vehicle drivers: considerations and unanswered questions.

PubMed

Zhang, Chunbai; Berger, Mark; Malhotra, Atul; Kales, Stefanos N

2012-11-01

Obstructive sleep apnea (OSA), a syndrome defined by breathing abnormalities during sleep, can lead to fatigue and excessive daytime sleepiness (EDS) with an increased risk of motor vehicle crashes. Identifying commercial motor vehicle operators with unrecognized OSA is a major public health priority. Portable monitors (PMs) are being actively marketed to trucking firms as potentially lower-cost and more accessible alternatives to the reference standard of in-laboratory polysomnography (PSG) in the diagnosis of OSA among commercial motor vehicle operators. Several factors regarding PMs remain uncertain in this unique patient population: their sensitivity and specificity; the cost-benefit ratio of the PMs versus PSG; potential barriers from human factors; and evolving technologic advancement. Human factors that alter test accuracy are a major concern among commercial drivers motivated to gain/maintain employment. Current available data using PMs as a diagnostic tool among CMV operators indicate relatively high data loss and high loss to follow-up. Loss to follow-up has also been an issue using PSG in commercial motor vehicle operators. Furthermore, PM testing and PM results interpretation protocols may have no sleep specialist oversight, and sometimes minimal physician oversight and involvement. Additional studies comparing unattended and unmonitored PMs directly against full in-laboratory PSG are needed to provide evidence for their efficacy among commercial motor vehicle operators.

Portable apparatus for separating sample and detecting target analytes

DOEpatents

Renzi, Ronald F.; Wally, Karl; Crocker, Robert W.; Stamps, James F.; Griffiths; Stewart K. ,; Fruetel, Julia A.; Horn, Brent A.; Shokair, Isaac R.; Yee, Daniel D.; VanderNoot, Victoria A.; Wiedenman, Boyd J.; West, Jason A. A.; Ferko, Scott M.

2008-11-18

Portable devices and methods for determining the presence of a target analyte using a portable device are provided. The portable device is preferably hand-held. A sample is injected to the portable device. A microfluidic separation is performed within the portable device and at least one separated component detected by a detection module within the portable device, in embodiments of the invention. A target analyte is identified, based on the separated component, and the presence of the target analyte is indicated on an output interface of the portable device, in accordance with embodiments of the invention.

40 CFR 59.653 - How do I test portable fuel containers?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 6 2012-07-01 2012-07-01 false How do I test portable fuel containers... Families § 59.653 How do I test portable fuel containers? You must test the portable fuel container as.... Perform a slosh test by filling the portable fuel container to 40 percent of its capacity with the fuel...

40 CFR 59.653 - How do I test portable fuel containers?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 6 2013-07-01 2013-07-01 false How do I test portable fuel containers... Families § 59.653 How do I test portable fuel containers? You must test the portable fuel container as.... Perform a slosh test by filling the portable fuel container to 40 percent of its capacity with the fuel...

40 CFR 59.653 - How do I test portable fuel containers?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 6 2014-07-01 2014-07-01 false How do I test portable fuel containers... Families § 59.653 How do I test portable fuel containers? You must test the portable fuel container as.... Perform a slosh test by filling the portable fuel container to 40 percent of its capacity with the fuel...

Toward performance portability of the Albany finite element analysis code using the Kokkos library

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demeshko, Irina; Watkins, Jerry; Tezaur, Irina K.

Performance portability on heterogeneous high-performance computing (HPC) systems is a major challenge faced today by code developers: parallel code needs to be executed correctly as well as with high performance on machines with different architectures, operating systems, and software libraries. The finite element method (FEM) is a popular and flexible method for discretizing partial differential equations arising in a wide variety of scientific, engineering, and industrial applications that require HPC. This paper presents some preliminary results pertaining to our development of a performance portable implementation of the FEM-based Albany code. Performance portability is achieved using the Kokkos library. We presentmore » performance results for the Aeras global atmosphere dynamical core module in Albany. Finally, numerical experiments show that our single code implementation gives reasonable performance across three multicore/many-core architectures: NVIDIA General Processing Units (GPU’s), Intel Xeon Phis, and multicore CPUs.« less

Toward performance portability of the Albany finite element analysis code using the Kokkos library

DOE PAGES

Demeshko, Irina; Watkins, Jerry; Tezaur, Irina K.; ...

2018-02-05

Performance portability on heterogeneous high-performance computing (HPC) systems is a major challenge faced today by code developers: parallel code needs to be executed correctly as well as with high performance on machines with different architectures, operating systems, and software libraries. The finite element method (FEM) is a popular and flexible method for discretizing partial differential equations arising in a wide variety of scientific, engineering, and industrial applications that require HPC. This paper presents some preliminary results pertaining to our development of a performance portable implementation of the FEM-based Albany code. Performance portability is achieved using the Kokkos library. We presentmore » performance results for the Aeras global atmosphere dynamical core module in Albany. Finally, numerical experiments show that our single code implementation gives reasonable performance across three multicore/many-core architectures: NVIDIA General Processing Units (GPU’s), Intel Xeon Phis, and multicore CPUs.« less

Creating the environment for driver distraction: A thematic framework of sociotechnical factors.

PubMed

Parnell, Katie J; Stanton, Neville A; Plant, Katherine L

2018-04-01

As modern society becomes more reliant on technology, its use within the vehicle is becoming a concern for road safety due to both portable and built-in devices offering sources of distraction. While the effects of distracting technologies are well documented, little is known about the causal factors that lead to the drivers' engagement with technological devices. The relevance of the sociotechnical system within which the behaviour occurs requires further research. This paper presents two experiments, the first aims to assess the drivers self-reported decision to engage with technological tasks while driving and their reasoning for doing so with respect to the wider sociotechnical system. This utilised a semi-structured interview method, conducted with 30 drivers to initiate a discussion on their likelihood of engaging with 22 different tasks across 7 different road types. Inductive thematic analysis provided a hierarchical thematic framework that detailed the self-reported causal factors that influence the drivers' use of technology whilst driving. The second experiment assessed the relevance of the hierarchical framework to a model of distraction that was established from within the literature on the drivers use of distracting technologies while driving. The findings provide validation for some relationships studied in the literature, as well as providing insights into relationships that require further study. The role of the sociotechnical system in the engagement of distractions while driving is highlighted, with the causal factors reported by drivers suggesting the importance of considering the wider system within which the behaviour is occurring and how it may be creating the conditions for distraction to occur. This supports previous claims made within the literature based model. Recommendations are proposed that encourage a movement away from individual focused countermeasures towards systemic actors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Copy Hiding Application Interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Holger; Poliakoff, David; Robinson, Peter

2016-10-06

CHAI is a light-weight framework which abstracts the automated movement of data (e.g. to/from Host/Device) via RAJA like performance portability programming model constructs. It can be viewed as a utility framework and an adjunct to FAJA (A Performance Portability Framework). Performance Portability is a technique that abstracts the complexities of modern Heterogeneous Architectures while allowing the original program to undergo incremental minimally invasive code changes in order to adapt to the newer architectures.

Understanding Portability of a High-Level Programming Model on Contemporary Heterogeneous Architectures

DOE PAGES

Sabne, Amit J.; Sakdhnagool, Putt; Lee, Seyong; ...

2015-07-13

Accelerator-based heterogeneous computing is gaining momentum in the high-performance computing arena. However, the increased complexity of heterogeneous architectures demands more generic, high-level programming models. OpenACC is one such attempt to tackle this problem. Although the abstraction provided by OpenACC offers productivity, it raises questions concerning both functional and performance portability. In this article, the authors propose HeteroIR, a high-level, architecture-independent intermediate representation, to map high-level programming models, such as OpenACC, to heterogeneous architectures. They present a compiler approach that translates OpenACC programs into HeteroIR and accelerator kernels to obtain OpenACC functional portability. They then evaluate the performance portability obtained bymore » OpenACC with their approach on 12 OpenACC programs on Nvidia CUDA, AMD GCN, and Intel Xeon Phi architectures. They study the effects of various compiler optimizations and OpenACC program settings on these architectures to provide insights into the achieved performance portability.« less

Development and Applications of Portable Gas Chromatography-Mass Spectrometry for Emergency Responders, the Military, and Law-Enforcement Organizations.

PubMed

Leary, Pauline E; Dobson, Gareth S; Reffner, John A

2016-05-01

Portable gas chromatography-mass spectrometry (GC-MS) systems are being deployed for field use, and are designed with this goal in mind. Performance characteristics of instruments that are successful in the field are different from those of equivalent technologies that are successful in a laboratory setting. These field-portable systems are extending the capabilities of the field user, providing investigative leads and confirmatory identifications in real time. Many different types of users benefit from the availability of this technology including emergency responders, the military, and law-enforcement organizations. This manuscript describes performance characteristics that are important for field-portable instruments, especially field-portable GC-MS systems, and demonstrates the value of this equipment to the disciplines of explosives investigations, fire investigations, and counterfeit-drug detection. This paper describes the current state of portable GC-MS technology, including a review of the development of portable GC-MS, as well as a demonstration of the value of this capability using different examples. © The Author(s) 2016.

High performance 3D adaptive filtering for DSP based portable medical imaging systems

NASA Astrophysics Data System (ADS)

Bockenbach, Olivier; Ali, Murtaza; Wainwright, Ian; Nadeski, Mark

2015-03-01

Portable medical imaging devices have proven valuable for emergency medical services both in the field and hospital environments and are becoming more prevalent in clinical settings where the use of larger imaging machines is impractical. Despite their constraints on power, size and cost, portable imaging devices must still deliver high quality images. 3D adaptive filtering is one of the most advanced techniques aimed at noise reduction and feature enhancement, but is computationally very demanding and hence often cannot be run with sufficient performance on a portable platform. In recent years, advanced multicore digital signal processors (DSP) have been developed that attain high processing performance while maintaining low levels of power dissipation. These processors enable the implementation of complex algorithms on a portable platform. In this study, the performance of a 3D adaptive filtering algorithm on a DSP is investigated. The performance is assessed by filtering a volume of size 512x256x128 voxels sampled at a pace of 10 MVoxels/sec with an Ultrasound 3D probe. Relative performance and power is addressed between a reference PC (Quad Core CPU) and a TMS320C6678 DSP from Texas Instruments.

SVGA and XGA LCOS microdisplays for HMD applications

NASA Astrophysics Data System (ADS)

Bolotski, Michael; Alvelda, Phillip

1999-07-01

MicroDisplay liquid crystal on silicon (LCOS) display devices are based on a combination of technologies combined with the extreme integration capability of conventionally fabricated CMOS substrates. Two recent SVGA (800 X 600) pixel resolution designs were demonstrated based on 10 micron and 12.5-micron pixel pitch architectures. The resulting microdisplays measure approximately 10 mm and 12 mm in diagonal respectively. Further, an XGA (1024 X 768) resolution display fabricated with a 12.5-micron pixel pitch with a 16-mm diagonal was also demonstrated. Both the larger SVGA and the XGA design were based on the same 12.5-micron pixel-pitch design, demonstrating a quickly scalable design architecture for rapid prototyping life-cycles. All three microdisplay designs described above function in grayscale and high-performance Field-Sequential-Color (FSC) operating modes. The fast liquid crystal operating modes and new scalable high- performance pixel addressing architectures presented in this paper enable substantially improved color, contrast, and brightness while still satisfying the optical, packaging, and power requirements of portable commercial and defense applications including ultra-portable helmet, eyeglass, and heat-mounted systems. The entire suite of The MicroDisplay Corporation's technologies was devised to create a line of mixed-signal application-specific integrated circuits (ASIC) in single-chip display systems. Mixed-signal circuits can integrate computing, memory, and communication circuitry on the same substrate as the display drivers and pixel array for a multifunctional complete system-on-a-chip. For helmet and head-mounted displays this can include capabilities such as the incorporation of customized symbology and information storage directly on the display substrate. System-on-a-chip benefits also include reduced head supported weight requirements through the elimination of off-chip drive electronics.

Improving Driver Performance. A Curriculum for Licensed Drivers.

ERIC Educational Resources Information Center

Highway Users Federation for Safety and Mobility, Washington, DC.

Curriculum material presented in this manual is for use in the development of an instructional program for drivers who either want or need to improve their driving performance. Three principal units are included: man and highway transportation, driver performance, and factors influencing driver behavior. Each unit is further divided into episodes…

Note: A portable pulsed neutron source based on the smallest sealed-type plasma focus device.

PubMed

Niranjan, Ram; Rout, R K; Mishra, Prabhat; Srivastava, Rohit; Rawool, A M; Kaushik, T C; Gupta, Satish C

2011-02-01

Development and operation of a portable and compact pulsed neutron source based on sealed-type plasma focus (PF) device are reported. The unit is the smallest sealed-type neutron producing PF device. The effective volume of the PF unit is 33 cm(3) only. A compact size single capacitor (4 μF) is used as the energy driver. A battery based power supply unit is used for charging the capacitor and triggering the spark gap. The PF unit is operated at 10 kV (200 J) and at a deuterium gas filling pressure of 8 mb. The device is operated over a time span of 200 days and the neutron emissions have been observed for 200 shots without changing the gas in between the shots. The maximum yield of this device is 7.8 × 10(4) neutrons/pulse. Beyond 200 shots the yield is below the threshold (1050 neutrons/pulse) of our (3)He detector. The neutron energy is evaluated using time of flight technique and the value is (2.49 ± 0.27) MeV. The measured neutron pulse width is (24 ± 5) ns. Multishot and long duration operations envisage the potentiality of such portable device for repetitive mode of operation.

Decline of the performance of a portable axial-flow fan due to the friction and duct bending loss of a connected flexible duct.

PubMed

Ojima, Jun

2017-03-28

In a job site, a portable fan is often used to ventilate a confined space. When a portable fan is applied to such a space, the actual ventilation flow rate must be accurately estimated in advance because the safety level of contaminant and oxygen concentrations in the space will determine the ventilation requirements. When a portable fan is used with a flexible duct, the actual flow rate of the fan decreases due to the friction and duct bending loss of the duct. Intending to show the decline of a fan performance, the author conducted laboratory experiments and reported the quantitative effect of the friction and duct bending loss of a flexible duct to the flow rate of a portable fan. Four commercial portable fans of different specifications were procured for the experiments, and the decline of the performance of each portable fan due to the friction loss etc. of a connected flexible duct was investigated by measuring actual flow rate. The flow rate showed an obvious decrease from the rated flow rate when a flexible duct was connected. Connection of a straight polyester flexible duct and a straight aluminum flexible duct reduced the flow rates to 81.2 - 52.9% and less than 50%, respectively. The flow rate decreased with an increase of the bend angle of the flexible duct. It is recommended that flow rate check of a portable fan should be diligently carried out in every job site.

Shoulder-elbow exoskeleton as rehabilitation exerciser

NASA Astrophysics Data System (ADS)

Ianoşi, A.; Dimitrova, A.; Noveanu, S.; Tătar, O. M.; Mândru, D. S.

2016-08-01

This paper presents a 2 degree of freedom exoskeleton designed for the rehabilitation of the shoulder and elbow movement in the sagittal plane; a semi-portable design strategy was chosen, which enables an easy attachment to a standard medical chair as well as the patient upper limb. A dedicated driver enables the control from a graphical user interface, which also provides the option of customized rehabilitation exercises. The potential of future improvements is assessed, and recommendations of research direction are made in order to broaden the usability of the proposed device.

Monolithic device for modelocking and stabilization of frequency combs.

PubMed

Lee, C-C; Hayashi, Y; Silverman, K L; Feldman, A; Harvey, T; Mirin, R P; Schibli, T R

2015-12-28

We demonstrate a device that integrates a III-V semiconductor saturable absorber mirror with a graphene electro-optic modulator, which provides a monolithic solution to modelocking and noise suppression in a frequency comb. The device offers a pure loss modulation bandwidth exceeding 5 MHz and only requires a low voltage driver. This hybrid device provides not only compactness and simplicity in laser cavity design, but also small insertion loss, compared to the previous metallic-mirror-based modulators. We believe this work paves the way to portable and fieldable phase-coherent frequency combs.

Basic linear algebra subprograms for FORTRAN usage

NASA Technical Reports Server (NTRS)

Lawson, C. L.; Hanson, R. J.; Kincaid, D. R.; Krogh, F. T.

1977-01-01

A package of 38 low level subprograms for many of the basic operations of numerical linear algebra is presented. The package is intended to be used with FORTRAN. The operations in the package are dot products, elementary vector operations, Givens transformations, vector copy and swap, vector norms, vector scaling, and the indices of components of largest magnitude. The subprograms and a test driver are available in portable FORTRAN. Versions of the subprograms are also provided in assembly language for the IBM 360/67, the CDC 6600 and CDC 7600, and the Univac 1108.

Commercial Truck Driver Health and Safety: Exploring Distracted Driving Performance and Self-Reported Driving Skill.

PubMed

Stavrinos, Despina; Heaton, Karen; Welburn, Sharon C; McManus, Benjamin; Griffin, Russell; Fine, Philip R

2016-08-01

Reducing distracters detrimental to commercial truck driving is a critical component of improving the safety performance of commercial drivers, and makes the highways safer for all drivers. This study used a driving simulator to examine effects of cell phone, texting, and email distractions as well as self-reported driver optimism bias on the driving performance of commercial truck drivers. Results revealed that more visually demanding tasks were related to poorer driving performance. However, the cell phone task resulted in less off-the-road eye glances. Drivers reporting being "very skilled" displayed poorer driving performance than those reporting being "skilled." Onboard communication devices provide a practical, yet visually and manually demanding, solution for connecting drivers and dispatchers. Trucking company policies should minimize interaction between dispatchers and drivers when the truck is in motion. Training facilities should integrate driving simulators into the instruction of commercial drivers, targeting over-confident drivers. © 2016 The Author(s).

Using shadow page cache to improve isolated drivers performance.

PubMed

Zheng, Hao; Dong, Xiaoshe; Wang, Endong; Chen, Baoke; Zhu, Zhengdong; Liu, Chengzhe

2015-01-01

With the advantage of the reusability property of the virtualization technology, users can reuse various types and versions of existing operating systems and drivers in a virtual machine, so as to customize their application environment. In order to prevent users' virtualization environments being impacted by driver faults in virtual machine, Chariot examines the correctness of driver's write operations by the method of combining a driver's write operation capture and a driver's private access control table. However, this method needs to keep the write permission of shadow page table as read-only, so as to capture isolated driver's write operations through page faults, which adversely affect the performance of the driver. Based on delaying setting frequently used shadow pages' write permissions to read-only, this paper proposes an algorithm using shadow page cache to improve the performance of isolated drivers and carefully study the relationship between the performance of drivers and the size of shadow page cache. Experimental results show that, through the shadow page cache, the performance of isolated drivers can be greatly improved without impacting Chariot's reliability too much.

Using Shadow Page Cache to Improve Isolated Drivers Performance

PubMed Central

Dong, Xiaoshe; Wang, Endong; Chen, Baoke; Zhu, Zhengdong; Liu, Chengzhe

2015-01-01

With the advantage of the reusability property of the virtualization technology, users can reuse various types and versions of existing operating systems and drivers in a virtual machine, so as to customize their application environment. In order to prevent users' virtualization environments being impacted by driver faults in virtual machine, Chariot examines the correctness of driver's write operations by the method of combining a driver's write operation capture and a driver's private access control table. However, this method needs to keep the write permission of shadow page table as read-only, so as to capture isolated driver's write operations through page faults, which adversely affect the performance of the driver. Based on delaying setting frequently used shadow pages' write permissions to read-only, this paper proposes an algorithm using shadow page cache to improve the performance of isolated drivers and carefully study the relationship between the performance of drivers and the size of shadow page cache. Experimental results show that, through the shadow page cache, the performance of isolated drivers can be greatly improved without impacting Chariot's reliability too much. PMID:25815373

Portable monitoring for the diagnosis of obstructive sleep apnea.

PubMed

Collop, Nancy A

2008-11-01

The demand for expedient diagnosis of suspected obstructive sleep apnea (OSA) has increased due to improved awareness of sleep disorders. Polysomnography (PSG) is the current preferred diagnostic modality but is relatively inconvenient, expensive and inefficient. Portable monitoring has been developed and is widely used in countries outside the United States as an alternative approach. A portable monitor records fewer physiologic variables but is typically unattended and can be performed in the home. Numerous portable monitor studies have been performed over the past two to three decades. The US government and medical societies have extensively reviewed this literature several times in an attempt to determine if portable monitoring should be more broadly used for diagnosing OSA. In March 2008, the US Centers for Medicare and Medicaid Services released a statement allowing the use of portable monitoring to diagnose OSA and prescribe continuous positive airway pressure. This has potentially opened the door for more widespread use of these devices. This review will focus on the literature that has examined portable monitoring as a diagnostic tool for OSA. It is anticipated that portable monitoring as a diagnostic modality for OSA will be used more frequently in the United States following the Centers for Medicare and Medicaid Services ruling. Physicians and others considering the use of portable monitors should thoroughly understand the advantages and limitations of this technology.

Does early training improve driving skills of young novice French drivers?

PubMed

Freydier, Chloé; Berthelon, Catherine; Bastien-Toniazzo, Mireille

2016-11-01

The aim of this research was to study drivers' performances and divided attention depending on their initial training. The performances of young novice drivers who received early training, traditionally trained drivers and more experienced drivers were compared during a dual task consisting of a simulated car-following task and a number' parity judgment task. It was expected that, due to their limited driving experience, the young novice drivers would have more difficulty in adequately distributing their attention between the two tasks. Poorer performances by novice drivers than experienced drivers were therefore expected. The results indicate that traditionally trained drivers had more difficulties in speed regulation and maintaining their position in the lane than drivers with early training and experienced drivers. Performance impairment linked to driving inexperience was also found in the secondary task. The results were interpreted regarding the attentional resources involved in driving with a secondary task and supported the positive effects of French early training. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of the performance of portable precast concrete traffic barriers.

DOT National Transportation Integrated Search

1978-01-01

The portable precast concrete traffic barrier is used to separate high speed vehicular traffic and construction activities. However, since there was a lack of information on the barrier's performance in a construction zone environment, officials of t...

The reaction times of drivers aged 20 to 80 during a divided attention driving.

PubMed

Svetina, Matija

2016-11-16

Many studies addressing age-related changes in driving performance focus on comparing young vs. older drivers, which might lead to the biased conclusion that driving performance decreases only after the age of 65. The main aim of the study was to show that changes in driving performance are progressive throughout the adult years. A sample of 351 drivers aged 20 to 80 was assessed for their reaction times while driving between road cones. The drivers were exposed to 2 conditions varying according to task complexity. In single task conditions, the drivers performed a full stopping maneuver at a given signal; in dual task conditions, the drivers were distracted before the signal for stopping maneuver was triggered. Reaction times were compared across conditions and age groups. The results showed that both reaction times and variability of driving performance increased progressively between the ages of 20 and 80. The increase in both reaction times and variability was greater in the complex task condition. The high-performing quarter of elderly drivers performed equally well or better than younger drivers did. The data clearly supported the claim that driving performance changes steadily across age groups: both mean reaction time and interindividual variability progressively increase with age. In addition, a significant group of older drivers was identified who did not show the expected age-related decrease in performance. The findings have important implications, suggesting that in relation to driving, aging is a progressive phenomenon and may lead to variety of driving performance; age-related studies of driving performance should put more emphasis on investigating changes across the whole driver age range rather than only comparing younger and older drivers.

Portable head computed tomography scanner--technology and applications: experience with 3421 scans.

PubMed

Carlson, Andrew P; Yonas, Howard

2012-10-01

The use of head computed tomography (CT) is standard in the management of acute brain injury; however, there are inherent risks of transport of critically ill patients. Portable CT can be brought to the patient at any location. We describe the clinical use of a portable head CT scanner (CereTom: NeuroLogica: Danvers, MA) that can be brought to the patient's bedside or to other locations such as the operating room or angiography suite. Between June of 2006 and December of 2009, a total of 3421 portable CTs were performed. A total of 3278 (95.8%) were performed in the neuroscience intensive care unit (ICU) for an average of 2.6 neuroscience ICU CT scans per day. Other locations where CTs were performed included other ICUs (n = 97), the operating room (n = 53), the emergency department (n = 1), and the angiography suite (n = 2). Most studies were non-contrasted head CT, though other modalities including xenon/CT, contrasted CT, and CT angiography were performed. Portable head CT can reliably and consistently be performed at the patient's bedside. This should lead to decreased transportation-related morbidity and improved rapid decision making in the ICU, OR, and other locations. Further studies to confirm this clinical advantage are needed. Copyright © 2011 by the American Society of Neuroimaging.

GryphSens: A Smartphone-Based Portable Diagnostic Reader for the Rapid Detection of Progesterone in Milk

PubMed Central

Jang, Hyunwook; Ahmed, Syed Rahin; Neethirajan, Suresh

2017-01-01

Enzyme-linked immunosorbent assay (ELISA) is a popular assay technique for the detection and quantification of various biological substances due its high sensitivity and specificity. More often, it requires large and expensive laboratory instruments, which makes it difficult to conduct when the tests must be performed quickly at the point-of-care (POC). To increase portability and ease of use, we propose a portable diagnostic system based on a Raspberry Pi imaging sensor for the rapid detection of progesterone in milk samples. We designed, assembled, and tested a standalone portable diagnostic reader and validated it for progesterone detection against a standard ELISA assay using a commercial plate reader. The portable POC device yielded consistent results, regardless of differences in the cameras and flashlights between various smartphone devices. An Android application was built to provide front-end access to users, control the diagnostic reader, and display and store the progesterone measurement on the smartphone. The diagnostic reader takes images of the samples, reads the pixel values, processes the results, and presents the results on the handheld device. The proposed POC reader can perform to superior levels of performance as a plate reader, while adding the desirable qualities of portability and ease of use. PMID:28489036

GryphSens: A Smartphone-Based Portable Diagnostic Reader for the Rapid Detection of Progesterone in Milk.

PubMed

Jang, Hyunwook; Ahmed, Syed Rahin; Neethirajan, Suresh

2017-05-10

Enzyme-linked immunosorbent assay (ELISA) is a popular assay technique for the detection and quantification of various biological substances due its high sensitivity and specificity. More often, it requires large and expensive laboratory instruments, which makes it difficult to conduct when the tests must be performed quickly at the point-of-care (POC). To increase portability and ease of use, we propose a portable diagnostic system based on a Raspberry Pi imaging sensor for the rapid detection of progesterone in milk samples. We designed, assembled, and tested a standalone portable diagnostic reader and validated it for progesterone detection against a standard ELISA assay using a commercial plate reader. The portable POC device yielded consistent results, regardless of differences in the cameras and flashlights between various smartphone devices. An Android application was built to provide front-end access to users, control the diagnostic reader, and display and store the progesterone measurement on the smartphone. The diagnostic reader takes images of the samples, reads the pixel values, processes the results, and presents the results on the handheld device. The proposed POC reader can perform to superior levels of performance as a plate reader, while adding the desirable qualities of portability and ease of use.

Occupation exposed to road-traffic emissions and respiratory health among Congolese transit workers, particularly bus conductors, in Kinshasa: a cross-sectional study.

PubMed

Mbelambela, Etongola Papy; Hirota, Ryoji; Eitoku, Masamitsu; Muchanga, Sifa Marie Joelle; Kiyosawa, Hidenori; Yasumitsu-Lovell, Kahoko; Lawanga, Ontshick Leader; Suganuma, Narufumi

2017-03-20

Road-traffic emissions (RTE) induce adverse health effects, notably respiratory symptoms and respiratory diseases, as a result of pollutants deposited into the respiratory tract. The aim of this study was to evaluate the association between occupation groups of Congolese transit workers exposed to RTE, particularly bus conductors and respiratory health, in Kinshasa. A cross-sectional study was conducted from 2015 April 20 th to May 14 th , whose participants were bus conductors (n = 110), bus drivers (n = 107), taxi-motorcyclists (n = 102) and high school teachers (control group; n = 106). Subjects had completed the American Thoracic Society respiratory symptom questionnaire. Lung function test was performed by spirometry. Air pollutants levels of PM 2.5 , NO 2 and SO 2 were measured between 7:30 and 8:30 and 16:30-17:30 using a portable gas monitor. Multivariate analysis was performed to evaluate the association between occupation exposed to RTE and impaired pulmonary function, after adjustment by plausible confounders. The prevalence of mixed syndrome was 21.9% for bus conductors, 10.9% for bus drivers, 15.4% for taxi-motorcyclists and 7.1% for high school teachers with (p < 0.05). The risk of developing a mixed syndrome was seven times higher among bus conductors [OR = 7.64; 95% CI: 1.83-31.67; p < 0.05] than other groups. Additionally, the prevalence of respiratory syndromes increased with the duration of exposure. Occupation exposed to RTE is associated with impaired pulmonary function and the prevalence of respiratory symptoms among transit workers, especially bus conductors. Furthermore, this association increases with the duration of exposure suggesting the necessity to regulate these categories of occupations and to apply preventives measures.

The Influence of Motion Cues on Driver-Vehicle Performance in a Simulator

NASA Technical Reports Server (NTRS)

Repa, B. S.; Leucht, P. M.; Wierwille, W. W.

1981-01-01

Four different motion base configurations were studied on driving simulator. Differently responding vehicles were simulated on each motion configurations and the effects of the vehicle characteristics on driver vehicle system performance, driver control activity, and driver opinion ratings of vehicle performance during driving are compared for different motion configurations. Data show that: (1)) the effects of changes in vehicle characteristics on the different objective and subjective measures of driver vehicle performance are not disguised by the lack of physical motion; (2) fixed base simulator can be used to draw inferences despite the lack of motion; (3) the presence of motion tends to reduce path keeping errors and driver control activity; (4) roll and yaw motions are recommended because of their marked influence on driver vehicle performance (5) the importance of motion increases as the driving maneuvers become more extreme.

Towards large-scale data analysis: challenges in the design of portable systems and use of Cloud computing.

PubMed

Diaz, Javier; Arrizabalaga, Saioa; Bustamante, Paul; Mesa, Iker; Añorga, Javier; Goya, Jon

2013-01-01

Portable systems and global communications open a broad spectrum for new health applications. In the framework of electrophysiological applications, several challenges are faced when developing portable systems embedded in Cloud computing services. In order to facilitate new developers in this area based on our experience, five areas of interest are presented in this paper where strategies can be applied for improving the performance of portable systems: transducer and conditioning, processing, wireless communications, battery and power management. Likewise, for Cloud services, scalability, portability, privacy and security guidelines have been highlighted.

Real-time 3D adaptive filtering for portable imaging systems

NASA Astrophysics Data System (ADS)

Bockenbach, Olivier; Ali, Murtaza; Wainwright, Ian; Nadeski, Mark

2015-03-01

Portable imaging devices have proven valuable for emergency medical services both in the field and hospital environments and are becoming more prevalent in clinical settings where the use of larger imaging machines is impractical. 3D adaptive filtering is one of the most advanced techniques aimed at noise reduction and feature enhancement, but is computationally very demanding and hence often not able to run with sufficient performance on a portable platform. In recent years, advanced multicore DSPs have been introduced that attain high processing performance while maintaining low levels of power dissipation. These processors enable the implementation of complex algorithms like 3D adaptive filtering, improving the image quality of portable medical imaging devices. In this study, the performance of a 3D adaptive filtering algorithm on a digital signal processor (DSP) is investigated. The performance is assessed by filtering a volume of size 512x256x128 voxels sampled at a pace of 10 MVoxels/sec.

ENVIRONMENTAL TECHNOLOGY VERFICATION REPORT - FIELD PORTABLE X-RAY FLUORESCENCE ANALYZER - TN SPECTRACE, TN 9000 AND TN PB FIELD PORTABLE X-RAY FLOURESCENCE ANALYZERS

EPA Science Inventory

In April 1995, the U.S. Environmental Protection Agency (EPA) sponsored a demonstration of field portable X-ray fluorescence (FPXRF) analyzers. The primary objectives of this demonstration were to evaluate these analyzers for: (1) their analytical performance relative to standar...

75 FR 47036 - Small Business Size Standards: Waiver of the Nonmanufacturer Rule

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-04

... Spectrometry (CS-MS) Systems, High Performance Liquid Chromatography (HPLC) Systems, Gas Chromatography Mass...-portable CS-MS, HPLC, GC-MS, and, ICP-MS Laboratory Equipment under PSC 6640 (Laboratory Equipment and...-portable equipment, SBA is limiting the waiver to not-portable CS-MS Systems, HPLC Systems, GC-MS Systems...

Quantitative determinations using portable Raman spectroscopy.

PubMed

Navin, Chelliah V; Tondepu, Chaitanya; Toth, Roxana; Lawson, Latevi S; Rodriguez, Jason D

2017-03-20

A portable Raman spectrometer was used to develop chemometric models to determine percent (%) drug release and potency for 500mg ciprofloxacin HCl tablets. Parallel dissolution and chromatographic experiments were conducted alongside Raman experiments to assess and compare the performance and capabilities of portable Raman instruments in determining critical drug attributes. All batches tested passed the 30min dissolution specification and the Raman model for drug release was able to essentially reproduce the dissolution profiles obtained by ultraviolet spectroscopy at 276nm for all five batches of the 500mg ciprofloxacin tablets. The five batches of 500mg ciprofloxacin tablets also passed the potency (assay) specification and the % label claim for the entire set of tablets run were nearly identical, 99.4±5.1 for the portable Raman method and 99.2±1.2 for the chromatographic method. The results indicate that portable Raman spectrometers can be used to perform quantitative analysis of critical product attributes of finished drug products. The findings of this study indicate that portable Raman may have applications in the areas of process analytical technology and rapid pharmaceutical surveillance. Published by Elsevier B.V.

Outsourcing Security Services for Low Performance Portable Devices

NASA Astrophysics Data System (ADS)

Szentgyörgyi, Attila; Korn, András

The number of portable devices using wireless network technologies is on the rise. Some of these devices are incapable of, or at a disadvantage at using secure Internet services, because secure communication often requires comparatively high computing capacity. In this paper, we propose a solution which can be used to offer secure network services for low performance portable devices without severely degrading data transmission rates. We also show that using our approach these devices can utilize some secure network services which were so far unavailable to them due to a lack of software support. In order to back up our claims, we present performance measurement results obtained in a test network.

Kokkos: Enabling manycore performance portability through polymorphic memory access patterns

DOE PAGES

Carter Edwards, H.; Trott, Christian R.; Sunderland, Daniel

2014-07-22

The manycore revolution can be characterized by increasing thread counts, decreasing memory per thread, and diversity of continually evolving manycore architectures. High performance computing (HPC) applications and libraries must exploit increasingly finer levels of parallelism within their codes to sustain scalability on these devices. We found that a major obstacle to performance portability is the diverse and conflicting set of constraints on memory access patterns across devices. Contemporary portable programming models address manycore parallelism (e.g., OpenMP, OpenACC, OpenCL) but fail to address memory access patterns. The Kokkos C++ library enables applications and domain libraries to achieve performance portability on diversemore » manycore architectures by unifying abstractions for both fine-grain data parallelism and memory access patterns. In this paper we describe Kokkos’ abstractions, summarize its application programmer interface (API), present performance results for unit-test kernels and mini-applications, and outline an incremental strategy for migrating legacy C++ codes to Kokkos. Furthermore, the Kokkos library is under active research and development to incorporate capabilities from new generations of manycore architectures, and to address a growing list of applications and domain libraries.« less

NSTX-U Control System Upgrades

DOE PAGES

Erickson, K. G.; Gates, D. A.; Gerhardt, S. P.; ...

2014-06-01

The National Spherical Tokamak Experiment (NSTX) is undergoing a wealth of upgrades (NSTX-U). These upgrades, especially including an elongated pulse length, require broad changes to the control system that has served NSTX well. A new fiber serial Front Panel Data Port input and output (I/O) stream will supersede the aging copper parallel version. Driver support for the new I/O and cyber security concerns require updating the operating system from Redhat Enterprise Linux (RHEL) v4 to RedHawk (based on RHEL) v6. While the basic control system continues to use the General Atomics Plasma Control System (GA PCS), the effort to forwardmore » port the entire software package to run under 64-bit Linux instead of 32-bit Linux included PCS modifications subsequently shared with GA and other PCS users. Software updates focused on three key areas: (1) code modernization through coding standards (C99/C11), (2) code portability and maintainability through use of the GA PCS code generator, and (3) support of 64-bit platforms. Central to the control system upgrade is the use of a complete real time (RT) Linux platform provided by Concurrent Computer Corporation, consisting of a computer (iHawk), an operating system and drivers (RedHawk), and RT tools (NightStar). Strong vendor support coupled with an extensive RT toolset influenced this decision. The new real-time Linux platform, I/O, and software engineering will foster enhanced capability and performance for NSTX-U plasma control.« less

Implementation of the VGM Graphics System on the PDP-11/50 under the RSX-11M Operating System and Construction of a Compatible Software Driver for the Ramtek RM-9400.

DTIC Science & Technology

1982-06-01

no other. is the field of computer grapnIcs expanded, such limitations became a real liability. The inability to use one program at more tnan one...terms of these environmental factors. For example, some programs may be portable from one device to another as long as the computing environment is not...PemPOMMIN OROANI&ATIO NAMI AND A00RESS IQ. PROGRAM CLEMENT. PROJECT. TASK AREA a WORK UNiT muN9ERS Naval Postgraduate School Monterey, California 93940

Distracted pedestrian sustains orbital fracture while on cell phone.

PubMed

Edell, Aimée R; Jung, Jesse J; Solomon, Joel M; Palu, Richard N

2013-01-01

Use of cell phones in the general population has become increasingly commonplace. The distracting effects of cell phones among automobile drivers are well established, and legislation prohibits the use of handheld cell phones while driving in several states. Recent research has focused on the similar distracting effects of cell phones in the pedestrian population. In this report, an older gentleman suffered extensive facial trauma requiring surgery as a direct effect of cell phone use at the time the trauma occurred. This case highlights the role that portable electronic devices can play as a cause of ocular trauma.

The Safety Performance of Passenger Carrier Drivers

DOT National Transportation Integrated Search

2012-12-01

This paper examines the safety performance of passenger carrier drivers. Special emphasis is given to the motorcoach segment. A model that investigates the contribution of driver factors on the number of State-reportable crashes in which the driver w...

New Applications of Portable Raman Spectroscopy in Agri-Bio-Photonics

NASA Astrophysics Data System (ADS)

Voronine, Dmitri; Scully, Rob; Sanders, Virgil

2014-03-01

Modern optical techniques based on Raman spectroscopy are being used to monitor and analyze the health of cattle, crops and their natural environment. These optical tools are now available to perform fast, noninvasive analysis of live animals and plants in situ. We will report new applications of a portable handheld Raman spectroscopy to identification and taxonomy of plants. In addition, detection of organic food residues will be demonstrated. Advantages and limitations of current portable instruments will be discussed with suggestions for improved performance by applying enhanced Raman spectroscopic schemes.

A Study of Truck Drivers and Their Job Performance Regarding Highway Safety

ERIC Educational Resources Information Center

Nafukho, Fredrick M.; Hinton, Barbara E.; Graham, Carroll M.

2007-01-01

Limited research has addressed the issue of truck drivers and their performance regarding highway safety in terms of reduced number of crashes per driver. The primary purpose of this study was to determine how tractor trailer truck drivers' job performance could be improved while at the same time ensuring increased revenue for the transportation…

Performance evaluation of the Puritan-Bennett Crew-member portable protective breathing device as prescribed by portions of FAA Action Notice A-8150.2.

DOT National Transportation Integrated Search

1989-05-01

This study was undertaken, on request, to evaluate the performance of the Puritan-Bennett portable crew protective breathing device for contaminant leaks. O2, CO2 levels, inhalation/exhalation pressure, and inhalation temperature. Tests were conducte...

Association between unsafe driving performance and cognitive-perceptual dysfunction in older drivers.

PubMed

Park, Si-Woon; Choi, Eun Seok; Lim, Mun Hee; Kim, Eun Joo; Hwang, Sung Il; Choi, Kyung-In; Yoo, Hyun-Chul; Lee, Kuem Ju; Jung, Hi-Eun

2011-03-01

To find an association between cognitive-perceptual problems of older drivers and unsafe driving performance during simulated automobile driving in a virtual environment. Cross-sectional study. A driver evaluation clinic in a rehabilitation hospital. Fifty-five drivers aged 65 years or older and 48 drivers in their late twenties to early forties. All participants underwent evaluation of cognitive-perceptual function and driving performance, and the results were compared between older and younger drivers. The association between cognitive-perceptual function and driving performance was analyzed. Cognitive-perceptual function was evaluated with the Cognitive Perceptual Assessment for Driving (CPAD), a computer-based assessment tool consisting of depth perception, sustained attention, divided attention, the Stroop test, the digit span test, field dependency, and trail-making test A and B. Driving performance was evaluated with use of a virtual reality-based driving simulator. During simulated driving, car crashes were recorded, and an occupational therapist observed unsafe performances in controlling speed, braking, steering, vehicle positioning, making lane changes, and making turns. Thirty-five older drivers did not pass the CPAD test, whereas all of the younger drivers passed the test. When using the driving simulator, a significantly greater number of older drivers experienced car crashes and demonstrated unsafe performance in controlling speed, steering, and making lane changes. CPAD results were associated with car crashes, steering, vehicle positioning, and making lane changes. Older drivers who did not pass the CPAD test are 4 times more likely to experience a car crash, 3.5 times more likely to make errors in steering, 2.8 times more likely to make errors in vehicle positioning, and 6.5 times more likely to make errors in lane changes than are drivers who passed the CPAD test. Unsafe driving performance and car crashes during simulated driving were more prevalent in older drivers than in younger drivers. Unsafe performance in steering, vehicle positioning, making lane changes, and car crashes were associated with cognitive-perceptual dysfunction. Copyright © 2011 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

671-nm microsystem diode laser based on portable Raman sensor device for in-situ identification of meat spoilage

NASA Astrophysics Data System (ADS)

Sowoidnich, Kay; Schmidt, Heinar; Schwägele, Fredi; Kronfeldt, Heinz-Detlef

2011-05-01

Based on a miniaturized optical bench with attached 671 nm microsystem diode laser we present a portable Raman system for the rapid in-situ characterization of meat spoilage. It consists of a handheld sensor head (dimensions: 210 x 240 x 60 mm3) for Raman signal excitation and collection including the Raman optical bench, a laser driver, and a battery pack. The backscattered Raman radiation from the sample is analyzed by means of a custom-designed miniature spectrometer (dimensions: 200 x 190 x 70 mm3) with a resolution of 8 cm-1 which is fiber-optically coupled to the sensor head. A netbook is used to control the detector and for data recording. Selected cuts from pork (musculus longissimus dorsi and ham) stored refrigerated at 5 °C were investigated in timedependent measurement series up to three weeks to assess the suitability of the system for the rapid detection of meat spoilage. Using a laser power of 100 mW at the sample meat spectra can be obtained with typical integration times of 5 - 10 seconds. The complex spectra were analyzed by the multivariate statistical tool PCA (principal components analysis) to determine the spectral changes occurring during the storage period. Additionally, the Raman data were correlated with reference analyses performed in parallel. In that way, a distinction between fresh and spoiled meat can be found in the time slot of 7 - 8 days after slaughter. The applicability of the system for the rapid spoilage detection of meat and other food products will be discussed.

Driver performance and attention allocation in use of logo signs on freeway exit ramps.

PubMed

Zahabi, Maryam; Machado, Patricia; Lau, Mei Ying; Deng, Yulin; Pankok, Carl; Hummer, Joseph; Rasdorf, William; Kaber, David B

2017-11-01

The objective of this research was to quantify the effects of driver age, ramp signage configuration, including number of panels, logo format and sign familiarity, on driver performance and attention allocation when exiting freeways. Sixty drivers participated in a simulator study and analysis of variance models were used to assess response effects of the controlled manipulations. Results revealed elderly drivers to demonstrate worse performance and conservative control strategies as compared to middle-aged and young drivers. Elderly drivers also exhibited lower off-road fixation frequency and shorter off-road glance durations compared to middle-aged and young drivers. In general, drivers adopted a more conservative strategy when exposed to nine-panel signs as compared to six-panel signs and were more accurate in target detection when searching six-panels vs. nine and with familiar vs. unfamiliar logos. These findings provide an applicable guide for agency design of freeway ramp signage accounting for driver demographics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Satellite sound broadcasting system, portable reception

NASA Technical Reports Server (NTRS)

Golshan, Nasser; Vaisnys, Arvydas

1990-01-01

Studies are underway at JPL in the emerging area of Satellite Sound Broadcast Service (SSBS) for direct reception by low cost portable, semi portable, mobile and fixed radio receivers. This paper addresses the portable reception of digital broadcasting of monophonic audio with source material band limited to 5 KHz (source audio comparable to commercial AM broadcasting). The proposed system provides transmission robustness, uniformity of performance over the coverage area and excellent frequency reuse. Propagation problems associated with indoor portable reception are considered in detail and innovative antenna concepts are suggested to mitigate these problems. It is shown that, with the marriage of proper technologies a single medium power satellite can provide substantial direct satellite audio broadcast capability to CONUS in UHF or L Bands, for high quality portable indoor reception by low cost radio receivers.

21 CFR 868.6250 - Portable air compressor.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Identification. A portable air compressor is a device intended to provide compressed air for medical purposes, e.g., to drive ventilators and other respiratory devices. (b) Classification. Class II (performance...

21 CFR 868.6250 - Portable air compressor.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Identification. A portable air compressor is a device intended to provide compressed air for medical purposes, e.g., to drive ventilators and other respiratory devices. (b) Classification. Class II (performance...

Naturalistic distraction and driving safety in older drivers.

PubMed

Aksan, Nazan; Dawson, Jeffrey D; Emerson, Jamie L; Yu, Lixi; Uc, Ergun Y; Anderson, Steven W; Rizzo, Matthew

2013-08-01

In this study, we aimed to quantify and compare performance of middle-aged and older drivers during a naturalistic distraction paradigm (visual search for roadside targets) and to predict older drivers performance given functioning in visual, motor, and cognitive domains. Distracted driving can imperil healthy adults and may disproportionally affect the safety of older drivers with visual, motor, and cognitive decline. A total of 203 drivers, 120 healthy older (61 men and 59 women, ages 65 years and older) and 83 middle-aged drivers (38 men and 45 women, ages 40 to 64 years), participated in an on-road test in an instrumented vehicle. Outcome measures included performance in roadside target identification (traffic signs and restaurants) and concurrent driver safety. Differences in visual, motor, and cognitive functioning served as predictors. Older drivers identified fewer landmarks and drove slower but committed more safety errors than did middle-aged drivers. Greater familiarity with local roads benefited performance of middle-aged but not older drivers.Visual cognition predicted both traffic sign identification and safety errors, and executive function predicted traffic sign identification over and above vision. Older adults are susceptible to driving safety errors while distracted by common secondary visual search tasks that are inherent to driving. The findings underscore that age-related cognitive decline affects older drivers' management of driving tasks at multiple levels and can help inform the design of on-road tests and interventions for older drivers.

The Castle Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tom Anderson; David Culler; James Demmel

2000-02-16

The goal of the Castle project was to provide a parallel programming environment that enables the construction of high performance applications that run portably across many platforms. The authors approach was to design and implement a multilayered architecture, with higher levels building on lower ones to ensure portability, but with care taken not to introduce abstractions that sacrifice performance.

47 CFR 52.26 - NANC Recommendations on Local Number Portability Administration.

Code of Federal Regulations, 2012 CFR

2012-10-01

... perform a database query to determine if the telephone number has been ported to another local exchange carrier, the local exchange carrier may block the unqueried call only if performing the database query is... manage and oversee the local number portability administrators, subject to review by the NANC, but only...

47 CFR 52.26 - NANC Recommendations on Local Number Portability Administration.

Code of Federal Regulations, 2014 CFR

2014-10-01

... perform a database query to determine if the telephone number has been ported to another local exchange carrier, the local exchange carrier may block the unqueried call only if performing the database query is... manage and oversee the local number portability administrators, subject to review by the NANC, but only...

Embedded system of image storage based on fiber channel

NASA Astrophysics Data System (ADS)

Chen, Xiaodong; Su, Wanxin; Xing, Zhongbao; Wang, Hualong

2008-03-01

In domains of aerospace, aviation, aiming, and optic measure etc., the embedded system of imaging, processing and recording is absolutely necessary, which has small volume, high processing speed and high resolution. But the embedded storage technology becomes system bottleneck because of developing slowly. It is used to use RAID to promote storage speed, but it is unsuitable for the embedded system because of its big volume. Fiber channel (FC) technology offers a new method to develop the high-speed, portable storage system. In order to make storage subsystem meet the needs of high storage rate, make use of powerful Virtex-4 FPGA and high speed fiber channel, advance a project of embedded system of digital image storage based on Xilinx Fiber Channel Arbitrated Loop LogiCORE. This project utilizes Virtex- 4 RocketIO MGT transceivers to transmit the data serially, and connects many Fiber Channel hard drivers by using of Arbitrated Loop optionally. It can achieve 400MBps storage rate, breaks through the bottleneck of PCI interface, and has excellences of high-speed, real-time, portable and massive capacity.

Handling properties of diverse automobiles and correlation with full scale response data. [driver/vehicle response to aerodynamic disturbances

NASA Technical Reports Server (NTRS)

Hoh, R. H.; Weir, D. H.

1973-01-01

Driver/vehicle response and performance of a variety of vehicles in the presence of aerodynamic disturbances are discussed. Steering control is emphasized. The vehicles include full size station wagon, sedan, compact sedan, van, pickup truck/camper, and wagon towing trailer. Driver/vehicle analyses are used to estimate response and performance. These estimates are correlated with full scale data with test drivers and the results are used to refine the driver/vehicle models, control structure, and loop closure criteria. The analyses and data indicate that the driver adjusts his steering control properties (when he can) to achieve roughly the same level of performance despite vehicle variations. For the more disturbance susceptible vehicles, such as the van, the driver tightens up his control. Other vehicles have handling dynamics which cause him to loosen his control response, even though performance degrades.

Moving your laboratories to the field – Advantages and limitations of the use of field portable instruments in environmental sample analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gałuszka, Agnieszka, E-mail: Agnieszka.Galuszka@ujk.edu.pl; Migaszewski, Zdzisław M.; Namieśnik, Jacek

The recent rapid progress in technology of field portable instruments has increased their applications in environmental sample analysis. These instruments offer a possibility of cost-effective, non-destructive, real-time, direct, on-site measurements of a wide range of both inorganic and organic analytes in gaseous, liquid and solid samples. Some of them do not require the use of reagents and do not produce any analytical waste. All these features contribute to the greenness of field portable techniques. Several stationary analytical instruments have their portable versions. The most popular ones include: gas chromatographs with different detectors (mass spectrometer (MS), flame ionization detector, photoionization detector),more » ultraviolet–visible and near-infrared spectrophotometers, X-ray fluorescence spectrometers, ion mobility spectrometers, electronic noses and electronic tongues. The use of portable instruments in environmental sample analysis gives a possibility of on-site screening and a subsequent selection of samples for routine laboratory analyses. They are also very useful in situations that require an emergency response and for process monitoring applications. However, quantification of results is still problematic in many cases. The other disadvantages include: higher detection limits and lower sensitivity than these obtained in laboratory conditions, a strong influence of environmental factors on the instrument performance and a high possibility of sample contamination in the field. This paper reviews recent applications of field portable instruments in environmental sample analysis and discusses their analytical capabilities. - Highlights: • Field portable instruments are widely used in environmental sample analysis. • Field portable instruments are indispensable for analysis in emergency response. • Miniaturization of field portable instruments reduces resource consumption. • In situ analysis is in agreement with green analytical chemistry principles. • Performance requirements in field analysis stimulate technological progress.« less

Field comparison of portable and stationary instruments for outdoor urban air exposure assessments

NASA Astrophysics Data System (ADS)

Viana, M.; Rivas, I.; Reche, C.; Fonseca, A. S.; Pérez, N.; Querol, X.; Alastuey, A.; Álvarez-Pedrerol, M.; Sunyer, J.

2015-12-01

The performance of three portable monitors (micro-aethalometer AE51, DiscMini, Dusttrak DRX) was assessed for outdoor air exposure assessment in a representative Southern European urban environment. The parameters evaluated were black carbon, particle number concentration, alveolar lung-deposited surface area, mean particle diameter, PM10, PM2.5 and PM1. The performance was tested by comparison with widely used stationary instruments (MAAP, CPC, SMPS, NSAM, GRIMM aerosol spectrometer). Results evidenced a good agreement between most portable and stationary instruments, with R2 values mostly >0.80. Relative differences between portable and stationary instruments were mostly <20%, and <10% between different units of the same instrument. The only exception was found for the Dusttrak DRX measurements, for which occasional concentration jumps in the time series were detected. Our results validate the performance of the black carbon, particle number concentration, particle surface area and mean particle diameter monitors as indicative instruments (tier 2) for outdoor air exposure assessment studies.

The effect of feedback on attitudes toward cellular phone use while driving: a comparison between novice and experienced drivers.

PubMed

Wang, Ying; Zhang, Wei; Reimer, Bryan; Lavallière, Martin; Lesch, Mary F; Horrey, William J; Wu, Su

2010-10-01

To assess and compare the effectiveness of a simulation-based approach to change drivers' attitudes toward cellular phone use while driving for younger novice and older experienced drivers. Thirty young novice drivers were tested on a driving simulator in this study. Their performance in dealing with driving tasks was measured for a single task and dual tasks (driving while using a cellular phone) and compared to 30 older experienced drivers tested previously in another study. Half of the younger drivers received video-based feedback regarding their performance in the two conditions, with an emphasis on the contribution of dual-tasking to degraded performance. The other half did not receive any performance feedback. Drivers' perceptions and attitudes toward cellular phone use while driving were investigated by a questionnaire before, immediately after, and again one month following the simulation-based testing for both groups of drivers (feedback; no feedback). All drivers (including the novice and experienced) reported willingness to engage in driving and talking on a cellular phone in some situations. The simulated driving test showed that a secondary cellular phone task significantly degraded driving performance for both the novice and the experienced drivers. The feedback treatment group (both the novice and the experienced) showed significant attitude change toward cellular phone use while driving (toward being less favorable), whereas the control group had no attitude change. At the one-month follow-up, the benefit of feedback was sustained more so in the experienced driver group than the novice driver group, although both groups still benefited relative to the control conditions. Simulation-based feedback training is promising for short-term education in novice drivers but may be more effective in the long-term for drivers with higher levels of experience. Drivers with more experience appear to have a greater, more sustained benefit from the training than novices. Additional research is needed to better tailor this education method toward novice drivers. Simulation-based participative education approach through feedback needs to be better tailored toward novice drivers.

Automobile driver on-road performance test. Volume 1, final report

DOT National Transportation Integrated Search

1981-09-30

The Automobile Driver On-Road Performance Test (ADOPT) was developed during a three-phase project. In Phase 1, 51 candidate behaviors were identified and selected with the help of experts in the fields of traffic safety, measurement of driver perform...

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

PubMed

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

2017-08-01

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 participants followed DMV behind-the-wheel training guidelines for earning a driver's license. Participants were assessed pre- and post-training for driving-specific executive function (EF) abilities and tactical driving skills. ASD drivers showed worse baseline EF and driving skills than experienced drivers. At post-assessment, VRDST significantly improved driving and EF performance over RT. This study demonstrated feasibility and potential efficacy of VRDST for novice ASD drivers.

Effects of memory rehearsal on driver performance: experiment and theoretical account.

PubMed

Salvucci, Dario D; Beltowska, Joanna

2008-10-01

We report an experiment and a theoretical analysis concerning the effects of an exclusively cognitive task, specifically a memory rehearsal task, on driver performance. Although recent work on driver distraction has elucidated the sometimes significant effects of cognitive processing on driver performance, these studies have typically mixed cognitive with perceptual and motor processing, making it difficult to isolate the effects of cognitive processing alone. We asked participants to drive in a driving simulator during only the rehearsal stage of a serial-recall memory task while we measured their ability to maintain a central lane position and respond to the illumination of a lead vehicle's brake lights. Memory rehearsal significantly affected drivers' steering performance as measured by lateral deviation from lane center, and it also significantly affected drivers' response time to the braking stimulus for the higher load memory task. These results lend support to a theoretical account of cognitive distraction provided by threaded cognition theory in terms of a cognitive bottleneck in procedural processing, and they also suggest that consideration of task urgency may be important in accounting for performance trade-offs among concurrent tasks. The experiment augments the current understanding of cognitive driver distraction and suggests that even exclusively cognitive secondary tasks may sometimes affect driver performance.

Portable Long-Wavelength Infrared Camera for Civilian Application

NASA Technical Reports Server (NTRS)

Gunapala, S. D.; Krabach, T. N.; Bandara, S. V.; Liu, J. K.

1997-01-01

In this paper, we discuss the performance of this portable long-wavelength infrared camera in quantum efficiency, NEAT, minimum resolvable temperature differnce (MRTD), uniformity, etc. and its application in science, medicine and defense.

A predictive control framework for torque-based steering assistance to improve safety in highway driving

NASA Astrophysics Data System (ADS)

Ercan, Ziya; Carvalho, Ashwin; Tseng, H. Eric; Gökaşan, Metin; Borrelli, Francesco

2018-05-01

Haptic shared control framework opens up new perspectives on the design and implementation of the driver steering assistance systems which provide torque feedback to the driver in order to improve safety. While designing such a system, it is important to account for the human-machine interactions since the driver feels the feedback torque through the hand wheel. The controller should consider the driver's impact on the steering dynamics to achieve a better performance in terms of driver's acceptance and comfort. In this paper we present a predictive control framework which uses a model of driver-in-the-loop steering dynamics to optimise the torque intervention with respect to the driver's neuromuscular response. We first validate the system in simulations to compare the performance of the controller in nominal and model mismatch cases. Then we implement the controller in a test vehicle and perform experiments with a human driver. The results show the effectiveness of the proposed system in avoiding hazardous situations under different driver behaviours.

Driver behavior profiling: An investigation with different smartphone sensors and machine learning

PubMed Central

Ferreira, Jair; Carvalho, Eduardo; Ferreira, Bruno V.; de Souza, Cleidson; Suhara, Yoshihiko; Pentland, Alex

2017-01-01

Driver behavior impacts traffic safety, fuel/energy consumption and gas emissions. Driver behavior profiling tries to understand and positively impact driver behavior. Usually driver behavior profiling tasks involve automated collection of driving data and application of computer models to generate a classification that characterizes the driver aggressiveness profile. Different sensors and classification methods have been employed in this task, however, low-cost solutions and high performance are still research targets. This paper presents an investigation with different Android smartphone sensors, and classification algorithms in order to assess which sensor/method assembly enables classification with higher performance. The results show that specific combinations of sensors and intelligent methods allow classification performance improvement. PMID:28394925

Understanding the role of sleep quality and sleep duration in commercial driving safety.

PubMed

Lemke, Michael K; Apostolopoulos, Yorghos; Hege, Adam; Sönmez, Sevil; Wideman, Laurie

2016-12-01

Long-haul truck drivers in the United States suffer disproportionately high injury rates. Sleep is a critical factor in these outcomes, contributing to fatigue and degrading multiple aspects of safety-relevant performance. Both sleep duration and sleep quality are often compromised among truck drivers; however, much of the efforts to combat fatigue focus on sleep duration rather than sleep quality. Thus, the current study has two objectives: (1) to determine the degree to which sleep impacts safety-relevant performance among long-haul truck drivers; and (2) to evaluate workday and non-workday sleep quality and duration as predictors of drivers' safety-relevant performance. A non-experimental, descriptive, cross-sectional design was employed to collect survey and biometric data from 260 long-haul truck drivers. The Trucker Sleep Disorders Survey was developed to assess sleep duration and quality, the impact of sleep on job performance and accident risk, and other relevant work organization characteristics. Descriptive statistics assessed work organization variables, sleep duration and quality, and frequency of engaging in safety-relevant performance while sleepy. Linear regression analyses were conducted to evaluate relationships between sleep duration, sleep quality, and work organization variables with safety composite variables. Drivers reported long work hours, with over 70% of drivers working more than 11h daily. Drivers also reported a large number of miles driven per week, with an average of 2,812.61 miles per week, and frequent violations of hours-of-service rules, with 43.8% of drivers "sometimes to always" violating the "14-h rule." Sleep duration was longer, and sleep quality was better, on non-workdays compared on workdays. Drivers frequently operated motor vehicles while sleepy, and sleepiness impacted several aspects of safety-relevant performance. Sleep quality was better associated with driving while sleepy and with job performance and concentration than sleep duration. Sleep duration was better associated with accidents and accident risk than sleep quality. Sleep quality appears to be better associated with safety-relevant performance among long-haul truck drivers than sleep duration. Comprehensive and multilevel efforts are needed to meaningfully address sleep quality among drivers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Naturalistic distraction and driving safety in older drivers

PubMed Central

Aksan, Nazan; Dawson, Jeffrey D.; Emerson, Jamie L.; Yu, Lixi; Uc, Ergun Y.; Anderson, Steven W.; Rizzo, Matthew

2013-01-01

Objective This study aimed to quantify and compare performance of middle-aged and older drivers during a naturalistic distraction paradigm (visual search for roadside targets) and predict older driver performance given functioning in visual, motor, and cognitive domains. Background Distracted driving can imperil healthy adults and may disproportionally affect the safety of older drivers with visual, motor, and cognitive decline. Methods Two hundred and three drivers, 120 healthy older (61 men and 59 women, ages 65 years or greater) and 83 middle-aged drivers (38 men and 45 women, ages 40–64 years), participated in an on-road test in an instrumented vehicle. Outcome measures included performance in roadside target identification (traffic signs and restaurants) and concurrent driver safety. Differences in visual, motor, and cognitive functioning served as predictors. Results Older drivers identified fewer landmarks and drove slower but committed more safety errors than middle-aged drivers. Greater familiarity with local roads benefited performance of middle-aged but not older drivers. Visual cognition predicted both traffic sign identification and safety errors while executive function predicted traffic sign identification over and above vision. Conclusion Older adults are susceptible to driving safety errors while distracted by common secondary visual search tasks that are inherent to driving. The findings underscore that age-related cognitive decline affects older driver management of driving tasks at multiple levels, and can help inform the design of on-road tests and interventions for older drivers. PMID:23964422

Portable TXRF Spectrometer with 10{sup -11}g Detection Limit and Portable XRF Spectromicroscope with Sub-mm Spatial Resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kunimura, Shinsuke; Hatakeyama, So; Sasaki, Nobuharu

A portable total reflection X-ray fluorescence (TXRF) spectrometer that we have developed is applied to trace elemental analysis of water solutions. Although a 5 W X-ray tube is used in the portable TXRF spectrometer, detection limits of several ppb are achieved for 3d transition metal elements and trace elements in a leaching solution of soils, a leaching solution of solder, and alcoholic beverages are detected. Portable X-ray fluorescence (XRF) spectromicroscopes with a 1 W X-ray tube and an 8 W X-ray tube are also presented. Using the portable XRF spectromicroscope with the 1 W X-ray tube, 93 ppm of Crmore » is detected with an about 700 {mu}m spatial resolution. Spatially resolved elemental analysis of a mug painted with blue, red, green, and white is performed using the two portable spectromicroscopes, and the difference in elemental composition at each paint is detected.« less

Assessing Cognitive Ability and Simulator-Based Driving Performance in Poststroke Adults

PubMed Central

Falkmer, Torbjörn; Willstrand, Tania Dukic

2017-01-01

Driving is an important activity of daily living, which is increasingly relied upon as the population ages. It has been well-established that cognitive processes decline following a stroke and these processes may influence driving performance. There is much debate on the use of off-road neurological assessments and driving simulators as tools to predict driving performance; however, the majority of research uses unlicensed poststroke drivers, making the comparability of poststroke adults to that of a control group difficult. It stands to reason that in order to determine whether simulators and cognitive assessments can accurately assess driving performance, the baseline should be set by licenced drivers. Therefore, the aim of this study was to assess differences in cognitive ability and driving simulator performance in licensed community-dwelling poststroke drivers and controls. Two groups of licensed drivers (37 poststroke and 43 controls) were assessed using several cognitive tasks and using a driving simulator. The poststroke adults exhibited poorer cognitive ability; however, there were no differences in simulator performance between groups except that the poststroke drivers demonstrated less variability in driver headway. The application of these results as a prescreening toolbox for poststroke drivers is discussed. PMID:28559646

Idaho Driver Education Instructional Guide. Revised.

ERIC Educational Resources Information Center

Idaho State Dept. of Education, Boise.

This driver education instructional safety guide is organized in three sections: Driver Education; Motorcycle Education; and Driver Education for the Handicapped. The driver education section contains 10 units dealing with the following topics: parent orientation; student orientation; basic control skills; driver performance; driving regulations;…

The role of driver age in performance and attention allocation effects of roadway sign count, format and familiarity.

PubMed

Zahabi, Maryam; Machado, Patricia; Pankok, Carl; Lau, Mei Ying; Liao, Yi-Fan; Hummer, Joseph; Rasdorf, William; Kaber, David B

2017-09-01

White-on-blue logo signs are used to inform drivers of food, gas, lodging, and attraction businesses at highway interchanges. In this study, 60 drivers were asked to look for food and attraction targets on logo signs while driving in a realistic freeway simulation. The objective of the study was to quantify effects of the number of sign panels (six vs. nine), logo familiarity (familiar vs. unfamiliar), logo format (text vs. pictorial), and driver age (young, middle, and elderly) on performance, attention allocation and target identification accuracy. Results revealed elderly drivers to exhibit worse performance in comparison to middle-age and young groups even though they adopted a more conservative driving strategy. There was no significant effect of the number of panels, logo familiarity, and logo format on driver performance or attention allocation. In target identification, drivers were more accurate with familiar or text-based panels appearing in six-panel signs. Copyright © 2017 Elsevier Ltd. All rights reserved.

An exploratory study of long-haul truck drivers' secondary tasks and reasons for performing them.

PubMed

Iseland, Tobias; Johansson, Emma; Skoog, Siri; Dåderman, Anna M

2018-08-01

Research on drivers has shown how certain visual-manual secondary tasks, unrelated to driving, increase the risk of being involved in crashes. The purpose of the study was to investigate (1) if long-haul truck drivers in Sweden engage in secondary tasks while driving, what tasks are performed and how frequently, (2) the drivers' self-perceived reason/s for performing them, and (3) if psychological factors might reveal reasons for their engaging in secondary tasks. The study comprised 13 long-haul truck drivers and was conducted through observations, interviews, and questionnaires. The drivers performed secondary tasks, such as work environment related "necessities" (e.g., getting food and/or beverages from the refrigerator/bag, eating, drinking, removing a jacket, face rubbing, and adjusting the seat), interacting with a mobile phone/in-truck technology, and doing administrative tasks. The long-haul truck drivers feel bored and use secondary tasks as a coping strategy to alleviate boredom/drowsiness, and for social interaction. The higher number of performed secondary tasks could be explained by lower age, shorter driver experience, less openness to experience, lower honesty-humility, lower perceived stress, lower workload, and by higher health-related quality of life. These explanatory results may serve as a starting point for further studies on large samples to develop a safer and healthier environment for long-haul truck drivers. Copyright © 2018. Published by Elsevier Ltd.

Blood identification and discrimination between human and nonhuman blood using portable Raman spectroscopy.

PubMed

Fujihara, J; Fujita, Y; Yamamoto, T; Nishimoto, N; Kimura-Kataoka, K; Kurata, S; Takinami, Y; Yasuda, T; Takeshita, H

2017-03-01

Raman spectroscopy is commonly used in chemistry to identify molecular structure. This technique is a nondestructive analysis and needs no sample preparation. Recently, Raman spectroscopy has been shown to be effective as a multipurpose analytical method for forensic applications. In the present study, blood identification and discrimination between human and nonhuman blood were performed by a portable Raman spectrometer, which can be used at a crime scene. To identify the blood and to discriminate between human and nonhuman blood, Raman spectra of bloodstains from 11 species (human, rat, mouse, cow, horse, sheep, pig, rabbit, cat, dog, and chicken) were taken using a portable Raman spectrometer. Raman peaks for blood (742, 1001, 1123, 1247, 1341, 1368, 1446, 1576, and 1619 cm -1 ) could be observed by the portable Raman spectrometer in all 11 species, and the human bloodstain could be distinguished from the nonhuman ones by using a principal component analysis. This analysis can be performed on a bloodstain sample of at least 3 months old. The portable Raman spectrometer can be used at a crime scene, and this analysis is useful for forensic examination.

A Portable, High Resolution, Surface Measurement Device

NASA Technical Reports Server (NTRS)

Ihlefeld, Curtis M.; Burns, Bradley M.; Youngquist, Robert C.

2012-01-01

A high resolution, portable, surface measurement device has been demonstrated to provide micron-resolution topographical plots. This device was specifically developed to allow in-situ measurements of defects on the Space Shuttle Orbiter windows, but is versatile enough to be used on a wide variety of surfaces. This paper discusses the choice of an optical sensor and then the decisions required to convert a lab bench optical measurement device into an ergonomic portable system. The necessary trade-offs between performance and portability are presented along with a description of the device developed to measure Orbiter window defects.

Discrepancy analysis of driving performance of taxi drivers and non-professional drivers for red-light running violation and crash avoidance at intersections.

PubMed

Wu, Jiawei; Yan, Xuedong; Radwan, Essam

2016-06-01

Due to comfort, convenience, and flexibility, taxis have become increasingly more prevalent in China, especially in large cities. However, many violations and road crashes that occurred frequently were related to taxi drivers. This study aimed to investigate differences in driving performance between taxi drivers and non-professional drivers from the perspectives of red-light running violation and potential crash involvement based on a driving simulation experiment. Two typical scenarios were established in a driving simulator, which includes the red-light running violation scenario and the crash avoidance scenario. There were 49 participants, including 23 taxi drivers (14 males and 9 females) and 26 non-professional drivers (13 males and 13 females) recruited for this experiment. The driving simulation experiment results indicated that non-professional drivers paid more attention to red-light running violations in comparison to taxi drivers who had a higher probability of red-light running violation. Furthermore, it was found that taxi drivers were more inclined to turn the steering wheel in an attempt to avoid a potential collision and non-professional drivers had more abrupt deceleration behaviors when facing a potential crash. Moreover, the experiment results showed that taxi drivers had a smaller crash rate compared to non-professional drivers and had a better performance in terms of crash avoidance at the intersection. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effects of non-evaluative feedback on drivers' self-evaluation and performance.

PubMed

Dogan, Ebru; Steg, Linda; Delhomme, Patricia; Rothengatter, Talib

2012-03-01

Drivers' tend to overestimate their competences, which may result in risk taking behavior. Providing drivers with feedback has been suggested as one of the solutions to overcome drivers' inaccurate self-evaluations. In practice, many tests and driving simulators provide drivers with non-evaluative feedback, which conveys information on the level of performance but not on what caused the performance. Is this type of feedback indeed effective in reducing self-enhancement biases? The current study aimed to investigate the effect of non-evaluative performance feedback on drivers' self-evaluations using a computerized hazard perception test. A between-subjects design was used with one group receiving feedback on performance in the hazard perception test while the other group not receiving any feedback. The results indicated that drivers had a robust self-enhancement bias in their self-evaluations regardless of the presence of performance feedback and that they systematically estimated their performance to be higher than they actually achieved in the test. Furthermore, they devalued the credibility of the test instead of adjusting their self-evaluations in order to cope with the negative feelings following the failure feedback. We discuss the theoretical and practical implications of these counterproductive effects of non-evaluative feedback. Copyright © 2011 Elsevier Ltd. All rights reserved.

Safety performance of drivers with medical exemptions : how safe are drivers in a medical exemption program compared to those who are not? : analysis brief.

DOT National Transportation Integrated Search

2016-11-01

For commercial motor vehicle (CMV) drivers, safety performance depends not only on the condition of the vehicle being driven but also on the drivers ability to operate it. Because factors such as stopping time and distance, blind spots, and limite...

A numerical tool for reproducing driver behaviour: experiments and predictive simulations.

PubMed

Casucci, M; Marchitto, M; Cacciabue, P C

2010-03-01

This paper presents the simulation tool called SDDRIVE (Simple Simulation of Driver performance), which is the numerical computerised implementation of the theoretical architecture describing Driver-Vehicle-Environment (DVE) interactions, contained in Cacciabue and Carsten [Cacciabue, P.C., Carsten, O. A simple model of driver behaviour to sustain design and safety assessment of automated systems in automotive environments, 2010]. Following a brief description of the basic algorithms that simulate the performance of drivers, the paper presents and discusses a set of experiments carried out in a Virtual Reality full scale simulator for validating the simulation. Then the predictive potentiality of the tool is shown by discussing two case studies of DVE interactions, performed in the presence of different driver attitudes in similar traffic conditions.

Performance Assessment of a Custom, Portable, and Low-Cost Brain-Computer Interface Platform.

PubMed

McCrimmon, Colin M; Fu, Jonathan Lee; Wang, Ming; Lopes, Lucas Silva; Wang, Po T; Karimi-Bidhendi, Alireza; Liu, Charles Y; Heydari, Payam; Nenadic, Zoran; Do, An Hong

2017-10-01

Conventional brain-computer interfaces (BCIs) are often expensive, complex to operate, and lack portability, which confines their use to laboratory settings. Portable, inexpensive BCIs can mitigate these problems, but it remains unclear whether their low-cost design compromises their performance. Therefore, we developed a portable, low-cost BCI and compared its performance to that of a conventional BCI. The BCI was assembled by integrating a custom electroencephalogram (EEG) amplifier with an open-source microcontroller and a touchscreen. The function of the amplifier was first validated against a commercial bioamplifier, followed by a head-to-head comparison between the custom BCI (using four EEG channels) and a conventional 32-channel BCI. Specifically, five able-bodied subjects were cued to alternate between hand opening/closing and remaining motionless while the BCI decoded their movement state in real time and provided visual feedback through a light emitting diode. Subjects repeated the above task for a total of 10 trials, and were unaware of which system was being used. The performance in each trial was defined as the temporal correlation between the cues and the decoded states. The EEG data simultaneously acquired with the custom and commercial amplifiers were visually similar and highly correlated ( ρ = 0.79). The decoding performances of the custom and conventional BCIs averaged across trials and subjects were 0.70 ± 0.12 and 0.68 ± 0.10, respectively, and were not significantly different. The performance of our portable, low-cost BCI is comparable to that of the conventional BCIs. Platforms, such as the one developed here, are suitable for BCI applications outside of a laboratory.

The impact of the luminance, size and location of LED billboards on drivers' visual performance-Laboratory tests.

PubMed

Zalesinska, Malgorzata

2018-08-01

A proper visual performance by drivers can be ensured by, among else, a correct distribution of luminance in their field of view. At night, when the driver's sight is adapted to low luminance levels, high luminance level objects located near the road may be a source of glare, which is not only a nuisance, but it may also blind the driver. For many years, LED billboards (light-emitting diode billboards) have been installed near roads. Such billboards are usually large, have high luminance and show dynamically changing images. These parameters have a significant impact on the drivers' visual performance and, in turn, on road traffic safety. The study on the impact of the luminance, size and location of LED billboards on the drivers' visual performance was conducted on a volunteer group. Testing the impact of LED billboards on the visual performance of drivers in real-life conditions is very difficult. Therefore, the tests have been conducted in laboratory conditions, using a car driving simulator. The paper describes the testing procedure and tests results. The permissible luminance and areas of LED screens in two locations near the road, which significantly reduce the drivers' visual performance in municipal traffic at night, were determined by conducting an analysis of the results. Recommendations on the permissible luminance and areas of LED billboards were formulated. Copyright © 2018 Elsevier Ltd. All rights reserved.

Acoustic and Perceptual Measures of SATB Choir Performances on Two Types of Portable Choral Riser Units in Three Singer-Spacing Conditions

ERIC Educational Resources Information Center

Daugherty, James F.; Manternach, Jeremy N.; Brunkan, Melissa C.

2013-01-01

Under controlled conditions, we assessed acoustically (long-term average spectra) and perceptually (singer survey, listener survey) six performances of an soprano, alto, tenor, and bass (SATB) choir ("N" = 27) as it sang the same musical excerpt on two portable riser units (standard riser step height, taller riser step height) with…

LABORATORY EVALUATION OF SIX NEW/MODIFIED PORTABLE X-RAY FLUORESCENCE SPECTROMETERS FOR THE MEASUREMENT OF LEAD IN CHARACTERIZED PAINT FILMS AND RESEARCH MATERIAL BOARDS (TECHNICAL REPORT)

EPA Science Inventory

A laboratory study was performed in 1994-1995 to identify and estimate the influence of key characteristics for evaluating the performance of portable X-ray fluorescence (XRF) spectrometers. Six new/modified spectrometers, including HNU SEFA-Pb, Metorex X-MET, Niton X-L, Radiat...

LABORATORY EVALUATION OF SIX NEW/MODIFIED PORTABLE X-RAY FLUORESCENCE SPECTROMETERS FOR THE MEASUREMENT OF LEAD IN CHARACTERIZED PAINT FILMS AND RESEARCH MATERIAL BOARDS (APPENDICES)

EPA Science Inventory

A laboratory study was performed in 1994-1995 to identify and estimate the influence of key characteristics for evaluating the performance of portable X-ray fluorescence (XRF) spectrometers. Six new/modified spectrometers, including HNU SEFA-Pb, Metorex X-MET, Niton X-L, Radiat...

Research: Testing of a Novel Portable Body Temperature Conditioner Using a Thermal Manikin.

PubMed

Heller, Daniel; Heller, Alex; Moujaes, Samir; Williams, Shelley J; Hoffmann, Ryan; Sarkisian, Paul; Khalili, Kaveh; Rockenfeller, Uwe; Browder, Timothy D; Kuhls, Deborah A; Fildes, John J

2016-01-01

A battery-operated active cooling/heating device was developed to maintain thermoregulation of trauma victims in austere environments while awaiting evacuation to a hospital for further treatment. The use of a thermal manikin was adopted for this study in order to simulate load testing and evaluate the performance of this novel portable active cooling/heating device for both continuous (external power source) and battery power. The performance of the portable body temperature conditioner (PBTC) was evaluated through cooling/heating fraction tests to analyze the heat transfer between a thermal manikin and circulating water blanket to show consistent performance while operating under battery power. For the cooling/heating fraction tests, the ambient temperature was set to 15°C ± 1°C (heating) and 30°C ± 1°C (cooling). The PBTC water temperature was set to 37°C for the heating mode tests and 15°C for the cooling mode tests. The results showed consistent performance of the PBTC in terms of cooling/heating capacity while operating under both continuous and battery power. The PBTC functioned as intended and shows promise as a portable warming/cooling device for operation in the field.

Single- and dual-task performance during on-the-road driving at a low and moderate dose of alcohol: A comparison between young novice and more experienced drivers.

PubMed

Jongen, Stefan; van der Sluiszen, Nick N J J M; Brown, Dennis; Vuurman, Eric F P M

2018-05-01

Driving experience and alcohol are two factors associated with a higher risk of crash involvement in young novice drivers. Driving a car is a complex task involving multiple tasks leading to dividing attention. The aim of this study was to compare the single and combined effects of a low and moderate dose of alcohol on single- and dual-task performance between young novice and more experienced young drivers during actual driving. Nine healthy novice drivers were compared with 9 more experienced drivers in a three-way, placebo-controlled, cross-over study design. Driving performance was measured in actual traffic, with standard deviation of lateral position as the primary outcome variable. Secondary task performance was measured with an auditory word learning test during driving. Results showed that standard deviation of lateral position increased dose-dependently at a blood alcohol concentration (BAC) of 0.2 and 0.5 g/L in both novice and experienced drivers. Secondary task performance was impaired in both groups at a BAC of 0.5 g/L. Furthermore, it was found that driving performance in novice drivers was already impaired at a BAC of 0.2 g/L during dual-task performance. The findings suggest that young inexperienced drivers are especially vulnerable to increased mental load while under the influence of alcohol. © 2018 The Authors Human Psychopharmacology: Clinical and Experimental Published by John Wiley & Sons Ltd.

Correlation between driving errors and vigilance level: influence of the driver's age.

PubMed

Campagne, Aurelie; Pebayle, Thierry; Muzet, Alain

2004-01-01

During long and monotonous driving at night, most drivers progressively show signs of visual fatigue and loss of vigilance. Their capacity to maintain adequate driving performance usually is affected and varies with the age of the driver. The main question is to know, on one hand, if occurrence of fatigue and drowsiness is accompanied by a modification in the driving performance of the driver and, on the other hand, if this relationship partially depends on the driver's age. Forty-six male drivers, divided into three age categories: 20-30, 40-50, and 60-70 years, performed a 350-km motorway driving session at night on a driving simulator. Driving errors were measured in terms of number of running-off-the-road incidents (RORI) and large speed deviations. The evolution of physiological vigilance level was evaluated using electroencephalography (EEG) recording. In older drivers, in comparison with young and middle-aged drivers, the degradation of driving performance was correlated to the evolution of lower frequency waking EEG (i.e., theta). Contrary to young and middle-aged drivers, the deterioration of the vigilance level attested by EEG correlated with the increase in gravity of all studied driving errors in older drivers. Thus, depending on the age category considered, only part of the driving errors would constitute a relevant indication as for the occurrence of a state of low arousal.

Assessing drivers' response during automated driver support system failures with non-driving tasks.

PubMed

Shen, Sijun; Neyens, David M

2017-06-01

With the increase in automated driver support systems, drivers are shifting from operating their vehicles to supervising their automation. As a result, it is important to understand how drivers interact with these automated systems and evaluate their effect on driver responses to safety critical events. This study aimed to identify how drivers responded when experiencing a safety critical event in automated vehicles while also engaged in non-driving tasks. In total 48 participants were included in this driving simulator study with two levels of automated driving: (a) driving with no automation and (b) driving with adaptive cruise control (ACC) and lane keeping (LK) systems engaged; and also two levels of a non-driving task (a) watching a movie or (b) no non-driving task. In addition to driving performance measures, non-driving task performance and the mean glance duration for the non-driving task were compared between the two levels of automated driving. Drivers using the automated systems responded worse than those manually driving in terms of reaction time, lane departure duration, and maximum steering wheel angle to an induced lane departure event. These results also found that non-driving tasks further impaired driver responses to a safety critical event in the automated system condition. In the automated driving condition, driver responses to the safety critical events were slower, especially when engaged in a non-driving task. Traditional driver performance variables may not necessarily effectively and accurately evaluate driver responses to events when supervising autonomous vehicle systems. Thus, it is important to develop and use appropriate variables to quantify drivers' performance under these conditions. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

Design and optimization of a portable LQCD Monte Carlo code using OpenACC

NASA Astrophysics Data System (ADS)

Bonati, Claudio; Coscetti, Simone; D'Elia, Massimo; Mesiti, Michele; Negro, Francesco; Calore, Enrico; Schifano, Sebastiano Fabio; Silvi, Giorgio; Tripiccione, Raffaele

The present panorama of HPC architectures is extremely heterogeneous, ranging from traditional multi-core CPU processors, supporting a wide class of applications but delivering moderate computing performance, to many-core Graphics Processor Units (GPUs), exploiting aggressive data-parallelism and delivering higher performances for streaming computing applications. In this scenario, code portability (and performance portability) become necessary for easy maintainability of applications; this is very relevant in scientific computing where code changes are very frequent, making it tedious and prone to error to keep different code versions aligned. In this work, we present the design and optimization of a state-of-the-art production-level LQCD Monte Carlo application, using the directive-based OpenACC programming model. OpenACC abstracts parallel programming to a descriptive level, relieving programmers from specifying how codes should be mapped onto the target architecture. We describe the implementation of a code fully written in OpenAcc, and show that we are able to target several different architectures, including state-of-the-art traditional CPUs and GPUs, with the same code. We also measure performance, evaluating the computing efficiency of our OpenACC code on several architectures, comparing with GPU-specific implementations and showing that a good level of performance-portability can be reached.

LDRD final report on confinement of cluster fusion plasmas with magnetic fields.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Argo, Jeffrey W.; Kellogg, Jeffrey W.; Headley, Daniel Ignacio

2011-11-01

Two versions of a current driver for single-turn, single-use 1-cm diameter magnetic field coils have been built and tested at the Sandia National Laboratories for use with cluster fusion experiments at the University of Texas in Austin. These coils are used to provide axial magnetic fields to slow radial loss of electrons from laser-produced deuterium plasmas. Typical peak field strength achievable for the two-capacitor system is 50 T, and 200 T for the ten-capacitor system. Current rise time for both systems is about 1.7 {mu}s, with peak current of 500 kA and 2 MA, respectively. Because the coil must bemore » brought to the laser, the driver needs to be portable and drive currents in vacuum. The drivers are complete but laser-plasma experiments are still in progress. Therefore, in this report, we focus on system design, initial tests, and performance characteristics of the two-capacitor and ten-capacitors systems. The questions of whether a 200 T magnetic field can retard the breakup of a cluster-fusion plasma, and whether this field can enhance neutron production have not yet been answered. However, tools have been developed that will enable producing the magnetic fields needed to answer these questions. These are a two-capacitor, 400-kA system that was delivered to the University of Texas in 2010, and a 2-MA ten-capacitor system delivered this year. The first system allowed initial testing, and the second system will be able to produce the 200 T magnetic fields needed for cluster fusion experiments with a petawatt laser. The prototype 400-kA magnetic field driver system was designed and built to test the design concept for the system, and to verify that a portable driver system could be built that delivers current to a magnetic field coil in vacuum. This system was built copying a design from a fixed-facility, high-field machine at LANL, but made to be portable and to use a Z-machine-like vacuum insulator and vacuum transmission line. This system was sent to the University of Texas in Austin where magnetic fields up to 50 T have been produced in vacuum. Peak charge voltage and current for this system have been 100 kV and 490 kA. It was used this last year to verify injection of deuterium and surrogate clusters into these small, single-turn coils without shorting the coil. Initial test confirmed the need to insulate the inner surface of the coil, which requires that the clusters must be injected through small holes in an insulator. Tests with a low power laser confirmed that it is possible to inject clusters into the magnetic field coils through these holes without destroying the clusters. The university team also learned the necessity of maintaining good vacuum to avoid insulator, transmission line, and coil shorting. A 200-T, 2 MA system was also constructed using the experience from the first design to make the pulsed-power system more robust. This machine is a copy of the prototype design, but with ten 100-kV capacitors versus the two used in the prototype. It has additional inductance in the switch/capacitor unit to avoid breakdown seen in the prototype design. It also has slightly more inductance at the cable connection to the vacuum chamber. With this design we have been able to demonstrate 1 MA current into a 1 cm diameter coil with the vacuum chamber at air pressure. Circuit code simulations, including the additional inductance with the new design, agree well with the measured current at a charge voltage of 40 kV with a short circuit load, and at 50 kV with a coil. The code also predicts that with a charge voltage of 97 kV we will be able to get 2 MA into a 1 cm diameter coil, which will be sufficient for 200 T fields. Smaller diameter or multiple-turn coils will be able to achieve even higher fields, or be able to achieve 200-T fields with lower charge voltage. Work is now proceeding at the university under separate funding to verify operation at the 2-MA level, and to address issues of debris mitigation, measurement of the magnetic field, and operation in vacuum. We anticipate operation at full current with single-turn, magnetic field coils this fall, with 200 T experiments on the Texas Petawatt laser in the spring of 2012.« less

Effects of in-vehicle warning information displays with or without spatial compatibility on driving behaviors and response performance.

PubMed

Liu, Yung-Ching; Jhuang, Jing-Wun

2012-07-01

A driving simulator study was conducted to evaluate the effects of five in-vehicle warning information displays upon drivers' emergent response and decision performance. These displays include visual display, auditory displays with and without spatial compatibility, hybrid displays in both visual and auditory format with and without spatial compatibility. Thirty volunteer drivers were recruited to perform various tasks that involved driving, stimulus-response, divided attention and stress rating. Results show that for displays of single-modality, drivers benefited more when coping with visual display of warning information than auditory display with or without spatial compatibility. However, auditory display with spatial compatibility significantly improved drivers' performance in reacting to the divided attention task and making accurate S-R task decision. Drivers' best performance results were obtained for hybrid display with spatial compatibility. Hybrid displays enabled drivers to respond the fastest and achieve the best accuracy in both S-R and divided attention tasks. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Performance of an Additional Task During Level 2 Automated Driving: An On-Road Study Comparing Drivers With and Without Experience With Partial Automation.

PubMed

Solís-Marcos, Ignacio; Ahlström, Christer; Kircher, Katja

2018-05-01

To investigate the influence of prior experience with Level 2 automation on additional task performance during manual and Level 2 partially automated driving. Level 2 automation is now on the market, but its effects on driver behavior remain unclear. Based on previous studies, we could expect an increase in drivers' engagement in secondary tasks during Level 2 automated driving, but it is yet unknown how drivers will integrate all the ongoing demands in such situations. Twenty-one drivers (12 without, 9 with Level 2 automation experience) drove on a highway manually and with Level 2 automation (exemplified by Volvo Pilot Assist generation 2; PA2) while performing an additional task. In half of the conditions, the task could be interrupted (self-paced), and in the other half, it could not (system-paced). Drivers' visual attention, additional task performance, and other compensatory strategies were analyzed. Driving with PA2 led to decreased scores in the additional task and more visual attention to the dashboard. In the self-paced condition, all drivers looked more to the task and perceived a lower mental demand. The drivers experienced with PA2 used the system and the task more than the novice group and performed more overtakings. The additional task interfered more with Level 2 automation than with manual driving. The drivers, particularly the automation novice drivers, used some compensatory strategies. Automation designers need to consider these potential effects in the development of future automated systems.

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

PubMed

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, speed, and reaction time, whereas no significant predictor was found for young drivers with their own cars. Carless young drivers had poorer driving performance and were more overconfident of their self-reported driving skills compared to those young drivers with greater access to vehicles. Given that the lifetime mileage positively predicted the simulated violations measure of carless young drivers, immediate interventions are needed to help them increase driving exposure and gain driving experience gradually before moving to more challenging on-road driving tasks. Supplemental materials are available for this article.

mzDB: A File Format Using Multiple Indexing Strategies for the Efficient Analysis of Large LC-MS/MS and SWATH-MS Data Sets*

PubMed Central

Bouyssié, David; Dubois, Marc; Nasso, Sara; Gonzalez de Peredo, Anne; Burlet-Schiltz, Odile; Aebersold, Ruedi; Monsarrat, Bernard

2015-01-01

The analysis and management of MS data, especially those generated by data independent MS acquisition, exemplified by SWATH-MS, pose significant challenges for proteomics bioinformatics. The large size and vast amount of information inherent to these data sets need to be properly structured to enable an efficient and straightforward extraction of the signals used to identify specific target peptides. Standard XML based formats are not well suited to large MS data files, for example, those generated by SWATH-MS, and compromise high-throughput data processing and storing. We developed mzDB, an efficient file format for large MS data sets. It relies on the SQLite software library and consists of a standardized and portable server-less single-file database. An optimized 3D indexing approach is adopted, where the LC-MS coordinates (retention time and m/z), along with the precursor m/z for SWATH-MS data, are used to query the database for data extraction. In comparison with XML formats, mzDB saves ∼25% of storage space and improves access times by a factor of twofold up to even 2000-fold, depending on the particular data access. Similarly, mzDB shows also slightly to significantly lower access times in comparison with other formats like mz5. Both C++ and Java implementations, converting raw or XML formats to mzDB and providing access methods, will be released under permissive license. mzDB can be easily accessed by the SQLite C library and its drivers for all major languages, and browsed with existing dedicated GUIs. The mzDB described here can boost existing mass spectrometry data analysis pipelines, offering unprecedented performance in terms of efficiency, portability, compactness, and flexibility. PMID:25505153

ASC Tri-lab Co-design Level 2 Milestone Report 2015

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hornung, Rich; Jones, Holger; Keasler, Jeff

2015-09-23

In 2015, the three Department of Energy (DOE) National Laboratories that make up the Advanced Sci- enti c Computing (ASC) Program (Sandia, Lawrence Livermore, and Los Alamos) collaboratively explored performance portability programming environments in the context of several ASC co-design proxy applica- tions as part of a tri-lab L2 milestone executed by the co-design teams at each laboratory. The programming environments that were studied included Kokkos (developed at Sandia), RAJA (LLNL), and Legion (Stan- ford University). The proxy apps studied included: miniAero, LULESH, CoMD, Kripke, and SNAP. These programming models and proxy-apps are described herein. Each lab focused on amore » particular combination of abstractions and proxy apps, with the goal of assessing performance portability using those. Performance portability was determined by: a) the ability to run a single application source code on multiple advanced architectures, b) comparing runtime performance between \

Portable multi-node LQCD Monte Carlo simulations using OpenACC

NASA Astrophysics Data System (ADS)

Bonati, Claudio; Calore, Enrico; D'Elia, Massimo; Mesiti, Michele; Negro, Francesco; Sanfilippo, Francesco; Schifano, Sebastiano Fabio; Silvi, Giorgio; Tripiccione, Raffaele

This paper describes a state-of-the-art parallel Lattice QCD Monte Carlo code for staggered fermions, purposely designed to be portable across different computer architectures, including GPUs and commodity CPUs. Portability is achieved using the OpenACC parallel programming model, used to develop a code that can be compiled for several processor architectures. The paper focuses on parallelization on multiple computing nodes using OpenACC to manage parallelism within the node, and OpenMPI to manage parallelism among the nodes. We first discuss the available strategies to be adopted to maximize performances, we then describe selected relevant details of the code, and finally measure the level of performance and scaling-performance that we are able to achieve. The work focuses mainly on GPUs, which offer a significantly high level of performances for this application, but also compares with results measured on other processors.

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

PubMed

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.

Highly automated driving, secondary task performance, and driver state.

PubMed

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.

The Anonymity vs. Utility Dilemma

NASA Astrophysics Data System (ADS)

Bezzi, Michele; Pazzaglia, Jean-Christophe

The number, the type of users and their usage of the internet, computers and phones have evolved considerably, due to the emergence of the web 2.0, the decreasing cost of portable devices, the expansion of wired and wireless internet access and the digitalization of the main entertainment media. Protecting the assets of service and software providers has been the main driver for the development of security solutions in the past ten years. However, the users/customers/citizen rights have been too often neglected since the risk related to the wrong usage of personal related information was not considered by the other stakeholders. Today, the Right to Privacy is appearing on everyone’s radar and factors as regulations, increasing number of news stories on privacy breaches, brand damages, are forcing organizations to address user privacy as a priority. In this paper, we will briefly review the main business drivers behind the raising of privacy concerns, and outline some of the current technology solutions to address privacy requirements. Finally, we will describe some of the future challenges in the area of privacy.

Acceptability and validity of older driver screening with the DrivingHealth Inventory.

PubMed

Edwards, Jerri D; Leonard, Kathleen M; Lunsman, Melissa; Dodson, Joan; Bradley, Stacy; Myers, Charlsie A; Hubble, Bridgette

2008-05-01

Research has indicated that technology can be effectively used to identify high-risk older drivers. However, adaptation of such technology has been limited. Researchers debate whether older drivers represent a safety problem as well as whether they should be screened for driving fitness. The present study examined how drivers feel regarding technological screening and mandatory state testing. The validity and acceptability of a new technological screening battery for identifying high-risk drivers, the DrivingHealth Inventory (DHI), was also evaluated. In a sample of 258 Alabama drivers aged 18-87, older drivers performed significantly worse than younger drivers on sensory, cognitive, and physical subtests of the DHI, and older drivers with a crash history performed worse than older drivers without crashes. Regardless of age, 90% of participants supported states requiring screening for older drivers' license renewal. The majority of the participants (72%) supported use of technological screening batteries such as the DHI as a driver screening tool. Considering the acceptability and potential efficacy of the DHI, it may be a useful tool in evaluating driving fitness among older adults.

Portability and Cross-Platform Performance of an MPI-Based Parallel Polygon Renderer

NASA Technical Reports Server (NTRS)

Crockett, Thomas W.

1999-01-01

Visualizing the results of computations performed on large-scale parallel computers is a challenging problem, due to the size of the datasets involved. One approach is to perform the visualization and graphics operations in place, exploiting the available parallelism to obtain the necessary rendering performance. Over the past several years, we have been developing algorithms and software to support visualization applications on NASA's parallel supercomputers. Our results have been incorporated into a parallel polygon rendering system called PGL. PGL was initially developed on tightly-coupled distributed-memory message-passing systems, including Intel's iPSC/860 and Paragon, and IBM's SP2. Over the past year, we have ported it to a variety of additional platforms, including the HP Exemplar, SGI Origin2OOO, Cray T3E, and clusters of Sun workstations. In implementing PGL, we have had two primary goals: cross-platform portability and high performance. Portability is important because (1) our manpower resources are limited, making it difficult to develop and maintain multiple versions of the code, and (2) NASA's complement of parallel computing platforms is diverse and subject to frequent change. Performance is important in delivering adequate rendering rates for complex scenes and ensuring that parallel computing resources are used effectively. Unfortunately, these two goals are often at odds. In this paper we report on our experiences with portability and performance of the PGL polygon renderer across a range of parallel computing platforms.

ASC-ATDM Performance Portability Requirements for 2015-2019

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, Harold C.; Trott, Christian Robert

This report outlines the research, development, and support requirements for the Advanced Simulation and Computing (ASC ) Advanced Technology, Development, and Mitigation (ATDM) Performance Portability (a.k.a., Kokkos) project for 2015 - 2019 . The research and development (R&D) goal for Kokkos (v2) has been to create and demonstrate a thread - parallel programming model a nd standard C++ library - based implementation that enables performance portability across diverse manycore architectures such as multicore CPU, Intel Xeon Phi, and NVIDIA Kepler GPU. This R&D goal has been achieved for algorithms that use data parallel pat terns including parallel - for, parallelmore » - reduce, and parallel - scan. Current R&D is focusing on hierarchical parallel patterns such as a directed acyclic graph (DAG) of asynchronous tasks where each task contain s nested data parallel algorithms. This five y ear plan includes R&D required to f ully and performance portably exploit thread parallelism across current and anticipated next generation platforms (NGP). The Kokkos library is being evaluated by many projects exploring algorithm s and code design for NGP. Some production libraries and applications such as Trilinos and LAMMPS have already committed to Kokkos as their foundation for manycore parallelism an d performance portability. These five year requirements includes support required for current and antic ipated ASC projects to be effective and productive in their use of Kokkos on NGP. The greatest risk to the success of Kokkos and ASC projects relying upon Kokkos is a lack of staffing resources to support Kokkos to the degree needed by these ASC projects. This support includes up - to - date tutorials, documentation, multi - platform (hardware and software stack) testing, minor feature enhancements, thread - scalable algorithm consulting, and managing collaborative R&D.« less

Milestone Completion Report STCO04-1 AAPS: engagements with code teams, vendors, collaborators, developers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Draeger, E. W.

The Advanced Architecture and Portability Specialists team (AAPS) worked with a select set of LLNL application teams to develop and/or implement a portability strategy for next-generation architectures. The team also investigated new and updated programming models and helped develop programming abstractions targeting maintainability and performance portability. Significant progress was made on both fronts in FY17, resulting in multiple applications being significantly more prepared for the nextgeneration machines than before.

Effects of automobile steering characteristics on driver/vehicle system performance in discrete maneuvers

NASA Technical Reports Server (NTRS)

Klein, R. H.; Mcruer, D. T.

1975-01-01

A series of discrete maneuver tasks were used to evaluate the effects of steering gain and directional mode dynamic parameters on driver/vehicle responses. The importance and ranking of these parameters were evaluated through changes in subjective driver ratings and performance measures obtained from transient maneuvers such as a double lane change, an emergency lane change, and an unexpected obstacle. The unexpected obstacle maneuver proved more sensitive to individual driver differences than to vehicle differences. Results were based on full scale tests with an experienced test driver evaluating many different dynamic configurations plus seventeen ordinary drivers evaluating six key configurations.

Driver-initiated distractions: examining strategic adaptation for in-vehicle task initiation.

PubMed

Horrey, William J; Lesch, Mary F

2009-01-01

Today, drivers are faced with many in-vehicle activities that are potentially distracting. In many cases, they are not passive recipients of these tasks; rather, drivers decide whether or not (or how) to perform them. In this study, we examined whether drivers, given knowledge of the upcoming road demands, would strategically delay performing in-vehicle activities until demands were reduced. Twenty drivers drove an instrumented van around a closed track that was divided into sections of varying demands and difficulty. Drivers were asked to perform one of four in-vehicle tasks (e.g., phone conversation; read a text message; find an address; pick up an object on the floor); however, they were free to decide when to initiate these tasks, provided they finish them before a given deadline. Although drivers were fully aware of the relative demands of the road, they did not tend to strategically postpone tasks--a finding that was consistent across the different tasks (p >.05). Rather, drivers tended to initiate tasks regardless of the current driving conditions. This strategy frequently led to driving errors. Given the control that drivers have over many in-vehicle distractions, interventions that focus on strategic decisions and planning may have merit.

Effects of fog, driver experience and gender on driving behavior on S-curved road segments.

PubMed

Li, Xiaomeng; Yan, Xuedong; Wong, S C

2015-04-01

Driving on curved roads has been recognized as a significant safety issue for many years. However, driver behavior and the interactions among variables that affect driver performance on curves is complicated and not well understood. Previous studies have investigated various factors that influence driver performance on right- or left-turn curves, but have paid little attention to the effects of foggy weather, driver experience and gender on driver performance on complex curves. A driving simulator experiment was conducted in this study to evaluate the relationships between driving behavior on a continuous S-curve and foggy weather, driver experience and gender. The process of negotiating a curve was divided into three stages consisting of a straight segment, the transition from the straight segment to the S-curve and the S-curve. The experimental results indicated that drivers tended to drive more cautiously in heavy fog, but the driving risk was still increased, especially in the transition stage from the straight segment to the S-curve. The non-professional (NP) drivers were less sensitive to the impending change in the road geometry, and less skilled in both longitudinal and lateral vehicle control than the professional drivers. The NP female drivers in particular were found to be the most vulnerable group in S-curve driving. Copyright © 2015 Elsevier Ltd. All rights reserved.

Aeras: A next generation global atmosphere model

DOE PAGES

Spotz, William F.; Smith, Thomas M.; Demeshko, Irina P.; ...

2015-06-01

Sandia National Laboratories is developing a new global atmosphere model named Aeras that is performance portable and supports the quantification of uncertainties. These next-generation capabilities are enabled by building Aeras on top of Albany, a code base that supports the rapid development of scientific application codes while leveraging Sandia's foundational mathematics and computer science packages in Trilinos and Dakota. Embedded uncertainty quantification (UQ) is an original design capability of Albany, and performance portability is a recent upgrade. Other required features, such as shell-type elements, spectral elements, efficient explicit and semi-implicit time-stepping, transient sensitivity analysis, and concurrent ensembles, were not componentsmore » of Albany as the project began, and have been (or are being) added by the Aeras team. We present early UQ and performance portability results for the shallow water equations.« less

Performance Analysis and Portability of the PLUM Load Balancing System

NASA Technical Reports Server (NTRS)

Oliker, Leonid; Biswas, Rupak; Gabow, Harold N.

1998-01-01

The ability to dynamically adapt an unstructured mesh is a powerful tool for solving computational problems with evolving physical features; however, an efficient parallel implementation is rather difficult. To address this problem, we have developed PLUM, an automatic portable framework for performing adaptive numerical computations in a message-passing environment. PLUM requires that all data be globally redistributed after each mesh adaption to achieve load balance. We present an algorithm for minimizing this remapping overhead by guaranteeing an optimal processor reassignment. We also show that the data redistribution cost can be significantly reduced by applying our heuristic processor reassignment algorithm to the default mapping of the parallel partitioner. Portability is examined by comparing performance on a SP2, an Origin2000, and a T3E. Results show that PLUM can be successfully ported to different platforms without any code modifications.

The effects of text messaging on young drivers.

PubMed

Hosking, Simon G; Young, Kristie L; Regan, Michael A

2009-08-01

This study investigated the effects of using a cell phone to retrieve and send text messages on the driving performance of young novice drivers. Young drivers are particularly susceptible to driver distraction and have an increased risk of distraction-related crashes. Distractions from in-vehicle devices, particularly, those that require manual input, are known to cause decrements in driving performance. Twenty young novice drivers used a cell phone to retrieve and send text messages while driving a simulator. The amount of time that drivers spent not looking at the road when text messaging was up to approximately 400% greater than that recorded in baseline (notext-messaging) conditions. Furthermore, drivers' variability in lane position increased up to approximately 50%, and missed lane changes increased 140%. There was also an increase of up to approximately 150% in drivers' variability in following distances to lead vehicles. Previous research has shown that the risk of crashing while dialing a handheld device, such as when text messaging and driving, is more than double that of conversing on a cell phone. The present study has identified the detrimental effects of text messaging on driving performance that may underlie such increased crash risk. More effective road safety measures are needed to prevent and mitigate the adverse effects on driving performance of using cell phones to retrieve and send text messages.

Handheld probe for portable high frame photoacoustic/ultrasound imaging system

NASA Astrophysics Data System (ADS)

Daoudi, K.; van den Berg, P. J.; Rabot, O.; Kohl, A.; Tisserand, S.; Brands, P.; Steenbergen, W.

2013-03-01

Photoacoustics is a hybrid imaging modality that is based on the detection of acoustic waves generated by absorption of pulsed light by tissue chromophors. In current research, this technique uses large and costly photoacoustic systems with a low frame rate imaging. To open the door for widespread clinical use, a compact, cost effective and fast system is required. In this paper we report on the development of a small compact handset pulsed laser probe which will be connected to a portable ultrasound system for real-time photoacoustic imaging and ultrasound imaging. The probe integrates diode lasers driven by an electrical driver developed for very short high power pulses. It uses specifically developed highly efficient diode stacks with high frequency repetition rate up to 10 kHz, emitting at 800nm wavelength. The emitted beam is collimated and shaped with compact micro optics beam shaping system delivering a homogenized rectangular laser beam intensity distribution. The laser block is integrated with an ultrasound transducer in an ergonomically designed handset probe. This handset is a building block enabling for a low cost high frame rate photoacoustic and ultrasound imaging system. The probe was used with a modified ultrasound scanner and was tested by imaging a tissue mimicking phantom.

Vehicle capture system

NASA Astrophysics Data System (ADS)

Tacke, Kenneth L.

1998-12-01

Primex Aerospace Company, under contract with the U.S. Army Armament Research Development & Engineering Center (ARDEC), has developed a portable vehicle capture system for use at vehicle checkpoints. Currently when a vehicle does not stop at a checkpoint, there are three possible reactions: let the vehicle go unchallenged, pursue the vehicle or stop the vehicle with lethal force. This system provides a non-lethal alternative that will stop and contain the vehicle. The system is completely portable with the heaviest component weighing less than 120 pounds. It can be installed with no external electrical power or permanent anchors required. In its standby mode, the system does not impede normal traffic, but on command erects a barrier in less than 1.5 seconds. System tests have been conducted using 5,100 and 8.400 pound vehicles, traveling at speeds up to 45 mph. The system is designed to minimize vehicle damage and occupant injury, typically resulting in deceleration forces of less than 2.5 gs on the vehicle. According to the drivers involved in tests at 45 mph, the stopping forces feel similar to a panic stop with the vehicle brakes locked. The system is completely reusable and be rapidly reset.

Driving Simulator Performance in Novice Drivers with Autism Spectrum Disorder: The Role of Executive Functions and Basic Motor Skills

ERIC Educational Resources Information Center

Cox, Stephany M.; Cox, Daniel J.; Kofler, Michael J.; Moncrief, Matthew A.; Johnson, Ronald J.; Lambert, Ann E.; Cain, Sarah A.; Reeve, Ronald E.

2016-01-01

Previous studies have shown that individuals with autism spectrum disorder (ASD) demonstrate poorer driving performance than their peers and are less likely to obtain a driver's license. This study aims to examine the relationship between driving performance and executive functioning for novice drivers, with and without ASD, using a driving…

Characteristics and applications of small, portable gaseous air pollution monitors.

PubMed

McKercher, Grant R; Salmond, Jennifer A; Vanos, Jennifer K

2017-04-01

Traditional approaches for measuring air quality based on fixed measurements are inadequate for personal exposure monitoring. To combat this issue, the use of small, portable gas-sensing air pollution monitoring technologies is increasing, with researchers and individuals employing portable and mobile methods to obtain more spatially and temporally representative air pollution data. However, many commercially available options are built for various applications and based on different technologies, assumptions, and limitations. A review of the monitor characteristics of small, gaseous monitors is missing from current scientific literature. A state-of-the-art review of small, portable monitors that measure ambient gaseous outdoor pollutants was developed to address broad trends during the last 5-10 years, and to help future experimenters interested in studying gaseous air pollutants choose monitors appropriate for their application and sampling needs. Trends in small, portable gaseous air pollution monitor uses and technologies were first identified and discussed in a review of literature. Next, searches of online databases were performed for articles containing specific information related to performance, characteristics, and use of such monitors that measure one or more of three criteria gaseous air pollutants: ozone, nitrogen dioxide, and carbon monoxide. All data were summarized into reference tables for comparison between applications, physical features, sensing capabilities, and costs of the devices. Recent portable monitoring trends are strongly related to associated applications and audiences. Fundamental research requires monitors with the best individual performance, and thus the highest cost technology. Monitor networking favors real-time capabilities and moderate cost for greater reproduction. Citizen science and crowdsourcing applications allow for lower-cost components; however important strengths and limitations for each application must be addressed or acknowledged for the given use. Copyright © 2016 Elsevier Ltd. All rights reserved.

Miniaturised electrically actuated high pressure injection valve for portable capillary liquid chromatography.

PubMed

Li, Yan; Pace, Kirsten; Nesterenko, Pavel N; Paull, Brett; Stanley, Roger; Macka, Mirek

2018-04-01

A miniaturised high pressure 6-port injection valve has been designed and evaluated for its performance in order to facilitate the development of portable capillary high performance liquid chromatography (HPLC). The electrically actuated valve features a very small size (65 × 19 × 19mm) and light weight (33g), and therefore can be easily integrated in a miniaturised modular capillary LC system suited for portable field analysis. The internal volume of the injection valve was determined as 98 nL. The novel conical shape of the stator and rotor and the spring-loaded rotor performed well up to 32MPa (4641psi), the maximum operating pressure investigated. Suitability for application was demonstrated using a miniaturised capillary LC system applied to the chromatographic separation of a mixture of biogenic amines and common cations. The RSD (relative standard deviation) values of retention times and peak areas of 6 successive runs were 0.5-0.7% and 1.8-2.8% for the separation of biogenic amines, respectively, and 0.1-0.2% and 2.1-3.0% for the separation of cations, respectively. This performance was comparable with bench-top HPLC systems thus demonstrating the applicability of the valve for use in portable and miniaturised capillary HPLC systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Driver Behavior and Performance with Augmented Reality Pedestrian Collision Warning: An Outdoor User Study.

PubMed

Kim, Hyungil; Gabbard, Joseph L; Anon, Alexandre Miranda; Misu, Teruhisa

2018-04-01

This article investigates the effects of visual warning presentation methods on human performance in augmented reality (AR) driving. An experimental user study was conducted in a parking lot where participants drove a test vehicle while braking for any cross traffic with assistance from AR visual warnings presented on a monoscopic and volumetric head-up display (HUD). Results showed that monoscopic displays can be as effective as volumetric displays for human performance in AR braking tasks. The experiment also demonstrated the benefits of conformal graphics, which are tightly integrated into the real world, such as their ability to guide drivers' attention and their positive consequences on driver behavior and performance. These findings suggest that conformal graphics presented via monoscopic HUDs can enhance driver performance by leveraging the effectiveness of monocular depth cues. The proposed approaches and methods can be used and further developed by future researchers and practitioners to better understand driver performance in AR as well as inform usability evaluation of future automotive AR applications.

Driver Performance in the Moments Surrounding a Microsleep

PubMed Central

Boyle, Linda Ng; Tippin, Jon; Paul, Amit; Rizzo, Matthew

2009-01-01

This study examined if individuals who are at increased risk for drowsy-driving because of obstructive sleep apnea syndrome (OSAS), have impairments in driving performance in the moments during microsleep episodes as opposed to during periods of wakefulness. Twenty-four licensed drivers diagnosed with OSAS based on standard clinical and polysomnographic criteria, participated in an hour-long drive in a high-fidelity driving simulator with synchronous electroencephalographic (EEG) recordings for identification of microsleeps. The drivers showed significant deterioration in vehicle control during the microsleep episodes compared to driving performance in the absence of microsleeps on equivalent segments of roadway. The degree of performance decrement correlated with microsleep duration, particularly on curved roads. Results indicate that driving performance deteriorates during microsleep episodes. Detecting microsleeps in real-time and identifying how these episodes of transition between wakefulness and sleep impair driver performance is relevant to the design and implementation of countermeasures such as drowsy driver detection and alerting systems that use EEG technology. PMID:20090864

Exploring the association between working memory and driving performance in Parkinson's disease.

PubMed

Vardaki, Sophia; Devos, Hannes; Beratis, Ion; Yannis, George; Papageorgiou, Sokratis G

2016-05-18

The aim of this study was to explore whether varying levels of operational and tactical driving task demand differentially affect drivers with Parkinson's disease (PD) and control drivers in their sign recall. Study participants aged between 50 and 70 years included a group of drivers with PD (n = 10) and a group of age- and sex-matched control drivers (n = 10). Their performance in a sign recall task was measured using a driving simulator. Drivers in the control group performed better than drivers with PD in a sign recall task, but this trend was not statistically significant (P =.43). In addition, regardless of group membership, subjects' performance differed according to varying levels of task demand. Performance in the sign recall task was more likely to drop with increasing task demand (P =.03). This difference was significant when the variation in task demand was associated with a cognitive task; that is, when drivers were required to apply the instructions from working memory. Although the conclusions drawn from this study are tentative, the evidence presented here is encouraging with regard to the use of a driving simulator to examine isolated cognitive functions underlying driving performance in PD. With an understanding of its limitations, such driving simulation in combination with functional assessment batteries measuring physical, visual, and cognitive abilities could comprise one component of a multitiered system to evaluate medical fitness to drive.

Effect of Cognitive Demand on Functional Visual Field Performance in Senior Drivers with Glaucoma.

PubMed

Gangeddula, Viswa; Ranchet, Maud; Akinwuntan, Abiodun E; Bollinger, Kathryn; Devos, Hannes

2017-01-01

Purpose: To investigate the effect of cognitive demand on functional visual field performance in drivers with glaucoma. Method: This study included 20 drivers with open-angle glaucoma and 13 age- and sex-matched controls. Visual field performance was evaluated under different degrees of cognitive demand: a static visual field condition (C1), dynamic visual field condition (C2), and dynamic visual field condition with active driving (C3) using an interactive, desktop driving simulator. The number of correct responses (accuracy) and response times on the visual field task were compared between groups and between conditions using Kruskal-Wallis tests. General linear models were employed to compare cognitive workload, recorded in real-time through pupillometry, between groups and conditions. Results: Adding cognitive demand (C2 and C3) to the static visual field test (C1) adversely affected accuracy and response times, in both groups ( p < 0.05). However, drivers with glaucoma performed worse than did control drivers when the static condition changed to a dynamic condition [C2 vs. C1 accuracy; glaucoma: median difference (Q1-Q3) 3 (2-6.50) vs. 2 (0.50-2.50); p = 0.05] and to a dynamic condition with active driving [C3 vs. C1 accuracy; glaucoma: 2 (2-6) vs. 1 (0.50-2); p = 0.02]. Overall, drivers with glaucoma exhibited greater cognitive workload than controls ( p = 0.02). Conclusion: Cognitive demand disproportionately affects functional visual field performance in drivers with glaucoma. Our results may inform the development of a performance-based visual field test for drivers with glaucoma.

EVALUATION OF A PORTABLE FOURIER TRANSFORM INFRARED GAS ANALYZER FOR MEASUREMENTS OF AIR TOXICS IN POLLUTION PREVENTION RESEARCH

EPA Science Inventory

A portable Fourier transform infrared gas analyzer with a photoacoustic detector performed reliably during pollution prevention research at two industrial facilities. It exhibited good agreement (within approximately 6%) with other analytical instruments (dispersive infrared and ...

Flight Performance of a Man Portable Guided Projectile Concept

DTIC Science & Technology

2014-02-01

include precision guided technologies. The focus of this study is maneuvering projectiles launched from man portable weapon systems . A novel guided...5 Figure 5. Body-fixed coordinate system and aerodynamic angles...20 Figure 20. Earth and body-fixed coordinate systems and Euler angles. ........................................24

TESTING, PERFORMANCE VALIDATION AND QUALITY ASSURANCE/QUALITY CONTROL OF FIELD-PORTABLE INSTRUMENTATION

EPA Science Inventory

New technologies for field-portable monitoring instruments often have a long lead time in development and authorization. Some obstacles to the acceptance of these pilot technologies include concern about liabilities, reluctance to take risks on new technologies, and uncertainty a...

Effects of portable computing devices on posture, muscle activation levels and efficiency.

PubMed

Werth, Abigail; Babski-Reeves, Kari

2014-11-01

Very little research exists on ergonomic exposures when using portable computing devices. This study quantified muscle activity (forearm and neck), posture (wrist, forearm and neck), and performance (gross typing speed and error rates) differences across three portable computing devices (laptop, netbook, and slate computer) and two work settings (desk and computer) during data entry tasks. Twelve participants completed test sessions on a single computer using a test-rest-test protocol (30min of work at one work setting, 15min of rest, 30min of work at the other work setting). The slate computer resulted in significantly more non-neutral wrist, elbow and neck postures, particularly when working on the sofa. Performance on the slate computer was four times less than that of the other computers, though lower muscle activity levels were also found. Potential or injury or illness may be elevated when working on smaller, portable computers in non-traditional work settings. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Driving Behaviour Profile of Drivers with Autism Spectrum Disorder (ASD).

PubMed

Chee, Derserri Y; Lee, Hoe C; Patomella, Ann-Helen; Falkmer, Torbjörn

2017-09-01

The symptomatology of autism spectrum disorder (ASD) can make driving risky, but little is known about the on-road driving behaviour of individuals with ASD. This study assessed and compared the on-road driving performance of drivers with and without ASD, and explored how the symptomatology of ASD hinders or facilitates on-road driving performance. Sixteen drivers with ASD and 21 typically-developed drivers participated in the study. Drivers with ASD underperformed in vehicle manoeuvring, especially at left-turns, right-turns and pedestrian crossings. However, drivers with ASD outperformed the TD group in aspects related to rule-following such as using the indicator at roundabouts and checking for cross-traffic when approaching intersections. Drivers with ASD in the current study presented with a range of capabilities and weaknesses during driving.

Fusion of Optimized Indicators from Advanced Driver Assistance Systems (ADAS) for Driver Drowsiness Detection

PubMed Central

Daza, Iván G.; Bergasa, Luis M.; Bronte, Sebastián; Yebes, J. Javier; Almazán, Javier; Arroyo, Roberto

2014-01-01

This paper presents a non-intrusive approach for monitoring driver drowsiness using the fusion of several optimized indicators based on driver physical and driving performance measures, obtained from ADAS (Advanced Driver Assistant Systems) in simulated conditions. The paper is focused on real-time drowsiness detection technology rather than on long-term sleep/awake regulation prediction technology. We have developed our own vision system in order to obtain robust and optimized driver indicators able to be used in simulators and future real environments. These indicators are principally based on driver physical and driving performance skills. The fusion of several indicators, proposed in the literature, is evaluated using a neural network and a stochastic optimization method to obtain the best combination. We propose a new method for ground-truth generation based on a supervised Karolinska Sleepiness Scale (KSS). An extensive evaluation of indicators, derived from trials over a third generation simulator with several test subjects during different driving sessions, was performed. The main conclusions about the performance of single indicators and the best combinations of them are included, as well as the future works derived from this study. PMID:24412904

Software for keratometry measurements using portable devices

NASA Astrophysics Data System (ADS)

Iyomasa, C. M.; Ventura, L.; De Groote, J. J.

2010-02-01

In this work we present an image processing software for automatic astigmatism measurements developed for a hand held keratometer. The system projects 36 light spots, from LEDs, displayed in a precise circle at the lachrymal film of the examined cornea. The displacement, the size and deformation of the reflected image of these light spots are analyzed providing the keratometry. The purpose of this research is to develop a software that performs fast and precise calculations in mainstream mobile devices. In another words, a software that can be implemented in portable computer systems, which could be of low cost and easy to handle. This project allows portability for keratometers and is a previous work for a portable corneal topographer.

Laser Spiderweb Sensor Used with Portable Handheld Devices

NASA Technical Reports Server (NTRS)

Scott, David C. (Inventor); Ksendzov, Alexander (Inventor); George, Warren P. (Inventor); Smith, James A. (Inventor); Steinkraus, Joel M. (Inventor); Hofmann, Douglas C. (Inventor); Aljabri, Abdullah S. (Inventor); Bendig, Rudi M. (Inventor)

2017-01-01

A portable spectrometer, including a smart phone case storing a portable spectrometer, wherein the portable spectrometer includes a cavity; a source for emitting electromagnetic radiation that is directed on a sample in the cavity, wherein the electromagnetic radiation is reflected within the cavity to form multiple passes of the electromagnetic radiation through the sample; a detector for detecting the electromagnetic radiation after the electromagnetic radiation has made the multiple passes through the sample in the cavity, the detector outputting a signal in response to the detecting; and a device for communicating the signal to a smart phone, wherein the smart phone executes an application that performs a spectral analysis of the signal.

ALCOHOL AND DISTRACTION INTERACT TO IMPAIR DRIVING PERFORMANCE

PubMed Central

Harrison, Emily L. R.; Fillmore, Mark T.

2011-01-01

Background Recognition of the risks associated with alcohol intoxication and driver distraction has led to a wealth of simulated driving research aimed at studying the adverse effects of each of these factors. Research on driving has moved beyond the individual, separate examination of these factors to the examination of potential interactions between alcohol intoxication and driver distraction. In many driving situations, distractions are commonplace and might have little or no disruptive influence on primary driving functions. Yet, such distractions might become disruptive to a driver who is intoxicated. Methods The present study examined the interactive impairing effects of alcohol intoxication and driver distraction on simulated driving performance in 40 young adult drivers using a divided attention task as a distracter activity. The interactive influence of alcohol and distraction was tested by having drivers perform the driving task under four different conditions: 0.65 g/kg alcohol; 0.65 g/kg alcohol + divided attention; placebo; and placebo + divided attention. Results As hypothesized, divided attention had no impairing effect on driving performance in sober drivers. However, under alcohol, divided attention exacerbated the impairing effects of alcohol on driving precision. Conclusions Alcohol and distraction continue to be appropriate targets for research into ways to reduce the rates of driving-related fatalities and injuries. Greater consideration of how alcohol and distraction interact to impair aspects of driving performance can further efforts to create prevention and intervention measures to protect drivers, particularly young adults. PMID:21277119

Alcohol and distraction interact to impair driving performance.

PubMed

Harrison, Emily L R; Fillmore, Mark T

2011-08-01

Recognition of the risks associated with alcohol intoxication and driver distraction has led to a wealth of simulated driving research aimed at studying the adverse effects of each of these factors. Research on driving has moved beyond the individual, separate examination of these factors to the examination of potential interactions between alcohol intoxication and driver distraction. In many driving situations, distractions are commonplace and might have little or no disruptive influence on primary driving functions. Yet, such distractions might become disruptive to a driver who is intoxicated. The present study examined the interactive impairing effects of alcohol intoxication and driver distraction on simulated driving performance in 40 young adult drivers using a divided attention task as a distracter activity. The interactive influence of alcohol and distraction was tested by having drivers perform the driving task under four different conditions: 0.65 g/kg alcohol; 0.65 g/kg alcohol+divided attention; placebo; and placebo+divided attention. As hypothesized, divided attention had no impairing effect on driving performance in sober drivers. However, under alcohol, divided attention exacerbated the impairing effects of alcohol on driving precision. Alcohol and distraction continue to be appropriate targets for research into ways to reduce the rates of driving-related fatalities and injuries. Greater consideration of how alcohol and distraction interact to impair aspects of driving performance can further efforts to create prevention and intervention measures to protect drivers, particularly young adults. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Countermeasures to Improve the Driving Performance of Older Drivers.

ERIC Educational Resources Information Center

Ashman, Richard D.; And Others

1994-01-01

In a 2-year project, 105 older drivers were given physical therapy (flexibility exercises), perceptual therapy (to improve visual discrimination), and driver education; traffic engineering modifications were also made. All four interventions improved performance an average of 7.9%. Engineering was most cost effective on high-volume roads, the…

Research On Vehicle-Based Driver Status/Performance Monitoring; Development, Validation, And Refinement Of Algorithms For Detection Of Driver Drowsiness, Final Report

DOT National Transportation Integrated Search

1994-12-01

THIS REPORT SUMMARIZES THE RESULTS OF A 3-YEAR RESEARCH PROJECT TO DEVELOP RELIABLE ALGORITHMS FOR THE DETECTION OF MOTOR VEHICLE DRIVER IMPAIRMENT DUE TO DROWSINESS. THESE ALGORITHMS ARE BASED ON DRIVING PERFORMANCE MEASURES THAT CAN POTENTIALLY BE ...

Comparing handheld and hands-free cell phone usage behaviors while driving.

PubMed

Soccolich, Susan A; Fitch, Gregory M; Perez, Miguel A; Hanowski, Richard J

2014-01-01

The goal of this study was to compare cell phone usage behaviors while driving across 3 types of cell phones: handheld (HH) cell phones, portable hands-free (PHF) cell phones, and integrated hands-free (IHF) cell phones. Naturalistic driving data were used to observe HH, PHF, and IHF usage behaviors in participants' own vehicles without any instructions or manipulations by researchers. In addition to naturalistic driving data, drivers provided their personal cell phone call records. Calls during driving were sampled and observed in naturalistically collected video. Calls were reviewed to identify cell phone type used for, and duration of, cell phone subtasks, non-cell phone secondary tasks, and other use behaviors. Drivers in the study self-identified as HH, PHF, or IHF users if they reported using that cell phone type at least 50% of the time. However, each sampled call was classified as HH, PHF, or IHF if the talking/listening subtask was conducted using that cell phone type, without considering the driver's self-reported group. Drivers with PHF or IHF systems also used HH cell phones (IHF group used HH cell phone in 53.2% of the interactions, PHF group used HH cell phone for 55.5% of interactions). Talking/listening on a PHF phone or an IHF phone was significantly longer than talking/listening on an HH phone (P <.05). HH dialing was significantly longer in duration than PHF or IHF begin/answer tasks. End phone call task for HH phones was significantly longer in duration than the end phone call task for PHF and IHF phones. Of all the non-cell phone-related secondary tasks, eating or drinking was found to occur significantly more often during IHF subtasks (0.58%) than in HH subtasks (0.15%). Drivers observed to reach for their cell phone mostly kept their cell phone in the cup holder (36.3%) or in their seat or lap (29.0% of interactions); however, some observed locations may have required drivers to move out of position. Hands-free cell phone technologies reduce the duration of cell phone visual-manual tasks compared to handheld cell phones. However, drivers with hands-free cell phone technologies available to them still choose to use handheld cell phones to converse or complete cell phone visual-manual tasks for a noteworthy portion of interactions.

The impact of distraction mitigation strategies on driving performance.

PubMed

Donmez, Birsen; Boyle, Linda Ng; Lee, John D

2006-01-01

An experiment was conducted to assess the effects of distraction mitigation strategies on drivers' performance and productivity while engaged in an in-vehicle information system task. Previous studies show that in-vehicle tasks undermine driver safety and there is a need to mitigate driver distraction. An advising strategy that alerts drivers to potential dangers and a locking strategy that prevents the driver from continuing the distracting task were presented to 16 middle-aged and 12 older drivers in a driving simulator in two modes (auditory, visual) and two road conditions (curves, braking events). Distraction was a problem for both age groups. Visual distractions were more detrimental than auditory ones for curve negotiation, as depicted by more erratic steering, F (6, 155) = 26.76, p < .05. Drivers did brake more abruptly under auditory distractions, but this effect was mitigated by both the advising, t (155) = 8.37, p < .05, and locking strategies, t (155) = 8.49, p < .05. The locking strategy also resulted in longer minimum time to collision for middle-aged drivers engaged in visual distractions, F (6, 138) = 2.43, p < .05. Adaptive interfaces can reduce abrupt braking on curve entries resulting from auditory distractions and can also improve the braking response for distracted drivers. These strategies can be incorporated into existing in-vehicle systems, thus mitigating the effects of distraction and improving driver performance.

77 FR 11199 - Visual-Manual NHTSA Driver Distraction Guidelines for In-Vehicle Electronic Devices

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-24

...The National Highway Traffic Safety Administration (NHTSA) is concerned about the effects of distraction due to drivers' use of electronic devices on motor vehicle safety. Consequently, NHTSA is issuing nonbinding, voluntary NHTSA Driver Distraction Guidelines (NHTSA Guidelines) to promote safety by discouraging the introduction of excessively distracting devices in vehicles. This notice details the contents of the first phase of the NHTSA Driver Distraction Guidelines. These NHTSA Guidelines cover original equipment in-vehicle device secondary tasks (communications, entertainment, information gathering, and navigation tasks not required to drive are considered secondary tasks) performed by the driver through visual-manual means (meaning the driver looking at a device, manipulating a device-related control with the driver's hand, and watching for visual feedback). The proposed NHTSA Guidelines list certain secondary, non-driving related tasks that, based on NHTSA's research, are believed by the agency to interfere inherently with a driver's ability to safely control the vehicle. The Guidelines recommend that those in-vehicle devices be designed so that they cannot be used by the driver to perform such tasks while the driver is driving. For all other secondary, non-driving-related visual-manual tasks, the NHTSA Guidelines specify a test method for measuring the impact of task performance on driving safety while driving and time-based acceptance criteria for assessing whether a task interferes too much with driver attention to be suitable to perform while driving. If a task does not meet the acceptance criteria, the NHTSA Guidelines recommend that in- vehicle devices be designed so that the task cannot be performed by the driver while driving. In addition to identifying inherently distracting tasks and providing a means for measuring and evaluating the level of distraction associated with other non-driving-related tasks, the NHTSA Guidelines contain several design recommendations for in-vehicle devices in order to minimize their potential for distraction. NHTSA seeks comments on these NHTSA Guidelines and any suggestions for how to improve them so as to better enhance motor vehicle safety.

Drivers' and non-drivers' performance in a change detection task with static driving scenes: is there a benefit of experience?

PubMed

Zhao, Nan; Chen, Wenfeng; Xuan, Yuming; Mehler, Bruce; Reimer, Bryan; Fu, Xiaolan

2014-01-01

The 'looked-but-failed-to-see' phenomenon is crucial to driving safety. Previous research utilising change detection tasks related to driving has reported inconsistent effects of driver experience on the ability to detect changes in static driving scenes. Reviewing these conflicting results, we suggest that drivers' increased ability to detect changes will only appear when the task requires a pattern of visual attention distribution typical of actual driving. By adding a distant fixation point on the road image, we developed a modified change blindness paradigm and measured detection performance of drivers and non-drivers. Drivers performed better than non-drivers only in scenes with a fixation point. Furthermore, experience effect interacted with the location of the change and the relevance of the change to driving. These results suggest that learning associated with driving experience reflects increased skill in the efficient distribution of visual attention across both the central focus area and peripheral objects. This article provides an explanation for the previously conflicting reports of driving experience effects in change detection tasks. We observed a measurable benefit of experience in static driving scenes, using a modified change blindness paradigm. These results have translational opportunities for picture-based training and testing tools to improve driver skill.

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - FIELD PORTABLE X-RAY FLUORESCENCE ANALYZER - SCITEC, MAP SPECTRUM ANALYZER

EPA Science Inventory

In April 1995, the U.S. Environmental Protection Agency (EPA) sponsored a demonstration of field portable X-ray fluorescence (FPXRF) analyzers. The primary objectives of this demonstration were (1) to determine how well FPXRF analyzers perform in comparison to standard reference...

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - FIELD PORTABLE X-RAY FLUORESCENCE ANALYZER - HNU SYSTEMS, SEFA-P

EPA Science Inventory

In April 1995, the Environmental Protection Agency (EPA) conducted a demonstration of field portable X-ray fluorescence (FPXRF) Analyzers. The primary objectives of this demonstration were (1) to determine how well FPXRF analyzers perform in comparison to a standard reference m...

Assessing the driving performance of older adult drivers: on-road versus simulated driving.

PubMed

Lee, Hoe C; Cameron, Don; Lee, Andy H

2003-09-01

To validate a laboratory-based driving simulator in measuring on-road driving performance, 129 older adult drivers were assessed with both the simulator and an on-road test. The driving performance of the participants was gauged by appropriate and reliable age-specific assessment criteria, which were found to be negatively correlated with age. Using principal component analysis, two performance indices were developed from the criteria to represent the overall performance in simulated driving and the on-road assessment. There was significant positive association between the two indices, with the simulated driving performance index explaining over two-thirds of the variability of the on-road driving performance index, after adjustment for age and gender of the drivers. The results supported the validity of the driving simulator and it is a safer and more economical method than the on-road testing to assess the driving performance of older adult drivers.

Model driver screening and evaluation program. Volume 2, Maryland pilot older driver study

DOT National Transportation Integrated Search

2003-05-01

This research project studied the feasibility as well as the scientific validity and utility of performing functional capacity screening with older drivers. A Model Program was described encompassing procedures to detect functionally impaired drivers...

Position requirements for space station personnel and linkages to portable microcomputer performance assessment

NASA Technical Reports Server (NTRS)

Jeanneret, P. R.

1988-01-01

The development and use of a menu of performance tests that can be self-administered on a portable microcomputer are investigated. In order to identify, develop, or otherwise select the relevant human capabilities/attributes to measure and hence include in the performance battery, it is essential that an analysis be conducted of the jobs or functions that will be performed throughout a space shuttle mission. The primary job analysis instrument, the Position Analysis Questionnaire (PAQ), is discussed in detail so the reader will have sufficient background for understanding the application of the instrument to the various work activities included within the scope of the study, and the derivation of the human requirements (abilities/attributes) from the PAQ analyses. The research methodology is described and includes the procedures used for gathering the PAQ data. The results are presented in detail with specific emphasis on identifying critical requirements that can be measured with a portable computerized assessment battery. A discussion of the results is given with implications for future research.

Comparison of a novel bedside portable endoscopy device with nasogastric aspiration for identifying upper gastrointestinal bleeding.

PubMed

Choi, Jong Hwan; Choi, Jae Hyuk; Lee, Yoo Jin; Lee, Hyung Ki; Choi, Wang Yong; Kim, Eun Soo; Park, Kyung Sik; Cho, Kwang Bum; Jang, Byoung Kuk; Chung, Woo Jin; Hwang, Jae Seok

2014-07-07

To compare outcomes using the novel portable endoscopy with that of nasogastric (NG) aspiration in patients with gastrointestinal bleeding. Patients who underwent NG aspiration for the evaluation of upper gastrointestinal (UGI) bleeding were eligible for the study. After NG aspiration, we performed the portable endoscopy to identify bleeding evidence in the UGI tract. Then, all patients underwent conventional esophagogastroduodenoscopy as the gold-standard test. The sensitivity, specificity, and accuracy of the portable endoscopy for confirming UGI bleeding were compared with those of NG aspiration. In total, 129 patients who had GI bleeding signs or symptoms were included in the study (age 64.46 ± 13.79, 91 males). The UGI tract (esophagus, stomach, and duodenum) was the most common site of bleeding (81, 62.8%) and the cause of bleeding was not identified in 12 patients (9.3%). Specificity for identifying UGI bleeding was higher with the portable endoscopy than NG aspiration (85.4% vs 68.8%, P = 0.008) while accuracy was comparable. The accuracy of the portable endoscopy was significantly higher than that of NG in the subgroup analysis of patients with esophageal bleeding (88.2% vs 75%, P = 0.004). Food material could be detected more readily by the portable endoscopy than NG tube aspiration (20.9% vs 9.3%, P = 0.014). No serious adverse effect was observed during the portable endoscopy. The portable endoscopy was not superior to NG aspiration for confirming UGI bleeding site. However, this novel portable endoscopy device might provide a benefit over NG aspiration in patients with esophageal bleeding.

A portable battery for objective, non-obstrusive measures of human performances

NASA Technical Reports Server (NTRS)

Kennedy, R. S.

1984-01-01

The need for a standardized battery of human performance tests to measure the effects of various treatments is pointed out. Progress in such a program is reported. Three batteries are available which differ in length and the number of tests in the battery. All tests are implemented on a portable, lap held, briefcase size microprocessor. Performances measured include: information processing, memory, visual perception, reasoning, and motor skills, programs to determine norms, reliabilities, stabilities, factor structure of tests, comparisons with marker tests, apparatus suitability. Rationale for the battery is provided.

The impact of continuous driving time and rest time on commercial drivers' driving performance and recovery.

PubMed

Wang, Lianzhen; Pei, Yulong

2014-09-01

This real road driving study was conducted to investigate the effects of driving time and rest time on the driving performance and recovery of commercial coach drivers. Thirty-three commercial coach drivers participated in the study, and were divided into three groups according to driving time: (a) 2 h, (b) 3 h, and (c) 4 h. The Stanford Sleepiness Scale (SSS) was used to assess the subjective fatigue level of the drivers. One-way ANOVA was employed to analyze the variation in driving performance. The statistical analysis revealed that driving time had a significant effect on the subjective fatigue and driving performance measures among the three groups. After 2 h of driving, both the subjective fatigue and driving performance measures began to deteriorate. After 4 h of driving, all of the driving performance indicators changed significantly except for depth perception. A certain amount of rest time eliminated the negative effects of fatigue. A 15-minute rest allowed drivers to recover from a two-hour driving task. This needed to be prolonged to 30 min for driving tasks of 3 to 4 h of continuous driving. Drivers' attention, reactions, operating ability, and perceptions are all affected in turn after over 2 h of continuous driving. Drivers should take a certain amount of rest to recover from the fatigue effects before they continue driving. Copyright © 2014 National Safety Council and Elsevier Ltd. All rights reserved.

Automobile driver on-road performance test. Volume 3, Examiner's manual

DOT National Transportation Integrated Search

1981-09-30

This report provides procedures for administering and scoring the Automobile Driver On-Road Performance Test (ADOPT). The ADOPT checks 21 separate driving performances. Performances are checked at pre-determined locations along a 10-minute route and ...

Automobile driver on-road performance test. Volume 2, Administrator's manual

DOT National Transportation Integrated Search

1981-09-30

This report provides procedures for setting up, administering, and scoring the Automobile Driver On-Road Performance Test (ADOPT). The ADOPT checks 21 separate driving performances. Performances are checked at pre-determined locations along a 10-minu...

77 FR 12907 - Visual-Manual NHTSA Driver Distraction Guidelines for In-Vehicle Electronic Devices

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-02

... impact of task performance while driving on driving safety and time-based acceptance criteria for... feedback). The proposed NHTSA Guidelines list certain secondary, non-driving related tasks that, based on... cannot be used by the driver to perform such tasks while the driver is driving. For all other secondary...

Leukoaraiosis Significantly Worsens Driving Performance of Ordinary Older Drivers

PubMed Central

Zheng, Rencheng; Fang, Fang; Ohori, Masanori; Nakamura, Hiroki; Kumagai, Yasuhiho; Okada, Hiroshi; Teramura, Kazuhiko; Nakayama, Satoshi; Irimajiri, Akinori; Taoka, Hiroshi; Okada, Satoshi

2014-01-01

Background Leukoaraiosis is defined as extracellular space caused mainly by atherosclerotic or demyelinated changes in the brain tissue and is commonly found in the brains of healthy older people. A significant association between leukoaraiosis and traffic crashes was reported in our previous study; however, the reason for this is still unclear. Method This paper presents a comprehensive evaluation of driving performance in ordinary older drivers with leukoaraiosis. First, the degree of leukoaraiosis was examined in 33 participants, who underwent an actual-vehicle driving examination on a standard driving course, and a driver skill rating was also collected while the driver carried out a paced auditory serial addition test, which is a calculating task given verbally. At the same time, a steering entropy method was used to estimate steering operation performance. Results The experimental results indicated that a normal older driver with leukoaraiosis was readily affected by external disturbances and made more operation errors and steered less smoothly than one without leukoaraiosis during driving; at the same time, their steering skill significantly deteriorated. Conclusions Leukoaraiosis worsens the driving performance of older drivers because of their increased vulnerability to distraction. PMID:25295736

Effect of Cognitive Demand on Functional Visual Field Performance in Senior Drivers with Glaucoma

PubMed Central

Gangeddula, Viswa; Ranchet, Maud; Akinwuntan, Abiodun E.; Bollinger, Kathryn; Devos, Hannes

2017-01-01

Purpose: To investigate the effect of cognitive demand on functional visual field performance in drivers with glaucoma. Method: This study included 20 drivers with open-angle glaucoma and 13 age- and sex-matched controls. Visual field performance was evaluated under different degrees of cognitive demand: a static visual field condition (C1), dynamic visual field condition (C2), and dynamic visual field condition with active driving (C3) using an interactive, desktop driving simulator. The number of correct responses (accuracy) and response times on the visual field task were compared between groups and between conditions using Kruskal–Wallis tests. General linear models were employed to compare cognitive workload, recorded in real-time through pupillometry, between groups and conditions. Results: Adding cognitive demand (C2 and C3) to the static visual field test (C1) adversely affected accuracy and response times, in both groups (p < 0.05). However, drivers with glaucoma performed worse than did control drivers when the static condition changed to a dynamic condition [C2 vs. C1 accuracy; glaucoma: median difference (Q1–Q3) 3 (2–6.50) vs. controls: 2 (0.50–2.50); p = 0.05] and to a dynamic condition with active driving [C3 vs. C1 accuracy; glaucoma: 2 (2–6) vs. controls: 1 (0.50–2); p = 0.02]. Overall, drivers with glaucoma exhibited greater cognitive workload than controls (p = 0.02). Conclusion: Cognitive demand disproportionately affects functional visual field performance in drivers with glaucoma. Our results may inform the development of a performance-based visual field test for drivers with glaucoma. PMID:28912712

Method and apparatus of a portable imaging-based measurement with self calibration

DOEpatents

Chang, Tzyy-Shuh [Ann Arbor, MI; Huang, Hsun-Hau [Ann Arbor, MI

2012-07-31

A portable imaging-based measurement device is developed to perform 2D projection based measurements on an object that is difficult or dangerous to access. This device is equipped with self calibration capability and built-in operating procedures to ensure proper imaging based measurement.

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - FIELD PORTABLE X-RAY FLUORESCENCE ANALYZER - METOREX, INC. X-MET 920-P AND 940

EPA Science Inventory

In April 1995, the U.S. Environmental Protection Agency (EPA) sponsored a demonstration of field portable X-ray fluorescence (FPXRF) analyzers. The primary objectives of this demonstration were (1) to determine how well FPXRF analyzers perform in comparison to standard reference...

ESTE: Verification of Portable Optical and Thermal Imaging Devices for Leak Detection at Petroleum Refineries and Chemical Plants

EPA Science Inventory

This is an ESTE project summary brief. EPA’s Environmental Technology Verification Program (ETV) is verifying the performance of portable optical and thermal imaging devices for leak detection at petroleum refineries and chemical plans. Industrial facilities, such as chemical p...

78 FR 24817 - Visual-Manual NHTSA Driver Distraction Guidelines for In-Vehicle Electronic Devices

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-26

...The National Highway Traffic Safety Administration (NHTSA) is concerned about the effects of distraction on motor vehicle safety due to drivers' use of electronic devices. Consequently, NHTSA is issuing nonbinding, voluntary Driver Distraction Guidelines (NHTSA Guidelines) to promote safety by discouraging the introduction of excessively distracting devices in vehicles. This notice announces the issuance of the final version of the first phase of the NHTSA Guidelines. This first phase applies to original equipment (OE) in-vehicle electronic devices used by the driver to perform secondary tasks (communications, entertainment, information gathering, navigation tasks, etc. are considered secondary tasks) through visual-manual means (i.e., the driver looks at a device, manipulates a device-related control with his or her hand, and/or watches for visual feedback). The NHTSA Guidelines list certain secondary tasks believed by the agency to interfere inherently with a driver's ability to safely control the vehicle. The NHTSA Guidelines recommend that in-vehicle devices be designed so that they cannot be used by the driver to perform these inherently distracting secondary tasks while driving. For all other visual-manual secondary tasks, the NHTSA Guidelines specify a test method for measuring eye glance behavior during those tasks. Eye glance metrics are compared to acceptance criteria to evaluate whether a task interferes too much with driver attention, rendering it unsuitable for a driver to perform while driving. If a task does not meet the acceptance criteria, the NHTSA Guidelines recommend that the task be made inaccessible for performance by the driver while driving. In addition, the NHTSA Guidelines contain several recommendations to limit and reduce the potential for distraction associated with the use of OE in-vehicle electronic devices.

TECHNICAL NOTE: Portable audio electronics for impedance-based measurements in microfluidics

NASA Astrophysics Data System (ADS)

Wood, Paul; Sinton, David

2010-08-01

We demonstrate the use of audio electronics-based signals to perform on-chip electrochemical measurements. Cell phones and portable music players are examples of consumer electronics that are easily operated and are ubiquitous worldwide. Audio output (play) and input (record) signals are voltage based and contain frequency and amplitude information. A cell phone, laptop soundcard and two compact audio players are compared with respect to frequency response; the laptop soundcard provides the most uniform frequency response, while the cell phone performance is found to be insufficient. The audio signals in the common portable music players and laptop soundcard operate in the range of 20 Hz to 20 kHz and are found to be applicable, as voltage input and output signals, to impedance-based electrochemical measurements in microfluidic systems. Validated impedance-based measurements of concentration (0.1-50 mM), flow rate (2-120 µL min-1) and particle detection (32 µm diameter) are demonstrated. The prevailing, lossless, wave audio file format is found to be suitable for data transmission to and from external sources, such as a centralized lab, and the cost of all hardware (in addition to audio devices) is ~10 USD. The utility demonstrated here, in combination with the ubiquitous nature of portable audio electronics, presents new opportunities for impedance-based measurements in portable microfluidic systems.

Driver distraction by smartphone use (WhatsApp) in different age groups.

PubMed

Ortiz, C; Ortiz-Peregrina, S; Castro, J J; Casares-López, M; Salas, C

2018-08-01

This paper investigates the effect that texting with WhatsApp, one of the most common applications for instant messaging, exerts on driving performance. Because distracted driving also affects older drivers, who can have seriously compromised vision, we also analysed the associations between visual-function parameters and driving performance. A total of 75 drivers, experienced in sending WhatsApp messages (≥10WhatsApp messages/week), participated in this study and were divided into four age categories. Visual-function tests included contrast sensitivity with and without glare, retinal straylight and objective assessment of optical quality. Simulated driving performance was assessed under a baseline driving condition (without distraction) as well as a texting condition (WhatsApp messages) while driving. The participants used their own mobile phone. Lastly, objective results of driving performance were compared with subjective self-report data from the Driver Behaviour Questionnaire (DBQ). The analysis indicated that functional changes occurring with age, such as a lower contrast sensitivity and greater retinal straylight, were correlated with a higher number of collisions, longer distances driven outside the lane, and greater standard deviation of lateral position (SDLP). The results showed a significant main effect of age for the driving-performance parameters. Also, compared to the baseline, texting WhatsApp messages while driving worsens driving performance for all age groups, most notably among older participants. Thus, the older drivers' SDLP was ∼14% higher than that for the baseline average of all the other drivers and rose to 29% under distraction, reflecting the impact of secondary tasks. The negative effect of the use of the smartphone during driving was also reflected in the number of collisions, with a greater risk of accidents in all the groups of drivers (by 8.3% for young adults, 25.0% for adults, 80.5% for middle-aged adults, and 134.5% for older drivers). Lastly, participants' subjective responses indicated that younger drivers (18-24 years) had a higher risk of deliberately violating safe driving practices (p < 0.05). The present study demonstrates that texting WhatsApp messages while driving significantly impairs the ability to drive safely, with older drivers being the group most adversely affected. It would be recommendable to include other nonstandard vision tests, which have shown associations with driving performance, in the examination for driver licensing. This would help raise the awareness of older drivers concerning their visual limitations, permitting them to adopt compensatory measures to improve their driving safety. Nevertheless, it is also necessary to raise awareness among the younger drivers of the risks involved in behaviour behind the wheel. Copyright © 2018 Elsevier Ltd. All rights reserved.

Does attention capacity moderate the effect of driver distraction in older drivers?

PubMed

Cuenen, Ariane; Jongen, Ellen M M; Brijs, Tom; Brijs, Kris; Lutin, Mark; Van Vlierden, Karin; Wets, Geert

2015-04-01

With age, a decline in attention capacity may occur and this may impact driving performance especially while distracted. Although the effect of distraction on driving performance of older drivers has been investigated, the moderating effect of attention capacity on driving performance during distraction has not been investigated yet. Therefore, the aim was to investigate whether attention capacity has a moderating effect on older drivers' driving performance during visual distraction (experiment 1) and cognitive distraction (experiment 2). In a fixed-based driving simulator, older drivers completed a driving task without and with visual distraction (experiment 1, N=17, mean age 78 years) or cognitive distraction (experiment 2, N=35, mean age 76 years). Several specific driving measures of varying complexity (i.e., speed, lane keeping, following distance, braking behavior, and crashes) were investigated. In addition to these objective driving measures, subjective measures of workload and driving performance were also included. In experiment 1, crash occurrence increased with visual distraction and was negatively related to attention capacity. In experiment 2, complete stops at stop signs decreased, initiation of braking at pedestrian crossings was later, and crash occurrence increased with cognitive distraction. Interestingly, for a measure of lane keeping (i.e., standard deviation of lateral lane position (SDLP)), effects of both types of distraction were moderated by attention capacity. Despite the decrease of driving performance with distraction, participants estimated their driving performance during distraction as good. These results imply that attention capacity is important for driving. Driver assessment and training programs might therefore focus on attention capacity. Nonetheless, it is crucial to eliminate driver distraction as much as possible given the deterioration of performance on several driving measures in those with low and high attention capacity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of a computer-based training module on drivers' willingness to engage in distracting activities.

PubMed

Horrey, William J; Lesch, Mary F; Kramer, Arthur F; Melton, David F

2009-08-01

This study examines the effect of a computer-based training module on drivers' attitudes and behaviors with respect to in-vehicle distraction. Research findings on the negative performance implications of distraction call for the need to mitigate these adverse effects. Forty drivers (ages 18 to 20 yrs) were divided into two groups: a training group that completed the module and a control group that viewed an unrelated video. The training promoted enhanced metacognitive skills (e.g., planning, monitoring) and strategies to deal with distraction. Measures of willingness to perform in-vehicle activities while driving (involving the use of short videos) were assessed before and after the intervention. Drivers also performed in-vehicle tasks while driving an instrumented vehicle on a closed test track. Following the training, drivers in the training group showed a decline in their ratings of willingness to engage in distracting activities along with a corresponding increase in perceived risk. In contrast, ratings from drivers in the control group did not change on any measures. Drivers in the training group were also more likely to perform in-vehicle tasks while the vehicle was parked compared with the control group-an obvious safety benefit. However, there was no observable benefit of training for drivers who performed the distracting tasks while the vehicle was in motion. There may be some promise to such a training approach. The implications for distraction and training are discussed. Training general skills in dealing with potentially distracting in-vehicle tasks may help offset some of the negative outcomes associated with their use.

Seven Performance Drivers.

ERIC Educational Resources Information Center

Ross, Linda

2003-01-01

Recent work with automotive e-commerce clients led to the development of a performance analysis methodology called the Seven Performance Drivers, including: standards, incentives, capacity, knowledge and skill, measurement, feedback, and analysis. This methodology has been highly effective in introducing and implementing performance improvement.…

Quantitative assessment of driving performance in Parkinson's disease

PubMed Central

Wood, J; Worringham, C; Kerr, G; Mallon, K; Silburn, P

2005-01-01

Objectives: The primary aim of this study was to determine how Parkinson's disease (PD) affects driving performance. It also examined whether changes in driver safety were related to specific clinical disease markers or an individual's self rating of driving ability. Methods: The driving performance of 25 patients with idiopathic PD and 21 age matched controls was assessed on a standardised open road route by an occupational therapist and driving instructor, to provide overall safety ratings and specific driving error scores. Results: The drivers with PD were rated as significantly less safe (p<0.05) than controls, and more than half of the drivers with PD would not have passed a state based driving test. The driver safety ratings were more strongly related to disease duration (r = –0.60) than to their on time Unified Parkinson's Disease Rating Scale (r = –0.24). Drivers with PD made significantly more errors than the control group during manoeuvres that involved changing lanes and lane keeping, monitoring their blind spot, reversing, car parking, and traffic light controlled intersections. The driving instructor also had to intervene to avoid an incident significantly more often for drivers with PD than for controls. Interestingly, driver safety ratings were unrelated to an individual's rating of their own driving performance, and this was the case for all participants. Conclusions: As a group, drivers with PD are less safe to drive than age matched controls. Standard clinical markers cannot reliably predict driver safety. Further studies are required to ascertain whether the identified driving difficulties can be ameliorated. PMID:15654027

Training Laparoscopic Skills at Home: Residents' Opinion of a New Portable Tablet Box Trainer.

PubMed

van der Aa, Jessica E; Schreuder, Henk W R

2016-04-01

To determine residents' opinion about a new portable box trainer, to see if they would be interested in using this for training at home, and to give an overview of the box trainers that could be used at home. An expert opinion study was performed among 27 gynecology residents to determine the value of the portable box trainer in training their laparoscopic skills and the value of using it at home. Their opinions were scored on a 5-point Likert scale. Gynecology residents very much appreciated the portable box trainer in its design, size, visualization, light source, ability to record, and instruments (all median 4). They felt that the portable box trainer would be effective in training laparoscopic skills in general; in training hand-eye coordination, 3D perception, and tying knots (all median 4); and especially in training basic skills (median 5). Almost all residents would use the portable box trainer if they had one at home (median 5). The literature supports the hypothesis that training laparoscopic skills at home using a box trainer may be effective in acquiring and maintaining laparoscopic skills. Training laparoscopic skills at home using a portable box trainer may be of added value in the laparoscopic training of surgical residents. Residents feel positive about using the new portable box trainer that is presented and appreciate the possibility of training at home. © The Author(s) 2015.

Association between older driver characteristics, on-road driving test performance, and crash liability.

PubMed

Keall, Michael D; Frith, William J

2004-06-01

From May 1999, a new system for licensing older drivers was introduced in New Zealand. It included a practical on-road driving test with expanded scope, to be completed every two years from the time the driver turns 80. The relationship between crashes and test performance needed to be studied to inform the debate regarding the testing system. The population studied was all drivers who entered this licensing system during its first three years of operation. They were defined as crash involved if they were involved in an injury crash during the two years following their first licensure under the new system. Logistic regression was used to describe the risk of crash involvement in terms of driving test performance and other driver characteristics. Each driving test failure was associated with a 33% increase in the odds of crash involvement (95% CI 14% to 55%), controlling for age, gender, minor traffic violations, and whether the older driver lived with another licensed driver or not. Minor traffic violations in the two years following the driving test were associated with twice the odds of crash involvement. These results suggest that the new on-road driving test does identify older driver behaviors or limitations that are related to crash liability. It is anticipated that the results presented here will provide essential information for discussing older driver licensing systems, whose impact will grow in importance as the population of drivers ages.

Traffic Games: Modeling Freeway Traffic with Game Theory.

PubMed

Cortés-Berrueco, Luis E; Gershenson, Carlos; Stephens, Christopher R

2016-01-01

We apply game theory to a vehicular traffic model to study the effect of driver strategies on traffic flow. The resulting model inherits the realistic dynamics achieved by a two-lane traffic model and aims to incorporate phenomena caused by driver-driver interactions. To achieve this goal, a game-theoretic description of driver interaction was developed. This game-theoretic formalization allows one to model different lane-changing behaviors and to keep track of mobility performance. We simulate the evolution of cooperation, traffic flow, and mobility performance for different modeled behaviors. The analysis of these results indicates a mobility optimization process achieved by drivers' interactions.

Application of laboratory and portable attenuated total reflectance infrared spectroscopic approaches for rapid quantification of alpaca serum immunoglobulin G

PubMed Central

Burns, Jennifer B.; Riley, Christopher B.; Shaw, R. Anthony; McClure, J. Trenton

2017-01-01

The objective of this study was to develop and compare the performance of laboratory grade and portable attenuated total reflectance infrared (ATR-IR) spectroscopic approaches in combination with partial least squares regression (PLSR) for the rapid quantification of alpaca serum IgG concentration, and the identification of low IgG (<1000 mg/dL), which is consistent with the diagnosis of failure of transfer of passive immunity (FTPI) in neonates. Serum samples (n = 175) collected from privately owned, healthy alpacas were tested by the reference method of radial immunodiffusion (RID) assay, and laboratory grade and portable ATR-IR spectrometers. Various pre-processing strategies were applied to the ATR-IR spectra that were linked to corresponding RID-IgG concentrations, and then randomly split into two sets: calibration (training) and test sets. PLSR was applied to the calibration set and calibration models were developed, and the test set was used to assess the accuracy of the analytical method. For the test set, the Pearson correlation coefficients between the IgG measured by RID and predicted by both laboratory grade and portable ATR-IR spectrometers was 0.91. The average differences between reference serum IgG concentrations and the two IR-based methods were 120.5 mg/dL and 71 mg/dL for the laboratory and portable ATR-IR-based assays, respectively. Adopting an IgG concentration <1000 mg/dL as the cut-point for FTPI cases, the sensitivity, specificity, and accuracy for identifying serum samples below this cut point by laboratory ATR-IR assay were 86, 100 and 98%, respectively (within the entire data set). Corresponding values for the portable ATR-IR assay were 95, 99 and 99%, respectively. These results suggest that the two different ATR-IR assays performed similarly for rapid qualitative evaluation of alpaca serum IgG and for diagnosis of IgG <1000 mg/dL, the portable ATR-IR spectrometer performed slightly better, and provides more flexibility for potential application in the field. PMID:28651006

Application of laboratory and portable attenuated total reflectance infrared spectroscopic approaches for rapid quantification of alpaca serum immunoglobulin G.

PubMed

Elsohaby, Ibrahim; Burns, Jennifer B; Riley, Christopher B; Shaw, R Anthony; McClure, J Trenton

2017-01-01

The objective of this study was to develop and compare the performance of laboratory grade and portable attenuated total reflectance infrared (ATR-IR) spectroscopic approaches in combination with partial least squares regression (PLSR) for the rapid quantification of alpaca serum IgG concentration, and the identification of low IgG (<1000 mg/dL), which is consistent with the diagnosis of failure of transfer of passive immunity (FTPI) in neonates. Serum samples (n = 175) collected from privately owned, healthy alpacas were tested by the reference method of radial immunodiffusion (RID) assay, and laboratory grade and portable ATR-IR spectrometers. Various pre-processing strategies were applied to the ATR-IR spectra that were linked to corresponding RID-IgG concentrations, and then randomly split into two sets: calibration (training) and test sets. PLSR was applied to the calibration set and calibration models were developed, and the test set was used to assess the accuracy of the analytical method. For the test set, the Pearson correlation coefficients between the IgG measured by RID and predicted by both laboratory grade and portable ATR-IR spectrometers was 0.91. The average differences between reference serum IgG concentrations and the two IR-based methods were 120.5 mg/dL and 71 mg/dL for the laboratory and portable ATR-IR-based assays, respectively. Adopting an IgG concentration <1000 mg/dL as the cut-point for FTPI cases, the sensitivity, specificity, and accuracy for identifying serum samples below this cut point by laboratory ATR-IR assay were 86, 100 and 98%, respectively (within the entire data set). Corresponding values for the portable ATR-IR assay were 95, 99 and 99%, respectively. These results suggest that the two different ATR-IR assays performed similarly for rapid qualitative evaluation of alpaca serum IgG and for diagnosis of IgG <1000 mg/dL, the portable ATR-IR spectrometer performed slightly better, and provides more flexibility for potential application in the field.

Use patterns among early adopters of adaptive cruise control.

PubMed

Xiong, Huimin; Boyle, Linda Ng; Moeckli, Jane; Dow, Benjamin R; Brown, Timothy L

2012-10-01

The objective of this study was to investigate use patterns among early adopters of adaptive cruise control (ACC). Extended use ofACC may influence a driver's behavior in the long-term, which can have unintended safety consequences. The authors examined the use of a motion-based simulator by 24 participants (15 males and 9 females). Cluster analysis was performed on drivers' use of ACC and was based on their gap settings, speed settings, number of warnings issued, and ACC disengaged. The data were then examined on the basis of driving performance measures and drivers' subjective responses to trust in ACC, understanding of system operations, and driving styles. Driving performance measures included minimum time headway, adjusted minimum time to collision, and drivers' reaction time to critical events. Three groups of drivers were observed on the basis of risky behavior, moderately risky behavior, and conservative behavior. Drivers in the conservative group stayed farther behind the lead vehicle than did drivers in the other two groups. Risky drivers responded later to critical events and had more ACC warnings issued. Safety consequences with ACC may be more prevalent in some driver groups than others. The findings suggest that these safety implications are related to trust in automation, driving styles, understanding of system operations, and personalities. Potential applications of this research include enhanced design for next-generation ACC systems and countermeasures to improve safe driving with ACC.

Impact of Automation on Drivers' Performance in Agricultural Semi-Autonomous Vehicles.

PubMed

Bashiri, B; Mann, D D

2015-04-01

Drivers' inadequate mental workload has been reported as one of the negative effects of driving assistant systems and in-vehicle automation. The increasing trend of automation in agricultural vehicles raises some concerns about drivers' mental workload in such vehicles. Thus, a human factors perspective is needed to identify the consequences of such automated systems. In this simulator study, the effects of vehicle steering task automation (VSTA) and implement control and monitoring task automation (ICMTA) were investigated using a tractor-air seeder system as a case study. Two performance parameters (reaction time and accuracy of actions) were measured to assess drivers' perceived mental workload. Experiments were conducted using the tractor driving simulator (TDS) located in the Agricultural Ergonomics Laboratory at the University of Manitoba. Study participants were university students with tractor driving experience. According to the results, reaction time and number of errors made by drivers both decreased as the automation level increased. Correlations were found among performance parameters and subjective mental workload reported by the drivers.

Modelling the influence of sensory dynamics on linear and nonlinear driver steering control

NASA Astrophysics Data System (ADS)

Nash, C. J.; Cole, D. J.

2018-05-01

A recent review of the literature has indicated that sensory dynamics play an important role in the driver-vehicle steering task, motivating the design of a new driver model incorporating human sensory systems. This paper presents a full derivation of the linear driver model developed in previous work, and extends the model to control a vehicle with nonlinear tyres. Various nonlinear controllers and state estimators are compared with different approximations of the true system dynamics. The model simulation time is found to increase significantly with the complexity of the controller and state estimator. In general the more complex controllers perform best, although with certain vehicle and tyre models linearised controllers perform as well as a full nonlinear optimisation. Various extended Kalman filters give similar results, although the driver's sensory dynamics reduce control performance compared with full state feedback. The new model could be used to design vehicle systems which interact more naturally and safely with a human driver.

Driver's mental workload prediction model based on physiological indices.

PubMed

Yan, Shengyuan; Tran, Cong Chi; Wei, Yingying; Habiyaremye, Jean Luc

2017-09-15

Developing an early warning model to predict the driver's mental workload (MWL) is critical and helpful, especially for new or less experienced drivers. The present study aims to investigate the correlation between new drivers' MWL and their work performance, regarding the number of errors. Additionally, the group method of data handling is used to establish the driver's MWL predictive model based on subjective rating (NASA task load index [NASA-TLX]) and six physiological indices. The results indicate that the NASA-TLX and the number of errors are positively correlated, and the predictive model shows the validity of the proposed model with an R 2 value of 0.745. The proposed model is expected to provide a reference value for the new drivers of their MWL by providing the physiological indices, and the driving lesson plans can be proposed to sustain an appropriate MWL as well as improve the driver's work performance.

Steering disturbance rejection using a physics-based neuromusculoskeletal driver model

NASA Astrophysics Data System (ADS)

Mehrabi, Naser; Sharif Razavian, Reza; McPhee, John

2015-10-01

The aim of this work is to develop a comprehensive yet practical driver model to be used in studying driver-vehicle interactions. Drivers interact with their vehicle and the road through the steering wheel. This interaction forms a closed-loop coupled human-machine system, which influences the driver's steering feel and control performance. A hierarchical approach is proposed here to capture the complexity of the driver's neuromuscular dynamics and the central nervous system in the coordination of the driver's upper extremity activities, especially in the presence of external disturbance. The proposed motor control framework has three layers: the first (or the path planning) plans a desired vehicle trajectory and the required steering angles to perform the desired trajectory; the second (or the musculoskeletal controller) actuates the musculoskeletal arm to rotate the steering wheel accordingly; and the final layer ensures the precision control and disturbance rejection of the motor control units. The physics-based driver model presented here can also provide insights into vehicle control in relaxed and tensed driving conditions, which are simulated by adjusting the driver model parameters such as cognition delay and muscle co-contraction dynamics.

Comparison of a novel bedside portable endoscopy device with nasogastric aspiration for identifying upper gastrointestinal bleeding

PubMed Central

Choi, Jong Hwan; Choi, Jae Hyuk; Lee, Yoo Jin; Lee, Hyung Ki; Choi, Wang Yong; Kim, Eun Soo; Park, Kyung Sik; Cho, Kwang Bum; Jang, Byoung Kuk; Chung, Woo Jin; Hwang, Jae Seok

2014-01-01

AIM: To compare outcomes using the novel portable endoscopy with that of nasogastric (NG) aspiration in patients with gastrointestinal bleeding. METHODS: Patients who underwent NG aspiration for the evaluation of upper gastrointestinal (UGI) bleeding were eligible for the study. After NG aspiration, we performed the portable endoscopy to identify bleeding evidence in the UGI tract. Then, all patients underwent conventional esophagogastroduodenoscopy as the gold-standard test. The sensitivity, specificity, and accuracy of the portable endoscopy for confirming UGI bleeding were compared with those of NG aspiration. RESULTS: In total, 129 patients who had GI bleeding signs or symptoms were included in the study (age 64.46 ± 13.79, 91 males). The UGI tract (esophagus, stomach, and duodenum) was the most common site of bleeding (81, 62.8%) and the cause of bleeding was not identified in 12 patients (9.3%). Specificity for identifying UGI bleeding was higher with the portable endoscopy than NG aspiration (85.4% vs 68.8%, P = 0.008) while accuracy was comparable. The accuracy of the portable endoscopy was significantly higher than that of NG in the subgroup analysis of patients with esophageal bleeding (88.2% vs 75%, P = 0.004). Food material could be detected more readily by the portable endoscopy than NG tube aspiration (20.9% vs 9.3%, P = 0.014). No serious adverse effect was observed during the portable endoscopy. CONCLUSION: The portable endoscopy was not superior to NG aspiration for confirming UGI bleeding site. However, this novel portable endoscopy device might provide a benefit over NG aspiration in patients with esophageal bleeding. PMID:25009396

To call or not to call--that is the question (while driving).

PubMed

Tractinsky, Noam; Ram, Efrat Soffer; Shinar, David

2013-07-01

We studied whether decisions to engage in cell phone conversation while driving and the consequences of such decisions are related to the driver's age, to the road conditions (demands of the driving task), and to the driver's role in initiating the phone call (i.e. the driver as caller vs. as receiver). Two experiments were performed in a driving simulator in which driver age, road conditions and phone conversation, as a secondary task, were manipulated. Engagement in cell phone conversations, performance in the driving and the conversation tasks, and subjective effort assessment were recorded. In general, drivers were more willing to accept incoming calls than to initiate calls. In addition, older and younger drivers were more susceptible to the deleterious effects of phone conversations while driving than middle aged/experienced drivers. While older drivers were aware of this susceptibility by showing sensitivity to road conditions before deciding whether to engage in a call or not, young drivers showed no such sensitivity. The results can guide the development of young driver training programs and point at the need to develop context-aware management systems of in-vehicle cell phone conversations. Copyright © 2013 Elsevier Ltd. All rights reserved.

Handheld probe integrating laser diode and ultrasound transducer array for ultrasound/photoacoustic dual modality imaging.

PubMed

Daoudi, K; van den Berg, P J; Rabot, O; Kohl, A; Tisserand, S; Brands, P; Steenbergen, W

2014-10-20

Ultrasound and photoacoustics can be utilized as complementary imaging techniques to improve clinical diagnoses. Photoacoustics provides optical contrast and functional information while ultrasound provides structural and anatomical information. As of yet, photoacoustic imaging uses large and expensive systems, which limits their clinical application and makes the combination costly and impracticable. In this work we present and evaluate a compact and ergonomically designed handheld probe, connected to a portable ultrasound system for inexpensive, real-time dual-modality ultrasound/photoacoustic imaging. The probe integrates an ultrasound transducer array and a highly efficient diode stack laser emitting 130 ns pulses at 805 nm wavelength and a pulse energy of 0.56 mJ, with a high pulse repetition frequency of up to 10 kHz. The diodes are driven by a customized laser driver, which can be triggered externally with a high temporal stability necessary to synchronize the ultrasound detection and laser pulsing. The emitted beam is collimated with cylindrical micro-lenses and shaped using a diffractive optical element, delivering a homogenized rectangular light intensity distribution. The system performance was tested in vitro and in vivo by imaging a human finger joint.

The Portable Usability Testing Lab: A Flexible Research Tool.

ERIC Educational Resources Information Center

Hale, Michael E.; And Others

A group of faculty at the University of Georgia obtained funding for a research and development facility called the Learning and Performance Support Laboratory (LPSL). One of the LPSL's primary needs was obtaining a portable usability lab for software testing, so the facility obtained the "Luggage Lab 2000." The lab is transportable to…

The effects of cognitively demanding dual-task driving condition on elderly people's driving performance; Real driving monitoring.

PubMed

Ebnali, Mahdi; Ahmadnezhad, Pedram; Shateri, Alireza; Mazloumi, Adel; Ebnali Heidari, Majid; Nazeri, Ahmad Reza

2016-09-01

Using in-vehicle audio technologies such as audio systems and voice messages is regarded as a common secondary task. Such tasks, known as the sources of non-visual distraction, affect the driving performance. Given the elderly drivers' cognitive limitations, driving can be even more challenging to drivers. The current study examined how listening to economic news, as a cognitively demanding secondary task, affects elderly subjects' driving performance and whether their comprehension accuracy is associated with these effects. Participants of the study (N=22) drove in a real condition with and without listening to economic news. Measurements included driving performance (speed control, forward crash risk, and lateral lane position) and task performance (comprehension accuracy). The mean driving speed, duration of driving in unsafe zones and numbers of overtaking decreased significantly when drivers were engaged in the dual-task condition. Moreover, the cognitive secondary task led to a higher speed variability. Our results demonstrate that there was not a significant relationship between the lane changes and the activity of listening to economic news. However, a meaningful difference was observed between general comprehension and deep comprehension on the one hand and driving performance on the other. Another aspect of our study concerning the drivers' ages and their comprehension revealed a significant relationship between age above 75 and comprehension level. Drivers aging 75 and older showed a lower level of deep comprehension. Our study demonstrates that elderly drivers compensated driving performance with safety margin adoption while they were cognitively engaged. In this condition, however, maintaining speed proved more demanding for drivers aging 75 and older. Copyright © 2016 Elsevier Ltd. All rights reserved.

A rear-end collision risk assessment model based on drivers' collision avoidance process under influences of cell phone use and gender-A driving simulator based study.

PubMed

Li, Xiaomeng; Yan, Xuedong; Wu, Jiawei; Radwan, Essam; Zhang, Yuting

2016-12-01

Driver's collision avoidance performance has a direct link to the collision risk and crash severity. Previous studies demonstrated that the distracted driving, such as using a cell phone while driving, disrupted the driver's performance on road. This study aimed to investigate the manner and extent to which cell phone use and driver's gender affected driving performance and collision risk in a rear-end collision avoidance process. Forty-two licensed drivers completed the driving simulation experiment in three phone use conditions: no phone use, hands-free, and hand-held, in which the drivers drove in a car-following situation with potential rear-end collision risks caused by the leading vehicle's sudden deceleration. Based on the experiment data, a rear-end collision risk assessment model was developed to assess the influence of cell phone use and driver's gender. The cell phone use and driver's gender were found to be significant factors that affected the braking performances in the rear-end collision avoidance process, including the brake reaction time, the deceleration adjusting time and the maximum deceleration rate. The minimum headway distance between the leading vehicle and the simulator during the rear-end collision avoidance process was the final output variable, which could be used to measure the rear-end collision risk and judge whether a collision occurred. The results showed that although cell phone use drivers took some compensatory behaviors in the collision avoidance process to reduce the mental workload, the collision risk in cell phone use conditions was still higher than that without the phone use. More importantly, the results proved that the hands-free condition did not eliminate the safety problem associated with distracted driving because it impaired the driving performance in the same way as much as the use of hand-held phones. In addition, the gender effect indicated that although female drivers had longer reaction time than male drivers in critical situation, they were more quickly in braking with larger maximum deceleration rate, and they tended to keep a larger safety margin with the leading vehicle compared to male drivers. The findings shed some light on the further development of advanced collision avoidance technologies and the targeted intervention strategies about cell phone use while driving. Copyright © 2016 Elsevier Ltd. All rights reserved.

Use of portable ladders - field observations and self-reported safety performance in the cable TV industry.

PubMed

Chang, Wen-Ruey; Huang, Yueng-Hsiang; Brunette, Christopher; Lee, Jin

2017-11-01

Portable ladders incidents remain a major cause of falls from heights. This study reported field observations of environments, work conditions and safety behaviour involving portable ladders and their correlations with self-reported safety performance. Seventy-five professional installers of a company in the cable and other pay TV industry were observed for 320 ladder usages at their worksites. The participants also filled out a questionnaire to measure self-reported safety performance. Proper setup on slippery surfaces, correct method for ladder inclination setup and ladder secured at the bottom had the lowest compliance with best practices and training guidelines. The observation compliance score was found to have significant correlation with straight ladder inclined angle (Pearson's r = 0.23, p < 0.0002) and employees' self-reported safety participation (r = 0.29, p < 0.01). The results provide a broad perspective on employees' safety compliance and identify areas for improving safety behaviours. Practitioner Summary: A checklist was used while observing professional installers of a cable company for portable ladder usage at their worksites. Items that had the lowest compliance with best practices and training guidelines were identified. The results provide a broad perspective on employees' safety compliance and identify areas for improving safety behaviours.

The influence of vehicle aerodynamic and control response characteristics on driver-vehicle performance

NASA Technical Reports Server (NTRS)

Alexandridis, A. A.; Repa, B. S.; Wierwille, W. W.

1978-01-01

The effects of changes in understeer, control sensitivity, and location of the lateral aerodynamic center of pressure (c.p.) of a typical passenger car on the driver's opinion and on the performance of the driver-vehicle system were studied in a moving-base driving simulator. Twelve subjects with no prior experience on the simulator and no special driving skills performed regulation tasks in the presence of both random and step wind gusts.

Vehicle automation: a remedy for driver stress?

PubMed

Funke, G; Matthews, G; Warm, J S; Emo, A K

2007-08-01

The present study addressed the effects of stress, vehicle automation and subjective state on driver performance and mood in a simulated driving task. A total of 168 college students participated. Participants in the stress-induction condition completed a 'winter' drive, which included periodic loss of control episodes. Participants in the no-stress-induction condition were not exposed to loss of control. An additional, independent manipulation of vehicle speed was also conducted, consisting of two control conditions requiring manual speed regulation and a third in which vehicle speed was automatically regulated by the simulation. Stress and automation both influenced subjective distress, but the two factors did not interact. Driver performance data indicated that vehicle automation impacted performance similarly in the stress and no-stress conditions. Individual differences in subjective stress response and performance were also investigated. Resource theory provides a framework that partially but not completely explains the relationship between vehicle automation and driver stress. Implications for driver workload, safety and training are discussed.

Development Specification for the Feedwater Supply Assembly (FSA), FSA-431 with Integrated Auxiliary Feedwater Supply Assembly (AFSA), FSA-531

NASA Technical Reports Server (NTRS)

Anchondo, Ian; Campbell, Colin

2017-01-01

The FSA with Integrated Aux FSA Specification establishes the requirements for design, performance, and testing of the FSA-431/FSA-531 assembly in compliance with CTSD-ADV-780, Development Specification for the Advanced EMU (AEMU) Portable Life Support System (PLSS). This section contains the technical design and performance requirements for the integrated assembly of the Feedwater Supply Assembly and Auxiliary Feedwater Supply Assembly for the Advanced EVA Development Portable Life Support Subsystem (PLSS).

Using OpenOffice as a Portable Interface to JAVA-Based Applications

NASA Astrophysics Data System (ADS)

Comeau, T.; Garrett, B.; Richon, J.; Romelfanger, F.

2004-07-01

STScI previously used Microsoft Word and Microsoft Access, a Sybase ODBC driver, and the Adobe Acrobat PDF writer, along with a substantial amount of Visual Basic, to generate a variety of documents for the internal Space Telescope Grants Administration System (STGMS). While investigating an upgrade to Microsoft Office XP, we began considering alternatives, ultimately selecting an open source product, OpenOffice.org. This reduces the total number of products required to operate the internal STGMS system, simplifies the build system, and opens the possibility of moving to a non-Windows platform. We describe the experience of moving from Microsoft Office to OpenOffice.org, and our other internal uses of OpenOffice.org in our development environment.

Impacts of Fog Characteristics, Forward Illumination, and Warning Beacon Intensity Distribution on Roadway Hazard Visibility

PubMed Central

2016-01-01

Warning beacons are critical for the safety of transportation, construction, and utility workers. These devices need to produce sufficient luminous intensity to be visible without creating glare to drivers. Published standards for the photometric performance of warning beacons do not address their performance in conditions of reduced visibility such as fog. Under such conditions light emitted in directions other than toward approaching drivers can create scattered light that makes workers and other hazards less visible. Simulations of visibility of hazards under varying conditions of fog density, forward vehicle lighting, warning beacon luminous intensity, and intensity distribution were performed to assess their impacts on visual performance by drivers. Each of these factors can influence the ability of drivers to detect and identify workers and hazards along the roadway in work zones. Based on the results, it would be reasonable to specify maximum limits on the luminous intensity of warning beacons in directions that are unlikely to be seen by drivers along the roadway, limits which are not included in published performance specifications. PMID:27314058

Effect of Range Training: Comparison of Road Test Scores for Driver Education Students.

ERIC Educational Resources Information Center

Council, Forrest M.; And Others

The study compared the driver licensing test performance of two groups of driver education students: those involved in North Carolina's multi-vehicle range program and students in the "30 and 6" program (30 hours of class instruction and six hours of "behind the whell" instruction). It evaluated the performance of 3,049 applicants (all aged 16 and…

Alcohol effects on simulated driving performance and self-perceptions of impairment in DUI offenders

PubMed Central

Van Dyke, Nicholas; Fillmore, Mark T.

2014-01-01

Drivers with a history of driving under the influence (DUI) of alcohol self-report heightened impulsivity and display reckless driving behaviors as indicated by increased rates of vehicle crashes, moving violations, and traffic tickets. Such poor behavioral self-regulation could also increase sensitivity to the disruptive effects of alcohol on driving performance. The present study examined the degree to which DUI drivers display an increased sensitivity to the acute impairing effects of alcohol on simulated driving performance and overestimate their driving fitness following alcohol consumption. Adult drivers with a history of DUI and a demographically-matched group of drivers with no history of DUI (controls) were tested following a 0.65 g/kg alcohol and a placebo. Results indicated that alcohol impaired several measures of driving performance and there was no difference between DUI offenders and controls in these impairments. However, following alcohol DUI drivers self-reported a greater ability and willingness to drive compared with controls. These findings indicate that drivers with a history of DUI might perceive themselves as more fit to drive after drinking which could play an important role in their decisions to drink and drive. PMID:25347077

Driver fatigue and highway driving: a simulator study.

PubMed

Ting, Ping-Huang; Hwang, Jiun-Ren; Doong, Ji-Liang; Jeng, Ming-Chang

2008-06-09

Long duration of driving is a significant cause of fatigue-related accidents on motorways or major roadways. The fatigue caused by driving for extended periods acutely impairs driver alertness and performance and can compromise transportation safety. This study quantitatively measured the progression of driver fatigue and identified the conservative safe duration of continuous highway driving. Thirty young male subjects were analyzed during 90 min of laboratory-simulated highway driving. Sleepiness ratings (SSS) and reaction time (RT) tests were used to assess impairment of driver alertness and vigilance. Additionally, various measures of driving performance recorded throughout the experiment were used to measure temporal deterioration of driver performance from alert to fatigued using principal component analysis (PCA). The analytical results revealed that SSS scores, reaction times (RTs) and unstable driving performance significantly increased over time, indicating that excessive driving time is a significant fatigue factor and potential cause of fatigue-related accidents. Moreover, the analytical results indicated that 80 min was the safe limit for monotonous highway driving. Based on the experimental findings of this study, public awareness of the adverse affects of driver fatigue during long-distance driving should be enhanced. This study provides explicit information of fatigue development that can be used to prevent fatigue-related accidents.

Alcohol effects on simulated driving performance and self-perceptions of impairment in DUI offenders.

PubMed

Van Dyke, Nicholas; Fillmore, Mark T

2014-12-01

Drivers with a history of driving under the influence (DUI) of alcohol self-report heightened impulsivity and display reckless driving behaviors as indicated by increased rates of vehicle crashes, moving violations, and traffic tickets. Such poor behavioral self-regulation could also increase sensitivity to the disruptive effects of alcohol on driving performance. The present study examined the degree to which DUI drivers display an increased sensitivity to the acute impairing effects of alcohol on simulated driving performance and overestimate their driving fitness following alcohol consumption. Adult drivers with a history of DUI and a demographically matched group of drivers with no history of DUI (controls) were tested following a 0.65 g/kg alcohol and a placebo. Results indicated that alcohol impaired several measures of driving performance, and there was no difference between DUI offenders and controls in these impairments. However, following alcohol, DUI drivers self-reported a greater ability and willingness to drive compared with controls. These findings indicate that drivers with a history of DUI might perceive themselves as more fit to drive after drinking, which could play an important role in their decisions to drink and drive. PsycINFO Database Record (c) 2014 APA, all rights reserved.

49 CFR 391.53 - Driver investigation history file.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 5 2011-10-01 2011-10-01 false Driver investigation history file. 391.53 Section... Driver investigation history file. (a) After October 29, 2004, each motor carrier must maintain records relating to the investigation into the safety performance history of a new or prospective driver pursuant...

49 CFR 391.53 - Driver investigation history file.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 5 2014-10-01 2014-10-01 false Driver investigation history file. 391.53 Section... Driver investigation history file. (a) After October 29, 2004, each motor carrier must maintain records relating to the investigation into the safety performance history of a new or prospective driver pursuant...

49 CFR 391.53 - Driver investigation history file.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 5 2012-10-01 2012-10-01 false Driver investigation history file. 391.53 Section... Driver investigation history file. (a) After October 29, 2004, each motor carrier must maintain records relating to the investigation into the safety performance history of a new or prospective driver pursuant...

49 CFR 391.53 - Driver investigation history file.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 5 2013-10-01 2013-10-01 false Driver investigation history file. 391.53 Section... Driver investigation history file. (a) After October 29, 2004, each motor carrier must maintain records relating to the investigation into the safety performance history of a new or prospective driver pursuant...

49 CFR 391.53 - Driver investigation history file.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false Driver investigation history file. 391.53 Section... Driver investigation history file. (a) After October 29, 2004, each motor carrier must maintain records relating to the investigation into the safety performance history of a new or prospective driver pursuant...

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

PubMed

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 more engaged in non-driving-related activities braking harder than those with low activity-engagement during the takeover. Published by Elsevier Ltd.

Can vehicle longitudinal jerk be used to identify aggressive drivers? An examination using naturalistic driving data.

PubMed

Feng, Fred; Bao, Shan; Sayer, James R; Flannagan, Carol; Manser, Michael; Wunderlich, Robert

2017-07-01

This paper investigated the characteristics of vehicle longitudinal jerk (change rate of acceleration with respect to time) by using vehicle sensor data from an existing naturalistic driving study. The main objective was to examine whether vehicle jerk contains useful information that could be potentially used to identify aggressive drivers. Initial investigation showed that there are unique characteristics of vehicle jerk in drivers' gas and brake pedal operations. Thus two jerk-based metrics were examined: (1) driver's frequency of using large positive jerk when pressing the gas pedal, and (2) driver's frequency of using large negative jerk when pressing the brake pedal. To validate the performance of the two metrics, drivers were firstly divided into an aggressive group and a normal group using three classification methods (1) traveling at excessive speed (speeding), (2) following too closely to a front vehicle (tailgating), and (3) their association with crashes or near-crashes in the dataset. The results show that those aggressive drivers defined using any of the three methods above were associated with significantly higher values of the two jerk-based metrics. Between the two metrics the frequency of using large negative jerk seems to have better performance in identifying aggressive drivers. A sensitivity analysis shows the findings were largely consistent with varying parameters in the analysis. The potential applications of this work include developing quantitative surrogate safety measures to identify aggressive drivers and aggressive driving, which could be potentially used to, for example, provide real-time or post-ride performance feedback to the drivers, or warn the surrounding drivers or vehicles using the connected vehicle technologies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Is take-over time all that matters? The impact of visual-cognitive load on driver take-over quality after conditionally automated driving.

PubMed

Zeeb, Kathrin; Buchner, Axel; Schrauf, Michael

2016-07-01

Currently, development of conditionally automated driving systems which control both lateral and longitudinal vehicle guidance is attracting a great deal of attention. The driver no longer needs to constantly monitor the roadway, but must still be able to resume vehicle control if necessary. The relaxed attention requirement might encourage engagement in non-driving related secondary tasks, and the resulting effect on driver take-over is unclear. The aim of this study was to examine how engagement in three different naturalistic secondary tasks (writing an email, reading a news text, watching a video clip) impacted take-over performance. A driving simulator study was conducted and data from a total of 79 participants (mean age 40 years, 35 females) were used to examine response times and take-over quality. Drivers had to resume vehicle control in four different non-critical scenarios while engaging in secondary tasks. A control group did not perform any secondary tasks. There was no influence of the drivers' engagement in secondary tasks on the time required to return their hands to the steering wheel, and there seemed to be only little if any influence on the time the drivers needed to intervene in vehicle control. Take-over quality, however, deteriorated for distracted drivers, with drivers reading a news text and drivers watching a video deviating on average approximately 8-9cm more from the lane center. These findings seem to indicate that establishing motor readiness may be carried out almost reflexively, but cognitive processing of the situation is impaired by driver distraction. This, in turn, appears to determine take-over quality. The present findings emphasize the importance to consider both response times and take-over quality for a comprehensive understanding of factors that influence driver take-over. Furthermore, a training effect in response times was found to be moderated by the drivers' prior experience with driver assistance systems. This shows that besides driver distraction, driver-related factors influencing take-over performance exist. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hand-portable liquid chromatographic instrumentation.

PubMed

Sharma, Sonika; Tolley, Luke T; Tolley, H Dennis; Plistil, Alex; Stearns, Stanley D; Lee, Milton L

2015-11-20

Over the last four decades, liquid chromatography (LC) has experienced an evolution to smaller columns and particles, new stationary phases and low flow rate instrumentation. However, the development of person-portable LC has not followed, mainly due to difficulties encountered in miniaturizing pumps and detectors, and in reducing solvent consumption. The recent introduction of small, non-splitting pumping systems and UV-absorption detectors for use with capillary columns has finally provided miniaturized instrumentation suitable for high-performance hand-portable LC. Fully integrated microfabricated LC still remains a significant challenge. Ion chromatography (IC) has been successfully miniaturized and applied for field analysis; however, applications are mostly limited to inorganic and small organic ions. This review covers advancements that make possible more rapid expansion of portable forms of LC and IC. Copyright © 2015 Elsevier B.V. All rights reserved.

The effects of social interactions with in-vehicle agents on a driver's anger level, driving performance, situation awareness, and perceived workload.

PubMed

Jeon, Myounghoon; Walker, Bruce N; Gable, Thomas M

2015-09-01

Research has suggested that interaction with an in-vehicle software agent can improve a driver's psychological state and increase road safety. The present study explored the possibility of using an in-vehicle software agent to mitigate effects of driver anger on driving behavior. After either anger or neutral mood induction, 60 undergraduates drove in a simulator with two types of agent intervention. Results showed that both speech-based agents not only enhance driver situation awareness and driving performance, but also reduce their anger level and perceived workload. Regression models show that a driver's anger influences driving performance measures, mediated by situation awareness. The practical implications include design guidelines for the design of social interaction with in-vehicle software agents. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

The effects of alcohol on driver performance in a decision making situation

NASA Technical Reports Server (NTRS)

Allen, R. W.; Schwartz, S. H.; Stein, A. C.; Hogge, J. R.

1978-01-01

The results are reviewed of driving simulator and in-vehicle field test experiments of alcohol effects on driver risk taking. The objective was to investigate changes in risk taking under alcoholic intoxication and relate these changes to effects on traffic safety. The experiments involved complex 15 minute driving scenarios requiring decision making and steering and speed control throughout a series of typical driving situations. Monetary rewards and penalties were employed to simulate the real-world motivations inherent in driving. A full placebo experimental design was employed, and measures related to traffic safety, driver/vehicle performance and driver behavior were obtained. Alcohol impairment was found to increase the rate of accidents and speeding tickets. Behavioral measures showed these traffic safety effects to be due to impaired psychomotor performance and perceptual distortions. Subjective estimates of risk failed to show any change in the driver's willingness to take risks when intoxicated.

Scrolling and driving: how an MP3 player and its aftermarket controller affect driving performance and visual behavior.

PubMed

Lee, John D; Roberts, Shannon C; Hoffman, Joshua D; Angell, Linda S

2012-04-01

The aim of this study was to assess how scrolling through playlists on an MP3 player or its aftermarket controller affects driving performance and to examine how drivers adapt device use to driving demands. Drivers use increasingly complex infotainment devices that can undermine driving performance. The goal activation hypothesis suggests that drivers might fail to compensate for these demands, particularly with long tasks and large search set sizes. A total of 50 participants searched for songs in playlists of varying lengths using either an MP3 player or an aftermarket controller while negotiating road segments with traffic and construction in a medium-fidelity driving simulator. Searching through long playlists (580 songs) resulted in poor driving performance and required more long glances (longer than 2 s) to the device compared with other playlist lengths. The aftermarket controller also led to more long glances compared with the MP3 player. Drivers did not adequately adapt their behavior to roadway demand, as evident in their degraded driving performance. No significant performance differences were found between short playlists, the radio-tuning task, and the no-task condition. Selecting songs from long playlists undermined driving performance, and drivers did not sufficiently adapt their use of the device to the roadway demands, consistent with the goal activation hypothesis. The aftermarket controller degraded rather than enhanced performance. Infotainment systems should support drivers in managing distraction. Aftermarket controllers can have the unintended effect of making devices carried into the car less compatible with driving.These results can motivate development of new interfaces as alternatives to scrolling lists.

Validation of Rehabilitation Training Programs for Older Drivers

DOT National Transportation Integrated Search

2013-04-01

This project studied the effectiveness of four interventions designed to bolster safe performance among healthy older : drivers: (1) Classroom driver education with supplemental behind-the-wheel instruction; (2) Computer-based exercises : to improve ...

Technology for Ice Rinks

NASA Technical Reports Server (NTRS)

1983-01-01

Ron Urban's International Ice Shows set up portable ice rinks for touring troupes performing on temporary rinks at amusement parks, sports arenas, dinner theaters, shopping malls and civic centers. Key to enhanced rink portability, fast freezing and maintaining ice consistency is a mat of flexible tubing called ICEMAT, an offshoot of a solar heating system developed by Calmac, Mfg. under contract with Marshall.

Linear-Algebra Programs

NASA Technical Reports Server (NTRS)

Lawson, C. L.; Krogh, F. T.; Gold, S. S.; Kincaid, D. R.; Sullivan, J.; Williams, E.; Hanson, R. J.; Haskell, K.; Dongarra, J.; Moler, C. B.

1982-01-01

The Basic Linear Algebra Subprograms (BLAS) library is a collection of 38 FORTRAN-callable routines for performing basic operations of numerical linear algebra. BLAS library is portable and efficient source of basic operations for designers of programs involving linear algebriac computations. BLAS library is supplied in portable FORTRAN and Assembler code versions for IBM 370, UNIVAC 1100 and CDC 6000 series computers.

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

ERIC Educational Resources Information Center

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…

Assessment of suturing in the vertical plane shows the efficacy of the multi-degree-of-freedom needle driver for neonatal laparoscopy.

PubMed

Takazawa, Shinya; Ishimaru, Tetsuya; Fujii, Masahiro; Harada, Kanako; Sugita, Naohiko; Mitsuishi, Mamoru; Iwanaka, Tadashi

2013-11-01

We have developed a thin needle driver with multiple degrees-of-freedom (DOFs) for neonatal laparoscopic surgery. The tip of this needle driver has three DOFs for grasp, deflection and rotation. Our aim was to evaluate the performance of the multi-DOF needle driver in vertical plane suturing. Six pediatric surgeons performed four directional suturing tasks in the vertical plane using the multi-DOF needle driver and a conventional one. Assessed parameters were the accuracy of insertion and exit, the depth of suture, the inclination angle of the needle and the force applied on the model. In left and right direction sutures, the inclination angle of the needle with the multi-DOF needle driver was significantly smaller than that with the conventional one (p = 0.014, 0.042, respectively). In left and right direction sutures, the force for pulling the model with the multi-DOF needle driver was smaller than that with the conventional one (p = 0.036, 0.010, respectively). This study showed that multi-directional suturing on a vertical plane using the multi-DOF needle driver had better needle trajectories and was less invasive as compared to a conventional needle driver.

Initial Results of Accelerated Stress Testing on Single-Channel and Multichannel Drivers: Solid-State Lighting Technology Area

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

This report is the first in a series of studies on accelerated stress testing (AST) of drivers used for SSL luminaires, such as downlights, troffers, and streetlights. A representative group of two-stage commercial driver products was exposed to an AST environment consisting of 75°C and 75% relative humidity (7575). These drivers were a mix of single-channel drivers (i.e., a single output current for one LED primary) and multichannel drivers (i.e., separate output currents for multiple LED primaries). This AST environment was chosen because previous testing on downlights with integrated drivers demonstrated that 38% of the sample population failed in lessmore » than 2,500 hours of testing using this method. In addition to AST test results, the performance of an SSL downlight product incorporating an integrated, multichannel driver during extended room temperature operational life (RTOL) testing is also reported. A battery of measurements was used to evaluate these products during accelerated testing, including full electrical characterization (i.e., power consumption, PF, total harmonic distortion [THD], and inrush current) and photometric characterization of external LED loads attached to the drivers (i.e., flicker performance and lumen maintenance).« less

Road characteristics and driver fatigue: a simulator study.

PubMed

Oron-Gilad, Tal; Ronen, Adi

2007-09-01

Two experiments examined the influence of road characteristics on driver fatigue in a prolonged simulator drive. In experiment one, ten military truck drivers drove a mixed route, with straight, winding, and straight highway segments. In experiment two, 16 additional drivers drove either a straight, a winding, or a mixed route. Fatigue symptoms were assessed using performance, subjective, and psychophysiological measures (HRV). We hypothesized that drivers adopt different fatigue-coping strategies relative to the demands of the drive. Thus, on straight roads drivers are more likely to loosen their driving demands by either increasing their driving speed and/or not maintaining the lane position, as the road is tolerant to both strategies, whereas on winding roads, drivers are more likely to increase their speed but not their lane positioning. Our results confirm that decremental changes in driving performance varied among road types. In the straight road components, we found decrements in the quality of lane maintaining (experiment one) and steering quality (experiments one and two) and longitudinal speed (experiment two). In the winding road, we found that drivers increased their driving speed over time (experiments one and two).

An assessment of driver drowsiness, distraction, and performance in a naturalistic setting

DOT National Transportation Integrated Search

2011-02-01

This report documents the results of a study to characterize episodes of driver drowsiness and to assess the impact of drowsiness on driving performance. This data mining effort performed additional analyses on the data collected in an earlier FMCSA ...

Effects of Age-Related Macular Degeneration on Driving Performance

PubMed Central

Wood, Joanne M.; Black, Alex A.; Mallon, Kerry; Kwan, Anthony S.; Owsley, Cynthia

2018-01-01

Purpose To explore differences in driving performance of older adults with age-related macular degeneration (AMD) and age-matched controls, and to identify the visual determinants of driving performance in this population. Methods Participants included 33 older drivers with AMD (mean age [M] = 76.6 ± 6.1 years; better eye Age-Related Eye Disease Study grades: early [61%] and intermediate [39%]) and 50 age-matched controls (M = 74.6 ± 5.0 years). Visual tests included visual acuity, contrast sensitivity, visual fields, and motion sensitivity. On-road driving performance was assessed in a dual-brake vehicle by an occupational therapist (masked to drivers' visual status). Outcome measures included driving safety ratings (scale of 1–10, where higher values represented safer driving), types of driving behavior errors, locations at which errors were made, and number of critical errors (CE) requiring an instructor intervention. Results Drivers with AMD were rated as less safe than controls (4.8 vs. 6.2; P = 0.012); safety ratings were associated with AMD severity (early: 5.5 versus intermediate: 3.7), even after adjusting for age. Drivers with AMD had higher CE rates than controls (1.42 vs. 0.36, respectively; rate ratio 3.05, 95% confidence interval 1.47–6.36, P = 0.003) and exhibited more observation, lane keeping, and gap selection errors and made more errors at traffic light–controlled intersections (P < 0.05). Only motion sensitivity was significantly associated with driving safety in the AMD drivers (P = 0.005). Conclusions Drivers with early and intermediate AMD can exhibit impairments in their driving performance, particularly during complex driving situations; motion sensitivity was most strongly associated with driving performance. These findings have important implications for assessing the driving ability of older drivers with visual impairment. PMID:29340641

Driving Performance among Bioptic Telescope Users with Low Vision Two Years after Obtaining Their Driver's License: A Quasi-Experimental Study

ERIC Educational Resources Information Center

Vincent, Claude; Lachance, Jean-Paul; Deaudelin, Isabelle

2012-01-01

This study sought to compare road safety of new drivers with low vision who have followed a specific pilot bioptic training program with other groups of drivers all matched for age and driving experience. A quasi-experimental design was used two years after drivers obtained their license. Drivers were classified in the experimental group (n = 10,…

Effectiveness evaluation of simulative workshops for newly licensed drivers.

PubMed

Rosenbloom, Tova; Eldror, Ehud

2014-02-01

The current study set to examine the effects of simulator use in driving instruction on newly licensed drivers, comparing the road safety knowledge and reported intended behavior, as well as the actual driving performance of new drivers. Participants consisted of 280 newly licensed driver, of which 140 whose drivers license training included additional simulator-based lessons, and 140 drivers whose training precluded simulator-based lessons. All drivers answered questionnaires pertaining to their intended safe driving behaviors (according to Ajzen's (2000) theory of planned behavior), and to their traffic safety knowledge. Of the initial sample, 40 drivers received actual driving performance evaluation by an expert driving instructor, as well as by in-vehicle data recorders (IVDRs). We assumed that safer drivers report safer driving intentions, demonstrate greater traffic safety knowledge, evaluated as safer drivers by the driving instructor, and display lower and stable driving parameters on the IVDRs. We hypothesized that theoretical driving studies combined with practical training on simulators will elevate the safety level of novices driving. Hierarchical regression analyses on driving intentions indicated that drivers who did not receive simulator-based lessons demonstrated safer driving intentions compared to drivers who received simulator-based lessons. This pattern possibly indicating the drivers who received simulator-based lessons felt more confident in their driving abilities compared to drivers who did not receive simulated training. No significant difference was found in traffic safety knowledge, or in the evaluation of the expert driving instructor. IDVR data comparisons indicated drivers who received simulator-based lessons braked more often and were less prone to headway events, suggesting a more responsive driving style. These findings do not point to any significant advantage or disadvantage of the current simulator-based driving training over other driving training methods. Copyright © 2013 Elsevier Ltd. All rights reserved.

Manycore Performance-Portability: Kokkos Multidimensional Array Library

DOE PAGES

Edwards, H. Carter; Sunderland, Daniel; Porter, Vicki; ...

2012-01-01

Large, complex scientific and engineering application code have a significant investment in computational kernels to implement their mathematical models. Porting these computational kernels to the collection of modern manycore accelerator devices is a major challenge in that these devices have diverse programming models, application programming interfaces (APIs), and performance requirements. The Kokkos Array programming model provides library-based approach to implement computational kernels that are performance-portable to CPU-multicore and GPGPU accelerator devices. This programming model is based upon three fundamental concepts: (1) manycore compute devices each with its own memory space, (2) data parallel kernels and (3) multidimensional arrays. Kernel executionmore » performance is, especially for NVIDIA® devices, extremely dependent on data access patterns. Optimal data access pattern can be different for different manycore devices – potentially leading to different implementations of computational kernels specialized for different devices. The Kokkos Array programming model supports performance-portable kernels by (1) separating data access patterns from computational kernels through a multidimensional array API and (2) introduce device-specific data access mappings when a kernel is compiled. An implementation of Kokkos Array is available through Trilinos [Trilinos website, http://trilinos.sandia.gov/, August 2011].« less

Divided attention in young drivers under the influence of alcohol.

PubMed

Freydier, C; Berthelon, C; Bastien-Toniazzo, M; Gineyt, G

2014-06-01

The present research evaluates driving impairment linked to divided attention task and alcohol and determines whether it is higher for novice drivers than for experienced drivers. Novice and experienced drivers participated in three experimental sessions in which blood alcohol concentrations (BACs) were 0.0 g/L, 0.2 g/L, and 0.5 g/L. They performed a divided attention task with a main task of car-following task and an additional task of number parity identification. Driving performance, response time and accuracy on the additional task were measured. ANOVA showed a driving impairment and a decrease in additional task performance from a BAC of 0.5 g/L, particularly for novice drivers. Indeed, the latter adopt more risky behavior such as tailgating. In the divided attention task, driving impairment was found for all drivers and impairment on information processing accuracy was highlighted, notably in peripheral vision. The divided attention task used here provides a relevant method for identifying the effects of alcohol on cognitive functions and could be used in psychopharmacological research. Copyright © 2014 Elsevier Ltd. All rights reserved.

Driver performance modelling and its practical application to railway safety.

PubMed

Hamilton, W Ian; Clarke, Theresa

2005-11-01

This paper reports on the development and main features of a model of driver information processing. The work was conducted on behalf of Network Rail to meet a requirement to understand and manage the driver's interaction with the infrastructure through lineside reminder appliances. The model utilises cognitive theory and modelling techniques to describe driver performance in relation to infrastructure features and operational conditions. The model is capable of predicting the performance time, workload and error consequences of different operational conditions. The utility of the model is demonstrated through reports of its application to the following studies: Research on the effect of line speed on driver interaction with signals and signs. Calculation of minimum reading times for signals. Development of a human factors signals passed at danger (SPAD) hazard checklist, and a method to resolve conflicts between signal sighting solutions. Research on the demands imposed on drivers by European train control system (ETCS) driving in a UK context. The paper also reports on a validation of the model's utility as a tool for assessing cab and infrastructure drivability.

Evaluating the effects of bilingual traffic signs on driver performance and safety.

PubMed

Jamson, S L; Tate, F N; Jamson, A H

2005-12-15

Variable message signs (VMS) can provide immediate and relevant information to road users and bilingual VMS can provide great flexibility in countries where a significant proportion of the population speak an alternative language to the majority. The study reported here evaluates the effect of various bilingual VMS configurations on driver behaviour and safety. The aim of the study was to determine whether or not the visual distraction associated with bilingual VMS signs of different configurations (length, complexity) impacted on driving performance. A driving simulator was used to allow full control over the scenarios, road environment and sign configuration and both longitudinal and lateral driver performance was assessed. Drivers were able to read one- and two-line monolingual signs and two-line bilingual signs without disruption to their driving behaviour. However, drivers significantly reduced their speed in order to read four-line monolingual and four-line bilingual signs, accompanied by an increase in headway to the vehicle in front. This implies that drivers are possibly reading the irrelevant text on the bilingual sign and various methods for reducing this effect are discussed.

Physical characteristics of experienced and junior open-wheel car drivers.

PubMed

Raschner, Christian; Platzer, Hans-Peter; Patterson, Carson

2013-01-01

Despite the popularity of open-wheel car racing, scientific literature about the physical characteristics of competitive race car drivers is scarce. The purpose of this study was to compare selected fitness parameters of experienced and junior open-wheel race car drivers. The experienced drivers consisted of five Formula One, two GP2 and two Formula 3 drivers, and the nine junior drivers drove in the Formula Master, Koenig, BMW and Renault series. The following fitness parameters were tested: multiple reactions, multiple anticipation, postural stability, isometric upper body strength, isometric leg extension strength, isometric grip strength, cyclic foot speed and jump height. The group differences were calculated using the Mann-Whitney U-test. Because of the multiple testing strategy used, the statistical significance was Bonferroni corrected and set at P < 0.004. Significant differences between the experienced and junior drivers were found only for the jump height parameter (P = 0.002). The experienced drivers tended to perform better in leg strength (P = 0.009), cyclic foot speed (P = 0.024) and grip strength (P = 0.058). None of the other variables differed between the groups. The results suggested that the experienced drivers were significantly more powerful than the junior drivers: they tended to be quicker and stronger (18% to 25%) but without statistical significance. The experienced drivers demonstrated excellent strength and power compared with other high-performance athletes.

49 CFR 382.207 - Pre-duty use.

Code of Federal Regulations, 2010 CFR

2010-10-01

... functions within four hours after using alcohol. No employer having actual knowledge that a driver has used alcohol within four hours shall permit a driver to perform or continue to perform safety-sensitive...

A multimodal high-value curriculum affects drivers of utilization and performance on the high-value care component of the internal medicine in-training exam.

PubMed

Chau, Tom; Loertscher, Laura

2018-01-01

Background : Teaching the practice of high-value care (HVC) is an increasingly important function of graduate medical education but best practices and long-term outcomes remain unknown. Objective : Whether a multimodal curriculum designed to address specific drivers of low-value care would affect resident attitudes, skills, and performance of HVC as tested by the Internal Medicine In-Training Exam (ITE). Methods : In 2012, we performed a baseline needs assessment among internal medicine residents at a community program regarding drivers of healthcare utilization. We then created a multimodal curriculum with online interactive worksheets, lectures, and faculty buy-in to target specific skills, knowledge, and culture deficiencies. Perceived drivers of care and performance on the Internal Medicine ITE were assessed yearly through 2016. Results : Fourteen of 27 (52%) residents completed the initial needs assessment while the curriculum was eventually seen by at least 24 of 27 (89%). The ITE was taken by every resident every year. Long-term, 3-year follow-up demonstrated persistent improvement in many drivers of utilization (patient requests, reliance on subspecialists, defensive medicine, and academic curiosity) and improvement with sustained high performance on the high-value component of the ITE. Conclusion : A multimodal curriculum targeting specific drivers of low-value care can change culture and lead to sustained improvement in the practice of HVC.

The effect of performance feedback on drivers' hazard perception ability and self-ratings.

PubMed

Horswill, Mark S; Garth, Megan; Hill, Andrew; Watson, Marcus O

2017-04-01

Drivers' hazard perception ability has been found to predict crash risk, and novice drivers appear to be particularly poor at this skill. This competency appears to develop only slowly with experience, and this could partially be a result of poor quality performance feedback. We report an experiment in which we provided high-quality artificial feedback on individual drivers' performance in a validated video-based hazard perception test via either: (1) a graph-based comparison of hazard perception response times between the test-taker, the average driver, and an expert driver; (2) a video-based comparison between the same groups; or (3) both. All three types of feedback resulted in both an improvement in hazard perception performance and a reduction in self-rated hazard perception skill, compared with a no-feedback control group. Video-based and graph-based feedback combined resulted in a greater improvement in hazard perception performance than either of the individual components, which did not differ from one another. All three types of feedback eliminated participants' self-enhancement bias for hazard perception skill. Participants judged both interventions involving video feedback to be significantly more likely to improve their real-world driving than the no feedback control group. While all three forms of feedback had some value, the combined video and graph feedback intervention appeared to be the most effective across all outcome measures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Free-piston driver performance characterisation using experimental shock speeds through helium

NASA Astrophysics Data System (ADS)

Gildfind, D. E.; James, C. M.; Morgan, R. G.

2015-03-01

Tuned free-piston driver operation involves configuring the driver to produce a relatively steady blast of driver gas over the critical time scales of the experiment. For the purposes of flow condition development and parametric studies, it is useful to establish some average working values of the driver pressure and temperature for a given driver operating condition. However, in practise, these averaged values need to produce sufficiently accurate estimates of performance. In this study, two tuned driver conditions in the X2 expansion tube have been used to generate shock waves through a helium test gas. The measured shock speeds have then been used to calculate the effective driver gas pressure and temperature after diaphragm rupture. Since the driver gas is typically helium, or a mixture of helium and argon, and the test gas is also helium, ideal gas assumptions can be made without significant loss of accuracy. The technique is applicable to tuned free-piston drivers with a simple area change, as well as those using orifice plates. It is shown that this technique can be quickly used to establish average working driver gas properties which produce very good estimates of actual driven shock speed, across a wide range of operating conditions. The use of orifice plates to control piston dynamics at high driver gas sound speeds is also discussed in the paper, and a simple technique for calculating the restriction required to modify an established safe condition for use with lighter gases, such as pure helium, is presented.

Changes in driving behavior and cognitive performance with different breath alcohol concentration levels.

PubMed

Liu, Yung-Ching; Fu, Shing-Mei

2007-06-01

This study examines the changes in driving behavior and cognitive performance of drivers with different breath alcohol concentration (BrAC) levels. Eight licensed drivers, aged between 20 and 30 years, with BrAC levels of 0.00, 0.25, 0.4 and 0.5 mg/l performed simulated driving tests under high- and low-load conditions. Subjects were asked to assess their subjective psychological load at specified intervals and perform various tasks. The outcome was measured in terms of reaction times for task completion, accuracy rates, and driver's driving behavior. The effects of BrAC vary depending on the task. Performance of tasks involving attention shift, information processing, and short-term memory showed significant deterioration with increasing BrAC, while dangerous external vehicle driving behavior occurred only when the BrAC reached 0.4 mg/l and the deterioration was marked. We can conclude that the cognitive faculty is the first to be impaired by drinking resulting in deteriorated performance in tasks related to divided attention, short-term memory, logical reasoning, followed by visual perception. On the other hand, increasing alcohol dose may not pose an immediate impact on the external vehicle driving behavior but may negatively affect the driver's motor behavior even at low BrAC levels. Experience and will power could compensate for the negative influence of alcohol enabling the drivers to remain in full steering control. This lag between alcohol consumption and impaired driving performance may mislead the drivers in thinking that they are still capable of safe steering and cause them to ignore the potential dangers of drunk driving.

Design and implementation of a smartphone-based portable ultrasound pulsed-wave Doppler device for blood flow measurement.

PubMed

Huang, Chih-Chung; Lee, Po-Yang; Chen, Pay-Yu; Liu, Ting-Yu

2012-01-01

Blood flow measurement using Doppler ultrasound has become a useful tool for diagnosing cardiovascular diseases and as a physiological monitor. Recently, pocket-sized ultrasound scanners have been introduced for portable diagnosis. The present paper reports the implementation of a portable ultrasound pulsed-wave (PW) Doppler flowmeter using a smartphone. A 10-MHz ultrasonic surface transducer was designed for the dynamic monitoring of blood flow velocity. The directional baseband Doppler shift signals were obtained using a portable analog circuit system. After hardware processing, the Doppler signals were fed directly to a smartphone for Doppler spectrogram analysis and display in real time. To the best of our knowledge, this is the first report of the use of this system for medical ultrasound Doppler signal processing. A Couette flow phantom, consisting of two parallel disks with a 2-mm gap, was used to evaluate and calibrate the device. Doppler spectrograms of porcine blood flow were measured using this stand-alone portable device under the pulsatile condition. Subsequently, in vivo portable system verification was performed by measuring the arterial blood flow of a rat and comparing the results with the measurement from a commercial ultrasound duplex scanner. All of the results demonstrated the potential for using a smartphone as a novel embedded system for portable medical ultrasound applications. © 2012 IEEE

Advanced Infant Car Seat Would Increase Highway Safety

NASA Technical Reports Server (NTRS)

Dabney, Richard; Elrod, Susan

2004-01-01

An advanced infant car seat has been proposed to increase highway safety by reducing the incidence of crying, fussy behavior, and other child-related distractions that divert an adult driver s attention from driving. In addition to a conventional infant car seat with safety restraints, the proposed advanced infant car seat would include a number of components and subsystems that would function together as a comprehensive infant-care system that would keep its occupant safe, comfortable, and entertained, and would enable the driver to monitor the baby without having to either stop the car or turn around to face the infant during driving. The system would include a vibrator with bulb switch to operate; the switch would double as a squeeze toy that would make its own specific sound. A music subsystem would include loudspeakers built into the seat plus digital and analog circuitry that would utilize plug-in memory modules to synthesize music or a variety of other sounds. The music subsystem would include a built-in sound generator that could synthesize white noise or a human heartbeat to calm the baby to sleep. A second bulb switch could be used to control the music subsystem and would double as a squeeze toy that would make a distinct sound. An anti-noise sound-suppression system would isolate the baby from potentially disturbing ambient external noises. This subsystem would include small microphones, placed near the baby s ears, to detect ambient noise. The outputs of the microphone would be amplified and fed to the loudspeakers at appropriate amplitude and in a phase opposite that of the detected ambient noise, such that the net ambient sound arriving at the baby s ears would be almost completely cancelled. A video-camera subsystem would enable the driver to monitor the baby visually while continuing to face forward. One or more portable miniature video cameras could be embedded in the side of the infant car seat (see figure) or in a flip-down handle. The outputs of the video cameras would be transmitted by radio or infrared to a portable, miniature receiver/video monitor unit that would be attached to the dashboard of the car. The video-camera subsystem can also be used within transmission/reception range when the seat was removed from the car. The system would include a biotelemetric and tracking subsystem, which would include a Global Positioning System receiver for measuring its location. This subsystem would transmit the location of the infant car seat (even if the seat were not in a car) along with such biometric data as the baby s heart rate, perspiration rate, urinary status, temperature, and rate of breathing. Upon detecting any anomalies in the biometric data, this subsystem would send a warning to a paging device installed in the car or carried by the driver, so that the driver could pull the car off the road to attend to the baby. A motion detector in this subsystem would send a warning if the infant car seat were to be moved or otherwise disturbed unexpectedly while the infant was seated in it: this warning function, in combination with the position- tracking function, could help in finding a baby who had been kidnapped with the seat. Removable rechargeable batteries would enable uninterrupted functioning of all parts of the system while transporting the baby to and from the car. The batteries could be recharged via the cigarette-lighter outlet in the car or by use of an external AC-powered charger.

The relationship between driving simulation performance and obstructive sleep apnoea risk, daytime sleepiness, obesity and road traffic accident history of commercial drivers in Turkey.

PubMed

Demirdöğen Çetinoğlu, Ezgi; Görek Dilektaşlı, Aslı; Demir, Nefise Ateş; Özkaya, Güven; Acet, Nilüfer Aylin; Durmuş, Eda; Ursavaş, Ahmet; Karadağ, Mehmet; Ege, Ercüment

2015-09-01

Driving performance is known to be very sensitive to cognitive-psychomotor impairment. The aim of the study was to determine the relationship between obesity, risk of obstructive sleep apnoea (OSA), daytime sleepiness, history of road traffic accident (RTA) and performance on a driving simulator, among commercial drivers. We examined commercial vehicle drivers admitted to Psycho-Technical Assessment System (PTAS), which is a computer-aided system that includes a driving simulator test and tests assessing psychomotor-cognitive skills required for driving. Risk of OSA and daytime sleepiness were assessed by the Berlin Questionnaire and the Epworth Sleepiness Scale (ESS), respectively. A total of 282 commercial vehicle drivers were consecutively enrolled. The age range was 29-76 years. Thirty drivers were at high risk of OSA. Median ESS of the group was 2 (0-20). Forty-seven percent of the subjects at high risk of OSA failed in early reaction time test, while 28% of the drivers with low risk of OSA failed (p = 0.03). The obese drivers failed the peripheral vision test when compared with non-obese drivers (p = 0.02). ESS was higher for drivers with a history of RTA when compared to those without RTA (p = 0.02). Cognitive-psychomotor functions can be impaired in obese and high risk of OSA patients. In our opinion, requiring obese and/or high risk of OSA drivers to take PTAS tests that assess driving skills and psychomotor-cognitive functions crucial to those skills would significantly improve road traffic safety, which is of considerable importance to public health.

The impact of manufacturing complexity drivers on performance-a preliminary study

NASA Astrophysics Data System (ADS)

Huah Leang, Suh; Mahmood, Wan Hasrulnizzam Wan; Rahman, Muhamad Arfauz A.

2018-03-01

Manufacturing systems, in pursuit of cost, time and flexibility optimisation are becoming more and more complex, exhibiting a dynamic and nonlinear behaviour. Unpredictability is a distinct characteristic of such behaviour and effects production planning significantly. Therefore, this study was undertaken to investigate the priority level and current achievement of manufacturing performance in Malaysia’s manufacturing industry and the complexity drivers on manufacturing productivity performance. The results showed that Malaysia’s manufacturing industry prioritised product quality and they managed to achieve a good on time delivery performance. However, for other manufacturing performance, there was a difference where the current achievement of manufacturing performances in Malaysia’s manufacturing industry is slightly lower than the priority given to them. The strong correlation of significant value for priority status was observed between efficient production levelling (finished goods) and finish product management while the strong correlation of significant value for current achievement was minimised the number of workstation and factory transportation system. This indicates that complexity drivers have an impact towards manufacturing performance. Consequently, it is necessary to identify complexity drivers to achieve well manufacturing performance.

Research on Vehicle-Based Driver Status/Performance Monitoring, Part III

DOT National Transportation Integrated Search

1996-09-01

A driver drowsiness detection/alarm/countermeasures system was specified, tested and evaluated, resulting in the development of revised algorithms for the detection of driver drowsiness. Previous algorithms were examined in a test and evaluation stud...

Human Factors in the Automated Highway System: Transferring Control to the Driver

DOT National Transportation Integrated Search

1995-10-01

Driver capabilities and limitations must be considered to ensure successful implementation of the Automated Highway System (AHS). Human factors investigations of driver performance characteristics provide the basis for determining system design confi...

Research On Vehicle-Based Driver Status/Performance Monitoring, Part I

DOT National Transportation Integrated Search

1996-09-01

A driver drowsiness detection/alarm/countermeasures system was specified, tested and evaluated, resulting in the development of revised algorithms for the detection of driver drowsiness. Previous algorithms were examined in a test and evaluation stud...

Supplemental Driver Safety Program Development. Volume I--Development Research and Evaluation. Final Report.

ERIC Educational Resources Information Center

McPherson, Kenard; And Others

Instructional modules for driver education programs were prepared to improve safe driving knowledge, attitudes, and performances of 16- to 18-year-old drivers. These modules were designed to provide supplementary instruction in five content areas critical to the safe and efficient operation of motor vehicles by young drivers--speed management,…

A Study of Free-Piston Double-Diaphragm Drivers for Expansion Tubes. Report 1

NASA Technical Reports Server (NTRS)

Kendall, M. A.

1997-01-01

In recent years the free-piston double-diaphragm driver has been used to increase the performance of the XI pilot expansion tube to super-orbital test conditions. However, the actual performance of the double-diaphragm driver was found to be considerably less than ideal. An experimental study of the double-diaphragm driver was carried out on the XI facility over a range of conditions with the objective of determining the effect of. heat losses; and the non-ideal rupture of the 'light' secondary diaphragm on the driver performance. The disparity between the theoretical and measured performance envelope are highlighted. A viscous limit for the experiments vas established. Heat transfer behind the primary shock is shown to be the mechanism behind this limit Incident, reflected and transmitted shock trajectories for the secondary diaphragm were experimentally determined and compared with computed trajectories from a one-dimensional diaphragm inertia model. It was found that the diaphragm did influence the unsteady expansion. A good agreement between experimental and computed shock trajectories was obtained using a diaphragm inertia model assuming that the diaphragm mass became negligible 3 microns after shock impact.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Seyong; Kim, Jungwon; Vetter, Jeffrey S

This paper presents a directive-based, high-level programming framework for high-performance reconfigurable computing. It takes a standard, portable OpenACC C program as input and generates a hardware configuration file for execution on FPGAs. We implemented this prototype system using our open-source OpenARC compiler; it performs source-to-source translation and optimization of the input OpenACC program into an OpenCL code, which is further compiled into a FPGA program by the backend Altera Offline OpenCL compiler. Internally, the design of OpenARC uses a high- level intermediate representation that separates concerns of program representation from underlying architectures, which facilitates portability of OpenARC. In fact, thismore » design allowed us to create the OpenACC-to-FPGA translation framework with minimal extensions to our existing system. In addition, we show that our proposed FPGA-specific compiler optimizations and novel OpenACC pragma extensions assist the compiler in generating more efficient FPGA hardware configuration files. Our empirical evaluation on an Altera Stratix V FPGA with eight OpenACC benchmarks demonstrate the benefits of our strategy. To demonstrate the portability of OpenARC, we show results for the same benchmarks executing on other heterogeneous platforms, including NVIDIA GPUs, AMD GPUs, and Intel Xeon Phis. This initial evidence helps support the goal of using a directive-based, high-level programming strategy for performance portability across heterogeneous HPC architectures.« less

Evaluation of portable near-infrared spectroscopy for organic milk authentication.

PubMed

Liu, Ningjing; Parra, Hector Aya; Pustjens, Annemieke; Hettinga, Kasper; Mongondry, Philippe; van Ruth, Saskia M

2018-07-01

Organic products are vulnerable to fraud due to their premium price. Analytical methodology helps to manage the risk of fraud and due to the miniaturization of equipment, tests may nowadays even be rapidly applied on-site. The current study aimed to evaluate portable near infrared spectroscopy (NIRS) in combination with chemometrics to distinguish organic milk from other types of milk, and compare its performance with benchtop NIRS and fatty acid profiling by gas chromatography. The sample set included 37 organic retail milks and 50 non-organic retail milks (of which 36 conventional and 14 green 'pasture' milks). Partial least squares discriminant analysis was performed to build classification models and kernel density estimation (KDE) functions were calculated to generate non-parametric distributions for samples' class probabilities. These distributions showed that portable NIRS was successful to distinguish organic milks from conventional milks, and so were benchtop NIRS and fatty acid profiling procedures. However, it was less successful when 'pasture' milks were considered too, since their patterns occasionally resembled those of the organic milk group. Fatty acid profiling was capable of distinguishing organic milks from both non-organic milks though, including the 'pasture' milks. This comparative study revealed that the classification performance of the portable NIRS for this application was similar to that of the benchtop NIRS. Copyright © 2018 Elsevier B.V. All rights reserved.

Performance Portability Strategies for Grid C++ Expression Templates

NASA Astrophysics Data System (ADS)

Boyle, Peter A.; Clark, M. A.; DeTar, Carleton; Lin, Meifeng; Rana, Verinder; Vaquero Avilés-Casco, Alejandro

2018-03-01

One of the key requirements for the Lattice QCD Application Development as part of the US Exascale Computing Project is performance portability across multiple architectures. Using the Grid C++ expression template as a starting point, we report on the progress made with regards to the Grid GPU offloading strategies. We present both the successes and issues encountered in using CUDA, OpenACC and Just-In-Time compilation. Experimentation and performance on GPUs with a SU(3)×SU(3) streaming test will be reported. We will also report on the challenges of using current OpenMP 4.x for GPU offloading in the same code.

Automated Portable Test System (APTS) - A performance envelope assessment tool

NASA Technical Reports Server (NTRS)

Kennedy, R. S.; Dunlap, W. P.; Jones, M. B.; Wilkes, R. L.; Bittner, A. C., Jr.

1985-01-01

The reliability and stability of microcomputer-based psychological tests are evaluated. The hardware, test programs, and system control of the Automated Portable Test System, which assesses human performance and subjective status, are described. Subjects were administered 11 pen-and-pencil and microcomputer-based tests for 10 sessions. The data reveal that nine of the 10 tests stabilized by the third administration; inertial correlations were high and consistent. It is noted that the microcomputer-based tests display good psychometric properties in terms of differential stability and reliability.

A practical approach to portability and performance problems on massively parallel supercomputers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beazley, D.M.; Lomdahl, P.S.

1994-12-08

We present an overview of the tactics we have used to achieve a high-level of performance while improving portability for a large-scale molecular dynamics code SPaSM. SPaSM was originally implemented in ANSI C with message passing for the Connection Machine 5 (CM-5). In 1993, SPaSM was selected as one of the winners in the IEEE Gordon Bell Prize competition for sustaining 50 Gflops on the 1024 node CM-5 at Los Alamos National Laboratory. Achieving this performance on the CM-5 required rewriting critical sections of code in CDPEAC assembler language. In addition, the code made extensive use of CM-5 parallel I/Omore » and the CMMD message passing library. Given this highly specialized implementation, we describe how we have ported the code to the Cray T3D and high performance workstations. In addition we will describe how it has been possible to do this using a single version of source code that runs on all three platforms without sacrificing any performance. Sound too good to be true? We hope to demonstrate that one can realize both code performance and portability without relying on the latest and greatest prepackaged tool or parallelizing compiler.« less

DOE Centers of Excellence Performance Portability Meeting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neely, J. R.

2016-04-21

Performance portability is a phrase often used, but not well understood. The DOE is deploying systems at all of the major facilities across ASCR and ASC that are forcing application developers to confront head-on the challenges of running applications across these diverse systems. With GPU-based systems at the OLCF and LLNL, and Phi-based systems landing at NERSC, ACES (LANL/SNL), and the ALCF – the issue of performance portability is confronting the DOE mission like never before. A new best practice in the DOE is to include “Centers of Excellence” with each major procurement, with a goal of focusing efforts onmore » preparing key applications to be ready for the systems coming to each site, and engaging the vendors directly in a “shared fate” approach to ensuring success. While each COE is necessarily focused on a particular deployment, applications almost invariably must be able to run effectively across the entire DOE HPC ecosystem. This tension between optimizing performance for a particular platform, while still being able to run with acceptable performance wherever the resources are available, is the crux of the challenge we call “performance portability”. This meeting was an opportunity to bring application developers, software providers, and vendors together to discuss this challenge and begin to chart a path forward.« less

Experimental system for the control of surgically induced infections

NASA Technical Reports Server (NTRS)

Tevebaugh, M. D.

1971-01-01

The development tests to be performed on the experimental system are described in detail. The test equipment, conditions, and procedures are given. The portable clean room tests include assembly, collapsability, portability, and storage; laminar flow rate; static pressure; air flow pattern; and electrostatic buildup. The other tests are on the ventilation system, human factors evaluation, electrical subsystem, and material compatibility.

Development of a Portable Taste Sensor with a Lipid/Polymer Membrane

PubMed Central

Tahara, Yusuke; Nakashi, Kenichi; Ji, Ke; Ikeda, Akihiro; Toko, Kiyoshi

2013-01-01

We have developed a new portable taste sensor with a lipid/polymer membrane and conducted experiments to evaluate the sensor's performance. The fabricated sensor consists of a taste sensor chip (40 mm × 26 mm × 2.2 mm) with working and reference electrodes and a portable sensor device (80 mm × 25 mm × 20 mm). The working electrode consists of a taste-sensing site comprising a poly(hydroxyethyl)methacrylate (pHEMA) hydrogel layer with KCl as the electrolyte layer and a lipid/polymer membrane as the taste sensing element. The reference electrode comprises a polyvinyl chloride (PVC) membrane layer with a small hole and a pHEMA layer with KCl. The whole device is the size of a USB memory stick, making it suitable for portable use. The sensor's response to tannic acid as the standard astringency substance showed good accuracy and reproducibility, and was comparable with the performance of a commercially available taste sensing system. Thus, it is possible for this sensor to be used for in-field evaluations and it can make a significant contribution to the food industry, as well as in various fields of research. PMID:23325168

Recent Experiments Leading to the Characterization of the Performance of Portable (He-Ne)/CH4 Lasers: Part II: Results of the 1986 LPTF Absolute Frequency Measurements

NASA Astrophysics Data System (ADS)

Clairon, A.; Dahmani, B.; Acef, O.; Granveaud, M.; Domnin, Yu S.; Pouchkine, S. B.; Tatarenkov, V. M.; Felder, R.

1988-01-01

Comparison of the VNIIFTRI and LPTF frequency multiplication chains has been carried out through the measurement of the frequency of a portable VNIIFTRI (He-Ne)/CH4 laser. Agreement is within 100 Hz (1.1 parts in 1012) and is secured by the very good medium-term frequency repeatability of the (He-Ne)/CH4 VNIIFTRI portable laser (a few parts in 1013). On the same occasion a measurement of the frequency of the BIPM (He-Ne)/CH4 reference laser (B.3) has been performed at LPTF. Other experiments carried out on the BIPM laser show that the reproducibility of the (He-Ne)/CH4 system could be improved by a systematic study and then by a better control of the various perturbing factors which influence the shape of the methane-saturated absorption peak.

Results from a portable Adaptive Optics system on the 1 meter telescope at the Naval Observatory Flagstaff Station

NASA Astrophysics Data System (ADS)

Restaino, Sergio R.; Gilbreath, G. Charmaine; Payne, Don M.; Baker, Jeffrey T.; Martinez, Ty; DiVittorio, Michael; Mozurkewich, David; Friedman, Jeffrey

2003-02-01

In this paper we present results using a compact, portable adaptive optics system. The system was developed as a joint venture between the Naval Research Laboratory, Air Force Research Laboratory, and two small, New Mexico based-businesses. The system has a footprint of 18x24x18 inches and weighs less than 100 lbs. Key hardware design characteristics enable portability, easy mounting, and stable alignment. The system also enables quick calibration procedures, stable performance, and automatic adaptability to various pupil configurations. The system was tested during an engineering run in late July 2002 at the Naval Observatory Flagstaff Station one-meter telescope. Weather prevented extensive testing and the seeing during the run was marginal but a sufficient opportunity was provided for proof-of-concept, initial characterization of closed loop performance, and to start addressing some of the most pressing engineering and scientific issues.

Level-2 Milestone 5588: Deliver Strategic Plan and Initial Scalability Assessment by Advanced Architecture and Portability Specialists Team

DOE Office of Scientific and Technical Information (OSTI.GOV)

Draeger, Erik W.

This report documents the fact that the work in creating a strategic plan and beginning customer engagements has been completed. The description of milestone is: The newly formed advanced architecture and portability specialists (AAPS) team will develop a strategic plan to meet the goals of 1) sharing knowledge and experience with code teams to ensure that ASC codes run well on new architectures, and 2) supplying skilled computational scientists to put the strategy into practice. The plan will be delivered to ASC management in the first quarter. By the fourth quarter, the team will identify their first customers within PEMmore » and IC, perform an initial assessment and scalability and performance bottleneck for next-generation architectures, and embed AAPS team members with customer code teams to assist with initial portability development within standalone kernels or proxy applications.« less

Vehicle-based drowsy driver detection : current status and future prospects

DOT National Transportation Integrated Search

1994-01-01

Driver drowsiness is a major, though elusive, cause of traffic crashes. As part of its : IVHS/human factors program, NHTSA is supporting research to develop in-vehicle systems . : to continuously monitor driver alertness and performance. Scientific s...

Motorcoach Driver Fatigue Study, 2011

DOT National Transportation Integrated Search

2012-12-01

Eighty-four commercial motorcoach drivers participated in a month-long study of duty start time, total duty time, total sleep time per 24 hours, with sleepiness, fatigue, and performance measured as they were going on and off duty. Drivers worked the...

Examining physiological responses across different driving maneuvers during an on-road driving task: a pilot study comparing older and younger drivers.

PubMed

Koppel, S; Kuo, J; Berecki-Gisolf, J; Boag, R; Hue, Y-X; Charlton, J L

2015-01-01

This pilot study aimed to investigate physiological responses during an on-road driving task for older and younger drivers. Five older drivers (mean age = 74.60 years [2.97]) and 5 younger drivers (mean age = 30.00 years [3.08]) completed a series of cognitive assessments (Montreal Cognitive Assessment [MoCA], Mini Mental Status Examination [MMSE]; Trail Making Test [Trails A and Trails B]) and an on-road driving task along a predetermined, standardized urban route in their own vehicle. Driving performance was observed and scored by a single trained observer using a standardized procedure, where driving behaviors (appropriate and inappropriate) were scored for intersection negotiation, lane changing, and merging. During the on-road driving task, participants' heart rate (HR) was monitored with an unobtrusive physiological monitor. Younger drivers performed significantly better on all cognitive assessments compared to older drivers (MoCA: t(8) = 3.882, P <.01; MMSE: t(8) = 2.954, P <.05; Trails A: t(8) = -2.499, P <.05; Trails B: t(8) = -3.262, P <.05). Analyses of participants' performance during the on-road driving task revealed a high level of appropriate overall driving behavior (M = 87%, SD = 7.62, range = 73-95%), including intersection negotiation (M = 89%, SD = 8.37%), lane changing (M = 100%), and merging (M = 53%, SD = 28.28%). The overall proportion of appropriate driving behavior did not significantly differ across age groups (younger drivers: M = 87.6%, SD = 9.04; older drivers: M = 87.0%, SD = 6.96; t(8) = 0.118, P =.91). Although older drivers scored lower than younger drivers on the cognitive assessments, there was no indication of cognitive overload among older drivers based on HR response to the on-road driving task. The results provide preliminary evidence that mild age-related cognitive impairment may not pose a motor vehicle crash hazard for the wider older driver population. To maintain safe mobility of the aging population, further research into the specific crash risk factors in the older driver population is warranted.

Investigating cognitive ability and self-reported driving performance of post-stroke adults in a driving simulator.

PubMed

Blane, Alison; Falkmer, Torbjörn; Lee, Hoe C; Dukic Willstrand, Tania

2018-01-01

Background Safe driving is a complex activity that requires calibration. This means the driver can accurately assess the level of task demand required for task completion and can accurately evaluate their driving capability. There is much debate on the calibration ability of post-stroke drivers. Objectives The aim of this study was to assess the cognition, self-rated performance, and estimation of task demand in a driving simulator with post-stroke drivers and controls. Methods A between-groups study design was employed, which included a post-stroke driver group and a group of similarly aged older control drivers. Both groups were observed driving in two simulator-based driving scenarios and asked to complete the NASA Task Load Index (TLX) to assess their perceived task demand and self-rate their driving performance. Participants also completed a battery of psychometric tasks to assess attention and executive function, which was used to determine whether post-stroke cognitive impairment impacted on calibration. Results There was no difference in the amount of perceived task demand required to complete the driving task. Despite impairments in cognition, the post-stroke drivers were not more likely to over-estimate their driving abilities than controls. On average, the post-stroke drivers self-rated themselves more poorly than the controls and this rating was related to cognitive ability. Conclusion This study suggests that post-stroke drivers may be aware of their deficits and adjust their driving behavior. Furthermore, using self-performance measures alongside a driving simulator and cognitive assessments may provide complementary fitness-to-drive assessments, as well as rehabilitation tools during post-stroke recovery.

Display formats and commercial vehicle operator (CVO) workload

DOT National Transportation Integrated Search

1997-09-01

The objective of this study was to determine the effects of display modality, level of driver interaction, and amount of information on the driving performance and system operation performance of commercial drivers. Introducing any level of interacti...

Classifying Drivers' Cognitive Load Using EEG Signals.

PubMed

Barua, Shaibal; Ahmed, Mobyen Uddin; Begum, Shahina

2017-01-01

A growing traffic safety issue is the effect of cognitive loading activities on traffic safety and driving performance. To monitor drivers' mental state, understanding cognitive load is important since while driving, performing cognitively loading secondary tasks, for example talking on the phone, can affect the performance in the primary task, i.e. driving. Electroencephalography (EEG) is one of the reliable measures of cognitive load that can detect the changes in instantaneous load and effect of cognitively loading secondary task. In this driving simulator study, 1-back task is carried out while the driver performs three different simulated driving scenarios. This paper presents an EEG based approach to classify a drivers' level of cognitive load using Case-Based Reasoning (CBR). The results show that for each individual scenario as well as using data combined from the different scenarios, CBR based system achieved approximately over 70% of classification accuracy.

Falls Risk and Simulated Driving Performance in Older Adults

PubMed Central

Gaspar, John G.; Neider, Mark B.; Kramer, Arthur F.

2013-01-01

Declines in executive function and dual-task performance have been related to falls in older adults, and recent research suggests that older adults at risk for falls also show impairments on real-world tasks, such as crossing a street. The present study examined whether falls risk was associated with driving performance in a high-fidelity simulator. Participants were classified as high or low falls risk using the Physiological Profile Assessment and completed a number of challenging simulated driving assessments in which they responded quickly to unexpected events. High falls risk drivers had slower response times (~2.1 seconds) to unexpected events compared to low falls risk drivers (~1.7 seconds). Furthermore, when asked to perform a concurrent cognitive task while driving, high falls risk drivers showed greater costs to secondary task performance than did low falls risk drivers, and low falls risk older adults also outperformed high falls risk older adults on a computer-based measure of dual-task performance. Our results suggest that attentional differences between high and low falls risk older adults extend to simulated driving performance. PMID:23509627

Fatigue in Younger and Older Drivers: Effectiveness of an Alertness-Maintaining Task.

PubMed

Song, Woojin; Woon, Fu L; Doong, Alice; Persad, Carol; Tijerina, Louis; Pandit, Pooja; Cline, Carol; Giordani, Bruno

2017-09-01

The aim of this study was to examine the effects of an alertness-maintaining task (AMT) in older, fatigued drivers. Fatigue during driving increases crash risk, and previous research suggests that alertness and driving in younger adults may be improved using a secondary AMT during boring, fatigue-eliciting drives. However, the potential impact of an AMT on driving has not been investigated in older drivers whose ability to complete dual tasks has been shown to decline and therefore may be negatively affected with an AMT in driving. Younger ( n = 29) and older drivers ( n = 39) participated in a 50-minute simulated drive designed to induce fatigue, followed by four 10-minute sessions alternating between driving with and without an AMT. Younger drivers were significantly more affected by fatigue on driving performance than were older drivers but benefitted significantly from the AMT. Older drivers did not demonstrate increased driver errors with fatigue, and driving did not deteriorate significantly during participation in the AMT condition, although their speed was significantly more variable with the AMT. Consistent with earlier research, an AMT applied during fatiguing driving is effective in improving alertness and reducing driving errors in younger drivers. Importantly, older drivers were relatively unaffected by fatigue, and use of an AMT did not detrimentally affect their driving performance. These results support the potential use of an AMT as a new automotive technology to improve fatigue and promote driver safety, though the benefits of such technology may differ between different age groups.

Dynamic Discharge Arc Driver. [computerized simulation

NASA Technical Reports Server (NTRS)

Dannenberg, R. E.; Slapnicar, P. I.

1975-01-01

A computer program using nonlinear RLC circuit analysis was developed to accurately model the electrical discharge performance of the Ames 1-MJ energy storage and arc-driver system. Solutions of circuit parameters are compared with experimental circuit data and related to shock speed measurements. Computer analysis led to the concept of a Dynamic Discharge Arc Driver (DDAD) capable of increasing the range of operation of shock-driven facilities. Utilization of mass addition of the driver gas offers a unique means of improving driver performance. Mass addition acts to increase the arc resistance, which results in better electrical circuit damping with more efficient Joule heating, producing stronger shock waves. Preliminary tests resulted in an increase in shock Mach number from 34 to 39 in air at an initial pressure of 2.5 torr.

An on-road assessment of cognitive distraction: impacts on drivers' visual behavior and braking performance.

PubMed

Harbluk, Joanne L; Noy, Y Ian; Trbovich, Patricia L; Eizenman, Moshe

2007-03-01

In this on-road experiment, drivers performed demanding cognitive tasks while driving in city traffic. All task interactions were carried out in hands-free mode so that the 21 drivers were not required to take their visual attention away from the road or to manually interact with a device inside the vehicle. Visual behavior and vehicle control were assessed while they drove an 8 km city route under three conditions: no additional task, easy cognitive task and difficult cognitive task. Changes in visual behavior were most apparent when performance between the No Task and Difficult Task conditions were compared. When looking outside of the vehicle, drivers spent more time looking centrally ahead and spent less time looking to the areas in the periphery. Drivers also reduced their visual monitoring of the instruments and mirrors, with some drivers abandoning these tasks entirely. When approaching and driving through intersections, drivers made fewer inspection glances to traffic lights compared to the No Task condition and their scanning of intersection areas to the right was also reduced. Vehicle control was also affected; during the most difficult cognitive tasks there were more occurrences of hard braking. Although hands-free designs for telematics devices are intended to reduce or eliminate the distraction arising from manual operation of these units, the potential for cognitive distraction associated with their use must also be considered and appropriately assessed. These changes are captured in measures of drivers' visual behavior.

An empirical assessment of driver motivation and emotional states in perceived safety margins under varied driving conditions.

PubMed

Zhang, Yu; Kaber, David B

2013-01-01

Motivation models in driving behaviour postulate that driver motives and emotional states dictate risk tolerance under various traffic conditions. The present study used time and driver performance-based payment systems to manipulate motivation and risk-taking behaviour. Ten participants drove to a predefined location in a simulated driving environment. Traffic patterns (density and velocity) were manipulated to cause driver behaviour adjustments due to the need to conform with the social norms of the roadway. The driving environment complexity was investigated as a mediating factor in risk tolerance. Results revealed the performance-based payment system to closely relate to risk-taking behaviour as compared with the time-based payment system. Drivers conformed with social norms associated with specific traffic patterns. Higher roadway complexity led to a more conservative safety margins and speeds. This research contributes to the further development of motivational models of driver behaviour. This study provides empirical justification for two motivation factors in driver risk-taking decisions, including compliance with social norm and emotions triggered by incentives. Environment complexity was identified as a mediating factor in motivational behaviour model. This study also recommended safety margin measures sensitive to changes in driver risk tolerance.

Development of portable defocusing micro-scale spatially offset Raman spectroscopy.

PubMed

Realini, Marco; Botteon, Alessandra; Conti, Claudia; Colombo, Chiara; Matousek, Pavel

2016-05-10

We present, for the first time, portable defocusing micro-Spatially Offset Raman Spectroscopy (micro-SORS). Micro-SORS is a concept permitting the analysis of thin, highly turbid stratified layers beyond the reach of conventional Raman microscopy. The technique is applicable to the analysis of painted layers in cultural heritage (panels, canvases and mural paintings, painted statues and decorated objects in general) as well as in many other areas including polymer, biological and biomedical applications, catalytic and forensics sciences where highly turbid stratified layers are present and where invasive analysis is undesirable or impossible. So far the technique has been demonstrated only on benchtop Raman microscopes precluding the non-invasive analysis of larger samples and samples in situ. The new set-up is characterised conceptually on a range of artificially assembled two-layer systems demonstrating its benefits and performance across several application areas. These included stratified polymer sample, pharmaceutical tablet and layered paint samples. The same samples were also analysed by a high performance (non-portable) benchtop Raman microscope to provide benchmarking against our earlier research. The realisation of the vision of delivering portability to micro-SORS has a transformative potential spanning across multiple disciplines as it fully unlocks, for the first time, the non-invasive and non-destructive aspects of micro-SORS enabling it to be applied also to large and non-portable samples in situ without recourse to removing samples, or their fragments, for laboratory analysis on benchtop Raman microscopes.

Model driver screening and evaluation program. Volume 1, Project summary and model program recommendations

DOT National Transportation Integrated Search

2003-05-01

This research project studied the feasibility as well as the scientific validity and utility of performing functional capacity screening with older drivers. A Model Program was described encompassing procedures to detect functionally impaired drivers...

Commercial Motor Vehicle Driver Fatigue And Alertness Study Executive Summary

DOT National Transportation Integrated Search

1996-11-01

THE DRIVER FATIGUE AND ALERTNESS STUDY (DFAS) WAS THE LARGEST AND MOST COMPREHENSIVE OVER-THE-ROAD STUDY EVER CONDUCTED ON DRIVER FATIGUE AND ALERTNESS IN NORTH AMERICA. IT PROVIDES EXTENSIVE INFORMATION ON THE ALERTNESS, DRIVING PERFORMANCE, AND PHY...

MONICA: A Compact, Portable Dual Gamma Camera System for Mouse Whole-Body Imaging

PubMed Central

Xi, Wenze; Seidel, Jurgen; Karkareka, John W.; Pohida, Thomas J.; Milenic, Diane E.; Proffitt, James; Majewski, Stan; Weisenberger, Andrew G.; Green, Michael V.; Choyke, Peter L.

2009-01-01

Introduction We describe a compact, portable dual-gamma camera system (named “MONICA” for MObile Nuclear Imaging CAmeras) for visualizing and analyzing the whole-body biodistribution of putative diagnostic and therapeutic single photon emitting radiotracers in animals the size of mice. Methods Two identical, miniature pixelated NaI(Tl) gamma cameras were fabricated and installed “looking up” through the tabletop of a compact portable cart. Mice are placed directly on the tabletop for imaging. Camera imaging performance was evaluated with phantoms and field performance was evaluated in a weeklong In-111 imaging study performed in a mouse tumor xenograft model. Results Tc-99m performance measurements, using a photopeak energy window of 140 keV ± 10%, yielded the following results: spatial resolution (FWHM at 1-cm), 2.2-mm; sensitivity, 149 cps/MBq (5.5 cps/μCi); energy resolution (FWHM), 10.8%; count rate linearity (count rate vs. activity), r2 = 0.99 for 0–185 MBq (0–5 mCi) in the field-of-view (FOV); spatial uniformity, < 3% count rate variation across the FOV. Tumor and whole-body distributions of the In-111 agent were well visualized in all animals in 5-minute images acquired throughout the 168-hour study period. Conclusion Performance measurements indicate that MONICA is well suited to whole-body single photon mouse imaging. The field study suggests that inter-device communications and user-oriented interfaces included in the MONICA design facilitate use of the system in practice. We believe that MONICA may be particularly useful early in the (cancer) drug development cycle where basic whole-body biodistribution data can direct future development of the agent under study and where logistical factors, e.g. limited imaging space, portability, and, potentially, cost are important. PMID:20346864

The effects of age on crash risk associated with driver distraction.

PubMed

Guo, Feng; Klauer, Sheila G; Fang, Youjia; Hankey, Jonathan M; Antin, Jonathan F; Perez, Miguel A; Lee, Suzanne E; Dingus, Thomas A

2017-02-01

Driver distraction is a major contributing factor to crashes, which are the leading cause of death for the US population under 35 years of age. The prevalence of secondary-task engagement and its impacts on distraction and crashes may vary substantially by driver age. Driving performance and behaviour data were collected continuously using multiple cameras and sensors in situ for 3542 participant drivers recruited for up to 3 years for the Second Strategic Highway Research Program Naturalistic Driving Study. Secondary-task engagement at the onset of crashes and during normal driving segments was identified from videos. A case-cohort approach was used to estimate the crash odds ratios associated with, and the prevalence of, secondary tasks for four age groups: 16-20, 21-29, 30-64 and 65-98 years of age. Only severe crashes (property damage and higher severity) were included in the analysis. Secondary-task-induced distraction posed a consistently higher threat for drivers younger than 30 and above 65 when compared with middle-aged drivers, although senior drivers engaged in secondary tasks much less frequently than their younger counterparts. Secondary tasks with high visual-manual demand (e.g. visual-manual tasks performed on cell phones) affected drivers of all ages. Certain secondary tasks, such as operation of in-vehicle devices and talking/singing, increased the risk for only certain age groups. Teenaged, young adult drivers and senior drivers are more adversely impacted by secondary-task engagement than middle-aged drivers. Visual-manual distractions impact drivers of all ages, whereas cognitive distraction may have a larger impact on young drivers. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association

Traffic Games: Modeling Freeway Traffic with Game Theory

PubMed Central

Cortés-Berrueco, Luis E.; Gershenson, Carlos; Stephens, Christopher R.

2016-01-01

We apply game theory to a vehicular traffic model to study the effect of driver strategies on traffic flow. The resulting model inherits the realistic dynamics achieved by a two-lane traffic model and aims to incorporate phenomena caused by driver-driver interactions. To achieve this goal, a game-theoretic description of driver interaction was developed. This game-theoretic formalization allows one to model different lane-changing behaviors and to keep track of mobility performance. We simulate the evolution of cooperation, traffic flow, and mobility performance for different modeled behaviors. The analysis of these results indicates a mobility optimization process achieved by drivers’ interactions. PMID:27855176

EEG alpha spindles and prolonged brake reaction times during auditory distraction in an on-road driving study.

PubMed

Sonnleitner, Andreas; Treder, Matthias Sebastian; Simon, Michael; Willmann, Sven; Ewald, Arne; Buchner, Axel; Schrauf, Michael

2014-01-01

Driver distraction is responsible for a substantial number of traffic accidents. This paper describes the impact of an auditory secondary task on drivers' mental states during a primary driving task. N=20 participants performed the test procedure in a car following task with repeated forced braking on a non-public test track. Performance measures (provoked reaction time to brake lights) and brain activity (EEG alpha spindles) were analyzed to describe distracted drivers. Further, a classification approach was used to investigate whether alpha spindles can predict drivers' mental states. Results show that reaction times and alpha spindle rate increased with time-on-task. Moreover, brake reaction times and alpha spindle rate were significantly higher while driving with auditory secondary task opposed to driving only. In single-trial classification, a combination of spindle parameters yielded a median classification error of about 8% in discriminating the distracted from the alert driving. Reduced driving performance (i.e., prolonged brake reaction times) during increased cognitive load is assumed to be indicated by EEG alpha spindles, enabling the quantification of driver distraction in experiments on public roads without verbally assessing the drivers' mental states. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sensorimotor and postural control factors associated with driving safety in a community-dwelling older driver population.

PubMed

Lacherez, Philippe; Wood, Joanne M; Anstey, Kaarin J; Lord, Stephen R

2014-02-01

To establish whether sensorimotor function and balance are associated with on-road driving performance in older adults. The performance of 270 community-living adults aged 70-88 years recruited via the electoral roll was measured on a battery of peripheral sensation, strength, flexibility, reaction time, and balance tests and on a standardized measure of on-road driving performance. Forty-seven participants (17.4%) were classified as unsafe based on their driving assessment. Unsafe driving was associated with reduced peripheral sensation, lower limb weakness, reduced neck range of motion, slow reaction time, and poor balance in univariate analyses. Multivariate logistic regression analysis identified poor vibration sensitivity, reduced quadriceps strength, and increased sway on a foam surface with eyes closed as significant and independent risk factors for unsafe driving. These variables classified participants into safe and unsafe drivers with a sensitivity of 74% and specificity of 70%. A number of sensorimotor and balance measures were associated with driver safety and the multivariate model comprising measures of sensation, strength, and balance was highly predictive of unsafe driving in this sample. These findings highlight important determinants of driver safety and may assist in developing efficacious driver safety strategies for older drivers.

Driver performance measurement and analysis system (DPMAS). Volume 1, Description and operations manual

DOT National Transportation Integrated Search

1976-08-01

A prototype driver performance measurement and analysis system (DPMAS) has been developed for the National Highway Traffic Safety Administration (NHTSA). This system includes a completely instrumented 1974 Chevrolet Impala capable of digitally record...

A new portable vibrator for plaster pouring: effect on the marginal fit at cylinder-abutment

PubMed Central

de ANDRADE, Pâmela Cândida Aires Ribas; LUTHI, Leonardo Flores; STANLEY, Kyle; CARDOSO, Antônio Carlos

2012-01-01

Objective The aim of this study was to test a new portable vibrator for plaster pouring (developed for this purpose), comparing the effect of its use on the accuracy of working cast of implant-supported restorations to the conventional vibrator. Material and methods From a master cast with 2 implants, 30 transfer moldings were made randomly and divided into three groups: Group I (GI): pouring performed in an outsourced dental laboratory with conventional plaster vibrator (10 casts), Group II (GII): pouring performed in the laboratory of the Federal University of Santa Catarina (UFSC) with conventional plaster vibrator (10 casts) and Group III (GIII): pouring performed with the portable vibrator fabricated for this study (10 casts). The position of the analogue and marginal adaptation of the infrastructure were verified by testing the single screw on the master model and on the working model. The measurement of misfit was blindly performed with a precision microscope and analyzing unit, Quadra-Check 200. The data were statistically analyzed by analysis of variance (ANOVA) and the Holm-Sidak test (α=0.05). Results Means±standard deviations were as follows: GI: 19.19±4.73 µm; GII: 21.72±5.41 µm; GIII: 13.5±2.39 µm (P<0.05), with GIII significantly lower as compared to the other groups. Conclusion Within the limitations of this study, it was concluded that a greater accuracy of working cast was achieved when a portable vibrator was used for casting molds. PMID:23138736

Evaluating the evaluation of cancer driver genes

PubMed Central

Tokheim, Collin J.; Papadopoulos, Nickolas; Kinzler, Kenneth W.; Vogelstein, Bert; Karchin, Rachel

2016-01-01

Sequencing has identified millions of somatic mutations in human cancers, but distinguishing cancer driver genes remains a major challenge. Numerous methods have been developed to identify driver genes, but evaluation of the performance of these methods is hindered by the lack of a gold standard, that is, bona fide driver gene mutations. Here, we establish an evaluation framework that can be applied to driver gene prediction methods. We used this framework to compare the performance of eight such methods. One of these methods, described here, incorporated a machine-learning–based ratiometric approach. We show that the driver genes predicted by each of the eight methods vary widely. Moreover, the P values reported by several of the methods were inconsistent with the uniform values expected, thus calling into question the assumptions that were used to generate them. Finally, we evaluated the potential effects of unexplained variability in mutation rates on false-positive driver gene predictions. Our analysis points to the strengths and weaknesses of each of the currently available methods and offers guidance for improving them in the future. PMID:27911828

Temporal separation and self-rating of alertness as indicators of driver fatigue in commercial motor vehicle operators.

PubMed

Belz, Steven M; Robinson, Gary S; Casali, John G

2004-01-01

This on-road field investigation employed, for the first time, a completely automated trigger-based data collection system capable of evaluating driver performance in an extended-duration real-world commercial motor vehicle environment. The study examined the use of self-assessment of fatigue (Karolinska Sleepiness Scale) and temporal separation (minimum time to collision, minimum headway, and mean headway) as indicators of driver fatigue. Without exception, the correlation analyses for both the self-rating of alertness and temporal separation yielded models low in associative ability; neither metric was found to be a valid indicator of driver fatigue. In addition, based upon the data collected for this research, preliminary evidence suggests that driver fatigue onset within a real-world driving environment does not appear to follow the standard progression of events associated with the onset of fatigue within a simulated driving environment. Application of this research includes the development of an on-board driver performance/fatigue monitoring system that could potentially assist drivers in identifying the onset of fatigue.

Compiler-based code generation and autotuning for geometric multigrid on GPU-accelerated supercomputers

DOE PAGES

Basu, Protonu; Williams, Samuel; Van Straalen, Brian; ...

2017-04-05

GPUs, with their high bandwidths and computational capabilities are an increasingly popular target for scientific computing. Unfortunately, to date, harnessing the power of the GPU has required use of a GPU-specific programming model like CUDA, OpenCL, or OpenACC. Thus, in order to deliver portability across CPU-based and GPU-accelerated supercomputers, programmers are forced to write and maintain two versions of their applications or frameworks. In this paper, we explore the use of a compiler-based autotuning framework based on CUDA-CHiLL to deliver not only portability, but also performance portability across CPU- and GPU-accelerated platforms for the geometric multigrid linear solvers found inmore » many scientific applications. We also show that with autotuning we can attain near Roofline (a performance bound for a computation and target architecture) performance across the key operations in the miniGMG benchmark for both CPU- and GPU-based architectures as well as for a multiple stencil discretizations and smoothers. We show that our technology is readily interoperable with MPI resulting in performance at scale equal to that obtained via hand-optimized MPI+CUDA implementation.« less

Compiler-based code generation and autotuning for geometric multigrid on GPU-accelerated supercomputers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basu, Protonu; Williams, Samuel; Van Straalen, Brian

GPUs, with their high bandwidths and computational capabilities are an increasingly popular target for scientific computing. Unfortunately, to date, harnessing the power of the GPU has required use of a GPU-specific programming model like CUDA, OpenCL, or OpenACC. Thus, in order to deliver portability across CPU-based and GPU-accelerated supercomputers, programmers are forced to write and maintain two versions of their applications or frameworks. In this paper, we explore the use of a compiler-based autotuning framework based on CUDA-CHiLL to deliver not only portability, but also performance portability across CPU- and GPU-accelerated platforms for the geometric multigrid linear solvers found inmore » many scientific applications. We also show that with autotuning we can attain near Roofline (a performance bound for a computation and target architecture) performance across the key operations in the miniGMG benchmark for both CPU- and GPU-based architectures as well as for a multiple stencil discretizations and smoothers. We show that our technology is readily interoperable with MPI resulting in performance at scale equal to that obtained via hand-optimized MPI+CUDA implementation.« less

The application of integral performance criteria to the analysis of discrete maneuvers in a driving simulator

NASA Technical Reports Server (NTRS)

Repa, B. S.; Zucker, R. S.; Wierwille, W. W.

1977-01-01

The influence of vehicle transient response characteristics on driver-vehicle performance in discrete maneuvers as measured by integral performance criteria was investigated. A group of eight ordinary drivers was presented with a series of eight vehicle transfer function configurations in a driving simulator. Performance in two discrete maneuvers was analyzed by means of integral performance criteria. Results are presented.

The Evaluation of Cone Capsule as an Alternative Hull form for Portable Tsunami Lifeboat to Support Evacuation System in the Coastal Regions and Small Islands

NASA Astrophysics Data System (ADS)

Fauzan Zakki, Ahmad; Suharto; Windyandari, Aulia

2018-03-01

Several attempts have been made to reduce the risk of tsunami disasters such as the development of early warning systems, evacuation procedures training, coastal protection and coastal spatial planning. Although many efforts to mitigate the impact of the tsunami in Indonesia was made, no one has developed a portable disaster rescue vehicle/shelter as well as a lifeboat on ships and offshore building, which is always available when a disaster occurs. The aim of the paper is to evaluate the performance of cone capsule shaped hull form that would be used for the portable tsunami lifeboat. The investigation of the boat resistance, intact stability, and seakeeping characteristics was made. The numerical analysis results indicate that the cone capsule is reliable as an alternative hull form for the portable tsunami lifeboat.

Portable smartphone based quantitative phase microscope

NASA Astrophysics Data System (ADS)

Meng, Xin; Tian, Xiaolin; Yu, Wei; Kong, Yan; Jiang, Zhilong; Liu, Fei; Xue, Liang; Liu, Cheng; Wang, Shouyu

2018-01-01

To realize portable device with high contrast imaging capability, we designed a quantitative phase microscope using transport of intensity equation method based on a smartphone. The whole system employs an objective and an eyepiece as imaging system and a cost-effective LED as illumination source. A 3-D printed cradle is used to align these components. Images of different focal planes are captured by manual focusing, followed by calculation of sample phase via a self-developed Android application. To validate its accuracy, we first tested the device by measuring a random phase plate with known phases, and then red blood cell smear, Pap smear, broad bean epidermis sections and monocot root were also measured to show its performance. Owing to its advantages as accuracy, high-contrast, cost-effective and portability, the portable smartphone based quantitative phase microscope is a promising tool which can be future adopted in remote healthcare and medical diagnosis.

Portable Parallel Programming for the Dynamic Load Balancing of Unstructured Grid Applications

NASA Technical Reports Server (NTRS)

Biswas, Rupak; Das, Sajal K.; Harvey, Daniel; Oliker, Leonid

1999-01-01

The ability to dynamically adapt an unstructured -rid (or mesh) is a powerful tool for solving computational problems with evolving physical features; however, an efficient parallel implementation is rather difficult, particularly from the view point of portability on various multiprocessor platforms We address this problem by developing PLUM, tin automatic anti architecture-independent framework for adaptive numerical computations in a message-passing environment. Portability is demonstrated by comparing performance on an SP2, an Origin2000, and a T3E, without any code modifications. We also present a general-purpose load balancer that utilizes symmetric broadcast networks (SBN) as the underlying communication pattern, with a goal to providing a global view of system loads across processors. Experiments on, an SP2 and an Origin2000 demonstrate the portability of our approach which achieves superb load balance at the cost of minimal extra overhead.

The effects of age and workload on 3D spatial attention in dual-task driving.

PubMed

Pierce, Russell S; Andersen, George J

2014-06-01

In the present study we assessed whether the limits in visual-spatial attention associated with aging affect the spatial extent of attention in depth during driving performance. Drivers in the present study performed a car-following and light-detection task. To assess the extent of visual-spatial attention, we compared reaction times and accuracy to light change targets that varied in horizontal position and depth location. In addition, because workload has been identified as a factor that can change the horizontal and vertical extent of attention, we tested whether variability of the lead car speed influenced the extent of spatial attention for younger or older drivers. For younger drivers, reaction time (RT) to light-change targets varied as a function of distance and horizontal position. For older drivers RT varied only as a function of distance. There was a distance by horizontal position interaction for younger drivers but not for older drivers. Specifically, there was no effect of horizontal position at any given level of depth for older drivers. However, for younger drivers there was an effect of horizontal position for targets further in depth but not for targets nearer in depth. With regards to workload, we found no statistically reliable evidence that variability of the lead car speed had an effect on the spatial extent of attention for younger or older drivers. In a control experiment, we examined the effects of depth on light detection when the projected size and position of the targets was constant. Consistent with our previous results, we found that drivers' reaction time to light-change targets varied as a function of distance even when 2D position and size were controlled. Given that depth is an important dimension in driving performance, an important issue for assessing driving safety is to consider the limits of attention in the depth dimension. Therefore, we suggest that future research should consider the importance of depth as a dimension of spatial attention in relation to the assessment of driving performance. Copyright © 2014 Elsevier Ltd. All rights reserved.

Human Factors Design Of Automated Highway Systems: Scenario Definition

DOT National Transportation Integrated Search

1995-09-01

Attention to driver acceptance and performance issues during system design will be key to the success of the Automated Highway System (AHS). A first step in the process of defining driver roles and driver-system interface requirements of AHS is the d...

Vehicle and driver scheduling for public transit.

DOT National Transportation Integrated Search

2009-08-01

The problem of driver scheduling involves the construction of a legal set of shifts, including allowance : of overtime, which cover the blocks in a particular vehicle schedule. A shift is the work scheduled to be performed by : a driver in one day, w...

Assessment of a drowsy driver warning system for heavy-vehicle drivers : final report

DOT National Transportation Integrated Search

2009-04-01

Drowsiness has a globally negative impact on performance, slowing reaction time, decreasing situational awareness, and impairing judgment. A field operational test of an early prototype Drowsy Driver Warning System was conducted as a result of 12 yea...

Understanding driver performance variability and perception of risk : driver hazard perception research plan

DOT National Transportation Integrated Search

1998-01-01

The objectives of this research project were to develop a comprehensive and clearly defined research program to define, : measure, and quantify driver perception of hazards as it relates to highway design, operations, and safety, standards This was :...

An application of the driver behavior questionnaire to Chinese carless young drivers.

PubMed

Zhang, Qian; Jiang, Zuhua; Zheng, Dongpeng; Wang, Yifan; Man, Dong

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 turn into carless young drivers after licensure, and the safety issue associated with them has become a matter of great concern in China. Because few studies have examined the driving behaviors of these drivers, this study aims to utilize the Driver Behavior Questionnaire (DBQ) to investigate the self-reported driving behaviors of Chinese carless young drivers. A total of 523 Chinese carless young drivers (214 females, 309 males) with an average age of 21.91 years completed a questionnaire including the 27-item DBQ and demographics. The data were first randomized into 2 subsamples for factor analysis and then combined together for the following analyses. Both an exploratory factor analysis (EFA, n = 174) and a confirmatory factor analysis (CFA, n = 349) were performed to investigate the factor structure of the DBQ. Correlation analysis was conducted to examine the relationships between the demographics and the DBQ scales' variables. Multivariate linear regression and logistic regression were performed to investigate the prediction of the DBQ scales and crash involvement in the previous year. The EFA produced a 4-factor structure identified as errors, violations, attention lapses, and memory lapses, and the CFA revealed a good model fit after the removal of one item with a low factor loading and the permission of the error covariance between some items. The Chinese carless young drivers reported a comparatively low level of aberrant driving behaviors. The 3 most frequently reported behaviors were all lapses and the 3 least were all violations. Gender was the only significant predictor of the 2 lapses scales and lifetime mileage was the only significant predictor of the violations scale. Only the violations factor was found to be significantly predictive of crash involvement in the previous year. The current study provides evidence that the DBQ can successfully be utilized to examine the self-reported driving behaviors of Chinese carless young drivers. However, the factor structure as well as the level of reported aberrant driving behaviors suggests that Chinese carless young drivers are a special population and thus should be treated differently when interventions are performed. Supplemental materials are available for this article.

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

PubMed

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 driving rehabilitation specialist (CDRS). The data streams recorded by the DAS are uploaded to the data coordinating center for analysis. The Alabama VIP Older Driver Study is the first naturalistic older driver study specifically focused on the enrollment of drivers with vision impairment in order to study the relationship between visual dysfunction and driver safety and performance.

40 CFR Table 4 to Subpart Zzzz of... - Requirements for Performance Tests

Code of Federal Regulations, 2010 CFR

2010-07-01

... and outlet of the control device; and (1) Portable CO and O2 analyzer. (a) Using ASTM D6522-00 (2005... control device (1) Portable CO and O2 analyzer. (a) Using ASTM D6522-00 (2005) a,b (incorporated by..., appendix A, or ASTM Method D6522-00 (2005) (a) Measurements to determine O2 concentration must be made at...

Man-Portable Simultaneous Magnetometer and EM System (MSEMS)

DTIC Science & Technology

2008-12-01

expensive fluxgate magnetometers . This is because the interleaving hardware is expecting a Larmor signal as input; it performs period counting of the...Larmor signal between EM61 pulses to convert the frequency-based Larmor signal into nanotesla. A fluxgate magnetometer does not employ the resonance...FINAL REPORT Man-Portable Simultaneous Magnetometer and EM System (MSEMS) ESTCP Project MM-0414 December 2008 Robert Siegel Science

Distributed processing for features improvement in real-time portable medical devices.

PubMed

Mercado, Erwin John Saavedra

2008-01-01

Portable biomedical devices are being developed and incorporated in daily life. Nevertheless, their standalone capacity is diminished due to the lack of processing power required to face such duties as for example, signal artifacts robustness in EKG monitor devices. The following paper presents a multiprocessor architecture made from simple microcontrollers to provide an increase in processing performance, power consumption efficiency and lower cost.

Performance Comparison of Field Portable Instruments to the Scanning Mobility Particle Sizer Using Monodispersed and Polydispersed Sodium Chloride Aerosols.

PubMed

Vo, Evanly; Horvatin, Matthew; Zhuang, Ziqing

2018-05-21

This study compared the performance of the following field portable aerosol instrument sets to performance of the reference Scanning Mobility Particle Sizer (SMPS): the handheld CPC-3007, the portable aerosol mobility spectrometer (PAMS), the NanoScan scanning mobility particle sizer (NanoScan SMPS) combined with an optical particle sizer (OPS). Tests were conducted with monodispersed and polydispersed aerosols. Monodispersed aerosols were controlled at the approximate concentration of 1 × 105 particles cm-3 and four monodispersed particle sizes of 30, 60, 100, and 300 nm were selected and classified for the monodispersed aerosol test, while three different steady-state concentration levels (low, medium, and high: ~8 × 103, 5 × 104, and 1 × 105 particles cm-3, respectively) were selected for the polydispersed aerosol test. For all four monodispersed aerosol sizes, particle concentrations measured with the NanoScan SMPS were within 13% of those measured with the reference SMPS. Particle concentrations measured with the PAMS were within 25% of those measured with the reference SMPS. Concentrations measured with the handheld condensation particle counter were within 30% of those measured with the reference SMPS. For the polydispersed aerosols, the particle sizes and concentrations measured with the NanoScan-OPS compared most favorably with those measured with the reference SMPS for three different concentration levels of low, medium, and high (concentration deviations ≤10% for all three concentration levels; deviations of particle size ≤4%). Although the particle-size comparability between the PAMS and the reference SMPS was quite reasonable with the deviations within 10%, the polydispersed particle concentrations measured with the PAMS were within 36% of those measured with the reference SMPS. The results of this evaluation will be useful for selecting a suitable portable device for our next workplace study phase of respiratory protection assessment. This study also provided the advantages and limitations of each individual portable instrument and therefore results from this study can be used by industrial hygienists and safety professionals, with appropriate caution, when selecting a suitable portable instrument for aerosol particle measurement in nanotechnology workplaces.

Acceptance test report for portable exhauster POR-008/Skid F

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kriskovich, J.R.

1998-07-24

Portable Exhauster POR-008 was procured via HNF-0490, Specification for a Portable Exhausted System for Waste Tank Ventilation. Prior to taking ownership, acceptance testing was performed at the vendors. However at the conclusion of testing a number of issues remained that required resolution before the exhausters could be used by Project W-320. The purpose of acceptance testing documented by this report was to demonstrate compliance of the exhausters with the performance criteria established within HNF-O49O, Rev. 1 following a repair and upgrade effort at Hanford. In addition, data obtained during this testing is required for the resolution of outstanding Non-conformance Reportsmore » (NCR), and finally, to demonstrate the functionality of the associated software for the pressure control and high vacuum exhauster operating modes provided for by W-320. Additional testing not required by the ATP was also performed to assist in the disposition and close out of receiving inspection report and for application design information (system curve). Results of this testing are also captured within this document.« less

Adaptive Response Criteria in Road Hazard Detection Among Older Drivers

PubMed Central

Feng, Jing; Choi, HeeSun; Craik, Fergus I. M.; Levine, Brian; Moreno, Sylvain; Naglie, Gary; Zhu, Motao

2018-01-01

OBJECTIVES The majority of existing investigations on attention, aging, and driving have focused on the negative impacts of age-related declines in attention on hazard detection and driver performance. However, driving skills and behavioral compensation may accommodate the negative effects that age-related attentional decline places on driving performance. In this study, we examined an important question that had been largely neglected in the literature linking attention, aging, and driving: can top-down factors such as behavioral compensation, specifically adaptive response criteria, accommodate the negative impacts from age-related attention declines on hazard detection during driving? METHODS In the experiment, we used the Drive Aware Task, a task combining the driving context with well-controlled laboratory procedures measuring attention. We compared younger (n = 16, age 21 – 30) and older drivers (n = 21, age 65 – 79) on their attentional processing of hazards in driving scenes, indexed by percentage of correct and reaction time of hazard detection, as well as sensitivity and response criterion using the signal detection analysis. RESULTS Older drivers, in general, were less accurate and slower on the task than younger drivers. However, results from this experiment also revealed that older, but not younger, drivers adapted their response criteria when the traffic condition changed in the driving scenes. When there was more traffic in the driving scene, older drivers became more liberal in their responses, meaning that they were more likely to report that a driving hazard was detected. CONCLUSIONS Older drivers adopt compensatory strategies on hazard detection during driving . Our findings showed that, in the driving context, even at an old age our attentional functions are still adaptive according to environmental conditions. This leads to considerations on potential training methods to promote adaptive strategies which may help older drivers maintaining performance in road hazard detection. PMID:28898116

Proactive vs. reactive car driving: EEG evidence for different driving strategies of older drivers

PubMed Central

Wascher, Edmund; Getzmann, Stephan

2018-01-01

Aging is associated with a large heterogeneity in the extent of age-related changes in sensory, motor, and cognitive functions. All these functions can influence the performance in complex tasks like car driving. The present study aims to identify potential differences in underlying cognitive processes that may explain inter-individual variability in driving performance. Younger and older participants performed a one-hour monotonous driving task in a driving simulator under varying crosswind conditions, while behavioral and electrophysiological data were recorded. Overall, younger and older drivers showed comparable driving performance (lane keeping). However, there was a large difference in driving lane variability within the older group. Dividing the older group in two subgroups with low vs. high driving lane variability revealed differences between the two groups in electrophysiological correlates of mental workload, consumption of mental resources, and activation and sustaining of attention: Older drivers with high driving lane variability showed higher frontal Alpha and Theta activity than older drivers with low driving lane variability and—with increasing crosswind—a more pronounced decrease in Beta activity. These results suggest differences in driving strategies of older and younger drivers, with the older drivers using either a rather proactive and alert driving strategy (indicated by low driving lane variability and lower Alpha and Beta activity), or a rather reactive strategy (indicated by high driving lane variability and higher Alpha activity). PMID:29352314

A simulator-based analysis of engineering treatments for right-hook bicycle crashes at signalized intersections.

PubMed

Warner, Jennifer; Hurwitz, David S; Monsere, Christopher M; Fleskes, Kayla

2017-07-01

A right-hook crash is a crash between a right-turning motor vehicle and an adjacent through-moving bicycle. At signalized intersections, these crashes can occur during any portion of the green interval when conflicting bicycles and vehicles are moving concurrently. The objective of this research was to evaluate the effectiveness of four types of engineering countermeasures - regulatory signage, intersection pavement marking, smaller curb radius, and protected intersection design - at modifying driver behaviors that are known contributing factors in these crashes. This research focused on right-hook crashes that occur during the latter stage of the circular green indication at signalized intersections with a shared right-turn and through lane. Changes in driver performance in response to treatments were measured in a high-fidelity driving simulator. Twenty-eight participants each completed 22 right-turn maneuvers. A partially counterbalanced experimental design exposed drivers to critical scenarios, which had been determined in a previous experiment. For each turn, driver performance measures, including visual attention, crash avoidance, and potential crash severity, were collected. A total of 75 incidents (47 near-collisions and 28 collisions) were observed during the 616 right turns. All treatments had some positive effect on measured driver performance with respect to the right-turn vehicle conflicts. Further work is required to map the magnitude of these changes in driver performance to crash-based outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Correlation between Driver Subjective Fatigue and Bus Lateral Position in a Driving Simulator.

PubMed

Gharagozlou, Faramarz; Mazloumi, Adel; Saraji, Gebraeil Nasl; Nahvi, Ali; Ashouri, Mohammadreza; Mozaffari, Hamed

2015-08-01

Driver fatigue as a leading cause of death in the transportation industry can impair the driving performance in long-distance driving task. Studies on the links of driver subjective fatigue and the bus lateral position are still an exploratory issue that requires further investigation. This study aimed to determine the correlation between the driver subjective fatigue and the bus lateral position in a driving simulator. This descriptive-analytical research was conducted on 30 professional male bus drivers participated in a two-hour driving session. The driver subjective fatigue was assessed by the Fatigue Visual Analogue Scale (F-VAS) at 10-min intervals. Simultaneously, the performance measures of lane drifting as the mean and standard deviation of the bus lateral position (SDLP) were calculated during the simulated driving task. Descriptive statistics and the Spearman correlation coefficient were used to describe and analyze the data. Fatigue levels had an increasing trend as the time-on-task of driving increased. Time-on-task of driving had the greatest effect on the fatigue self-evaluation (r = 0.605, p < 0.0001). The results showed a significant correlation between fatigue self-evaluation and bus lateral position (r = 0.567, p < 0.0001). As the time of driving increased, driving performance was affected adversely, as shown by the increase in the SDLP. Even so, the effect of individual differences on driving performance should not be overlooked. This work concludes that predicting the state of a driver fatigue based on the group mean data has some complications for any application.

Correlation between Driver Subjective Fatigue and Bus Lateral Position in a Driving Simulator

PubMed Central

Gharagozlou, Faramarz; Mazloumi, Adel; Saraji, Gebraeil Nasl; Nahvi, Ali; Ashouri, Mohammadreza; Mozaffari, Hamed

2015-01-01

Background: Driver fatigue as a leading cause of death in the transportation industry can impair the driving performance in long-distance driving task. Studies on the links of driver subjective fatigue and the bus lateral position are still an exploratory issue that requires further investigation. This study aimed to determine the correlation between the driver subjective fatigue and the bus lateral position in a driving simulator. Methods: This descriptive-analytical research was conducted on 30 professional male bus drivers participated in a two-hour driving session. The driver subjective fatigue was assessed by the Fatigue Visual Analogue Scale (F-VAS) at 10-min intervals. Simultaneously, the performance measures of lane drifting as the mean and standard deviation of the bus lateral position (SDLP) were calculated during the simulated driving task. Descriptive statistics and the Spearman correlation coefficient were used to describe and analyze the data. Results: Fatigue levels had an increasing trend as the time-on-task of driving increased. Time-on-task of driving had the greatest effect on the fatigue self-evaluation (r = 0.605, p < 0.0001). The results showed a significant correlation between fatigue self-evaluation and bus lateral position (r = 0.567, p < 0.0001). Conclusion: As the time of driving increased, driving performance was affected adversely, as shown by the increase in the SDLP. Even so, the effect of individual differences on driving performance should not be overlooked. This work concludes that predicting the state of a driver fatigue based on the group mean data has some complications for any application. PMID:26396734

Early Experiences Writing Performance Portable OpenMP 4 Codes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joubert, Wayne; Hernandez, Oscar R

In this paper, we evaluate the recently available directives in OpenMP 4 to parallelize a computational kernel using both the traditional shared memory approach and the newer accelerator targeting capabilities. In addition, we explore various transformations that attempt to increase application performance portability, and examine the expressiveness and performance implications of using these approaches. For example, we want to understand if the target map directives in OpenMP 4 improve data locality when mapped to a shared memory system, as opposed to the traditional first touch policy approach in traditional OpenMP. To that end, we use recent Cray and Intel compilersmore » to measure the performance variations of a simple application kernel when executed on the OLCF s Titan supercomputer with NVIDIA GPUs and the Beacon system with Intel Xeon Phi accelerators attached. To better understand these trade-offs, we compare our results from traditional OpenMP shared memory implementations to the newer accelerator programming model when it is used to target both the CPU and an attached heterogeneous device. We believe the results and lessons learned as presented in this paper will be useful to the larger user community by providing guidelines that can assist programmers in the development of performance portable code.« less

Portable microfluidic platform for real-time, high sensitive detection and identification of trichloroethylene and other organochloride compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jensen, Erik

In this successful SBIR Phase II effort, HJ Science & Technology, Inc. has designed and built a novel portable instrument capable of performing automated aqueous organochloride (chlorinated solvent) speciation analysis for environmental monitoring at DoE sites. Our technique employs performing organochloride conjugation, labeling the conjugate with an efficient fluorophore, and performing on-chip capillary electrophoresis separation with laser induced fluorescence detection. The key component of the portable instrument is a novel microfluidic chip capable of complete “end-to-end” automation of sample preparation, conjugation, labeling, and μCE separation and detection. In addition, the Phase II prototype includes key supporting instrumentation such as themore » optical module, pneumatic manifold, electronics, software, etc. As such, we have achieved all of the following 4 Phase II technical objectives: 1) Further refine and optimize the “on-chip” automation of the organochloride conjugation and labeling protocol, 2) Further improve the microfluidic chip fabrication process and the pneumatic manifold design in order to address issues related to performance consistency, product yield, performance reliability, and user friendliness, 3) Design and build the supporting components of the Phase II prototype including optical module, electronics, and software, and 4) Assemble the Phase II prototype hardware.« less

"Keep on Truckin'" Literacy Program [for Adults]: Performance Report; Teacher's Handbook; Final External Evaluation Report.

ERIC Educational Resources Information Center

Indian Hills Community Coll., Ottumwa, IA.

This document is composed of a performance report, a teacher's handbook, and an evaluation report of a workplace literacy program to prepare drivers for the Commercial Drivers' License examination. The performance report addresses actual accomplishments of five objectives. It identifies the number and characteristics of project participants who…

Evaluation of the Impact of Spectral Power Distribution on Driver Performance

DOT National Transportation Integrated Search

2015-08-01

This project is a complete investigation of the impact of light-source spectrum on driver visual performance. In a series of human factors experiments, the effect of overhead lighting and headlamp spectral power distribution was evaluated with respec...

Evaluation of safe performance secondary school driver education curriculum demonstration project

DOT National Transportation Integrated Search

1983-06-01

The primary objective of this Project was to determine the crash reduction potential of a quality, competency-based driver training program known as the Safe Performance Curriculum (SPC). The experimental design called for the random assignment of 18...

The effects of text messaging on young novice driver performance

DOT National Transportation Integrated Search

2006-02-01

This project aimed to evaluate, using the advanced driving simulator located at the Monash University Accident Research Centre, the effects of text (SMS) messaging on the driving performance of young novice drivers. Twenty participants drove on a sim...

Effects of sleep schedules on commercial motor vehicle driver performance : part 1

DOT National Transportation Integrated Search

2000-09-01

The Federal Motor Carrier Safety Administration sponsored a study to gather and analyze data on commercial motor vehicle (CMV) driver rest and recovery cycles, effects of partial sleep deprivation, and prediction of subsequent performance. The study ...

Effects of sleep schedules on commercial motor vehicle driver performance : part 2

DOT National Transportation Integrated Search

2000-09-01

The Federal Motor Carrier Safety Administration sponsored a study to gather and analyze data on commercial motor vehicle driver rest and recovery cycles, effects of partial sleep deprivation, and prediction of subsequent performance. The study began ...

Investigating the roles of touchscreen and physical control interface characteristics on driver distraction and multitasking performance.

DOT National Transportation Integrated Search

2016-01-01

This study aimed to assess the potential of driver distraction, task performance, orientation of : attention, and perceived workload in a multitasking situation involving interaction with touchscreen : interface, compared to physical interface. Autho...

Test procedures and performance measures sensitive to automobile steering dynamics. [considering operator/vehicle responses

NASA Technical Reports Server (NTRS)

Klein, R. H.; Mcruer, D. T.; Weir, D.

1975-01-01

A maneuver complex and related performance measures used to evaluate driver/vehicle system responses as effected by variations in the directional response characteristics of passenger cars are described. The complex consists of normal and emergency maneuvers (including random and discrete disturbances) which, taken as a whole, represent all classes of steering functions and all modes of driver response behavior. Measures of driver/vehicle system response and performance in regulation tasks included direct describing function measurements and rms yaw velocity. In transient maneuvers, measures such as steering activity and cone strikes were used.

Improving School Bus Driver Performance.

ERIC Educational Resources Information Center

Farmer, Ernest

This reference source is intended to assist the school bus driver training instructor in course preparation. Instructional units for program planning each contain pertinent course questions, a summary, and evaluation questions. Unit 1, "Introduction to the School Bus Driver Training Program," focuses on basic course objectives and…

Profound Tissue Specificity in Proliferation Control Underlies Cancer Drivers and Aneuploidy Patterns.

PubMed

Sack, Laura Magill; Davoli, Teresa; Li, Mamie Z; Li, Yuyang; Xu, Qikai; Naxerova, Kamila; Wooten, Eric C; Bernardi, Ronald J; Martin, Timothy D; Chen, Ting; Leng, Yumei; Liang, Anthony C; Scorsone, Kathleen A; Westbrook, Thomas F; Wong, Kwok-Kin; Elledge, Stephen J

2018-04-05

Genomics has provided a detailed structural description of the cancer genome. Identifying oncogenic drivers that work primarily through dosage changes is a current challenge. Unrestrained proliferation is a critical hallmark of cancer. We constructed modular, barcoded libraries of human open reading frames (ORFs) and performed screens for proliferation regulators in multiple cell types. Approximately 10% of genes regulate proliferation, with most performing in an unexpectedly highly tissue-specific manner. Proliferation drivers in a given cell type showed specific enrichment in somatic copy number changes (SCNAs) from cognate tumors and helped predict aneuploidy patterns in those tumors, implying that tissue-type-specific genetic network architectures underlie SCNA and driver selection in different cancers. In vivo screening confirmed these results. We report a substantial contribution to the catalog of SCNA-associated cancer drivers, identifying 147 amplified and 107 deleted genes as potential drivers, and derive insights about the genetic network architecture of aneuploidy in tumors. Copyright © 2018 Elsevier Inc. All rights reserved.

MPF: A portable message passing facility for shared memory multiprocessors

NASA Technical Reports Server (NTRS)

Malony, Allen D.; Reed, Daniel A.; Mcguire, Patrick J.

1987-01-01

The design, implementation, and performance evaluation of a message passing facility (MPF) for shared memory multiprocessors are presented. The MPF is based on a message passing model conceptually similar to conversations. Participants (parallel processors) can enter or leave a conversation at any time. The message passing primitives for this model are implemented as a portable library of C function calls. The MPF is currently operational on a Sequent Balance 21000, and several parallel applications were developed and tested. Several simple benchmark programs are presented to establish interprocess communication performance for common patterns of interprocess communication. Finally, performance figures are presented for two parallel applications, linear systems solution, and iterative solution of partial differential equations.

Assessment of automated analysis of portable oximetry as a screening test for moderate-to-severe sleep apnea in patients with chronic obstructive pulmonary disease

PubMed Central

Andrés-Blanco, Ana M.; Álvarez, Daniel; Crespo, Andrea; Arroyo, C. Ainhoa; Cerezo-Hernández, Ana; Gutiérrez-Tobal, Gonzalo C.; Hornero, Roberto

2017-01-01

Background The coexistence of obstructive sleep apnea syndrome (OSAS) and chronic obstructive pulmonary disease (COPD) leads to increased morbidity and mortality. The development of home-based screening tests is essential to expedite diagnosis. Nevertheless, there is still very limited evidence on the effectiveness of portable monitoring to diagnose OSAS in patients with pulmonary comorbidities. Objective To assess the influence of suffering from COPD in the performance of an oximetry-based screening test for moderate-to-severe OSAS, both in the hospital and at home. Methods A total of 407 patients showing moderate-to-high clinical suspicion of OSAS were involved in the study. All subjects underwent (i) supervised portable oximetry simultaneously to in-hospital polysomnography (PSG) and (ii) unsupervised portable oximetry at home. A regression-based multilayer perceptron (MLP) artificial neural network (ANN) was trained to estimate the apnea-hypopnea index (AHI) from portable oximetry recordings. Two independent validation datasets were analyzed: COPD versus non-COPD. Results The portable oximetry-based MLP ANN reached similar intra-class correlation coefficient (ICC) values between the estimated AHI and the actual AHI for the non-COPD and the COPD groups either in the hospital (non-COPD: 0.937, 0.909–0.956 CI95%; COPD: 0.936, 0.899–0.960 CI95%) and at home (non-COPD: 0.731, 0.631–0.808 CI95%; COPD: 0.788, 0.678–0.864 CI95%). Regarding the area under the receiver operating characteristics curve (AUC), no statistically significant differences (p >0.01) between COPD and non-COPD groups were found in both settings, particularly for severe OSAS (AHI ≥30 events/h): 0.97 (0.92–0.99 CI95%) non-COPD vs. 0.98 (0.92–1.0 CI95%) COPD in the hospital, and 0.87 (0.79–0.92 CI95%) non-COPD vs. 0.86 (0.75–0.93 CI95%) COPD at home. Conclusion The agreement and the diagnostic performance of the estimated AHI from automated analysis of portable oximetry were similar regardless of the presence of COPD both in-lab and at-home. Particularly, portable oximetry could be used as an abbreviated screening test for moderate-to-severe OSAS in patients with COPD. PMID:29176802

Assessment of automated analysis of portable oximetry as a screening test for moderate-to-severe sleep apnea in patients with chronic obstructive pulmonary disease.

PubMed

Andrés-Blanco, Ana M; Álvarez, Daniel; Crespo, Andrea; Arroyo, C Ainhoa; Cerezo-Hernández, Ana; Gutiérrez-Tobal, Gonzalo C; Hornero, Roberto; Del Campo, Félix

2017-01-01

The coexistence of obstructive sleep apnea syndrome (OSAS) and chronic obstructive pulmonary disease (COPD) leads to increased morbidity and mortality. The development of home-based screening tests is essential to expedite diagnosis. Nevertheless, there is still very limited evidence on the effectiveness of portable monitoring to diagnose OSAS in patients with pulmonary comorbidities. To assess the influence of suffering from COPD in the performance of an oximetry-based screening test for moderate-to-severe OSAS, both in the hospital and at home. A total of 407 patients showing moderate-to-high clinical suspicion of OSAS were involved in the study. All subjects underwent (i) supervised portable oximetry simultaneously to in-hospital polysomnography (PSG) and (ii) unsupervised portable oximetry at home. A regression-based multilayer perceptron (MLP) artificial neural network (ANN) was trained to estimate the apnea-hypopnea index (AHI) from portable oximetry recordings. Two independent validation datasets were analyzed: COPD versus non-COPD. The portable oximetry-based MLP ANN reached similar intra-class correlation coefficient (ICC) values between the estimated AHI and the actual AHI for the non-COPD and the COPD groups either in the hospital (non-COPD: 0.937, 0.909-0.956 CI95%; COPD: 0.936, 0.899-0.960 CI95%) and at home (non-COPD: 0.731, 0.631-0.808 CI95%; COPD: 0.788, 0.678-0.864 CI95%). Regarding the area under the receiver operating characteristics curve (AUC), no statistically significant differences (p >0.01) between COPD and non-COPD groups were found in both settings, particularly for severe OSAS (AHI ≥30 events/h): 0.97 (0.92-0.99 CI95%) non-COPD vs. 0.98 (0.92-1.0 CI95%) COPD in the hospital, and 0.87 (0.79-0.92 CI95%) non-COPD vs. 0.86 (0.75-0.93 CI95%) COPD at home. The agreement and the diagnostic performance of the estimated AHI from automated analysis of portable oximetry were similar regardless of the presence of COPD both in-lab and at-home. Particularly, portable oximetry could be used as an abbreviated screening test for moderate-to-severe OSAS in patients with COPD.

The Roles and Performance of Professional Driving Instructors in Novice Driver Education

PubMed Central

Jawi, Zulhaidi M.; Deros, Baba M.; Rashid, Ahmad A. A.; Isa, Mohd H. M.; Awang, Azmi

2017-01-01

This review article aimed to analyse existing literature regarding the roles and performance of professional driving instructors (PDIs) in novice driver education (DE). A systematic classification scheme was adopted to analyse identified articles to determine the study context of PDIs in novice DE, the competency level of PDIs in relation to experienced and learner drivers and the contributions of PDIs to the novice driver learning process. A total of 14 original research articles were identified, with no systematic reviews or meta-analyses available. Overall, all of the articles were found to be inadequate in providing an in-depth understanding of the roles and performance of PDIs in novice DE. There is an urgent need to improve current understanding of the roles of PDIs in novice DE and to work towards an internationally recognised PDI management approach. PMID:29062549

The Roles and Performance of Professional Driving Instructors in Novice Driver Education.

PubMed

Jawi, Zulhaidi M; Deros, Baba M; Rashid, Ahmad A A; Isa, Mohd H M; Awang, Azmi

2017-08-01

This review article aimed to analyse existing literature regarding the roles and performance of professional driving instructors (PDIs) in novice driver education (DE). A systematic classification scheme was adopted to analyse identified articles to determine the study context of PDIs in novice DE, the competency level of PDIs in relation to experienced and learner drivers and the contributions of PDIs to the novice driver learning process. A total of 14 original research articles were identified, with no systematic reviews or meta-analyses available. Overall, all of the articles were found to be inadequate in providing an in-depth understanding of the roles and performance of PDIs in novice DE. There is an urgent need to improve current understanding of the roles of PDIs in novice DE and to work towards an internationally recognised PDI management approach.

The utility of the AusEd driving simulator in the clinical assessment of driver fatigue.

PubMed

Desai, Anup V; Wilsmore, Brad; Bartlett, Delwyn J; Unger, Gunnar; Constable, Ben; Joffe, David; Grunstein, Ronald R

2007-08-01

Several driving simulators have been developed which range in complexity from PC based driving tasks to advanced "real world" simulators. The AusEd driving simulator is a PC based task, which was designed to be conducive to and test for driver fatigue. This paper describes the AusEd driving simulator in detail, including the technical requirements, hardware, screen and file outputs, and analysis software. Some aspects of the test are standardized, while others can be modified to suit the experimental situation. The AusEd driving simulator is sensitive to performance decrement from driver fatigue in the laboratory setting, potentially making it useful as a laboratory or office based test for driver fatigue risk management. However, more research is still needed to correlate laboratory based simulator performance with real world driving performance and outcomes.

Age-Related Differences in Vehicle Control and Eye Movement Patterns at Intersections: Older and Middle-Aged Drivers

PubMed Central

Yamani, Yusuke; Horrey, William J.; Liang, Yulan; Fisher, Donald L.

2016-01-01

Older drivers are at increased risk of intersection crashes. Previous work found that older drivers execute less frequent glances for detecting potential threats at intersections than middle-aged drivers. Yet, earlier work has also shown that an active training program doubled the frequency of these glances among older drivers, suggesting that these effects are not necessarily due to age-related functional declines. In light of findings, the current study sought to explore the ability of older drivers to coordinate their head and eye movements while simultaneously steering the vehicle as well as their glance behavior at intersections. In a driving simulator, older (M = 76 yrs) and middle-aged (M = 58 yrs) drivers completed different driving tasks: (1) travelling straight on a highway while scanning for peripheral information (a visual search task) and (2) navigating intersections with areas potential hazard. The results replicate that the older drivers did not execute glances for potential threats to the sides when turning at intersections as frequently as the middle-aged drivers. Furthermore, the results demonstrate costs of performing two concurrent tasks, highway driving and visual search task on the side displays: the older drivers performed more poorly on the visual search task and needed to correct their steering positions more compared to the middle-aged counterparts. The findings are consistent with the predictions and discussed in terms of a decoupling hypothesis, providing an account for the effects of the active training program. PMID:27736887

Portable tongue-supported human computer interaction system design and implementation.

PubMed

Quain, Rohan; Khan, Masood Mehmood

2014-01-01

Tongue supported human-computer interaction (TSHCI) systems can help critically ill patients interact with both computers and people. These systems can be particularly useful for patients suffering injuries above C7 on their spinal vertebrae. Despite recent successes in their application, several limitations restrict performance of existing TSHCI systems and discourage their use in real life situations. This paper proposes a low-cost, less-intrusive, portable and easy to use design for implementing a TSHCI system. Two applications of the proposed system are reported. Design considerations and performance of the proposed system are also presented.

Automated Portable Test (APT) System: overview and prospects

NASA Technical Reports Server (NTRS)

Bittner, A. C.; Smith, M. G.; Kennedy, R. S.; Staley, C. F.; Harbeson, M. M.

1985-01-01

The Automated Portable Test (APT) System is a notebook-sized, computer-based, human-performance and subjective-status assessment system. It is now being used in a wide range of environmental studies (e.g., simulator aftereffects, flight tests, drug effects, and hypoxia). Three questionnaires and 15 performance tests have been implemented, and the adaptation of 30 more tests is underway or is planned. The APT System is easily transportable, is inexpensive, and has the breadth of expansion options required for field and laboratory applications. The APT System is a powerful and expandable tool for human assessment in remote and unusual environments.

Convolutional Neural Network-Based Classification of Driver's Emotion during Aggressive and Smooth Driving Using Multi-Modal Camera Sensors.

PubMed

Lee, Kwan Woo; Yoon, Hyo Sik; Song, Jong Min; Park, Kang Ryoung

2018-03-23

Because aggressive driving often causes large-scale loss of life and property, techniques for advance detection of adverse driver emotional states have become important for the prevention of aggressive driving behaviors. Previous studies have primarily focused on systems for detecting aggressive driver emotion via smart-phone accelerometers and gyro-sensors, or they focused on methods of detecting physiological signals using electroencephalography (EEG) or electrocardiogram (ECG) sensors. Because EEG and ECG sensors cause discomfort to drivers and can be detached from the driver's body, it becomes difficult to focus on bio-signals to determine their emotional state. Gyro-sensors and accelerometers depend on the performance of GPS receivers and cannot be used in areas where GPS signals are blocked. Moreover, if driving on a mountain road with many quick turns, a driver's emotional state can easily be misrecognized as that of an aggressive driver. To resolve these problems, we propose a convolutional neural network (CNN)-based method of detecting emotion to identify aggressive driving using input images of the driver's face, obtained using near-infrared (NIR) light and thermal camera sensors. In this research, we conducted an experiment using our own database, which provides a high classification accuracy for detecting driver emotion leading to either aggressive or smooth (i.e., relaxed) driving. Our proposed method demonstrates better performance than existing methods.

Effects of sleep schedules on commercial motor vehicle driver performance

DOT National Transportation Integrated Search

2000-05-01

The project entitled "Effects of Sleep Schedules on Commercial Motor Vehicle Driver Performance" was comprised of two studies; a field study and a laboratory study. In the field study, wrist actigraphy was used to determine amounts of sleep in long-v...

78 FR 41187 - Driver Qualifications: Skill Performance Evaluation; Virginia Department of Motor Vehicles...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-09

... DEPARTMENT OF TRANSPORTATION Federal Motor Carrier Safety Administration [Docket No. FMCSA-2013-0147] Driver Qualifications: Skill Performance Evaluation; Virginia Department of Motor Vehicles' Application for Exemption AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Notice of...

Supporting anticipation in driving through attentional and interpretational in-vehicle displays.

PubMed

Stahl, Patrick; Donmez, Birsen; Jamieson, Greg A

2016-06-01

This paper evaluates two different types of in-vehicle interfaces to support anticipation in driving: one aids attention allocation and the other aids interpretation of traffic in addition to attention allocation. Anticipation is a competency that has been shown to facilitate safety and eco-driving through the efficient positioning of a vehicle for probable, upcoming changes in traffic. This competency has been shown to improve with driving experience. In an earlier simulator study, we showed that compared to novice drivers, experienced drivers exhibited a greater number of timely actions to avoid upcoming traffic conflicts. In this study, we seek to facilitate anticipation in general and for novice drivers in particular, who appear to lack the competency. We hypothesize that anticipation depends on two major steps and that it can be supported by aiding each: (1) conscious perception of relevant cues, and (2) effective processing of these cues to create a situational assessment as a basis for anticipation of future developments. We conducted a simulator experiment with 24 experienced and 24 novice drivers to evaluate two interfaces that were designed to aid the two hypothesized steps of anticipation. The attentional interface was designed to direct attention toward the most relevant cue. The interpretational interface represented several cues, and in addition to directing attention also aimed to aid sense-making of these cues. The results confirmed our hypothesis that novice drivers' anticipation performance, as measured through timely actions to avoid upcoming traffic conflicts, would be improved with either interface type. However, results contradicted our expectation that novice drivers would obtain larger improvements with the interpretational interface. Experienced drivers performed better than novice drivers to begin with and did not show any statistically significant improvements with either interface. Both interfaces improved anticipation performance for novice drivers. Future research should evaluate the effectiveness of these interfaces in a wider variety of driving conditions, such as when the driver is multitasking. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis of Human Factors Research on Older Drivers and Highway Safety. Volume I: Older Driver Research Synthesis

DOT National Transportation Integrated Search

1997-10-01

The overall goals in this project were to perform literature reviews and syntheses, using meta-analytic techniques, where appropriate, for a broad and comprehensive body of research findings on older driver needs and (diminished) capabilities, and a ...

SYNTHESIS OF HUMAN FACTORS RESEARCH ON OLDER DRIVERS AND HIGHWAY SAFETY, Volume I: Older Driver Research Synthesis

DOT National Transportation Integrated Search

1999-11-23

The overall goals in this project were to perform literature reviews and syntheses, using meta-analytic techniques, where appropriate, for a broad and comprehensive body of research findings on older driver needs and (diminished) capabilities, and a ...

The influence of daily sleep patterns of commercial truck drivers on driving performance

PubMed Central

Chen, Guang Xiang; Fang, Youjia; Guo, Feng; Hanowski, Richard J.

2016-01-01

Fatigued and drowsy driving has been found to be a major cause of truck crashes. Lack of sleep is the number one cause of fatigue and drowsiness. However, there are limited data on the sleep patterns (sleep duration, sleep percentage in the duration of non-work period, and the time when sleep occurred) of truck drivers in non-work periods and the impact on driving performance. This paper examined sleep patterns of 96 commercial truck drivers during non-work periods and evaluated the influence these sleep patterns had on truck driving performance. Data were from the Naturalistic Truck Driving Study. Each driver participated in the study for approximately four weeks. A shift was defined as a non-work period followed by a work period. A total of 1397 shifts were identified. Four distinct sleep patterns were identified based on sleep duration, sleep start/end point in a non-work period, and the percentage of sleep with reference to the duration of non-work period. Driving performance was measured by safety-critical events, which included crashes, near-crashes, crash-relevant conflicts, and unintentional lane deviations. Negative binomial regression was used to evaluate the association between the sleep patterns and driving performance, adjusted for driver demographic information. The results showed that the sleep pattern with the highest safety-critical event rate was associated with shorter sleep, sleep in the early stage of a non-work period, and less sleep between 1 a.m. and 5 a.m. This study also found that male drivers, with fewer years of commercial vehicle driving experience and higher body mass index, were associated with deteriorated driving performance and increased driving risk. The results of this study could inform hours-of-service policy-making and benefit safety management in the trucking industry. PMID:26954762

Reactivity, stability, and strength performance capacity in motor sports.

PubMed

Baur, H; Müller, S; Hirschmüller, A; Huber, G; Mayer, F

2006-11-01

Racing drivers require multifaceted cognitive and physical abilities in a multitasking situation. A knowledge of their physical capacities may help to improve fitness and performance. To compare reaction time, stability performance capacity, and strength performance capacity of élite racing drivers with those of age-matched, physically active controls. Eight élite racing drivers and 10 physically active controls matched for age and weight were tested in a reaction and determination test requiring upper and lower extremity responses to visual and audio cues. Further tests comprised evaluation of one-leg postural stability on a two-dimensional moveable platform, measures of maximum strength performance capacity of the extensors of the leg on a leg press, and a test of force capacity of the arms in a sitting position at a steering wheel. An additional arm endurance test consisted of isometric work at the steering wheel at +30 degrees and -30 degrees where an eccentric threshold load of 30 N.m was applied. Subjects had to hold the end positions above this threshold until exhaustion. Univariate one way analysis of variance (alpha = 0.05) including a Bonferroni adjustment was used to detect group differences between the drivers and controls. The reaction time of the racing drivers was significantly faster than the controls (p = 0.004). The following motor reaction time and reaction times in the multiple determination test did not differ between the groups. No significant differences (p>0.05) were found for postural stability, leg extensor strength, or arm strength and endurance. Racing drivers have faster reaction times than age-matched physically active controls. Further development of motor sport-specific test protocols is suggested. According to the requirements of motor racing, strength and sensorimotor performance capacity can potentially be improved.

Monitoring driver fatigue using a single-channel electroencephalographic device: A validation study by gaze-based, driving performance, and subjective data.

PubMed

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.

Portable and cost-effective pixel super-resolution on-chip microscope for telemedicine applications.

PubMed

Bishara, Waheb; Sikora, Uzair; Mudanyali, Onur; Su, Ting-Wei; Yaglidere, Oguzhan; Luckhart, Shirley; Ozcan, Aydogan

2011-01-01

We report a field-portable lensless on-chip microscope with a lateral resolution of <1 μm and a large field-of-view of ~24 mm(2). This microscope is based on digital in-line holography and a pixel super-resolution algorithm to process multiple lensfree holograms and obtain a single high-resolution hologram. In its compact and cost-effective design, we utilize 23 light emitting diodes butt-coupled to 23 multi-mode optical fibers, and a simple optical filter, with no moving parts. Weighing only ~95 grams, we demonstrate the performance of this field-portable microscope by imaging various objects including human malaria parasites in thin blood smears.

Drivers' communicative interactions: on-road observations and modelling for integration in future automation systems.

PubMed

Portouli, Evangelia; Nathanael, Dimitris; Marmaras, Nicolas

2014-01-01

Social interactions with other road users are an essential component of the driving activity and may prove critical in view of future automation systems; still up to now they have received only limited attention in the scientific literature. In this paper, it is argued that drivers base their anticipations about the traffic scene to a large extent on observations of social behaviour of other 'animate human-vehicles'. It is further argued that in cases of uncertainty, drivers seek to establish a mutual situational awareness through deliberate communicative interactions. A linguistic model is proposed for modelling these communicative interactions. Empirical evidence from on-road observations and analysis of concurrent running commentary by 25 experienced drivers support the proposed model. It is suggested that the integration of a social interactions layer based on illocutionary acts in future driving support and automation systems will improve their performance towards matching human driver's expectations. Practitioner Summary: Interactions between drivers on the road may play a significant role in traffic coordination. On-road observations and running commentaries are presented as empirical evidence to support a model of such interactions; incorporation of drivers' interactions in future driving support and automation systems may improve their performance towards matching driver's expectations.

A driving simulator study of driver performance on deceleration lanes.

PubMed

Calvi, A; Benedetto, A; De Blasiis, M R

2012-03-01

Deceleration lanes are important because they help drivers transition from high-speed lanes to low-speed ramps. Although they are designed to allow vehicles to depart the freeway safely and efficiently, many studies report high accident rates on exit ramps with the highest percentage of crashes taking place in deceleration lanes. This paper describes the results of a driving simulator study that focused on driving performance while approaching a divergence area and decelerating during the exiting maneuver. Three different traffic scenarios were simulated to analyze the influence of traffic volume on driving performance. Thirty drivers drove in the simulator in these scenarios while data on their lateral position, speed and deceleration were collected. Our results indicate there are considerable differences between the main assumptions of models generally used to design deceleration lanes and actual driving performance. In particular, diverging drivers begin to decelerate before arriving at the deceleration lane, causing interference with the main flow. Moreover, speeds recorded at the end of the deceleration lane exceed those for which the ramp's curves are designed; this creates risky driving conditions that could explain the high crash rates found in studies of exit ramps. Finally, statistical analyses demonstrate significant influences of traffic volume on some aspects of exiting drivers' performance: lower traffic volume results in elevated exiting speed and deceleration, and diverging drivers begin to decelerate earlier along the main lane when traffic volume is low. However, speeds at the end of the deceleration lane and the site of lane changing are not significantly influenced by traffic volume. Copyright © 2011 Elsevier Ltd. All rights reserved.

On-Road Driving Performance by Persons with Hemianopia and Quadrantanopia

PubMed Central

Wood, Joanne M.; McGwin, Gerald; Elgin, Jennifer; Vaphiades, Michael S.; Braswell, Ronald A.; DeCarlo, Dawn K.; Kline, Lanning B.; Meek, G. Christine; Searcey, Karen; Owsley, Cynthia

2009-01-01

Purpose This study was designed to examine the on-road driving performance of drivers with hemianopia and quadrantanopia compared with age-matched controls. Methods Participants included persons with hemianopia or quadrantanopia and those with normal visual fields. Visual and cognitive function tests were administered, including confirmation of hemianopia and quadrantanopia through visual field testing. Driving performance was assessed using a dual-brake vehicle and monitored by a certified driving rehabilitation specialist. The route was 14.1 miles of city and interstate driving. Two “back-seat” evaluators masked to drivers’ clinical characteristics independently assessed driving performance using a standard scoring system. Results Participants were 22 persons with hemianopia and 8 with quadrantanopia (mean age, 53 ± 20 years) and 30 participants with normal fields (mean age, 52 ± 19 years). Inter-rater agreement for back-seat evaluators was 96%. All drivers with normal fields were rated as safe to drive, while 73% (16/22) of hemianopic and 88% (7/8) of quadrantanopic drivers received safe ratings. Drivers with hemianopia or quadrantanopia who displayed on-road performance problems tended to have difficulty with lane position, steering steadiness, and gap judgment compared to controls. Clinical characteristics associated with unsafe driving were slowed visual processing speed, reduced contrast sensitivity and visual field sensitivity. Conclusions Some drivers with hemianopia or quadrantanopia are fit to drive compared with age-matched control drivers. Results call into question the fairness of governmental policies that categorically deny licensure to persons with hemianopia or quadrantanopia without the opportunity for on-road evaluation. PMID:18936138

A menu of self-administered microcomputer-based neurotoxicology tests

NASA Technical Reports Server (NTRS)

Kennedy, Robert S.; Wilkes, Robert L.; Kuntz, Lois-Ann; Baltzley, Dennis R.

1988-01-01

This study examined the feasibility of repeated self-administration of a newly developed battery of mental acuity tests. Researchers developed this battery to be used to screen the fitness for duty of persons in at-risk occupations (astronauts, race car drivers), or those who may be exposed to environmental stress, toxic agents, or disease. The menu under study contained cognitive and motor tests implemented on a portable microcomputer including: a five-test core battery, lasting six minutes, which had demonstrable reliabilities and stability from several previous repeated-measures studies, and also 13 new tests, lasting 42 minutes, which had appeared in other batteries but had not yet been evaluated for repeated-measures implementation in this medium. Sixteen subjects self-administered the battery over 10 repeated sessions. The hardware performed well throughout the study and the tests appeared to be easily self-administered. Stabilities and reliabilities of the test from the core battery were comparable to those obtained previously under more controlled experimental conditions. Analyses of metric properties of the remaining 13 tests produced eight additional tests with satisfactory properties. Although the average retest reliability was high, cross-correlations between tests were low, indicating factorial richness. The menu can be used to form batteries of flexible total testing time which are likely to tap different mental processes and functions.

Skylab astronaut life support assembly

NASA Technical Reports Server (NTRS)

Brown, J. T.

1972-01-01

A comparative study was performed to define an optimum portable life support system for suited operations inside and outside the Skylab Program. Emphasis was placed on utilization of qualified equipment, modified versions of qualified equipment, and new systems made up to state-of-the-art components. Outlined are the mission constraints, operational modes, and evaluation ground rules by which the Skylab portable life support system was selected and the resulting design.

Performance assessment of an onboard monitoring system for commercial motor vehicle drivers : a field operational test.

DOT National Transportation Integrated Search

2016-11-01

The onboard monitoring system (OBMS) field operational test (FOT) was conducted to determine whether onboard monitoring systems that provide real-time performance feedback to commercial truck and motorcoach drivers could reduce the number of safety-c...

Performance assessment of an onboard monitoring system for CMV drivers : a field operational test : research brief.

DOT National Transportation Integrated Search

2016-11-01

The primary goal of an onboard monitoring system (OBMS) is to enhance driver performance and safety. OBMSs are employed with the expectation that feedback provided concurrently (via flashing feedback lights in the vehicle) and cumulatively (via coach...

The Effect of Low-Frequency Road Noise on Driver Sleepiness and Performance

PubMed Central

Anund, Anna; Lahti, Eva; Fors, Carina; Genell, Anders

2015-01-01

It is a well-known fact today that driver sleepiness is a contributory factor in crashes. Factors considered as sleepiness contributor are mostly related to time of the day, hours being awake and hours slept. Factors contributing to active and passive fatigue are mostly focusing on the level of cognitive load. Less is known what role external factors, e.g. type of road, sound/noise, vibrations etc., have on the ability to stay awake both under conditions of sleepiness and under active or passive fatigue. The aim of this moving base driving simulator study with 19 drivers participating in a random order day and night time, was to evaluate the effect of low-frequency road noise on driver sleepiness and performance, including both long-term and short-term effects. The results support to some extent the hypothesis that road-induced interior vehicle sound affects driving performance and driver sleepiness. Increased low-frequency noise helps to reduce speed during both day- and night time driving, but also contributes to increase the number of lane crossings during night time. PMID:25874883

Driver fatigue alarm based on eye detection and gaze estimation

NASA Astrophysics Data System (ADS)

Sun, Xinghua; Xu, Lu; Yang, Jingyu

2007-11-01

The driver assistant system has attracted much attention as an essential component of intelligent transportation systems. One task of driver assistant system is to prevent the drivers from fatigue. For the fatigue detection it is natural that the information about eyes should be utilized. The driver fatigue can be divided into two types, one is the sleep with eyes close and another is the sleep with eyes open. Considering that the fatigue detection is related with the prior knowledge and probabilistic statistics, the dynamic Bayesian network is used as the analysis tool to perform the reasoning of fatigue. Two kinds of experiments are performed to verify the system effectiveness, one is based on the video got from the laboratory and another is based on the video got from the real driving situation. Ten persons participate in the test and the experimental result is that, in the laboratory all the fatigue events can be detected, and in the practical vehicle the detection ratio is about 85%. Experiments show that in most of situations the proposed system works and the corresponding performance is satisfying.

The effect of low-frequency road noise on driver sleepiness and performance.

PubMed

Anund, Anna; Lahti, Eva; Fors, Carina; Genell, Anders

2015-01-01

It is a well-known fact today that driver sleepiness is a contributory factor in crashes. Factors considered as sleepiness contributor are mostly related to time of the day, hours being awake and hours slept. Factors contributing to active and passive fatigue are mostly focusing on the level of cognitive load. Less is known what role external factors, e.g. type of road, sound/noise, vibrations etc., have on the ability to stay awake both under conditions of sleepiness and under active or passive fatigue. The aim of this moving base driving simulator study with 19 drivers participating in a random order day and night time, was to evaluate the effect of low-frequency road noise on driver sleepiness and performance, including both long-term and short-term effects. The results support to some extent the hypothesis that road-induced interior vehicle sound affects driving performance and driver sleepiness. Increased low-frequency noise helps to reduce speed during both day- and night time driving, but also contributes to increase the number of lane crossings during night time.

Determining the Relationship between Drivers' Level of Education, Training, Working Conditions, and Job Performance in Kenya.

ERIC Educational Resources Information Center

Nafukho, Fredrick Muyia; Hinton, Barbara E.

2003-01-01

Multiple regression analyses of data from 143 public transportation drivers in Kenya indicated that driver experience and hours worked were significantly related to rates of traffic accidents. Educational level, training, salary, and average speed were not related. (Contains 45 references.) (SK)

Driving and Low Vision: An Evidence-Based Review of Rehabilitation

ERIC Educational Resources Information Center

Strong, J. Graham; Jutai, Jeffrey W.; Russell-Minda, Elizabeth; Evans, Mal

2008-01-01

This systematic review of the effectiveness of driver rehabilitation interventions found that driver training programs enhance driving skills and awareness, but further research is needed to determine their effectiveness in improving driving performance of drivers with low vision. More research is also needed to determine the effectiveness of low…

Perceptions of Heat Risk to Health: A Qualitative Study of Professional Bus Drivers and Their Managers in Jinan, China

PubMed Central

Zhou, Lin; Xin, Zheng; Bai, Li; Wan, Fangjun; Wang, Yongming; Sang, Shaowei; Liu, Shouqin; Zhang, Ji; Liu, Qiyong

2014-01-01

Summer extreme heat threatens the health of individuals, especially persons who are involved in outdoor activities. Ensuring the normal function of a city, bus drivers are among those who participate in outdoor physical activities and are exposed to excessive heat in hot summer weather. This qualitative study was performed to explore professional bus drivers’ in-depth views of extreme heat risks to their health, and ultimately develop targeted advice and policy interventions for city bus drivers. An interview-based study was performed among professional bus drivers in Jinan, China, including four focus groups with professional bus drivers (n = 37) and three interviews with their managers (n = 14). Five central themes or categories from the bus driver interviews were found: concerns about summer heat; health effects related to extreme heat; adaptive measures; barriers in implementing these adaptive measures; and suggested interventions. The beneficial role of cooling facilities (particularly air-conditioning) during extreme heat are addressed. The barriers not only impede the implementation of behavioral adaptive measures but also enhance the negative attitudes of bus drivers towards their effectiveness. The responsibilities of managers in promoting preventive actions are addressed. PMID:24477213

Simulated Driving Assessment (SDA) for Teen Drivers: Results from a Validation Study

PubMed Central

McDonald, Catherine C.; Kandadai, Venk; Loeb, Helen; Seacrist, Thomas S.; Lee, Yi-Ching; Winston, Zachary; Winston, Flaura K.

2015-01-01

Background Driver error and inadequate skill are common critical reasons for novice teen driver crashes, yet few validated, standardized assessments of teen driving skills exist. The purpose of this study was to evaluate the construct and criterion validity of a newly developed Simulated Driving Assessment (SDA) for novice teen drivers. Methods The SDA's 35-minute simulated drive incorporates 22 variations of the most common teen driver crash configurations. Driving performance was compared for 21 inexperienced teens (age 16–17 years, provisional license ≤90 days) and 17 experienced adults (age 25–50 years, license ≥5 years, drove ≥100 miles per week, no collisions or moving violations ≤3 years). SDA driving performance (Error Score) was based on driving safety measures derived from simulator and eye-tracking data. Negative driving outcomes included simulated collisions or run-off-the-road incidents. A professional driving evaluator/instructor reviewed videos of SDA performance (DEI Score). Results The SDA demonstrated construct validity: 1.) Teens had a higher Error Score than adults (30 vs. 13, p=0.02); 2.) For each additional error committed, the relative risk of a participant's propensity for a simulated negative driving outcome increased by 8% (95% CI: 1.05–1.10, p<0.01). The SDA demonstrated criterion validity: Error Score was correlated with DEI Score (r=−0.66, p<0.001). Conclusions This study supports the concept of validated simulated driving tests like the SDA to assess novice driver skill in complex and hazardous driving scenarios. The SDA, as a standard protocol to evaluate teen driver performance, has the potential to facilitate screening and assessment of teen driving readiness and could be used to guide targeted skill training. PMID:25740939

What's skill got to do with it? Vehicle automation and driver mental workload.

PubMed

Young, M S; Stanton, N A

2007-08-01

Previous research has found that vehicle automation systems can reduce driver mental workload, with implications for attentional resources that can be detrimental to performance. The present paper considers how the development of automaticity within the driving task may influence performance in underload situations. Driver skill and vehicle automation were manipulated in a driving simulator, with four levels of each variable. Mental workload was assessed using a secondary task measure and eye movements were recorded to infer attentional capacity. The effects of automation on driver mental workload were quite robust across skill levels, but the most intriguing findings were from the eye movement data. It was found that, with little exception, attentional capacity and mental workload were directly related at all levels of driver skill, consistent with earlier studies. The results are discussed with reference to applied theories of cognition and the design of automation.

A learning-based autonomous driver: emulate human driver's intelligence in low-speed car following

NASA Astrophysics Data System (ADS)

Wei, Junqing; Dolan, John M.; Litkouhi, Bakhtiar

2010-04-01

In this paper, an offline learning mechanism based on the genetic algorithm is proposed for autonomous vehicles to emulate human driver behaviors. The autonomous driving ability is implemented based on a Prediction- and Cost function-Based algorithm (PCB). PCB is designed to emulate a human driver's decision process, which is modeled as traffic scenario prediction and evaluation. This paper focuses on using a learning algorithm to optimize PCB with very limited training data, so that PCB can have the ability to predict and evaluate traffic scenarios similarly to human drivers. 80 seconds of human driving data was collected in low-speed (< 30miles/h) car-following scenarios. In the low-speed car-following tests, PCB was able to perform more human-like carfollowing after learning. A more general 120 kilometer-long simulation showed that PCB performs robustly even in scenarios that are not part of the training set.

Distracted Driving and Risk of Road Crashes among Novice and Experienced Drivers

PubMed Central

Klauer, Sheila G.; Guo, Feng; Simons-Morton, Bruce G.; Ouimet, Marie Claude; Lee, Suzanne E.; Dingus, Thomas A.

2014-01-01

BACKGROUND Distracted driving attributable to the performance of secondary tasks is a major cause of motor vehicle crashes both among teenagers who are novice drivers and among adults who are experienced drivers. METHODS We conducted two studies on the relationship between the performance of secondary tasks, including cell-phone use, and the risk of crashes and near-crashes. To facilitate objective assessment, accelerometers, cameras, global positioning systems, and other sensors were installed in the vehicles of 42 newly licensed drivers (16.3 to 17.0 years of age) and 109 adults with more driving experience. RESULTS During the study periods, 167 crashes and near-crashes among novice drivers and 518 crashes and near-crashes among experienced drivers were identified. The risk of a crash or near-crash among novice drivers increased significantly if they were dialing a cell phone (odds ratio, 8.32; 95% confidence interval [CI], 2.83 to 24.42), reaching for a cell phone (odds ratio, 7.05; 95% CI, 2.64 to 18.83), sending or receiving text messages (odds ratio, 3.87; 95% CI, 1.62 to 9.25), reaching for an object other than a cell phone (odds ratio, 8.00; 95% CI, 3.67 to 17.50), looking at a roadside object (odds ratio, 3.90; 95% CI, 1.72 to 8.81), or eating (odds ratio, 2.99; 95% CI, 1.30 to 6.91). Among experienced drivers, dialing a cell phone was associated with a significantly increased risk of a crash or near-crash (odds ratio, 2.49; 95% CI, 1.38 to 4.54); the risk associated with texting or accessing the Internet was not assessed in this population. The prevalence of high-risk attention to secondary tasks increased over time among novice drivers but not among experienced drivers. CONCLUSIONS The risk of a crash or near-crash among novice drivers increased with the performance of many secondary tasks, including texting and dialing cell phones. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Highway Traffic Safety Administration.) PMID:24382065

Distracted driving and risk of road crashes among novice and experienced drivers.

PubMed

Klauer, Sheila G; Guo, Feng; Simons-Morton, Bruce G; Ouimet, Marie Claude; Lee, Suzanne E; Dingus, Thomas A

2014-01-02

Distracted driving attributable to the performance of secondary tasks is a major cause of motor vehicle crashes both among teenagers who are novice drivers and among adults who are experienced drivers. We conducted two studies on the relationship between the performance of secondary tasks, including cell-phone use, and the risk of crashes and near-crashes. To facilitate objective assessment, accelerometers, cameras, global positioning systems, and other sensors were installed in the vehicles of 42 newly licensed drivers (16.3 to 17.0 years of age) and 109 adults with more driving experience. During the study periods, 167 crashes and near-crashes among novice drivers and 518 crashes and near-crashes among experienced drivers were identified. The risk of a crash or near-crash among novice drivers increased significantly if they were dialing a cell phone (odds ratio, 8.32; 95% confidence interval [CI], 2.83 to 24.42), reaching for a cell phone (odds ratio, 7.05; 95% CI, 2.64 to 18.83), sending or receiving text messages (odds ratio, 3.87; 95% CI, 1.62 to 9.25), reaching for an object other than a cell phone (odds ratio, 8.00; 95% CI, 3.67 to 17.50), looking at a roadside object (odds ratio, 3.90; 95% CI, 1.72 to 8.81), or eating (odds ratio, 2.99; 95% CI, 1.30 to 6.91). Among experienced drivers, dialing a cell phone was associated with a significantly increased risk of a crash or near-crash (odds ratio, 2.49; 95% CI, 1.38 to 4.54); the risk associated with texting or accessing the Internet was not assessed in this population. The prevalence of high-risk attention to secondary tasks increased over time among novice drivers but not among experienced drivers. The risk of a crash or near-crash among novice drivers increased with the performance of many secondary tasks, including texting and dialing cell phones. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Highway Traffic Safety Administration.).

Clandestine laboratory scene investigation and processing using portable GC/MS

NASA Astrophysics Data System (ADS)

Matejczyk, Raymond J.

1997-02-01

This presentation describes the use of portable gas chromatography/mass spectrometry for on-scene investigation and processing of clandestine laboratories. Clandestine laboratory investigations present special problems to forensic investigators. These crime scenes contain many chemical hazards that must be detected, identified and collected as evidence. Gas chromatography/mass spectrometry performed on-scene with a rugged, portable unit is capable of analyzing a variety of matrices for drugs and chemicals used in the manufacture of illicit drugs, such as methamphetamine. Technologies used to detect various materials at a scene have particular applications but do not address the wide range of samples, chemicals, matrices and mixtures that exist in clan labs. Typical analyses performed by GC/MS are for the purpose of positively establishing the identity of starting materials, chemicals and end-product collected from clandestine laboratories. Concerns for the public and investigator safety and the environment are also important factors for rapid on-scene data generation. Here is described the implementation of a portable multiple-inlet GC/MS system designed for rapid deployment to a scene to perform forensic investigations of clandestine drug manufacturing laboratories. GC/MS has long been held as the 'gold standard' in performing forensic chemical analyses. With the capability of GC/MS to separate and produce a 'chemical fingerprint' of compounds, it is utilized as an essential technique for detecting and positively identifying chemical evidence. Rapid and conclusive on-scene analysis of evidence will assist the forensic investigators in collecting only pertinent evidence thereby reducing the amount of evidence to be transported, reducing chain of custody concerns, reducing costs and hazards, maintaining sample integrity and speeding the completion of the investigative process.

Saccadic eye movement performance as an indicator of driving ability in elderly drivers.

PubMed

Schmitt, Kai-Uwe; Seeger, Rolf; Fischer, Hartmut; Lanz, Christian; Muser, Markus; Walz, Felix; Schwarz, Urs

2015-01-01

Regular checking of the fitness to drive of elderly car-license holders is required in some countries, and this will become increasingly important as more countries face aging populations. The present study investigated whether the analysis of saccadic eye movements could be used as a screening method for the assessment of driving ability. Three different paradigms (prosaccades, antisaccades, and visuovisual interactive (VVI) saccades) were used to test saccadic eye movements in 144 participants split into four groups: elderly drivers who came to the attention of road authorities for suspected lack of fitness to drive, a group of elderly drivers who served as a comparison group, a group of neurology patients with established brain lesion diagnoses, and a young comparison group. The group of elderly drivers with suspected deficits in driving skills also underwent a medical examination and a practical on-road driving test. The results of the saccadic eye tests of the different groups were compared. Antisaccade results indicated a strong link to driving behaviour: elderly drivers who were not fit to drive exhibited a poor performance on the antisaccade task and the performance in the VVI task was also clearly poorer in this group. Testing saccadic eye movements appears to be a promising and efficient method for screening large numbers of people such as elderly drivers. This study indicated a link between antisaccade performance and the ability to drive. Hence, measuring saccadic eye movements should be considered as a tool for screening the fitness to drive.

Self-Regulation of Driving Behavior in People with Parkinson Disease.

PubMed

Stolwyk, Renerus J; Scally, Karen A; Charlton, Judith L; Bradshaw, John L; Iansek, Robert; Georgiou-Karistianis, Nellie

2015-06-01

To determine the extent and nature of driving self-regulation in drivers with Parkinson disease (PD) and factors associated with self-regulatory practices. Although people with PD have consistently been shown to have driving impairments, few studies have examined self-regulatory driving practices and their relationship to driving performance. We used a self-report driving questionnaire to examine driving self-regulation in 37 drivers with PD and 37 healthy age-matched controls. We also analyzed factors associated with self-regulatory practices, primarily demographic, disease-related, psychological, and simulated driving performance variables. The drivers with PD reported significantly higher rates of self-perceived decline in their driving ability (P=0.008) and driving significantly shorter distances per week (P=0.004) than controls. Unfamiliar situations (P=0.009), in-car distractions (P<0.001), low visibility conditions (P=0.004), and long journeys (P=0.003) were particularly challenging for the drivers with PD, and their pattern of driving avoidance mirrored these difficulties. The use of self-regulatory strategies among drivers with PD was associated with female sex (rho=0.42, P=0.009) and perceived decline in driving ability (rho=-0.55, P<0.001), but not with age or objective measures of disease severity, cognition, or simulated driving performance. Drivers with PD reported driving less overall and restricting their driving to avoid particularly difficult circumstances. Further research is warranted on effective use of self-regulation strategies to improve driving performance in people with PD.

Estimating Driving Performance Based on EEG Spectrum Analysis

NASA Astrophysics Data System (ADS)

Lin, Chin-Teng; Wu, Ruei-Cheng; Jung, Tzyy-Ping; Liang, Sheng-Fu; Huang, Teng-Yi

2005-12-01

The growing number of traffic accidents in recent years has become a serious concern to society. Accidents caused by driver's drowsiness behind the steering wheel have a high fatality rate because of the marked decline in the driver's abilities of perception, recognition, and vehicle control abilities while sleepy. Preventing such accidents caused by drowsiness is highly desirable but requires techniques for continuously detecting, estimating, and predicting the level of alertness of drivers and delivering effective feedbacks to maintain their maximum performance. This paper proposes an EEG-based drowsiness estimation system that combines electroencephalogram (EEG) log subband power spectrum, correlation analysis, principal component analysis, and linear regression models to indirectly estimate driver's drowsiness level in a virtual-reality-based driving simulator. Our results demonstrated that it is feasible to accurately estimate quantitatively driving performance, expressed as deviation between the center of the vehicle and the center of the cruising lane, in a realistic driving simulator.

A driver-adaptive stability control strategy for sport utility vehicles

NASA Astrophysics Data System (ADS)

Zhu, Shenjin; He, Yuping

2017-08-01

Conventional vehicle stability control (VSC) systems are designed for average drivers. For a driver with a good driving skill, the VSC systems may be redundant; for a driver with a poor driving skill, the VSC intervention may be inadequate. To increase safety of sport utility vehicles (SUVs), this paper proposes a novel driver-adaptive VSC (DAVSC) strategy based on scaling the target yaw rate commanded by the driver. The DAVSC system is adaptive to drivers' driving skills. More control effort would be exerted for drivers with poor driving skills, and vice versa. A sliding mode control (SMC)-based differential braking (DB) controller is designed using a three degrees of freedom (DOF) yaw-plane model. An eight DOF nonlinear yaw-roll model is used to simulate the SUV dynamics. Two driver models, namely longitudinal and lateral, are used to 'drive' the virtual SUV. By integrating the virtual SUV, the DB controller, and the driver models, the performance of the DAVSC system is investigated. The simulations demonstrate the effectiveness of the DAVSC strategy.

Discovering potential driver genes through an integrated model of somatic mutation profiles and gene functional information.

PubMed

Xi, Jianing; Wang, Minghui; Li, Ao

2017-09-26

The accumulating availability of next-generation sequencing data offers an opportunity to pinpoint driver genes that are causally implicated in oncogenesis through computational models. Despite previous efforts made regarding this challenging problem, there is still room for improvement in the driver gene identification accuracy. In this paper, we propose a novel integrated approach called IntDriver for prioritizing driver genes. Based on a matrix factorization framework, IntDriver can effectively incorporate functional information from both the interaction network and Gene Ontology similarity, and detect driver genes mutated in different sets of patients at the same time. When evaluated through known benchmarking driver genes, the top ranked genes of our result show highly significant enrichment for the known genes. Meanwhile, IntDriver also detects some known driver genes that are not found by the other competing approaches. When measured by precision, recall and F1 score, the performances of our approach are comparable or increased in comparison to the competing approaches.

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

PubMed

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.

Studying the response of drivers against different collision warning systems: a review

NASA Astrophysics Data System (ADS)

Muzammel, M.; Yusoff, M. Zuki; Malik, A. Saeed; Mohamad Saad, M. Naufal; Meriaudeau, F.

2017-03-01

The number of vehicle accidents is rapidly increasing and causing significant economic losses in many countries. According to the World Health Organization, road accidents will become the fifth major cause of death by the year 2030. To minimize these accidents different types of collision warning systems have been proposed for motor vehicle drivers. These systems can early detect and warn the drivers about the potential danger, up to a certain accuracy. Many researchers study the effectiveness of these systems by using different methods, including Electroencephalography (EEG). From the literature review, it has been observed that, these systems increase the drivers' response and can help to minimize the accidents that may occur due to drivers unconsciousness. For these collision warning systems, tactile early warnings are found more effective as compared to the auditory and visual early warnings. This review also highlights the areas, where further research can be performed to fully analyze the collision warning system. For example, some contradictions are found among researchers, about these systems' performance for drivers within different age groups. Similarly, most of the EEG studies focus on the front collision warning systems and only give beep sound to alert the drivers. Therefore, EEG study can be performed for the rear end collision warning systems, against proper auditory warning messages which indicate the types of hazards. This EEG study will help to design more friendly collision warning system and may save many lives.

Effects of electronic billboards on driver distraction.

PubMed

Dukic, Tania; Ahlstrom, Christer; Patten, Christopher; Kettwich, Carmen; Kircher, Katja

2013-01-01

There is an increase in electronic advertising billboards along major roads, which may cause driver distraction due to the highly conspicuous design of the electronic billboards. Yet limited research on the impact of electronic billboards on driving performance and driver behavior is available. The Swedish Transport Administration recently approved the installation of 12 electronic billboards for a trial period along a 3-lane motorway with heavy traffic running through central Stockholm, Sweden. The aim of this study was to evaluate the effect of these electronic billboards on visual behavior and driving performance. A total of 41 drivers were recruited to drive an instrumented vehicle passing 4 of the electronic billboards during day and night conditions. A driver was considered visually distracted when looking at a billboard continuously for more than 2 s or if the driver looked away from the road for a high percentage of time. Dependent variables were eye-tracking measures and driving performance measures. The visual behavior data showed that drivers had a significantly longer dwell time, a greater number of fixations, and longer maximum fixation duration when driving past an electronic billboard compared to other signs on the same road stretches. No differences were found for the factors day/night, and no effect was found for the driving behavior data. Electronic billboards have an effect on gaze behavior by attracting more and longer glances than regular traffic signs. Whether the electronic billboards attract too much attention and constitute a traffic safety hazard cannot be answered conclusively based on the present data.

Development of the International Space Station (ISS) Fine Water Mist (FWM) Portable Fire Extinguisher

NASA Technical Reports Server (NTRS)

Rodriquez, Branelle; Graf, John; Carlile, Christie; Young, GIna

2012-01-01

The National Aeronautics and Space Administration (NASA) is developing a Fine Water Mist (FWM) Portable Fire Extinguisher (PFE) for use on the International Space Station (ISS). The ISS presently uses two different types of fire extinguishers: a water foam extinguisher in the Russian Segment, and a carbon dioxide extinguisher in the United States Orbital Segments, which include Columbus and Kibo pressurized elements. Currently, there are operational concerns with the emergency breathing equipment and the carbon dioxide extinguisher. The toxicity of the carbon dioxide requires the crew members to have an oxygen supply present during a fire event, therefore inherently creating an unsafe environment. The FWM PFE extinguishes a fire without creating a hazardous breathing environment for crew members. The following paper will discuss the unique functional and performance requirements that have been levied on the FWM PFE, identify unique microgravity design considerations for liquid and gas systems, as well as discuss the NASA ISS specific fire standards that were developed to establish an acceptable portable fire extinguisher s performance.

Smartphone based hand-held quantitative phase microscope using the transport of intensity equation method.

PubMed

Meng, Xin; Huang, Huachuan; Yan, Keding; Tian, Xiaolin; Yu, Wei; Cui, Haoyang; Kong, Yan; Xue, Liang; Liu, Cheng; Wang, Shouyu

2016-12-20

In order to realize high contrast imaging with portable devices for potential mobile healthcare, we demonstrate a hand-held smartphone based quantitative phase microscope using the transport of intensity equation method. With a cost-effective illumination source and compact microscope system, multi-focal images of samples can be captured by the smartphone's camera via manual focusing. Phase retrieval is performed using a self-developed Android application, which calculates sample phases from multi-plane intensities via solving the Poisson equation. We test the portable microscope using a random phase plate with known phases, and to further demonstrate its performance, a red blood cell smear, a Pap smear and monocot root and broad bean epidermis sections are also successfully imaged. Considering its advantages as an accurate, high-contrast, cost-effective and field-portable device, the smartphone based hand-held quantitative phase microscope is a promising tool which can be adopted in the future in remote healthcare and medical diagnosis.

Development of High Precision Metal Micro-Electro-Mechanical-Systems Column for Portable Surface Acoustic Wave Gas Chromatograph

NASA Astrophysics Data System (ADS)

Iwaya, Takamitsu; Akao, Shingo; Sakamoto, Toshihiro; Tsuji, Toshihiro; Nakaso, Noritaka; Yamanaka, Kazushi

2012-07-01

In the field of environmental measurement and security, a portable gas chromatograph (GC) is required for the on-site analysis of multiple hazardous gases. Although the gas separation column has been downsized using micro-electro-mechanical-systems (MEMS) technology, an MEMS column made of silicon and glass still does not have sufficient robustness and a sufficiently low fabrication cost for a portable GC. In this study, we fabricated a robust and inexpensive high-precision metal MEMS column by combining diffusion-bonded etched stainless-steel plates with alignment evaluation using acoustic microscopy. The separation performance was evaluated using a desktop GC with a flame ionization detector and we achieved the high separation performance comparable to the best silicon MEMS column fabricated using a dynamic coating method. As an application, we fabricated a palm-size surface acoustic wave (SAW) GC combining this column with a ball SAW sensor and succeeded in separating and detecting a mixture of volatile organic compounds.

Speckle-based portable device for in-situ metrology of x-ray mirrors at Diamond Light Source

NASA Astrophysics Data System (ADS)

Wang, Hongchang; Kashyap, Yogesh; Zhou, Tunhe; Sawhney, Kawal

2017-09-01

For modern synchrotron light sources, the push toward diffraction-limited and coherence-preserved beams demands accurate metrology on X-ray optics. Moreover, it is important to perform in-situ characterization and optimization of X-ray mirrors since their ultimate performance is critically dependent on the working conditions. Therefore, it is highly desirable to develop a portable metrology device, which can be easily implemented on a range of beamlines for in-situ metrology. An X-ray speckle-based portable device for in-situ metrology of synchrotron X-ray mirrors has been developed at Diamond Light Source. Ultra-high angular sensitivity is achieved by scanning the speckle generator in the X-ray beam. In addition to the compact setup and ease of implementation, a user-friendly graphical user interface has been developed to ensure that characterization and alignment of X-ray mirrors is simple and fast. The functionality and feasibility of this device is presented with representative examples.

Development of Accomodation Models for Soldiers in Vehicles: Driver

DTIC Science & Technology

2014-09-01

human needs and performance. A small section of this standard addresses the design of vehicle seats and the layout of the driver workstation...drivers and passengers (squad). The study was designed to focus on tactical vehicle (truck) designs with fixed driver heel points and H30 values...fore-aft and vertically, along with adjusting the seat back angle, to obtain a comfortable driving position. The Soldier’s posture and seat adjustments

Portable and programmable clinical EOG diagnostic system.

PubMed

Chen, S C; Tsai, T T; Luo, C H

2000-01-01

Monitoring eye movements is clinically important in diagnosis of diseases of the central nervous system. Electrooculography (EOG) is one method of obtaining such records which uses skin electrodes, and utilizes the anterior posterior polarization of the eye. A new EOG diagnostic system has been developed that utilizes two off-the-shelf portable notebook computers, one projector and simple electronic hardware. It can be operated under Windows 95, 98, NT, and has significant advantages over any other similar equipment, including programmability, portability, improved safety and low cost. Especially, portability of the instrument is extremely important for acutely ill or handicapped patients. The purpose of this paper is to introduce the techniques of computer animation, data acquisition, real time analysis of measured data, and database management to implement a portable, programmable and inexpensive contacting EOG instrument. It is very convenient to replace the present expensive, inflexible and large-sized commercially available EOG instruments. A lot of interesting stimulation patterns for clinical application can be created easily in different shape, time sequence, and colour by programming in Delphi language. With the help of Winstar (a software package that is used to control I/O and interrupt functions of the computer under Windows 95, 98, NT), the I/O communication between two notebook computers and A/D interface module can be effectively programmed. In addition, the new EOG diagnostic system is battery operated and it has the advantages of low noise as well as isolation from electricity. Two kinds of EOG tests, pursuit and saccade, were performed on 20 normal subjects with this new portable and programmable instrument. Based on the test result, the performance of the new instrument is superior to the other commercially available instruments. In conclusion, we hope that it will be more convenient for doctors and researchers to do the clinical EOG diagnosis and basic medical science research by using this new creation.

[Comparative Study of Patient Identifications for Conventional and Portable Chest Radiographs Utilizing ROC Analysis].

PubMed

Kawashima, Hiroki; Hayashi, Norio; Ohno, Naoki; Matsuura, Yukihiro; Sanada, Shigeru

2015-08-01

To evaluate the patient identification ability of radiographers, previous and current chest radiographs were assessed with observer study utilizing a receiver operating characteristics (ROCs) analysis. This study included portable and conventional chest radiographs from 43 same and 43 different patients. The dataset used in this study was divided into the three following groups: (1) a pair of portable radiographs, (2) a pair of conventional radiographs, and (3) a combination of each type of radiograph. Seven observers participated in this ROC study, which aimed to identify same or different patients, using these datasets. ROC analysis was conducted to calculate the average area under ROC curve obtained by each observer (AUCave), and a statistical test was performed using the multi-reader multi-case method. Comparable results were obtained with pairs of portable (AUCave: 0.949) and conventional radiographs (AUCave: 0.951). In a comparison between the same modality, there were no significant differences. In contrast, the ability to identify patients by comparing a portable and conventional radiograph (AUCave: 0.873) was lower than with the matching datasets (p=0.002 and p=0.004, respectively). In conclusion, the use of different imaging modalities reduces radiographers' ability to identify their patients.

Small Portable PEM Fuel Cell Systems for NASA Exploration Missions

NASA Technical Reports Server (NTRS)

Burke, Kenneth A.

2005-01-01

Oxygen-Hydrogen PEM-based fuel cell systems are being examined as a portable power source alternative in addition to advanced battery technology. Fuel cell power systems have been used by the Gemini, Apollo, and Space Shuttle programs. These systems have not been portable, but have been integral parts of their spacecraft, and have used reactants from a separate cryogenic supply. These systems typically have been higher in power. They also have had significant ancillary equipment sections that perform the pumping of reactants and coolant through the fuel cell stack and the separation of the product water from the unused reactant streams. The design of small portable fuel cell systems will be a significant departure from these previous designs. These smaller designs will have very limited ancillary equipment, relying on passive techniques for reactant and thermal management, and the reactant storage will be an integral part of the fuel cell system. An analysis of the mass and volume for small portable fuel cell systems was done to evaluate and quantify areas of technological improvement. A review of current fuel cell technology as well as reactant storage and management technology was completed to validate the analysis and to identify technology challenges

Portable DMFC system with methanol sensor-less control

NASA Astrophysics Data System (ADS)

Chen, C. Y.; Liu, D. H.; Huang, C. L.; Chang, C. L.

This work develops a prototype 20 W portable DMFC by system integration of stack, condenser, methanol sensor-less control and start-up characteristics. The effects of these key components and control schemes on the performance are also discussed. To expedite the use of portable DMFC in electronic applications, the system utilizes a novel methanol sensor-less control method, providing improved fuel efficiency, durability, miniaturization and cost reduction. The operating characteristics of the DMFC stack are applied to control the fuel ejection time and period, enabling the system to continue operating even when the MEAs of the stack are deteriorated. The portable system is also designed with several features including water balance and quick start-up (in 5 min). Notably, the proposed system using methanol sensor-less control with injection of pure methanol can power the DVD player and notebook PC. The system specific energy and energy density following three days of operation are 362 Wh kg -1 and 335 Wh L -1, respectively, which are better than those of lithium batteries (∼150 Wh kg -1 and ∼250 Wh L -). This good energy storage feature demonstrates that the portable DMFC is likely to be valuable in computer, communication and consumer electronic (3C) markets.

RIS4E at Kilauea's December 1974 Flow: Chemical, mineralogical and spectral characteristics of Hawaiian basaltic alteration products measured with portable instruments

NASA Astrophysics Data System (ADS)

Young, K. E.; Rogers, D.; Dyar, M. D.; Ito, G.; Yant, M.; McAdam, A.; Bleacher, J. E.; Glotch, T. D.

2015-12-01

A major objective of the SSERVI RIS4E (Remote, In-situ, and Synchrotron Studies for Science and Exploration) investigation is to evaluate the performance of portable chemical and mineralogical instruments in a variety of planetary volcanic analog settings. To that end, we used a suite of true/proxy portable instruments (XRF, LIBS, XRD, near-IR and mid-IR spectrometers), to measure the chemical and spectral characteristics of young basaltic flows (erupted December 1974, or D1974) within the southwest rift zone of Kilauea, Hawaii. The D1974 lavas exhibit multiple flow morphologies and textures, and have undergone alteration by a variety of processes, including acid weathering, oxidation and devitrification. The mineralogy, chemistry and infrared spectral properties of select samples from these altered surfaces have been well characterized by previous groups using high resolution (e.g. SEM, TEM) and/or laboratory measurements (XRD, Mossbauer, infrared). Typical alteration products include coatings of Fe-Ti-oxide +/- an overlying silica-rich coating. Coatings are commonly discontinuous and vary in color. Oxidation fronts are also present, most visible as reddish brown discoloration along the edges of broken and uplifted flow crusts. The previous detailed characterizations provide the basis for evaluating instrument performance and also allow us to assess areas where portable instruments can contribute new information to current understanding. These areas include characterizing the spatial variability in alteration chemistry/mineralogy, relating chemical/mineralogical properties to texture and context, and comparing chemical/mineralogical variations with infrared spectral properties. Because infrared spectra are commonly used to assess compositional variations of a site remotely, either from the ground or from orbit, relating changes in chemistry and mineralogy to spectral variations is particularly important. Last, the D1974 site provides an excellent location to test the performance of portable chemical instruments on coated surfaces of variable texture. Results from this multi-technique approach will be presented at the meeting.

Development of Portable Venturi Kiln for Agricultural Waste Utilization by Carbonization Process

NASA Astrophysics Data System (ADS)

Agustina, S. E.; Chasanah, N.; Eris, A. P.

2018-05-01

Many types of kiln or carbonization equipment have been developed, but most of them were designed for big capacity and some also having low performance. This research aims to develop kiln, especially portable metal kiln, which has higher performance, more environmental- friendly, and can be used for several kinds of biomass or agricultural waste (not exclusive for one kind of biomass) as feeding material. To improve the kiln performance, a venturi drum type of portable kiln has been designed with an optimum capacity of 12.45 kg coconut shells. Basic idea of those design is heat flow improvement causing by venturi effect. The performance test for coconut shell carbonization shows that the carbonization process takes about 60-90 minutes to produce average yields of 23.8%., and the highest temperature of the process was 441 °C. The optimum performance has been achieved in the 4th test, which was producing 24% yield of highest charcoal quality (represented by LHV) in 65 minutes process at average temperature level 485 °C. For pecan shell and palm shell, design modification has been done by adding 6 air inlet holes and 3 ignition column to get better performance. While operation procedure should be modified on loading and air supply, depending on each biomass characteristic. The result of performance test showed that carbonization process of pecan shell produce 17 % yield, and palm shell produce 15% yield. Based on Indonesian Standard (SNI), all charcoal produced in those carbonization has good quality level.

On the Efficacy of Source Code Optimizations for Cache-Based Systems

NASA Technical Reports Server (NTRS)

VanderWijngaart, Rob F.; Saphir, William C.

1998-01-01

Obtaining high performance without machine-specific tuning is an important goal of scientific application programmers. Since most scientific processing is done on commodity microprocessors with hierarchical memory systems, this goal of "portable performance" can be achieved if a common set of optimization principles is effective for all such systems. It is widely believed, or at least hoped, that portable performance can be realized. The rule of thumb for optimization on hierarchical memory systems is to maximize temporal and spatial locality of memory references by reusing data and minimizing memory access stride. We investigate the effects of a number of optimizations on the performance of three related kernels taken from a computational fluid dynamics application. Timing the kernels on a range of processors, we observe an inconsistent and often counterintuitive impact of the optimizations on performance. In particular, code variations that have a positive impact on one architecture can have a negative impact on another, and variations expected to be unimportant can produce large effects. Moreover, we find that cache miss rates - as reported by a cache simulation tool, and confirmed by hardware counters - only partially explain the results. By contrast, the compiler-generated assembly code provides more insight by revealing the importance of processor-specific instructions and of compiler maturity, both of which strongly, and sometimes unexpectedly, influence performance. We conclude that it is difficult to obtain performance portability on modern cache-based computers, and comment on the implications of this result.

On the Efficacy of Source Code Optimizations for Cache-Based Systems

NASA Technical Reports Server (NTRS)

VanderWijngaart, Rob F.; Saphir, William C.; Saini, Subhash (Technical Monitor)

1998-01-01

Obtaining high performance without machine-specific tuning is an important goal of scientific application programmers. Since most scientific processing is done on commodity microprocessors with hierarchical memory systems, this goal of "portable performance" can be achieved if a common set of optimization principles is effective for all such systems. It is widely believed, or at least hoped, that portable performance can be realized. The rule of thumb for optimization on hierarchical memory systems is to maximize temporal and spatial locality of memory references by reusing data and minimizing memory access stride. We investigate the effects of a number of optimizations on the performance of three related kernels taken from a computational fluid dynamics application. Timing the kernels on a range of processors, we observe an inconsistent and often counterintuitive impact of the optimizations on performance. In particular, code variations that have a positive impact on one architecture can have a negative impact on another, and variations expected to be unimportant can produce large effects. Moreover, we find that cache miss rates-as reported by a cache simulation tool, and confirmed by hardware counters-only partially explain the results. By contrast, the compiler-generated assembly code provides more insight by revealing the importance of processor-specific instructions and of compiler maturity, both of which strongly, and sometimes unexpectedly, influence performance. We conclude that it is difficult to obtain performance portability on modern cache-based computers, and comment on the implications of this result.

A design methodology for portable software on parallel computers

NASA Technical Reports Server (NTRS)

Nicol, David M.; Miller, Keith W.; Chrisman, Dan A.

1993-01-01

This final report for research that was supported by grant number NAG-1-995 documents our progress in addressing two difficulties in parallel programming. The first difficulty is developing software that will execute quickly on a parallel computer. The second difficulty is transporting software between dissimilar parallel computers. In general, we expect that more hardware-specific information will be included in software designs for parallel computers than in designs for sequential computers. This inclusion is an instance of portability being sacrificed for high performance. New parallel computers are being introduced frequently. Trying to keep one's software on the current high performance hardware, a software developer almost continually faces yet another expensive software transportation. The problem of the proposed research is to create a design methodology that helps designers to more precisely control both portability and hardware-specific programming details. The proposed research emphasizes programming for scientific applications. We completed our study of the parallelizability of a subsystem of the NASA Earth Radiation Budget Experiment (ERBE) data processing system. This work is summarized in section two. A more detailed description is provided in Appendix A ('Programming Practices to Support Eventual Parallelism'). Mr. Chrisman, a graduate student, wrote and successfully defended a Ph.D. dissertation proposal which describes our research associated with the issues of software portability and high performance. The list of research tasks are specified in the proposal. The proposal 'A Design Methodology for Portable Software on Parallel Computers' is summarized in section three and is provided in its entirety in Appendix B. We are currently studying a proposed subsystem of the NASA Clouds and the Earth's Radiant Energy System (CERES) data processing system. This software is the proof-of-concept for the Ph.D. dissertation. We have implemented and measured the performance of a portion of this subsystem on the Intel iPSC/2 parallel computer. These results are provided in section four. Our future work is summarized in section five, our acknowledgements are stated in section six, and references for published papers associated with NAG-1-995 are provided in section seven.

Driving performance at lateral system limits during partially automated driving.

PubMed

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.

Modeling driver stop/run behavior at the onset of a yellow indication considering driver run tendency and roadway surface conditions.

PubMed

Elhenawy, Mohammed; Jahangiri, Arash; Rakha, Hesham A; El-Shawarby, Ihab

2015-10-01

The ability to model driver stop/run behavior at signalized intersections considering the roadway surface condition is critical in the design of advanced driver assistance systems. Such systems can reduce intersection crashes and fatalities by predicting driver stop/run behavior. The research presented in this paper uses data collected from two controlled field experiments on the Smart Road at the Virginia Tech Transportation Institute (VTTI) to model driver stop/run behavior at the onset of a yellow indication for different roadway surface conditions. The paper offers two contributions. First, it introduces a new predictor related to driver aggressiveness and demonstrates that this measure enhances the modeling of driver stop/run behavior. Second, it applies well-known artificial intelligence techniques including: adaptive boosting (AdaBoost), random forest, and support vector machine (SVM) algorithms as well as traditional logistic regression techniques on the data in order to develop a model that can be used by traffic signal controllers to predict driver stop/run decisions in a connected vehicle environment. The research demonstrates that by adding the proposed driver aggressiveness predictor to the model, there is a statistically significant increase in the model accuracy. Moreover the false alarm rate is significantly reduced but this reduction is not statistically significant. The study demonstrates that, for the subject data, the SVM machine learning algorithm performs the best in terms of optimum classification accuracy and false positive rates. However, the SVM model produces the best performance in terms of the classification accuracy only. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Role of Interaction Patterns with Hybrid Electric Vehicle Eco-Features for Drivers' Eco-Driving Performance.

PubMed

Arend, Matthias G; Franke, Thomas

2017-03-01

The objective of the present research was to understand drivers' interaction patterns with hybrid electric vehicles' (HEV) eco-features (electric propulsion, regenerative braking, neutral mode) and their relationship to fuel efficiency and driver characteristics (technical system knowledge, eco-driving motivation). Eco-driving (driving behaviors performed to achieve higher fuel efficiency) has the potential to reduce CO 2 emissions caused by road vehicles. Eco-driving in HEVs is particularly challenging due to the systems' dynamic energy flows. As a result, drivers are likely to show diverse eco-driving behaviors, depending on factors like knowledge and motivation. The eco-features represent an interface for the control of the systems' energy flows. A sample of 121 HEV drivers who had constantly logged their fuel consumption prior to the study participated in an online questionnaire. Drivers' interaction patterns with the eco-features were related to fuel efficiency. A common factor was identified in an exploratory factor analysis, characterizing the intensity of actively dealing with electric energy, which was also related to fuel efficiency. Driver characteristics were not related to this factor, yet they were significant predictors of fuel efficiency. From the perspective of user-energy interaction, the relationship of the aggregated factor to fuel efficiency emphasizes the central role of drivers' perception of and interaction with energy conversions in determining HEV eco-driving success. To arrive at an in-depth understanding of drivers' eco-driving behaviors that can guide interface design, authors of future research should be concerned with the psychological processes that underlie drivers' interaction patterns with eco-features.

The effects of practice with MP3 players on driving performance.

PubMed

Chisholm, S L; Caird, J K; Lockhart, J

2008-03-01

This study examined the effects of repeated iPod interactions on driver performance to determine if performance decrements decreased with practice. Nineteen younger drivers (mean age=19.4, range 18-22) participated in a seven session study in the University of Calgary Driving Simulator (UCDS). Drivers encountered a number of critical events on the roadways while interacting with an iPod including a pedestrian entering the roadway, a vehicle pullout, and a lead vehicle braking. Measures of hazard response, vehicle control, eye movements, and secondary task performance were analyzed. Increases in perception response time (PRT) and collisions were found while drivers were performing the difficult iPod tasks, which involved finding a specific song within the song titles menu. Over the course of the six experimental sessions, driving performance improved in all conditions. Difficult iPod interactions significantly increased the amount of visual attention directed into the vehicle above that of the baseline condition. With practice, slowed responses to driving hazards while interacting with the iPod declined somewhat, but a decrement still remained relative to the baseline condition. The multivariate results suggest that access to difficult iPod tasks while vehicles are in motion should be curtailed.

Maximal clique enumeration with data-parallel primitives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lessley, Brenton; Perciano, Talita; Mathai, Manish

The enumeration of all maximal cliques in an undirected graph is a fundamental problem arising in several research areas. We consider maximal clique enumeration on shared-memory, multi-core architectures and introduce an approach consisting entirely of data-parallel operations, in an effort to achieve efficient and portable performance across different architectures. We study the performance of the algorithm via experiments varying over benchmark graphs and architectures. Overall, we observe that our algorithm achieves up to a 33-time speedup and 9-time speedup over state-of-the-art distributed and serial algorithms, respectively, for graphs with higher ratios of maximal cliques to total cliques. Further, we attainmore » additional speedups on a GPU architecture, demonstrating the portable performance of our data-parallel design.« less

Real time software for a heat recovery steam generator control system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valdes, R.; Delgadillo, M.A.; Chavez, R.

1995-12-31

This paper is addressed to the development and successful implementation of a real time software for the Heat Recovery Steam Generator (HRSG) control system of a Combined Cycle Power Plant. The real time software for the HRSG control system physically resides in a Control and Acquisition System (SAC) which is a component of a distributed control system (DCS). The SAC is a programmable controller. The DCS installed at the Gomez Palacio power plant in Mexico accomplishes the functions of logic, analog and supervisory control. The DCS is based on microprocessors and the architecture consists of workstations operating as a Man-Machinemore » Interface (MMI), linked to SAC controllers by means of a communication system. The HRSG real time software is composed of an operating system, drivers, dedicated computer program and application computer programs. The operating system used for the development of this software was the MultiTasking Operating System (MTOS). The application software developed at IIE for the HRSG control system basically consisted of a set of digital algorithms for the regulation of the main process variables at the HRSG. By using the multitasking feature of MTOS, the algorithms are executed pseudo concurrently. In this way, the applications programs continuously use the resources of the operating system to perform their functions through a uniform service interface. The application software of the HRSG consist of three tasks, each of them has dedicated responsibilities. The drivers were developed for the handling of hardware resources of the SAC controller which in turn allows the signals acquisition and data communication with a MMI. The dedicated programs were developed for hardware diagnostics, task initializations, access to the data base and fault tolerance. The application software and the dedicated software for the HRSG control system was developed using C programming language due to compactness, portability and efficiency.« less

Portable oxygen subsystem. [design analysis and performance tests

NASA Technical Reports Server (NTRS)

1975-01-01

The concept and design of a portable oxygen device for use in the space shuttle orbiter is presented. Hardware fabrication and acceptance tests (i.e., breadboard models) are outlined and discussed. Optimization of the system (for weight, volume, safety, costs) is discussed. The device is of the rebreather type, and provides a revitalized breathing gas supply to a crewman for denitrogenization and emergency activities. Engineering drawings and photographs of the device are shown.

Ruggedized Portable Instrumentation Package for Marine Mammal Evoked Potential Hearing Measurements (DURIP)

DTIC Science & Technology

2011-09-30

NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Hawaii Institute of Marine Biology,Marine Mammal...Program Hawaii Institute of Marine Biology P.O. Box 1106 Kailua, Hawaii 96734 phone: (808) 247-5297 fax: (808) 247-5831 email: nachtiga...portable equipment was used at the Hilo Stranding Center to obtain the audiograms. Ready and available for RIMPAC excercises. 2 IMPACT

Tractor Trailer Driver's Training Programs. Performance Report.

ERIC Educational Resources Information Center

New Hampshire Vocational Technical Coll., Nashua.

This document describes a project to develop a 320-hour tractor trailer driver training program and a 20-hour commercial driver licensing upgrade training program. Of 34 graduates from the training program, 28 secured employment in the trucking industry. From August 1989 to June 1990, 725 students were trained in the upgrade training program with…

29 CFR 541.504 - Drivers who sell.

Code of Federal Regulations, 2010 CFR

2010-07-01

... products may qualify as exempt outside sales employees only if the employee has a primary duty of making sales. In determining the primary duty of drivers who sell, work performed incidental to and in... determining if a driver has a primary duty of making sales, including, but not limited to: a comparison of the...

29 CFR 541.504 - Drivers who sell.

Code of Federal Regulations, 2011 CFR

2011-07-01

... products may qualify as exempt outside sales employees only if the employee has a primary duty of making sales. In determining the primary duty of drivers who sell, work performed incidental to and in... determining if a driver has a primary duty of making sales, including, but not limited to: a comparison of the...

Portable implementation model for CFD simulations. Application to hybrid CPU/GPU supercomputers

NASA Astrophysics Data System (ADS)

Oyarzun, Guillermo; Borrell, Ricard; Gorobets, Andrey; Oliva, Assensi

2017-10-01

Nowadays, high performance computing (HPC) systems experience a disruptive moment with a variety of novel architectures and frameworks, without any clarity of which one is going to prevail. In this context, the portability of codes across different architectures is of major importance. This paper presents a portable implementation model based on an algebraic operational approach for direct numerical simulation (DNS) and large eddy simulation (LES) of incompressible turbulent flows using unstructured hybrid meshes. The strategy proposed consists in representing the whole time-integration algorithm using only three basic algebraic operations: sparse matrix-vector product, a linear combination of vectors and dot product. The main idea is based on decomposing the nonlinear operators into a concatenation of two SpMV operations. This provides high modularity and portability. An exhaustive analysis of the proposed implementation for hybrid CPU/GPU supercomputers has been conducted with tests using up to 128 GPUs. The main objective consists in understanding the challenges of implementing CFD codes on new architectures.

Scalable and massively parallel Monte Carlo photon transport simulations for heterogeneous computing platforms

NASA Astrophysics Data System (ADS)

Yu, Leiming; Nina-Paravecino, Fanny; Kaeli, David; Fang, Qianqian

2018-01-01

We present a highly scalable Monte Carlo (MC) three-dimensional photon transport simulation platform designed for heterogeneous computing systems. Through the development of a massively parallel MC algorithm using the Open Computing Language framework, this research extends our existing graphics processing unit (GPU)-accelerated MC technique to a highly scalable vendor-independent heterogeneous computing environment, achieving significantly improved performance and software portability. A number of parallel computing techniques are investigated to achieve portable performance over a wide range of computing hardware. Furthermore, multiple thread-level and device-level load-balancing strategies are developed to obtain efficient simulations using multiple central processing units and GPUs.

A portable battery-powered flow injection monitor for the in situ analysis of nitrate in natural waters

PubMed Central

Blundell, N. J.; Hopkins, A.; Worsfold, P. J.; Casey, H.

1993-01-01

The design and performance of a portable, automated flow injection (FI)-based photometric monitor are described. The system is controlled by an in-house microcomputer system that enables the monitor (including a solid state detector) to operate from a 12 V battery supply. The monitor uses the cadmium reduction/diazotization method to analyse for nitrate with a linear range of 0 to 12 mg l-1 and a limit of detection of 0.05 mg l-1 (NO3-N). The hardware and software design, monitor performance and results obtained during unattended operation are presented. PMID:18924971

A review of digital microfluidics as portable platforms for lab-on a-chip applications.

PubMed

Samiei, Ehsan; Tabrizian, Maryam; Hoorfar, Mina

2016-07-07

Following the development of microfluidic systems, there has been a high tendency towards developing lab-on-a-chip devices for biochemical applications. A great deal of effort has been devoted to improve and advance these devices with the goal of performing complete sets of biochemical assays on the device and possibly developing portable platforms for point of care applications. Among the different microfluidic systems used for such a purpose, digital microfluidics (DMF) shows high flexibility and capability of performing multiplex and parallel biochemical operations, and hence, has been considered as a suitable candidate for lab-on-a-chip applications. In this review, we discuss the most recent advances in the DMF platforms, and evaluate the feasibility of developing multifunctional packages for performing complete sets of processes of biochemical assays, particularly for point-of-care applications. The progress in the development of DMF systems is reviewed from eight different aspects, including device fabrication, basic fluidic operations, automation, manipulation of biological samples, advanced operations, detection, biological applications, and finally, packaging and portability of the DMF devices. Success in developing the lab-on-a-chip DMF devices will be concluded based on the advances achieved in each of these aspects.

Photometric requirements for portable changeable message signs.

DOT National Transportation Integrated Search

2001-09-01

This project reviewed the performance of pchangeable message signs (PCMSs) and developed photometric standards to establish performance requirements. In addition, researchers developed photometric test methods and recommended them for use in evaluati...

Pediatric digital chest imaging.

PubMed

Tarver, R D; Cohen, M; Broderick, N J; Conces, D J

1990-01-01

The Philips Computed Radiography system performs well with pediatric portable chest radiographs, handling the throughout of a busy intensive care service 24 hours a day. Images are excellent and routinely provide a conventional (unenhanced) image and an edge-enhanced image. Radiation dose is decreased by the lowered frequency of repeat examinations and the ability of the plates to respond to a much lower dose and still provide an adequate image. The high quality and uniform density of serial PCR portable radiographs greatly enhances diagnostic content of the films. Decreased resolution has not been a problem clinically. Image manipulation and electronic transfer to remote viewing stations appear to be helpful and are currently being evaluated further. The PCR system provides a marked improvement in pediatric portable chest radiology.

Portable programming on parallel/networked computers using the Application Portable Parallel Library (APPL)

NASA Technical Reports Server (NTRS)

Quealy, Angela; Cole, Gary L.; Blech, Richard A.

1993-01-01

The Application Portable Parallel Library (APPL) is a subroutine-based library of communication primitives that is callable from applications written in FORTRAN or C. APPL provides a consistent programmer interface to a variety of distributed and shared-memory multiprocessor MIMD machines. The objective of APPL is to minimize the effort required to move parallel applications from one machine to another, or to a network of homogeneous machines. APPL encompasses many of the message-passing primitives that are currently available on commercial multiprocessor systems. This paper describes APPL (version 2.3.1) and its usage, reports the status of the APPL project, and indicates possible directions for the future. Several applications using APPL are discussed, as well as performance and overhead results.

Portable outgas detection apparatus

DOEpatents

Haney, Steven Julian; Malinowski, Michael E.

2004-05-11

A portable device for detecting surface outgas contaminants of an article includes: (i) a portable housing that has a chamber which is in communication with a port that is adapted to be sealably attached to a surface of the article; (ii) a mass spectrometer that is coupled to the chamber for analyzing gaseous materials in the chamber; and (iii) means for generating a vacuum within the chamber thereby drawing outgas contaminants from the surface of the article into the chamber for analysis by the mass spectrometer. By performing a mass spectrometric analysis of the surface of interest and comparing the data with mass spectrometric data ascertained with the device from a clean surface, the type and amount of outgas contaminants, if any, can be determined.

Through the Looking Glass: A Review of the Literature Investigating the Impact of Glaucoma on Crash Risk, Driving Performance, and Driver Self-Regulation in Older Drivers.

PubMed

Blane, Alison

2016-01-01

Glaucoma can result in insidious degradation of the peripheral visual field. This can severely affect everyday life and impact fitness-to-drive. Despite the high prevalence of glaucoma in older adults and the increasing longevity of the overall population, the impact of glaucoma on driving performance, driving practices, and crash risk remains unclear and under examined. This review examines the literature that investigates glaucoma and crash risk, driving performance, cognitive demand, driving self-regulation, and driving cessation in older drivers. A search of the literature relating to driving performance, crash risk, driver self-regulation, and cognitive workload in drivers with glaucoma was conducted between September 2013 and December 2013. This review has identified that the literature related to glaucoma and driving performance, crash risk, cognitive demand, and driving practices in older adults is inconsistent. There is a particular lack of consensus about whether glaucoma is associated with an increased risk of a car crash, although further information available relating to driving performance and driver habits suggests that there is a negative impact of glaucoma. Specifically, when the driving performance of glaucoma patients with moderate to severe visual field loss is assessed using either on-road or off-road techniques, they are found to perform poorly. There is also some debate around the amount of insight glaucoma patients have into the effect of the disease on their driving ability. The research suggests that patients with glaucoma find driving situations (particularly driving at night) increasingly difficult. Furthermore, there appears to be a tendency for drivers with glaucoma to alter their driving habits or to voluntarily cease driving completely; however, this is not the case for all glaucoma patients and the finding may differ depending on the laterality of visual field loss. There is little literature available that investigates glaucoma and its relationship with driving. The few studies that have been conducted are varied in methodology and the results available are highly inconsistent. With an ageing population and heavy reliance on driving for personal mobility, further research into measuring the impact of glaucoma and driving is crucial to ensure a sustained quality of life for the elderly. The potential for future research is discussed.

X3 expansion tube driver gas spectroscopy and temperature measurements

NASA Astrophysics Data System (ADS)

Parekh, V.; Gildfind, D.; Lewis, S.; James, C.

2018-07-01

The University of Queensland's X3 facility is a large, free-piston driven expansion tube used for super-orbital and high Mach number scramjet aerothermodynamic studies. During recent development of new scramjet test flow conditions, experimentally measured shock speeds were found to be significantly lower than that predicted by initial driver performance calculations. These calculations were based on ideal, isentropic compression of the driver gas and indicated that loss mechanisms, not accounted for in the preliminary analysis, were significant. The critical determinant of shock speed is peak driver gas sound speed, which for a given gas composition depends on the peak driver gas temperature. This temperature may be inaccurately estimated if an incorrect fill temperature is assumed, or if heat losses during driver gas compression are significant but not accounted for. For this study, the ideal predicted peak temperature was 3750 K, without accounting for losses. However, a much lower driver temperature of 2400 K is suggested based on measured experimental shock speeds. This study aimed to measure initial and peak driver gas temperatures for a representative X3 operating condition. Examination of the transient temperatures of the driver gas and compression tube steel wall during the initial fill process showed that once the filling process was complete, the steady-state driver gas temperature closely matched the tube wall temperature. Therefore, while assuming the gas is initially at the ambient laboratory temperature is not a significant source of error, it can be entirely mitigated by simply monitoring tube wall temperature. Optical emission spectroscopy was used to determine the driver gas spectra after diaphragm rupture; the driver gas emission spectrum exhibited a significant continuum radiation component, with prominent spectral lines attributed to contamination of the gas. A graybody approximation of the continuum suggested a peak driver gas temperature of 3200 K; uncertainty associated with the blackbody curve fit is ±100 K. However, work is required to quantify additional sources of uncertainty due to the graybody assumption and the presence of contaminant particles in the driver gas; these are potentially significant. The estimate of the driver gas temperature suggests that driver heat losses are not the dominant contributor to the lower-than-expected shock speeds for X3. Since both the driver temperature and pressure have been measured, investigation of total pressure losses during driver gas expansion across the diaphragm and driver-to-driven tube area change (currently not accounted for) is recommended for future studies as the likely mechanism for the observed performance gap.

X3 expansion tube driver gas spectroscopy and temperature measurements

NASA Astrophysics Data System (ADS)

Parekh, V.; Gildfind, D.; Lewis, S.; James, C.

2017-11-01

The University of Queensland's X3 facility is a large, free-piston driven expansion tube used for super-orbital and high Mach number scramjet aerothermodynamic studies. During recent development of new scramjet test flow conditions, experimentally measured shock speeds were found to be significantly lower than that predicted by initial driver performance calculations. These calculations were based on ideal, isentropic compression of the driver gas and indicated that loss mechanisms, not accounted for in the preliminary analysis, were significant. The critical determinant of shock speed is peak driver gas sound speed, which for a given gas composition depends on the peak driver gas temperature. This temperature may be inaccurately estimated if an incorrect fill temperature is assumed, or if heat losses during driver gas compression are significant but not accounted for. For this study, the ideal predicted peak temperature was 3750 K, without accounting for losses. However, a much lower driver temperature of 2400 K is suggested based on measured experimental shock speeds. This study aimed to measure initial and peak driver gas temperatures for a representative X3 operating condition. Examination of the transient temperatures of the driver gas and compression tube steel wall during the initial fill process showed that once the filling process was complete, the steady-state driver gas temperature closely matched the tube wall temperature. Therefore, while assuming the gas is initially at the ambient laboratory temperature is not a significant source of error, it can be entirely mitigated by simply monitoring tube wall temperature. Optical emission spectroscopy was used to determine the driver gas spectra after diaphragm rupture; the driver gas emission spectrum exhibited a significant continuum radiation component, with prominent spectral lines attributed to contamination of the gas. A graybody approximation of the continuum suggested a peak driver gas temperature of 3200 K; uncertainty associated with the blackbody curve fit is ±100 K. However, work is required to quantify additional sources of uncertainty due to the graybody assumption and the presence of contaminant particles in the driver gas; these are potentially significant. The estimate of the driver gas temperature suggests that driver heat losses are not the dominant contributor to the lower-than-expected shock speeds for X3. Since both the driver temperature and pressure have been measured, investigation of total pressure losses during driver gas expansion across the diaphragm and driver-to-driven tube area change (currently not accounted for) is recommended for future studies as the likely mechanism for the observed performance gap.

Portable, real-time alloy identification of metallic wear debris from machinery lubrication systems: laser-induced breakdown spectroscopy versus x-ray fluorescence

NASA Astrophysics Data System (ADS)

Suresh, Pooja

2014-05-01

Alloy identification of oil-borne wear debris captured on chip detectors, filters and magnetic plugs allows the machinery maintainer to assess the health of the engine or gearbox and identify specific component damage. Today, such identification can be achieved in real time using portable, at-line laser-induced breakdown spectroscopy (LIBS) and Xray fluorescence (XRF) instruments. Both techniques can be utilized in various industries including aviation, marine, railways, heavy diesel and other industrial machinery with, however, some substantial differences in application and instrument performance. In this work, the performances of a LIBS and an XRF instrument are compared based on measurements of a wide range of typical aerospace alloys including steels, titanium, aluminum and nickel alloys. Measurement results were analyzed with a staged correlation technique specifically developed for the purposes of this study - identifying the particle alloy composition using a pre-recorded library of spectral signatures. The analysis is performed in two stages: first, the base element of the alloy is determined by correlation with the stored elemental spectra and then, the alloy is identified by matching the particle's spectral signature using parametric correlation against the stored spectra of all alloys that have the same base element. The correlation analysis has achieved highly repeatable discrimination between alloys of similar composition. Portable LIBS demonstrates higher detection accuracy and better identification of alloys comprising lighter elements as compared to that of the portable XRF system, and reveals a significant reduction in the analysis time over XRF.

Analysis of Driver Evasive Maneuvering Prior to Intersection Crashes Using Event Data Recorders.

PubMed

Scanlon, John M; Kusano, Kristofer D; Gabler, Hampton C

2015-01-01

Intersection crashes account for over 4,500 fatalities in the United States each year. Intersection Advanced Driver Assistance Systems (I-ADAS) are emerging vehicle-based active safety systems that have the potential to help drivers safely navigate across intersections and prevent intersection crashes and injuries. The performance of an I-ADAS is expected to be highly dependent upon driver evasive maneuvering prior to an intersection crash. Little has been published, however, on the detailed evasive kinematics followed by drivers prior to real-world intersection crashes. The objective of this study was to characterize the frequency, timing, and kinematics of driver evasive maneuvers prior to intersection crashes. Event data recorders (EDRs) downloaded from vehicles involved in intersection crashes were investigated as part of NASS-CDS years 2001 to 2013. A total of 135 EDRs with precrash vehicle speed and braking application were downloaded to investigate evasive braking. A smaller subset of 59 EDRs that collected vehicle yaw rate was additionally analyzed to investigate evasive steering. Each vehicle was assigned to one of 3 precrash movement classifiers (traveling through the intersection, completely stopped, or rolling stop) based on the vehicle's calculated acceleration and observed velocity profile. To ensure that any significant steering input observed was an attempted evasive maneuver, the analysis excluded vehicles at intersections that were turning, driving on a curved road, or performing a lane change. Braking application at the last EDR-recorded time point was assumed to indicate evasive braking. A vehicle yaw rate greater than 4° per second was assumed to indicate an evasive steering maneuver. Drivers executed crash avoidance maneuvers in four-fifths of intersection crashes. A more detailed analysis of evasive braking frequency by precrash maneuver revealed that drivers performing complete or rolling stops (61.3%) braked less often than drivers traveling through the intersection without yielding (79.0%). After accounting for uncertainty in the timing of braking and steering data, the median evasive braking time was found to be between 0.5 to 1.5 s prior to impact, and the median initial evasive steering time was found to occur between 0.5 and 0.9 s prior to impact. The median average evasive braking deceleration for all cases was found to be 0.58 g. The median of the maximum evasive vehicle yaw rates was found to be 8.2° per second. Evasive steering direction was found to be most frequently in the direction of travel of the approaching vehicle. The majority of drivers involved in intersection crashes were alert enough to perform an evasive action. Most drivers used a combination of steering and braking to avoid a crash. The average driver attempted to steer and brake at approximately the same time prior to the crash.

Developing Information Power Grid Based Algorithms and Software

NASA Technical Reports Server (NTRS)

Dongarra, Jack

1998-01-01

This exploratory study initiated our effort to understand performance modeling on parallel systems. The basic goal of performance modeling is to understand and predict the performance of a computer program or set of programs on a computer system. Performance modeling has numerous applications, including evaluation of algorithms, optimization of code implementations, parallel library development, comparison of system architectures, parallel system design, and procurement of new systems. Our work lays the basis for the construction of parallel libraries that allow for the reconstruction of application codes on several distinct architectures so as to assure performance portability. Following our strategy, once the requirements of applications are well understood, one can then construct a library in a layered fashion. The top level of this library will consist of architecture-independent geometric, numerical, and symbolic algorithms that are needed by the sample of applications. These routines should be written in a language that is portable across the targeted architectures.

Portable oxygen concentrators versus oxygen cylinder during walking in interstitial lung disease: A randomized crossover trial.

PubMed

Khor, Yet H; McDonald, Christine F; Hazard, Anita; Symons, Karen; Westall, Glen; Glaspole, Ian; Goh, Nicole S L; Holland, Anne E

2017-11-01

Ambulatory oxygen therapy is often provided to patients with interstitial lung disease (ILD). Lightweight portable oxygen concentrators (POCs) provide an alternative to traditional portable systems such as compressed oxygen cylinders; however, their efficacy in patients with ILD has not been assessed. This study aimed to evaluate the clinical performance of three ambulatory oxygen systems (two different POCs and a compressed oxygen cylinder) during 6-min walk tests (6MWTs) in patients with ILD and exertional desaturation. A total of 20 participants with ILD of varying aetiologies who demonstrated exertional desaturation to <90% on room air during 6MWT were recruited. Each participant performed two 6MWTs while breathing room air. On a subsequent day, two further 6MWTs were performed, in random order: one breathing oxygen via a POC (either the Inogen One G2 POC or the EverGo POC at the setting of 6) and one with a compressed oxygen cylinder (at 5 L/min). There were no significant differences in nadir oxygen saturation (SpO 2 ) during 6MWTs using different portable oxygen devices (Trial 1: mean SpO 2 for Inogen One G2 POC: 82.3 ± 3.5% vs oxygen cylinder: 80.3 ± 2.2%, P = 0.14; Trial 2: mean SpO 2 for EverGo POC: 85.7 ± 7.7% vs oxygen cylinder: 86.1 ± 6.1%, P = 0.79). The mean 6-min walk distances were not significantly different among the three devices. The performance of the Inogen One G2 POC and the EverGo POC had comparable performance with that of the compressed oxygen cylinder during walking in patients with ILD and exertional desaturation. © 2017 Asian Pacific Society of Respirology.

Ear diseases among secondary school students in Xi'an, China: the role of portable audio device use, insomnia and academic stress.

PubMed

Chen, Yang; Li, Xu; Xu, Zhan; Li, Zonghua; Zhang, Pengzhi; He, Ya; Wang, Fangyuan; Qiu, Jianhua

2011-06-08

Hearing impairment negatively impacts students' development of academic, language and social skills. Even minimal unilateral hearing loss can hinder educational performance. We investigated the prevalence of ear diseases among secondary school students in the city of Xi'an, China in order to provide a foundation for evidence-based hearing healthcare. A stratified random sampling survey was conducted in 29 secondary schools. Demographics and medical histories were collected, and otologic examinations were performed. Questionnaires were administered to assess insomnia, academic stress and use of portable audio devices. Logistic regression analysis was used to identify factors associated with hearing impairment, and the association of sensorineural hearing loss with insomnia, academic stress and the use of portable audio devices was analyzed with the chi-square test. The percentage of students with some form of ear disease was 3.32%. External ear disease, middle ear disease and sensorineural hearing loss occurred in 1.21%, 0.64% and 1.47% of the students, respectively. Boys had a relatively higher prevalence of ear disease than girls. According to our survey, the prevalence of sensorineural hearing loss increased significantly among the students with insomnia and extended use of portable audio devices, but not among those with elevated levels of academic stress. Hearing aids and surgical treatment were needed in 1.47% and 0.89% of the students, respectively. There is a high prevalence of ear disease among secondary school students, and this should be given more attention. Insomnia and the excessive use of portable audio devices may be related to adolescent sensorineural hearing loss. It is important to establish and comply with an evidence-based preventive strategy.

Vision-based method for detecting driver drowsiness and distraction in driver monitoring system

NASA Astrophysics Data System (ADS)

Jo, Jaeik; Lee, Sung Joo; Jung, Ho Gi; Park, Kang Ryoung; Kim, Jaihie

2011-12-01

Most driver-monitoring systems have attempted to detect either driver drowsiness or distraction, although both factors should be considered for accident prevention. Therefore, we propose a new driver-monitoring method considering both factors. We make the following contributions. First, if the driver is looking ahead, drowsiness detection is performed; otherwise, distraction detection is performed. Thus, the computational cost and eye-detection error can be reduced. Second, we propose a new eye-detection algorithm that combines adaptive boosting, adaptive template matching, and blob detection with eye validation, thereby reducing the eye-detection error and processing time significantly, which is hardly achievable using a single method. Third, to enhance eye-detection accuracy, eye validation is applied after initial eye detection, using a support vector machine based on appearance features obtained by principal component analysis (PCA) and linear discriminant analysis (LDA). Fourth, we propose a novel eye state-detection algorithm that combines appearance features obtained using PCA and LDA, with statistical features such as the sparseness and kurtosis of the histogram from the horizontal edge image of the eye. Experimental results showed that the detection accuracies of the eye region and eye states were 99 and 97%, respectively. Both driver drowsiness and distraction were detected with a success rate of 98%.

Design and Qualification of a SmallSat Stepper Motor Driver, Flight Results On-Board the Yes2 Satellite

NASA Astrophysics Data System (ADS)

Graczyk, R.; Kruijff, M.; Spiliotopoulos, I.

2008-08-01

Drivers for stepper motors are a commonly required critical technology for small satellites. This paper highlights the stepper driver design, test, and mission performance for the second Young Engineers' Satellite (YES2). The unit integrates the required digital and power parts and was developed with generic low-cost satellite applications in mind. One of the key mechanisms in YES2 is a friction brake containing a stepper motor which is in turn controlled by a stepper driver. The friction brake was used to control the deployment speed such that the tether deployed according to a pre-described two-stage trajectory. The stepper driver was itself commanded by an on-board computer that used tether deployment data as input and provided the new required position of the brake as output. The stepper driver design was driven by the requirements of a low cost yet reliable redundant design, use of a micro-controller and software commonly known to students, very small dimension, good thermal behavior and capable of delivering high torque at high efficiency. The work followed as much as possible ESA's design standards and was qualified by electromagnetic compatibility, thermal vacuum and shaker tests. It was functionally tested in real-time ground tether deployments. Mission data shows the stepper driver performed well in flight.

Driving Comparisons Between Young Adults with Autism Spectrum Disorder and Typical Development.

PubMed

Patrick, Kristina E; Hurewitz, Felicia; McCurdy, Mark D; Agate, Frederic Taylor; Daly, Brian P; Tarazi, Reem A; Chute, Douglas L; Schultheis, Maria T

2018-05-18

Many individuals with autism spectrum disorder (ASD) are reluctant to pursue driving because of concerns about their ability to drive safely. This study aimed to assess differences in simulated driving performance in young adults with ASD and typical development, examining relationships between driving performance and the level of experience (none, driver's permit, licensed) across increasingly difficult driving environments. Participants included 50 English-speaking young adults (16-26 years old) with ASD matched for sex, age, and licensure with 50 typically-developing (TD) peers. Participants completed a structured driving assessment using a virtual-reality simulator that included increasingly complex environmental demands. Differences in mean speed and speed and lane variability by diagnostic group and driving experience were analyzed using multilevel linear modeling. Young adults with ASD demonstrated increased variability in speed and lane positioning compared with controls, even during low demand tasks. When driving demands became more complex, group differences were moderated by driving experience such that licensed drivers with ASD drove similarly to TD licensed drivers for most tasks, whereas unlicensed drivers with ASD had more difficulty with speed and lane management than TD drivers. Findings suggest that young adults with ASD may have more difficulty with basic driving skills than peers, particularly in the early stages of driver training. Increased difficulty compared with peers increases as driving demands become more complex, suggesting that individuals with ASD may benefit from a slow and gradual approach to driver training. Future studies should evaluate predictors of driving performance, on-road driving, and ASD-specific driving interventions.

Introducing a multivariate model for predicting driving performance: the role of driving anger and personal characteristics.

PubMed

Roidl, Ernst; Siebert, Felix Wilhelm; Oehl, Michael; Höger, Rainer

2013-12-01

Maladaptive driving is an important source of self-inflicted accidents and this driving style could include high speeds, speeding violations, and poor lateral control of the vehicle. The literature suggests that certain groups of drivers, such as novice drivers, males, highly motivated drivers, and those who frequently experience anger in traffic, tend to exhibit more maladaptive driving patterns compared to other drivers. Remarkably, no coherent framework is currently available to describe the relationships and distinct influences of these factors. We conducted two studies with the aim of creating a multivariate model that combines the aforementioned factors, describes their relationships, and predicts driving performance more precisely. The studies employed different techniques to elicit emotion and different tracks designed to explore the driving behaviors of participants in potentially anger-provoking situations. Study 1 induced emotions with short film clips. Study 2 confronted the participants with potentially anger-inducing traffic situations during the simulated drive. In both studies, participants who experienced high levels of anger drove faster and exhibited greater longitudinal and lateral acceleration. Furthermore, multiple linear regressions and path-models revealed that highly motivated male drivers displayed the same behavior independent of their emotional state. The results indicate that anger and specific risk characteristics lead to maladaptive changes in important driving parameters and that drivers with these specific risk factors are prone to experience more anger while driving, which further worsens their driving performance. Driver trainings and anger management courses will profit from these findings because they help to improve the validity of assessments of anger related driving behavior. © 2013.

Prevalence of at-risk drinking among Brazilian truck drivers and its interference on the performance of executive cognitive tasks.

PubMed

de Oliveira, Lucio Garcia; Leopoldo, Kae; Gouvea, Marcela Julio Cesar; Barroso, Lucia Pereira; Gouveia, Paula Adriana Rodrigues; Muñoz, Daniel Romero; Leyton, Vilma

2016-09-01

Binge drinking (BD) has been associated with an increase in the risk of alcohol-related injuries. Alcohol continues to be the main substance consumed by truck drivers, a population of special concern, since they are often involved in traffic accidents. The aim of this study was to estimate the prevalence of BD and its interference in the executive functioning among truck drivers in Sao Paulo, Brazil. A non-probabilistic sample of 684 truck drivers was requested to answer a structured research instrument on their demographic data and alcohol use. They performed cognitive tests to assess their executive functioning and inventories about confounding variables. The participants were then divided according to their involvement in BD. 17.5% of the interviewees have reported being engaged in BD. Binge drinkers showed a better performance on one test, despite having done so at the expense of more mistakes and lower accuracy. More interestingly, binge drinkers took three seconds longer than non-binge drinkers to inhibit an inadequate response, which is worrisome in the context of traffic. Overall, the deleterious effect of BD on performance remained after controlling for the effects of confounding variables in regression logistic models. As the use of alcohol among truck drivers may be as a way to get by with their work conditions, we believe that a negotiation between their work organization and public authorities would reduce such use, preventing negative interferences on truck drivers' cognitive functioning, which by its turn may also prevent traffic accidents. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

How accurately do drivers evaluate their own driving behavior? An on-road observational study.

PubMed

Amado, Sonia; Arıkan, Elvan; Kaça, Gülin; Koyuncu, Mehmet; Turkan, B Nilay

2014-02-01

Self-assessment of driving skills became a noteworthy research subject in traffic psychology, since by knowing one's strenghts and weaknesses, drivers can take an efficient compensatory action to moderate risk and to ensure safety in hazardous environments. The current study aims to investigate drivers' self-conception of their own driving skills and behavior in relation to expert evaluations of their actual driving, by using naturalistic and systematic observation method during actual on-road driving session and to assess the different aspects of driving via comprehensive scales sensitive to different specific aspects of driving. 19-63 years old male participants (N=158) attended an on-road driving session lasting approximately 80min (45km). During the driving session, drivers' errors and violations were recorded by an expert observer. At the end of the driving session, observers completed the driver evaluation questionnaire, while drivers completed the driving self-evaluation questionnaire and Driver Behavior Questionnaire (DBQ). Low to moderate correlations between driver and observer evaluations of driving skills and behavior, mainly on errors and violations of speed and traffic lights was found. Furthermore, the robust finding that drivers evaluate their driving performance as better than the expert was replicated. Over-positive appraisal was higher among drivers with higher error/violation score and with the ones that were evaluated by the expert as "unsafe". We suggest that the traffic environment might be regulated by increasing feedback indicators of errors and violations, which in turn might increase the insight into driving performance. Improving self-awareness by training and feedback sessions might play a key role for reducing the probability of risk in their driving activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assisting People with Developmental Disabilities to Improve Pointing Efficiency with an Automatic Pointing Assistive Program

ERIC Educational Resources Information Center

Shih, Ching-Hsiang; Hsu, Nai-Yun; Shih, Ching-Tien

2009-01-01

This study evaluated whether two children with developmental disabilities would be able to improve their pointing performance through an Automatic Pointing Assistive Program (APAP) and a newly developed mouse driver (i.e. a new mouse driver replaces standard mouse driver, and is able to intercept mouse click action). Initially, both participants…

Assisting People with Developmental Disabilities Improve Their Collaborative Pointing Efficiency with a Multiple Cursor Automatic Pointing Assistive Program

ERIC Educational Resources Information Center

Shih, Ching-Hsiang; Cheng, Hsiao-Fen; Li, Chia-Chun; Shih, Ching-Tien; Chiang, Ming-Shan

2010-01-01

This study evaluated whether four persons (two groups) with developmental disabilities would be able to improve their collaborative pointing performance through a Multiple Cursor Automatic Pointing Assistive Program (MCAPAP) with a newly developed mouse driver (i.e., a new mouse driver replaces standard mouse driver, and is able to…

Long-Haul Truck Idling Burns Up Profits

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2015-08-12

Long-haul truck drivers perform a vitally important service. In the course of their work, they must take rest periods as required by federal law. Most drivers remain in their trucks, which they keep running to provide power for heating, cooling, and other necessities. Such idling, however, comes at a cost; it is an expensive and polluting way to keep drivers safe and comfortable. Increasingly affordable alternatives to idling not only save money and reduce pollution, but also help drivers get a better night's rest.

Effects of Fear-Arousing Components of Driver Education on Students' Safety Attitudes and Simulator Performance

ERIC Educational Resources Information Center

Griffeth, Rodger W.; Rogers, Ronald W.

1976-01-01

Examining the effects of the noxiousness of an automobile accident, probability of being in an accident, and efficacy of safe driving practices on driver education students, the results disclosed that all three independent variables affected attitudes toward safety, and performance on the simulator. (Author/BW)

Development of a model performance-based sign sheeting specification based on the evaluation of nighttime traffic signs using legibility and eye-tracker data.

DOT National Transportation Integrated Search

2010-09-01

This project focused on the evaluation of traffic sign sheeting performance in terms of meeting the nighttime : driver needs. The goal was to develop a nighttime driver needs specification for traffic signs. The : researchers used nighttime sign legi...

Driving and Low Vision: Validity of Assessments for Predicting Performance of Drivers

ERIC Educational Resources Information Center

Strong, J. Graham; Jutai, Jeffrey W.; Russell-Minda, Elizabeth; Evans, Mal

2008-01-01

The authors conducted a systematic review to examine whether vision-related assessments can predict the driving performance of individuals who have low vision. The results indicate that measures of visual field, contrast sensitivity, cognitive and attention-based tests, and driver screening tools have variable utility for predicting real-world…

How we can measure the non-driving-task engagement in automated driving: Comparing flow experience and workload.

PubMed

Ko, Sang Min; Ji, Yong Gu

2018-02-01

In automated driving, a driver can completely concentrate on non-driving-related tasks (NDRTs). This study investigated the flow experience of a driver who concentrated on NDRTs and tasks that induce mental workload under conditional automation. Participants performed NDRTs under different demand levels: a balanced demand-skill level (fit condition) to induce flow, low-demand level to induce boredom, and high-demand level to induce anxiety. In addition, they performed the additional N-Back task, which artificially induces mental workload. The results showed participants had the longest reaction time when they indicated the highest flow score, and had the longest gaze-on time, road-fixation time, hands-on time, and take-over time under the fit condition. Significant differences were not observed in the driver reaction times in the fit condition and the additional N-Back task, indicating that performing NDRTs that induce a high flow experience could influence driver reaction time similar to performing tasks with a high mental workload. Copyright © 2017. Published by Elsevier Ltd.

Modeling take-over performance in level 3 conditionally automated vehicles.

PubMed

Gold, Christian; Happee, Riender; Bengler, Klaus

2018-07-01

Taking over vehicle control from a Level 3 conditionally automated vehicle can be a demanding task for a driver. The take-over determines the controllability of automated vehicle functions and thereby also traffic safety. This paper presents models predicting the main take-over performance variables take-over time, minimum time-to-collision, brake application and crash probability. These variables are considered in relation to the situational and driver-related factors time-budget, traffic density, non-driving-related task, repetition, the current lane and driver's age. Regression models were developed using 753 take-over situations recorded in a series of driving simulator experiments. The models were validated with data from five other driving simulator experiments of mostly unrelated authors with another 729 take-over situations. The models accurately captured take-over time, time-to-collision and crash probability, and moderately predicted the brake application. Especially the time-budget, traffic density and the repetition strongly influenced the take-over performance, while the non-driving-related tasks, the lane and drivers' age explained a minor portion of the variance in the take-over performances. Copyright © 2017 Elsevier Ltd. All rights reserved.

Making Information Visible, Accessible, and Understandable: Meta-Data and Registries

DTIC Science & Technology

2007-07-01

the data created, the length of play time, album name, and the genre. Without resource metadata, portable digital music players would not be so...notion of a catalog card in a library. An example of metadata is the description of a music file specifying the creator, the artist that performed the song...describe struc- ture and formatting which are critical to interoperability and the management of databases. Going back to the portable music player example

Portable gas chromatograph mass spectrometer for on-site chemical analyses

DOEpatents

Haas, Jeffrey S.; Bushman, John F.; Howard, Douglas E.; Wong, James L.; Eckels, Joel D.

2002-01-01

A portable, lightweight (approximately 25 kg) gas chromatograph mass spectrometer, including the entire vacuum system, can perform qualitative and quantitative analyses of all sample types in the field. The GC/MS has a conveniently configured layout of components for ease of serviceability and maintenance. The GC/MS system can be transported under operating or near-operating conditions (i.e., under vacuum and at elevated temperature) to reduce the downtime before samples can be analyzed on-site.

The drive-wise project: driving simulator training increases real driving performance in healthy older drivers

PubMed Central

Casutt, Gianclaudio; Theill, Nathan; Martin, Mike; Keller, Martin; Jäncke, Lutz

2014-01-01

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 one of three groups: (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 orthogonal 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. PMID:24860497

Distraction produces over-additive increases in the degree to which alcohol impairs driving performance.

PubMed

Van Dyke, Nicholas A; Fillmore, Mark T

2015-12-01

Research indicates that alcohol intoxication and increased demands on drivers' attention from distractions (e.g., passengers and cell phones) contribute to poor driving performance and increased rates of traffic accidents and fatalities. The present study examined the separate and combined effects of alcohol and distraction on simulated driving performance at blood alcohol concentrations (BrACs) below the legal driving limit in the USA (i.e., 0.08 %). Fifty healthy adult drivers (36 men and 14 women) were tested in a driving simulator following a 0.65-g/kg dose of alcohol and a placebo. Drivers completed two drive tests: a distracted drive, which included a two-choice detection task, and an undistracted control drive. Multiple indicators of driving performance, such as drive speed, within-lane deviation, steering rate, and lane exceedances were measured. Alcohol and distraction each impaired measures of driving performance. Moreover, the magnitude of alcohol impairment was increased by at least twofold when tested under the distracting versus the undistracted condition. The findings highlight the need for a clearer understanding of how common distractions impact intoxicated drivers, especially at BrACs that are currently legal for driving in the USA.

Real-time driver fatigue detection based on face alignment

NASA Astrophysics Data System (ADS)

Tao, Huanhuan; Zhang, Guiying; Zhao, Yong; Zhou, Yi

2017-07-01

The performance and robustness of fatigue detection largely decrease if the driver with glasses. To address this issue, this paper proposes a practical driver fatigue detection method based on face alignment at 3000 FPS algorithm. Firstly, the eye regions of the driver are localized by exploiting 6 landmarks surrounding each eye. Secondly, the HOG features of the extracted eye regions are calculated and put into SVM classifier to recognize the eye state. Finally, the value of PERCLOS is calculated to determine whether the driver is drowsy or not. An alarm will be generated if the eye is closed for a specified period of time. The accuracy and real-time on testing videos with different drivers demonstrate that the proposed algorithm is robust and obtain better accuracy for driver fatigue detection compared with some previous method.

Feasibility of a portable X-ray fluorescence device for bone lead measurements of condor bones.

PubMed

Specht, Aaron J; Parish, Chris N; Wallens, Emma K; Watson, Rick T; Nie, Linda H; Weisskopf, Marc G

2018-02-15

Lead based ammunition is a primary source of lead exposure, especially for scavenging wildlife. Lead poisoning remains the leading cause of diagnosed death for the critically endangered California condors, which are annually monitored via blood tests for lead exposure. The results of these tests are helpful in determining recent exposure in condors and in defining the potential for exposure to other species including humans. Since condors are victim to acute and chronic lead exposure, being able to measure both would lend valuable information on the rates of exposure and accumulation through time. A commercial portable X-ray fluorescence (XRF) device has been optimized to measure bone lead in vivo in humans, but this device could also be valuable for field measurements of bone lead in avian species. In this study, we performed measurements of bone Pb in excised, bare condor bones using inductively coupled plasma mass spectrometry (ICP-MS), a cadmium 109 (Cd-109) K-shell X-ray fluorescence (KXRF) system, and a portable XRF system. Both KXRF and portable XRF bone Pb measurement techniques demonstrated good correlations with ICP-MS results (r=0.93 and r=0.92 respectively), even with increasing skin thickness (r=0.86 between ICP-MS and portable XRF at 1.54mm of soft tissue). In conclusion, our results suggest that a portable XRF could be a useful option for measurement of bone Pb in avian species in the field. Copyright © 2017 Elsevier B.V. All rights reserved.

Moving your laboratories to the field--Advantages and limitations of the use of field portable instruments in environmental sample analysis.

PubMed

Gałuszka, Agnieszka; Migaszewski, Zdzisław M; Namieśnik, Jacek

2015-07-01

The recent rapid progress in technology of field portable instruments has increased their applications in environmental sample analysis. These instruments offer a possibility of cost-effective, non-destructive, real-time, direct, on-site measurements of a wide range of both inorganic and organic analytes in gaseous, liquid and solid samples. Some of them do not require the use of reagents and do not produce any analytical waste. All these features contribute to the greenness of field portable techniques. Several stationary analytical instruments have their portable versions. The most popular ones include: gas chromatographs with different detectors (mass spectrometer (MS), flame ionization detector, photoionization detector), ultraviolet-visible and near-infrared spectrophotometers, X-ray fluorescence spectrometers, ion mobility spectrometers, electronic noses and electronic tongues. The use of portable instruments in environmental sample analysis gives a possibility of on-site screening and a subsequent selection of samples for routine laboratory analyses. They are also very useful in situations that require an emergency response and for process monitoring applications. However, quantification of results is still problematic in many cases. The other disadvantages include: higher detection limits and lower sensitivity than these obtained in laboratory conditions, a strong influence of environmental factors on the instrument performance and a high possibility of sample contamination in the field. This paper reviews recent applications of field portable instruments in environmental sample analysis and discusses their analytical capabilities. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of advertising billboards during simulated driving.

PubMed

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.

Distraction and task engagement: How interesting and boring information impact driving performance and subjective and physiological responses.

PubMed

Horrey, William J; Lesch, Mary F; Garabet, Angela; Simmons, Lucinda; Maikala, Rammohan

2017-01-01

As more devices and services are integrated into vehicles, drivers face new opportunities to perform additional tasks while driving. While many studies have explored the detrimental effects of varying task demands on driving performance, there has been little attention devoted to tasks that vary in terms of personal interest or investment-a quality we liken to the concept of task engagement. The purpose of this study was to explore the impact of task engagement on driving performance, subjective appraisals of performance and workload, and various physiological measurements. In this study, 31 participants (M = 37 yrs) completed three driving conditions in a driving simulator: listening to boring auditory material; listening to interesting material; and driving with no auditory material. Drivers were simultaneously monitored using near-infrared spectroscopy, heart monitoring and eye tracking systems. Drivers exhibited less variability in lane keeping and headway maintenance for both auditory conditions; however, response times to critical braking events were longer in the interesting audio condition. Drivers also perceived the interesting material to be less demanding and less complex, although the material was objectively matched for difficulty. Drivers showed a reduced concentration of cerebral oxygenated hemoglobin when listening to interesting material, compared to baseline and boring conditions, yet they exhibited superior recognition for this material. The practical implications, from a safety standpoint, are discussed. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Reading text while driving: understanding drivers' strategic and tactical adaptation to distraction.

PubMed

Liang, Yulan; Horrey, William J; Hoffman, Joshua D

2015-03-01

In this study, we investigated how drivers adapt secondary-task initiation and time-sharing behavior when faced with fluctuating driving demands. Reading text while driving is particularly detrimental; however, in real-world driving, drivers actively decide when to perform the task. In a test track experiment, participants were free to decide when to read messages while driving along a straight road consisting of an area with increased driving demands (demand zone) followed by an area with low demands. A message was made available shortly before the vehicle entered the demand zone. We manipulated the type of driving demands (baseline, narrow lane, pace clock, combined), message format (no message, paragraph, parsed), and the distance from the demand zone when the message was available (near, far). In all conditions, drivers started reading messages (drivers' first glance to the display) before entering or before leaving the demand zone but tended to wait longer when faced with increased driving demands. While reading messages, drivers looked more or less off road, depending on types of driving demands. For task initiation, drivers avoid transitions from low to high demands; however, they are not discouraged when driving demands are already elevated. Drivers adjust time-sharing behavior according to driving demands while performing secondary tasks. Nonetheless, such adjustment may be less effective when total demands are high. This study helps us to understand a driver's role as an active controller in the context of distracted driving and provides insights for developing distraction interventions. © 2014, Human Factors and Ergonomics Society.

The influence of daily sleep patterns of commercial truck drivers on driving performance.

PubMed

Chen, Guang Xiang; Fang, Youjia; Guo, Feng; Hanowski, Richard J

2016-06-01

Fatigued and drowsy driving has been found to be a major cause of truck crashes. Lack of sleep is the number one cause of fatigue and drowsiness. However, there are limited data on the sleep patterns (sleep duration, sleep percentage in the duration of non-work period, and the time when sleep occurred) of truck drivers in non-work periods and the impact on driving performance. This paper examined sleep patterns of 96 commercial truck drivers during non-work periods and evaluated the influence these sleep patterns had on truck driving performance. Data were from the Naturalistic Truck Driving Study. Each driver participated in the study for approximately four weeks. A shift was defined as a non-work period followed by a work period. A total of 1397 shifts were identified. Four distinct sleep patterns were identified based on sleep duration, sleep start/end point in a non-work period, and the percentage of sleep with reference to the duration of non-work period. Driving performance was measured by safety-critical events, which included crashes, near-crashes, crash-relevant conflicts, and unintentional lane deviations. Negative binomial regression was used to evaluate the association between the sleep patterns and driving performance, adjusted for driver demographic information. The results showed that the sleep pattern with the highest safety-critical event rate was associated with shorter sleep, sleep in the early stage of a non-work period, and less sleep between 1 a.m. and 5 a.m. This study also found that male drivers, with fewer years of commercial vehicle driving experience and higher body mass index, were associated with deteriorated driving performance and increased driving risk. The results of this study could inform hours-of-service policy-making and benefit safety management in the trucking industry. Published by Elsevier Ltd.

The effects of sleep loss on young drivers' performance: A systematic review.

PubMed

Shekari Soleimanloo, Shamsi; White, Melanie J; Garcia-Hansen, Veronica; Smith, Simon S

2017-01-01

Young drivers (18-24 years) are over-represented in sleep-related crashes (comprising one in five fatal crashes in developed countries) primarily due to decreased sleep opportunity, lower tolerance for sleep loss, and ongoing maturation of brain areas associated with driving-related decision making. Impaired driving performance is the proximal reason for most car crashes. There is still a limited body of evidence examining the effects of sleep loss on young drivers' performance, with discrepancies in the methodologies used, and in the definition of outcomes. This study aimed to identify the direction and magnitude of the effects of sleep loss on young drivers' performance, and to appraise the quality of current evidence via a systematic review. Based on the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) approach, 16 eligible studies were selected for review, and their findings summarised. Next, critical elements of these studies were identified, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines augmented to rate those elements. Using those criteria, the quality of individual papers was calculated and the overall body of evidence for each driving outcome were assigned a quality ranking (from 'very low' to 'high-quality'). Two metrics, the standard deviation of lateral position and number of line crossings, were commonly reported outcomes (although in an overall 'low-quality' body of evidence), with significant impairments after sleep loss identified in 50% of studies. While speed-related outcomes and crash events (also with very low- quality evidence) both increased under chronic sleep loss, discrepant findings were reported under conditions of acute total sleep deprivation. It is crucial to obtain more reliable data about the effects of sleep loss on young drivers' performance by using higher quality experimental designs, adopting common protocols, and the use of consistent metrics and reporting of findings based on GRADE criteria and the PRISMA statement. Key words: Young drivers, sleep loss, driving performance, PRISMA, the GRADE, systematic review.

Performance of a portable chain flail delimber/debarker processing northern hardwoods.

Treesearch

Michael A. Thompson; John A. Sturos

1991-01-01

Evaluates the performance of a Peterson Pacific 4800 chain flail delimber/debarker processing pole-size hardwoods in northern Michigan. Describes the productivity, cost, and delimbing/debarking quality achieved by the flail.

An Agent-Based Intervention to Assist Drivers Under Stereotype Threat: Effects of In-Vehicle Agents' Attributional Error Feedback.

PubMed

Joo, Yeon Kyoung; Lee-Won, Roselyn J

2016-10-01

For members of a group negatively stereotyped in a domain, making mistakes can aggravate the influence of stereotype threat because negative stereotypes often blame target individuals and attribute the outcome to their lack of ability. Virtual agents offering real-time error feedback may influence performance under stereotype threat by shaping the performers' attributional perception of errors they commit. We explored this possibility with female drivers, considering the prevalence of the "women-are-bad-drivers" stereotype. Specifically, we investigated how in-vehicle voice agents offering error feedback based on responsibility attribution (internal vs. external) and outcome attribution (ability vs. effort) influence female drivers' performance under stereotype threat. In addressing this question, we conducted an experiment in a virtual driving simulation environment that provided moment-to-moment error feedback messages. Participants performed a challenging driving task and made mistakes preprogrammed to occur. Results showed that the agent's error feedback with outcome attribution moderated the stereotype threat effect on driving performance. Participants under stereotype threat had a smaller number of collisions when the errors were attributed to effort than to ability. In addition, outcome attribution feedback moderated the effect of responsibility attribution on driving performance. Implications of these findings are discussed.

Portable devices and mobile instruments for infectious diseases point-of-care testing.

PubMed

Bissonnette, Luc; Bergeron, Michel G

2017-05-01

Rapidity, simplicity, and portability are highly desirable characteristics of tests and devices designed for performing diagnostics at the point of care (POC), either near patients managed in healthcare facilities or to offer bioanalytical alternatives in external settings. By reducing the turnaround time of the diagnostic cycle, POC diagnostics can reduce the dissemination, morbidity, and mortality of infectious diseases and provide tools to control the global threat of antimicrobial resistance. Areas covered: A literature search of PubMed and Google Scholar, and extensive mining of specialized publications, Internet resources, and manufacturers' websites have been used to organize and write this overview of the challenges and requirements associated with the development of portable sample-to-answer diagnostics, and showcase relevant examples of handheld devices, portable instruments, and less mobile systems which may or could be operated at POC. Expert commentary: Rapid (<1 h) diagnostics can contribute to control infectious diseases and antimicrobial resistant pathogens. Portable devices or instruments enabling sample-to-answer bioanalysis can provide rapid, robust, and reproducible testing at the POC or close from it. Beyond testing, to realize some promises of personalized/precision medicine, it will be critical to connect instruments to healthcare data management systems, to efficiently link decentralized testing results to the electronic medical record of patients.

Portable guided-mode resonance biosensor platform for point-of-care testing

NASA Astrophysics Data System (ADS)

Sung, Gun Yong; Kim, Wan-Joong; Ko, Hyunsung; Kim, Bong K.; Kim, Kyung-Hyun; Huh, Chul; Hong, Jongcheol

2012-10-01

It represents a viable solution for the realization of a portable biosensor platform that could screen/diagnose acute myocardial infarction by measuring cardiac marker concentrations such as cardiac troponin I (cTnI), creatine kinase MB (CK-MB), and myoglobin (MYO) for application to u-health monitoring system. The portable biosensor platform introduced in this presentation has a more compact structure and a much higher measuring resolution than a conventional spectrometer system. Portable guided-mode resonance (GMR) biosensor platform was composed of a biosensor chip stage, an optical pick-up module, and a data display panel. Disposable plastic GMR biosensor chips with nano-grating patterns were fabricated by injection-molding. Whole blood filtration and label-free immunoassay were performed on these single chips, automatically. Optical pick-up module was fabricated by using the miniaturized bulk optics and the interconnecting optical fibers and a tunable VCSEL (vertical cavity surface emitting laser). The reflectance spectrum from the GMR biosensor was measured by the optical pick-up module. Cardiac markers in human serum with concentrations less than 0.1ng/mL were analyzed using a GMR biosensor. Analysis time was 30min, which is short enough to meet clinical requirements. Our results show that the GMR biosensor will be very useful in developing lowcost portable biosensors that can screen for cardiac diseases.

Portable FAIMS: Applications and Future Perspectives.

PubMed

Costanzo, Michael T; Boock, Jared J; Kemperman, Robin H J; Wei, Michael S; Beekman, Christopher R; Yost, Richard A

2017-11-01

Miniaturized mass spectrometry (MMS) is optimal for a wide variety of applications that benefit from field-portable instrumentation. Like MMS, field asymmetric ion mobility spectrometry (FAIMS) has proven capable of providing in situ analysis, allowing researchers to bring the lab to the sample. FAIMS compliments MMS very well, but has the added benefit of operating at atmospheric pressure, unlike MS. This distinct advantage makes FAIMS uniquely suited for portability. Since its inception, FAIMS has been envisioned as a field-portable device, as it affords less expense and greater simplicity than many similar methods. Ideally, these are simple, robust devices that may be operated by non-professional personnel, yet still provide adequate data when in the field. While reducing the size and complexity tends to bring with it a loss of performance and accuracy, this is made up for by the incredibly high throughput and overall convenience of the instrument. Moreover, the FAIMS device used in the field can be brought back to the lab, and coupled to a conventional mass spectrometer to provide any necessary method development and compound validation. This work discusses the various considerations, uses, and applications for portable FAIMS instrumentation, and how the future of each applicable field may benefit from the development and acceptance of such a device.

Comparison of focused cognitive training and portable "brain-games" on functional outcomes for vocational rehabilitation participants.

PubMed

Bell, Morris D; Laws, Holly; Pittman, Brian; Johannesen, Jason K

2018-01-29

Cognitive remediation performed in a cognitive laboratory was compared with a sham control using portable brain games to study effects on vocational, neurocognitive, and functional outcomes for participants with psychotic disorders in vocational rehabilitation (VR). Seventy-seven participants (61% schizophrenia, 39% other psychosis) in transitional (45.5%) or supported employment (54.5%) were randomly assigned to 6 months of portable cognitive-games (CG) or cognitive remediation (CR) plus a weekly goal-setting group, and evaluated during training, post-training and at 12 months. Overall rates of employment did not differ significantly at 12-month follow-up; however, VR + CG attained employment more rapidly during training. A significant time by condition interaction favored VR + CR on Quality of Life Total Score and Instrumental Functioning over 12 months. Neurocognitive outcomes favored VR + CR, particularly on attention. Training hours related significantly to neurocognitive improvement regardless of condition. No differences were found in training adherence despite portability for VR + CG. Results indicate that VR + CR had significantly greater effect than VR + CG on neurocognition and community functioning, but not on employment outcome. Job attainment rates during the training period revealed a potential advantage for portable training raising new questions concerning how cognitive remediation can be most effectively integrated with VR.

High performance thyratron driver with low jitter.

PubMed

Verma, Rishi; Lee, P; Springham, S V; Tan, T L; Rawat, R S

2007-08-01

We report the design and development of insulated gate bipolar junction transistor based high performance driver for operating thyratrons in grounded grid mode. With careful design, the driver meets the specification of trigger output pulse rise time less than 30 ns, jitter less than +/-1 ns, and time delay less than 160 ns. It produces a -600 V pulse of 500 ns duration (full width at half maximum) at repetition rate ranging from 1 Hz to 1.14 kHz. The developed module also facilitates heating and biasing units along with protection circuitry in one complete package.

Commercial golf glove effects on golf performance and forearm muscle activity.

PubMed

Sorbie, Graeme G; Darroch, Paul; Grace, Fergal M; Gu, Yaodong; Baker, Julien S; Ugbolue, Ukadike C

2017-01-01

The study aimed to determine whether or not commercial golf gloves influence performance variables and forearm muscle activity during golf play. Fifteen golfers participated in the laboratory based study, each performing 8 golf swings with a Driver and 7-iron whilst wearing a glove and 8 without wearing the glove. Club head speed, ball speed and absolute carry distance performance variables were calculated. Surface electromyography was recorded from the flexor digitorum superficialis and extensor carpi radialis brevis on both forearm muscles. Club head speed, ball speed and absolute carry distance was significantly higher when using the Driver with the glove in comparison to the Driver without the glove (p < 0.05). No significant differences were evident when using the 7-iron and no significant differences were displayed in muscle activity in either of the conditions. Findings from this study suggest that driving performance is improved when wearing a glove.

Comment on "Influence of shaft length on golf driving performance".

PubMed

Glazier, Paul S

2009-06-01

Kenny et al. (2008) reported that low-handicap golfers were able to produce longer carry distances with longer drivers with no concomitant decrease in accuracy. However, it was not clear whether these increments in performance were an artefact of shaft length or some other unaccounted for characteristic of the experimental drivers used. Furthermore, it was difficult to determine whether these performance gains were experienced by all or only a few of the golfers studied. Additional research is required to substantiate these findings and also to establish how shaft length is related to performance and technique in less accomplished golfers. Regardless of skill level, the realization of the potential performance benefits associated with longer drivers is, to some degree, likely to be individual-specific. Accordingly, suitable research designs emphasizing the individual--with appropriate sample and trial sizes to achieve the requisite level of statistical significance, effect size, and power--are required.

Deficits in Attention and Visual Processing but not Global Cognition Predict Simulated Driving Errors in Drivers Diagnosed With Mild Alzheimer's Disease.

PubMed

Yamin, Stephanie; Stinchcombe, Arne; Gagnon, Sylvain

2016-06-01

This study sought to predict driving performance of drivers with Alzheimer's disease (AD) using measures of attention, visual processing, and global cognition. Simulated driving performance of individuals with mild AD (n = 20) was contrasted with performance of a group of healthy controls (n = 21). Performance on measures of global cognitive function and specific tests of attention and visual processing were examined in relation to simulated driving performance. Strong associations were observed between measures of attention, notably the Test of Everyday Attention (sustained attention; r = -.651, P = .002) and the Useful Field of View (r = .563, P = .010), and driving performance among drivers with mild AD. The Visual Object and Space Perception Test-object was significantly correlated with the occurrence of crashes (r = .652, P = .002). Tests of global cognition did not correlate with simulated driving outcomes. The results suggest that professionals exercise caution when extrapolating driving performance based on global cognitive indicators. © The Author(s) 2015.

Approaches of truck drivers and non-truck drivers toward reckless on-road behavior.

PubMed

Rosenbloom, Tova; Eldror, Ehud; Shahar, Amit

2009-07-01

The purpose of the study was to compare the reported approaches of truck drivers to those of non-truck drivers toward reckless on-road behaviors. One hundred and sixty-seven adult males, including 70 non-truck drivers, completed the questionnaires voluntarily. The truck drivers were employees of a concrete manufacturing company working at various company plants throughout Israel. Seventy were professional mixer truckers and 27 were tip-truckers. The participants completed the Reckless Driving Self-Report Scale based on Taubman Ben-Ari et al. [Taubman Ben-Ari, O., Florian, V., Mikulincer, M., 1999. The impact of mortality salience on reckless driving: a test of terror management mechanisms. Journal of Personality and Social Psychology 76, 35-45], adapted for truck drivers for this study. It was expected that non-professional, as compared to professional (truck) drivers, would be more permissive regarding reckless driving, since driving risks are less prominent in their daily driving experience. An ANOVA performed on mean reckless-driving scores yielded significant results. The post hoc Schéffe test indicated significantly higher reckless-driving scores for automobile drivers as compared to both mixer-truck driver scores and tip-truck driver scores. In addition, the reckless-driving scores for mixer-truck drivers were significantly higher than the tip-truck driver scores. We discuss various explanations for the findings and consider possible implications for training strategies in organizations as well as for media campaigns focused on mutual safe road use of truck drivers and private vehicle drivers.

Assisting People with Multiple Disabilities by Improving Their Computer Pointing Efficiency with an Automatic Target Acquisition Program

ERIC Educational Resources Information Center

Shih, Ching-Hsiang; Shih, Ching-Tien; Peng, Chin-Ling

2011-01-01

This study evaluated whether two people with multiple disabilities would be able to improve their pointing performance through an Automatic Target Acquisition Program (ATAP) and a newly developed mouse driver (i.e. a new mouse driver replaces standard mouse driver, and is able to monitor mouse movement and intercept click action). Initially, both…

Assisting People with Developmental Disabilities to Improve Pointing Efficiency with a Dual Cursor Automatic Pointing Assistive Program

ERIC Educational Resources Information Center

Shih, Ching-Hsiang; Chung, Chiao-Chen; Chiang, Ming-Shan; Shih, Ching-Tien

2010-01-01

This study evaluated whether two persons with developmental disabilities would be able to improve their pointing performance through a Dual Cursor Automatic Pointing Assistive Program (DCAPAP) with a newly developed mouse driver (i.e., a new mouse driver replaces standard mouse driver, and is able to intercept/detect mouse movement action). First,…

Driving with advanced vehicle technology: A qualitative investigation of older drivers' perceptions and motivations for use.

PubMed

Gish, Jessica; Vrkljan, Brenda; Grenier, Amanda; Van Miltenburg, Benita

2017-09-01

For older drivers, in-vehicle technology offers much potential to improve safety and increase longevity of retaining both licensure and community mobility. However, little is known about how older drivers perceive Advanced Vehicle Technologies (AVTs) based on everyday driving experience. Interviews with 35 older drivers (20 men; 15 women) aged 60-85 who owned a vehicle with at least two AVTs (e.g., back-up camera, lane departure warning) were conducted to explore the meanings that older drivers assigned to AVTs and motivations for use, including whether age-related functional changes were part of their automobile purchase decision. Findings indicate that age-related changes are not a primary reason for why older adults seek out AVTs, but they still perceived and experienced AVTs to counteract age-related changes in driving performance based upon changes they felt occurring within the body. Older drivers also described AVTs as generating a sense of comfort behind-the-wheel. Comfort with this technology was equated with convenience, ease of use, and increased feelings of safety. Discussion emphasizes how assessments of the quality of driving performance and value of technology occur in relation to an aging body. Copyright © 2016 Elsevier Ltd. All rights reserved.

Portable computing - A fielded interactive scientific application in a small off-the-shelf package

NASA Technical Reports Server (NTRS)

Groleau, Nicolas; Hazelton, Lyman; Frainier, Rich; Compton, Michael; Colombano, Silvano; Szolovits, Peter

1993-01-01

Experience with the design and implementation of a portable computing system for STS crew-conducted science is discussed. Principal-Investigator-in-a-Box (PI) will help the SLS-2 astronauts perform vestibular (human orientation system) experiments in flight. PI is an interactive system that provides data acquisition and analysis, experiment step rescheduling, and various other forms of reasoning to astronaut users. The hardware architecture of PI consists of a computer and an analog interface box. 'Off-the-shelf' equipment is employed in the system wherever possible in an effort to use widely available tools and then to add custom functionality and application codes to them. Other projects which can help prospective teams to learn more about portable computing in space are also discussed.

Toward Portable Breath Acetone Analysis for Diabetes Detection

PubMed Central

Righettoni, Marco; Tricoli, Antonio

2013-01-01

Diabetes is a lifelong condition that may cause death and seriously affects the quality of life of a rapidly growing number of individuals. Acetone is a selective breath marker for diabetes that may contribute to the monitoring of related metabolic disorder and thus simplify the management of this illness. Here, the overall performance of Si-doped WO3 nanoparticles made by flame spray pyrolysis as portable acetone detectors is critically reviewed focusing on the requirements for medical diagnostic. The effect of flow rate, chamber volume and acetone dissociation within the measuring chamber are discussed with respect to the calibration of the sensor response. The challenges for the fabrication of portable breath acetone sensors based on chemo-resistive detectors are underlined indicating possible solutions and novel research directions. PMID:21828897

SkinScan©: A PORTABLE LIBRARY FOR MELANOMA DETECTION ON HANDHELD DEVICES

PubMed Central

Wadhawan, Tarun; Situ, Ning; Lancaster, Keith; Yuan, Xiaojing; Zouridakis, George

2011-01-01

We have developed a portable library for automated detection of melanoma termed SkinScan© that can be used on smartphones and other handheld devices. Compared to desktop computers, embedded processors have limited processing speed, memory, and power, but they have the advantage of portability and low cost. In this study we explored the feasibility of running a sophisticated application for automated skin cancer detection on an Apple iPhone 4. Our results demonstrate that the proposed library with the advanced image processing and analysis algorithms has excellent performance on handheld and desktop computers. Therefore, deployment of smartphones as screening devices for skin cancer and other skin diseases can have a significant impact on health care delivery in underserved and remote areas. PMID:21892382

Design and Fabrication of Multifunctional Portable Bi2Te3-Based Thermoelectric Camping Lamp

NASA Astrophysics Data System (ADS)

Zhou, Yi; Li, Gongping

2018-05-01

Camping lamps have been widely used in the lighting, power supply, and intelligent electronic equipment fields. However, applications of traditional chemical and solar camping lamps are largely limited by the physical size of the source and operating conditions. A new prototype multifunctional portable Bi2Te3-based thermoelectric camping lamp (TECL) has been designed and fabricated. Ten parallel light-emitting diodes were lit directly by a Bi2Te3-based thermoelectric generator (TEG). The highest short-circuit current of 0.38 A and open-circuit voltage of 4.2 V were obtained at temperature difference of 115 K. This TECL is attractive for use in multifunctional and extreme applications as it integrates a portable heat source, high-performance TEG, and power management unit.

Design and Fabrication of Multifunctional Portable Bi2Te3-Based Thermoelectric Camping Lamp

NASA Astrophysics Data System (ADS)

Zhou, Yi; Li, Gongping

2018-07-01

Camping lamps have been widely used in the lighting, power supply, and intelligent electronic equipment fields. However, applications of traditional chemical and solar camping lamps are largely limited by the physical size of the source and operating conditions. A new prototype multifunctional portable Bi2Te3-based thermoelectric camping lamp (TECL) has been designed and fabricated. Ten parallel light-emitting diodes were lit directly by a Bi2Te3-based thermoelectric generator (TEG). The highest short-circuit current of 0.38 A and open-circuit voltage of 4.2 V were obtained at temperature difference of 115 K. This TECL is attractive for use in multifunctional and extreme applications as it integrates a portable heat source, high-performance TEG, and power management unit.

[Development of a medical equipment support information system based on PDF portable document].

PubMed

Cheng, Jiangbo; Wang, Weidong

2010-07-01

According to the organizational structure and management system of the hospital medical engineering support, integrate medical engineering support workflow to ensure the medical engineering data effectively, accurately and comprehensively collected and kept in electronic archives. Analyse workflow of the medical, equipment support work and record all work processes by the portable electronic document. Using XML middleware technology and SQL Server database, complete process management, data calculation, submission, storage and other functions. The practical application shows that the medical equipment support information system optimizes the existing work process, standardized and digital, automatic and efficient orderly and controllable. The medical equipment support information system based on portable electronic document can effectively optimize and improve hospital medical engineering support work, improve performance, reduce costs, and provide full and accurate digital data

Assessing the utility of TAM, TPB, and UTAUT for advanced driver assistance systems.

PubMed

Rahman, Md Mahmudur; Lesch, Mary F; Horrey, William J; Strawderman, Lesley

2017-11-01

Advanced Driver Assistance Systems (ADAS) are intended to enhance driver performance and improve transportation safety. The potential benefits of these technologies, such as reduction in number of crashes, enhancing driver comfort or convenience, decreasing environmental impact, etc., have been acknowledged by transportation safety researchers and federal transportation agencies. Although these systems afford safety advantages, they may also challenge the traditional role of drivers in operating vehicles. Driver acceptance, therefore, is essential for the implementation of these systems into the transportation system. Recognizing the need for research into the factors affecting driver acceptance, this study assessed the utility of the Technology Acceptance Model (TAM), the Theory of Planned Behavior (TPB), and the Unified Theory of Acceptance and Use of Technology (UTAUT) for modelling driver acceptance in terms of Behavioral Intention to use an ADAS. Each of these models propose a set of factors that influence acceptance of a technology. Data collection was done using two approaches: a driving simulator approach and an online survey approach. In both approaches, participants interacted with either a fatigue monitoring system or an adaptive cruise control system combined with a lane-keeping system. Based on their experience, participants responded to several survey questions to indicate their attitude toward using the ADAS and their perception of its usefulness, usability, etc. A sample of 430 surveys were collected for this study. Results found that all the models (TAM, TPB, and UTAUT) can explain driver acceptance with their proposed sets of factors, each explaining 71% or more of the variability in Behavioral Intention. Among the models, TAM was found to perform the best in modelling driver acceptance followed by TPB. The findings of this study confirm that these models can be applied to ADAS technologies and that they provide a basis for understanding driver acceptance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Simulated Driving Assessment (SDA) for teen drivers: results from a validation study.

PubMed

McDonald, Catherine C; Kandadai, Venk; Loeb, Helen; Seacrist, Thomas S; Lee, Yi-Ching; Winston, Zachary; Winston, Flaura K

2015-06-01

Driver error and inadequate skill are common critical reasons for novice teen driver crashes, yet few validated, standardised assessments of teen driving skills exist. The purpose of this study is to evaluate the construct and criterion validity of a newly developed Simulated Driving Assessment (SDA) for novice teen drivers. The SDA's 35 min simulated drive incorporates 22 variations of the most common teen driver crash configurations. Driving performance was compared for 21 inexperienced teens (age 16-17 years, provisional license ≤90 days) and 17 experienced adults (age 25-50 years, license ≥5 years, drove ≥100 miles per week, no collisions or moving violations ≤3 years). SDA driving performance (Error Score) was based on driving safety measures derived from simulator and eye-tracking data. Negative driving outcomes included simulated collisions or run-off-the-road incidents. A professional driving evaluator/instructor (DEI Score) reviewed videos of SDA performance. The SDA demonstrated construct validity: (1) teens had a higher Error Score than adults (30 vs. 13, p=0.02); (2) For each additional error committed, the RR of a participant's propensity for a simulated negative driving outcome increased by 8% (95% CI 1.05 to 1.10, p<0.01). The SDA-demonstrated criterion validity: Error Score was correlated with DEI Score (r=-0.66, p<0.001). This study supports the concept of validated simulated driving tests like the SDA to assess novice driver skill in complex and hazardous driving scenarios. The SDA, as a standard protocol to evaluate teen driver performance, has the potential to facilitate screening and assessment of teen driving readiness and could be used to guide targeted skill training. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Real-time driver drowsiness feedback improves driver alertness and self-reported driving performance.

PubMed

Aidman, Eugene; Chadunow, Carolyn; Johnson, Kayla; Reece, John

2015-08-01

Driver drowsiness has been implicated as a major causal factor in road accidents. Tools that allow remote monitoring and management of driver fatigue are used in the mining and road transport industries. Increasing drivers' own awareness of their drowsiness levels using such tools may also reduce risk of accidents. The study examined the effects of real-time blink-velocity-derived drowsiness feedback on driver performance and levels of alertness in a military setting. A sample of 15 Army Reserve personnel (1 female) aged 21-59 (M=41.3, SD=11.1) volunteered to being monitored by an infra-red oculography-based Optalert Alertness Monitoring System (OAMS) while they performed their regular driving tasks, including on-duty tasks and commuting to and from duty, for a continuous period of 4-8 weeks. For approximately half that period, blink-velocity-derived Johns Drowsiness Scale (JDS) scores were fed back to the driver in a counterbalanced repeated-measures design, resulting in a total of 419 driving periods under "feedback" and 385 periods under "no-feedback" condition. Overall, the provision of real-time feedback resulted in reduced drowsiness (lower JDS scores) and improved alertness and driving performance ratings. The effect was small and varied across the 24-h circadian cycle but it remained robust after controlling for time of day and driving task duration. Both the number of JDS peaks counted for each trip and their duration declined in the presence of drowsiness feedback, indicating a dynamic pattern that is consistent with a genuine, entropy-reducing feedback mechanism (as distinct from random re-alerting) behind the observed effect. Its mechanisms and practical utility have yet to be fully explored. Direct examination of the alternative, random re-alerting explanation of this feedback effect is an important step for future research. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Measuring "Progress": Performativity as Both Driver and Constraint in School Innovation

ERIC Educational Resources Information Center

Solomon, Yvette; Lewin, Cathy

2016-01-01

In this paper, we describe one secondary school's radical attempt to rethink the shape and purpose of education for its pupils, and its subsequent return to more traditional methods in the face of pressures of performativity and accountability. Framing our analysis within activity theory and its emphasis on contradiction as a driver for change, we…

Prediction of fatigue-related driver performance from EEG data by deep Riemannian model.

PubMed

Hajinoroozi, Mehdi; Jianqiu Zhang; Yufei Huang

2017-07-01

Prediction of the drivers' drowsy and alert states is important for safety purposes. The prediction of drivers' drowsy and alert states from electroencephalography (EEG) using shallow and deep Riemannian methods is presented. For shallow Riemannian methods, the minimum distance to Riemannian mean (mdm) and Log-Euclidian metric are investigated, where it is shown that Log-Euclidian metric outperforms the mdm algorithm. In addition the SPDNet, a deep Riemannian model, that takes the EEG covariance matrix as the input is investigated. It is shown that SPDNet outperforms all tested shallow and deep classification methods. Performance of SPDNet is 6.02% and 2.86% higher than the best performance by the conventional Euclidian classifiers and shallow Riemannian models, respectively.

Description and operating performance of a parallel-rail electric-arc system with helium driver gas for the Langley 6-inch expansion tube

NASA Technical Reports Server (NTRS)

Moore, J. A.

1976-01-01

A parallel-rail arc-discharge system to heat and pressurize the initial helium driver gas of the Langley 6-inch expansion tube is described. This system was designed for a 2.44-m-long driver vessel rated at 138 MPa, with a distance between rails of 20.3 cm. Electric energy was obtained from a capacitor storage system rated at 12,000 V with a maximum energy of 5 MJ. Tests were performed over a range of energy from 1.74 MJ to the maximum value. The operating experience and system performance are discussed, along with results from a limited number of expansion-tube tests with air and carbon dioxide as test gases.

A wireless handheld probe with spectrally constrained evolution strategies for diffuse optical imaging of tissue

NASA Astrophysics Data System (ADS)

Flexman, M. L.; Kim, H. K.; Stoll, R.; Khalil, M. A.; Fong, C. J.; Hielscher, A. H.

2012-03-01

We present a low-cost, portable, wireless diffuse optical imaging device. The handheld device is fast, portable, and can be applied to a wide range of both static and dynamic imaging applications including breast cancer, functional brain imaging, and peripheral artery disease. The continuous-wave probe has four near-infrared wavelengths and uses digital detection techniques to perform measurements at 2.3 Hz. Using a multispectral evolution algorithm for chromophore reconstruction, we can measure absolute oxygenated and deoxygenated hemoglobin concentration as well as scattering in tissue. Performance of the device is demonstrated using a series of liquid phantoms comprised of Intralipid®, ink, and dye.

Evaluation of a new portable glucose meter designed for the use in cats.

PubMed

Zini, E; Moretti, S; Tschuor, F; Reusch, C E

2009-09-01

Portable blood glucose meters (PBGMs) are useful in the management of diabetes mellitus in cats. In the present study we compared the performance of two PBGMs: the AlphaTRAK (Abbott Animal Health, Maidenhead, England) specifically developed for dogs and cats, and the Ascensia ELITE (Bayer HealthCare, Zurich, Switzerland) developed for humans. Quality parameters, including precision and accuracy, were better for the AlphaTRAK meter compared to Ascensia ELITE. While the AlphaTRAK meter results did not differ from the reference method, results from the Ascensia ELITE were significantly (P<0.001) lower. The superior performance of the AlphaTRAK meter supports its use to monitor blood glucose levels in cats.

Detection of indoor biological hazards using the man-portable laser induced breakdown spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Munson, Chase A.; Gottfried, Jennifer L.; Snyder, Emily Gibb

2008-11-01

The performance of a man-portable laser induced breakdown spectrometer was evaluated for the detection of biological powders on indoor office surfaces and wipe materials. Identification of pure unknown powders was performed by comparing against a library of spectra containing biological agent surrogates and confusant materials, such as dusts, diesel soot, natural and artificial sweeteners, and drink powders, using linear correlation analysis. Simple models constructed using a second technique, partial least squares discriminant analysis, successfully identified Bacillus subtilis (BG) spores on wipe materials and office surfaces. Furthermore, these models were able to identify BG on materials not used in the trainingmore » of the model.« less

How star women build portable skills.

PubMed

Groysberg, Boris

2008-02-01

In May 2004, with the war for talent in high gear, Groysberg and colleagues from Harvard Business School wrote in these pages about the risks of hiring star performers away from competitors. After studying the fortunes of more than 1,000 star stock analysts, they found that when a star switched companies, not only did his performance plunge, so did the effectiveness of the group he joined and the market value of his new company. But further analysis of the data reveals that it's not that simple. In fact, one group of analysts reliably maintained star rankings even after changing employers: women. Unlike their male counterparts, female stars who switched firms performed just as well, in the aggregate, as those who stayed put. The 189 star women in the sample (18% of the star analysts studied) achieved a higher rank after switching firms than the men did. Why the discrepancy? First, says the author, the best female analysts appear to have built their franchises on portable, external relationships with clients and the companies they covered, rather than on relationships rooted within their firms. By contrast, male analysts built up greater firm- and team-specific human capital by investing more in the internal networks and unique capabilities and resources of their own companies. Second, women took greater care when assessing a prospective new employer. In this article, Groysberg explores the reasons behind the star women's portable performance.

Portable oil bath for high-accuracy resistance transfer and maintenance

NASA Astrophysics Data System (ADS)

Shiota, Fuyuhiko

1999-10-01

A portable oil bath containing one standard resistor for high-accuracy resistance transfer and maintenance was developed and operated for seven years in the National Research Laboratory of Metrology. The aim of the bath is to save labor and apparatus for high-accuracy resistance transfer and maintenance by consistently keeping the standard resistor in an optimum environmental condition. The details of the prototype system, including its performance, are described together with some suggestions for a more practical bath design, which adopts the same concept.

Solar Photovoltaic Technology Assessment for Soldier-Portable and Mobile Power

DTIC Science & Technology

2010-06-16

S ol di er -P or ta bl e an d M ob ile P ow er Solar Photovoltaic Technology Assessment for Soldier-Portable and Mobile Power Cao Chung, US...21005 DESTRUCTION NOTICE- Destroy by any method that will prevent disclosure of contents or reconstruction of the document. PTAE - TR – 10 – 01...NUMBER 6. AUTHOR( S ) Cao Chung 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) U.S

Exploring microdischarges for portable sensing applications.

PubMed

Gianchandani, Y B; Wright, S A; Eun, C K; Wilson, C G; Mitra, B

2009-10-01

This paper describes the use of microdischarges as transducing elements in sensors and detectors. Chemical and physical sensing of gases, chemical sensing of liquids, and radiation detection are described. These applications are explored from the perspective of their use in portable microsystems, with emphasis on compactness, power consumption, the ability to operate at or near atmospheric pressure (to reduce pumping challenges), and the ability to operate in an air ambient (to reduce the need for reservoirs of carrier gases). Manufacturing methods and performance results are described for selected examples.

Variable-focus liquid lens for portable applications

NASA Astrophysics Data System (ADS)

Kuiper, Stein; Hendriks, Benno H.; Huijbregts, Laura J.; Hirschberg, A. Mico; Renders, Christel A.; van As, Marco A.

2004-10-01

The meniscus between two immiscible liquids can be used as an optical lens. A change in curvature of this meniscus by electrowetting leads to a change in focal distance. We demonstrate that two liquids in a tube form a self-centered tunable lens of high optical quality. Several properties were studied, such as optical performance, electrical characteristics and dynamic behavior. We designed and constructed a miniature camera module based on this tunable lens and show that it is very well suited for use in portable applications.

A flexible system for vital signs monitoring in hospital general care wards based on the integration of UNIX-based workstations, standard networks and portable vital signs monitors.

PubMed

Welch, J P; Sims, N; Ford-Carlton, P; Moon, J B; West, K; Honore, G; Colquitt, N

1991-01-01

The article describes a study conducted on general surgical and thoracic surgical floors of a 1000-bed hospital to assess the impact of a new network for portable patient care devices. This network was developed to address the needs of hospital patients who need constant, multi-parameter, vital signs surveillance, but do not require intensive nursing care. Bedside wall jacks were linked to UNIX-based workstations using standard digital network hardware, creating a flexible system (for general care floors of the hospital) that allowed the number of monitored locations to increase and decrease as patient census and acuity levels varied. It also allowed the general care floors to provide immediate, centralized vital signs monitoring for patients who unexpectedly became unstable, and permitted portable monitors to travel with patients as they were transferred between hospital departments. A disk-based log within the workstation automatically collected performance data, including patient demographics, monitor alarms, and network status for analysis. The log has allowed the developers to evaluate the use and performance of the system.

Application of handheld and portable spectrometers for screening acrylamide content in commercial potato chips.

PubMed

Ayvaz, Huseyin; Rodriguez-Saona, Luis E

2015-05-01

The most common methods for acrylamide analysis in foods require the use of LC-MS/MS and GC-MS. Although these methods have great analytical performance, they need intensive sample preparation, highly specialised instrumentation, and are time consuming. In this study, portable and handheld infrared spectrometers were evaluated as rapid methods for screening acrylamide in potato chips and their performances were compared to those of benchtop infrared systems. The acrylamide content of 64 commercial potato chips (169-2453 μg/kg) was determined by LC-MS/MS. Spectral data were collected using mid-infrared (MIR) and near-infrared (NIR) spectrometers. Partial least squares regression (PLSR) calibration models were developed to predict acrylamide levels. Overall, good linear correlation was found between the predicted acrylamide levels and actual measured acrylamide concentrations by LC-MS/MS (rPred > 0.90 and SEP < 100 μg/kg). Our results indicate that portable and handheld spectrometers can be used as simple and rapid alternatives for acrylamide analysis in potato chips. Copyright © 2014 Elsevier Ltd. All rights reserved.

Portable mini-chamber for temperature dependent studies using small angle and wide angle x-ray scattering

NASA Astrophysics Data System (ADS)

Dev, Arun Singh; Kumar, Dileep; Potdar, Satish; Pandit, Pallavi; Roth, Stephan V.; Gupta, Ajay

2018-04-01

The present work describes the design and performance of a vacuum compatible portable mini chamber for temperature dependent GISAXS and GIWAXS studies of thin films and multilayer structures. The water cooled body of the chamber allows sample annealing up to 900 K using ultra high vacuum compatible (UHV) pyrolytic boron nitride heater, thus making it possible to study the temperature dependent evolution of structure and morphology of two-dimensional nanostructured materials. Due to its light weight and small size, the chamber is portable and can be accommodated at synchrotron facilities worldwide. A systematic illustration of the versatility of the chamber has been demonstrated at beamline P03, PETRA-III, DESY, Hamburg, Germany. Temperature dependent grazing incidence small angle x-ray scattering (GISAXS) and grazing incidence wide angle x-ray scattering (GIWAXS) measurements were performed on oblique angle deposited Co/Ag multilayer structure, which jointly revealed that the surface diffusion in Co columns in Co/Ag multilayer enhances by increasing temperature from RT to ˜573 K. This results in a morphology change from columnar tilted structure to densely packed morphological isotropic multilayer.

Exposure to particles and nitrogen dioxide among taxi, bus and lorry drivers.

PubMed

Lewné, Marie; Nise, Gun; Lind, Marie-Louise; Gustavsson, Per

2006-03-01

The aims of this study have been to investigate the occurrence of systematic differences in the personal exposure to motor exhaust between different groups of taxi, bus and lorry drivers, and to study if these are influenced by the choice of exposure indicator. We used one indicator of the gaseous phase, nitrogen dioxide (NO(2)), and one of the particle phase (measured by DataRAM), of the exhausts. A total of 121 drivers were included in the study: 39 taxi drivers, 42 bus drivers and 40 lorry drivers. Personal measurements were performed during one working day. Nitrogen dioxide was measured with passive diffusive samplers and particles with Data-RAM, a logging instrument using nephelometric monitoring. The instrument measures particles between 0.1 and 10 microm in size. The average exposure to NO(2) for lorry drivers was 68 microg/m(3); for bus drivers 60 microg/m(3) and for taxi drivers 48 microg/m(3). For particles the exposure was 57 microg/m(3) for lorry drivers, 44 microg/m(3) for bus drivers and 26 microg/m(3) for taxi drivers. The result remained unchanged when exposures were adjusted for variation in urban background levels of NO(2) and particulate matter with an aerodynamic diameter <10 microm (PM(10)). Lorry drivers experienced the highest exposure and taxi drivers the lowest with bus drivers in an intermediate position, regardless of whether NO(2) or particles were used as exposure indicator. The levels of both NO(2) and particles were higher for bus drivers in the city than for them driving in the suburbs. Using diesel or petrol as a fuel for taxis had no influence on the exposure for the drivers, indicating that the taxi drivers' exposure mainly depends on exhaust from surrounding traffic.

Neurocognitive Correlates of Young Drivers' Performance in a Driving Simulator.

PubMed

Guinosso, Stephanie A; Johnson, Sara B; Schultheis, Maria T; Graefe, Anna C; Bishai, David M

2016-04-01

Differences in neurocognitive functioning may contribute to driving performance among young drivers. However, few studies have examined this relation. This pilot study investigated whether common neurocognitive measures were associated with driving performance among young drivers in a driving simulator. Young drivers (19.8 years (standard deviation [SD] = 1.9; N = 74)) participated in a battery of neurocognitive assessments measuring general intellectual capacity (Full-Scale Intelligence Quotient, FSIQ) and executive functioning, including the Stroop Color-Word Test (cognitive inhibition), Wisconsin Card Sort Test-64 (cognitive flexibility), and Attention Network Task (alerting, orienting, and executive attention). Participants then drove in a simulated vehicle under two conditions-a baseline and driving challenge. During the driving challenge, participants completed a verbal working memory task to increase demand on executive attention. Multiple regression models were used to evaluate the relations between the neurocognitive measures and driving performance under the two conditions. FSIQ, cognitive inhibition, and alerting were associated with better driving performance at baseline. FSIQ and cognitive inhibition were also associated with better driving performance during the verbal challenge. Measures of cognitive flexibility, orienting, and conflict executive control were not associated with driving performance under either condition. FSIQ and, to some extent, measures of executive function are associated with driving performance in a driving simulator. Further research is needed to determine if executive function is associated with more advanced driving performance under conditions that demand greater cognitive load. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

DriveID: safety innovation through individuation.

PubMed

Sawyer, Ben; Teo, Grace; Mouloua, Mustapha

2012-01-01

The driving task is highly complex and places considerable perceptual, physical and cognitive demands on the driver. As driving is fundamentally an information processing activity, distracted or impaired drivers have diminished safety margins compared with non- distracted drivers (Hancock and Parasuraman, 1992; TRB 1998 a & b). This competition for sensory and decision making capacities can lead to failures that cost lives. Some groups, teens and elderly drivers for example, have patterns of systematically poor perceptual, physical and cognitive performance while driving. Although there are technologies developed to aid these different drivers, these systems are often misused and underutilized. The DriveID project aims to design and develop a passive, automated face identification system capable of robustly identifying the driver of the vehicle, retrieve a stored profile, and intelligently prescribing specific accident prevention systems and driving environment customizations.

Driving cessation and increased depressive symptoms.

PubMed

Ragland, David R; Satariano, William A; MacLeod, Kara E

2005-03-01

To understand the consequences of driving cessation in older adults, the authors evaluated depression in former drivers compared with active drivers. Depression (as assessed using the Center for Epidemiological Studies Depression Scale), driving status, sociodemographic factors, health status, and cognitive function were evaluated for a cohort of 1953 residents of Sonoma County, California, aged 55 years and older, as part of a community-based study of aging and physical performance. The authors re-interviewed 1772 participants who were active drivers at baseline 3 years later. At baseline, former drivers reported higher levels of depression than did active drivers even after the authors controlled for age, sex, education, health, and marital status. In a longitudinal analysis, drivers who stopped driving during the 3-year interval (i.e., former drivers) reported higher levels of depressive symptoms than did those who remained active drivers, after the authors controlled for changes in health status and cognitive function. Increased depression for former drivers was substantially higher in men than in women. With increasing age, many older adults reduce and then stop driving. Increased depression may be among the consequences associated with driving reduction or cessation.

[Reliability and validity of Driving Anger Scale in professional drivers in China].

PubMed

Li, Z; Yang, Y M; Zhang, C; Li, Y; Hu, J; Gao, L W; Zhou, Y X; Zhang, X J

2017-11-10

Objective: To assess the reliability and validity of the Chinese version of Driving Anger Scale (DAS) in professional drivers in China and provide a scientific basis for the application of the scale in drivers in China. Methods: Professional drivers, including taxi drivers, bus drivers, truck drivers and school bus drivers, were selected to complete the questionnaire. Cronbach's α and split-half reliability were calculated to evaluate the reliability of DAS, and content, contract, discriminant and convergent validity were performed to measure the validity of the scale. Results: The overall Cronbach's α of DAS was 0.934 and the split-half reliability was 0.874. The correlation coefficient of each subscale with the total scale was 0.639-0.922. The simplified version of DAS supported a presupposed six-factor structure, explaining 56.371% of the total variance revealed by exploratory factor analysis. The DAS had good convergent and discriminant validity, with the success rate of calibration experiment of 100%. Conclusion: DAS has a good reliability and validity in professional drivers in China, and the use of DAS is worth promoting in divers.

Driver's Enhanced Vision System (DEVS)

DOT National Transportation Integrated Search

1996-12-23

This advisory circular (AC) contains performance standards, specifications, and : recommendations for Drivers Enhanced Vision sSystem (DEVS). The FAA recommends : the use of the guidance in this publication for the design and installation of : DEVS e...

77 FR 24247 - Privacy Act of 1974; System of Records Notice

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-23

... competence and performance in evaluating the CMV driver health and fitness and to detect irregularities in... CMV driver health and fitness and to detect irregularities in examination procedures. Certified...

Live stop-controlled intersection data collection.

DOT National Transportation Integrated Search

2007-01-01

This report describes an experimental investigation performed at live intersections to gather infrastructure-based naturalistic driver approach behavior data. This data was collected and analyzed with the goal of understanding how drivers approach in...

Individual differences in cognitive functioning predict effectiveness of a heads-up Lane Departure Warning for younger and older drivers

PubMed Central

Aksan, Nazan; Sager, Lauren; Hacker, Sarah; Lester, Benjamin; Dawson, Jeffrey; Rizzo, Matthew; Ebe, Kazutoshi; Foley, James

2016-01-01

The effectiveness of an idealized lane departure warning (LDW) was evaluated in an interactive fixed base driving simulator. Thirty-eight older (mean age = 77 years) and 40 younger drivers (mean age = 35 years) took four different drives/routes similar in road culture composition and hazards encountered with and without LDW. The four drives were administered over visits separated approximately by two weeks to examine changes in long-term effectiveness of LDW. Performance metrics were number of LDW activations and average correction time to each LDW. LDW reduced correction time to re-center the vehicle by 1.34 seconds on average (95% CI = 1.12–1.57 seconds) but did not reduce the number of times the drivers drifted enough in their lanes to activate the system (LDW activations). The magnitude of reductions in average correction RT was similar for older and younger drivers and did not change with repeated exposures across visits. The contribution of individual differences in basic visual and motor function, as well as cognitive function to safety gains from LDW was also examined. Cognitive speed of processing predicted lane keeping performance for older and younger drivers. Differences in memory, visuospatial construction, and executive function tended to predict performance differences among older but not younger drivers. Cognitive functioning did not predict changes in the magnitude of safety benefits from LDW over time. Implications are discussed with respect to real-world safety systems. PMID:27898370