Effectiveness of Green Warning Lights with Different Flashing Patterns for Winter Maintenance Operations

2021 ◽  
pp. 036119812110081
Author(s):  
Fatemeh Fakhrmoosavi ◽  
Ramin Saedi ◽  
Farish Jazlan ◽  
Ali Zockaie ◽  
Mehrnaz Ghamami ◽  
...  
Keyword(s):  
Human Subjects ◽  
Test Results ◽  
Night Time ◽  
Winter Maintenance ◽  
Warning Light ◽  
Rigorous Study ◽  
Static Versus Dynamic ◽  
Color Combinations ◽  
Warning Lights ◽  
Pavement Friction

Snow removal activities are performed by roadway agencies to enhance winter mobility and safety. Slower travel speeds during these operations, combined with low visibility and reduced pavement friction, mean that safety and collision avoidance remain a persistent concern. Many studies have implemented signing and lighting technologies to improve the visibility of snowplows. Although a few studies have evaluated the use of different colors on snowplows, there is no rigorous study that evaluates the potential impacts of using green warning lights for winter maintenance operations. This study, therefore, investigates the impacts of various warning light configurations on the visibility of snowplows, with the focus on green lights. To this end, 37 warning light configurations are designed using various color combinations (green and amber), and flashing patterns (single and quad) on the back (LED), the top (beacon), or both, of snowplows. These configurations are evaluated to identify the most effective configurations. Three sets of experiments are designed and implemented: static, dynamic, and weather to evaluate the visibility effectiveness in different contexts: day versus night, clear versus snowy weather, and static versus dynamic scenarios. Human subjects are employed to conduct the experiments and the test results are evaluated using statistical analyses. The conspicuity during the day time and glare during the night time are statistically different among various configurations. In addition, adding green lights with a single flash pattern to amber warning lights improves the conspicuity, while keeping the glare at an acceptable level relative to configurations using only amber.

Behavioral Analysis of Drivers Following Winter Maintenance Trucks Enabled with Collision Avoidance System

2019 ◽  
Vol 2673 (10) ◽  
pp. 394-404
Author(s):  
Rajat Verma ◽  
Ramin Saedi ◽  
Ali Zockaie ◽  
Timothy J. Gates
Keyword(s):  
Collision Avoidance ◽  
Traffic Safety ◽  
Response Times ◽  
Regression Tree ◽  
Field Testing ◽  
Operating Conditions ◽  
Classification And Regression Tree ◽  
Crash Risk ◽  
Winter Maintenance ◽  
Warning Light

Winter maintenance trucks (WMTs) often operate at lower speeds during inclement weather and roadway conditions, creating potential safety issues for motorists following close behind. In this study, a new prototype radar-based rear-end collision avoidance and mitigation system (CAMS) was tested to assess its impact on the behavior of drivers following WMTs. The system is designed to flash an auxiliary rear-facing warning light upon detection of a vehicle encroaching within an unsafe relative headway with the rear of the WMT. A series of field evaluations was performed during actual winter maintenance operations to assess the effectiveness of the system compared with normal operating conditions (i.e., without the CAMS warning light) toward improving driver behavior related to rear-end crash risk. Specifically, two measures were assessed: (a) rate of vehicles encroaching beyond a safe time headway threshold to the rear of the WMT, and (b) the reaction–response time of drivers. Classification and regression tree models were created for identifying the relevant factors influential in determining the change in driver response. The results indicate that this warning light was effective in reducing the likelihood of the subject drivers crossing beyond a relative headway of 4.5 s. It was also effective in reducing the reaction and response times of the drivers by 0.83 and 0.55 s (36% and 20% reduction), respectively. Although the results were encouraging, additional field testing is recommended before conclusions are drawn regarding the traffic safety impacts of the system.

Special Flashing Warning Lights for Construction, Maintenance, and Service Vehicles: Are Amber Beacons Always Enough?

2000 ◽  
Vol 1715 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Gerald L. Ullman
Keyword(s):  
Blue Light ◽  
San Antonio ◽  
Field Studies ◽  
Fort Worth ◽  
Amber Light ◽  
Warning Light ◽  
Texas Department ◽  
Color Combinations ◽  
Light Color ◽  
Traffic Behavior

Ways to improve the Texas Department of Transportation’s (TxDOT’s) current vehicle warning light policy were researched. Tasks included a survey of motorist perceptions of different warning light color combinations and also field studies of the effect of selected color combinations on traffic behavior. The motorist survey, conducted at driver licensing stations in Dallas–Fort Worth, San Antonio, and Houston, indicated that the combination of blue and amber lights implied a slightly greater sense of hazard to motorists than did the amber light alone. However, this greater sense of hazard did not necessarily translate into differences in how motorists believed they needed to respond. Field studies conducted at freeway locations in San Antonio and Houston investigated the effect of selected, alternative vehicle warning-light color combinations on vehicle speeds, lane choice, and braking activity. Researchers found significant reductions in speeds at a few sites—but not all—for the amber and blue warning light color combination when compared with speeds observed when only an amber warning light was used. In addition, the data suggested a trend toward increased brake usage for the red, amber, and blue light configuration compared with the amber-light-only configuration. There also was evidence that the amber-and-blue light configuration slightly increased the frequency of brake applications. Furthermore, the use of a law enforcement vehicle during testing resulted in significantly more brake-light activations than did a TxDOT courtesy patrol vehicle outfitted with the same warning light colors.

scholarly journals AZD5213: a novel histamine H3 receptor antagonist permitting high daytime and low nocturnal H3 receptor occupancy, a PET study in human subjects

2013 ◽  
Vol 16 (6) ◽  
pp. 1231-1239 ◽  
Author(s):  
Aurelija Jucaite ◽  
Akihiro Takano ◽  
Emma Boström ◽  
Karl-Gustav Jostell ◽  
Per Stenkrona ◽  
...  
Keyword(s):  
Time Course ◽  
Human Subjects ◽  
Plasma Concentrations ◽  
Receptor Occupancy ◽  
Pharmacokinetic Profile ◽  
Affinity Constant ◽  
Night Time ◽  
Histamine H3 Receptor ◽  
H3 Receptor ◽  
Histamine H3

AbstractThe histamine H3 receptor represents an appealing central nervous system drug target due to its important role in the neurobiology of cognition and wake-sleep regulation. The therapeutic benefit of H3 antagonists/inverse agonists may be hampered by disruption of sleep that has been observed in humans with prolonged high H3 receptor occupancy (H3RO), extending into night-time. AZD5213 is a highly selective H3 antagonist (in vitro inverse agonist) developed to achieve a pharmacokinetic profile permitting circadian fluctuations of H3RO. Its efficacy has been demonstrated in rodent behavioural models of cognition. In human subjects, AZD5213 was safe and well tolerated following repeated doses (1–14 mg/d) and demonstrated a short (∼5 h) half-life. In this PET study H3RO was measured using the radioligand [11C]GSK189254 ([11C]AZ12807110) in seven young male volunteers following single doses of AZD5213 (0.05–30 mg). H3RO was calculated using the Lassen plot method. The plasma concentrations and the affinity constant (Ki,pl 1.14 nmol/l, corresponding to the plasma concentration required to occupy 50% of available receptors) were used to estimate the H3RO time-course. AZD5213 showed dose and concentration dependent H3RO ranging from 16 to 90%. These binding characteristics and the pharmacokinetic profile of AZD5213 indicate that high daytime and low night-time H3RO could be achieved following once daily oral dosing of AZD5213. Fluctuations of H3RO following circadian rhythm of the histamine system may be expected to reduce the risk of sleep disruption while maintaining daytime efficacy. AZD5213 may thus be an optimal compound to evaluate the clinical benefit of selective H3 antagonism in cognitive disorders.

“Reverse” Stroop Effect in the Performance of Schizophrenics

1983 ◽  
Vol 56 (1) ◽  
pp. 99-106 ◽  
Author(s):  
Rudolf R. Abramczyk ◽  
Donald E. Jordan ◽  
Mark Hegel
Keyword(s):  
Stroop Effect ◽  
Group Performance ◽  
Color Word ◽  
Control Group ◽  
Test Results ◽  
Reverse Effect ◽  
Control Data ◽  
Interference Test ◽  
Schizophrenic Patients ◽  
Color Combinations

The hypothesis was tested that a group of 30 schizophrenic in contrast to a control group of 35 non-schizophrenic patients would demonstrate substantial and significantly more “Reverse” interference in reading incongruent word-color combinations on the Stroop Color-Word Interference Test. Results supported the hypothesis. A “reverse” interference of 19% and of 9% was observed in the groups' performances, respectively. The group performance differences were much larger on both the classical “Stroop” and “Reverse” interference tasks than on corresponding non-interference tasks. But these interactions were not statistically significant. Measures of absolute and proportional performance decrements on the interference tasks showed no correlations between “Stroop” and “Reverse” interference. Issues discussed included impaired selective attention in schizophrenics' performance, the unexpected high “Reverse” effect in control data and the psychodiagnostic applications of reverse interference.

scholarly journals “Visual Affluence” in Social Photography: Applicability of Image Segmentation as a Visually Oriented Approach to Study Instagram Hashtags

2020 ◽  
Vol 6 (2) ◽  
pp. 205630512092475
Author(s):  
Chamil Rathnayake ◽  
Irida Ntalla
Keyword(s):  
Image Segmentation ◽  
Visual Imagery ◽  
Hybrid Methods ◽  
Test Results ◽  
Visual Content ◽  
Visual Attributes ◽  
Micro Level ◽  
Social Markers ◽  
Color Combinations ◽  
Oriented Approach

The aim of the study is to examine the applicability of image segmentation—identification of objects/regions by partitioning images—to examine online social photography. We argue that the need for a meaning-independent reading of online social photography within social markers, such as hashtags, arises due to two characteristics of social photography: (1) internal incongruence resulting from user-driven construction and (2) variability of content in terms of visual attributes, such as color combinations, brightness, and details in backgrounds. We suggest visual affluence—plenitude of visual stimuli, such as objects and surfaces containing a variety of color regions, present in visual imagery—as a basis for classifying visual content and image segmentation as a technique to measure affluence. We demonstrate that images containing objects with complex texture and background patterns are more affluent, while images that include blurry backgrounds are less affluent than others. Moreover, images that contain letters and dark, single-color backgrounds are less affluent than images that include subtle shades. Mann–Whitney U test results for ten pairs of hashtags showed that eight pairs had significant differences in visual affluence. The proposed measure can be used to encourage a “visually oriented” turn in online social photography research that can benefit from hybrid methods that are able to extrapolate micro-level findings to macro-level effects.

Warning Light Flash Frequency as a Method for Visual Communication to Drivers

2021 ◽  
pp. 036119812098332
Author(s):  
Nicholas P. Skinner ◽  
Timothy T. LaPlumm ◽  
John D. Bullough
Keyword(s):  
Laboratory Study ◽  
Visual Communication ◽  
Light Flash ◽  
Work Zone ◽  
Warning Light ◽  
Potential Risks ◽  
Photosensitive Epilepsy ◽  
Warning Lights ◽  
Service Vehicles

Service vehicles use flashing warning lights to indicate their presence to approaching drivers. Present standards offer ranges of flash frequencies to enhance conspicuity and avoid potential risks of photosensitive epilepsy or other issues. But, in practice, the flash frequency is not varied in specific situations. Previous studies have indicated that people interpret faster flash frequencies as more “urgent” than slower flash frequencies. Building on these findings, a laboratory study was conducted to identify whether drivers might be able to use cues from the frequency of flashing warning lights to anticipate how a service vehicle might behave in a work zone or other incident scene. The results suggest that even if they are not taught about the interpretation of different flash frequencies, drivers can differentiate between 1 Hz and 4 Hz flashing lights and learn to make accurate predictions about their meaning. The results also indicate that there are no reliable differences between 1 Hz and 4 Hz flashing in relation to a driver’s ability to detect when a service vehicle has begun to move. Based on the results, a preliminary suggestion is made to use lights flashing at 1 Hz when a service vehicle is moving forward, and 4 Hz when it is traveling in reverse.

scholarly journals Flight Parameter Display System For The Mi-17 Helicopter – Test Results

2015 ◽  
Vol 36 (1) ◽  
pp. 47-62
Author(s):  
Grzegorz Bęczkowski ◽  
Jarosław Krzonkalla ◽  
Maj Mordzonek ◽  
Stanisław Rymaszewski ◽  
Franciszek Zgrzywa
Keyword(s):  
Air Force ◽  
Night Vision ◽  
Test Results ◽  
Display System ◽  
Night Time ◽  
Flight Tests ◽  
Technical Requirements ◽  
Flight Parameters ◽  
Main Components ◽  
And Function

AbstractThis article presents flight tests of a newly developed Helmet-Mounted Flight Parameters Display System (SWPL). Presented system is designed to illustrate full piloting and navigational information, warning about emergency on the helicopter’s board and signaling on-board helicopter systems failures on the translucent display. The system is designed to work in day and night time conditions. In night time conditions, the system cooperates with night vision goggles applicable in Polish Air Force. The article presents the main components of the tested system, along with their purpose and function. It also describes in detail the methods of display implemented in the system and the amount of displayed information. The article discusses the required range and the actual course of the flight tests of that system. Tests were conducted on a Mi-17-1V helicopter. The results of the flight tests of the Helmet-Mounted Display System are given in conclusion, in particular regarding meeting the tactical and technical requirements of the system.

scholarly journals Backstepping Control of Open-Chain Linkages Actuated by Antagonistic Hill Muscles

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Holly Warner ◽  
Hanz Richter ◽  
Antonie J. van den Bogert
Keyword(s):  
Inverse Dynamics ◽  
Human Subjects ◽  
Kinematic Chain ◽  
Test Results ◽  
Robotic Rehabilitation ◽  
Healthcare Applications ◽  
Human Machine Interaction ◽  
Open Chain ◽  
Prosthetic Devices ◽  
Machine Interaction

Abstract For human–machine interaction, the forward progression of technology, particularly controls, regularly brings about new possibilities. Indeed, healthcare applications have flourished in recent years, including robotic rehabilitation, exercise, and prosthetic devices. Testing these devices with human subjects is inherently risky and frequently inconsistent. This work offers a novel simulation framework toward overcoming many of these difficulties. Specifically, generating a closed-loop dynamic model of a human or a human subsystem that can connect to device simulations allows simulated human–machine interaction. In this work, a muscle-actuated open kinematic chain linkage is generated to simulate the human, and a backstepping controller based on inverse dynamics is derived. The control architecture directly addresses muscle redundancy, and two options to resolve this redundancy are evaluated. The specific case of a muscle-actuated arm linkage is developed to illustrate the framework. Trajectory tracking is achieved in simulation. The muscles recruited to meet the tracking goal are in agreement with the method used to solve the redundancy problem. In the future coupling such simulations to any relevant simulation of a machine will provide safe, insightful preprototype test results.

scholarly journals Toward the development of standards for yellow flashing lights used in work zones

2016 ◽  
Vol 50 (4) ◽  
pp. 552-570 ◽  
Author(s):  
MS Rea ◽  
JD Bullough ◽  
LC Radetsky ◽  
NP Skinner ◽  
A Bierman
Keyword(s):  
Field Study ◽  
Work Zone ◽  
Luminous Intensity ◽  
Work Zones ◽  
Driver Safety ◽  
Visual Discomfort ◽  
Directional Information ◽  
Warning Light ◽  
Warning Lights ◽  
Current Standards

Flashing yellow warning lights are important for worker and driver safety in work zones. Current standards for these lights do not address whether and how they should be coordinated to provide directional information to drivers navigating through work zones. A field study was conducted to assess driver responses to warning lights. The luminous intensities and flash patterns of warning lights along a simulated work zone were varied during daytime and nighttime. During the daytime, driver responses were relatively insensitive to warning light characteristics, although drivers preferred sequential and synchronised flash patterns over random, uncoordinated flashing. At nighttime, the combination of a temporal peak luminous intensity of 25 cd and a sequential flash pattern was optimal for providing directional information. A single initial warning light having a higher luminous intensity may help drivers detect the work zone without creating unacceptable visual discomfort.

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