Laparoendoscopic single site (LESS) in vivo suturing using a magnetic anchoring and guidance system (MAGS) camera in a porcine model: impact on ergonomics and workload.

PubMed

Yin, Gang; Han, Woong Kyu; Faddegon, Stephen; Tan, Yung Khan; Liu, Zhuo-Wei; Olweny, Ephrem O; Scott, Daniel J; Cadeddu, Jeffrey A

2013-01-01

To compare the ergonomics and workload of the surgeon during single-site suturing while using the magnetic anchoring and guidance system (MAGS) camera vs a conventional laparoscope. Seven urologic surgeons were enrolled and divided into an expert group (n=2) and a novice group (n=5) according to their laparoendoscopic single-site (LESS) experience. Each surgeon performed 2 conventional LESS and 2 MAGS camera-assisted LESS vesicostomy closures in a porcine model. A Likert scale (scoring 1-5) questionnaire assessing workload, ergonomics, technical difficulty, visualization, and needle handling, as well as a validated National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire were used to evaluate the tasks and workloads. MAGS LESS suturing was universally favored by expert and novice surgeons compared with conventional LESS in workload (3.4 vs 4.2), ergonomics (3.4 vs 4.4), technical challenge (3.3 vs 4.3), visualization (2.4 vs 3.3), and needle handling (3.1 vs 3.9 respectively; P<.05 for all categories). Surgeon NASA-TLX assessments found MAGS LESS suturing significantly decreased the workload in physical demand (P=.004), temporal demand (P=.017), and effort (P=.006). External instrument clashing was significantly reduced in MAGS LESS suturing (P<.001). The total operative time of MAGS LESS suturing was comparable to that of conventional LESS (P=.89). MAGS camera technology significantly decreased surgeon workload and improved ergonomics. Nevertheless, LESS suturing and knot tying remains a challenging task that requires training, regardless of which camera is used. Copyright © 2013 Elsevier Inc. All rights reserved.

Brain biomarkers based assessment of cognitive workload in pilots under various task demands.

PubMed

Gentili, Rodolphe J; Rietschel, Jeremy C; Jaquess, Kyle J; Lo, Li-Chuan; Prevost, Michael; Miller, Matt W; Mohler, Jessica M; Oh, Hyuk; Tan, Ying Ying; Hatfield, Bradley D

2014-01-01

Cognitive workload is an important element of cognitive-motor performance such as that exhibited during the piloting of an aircraft. Namely, an increase in task demands on the pilot can elevate cognitive information processing and, thus, the risk of human error. As such, there is a need to develop methods that reliably assess mental workload in pilots within operational settings. The present study contributes to this research goal by identifying physiological and brain biomarkers of cognitive workload and attentional reserve during a simulated aircraft piloting task under three progressive levels of challenge. A newly developed experimental method was employed by which electroencephalography (EEG) was acquired via a dry (i.e., gel-free sensors) system using few scalp sites. Self-reported responses to surveys and piloting performance indicators were analyzed. The findings revealed that as the challenge (task demands) increased, the perceived mental load increased, attentional reserve was attenuated, and task performance decreased. Such an increase in task demands was also reflected by changes in heart rate variability (HRV), as well as in the amplitude of the P300 component of event-related potentials to auditory probes, and in the spectral power of specific EEG frequency bands. This work provides a first step towards a long-term goal to develop a composite system of biomarkers for real-time cognitive workload assessment and state assessment of pilots in operational settings.

The workload book: Assessment of operator workload to engineering systems

NASA Technical Reports Server (NTRS)

Gopher, D.

1983-01-01

The structure and initial work performed toward the creation of a handbook for workload analysis directed at the operational community of engineers and human factors psychologists are described. The goal, when complete, will be to make accessible to such individuals the results of theoretically-based research that are of practical interest and utility in the analysis and prediction of operator workload in advanced and existing systems. In addition, the results of laboratory study focused on the development of a subjective rating technique for workload that is based on psychophysical scaling techniques are described.

Using Pair Wise Rankings in the Assessment of Adaptive Aiding

DTIC Science & Technology

2017-02-22

Aviation Psychology (ISAP) 9 – 11 May 2017 14. ABSTRACT In remotely piloted aircraft (RPA) operations, operator cognitive workload is an important concern...Force Research Laboratory Wright-Patterson AFB, Ohio In remotely piloted aircraft (RPA) operations, operator cognitive workload is an important...model in future research. Operator cognitive workload is an important concern in remotely piloted aircraft (RPA) operations. RPA use is

Voice measures of workload in the advanced flight deck: Additional studies

NASA Technical Reports Server (NTRS)

Schneider, Sid J.; Alpert, Murray

1989-01-01

These studies investigated acoustical analysis of the voice as a measure of workload in individual operators. In the first study, voice samples were recorded from a single operator during high, medium, and low workload conditions. Mean amplitude, frequency, syllable duration, and emphasis all tended to increase as workload increased. In the second study, NASA test pilots performed a laboratory task, and used a flight simulator under differing work conditions. For two of the pilots, high workload in the simulator brought about greater amplitude, peak duration, and stress. In both the laboratory and simulator tasks, high workload tended to be associated with more statistically significant drop-offs in the acoustical measures than were lower workload levels. There was a great deal of intra-subject variability in the acoustical measures. The results suggested that in individual operators, increased workload might be revealed by high initial amplitude and frequency, followed by rapid drop-offs over time.

[Effects of mental workload on work ability in primary and secondary school teachers].

PubMed

Xiao, Yuanmei; Li, Weijuan; Ren, Qingfeng; Ren, Xiaohui; Wang, Zhiming; Wang, Mianzhen; Lan, Yajia

2015-02-01

To investigate the change pattern of primary and secondary school teachers' work ability with the changes in their mental workload. A total of 901 primary and secondary school teachers were selected by random cluster sampling, and then their mental workload and work ability were assessed by National Aeronautics and Space Administration-Task Load Index (NASA-TLX) and Work Ability Index (WAI) questionnaires, whose reliability and validity had been tested. The effects of their mental workload on the work ability were analyzed. Primary and secondary school teachers' work ability reached the highest level at a certain level of mental workload (55.73< mental workload ≤ 64.10). When their mental workload was lower than the level, their work ability had a positive correlation with the mental workload. Their work ability increased or maintained stable with the increasing mental workload. Moreover, the percentage of teachers with good work ability increased, while that of teachers with moderate work ability decreased. But when their mental workload was higher than the level, their work ability had a negative correlation with the mental workload. Their work ability significantly decreased with the increasing mental workload (P < 0.01). Furthermore, the percentage of teachers with good work ability decreased, while that of teachers with moderate work ability increased (P < 0.001). Too high or low mental workload will result in the decline of primary and secondary school teachers' work ability. Moderate mental workload (55.73∼64.10) will benefit the maintaining and stabilization of their work ability.

NASA TLA workload analysis support. Volume 1: Detailed task scenarios for general aviation and metering and spacing studies

NASA Technical Reports Server (NTRS)

Sundstrom, J. L.

1980-01-01

The techniques required to produce and validate six detailed task timeline scenarios for crew workload studies are described. Specific emphasis is given to: general aviation single pilot instrument flight rules operations in a high density traffic area; fixed path metering and spacing operations; and comparative workload operation between the forward and aft-flight decks of the NASA terminal control vehicle. The validation efforts also provide a cursory examination of the resultant demand workload based on the operating procedures depicted in the detailed task scenarios.

Pilot workload, performance and aircraft control automation

NASA Technical Reports Server (NTRS)

Hart, S. G.; Sheridan, T. B.

1984-01-01

Conceptual and practical issues associated with the design, operation, and performance of advanced systems and the impact of such systems on the human operators are reviewed. The development of highly automated systems is driven by the availability of new technology and the requirement that operators safely and economically perform more and more activities in increasingly difficult and hostile environments. It is noted that the operators workload may become a major area of concern in future design considerations. Little research was done to determine how automation and workload relate to each other, although it is assumed that the abstract, supervisory, or management roles that are performed by operators of highly automated systems will impose increased mental workload. The relationship between performance and workload is discussed in relation to highly complex and automated environments.

The impact of intra-operative interruptions on surgeons' perceived workload: an observational study in elective general and orthopedic surgery.

PubMed

Weigl, Matthias; Antoniadis, Sophia; Chiapponi, Costanza; Bruns, Christiane; Sevdalis, Nick

2015-01-01

Surgeons' intra-operative workload is critical for effective and safe surgical performance. Detrimental conditions in the operating room (OR) environment may add to perceived workload and jeopardize surgical performance and outcomes. This study aims to evaluate the impact of different intra-operative workflow interruptions on surgeons' capacity to manage their workload safely and efficiently. This was an observational study of intra-operative interruptions and self-rated workload in two surgical specialties (general, orthopedic/trauma surgery). Intra-operative interruptions were assessed via expert observation using a well-validated observation tool. Surgeons, nurses, and anesthesiologists assessed their intra-operative workload directly after case completion based on three items of the validated Surgery Task Load Index (mental demand, situational stress, distraction). A total of 56 elective cases (35 open, 21 laparoscopic) with 94 workload ratings were included. Mean intra-operative duration was 1 h 37 min. Intra-operative interruptions were on average observed 9.78 times per hour. People who entered/exited the OR (30.6 %) as well as telephone-/beeper-related disruptions (23.6 %) occurred most often. Equipment and OR environment-related interruptions were associated with highest interference with team functioning particularly in laparoscopic procedures. After identifying task and procedural influences, partial correlational analyses revealed that case-irrelevant communications were negatively associated with surgeons' mental fatigue and situational stress, whereas surgeons' reported distraction was increased by case-irrelevant communication and procedural disruptions. OR nurses' and anesthesiologists' perceived workload was also related to intra-operative interruption events. Our study documents the unique contribution of different interruptions on surgeons' workload; whereas case-irrelevant communications may be beneficial for mental fatigue and stress in routine cases, procedural interruptions and case-irrelevant communication may contribute to surgeons' mental focus deteriorating. Well-designed OR environments, surgical leadership, and awareness can help to control unnecessary interruptions for effective and safe surgical care.

Levels of Information Processing in a Fitts law task (LIPFitts)

NASA Technical Reports Server (NTRS)

Mosier, K. L.; Hart, S. G.

1986-01-01

State-of-the-art flight technology has restructured the task of human operators, decreasing the need for physical and sensory resources, and increasing the quantity of cognitive effort required, changing it qualitatively. Recent technological advances have the most potential for impacting a pilot in two areas: performance and mental workload. In an environment in which timing is critical, additional cognitive processing can cause performance decrements, and increase a pilot's perception of the mental workload involved. The effects of stimulus processing demands on motor response performance and subjective mental workload are examined, using different combinations of response selection and target acquisition tasks. The information processing demands of the response selection were varied (e.g., Sternberg memory set tasks, math equations, pattern matching), as was the difficulty of the response execution. Response latency as well as subjective workload ratings varied in accordance with the cognitive complexity of the task. Movement times varied according to the difficulty of the response execution task. Implications in terms of real-world flight situations are discussed.

Assessment of energy balance of Indian farm women in relation to their nutritional profile in lean and peak agricultural seasons.

PubMed

Singh, Suman; Sinwal, Sushma; Rathore, Hemu

2012-01-01

In India, the farm women are not only involved in household activities but also contribute in various farm operations, animal husbandry. The objective was to assess nutritional profile of the farmwomen and their occupational health problems, to compare the physiological workload in lean and peak seasons and to find out relationship between physiological workload and nutritional intake. The study was conducted on a sample of 90 farmwomen. Energy Intake was calculated using physiological fuel values of carbohydrate, fat and protein. Energy Expenditure Rate (EER), Total Energy Expenditure (TEE) and Energy Balance were calculated. The physiological workload was assessed using sub-maximal workload technique. The results revealed that all the respondents of all categories were, more or less, performing all the agriculture, allied and household activities. In all the agriculture activities physiological hazards such as body pain and fatigue were dominant. Dietary, nutritional and energy intake was lower for heavy workers, from all landholding and BMI categories. HR and OCR were in linear relationship in all BMI categories. Physical work capacity increased with good nutritional status and decreased with age. Regression equations were suggested for calculating oxygen consumption (y) at their known heart rate (x) during various agriculture operations.

Timesharing performance as an indicator of pilot mental workload

NASA Technical Reports Server (NTRS)

Casper, Patricia A.

1988-01-01

The research was performed in two simultaneous phases, each intended to identify and manipulate factors related to operator mental workload. The first phase concerned evaluation of attentional deficits (workloads) in a timesharing task. Work in the second phase involved incorporating the results from these and other experiments into an expert system designed to provide workload metric selection advice to nonexperts in the field interested in operator workload. The results of the experiments conducted are summarized.

Intra-operative disruptions, surgeon's mental workload, and technical performance in a full-scale simulated procedure.

PubMed

Weigl, Matthias; Stefan, Philipp; Abhari, Kamyar; Wucherer, Patrick; Fallavollita, Pascal; Lazarovici, Marc; Weidert, Simon; Euler, Ekkehard; Catchpole, Ken

2016-02-01

Surgical flow disruptions occur frequently and jeopardize perioperative care and surgical performance. So far, insights into subjective and cognitive implications of intra-operative disruptions for surgeons and inherent consequences for performance are inconsistent. This study aimed to investigate the effect of surgical flow disruption on surgeon's intra-operative workload and technical performance. In a full-scale OR simulation, 19 surgeons were randomly allocated to either of the two disruption scenarios (telephone call vs. patient discomfort). Using a mixed virtual reality simulator with a computerized, high-fidelity mannequin, all surgeons were trained in performing a vertebroplasty procedure and subsequently performed such a procedure under experimental conditions. Standardized measures on subjective workload and technical performance (trocar positioning deviation from expert-defined standard, number, and duration of X-ray acquisitions) were collected. Intra-operative workload during simulated disruption scenarios was significantly higher compared to training sessions (p < .01). Surgeons in the telephone call scenario experienced significantly more distraction compared to their colleagues in the patient discomfort scenario (p < .05). However, workload tended to be increased in surgeons who coped with distractions due to patient discomfort. Technical performance was not significantly different between both disruption scenarios. We found a significant association between surgeons' intra-operative workload and technical performance such that surgeons with increased mental workload tended to perform worse (β = .55, p = .04). Surgical flow disruptions affect surgeons' intra-operative workload. Increased mental workload was associated with inferior technical performance. Our simulation-based findings emphasize the need to establish smooth surgical flow which is characterized by a low level of process deviations and disruptions.

The effect of a slack-pulling device in reducing operator physiological workload during log winching operations.

PubMed

Spinelli, Raffaele; Aalmo, Giovanna Ottaviani; Magagnotti, Natascia

2015-01-01

The authors conducted a comparative test to determine whether the introduction of a hydraulic slack puller allowed reducing the physiological workload of operators assigned to log winching tasks. The tests were conducted in northern Italy, on the mountains near Como. The study involved five volunteer subjects, considered representatives of the regional logging workforce. Physiological workload was determined by measuring the operators' heart rate upon completion of specific tasks. The slack puller improved the efficiency of downhill winching, since it allowed a single operator to pull out the cable on his own, without requiring the assistance of a colleague. However, introduction of the slack puller did not result in any reductions of operator physiological workload. The main stressor when working on a steep slope is moving up and down the slope: pulling a cable is only a secondary stressor. Any measures targeting secondary stressors are unlikely to produce dramatic reductions of operator workload.

Workload of the VTS Sector Operator And Implications for Task Design

DOT National Transportation Integrated Search

1994-12-01

This study identifies the factors determining the VTS sector operator's workload and recommends : the most appropriate use of automation to manage that workload. Investigations were conducted at : VTS New York (Governors Island) and at VTS Puget Soun...

Robotic assistance improves intracorporeal suturing performance and safety in the operating room while decreasing operator workload.

PubMed

Stefanidis, Dimitrios; Wang, Fikre; Korndorffer, James R; Dunne, J Bruce; Scott, Daniel J

2010-02-01

Intracorporeal suturing is one of the most difficult laparoscopic tasks. The purpose of this study was to assess the impact of robotic assistance on novice suturing performance, safety, and workload in the operating room. Medical students (n = 34), without prior laparoscopic suturing experience, were enrolled in an Institutional Review Board-approved, randomized protocol. After viewing an instructional video, subjects were tested in intracorporeal suturing on two identical, live, porcine Nissen fundoplication models; they placed three gastro-gastric sutures using conventional laparoscopic instruments in one model and using robotic assistance (da Vinci) in the other, in random order. Each knot was objectively scored based on time, accuracy, and security. Injuries to surrounding structures were recorded. Workload was assessed using the validated National Aeronautics and Space Administration (NASA) task load index (TLX) questionnaire, which measures the subjects' self-reported performance, effort, frustration, and mental, physical, and temporal demands of the task. Analysis was by paired t-test; p < 0.05 was considered significant. Compared with laparoscopy, robotic assistance enabled subjects to suture faster (595 +/- 22 s versus 459 +/- 137 s, respectively; p < 0.001), achieve higher overall scores (0 +/- 1 versus 95 +/- 128, respectively; p < 0.001), and commit fewer errors per knot (1.15 +/- 1.35 versus 0.05 +/- 0.26, respectively; p < 0.001). Subjects' overall score did not improve between the first and third attempt for laparoscopic suturing (0 +/- 0 versus 0 +/- 0; p = NS) but improved significantly for robotic suturing (49 +/- 100 versus 141 +/- 152; p < 0.001). Moreover, subjects indicated on the NASA-TLX scale that the task was more difficult to perform with laparoscopic instruments compared with robotic assistance (99 +/- 15 versus 57 +/- 23; p < 0.001). Compared with standard laparoscopy, robotic assistance significantly improved intracorporeal suturing performance and safety of novices in the operating room while decreasing their workload. Moreover, the robot significantly shortened the learning curve of this difficult task. Further study is needed to assess the value of robotic assistance for experienced surgeons, and validated robotic training curricula need to be developed.

Pupillometric measurement of operator workload

NASA Technical Reports Server (NTRS)

Beatty, J.

1981-01-01

Pupillometry as a method of measuring workload is described. Pupillometric measures provide an indication of momentary fluctuations in central nervous system excitability that occur as cognitive operations are performed; the magnitude of these changes may serve as a sensitive indicator of the workload imposed by cognitive tasks.

Crew workload strategies in advanced cockpits

NASA Technical Reports Server (NTRS)

Hart, Sandra G.

1990-01-01

Many methods of measuring and predicting operator workload have been developed that provide useful information in the design, evaluation, and operation of complex systems and which aid in developing models of human attention and performance. However, the relationships between such measures, imposed task demands, and measures of performance remain complex and even contradictory. It appears that we have ignored an important factor: people do not passively translate task demands into performance. Rather, they actively manage their time, resources, and effort to achieve an acceptable level of performance while maintaining a comfortable level of workload. While such adaptive, creative, and strategic behaviors are the primary reason that human operators remain an essential component of all advanced man-machine systems, they also result in individual differences in the way people respond to the same task demands and inconsistent relationships among measures. Finally, we are able to measure workload and performance, but interpreting such measures remains difficult; it is still not clear how much workload is too much or too little nor the consequences of suboptimal workload on system performance and the mental, physical, and emotional well-being of the human operators. The rationale and philosophy of a program of research developed to address these issues will be reviewed and contrasted to traditional methods of defining, measuring, and predicting human operator workload. Viewgraphs are given.

Evaluation of the Display of Cognitive State Feedback to Drive Adaptive Task Sharing

PubMed Central

Dorneich, Michael C.; Passinger, Břetislav; Hamblin, Christopher; Keinrath, Claudia; Vašek, Jiři; Whitlow, Stephen D.; Beekhuyzen, Martijn

2017-01-01

This paper presents an adaptive system intended to address workload imbalances between pilots in future flight decks. Team performance can be maximized when task demands are balanced within crew capabilities and resources. Good communication skills enable teams to adapt to changes in workload, and include the balancing of workload between team members This work addresses human factors priorities in the aviation domain with the goal to develop concepts that balance operator workload, support future operator roles and responsibilities, and support new task requirements, while allowing operators to focus on the most safety critical tasks. A traditional closed-loop adaptive system includes the decision logic to turn automated adaptations on and off. This work takes a novel approach of replacing the decision logic, normally performed by the automation, with human decisions. The Crew Workload Manager (CWLM) was developed to objectively display the workload between pilots and recommend task sharing; it is then the pilots who “close the loop” by deciding how to best mitigate unbalanced workload. The workload was manipulated by the Shared Aviation Task Battery (SAT-B), which was developed to provide opportunities for pilots to mitigate imbalances in workload between crew members. Participants were put in situations of high and low workload (i.e., workload was manipulated as opposed to being measured), the workload was then displayed to pilots, and pilots were allowed to decide how to mitigate the situation. An evaluation was performed that utilized the SAT-B to manipulate workload and create workload imbalances. Overall, the CWLM reduced the time spent in unbalanced workload and improved the crew coordination in task sharing while not negatively impacting concurrent task performance. Balancing workload has the potential to improve crew resource management and task performance over time, and reduce errors and fatigue. Paired with a real-time workload measurement system, the CWLM could help teams manage their own task load distribution. PMID:28400716

Evaluation of the Display of Cognitive State Feedback to Drive Adaptive Task Sharing.

PubMed

Dorneich, Michael C; Passinger, Břetislav; Hamblin, Christopher; Keinrath, Claudia; Vašek, Jiři; Whitlow, Stephen D; Beekhuyzen, Martijn

2017-01-01

This paper presents an adaptive system intended to address workload imbalances between pilots in future flight decks. Team performance can be maximized when task demands are balanced within crew capabilities and resources. Good communication skills enable teams to adapt to changes in workload, and include the balancing of workload between team members This work addresses human factors priorities in the aviation domain with the goal to develop concepts that balance operator workload, support future operator roles and responsibilities, and support new task requirements, while allowing operators to focus on the most safety critical tasks. A traditional closed-loop adaptive system includes the decision logic to turn automated adaptations on and off. This work takes a novel approach of replacing the decision logic, normally performed by the automation, with human decisions. The Crew Workload Manager (CWLM) was developed to objectively display the workload between pilots and recommend task sharing; it is then the pilots who "close the loop" by deciding how to best mitigate unbalanced workload. The workload was manipulated by the Shared Aviation Task Battery (SAT-B), which was developed to provide opportunities for pilots to mitigate imbalances in workload between crew members. Participants were put in situations of high and low workload (i.e., workload was manipulated as opposed to being measured), the workload was then displayed to pilots, and pilots were allowed to decide how to mitigate the situation. An evaluation was performed that utilized the SAT-B to manipulate workload and create workload imbalances. Overall, the CWLM reduced the time spent in unbalanced workload and improved the crew coordination in task sharing while not negatively impacting concurrent task performance. Balancing workload has the potential to improve crew resource management and task performance over time, and reduce errors and fatigue. Paired with a real-time workload measurement system, the CWLM could help teams manage their own task load distribution.

Individual differences in response to automation: the five factor model of personality.

PubMed

Szalma, James L; Taylor, Grant S

2011-06-01

This study examined the relationship of operator personality (Five Factor Model) and characteristics of the task and of adaptive automation (reliability and adaptiveness-whether the automation was well-matched to changes in task demand) to operator performance, workload, stress, and coping. This represents the first investigation of how the Five Factors relate to human response to automation. One-hundred-sixty-one college students experienced either 75% or 95% reliable automation provided with task loads of either two or four displays to be monitored. The task required threat detection in a simulated uninhabited ground vehicle (UGV) task. Task demand exerted the strongest influence on outcome variables. Automation characteristics did not directly impact workload or stress, but effects did emerge in the context of trait-task interactions that varied as a function of the dimension of workload and stress. The pattern of relationships of traits to dependent variables was generally moderated by at least one task factor. Neuroticism was related to poorer performance in some conditions, and all five traits were associated with at least one measure of workload and stress. Neuroticism generally predicted increased workload and stress and the other traits predicted decreased levels of these states. However, in the case of the relation of Extraversion and Agreeableness to Worry, Frustration, and avoidant coping, the direction of effects varied across task conditions. The results support incorporation of individual differences into automation design by identifying the relevant person characteristics and using the information to determine what functions to automate and the form and level of automation.

The effects of practice on tracking and subjective workload

NASA Technical Reports Server (NTRS)

Hancock, P. A.; Robinson, M. A.; Chu, A. L.; Hansen, D. R.; Vercruyssen, M.

1989-01-01

Six college-age male subjects performed one hundred, two-minute trials on a second-order tracking task. After each trial, subjects estimated perceived workload using both the NASA TLX and SWAT workload assessment procedures. Results confirmed an expected performance improvement on the tracking task which followed traditional learning curves within the performance of each individual. Perceived workload also decreased for both scales across trials. While performance variability significantly decreased across trials, workload variability remained constant. One month later, the same subjects returned to complete the second experiment in the sequence which was a retention replication of the first experiment. Results replicated those for the first experiment except that both performance error and workload were at reduced overall levels. Results in general affirm a parallel workload reduction with performance improvement, an observation consistent with a resource-based view of automaticity.

Workload - An examination of the concept

NASA Technical Reports Server (NTRS)

Gopher, Daniel; Donchin, Emanuel

1986-01-01

The relations between task difficulty and workload and workload and performance are examined. The architecture and limitations of the central processor are discussed. Various procedures for measuring workload are described and evaluated. Consideration is given to normative and descriptive approaches; subjective, performance, and arousal measures; performance operating characteristics; and psychophysiological measures of workload.

Mental workload measurement for emergency operating procedures in digital nuclear power plants.

PubMed

Gao, Qin; Wang, Yang; Song, Fei; Li, Zhizhong; Dong, Xiaolu

2013-01-01

Mental workload is a major consideration for the design of emergency operation procedures (EOPs) in nuclear power plants. Continuous and objective measures are desired. This paper compares seven mental workload measurement methods (pupil size, blink rate, blink duration, heart rate variability, parasympathetic/sympathetic ratio, total power and (Goals, Operations, Methods, and Section Rules)-(Keystroke Level Model) GOMS-KLM-based workload index) with regard to sensitivity, validity and intrusiveness. Eighteen participants performed two computerised EOPs of different complexity levels, and mental workload measures were collected during the experiment. The results show that the blink rate is sensitive to both the difference in the overall task complexity and changes in peak complexity within EOPs, that the error rate is sensitive to the level of arousal and correlate to the step error rate and that blink duration increases over the task period in both low and high complexity EOPs. Cardiac measures were able to distinguish tasks with different overall complexity. The intrusiveness of the physiological instruments is acceptable. Finally, the six physiological measures were integrated using group method of data handling to predict perceived overall mental workload. The study compared seven measures for evaluating the mental workload with emergency operation procedure in nuclear power plants. An experiment with simulated procedures was carried out, and the results show that eye response measures are useful for assessing temporal changes of workload whereas cardiac measures are useful for evaluating the overall workload.

Tactile display landing safety and precision improvements for the Space Shuttle

NASA Astrophysics Data System (ADS)

Olson, John M.

A tactile display belt using 24 electro-mechanical tactile transducers (tactors) was used to determine if a modified tactile display system, known as the Tactile Situation Awareness System (TSAS) improved the safety and precision of a complex spacecraft (i.e. the Space Shuttle Orbiter) in guided precision approaches and landings. The goal was to determine if tactile cues enhance safety and mission performance through reduced workload, increased situational awareness (SA), and an improved operational capability by increasing secondary cognitive workload capacity and human-machine interface efficiency and effectiveness. Using both qualitative and quantitative measures such as NASA's Justiz Numerical Measure and Synwork1 scores, an Overall Workload (OW) measure, the Cooper-Harper rating scale, and the China Lake Situational Awareness scale, plus Pre- and Post-Flight Surveys, the data show that tactile displays decrease OW, improve SA, counteract fatigue, and provide superior warning and monitoring capacity for dynamic, off-nominal, high concurrent workload scenarios involving complex, cognitive, and multi-sensory critical scenarios. Use of TSAS for maintaining guided precision approaches and landings was generally intuitive, reduced training times, and improved task learning effects. Ultimately, the use of a homogeneous, experienced, and statistically robust population of test pilots demonstrated that the use of tactile displays for Space Shuttle approaches and landings with degraded vehicle systems, weather, and environmental conditions produced substantial improvements in safety, consistency, reliability, and ease of operations under demanding conditions. Recommendations for further analysis and study are provided in order to leverage the results from this research and further explore the potential to reduce the risk of spaceflight and aerospace operations in general.

Mental workload measurement in operator control room using NASA-TLX

NASA Astrophysics Data System (ADS)

Sugarindra, M.; Suryoputro, M. R.; Permana, A. I.

2017-12-01

The workload, encountered a combination of physical workload and mental workload, is a consequence of the activities for workers. Central control room is one department in the oil processing company, employees tasked with monitoring the processing unit for 24 hours nonstop with a combination of 3 shifts in 8 hours. NASA-TLX (NASA Task Load Index) is one of the subjective mental workload measurement using six factors, namely the Mental demand (MD), Physical demand (PD), Temporal demand (TD), Performance (OP), Effort (EF), frustration levels (FR). Measurement of a subjective mental workload most widely used because it has a high degree of validity. Based on the calculation of the mental workload, there at 5 units (DTU, NPU, HTU, DIST and OPS) at the control chamber (94; 83.33; 94.67; 81, 33 and 94.67 respectively) that categorize as very high mental workload. The high level of mental workload on the operator in the Central Control Room is a requirement to have high accuracy, alertness and can make decisions quickly

Mental distress and effort to engage an image-guided navigation system in the surgical training of endoscopic sinus surgery: a prospective, randomised clinical trial.

PubMed

Theodoraki, M N; Ledderose, G J; Becker, S; Leunig, A; Arpe, S; Luz, M; Stelter, K

2015-04-01

The use of image-guided navigation systems in the training of FESS is discussed controversy. Many experienced sinus surgeons report a better spatial orientation and an improved situational awareness intraoperatively. But many fear that the navigation system could be a disadvantage in the surgical training because of a higher mental demand and a possible loss of surgical skills. This clinical field study investigates mental and physical demands during transnasal surgery with and without the aid of a navigation system at an early stage in FESS training. Thirty-two endonasal sinus surgeries done by eight different trainee surgeons were included. After randomization, one side of each patient was operated by use of a navigation system, the other side without. During the whole surgery, the surgeons were connected to a biofeedback device measuring the heart rate, the heart rate variability, the respiratory frequency and the masticator EMG. Stress situations could be identified by an increase of the heart rate frequency and a decrease of the heart rate variability. The mental workload during a FESS procedure is high compared to the baseline before and after surgery. The mental workload level when using the navigation did not significantly differ from the side without using the navigation. Residents with more than 30 FESS procedures already done, showed a slightly decreased mental workload when using the navigation. An additional workload shift toward the navigation system could not be observed in any surgeon. Remarkable other stressors could be identified during this study: the behavior of the supervisor or the use of the 45° endoscope, other colleagues or students entering the theatre, poor vision due to bleeding and the preoperative waiting when measuring the baseline. The mental load of young surgeons in FESS surgery is tremendous. The application of a navigation system did not cause a higher mental workload or distress. The device showed a positive effort to engage for the trainees with more than 30 FESS procedures done. In this subgroup it even leads to decreased mental workload.

The effects of display and autopilot functions on pilot workload for Single Pilot Instrument Flight Rule (SPIFR) operations

NASA Technical Reports Server (NTRS)

Hoh, Roger H.; Smith, James C.; Hinton, David A.

1987-01-01

An analytical and experimental research program was conducted to develop criteria for pilot interaction with advanced controls and displays in single pilot instrument flight rules (SPIFR) operations. The analytic phase reviewed fundamental considerations for pilot workload taking into account existing data, and using that data to develop a divided attention SPIFR pilot workload model. The pilot model was utilized to interpret the two experimental phases. The first experimental phase was a flight test program that evaluated pilot workload in the presence of current and near-term displays and autopilot functions. The second experiment was conducted on a King Air simulator, investigating the effects of co-pilot functions in the presence of very high SPIFR workload. The results indicate that the simplest displays tested were marginal for SPIFR operations. A moving map display aided the most in mental orientation, but had inherent deficiencies as a stand alone replacement for an HSI. Autopilot functions were highly effective for reducing pilot workload. The simulator tests showed that extremely high workload situations can be adequately handled when co-pilot functions are provided.

Timesharing performance as an indicator of pilot mental workload

NASA Technical Reports Server (NTRS)

Casper, Patricia A.; Kantowitz, Barry H.; Sorkin, Robert D.

1988-01-01

Attentional deficits (workloads) were evaluated in a timesharing task. The results from this and other experiments were incorporated into an expert system designed to provide workload metric selection advice to non-experts in the field interested in operator workload.

Comparative evaluation of workload estimation techniques in piloting tasks

NASA Technical Reports Server (NTRS)

Wierwille, W. W.

1983-01-01

Techniques to measure operator workload in a wide range of situations and tasks were examined. The sensitivity and intrusion of a wide variety of workload assessment techniques in simulated piloting tasks were investigated. Four different piloting tasks, psychomotor, perceptual, mediational, and communication aspects of piloting behavior were selected. Techniques to determine relative sensitivity and intrusion were applied. Sensitivity is the relative ability of a workload estimation technique to discriminate statistically significant differences in operator loading. High sensitivity requires discriminable changes in score means as a function of load level and low variation of the scores about the means. Intrusion is an undesirable change in the task for which workload is measured, resulting from the introduction of the workload estimation technique or apparatus.

Factors influencing selection of internal medicine residency--a prospective study.

PubMed

Pereg, David; Gronich, Naomi; Lishner, Michael

2006-08-01

Recently, the popularity of internal medicine residency has been decreasing. We studied the effect of an improved working environment and a decrease in residents' workload on the selection of internal medicine residency. An organizational diagnosis team joined our department and identified several causes for residents' heavy workload. These findings were subsequently discussed in a workshop and led to a modification of the daily routine and a parallel decrease in workload and rise in residents' satisfaction. Following these changes, the demand for residency in our department rose. We conclude that an improvement in the working environment and workload during residency increases the residents' satisfaction and the demand for residency in internal medicine.

Interactive Query Processing in Big Data Systems: A Cross Industry Study of MapReduce Workloads

DTIC Science & Technology

2012-04-02

invite cluster operators and the broader data management commu- nity to share additional knowledge about their MapReduce workloads. 9. ACKNOWLEDGMENTS...against real- life production MapReduce workloads. Knowledge of such workloads is currently limited to a handful of technology companies [19, 8, 48, 41...database management insights would benefit from checking workload assumptions against empirical measurements. The broad spectrum of workloads analyzed allows

An Approach to Quantify Workload in a System of Agents

NASA Technical Reports Server (NTRS)

Stocker, Richard; Rungta, Neha; Mercer, Eric; Raimondi, Franco; Holbrook, Jon; Cardoza, Colleen; Goodrich, Michael

2015-01-01

The role of humans in aviation and other domains continues to shift from manual control to automation monitoring. Studies have found that humans are often poorly suited for monitoring roles, and workload can easily spike in off-nominal situations. Current workload measurement tools, like NASA TLX, use human operators to assess their own workload after using a prototype system. Such measures are used late in the design process and can result in ex- pensive alterations when problems are discovered. Our goal in this work is to provide a quantitative workload measure for use early in the design process. We leverage research in human cognition to de ne metrics that can measure workload on belief-desire-intentions based multi-agent systems. These measures can alert designers to potential workload issues early in design. We demonstrate the utility of our approach by characterizing quantitative differences in the workload for a single pilot operations model compared to a traditional two pilot model.

Construction of a survey to assess workload and fatigue among AMT operators in Mexico.

PubMed

Hernández Arellano, Juan Luis; Ibarra Mejía, Gabriel; Serratos Pérez, J Nieves; García Alcaraz, Jorge Luis; Brunette, María Julia

2012-01-01

Operators of machinery classified as Advanced Manufacturing Technology (AMT) are exposed to high levels of workload and fatigue. However, only few studies have been conducted on this topic in Hispanic-American countries workers. Several instruments be used to assess workload and fatigue; however, only few of them have been adapted to Spanish language. This paper reports on the development and validity testing of a survey instrument in Spanish, aiming to subjectively assess workload and fatigue among AMT operators in Mexico. After an exhaustive literature review in search of already available measurement instruments, they were adapted for content and later translated into Spanish; a pilot test was conducted to evaluate validity and reliability; afterwards appropriate modifications were made to the testing instruments. Final version of the instrument was applied to a group of 121 operators of CNC lathes. Reliability was analyzed using KMO and Cronbach alpha indices. For the assessment of workload, both NASA-TLX and ISTAS 21 methods were incorporated to the survey instrument. As for fatigue assessment tools, these were SOFI-S, FAS and OFER questionnaires. RESULTS show KMO value and Cronbach alpha above 0.6.Conclusions. The survey instrument as designed, allows the collection of reliable and valid data regarding workload and fatigue among AMT operators in Mexico.

Using near infrared spectroscopy and heart rate variability to detect mental overload.

PubMed

Durantin, G; Gagnon, J-F; Tremblay, S; Dehais, F

2014-02-01

Mental workload is a key factor influencing the occurrence of human error, especially during piloting and remotely operated vehicle (ROV) operations, where safety depends on the ability of pilots to act appropriately. In particular, excessively high or low mental workload can lead operators to neglect critical information. The objective of the present study is to investigate the potential of functional near infrared spectroscopy (fNIRS) - a non-invasive method of measuring prefrontal cortex activity - in combination with measurements of heart rate variability (HRV), to predict mental workload during a simulated piloting task, with particular regard to task engagement and disengagement. Twelve volunteers performed a computer-based piloting task in which they were asked to follow a dynamic target with their aircraft, a task designed to replicate key cognitive demands associated with real life ROV operating tasks. In order to cover a wide range of mental workload levels, task difficulty was manipulated in terms of processing load and difficulty of control - two critical sources of workload associated with piloting and remotely operating a vehicle. Results show that both fNIRS and HRV are sensitive to different levels of mental workload; notably, lower prefrontal activation as well as a lower LF/HF ratio at the highest level of difficulty, suggest that these measures are suitable for mental overload detection. Moreover, these latter measurements point toward the existence of a quadratic model of mental workload. Copyright © 2013 Elsevier B.V. All rights reserved.

An Evaluation of Controller and Pilot Performance, Workload and Acceptability under a NextGen Concept for Dynamic Weather Adapted Arrival Routing

NASA Technical Reports Server (NTRS)

Johnson, Walter W.; Lachter, Joel; Brandt, Summer; Koteskey, Robert; Dao, Arik-Quang; Kraut, Josh; Ligda, Sarah; Battiste, Vernol

2012-01-01

In todays terminal operations, controller workload increases and throughput decreases when fixed standard terminal arrival routes (STARs) are impacted by storms. To circumvent this operational constraint, Prete, Krozel, Mitchell, Kim and Zou (2008) proposed to use automation to dynamically adapt arrival and departure routing based on weather predictions. The present study examined this proposal in the context of a NextGen trajectory-based operation concept, focusing on the acceptability and its effect on the controllers ability to manage traffic flows. Six controllers and twelve transport pilots participated in a human-in-the-loop simulation of arrival operations into Louisville International Airport with interval management requirements. Three types of routing structures were used: Static STARs (similar to current routing, which require the trajectories of individual aircraft to be modified to avoid the weather), Dynamic routing (automated adaptive routing around weather), and Dynamic Adjusted routing (automated adaptive routing around weather with aircraft entry time adjusted to account for differences in route length). Spacing Responsibility, whether responsibility for interval management resided with the controllers (as today), or resided with the pilot (who used a flight deck based automated spacing algorithm), was also manipulated. Dynamic routing as a whole was rated superior to static routing, especially by pilots, both in terms of workload reduction and flight path safety. A downside of using dynamic routing was that the paths flown in the dynamic conditions tended to be somewhat longer than the paths flown in the static condition.

Cardiac-Activity Measures for Assessing Airport Ramp-Tower Controller's Workload

NASA Technical Reports Server (NTRS)

Hayashi, Miwa; Dulchinos, Victoria

2016-01-01

Heart rate (HR) and heart rate variability (HRV) potentially offer objective, continuous, and non-intrusive measures of human-operators mental workload. Such measurement capability is attractive for workload assessment in complex laboratory simulations or safety-critical field testing. The present study compares mean HR and HRV data with self-reported subjective workload ratings collected during a high-fidelity human-in-the-loop simulation of airport ramp traffic control operations, which involve complex cognitive and coordination tasks. Mean HR was found to be weakly sensitive to the workload ratings, while HRV was not sensitive or even contradictory to the assumptions. Until more knowledge on stress response mechanisms of the autonomic nervous system is obtained, it is recommended that these cardiac-activity measures be used with other workload assessment tools, such as subjective measures.

Impact of computerized information systems on workload in operating room and intensive care unit.

PubMed

Bosman, R J

2009-03-01

The number of operating rooms and intensive care departments equipped with a clinical information system (CIS) is rapidly expanding. Amongst the putative advantages of such an installation, reduction in workload for the clinician is one of the most appealing. The scarce studies looking at workload variations associated with the implementation of a CIS, only focus on direct workload discarding indirect changes in workload. Descriptions of the various methods to quantify workload are provided. The hypothesis that a third generation CIS can reduce documentation time for ICU nurses and increase time they spend on patient care, is supported by recent literature. Though it seems obvious to extrapolate these advantages of a CIS to the anesthesiology department or physicians in the intensive care, studies examining this assumption are scarce.

Cardiac-Activity Measures for Assessing Airport Ramp-Tower Controller's Workload

NASA Technical Reports Server (NTRS)

Hayashi, Miwa; Dulchinos, Victoria L.

2016-01-01

Heart rate (HR) and heart rate variability (HRV) potentially offer objective, continuous, and non-intrusive measures of human-operator's mental workload. Such measurement capability is attractive for workload assessment in complex laboratory simulations or safety-critical field testing. The present study compares mean HR and HRV data with self-reported subjective workload ratings collected during a high-fidelity human-in-the-loop simulation of airport ramp traffic control operations, which involve complex cognitive and coordination tasks. Mean HR was found to be weakly sensitive to the workload ratings, while HRV was not sensitive or even contradictory to the assumptions. Until more knowledge on stress response mechanisms of the autonomic nervous system is obtained, it is recommended that these cardiac-activity measures be used with other workload assessment tools, such as subjective measures.

An analysis of scatter decomposition

NASA Technical Reports Server (NTRS)

Nicol, David M.; Saltz, Joel H.

1990-01-01

A formal analysis of a powerful mapping technique known as scatter decomposition is presented. Scatter decomposition divides an irregular computational domain into a large number of equal sized pieces, and distributes them modularly among processors. A probabilistic model of workload in one dimension is used to formally explain why, and when scatter decomposition works. The first result is that if correlation in workload is a convex function of distance, then scattering a more finely decomposed domain yields a lower average processor workload variance. The second result shows that if the workload process is stationary Gaussian and the correlation function decreases linearly in distance until becoming zero and then remains zero, scattering a more finely decomposed domain yields a lower expected maximum processor workload. Finally it is shown that if the correlation function decreases linearly across the entire domain, then among all mappings that assign an equal number of domain pieces to each processor, scatter decomposition minimizes the average processor workload variance. The dependence of these results on the assumption of decreasing correlation is illustrated with situations where a coarser granularity actually achieves better load balance.

Comparison of a brain-based adaptive system and a manual adaptable system for invoking automation.

PubMed

Bailey, Nathan R; Scerbo, Mark W; Freeman, Frederick G; Mikulka, Peter J; Scott, Lorissa A

2006-01-01

Two experiments are presented examining adaptive and adaptable methods for invoking automation. Empirical investigations of adaptive automation have focused on methods used to invoke automation or on automation-related performance implications. However, no research has addressed whether performance benefits associated with brain-based systems exceed those in which users have control over task allocations. Participants performed monitoring and resource management tasks as well as a tracking task that shifted between automatic and manual modes. In the first experiment, participants worked with an adaptive system that used their electroencephalographic signals to switch the tracking task between automatic and manual modes. Participants were also divided between high- and low-reliability conditions for the system-monitoring task as well as high- and low-complacency potential. For the second experiment, participants operated an adaptable system that gave them manual control over task allocations. Results indicated increased situation awareness (SA) of gauge instrument settings for individuals high in complacency potential using the adaptive system. In addition, participants who had control over automation performed more poorly on the resource management task and reported higher levels of workload. A comparison between systems also revealed enhanced SA of gauge instrument settings and decreased workload in the adaptive condition. The present results suggest that brain-based adaptive automation systems may enhance perceptual level SA while reducing mental workload relative to systems requiring user-initiated control. Potential applications include automated systems for which operator monitoring performance and high-workload conditions are of concern.

Psychophysiological measures of cognitive workload in laboratory and flight

NASA Technical Reports Server (NTRS)

Wilson, Glenn F.; Badeau, Albert

1993-01-01

Psychophysiological data have been recorded during different levels of cognitive workload in laboratory and flight settings. Cardiac, eye blink, and brain data have shown meaningful changes as a function of the levels of mental workload. Increased cognitive workload is generally associated with increased heart rates, decreased blink rates and eye closures, and decreased evoked potential amplitudes. However, comparisons of laboratory and flight data show that direct transference of laboratory findings to the flight environment is not possible in many cases. While the laboratory data are valuable, a data base from flight is required so that 'real world' data can be properly interpreted.

EEG correlates of task engagement and mental workload in vigilance, learning, and memory tasks.

PubMed

Berka, Chris; Levendowski, Daniel J; Lumicao, Michelle N; Yau, Alan; Davis, Gene; Zivkovic, Vladimir T; Olmstead, Richard E; Tremoulet, Patrice D; Craven, Patrick L

2007-05-01

The ability to continuously and unobtrusively monitor levels of task engagement and mental workload in an operational environment could be useful in identifying more accurate and efficient methods for humans to interact with technology. This information could also be used to optimize the design of safer, more efficient work environments that increase motivation and productivity. The present study explored the feasibility of monitoring electroencephalo-graphic (EEG) indices of engagement and workload acquired unobtrusively and quantified during performance of cognitive tests. EEG was acquired from 80 healthy participants with a wireless sensor headset (F3-F4,C3-C4,Cz-POz,F3-Cz,Fz-C3,Fz-POz) during tasks including: multi-level forward/backward-digit-span, grid-recall, trails, mental-addition, 20-min 3-Choice Vigilance, and image-learning and memory tests. EEG metrics for engagement and workload were calculated for each 1 -s of EEG. Across participants, engagement but not workload decreased over the 20-min vigilance test. Engagement and workload were significantly increased during the encoding period of verbal and image-learning and memory tests when compared with the recognition/ recall period. Workload but not engagement increased linearly as level of difficulty increased in forward and backward-digit-span, grid-recall, and mental-addition tests. EEG measures correlated with both subjective and objective performance metrics. These data in combination with previous studies suggest that EEG engagement reflects information-gathering, visual processing, and allocation of attention. EEG workload increases with increasing working memory load and during problem solving, integration of information, analytical reasoning, and may be more reflective of executive functions. Inspection of EEG on a second-by-second timescale revealed associations between workload and engagement levels when aligned with specific task events providing preliminary evidence that second-by-second classifications reflect parameters of task performance.

Plastic surgical operative workload in major trauma patients following establishment of the major trauma network in England: A retrospective cohort study.

PubMed

Hendrickson, S A; Khan, M A; Verjee, L S; Rahman, K M A; Simmons, J; Hettiaratchy, S P

2016-07-01

The introduction of major trauma centres (MTCs) in England has led to 63% reduction in trauma mortality.(1) The role of plastic surgeons supporting these centres has not been quantified previously. This study aimed to quantify plastic surgical workload at an urban MTC to determine the contribution of plastic surgeons to major trauma care. All Trauma Audit and Research Network (TARN)-recorded major trauma patients who presented to an urban MTC in 2013 and underwent an operation were identified retrospectively. Patients who underwent plastic surgery were identified and the type and date of procedure(s) were recorded. The trauma operative workload data of another tertiary surgical specialty and local historical plastics workload data from pre-MTC go-live were collected for comparison. Of the 416 major trauma patients who required surgical intervention, 29% (n = 122) underwent plastic surgery. Of these patients, 43% had open lower limb fractures, necessitating plastic surgical involvement according to British Orthopaedic Association Standards for Trauma (BOAST) 4 guidance. The overall plastic surgery operative workload increased sevenfold post-MTC go-live. A similar proportion of the same cohort required neurosurgery (n = 115; p = 0.589). This study quantifies plastic surgery involvement in major trauma and demonstrates that plastic surgical operative workload is at least on par with other tertiary surgical specialties. It also reports one centre's experience of a significant change in plastic surgery activity following designation of MTC status. The quantity of plastic surgical operative workload in major trauma must be considered when planning major trauma service design and workforce provision, and for plastic surgical postgraduate training. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Psychophysical workload in the operating room: primary surgeon versus assistant.

PubMed

Rieger, Annika; Fenger, Sebastian; Neubert, Sebastian; Weippert, Matthias; Kreuzfeld, Steffi; Stoll, Regina

2015-07-01

Working in the operating room is characterized by high demands and overall workload of the surgical team. Surgeons often report that they feel more stressed when operating as a primary surgeon than in the function as an assistant which has been confirmed in recent studies. In this study, intra-individual workload was assessed in both intraoperative functions using a multidimensional approach that combined objective and subjective measures in a realistic work setting. Surgeons' intraoperative psychophysiologic workload was assessed through a mobile health system. 25 surgeons agreed to take part in the 24-hour monitoring by giving their written informed consent. The mobile health system contained a sensor electronic module integrated in a chest belt and measuring physiological parameters such as heart rate (HR), breathing rate (BR), and skin temperature. Subjective workload was assessed pre- and postoperatively using an electronic version of the NASA-TLX on a smartphone. The smartphone served as a communication unit and transferred objective and subjective measures to a communication server where data were stored and analyzed. Working as a primary surgeon did not result in higher workload. Neither NASA-TLX ratings nor physiological workload indicators were related to intraoperative function. In contrast, length of surgeries had a significant impact on intraoperative physical demands (p < 0.05; η(2) = 0.283), temporal demands (p < 0.05; η(2) = 0.260), effort (p < 0.05; η(2) = 0.287), and NASA-TLX sum score (p < 0.01; η(2) = 0.287). Intra-individual workload differences do not relate to intraoperative role of surgeons when length of surgery is considered as covariate. An intelligent operating management that considers the length of surgeries by implementing short breaks could contribute to the optimization of intraoperative workload and the preservation of surgeons' health, respectively. The value of mobile health systems for continuous psychophysiologic workload assessment was shown.

MEASURING WORKLOAD OF ICU NURSES WITH A QUESTIONNAIRE SURVEY: THE NASA TASK LOAD INDEX (TLX).

PubMed

Hoonakker, Peter; Carayon, Pascale; Gurses, Ayse; Brown, Roger; McGuire, Kerry; Khunlertkit, Adjhaporn; Walker, James M

2011-01-01

High workload of nurses in Intensive Care Units (ICUs) has been identified as a major patient safety and worker stress problem. However, relative little attention has been dedicated to the measurement of workload in healthcare. The objectives of this study are to describe and examine several methods to measure workload of ICU nurses. We then focus on the measurement of ICU nurses' workload using a subjective rating instrument: the NASA TLX.We conducted secondary data analysis on data from two, multi-side, cross-sectional questionnaire studies to examine several instruments to measure ICU nurses' workload. The combined database contains the data from 757 ICU nurses in 8 hospitals and 21 ICUs.Results show that the different methods to measure workload of ICU nurses, such as patient-based and operator-based workload, are only moderately correlated, or not correlated at all. Results show further that among the operator-based instruments, the NASA TLX is the most reliable and valid questionnaire to measure workload and that NASA TLX can be used in a healthcare setting. Managers of hospitals and ICUs can benefit from the results of this research as it provides benchmark data on workload experienced by nurses in a variety of ICUs.

MEASURING WORKLOAD OF ICU NURSES WITH A QUESTIONNAIRE SURVEY: THE NASA TASK LOAD INDEX (TLX)

PubMed Central

Hoonakker, Peter; Carayon, Pascale; Gurses, Ayse; Brown, Roger; McGuire, Kerry; Khunlertkit, Adjhaporn; Walker, James M.

2012-01-01

High workload of nurses in Intensive Care Units (ICUs) has been identified as a major patient safety and worker stress problem. However, relative little attention has been dedicated to the measurement of workload in healthcare. The objectives of this study are to describe and examine several methods to measure workload of ICU nurses. We then focus on the measurement of ICU nurses’ workload using a subjective rating instrument: the NASA TLX. We conducted secondary data analysis on data from two, multi-side, cross-sectional questionnaire studies to examine several instruments to measure ICU nurses’ workload. The combined database contains the data from 757 ICU nurses in 8 hospitals and 21 ICUs. Results show that the different methods to measure workload of ICU nurses, such as patient-based and operator-based workload, are only moderately correlated, or not correlated at all. Results show further that among the operator-based instruments, the NASA TLX is the most reliable and valid questionnaire to measure workload and that NASA TLX can be used in a healthcare setting. Managers of hospitals and ICUs can benefit from the results of this research as it provides benchmark data on workload experienced by nurses in a variety of ICUs. PMID:22773941

Use of the RoboFlag synthetic task environment to investigate workload and stress responses in UAV operation.

PubMed

Guznov, Svyatoslav; Matthews, Gerald; Funke, Gregory; Dukes, Allen

2011-09-01

Use of unmanned aerial vehicles (UAVs) is an increasingly important element of military missions. However, controlling UAVs may impose high stress and workload on the operator. This study evaluated the use of the RoboFlag simulated environment as a means for profiling multiple dimensions of stress and workload response to a task requiring control of multiple vehicles (robots). It tested the effects of two workload manipulations, environmental uncertainty (i.e., UAV's visual view area) and maneuverability, in 64 participants. The findings confirmed that the task produced substantial workload and elevated distress. Dissociations between the stress and performance effects of the manipulations confirmed the utility of a multivariate approach to assessment. Contrary to expectations, distress and some aspects of workload were highest in the low-uncertainty condition, suggesting that overload of information may be an issue for UAV interface designers. The strengths and limitations of RoboFlag as a methodology for investigating stress and workload responses are discussed.

The Differential Effect of Sustained Operations on Psychomotor Skills of Helicopter Pilots.

PubMed

McMahon, Terry W; Newman, David G

2018-06-01

Flying a helicopter is a complex psychomotor skill requiring constant control inputs from pilots. A deterioration in psychomotor performance of a helicopter pilot may be detrimental to operational safety. The aim of this study was to test the hypothesis that psychomotor performance deteriorates over time during sustained operations and that the effect is more pronounced in the feet than the hands. The subjects were helicopter pilots conducting sustained multicrew offshore flight operations in a demanding environment. The remote flight operations involved constant workload in hot environmental conditions with complex operational tasking. Over a period of 6 d 10 helicopter pilots were tested. At the completion of daily flying duties, a helicopter-specific screen-based compensatory tracking task measuring tracking accuracy (over a 5-min period) tested both hands and feet. Data were compared over time and tested for statistical significance for both deterioration and differential effect. A statistically significant deterioration of psychomotor performance was evident in the pilots over time for both hands and feet. There was also a statistically significant differential effect between the hands and the feet in terms of tracking accuracy. The hands recorded a 22.6% decrease in tracking accuracy, while the feet recorded a 39.9% decrease in tracking accuracy. The differential effect may be due to prioritization of limb movement by the motor cortex due to factors such as workload-induced cognitive fatigue. This may result in a greater reduction in performance in the feet than the hands, posing a significant risk to operational safety.McMahon TW, Newman DG. The differential effect of sustained operations on psychomotor skills of helicopter pilots. Aerosp Med Hum Perform. 2018; 89(6):496-502.

Heart Rate Variability as a Measure of Airport Ramp-Traffic Controllers Workload

NASA Technical Reports Server (NTRS)

Hayashi, Miwa; Dulchinos, Victoria Lee

2016-01-01

Heart Rate Variability (HRV) has been reported to reflect the person's cognitive and emotional stress levels, and may offer an objective measure of human-operator's workload levels, which are recorded continuously and unobtrusively to the task performance. The present paper compares the HRV data collected during a human-in-the-loop simulation of airport ramp-traffic control operations with the controller participants' own verbal self-reporting ratings of their workload.

A Study on the Validity of a Task Complexity Measure for Emergency Operating Procedures of Nuclear Power Plants—Comparing With a Subjective Workload

NASA Astrophysics Data System (ADS)

Park, J.; Jung, W.

2006-10-01

In this study, the appropriateness of the task complexity (TACOM) measure that can quantify the complexity of emergency tasks was investigated by comparing subjective workload scores with the associated TACOM scores. To this end, based on the NASA-TLX (task load index) technique, 18 operators were asked to subjectively estimate perceived workload for 23 emergency tasks that were specified in the emergency operating procedures of the reference nuclear power plants. As the result of comparisons, it was observed that subjective workload scores increase in proportion to the increase of TACOM scores. Therefore, it is expect that the TACOM measure can be used as a serviceable method to quantify the complexity of emergency tasks

Crew procedures for microwave landing system operations

NASA Technical Reports Server (NTRS)

Summers, Leland G.

1987-01-01

The objective of this study was to identify crew procedures involved in Microwave Landing System (MLS) operations and to obtain a preliminary assessment of crew workload. The crew procedures were identified for three different complements of airborne equipment coupled to an autopilot. Using these three equipment complements, crew tasks were identified for MLS approaches and precision departures and compared to an ILS approach and a normal departure. Workload comparisons between the approaches and departures were made by using a task-timeline analysis program that obtained workload indexes, i.e., the radio of time required to complete the tasks to the time available. The results showed an increase in workload for the MLS scenario for one of the equipment complements. However, even this workload was within the capacity of two crew members.

Workload: Measurement and Management

NASA Technical Reports Server (NTRS)

Gore, Brian Francis; Casner, Stephen

2010-01-01

Poster: The workload research project has as its task to survey the available literature on: (1) workload measurement techniques; and (2) the effects of workload on operator performance. The first set of findings provides practitioners with a collection of simple-to-use workload measurement techniques along with characterizations of the kinds of tasks each technique has been shown reliably address. This allows design practitioners to select and use the most appropriate techniques for the task(s) at hand. The second set of findings provides practitioners with the guidance they need to design for appropriate kinds and amounts of workload across all tasks for which the operator is responsible. This guidance helps practitioners design systems and procedures that ensure appropriate levels of engagement across all tasks, and avoid designs and procedures that result in operator boredom, complacency, loss of awareness, undue levels of stress, or skill atrophy that can result from workload that distracts operators from the tasks they perform and monitor, workload levels that are too low, too high, or too consistent or predictable. Only those articles that were peer reviewed, long standing and generally accepted in the field, and applicable to a relevant range of conditions in a select domain of interest, in analogous "extreme" environments to those in space were included. In addition, all articles were reviewed and evaluated on uni-dimensional and multi-dimensional considerations. Casner & Gore also examined the notion of thresholds and the conditions that may benefit mostly from the various methodological approaches. Other considerations included whether the tools would be suitable for guiding a requirement-related and design-related question. An initial review of over 225 articles was conducted and entered into an EndNote database. The reference list included a range of conditions in the domain of interest (subjective/objective measures), the seminal works in workload, as well as summary works

"Operation Workload" : a study of passenger energy expenditure during an emergency evacuation.

DOT National Transportation Integrated Search

1989-03-01

In an earlier study at the Civil Aeromedical Institute, workloads were determined for passengers during an emergency evacuation. The evacuation tests were conducted in an orderly manner and were suggested as representative of a moderate workload. The...

Modified Petri net model sensitivity to workload manipulations

NASA Technical Reports Server (NTRS)

White, S. A.; Mackinnon, D. P.; Lyman, J.

1986-01-01

Modified Petri Nets (MPNs) are investigated as a workload modeling tool. The results of an exploratory study of the sensitivity of MPNs to work load manipulations in a dual task are described. Petri nets have been used to represent systems with asynchronous, concurrent and parallel activities (Peterson, 1981). These characteristics led some researchers to suggest the use of Petri nets in workload modeling where concurrent and parallel activities are common. Petri nets are represented by places and transitions. In the workload application, places represent operator activities and transitions represent events. MPNs have been used to formally represent task events and activities of a human operator in a man-machine system. Some descriptive applications demonstrate the usefulness of MPNs in the formal representation of systems. It is the general hypothesis herein that in addition to descriptive applications, MPNs may be useful for workload estimation and prediction. The results are reported of the first of a series of experiments designed to develop and test a MPN system of workload estimation and prediction. This first experiment is a screening test of MPN model general sensitivity to changes in workload. Positive results from this experiment will justify the more complicated analyses and techniques necessary for developing a workload prediction system.

Multi-Robot Interfaces and Operator Situational Awareness: Study of the Impact of Immersion and Prediction

PubMed Central

Peña-Tapia, Elena; Martín-Barrio, Andrés; Olivares-Méndez, Miguel A.

2017-01-01

Multi-robot missions are a challenge for operators in terms of workload and situational awareness. These operators have to receive data from the robots, extract information, understand the situation properly, make decisions, generate the adequate commands, and send them to the robots. The consequences of excessive workload and lack of awareness can vary from inefficiencies to accidents. This work focuses on the study of future operator interfaces of multi-robot systems, taking into account relevant issues such as multimodal interactions, immersive devices, predictive capabilities and adaptive displays. Specifically, four interfaces have been designed and developed: a conventional, a predictive conventional, a virtual reality and a predictive virtual reality interface. The four interfaces have been validated by the performance of twenty-four operators that supervised eight multi-robot missions of fire surveillance and extinguishing. The results of the workload and situational awareness tests show that virtual reality improves the situational awareness without increasing the workload of operators, whereas the effects of predictive components are not significant and depend on their implementation. PMID:28749407

UNIX-based operating systems robustness evaluation

NASA Technical Reports Server (NTRS)

Chang, Yu-Ming

1996-01-01

Robust operating systems are required for reliable computing. Techniques for robustness evaluation of operating systems not only enhance the understanding of the reliability of computer systems, but also provide valuable feed- back to system designers. This thesis presents results from robustness evaluation experiments on five UNIX-based operating systems, which include Digital Equipment's OSF/l, Hewlett Packard's HP-UX, Sun Microsystems' Solaris and SunOS, and Silicon Graphics' IRIX. Three sets of experiments were performed. The methodology for evaluation tested (1) the exception handling mechanism, (2) system resource management, and (3) system capacity under high workload stress. An exception generator was used to evaluate the exception handling mechanism of the operating systems. Results included exit status of the exception generator and the system state. Resource management techniques used by individual operating systems were tested using programs designed to usurp system resources such as physical memory and process slots. Finally, the workload stress testing evaluated the effect of the workload on system performance by running a synthetic workload and recording the response time of local and remote user requests. Moderate to severe performance degradations were observed on the systems under stress.

Estimation of duration and mental workload at differing times of day by males and females

NASA Technical Reports Server (NTRS)

Hancock, P. A.; Rodenburg, G. J.; Mathews, W. D.; Vercruyssen, M.

1988-01-01

Two experiments are reported which investigated whether male and female operator duration estimation and subjective workload followed conventional circadian fluctuation. In the first experiment, twenty-four subjects performed a filled time-estimation task in a constant blacked-out, noise-reduced environment at 0800, 1200, 1600, and 2000 h. In the second experiment, twelve subjects performed an unfilled time estimation task in similar conditions at 0900, 1400, and 1900 h. At the termination of all experimental sessions, participants completed the NASA TLX workload assessment questionnaire as a measure of perceived mental workload. Results indicated that while physiological response followed an expected pattern, estimations of duration and subjective perception of workload showed no significant effects for time-of-day. In each of the experiments, however, there were significant differences in durational estimates and mental workload response depending upon the gender of the participant. Results are taken to support the assertion that subjective workload is responsive largely to task-related factors and indicates the important differences that may be expected due to operator gender.

Using the NASA Task Load Index to Assess Workload in Electronic Medical Records.

PubMed

Hudson, Darren; Kushniruk, Andre W; Borycki, Elizabeth M

2015-01-01

Electronic medical records (EMRs) has been expected to decrease health professional workload. The NASA Task Load Index has become an important tool for assessing workload in many domains. However, its application in assessing the impact of an EMR on nurse's workload has remained to be explored. In this paper we report the results of a study of workload and we explore the utility of applying the NASA Task Load Index to assess impact of an EMR at the end of its lifecycle on nurses' workload. It was found that mental and temporal demands were the most responsible for the workload. Further work along these lines is recommended.

Modeling of Driver Steering Operations in Lateral Wind Disturbances toward Driver Assistance System

NASA Astrophysics Data System (ADS)

Kurata, Yoshinori; Wada, Takahiro; Kamiji, Norimasa; Doi, Shun'ichi

Disturbances decrease vehicle stability and increase driver's mental and physical workload. Especially unexpected disturbances such as lateral winds have severe effect on vehicle stability and driver's workload. This study aims at building a driver model of steering operations in lateral wind toward developing effective driver assistance system. First, the relationship between the driver's lateral motion and its reactive quick steering behavior is investigated using driving simulator with lateral 1dof motion. In the experiments, four different wind patterns are displayed by the simulator. As the results, strong correlation was found between the driver's head lateral jerk by the lateral disturbance and the angular acceleration of the steering wheel. Then, we build a mathematical model of driver's steering model from lateral disturbance input to steering torque of the reactive quick feed-forward steering based on the experimental results. Finally, validity of the proposed model is shown by comparing the steering torque of experimental results and that of simulation results.

Advanced Multimodal Solutions for Information Presentation

NASA Technical Reports Server (NTRS)

Wenzel, Elizabeth M.; Godfroy-Cooper, Martine

2018-01-01

High-workload, fast-paced, and degraded sensory environments are the likeliest candidates to benefit from multimodal information presentation. For example, during EVA (Extra-Vehicular Activity) and telerobotic operations, the sensory restrictions associated with a space environment provide a major challenge to maintaining the situation awareness (SA) required for safe operations. Multimodal displays hold promise to enhance situation awareness and task performance by utilizing different sensory modalities and maximizing their effectiveness based on appropriate interaction between modalities. During EVA, the visual and auditory channels are likely to be the most utilized with tasks such as monitoring the visual environment, attending visual and auditory displays, and maintaining multichannel auditory communications. Previous studies have shown that compared to unimodal displays (spatial auditory or 2D visual), bimodal presentation of information can improve operator performance during simulated extravehicular activity on planetary surfaces for tasks as diverse as orientation, localization or docking, particularly when the visual environment is degraded or workload is increased. Tactile displays offer a third sensory channel that may both offload information processing effort and provide a means to capture attention when urgently required. For example, recent studies suggest that including tactile cues may result in increased orientation and alerting accuracy, improved task response time and decreased workload, as well as provide self-orientation cues in microgravity on the ISS (International Space Station). An important overall issue is that context-dependent factors like task complexity, sensory degradation, peripersonal vs. extrapersonal space operations, workload, experience level, and operator fatigue tend to vary greatly in complex real-world environments and it will be difficult to design a multimodal interface that performs well under all conditions. As a possible solution, adaptive systems have been proposed in which the information presented to the user changes as a function of taskcontext-dependent factors. However, this presupposes that adequate methods for detecting andor predicting such factors are developed. Further, research in adaptive systems for aviation suggests that they can sometimes serve to increase workload and reduce situational awareness. It will be critical to develop multimodal display guidelines that include consideration of smart systems that can select the best display method for a particular contextsituation.The scope of the current work is an analysis of potential multimodal display technologies for long duration missions and, in particular, will focus on their potential role in EVA activities. The review will address multimodal (combined visual, auditory andor tactile) displays investigated by NASA, industry, and DoD (Dept. of Defense). It also considers the need for adaptive information systems to accommodate a variety of operational contexts such as crew status (e.g., fatigue, workload level) and task environment (e.g., EVA, habitat, rover, spacecraft). Current approaches to guidelines and best practices for combining modalities for the most effective information displays are also reviewed. Potential issues in developing interface guidelines for the Exploration Information System (EIS) are briefly considered.

Crew workload-management strategies - A critical factor in system performance

NASA Technical Reports Server (NTRS)

Hart, Sandra G.

1989-01-01

This paper reviews the philosophy and goals of the NASA/USAF Strategic Behavior/Workload Management Program. The philosophical foundation of the program is based on the assumption that an improved understanding of pilot strategies will clarify the complex and inconsistent relationships observed among objective task demands and measures of system performance and pilot workload. The goals are to: (1) develop operationally relevant figures of merit for performance, (2) quantify the effects of strategic behaviors on system performance and pilot workload, (3) identify evaluation criteria for workload measures, and (4) develop methods of improving pilots' abilities to manage workload extremes.

An Annotated Bibliography on Operator Mental Workload Assessment

DTIC Science & Technology

1980-03-26

The descriptors associated with each citation designate the general workload classification, the specific workload classification, tue type of...systems, with all of their advanced sen3ors and avionics, must be compatible with the capabilities and limitations of the aircrew. During the design ...constructs or models was included only if mental workload was at least potentially assessable from the constructs or models. C. Experimental design . A

Research papers and publications (1981-1987): Workload research program

NASA Technical Reports Server (NTRS)

Hart, Sandra G. (Compiler)

1987-01-01

An annotated bibliography of the research reports written by participants in NASA's Workload Research Program since 1981 is presented, representing the results of theoretical and applied research conducted at Ames Research Center and at universities and industrial laboratories funded by the program. The major program elements included: 1) developing an understanding of the workload concept; 2) providing valid, reliable, and practical measures of workload; and 3) creating a computer model to predict workload. The goal is to provide workload-related design principles, measures, guidelines, and computational models. The research results are transferred to user groups by establishing close ties with manufacturers, civil and military operators of aerospace systems, and regulatory agencies; publishing scientific articles; participating in and sponsoring workshops and symposia; providing information, guidelines, and computer models; and contributing to the formulation of standards. In addition, the methods and theories developed have been applied to specific operational and design problems at the request of a number of industry and government agencies.

Experiment Description and Results for Arrival Operations Using Interval Management with Spacing to Parallel Dependent Runways (IMSPiDR)

NASA Technical Reports Server (NTRS)

Baxley, Brian T.; Murdoch, Jennifer L.; Swieringa, Kurt A.; Barmore, Bryan E.; Capron, William R.; Hubbs, Clay E.; Shay, Richard F.; Abbott, Terence S.

2013-01-01

The predicted increase in the number of commercial aircraft operations creates a need for improved operational efficiency. Two areas believed to offer increases in aircraft efficiency are optimized profile descents and dependent parallel runway operations. Using Flight deck Interval Management (FIM) software and procedures during these operations, flight crews can achieve by the runway threshold an interval assigned by air traffic control (ATC) behind the preceding aircraft that maximizes runway throughput while minimizing additional fuel consumption and pilot workload. This document describes an experiment where 24 pilots flew arrivals into the Dallas Fort-Worth terminal environment using one of three simulators at NASA?s Langley Research Center. Results indicate that pilots delivered their aircraft to the runway threshold within +/- 3.5 seconds of their assigned time interval, and reported low workload levels. In general, pilots found the FIM concept, procedures, speeds, and interface acceptable. Analysis of the time error and FIM speed changes as a function of arrival stream position suggest the spacing algorithm generates stable behavior while in the presence of continuous (wind) or impulse (offset) error. Concerns reported included multiple speed changes within a short time period, and an airspeed increase followed shortly by an airspeed decrease.

Using machine learning and real-time workload assessment in a high-fidelity UAV simulation environment

NASA Astrophysics Data System (ADS)

Monfort, Samuel S.; Sibley, Ciara M.; Coyne, Joseph T.

2016-05-01

Future unmanned vehicle operations will see more responsibilities distributed among fewer pilots. Current systems typically involve a small team of operators maintaining control over a single aerial platform, but this arrangement results in a suboptimal configuration of operator resources to system demands. Rather than devoting the full-time attention of several operators to a single UAV, the goal should be to distribute the attention of several operators across several UAVs as needed. Under a distributed-responsibility system, operator task load would be continuously monitored, with new tasks assigned based on system needs and operator capabilities. The current paper sought to identify a set of metrics that could be used to assess workload unobtrusively and in near real-time to inform a dynamic tasking algorithm. To this end, we put 20 participants through a variable-difficulty multiple UAV management simulation. We identified a subset of candidate metrics from a larger pool of pupillary and behavioral measures. We then used these metrics as features in a machine learning algorithm to predict workload condition every 60 seconds. This procedure produced an overall classification accuracy of 78%. An automated tasker sensitive to fluctuations in operator workload could be used to efficiently delegate tasks for teams of UAV operators.

A unique approach to quantifying the changing workload and case mix in laparoscopic colorectal surgery.

PubMed

Shah, P R; Gupta, V; Haray, P N

2011-03-01

Laparoscopic colorectal surgery includes a range of operations with differing technical difficulty, and traditional parameters, such as conversion and complication rates, may not be sensitive enough to assess the complexity of these procedures. This study aims to define a reproducible and reliable tool for quantifying the total workload and the complexity of the case mix. This is a review of a single surgeon's 10-year experience. The intermediate equivalent value scoring system was used to code complexity of cases. To assess changes in the workload and case mix, the period has been divided into five phases. Three hundred and forty-nine laparoscopic operations were performed, of which there were 264 (75.6%) resections. The overall conversion rate was 17.8%, with progressive improvement over the phases. Complex major operation (CMO), as defined in the British United Provident Association (BUPA) schedule of procedures, accounted for 35% of the workload. In spite of similar numbers of cases in each phase, there was a steady increase in the workload score, correlating with the increasing complexity of the case mix. There was no significant difference in the conversion and complications rates between CMO and non-CMO. The paradoxical increase in the mean operating time with increasing experience corresponded to the progressive increase in the workload score, reflecting the increasing complexity of the case mix. This article establishes a reliable and reproducible tool for quantifying the total laparoscopic colorectal workload of an individual surgeon or of an entire department, while at the same time providing a measure of the complexity of the case mix. © 2011 The Authors. Colorectal Disease © 2011 The Association of Coloproctology of Great Britain and Ireland.

State of science: mental workload in ergonomics.

PubMed

Young, Mark S; Brookhuis, Karel A; Wickens, Christopher D; Hancock, Peter A

2015-01-01

Mental workload (MWL) is one of the most widely used concepts in ergonomics and human factors and represents a topic of increasing importance. Since modern technology in many working environments imposes ever more cognitive demands upon operators while physical demands diminish, understanding how MWL impinges on performance is increasingly critical. Yet, MWL is also one of the most nebulous concepts, with numerous definitions and dimensions associated with it. Moreover, MWL research has had a tendency to focus on complex, often safety-critical systems (e.g. transport, process control). Here we provide a general overview of the current state of affairs regarding the understanding, measurement and application of MWL in the design of complex systems over the last three decades. We conclude by discussing contemporary challenges for applied research, such as the interaction between cognitive workload and physical workload, and the quantification of workload 'redlines' which specify when operators are approaching or exceeding their performance tolerances.

Eye Tracking Metrics for Workload Estimation in Flight Deck Operation

NASA Technical Reports Server (NTRS)

Ellis, Kyle; Schnell, Thomas

2010-01-01

Flight decks of the future are being enhanced through improved avionics that adapt to both aircraft and operator state. Eye tracking allows for non-invasive analysis of pilot eye movements, from which a set of metrics can be derived to effectively and reliably characterize workload. This research identifies eye tracking metrics that correlate to aircraft automation conditions, and identifies the correlation of pilot workload to the same automation conditions. Saccade length was used as an indirect index of pilot workload: Pilots in the fully automated condition were observed to have on average, larger saccadic movements in contrast to the guidance and manual flight conditions. The data set itself also provides a general model of human eye movement behavior and so ostensibly visual attention distribution in the cockpit for approach to land tasks with various levels of automation, by means of the same metrics used for workload algorithm development.

Neutron beam irradiation study of workload dependence of SER in a microprocessor

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

Michalak, Sarah E; Graves, Todd L; Hong, Ted

It is known that workloads are an important factor in soft error rates (SER), but it is proving difficult to find differentiating workloads for microprocessors. We have performed neutron beam irradiation studies of a commercial microprocessor under a wide variety of workload conditions from idle, performing no operations, to very busy workloads resembling real HPC, graphics, and business applications. There is evidence that the mean times to first indication of failure, MTFIF defined in Section II, may be different for some of the applications.

Workload Capacity: A Response Time-Based Measure of Automation Dependence.

PubMed

Yamani, Yusuke; McCarley, Jason S

2016-05-01

An experiment used the workload capacity measure C(t) to quantify the processing efficiency of human-automation teams and identify operators' automation usage strategies in a speeded decision task. Although response accuracy rates and related measures are often used to measure the influence of an automated decision aid on human performance, aids can also influence response speed. Mean response times (RTs), however, conflate the influence of the human operator and the automated aid on team performance and may mask changes in the operator's performance strategy under aided conditions. The present study used a measure of parallel processing efficiency, or workload capacity, derived from empirical RT distributions as a novel gauge of human-automation performance and automation dependence in a speeded task. Participants performed a speeded probabilistic decision task with and without the assistance of an automated aid. RT distributions were used to calculate two variants of a workload capacity measure, COR(t) and CAND(t). Capacity measures gave evidence that a diagnosis from the automated aid speeded human participants' responses, and that participants did not moderate their own decision times in anticipation of diagnoses from the aid. Workload capacity provides a sensitive and informative measure of human-automation performance and operators' automation dependence in speeded tasks. © 2016, Human Factors and Ergonomics Society.

Cognitive consequences of clumsy automation on high workload, high consequence human performance

NASA Technical Reports Server (NTRS)

Cook, Richard I.; Woods, David D.; Mccolligan, Elizabeth; Howie, Michael B.

1991-01-01

The growth of computational power has fueled attempts to automate more of the human role in complex problem solving domains, especially those where system faults have high consequences and where periods of high workload may saturate the performance capacity of human operators. Examples of these domains include flightdecks, space stations, air traffic control, nuclear power operation, ground satellite control rooms, and surgical operating rooms. Automation efforts may have unanticipated effects on human performance, particularly if they increase the workload at peak workload times or change the practitioners' strategies for coping with workload. Smooth and effective changes in automation requires detailed understanding of the congnitive tasks confronting the user: it has been called user centered automation. The introduction of a new computerized technology in a group of hospital operating rooms used for heart surgery was observed. The study revealed how automation, especially 'clumsy automation', effects practitioner work patterns and suggest that clumsy automation constrains users in specific and significant ways. Users tailor both the new system and their tasks in order to accommodate the needs of process and production. The study of this tailoring may prove a powerful tool for exposing previously hidden patterns of user data processing, integration, and decision making which may, in turn, be useful in the design of more effective human-machine systems.

An Ecological Approach to the Design of UAV Ground Control Station (GCS) Status Displays

NASA Technical Reports Server (NTRS)

Dowell, Susan; Morphew, Ephimia; Shively, Jay

2003-01-01

Use of UAVs in military and commercial applications will continue to increase. However, there has been limited research devoted to UAV GCS design. The current study employed an ecological approach to interfac e design. Ecological Interface Design (EID) can be characterized as r epresenting the properties of a system, such that an operator is enco uraged to use skill-based behavior when problem solving. When more ef fortful cognitive processes become necessary due to unfamiliar situations, the application of EID philosophy supports the application of kn owledge-based behavior. With advances toward multiple UAV command and control, operators need GCS interfaces designed to support understan ding of complex systems. We hypothesized that use of EID principles f or the display of UAV status information would result in better opera tor performance and situational awareness, while decreasing workload. Pilots flew a series of missions with three UAV GCS displays of statu s information (Alphanumeric, Ecological, and Hybrid display format). Measures of task performance, Situational Awareness, and workload dem onstrated the benefits of using an ecological approach to designing U AV GCS displays. The application of ecological principles to the design of UAV GCSs is a promising area for improving UAV operations.

Heavy vehicle driver workload assessment. Task 7A, in-cab text message system and cellular phone use by heavy vehicle drivers on road

DOT National Transportation Integrated Search

This report covers the seventh in a series of tasks involving the assessment of driver workload in heavy vehicle operation associated with in-cab devices or systems. This report addresses the application of a workload assessment protocol and measurem...

Subjective scaling of mental workload in a multi-task environment

NASA Technical Reports Server (NTRS)

Daryanian, B.

1982-01-01

Those factors in a multi-task environment that contribute to the operators' "sense" of mental workload were identified. The subjective judgment as conscious experience of mental effort was decided to be the appropriate method of measurement. Thurstone's law of comparative judgment was employed in order to construct interval scales of subjective mental workload from paired comparisons data. An experimental paradigm (Simulated Multi-Task Decision-Making Environment) was employed to represent the ideal experimentally controlled environment in which human operators were asked to "attend" to different cases of Tulga's decision making tasks. Through various statistical analyses it was found that, in general, a lower number of tasks-to-be-processed per unit time (a condition associated with longer interarrival times), results in a lower mental workload, a higher consistency of judgments within a subject, a higher degree of agreement among the subjects, and larger distances between the cases on the Thurstone scale of subjective mental workload. The effects of various control variables and their interactions, and the different characteristics of the subjects on the variation of subjective mental workload are demonstrated.

The psychometrics of mental workload: multiple measures are sensitive but divergent.

PubMed

Matthews, Gerald; Reinerman-Jones, Lauren E; Barber, Daniel J; Abich, Julian

2015-02-01

A study was run to test the sensitivity of multiple workload indices to the differing cognitive demands of four military monitoring task scenarios and to investigate relationships between indices. Various psychophysiological indices of mental workload exhibit sensitivity to task factors. However, the psychometric properties of multiple indices, including the extent to which they intercorrelate, have not been adequately investigated. One hundred fifty participants performed in four task scenarios based on a simulation of unmanned ground vehicle operation. Scenarios required threat detection and/or change detection. Both single- and dual-task scenarios were used. Workload metrics for each scenario were derived from the electroencephalogram (EEG), electrocardiogram, transcranial Doppler sonography, functional near infrared, and eye tracking. Subjective workload was also assessed. Several metrics showed sensitivity to the differing demands of the four scenarios. Eye fixation duration and the Task Load Index metric derived from EEG were diagnostic of single-versus dual-task performance. Several other metrics differentiated the two single tasks but were less effective in differentiating single- from dual-task performance. Psychometric analyses confirmed the reliability of individual metrics but failed to identify any general workload factor. An analysis of difference scores between low- and high-workload conditions suggested an effort factor defined by heart rate variability and frontal cortex oxygenation. General workload is not well defined psychometrically, although various individual metrics may satisfy conventional criteria for workload assessment. Practitioners should exercise caution in using multiple metrics that may not correspond well, especially at the level of the individual operator.

Adaptation of time line analysis program to single pilot instrument flight research

NASA Technical Reports Server (NTRS)

Hinton, D. A.; Shaughnessy, J. D.

1978-01-01

A data base was developed for SPIFR operation and the program was run. The outputs indicated that further work was necessary on the workload models. In particular, the workload model for the cognitive channel should be modified as the output workload appears to be too small. Included in the needed refinements are models to show the workload when in turbulence, when overshooting a radial or glideslope, and when copying air traffic control clearances.

Transport pilot workload - A comparison of two subjective techniques

NASA Technical Reports Server (NTRS)

Battiste, Vernol; Bortolussi, Michael

1988-01-01

Although SWAT and NASA-TLX workload scales have been compared on numerous occasions, they have not been compared in the context of transport operations. Transport pilot workload has traditionally been classified as long periods of low workload with occasional spikes of high workload. Thus, the relative sensitivity of the scales to variations in workload at the low end of the scale were evaluated. This study was a part of a larger study which investigated workload measures for aircraft certification, conducted in a Phase II certified Link/Boeing 727 simulator. No significant main effects were found for any performance-based measures of workload. However, both SWAT and NASA-TLX were sensitive to differences between high and low workload flights and to differences among flight segments. NASA-TLX (but not SWAT) was sensitive to the increase in workload during the cruise segment of the high workload flight. Between-subject variability was high for SWAT. NASA-TLX was found to be stable when compared in the test/retest paradigm. A test/retest by segment interaction suggested that this was not the case for SWAT ratings.

Evaluation of Physiologically-Based Artificial Neural Network Models to Detect Operator Workload in Remotely Piloted Aircraft Operations

DTIC Science & Technology

2016-07-13

to a computer via Bluetooth . Respiration is captured as a breathing waveform signal using a capacitive pressure sensor, sampled at 18 Hz. The...dropouts in the Bluetooth signal and artifacts caused by body movement. Workload models. Four artificial neural network models were created using

Utility of an airframe referenced spatial auditory display for general aviation operations

NASA Astrophysics Data System (ADS)

Naqvi, M. Hassan; Wigdahl, Alan J.; Ranaudo, Richard J.

2009-05-01

The University of Tennessee Space Institute (UTSI) completed flight testing with an airframe-referenced localized audio cueing display. The purpose was to assess its affect on pilot performance, workload, and situational awareness in two scenarios simulating single-pilot general aviation operations under instrument meteorological conditions. Each scenario consisted of 12 test procedures conducted under simulated instrument meteorological conditions, half with the cue off, and half with the cue on. Simulated aircraft malfunctions were strategically inserted at critical times during each test procedure. Ten pilots participated in the study; half flew a moderate workload scenario consisting of point to point navigation and holding pattern operations and half flew a high workload scenario consisting of non precision approaches and missed approach procedures. Flight data consisted of aircraft and navigation state parameters, NASA Task Load Index (TLX) assessments, and post-flight questionnaires. With localized cues there was slightly better pilot technical performance, a reduction in workload, and a perceived improvement in situational awareness. Results indicate that an airframe-referenced auditory display has utility and pilot acceptance in general aviation operations.

Adaptive Automation Triggered by EEG-Based Mental Workload Index: A Passive Brain-Computer Interface Application in Realistic Air Traffic Control Environment.

PubMed

Aricò, Pietro; Borghini, Gianluca; Di Flumeri, Gianluca; Colosimo, Alfredo; Bonelli, Stefano; Golfetti, Alessia; Pozzi, Simone; Imbert, Jean-Paul; Granger, Géraud; Benhacene, Raïlane; Babiloni, Fabio

2016-01-01

Adaptive Automation (AA) is a promising approach to keep the task workload demand within appropriate levels in order to avoid both the under - and over-load conditions, hence enhancing the overall performance and safety of the human-machine system. The main issue on the use of AA is how to trigger the AA solutions without affecting the operative task. In this regard, passive Brain-Computer Interface (pBCI) systems are a good candidate to activate automation, since they are able to gather information about the covert behavior (e.g., mental workload) of a subject by analyzing its neurophysiological signals (i.e., brain activity), and without interfering with the ongoing operational activity. We proposed a pBCI system able to trigger AA solutions integrated in a realistic Air Traffic Management (ATM) research simulator developed and hosted at ENAC (É cole Nationale de l'Aviation Civile of Toulouse, France). Twelve Air Traffic Controller (ATCO) students have been involved in the experiment and they have been asked to perform ATM scenarios with and without the support of the AA solutions. Results demonstrated the effectiveness of the proposed pBCI system, since it enabled the AA mostly during the high-demanding conditions (i.e., overload situations) inducing a reduction of the mental workload under which the ATCOs were operating. On the contrary, as desired, the AA was not activated when workload level was under the threshold, to prevent too low demanding conditions that could bring the operator's workload level toward potentially dangerous conditions of underload.

Adaptive Automation Triggered by EEG-Based Mental Workload Index: A Passive Brain-Computer Interface Application in Realistic Air Traffic Control Environment

PubMed Central

Aricò, Pietro; Borghini, Gianluca; Di Flumeri, Gianluca; Colosimo, Alfredo; Bonelli, Stefano; Golfetti, Alessia; Pozzi, Simone; Imbert, Jean-Paul; Granger, Géraud; Benhacene, Raïlane; Babiloni, Fabio

2016-01-01

Adaptive Automation (AA) is a promising approach to keep the task workload demand within appropriate levels in order to avoid both the under- and over-load conditions, hence enhancing the overall performance and safety of the human-machine system. The main issue on the use of AA is how to trigger the AA solutions without affecting the operative task. In this regard, passive Brain-Computer Interface (pBCI) systems are a good candidate to activate automation, since they are able to gather information about the covert behavior (e.g., mental workload) of a subject by analyzing its neurophysiological signals (i.e., brain activity), and without interfering with the ongoing operational activity. We proposed a pBCI system able to trigger AA solutions integrated in a realistic Air Traffic Management (ATM) research simulator developed and hosted at ENAC (École Nationale de l'Aviation Civile of Toulouse, France). Twelve Air Traffic Controller (ATCO) students have been involved in the experiment and they have been asked to perform ATM scenarios with and without the support of the AA solutions. Results demonstrated the effectiveness of the proposed pBCI system, since it enabled the AA mostly during the high-demanding conditions (i.e., overload situations) inducing a reduction of the mental workload under which the ATCOs were operating. On the contrary, as desired, the AA was not activated when workload level was under the threshold, to prevent too low demanding conditions that could bring the operator's workload level toward potentially dangerous conditions of underload. PMID:27833542

The Independence and Interdependence of Coacting Observers in Regard to Performance Efficiency, Workload, and Stress in a Vigilance Task.

PubMed

Funke, Gregory J; Warm, Joel S; Baldwin, Carryl L; Garcia, Andre; Funke, Matthew E; Dillard, Michael B; Finomore, Victor S; Matthews, Gerald; Greenlee, Eric T

2016-09-01

We investigated performance, workload, and stress in groups of paired observers who performed a vigilance task in a coactive (independent) manner. Previous studies have demonstrated that groups of coactive observers detect more signals in a vigilance task than observers working alone. Therefore, the use of such groups might be effective in enhancing signal detection in operational situations. However, concern over appearing less competent than one's cohort might induce elevated levels of workload and stress in coactive group members and thereby undermine group performance benefits. Accordingly, we performed the initial experiment comparing workload and stress in observers who performed a vigilance task coactively with those of observers who performed the vigilance task alone. Observers monitored a video display for collision flight paths in a simulated unmanned aerial vehicle control task. Self-reports of workload and stress were secured via the NASA-Task Load Index and the Dundee Stress State Questionnaire, respectively. Groups of coactive observers detected significantly more signals than did single observers. Coacting observers did not differ significantly from those operating by themselves in terms of workload but did in regard to stress; posttask distress was significantly lower for coacting than for single observers. Performing a visual vigilance task in a coactive manner with another observer does not elevate workload above that of observers working alone and serves to attenuate the stress associated with vigilance task performance. The use of coacting observers could be an effective vehicle for enhancing performance efficiency in operational vigilance. © 2016, Human Factors and Ergonomics Society.

Real-Time Performance Feedback for the Manual Control of Spacecraft

NASA Astrophysics Data System (ADS)

Karasinski, John Austin

Real-time performance metrics were developed to quantify workload, situational awareness, and manual task performance for use as visual feedback to pilots of aerospace vehicles. Results from prior lunar lander experiments with variable levels of automation were replicated and extended to provide insights for the development of real-time metrics. Increased levels of automation resulted in increased flight performance, lower workload, and increased situational awareness. Automated Speech Recognition (ASR) was employed to detect verbal callouts as a limited measure of subjects' situational awareness. A one-dimensional manual tracking task and simple instructor-model visual feedback scheme was developed. This feedback was indicated to the operator by changing the color of a guidance element on the primary flight display, similar to how a flight instructor points out elements of a display to a student pilot. Experiments showed that for this low-complexity task, visual feedback did not change subject performance, but did increase the subjects' measured workload. Insights gained from these experiments were applied to a Simplified Aid for EVA Rescue (SAFER) inspection task. The effects of variations of an instructor-model performance-feedback strategy on human performance in a novel SAFER inspection task were investigated. Real-time feedback was found to have a statistically significant effect of improving subject performance and decreasing workload in this complicated four degree of freedom manual control task with two secondary tasks.

Special Operations Forces: Opportunities Exist to Improve Transparency of Funding and Assess Potential to Lessen Some Deployments

DTIC Science & Technology

2015-07-01

pace of special operations deployments, but opportunities may exist to better balance the workload across the joint force because activities...executes funding in operation and maintenance; procurement; research , development, test, and evaluation; and military construction accounts.13 SOCOM...regional awareness. Moreover, officials noted that increases in civilian positions were driven partly by DOD’s attempts to rebalance workload and become a

Recent trends in workload, input costs, and expenditures in the Air Force Medical Service Direct Care System.

PubMed

Robbins, Anthony S; Moilanen, Dale A; Fonseca, Vincent P; Chao, Susan Y

2002-04-01

A study was conducted to examine the relationship between two types of trends in the Air Force Medical Service Direct Care System (AFMS/DCS): trends in expenditures, total and by categories; and trends in medical workload, defined as the sum of inpatient admissions and outpatient clinic visits. Expenditure and medical workload data were extracted from the Medical Expense and Performance Reporting System Executive Query System. Medical inflation data were obtained from the Bureau of Labor Statistics Producer Price Index series. Between fiscal years 1995 and 1999, the AFMS/DCS experienced a 21.2% decrease in medical workload, but total (nominal) expenditures declined only 3.6%. Of all expenditure categories, only inpatient medical care, outpatient medical care, and military-funded private sector care for active duty personnel (supplemental care) have any direct relationship with AFMS/DCS medical workload. Real expenditures for the three categories above decreased by 20.3% during the 5-year period. Accounting for inflation and considering only expenditures related to medical workload, these results suggest that the AFMS/DCS is spending approximately 20% less money to do approximately 20% less work.

Interaction between workload and training - Converging evidence from psychophysiology and performance measurement

NASA Technical Reports Server (NTRS)

Kramer, Arthur F.

1986-01-01

Traditionally, the domains of mental workload and training have been studied in isolation even though they share many common characteristics. The present paper integrates findings from psychophysiological and performance-based studies which address both of these issues. By augmenting traditional indices of skill acquisition such as RMS error scores, reaction times, and accuracy measures with psychophysiological measures such as the event-related brain potential, it is shown that workload effects can be assessed throughout the training process. More specifically, it is argued that the development of skill and the effects of workload on the human operator can be modeled within the framework of resource theories of attentional allocation. Also described is how converging evidence from psychophysiological and behavioral studies can be used to examine subtle changes in operator strategies during training.

High-energy phosphate metabolism during incremental calf exercise in humans measured by 31 phosphorus magnetic resonance spectroscopy (31P MRS).

PubMed

Schocke, Michael F H; Esterhammer, Regina; Kammerlander, Christian; Rass, Anton; Kremser, Christian; Fraedrich, Gustav; Jaschke, Werner R; Greiner, Andreas

2004-01-01

Several previous 31 phosphorus magnetic resonance spectroscopy ((31)P MRS) studies performing incremental or progressive muscle exercises have observed that a decrease in pH is accompanied with an acceleration in phosphocreatine (PCr) hydrolysis. The purpose of this study was to investigate the relationship between PCr breakdown and pH during isotonic, exhaustive, incremental plantar flexion exercises. We included eight healthy, male volunteers into this study. Using a 1.5 Tesla MR scanner and a self-built exercise bench, we performed serial free induction decay (FID) (31)P MRS measurements with a time resolution of 1 min at rest, isotonic calf muscle exercise, and recovery. The exercise protocol consisted of 5-min intervals with 4.5, 6, 7.5, and 9 W workload followed by 9-min recovery. Changes in PCr and inorganic phosphate (Pi) were determined as percent changes in comparison to the baseline. In addition, pH values were calculated. This study obtained significant decreases in PCr corresponding to the gradual increases in workload. In each workload level that was succeeded by all volunteers, PCr hydrolysis passed into a steady state. After an early biphasic response, we detected a significant decrease in pH from the first to the second minute of the 6-W workload level followed by a further continuous decrease in pH up to the second minute of the recovery phase. The decrease in pH was not accompanied by acceleration in PCr hydrolysis. In conclusion, this study shows that PCr hydrolysis during incremental plantar flexion exercises passes into a steady state at different workload levels. The observed decrease in pH does not result in acceleration of PCr hydrolysis.

Mental workload in decision and control

NASA Technical Reports Server (NTRS)

Sheridan, T. B.

1979-01-01

This paper briefly reviews the problems of defining and measuring the 'mental workload' of aircraft pilots and other human operators of complex dynamic systems. Of the alternative approaches the author indicates a clear preference for the use of subjective scaling. Some recent experiments from MIT and elsewhere are described which utilize subjective mental workload scales in conjunction with human decision and control tasks in the laboratory. Finally a new three-dimensional mental workload rating scale, under current development for use by IFR aircraft pilots, is presented.

Viewing the workload of vigilance through the lenses of the NASA-TLX and the MRQ.

PubMed

Finomore, Victor S; Shaw, Tyler H; Warm, Joel S; Matthews, Gerald; Boles, David B

2013-12-01

The aim of this study was to compare the effectiveness of a new index of perceived mental workload, the Multiple Resource Questionnaire (MRQ), with the standard measure of workload used in the study of vigilance, the NASA Task Load Index (NASA-TLX). The NASA-TLX has been used extensively to demonstrate that vigilance tasks impose a high level of workload on observers. However, this instrument does not specify the information-processing resources needed for task performance. The MRQ offers a tool to measure the workload associated with vigilance assignments in which such resources can be identified. Two experiments were performed in which factors known to influence task demand were varied. Included were the detection of stimulus presence or absence, detecting critical signals by means of successive-type (absolute judgment) and simultaneous-type (comparative judgment) discriminations, and operating under multitask vs. single-task conditions. The MRQ paralleled the NASA-TLX in showing that vigilance tasks generally induce high levels of workload and that workload scores are greater in detecting stimulus absence than presence and in making successive as compared to simultaneous-type discriminations. Additionally, the MRQ was more effective than the NASA-TLX in reflecting higher workload in the context of multitask than in single-task conditions. The resource profiles obtained with MRQ fit well with the nature of the vigilance tasks employed, testifying to the scale's content validity. The MRQ may be a meaningful addition to the NASA-TLX for measuring the workload of vigilance assignments. By uncovering knowledge representation associated with different tasks, the MRQ may aid in designing operational vigilance displays.

The role of human-automation consensus in multiple unmanned vehicle scheduling.

PubMed

Cummings, M L; Clare, Andrew; Hart, Christin

2010-02-01

This study examined the impact of increasing automation replanning rates on operator performance and workload when supervising a decentralized network of heterogeneous unmanned vehicles. Futuristic unmanned vehicles systems will invert the operator-to-vehicle ratio so that one operator can control multiple dissimilar vehicles connected through a decentralized network. Significant human-automation collaboration will be needed because of automation brittleness, but such collaboration could cause high workload. Three increasing levels of replanning were tested on an existing multiple unmanned vehicle simulation environment that leverages decentralized algorithms for vehicle routing and task allocation in conjunction with human supervision. Rapid replanning can cause high operator workload, ultimately resulting in poorer overall system performance. Poor performance was associated with a lack of operator consensus for when to accept the automation's suggested prompts for new plan consideration as well as negative attitudes toward unmanned aerial vehicles in general. Participants with video game experience tended to collaborate more with the automation, which resulted in better performance. In decentralized unmanned vehicle networks, operators who ignore the automation's requests for new plan consideration and impose rapid replans both increase their own workload and reduce the ability of the vehicle network to operate at its maximum capacity. These findings have implications for personnel selection and training for futuristic systems involving human collaboration with decentralized algorithms embedded in networks of autonomous systems.

Mental workload associated with operating an agricultural sprayer: an empirical approach.

PubMed

Dey, A K; Mann, D D

2011-04-01

Agricultural spraying involves two major tasks: guiding a sprayer in response to a GPS navigation device, and simultaneous monitoring of rear-attached booms under various illumination and terrain difficulty levels. The aim of the present study was to investigate the effect of illumination, task difficulty, and task level on the mental workload of an individual operating an agricultural sprayer in response to a commercial GPS lightbar, and to explore the sensitivity of the NASA-TLX and SSWAT subjective rating scales in discriminating the subjective experienced workload under various task, illumination, and difficulty levels. Mental workload was measured using performance measures (lateral root mean square error and reaction time), physiological measures (0.1 Hz power of HRV, latency of the P300 component of event-related potential, and eye-glance behavior), and two subjective rating scales (NASA-TLX and SSWAT). Sixteen male university students participated in this experiment, and a fixed-base high-fidelity agricultural tractor simulator was used to create a simulated spraying task. All performance measures, the P300 latency, and subjective rating scales showed a common trend that mental workload increased with the change in illumination from day to night, with task difficulty from low to high, and with task type from single to dual. The 0.1 Hz power of HRV contradicted the performance measures. Eye-glance data showed that under night illumination, participants spent more time looking at the lightbar for guidance information. A similar trend was observed with the change in task type from single to dual. Both subjective rating scales showed a common trend of increasing mental workload with the change in illumination, difficulty, and task levels. However, the SSWAT scale was more sensitive than the NASA-TLX scale. With the change in illumination, difficulty, and task levels, participants spent more mental resources to meet the increased task demand; hence, the illumination, task difficulty, and task level affected the mental workload of an agricultural sprayer operator operating a sprayer in response to a GPS lightbar.

How the workload impacts on cognitive cooperation: A pilot study.

PubMed

Sciaraffa, Nicolina; Borghini, Gianluca; Arico, Pietro; Di Flumeri, Gianluca; Toppi, Jlenia; Colosimo, Alfredo; Bezerianos, Anastatios; Thakor, Nitish V; Babiloni, Fabio

2017-07-01

Cooperation degradation can be seen as one of the main causes of human errors. Poor cooperation could arise from aberrant mental processes, such as mental overload, that negatively affect the user's performance. Using different levels of difficulty in a cooperative task, we combined behavioural, subjective and neurophysiological data with the aim to i) quantify the mental workload under which the crew was operating, ii) evaluate the degree of their cooperation, and iii) assess the impact of the workload demands on the cooperation levels. The combination of such data showed that high workload demand impacted significantly on the performance, workload perception, and degree of cooperation.

Workers' load and job-related stress after a reform and work system change in a hospital kitchen in Japan.

PubMed

Matsuzuki, Hiroe; Haruyama, Yasuo; Muto, Takashi; Aikawa, Kaoru; Ito, Akiyoshi; Katamoto, Shizuo

2013-03-01

Many kitchen work environments are considered to be severe; however, when kitchens are reformed or work systems are changed, the question of how this influences kitchen workers and environments arises. The purpose of this study is to examine whether there was a change in workload and job-related stress for workers after a workplace environment and work system change in a hospital kitchen. The study design is a pre-post comparison of a case, performed in 2006 and 2008. The air temperature and humidity in the workplace were measured. Regarding workload, work hours, fluid loss, heart rate, and amount of activity [metabolic equivalents of task (METs)] of 7 and 8 male subjects pre- and post-reform, respectively, were measured. Job-related stress was assessed using a self-reporting anonymous questionnaire for 53 and 45 workers pre- and post-system change, respectively. After the reform and work system change, the kitchen space had increased and air-conditioners had been installed. The workplace environment changes included the introduction of temperature-controlled wagons whose operators were limited to male workers. The kitchen air temperature decreased, so fluid loss in the subjects decreased significantly. However, heart rate and METs in the subjects increased significantly. As for job-related stress, although workplace environment scores improved, male workers' total job stress score increased. These results suggest that not only the workplace environment but also the work system influenced the workload and job stress on workers.

Impact of three task demand factors on simulated unmanned system intelligence, surveillance, and reconnaissance operations.

PubMed

Abich, Julian; Reinerman-Jones, Lauren; Matthews, Gerald

2017-06-01

The present study investigated how three task demand factors influenced performance, subjective workload and stress of novice intelligence, surveillance, and reconnaissance operators within a simulation of an unmanned ground vehicle. Manipulations were task type, dual-tasking and event rate. Participants were required to discriminate human targets within a street scene from a direct video feed (threat detection [TD] task) and detect changes in symbols presented in a map display (change detection [CD] task). Dual-tasking elevated workload and distress, and impaired performance for both tasks. However, with increasing event rate, CD task deteriorated, but TD improved. Thus, standard workload models provide a better guide to evaluating the demands of abstract symbols than to processing realistic human characters. Assessment of stress and workload may be especially important in the design and evaluation of systems in which human character critical signals must be detected in video images. Practitioner Summary: This experiment assessed subjective workload and stress during threat and CD tasks performed alone and in combination. Results indicated an increase in event rate led to significant improvements in performance during TD, but decrements during CD, yet both had associated increases in workload and engagement.

Pilot and Controller Workload and Situation Awareness with Three Traffic Management Concept

NASA Technical Reports Server (NTRS)

Vu, Kim-Phuong L.; Strybel, Thomas Z.; Kraut, Joshua; Bacon, Paige; Minakata, Katsumi; Battiste, Vernol; Johnson, Walter

2010-01-01

This paper reports on workload and situation awareness of pilots and controllers participating in a human-in-the-loop simulation using three different distributed air-ground traffic management concepts. Eight experimental pilots started the scenario in an en-route phase of flight and were asked to avoid convective weather while performing spacing and merging tasks along with a continuous descent approach (CDA) into Louisville Standiford Airport (SDF). Two controllers managed the sectors through which the pilots flew, with one managing a sector that included the Top of Descent, and the other managing a sector that included the merge point for arrival into SDF. At 3-minute intervals in the scenario, pilots and controllers were probed on their workload or situation awareness. We employed one of three concepts of operation that distributed separation responsibility across human controllers, pilots, and automation to measure changes in operator situation awareness and workload. We found that when pilots were responsible for separation, they had higher levels of awareness, but not necessarily higher levels of workload. When controllers are responsible and actively engaged, they showed higher workload levels compared to pilots and changes in awareness that were dependent on sector characteristics.

Prediction of Traffic Complexity and Controller Workload in Mixed Equipage NextGen Environments

NASA Technical Reports Server (NTRS)

Lee, Paul U.; Prevot, Thomas

2012-01-01

Controller workload is a key factor in limiting en route air traffic capacity. Past efforts to quantify and predict workload have resulted in identifying objective metrics that correlate well with subjective workload ratings during current air traffic control operations. Although these metrics provide a reasonable statistical fit to existing data, they do not provide a good mechanism for estimating controller workload for future air traffic concepts and environments that make different assumptions about automation, enabling technologies, and controller tasks. One such future environment is characterized by en route airspace with a mixture of aircraft equipped with and without Data Communications (Data Comm). In this environment, aircraft with Data Comm will impact controller workload less than aircraft requiring voice communication, altering the close correlation between aircraft count and controller workload that exists in current air traffic operations. This paper outlines a new trajectory-based complexity (TBX) calculation that was presented to controllers during a human-in-the-loop simulation. The results showed that TBX accurately estimated the workload in a mixed Data Comm equipage environment and the resulting complexity values were understood and readily interpreted by the controllers. The complexity was represented as a "modified aircraft account" that weighted different complexity factors and summed them in such a way that the controllers could effectively treat them as aircraft count. The factors were also relatively easy to tune without an extensive data set. The results showed that the TBX approach is well suited for presenting traffic complexity in future air traffic environments.

Exercise in space: the European Space Agency approach to in-flight exercise countermeasures for long-duration missions on ISS.

PubMed

Petersen, Nora; Jaekel, Patrick; Rosenberger, Andre; Weber, Tobias; Scott, Jonathan; Castrucci, Filippo; Lambrecht, Gunda; Ploutz-Snyder, Lori; Damann, Volker; Kozlovskaya, Inessa; Mester, Joachim

2016-01-01

To counteract microgravity (µG)-induced adaptation, European Space Agency (ESA) astronauts on long-duration missions (LDMs) to the International Space Station (ISS) perform a daily physical exercise countermeasure program. Since the first ESA crewmember completed an LDM in 2006, the ESA countermeasure program has strived to provide efficient protection against decreases in body mass, muscle strength, bone mass, and aerobic capacity within the operational constraints of the ISS environment and the changing availability of on-board exercise devices. The purpose of this paper is to provide a description of ESA's individualised approach to in-flight exercise countermeasures and an up-to-date picture of how exercise is used to counteract physiological changes resulting from µG-induced adaptation. Changes in the absolute workload for resistive exercise, treadmill running and cycle ergometry throughout ESA's eight LDMs are also presented, and aspects of pre-flight physical preparation and post-flight reconditioning outlined. With the introduction of the advanced resistive exercise device (ARED) in 2009, the relative contribution of resistance exercise to total in-flight exercise increased (33-46 %), whilst treadmill running (42-33 %) and cycle ergometry (26-20 %) decreased. All eight ESA crewmembers increased their in-flight absolute workload during their LDMs for resistance exercise and treadmill running (running speed and vertical loading through the harness), while cycle ergometer workload was unchanged across missions. Increased or unchanged absolute exercise workloads in-flight would appear contradictory to typical post-flight reductions in muscle mass and strength, and cardiovascular capacity following LDMs. However, increased absolute in-flight workloads are not directly linked to changes in exercise capacity as they likely also reflect the planned, conservative loading early in the mission to allow adaption to µG exercise, including personal comfort issues with novel exercise hardware (e.g. the treadmill harness). Inconsistency in hardware and individualised support concepts across time limit the comparability of results from different crewmembers, and questions regarding the difference between cycling and running in µG versus identical exercise here on Earth, and other factors that might influence in-flight exercise performance, still require further investigation.

Assessment of operators' mental workload using physiological and subjective measures in cement, city traffic and power plant control centers.

PubMed

Fallahi, Majid; Motamedzade, Majid; Heidarimoghadam, Rashid; Soltanian, Ali Reza; Miyake, Shinji

2016-01-01

The present study aimed to evaluate the operators' mental workload (MW) of cement, city traffic control and power plant control centers using subjective and objective measures during system vital parameters monitoring. This cross-sectional study was conducted from June 2014 to February 2015 at the cement, city traffic control and power plant control centers. Electrocardiography and electroencephalography data were recorded from forty males during performing their daily working in resting, low mental workload (LMW), high mental workload (HMW) and recovery conditions (each block 5 minutes). The NASA-Task Load Index (TLX) was used to evaluate the subjective workload of the operators. The results showed that increasing MW had a significant effect on the operators subjective responses in two conditions ([1,53] = 216.303, P < 0.001, η2 = 0.803). Also,the Task-MW interaction effect on operators subjective responses was significant (F [3, 53] = 12.628,P < 0.001, η2 = 0.417). Analysis of repeated measures analysis of variance (ANOVA) indicated that increasing mental demands had a significant effect on heart rate, low frequency/high frequency ratio, theta and alpha band activity. The results suggested that when operators' mental demands especially in traffic control and power plant tasks increased, their mental fatigue and stress level increased and their mental health deteriorated. Therefore, it may be necessary to implement an ergonomic program or administrative control to manage mental probably health in these control centers. Furthermore, by evaluating MW, the control center director can organize the human resources for each MW condition to sustain the appropriate performance as well as improve system functions.

Talking to your car can drive you to distraction.

PubMed

Strayer, David L; Cooper, Joel M; Turrill, Jonna; Coleman, James R; Hopman, Rachel J

2016-01-01

This research examined the impact of in-vehicle information system (IVIS) interactions on the driver's cognitive workload; 257 subjects participated in a weeklong evaluation of the IVIS interaction in one of ten different model-year 2015 automobiles. After an initial assessment of the cognitive workload associated with using the IVIS, participants took the vehicle home for 5 days and practiced using the system. At the end of the 5 days of practice, participants returned and the workload of these IVIS interactions was reassessed. The cognitive workload was found to be moderate to high, averaging 3.34 on a 5-point scale and ranged from 2.37 to 4.57. The workload was associated with the intuitiveness and complexity of the system and the time it took participants to complete the interaction. The workload experienced by older drivers was significantly greater than that experienced by younger drivers performing the same operations. Practice did not eliminate the interference from IVIS interactions. In fact, IVIS interactions that were difficult on the first day were still relatively difficult to perform after a week of practice. Finally, there were long-lasting residual costs after the IVIS interactions had terminated. The higher levels of workload should serve as a caution that these voice-based interactions can be cognitively demanding and ought not to be used indiscriminately while operating a motor vehicle.

A passive brain-computer interface application for the mental workload assessment on professional air traffic controllers during realistic air traffic control tasks.

PubMed

Aricò, P; Borghini, G; Di Flumeri, G; Colosimo, A; Pozzi, S; Babiloni, F

2016-01-01

In the last decades, it has been a fast-growing concept in the neuroscience field. The passive brain-computer interface (p-BCI) systems allow to improve the human-machine interaction (HMI) in operational environments, by using the covert brain activity (eg, mental workload) of the operator. However, p-BCI technology could suffer from some practical issues when used outside the laboratories. In particular, one of the most important limitations is the necessity to recalibrate the p-BCI system each time before its use, to avoid a significant reduction of its reliability in the detection of the considered mental states. The objective of the proposed study was to provide an example of p-BCIs used to evaluate the users' mental workload in a real operational environment. For this purpose, through the facilities provided by the École Nationale de l'Aviation Civile of Toulouse (France), the cerebral activity of 12 professional air traffic control officers (ATCOs) has been recorded while performing high realistic air traffic management scenarios. By the analysis of the ATCOs' brain activity (electroencephalographic signal-EEG) and the subjective workload perception (instantaneous self-assessment) provided by both the examined ATCOs and external air traffic control experts, it has been possible to estimate and evaluate the variation of the mental workload under which the controllers were operating. The results showed (i) a high significant correlation between the neurophysiological and the subjective workload assessment, and (ii) a high reliability over time (up to a month) of the proposed algorithm that was also able to maintain high discrimination accuracies by using a low number of EEG electrodes (~3 EEG channels). In conclusion, the proposed methodology demonstrated the suitability of p-BCI systems in operational environments and the advantages of the neurophysiological measures with respect to the subjective ones. © 2016 Elsevier B.V. All rights reserved.

Cockpit Adaptive Automation and Pilot Performance

NASA Technical Reports Server (NTRS)

Parasuraman, Raja

2001-01-01

The introduction of high-level automated systems in the aircraft cockpit has provided several benefits, e.g., new capabilities, enhanced operational efficiency, and reduced crew workload. At the same time, conventional 'static' automation has sometimes degraded human operator monitoring performance, increased workload, and reduced situation awareness. Adaptive automation represents an alternative to static automation. In this approach, task allocation between human operators and computer systems is flexible and context-dependent rather than static. Adaptive automation, or adaptive task allocation, is thought to provide for regulation of operator workload and performance, while preserving the benefits of static automation. In previous research we have reported beneficial effects of adaptive automation on the performance of both pilots and non-pilots of flight-related tasks. For adaptive systems to be viable, however, such benefits need to be examined jointly in the context of a single set of tasks. The studies carried out under this project evaluated a systematic method for combining different forms of adaptive automation. A model for effective combination of different forms of adaptive automation, based on matching adaptation to operator workload was proposed and tested. The model was evaluated in studies using IFR-rated pilots flying a general-aviation simulator. Performance, subjective, and physiological (heart rate variability, eye scan-paths) measures of workload were recorded. The studies compared workload-based adaptation to to non-adaptive control conditions and found evidence for systematic benefits of adaptive automation. The research provides an empirical basis for evaluating the effectiveness of adaptive automation in the cockpit. The results contribute to the development of design principles and guidelines for the implementation of adaptive automation in the cockpit, particularly in general aviation, and in other human-machine systems. Project goals were met or exceeded. The results of the research extended knowledge of automation-related performance decrements in pilots and demonstrated the positive effects of adaptive task allocation. In addition, several practical implications for cockpit automation design were drawn from the research conducted. A total of 12 articles deriving from the project were published.

Strategic workload management and decision biases in aviation

NASA Technical Reports Server (NTRS)

Raby, Mireille; Wickens, Christopher D.

1994-01-01

Thirty pilots flew three simulated landing approaches under conditions of low, medium, and high workload. Workload conditions were created by varying time pressure and external communications requirements. Our interest was in how the pilots strategically managed or adapted to the increasing workload. We independently assessed the pilot's ranking of the priority of different discrete tasks during the approach and landing. Pilots were found to sacrifice some aspects of primary flight control as workload increased. For discrete tasks, increasing workload increased the amount of time in performing the high priority tasks, decreased the time in performing those of lowest priority, and did not affect duration of performance episodes or optimality of scheduling of tasks of any priority level. Individual differences analysis revealed that high-performing subjects scheduled discrete tasks earlier in the flight and shifted more often between different activities.

Causes of dissociation between subjective workload measures and performance - Caveats for the use of subjective assessments

NASA Technical Reports Server (NTRS)

Vidulich, M. A.; Wickens, C. D.

1985-01-01

Dissociations between subjective workload assessments and performance were investigated. The difficulty of a Sternberg memory search task was manipulated by varying stimulus presentation rate, stimulus discernibility, value of good performance, and automaticity of performance. All Sternberg task conditions were performed both alone and concurrently with a tracking task. Bipolar subjective workload assessments were collected. Dissociations between workload and performance were found related to automaticity, presentation rate, and motivation level. The results were interpreted as supporting the hypothesis that the specific cognitive processes responsible for subjective assessments can differ from those responsible for performance. The potential contamination these dissociations could inflict on operational workload assessments is discussed.

Using Neural Networks to Explore Air Traffic Controller Workload

NASA Technical Reports Server (NTRS)

Martin, Lynne; Kozon, Thomas; Verma, Savita; Lozito, Sandra C.

2006-01-01

When a new system, concept, or tool is proposed in the aviation domain, one concern is the impact that this will have on operator workload. As an experience, workload is difficult to measure in a way that will allow comparison of proposed systems with those already in existence. Chatterji and Sridhar (2001) suggested a method by which airspace parameters can be translated into workload ratings, using a neural network. This approach was employed, and modified to accept input from a non-real time airspace simulation model. The following sections describe the preparations and testing work that will enable comparison of a future airspace concept with a current day baseline in terms of workload levels.

Novel method of measuring the mental workload of anaesthetists during clinical practice.

PubMed

Byrne, A J; Oliver, M; Bodger, O; Barnett, W A; Williams, D; Jones, H; Murphy, A

2010-12-01

Cognitive overload has been recognized as a significant cause of error in industries such as aviation and measuring mental workload has become a key method of improving safety. The aim of this study was to pilot the use of a new method of measuring mental workload in the operating theatre using a previously published methodology. The mental workload of the anaesthetists was assessed by measuring their response times to a wireless vibrotactile device and the NASA TLX subjective workload score during routine surgical procedures. Primary task workload was inferred from the phase of anaesthesia. Significantly increased response time was associated with the induction phase of anaesthesia compared with maintenance/emergence, non-consultant grade, and during more complex cases. Increased response was also associated with self-reported mental load, physical load, and frustration. These findings are consistent with periods of increased mental workload and with the findings of other studies using similar techniques. These findings confirm the importance of mental workload to the performance of anaesthetists and suggest that increased mental workload is likely to be a common problem in clinical practice. Although further studies are required, the method described may be useful for the measurement of the mental workload of anaesthetists.

Innovative technology conserves resources and generates savings: a case study from the Sunnybrook Regional Processing Centre.

PubMed

Karim, Abdool Z

2009-01-01

The regional processing centre at Sunnybrook Health Sciences Centre recently faced the substantial challenge of increasing cleaning capacity to meet the current workload and anticipated future demand without increasing its operating budget. The solution, upgrading its cleaning and decontamination system to a highly automated system, met both objectives. An analysis of the impact of the change found that the new system provided additional benefits, including improved productivity and cleaning quality; decreased costs; reduced water, electricity and chemical use; improved worker safety and morale; and decreased overtime. Investing in innovative technology improved key departmental outcomes while meeting institutional environmental and cost savings objectives.

Pilot Subjective Assessments During an Investigation of Separation Function Allocation Using a Human-In-The-Loop Simulation

NASA Technical Reports Server (NTRS)

Burke, Kelly A.; Wing, David J.; Lewis, Timothy

2013-01-01

Two human-in-the-loop simulation experiments were conducted to investigate allocation of separation assurance functions between ground and air and between humans and automation. The experiments modeled a mixed-operations concept in which aircraft receiving ground-based separation services shared the airspace with aircraft providing their own separation service (i.e., self-separation). The two experiments, one pilot-focused and the other controller-focused, addressed selected key issues of mixed operations and modeling an emergence of NextGen technologies and procedures. This paper focuses on the results of the subjective assessments of pilots collected during the pilot-focused human-in-the-loop simulation, specifically workload and situation awareness. Generally the results revealed that across all conditions, pilots' perceived workload was low to medium, with the highest reported levels of workload occurring when the pilots experienced a loss of separation during the scenario. Furthermore, the results from the workload data and situation awareness data were complimentary such that when pilots reported lower levels of workload they also experienced higher levels of situation awareness.

Evaluation of 16 measures of mental workload using a simulated flight task emphasizing mediational activity

NASA Technical Reports Server (NTRS)

Wierwille, W. W.; Rahimi, M.; Casali, J. G.

1985-01-01

As aircraft and other systems become more automated, a shift is occurring in human operator participation in these systems. This shift is away from manual control and toward activities that tap the higher mental functioning of human operators. Therefore, an experiment was performed in a moving-base flight simulator to assess mediational (cognitive) workload measurement. Specifically, 16 workload estimation techniques were evaluated as to their sensitivity and intrusion in a flight task emphasizing mediational behavior. Task loading, using navigation problems presented on a display, was treated as an independent variable, and workload-measure values were treated as dependent variables. Results indicate that two mediational task measures, two rating scale measures, time estimation, and two eye behavior measures were reliably sensitive to mediational loading. The time estimation measure did, however, intrude on mediational task performance. Several of the remaining measures were completely insensitive to mediational load.

Documentation and Evaluation of Comparability of Overhead Costs Reported for Depot Level Maintenance.

DTIC Science & Technology

1984-12-01

operating results (income statement) and financial condition ( balance sheet) are developed. From this data, stabilized rates are developed and adjusted to...funding budgets based on projected workloads developed at workload conferences. The workload subsystem distributes and balances projected manhours at...is the validation criteria. However, any account with a credit balance is deleted from the UCA data which causes a minor but identifiable

Application and Validation of Workload Assessment Techniques

DTIC Science & Technology

1993-03-01

tech ical report documents the process and outcome of meeting this objective. Procedure: A series of eight separate studies was conducted using three...development process . The task analysis and simulation technique was shown to have the capability to track empirical workload ratings. More research is...operator workload during the systems acquisi- tion process , and (b) a pamphlet for the managers of Army systems that describes the need and some procedures

Human interaction with robotic systems: performance and workload evaluations.

PubMed

Reinerman-Jones, L; Barber, D J; Szalma, J L; Hancock, P A

2017-10-01

We first tested the effect of differing tactile informational forms (i.e. directional cues vs. static cues vs. dynamic cues) on objective performance and perceived workload in a collaborative human-robot task. A second experiment evaluated the influence of task load and informational message type (i.e. single words vs. grouped phrases) on that same collaborative task. In both experiments, the relationship of personal characteristics (attentional control and spatial ability) to performance and workload was also measured. In addition to objective performance and self-report of cognitive load, we evaluated different physiological responses in each experiment. Results showed a performance-workload association for directional cues, message type and task load. EEG measures however, proved generally insensitive to such task load manipulations. Where significant EEG effects were observed, right hemisphere amplitude differences predominated, although unexpectedly these latter relationships were negative. Although EEG measures were partially associated with performance, they appear to possess limited utility as measures of workload in association with tactile displays. Practitioner Summary: As practitioners look to take advantage of innovative tactile displays in complex operational realms like human-robotic interaction, associated performance effects are mediated by cognitive workload. Despite some patterns of association, reliable reflections of operator state can be difficult to discern and employ as the number, complexity and sophistication of these respective measures themselves increase.

Circadian rhythms in myocardial metabolism and contractile function: influence of workload and oleate.

PubMed

Durgan, David J; Moore, Michael W S; Ha, Ngan P; Egbejimi, Oluwaseun; Fields, Anna; Mbawuike, Uchenna; Egbejimi, Anu; Shaw, Chad A; Bray, Molly S; Nannegari, Vijayalakshmi; Hickson-Bick, Diane L; Heird, William C; Dyck, Jason R B; Chandler, Margaret P; Young, Martin E

2007-10-01

Multiple extracardiac stimuli, such as workload and circulating nutrients (e.g., fatty acids), known to influence myocardial metabolism and contractile function exhibit marked circadian rhythms. The aim of the present study was to investigate whether the rat heart exhibits circadian rhythms in its responsiveness to changes in workload and/or fatty acid (oleate) availability. Thus, hearts were isolated from male Wistar rats (housed during a 12:12-h light-dark cycle: lights on at 9 AM) at 9 AM, 3 PM, 9 PM, and 3 AM and perfused in the working mode ex vivo with 5 mM glucose plus either 0.4 or 0.8 mM oleate. Following 20-min perfusion at normal workload (i.e., 100 cm H(2)O afterload), hearts were challenged with increased workload (140 cm H(2)O afterload plus 1 microM epinephrine). In the presence of 0.4 mM oleate, myocardial metabolism exhibited a marked circadian rhythm, with decreased rates of glucose oxidation, increased rates of lactate release, decreased glycogenolysis capacity, and increased channeling of oleate into nonoxidative pathways during the light phase. Rat hearts also exhibited a modest circadian rhythm in responsiveness to the workload challenge when perfused in the presence of 0.4 mM oleate, with increased myocardial oxygen consumption at the dark-to-light phase transition. However, rat hearts perfused in the presence of 0.8 mM oleate exhibited a markedly blunted contractile function response to the workload challenge during the light phase. In conclusion, these studies expose marked circadian rhythmicities in myocardial oxidative and nonoxidative metabolism as well as responsiveness of the rat heart to changes in workload and fatty acid availability.

Higher mental workload is associated with poorer laparoscopic performance as measured by the NASA-TLX tool.

PubMed

Yurko, Yuliya Y; Scerbo, Mark W; Prabhu, Ajita S; Acker, Christina E; Stefanidis, Dimitrios

2010-10-01

Increased workload during task performance may increase fatigue and facilitate errors. The National Aeronautics and Space Administration-Task Load Index (NASA-TLX) is a previously validated tool for workload self-assessment. We assessed the relationship of workload and performance during simulator training on a complex laparoscopic task. NASA-TLX workload data from three separate trials were analyzed. All participants were novices (n = 28), followed the same curriculum on the fundamentals of laparoscopic surgery suturing model, and were tested in the animal operating room (OR) on a Nissen fundoplication model after training. Performance and workload scores were recorded at baseline, after proficiency achievement, and during the test. Performance, NASA-TLX scores, and inadvertent injuries during the test were analyzed and compared. Workload scores declined during training and mirrored performance changes. NASA-TLX scores correlated significantly with performance scores (r = -0.5, P < 0.001). Participants with higher workload scores caused more inadvertent injuries to adjacent structures in the OR (r = 0.38, P < 0.05). Increased mental and physical workload scores at baseline correlated with higher workload scores in the OR (r = 0.52-0.82; P < 0.05) and more inadvertent injuries (r = 0.52, P < 0.01). Increased workload is associated with inferior task performance and higher likelihood of errors. The NASA-TLX questionnaire accurately reflects workload changes during simulator training and may identify individuals more likely to experience high workload and more prone to errors during skill transfer to the clinical environment.

Analysis of mental workload of electrical power plant operators of control and operation centers.

PubMed

Vitório, Daiana Martins; Masculo, Francisco Soares; Melo, Miguel O B C

2012-01-01

Electrical systems can be categorized as critical systems where failure can result in significant financial loss, injury or threats to human life. The operators of the electric power control centers perform an activity in a specialized environment and have to carry it out by mobilizing knowledge and reasoning to which they have adequate training under the terms of the existing rules. To reach this there is a common mental request of personnel involved in these centers due the need to maintain attention, memory and reasoning request. In this sense, this study aims to evaluate the Mental Workload of technical workers of the Control Centers of Electrical Energy. It was undertaken a research on operators control centers of the electricity sector in Northeast Brazil. It was used for systematic observations, followed by interview and application of the instrument National Aeronautics and Space Administration Task Load Index known as NASA-TLX. As a result there will be subsidies for an assessment of mental workload of operators, and a contribution to improving the processes of managing the operation of electric utilities and the quality of workers.

A simple method to equalize the workload when operating several small wastewater treatment plants: a case study.

PubMed

De Feo, G; De Gisi, S; Galasso, M

2013-01-01

The aim of the present study is to define a simple (and easy to use) method to equalize the workload of personnel operating several small wastewater treatment plants (SWWTPs). The approach is illustrated through a case study which is the result of collaboration between researchers and a water and wastewater management company operating in Southern Italy. The topic is important since personnel have a significant impact on the operating costs of SWWTPs, and the approach outlined results in the minimum number of staff being required to assure the management of the service. Four kinds of work units are considered: plant managers, assistant plant managers, laboratory technicians and executives. In order to develop a practical, feasible and easy to use method, the workload was evaluated considering only the population equivalent (PE) and the number of plants managed. The core of the method is the evaluation of the percentage of time that the personnel units devote to the operation of SWWTPs of the municipality considered. The proposed procedure offers a useful tool to equalize the workload, both in terms of PE and the number of plants managed, the procedure being easily modifiable to introduce other evaluation criteria. By using familiar concepts such as PE and number of plants managed, the approach of the method can easily be understood by management. It can also be readily adapted to other similar situations.

Tactical decision making for selective expansion of operating room resources incorporating financial criteria and uncertainty in subspecialties' future workloads.

PubMed

Dexter, Franklin; Ledolter, Johannes; Wachtel, Ruth E

2005-05-01

We considered the allocation of operating room (OR) time at facilities where the strategic decision had been made to increase the number of ORs. Allocation occurs in two stages: a long-term tactical stage followed by short-term operational stage. Tactical decisions, approximately 1 yr in advance, determine what specialized equipment and expertise will be needed. Tactical decisions are based on estimates of future OR workload for each subspecialty or surgeon. We show that groups of surgeons can be excluded from consideration at this tactical stage (e.g., surgeons who need intensive care beds or those with below average contribution margins per OR hour). Lower and upper limits are estimated for the future demand of OR time by the remaining surgeons. Thus, initial OR allocations can be accomplished with only partial information on future OR workload. Once the new ORs open, operational decision-making based on OR efficiency is used to fill the OR time and adjust staffing. Surgeons who were not allocated additional time at the tactical stage are provided increased OR time through operational adjustments based on their actual workload. In a case study from a tertiary hospital, future demand estimates were needed for only 15% of surgeons, illustrating the practicality of these methods for use in tactical OR allocation decisions.

Depot Maintenance: Executed Workload and Maintenance Operations at DOD Depots

DTIC Science & Technology

2017-02-03

Page 1 GAO-17-82R Depot Maintenance 441 G St. N.W. Washington, DC 20548 February 3, 2017 The Honorable John McCain Chairman The...Smith Ranking Member Committee on Armed Services House of Representatives Depot Maintenance : Executed Workload and Maintenance Operations at DOD...Depots The Department of Defense (DOD) uses its maintenance capabilities to maintain, overhaul, and repair its military weapon systems (such as

Managing Workload in Human-Robot Interaction: A Review of Empirical Studies

DTIC Science & Technology

2010-01-01

central concern in determining successful teleoperation. Regardless of the sophistication of the technology, a robot is oper- ated – with different levels...by many characteristics, including the type of workload manipulation, the apparatus used, task char- acteristics, and/or type of outcome measures . Due...linguistic patterns. Further- more, this interference may not even be detected if operators do not explicitly measure team communication performance, or re

DDG 51 Operational Evaluation: Measures of Workload from Combat Information Center Communication Patterns

DTIC Science & Technology

1992-09-01

RAIDS ......... 39 ix I. INTRODUCTION Communication is the act of sharing information. This thesis is about human communication , but human ...high costs, high stakes, high drama, and Ligh workload. From a methodological perspective, this thesis is about using natural human communication patterns...34* Fourth. The Operational Test and Evaluation (OPEVAL) of USS ARLEIGH BURKE (DDG 51) presented an opportunity to examine human communication patterns

Workload, Stress, and Situation Awareness of Soldiers Who are Controlling Unmanned Vehicles in Future Urban Operations

DTIC Science & Technology

2007-04-01

subjective self-ratings of perceived workload, the National Aeronautics and Space Administration ( NASA )-Task Load Index ( TLX ) was used. The NASA TLX ...Staveland, L. E. Development of a NASA - TLX (Task Load Index): Results of Empirical and Theoretical Research. In Human Mental Workload, edited by P.A...system? Please complete the following SHORT surveys (nine questions total) for the missions that you performed today. 19 NASA TLX

Toward an Operational Definition of Workload: A Workload Assessment of Aviation Maneuvers

DTIC Science & Technology

2010-08-01

and evaluated by the learner . With practice, the learner moves into the second phase, where optimal strategies are strengthened. The final stage of...The first phase demands a great amount of resources as performance is slow and prone to errors. During this phase, strategies are being formulated...asked to assess mental, physical, visual, aural , and verbal demands of each task. The new assessment is a cost effective method of assessing workload

Heavy vehicle driver workload assessment. Task 1, task analysis data and protocols review

DOT National Transportation Integrated Search

This report contains a review of available task analytic data and protocols pertinent to heavy vehicle operation and determination of the availability and relevance of such data to heavy vehicle driver workload assessment. Additionally, a preliminary...

Intelligent Agent Transparency in Human-Agent Teaming for Multi-UxV Management.

PubMed

Mercado, Joseph E; Rupp, Michael A; Chen, Jessie Y C; Barnes, Michael J; Barber, Daniel; Procci, Katelyn

2016-05-01

We investigated the effects of level of agent transparency on operator performance, trust, and workload in a context of human-agent teaming for multirobot management. Participants played the role of a heterogeneous unmanned vehicle (UxV) operator and were instructed to complete various missions by giving orders to UxVs through a computer interface. An intelligent agent (IA) assisted the participant by recommending two plans-a top recommendation and a secondary recommendation-for every mission. A within-subjects design with three levels of agent transparency was employed in the present experiment. There were eight missions in each of three experimental blocks, grouped by level of transparency. During each experimental block, the IA was incorrect three out of eight times due to external information (e.g., commander's intent and intelligence). Operator performance, trust, workload, and usability data were collected. Results indicate that operator performance, trust, and perceived usability increased as a function of transparency level. Subjective and objective workload data indicate that participants' workload did not increase as a function of transparency. Furthermore, response time did not increase as a function of transparency. Unlike previous research, which showed that increased transparency resulted in increased performance and trust calibration at the cost of greater workload and longer response time, our results support the benefits of transparency for performance effectiveness without additional costs. The current results will facilitate the implementation of IAs in military settings and will provide useful data to the design of heterogeneous UxV teams. © 2016, Human Factors and Ergonomics Society.

Impact of adding additional providers to resident workload and the resident experience on a medical consultation rotation.

PubMed

Fang, Michele; Linson, Eric; Suneja, Manish; Kuperman, Ethan F

2017-02-22

Excellence in Graduate Medical Education requires the right clinical environment with an appropriate workload where residents have enough patients to gain proficiency in medicine with optimal time for reflection. The Accreditation Council for Graduate Medical Education (ACGME) has focused more on work hours rather than workload; however, high resident workload has been associated with lower resident participation in education and fatigue-related errors. Recognizing the potential risks associated with high resident workload and being mindful of the costs of reducing resident workload, we sought to reduce residents' workload by adding an advanced practice provider (APP) to the surgical comanagement service (SCM) and study its effect on resident satisfaction and perceived educational value of the rotation. In Fiscal Year (FY) 2014 and 2015, an additional faculty member was added to the SCM rotation. In FY 2014, the faculty member was a staff physician, and in FY 2015, the faculty member was an APP.. Resident workload was assessed using billing data. We measured residents' perceptions of the rotation using an anonymous electronic survey tool. We compared FY2014-2015 data to the baseline FY2013. The number of patients seen per resident per day decreased from 8.0(SD 3.3) in FY2013 to 5.0(SD 1.9) in FY2014 (p < 0.001) and 5.7(SD 2.0) in FY2015 (p < 0.001). A higher proportion of residents reported "just right" patient volume (64.4%, 91.7%, 96.7% in FY2013, 2014, 2015 respectively p < 0.001), meeting curricular goals (79.9%, 95.0%, 97.2%, in FY2013, 2014 and 2015 respectively p < 0.001), and overall educational value of the rotation (40.0%, 72.2%, 72.6% in FY2013, 2014, 2015 respectively, p < 0.001). Decreasing resident workload through adding clinical faculty (both staff physician and APPs) was associated with improvements on resident perceived educational value and clinical experience of a medical consultation rotation.

Workload and Performance in Air Traffic Control: Exploring the Influence of Levels of Automation and Variation in Task Demand

NASA Technical Reports Server (NTRS)

Edwards, Tamsyn El; Martin, Lynne; Bienert, Nancy; Mercer, Joey

2017-01-01

In air traffic control, task demand and workload have important implications for the safety and efficiency of air traffic. Task demand is dynamic, however, research on demand transitions and associated controller perception and performance is limited. In addition, there is a comparatively restricted understanding of the influence of task demand transitions on workload and performance, in association with automation. This study used an air traffic control simulation to investigate the influence of task demand transitions and two conditions of varying automation, on workload and efficiency-related performance. Findings showed that a both the direction of the task demand variation, and the amount of automation, influenced the relationship between workload and performance. Further research is needed to enhance understanding of demand transition and workload history effects on operator experience and performance, in both air traffic control and other safety-critical domains.

Effect of Dynamic Sector Boundary Changes on Air Traffic Controllers

NASA Technical Reports Server (NTRS)

Jung, Jaewoo; Lee, Paul; Kessell, Angela; Homola, Jeff; Zelinski, Shannon

2010-01-01

The effect of dynamic sector boundary changes on air traffic controller workload was investigated with data from a human-in-the-loop simulation. Multiple boundary changes were made during simulated operations, and controller rating of workload was recorded. Analysis of these data showed an increase of 16.9% in controller workload due to boundary changes. This increased workload was correlated with the number of aircraft handoffs and change in sector volume. There was also a 12.7% increase in average workload due to the changed sector design after boundary changes. This increase was correlated to traffic flow crossing points getting closer to sector boundaries and an increase in the number of flights with short dwell time in a sector. This study has identified some of the factors that affect controller workload when sector boundaries are changed, but more research is needed to better understand their relationships.

Heavy vehicle driver workload assessment. Task 6, baseline data study

DOT National Transportation Integrated Search

This report covers the sixth in a series of tasks involving the assessment of driver workload in heavy vehicle operation associated with in-cab devices or systems. A review of the overall study was provided by Tijerina, Kantowitz, Kiger, and Rockwell...

Psychophysiological response to cognitive workload during symmetrical, asymmetrical and dual-task walking.

PubMed

Knaepen, Kristel; Marusic, Uros; Crea, Simona; Rodríguez Guerrero, Carlos D; Vitiello, Nicola; Pattyn, Nathalie; Mairesse, Olivier; Lefeber, Dirk; Meeusen, Romain

2015-04-01

Walking with a lower limb prosthesis comes at a high cognitive workload for amputees, possibly affecting their mobility, safety and independency. A biocooperative prosthesis which is able to reduce the cognitive workload of walking could offer a solution. Therefore, we wanted to investigate whether different levels of cognitive workload can be assessed during symmetrical, asymmetrical and dual-task walking and to identify which parameters are the most sensitive. Twenty-four healthy subjects participated in this study. Cognitive workload was assessed through psychophysiological responses, physical and cognitive performance and subjective ratings. The results showed that breathing frequency and heart rate significantly increased, and heart rate variability significantly decreased with increasing cognitive workload during walking (p<.05). Performance measures (e.g., cadence) only changed under high cognitive workload. As a result, psychophysiological measures are the most sensitive to identify changes in cognitive workload during walking. These parameters reflect the cognitive effort necessary to maintain performance during complex walking and can easily be assessed regardless of the task. This makes them excellent candidates to feed to the control loop of a biocooperative prosthesis in order to detect the cognitive workload. This information can then be used to adapt the robotic assistance to the patient's cognitive abilities. Copyright © 2015 Elsevier B.V. All rights reserved.

Spatialized audio improves call sign recognition during multi-aircraft control.

PubMed

Kim, Sungbin; Miller, Michael E; Rusnock, Christina F; Elshaw, John J

2018-07-01

We investigated the impact of a spatialized audio display on response time, workload, and accuracy while monitoring auditory information for relevance. The human ability to differentiate sound direction implies that spatial audio may be used to encode information. Therefore, it is hypothesized that spatial audio cues can be applied to aid differentiation of critical versus noncritical verbal auditory information. We used a human performance model and a laboratory study involving 24 participants to examine the effect of applying a notional, automated parser to present audio in a particular ear depending on information relevance. Operator workload and performance were assessed while subjects listened for and responded to relevant audio cues associated with critical information among additional noncritical information. Encoding relevance through spatial location in a spatial audio display system--as opposed to monophonic, binaural presentation--significantly reduced response time and workload, particularly for noncritical information. Future auditory displays employing spatial cues to indicate relevance have the potential to reduce workload and improve operator performance in similar task domains. Furthermore, these displays have the potential to reduce the dependence of workload and performance on the number of audio cues. Published by Elsevier Ltd.

Unsupervised classification of operator workload from brain signals.

PubMed

Schultze-Kraft, Matthias; Dähne, Sven; Gugler, Manfred; Curio, Gabriel; Blankertz, Benjamin

2016-06-01

In this study we aimed for the classification of operator workload as it is expected in many real-life workplace environments. We explored brain-signal based workload predictors that differ with respect to the level of label information required for training, including entirely unsupervised approaches. Subjects executed a task on a touch screen that required continuous effort of visual and motor processing with alternating difficulty. We first employed classical approaches for workload state classification that operate on the sensor space of EEG and compared those to the performance of three state-of-the-art spatial filtering methods: common spatial patterns (CSPs) analysis, which requires binary label information; source power co-modulation (SPoC) analysis, which uses the subjects' error rate as a target function; and canonical SPoC (cSPoC) analysis, which solely makes use of cross-frequency power correlations induced by different states of workload and thus represents an unsupervised approach. Finally, we investigated the effects of fusing brain signals and peripheral physiological measures (PPMs) and examined the added value for improving classification performance. Mean classification accuracies of 94%, 92% and 82% were achieved with CSP, SPoC, cSPoC, respectively. These methods outperformed the approaches that did not use spatial filtering and they extracted physiologically plausible components. The performance of the unsupervised cSPoC is significantly increased by augmenting it with PPM features. Our analyses ensured that the signal sources used for classification were of cortical origin and not contaminated with artifacts. Our findings show that workload states can be successfully differentiated from brain signals, even when less and less information from the experimental paradigm is used, thus paving the way for real-world applications in which label information may be noisy or entirely unavailable.

Unsupervised classification of operator workload from brain signals

NASA Astrophysics Data System (ADS)

Schultze-Kraft, Matthias; Dähne, Sven; Gugler, Manfred; Curio, Gabriel; Blankertz, Benjamin

2016-06-01

Objective. In this study we aimed for the classification of operator workload as it is expected in many real-life workplace environments. We explored brain-signal based workload predictors that differ with respect to the level of label information required for training, including entirely unsupervised approaches. Approach. Subjects executed a task on a touch screen that required continuous effort of visual and motor processing with alternating difficulty. We first employed classical approaches for workload state classification that operate on the sensor space of EEG and compared those to the performance of three state-of-the-art spatial filtering methods: common spatial patterns (CSPs) analysis, which requires binary label information; source power co-modulation (SPoC) analysis, which uses the subjects’ error rate as a target function; and canonical SPoC (cSPoC) analysis, which solely makes use of cross-frequency power correlations induced by different states of workload and thus represents an unsupervised approach. Finally, we investigated the effects of fusing brain signals and peripheral physiological measures (PPMs) and examined the added value for improving classification performance. Main results. Mean classification accuracies of 94%, 92% and 82% were achieved with CSP, SPoC, cSPoC, respectively. These methods outperformed the approaches that did not use spatial filtering and they extracted physiologically plausible components. The performance of the unsupervised cSPoC is significantly increased by augmenting it with PPM features. Significance. Our analyses ensured that the signal sources used for classification were of cortical origin and not contaminated with artifacts. Our findings show that workload states can be successfully differentiated from brain signals, even when less and less information from the experimental paradigm is used, thus paving the way for real-world applications in which label information may be noisy or entirely unavailable.

A Summary of Crew Workload and Situational Awareness Ratings for U.S. Army Aviation Aircraft

DTIC Science & Technology

2014-06-01

Engineering Directorate (ARL/HRED) assesses crewstation design for new and upgraded U.S. Army Aviation aircraft during simulations and operational...crewstation design for new and upgraded Army Aviation aircraft during simulations and operational testing. The assessments are conducted to identify...crewstation design . To date, more than 12,000 pilot workload ratings and 3000 pilot SA ratings have been collected by ARL/HRED for Army aircraft . This report

POPCORN: a Supervisory Control Simulation for Workload and Performance Research

NASA Technical Reports Server (NTRS)

Hart, S. G.; Battiste, V.; Lester, P. T.

1984-01-01

A multi-task simulation of a semi-automatic supervisory control system was developed to provide an environment in which training, operator strategy development, failure detection and resolution, levels of automation, and operator workload can be investigated. The goal was to develop a well-defined, but realistically complex, task that would lend itself to model-based analysis. The name of the task (POPCORN) reflects the visual display that depicts different task elements milling around waiting to be released and pop out to be performed. The operator's task was to complete each of 100 task elements that ere represented by different symbols, by selecting a target task and entering the desired a command. The simulated automatic system then completed the selected function automatically. Highly significant differences in performance, strategy, and rated workload were found as a function of all experimental manipulations (except reward/penalty).

Assessment of Crew Workload for the RAH-66 Comanche Force Development Experiment 1

DTIC Science & Technology

2001-10-01

Scale and a cockpit controls and displays usability questionnaire . Results of the assessment indicate that (a) workload was tolerable for the pilots...Workload Levels Between Front Seat and Back Seat 13 3.4 Pilot Responses to Controls and Displays Usability Questionnaire 13 3.5 HMD Symbology 13 4... questionnaire . The data were analyzed to determine if the pilot flying the aircraft (pilot on controls) and the pilot operating the mission equipment

Subjective rating scales as a workload

NASA Technical Reports Server (NTRS)

Bird, K. L.

1981-01-01

A multidimensional bipolar-adjective rating scale is employed as a subjective measure of operator workload in the performance of a one-axis tracking task. The rating scale addressed several dimensions of workload, including cognitive, physical, and perceptual task loading as well as fatigue and stress effects. Eight subjects performed a one-axis tracking task (with six levels of difficulty) and rated these tasks on several workload dimensions. Performance measures were tracking error RMS (root-mean square) and the standard deviation of control stick output. Significant relationships were observed between these performance measures and skill required, task complexity, attention level, task difficulty, task demands, and stress level.

Effect of system workload on operating system reliability - A study on IBM 3081

NASA Technical Reports Server (NTRS)

Iyer, R. K.; Rossetti, D. J.

1985-01-01

This paper presents an analysis of operating system failures on an IBM 3081 running VM/SP. Three broad categories of software failures are found: error handling, program control or logic, and hardware related; it is found that more than 25 percent of software failures occur in the hardware/software interface. Measurements show that results on software reliability cannot be considered representative unless the system workload is taken into account. The overall CPU execution rate, although measured to be close to 100 percent most of the time, is not found to correlate strongly with the occurrence of failures. Possible reasons for the observed workload failure dependency, based on detailed investigations of the failure data, are discussed.

The Effects of Workload and Working Conditions on Operating Room Nurses and Technicians.

PubMed

Uğurlu, Ziyafet; Karahan, Azize; Ünlü, Hayriye; Abbasoğlu, Aysel; Özhan Elbaş, Nalan; Avcı Işık, Sevcan; Tepe, Aylin

2015-09-01

This study was conducted between August 15 and September 20, 2013, to determine the effects of workload and working conditions on operating room (OR) nurses and technicians. The study sample included 74 OR nurses and technicians working in a private university's six hospitals. The Individual Workload Perception Scale and a questionnaire that collected data on risk and environmental factors were used. The mean age of study participants was 29.3 ± 6.7 years, and 62.2% of the participants were female. More than 90% of the nurses and technicians had experienced spills or splashing of blood or other body fluids; anesthetic gases and radiation had affected 63.5% and 71.6% of nurses and technicians, respectively; 63.5% reported lumbar pain; and 46.6% defined the work environment as very stressful. The average workload scale score was 32.4 ± 6.2 (min = 11, max = 55). OR nurses and technicians are exposed to many occupational risks. © 2015 The Author(s).

Control/display trade-off study for single-pilot instrument flight rule operations

NASA Technical Reports Server (NTRS)

Hoh, R.

1983-01-01

The objectives were to determine minimum autopilot functions and displays required to keep pilot workload at an acceptable level; to determine what constitutes an acceptable level of workload; to identify critical tasks; and to suggest specific experiments required to refine conclusions. It was determined that workload relief is derived from basic stability augmentation; that complex autopilots can lead to serious blunders; and that displays need to enhance positional awareness and minimize the likelihood of false hypothesis.

Measuring neurophysiological signals in aircraft pilots and car drivers for the assessment of mental workload, fatigue and drowsiness.

PubMed

Borghini, Gianluca; Astolfi, Laura; Vecchiato, Giovanni; Mattia, Donatella; Babiloni, Fabio

2014-07-01

This paper reviews published papers related to neurophysiological measurements (electroencephalography: EEG, electrooculography EOG; heart rate: HR) in pilots/drivers during their driving tasks. The aim is to summarise the main neurophysiological findings related to the measurements of pilot/driver's brain activity during drive performance and how particular aspects of this brain activity could be connected with the important concepts of "mental workload", "mental fatigue" or "situational awareness". Review of the literature suggests that exists a coherent sequence of changes for EEG, EOG and HR variables during the transition from normal drive, high mental workload and eventually mental fatigue and drowsiness. In particular, increased EEG power in theta band and a decrease in alpha band occurred in high mental workload. Successively, increased EEG power in theta as well as delta and alpha bands characterise the transition between mental workload and mental fatigue. Drowsiness is also characterised by increased blink rate and decreased HR values. The detection of such mental states is actually performed "offline" with accuracy around 90% but not online. A discussion on the possible future applications of findings provided by these neurophysiological measurements in order to improve the safety of the vehicles will be also presented. Copyright © 2012 Elsevier Ltd. All rights reserved.

National culture moderates the influence of mental effort on subjective and cardiovascular measures.

PubMed

Widyanti, Ari; de Waard, Dick; Johnson, Addie; Mulder, Ben

2013-01-01

Subjective measures of mental effort have been shown to be relatively insensitive in Indonesian participants. An open question is whether this insensitivity reflects how mental effort is experienced or how it is reported. We compared the performance, subjective workload ratings, heart rate and heart-rate variability (HRV) of 31 Dutch and 30 Indonesian participants under single- and dual-task conditions. Indonesians performed faster but less accurately and used a narrower range of subjective workload ratings than did the Dutch. Dutch participants showed a decrease in HRV both in the mid-frequency (MF) and high-frequency bands and an increase in heart rate during task performance compared with the resting period. Indonesians showed this pattern in the MF band only. The decrease of HRV in the MF band in both groups suggests that the relative insensitivity of subjective mental effort scales among Indonesians has to do with how workload is reported rather than with how it is experienced. The sensitivity of the subjective measures of mental workload has been shown to depend on culture. Here, we show that heart-rate variability reacts similarly to workload in Eastern as in Western participants. This suggests that culture influences more how invested mental effort is reported than how it is experienced psychophysiologically.

Influence of Yo-Yo IR2 Scores on Internal and External Workloads and Fatigue Responses of Tag Football Players during Tournament Competition

PubMed Central

2015-01-01

The purpose of this study was to: a) identify changes in jump height and perceived well-being as indirect markers of fatigue, b) determine the internal and external workloads performed by players, and c) examine the influence of Yo-Yo IR2 on changes in jump height, perceived well-being and internal and external workloads during a tag football tournament. Microtechnology devices combined with heart rate (HR) chest straps provided external and internal measures of match work-rate and workload for twelve male tag football players during the 2014 Australian National Championships. Jump height and perceived well-being were assessed prior to and during the tournament as indirect measures of fatigue. Changes in work-rate, workload and fatigue measures between high- and low-fitness groups were examined based on players’ Yo-Yo IR2 score using a median split technique. The low- and high-fitness groups reported similar mean HR, PlayerloadTM/min, and distance/min for matches, however the low-fitness group reported higher perceived match-intensities (ES = 0.90–1.35) for several matches. Further, the high-fitness group reported higher measures of tournament workload, including distance (ES = 0.71), PlayerloadTM (ES = 0.85) and Edwards’ training impulse (TRIMP) (ES = 1.23) than the low-fitness group. High- and low-fitness groups both showed large decreases (ES = 1.46–1.49) in perceived well-being during the tournament, although jump height did not decrease below pre-tournament values. Increased Yo-Yo IR2 appears to offer a protective effect against player fatigue despite increased workloads during a tag football tournament. It is vital that training programs adequately prepare tag football players for tournament competition to maximise performance and minimise player fatigue. PMID:26465599

Projection of the dental workforce from 2011 to 2020, based on the actual workload of 6762 dentists in 2010 in Taiwan.

PubMed

Huang, Chiung Shing; Cher, Tsang-Lie; Lin, Chun-Pin; Wu, Kai-Ming

2013-09-01

Planning of the dental workforce, especially the number of dentists, requires the data of actual dental workloads. This study attempts to make projections of the dental workforce from 2011 to 2020, based on a survey of the actual workload of 6762 dentists in 2010. In 2010, a database of 11,449 current dentists was retrieved from the file of Department of Health, Executive Yuan, Taipei, Taiwan. Questionnaires with the information of each dentist and 10 questions regarding the actual workload were sent to each dentist with a return envelope. The actual workload of the dentists who returned the questionnaires was analyzed. A projection of dental workforce from 2011 to 2020 was calculated, based on the actual workload. An analysis of the actual dental workload was conducted on 6762 (59.1%) returned questionnaires. The dentist-to-population ratio (defined as the number of dentists per 10,000 people) was 5.0 in 2010. The supply of 400 dentists per year remained constant from 2006 to 2010, and is expected to be sustained for the next 10 years. Because the population of Taiwan will begin to decrease within the next 10 years, we estimate that the dentist-to-population ratio will increase to 6.0 by the year 2020 or earlier. After adjusting for working hours, working days, and gender differences, surplus dentists will number approximately 1069 in 2020. An oversupply of dentists and a decrease in population will result in a surplus of dentists. To make better projections of the dental workforce, surplus dentists can be arranged to care for the aged, disabled people, and underserved people. Copyright © 2013. Published by Elsevier B.V.

The effects of acceleration stress on human workload and manual control

NASA Technical Reports Server (NTRS)

Gill, R. T.; Albery, W. B.; Ward, S. L.

1986-01-01

The effects of +Gz stress on operator task performance and workload were assessed. Subjects were presented a two dimensional maze and were required to solve it as rapidly as possible (by moving a light dot through it via a trim switch on a control stick) while under G-stress at levels from +1 Gz to +6 Gz. The G-stress was provided by a human centrifuge. The effects of this stress were assessed by two techniques; (1) objective performance measures on the primary maze-solving task, and (2) subjective workload measures obtained using the subjective workload assessment technique (SWAT). It was found that while neither moderate (+3 Gz) nor high (+5 Gz and +6 Gz) levels of G-stress affected maze solving performance, the high G levels did increase significantly the subjective workload of the maze task.

Twentieth Annual Conference on Manual Control, Volume 2

NASA Technical Reports Server (NTRS)

Hart, S. G. (Compiler); Hartzell, E. J. (Compiler)

1984-01-01

Volume II contains thirty two complete manuscripts and five abstracts. The topics covered include the application of event-related brain potential analysis to operational problems, the subjective evaluation of workload, mental models, training, crew interaction analysis, multiple task performance, and the measurement of workload and performance in simulation.

Display/control requirements for VTOL aircraft

NASA Technical Reports Server (NTRS)

Hoffman, W. C.; Curry, R. E.; Kleinman, D. L.; Hollister, W. M.; Young, L. R.

1975-01-01

Quantative metrics were determined for system control performance, workload for control, monitoring performance, and workload for monitoring. Pilot tasks were allocated for navigation and guidance of automated commercial V/STOL aircraft in all weather conditions using an optimal control model of the human operator to determine display elements and design.

Task acceptability and workload of driving city streets, rural roads, and expressways : ratings from video clips.

DOT National Transportation Integrated Search

2007-05-01

Subjects rated the workload of clips of forward road scenes (from the advanced collision avoidance system (ACAS) field operational test) in relation to 2 anchor clips of Level of Service (LOS) A and E (light and heavy traffic), and indicated if they ...

Teaching the Surgical Craft: Surgery Residents Perception of the Operating Theater Educational Environment in a Tertiary Institution in Nigeria

PubMed Central

Ibrahim, Abdulrasheed; Delia, Ibrahim Z; Edaigbini, Sunday A; Abubakar, Amina; Dahiru, Ismail L; Lawal, Zakari Y

2013-01-01

Background: The transformation of a surgical trainee into a surgeon is strongly influenced by the quality of teaching in the operating theater. This study investigates the perceptions of residents about the educational environment of the operating theater and identifies variables that may improve the operating theater education of our trainees. Materials and Methods: Residents in the department of surgery anonymously evaluated teaching in the operating room using the operating theater education environment measure. The residents evaluated 33 variables that might have an impact on their surgical skills within the operating theater. The variables were grouped into four subscales; teaching and training, learning opportunities, operating theater atmosphere and workload/supervision/support. Differences between male and female residents and junior and senior registrars were assessed using Mann-Whitney test. Statistical analysis was completed with the statistics package for the social sciences version 17. Results: A total of 33 residents were participated in this study. Twenty nine (88%) males and 4 (12%) females. 30 (90%) were junior registrars. The mean total score was 67.5%. Operating theater atmosphere subscale had the highest score of 79.2% while workload/supervision/support subscale had the least score of 48.3%. There were significant differences between male and female resident's perception of workload/supervision/support P < 0.05; however, there was no significant differences in junior registrar versus senior registrar's perception of the education environment in all the subscales P > 0.05. Conclusion: This study has shown a satisfactory teaching environment based on the existing local realities of means, resources and tools and highlighted the need for improvement in workload/supervision/support in our institution. An acceptable learning environment in the operating theatre will produce surgeons that are technically competent to bridge the gap in the enormous unmet need for surgical care in Nigeria. PMID:24497753

Emergency medical equipment storage: benefits of visual cues tested in field and simulated settings.

PubMed

Grundgeiger, Tobias; Harris, Bonnie; Ford, Nicholas; Abbey, Michael; Sanderson, Penelope M; Venkatesh, Balasubramanian

2014-08-01

We tested the effectiveness of an illustrated divider ("the divider") for bedside emergency equipment drawers in an intensive care unit (ICU). In Study I, we assessed whether the divider increases completeness and standardizes the locations of emergency equipment within the drawer. In Study 2, we investigated whether the divider decreases nurses' restocking and retrieval times and decreases their workload. Easy access to fully stocked emergency equipment is important during emergencies. However, inefficient equipment storage and cognitively demanding work settings might mean that drawers are incompletely stocked and access to items is slow. A pre-post-post study investigated drawer completeness and item locations before and after the introduction of the divider to 30 ICU drawers. A subsequent experiment measured item restocking time, item retrieval time, and subjective workload for nurses. At 2 weeks and 10 weeks after the divider was introduced, the completeness of the drawer increased significantly compared with before the divider was introduced. The divider decreased the variability of the locations of the 17 items in the drawer to 16% of its original value. Study 2 showed that restocking times but not retrieval times were significantly faster with the divider present For both tasks, nurses rated their workload lower with the divider. The divider improved the standardization and completeness of emergency equipment. In addition, restocking times and workload were decreased with the divider. Redesigning storage for certain equipment using human factors design principles can help to speed and standardize restocking and ease access to equipment.

Use of Data Comm by Flight Crew in High-Density Terminal Areas

NASA Technical Reports Server (NTRS)

Baxley, Brian T.; Norman, Robert M.; Ellis, Kyle K. E.; Latorella, Kara A.; Comstock, James R.; Adams, Cathy A.

2010-01-01

This paper describes a collaborative FAA and NASA experiment using 22 commercial airline pilots to determine the effect of using Datalink Communication (Data Comm) to issue messages in busy, terminal area operations. Four conditions were defined that span current day to future flight deck equipage levels (voice communication only, Data Comm only, Data Comm with Moving Map Display, Data Comm with Moving Map displaying taxi route), and each condition was used to create an arrival and a departure scenario at the Boston Logan Airport. These eight scenarios were repeated twice for a total of 16 scenarios for each of the eleven crews. Quantitative data was collected on subject reaction time and eye tracking information. Questionnaires collected subjective feedback on workload and acceptability to the flight crew for using Data Comm in a busy terminal area. 95% of the Data Comm messages were responded to by the flight crew within one minute; however, post experiment debrief comments revealed almost unanimous consensus that two minutes was a reasonable expectation for crew response. Eye tracking data indicated an insignificant decrease in head-up time for the Pilot Flying when Data Comm was introduced; however, the Pilot Monitoring had significantly less head-up time. Data Comm workload was rated as operationally acceptable by both crew members in all conditions in flight at any altitude above the Final Approach Fix in terms of response time and workload. Results also indicate the use of Data Comm during surface operations was acceptable, the exception being the simultaneous use of voice, Data Comm, and audio chime required for an aircraft to cross an active runway. Many crews reported they believed Data Comm messages would be acceptable after the Final Approach Fix or to cross a runway if the message was not accompanied by a chime and there was not a requirement to immediately respond to the uplink message.

Exploring design features for enhancing players' challenge in strategy games.

PubMed

Hsu, Shang Hwa; Wen, Ming-Hui; Wu, Muh-Cherng

2007-06-01

This paper examines how to make a player feel more challenged in a strategic computer game. It is hypothesized that information availability and resource advantage affect play difficulty, which in turn affects the challenge experienced. The difficulty of play can be defined in terms of the mental workload that players experience and the physical effort that players exert. Forty-five male college and graduate students participated in a 3 x 3 (information availability x resource advantage) between-subjects factorial design experiment. This experiment measured player mental workload, physical effort, and challenge. The results indicate that information availability affects player mental workload, and resource advantage affects levels of player physical effort, respectively. Moreover, the relationship between mental workload and challenge was found to be an inverted U-shaped curve; in other words, too much or too little mental workload may decrease player challenge. The relationship between physical effort and challenge exhibited similar characteristics.

Influence of patient and provider factors on the workload of on-call physicians

PubMed Central

Hsu, Nin-Chieh; Huang, Chun-Che; Jerng, Jih-Shuin; Hsu, Chia-Hao; Yang, Ming-Chin; Chang, Ray-E; Ko, Wen-Je; Yu, Chong-Jen

2016-01-01

Abstract Factors associated with the physician workload are scarcely reported. The study aims to investigate the associated factors of on-call physician workload based on a published conceptual framework. The study was conducted in a general internal medicine unit of National Taiwan University Hospital. On-call physician workloads were recorded on a shift basis from 1198 hospitalized patients between May 2010 and April 2011. The proxy of on-call workloads included night calls, bedside evaluation/management (E/M), and performing clinical procedures in a shift. Multivariable logistic and negative binomial regression models were used to determine the factors associated with the workloads of on-call physicians. During the study period, 378 (31.6%) of patients had night calls with related workloads. Multivariate analysis showed that the number of patients with unstable conditions in a shift (odds ratio [OR] 1.89 and 1.66, respectively) and the intensive care unit (ICU) training of the nurse leader (OR 2.87 and 3.08, respectively) resulted in higher likelihood of night calls to and bedside E/M visits by the on-call physician. However, ICU training of nurses (OR = 0.37, 95% confidence interval: 0.16–0.86) decreased the demand of performing clinical procedures by the on-call physician. Moreover, number of patients with unstable conditions (risk ratio [RR] 1.52 and 1.55, respectively) had significantly increased the number of night calls and bedside E/M by on-call physicians by around 50%. Nurses with N1 level (RR 2.16 and 2.71, respectively) were more likely to place night calls and facilitate bedside E/M by the on-call physician compared to nurses with N0 level. In addition, the nurse leaders with ICU training (RR 1.72 and 3.07, respectively) had significant increases in night calls and bedside E/M by the on-call physician compared to those without ICU training. On-call physician workload is associated with patient factors and the training of nurses. Number of unstable patients in a shift may be considered in predicting workload. The training of nurses may improve patient safety and decrease demand for clinical procedure. PMID:27583910

Influence of patient and provider factors on the workload of on-call physicians: A general internal medicine cohort observational study.

PubMed

Hsu, Nin-Chieh; Huang, Chun-Che; Jerng, Jih-Shuin; Hsu, Chia-Hao; Yang, Ming-Chin; Chang, Ray-E; Ko, Wen-Je; Yu, Chong-Jen

2016-08-01

Factors associated with the physician workload are scarcely reported. The study aims to investigate the associated factors of on-call physician workload based on a published conceptual framework.The study was conducted in a general internal medicine unit of National Taiwan University Hospital. On-call physician workloads were recorded on a shift basis from 1198 hospitalized patients between May 2010 and April 2011. The proxy of on-call workloads included night calls, bedside evaluation/management (E/M), and performing clinical procedures in a shift. Multivariable logistic and negative binomial regression models were used to determine the factors associated with the workloads of on-call physicians.During the study period, 378 (31.6%) of patients had night calls with related workloads. Multivariate analysis showed that the number of patients with unstable conditions in a shift (odds ratio [OR] 1.89 and 1.66, respectively) and the intensive care unit (ICU) training of the nurse leader (OR 2.87 and 3.08, respectively) resulted in higher likelihood of night calls to and bedside E/M visits by the on-call physician. However, ICU training of nurses (OR = 0.37, 95% confidence interval: 0.16-0.86) decreased the demand of performing clinical procedures by the on-call physician. Moreover, number of patients with unstable conditions (risk ratio [RR] 1.52 and 1.55, respectively) had significantly increased the number of night calls and bedside E/M by on-call physicians by around 50%. Nurses with N1 level (RR 2.16 and 2.71, respectively) were more likely to place night calls and facilitate bedside E/M by the on-call physician compared to nurses with N0 level. In addition, the nurse leaders with ICU training (RR 1.72 and 3.07, respectively) had significant increases in night calls and bedside E/M by the on-call physician compared to those without ICU training.On-call physician workload is associated with patient factors and the training of nurses. Number of unstable patients in a shift may be considered in predicting workload. The training of nurses may improve patient safety and decrease demand for clinical procedure.

Proceedings of the DoD Workload Assessment Workshop on Workload Assessment Techniques and Tools Held in Dayton Ohio on 27-28 September 1986.

DTIC Science & Technology

1987-09-15

memory task. Subjects in the experiment were required to monitor a visual display and update the status of four categories of information that changed ...Kahneman, D., 1966, Pupillary changes in two memory tasks, Psychonomic Science, 55:371-372. Casali, J. G. and Wierwille, W. W., 1982, A sensitivity...operator to deal with the demands. 3. The level of operator performance that results from the inter - action of task demands and capacity/effort

Optimizing the balance between task automation and human manual control in simulated submarine track management.

PubMed

Chen, Stephanie I; Visser, Troy A W; Huf, Samuel; Loft, Shayne

2017-09-01

Automation can improve operator performance and reduce workload, but can also degrade operator situation awareness (SA) and the ability to regain manual control. In 3 experiments, we examined the extent to which automation could be designed to benefit performance while ensuring that individuals maintained SA and could regain manual control. Participants completed a simulated submarine track management task under varying task load. The automation was designed to facilitate information acquisition and analysis, but did not make task decisions. Relative to a condition with no automation, the continuous use of automation improved performance and reduced subjective workload, but degraded SA. Automation that was engaged and disengaged by participants as required (adaptable automation) moderately improved performance and reduced workload relative to no automation, but degraded SA. Automation engaged and disengaged based on task load (adaptive automation) provided no benefit to performance or workload, and degraded SA relative to no automation. Automation never led to significant return-to-manual deficits. However, all types of automation led to degraded performance on a nonautomated task that shared information processing requirements with automated tasks. Given these outcomes, further research is urgently required to establish how to design automation to maximize performance while keeping operators cognitively engaged. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Workload of Team Leaders and Team Members During a Simulated Sepsis Scenario.

PubMed

Tofil, Nancy M; Lin, Yiqun; Zhong, John; Peterson, Dawn Taylor; White, Marjorie Lee; Grant, Vincent; Grant, David J; Gottesman, Ronald; Sudikoff, Stephanie N; Adler, Mark; Marohn, Kimberly; Davidson, Jennifer; Cheng, Adam

2017-09-01

Crisis resource management principles dictate appropriate distribution of mental and/or physical workload so as not to overwhelm any one team member. Workload during pediatric emergencies is not well studied. The National Aeronautics and Space Administration-Task Load Index is a multidimensional tool designed to assess workload validated in multiple settings. Low workload is defined as less than 40, moderate 40-60, and greater than 60 signify high workloads. Our hypothesis is that workload among both team leaders and team members is moderate to high during a simulated pediatric sepsis scenario and that team leaders would have a higher workload than team members. Multicenter observational study. Nine pediatric simulation centers (five United States, three Canada, and one United Kingdom). Team leaders and team members during a 12-minute pediatric sepsis scenario. National Aeronautics and Space Administration-Task Load Index. One hundred twenty-seven teams were recruited from nine sites. One hundred twenty-seven team leaders and 253 team members completed the National Aeronautics and Space Administration-Task Load Index. Team leader had significantly higher overall workload than team member (51 ± 11 vs 44 ± 13; p < 0.01). Team leader had higher workloads in all subcategories except in performance where the values were equal and in physical demand where team members were higher than team leaders (29 ± 22 vs 18 ± 16; p < 0.01). The highest category for each group was mental 73 ± 13 for team leader and 60 ± 20 for team member. For team leader, two categories, mental (73 ± 17) and effort (66 ± 16), were high workload, most domains for team member were moderate workload levels. Team leader and team member are under moderate workloads during a pediatric sepsis scenario with team leader under high workloads (> 60) in the mental demand and effort subscales. Team leader average significantly higher workloads. Consideration of decreasing team leader responsibilities may improve team workload distribution.

Memory and subjective workload assessment

NASA Technical Reports Server (NTRS)

Staveland, L.; Hart, S.; Yeh, Y. Y.

1986-01-01

Recent research suggested subjective introspection of workload is not based upon specific retrieval of information from long term memory, and only reflects the average workload that is imposed upon the human operator by a particular task. These findings are based upon global ratings of workload for the overall task, suggesting that subjective ratings are limited in ability to retrieve specific details of a task from long term memory. To clarify the limits memory imposes on subjective workload assessment, the difficulty of task segments was varied and the workload of specified segments was retrospectively rated. The ratings were retrospectively collected on the manipulations of three levels of segment difficulty. Subjects were assigned to one of two memory groups. In the Before group, subjects knew before performing a block of trials which segment to rate. In the After group, subjects did not know which segment to rate until after performing the block of trials. The subjective ratings, RTs (reaction times) and MTs (movement times) were compared within group, and between group differences. Performance measures and subjective evaluations of workload reflected the experimental manipulations. Subjects were sensitive to different difficulty levels, and recalled the average workload of task components. Cueing did not appear to help recall, and memory group differences possibly reflected variations in the groups of subjects, or an additional memory task.

Flight deck crew coordination indices of workload and situation awareness in terminal operations

NASA Astrophysics Data System (ADS)

Ellis, Kyle Kent Edward

Crew coordination in the context of aviation is a specifically choreographed set of tasks performed by each pilot, defined for each phase of flight. Based on the constructs of effective Crew Resource Management and SOPs for each phase of flight, a shared understanding of crew workload and task responsibility is considered representative of well-coordinated crews. Nominal behavior is therefore defined by SOPs and CRM theory, detectable through pilot eye-scan. This research investigates the relationship between the eye-scan exhibited by each pilot and the level of coordination between crewmembers. Crew coordination was evaluated based on each pilot's understanding of the other crewmember's workload. By contrasting each pilot's workload-understanding, crew coordination was measured as the summed absolute difference of each pilot's understanding of the other crewmember's reported workload, resulting in a crew coordination index. The crew coordination index rates crew coordination on a scale ranging across Excellent, Good, Fair and Poor. Eye-scan behavior metrics were found to reliably identify a reduction in crew coordination. Additionally, crew coordination was successfully characterized by eye-scan behavior data using machine learning classification methods. Identifying eye-scan behaviors on the flight deck indicative of reduced crew coordination can be used to inform training programs and design enhanced avionics that improve the overall coordination between the crewmembers and the flight deck interface. Additionally, characterization of crew coordination can be used to develop methods to increase shared situation awareness and crew coordination to reduce operational and flight technical errors. Ultimately, the ability to reduce operational and flight technical errors made by pilot crews improves the safety of aviation.

The multi-attribute task battery for human operator workload and strategic behavior research

NASA Technical Reports Server (NTRS)

Comstock, J. Raymond, Jr.; Arnegard, Ruth J.

1992-01-01

The Multi-Attribute Task (MAT) Battery provides a benchmark set of tasks for use in a wide range of lab studies of operator performance and workload. The battery incorporates tasks analogous to activities that aircraft crewmembers perform in flight, while providing a high degree of experimenter control, performance data on each subtask, and freedom to use nonpilot test subjects. Features not found in existing computer based tasks include an auditory communication task (to simulate Air Traffic Control communication), a resource management task permitting many avenues or strategies of maintaining target performance, a scheduling window which gives the operator information about future task demands, and the option of manual or automated control of tasks. Performance data are generated for each subtask. In addition, the task battery may be paused and onscreen workload rating scales presented to the subject. The MAT Battery requires a desktop computer with color graphics. The communication task requires a serial link to a second desktop computer with a voice synthesizer or digitizer card.

Real time workload classification from an ambulatory wireless EEG system using hybrid EEG electrodes.

PubMed

Matthews, R; Turner, P J; McDonald, N J; Ermolaev, K; Manus, T; Shelby, R A; Steindorf, M

2008-01-01

This paper describes a compact, lightweight and ultra-low power ambulatory wireless EEG system based upon QUASAR's innovative noninvasive bioelectric sensor technologies. The sensors operate through hair without skin preparation or conductive gels. Mechanical isolation built into the harness permits the recording of high quality EEG data during ambulation. Advanced algorithms developed for this system permit real time classification of workload during subject motion. Measurements made using the EEG system during ambulation are presented, including results for real time classification of subject workload.

Effect of Tire Pressure to Physical Workload at Operating a Manual Wheelchair.

PubMed

Booka, Masayuki; Yoneda, Ikuo; Hashizume, Tsutomu; Lee, Hokyoo; Oku, Hidehisa; Fujisawa, Shoichiro

2015-01-01

It is often experienced that low tire pressure of the wheelchair not only increases running resistance, but also reduces parking brake performance. In this study, the required driving forces for different tire pressures were experimentally measured and evaluated. It was indicated from the result that the wheelchair with proper tire pressure could be run with less workload of wheelchair-user. Then it was also indicated that the wheelchair with a lower tire pressure needed more workload of wheelchair-user even on hard level surface.

Operating room clinicians' ratings of workload: a vignette simulation study.

PubMed

Wallston, Kenneth A; Slagle, Jason M; Speroff, Ted; Nwosu, Sam; Crimin, Kimberly; Feurer, Irene D; Boettcher, Brent; Weinger, Matthew B

2014-06-01

Increased clinician workload is associated with medical errors and patient harm. The Quality and Workload Assessment Tool (QWAT) measures anticipated (pre-case) and perceived (post-case) clinical workload during actual surgical procedures using ratings of individual and team case difficulty from every operating room (OR) team member. The purpose of this study was to examine the QWAT ratings of OR clinicians who were not present in the OR but who read vignettes compiled from actual case documentation to assess interrater reliability and agreement with ratings made by clinicians involved in the actual cases. Thirty-six OR clinicians (13 anesthesia providers, 11 surgeons, and 12 nurses) used the QWAT to rate 6 cases varying from easy to moderately difficult based on actual ratings made by clinicians involved with the cases. Cases were presented and rated in random order. Before rating anticipated individual and team difficulty, the raters read prepared clinical vignettes containing case synopses and much of the same written case information that was available to the actual clinicians before the onset of each case. Then, before rating perceived individual and team difficulty, they read part 2 of the vignette consisting of detailed role-specific intraoperative data regarding the anesthetic and surgical course, unusual events, and other relevant contextual factors. Surgeons had higher interrater reliability on the QWAT than did OR nurses or anesthesia providers. For the anticipated individual and team workload ratings, there were no statistically significant differences between the actual ratings and the ratings obtained from the vignettes. There were differences for the 3 provider types in perceived individual workload for the median difficulty cases and in the perceived team workload for the median and more difficult cases. The case difficulty items on the QWAT seem to be sufficiently reliable and valid to be used in other studies of anticipated and perceived clinical workload of surgeons. Perhaps because of the limitations of the clinical documentation shown to anesthesia providers and OR nurses in the current vignette study, more evidence needs to be gathered to demonstrate the criterion-related validity of the QWAT difficulty items for assessing the workload of nonsurgeon OR clinicians.

EFFECTIVE INDICES FOR MONITORING MENTAL WORKLOAD WHILE PERFORMING MULTIPLE TASKS.

PubMed

Hsu, Bin-Wei; Wang, Mao-Jiun J; Chen, Chi-Yuan; Chen, Fang

2015-08-01

This study identified several physiological indices that can accurately monitor mental workload while participants performed multiple tasks with the strategy of maintaining stable performance and maximizing accuracy. Thirty male participants completed three 10-min. simulated multitasks: MATB (Multi-Attribute Task Battery) with three workload levels. Twenty-five commonly used mental workload measures were collected, including heart rate, 12 HRV (heart rate variability), 10 EEG (electroencephalography) indices (α, β, θ, α/θ, θ/β from O1-O2 and F4-C4), and two subjective measures. Analyses of index sensitivity showed that two EEG indices, θ and α/θ (F4-C4), one time-domain HRV-SDNN (standard deviation of inter-beat intervals), and four frequency-domain HRV: VLF (very low frequency), LF (low frequency), %HF (percentage of high frequency), and LF/HF were sensitive to differentiate high workload. EEG α/θ (F4-C4) and LF/HF were most effective for monitoring high mental workload. LF/HF showed the highest correlations with other physiological indices. EEG α/θ (F4-C4) showed strong correlations with subjective measures across different mental workload levels. Operation strategy would affect the sensitivity of EEG α (F4-C4) and HF.

Quantification of pilot workload via instrument scan

NASA Technical Reports Server (NTRS)

Tole, J. R.; Stephens, A. T.; Harris, R. L., Sr.; Ephrath, A.

1982-01-01

The use of visual scanning behavior as an indicator of pilot workload is described. The relationship between level of performance on a constant piloting task under simulated IFR conditions, the skill of the pilot the level of mental workload induced by an additional verbal task imposed on the basic control task, and visual scanning behavior is investigated. An increase in fixation dwell times, especially on the primary instrument with increased mental loading is indicated. Skilled subjects 'stared' less under increased loading than did novice pilots. Sequences of instrument fixations were also examined. The percentage occurrence of the subject's most used sequences decreased with increased task difficulty for novice subjects but not for highly skilled subjects. Entropy rate (bits/sec) of the sequence of fixations was also used to quantify the scan pattern. It consistently decreased for most subjects as the four loading levels used increased.

Fault and Error Latency Under Real Workload: an Experimental Study. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Chillarege, Ram

1986-01-01

A practical methodology for the study of fault and error latency is demonstrated under a real workload. This is the first study that measures and quantifies the latency under real workload and fills a major gap in the current understanding of workload-failure relationships. The methodology is based on low level data gathered on a VAX 11/780 during the normal workload conditions of the installation. Fault occurrence is simulated on the data, and the error generation and discovery process is reconstructed to determine latency. The analysis proceeds to combine the low level activity data with high level machine performance data to yield a better understanding of the phenomena. A strong relationship exists between latency and workload and that relationship is quantified. The sampling and reconstruction techniques used are also validated. Error latency in the memory where the operating system resides was studied using data on the physical memory access. Fault latency in the paged section of memory was determined using data from physical memory scans. Error latency in the microcontrol store was studied using data on the microcode access and usage.

Input Device Characteristics Contribute to Performance during Training to Operate a Simulated Micro-Unmanned Aerial Vehicle

DTIC Science & Technology

2010-10-01

mission, participants were given the NASA Task Load Index ( NASA TLX ) to measure subjective workload. Additional performance measures included mission...16 NASA TLX Workload Analyses...worksheet (See Appendix C), the Hidden Patterns Test (ETS, 1976), and an electronic form of the NASA Task Load Index ( TLX ; Hart & Staveland, 1988). The

Two Levels of Caffeine Ingestion on Blood Lactate and Free Fatty Acid Responses during Incremental Exercise.

ERIC Educational Resources Information Center

McNaughton, Lars

1987-01-01

Research was conducted to determine the effects of two doses of caffeine on the lactate threshold and also to examine the effects on substrate utilization during incremental cycle ergometry. Results found that caffeine increased heart rates and free fatty acid levels for all workloads and decreased blood lactate levels at some of the workloads.…

Pilot Mental Workload with Predictive System Status Information

NASA Technical Reports Server (NTRS)

Trujillo, Anna C.

1998-01-01

Research has shown a strong pilot preference for predictive information of aircraft system status in the flight deck. However, the mental workload associated with using this predictive information has not been ascertained. The study described here attempted to measure mental workload. In this simulator experiment, three types of predictive information (none, whether a parameter was changing abnormally, and the time for a parameter to reach an alert range) and four initial times to a parameter alert range (1 minute, 5 minutes, 15 minutes, and ETA+45 minutes) were tested to determine their effects on subjects mental workload. Subjective workload ratings increased with increasing predictive information (whether a parameter was changing abnormally or the time for a parameter to reach an alert range). Subjective situation awareness decreased with more predictive information but it became greater with increasing initial times to a parameter alert range. Also, subjective focus changed depending on the type of predictive information. Lastly, skin temperature fluctuated less as the initial time to a parameter alert range increased.

Development of a job rotation scheduling algorithm for minimizing accumulated work load per body parts.

PubMed

Song, JooBong; Lee, Chaiwoo; Lee, WonJung; Bahn, Sangwoo; Jung, ChanJu; Yun, Myung Hwan

2015-01-01

For the successful implementation of job rotation, jobs should be scheduled systematically so that physical workload is evenly distributed with the use of various body parts. However, while the potential benefits are widely recognized by research and industry, there is still a need for a more effective and efficient algorithm that considers multiple work-related factors in job rotation scheduling. This study suggests a type of job rotation algorithm that aims to minimize musculoskeletal disorders with the approach of decreasing the overall workload. Multiple work characteristics are evaluated as inputs to the proposed algorithm. Important factors, such as physical workload on specific body parts, working height, involvement of heavy lifting, and worker characteristics such as physical disorders, are included in the algorithm. For evaluation of the overall workload in a given workplace, an objective function was defined to aggregate the scores from the individual factors. A case study, where the algorithm was applied at a workplace, is presented with an examination on its applicability and effectiveness. With the application of the suggested algorithm in case study, the value of the final objective function, which is the weighted sum of the workload in various body parts, decreased by 71.7% when compared to a typical sequential assignment and by 84.9% when compared to a single job assignment, which is doing one job all day. An algorithm was developed using the data from the ergonomic evaluation tool used in the plant and from the known factors related to workload. The algorithm was developed so that it can be efficiently applied with a small amount of required inputs, while covering a wide range of work-related factors. A case study showed that the algorithm was beneficial in determining a job rotation schedule aimed at minimizing workload across body parts.

Assessment of operators’ mental workload using physiological and subjective measures in cement, city traffic and power plant control centers

PubMed Central

Fallahi, Majid; Motamedzade, Majid; Heidarimoghadam, Rashid; Soltanian, Ali Reza; Miyake, Shinji

2016-01-01

Background: The present study aimed to evaluate the operators’ mental workload (MW) of cement, city traffic control and power plant control centers using subjective and objective measures during system vital parameters monitoring. Methods: This cross-sectional study was conducted from June 2014 to February 2015 at the cement, city traffic control and power plant control centers. Electrocardiography and electroencephalography data were recorded from forty males during performing their daily working in resting, low mental workload (LMW), high mental workload (HMW) and recovery conditions (each block 5 minutes). The NASA-Task Load Index (TLX) was used to evaluate the subjective workload of the operators. Results: The results showed that increasing MW had a significant effect on the operators subjective responses in two conditions ([1,53] = 216.303, P < 0.001, η2 = 0.803). Also,the Task-MW interaction effect on operators subjective responses was significant (F [3, 53] = 12.628,P < 0.001, η2 = 0.417). Analysis of repeated measures analysis of variance (ANOVA) indicated that increasing mental demands had a significant effect on heart rate, low frequency/high frequency ratio, theta and alpha band activity. Conclusion: The results suggested that when operators’ mental demands especially in traffic control and power plant tasks increased, their mental fatigue and stress level increased and their mental health deteriorated. Therefore, it may be necessary to implement an ergonomic program or administrative control to manage mental probably health in these control centers. Furthermore, by evaluating MW, the control center director can organize the human resources for each MW condition to sustain the appropriate performance as well as improve system functions. PMID:27386425

Improved lower extremity pedaling mechanics in individuals with stroke under maximal workloads.

PubMed

Linder, Susan M; Rosenfeldt, Anson B; Bazyk, Andrew S; Koop, Mandy Miller; Ozinga, Sarah; Alberts, Jay L

2018-05-01

Background Individuals with stroke present with motor control deficits resulting in the abnormal activation and timing of agonist and antagonist muscles and inefficient movement patterns. The analysis of pedaling biomechanics provides a window into understanding motor control deficits, which vary as a function of workload. Understanding the relationship between workload and motor control is critical when considering exercise prescription during stroke rehabilitation. Objectives To characterize pedaling kinematics and motor control processes under conditions in which workload was systematically increased to an eventual patient-specific maximum. Methods A cohort study was conducted in which 18 individuals with chronic stroke underwent a maximal exertion cardiopulmonary exercise test on a stationary cycle ergometer, during which pedaling torque was continuously recorded. Measures of force production, pedaling symmetry, and pedaling smoothness were obtained. Results Mean Torque increased significantly (p < 0.05) for both legs from initial to terminal workloads. Mean torque Symmetry Index, calculated for down and upstroke portions of the pedaling action, improved from 0.37(0.29) to 0.29(0.35) during downstroke (p = 0.007), and worsened during the upstroke: -0.37(0.38) to -0.62(0.46) (p < 0.001) from initial to terminal workloads. Low Torque Duration improved from initial to terminal workloads, decreasing from 121.1(52.9) to 58.1(39.6) degrees (p < 0.001), respectively. Smoothness of pedaling improved significantly from initial to terminal workloads (p < 0.001). Conclusions Improved pedaling kinematics at terminal workloads indicate that individuals with stroke demonstrate improved motor control with respect to the timing, sequencing, and activation of hemiparetic lower extremity musculature compared to lower workloads. Therapeutic prescription involving higher resistance may be necessary to sufficiently engage and activate the paretic lower extremity.

An Investigation of the Combined Effect of Stress, Fatigue and Workload on Human Performance: Position Paper

NASA Technical Reports Server (NTRS)

Mock, Jessica

2005-01-01

Stress, fatigue, and workload affect worker performance. NSF reported that 61% of respondents state losing concentration at work while 79% occasionally or frequently made errors as a result of being fatigued. Shift work, altered work schedules, long hours of continuous wakefulness, and sleep loss can create sleep and circadian disruptions that degrade waking fundions causing stress and fatigue. Review of the literature has proven void of information that links the combined effects of fatigue, stress, and workload to human performance. This paper will address which occupational factors within stress, fatigue, and workload were identified as occupational contributors to performance changes. The results of this research will be apglied to underlying models and algorithms that will help predict performance changes in control room operators.

Shift scheduling model considering workload and worker’s preference for security department

NASA Astrophysics Data System (ADS)

Herawati, A.; Yuniartha, D. R.; Purnama, I. L. I.; Dewi, LT

2018-04-01

Security department operates for 24 hours and applies shift scheduling to organize its workers as well as in hotel industry. This research has been conducted to develop shift scheduling model considering the workers physical workload using rating of perceived exertion (RPE) Borg’s Scale and workers’ preference to accommodate schedule flexibility. The mathematic model is developed in integer linear programming and results optimal solution for simple problem. Resulting shift schedule of the developed model has equally distribution shift allocation among workers to balance the physical workload and give flexibility for workers in working hours arrangement.

Improving striping operations through system optimization.

DOT National Transportation Integrated Search

2015-09-01

Striping operations generate a significant workload for Missouri Department of Transportation (MoDOT) maintenance : operations. The requirement for each striping crew to replenish its stock of paint and other consumable items from a bulk storage : fa...

Design and test of a situation-augmented display for an unmanned aerial vehicle monitoring task.

PubMed

Lu, Jen-Li; Horng, Ruey-Yun; Chao, Chin-Jung

2013-08-01

In this study, a situation-augmented display for unmanned aerial vehicle (UAV) monitoring was designed, and its effects on operator performance and mental workload were examined. The display design was augmented with the knowledge that there is an invariant flight trajectory (formed by the relationship between altitude and velocity) for every flight, from takeoff to landing. 56 participants were randomly assigned to the situation-augmented display or a conventional display condition to work on 4 (number of abnormalities) x 2 (noise level) UAV monitoring tasks three times. Results showed that the effects of situation-augmented display on flight completion time and time to detect abnormalities were robust under various workload conditions, but error rate and perceived mental workload were unaffected by the display type. Results suggest that the UAV monitoring task is extremely difficult, and that display devices providing high-level situation-awareness may improve operator monitoring performance.

Agent-Supported Mission Operations Teamwork

NASA Technical Reports Server (NTRS)

Malin, Jane T.

2003-01-01

This slide presentation reviews the development of software agents to support of mission operations teamwork. The goals of the work was to make automation by agents easy to use, supervise and direct, manage information and communication to decrease distraction, interruptions, workload and errors, reduce mission impact of off-nominal situations and increase morale and decrease turnover. The accomplishments or the project are: 1. Collaborative agents - mixed initiative and creation of instructions for mediating agent 2. Methods for prototyping, evaluating and evolving socio-technical systems 3. Technology infusion: teamwork tools in mISSIons 4. Demonstrations in simulation testbed An example of the use of agent is given, the use of an agent to monitor a N2 tank leak. An incomplete instruction to the agent is handled with mediating assistants, or Intelligent Briefing and Response Assistant (IBRA). The IBRA Engine also watches data stream for triggers and executes Act-Whenever actions. There is also a Briefing and Response Instruction (BRI) which is easy for a discipline specialist to create through a BRI editor.

The smartphone and the driver's cognitive workload: A comparison of Apple, Google, and Microsoft's intelligent personal assistants.

PubMed

Strayer, David L; Cooper, Joel M; Turrill, Jonna; Coleman, James R; Hopman, Rachel J

2017-06-01

The goal of this research was to examine the impact of voice-based interactions using 3 different intelligent personal assistants (Apple's Siri , Google's Google Now for Android phones, and Microsoft's Cortana ) on the cognitive workload of the driver. In 2 experiments using an instrumented vehicle on suburban roadways, we measured the cognitive workload of drivers when they used the voice-based features of each smartphone to place a call, select music, or send text messages. Cognitive workload was derived from primary task performance through video analysis, secondary-task performance using the Detection Response Task (DRT), and subjective mental workload. We found that workload was significantly higher than that measured in the single-task drive. There were also systematic differences between the smartphones: The Google system placed lower cognitive demands on the driver than the Apple and Microsoft systems, which did not differ. Video analysis revealed that the difference in mental workload between the smartphones was associated with the number of system errors, the time to complete an action, and the complexity and intuitiveness of the devices. Finally, surprisingly high levels of cognitive workload were observed when drivers were interacting with the devices: "on-task" workload measures did not systematically differ from that associated with a mentally demanding Operation Span (OSPAN) task. The analysis also found residual costs associated using each of the smartphones that took a significant time to dissipate. The data suggest that caution is warranted in the use of smartphone voice-based technology in the vehicle because of the high levels of cognitive workload associated with these interactions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Analytic and subjective assessments of operator workload imposed by communications tasks in transport aircraft

NASA Technical Reports Server (NTRS)

Eckel, J. S.; Crabtree, M. S.

1984-01-01

Analytical and subjective techniques that are sensitive to the information transmission and processing requirements of individual communications-related tasks are used to assess workload imposed on the aircrew by A-10 communications requirements for civilian transport category aircraft. Communications-related tasks are defined to consist of the verbal exchanges between crews and controllers. Three workload estimating techniques are proposed. The first, an information theoretic analysis, is used to calculate bit values for perceptual, manual, and verbal demands in each communication task. The second, a paired-comparisons technique, obtains subjective estimates of the information processing and memory requirements for specific messages. By combining the results of the first two techniques, a hybrid analytical scale is created. The third, a subjective rank ordering of sequences of communications tasks, provides an overall scaling of communications workload. Recommendations for future research include an examination of communications-induced workload among the air crew and the development of simulation scenarios.

Putting the brain to work: neuroergonomics past, present, and future.

PubMed

Parasuraman, Raja; Wilson, Glenn F

2008-06-01

The authors describe research and applications in prominent areas of neuroergonomics. Because human factors/ergonomics examines behavior and mind at work, it should include the study of brain mechanisms underlying human performance. Neuroergonomic studies are reviewed in four areas: workload and vigilance, adaptive automation, neuroengineering, and molecular genetics and individual differences. Neuroimaging studies have helped identify the components of mental workload, workload assessment in complex tasks, and resource depletion in vigilance. Furthermore, real-time neurocognitive assessment of workload can trigger adaptive automation. Neural measures can also drive brain-computer interfaces to provide disabled users new communication channels. Finally, variants of particular genes can be associated with individual differences in specific cognitive functions. Neuroergonomics shows that considering what makes work possible - the human brain - can enrich understanding of the use of technology by humans and can inform technological design. Applications of neuroergonomics include the assessment of operator workload and vigilance, implementation of real-time adaptive automation, neuroengineering for people with disabilities, and design of selection and training methods.

Measurement-based analysis of error latency. [in computer operating system

NASA Technical Reports Server (NTRS)

Chillarege, Ram; Iyer, Ravishankar K.

1987-01-01

This paper demonstrates a practical methodology for the study of error latency under a real workload. The method is illustrated with sampled data on the physical memory activity, gathered by hardware instrumentation on a VAX 11/780 during the normal workload cycle of the installation. These data are used to simulate fault occurrence and to reconstruct the error discovery process in the system. The technique provides a means to study the system under different workloads and for multiple days. An approach to determine the percentage of undiscovered errors is also developed and a verification of the entire methodology is performed. This study finds that the mean error latency, in the memory containing the operating system, varies by a factor of 10 to 1 (in hours) between the low and high workloads. It is found that of all errors occurring within a day, 70 percent are detected in the same day, 82 percent within the following day, and 91 percent within the third day. The increase in failure rate due to latency is not so much a function of remaining errors but is dependent on whether or not there is a latent error.

A Distinct Role of the Queen in Coordinated Workload and Soil Distribution in Eusocial Naked Mole-Rats

PubMed Central

Kutsukake, Nobuyuki; Inada, Masayuki; Sakamoto, Shinsuke H.; Okanoya, Kazuo

2012-01-01

We investigated how group members achieve collective decision-making, by considering individual intrinsic behavioural rules and behavioural mechanisms for maintaining social integration. Using a simulated burrow environment, we investigated the behavioural rules of coordinated workload for soil distribution in a eusocial mammal, the naked mole-rat (Heterocephalus glaber). We tested two predictions regarding a distinct role of the queen, a socially dominant individual in the caste system: the presence of a queen would increase the workload of other caste individuals, and the cues by a queen would affect the soil distribution. In experiment 1, we placed four individuals of various castes from the same colony into an experimental burrow. Workers exhibited the highest frequency of workload compared to other castes. The presence of a queen activated the workload by other individuals. Individuals showed a consistent workload in a particular direction so as to bias the soil distribution. These results suggest that individuals have a consensus on soil distribution and that the queen plays a distinct role. In experiment 2, we placed the odour of a queen in one of four cells and observed its effect on other individuals’ workload and soil distribution. Relative to other cells, individuals frequently dug in the queen cell so the amount of soil in the queen cell decreased. These results suggest that queen odour is an important cue in coordinated workload and soil distribution in this species. PMID:22957085

Individual differences in cardiorespiratory measures of mental workload: An investigation of negative affectivity and cognitive avoidant coping in pilot candidates.

PubMed

Grassmann, Mariel; Vlemincx, Elke; von Leupoldt, Andreas; Van den Bergh, Omer

2017-03-01

Cardiorespiratory measures provide useful information in addition to well-established self-report measures when monitoring operator capacity. The purpose of our study was to refine the assessment of operator load by considering individual differences in personality and their associations with cardiorespiratory activation. Physiological and self-report measures were analyzed in 115 pilot candidates at rest and while performing a multiple task covering perceptual speed, spatial orientation, and working memory. In the total sample and particularly in individuals with a general tendency to worry a lot, a cognitive avoidant coping style was associated with a smaller task-related increase in heart rate. Negative affectivity was found to moderate the association between cardiac and self-reported arousal. Given that physiological and self-report measures of mental workload are usually combined when evaluating operator load (e.g., in pilot selection and training), our findings suggest that integrating individual differences may reduce unexplained variance and increase the validity of workload assessments. Copyright © 2016 Elsevier Ltd. All rights reserved.

A flight investigation of simulated data-link communications during single-pilot IFR flight. Volume 2: Flight evaluations

NASA Technical Reports Server (NTRS)

Parker, J. F., Jr.; Duffy, J. W.

1982-01-01

Key problems in single pilot instrument flight operations are in the management of flight data and the processing of cockpit information during conditions of heavy workload. A flight data console was developed to allow simulation of a digital data link to replace the current voice communications stem used in air traffic control. This is a human factors evaluation of a data link communications system to determine how such a system might reduce cockpit workload, improve flight proficiency, and be accepted by general aviation pilots. The need for a voice channel as backup to a digital link is examined. The evaluations cover both airport terminal area operations and full mission instrument flight. Results show that general aviation pilots operate well with a digital data link communications system. The findings indicate that a data link system for pilot/ATC communications, with a backup voice channel, is well accepted by general aviation pilots and is considered to be safer, more efficient, and result in less workload than the current voice system.

UAV-guided navigation for ground robot tele-operation in a military reconnaissance environment.

PubMed

Chen, Jessie Y C

2010-08-01

A military reconnaissance environment was simulated to examine the performance of ground robotics operators who were instructed to utilise streaming video from an unmanned aerial vehicle (UAV) to navigate his/her ground robot to the locations of the targets. The effects of participants' spatial ability on their performance and workload were also investigated. Results showed that participants' overall performance (speed and accuracy) was better when she/he had access to images from larger UAVs with fixed orientations, compared with other UAV conditions (baseline- no UAV, micro air vehicle and UAV with orbiting views). Participants experienced the highest workload when the UAV was orbiting. Those individuals with higher spatial ability performed significantly better and reported less workload than those with lower spatial ability. The results of the current study will further understanding of ground robot operators' target search performance based on streaming video from UAVs. The results will also facilitate the implementation of ground/air robots in military environments and will be useful to the future military system design and training community.

Motives for early retirement of self-employed GPs in the Netherlands: a comparison of two time periods.

PubMed

Van Greuningen, Malou; Heiligers, Phil J M; Van der Velden, Lud F J

2012-12-18

The high cost of training and the relatively long period of training for physicians make it beneficial to stimulate physicians to retire later. Therefore, a better understanding of the link between the factors influencing the decision to retire and actual turnover would benefit policies designed to encourage later retirement. This study focuses on actual GP turnover and the determining factors for this in the Netherlands. The period 2003-2007 saw fewer GPs retiring from general practice than the period 1998-2002. In addition, GPs' retirement age was higher in 2003-2007. For these two periods, we analysed work perception, objective workload and reasons for leaving, and related these with the probability that GPs would leave general practice at an early age. In 2003, a first retrospective survey was sent to 520 self-employed GPs who had retired between 1998 and 2002. In 2008, the same survey was sent to 405 GPs who had retired between 2003 and 2007. The response rates were 60% and 54%, respectively. Analyses were done to compare work perception, objective workload, external factors and personal reasons for retiring. For both male and female GPs, work perception was different in the periods under scrutiny: both groups reported greater job satisfaction and a lower degree of emotional exhaustion in the later period, although there was no notable difference in subjective workload. The objective workload was lower in the second period. Moreover, most external factors and personal reasons that may contribute to the decision to retire were reported as less important in the second period. There was a stronger decrease in the probability that female GPs leave general practice within one year than for male GPs. This underscores the gender differences and the need for disaggregated data collection. The results of this study suggest that the decrease in the probability of GPs leaving general practice within one year and the increasing retirement age are caused by a decrease in the objective workload, a change in GPs' work perception, external factors and personal reasons. Based on the results of this study, we consider workload reduction policies are the most useful instruments to control retention and retirement.

Novel Estimation of Pilot Performance Characteristics

NASA Technical Reports Server (NTRS)

Bachelder, Edward N.; Aponso, Bimal

2017-01-01

Two mechanisms internal to the pilot that affect performance during a tracking task are: 1) Pilot equalization (i.e. lead/lag); and 2) Pilot gain (i.e. sensitivity to the error signal). For some applications McRuer's Crossover Model can be used to anticipate what equalization will be employed to control a vehicle's dynamics. McRuer also established approximate time delays associated with different types of equalization - the more cognitive processing that is required due to equalization difficulty, the larger the time delay. However, the Crossover Model does not predict what the pilot gain will be. A nonlinear pilot control technique, observed and coined by the authors as 'amplitude clipping', is shown to improve stability, performance, and reduce workload when employed with vehicle dynamics that require high lead compensation by the pilot. Combining linear and nonlinear methods a novel approach is used to measure the pilot control parameters when amplitude clipping is present, allowing precise measurement in real time of key pilot control parameters. Based on the results of an experiment which was designed to probe workload primary drivers, a method is developed that estimates pilot spare capacity from readily observable measures and is tested for generality using multi-axis flight data. This paper documents the initial steps to developing a novel, simple objective metric for assessing pilot workload and its variation over time across a wide variety of tasks. Additionally, it offers a tangible, easily implementable methodology for anticipating a pilot's operating parameters and workload, and an effective design tool. The model shows promise in being able to precisely predict the actual pilot settings and workload, and observed tolerance of pilot parameter variation over the course of operation. Finally, an approach is proposed for generating Cooper-Harper ratings based on the workload and parameter estimation methodology.

Sixteenth Annual Conference on Manual Control

NASA Technical Reports Server (NTRS)

1982-01-01

Manual control is discussed in terms of operator modeling, measurement of human response, mental workload, pilot/operator opinion, effects of motion, aircraft displays, supervisory control, automobile driving, and remote manipulation.

A Systematic Approach for Engagement Analysis Under Multitasking Environments

NASA Technical Reports Server (NTRS)

Zhang, Guangfan; Leddo, John; Xu, Roger; Richey, Carl; Schnell, Tom; McKenzie, Frederick; Li, Jiang

2011-01-01

An overload condition can lead to high stress for an operator and further cause substantial drops in performance. On the other extreme, in automated systems, an operator may become underloaded; in which case, it is difficult for the operator to maintain sustained attention. When an unexpected event occurs, either internal or external to the automated system, a disengaged operation may neglect, misunderstand, or respond slowly/inappropriately to the situation. In this paper, we discuss a systematic approach monitor for extremes of cognitive workload and engagement in multitasking environments. Inferences of cognitive workload ar engagement are based on subjective evaluations, objective performance measures, physiological signals, and task analysis results. The systematic approach developed In this paper aggregates these types of information collected under the multitasking environment and can provide a real-time assessment or engagement.

Closed loop models for analyzing the effects of simulator characteristics. [digital simulation of human operators

NASA Technical Reports Server (NTRS)

Baron, S.; Muralidharan, R.; Kleinman, D. L.

1978-01-01

The optimal control model of the human operator is used to develop closed loop models for analyzing the effects of (digital) simulator characteristics on predicted performance and/or workload. Two approaches are considered: the first utilizes a continuous approximation to the discrete simulation in conjunction with the standard optimal control model; the second involves a more exact discrete description of the simulator in a closed loop multirate simulation in which the optimal control model simulates the pilot. Both models predict that simulator characteristics can have significant effects on performance and workload.

Hysteresis in Mental Workload and Task Performance: The Influence of Demand Transitions and Task Prioritization.

PubMed

Jansen, Reinier J; Sawyer, Ben D; van Egmond, René; de Ridder, Huib; Hancock, Peter A

2016-12-01

We examine how transitions in task demand are manifested in mental workload and performance in a dual-task setting. Hysteresis has been defined as the ongoing influence of demand levels prior to a demand transition. Authors of previous studies predominantly examined hysteretic effects in terms of performance. However, little is known about the temporal development of hysteresis in mental workload. A simulated driving task was combined with an auditory memory task. Participants were instructed to prioritize driving or to prioritize both tasks equally. Three experimental conditions with low, high, and low task demands were constructed by manipulating the frequency of lane changing. Multiple measures of subjective mental workload were taken during experimental conditions. Contrary to our prediction, no hysteretic effects were found after the high- to low-demand transition. However, a hysteretic effect in mental workload was found within the high-demand condition, which degraded toward the end of the high condition. Priority instructions were not reflected in performance. Online assessment of both performance and mental workload demonstrates the transient nature of hysteretic effects. An explanation for the observed hysteretic effect in mental workload is offered in terms of effort regulation. An informed arrival at the scene is important in safety operations, but peaks in mental workload should be avoided to prevent buildup of fatigue. Therefore, communication technologies should incorporate the historical profile of task demand. © 2016, Human Factors and Ergonomics Society.

Assessment of pilot workload with the introduction of an airborne threat-alert system

NASA Technical Reports Server (NTRS)

Battiste, Vernol; Bortolussi, Michael R.

1989-01-01

Simulated line operations were used to assess the value of the TCAS on the pilot's ability to avoid a collision and to determine the effects of various display configurations and information contents on the flight-crew performance and workload. The crew flew a Phase II Link/Boeing 727 simulator in a simulated ATC environment. Four levels of collision avoidance information were evaluated using the following TCAS display formats: no TCAS information, TCAS information with no traffic display information, TCAS information with threat-activated traffic display information, and TCAS information with a full-time traffic display of threat information. It was found that the use of a threat-activated TCAS display significantly reduced the first officers' workload was significantly reduced by the threat-activated TCAS display, as were the workloads of the captain and the second officer.

The Gain of Resource Delegation in Distributed Computing Environments

NASA Astrophysics Data System (ADS)

Fölling, Alexander; Grimme, Christian; Lepping, Joachim; Papaspyrou, Alexander

In this paper, we address job scheduling in Distributed Computing Infrastructures, that is a loosely coupled network of autonomous acting High Performance Computing systems. In contrast to the common approach of mutual workload exchange, we consider the more intuitive operator's viewpoint of load-dependent resource reconfiguration. In case of a site's over-utilization, the scheduling system is able to lease resources from other sites to keep up service quality for its local user community. Contrary, the granting of idle resources can increase utilization in times of low local workload and thus ensure higher efficiency. The evaluation considers real workload data and is done with respect to common service quality indicators. For two simple resource exchange policies and three basic setups we show the possible gain of this approach and analyze the dynamics in workload-adaptive reconfiguration behavior.

Robust Models for Operator Workload Estimation

DTIC Science & Technology

2015-03-01

piloted aircraft (RPA) simultaneously, a vast improvement in resource utilization compared to existing operations that require several operators per...into distinct cognitive channels (visual, auditory, spatial, etc.) based on our ability to multitask effectively as long as no one channel is

Cognitive Workload and Sleep Restriction Interact to Influence Sleep Homeostatic Responses

PubMed Central

Goel, Namni; Abe, Takashi; Braun, Marcia E.; Dinges, David F.

2014-01-01

Study Objectives: Determine the effects of high versus moderate workload on sleep physiology and neurobehavioral measures, during sleep restriction (SR) and no sleep restriction (NSR) conditions. Design: Ten-night experiment involving cognitive workload and SR manipulations. Setting: Controlled laboratory environment. Participants: Sixty-three healthy adults (mean ± standard deviation: 33.2 ± 8.7 y; 29 females), age 22–50 y. Interventions: Following three baseline 8 h time in bed (TIB) nights, subjects were randomized to one of four conditions: high cognitive workload (HW) + SR; moderate cognitive workload (MW) + SR; HW + NSR; or MW + NSR. SR entailed 5 consecutive nights at 4 h TIB; NSR entailed 5 consecutive nights at 8 h TIB. Subjects received three workload test sessions/day consisting of 15-min preworkload assessments, followed by a 60-min (MW) or 120-min (HW) workload manipulation comprised of visually based cognitive tasks, and concluding with 15-min of postworkload assessments. Experimental nights were followed by two 8-h TIB recovery sleep nights. Polysomnography was collected on baseline night 3, experimental nights 1, 4, and 5, and recovery night 1 using three channels (central, frontal, occipital [C3, Fz, O2]). Measurements and Results: High workload, regardless of sleep duration, increased subjective fatigue and sleepiness (all P < 0.05). In contrast, sleep restriction produced cumulative increases in Psychomotor Vigilance Test (PVT) lapses, fatigue, and sleepiness and decreases in PVT response speed and Maintenance of Wakefulness Test (MWT) sleep onset latencies (all P < 0.05). High workload produced longer sleep onset latencies (P < 0.05, d = 0.63) and less wake after sleep onset (P < 0.05, d = 0.64) than moderate workload. Slow-wave energy—the putative marker of sleep homeostasis—was higher at O2 than C3 only in the HW + SR condition (P < 0.05). Conclusions: High cognitive workload delayed sleep onset, but it also promoted sleep homeostatic responses by increasing subjective fatigue and sleepiness, and producing a global sleep homeostatic response by reducing wake after sleep onset. When combined with sleep restriction, high workload increased local (occipital) sleep homeostasis, suggesting a use-dependent sleep response to visual work. We conclude that sleep restriction and cognitive workload interact to influence sleep homeostasis. Citation: Goel N, Abe T, Braun ME, Dinges DF. Cognitive workload and sleep restriction interact to influence sleep homeostatic responses. SLEEP 2014;37(11):1745-1756. PMID:25364070

A Manpower Model for U.S. Navy Operational Contracting

DTIC Science & Technology

2012-06-01

Accomplishment Time RFP Request For Proposal SAF/FM Air Force Financial Management SAP Simplified Acquisition Procedures SAT Simplified...conformance and seller’s release of claim (Garrett, 2007). 2. Contract Size and its Effect on Workload Simplified acquisition procedures ( SAP ) were...the SAP dollar threshold. 14 The drastic reduction in KO workload through the use of SAP is unmatched by any federal authorization that came

A Semi-Preemptive Garbage Collector for Solid State Drives

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

Lee, Junghee; Kim, Youngjae; Shipman, Galen M

2011-01-01

NAND flash memory is a preferred storage media for various platforms ranging from embedded systems to enterprise-scale systems. Flash devices do not have any mechanical moving parts and provide low-latency access. They also require less power compared to rotating media. Unlike hard disks, flash devices use out-of-update operations and they require a garbage collection (GC) process to reclaim invalid pages to create free blocks. This GC process is a major cause of performance degradation when running concurrently with other I/O operations as internal bandwidth is consumed to reclaim these invalid pages. The invocation of the GC process is generally governedmore » by a low watermark on free blocks and other internal device metrics that different workloads meet at different intervals. This results in I/O performance that is highly dependent on workload characteristics. In this paper, we examine the GC process and propose a semi-preemptive GC scheme that can preempt on-going GC processing and service pending I/O requests in the queue. Moreover, we further enhance flash performance by pipelining internal GC operations and merge them with pending I/O requests whenever possible. Our experimental evaluation of this semi-preemptive GC sheme with realistic workloads demonstrate both improved performance and reduced performance variability. Write-dominant workloads show up to a 66.56% improvement in average response time with a 83.30% reduced variance in response time compared to the non-preemptive GC scheme.« less

General surgery workloads and practice patterns in the United States, 2007 to 2009: a 10-year update from the American Board of Surgery.

PubMed

Valentine, R James; Jones, Andrew; Biester, Thomas W; Cogbill, Thomas H; Borman, Karen R; Rhodes, Robert S

2011-09-01

To assess changes in general surgery workloads and practice patterns in the past decade. Nearly 80% of graduating general surgery residents pursue additional training in a surgical subspecialty. This has resulted in a shortage of general surgeons, especially in rural areas. The purpose of this study is to characterize the workloads and practice patterns of general surgeons versus certified surgical subspecialists and to compare these data with those from a previous decade. The surgical operative logs of 4968 individuals recertifying in surgery 2007 to 2009 were reviewed. Data from 3362 (68%) certified only in Surgery (GS) were compared with 1606 (32%) with additional American Board of Medical Specialties certificates (GS+). Data from GS surgeons were also compared with data from GS surgeons recertifying 1995 to 1997. Independent variables were compared using factorial ANOVA. GS surgeons performed a mean of 533 ± 365 procedures annually. Women GS performed far more breast operations and fewer abdomen, alimentary tract and laparoscopic procedures compared to men GS (P < 0.001). GS surgeons recertifying at 10 years performed more abdominal, alimentary tract and laparoscopic procedures compared to those recertifying at 20 or 30 years (P < 0.001). Rural GS surgeons performed far more endoscopic procedures and fewer abdominal, alimentary tract, and laparoscopic procedures than urban counterparts (P < 0.001). The United States medical school graduates had similar workloads and distribution of operations to international medical graduates. Compared to 1995 to 1997, GS surgeons from 2007 to 2009 performed more procedures, especially endoscopic and laparoscopic. GS+ surgeons performed 15% to 33% of all general surgery procedures. GS practice patterns are heterogeneous; gender, age, and practice setting significantly affect operative caseloads. A substantial portion of general surgery procedures currently are performed by GS+ surgeons, whereas GS surgeons continue to perform considerable numbers of specialty operations. Reduced general surgery operative experience in GS+ residencies may negatively impact access to general surgical care. Similarly, narrowing GS residency operative experience may impair specialty operation access.

[The Relation between the Height of Radiographic Table and Workloads of Radiologic Technologist in General X-ray Examinations].

PubMed

Hattori, Akiko; Mizoguchi, Noriko; Arimura, Hisao; Fukano, Yuuichi; Umezu, Yoshiyuki; Yabuuchi, Hidetake

2015-12-01

Workloads of radiological technologists under different conditions of heights of radiographic table and/or X-ray tube assembly were calculated using a software for preventing musculoskeletal complaint to investigate optimal working environment for general X-ray examinations. In the patient positioning, compressive force of lumbar disc decreased at higher radiographic table within the range of 45-90 cm. On the other hand, workload of the shoulder joint increased with increase in the height of radiographic table. Load of the shoulder joint similarly increased as the height of the X-ray tube assembly increased. Compressive force of lumbar disc reduced by approximately 10-30% as the height ratio of the radiographic table to body height increased by approximately 40%, compared to the lowest table of 45 cm. Muscle load of a 50-years-old woman was approximately double compared to a 30-year-old man, even in the same workload. It is important to keep suitable height of radiographic table for reduction of the workloads of lumbar rather than shoulder joint, because floating-type radiographic table is generally used.

The impact of draught related to air velocity, air temperature and workload.

PubMed

Griefahn, B; Künemund, C; Gehring, U

2001-08-01

This experimental study was designed to test the hypotheses that the effects of draught increase with higher air velocity, with lower air temperature, and with lower workload. Thirty healthy young males were exposed to horizontal draught during 55 min while they operated an arm ergometer in a standing posture. Air velocity, air temperature, and workload were varied in 3 steps each, between 11 and 23 degrees C, 0.1 and 0.3 m/s, and 104 to 156 W/m2, respectively. The 27 combinations were distributed over subjects in a fractional factorial 3(3)-design. The participants were clothed for thermal neutrality. Workload was measured at the end of the sessions by respirometry. Draught-induced annoyance was determined every 5 min, separately for 10 body sites. Corresponding skin temperature was also recorded. The hypotheses were verified for the influence of air velocity and air temperature. Regarding workload, local heat production is probably decisive, meaning that draft-induced local annoyance is inversely related to workload in active but independent from workload in non-active body areas. To improve the situation for the workers concerned it is suggested to apply protective gloves that cover an as great area of the forearms as possible and to limit airflows to mean velocities of less than 0.2 m/s (with turbulence intensities of 50%).

Improving striping operations through system optimization - phase 2 : final report.

DOT National Transportation Integrated Search

2016-07-01

Striping operations generate a significant workload for MoDOT maintenance operations. The requirement for each striping crew : to replenish its stock of paint and other consumable items from a bulk storage facility, along with the necessity to make s...

Heterogeneous Clustering: Operational and User Impacts

NASA Technical Reports Server (NTRS)

Salm, Saita Wood

1999-01-01

Heterogeneous clustering can improve overall utilization of multiple hosts and can provide better turnaround to users by balancing workloads across hosts. Building a cluster requires both operational changes and revisions in user scripts.

No time for teaching? Inpatient attending physicians' workload and teaching before and after the implementation of the 2003 duty hours regulations.

PubMed

Roshetsky, Lisa M; Coltri, Ainoa; Flores, Andrea; Vekhter, Ben; Humphrey, Holly J; Meltzer, David O; Arora, Vineet M

2013-09-01

Understanding the association between attending physicians' workload and teaching is critical to preserving residents' learning experience. The authors tested the association between attending physicians' self-reported workload and perceptions of time for teaching before and after the 2003 resident duty hours regulations. From 2001 to 2008, the authors surveyed all inpatient general medicine attending physicians at a teaching hospital. To measure workload, they used a conceptual framework to create a composite score from six domains (mental demand, physical demand, temporal demand, effort, performance, frustration). They measured time for teaching using (1) open-ended responses to hours per week spent doing didactic teaching and (2) responses (agree, strongly agree) to the statement "I had enough time for teaching." They conducted multivariate logistic regression analyses, controlling for month, year, and clustering by attending physicians, to test the association between workload scores and time for teaching. Of 738 eligible attending physicians, 482 (65%) completed surveys. Respondents spent a median of three hours per week dedicated to teaching. Less than half (198; 43%) reporting enough time for teaching. The composite workload scores were normally distributed (median score of 15) and demonstrated a weak positive correlation with actual patient volume (r = 0.25). The odds of an attending physician reporting enough time for teaching declined by 21% for each point increase in composite workload score (odds ratio = 0.79 [95% confidence interval 0.69-0.91]; P = .001). The authors found that attending physicians' greater self-perceived workload was associated with decreased time for teaching.

Preliminary study of the pilot's workload during emergency procedures in helicopters air operations.

PubMed

Bezerra, Flávio G V; Ribeiro, Selma L O

2012-01-01

Military air operations and law enforcement operations in helicopters are examples of activities that require high performance of the operator. This article aimed at presenting a preliminary analysis of data obtained in the initial study in order to validate the instruments and the research protocol that focuses on the analysis of the workload imposed on helicopter pilots in emergency situations. The research was conducted in an environment of real flight training and used the NASA-TLX Scale to assess the workload and an interview guide to obtain reports on the main tasks performed. Preliminary data obtained is related to the participation of 10 (ten) volunteer pilots with experience in different types of helicopters. Four scenarios involving helicopter emergency procedures of HB-350 "Squirrel" were outlined. For this article, the analysis used only the data regarding the Physical and Mental Demands of the NASA-TLX Scale. Preliminarily, the results indicate that the "time pressure" as a factor contributing to increase mental requirement in emergency situations in flight, and that this increase was reflected in the request of mental processes such as: identification of the breakdown, attention and monitoring parameters. Future steps include extending the sample and adding physiological tools to better understand the effects of these types of emergencies on pilot performance and flight safety.

Measuring Workload Differences Between Short-term Memory and Long-term Memory Scenarios in a Simulated Flight Environment

NASA Technical Reports Server (NTRS)

Berg, S. L.; Sheridan, T. B.

1984-01-01

Four highly experienced Air Force pilots each flew four simulated flight scenarios. Two scenarios required a great deal of aircraft maneuvering. The other two scenarios involved less maneuvering, but required remembering a number of items. All scenarios were designed to be equaly challenging. Pilot's Subjective Ratings for Activity-level, Complexity, Difficulty, Stress, and Workload were higher for the manuevering scenarios than the memory scenarios. At a moderate workload level, keeping the pilots active resulted in better aircraft control. When required to monitor and remember items, aircraft control tended to decrease. Pilots tended to weigh information about the spatial positioning and performance of their aircraft more heavily than other items.

Training and testing ERP-BCIs under different mental workload conditions

NASA Astrophysics Data System (ADS)

Ke, Yufeng; Wang, Peiyuan; Chen, Yuqian; Gu, Bin; Qi, Hongzhi; Zhou, Peng; Ming, Dong

2016-02-01

Objective. As one of the most popular and extensively studied paradigms of brain-computer interfaces (BCIs), event-related potential-based BCIs (ERP-BCIs) are usually built and tested in ideal laboratory settings in most existing studies, with subjects concentrating on stimuli and intentionally avoiding possible distractors. This study is aimed at examining the effect of simultaneous mental activities on ERP-BCIs by manipulating various levels of mental workload during the training and/or testing of an ERP-BCI. Approach. Mental workload was manipulated during the training or testing of a row-column P300-speller to investigate how and to what extent the spelling performance and the ERPs evoked by the oddball stimuli are affected by simultaneous mental workload. Main results. Responses of certain ERP components, temporal-occipital N200 and the late reorienting negativity evoked by the oddball stimuli and the classifiability of ERP features between targets and non-targets decreased with the increase of mental workload encountered by the subject. However, the effect of mental workload on the performance of ERP-BCI was not always negative but depended on the conditions where the ERP-BCI was built and applied. The performance of ERP-BCI built under an ideal lab setting without any irrelevant mental activities declined with the increasing mental workload of the testing data. However, the performance was significantly improved when an ERP-BCI was built under an appropriate mental workload level, compared to that built under speller-only conditions. Significance. The adverse effect of concurrent mental activities may present a challenge for ERP-BCIs trained in ideal lab settings but which are to be used in daily work, especially when users are performing demanding mental processing. On the other hand, the positive effects of the mental workload of the training data suggest that introducing appropriate mental workload during training ERP-BCIs is of potential benefit to the performance in practical applications.

The Multi-Attribute Task Battery II (MATB-II) Software for Human Performance and Workload Research: A User's Guide

NASA Technical Reports Server (NTRS)

Santiago-Espada, Yamira; Myer, Robert R.; Latorella, Kara A.; Comstock, James R., Jr.

2011-01-01

The Multi-Attribute Task Battery (MAT Battery). is a computer-based task designed to evaluate operator performance and workload, has been redeveloped to operate in Windows XP Service Pack 3, Windows Vista and Windows 7 operating systems.MATB-II includes essentially the same tasks as the original MAT Battery, plus new configuration options including a graphical user interface for controlling modes of operation. MATB-II can be executed either in training or testing mode, as defined by the MATB-II configuration file. The configuration file also allows set up of the default timeouts for the tasks, the flow rates of the pumps and tank levels of the Resource Management (RESMAN) task. MATB-II comes with a default event file that an experimenter can modify and adapt

Effects of a psychophysiological system for adaptive automation on performance, workload, and the event-related potential P300 component

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J 3rd; Freeman, Frederick G.; Scerbo, Mark W.; Mikulka, Peter J.; Pope, Alan T.

2003-01-01

The present study examined the effects of an electroencephalographic- (EEG-) based system for adaptive automation on tracking performance and workload. In addition, event-related potentials (ERPs) to a secondary task were derived to determine whether they would provide an additional degree of workload specificity. Participants were run in an adaptive automation condition, in which the system switched between manual and automatic task modes based on the value of each individual's own EEG engagement index; a yoked control condition; or another control group, in which task mode switches followed a random pattern. Adaptive automation improved performance and resulted in lower levels of workload. Further, the P300 component of the ERP paralleled the sensitivity to task demands of the performance and subjective measures across conditions. These results indicate that it is possible to improve performance with a psychophysiological adaptive automation system and that ERPs may provide an alternative means for distinguishing among levels of cognitive task demand in such systems. Actual or potential applications of this research include improved methods for assessing operator workload and performance.

Development of Principles for Multimodal Displays in Army Human-Robot Operations

DTIC Science & Technology

2010-06-01

Research Laboratory ATTN: RDRL- HRM -D Aberdeen Proving Ground, MD 21005-5425 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT...the practical limitations of various cognitive resource channels for HRI tasks. 2.1.2 Purpose Now that MRT and the common workload manipulations...with more mission targets. • Workload conditions were not counter-balanced for practice effects. 7 Increasing task difficulty generally

Abstracts of ARI Research Publications FY 1983

DTIC Science & Technology

1983-10-01

and the relationship between SM usage and the soldier’s ability to perform his or her job skills , as measured by 2 SQT scores. Questionnaire data were...System (ACES) on soldier performance. Four -’ ACES programs were selected for evaluation: Basic Skills Education Program I, Literacy Phase (BSEP I...the prototype system was operated at Fort Carson, CO, the relationships among maintenance workload, efficiency, and skill were studied. As workload

The Impact of Data Communications Messages in the Terminal Area on Flight Crew Workload and Eye Scanning

NASA Technical Reports Server (NTRS)

Comstock, James R., Jr.; Baxley, Brian T.; Norman, Robert M.; Ellis, Kyle K. E.; Adams, Cathy A.; Latorella, Kara A.; Lynn, William A.

2010-01-01

This paper, to accompany a discussion panel, describes a collaborative FAA and NASA research study to determine the effect Data Communications (Data Comm) messages have on flight crew workload and eye scanning behavior in busy terminal area operations. In the Next Generation Air Transportation System Concept of Operations, for the period 2017-2022, the FAA envisions Data Comm between controllers and the flight crew to become the primary means of communicating non-time critical information. Four research conditions were defined that span current day to future equipage levels (Voice with Paper map, Data Comm with Paper map, Data Comm with Moving Map Display with ownship position displayed, Data Comm with Moving Map, ownship and taxi route displayed), and were used to create arrival and departure scenarios at Boston Logan Airport. Preliminary results for workload, situation awareness, and pilot head-up time are presented here. Questionnaire data indicated that pilot acceptability, workload, and situation awareness ratings were favorable for all of the conditions tested. Pilots did indicate that there were times during final approach and landing when they would prefer not to hear the message chime, and would not be able to make a quick response due to high priority tasks in the cockpit.

Multi-Attribute Task Battery - Applications in pilot workload and strategic behavior research

NASA Technical Reports Server (NTRS)

Arnegard, Ruth J.; Comstock, J. R., Jr.

1991-01-01

The Multi-Attribute Task (MAT) Battery provides a benchmark set of tasks for use in a wide range of lab studies of operator performance and workload. The battery incorporates tasks analogous to activities that aircraft crewmembers perform in flight, while providing a high degree of experimenter control, performance data on each subtask, and freedom to nonpilot test subjects. Features not found in existing computer based tasks include an auditory communication task (to simulate Air Traffic Control communication), a resource management task permitting many avenues or strategies of maintaining target performance, a scheduling window which gives the operator information about future task demands, and the option of manual or automated control of tasks. Performance data are generated for each subtask. In addition, the task battery may be paused and onscreen workload rating scales presented to the subject. The MAT Battery requires a desktop computer with color graphics. The communication task requires a serial link to a second desktop computer with a voice synthesizer or digitizer card.

Twelfth Annual Conference on Manual Control

NASA Technical Reports Server (NTRS)

Wempe, T. E.

1976-01-01

Main topics discussed cover multi-task decision making, attention allocation and workload measurement, displays and controls, nonvisual displays, tracking and other psychomotor tasks, automobile driving, handling qualities and pilot ratings, remote manipulation, system identification, control models, and motion and visual cues. Sixty-five papers are included with presentations on results of analytical studies to develop and evaluate human operator models for a range of control task, vehicle dynamics and display situations; results of tests of physiological control systems and applications to medical problems; and on results of simulator and flight tests to determine display, control and dynamics effects on operator performance and workload for aircraft, automobile, and remote control systems.

Reliability and performance of a system-on-a-chip by predictive wear-out based activation of functional components

DOEpatents

Cher, Chen-Yong; Coteus, Paul W; Gara, Alan; Kursun, Eren; Paulsen, David P; Schuelke, Brian A; Sheets, II, John E; Tian, Shurong

2013-10-01

A processor-implemented method for determining aging of a processing unit in a processor the method comprising: calculating an effective aging profile for the processing unit wherein the effective aging profile quantifies the effects of aging on the processing unit; combining the effective aging profile with process variation data, actual workload data and operating conditions data for the processing unit; and determining aging through an aging sensor of the processing unit using the effective aging profile, the process variation data, the actual workload data, architectural characteristics and redundancy data, and the operating conditions data for the processing unit.

Development and experimental evaluation of an alarm concept for an integrated surgical workstation.

PubMed

Zeißig, Eva-Maria; Janß, Armin; Dell'Anna-Pudlik, Jasmin; Ziefle, Martina; Radermacher, Klaus

2016-04-01

Alarm conditions of the technical equipment in operating rooms represent a prevalent cause for interruptions of surgeons and scrub nurses, resulting in an increase of workload and potential reduction of patient safety. In this work, an alarm concept for an integrated operating room system based on open communication standards is developed and tested. In a laboratory experiment, the reactions of surgeons were analysed, comparing the displaying of alarms on an integrated workstation and on single devices: disruptive effects of alarm handling on primary task (ratings of perceived distraction, resumption lag, deterioration of speed, accuracy, and prospective memory), efficiency and effectiveness of identification of alarms, as well as perceived workload were included. The identification of the alarm cause is significantly more efficient and effective with the integrated alarm concept. Moreover, a slightly lower deterioration of performance of the primary task due to the interruption of alarm handling was observed. Displaying alarms on an integrated workstation supports alarm handling and consequently reduces disruptive effects on the primary task. The findings show that even small changes can reduce workload in a complex work environment like the operating room, resulting in improved patient safety.

Human Factors Assessment: The Passive Final Approach Spacing Tool (pFAST) Operational Evaluation

NASA Technical Reports Server (NTRS)

Lee, Katharine K.; Sanford, Beverly D.

1998-01-01

Automation to assist air traffic controllers in the current terminal and en route air traff ic environments is being developed at Ames Research Center in conjunction with the Federal Aviation Administration. This automation, known collectively as the Center-TRACON Automation System (CTAS), provides decision- making assistance to air traffic controllers through computer-generated advisories. One of the CTAS tools developed specifically to assist terminal area air traffic controllers is the Passive Final Approach Spacing Tool (pFAST). An operational evaluation of PFAST was conducted at the Dallas/Ft. Worth, Texas, Terminal Radar Approach Control (TRACON) facility. Human factors data collected during the test describe the impact of the automation upon the air traffic controller in terms of perceived workload and acceptance. Results showed that controller self-reported workload was not significantly increased or reduced by the PFAST automation; rather, controllers reported that the levels of workload remained primarily the same. Controller coordination and communication data were analyzed, and significant differences in the nature of controller coordination were found. Controller acceptance ratings indicated that PFAST was acceptable. This report describes the human factors data and results from the 1996 Operational Field Evaluation of Passive FAST.

Personnel's health surveillance at work: effect of age, body mass index, and shift work on mental workload and work ability index.

PubMed

Safari, Shahram; Akbari, Jafar; Kazemi, Meghdad; Mououdi, Mohammad Amin; Mahaki, Behzad

2013-01-01

Two great changes in developed countries are taking place: populations are ageing and becoming increasingly overweight. Combination of these factors with shift work is a risk factor for work ability and mental workload that are dynamic processes which change greatly throughout an individual's work life. The aim of this study was to investigate mental workload and work ability in textile workers and to identify factors which affect work ability and mental workload. This cross-sectional study was carried out among 194 male workers in textile industry. Employees based on their job group and work conditions have been divided into 6 categories. They completed work ability index and mental workload questionnaires during three work shifts. Body mass index (BMI) and demographic details were recorded. All of the participants rated their work ability as moderate with high mental workload. The mean WAI and mental workload in age group were significant. The mean BMI was 25.5 kg/m(2) (standard deviation 4.1) and the mean age was 40.22 years. There was a statistically significant correlation between work ability index and shift work. Unlike the previous study, a decrease point in WAI started in early age that may be due to life-style work and another psychological factor; on the other hand, NASA-TLX revealed high score in six subscales that can be another reason for low WAI.

Personnel's Health Surveillance at Work: Effect of Age, Body Mass Index, and Shift Work on Mental Workload and Work Ability Index

PubMed Central

Safari, Shahram; Akbari, Jafar; Kazemi, Meghdad; Mououdi, Mohammad Amin; Mahaki, Behzad

2013-01-01

Introduction. Two great changes in developed countries are taking place: populations are ageing and becoming increasingly overweight. Combination of these factors with shift work is a risk factor for work ability and mental workload that are dynamic processes which change greatly throughout an individual's work life. The aim of this study was to investigate mental workload and work ability in textile workers and to identify factors which affect work ability and mental workload. Methods. This cross-sectional study was carried out among 194 male workers in textile industry. Employees based on their job group and work conditions have been divided into 6 categories. They completed work ability index and mental workload questionnaires during three work shifts. Body mass index (BMI) and demographic details were recorded. Results. All of the participants rated their work ability as moderate with high mental workload. The mean WAI and mental workload in age group were significant. The mean BMI was 25.5 kg/m2 (standard deviation 4.1) and the mean age was 40.22 years. There was a statistically significant correlation between work ability index and shift work. Conclusions. Unlike the previous study, a decrease point in WAI started in early age that may be due to life-style work and another psychological factor; on the other hand, NASA-TLX revealed high score in six subscales that can be another reason for low WAI. PMID:23956756

Counting the cost of social disadvantage in primary care: retrospective analysis of patient data.

PubMed

Worrall, A; Rea, J N; Ben-Shlomo, Y

1997-01-04

To cost the relation between socioeconomic status and various measures of primary care workload and assess the adequacy of current "deprivation" payments in relation to actual costings for patients living in qualifying areas. Retrospective data on primary care were collected over a 4.5 year period from both computerised and manually filed records. Standardised data on socioeconomic status were obtained by postal questionnaire. Inner city group practice with a socioeconomically diverse population. 382 male and female subjects of all ages, with a total of 1296 person years of observation. Primary care costs resulting from consultations with a general practitioner or a practice nurse and both new and repeat prescriptions. Morbidity, workload, and costs of drug treatment increased with decreasing socioeconomic status. The difference in cost for patients in social classes IV and V combined compared with those in I and II combined was about 150 Pounds per person year at risk (47 Pounds for workload and 103 Pounds for drugs). Deprivation payments met only half the extra workload cost for patients from qualifying wards. The greater workload caused by social disadvantage has been previously underestimated by simple consultation rates. The absolute difference in costs for socially disadvantaged patients increase as more detailed measures of workload and drug treatment are included. Current deprivation payments only partially offset the increased expenditure on workload. This shortfall will have to be addressed to attract general practitioners to, or retain them in, deprived areas.

Cognitive context detection using pupillary measurements

NASA Astrophysics Data System (ADS)

Mannaru, Pujitha; Balasingam, Balakumar; Pattipati, Krishna; Sibley, Ciara; Coyne, Joseph

2016-05-01

In this paper, we demonstrate the use of pupillary measurements as indices of cognitive workload. We analyze the pupillary data of twenty individuals engaged in a simulated Unmanned Aerial System (UAS) operation in order to understand and characterize the behavior of pupil dilation under varying task load (i.e., workload) levels. We present three metrics that can be employed as real-time indices of cognitive workload. In addition, we develop a predictive system utilizing the pupillary metrics to demonstrate cognitive context detection within simulated supervisory control of UAS. Further, we use pupillary data collected concurrently from the left and right eye and present comparative results of the use of separate vs. combined pupillary data for detecting cognitive context.

Full Scale Evaluation of How Task-Based Overview Displays Impact Operator Workload and Situation Awareness When in Emergency Procedure Space

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

Spielman, Zachary; Hill, Racheal; LeBlanc, Katya

Control room modernization is critical to extending the life of the 99 operating commercial nuclear power plants (NPP) within the United States. However, due to the lack of evidence demonstrating the efficiency and effectiveness of recent candidate technologies, current NPP control rooms operate without the benefit of various newer technologies now available. As nuclear power plants begin to extend their licenses to continue operating for another 20 years, there is increased interest in modernizing the control room and supplementing the existing control boards with advanced technologies. As part of a series of studies investigating the benefits of advanced control roommore » technologies, the researchers conducted an experimental study to observe the effect of Task-Based Overview Displays (TODs) on operator workload and situation awareness (SA) while completing typical operating scenarios. Researchers employed the Situation Awareness Rating Technique (SART) and the NASA Task Load Index (TLX) as construct measures.« less

Motives for early retirement of self-employed GPs in the Netherlands: a comparison of two time periods

PubMed Central

2012-01-01

Background The high cost of training and the relatively long period of training for physicians make it beneficial to stimulate physicians to retire later. Therefore, a better understanding of the link between the factors influencing the decision to retire and actual turnover would benefit policies designed to encourage later retirement. This study focuses on actual GP turnover and the determining factors for this in the Netherlands. The period 2003–2007 saw fewer GPs retiring from general practice than the period 1998–2002. In addition, GPs’ retirement age was higher in 2003–2007. For these two periods, we analysed work perception, objective workload and reasons for leaving, and related these with the probability that GPs would leave general practice at an early age. Methods In 2003, a first retrospective survey was sent to 520 self-employed GPs who had retired between 1998 and 2002. In 2008, the same survey was sent to 405 GPs who had retired between 2003 and 2007. The response rates were 60% and 54%, respectively. Analyses were done to compare work perception, objective workload, external factors and personal reasons for retiring. Results For both male and female GPs, work perception was different in the periods under scrutiny: both groups reported greater job satisfaction and a lower degree of emotional exhaustion in the later period, although there was no notable difference in subjective workload. The objective workload was lower in the second period. Moreover, most external factors and personal reasons that may contribute to the decision to retire were reported as less important in the second period. There was a stronger decrease in the probability that female GPs leave general practice within one year than for male GPs. This underscores the gender differences and the need for disaggregated data collection. Conclusions The results of this study suggest that the decrease in the probability of GPs leaving general practice within one year and the increasing retirement age are caused by a decrease in the objective workload, a change in GPs’ work perception, external factors and personal reasons. Based on the results of this study, we consider workload reduction policies are the most useful instruments to control retention and retirement. PMID:23249631

Use of EEG workload indices for diagnostic monitoring of vigilance decrement.

PubMed

Kamzanova, Altyngul T; Kustubayeva, Almira M; Matthews, Gerald

2014-09-01

A study was run to test which of five electroencephalographic (EEG) indices was most diagnostic of loss of vigilance at two levels of workload. EEG indices of alertness include conventional spectral power measures as well as indices combining measures from multiple frequency bands, such as the Task Load Index (TLI) and the Engagement Index (El). However, it is unclear which indices are optimal for early detection of loss of vigilance. Ninety-two participants were assigned to one of two experimental conditions, cued (lower workload) and uncued (higher workload), and then performed a 40-min visual vigilance task. Performance on this task is believed to be limited by attentional resource availability. EEG was recorded continuously. Performance, subjective state, and workload were also assessed. The task showed a vigilance decrement in performance; cuing improved performance and reduced subjective workload. Lower-frequency alpha (8 to 10.9 Hz) and TLI were most sensitive to the task parameters. The magnitude of temporal change was larger for lower-frequency alpha. Surprisingly, higher TLI was associated with superior performance. Frontal theta and El were influenced by task workload only in the final period of work. Correlational data also suggested that the indices are distinct from one another. Lower-frequency alpha appears to be the optimal index for monitoring vigilance on the task used here, but further work is needed to test how diagnosticity of EEG indices varies with task demands. Lower-frequency alpha may be used to diagnose loss of operator alertness on tasks requiring vigilance.

Cardiopulmonary data-acquisition system

NASA Technical Reports Server (NTRS)

Crosier, W. G.; Reed, R. A.

1981-01-01

Computerized system controls and monitors bicycle and treadmill cardiovascular stress tests. It acquires and reduces stress data and displays heart rate, blood pressure, workload, respiratory rate, exhaled-gas composition, and other variables. Data are printed on hard-copy terminal every 30 seconds for quick operator response to patient. Ergometer workload is controlled in real time according to experimental protocol. Collected data are stored directly on tape in analog form and on floppy disks in digital form for later processing.

Electromagnetic Metrics of Mental Workload.

DTIC Science & Technology

1987-09-01

anxiety ). A decrease in performance accuracy has been used in the context of over- load, however it has also been associated with a "high workload". 1.2...heart rate variability ( HRV ) to refer to any varia- tion from a constant heart rate. The term HRV shall not refer to any specific method of numerically...in using HRV as a measure of mental load arose after Kalsbeek & Ettema (1963) reported that HRV was "gradu- ally suppressed when increasing the

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...

Intracorporeal suturing: Transfer from Fundamentals of Laparoscopic Surgery to cadavers results in substantial increase in mental workload.

PubMed

Britt, Rebecca C; Scerbo, Mark W; Montano, Michael; Kennedy, Rebecca A; Prytz, Erik; Stefanidis, Dimitrios

2015-11-01

A spatial secondary task developed by the authors was used to measure the mental workload of the participant when transferring suturing skills from a box simulator to more realistic surgical conditions using a fresh cadaver. We hypothesized that laparoscopic suturing on genuine bowel would be more challenging than on the Fundamentals of Laparoscopic Surgery (FLS)-simulated bowel as reflected in differences on both suturing and secondary task scores. We trained 14 surgical assistant students to FLS proficiency in intracorporeal suturing. Participants practiced suturing on the FLS box for 30 minutes and then were tested on both the FLS box and the bowel of a fresh cadaver using the spatial, secondary dual-task conditions developed by the authors. Suturing times increased by >333% when moving from the FLS platform to the cadaver F(1,13) = 44.04, P < .001. The increased completion times were accompanied by a 70% decrease in secondary task scores, F(1,13) = 21.21, P < .001. The mental workload associated with intracorporeal suturing increases dramatically when trainees transfer from the FLS platform to human tissue under more realistic conditions of suturing. The increase in mental workload is indexed by both an increase in suturing times and a decrease in the ability to attend to the secondary task. Copyright © 2015 Elsevier Inc. All rights reserved.

Surgeons' display reduced mental effort and workload while performing robotically assisted surgical tasks, when compared to conventional laparoscopy.

PubMed

Moore, Lee J; Wilson, Mark R; McGrath, John S; Waine, Elizabeth; Masters, Rich S W; Vine, Samuel J

2015-09-01

Research has demonstrated the benefits of robotic surgery for the patient; however, research examining the benefits of robotic technology for the surgeon is limited. This study aimed to adopt validated measures of workload, mental effort, and gaze control to assess the benefits of robotic surgery for the surgeon. We predicted that the performance of surgical training tasks on a surgical robot would require lower investments of workload and mental effort, and would be accompanied by superior gaze control and better performance, when compared to conventional laparoscopy. Thirty-two surgeons performed two trials on a ball pick-and-drop task and a rope-threading task on both robotic and laparoscopic systems. Measures of workload (the surgery task load index), mental effort (subjective: rating scale for mental effort and objective: standard deviation of beat-to-beat intervals), gaze control (using a mobile eye movement recorder), and task performance (completion time and number of errors) were recorded. As expected, surgeons performed both tasks more quickly and accurately (with fewer errors) on the robotic system. Self-reported measures of workload and mental effort were significantly lower on the robotic system compared to the laparoscopic system. Similarly, an objective cardiovascular measure of mental effort revealed lower investment of mental effort when using the robotic platform relative to the laparoscopic platform. Gaze control distinguished the robotic from the laparoscopic systems, but not in the predicted fashion, with the robotic system associated with poorer (more novice like) gaze control. The findings highlight the benefits of robotic technology for surgical operators. Specifically, they suggest that tasks can be performed more proficiently, at a lower workload, and with the investment of less mental effort, this may allow surgeons greater cognitive resources for dealing with other demands such as communication, decision-making, or periods of increased complexity in the operating room.

Assessing Impact of Dual Sensor Enhanced Flight Vision Systems on Departure Performance

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Etherington, Timothy J.; Severance, Kurt; Bailey, Randall E.

2016-01-01

Synthetic Vision (SV) and Enhanced Flight Vision Systems (EFVS) may serve as game-changing technologies to meet the challenges of the Next Generation Air Transportation System and the envisioned Equivalent Visual Operations (EVO) concept - that is, the ability to achieve the safety and operational tempos of current-day Visual Flight Rules operations irrespective of the weather and visibility conditions. One significant obstacle lies in the definition of required equipage on the aircraft and on the airport to enable the EVO concept objective. A motion-base simulator experiment was conducted to evaluate the operational feasibility and pilot workload of conducting departures and approaches on runways without centerline lighting in visibility as low as 300 feet runway visual range (RVR) by use of onboard vision system technologies on a Head-Up Display (HUD) without need or reliance on natural vision. Twelve crews evaluated two methods of combining dual sensor (millimeter wave radar and forward looking infrared) EFVS imagery on pilot-flying and pilot-monitoring HUDs. In addition, the impact of adding SV to the dual sensor EFVS imagery on crew flight performance and workload was assessed. Using EFVS concepts during 300 RVR terminal operations on runways without centerline lighting appears feasible as all EFVS concepts had equivalent (or better) departure performance and landing rollout performance, without any workload penalty, than those flown with a conventional HUD to runways having centerline lighting. Adding SV imagery to EFVS concepts provided situation awareness improvements but no discernible improvements in flight path maintenance.

Pilot study on verification of effectiveness on operability of assistance system for robotic tele-surgery using simulation.

PubMed

Kawamura, Kazuya; Kobayashi, Yo; Fujie, Masakatsu G

2010-01-01

Tele-surgery enables medical care even in remote regions, and has been accomplished in clinical cases by means of dedicated communication lines. To make tele-surgery a more widespread method of providing medical care, a surgical environment needs to be made available using public lines of communication, such as the Internet. Moreover, a support system during surgery is required, as the use of surgical tools is performed in an environment subject to delay. In our research, we focus on the operability of specific tasks conducted by surgeons during a medical procedure, with the aim of clarifying, by means of a simulation, the optimum environment for robotic tele-surgery. In the study, we set up experimental systems using our proposed simulation system. In addition, we investigate the mental workloads on subjects and verify the effect of visual-assistance information as a pilot study. The operability of the task of gripping soft tissue was evaluated using a subjective workload assessment tool, the NASA Task Load Index. Results show that the tasks were completed, but the workload did not improve to less than 300ms and 400ms in the simulated environment. Verifying the effect of the support system was an important task under a more-than 200ms delay using this experiment, and future studies will evaluate the operability of the system under varying conditions of comfort. In addition, an intra-operative assistance system will be constructed using a simulation.

Workload, Fatigue and Muscle Damage in an u20 Rugby Union Team Over an Intensified International Tournament.

PubMed

Lacome, Mathieu; Carling, Christopher; Hager, Jean-Philippe; Dine, Gerard; Piscione, Julien

2018-02-12

This study examined the effects of an intensified tournament on workload, perceptual and neuromuscular fatigue and muscle damage responses in an international under-20 rugby union team. Players were subdivided into two groups according to match-play exposure time: high (HEG, n=13) and low (LEG, n=11). Measures monitored over the 19-day period included training session (n=10) and match (n=5) workload determined via global positioning systems and session ratings of perceived exertion (sRPE). Wellbeing scores, countermovement jump height performance (CMJ) and blood creatine kinase [CK]b concentrations were collected at various time points. Analysis of workload cumulated across the tournament entirety for training and match-play combined showed that high-speed running distance was similar between groups while a very likely larger sRPE load was reported in HEG vs. LEG. In HEG high-speed activity fluctuated across the 5 successive matches albeit with no clear trend for a progressive decrease. No clear tendency for a progressive decrease in wellbeing scores prior to or following matches was observed in either group. In HEG trivial to possibly small reductions in post-match CMJ performance were observed while unclear to most likely moderate increases in pre-match [CK]b concentrations occurred until prior to match 4. The magnitude of match-to-match changes in external workload, perceptual and neuromuscular fatigue and muscle damage was generally unclear or small. These results suggest that irrespective of exposure time to match-play players generally maintained performance and readiness to play across the intensified tournament. These findings support the need for holistic systematic player monitoring programmes.

Effects of body position on exercise capacity and pulmonary vascular pressure-flow relationships.

PubMed

Forton, Kevin; Motoji, Yoshiki; Deboeck, Gael; Faoro, Vitalie; Naeije, Robert

2016-11-01

There has been revival of interest in exercise testing of the pulmonary circulation for the diagnosis of pulmonary vascular disease, but there still is uncertainty about body position and the most relevant measurements. Doppler echocardiography pulmonary hemodynamic measurements were performed at progressively increased workloads in 26 healthy adult volunteers in supine, semirecumbent, and upright positions that were randomly assigned at 24-h intervals. Mean pulmonary artery pressure (mPAP) was estimated from the maximum tricuspid regurgitation jet velocity. Cardiac output was calculated from the left ventricular outflow velocity-time integral. Pulmonary vascular distensibility α-index, the percent change of vessel diameter per millimeter mercury of mPAP, was calculated from multipoint mPAP-cardiac output plots. Body position did not affect maximum oxygen uptake (Vo 2max ), maximum respiratory exchange ratio, ventilatory equivalent for carbon dioxide, or slope of mPAP-cardiac output relationships, which was on average of 1.5 ± 0.4 mmHg·l -1 ·min -1 Maximum mPAP, cardiac output, and total pulmonary vascular resistance were, respectively, 34 ± 4 mmHg, 18 ± 3 l/min, and 1.9 ± 0.3 Wood units. However, the semirecumbent position was associated with a 10% decrease in maximum workload. Furthermore, cardiac output-workload or cardiac output-Vo 2 relationships were nonlinear and variable. These results suggest that body position does not affect maximum exercise testing of the pulmonary circulation when results are expressed as mPAP-cardiac output or maximum total pulmonary vascular resistance. Maximum workload is decreased in semirecumbent compared with upright exercise. Workload or Vo 2 cannot reliably be used as surrogates for cardiac output. Copyright © 2016 the American Physiological Society.

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.

A study of the relationship between the performance and dependability of a fault-tolerant computer

NASA Technical Reports Server (NTRS)

Goswami, Kumar K.

1994-01-01

This thesis studies the relationship by creating a tool (FTAPE) that integrates a high stress workload generator with fault injection and by using the tool to evaluate system performance under error conditions. The workloads are comprised of processes which are formed from atomic components that represent CPU, memory, and I/O activity. The fault injector is software-implemented and is capable of injecting any memory addressable location, including special registers and caches. This tool has been used to study a Tandem Integrity S2 Computer. Workloads with varying numbers of processes and varying compositions of CPU, memory, and I/O activity are first characterized in terms of performance. Then faults are injected into these workloads. The results show that as the number of concurrent processes increases, the mean fault latency initially increases due to increased contention for the CPU. However, for even higher numbers of processes (less than 3 processes), the mean latency decreases because long latency faults are paged out before they can be activated.

A Study of VITOM in Pediatric Surgery and Urology: Evaluation of Technology Acceptance and Usability by Operating Team and Surgeon Musculoskeletal Discomfort.

PubMed

Frykman, Philip K; Freedman, Andrew L; Kane, Timothy D; Cheng, Zhi; Petrosyan, Mikael; Catchpole, Kenneth

2017-02-01

We studied operating team acceptability of Video Telescopic Monitor (VITOM ® ) exoscope by exploring the ease of use of the device in two centers. We also assessed factors affecting surgeon musculoskeletal discomfort. We focused on how the operating team interacted with the VITOM system with surrogate measures of usefulness, image quality, ease of use, workload, and setup time. Multivariable linear regression was used to model the relationships between team role, experience, and setup time. Relationships between localized musculoskeletal discomfort and use of VITOM alone, and with loupes, were also analyzed. Four surgeons, 7 surgical techs, 7 circulating nurses, and 13 surgical residents performed 70 pediatric surgical and urological operations. We found that subjective views of each team member were consistently positive with 69%-74% agreed or strongly agreed that VITOM enhanced their ability to perform their job and improved the surgical process. Unexpectedly, the scrub techs and nurses perceived more value and utility of VITOM, presumably because it provides them a view of the operative field that would otherwise be unavailable to them. Team members rated perceptions of image quality highly and workload generally satisfactory. Not surprisingly, setup time decreased with team experience and multivariable modeling showed significant correlations with surgeon and surgical tech experience, but not circulating nurse. An important finding was that surgeon neck discomfort was reduced with use of VITOM alone for magnification, compared with use of loupes and VITOM. The most likely explanation for these findings is improved posture with the neck at a neutral position when viewing the VITOM images, compared with neck flexion with loupes, and thus, a less favorable ergonomic position. This study suggests that there may be small drawbacks associated with VITOM use initially, but these reduce with increased experience and benefit both the surgeon and the rest of the team.

Varying Levels of Automation on UAS Operator Responses to Traffic Resolution Advisories in Civil Airspace

NASA Technical Reports Server (NTRS)

Kenny, Caitlin; Fern, Lisa

2012-01-01

Continuing demand for the use of Unmanned Aircraft Systems (UAS) has put increasing pressure on operations in civil airspace. The need to fly UAS in the National Airspace System (NAS) in order to perform missions vital to national security and defense, emergency management, and science is increasing at a rapid pace. In order to ensure safe operations in the NAS, operators of unmanned aircraft, like those of manned aircraft, may be required to maintain separation assurance and avoid loss of separation with other aircraft while performing their mission tasks. This experiment investigated the effects of varying levels of automation on UAS operator performance and workload while responding to conflict resolution instructions provided by the Tactical Collision Avoidance System II (TCAS II) during a UAS mission in high-density airspace. The purpose of this study was not to investigate the safety of using TCAS II on UAS, but rather to examine the effect of automation on the ability of operators to respond to traffic collision alerts. Six licensed pilots were recruited to act as UAS operators for this study. Operators were instructed to follow a specified mission flight path, while maintaining radio contact with Air Traffic Control and responding to TCAS II resolution advisories. Operators flew four, 45 minute, experimental missions with four different levels of automation: Manual, Knobs, Management by Exception, and Fully Automated. All missions included TCAS II Resolution Advisories (RAs) that required operator attention and rerouting. Operator compliance and reaction time to RAs was measured, and post-run NASA-TLX ratings were collected to measure workload. Results showed significantly higher compliance rates, faster responses to TCAS II alerts, as well as less preemptive operator actions when higher levels of automation are implemented. Physical and Temporal ratings of workload were significantly higher in the Manual condition than in the Management by Exception and Fully Automated conditions.

Increasing pressure ulcer rates and changes in delivery of care: a retrospective analysis at a University Clinic.

PubMed

Stausberg, Jürgen; Lehmann, Nils; Kröger, Knut; Maier, Irene; Schneider, Helmut; Niebel, Wolfgang

2010-06-01

To evaluate the relation between pressure ulcers and delivery of care. No decrease of pressure ulcer rates could be recognised in acute hospital care, despite intensive efforts in prevention. Furthermore, reports show increasing rates. Retrospective analysis of hospital data. The study included all inpatients from year 1 (2003/2004) and 4 (2006/2007) of the interdisciplinary decubitus project. Information on ulcers was recorded at admission, discharge and in case of new events. We analysed the effect of age, length of stay, operation and intensive care episode. In logistic regression, we used the existence of ulcers and the appearance of new ulcers as dependent variables. Parallel to a decrease in the number of inpatients, age, length of stay and operation frequency rose between 2003 and 2007. Higher age, longer length of stay, operation, intensive care episode and year 4 raise the odds for ulcers in univariate and with exception of operation in multivariate analyses. With exception of operation and year 4, the same variables raise the odds for new ulcers, too. The increase of pressure ulcer frequency could be related to changes in delivery of care. The adverse event pressure ulcer will become more important in hospital care. There is no decrease in pressure ulcer rates, albeit enormous efforts in prevention. Hospital care has been facing changes in case mix. Age, length of stay and intensive care episodes are related to increasing ulcer rates at a University Clinic. Nursing management has to be aware of additional workload for pressure ulcer management in the future.

Dual Frequency Head Maps: A New Method for Indexing Mental Workload Continuously during Execution of Cognitive Tasks

PubMed Central

Radüntz, Thea

2017-01-01

One goal of advanced information and communication technology is to simplify work. However, there is growing consensus regarding the negative consequences of inappropriate workload on employee's health and the safety of persons. In order to develop a method for continuous mental workload monitoring, we implemented a task battery consisting of cognitive tasks with diverse levels of complexity and difficulty. We conducted experiments and registered the electroencephalogram (EEG), performance data, and the NASA-TLX questionnaire from 54 people. Analysis of the EEG spectra demonstrates an increase of the frontal theta band power and a decrease of the parietal alpha band power, both under increasing task difficulty level. Based on these findings we implemented a new method for monitoring mental workload, the so-called Dual Frequency Head Maps (DFHM) that are classified by support vectors machines (SVMs) in three different workload levels. The results are in accordance with the expected difficulty levels arising from the requirements of the tasks on the executive functions. Furthermore, this article includes an empirical validation of the new method on a secondary subset with new subjects and one additional new task without any adjustment of the classifiers. Hence, the main advantage of the proposed method compared with the existing solutions is that it provides an automatic, continuous classification of the mental workload state without any need for retraining the classifier—neither for new subjects nor for new tasks. The continuous workload monitoring can help ensure good working conditions, maintain a good level of performance, and simultaneously preserve a good state of health. PMID:29276490

Mental workload and motor performance dynamics during practice of reaching movements under various levels of task difficulty.

PubMed

Shuggi, Isabelle M; Oh, Hyuk; Shewokis, Patricia A; Gentili, Rodolphe J

2017-09-30

The assessment of mental workload can inform attentional resource allocation during task performance that is essential for understanding the underlying principles of human cognitive-motor behavior. While many studies have focused on mental workload in relation to human performance, a modest body of work has examined it in a motor practice/learning context without considering individual variability. Thus, this work aimed to examine mental workload by employing the NASA TLX as well as the changes in motor performance resulting from the practice of a novel reaching task. Two groups of participants practiced a reaching task at a high and low nominal difficulty during which a group-level analysis assessed the mental workload, motor performance and motor improvement dynamics. A secondary cluster analysis was also conducted to identify specific individual patterns of cognitive-motor responses. Overall, both group- and cluster-level analyses revealed that: (i) all participants improved their performance throughout motor practice, and (ii) an increase in mental workload was associated with a reduction of the quality of motor performance along with a slower rate of motor improvement. The results are discussed in the context of the optimal challenge point framework and in particular it is proposed that under the experimental conditions employed here, functional task difficulty: (i) would possibly depend on an individuals' information processing capabilities, and (ii) could be indexed by the level of mental workload which, when excessively heightened can decrease the quality of performance and more generally result in delayed motor improvements. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Cardiovascular responses to plyometric exercise are affected by workload in athletes.

PubMed

Arazi, Hamid; Asadi, Abbas; Mahdavi, Seyed Amir; Nasiri, Seyed Omid Mirfalah

2014-01-01

With regard to blood pressure responses to plyometric exercise and decreasing blood pressure after exercise (post-exercise hypotension), the influence of different workloads of plyometric exercise on blood pressure is not clear. The purpose of this investigation was to examine the effects of a low, moderate and high workload of plyometric exercise on the post-exercise systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR) and rate-pressure product (RPP) responses in athletes. TEN MALE ATHLETES (AGE: 22.6 ±0.5 years; height: 178.2 ±3.3 cm; and body mass: 75.2 ±2.8 kg) underwent PE protocols involving 5 × 10 reps (Low Workload - LW), 10 × 10 reps (Moderate Workload - MW), and 15 × 10 reps (High Workload - HW) depth jump exercise from a 50-cm box in 3 non-consecutive days. After each exercise session, SBP, DBP and HR were measured every 10 min for a period of 70 min. No significant differences were observed among post-exercise SBP and DBP when the protocols (LW, MW and HW) were compared. The MW and HW protocols showed greater increases in HR compared with LW. Also the HW indicated greater increases than LW in RPP at post-exercise (p < 0.05). All protocols increased SBP, HR and RPP responses at the 10(th) and 20(th) min of post-exercise. With regard to different workloads of plyometric exercise, HW condition indicated greater increases in HR and RPP and strength and conditioning professionals and athletes must keep in their mind that HW of plyometric exercise induces greater cardiovascular responses.

Longitudinal flying qualities criteria for single-pilot instrument flight operations

NASA Technical Reports Server (NTRS)

Stengel, R. F.; Bar-Gill, A.

1983-01-01

Modern estimation and control theory, flight testing, and statistical analysis were used to deduce flying qualities criteria for General Aviation Single Pilot Instrument Flight Rule (SPIFR) operations. The principal concern is that unsatisfactory aircraft dynamic response combined with high navigation/communication workload can produce problems of safety and efficiency. To alleviate these problems. The relative importance of these factors must be determined. This objective was achieved by flying SPIFR tasks with different aircraft dynamic configurations and assessing the effects of such variations under these conditions. The experimental results yielded quantitative indicators of pilot's performance and workload, and for each of them, multivariate regression was applied to evaluate several candidate flying qualities criteria.

Case Study: Influences of Uncertainties and Traffic Scenario Difficulties in a Human-in-the-Loop Simulation

NASA Technical Reports Server (NTRS)

Bienert, Nancy; Mercer, Joey; Homola, Jeffrey; Morey, Susan; Prevot, Thomas

2014-01-01

This paper presents a case study of how factors such as wind prediction errors and metering delays can influence controller performance and workload in Human-In-The-Loop simulations. Retired air traffic controllers worked two arrival sectors adjacent to the terminal area. The main tasks were to provide safe air traffic operations and deliver the aircraft to the metering fix within +/- 25 seconds of the scheduled arrival time with the help of provided decision support tools. Analyses explore the potential impact of metering delays and system uncertainties on controller workload and performance. The results suggest that trajectory prediction uncertainties impact safety performance, while metering fix accuracy and workload appear subject to the scenario difficulty.

Advanced helicopter cockpit and control configurations for helicopter combat missions

NASA Technical Reports Server (NTRS)

Haworth, Loran A.; Atencio, Adolph, Jr.; Bivens, Courtland; Shively, Robert; Delgado, Daniel

1987-01-01

Two piloted simulations were conducted by the U.S. Army Aeroflightdynamics Directorate to evaluate workload and helicopter-handling qualities requirements for single pilot operation in a combat Nap-of-the-Earth environment. The single-pilot advanced cockpit engineering simulation (SPACES) investigations were performed on the NASA Ames Vertical Motion Simulator, using the Advanced Digital Optical Control System control laws and an advanced concepts glass cockpit. The first simulation (SPACES I) compared single pilot to dual crewmember operation for the same flight tasks to determine differences between dual and single ratings, and to discover which control laws enabled adequate single-pilot helicopter operation. The SPACES II simulation concentrated on single-pilot operations and use of control laws thought to be viable candidates for single pilot operations workload. Measures detected significant differences between single-pilot task segments. Control system configurations were task dependent, demonstrating a need for inflight reconfigurable control system to match the optimal control system with the required task.

Experimental Evaluation of Computer-Aided Tele-operation (CATO) and Computer-Aided Robotic Manipulation (CARMAN) Technology

DTIC Science & Technology

2010-08-01

Consent Form 29 Appendix B. Demographics Questionnaire 35 Appendix C. NASA TLX Questionnaire 39 Appendix D. Symptom Questionnaire 41 List of Symbols...Index ( NASA - TLX ) Participants were given the NASA - TLX subjective workload rating at the end of each task (appendix C, Hart and Staveland, 1987).1 The... NASA - TLX is a multi-dimensional rating procedure that derives an overall workload score based on a weighted average of ratings on six subscales

Ground operation of the mobile servicing system on Space Station Freedom

NASA Astrophysics Data System (ADS)

Wojcik, Z. A.

1992-11-01

Space Station Freedom (SSF) will be assembled in the 1995 to 2000 time period, when permanently manned capability (PMC) will be achieved. During the build phase and after PMC, the Mobile Servicing System (MSS) will be used as a tool to assist crew in the building and in assembly and all maintenance aspects of SSF. Operation of the MSS will be executed and controlled by on-orbit crew, thereby having an impact on the limited crew time and resources. The current plan specifies that the MSS will not be operable when crew are not present. Simulations have been carried out to quantify the maintenance workload expected over the life of SSF. These simulations predict a peak in maintenance demand occurring even before PMC is achieved. The MSS is key to executing those maintenance tasks, and as a result, the demands on MSS crew resource will likely exceed availability, thereby creating a backlog of maintenance actions and negatively impacting SSF effectiveness. Ground operated telerobotics (GOT), the operation of the MSS from the ground, is being proposed as an approach to reducing the anticipated maintenance backlog, along with reducing crew workload when the MSS is executing simple or repetitive tasks. GOT would be implemented in a phased approach, both in terms of the type of activity carried out and the point of control gradually passing from on-orbit crew to ground personnel. The benefits of GOT are expressed in terms of reduced on-orbit crew workload, greater availability of the MSS during the post-PMC period, and the ability to significantly reduce or even eliminate any maintenance action backlog. The benefits section compares GOT with crew operation timelines, and identifies other benefits of GOT. Critical factors such as safety, space-ground communication latency, simulation, operations planning, and design considerations are reviewed.

Cloudweaver: Adaptive and Data-Driven Workload Manager for Generic Clouds

NASA Astrophysics Data System (ADS)

Li, Rui; Chen, Lei; Li, Wen-Syan

Cloud computing denotes the latest trend in application development for parallel computing on massive data volumes. It relies on clouds of servers to handle tasks that used to be managed by an individual server. With cloud computing, software vendors can provide business intelligence and data analytic services for internet scale data sets. Many open source projects, such as Hadoop, offer various software components that are essential for building a cloud infrastructure. Current Hadoop (and many others) requires users to configure cloud infrastructures via programs and APIs and such configuration is fixed during the runtime. In this chapter, we propose a workload manager (WLM), called CloudWeaver, which provides automated configuration of a cloud infrastructure for runtime execution. The workload management is data-driven and can adapt to dynamic nature of operator throughput during different execution phases. CloudWeaver works for a single job and a workload consisting of multiple jobs running concurrently, which aims at maximum throughput using a minimum set of processors.

A better way of fitting clips? A comparative study with respect to physical workload.

PubMed

Gaudez, Clarisse; Wild, Pascal; Aublet-Cuvelier, Agnès

2015-11-01

The clip fitting task is a frequently encountered assembly operation in the car industry. It can cause upper limb pain. During task laboratory simulations, upper limb muscular activity and external force were compared for 4 clip fitting methods: with the bare hand, with an unpowered tool commonly used at a company and with unpowered and powered prototype tools. None of the 4 fitting methods studied induced a lower overall workload than the other three. Muscle activity was lower at the dominant limb when using the unpowered tools and at the non-dominant limb with the bare hand or with the powered tool. Fitting clips with the bare hand required a higher external force than fitting with the three tools. Evaluation of physical workload was different depending on whether external force or muscle activity results were considered. Measuring external force only, as recommended in several standards, is insufficient for evaluating physical workload. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Metrics for Operator Situation Awareness, Workload, and Performance in Automated Separation Assurance Systems

NASA Technical Reports Server (NTRS)

Strybel, Thomas Z.; Vu, Kim-Phuong L.; Battiste, Vernol; Dao, Arik-Quang; Dwyer, John P.; Landry, Steven; Johnson, Walter; Ho, Nhut

2011-01-01

A research consortium of scientists and engineers from California State University Long Beach (CSULB), San Jose State University Foundation (SJSUF), California State University Northridge (CSUN), Purdue University, and The Boeing Company was assembled to evaluate the impact of changes in roles and responsibilities and new automated technologies, being introduced in the Next Generation Air Transportation System (NextGen), on operator situation awareness (SA) and workload. To meet these goals, consortium members performed systems analyses of NextGen concepts and airspace scenarios, and concurrently evaluated SA, workload, and performance measures to assess their appropriateness for evaluations of NextGen concepts and tools. The following activities and accomplishments were supported by the NRA: a distributed simulation, metric development, systems analysis, part-task simulations, and large-scale simulations. As a result of this NRA, we have gained a greater understanding of situation awareness and its measurement, and have shared our knowledge with the scientific community. This network provides a mechanism for consortium members, colleagues, and students to pursue research on other topics in air traffic management and aviation, thus enabling them to make greater contributions to the field

Sensitivity and diagnosticity of NASA-TLX and simplified SWAT to assess the mental workload associated with operating an agricultural sprayer.

PubMed

Dey, Asit; Mann, Danny D

2010-07-01

The objectives of the present study were: a) to investigate three continuous variants of the NASA-Task Load Index (TLX) (standard NASA (CNASA), average NASA (C1NASA) and principal component NASA (PCNASA)) and five different variants of the simplified subjective workload assessment technique (SSWAT) (continuous standard SSWAT (CSSWAT), continuous average SSWAT (C1SSWAT), continuous principal component SSWAT (PCSSWAT), discrete event-based SSWAT (D1SSWAT) and discrete standard SSWAT (DSSWAT)) in terms of their sensitivity and diagnosticity to assess the mental workload associated with agricultural spraying; b) to compare and select the best variants of NASA-TLX and SSWAT for future mental workload research in the agricultural domain. A total of 16 male university students (mean 30.4 +/- 12.5 years) participated in this study. All the participants were trained to drive an agricultural spraying simulator. Sensitivity was assessed by the ability of the scales to report the maximum change in workload ratings due to the change in illumination and difficulty levels. In addition, the factor loading method was used to quantify sensitivity. The diagnosticity was assessed by the ability of the scale to diagnose the change in task levels from single to dual. Among all the variants of NASA-TLX and SSWAT, PCNASA and discrete variants of SSWAT showed the highest sensitivity and diagnosticity. Moreover, among all the variants of NASA and SSWAT, the discrete variants of SSWAT showed the highest sensitivity and diagnosticity but also high between-subject variability. The continuous variants of both scales had relatively low sensitivity and diagnosticity and also low between-subject variability. Hence, when selecting a scale for future mental workload research in the agricultural domain, a researcher should decide what to compromise: 1) between-subject variability or 2) sensitivity and diagnosticity. STATEMENT OF RELEVANCE: The use of subjective workload scales is very popular in mental workload research. The present study investigated the different variants of two popular workload rating scales (i.e. NASA-TLX and SSWAT) in terms of their sensitivity and diagnositicity and selected the best variants of each scale for future mental workload research.

Fog-computing concept usage as means to enhance information and control system reliability

NASA Astrophysics Data System (ADS)

Melnik, E. V.; Klimenko, A. B.; Ivanov, D. Ya

2018-05-01

This paper focuses on the reliability issue of information and control systems (ICS). The authors propose using the elements of the fog-computing concept to enhance the reliability function. The key idea of fog-computing is to shift computations to the fog-layer of the network, and thus to decrease the workload of the communication environment and data processing components. As for ICS, workload also can be distributed among sensors, actuators and network infrastructure facilities near the sources of data. The authors simulated typical workload distribution situations for the “traditional” ICS architecture and for the one with fogcomputing concept elements usage. The paper contains some models, selected simulation results and conclusion about the prospects of the fog-computing as a means to enhance ICS reliability.

Neurophysiologic monitoring of mental workload and fatigue during operation of a flight simulator

NASA Astrophysics Data System (ADS)

Smith, Michael E.; Gevins, Alan

2005-05-01

In one experiment, EEG recordings were made during a daytime session while 16 well-rested participants performed versions of a PC flight simulator task that were either low, moderate, or high in difficulty. In another experiment, the same subjects repeatedly performed high difficulty versions of the same task during an all night session with total sleep deprivation. Multivariate EEG metrics of cortical activation were derived for frontal brain regions essential for working memory and executive control processes that are presumably important for maintaining situational awareness, central brain regions essential for sensorimotor control, and posterior parietal and occipital regions essential for visuoperceptual processing. During the daytime session each of these regional measures displayed greater activation during the high difficulty task than during the low difficulty task, and degree of cortical activation was positively correlated with subjective workload ratings in these well-rested subjects. During the overnight session, cortical activation declined with time-on-task, and the degree of this decline over frontal regions was negatively correlated with subjective workload ratings. Since participants were already highly skilled in the task, such changes likely reflect fatigue-related diminishment of frontal executive capability rather than practice effects. These findings suggest that the success of efforts to gauge mental workload via proxy cortical activation measures in the context of adaptive automation systems will likely depend on use of user models that take both task demands and the operator"s state of alertness into account. Further methodological development of the measurement approach outlined here would be required to achieve a practical, effective objective means for monitoring transient changes in cognitive brain function during performance of complex real-world tasks.

Anthropometric considerations for a 4-axis side-arm flight controller

NASA Technical Reports Server (NTRS)

Debellis, W. B.

1986-01-01

A data base on multiaxis side-arm flight controls was generated. The rapid advances in fly-by-light technology, automatic stability systems, and onboard computers have combined to create flexible flight control systems which could reduce the workload imposed on the operator by complex new equipment. This side-arm flight controller combines four controls into one unit and should simplify the pilot's task. However, the use of a multiaxis side-arm flight controller without complete cockpit integration may tend to increase the pilot's workload.

Using theta and alpha band power to assess cognitive workload in multitasking environments.

PubMed

Puma, Sébastien; Matton, Nadine; Paubel, Pierre-V; Raufaste, Éric; El-Yagoubi, Radouane

2018-01-01

Cognitive workload is of central importance in the fields of human factors and ergonomics. A reliable measurement of cognitive workload could allow for improvements in human machine interface designs and increase safety in several domains. At present, numerous studies have used electroencephalography (EEG) to assess cognitive workload, reporting the rise in cognitive workload to be associated with increases in theta band power and decreases in alpha band power. However, results have been inconsistent with some failing to reach the required level of significance. We hypothesized that the lack of consistency could be related to individual differences in task performance and/or to the small sample sizes in most EEG studies. In the present study we used EEG to assess the increase in cognitive workload occurring in a multitasking environment while taking into account differences in performance. Twenty participants completed a task commonly used in airline pilot recruitment, which included an increasing number of concurrent sub-tasks to be processed from one to four. Subjective ratings, performances scores, pupil size and EEG signals were recorded. Results showed that increases in EEG alpha and theta band power reflected increases in the involvement of cognitive resources for the completion of one to three subtasks in a multitasking environment. These values reached a ceiling when performances dropped. Consistent differences in levels of alpha and theta band power were associated to levels of task performance: highest performance was related to lowest band power. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of mental workload on muscle endurance, fatigue, and recovery during intermittent static work.

PubMed

Mehta, Ranjana K; Agnew, Michael J

2012-08-01

Most occupational tasks involve some level of mental/cognitive processing in addition to physical work; however, the etiology of work-related musculoskeletal disorders (WMSDs) due to these demands remains unclear. The aim of this study was to quantify the interactive effects of physical and mental workload on muscle endurance, fatigue, and recovery during intermittent work. Twelve participants, balanced by gender, performed intermittent static shoulder abductions to exhaustion at 15, 35, and 55% of individual maximal voluntary contraction (MVC), in the absence (control) and presence (concurrent) of a mental arithmetic task. Changes in muscular capacity were determined using endurance time, strength decline, electromyographic (EMG) fatigue indicators, muscle oxygenation, and heart rate measures. Muscular recovery was quantified through changes in strength and physiological responses. Mental workload was associated with shorter endurance times, specifically at 35% MVC, and greater strength decline. EMG and oxygenation measures showed similar changes during fatigue manifestation during concurrent conditions compared to the control, despite shorter endurance times. Moreover, decreased heart rate variability during concurrent demand conditions indicated increased mental stress. Although strength recovery was not influenced by mental workload, a slower heart rate recovery was observed after concurrent demand conditions. The findings from this study provide fundamental evidence that physical capacity (fatigability and recovery) is adversely affected by mental workload. Thus, it is critical to determine or evaluate occupational demands based on modified muscular capacity (due to mental workload) to reduce risk of WMSD development.

Trajectory-Based Complexity (TBX): A Modified Aircraft Count to Predict Sector Complexity During Trajectory-Based Operations

NASA Technical Reports Server (NTRS)

Prevot, Thomas; Lee, Paul U.

2011-01-01

In this paper we introduce a new complexity metric to predict -in real-time- sector complexity for trajectory-based operations (TBO). TBO will be implemented in the Next Generation Air Transportation System (NextGen). Trajectory-Based Complexity (TBX) is a modified aircraft count that can easily be computed and communicated in a TBO environment based upon predictions of aircraft and weather trajectories. TBX is scaled to aircraft count and represents an alternate and additional means to manage air traffic demand and capacity with more consideration of dynamic factors such as weather, aircraft equipage or predicted separation violations, as well as static factors such as sector size. We have developed and evaluated TBX in the Airspace Operations Laboratory (AOL) at the NASA Ames Research Center during human-in-the-loop studies of trajectory-based concepts since 2009. In this paper we will describe the TBX computation in detail and present the underlying algorithm. Next, we will describe the specific TBX used in an experiment at NASA's AOL. We will evaluate the performance of this metric using data collected during a controller-inthe- loop study on trajectory-based operations at different equipage levels. In this study controllers were prompted at regular intervals to rate their current workload on a numeric scale. When comparing this real-time workload rating to the TBX values predicted for these time periods we demonstrate that TBX is a better predictor of workload than aircraft count. Furthermore we demonstrate that TBX is well suited to be used for complexity management in TBO and can easily be adjusted to future operational concepts.

Graph theoretical analysis of EEG functional network during multi-workload flight simulation experiment in virtual reality environment.

PubMed

Shengqian Zhang; Yuan Zhang; Yu Sun; Thakor, Nitish; Bezerianos, Anastasios

2017-07-01

The research field of mental workload has attracted abundant researchers as mental workload plays a crucial role in real-life performance and safety. While previous studies have examined the neural correlates of mental workload in 2D scenarios (i.e., presenting stimuli on a computer screen (CS) environment using univariate methods (e.g., EEG channel power), it is still unclear of the findings of one that uses multivariate approach using graphical theory and the effects of a 3D environment (i.e., presenting stimuli on a Virtual Reality (VR)). In this study, twenty subjects undergo flight simulation in both CS and VR environment with three stages each. After preprocessing, the Electroencephalogram (EEG) signals were a connectivity matrix based on Phase Lag Index (PLI) will be constructed. Graph theory analysis then will be applied based on their global efficiency, local efficiency and nodal efficiency on both alpha and theta band. For global efficiency and local efficiency, VR values are generally lower than CS in both bands. For nodal efficiency, the regions that show at least marginally significant decreases are very different for CS and VR. These findings suggest that 3D simulation effects a higher mental workload than 2D simulation and that they each involved a different brain region.

Cardiovascular responses to plyometric exercise are affected by workload in athletes

PubMed Central

Arazi, Hamid; Mahdavi, Seyed Amir; Nasiri, Seyed Omid Mirfalah

2014-01-01

Introduction With regard to blood pressure responses to plyometric exercise and decreasing blood pressure after exercise (post-exercise hypotension), the influence of different workloads of plyometric exercise on blood pressure is not clear. Aim The purpose of this investigation was to examine the effects of a low, moderate and high workload of plyometric exercise on the post-exercise systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR) and rate-pressure product (RPP) responses in athletes. Material and methods Ten male athletes (age: 22.6 ±0.5 years; height: 178.2 ±3.3 cm; and body mass: 75.2 ±2.8 kg) underwent PE protocols involving 5 × 10 reps (Low Workload – LW), 10 × 10 reps (Moderate Workload – MW), and 15 × 10 reps (High Workload – HW) depth jump exercise from a 50-cm box in 3 non-consecutive days. After each exercise session, SBP, DBP and HR were measured every 10 min for a period of 70 min. Results No significant differences were observed among post-exercise SBP and DBP when the protocols (LW, MW and HW) were compared. The MW and HW protocols showed greater increases in HR compared with LW. Also the HW indicated greater increases than LW in RPP at post-exercise (p < 0.05). Conclusions All protocols increased SBP, HR and RPP responses at the 10th and 20th min of post-exercise. With regard to different workloads of plyometric exercise, HW condition indicated greater increases in HR and RPP and strength and conditioning professionals and athletes must keep in their mind that HW of plyometric exercise induces greater cardiovascular responses. PMID:24799919

Assessing Dual Sensor Enhanced Flight Vision Systems to Enable Equivalent Visual Operations

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Etherington, Timothy J.; Severance, Kurt; Bailey, Randall E.; Williams, Steven P.; Harrison, Stephanie J.

2016-01-01

Flight deck-based vision system technologies, such as Synthetic Vision (SV) and Enhanced Flight Vision Systems (EFVS), may serve as a revolutionary crew/vehicle interface enabling technologies to meet the challenges of the Next Generation Air Transportation System Equivalent Visual Operations (EVO) concept - that is, the ability to achieve the safety of current-day Visual Flight Rules (VFR) operations and maintain the operational tempos of VFR irrespective of the weather and visibility conditions. One significant challenge lies in the definition of required equipage on the aircraft and on the airport to enable the EVO concept objective. A motion-base simulator experiment was conducted to evaluate the operational feasibility, pilot workload and pilot acceptability of conducting straight-in instrument approaches with published vertical guidance to landing, touchdown, and rollout to a safe taxi speed in visibility as low as 300 ft runway visual range by use of onboard vision system technologies on a Head-Up Display (HUD) without need or reliance on natural vision. Twelve crews evaluated two methods of combining dual sensor (millimeter wave radar and forward looking infrared) EFVS imagery on pilot-flying and pilot-monitoring HUDs as they made approaches to runways with and without touchdown zone and centerline lights. In addition, the impact of adding SV to the dual sensor EFVS imagery on crew flight performance, workload, and situation awareness during extremely low visibility approach and landing operations was assessed. Results indicate that all EFVS concepts flown resulted in excellent approach path tracking and touchdown performance without any workload penalty. Adding SV imagery to EFVS concepts provided situation awareness improvements but no discernible improvements in flight path maintenance.

Shift manager workload assessment - A case study

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

Berntson, K.; Kozak, A.; Malcolm, J. S.

2006-07-01

In early 2003, Bruce Power restarted two of its previously laid up units in the Bruce A generating station, Units 3 and 4. However, due to challenges relating to the availability of personnel with active Shift Manager licenses, an alternate shift structure was proposed to ensure the safe operation of the station. This alternate structure resulted in a redistribution of responsibility, and a need to assess the resulting changes in workload. Atomic Energy of Canada Limited was contracted to perform a workload assessment based on the new shift structure, and to provide recommendations, if necessary, to ensure Shift Managers hadmore » sufficient resources available to perform their required duties. This paper discusses the performance of that assessment, and lessons learned as a result of the work performed during the Restart project. (authors)« less

Situation Awareness and Workload Measures for SAFOR

NASA Technical Reports Server (NTRS)

DeMaio, Joe; Hart, Sandra G.; Allen, Ed (Technical Monitor)

1999-01-01

The present research was conducted in support of the NASA Safe All-Weather Flight Operations for Rotorcraft (SAFOR) program. The purpose of the work was to investigate the utility of two measurement tools developed by the British Defense Evaluation Research Agency. These tools were a subjective workload assessment scale, the DRA Workload Scale (DRAWS), and a situation awareness measurement tool in which the crews self-evaluation of performance is compared against actual performance. These two measurement tools were evaluated in the context of a test of an innovative approach to alerting the crew by way of a helmet mounted display. The DRAWS was found to be usable, but it offered no advantages over extant scales, and it had only limited resolution. The performance self-evaluation metric of situation awareness was found to be highly effective.

The Small Aircraft Transportation System Higher Volume Operations (SATS HVO) Flight Experiment

NASA Technical Reports Server (NTRS)

Williams, Daniel M.; Murdoch, Jennifer L.; Adams, Catherine H.

2005-01-01

This paper provides a summary of conclusions from the Small Aircraft Transportation System (SATS) Higher Volume Operations (HVO) Flight Experiment which NASA conducted to determine pilot acceptability of the HVO concept for normal conditions. The SATS HVO concept improves efficiency at non-towered, non-radar airports in Instrument Meteorological Conditions (IMC) while achieving a level of safety equal to today s system. Reported are results from flight experiment data that indicate that the SATS HVO concept is viable. The success of the SATS HVO concept is based on acceptable pilot workload, performance, and subjective criteria when compared to the procedural control operations in use today at non-towered, non-radar controlled airfields in IMC. The HVO Flight Experiment, flown on NASA's Cirrus SR22, used a subset of the HVO Simulation Experiment scenarios and evaluation pilots in order to validate the simulation experiment results. HVO and Baseline (today s system) scenarios flown included: single aircraft arriving for a GPS non-precision approach; aircraft arriving for the approach with multiple traffic aircraft; and aircraft arriving for the approach with multiple traffic aircraft and then conducting a missed approach. Results reveal that all twelve low-time instrument-rated pilots preferred SATS HVO when compared to current procedural separation operations. These pilots also flew the HVO procedures safely and proficiently without additional workload in comparison to today s system (Baseline). Detailed results of pilot flight technical error, and their subjective assessments of workload and situation awareness are presented in this paper.

Structured analysis and modeling of complex systems

NASA Technical Reports Server (NTRS)

Strome, David R.; Dalrymple, Mathieu A.

1992-01-01

The Aircrew Evaluation Sustained Operations Performance (AESOP) facility at Brooks AFB, Texas, combines the realism of an operational environment with the control of a research laboratory. In recent studies we collected extensive data from the Airborne Warning and Control Systems (AWACS) Weapons Directors subjected to high and low workload Defensive Counter Air Scenarios. A critical and complex task in this environment involves committing a friendly fighter against a hostile fighter. Structured Analysis and Design techniques and computer modeling systems were applied to this task as tools for analyzing subject performance and workload. This technology is being transferred to the Man-Systems Division of NASA Johnson Space Center for application to complex mission related tasks, such as manipulating the Shuttle grappler arm.

Avionic technology testing by using a cognitive neurometric index: A study with professional helicopter pilots.

PubMed

Borghini, Gianluca; Aricò, Pietro; Di Flumeri, Gianluca; Salinari, Serenella; Colosimo, Alfredo; Bonelli, Stefano; Napoletano, Linda; Ferreira, Ana; Babiloni, Fabio

2015-01-01

In this study, we investigated the possibility to evaluate the impact of different avionic technologies on the mental workload of helicopter's pilots by measuring their brain activity with the EEG during a series of simulated missions carried out at AgustaWestland facilities in Yeovil (UK). The tested avionic technologies were: i) Head-Up Display (HUD); ii) Head-Mounted Display (HMD); iii) Full Conformal symbology (FC); iv) Flight Guidance (FG) symbology; v) Synthetic Vision System (SVS); and vi) Radar Obstacles (RO) detection system. It has been already demonstrated that in cognitive tasks, when the cerebral workload increases the EEG power spectral density (PSD) in theta band over frontal areas increases, and the EEG PSD in alpha band decreases over parietal areas. A mental workload index (MWL) has been here defined as the ratio between the frontal theta and parietal alpha EEG PSD values. Such index has been used for testing and comparing the different avionic technologies. Results suggested that the HUD provided a significant (p<;.05) workload reduction across all the flight scenarios with respect to the other technologies. In addition, the simultaneous use of FC and FG technologies (FC+FG) produced a significant decrement of the workload (p<;.01) with respect to the use of only the FC. Moreover, the use of the SVS technology provided on Head Down Display (HDD) with the simultaneous use of FC+FG and the RO seemed to produce a lower cerebral workload when compared with the use of only the FC. Interestingly, the workload estimation by means of subjective measures, provided by pilots through a NASA-TLX questionnaire, did not provide any significant differences among the different flight scenarios. These results suggested that the proposed MWL cognitive neurometrics could be used as a reliable measure of the user's mental workload, being a valid indicator for the comparison and the test of different avionic technologies.

Robotic inspection for vehicle-borne contraband

NASA Astrophysics Data System (ADS)

Witus, Gary; Gerhart, Grant; Smuda, W.; Andrusz, H.

2006-05-01

Vehicle-borne smuggling is widespread because of the availability, flexibility and capacity of the cars and trucks. Inspecting vehicles at border crossings and checkpoints are key security elements. At the present time, most vehicle security inspections at home and abroad are conducted manually. Remotely operated vehicle inspection robots could be integrated into the operating procedures to improve throughput while reducing the workload burden on security personnel. The robotic inspection must be effective at detecting contraband and efficient at clearing the "clean" vehicles that make up the bulk of the traffic stream, while limiting the workload burden on the operators. In this paper, we present a systems engineering approach to robotic vehicle inspection. We review the tactics, techniques and procedures to interdict contraband. We present an operational concept for robotic vehicle inspection within this framework, and identify needed capabilities. We review the technologies currently available to meet these needs. Finally, we summarize the immediate potential and R&D challenges for effective contraband detection robots.

EEG and ECG changes during simulator operation reflect mental workload and vigilance.

PubMed

Dussault, Caroline; Jouanin, Jean-Claude; Philippe, Matthieu; Guezennec, Charles-Yannick

2005-04-01

Performing mission tasks in a simulator influences many neurophysiological measures. Quantitative assessments of electroencephalography (EEG) and electrocardiography (ECG) have made it possible to develop indicators of mental workload and to estimate relative physiological responses to cognitive requirements. To evaluate the effects of mental workload without actual physical risk, we studied the cortical and cardiovascular changes that occurred during simulated flight. There were 12 pilots (8 novices and 4 experts) who simulated a flight composed of 10 sequences that induced several different mental workload levels. EEG was recorded at 12 electrode sites during rest and flight sequences; ECG activity was also recorded. Subjective tests were used to evaluate anxiety and vigilance levels. Theta band activity was lower during the two simulated flight rest sequences than during visual and instrument flight sequences at central, parietal, and occipital sites (p < 0.05). On the other hand, rest sequences resulted in higher beta (at the C4 site; p < 0.05) and gamma (at the central, parietal, and occipital sites; p < 0.05) power than active segments. The mean heart rate (HR) was not significantly different during any simulated flight sequence, but HR was lower for expert subjects than for novices. The subjective tests revealed no significant anxiety and high values for vigilance levels before and during flight. The different flight sequences performed on the simulator resulted in electrophysiological changes that expressed variations in mental workload. These results corroborate those found during study of real flights, particularly during sequences requiring the heaviest mental workload.

78 FR 42037 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-15

... strategies to decrease the NRFU workload and contact strategies to decrease the cost of NRFU. This pre-test... to increase the level of data quality. Specifically, this pre-test will use current Census... records and (2) employing an adaptive contact strategy tailored to each household. This pre-test will...

[Correlation of mental fatigue due to work load and professional qualifications of physicians].

PubMed

Wichrowski, A; Dudek, B

1988-01-01

The results presented in the paper refer to the relationship between physicians' professional qualifications and mental fatigue. It was that professional qualifications determining man's capabilities affect the level and structure of mental fatigue caused by work. Furthermore, it was assumed that this workload is multidimensional, and so its following five dimensions were singled out: mental difficulties, monotony, risk and responsibility, moral conflicts and dilemmas. The level of qualifications was measured by the length of employment and specialization and scientific degrees. The studies involved 10% of randomly selected physicians from all over Poland. The obtained results indicate that with increasing length of employment the workload due to moral dilemmas, risk and responsibility and mental difficulties, gets reduced; on the other hand, the load resulting from work monotony is increased. Also the specialization degree affects the workload caused by the risk, responsibility and moral dilemmas. Noticeable here is the trend towards a reduction in the workload with increasing specialization degrees. Instead, the higher the scientific degree the higher the sense of load due to risk and responsibility with simultaneous decrease in the load due to work monotony.

A multidisciplinary approach of workload assessment in real-job situations: investigation in the field of aerospace activities.

PubMed

Mélan, Claudine; Cascino, Nadine

2014-01-01

The present contribution presents two field studies combining tools and methods from cognitive psychology and from occupational psychology in order to perform a thorough investigation of workload in employees. Cognitive load theory proposes to distinguish different load categories of working memory, in a context of instruction. Intrinsic load is inherent to the task, extraneous load refers to components of a learning environment that may be modified to reduce total load, and germane load enables schemas construction and thus efficient learning. We showed previously that this theoretical framework may be successfully extended to working memory tasks in non-instructional designs. Other theoretical models, issued from the field of occupational psychology, account for an individual's perception of work demands or requirements in the context of different psychosocial features of the (work) environment. Combining these approaches is difficult as workload assessment by job-perception questionnaires explore an individual's overall job-perception over a large time-period, whereas cognitive load investigations in working memory tasks are typically performed within short time-periods. We proposed an original methodology enabling investigation of workload and load factors in a comparable time-frame. We report two field studies investigating workload on different shift-phases and between work-shifts, with two custom-made tools. The first one enabled workload assessment by manipulating intrinsic load (task difficulty) and extraneous load (time pressure) in a working-memory task. The second tool was a questionnaire based on the theoretical concepts of work-demands, control, and psychosocial support. Two additional dimensions suspected to contribute to job-perception, i.e., work-family conflicts and availability of human and technical resources were also explored. Results of workload assessments were discussed in light of operators' alertness and job-performance.

Is the "sterile cockpit" concept applicable to cardiovascular surgery critical intervals or critical events? The impact of protocol-driven communication during cardiopulmonary bypass.

PubMed

Wadhera, Rishi K; Parker, Sarah Henrickson; Burkhart, Harold M; Greason, Kevin L; Neal, James R; Levenick, Katherine M; Wiegmann, Douglas A; Sundt, Thoralf M

2010-02-01

There is general enthusiasm for applying strategies from aviation directly to medical care; the application of the "sterile cockpit" rule to surgery has accordingly been suggested. An implicit prerequisite to the evidence-based transfer of such a concept to the clinical domain, however, is definition of periods of high mental workload analogous to takeoff and landing. We measured cognitive demands among operating room staff, mapped critical events, and evaluated protocol-driven communication. With the National Aeronautics and Space Administration Task Load Index and semistructured focus groups, we identified common critical stages of cardiac surgical cases. Intraoperative communication was assessed before (n = 18) and after (n = 16) introduction of a structured communication protocol. Cognitive workload measures demonstrated high temporal diversity among caregivers in various roles. Eight critical events during cardiopulmonary bypass were then defined. A structured, unambiguous verbal communication protocol for these events was then implemented. Observations of 18 cases before implementation including 29.6 hours of cardiopulmonary bypass with 632 total communication exchanges (average 35.1 exchanges/case) were compared with observations of 16 cases after implementation including 23.9 hours of cardiopulmonary bypass with 748 exchanges (average 46.8 exchanges/case, P = .06). Frequency of communication breakdowns per case decreased significantly after implementation (11.5 vs 7.3 breakdowns/case, P = .008). Because of wide variations is cognitive workload among caregivers, effective communication can be structured around critical events rather than defined intervals analogous to the sterile cockpit, with reduction in communication breakdowns. 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

The effects of task difficulty and workload on training

NASA Technical Reports Server (NTRS)

Mane, Amir; Wickens, Christopher D.

1986-01-01

Four hypotheses regarding the possible effects of workload and task difficulty on training are proposed. These are: (1) increased levels of task difficulty will facilitate learning to the extent that these increases are (a) resource loading and (b) intrinsic to the component task to be learned; (2) decrease of task difficulty will facilitate learning to the extent that these decreases (a) reduce the resource load and (b) are extrinsic of the component task to be learned; (3) the lerner's tendency to conserve resources may bead to the adoption of undesirable, short-term, low resource strategies early in training; and (4) the effect of changes in resource demand on learning will depend upon the similarity of the resource whose demand is changed to the resource involved in learning.

An Unobtrusive System to Measure, Assess, and Predict Cognitive Workload in Real-World Environments

NASA Technical Reports Server (NTRS)

Bracken, Bethany K.; Palmon, Noa; Elkin-Frankston, Seth; Irvin, Scott; Jenkins, Michael; Farry, Mike

2017-01-01

Across many careers, individuals face alternating periods of high and low attention and cognitive workload, which can result in impaired cognitive functioning and can be detrimental to job performance. For example, some professions (e.g., fire fighters, emergency medical personnel, doctors and nurses working in an emergency room, pilots) require long periods of low workload (boredom), followed by sudden, high-tempo operations during which they may be required to respond to an emergency and perform at peak cognitive levels. Conversely, other professions (e.g., air traffic controllers, market investors in financial industries, analysts) require long periods of high workload and multitasking during which the addition of just one more task results in cognitive overload resulting in mistakes. An unobtrusive system to measure, assess, and predict cognitive workload could warn individuals, their teammates, or their supervisors when steps should be taken to augment cognitive readiness. In this talk I will describe an approach to this problem that we have found to be successful across work domains including: (1) a suite of unobtrusive, field-ready neurophysiological, physiological, and behavioral sensors that are chosen to best suit the target environment; (2) custom algorithms and statistical techniques to process and time-align raw data originating from the sensor suite; (3) probabilistic and statistical models designed to interpret the data into the human state of interest (e.g., cognitive workload, attention, fatigue); (4) and machine-learning techniques to predict upcoming performance based on the current pattern of events, and (5) display of each piece of information depending on the needs of the target user who may or may not want to drill down into the functioning of the system to determine how conclusions about human state and performance are determined. I will then focus in on our experimental results from our custom functional near-infrared spectroscopy sensor, designed to operate in real-world environments to be worn comfortably (e.g., positioned into a baseball cap or a surgeons cap) to measure changes in brain blood oxygenation without adding burden to the individual being assessed.

Initial Investigation of Reaction Control System Design on Spacecraft Handling Qualities for Earth Orbit Docking

NASA Technical Reports Server (NTRS)

Bailey, Randall E.; Jackson, E. Bruce; Goodrich, Kenneth H.; Ragsdale, W. Al; Neuhaus, Jason; Barnes, Jim

2008-01-01

A program of research, development, test, and evaluation is planned for the development of Spacecraft Handling Qualities guidelines. In this first experiment, the effects of Reaction Control System design characteristics and rotational control laws were evaluated during simulated proximity operations and docking. Also, the influence of piloting demands resulting from varying closure rates was assessed. The pilot-in-the-loop simulation results showed that significantly different spacecraft handling qualities result from the design of the Reaction Control System. In particular, cross-coupling between translational and rotational motions significantly affected handling qualities as reflected by Cooper-Harper pilot ratings and pilot workload, as reflected by Task-Load Index ratings. This influence is masked but only slightly by the rotational control system mode. While rotational control augmentation using Rate Command Attitude Hold can reduce the workload (principally, physical workload) created by cross-coupling, the handling qualities are not significantly improved. The attitude and rate deadbands of the RCAH introduced significant mental workload and control compensation to evaluate when deadband firings would occur, assess their impact on docking performance, and apply control inputs to mitigate that impact.

Measurement of operator workload in an information processing task

NASA Technical Reports Server (NTRS)

Jenney, L. L.; Older, H. J.; Cameron, B. J.

1972-01-01

This was an experimental study to develop an improved methodology for measuring workload in an information processing task and to assess the effects of shift length and communication density (rate of information flow) on the ability to process and classify verbal messages. Each of twelve subjects was exposed to combinations of three shift lengths and two communication densities in a counterbalanced, repeated measurements experimental design. Results indicated no systematic variation in task performance measures or in other dependent measures as a function of shift length or communication density. This is attributed to the absence of a secondary loading task, an insufficiently taxing work schedule, and the lack of psychological stress. Subjective magnitude estimates of workload showed fatigue (and to a lesser degree, tension) to be a power function of shift length. Estimates of task difficulty and fatigue were initially lower but increased more sharply over time under low density than under high density conditions. An interpretation of findings and recommedations for furture research are included. This research has major implications to human workload problems in information processing of air traffic control verbal data.

A simulator investigation of the use of digital data link for pilot/ATC communications in a single pilot operation

NASA Technical Reports Server (NTRS)

Hinton, David A.; Lohr, Gary W.

1988-01-01

Studies have shown that radio communications between pilots and air traffic control contribute to high pilot workload and are subject to various errors. These errors result from congestion on the voice radio channel, and missed and misunderstood messages. The use of digital data link has been proposed as a means of reducing this workload and error rate. A critical factor, however, in determining the potential benefit of data link will be the interface between future data link systems and the operator of those systems, both in the air and on the ground. The purpose of this effort was to evaluate the pilot interface with various levels of data link capability, in simulated general aviation, single-pilot instrument flight rule operations. Results show that the data link reduced demands on pilots' short-term memory, reduced the number of communication transmissions, and permitted the pilots to more easily allocate time to critical cockpit tasks while receiving air traffic control messages. The pilots who participated unanimously indicated a preference for data link communications over voice-only communications. There were, however, situations in which the pilot preferred the use of voice communications, and the ability for pilots to delay processing the data link messages, during high workload events, caused delays in the acknowledgement of messages to air traffic control.

A perspective on the FAA approval process: Integrating rotorcraft displays, controls and workload

NASA Technical Reports Server (NTRS)

Green, David L.; Hart, Jake; Hwoschinsky, Peter

1993-01-01

The FAA is responsible for making the determination that a helicopter is safe for IFR operations in the National Airspace System (NAS). This involves objective and subjective evaluations of cockpit displays, flying qualities, procedures and human factors as they affect performance and workload. After all of the objective evaluations are completed, and all Federal Regulations have been met, FAA pilots make the final subjective judgement as to suitability for use by civil pilots in the NAS. The paper uses the flying qualities and pilot workload characteristics of a small helicopter to help examine the FAA pilot's involvement in this process. The result highlights the strengths of the process and its importance to the approval of new aircraft and equipments for civil IFR helicopter applications. The paper also identifies opportunities for improvement.

W-MAC: A Workload-Aware MAC Protocol for Heterogeneous Convergecast in Wireless Sensor Networks

PubMed Central

Xia, Ming; Dong, Yabo; Lu, Dongming

2011-01-01

The power consumption and latency of existing MAC protocols for wireless sensor networks (WSNs) are high in heterogeneous convergecast, where each sensor node generates different amounts of data in one convergecast operation. To solve this problem, we present W-MAC, a workload-aware MAC protocol for heterogeneous convergecast in WSNs. A subtree-based iterative cascading scheduling mechanism and a workload-aware time slice allocation mechanism are proposed to minimize the power consumption of nodes, while offering a low data latency. In addition, an efficient schedule adjustment mechanism is provided for adapting to data traffic variation and network topology change. Analytical and simulation results show that the proposed protocol provides a significant energy saving and latency reduction in heterogeneous convergecast, and can effectively support data aggregation to further improve the performance. PMID:22163753

Does physical or psychosocial workload modify the effect of musculoskeletal pain on sickness absence? A prospective study among the Finnish population.

PubMed

Neupane, Subas; Pensola, Tiina; Haukka, Eija; Ojajärvi, Anneli; Leino-Arjas, Päivi

2016-07-01

Previously, among food industry workers, multisite pain predicted sickness absence (SA) only in those with low biomechanical workload. Here we studied among a wide range of occupations whether the relationship of pain with SA was modified by the level of physical or psychosocial workload. A nationally representative sample (Health 2000 Survey) comprised 3420 occupationally active Finns aged 30-55 years. Baseline data on musculoskeletal pain during the preceding month, strenuous work history, current physical workload, job demands, job control, support at work, lifestyle, and chronic diseases were obtained in 2000/2001 by questionnaire, interview, and clinical examination. Musculoskeletal pain in 18 body locations was combined into four sites (neck, upper limbs, low back, and lower limbs) and classified as no pain, single-site pain, and multisite pain (2-4 sites). The data were linked with information from national registers on annual SA periods lasting ≥10 workdays for 2002-2008. Negative binomial regression analysis was used. At baseline, one-third of the study sample reported single-site and one-third multisite pain. Allowing for gender and age, the employees with multisite pain in strata with high physical workload and high job demands tended to have the highest risk of SA, but no statistically significant interactive effects between work factors and pain were observed. Further adjustment for health-related lifestyle and chronic diseases decreased the risk estimates in all strata. We did not find evidence for significant modification by physical or psychosocial workload of the relationship between musculoskeletal pain and SA periods lasting ≥10 workdays.

Thermoregulatory models of safety-for-flight issues for space operations

NASA Astrophysics Data System (ADS)

Pisacane, V. L.; Kuznetz, L. H.; Logan, J. S.; Clark, J. B.; Wissler, E. H.

2006-10-01

This study investigates the use of a mathematical model for thermoregulation as a tool in safety-of-flight issues and proposed solutions for mission operations of the Space Shuttle and the International Space Station. Specifically, this study assesses the effects of elevated cabin temperature and metabolic loads on astronauts wearing the Advanced Crew Escape Suit (ACES) and the Liquid Cooled Ventilation Garment (LCVG). The 225-node Wissler model is validated by comparison with two ground-based human subject tests, firefighters, and surrogate astronauts under anomalous conditions that show good agreement. Subsequent simulations indicate that the performance of the ACES/LCVG is marginal. Increases in either workload or cabin temperature from the nominal will increase rectal temperature, stored heat load, heart rate, and sweating leading to possible deficits in the ability of the astronauts to perform cognitive and motor tasks that could affect the safety of the mission, especially the safe landing of the Shuttle. Specific relationships are given between cabin temperature and metabolic rate that define the threshold for decreased manual dexterity and loss of tracking skills. Model results indicate that the most effective mitigation strategy would be to decrease the LCVG inlet temperature. Methods of accomplishing this are also proposed.

Time estimation as a secondary task to measure workload. [attention sharing effect on operator performance

NASA Technical Reports Server (NTRS)

Hart, S. G.

1975-01-01

Variation in the length of time productions and verbal estimates of duration was investigated to determine the influence of concurrent activity on operator time perception. The length of 10-, 20-, and 30-sec intervals produced while performing six different compensatory tracking tasks was significantly longer, 23% on the average, than those produced while performing no other task. Verbal estimates of session duration, taken at the end of each of 27 experimental sessions, reflected a parallel increase in subjective underestimation of the passage of time as the difficulty of the task performed increased. These data suggest that estimates of duration made while performing a manual control task provide stable and sensitive measures of the workload imposed by the primary task, with minimal interference.

NASA-Ames workload research program

NASA Technical Reports Server (NTRS)

Hart, Sandra

1988-01-01

Research has been underway for several years to develop valid and reliable measures and predictors of workload as a function of operator state, task requirements, and system resources. Although the initial focus of this research was on aeronautics, the underlying principles and methodologies are equally applicable to space, and provide a set of tools that NASA and its contractors can use to evaluate design alternatives from the perspective of the astronauts. Objectives and approach of the research program are described, as well as the resources used in conducting research and the conceptual framework around which the program evolved. Next, standardized tasks are described, in addition to predictive models and assessment techniques and their application to the space program. Finally, some of the operational applications of these tasks and measures are reviewed.

A systematic review of the effect of different models of after-hours primary medical care services on clinical outcome, medical workload, and patient and GP satisfaction.

PubMed

Leibowitz, Ruth; Day, Susan; Dunt, David

2003-06-01

The organization of after-hours primary medical care services is changing in many countries. Increasing demand, economic considerations and changes in doctors' attitudes are fueling these changes. Information for policy makers in this field is needed. However, a comprehensive review of the international literature that compares the effects of one model of after-hours care with another is lacking. The aim of this study was to carry out a systematic review of the international literature to determine what evidence exists about the effect of different models of out-of-hours primary medical care service on outcome. Original studies and systematic reviews written since 1976 on the subject of 'after-hours primary medical care services' were identified. Databases searched were Medline/Premedline, CINAHL, HealthSTAR, Current Contents, Cochrane Reviews, DARE, EBM Reviews and EconLit. For each paper where the optimal design would have been an interventional study, the 'level' of evidence was assessed as described in the National Health and Medical Research Council Handbook. 'Comparative' studies (levels I, II, III and IV pre-/post-test studies) were included in this review. Six main models of after-hours primary care services (not mutually exclusive) were identified: practice-based services, deputizing services, emergency departments, co-operatives, primary care centres, and telephone triage and advice services. Outcomes were divided into the following categories: clinical outcomes, medical workload, and patient and GP satisfaction. The results indicate that the introduction of a telephone triage and advice service for after-hours primary medical care may reduce the immediate medical workload. Deputizing services increase immediate medical workload because of the low use of telephone advice and the high home visiting rate. Co-operatives, which use telephone triage and primary care centres and have a low home visiting rate, reduce immediate medical workload. There is little evidence on the effect of different service models on subsequent medical workload apart from the finding that GPs working in emergency departments may reduce the subsequent medical workload. There was very little evidence about the advantages of one service model compared with another in relation to clinical outcome. Studies consistently showed patient dissatisfaction with telephone consultations. The rapid growth in telephone triage and advice services appears to have the advantage of reducing immediate medical workload through the substitution of telephone consultations for in-person consultations, and this has the potential to reduce costs. However, this has to be balanced with the finding of reduced patient satisfaction when in-person consultations are replaced by telephone consultations. These findings should be borne in mind by policy makers deciding on the shape of future services.

Evaluating mental workload of two-dimensional and three-dimensional visualization for anatomical structure localization.

PubMed

Foo, Jung-Leng; Martinez-Escobar, Marisol; Juhnke, Bethany; Cassidy, Keely; Hisley, Kenneth; Lobe, Thom; Winer, Eliot

2013-01-01

Visualization of medical data in three-dimensional (3D) or two-dimensional (2D) views is a complex area of research. In many fields 3D views are used to understand the shape of an object, and 2D views are used to understand spatial relationships. It is unclear how 2D/3D views play a role in the medical field. Using 3D views can potentially decrease the learning curve experienced with traditional 2D views by providing a whole representation of the patient's anatomy. However, there are challenges with 3D views compared with 2D. This current study expands on a previous study to evaluate the mental workload associated with both 2D and 3D views. Twenty-five first-year medical students were asked to localize three anatomical structures--gallbladder, celiac trunk, and superior mesenteric artery--in either 2D or 3D environments. Accuracy and time were taken as the objective measures for mental workload. The NASA Task Load Index (NASA-TLX) was used as a subjective measure for mental workload. Results showed that participants viewing in 3D had higher localization accuracy and a lower subjective measure of mental workload, specifically, the mental demand component of the NASA-TLX. Results from this study may prove useful for designing curricula in anatomy education and improving training procedures for surgeons.

Implementation of ergonomics in the management of parking increasing the quality of living parking park in mall Robinson Denpasar city

NASA Astrophysics Data System (ADS)

Sutapa, I. K.; Sudiarsa, I. M.

2018-01-01

The problems that often arise in the area of Denpasar City mostly caused by parking problems at the centers of activities such as shopping centers. The problems that occur not only because of the large number of vehicles that parked but also the result of the condition of parking officers who have not received attention, there is no concern about the physical condition of parking attendants because doing night guard duty. To improve the quality of parking officer, ergonomic parking lot is improved through the application of appropriate technology with systemic, holistic, interdisciplinary and participatory approach. The general objective of the research is to know the implementation of ergonomics in parking management on the improvement of the quality of parking officer in Robinson shopping center. The indicator of the quality of the parking officer work is the decrease of musculoskeletal complaints, fatigue, workload, boredom and increasing work motivation. The study was conducted using the same subject design, involving 10 subjects as a simple random sample. Intervention is done by arrangement of ergonomic basement motorcycle parking. Measurements done before and after repair. Washing out (WO) for 14 days. The data obtained were analyzed descriptively, tested normality (shapirowilk) and homogeneity (Levene Test). For normal and homogeneous distribution data, different test with One Way Anova, different test between Period with Post Hoc. Normally distributed and non-homogeneous data, different test with Friedman Test, different test between periods using Wilcoxon test. Data were analyzed with significance level of 5%. The results showed that the implementation of ergonomic in the management of parking area of the court decreased musculoskeletal complaints by 15.10% (p <0.05), decreased fatigue rate by 22.06% (p <0.05), decreased workload by 21, 90 % (P <0,05), decrease boredom 15,85% (p <0,05) and motivation improvement 37, 68% (p <0,05). It is concluded that the implementation of ergonomics in parking management of the parking lot improves the quality of the parking officer work from: (1) decrease of musculoskeletal complaints, (2) decrease of melting rate, (3) decrease of parking workload, decreasing boredom and increasing work motivation.

Bringing the CMS distributed computing system into scalable operations

NASA Astrophysics Data System (ADS)

Belforte, S.; Fanfani, A.; Fisk, I.; Flix, J.; Hernández, J. M.; Kress, T.; Letts, J.; Magini, N.; Miccio, V.; Sciabà, A.

2010-04-01

Establishing efficient and scalable operations of the CMS distributed computing system critically relies on the proper integration, commissioning and scale testing of the data and workload management tools, the various computing workflows and the underlying computing infrastructure, located at more than 50 computing centres worldwide and interconnected by the Worldwide LHC Computing Grid. Computing challenges periodically undertaken by CMS in the past years with increasing scale and complexity have revealed the need for a sustained effort on computing integration and commissioning activities. The Processing and Data Access (PADA) Task Force was established at the beginning of 2008 within the CMS Computing Program with the mandate of validating the infrastructure for organized processing and user analysis including the sites and the workload and data management tools, validating the distributed production system by performing functionality, reliability and scale tests, helping sites to commission, configure and optimize the networking and storage through scale testing data transfers and data processing, and improving the efficiency of accessing data across the CMS computing system from global transfers to local access. This contribution reports on the tools and procedures developed by CMS for computing commissioning and scale testing as well as the improvements accomplished towards efficient, reliable and scalable computing operations. The activities include the development and operation of load generators for job submission and data transfers with the aim of stressing the experiment and Grid data management and workload management systems, site commissioning procedures and tools to monitor and improve site availability and reliability, as well as activities targeted to the commissioning of the distributed production, user analysis and monitoring systems.

Cardiovascular correlates of emotional state, cognitive workload and time-on-task effect during a realistic flight simulation.

PubMed

Hidalgo-Muñoz, Antonio R; Mouratille, Damien; Matton, Nadine; Causse, Mickaël; Rouillard, Yves; El-Yagoubi, Radouane

2018-04-05

In aviation, emotion and cognitive workload can considerably increase the probability of human error. An accurate online physiological monitoring of pilot's mental state could prevent accidents. The heart rate (HR) and heart rate variability (HRV) of 21 private pilots were analysed during two realistic flight simulator scenarios. Emotion was manipulated by a social stressor and cognitive workload with the difficulty of a secondary task. Our results confirmed the sensitivity of the HR to cognitive demand and training effects, with increased HR when the task was more difficult and decreased HR with training (time-on-task). Training was also associated with an increased HRV, with increased values along the flight scenario time course. Finally, the social stressor seemed to provoke an emotional reaction that enhanced motivation and performance on the secondary task. However, this was not reflected by the cardiovascular activity. Copyright © 2018 Elsevier B.V. All rights reserved.

Simulation Evaluation of Equivalent Vision Technologies for Aerospace Operations

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Williams, Steven P.; Wilz, Susan J.; Arthur, Jarvis J.

2009-01-01

A fixed-based simulation experiment was conducted in NASA Langley Research Center s Integration Flight Deck simulator to investigate enabling technologies for equivalent visual operations (EVO) in the emerging Next Generation Air Transportation System operating environment. EVO implies the capability to achieve or even improve on the safety of current-day Visual Flight Rules (VFR) operations, maintain the operational tempos of VFR, and perhaps even retain VFR procedures - all independent of the actual weather and visibility conditions. Twenty-four air transport-rated pilots evaluated the use of Synthetic/Enhanced Vision Systems (S/EVS) and eXternal Vision Systems (XVS) technologies as enabling technologies for future all-weather operations. The experimental objectives were to determine the feasibility of XVS/SVS/EVS to provide for all weather (visibility) landing capability without the need (or ability) for a visual approach segment and to determine the interaction of XVS/EVS and peripheral vision cues for terminal area and surface operations. Another key element of the testing investigated the pilot's awareness and reaction to non-normal events (i.e., failure conditions) that were unexpectedly introduced into the experiment. These non-normal runs served as critical determinants in the underlying safety of all-weather operations. Experimental data from this test are cast into performance-based approach and landing standards which might establish a basis for future all-weather landing operations. Glideslope tracking performance appears to have improved with the elimination of the approach visual segment. This improvement can most likely be attributed to the fact that the pilots didn't have to simultaneously perform glideslope corrections and find required visual landing references in order to continue a landing. Lateral tracking performance was excellent regardless of the display concept being evaluated or whether or not there were peripheral cues in the side window. Although workload ratings were significantly less when peripheral cues were present compared to when there were none, these differences appear to be operationally inconsequential. Larger display concepts tested in this experiment showed significant situation awareness (SA) improvements and workload reductions compared to smaller display concepts. With a fixed display size, a color display was more influential in SA and workload ratings than a collimated display.

Long-term forecasting of anesthesia workload in operating rooms from changes in a hospital's local population can be inaccurate.

PubMed

Masursky, Danielle; Dexter, Franklin; O'Leary, Colleen E; Applegeet, Carol; Nussmeier, Nancy A

2008-04-01

Anesthesia department planning depends on forecasting future demand for perioperative services. Little is known about long-range forecasting of anesthesia workload. We studied operating room (OR) times at Hospital A over 16 yr (1991-2006), anesthesia times at Hospital B over 26 yr (1981-2006), and cases at Hospital C over 13 yr (1994-2006). Each hospital is >100 yr old and is located in a US city with other hospitals that are >50 yr old. Hospitals A and B are the sole University hospitals in their metropolitan statistical areas (and many counties beyond). Hospital C is the sole tertiary hospital for >375 km. Each hospital's choice of a measure of anesthesia work to be analyzed was likely unimportant, as the annual hours of anesthesia correlated highly both with annual numbers of cases (r = 0.98) and with American Society of Anesthesiologist's Relative Value Guide units of work (r = 0.99). Despite a 2% decline in the local population, the hours of OR time at Hospital A increased overall (Pearson r = -0.87, P < 0.001) and for children (r = -0.84). At Hospital B, there was a strong positive correlation between population and hours of anesthesia (r = 0.97, P < 0.001), but not between annual increases in population and workload (r = -0.18). At Hospital C, despite a linear increase in population, the annual numbers of cases increased, declined with opening of two outpatient surgery facilities, and then stabilized. The predictive value of local personal income was low. In contrast, the annual increases in the hours of OR time and anesthesia could be modeled using simple time series methods. Although growth of the elderly population is a simple justification for building more ORs, managers should be cautious in arguing for strategic changes in capacity at individual hospitals based on future changes in the national age-adjusted population. Local population can provide little value in forecasting future anesthesia workloads at individual hospitals. In addition, anesthesia groups and hospital administrators should not focus on quarterly changes in workload, because workload can vary widely, despite consistent patterns over decades. To facilitate long-range planning, anesthesia groups and hospitals should save their billing and OR time data, display it graphically over years, and supplement with corresponding forecasting methods (e.g., staff an additional OR when an upper prediction bound of workload per OR exceeds a threshold).

Moderating effects of leader-member exchange (LMX) on job burnout in dietitians and chefs of institutional foodservice

PubMed Central

2011-01-01

The objectives of the study were to investigate job burnout and leader-member exchange (LMX) levels as well as to evaluate buffering effects of LMX on burnout among dietitians and chefs at institutional foodservices. Hypotheses were proposed based on the Job Demands-Resources model and LMX theory. The study population consisted of dietitians and chefs who were in charge of managing unit operations in a nationwide contract management company. Positive/negative affectivity, workload, job burnout, and LMX scales that had been validated in previous research were adopted. A total of 552 questionnaires were distributed and 154 responses were returned. Results indicated that respondents' burnout levels were moderate and emotional exhaustion was greater than cynicism. In terms of LMX, the surveyed dietitians and chefs showed higher respect toward their supervisors than loyalty. When positive affectivity and negative affectivity were controlled, workload influenced emotional exhaustion and professional efficacy significantly. With affectivity and workload controlled, however, LMX did not influence any dimensions of burnout. The moderating effect of LMX on the relationship between workload and cynicism was significant. That is, the effect of workload on cynicism was weak if the dietitians and chefs perceived the relationship with their supervisor positively. Based on the findings and literature reviewed, how to mitigate job burnout among foodservice managers is discussed. PMID:21487501

Human System Simulation in Support of Human Performance Technical Basis at NPPs

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

David Gertman; Katya Le Blanc; alan mecham

2010-06-01

This paper focuses on strategies and progress toward establishing the Idaho National Laboratory’s (INL’s) Human Systems Simulator Laboratory at the Center for Advanced Energy Studies (CAES), a consortium of Idaho State Universities. The INL is one of the National Laboratories of the US Department of Energy. One of the first planned applications for the Human Systems Simulator Laboratory is implementation of a dynamic nuclear power plant simulation (NPP) where studies of operator workload, situation awareness, performance and preference will be carried out in simulated control rooms including nuclear power plant control rooms. Simulation offers a means by which to reviewmore » operational concepts, improve design practices and provide a technical basis for licensing decisions. In preparation for the next generation power plant and current government and industry efforts in support of light water reactor sustainability, human operators will be attached to a suite of physiological measurement instruments and, in combination with traditional Human Factors Measurement techniques, carry out control room tasks in simulated advanced digital and hybrid analog/digital control rooms. The current focus of the Human Systems Simulator Laboratory is building core competence in quantitative and qualitative measurements of situation awareness and workload. Of particular interest is whether introduction of digital systems including automated procedures has the potential to reduce workload and enhance safety while improving situation awareness or whether workload is merely shifted and situation awareness is modified in yet to be determined ways. Data analysis is carried out by engineers and scientists and includes measures of the physical and neurological correlates of human performance. The current approach supports a user-centered design philosophy (see ISO 13407 “Human Centered Design Process for Interactive Systems, 1999) wherein the context for task performance along with the requirements of the end-user are taken into account during the design process and the validity of design is determined through testing of real end users« less

Ergonomic Work Station Design to Improve Workload Quality and Productivity of the Craffsmen

NASA Astrophysics Data System (ADS)

Widana, IK; Wayan Sumetri, Ni; Ketut Sutapa, I.

2018-01-01

This study is a research on ergonomics field, especially for ergonomics work station. This research begins with direct observation on the work process of carving craft. In addition to the aspect of occupational health, the stages of the process are also subject matter in the effort to solve the research problem. In accordance with the master plan of research of Bali State Polytechnic, problem solving will be focused on human aspect and utilization of appropriate technology, so that will get the work process ENASEP (effective, convenient, safe, healthy, efficient and productive) Technical easy to work, economical, ergonomic, energy saving, environmentally friendly and in accordance with the trend of the era. The method to be used in this research is experimental with the same subject design. Involves 9 samples who perform activities on conditions before and after treatment. Data on environmental conditions were analyzed by Mann-Whitney test. Data on work productivity and workload were tested with two pair sample t-test at a significance level of 5%. The results showed that by utilizing ergonomic work stations, occupational health indicators such as workload showed better signs, indicated by decreased the workload. In addition to occupational health, productivity indicators also increased significantly.

Workshop on Workload and Training, and Examination of their Interactions: Executive summary

NASA Technical Reports Server (NTRS)

Donchin, Emanuel; Hart, Sandra G.; Hartzell, Earl J.

1987-01-01

The goal of the workshop was to bring together experts in the fields of workload and training and representatives from the Dept. of Defense and industrial organizations who are reponsible for specifying, building, and managing advanced, complex systems. The challenging environments and requirements imposed by military helicopter missions and space station operations were presented as the focus for the panel discussions. The workshop permitted a detailed examination of the theoretical foundations of the fields of training and workload, as well as their practical applications. Furthermore, it created a forum where government, industry, and academic experts were able to examine each other's concepts, values, and goals. The discussions pointed out the necessity for a more efficient and effective flow of information among the groups respresented. The executive summary describes the rationale of the meeting, summarizes the primary points of discussion, and lists the participants and some of their summary comments.

Single Pilot Workload Management During Cruise in Entry Level Jets

NASA Technical Reports Server (NTRS)

Burian, Barbara K.; Pruchnicki, Shawn; Christopher, Bonny; Silverman, Evan; Hackworth, Carla; Rogers, Jason; Williams, Kevin; Drechsler, Gena; Runnels, Barry; Mead, Andy

2013-01-01

Advanced technologies and automation are important facilitators of single pilot operations, but they also contribute to the workload management challenges faced by the pilot. We examined task completion, workload management, and automation use in an entry level jet (ELJ) flown by single pilots. Thirteen certificated Cessna Citation Mustang (C510-S) pilots flew an instrument flight rules (IFR) experimental flight in a Cessna Citation Mustang simulator. At one point participants had to descend to meet a crossing restriction prior to a waypoint and prepare for an instrument approach into an un-towered field while facilitating communication from a lost pilot who was flying too low for ATC to hear. Four participants experienced some sort of difficulty with regard to meeting the crossing restriction and almost half (n=6) had problems associated with the instrument approach. Additional errors were also observed including eight participants landing at the airport with an incorrect altimeter setting.

Comparison of Procedures for Dual and Triple Closely Spaced Parallel Runways

NASA Technical Reports Server (NTRS)

Verma, Savita; Ballinger, Deborah; Subramanian Shobana; Kozon, Thomas

2012-01-01

A human-in-the-loop high fidelity flight simulation experiment was conducted, which investigated and compared breakout procedures for Very Closely Spaced Parallel Approaches (VCSPA) with two and three runways. To understand the feasibility, usability and human factors of two and three runway VCSPA, data were collected and analyzed on the dependent variables of breakout cross track error and pilot workload. Independent variables included number of runways, cause of breakout and location of breakout. Results indicated larger cross track error and higher workload using three runways as compared to 2-runway operations. Significant interaction effects involving breakout cause and breakout location were also observed. Across all conditions, cross track error values showed high levels of breakout trajectory accuracy and pilot workload remained manageable. Results suggest possible avenues of future adaptation for adopting these procedures (e.g., pilot training), while also showing potential promise of the concept.

The impact of heat stress on operative performance and cognitive function during simulated laparoscopic operative tasks.

PubMed

Berg, Regan J; Inaba, Kenji; Sullivan, Maura; Okoye, Obi; Siboni, Stefano; Minneti, Michael; Teixeira, Pedro G; Demetriades, Demetrios

2015-01-01

Increasing ambient temperature to prevent intraoperative patient hypothermia remains widely advocated despite unconvincing evidence of efficacy. Heat stress is associated with decreased cognitive and psychomotor performance across multiple tasks but remains unexamined in an operative context. We assessed the impact of increased ambient temperature on laparoscopic operative performance and surgeon cognitive stress. Forty-two performance measures were obtained from 21 surgery trainees participating in the counter-balanced, within-subjects study protocol. Operative performance was evaluated with adaptations of the validated, peg-transfer, and intracorporeal knot-tying tasks from the Fundamentals of Laparoscopic Surgery program. Participants trained to proficiency before enrollment. Task performance was measured at two ambient temperatures, 19 and 26°C (66 and 79°F). Participants were randomly counterbalanced to initial hot or cold exposure before crossing over to the alternate environment. Cognitive stress was measured using the validated Surgical Task Load Index (SURG-TLX). No differences in performance of the peg-transfer and intracorporeal knot-tying tasks were seen across ambient conditions. Assessed via use of the six bipolar scales of the SURG-TLX, we found differences in task workload between the hot and cold conditions in the areas of physical demands (hot 10 [3-12], cold 5 [2.5-9], P = .013) and distractions (hot 8 [3.5-15.5], cold 3 [1.5-5.5], P = .001). Participant perception of distraction remained greater in the hot condition on full scoring of the SURG-TLX. Increasing ambient temperature to levels advocated for prevention of intraoperative hypothermia does not greatly decrease technical performance in short operative tasks. Surgeons, however, do report increased perceptions of distraction and physical demand. The impact of these findings on performance and outcomes during longer operative procedures remains unclear. Copyright © 2015 Elsevier Inc. All rights reserved.

Performance Evaluation of a Firm Real-Time DataBase System

DTIC Science & Technology

1995-01-01

after its deadline has passed. StarBase differs from previous real-time database work in that a) it relies on a real - time operating system which...StarBase, running on a real - time operating system kernel, RT-Mach. We discuss how performance was evaluated in StarBase using the StarBase workload

Individual Differences in Response to Automation: The Five Factor Model of Personality

ERIC Educational Resources Information Center

Szalma, James L.; Taylor, Grant S.

2011-01-01

This study examined the relationship of operator personality (Five Factor Model) and characteristics of the task and of adaptive automation (reliability and adaptiveness--whether the automation was well-matched to changes in task demand) to operator performance, workload, stress, and coping. This represents the first investigation of how the Five…

Unmanned Aircraft System (UAS) Delegation of Separation in NextGen Airspace

NASA Technical Reports Server (NTRS)

Kenny, Caitlin A.; Shively, Robert J.; Jordan, Kevin

2014-01-01

The purpose of this study was to determine the feasibility of unmanned aircraft systems (UAS) performing delegated separation in the national airspace system (NAS). Delegated separation is the transfer of responsibility for maintaining separation between aircraft or vehicles from air navigation service providers to the relevant pilot or flight operator. The effects of delegated separation and traffic display information level were collected through performance, workload, and situation awareness measures. The results of this study show benefits related to the use of conflict detection alerts being shown on the UAS operator's cockpit situation display (CSD), and to the use of full delegation. Overall, changing the level of separation responsibility and adding conflict detection alerts on the CSD was not found to have an adverse effect on performance as shown by the low amounts of losses of separation. The use of conflict detection alerts on the CSD and full delegation responsibilities given to the UAS operator were found to create significantly reduced workload, significantly increased situation awareness and significantly easier communications between the UAS operator and air traffic controller without significantly increasing the amount of losses of separation.

Automation trust and attention allocation in multitasking workspace.

PubMed

Karpinsky, Nicole D; Chancey, Eric T; Palmer, Dakota B; Yamani, Yusuke

2018-07-01

Previous research suggests that operators with high workload can distrust and then poorly monitor automation, which has been generally inferred from automation dependence behaviors. To test automation monitoring more directly, the current study measured operators' visual attention allocation, workload, and trust toward imperfect automation in a dynamic multitasking environment. Participants concurrently performed a manual tracking task with two levels of difficulty and a system monitoring task assisted by an unreliable signaling system. Eye movement data indicate that operators allocate less visual attention to monitor automation when the tracking task is more difficult. Participants reported reduced levels of trust toward the signaling system when the tracking task demanded more focused visual attention. Analyses revealed that trust mediated the relationship between the load of the tracking task and attention allocation in Experiment 1, an effect that was not replicated in Experiment 2. Results imply a complex process underlying task load, visual attention allocation, and automation trust during multitasking. Automation designers should consider operators' task load in multitasking workspaces to avoid reduced automation monitoring and distrust toward imperfect signaling systems. Copyright © 2018. Published by Elsevier Ltd.

Suggestion of Design Evaluation Plan based on Star Life Cycle to introduce the Information Minimalism Concept of KOREA Nuclear Plant

NASA Astrophysics Data System (ADS)

Jang, Gwi-sook; Lee, Seung-min; Park, Gee-yong

2018-01-01

The design of Korea Nuclear Power Plant (NPP) main control rooms (MCR) has been changed to be fully digitalized. Five or six display devices are assigned to each operator in NPP MCR to provide the information of safety parameter and plant status, and various control functions by connecting computerized control devices. Under this circumstance, the distributed displays can induce a dispersion of the operators' attention and increase the workload while conducting monitoring and control tasks efficiently. In addition, to support human operators to reduce their workload and increase the performance, the concepts of the ecological interface design (EID) and the operator-centered design were applied to the design HMI display. However these designs are applied to a limited set of screens and did not differ largely from the traditional HMI design in that the layout of the information is somewhere similar to P&IDs. In this paper, we propose a design evaluation plan based on star life cycle to introduce the information minimalism concept for designing an HMI display.

Unmanned aircraft system (UAS) delegation of separation in NextGen airspace

NASA Astrophysics Data System (ADS)

Kenny, Caitlin A.

The purpose of this thesis was to determine the feasibility of unmanned aircraft systems (UAS) performing delegated separation in the national airspace system (NAS). Delegated separation is the transfer of responsibility for maintaining separation between aircraft or vehicles from air navigation service providers to the relevant pilot or flight operator. The effects of delegated separation and traffic display information level were collected through performance, workload, and situation awareness measures. The results of this study showed benefits related to the use of conflict detection alerts being shown on the UAS operator's cockpit situation display (CSD) and to the use of full delegation. Overall, changing the level of separation responsibility and adding conflict detection alerts on the CSD were not found to have an adverse effect on performance as shown by the low amounts of losses of separation. The use of conflict detection alerts on the CSD and full delegation responsibilities given to the UAS operator were found to create significantly reduced workload, significantly increased situation awareness and significantly easier communications between the UAS operator and air traffic controller without significantly increasing the amount of losses of separation.

Position verification systems for an automated highway system.

DOT National Transportation Integrated Search

2015-03-01

Automated vehicles promote road safety, fuel efficiency, and reduced travel time by decreasing traffic : congestion and driver workload. In a vehicle platoon (grouping vehicles to increase road capacity by : managing distance between vehicles using e...

Integrated Design of a Telerobotic Workstation

NASA Technical Reports Server (NTRS)

Rochlis, Jennifer L.; Clarke, John-Paul

2001-01-01

The experiments described in this paper are part of a larger joint MIT/NASA research effort that focuses on the development of a methodology for designing and evaluating integrated interfaces for highly dexterous and multi-functional telerobots. Specifically, a telerobotic workstation is being designed for an Extravehicular Activity (EVA) anthropomorphic space station telerobot. Previous researchers have designed telerobotic workstations based upon performance of discrete subsets of tasks (for example, peg-in-hole, tracking, etc.) without regard for transitions that operators go through between tasks performed sequentially in the context of larger integrated tasks. The exploratory research experiments presented here took an integrated approach and assessed how subjects operating a full-immersion telerobot perform during the transitions between sub-tasks of two common EVA tasks. Preliminary results show that up to 30% of total task time is spent gaining and maintaining Situation Awareness (SA) of their task space and environment during transitions. Although task performance improves over the two trial days, the percentage of time spent on SA remains the same. This method identifies areas where workstation displays and feedback mechanisms are most needed to increase operator performance and decrease operator workload - areas that previous research methods have not been able to address.

Extending Validated Human Performance Models to Explore NextGen Concepts

NASA Technical Reports Server (NTRS)

Gore, Brian Francis; Hooey, Becky Lee; Mahlstedt, Eric; Foyle, David C.

2012-01-01

To meet the expected increases in air traffic demands, NASA and FAA are researching and developing Next Generation Air Transportation System (NextGen) concepts. NextGen will require substantial increases in the data available to pilots on the flight deck (e.g., weather,wake, traffic trajectory predictions, etc.) to support more precise and closely coordinated operations (e.g., self-separation, RNAV/RNP, and closely spaced parallel operations, CSPOs). These NextGen procedures and operations, along with the pilot's roles and responsibilities, must be designed with consideration of the pilot's capabilities and limitations. Failure to do so will leave the pilots, and thus the entire aviation system, vulnerable to error. A validated Man-machine Integration and design Analysis System (MIDAS) v5 model was extended to evaluate anticipated changes to flight deck and controller roles and responsibilities in NextGen approach and Land operations. Compared to conditions when the controllers are responsible for separation on decent to land phase of flight, the output from these model predictions suggest that the flight deck response time to detect the lead aircraft blunder will decrease, pilot scans to the navigation display will increase, and workload will increase.

Physical workload, leisure-time physical activity, obesity and smoking as predictors of multisite musculoskeletal pain. A 2-year prospective study of kitchen workers.

PubMed

Haukka, Eija; Ojajärvi, Anneli; Takala, Esa-Pekka; Viikari-Juntura, Eira; Leino-Arjas, Päivi

2012-07-01

The aim of this prospective study was to examine the role of physical workload, leisure-time physical activity, obesity and smoking in predicting the occurrence and course of multisite musculoskeletal pain (MSP). Data on physical and psychosocial workload, lifestyle factors and MSP were based on questionnaire surveys of 385 Finnish female kitchen workers. MSP (defined as pain at three or more of seven sites) during the past 3 months was measured repeatedly at 3-month intervals over 2 years. Four different patterns (trajectories) in the course of MSP were identified. The authors analysed whether the determinants at baseline predicted the occurrence of MSP (1) at the 2-year follow-up and (2) over the total of nine measurements during the 2 years by exploiting the MSP trajectories. Logistic regression was used. High physical workload at baseline was an independent predictor of MSP at the 2-year follow-up (OR 3.8, 95% CI 1.7 to 8.5) in a model allowing for age, psychosocial factors at work and lifestyle. High physical workload (OR 2.0, 95% CI 1.0 to 4.0) and moderate (OR 2.4, 95% CI 1.2 to 4.9) or low (OR 2.3, 95% CI 1.1 to 4.7) physical activity predicted persistent MSP. Obesity (OR 2.8, 95% CI 1.0 to 7.8) predicted an increased, and not being obese (OR 3.7, 95% CI 1.1 to 12.7) a decreased, prevalence of MSP in models similarly including all covariates. Smoking had no effect. The results emphasise the importance of high physical workload, low to moderate physical activity and obesity as potential modifiable risk factors for the occurrence and course of MSP over time.

The Relationship between Social Capital in Hospitals and Physician Job Satisfaction

PubMed Central

Ommen, Oliver; Driller, Elke; Köhler, Thorsten; Kowalski, Christoph; Ernstmann, Nicole; Neumann, Melanie; Steffen, Petra; Pfaff, Holger

2009-01-01

Background Job satisfaction in the hospital is an important predictor for many significant management ratios. Acceptance in professional life or high workload are known as important predictors for job satisfaction. The influence of social capital in hospitals on job satisfaction within the health care system, however, remains to be determined. Thus, this article aimed at analysing the relationship between overall job satisfaction of physicians and social capital in hospitals. Methods The results of this study are based upon questionnaires sent by mail to 454 physicians working in the field of patient care in 4 different German hospitals in 2002. 277 clinicians responded to the poll, for a response rate of 61%. Analysis was performed using three linear regression models with physician overall job satisfaction as the dependent variable and age, gender, professional experience, workload, and social capital as independent variables. Results The first regression model explained nearly 9% of the variance of job satisfaction. Whereas job satisfaction increased slightly with age, gender and professional experience were not identified as significant factors to explain the variance. Setting up a second model with the addition of subjectively-perceived workload to the analysis, the explained variance increased to 18% and job satisfaction decreased significantly with increasing workload. The third model including social capital in hospital explained 36% of the variance with social capital, professional experience and workload as significant factors. Conclusion This analysis demonstrated that the social capital of an organisation, in addition to professional experience and workload, represents a significant predictor of overall job satisfaction of physicians working in the field of patient care. Trust, mutual understanding, shared aims, and ethical values are qualities of social capital that unify members of social networks and communities and enable them to act cooperatively. PMID:19445692

Mental Workload and Performance Experiment (MWPE) Team in the Spacelab Payload Operations Control

NASA Technical Reports Server (NTRS)

1992-01-01

The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured is the Mental Workload and Performance Experiment (MWPE) team in the SL POCC) during STS-42, IML-1 mission.

Mental Workload and Performance Experiment (MWPE) Team in the Spacelab Payload Operations Control

NASA Technical Reports Server (NTRS)

1992-01-01

The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured activities are of the Mental Workload and Performance Experiment (MWPE) team in the SL POCC during the IML-1 mission.

Spot and Runway Departure Advisor

NASA Technical Reports Server (NTRS)

Jung, Yoon Chul

2013-01-01

The Spot and Runway Departure Advisor (SARDA) is a research prototype of a decision support tool for ATC tower controllers to assist in manging and controlling traffic on the surface of an airport. SARDA employs a scheduler to generate an optimal runway schedule and gate push-back - spot release sequence and schedule that improves efficiency of surface operations. The advisories for ATC tower controllers are displayed on an Electronic Flight Strip (EFS) system. The human-in-the-loop simulation of the SARDA tool was conducted for east operations of Dallas-Ft. Worth International Airport (DFW) to evaluate performance of the SARDA tool and human factors, such as situational awareness and workload. The results indicates noticeable taxi delay reduction and fuel savings by using the SARDA tool. Reduction in controller workload were also observed throughout the scenario runs. The future plan includes modeling and simulation of the ramp operations of the Charlotte International Airport, and develop a decision support tool for the ramp controllers.

Platform-Independence and Scheduling In a Multi-Threaded Real-Time Simulation

NASA Technical Reports Server (NTRS)

Sugden, Paul P.; Rau, Melissa A.; Kenney, P. Sean

2001-01-01

Aviation research often relies on real-time, pilot-in-the-loop flight simulation as a means to develop new flight software, flight hardware, or pilot procedures. Often these simulations become so complex that a single processor is incapable of performing the necessary computations within a fixed time-step. Threads are an elegant means to distribute the computational work-load when running on a symmetric multi-processor machine. However, programming with threads often requires operating system specific calls that reduce code portability and maintainability. While a multi-threaded simulation allows a significant increase in the simulation complexity, it also increases the workload of a simulation operator by requiring that the operator determine which models run on which thread. To address these concerns an object-oriented design was implemented in the NASA Langley Standard Real-Time Simulation in C++ (LaSRS++) application framework. The design provides a portable and maintainable means to use threads and also provides a mechanism to automatically load balance the simulation models.

Dynamic Voltage-Frequency and Workload Joint Scaling Power Management for Energy Harvesting Multi-Core WSN Node SoC

PubMed Central

Li, Xiangyu; Xie, Nijie; Tian, Xinyue

2017-01-01

This paper proposes a scheduling and power management solution for energy harvesting heterogeneous multi-core WSN node SoC such that the system continues to operate perennially and uses the harvested energy efficiently. The solution consists of a heterogeneous multi-core system oriented task scheduling algorithm and a low-complexity dynamic workload scaling and configuration optimization algorithm suitable for light-weight platforms. Moreover, considering the power consumption of most WSN applications have the characteristic of data dependent behavior, we introduce branches handling mechanism into the solution as well. The experimental result shows that the proposed algorithm can operate in real-time on a lightweight embedded processor (MSP430), and that it can make a system do more valuable works and make more than 99.9% use of the power budget. PMID:28208730

Control strategies for a telerobot

NASA Technical Reports Server (NTRS)

Ohara, John; Stasi, Bill

1989-01-01

One of the major issues impacting the utility of telerobotic systems for space is the development of effective control strategies. For near-term applications, telerobot control is likely to utilize teleoperation methodologies with integrated supervisory control capabilities to assist the operator. Two different approaches to telerobotic control are evaluated: bilateral force reflecting master controllers and proportional rate six degrees-of-freedom hand controllers. The controllers' performance of single manipulator arm tasks is compared. Simultaneous operation of both manipulator arms and complex multiaxis slave arm movements is investigated. Task times are significantly longer and fewer errors are committed with the hand controllers. The hand controllers are also rated significantly higher in cognitive and manual control workload on the two-arm task. The master controllers are rated significantly higher in physical workload. The implications of these findings for space teleoperations and higher levels of control are discussed.

Dynamic Voltage-Frequency and Workload Joint Scaling Power Management for Energy Harvesting Multi-Core WSN Node SoC.

PubMed

Li, Xiangyu; Xie, Nijie; Tian, Xinyue

2017-02-08

This paper proposes a scheduling and power management solution for energy harvesting heterogeneous multi-core WSN node SoC such that the system continues to operate perennially and uses the harvested energy efficiently. The solution consists of a heterogeneous multi-core system oriented task scheduling algorithm and a low-complexity dynamic workload scaling and configuration optimization algorithm suitable for light-weight platforms. Moreover, considering the power consumption of most WSN applications have the characteristic of data dependent behavior, we introduce branches handling mechanism into the solution as well. The experimental result shows that the proposed algorithm can operate in real-time on a lightweight embedded processor (MSP430), and that it can make a system do more valuable works and make more than 99.9% use of the power budget.

Eleven quick tips for architecting biomedical informatics workflows with cloud computing.

PubMed

Cole, Brian S; Moore, Jason H

2018-03-01

Cloud computing has revolutionized the development and operations of hardware and software across diverse technological arenas, yet academic biomedical research has lagged behind despite the numerous and weighty advantages that cloud computing offers. Biomedical researchers who embrace cloud computing can reap rewards in cost reduction, decreased development and maintenance workload, increased reproducibility, ease of sharing data and software, enhanced security, horizontal and vertical scalability, high availability, a thriving technology partner ecosystem, and much more. Despite these advantages that cloud-based workflows offer, the majority of scientific software developed in academia does not utilize cloud computing and must be migrated to the cloud by the user. In this article, we present 11 quick tips for architecting biomedical informatics workflows on compute clouds, distilling knowledge gained from experience developing, operating, maintaining, and distributing software and virtualized appliances on the world's largest cloud. Researchers who follow these tips stand to benefit immediately by migrating their workflows to cloud computing and embracing the paradigm of abstraction.

Eleven quick tips for architecting biomedical informatics workflows with cloud computing

PubMed Central

Moore, Jason H.

2018-01-01

Cloud computing has revolutionized the development and operations of hardware and software across diverse technological arenas, yet academic biomedical research has lagged behind despite the numerous and weighty advantages that cloud computing offers. Biomedical researchers who embrace cloud computing can reap rewards in cost reduction, decreased development and maintenance workload, increased reproducibility, ease of sharing data and software, enhanced security, horizontal and vertical scalability, high availability, a thriving technology partner ecosystem, and much more. Despite these advantages that cloud-based workflows offer, the majority of scientific software developed in academia does not utilize cloud computing and must be migrated to the cloud by the user. In this article, we present 11 quick tips for architecting biomedical informatics workflows on compute clouds, distilling knowledge gained from experience developing, operating, maintaining, and distributing software and virtualized appliances on the world’s largest cloud. Researchers who follow these tips stand to benefit immediately by migrating their workflows to cloud computing and embracing the paradigm of abstraction. PMID:29596416

The vacuum platform

NASA Astrophysics Data System (ADS)

McNab, A.

2017-10-01

This paper describes GridPP’s Vacuum Platform for managing virtual machines (VMs), which has been used to run production workloads for WLCG and other HEP experiments. The platform provides a uniform interface between VMs and the sites they run at, whether the site is organised as an Infrastructure-as-a-Service cloud system such as OpenStack, or an Infrastructure-as-a-Client system such as Vac. The paper describes our experience in using this platform, in developing and operating VM lifecycle managers Vac and Vcycle, and in interacting with VMs provided by LHCb, ATLAS, ALICE, CMS, and the GridPP DIRAC service to run production workloads.

Air National Guard Fighters the Total Force (Maxwell Paper, Number 1)

DTIC Science & Technology

1996-05-01

child abuse cases, 9 percent rise in spousal abuse reports, and an 11 percent rise in alcohol abuse. While these figures represent only one fighter wing, they highlight some of the potential problems that may be encountered by other active duty units as they too struggle under an ever increasing workload. These problems and a growing belief that long-term readiness may soon suffer if the workload is not reduced, convinced Defense Secretary William Perry to direct a greater role for the Air National Guard in peacetime contingency operations. The Air National Guard is no

Effects of Pressure Support Ventilation May Be Lost at High Exercise Intensities in People with COPD.

PubMed

Anekwe, David; de Marchie, Michel; Spahija, Jadranka

2017-06-01

Pressure support ventilation (PSV) may be used for exercise training in chronic obstructive pulmonary disease (COPD), but its acute effect on maximum exercise capacity is not fully known. The objective of this study was to evaluate the effect of 10 cm H 2 O PSV and a fixed PSV level titrated to patient comfort at rest on maximum exercise workload (WLmax), breathing pattern and metabolic parameters during a symptom-limited incremental bicycle test in individuals with COPD. Eleven individuals with COPD (forced expiratory volume in one second: 49 ± 16%; age: 64 ± 7 years) performed three exercise tests: without a ventilator, with 10 cm H 2 O of PSV and with a fixed level titrated to comfort at rest, using a SERVO-i ventilator. Tests were performed in randomized order and at least 48 hours apart. The WLmax, breathing pattern, metabolic parameters, and mouth pressure (Pmo) were compared using repeated measures analysis of variance. Mean PSV during titration was 8.2 ± 4.5 cm H 2 O. There was no difference in the WLmax achieved during the three tests. At rest, PSV increased the tidal volume, minute ventilation, and mean inspiratory flow with a lower end-tidal CO 2 ; this was not sustained at peak exercise. Pmo decreased progressively (decreased unloading) with PSV at workloads close to peak, suggesting the ventilator was unable to keep up with the increased ventilatory demand at high workloads. In conclusion, with a Servo-i ventilator, 10 cm H 2 O of PSV and a fixed level of PSV established by titration to comfort at rest, is ineffective for the purpose of achieving higher exercise workloads as the acute physiological effects may not be sustained at peak exercise.

Workload, mental health and burnout indicators among female physicians.

PubMed

Győrffy, Zsuzsa; Dweik, Diana; Girasek, Edmond

2016-04-01

Female doctors in Hungary have worse indicators of physical and mental health compared with other professional women. We aimed to cast light on possible indicators of mental health, workload, and burnout of female physicians. Two time-points (T) were compared, in 2003 (T1 n = 408) and 2013 (T2 n = 2414), based on two nationally representative surveys of female doctors, and comparison made with data from other professional control groups. Independent samples t test or chi-squared test was used both for the two time-point comparison and the comparison between the index and the control groups. The background factors of sleep disorders and burnout were assessed by binary logistic regression analysis. No significant differences in the rates of depressive symptoms and suicidal thoughts and attempts were detected between the 2003 and 2013 cohorts, but the prevalence of sleep disorders increased. The workload increased, and there was less job satisfaction in 2013 than in 2003, coupled to more stressful or difficult work-related situations. The personal accomplishment component of burnout significantly decreased in line with the declining work-related satisfaction. Compared to the professional control groups, the prevalence of depressive symptoms, suicide attempts, and sleep disorders was higher among female physicians at both time-points. The number of workplaces, frequency of work-related stressful situations, and intensive role conflict was associated with sleep disorders and decreased personal accomplishment. In comparison with the other professional groups, female doctors had worse mental health indicators with regard to depression, suicidal ideas, and sleep disorders both in 2003 and 2013 while within professional strata the changes seemed to be less. Increasing workload had a clear impact on sleep disorders and the personal accomplishment dimension of burnout.

Neuro-muscular fatigue and recovery dynamics following anaerobic interval workload.

PubMed

Skof, B; Strojnik, V

2006-03-01

The aim of this study was to determine the influence of anaerobic running on muscle contractile characteristics and voluntary muscle activation level during MVC as well as the dynamics of their recovery during a 2-hour period. Seven well-trained runners performed 5 x 300 m at submaximal velocity with a 1-minute active recovery interval between the runs. The average run velocity was 6.69 m.s(-1), which represented 77 % of their top velocity. Contractile characteristics of the vastus lateralis and activation level of quadriceps femoris muscles were measured before and immediately after the runs and within the 120-minute time interval that followed the workload. To do this we used: single twitch, low- and high-frequency electrical stimulation, maximal voluntary knee extension test, and muscle activation level test. After the exercise the maximal twitch torque (T(TW)) decreased for 28 +/- 3.7 % (p < 0.001) and torque at stimulation with 20 Hz and 100 Hz were 19.2 +/- 4.6 % (p < 0.01) and 7.5 +/- 2.3 % (p < 0.05) lower, respectively, while MVC torque and activation level remained unchanged. Subjects with higher blood lactate accumulation level showed significant decrease in the torque at low frequency stimulation (T(F20)) (r = - 0.80; p < 0.01) and T(TW) (r = - 0.92; p < 0.01). The restoration of twitch torque took a short time despite the fact that blood lactate concentration remained high. Ten minutes after the last interval run the twitch torque exceeded the pre-workload value by 11 % (p < 0.01). Potentiation lasted until the 40th min. It was concluded that fatigue after the anaerobic interval workload was peripheral in character and caused by contractile mechanisms disturbances.

Does daily nurse staffing match ward workload variability? Three hospitals' experiences.

PubMed

Gabbay, Uri; Bukchin, Michael

2009-01-01

Nurse shortage and rising healthcare resource burdens mean that appropriate workforce use is imperative. This paper aims to evaluate whether daily nursing staffing meets ward workload needs. Nurse attendance and daily nurses' workload capacity in three hospitals were evaluated. Statistical process control was used to evaluate intra-ward nurse workload capacity and day-to-day variations. Statistical process control is a statistics-based method for process monitoring that uses charts with predefined target measure and control limits. Standardization was performed for inter-ward analysis by converting ward-specific crude measures to ward-specific relative measures by dividing observed/expected. Two charts: acceptable and tolerable daily nurse workload intensity, were defined. Appropriate staffing indicators were defined as those exceeding predefined rates within acceptable and tolerable limits (50 percent and 80 percent respectively). A total of 42 percent of the overall days fell within acceptable control limits and 71 percent within tolerable control limits. Appropriate staffing indicators were met in only 33 percent of wards regarding acceptable nurse workload intensity and in only 45 percent of wards regarding tolerable workloads. The study work did not differentiate crude nurse attendance and it did not take into account patient severity since crude bed occupancy was used. Double statistical process control charts and certain staffing indicators were used, which is open to debate. Wards that met appropriate staffing indicators prove the method's feasibility. Wards that did not meet appropriate staffing indicators prove the importance and the need for process evaluations and monitoring. Methods presented for monitoring daily staffing appropriateness are simple to implement either for intra-ward day-to-day variation by using nurse workload capacity statistical process control charts or for inter-ward evaluation using standardized measure of nurse workload intensity. The real challenge will be to develop planning systems and implement corrective interventions such as dynamic and flexible daily staffing, which will face difficulties and barriers. The paper fulfils the need for workforce utilization evaluation. A simple method using available data for daily staffing appropriateness evaluation, which is easy to implement and operate, is presented. The statistical process control method enables intra-ward evaluation, while standardization by converting crude into relative measures enables inter-ward analysis. The staffing indicator definitions enable performance evaluation. This original study uses statistical process control to develop simple standardization methods and applies straightforward statistical tools. This method is not limited to crude measures, rather it uses weighted workload measures such as nursing acuity or weighted nurse level (i.e. grade/band).

The Effects of Aviation Weather Information Systems on General Aviation Weather Information Systems on General Pilots' Workload

NASA Technical Reports Server (NTRS)

Scerbo, Mark; Coyne, Joseph; Burt, Jennifer L. (Technical Monitor)

2002-01-01

My work at NASA Langley has focused around Aviation Weather Information CAWING displays. The majority of my time at LYRIC has been spent on the Workload and Relative Position (WaRP) Study. The goal of this project is to determine how an AWIN display at various positions within the cockpit affects pilot performance and workload. The project is being conducted in Languages Cessna 206H research aircraft. During the past year the design of the experiment was finalized and approved. Despite facing several delays the data collection was completed in early February. Alter the completion of the data collection an extensive data entry task began. This required recording air speed, altitude, course heading, bank angle, and vertical speed information from videos of the primary flight displays. This data was then used to determine root mean square error (RMSE) for each experimental condition. In addition to the performance data (RMSE) taken from flight path deviation, the study also collected data on pilot;s accuracy in reporting weather information, and a subjective rating of workload from the pilot. The data for this experiment is currently being analyzed. Overall the current experiment should help to determine potential costs and benefits associated with AWIN displays. The data will be used to determine if a private pilot can safely fly a general aviation aircraft while operating a weather display. Clearly a display that adds to the pilot#s already heavy workload represents a potential problem. The study will compare the use of an AWIN display to conventional means of acquiring weather data. The placement of the display within the cockpit (i.e., either on the yoke, kneeboard, or panel) will be also compared in terms of workload, performance, and pilot preference.

Measuring and managing radiologist workload: a method for quantifying radiologist activities and calculating the full-time equivalents required to operate a service.

PubMed

MacDonald, Sharyn L S; Cowan, Ian A; Floyd, Richard A; Graham, Rob

2013-10-01

Accurate and transparent measurement and monitoring of radiologist workload is highly desirable for management of daily workflow in a radiology department, and for informing decisions on department staffing needs. It offers the potential for benchmarking between departments and assessing future national workforce and training requirements. We describe a technique for quantifying, with minimum subjectivity, all the work carried out by radiologists in a tertiary department. Six broad categories of clinical activities contributing to radiologist workload were identified: reporting, procedures, trainee supervision, clinical conferences and teaching, informal case discussions, and administration related to referral forms. Time required for reporting was measured using data from the radiology information system. Other activities were measured by observation and timing by observers, and based on these results and extensive consultation, the time requirements and frequency of each activity was agreed on. An activity list was created to record this information and to calculate the total clinical hours required to meet the demand for radiologist services. Diagnostic reporting accounted for approximately 35% of radiologist clinical time; procedures, 23%; trainee supervision, 15%; conferences and tutorials, 14%; informal case discussions, 10%; and referral-related administration, 3%. The derived data have been proven reliable for workload planning over the past 3 years. A transparent and robust method of measuring radiologists' workload has been developed, with subjective assessments kept to a minimum. The technique has value for daily workload and longer term planning. It could be adapted for widespread use. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

Movable Cameras And Monitors For Viewing Telemanipulator

NASA Technical Reports Server (NTRS)

Diner, Daniel B.; Venema, Steven C.

1993-01-01

Three methods proposed to assist operator viewing telemanipulator on video monitor in control station when video image generated by movable video camera in remote workspace of telemanipulator. Monitors rotated or shifted and/or images in them transformed to adjust coordinate systems of scenes visible to operator according to motions of cameras and/or operator's preferences. Reduces operator's workload and probability of error by obviating need for mental transformations of coordinates during operation. Methods applied in outer space, undersea, in nuclear industry, in surgery, in entertainment, and in manufacturing.

Results from the Veterans Health Administration ICD-10-CM/PCS Coding Pilot Study.

PubMed

Weems, Shelley; Heller, Pamela; Fenton, Susan H

2015-01-01

The Veterans Health Administration (VHA) of the US Department of Veterans Affairs has been preparing for the October 1, 2015, conversion to the International Classification of Diseases, Tenth Revision, Clinical Modification and Procedural Coding System (ICD-10-CM/PCS) for more than four years. The VHA's Office of Informatics and Analytics ICD-10 Program Management Office established an ICD-10 Learning Lab to explore expected operational challenges. This study was conducted to determine the effects of the classification system conversion on coding productivity. ICD codes are integral to VHA business processes and are used for purposes such as clinical studies, performance measurement, workload capture, cost determination, Veterans Equitable Resource Allocation (VERA) determination, morbidity and mortality classification, indexing of hospital records by disease and operations, data storage and retrieval, research purposes, and reimbursement. The data collection for this study occurred in multiple VHA sites across several months using standardized methods. It is commonly accepted that coding productivity will decrease with the implementation of ICD-10-CM/PCS. The findings of this study suggest that the decrease will be more significant for inpatient coding productivity (64.5 percent productivity decrease) than for ambulatory care coding productivity (6.7 percent productivity decrease). This study reveals the following important points regarding ICD-10-CM/PCS coding productivity: 1. Ambulatory care ICD-10-CM coding productivity is not expected to decrease as significantly as inpatient ICD-10-CM/PCS coding productivity. 2. Coder training and type of record (inpatient versus outpatient) affect coding productivity. 3. Inpatient coding productivity is decreased when a procedure requiring ICD-10-PCS coding is present. It is highly recommended that organizations perform their own analyses to determine the effects of ICD-10-CM/PCS implementation on coding productivity.

Results from the Veterans Health Administration ICD-10-CM/PCS Coding Pilot Study

PubMed Central

Weems, Shelley; Heller, Pamela; Fenton, Susan H.

2015-01-01

The Veterans Health Administration (VHA) of the US Department of Veterans Affairs has been preparing for the October 1, 2015, conversion to the International Classification of Diseases, Tenth Revision, Clinical Modification and Procedural Coding System (ICD-10-CM/PCS) for more than four years. The VHA's Office of Informatics and Analytics ICD-10 Program Management Office established an ICD-10 Learning Lab to explore expected operational challenges. This study was conducted to determine the effects of the classification system conversion on coding productivity. ICD codes are integral to VHA business processes and are used for purposes such as clinical studies, performance measurement, workload capture, cost determination, Veterans Equitable Resource Allocation (VERA) determination, morbidity and mortality classification, indexing of hospital records by disease and operations, data storage and retrieval, research purposes, and reimbursement. The data collection for this study occurred in multiple VHA sites across several months using standardized methods. It is commonly accepted that coding productivity will decrease with the implementation of ICD-10-CM/PCS. The findings of this study suggest that the decrease will be more significant for inpatient coding productivity (64.5 percent productivity decrease) than for ambulatory care coding productivity (6.7 percent productivity decrease). This study reveals the following important points regarding ICD-10-CM/PCS coding productivity: Ambulatory care ICD-10-CM coding productivity is not expected to decrease as significantly as inpatient ICD-10-CM/PCS coding productivity.Coder training and type of record (inpatient versus outpatient) affect coding productivity.Inpatient coding productivity is decreased when a procedure requiring ICD-10-PCS coding is present. It is highly recommended that organizations perform their own analyses to determine the effects of ICD-10-CM/PCS implementation on coding productivity. PMID:26396553

Advanced Pathway Guidance Evaluations on a Synthetic Vision Head-Up Display

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Prinzel, Lawrence J., III; Arthur, Jarvis J., III; Bailey, Randall E.

2005-01-01

NASA's Synthetic Vision Systems (SVS) project is developing technologies with practical applications to potentially eliminate low visibility conditions as a causal factor to civil aircraft accidents while replicating the operational benefits of clear day flight operations, regardless of the actual outside visibility condition. A major thrust of the SVS project involves the development/demonstration of affordable, certifiable display configurations that provide intuitive out-the-window terrain and obstacle information with advanced guidance for commercial and business aircraft. This experiment evaluated the influence of different pathway and guidance display concepts upon pilot situation awareness (SA), mental workload, and flight path tracking performance for Synthetic Vision display concepts using a Head-Up Display (HUD). Two pathway formats (dynamic and minimal tunnel presentations) were evaluated against a baseline condition (no tunnel) during simulated instrument meteorological conditions approaches to Reno-Tahoe International airport. Two guidance cues (tadpole, follow-me aircraft) were also evaluated to assess their influence. Results indicated that the presence of a tunnel on an SVS HUD had no effect on flight path performance but that it did have significant effects on pilot SA and mental workload. The dynamic tunnel concept with the follow-me aircraft guidance symbol produced the lowest workload and provided the highest SA among the tunnel concepts evaluated.

Pathway Design Effects on Synthetic Vision Head-Up Displays

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Prinzel, Lawrence J., III; Arthur, Jarvis J., III; Bailey, Randall E.

2004-01-01

NASA s Synthetic Vision Systems (SVS) project is developing technologies with practical applications that will eliminate low visibility conditions as a causal factor to civil aircraft accidents while replicating the operational benefits of clear day flight operations, regardless of the actual outside visibility condition. A major thrust of the SVS project involves the development/demonstration of affordable, certifiable display configurations that provide intuitive out-the-window terrain and obstacle information with advanced pathway guidance for transport aircraft. This experiment evaluated the influence of different tunnel and guidance concepts upon pilot situation awareness (SA), mental workload, and flight path tracking performance for Synthetic Vision display concepts using a Head-Up Display (HUD). Two tunnel formats (dynamic, minimal) were evaluated against a baseline condition (no tunnel) during simulated IMC approaches to Reno-Tahoe International airport. Two guidance cues (tadpole, follow-me aircraft) were also evaluated to assess their influence on the tunnel formats. Results indicated that the presence of a tunnel on an SVS HUD had no effect on flight path performance but that it did have significant effects on pilot SA and mental workload. The dynamic tunnel concept with the follow-me aircraft guidance symbol produced the lowest workload and provided the highest SA among the tunnel concepts evaluated.

Health workforce planning and service expansion during an economic crisis: A case study of the national breast screening programme in Ireland.

PubMed

McHugh, S M; Tyrrell, E; Johnson, B; Healy, O; Perry, I J; Normand, C

2015-12-01

This article aims to estimate the workforce and resource implications of the proposed age extension of the national breast screening programme, under the economic constraints of reduced health budgets and staffing levels in the Irish health system. Using a mixed method design, a purposive sample of 20 participants were interviewed and data were analysed thematically (June-September 2012). Quantitative data (programme-level activity data, screening activity, staffing levels and screening plans) were used to model potential workload and resource requirements. The analysis indicates that over 90% operational efficiency was achieved throughout the first six months of 2012. Accounting for maternity leave (10%) and sick leave (3.5%), 16.1 additional radiographers (whole time equivalent) would be required for the workload created by the age extension of the screening programme, at 90% operational efficiency. The results suggest that service expansion is possible with relatively minimal additional radiography resources if the efficiency of the skill mix and the use of equipment are improved. Investing in the appropriate skill mix should not be limited to clinical groups but should also include administrative staff to manage and support the service. Workload modelling may contribute to improved health workforce planning and service efficiency. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Impacts of Intelligent Automated Quality Control on a Small Animal APD-Based Digital PET Scanner

NASA Astrophysics Data System (ADS)

Charest, Jonathan; Beaudoin, Jean-François; Bergeron, Mélanie; Cadorette, Jules; Arpin, Louis; Lecomte, Roger; Brunet, Charles-Antoine; Fontaine, Réjean

2016-10-01

Stable system performance is mandatory to warrant the accuracy and reliability of biological results relying on small animal positron emission tomography (PET) imaging studies. This simple requirement sets the ground for imposing routine quality control (QC) procedures to keep PET scanners at a reliable optimal performance level. However, such procedures can become burdensome to implement for scanner operators, especially taking into account the increasing number of data acquisition channels in newer generation PET scanners. In systems using pixel detectors to achieve enhanced spatial resolution and contrast-to-noise ratio (CNR), the QC workload rapidly increases to unmanageable levels due to the number of independent channels involved. An artificial intelligence based QC system, referred to as Scanner Intelligent Diagnosis for Optimal Performance (SIDOP), was proposed to help reducing the QC workload by performing automatic channel fault detection and diagnosis. SIDOP consists of four high-level modules that employ machine learning methods to perform their tasks: Parameter Extraction, Channel Fault Detection, Fault Prioritization, and Fault Diagnosis. Ultimately, SIDOP submits a prioritized faulty channel list to the operator and proposes actions to correct them. To validate that SIDOP can perform QC procedures adequately, it was deployed on a LabPET™ scanner and multiple performance metrics were extracted. After multiple corrections on sub-optimal scanner settings, a 8.5% (with a 95% confidence interval (CI) of [7.6, 9.3]) improvement in the CNR, a 17.0% (CI: [15.3, 18.7]) decrease of the uniformity percentage standard deviation, and a 6.8% gain in global sensitivity were observed. These results confirm that SIDOP can indeed be of assistance in performing QC procedures and restore performance to optimal figures.

39 CFR 3.6 - Information furnished to Board-financial and operating reports.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the following categories: (1) Mail volume by class; (2) Income and expense by principal categories; (3... workload and resource utilization); and (6) changes in postal costs. (b) These statements shall include...

Neural mechanisms underlying catastrophic failure in human-machine interaction during aerial navigation.

PubMed

Saproo, Sameer; Shih, Victor; Jangraw, David C; Sajda, Paul

2016-12-01

We investigated the neural correlates of workload buildup in a fine visuomotor task called the boundary avoidance task (BAT). The BAT has been known to induce naturally occurring failures of human-machine coupling in high performance aircraft that can potentially lead to a crash-these failures are termed pilot induced oscillations (PIOs). We recorded EEG and pupillometry data from human subjects engaged in a flight BAT simulated within a virtual 3D environment. We find that workload buildup in a BAT can be successfully decoded from oscillatory features in the electroencephalogram (EEG). Information in delta, theta, alpha, beta, and gamma spectral bands of the EEG all contribute to successful decoding, however gamma band activity with a lateralized somatosensory topography has the highest contribution, while theta band activity with a fronto-central topography has the most robust contribution in terms of real-world usability. We show that the output of the spectral decoder can be used to predict PIO susceptibility. We also find that workload buildup in the task induces pupil dilation, the magnitude of which is significantly correlated with the magnitude of the decoded EEG signals. These results suggest that PIOs may result from the dysregulation of cortical networks such as the locus coeruleus (LC)-anterior cingulate cortex (ACC) circuit. Our findings may generalize to similar control failures in other cases of tight man-machine coupling where gains and latencies in the control system must be inferred and compensated for by the human operators. A closed-loop intervention using neurophysiological decoding of workload buildup that targets the LC-ACC circuit may positively impact operator performance in such situations.

Neural mechanisms underlying catastrophic failure in human-machine interaction during aerial navigation

NASA Astrophysics Data System (ADS)

Saproo, Sameer; Shih, Victor; Jangraw, David C.; Sajda, Paul

2016-12-01

Objective. We investigated the neural correlates of workload buildup in a fine visuomotor task called the boundary avoidance task (BAT). The BAT has been known to induce naturally occurring failures of human-machine coupling in high performance aircraft that can potentially lead to a crash—these failures are termed pilot induced oscillations (PIOs). Approach. We recorded EEG and pupillometry data from human subjects engaged in a flight BAT simulated within a virtual 3D environment. Main results. We find that workload buildup in a BAT can be successfully decoded from oscillatory features in the electroencephalogram (EEG). Information in delta, theta, alpha, beta, and gamma spectral bands of the EEG all contribute to successful decoding, however gamma band activity with a lateralized somatosensory topography has the highest contribution, while theta band activity with a fronto-central topography has the most robust contribution in terms of real-world usability. We show that the output of the spectral decoder can be used to predict PIO susceptibility. We also find that workload buildup in the task induces pupil dilation, the magnitude of which is significantly correlated with the magnitude of the decoded EEG signals. These results suggest that PIOs may result from the dysregulation of cortical networks such as the locus coeruleus (LC)—anterior cingulate cortex (ACC) circuit. Significance. Our findings may generalize to similar control failures in other cases of tight man-machine coupling where gains and latencies in the control system must be inferred and compensated for by the human operators. A closed-loop intervention using neurophysiological decoding of workload buildup that targets the LC-ACC circuit may positively impact operator performance in such situations.

The Impact of Operating Room Distractions on Stress, Workload, and Teamwork.

PubMed

Wheelock, Ana; Suliman, Amna; Wharton, Rupert; Babu, E D; Hull, Louise; Vincent, Charles; Sevdalis, Nick; Arora, Sonal

2015-06-01

To investigate whether distractions in the operating room (OR) are associated with higher mental workload and stress, and poorer teamwork among OR personnel. Engaging in multiple tasks can affect performance. There is little research on the effect of distractions on surgical team members' behavior and cognitive processes. Ninety general surgery cases were observed in real time. Cases were assessed by a surgeon and a behavioral scientist using 4 validated tools: OR Distractions Assessment Form, the Observational Teamwork Assessment for Surgery tool, NASA-Task Load Index, and short form of the State Trait Anxiety Inventory. Analysis of variance was performed to evaluate significant differences between teamwork, workload, and stress level among team members. Correlations (Pearson r) were computed to evaluate associations between variables. The most prevalent distractions were those initiated by external staff, followed by case-irrelevant conversations. Case-irrelevant conversations were associated with poorer team performance. Irrelevant conversations initiated by surgeons were associated with lower teamwork in surgeons (across team skills: r = -0.44 to -0.58, P < 0.05 to 0.01) and anesthesiologists (r = -0.38 and r = -0.40, for coordination and leadership; P < 0.05). Equipment-related distractions correlated with higher stress (r = 0.48, P < 0.05) and lower teamwork (across team skills: r = -0.42 to -0.50, P < 0.05) in nurses. Acoustic distractions correlated with higher stress in surgeons (r = 0.32, P < 0.05) and higher workload in anesthesiologists (r = 0.30, P < 0.05). Although some distractions may be inevitable in the OR, they can also be detrimental to the team. A deeper understanding of the effect of distractions on teams and their outcomes can lead to targeted quality improvement.

Twenty-First Annual Conference on Manual Control

NASA Technical Reports Server (NTRS)

Miller, R. A. (Compiler); Jagacinski, R. J. (Compiler)

1986-01-01

The proceedings of the entitled conference are presented. Twenty-nine manuscripts and eight abstracts pertaining to workload, attention and errors, controller evaluation, movement skills, coordination and decision making, display evaluation and human operator modeling and manual control.

POPEYE: A production rule-based model of multitask supervisory control (POPCORN)

NASA Technical Reports Server (NTRS)

Townsend, James T.; Kadlec, Helena; Kantowitz, Barry H.

1988-01-01

Recent studies of relationships between subjective ratings of mental workload, performance, and human operator and task characteristics have indicated that these relationships are quite complex. In order to study the various relationships and place subjective mental workload within a theoretical framework, we developed a production system model for the performance component of the complex supervisory task called POPCORN. The production system model is represented by a hierarchial structure of goals and subgoals, and the information flow is controlled by a set of condition-action rules. The implementation of this production system, called POPEYE, generates computer simulated data under different task difficulty conditions which are comparable to those of human operators performing the task. This model is the performance aspect of an overall dynamic psychological model which we are developing to examine and quantify relationships between performance and psychological aspects in a complex environment.

Qualitative job stress and ego aptitude in male scientific researchers.

PubMed

Sakagami, Yu

2016-11-22

Job environments have been fundamentally changed by globalization and modern technological innovation. Qualitative workload is expected to increase more than quantitative workload through this rapid technological innovation. Especially, in developed countries, qualitative workload is expected to become a primary job-related stress factor in the near future. Therefore, it is essential to clarify the characteristics of qualitative workload and to determine how to cope with it effectively. Since job stress level and ego aptitude are correlated and qualitative overload increases stress, we examined qualitative overload and ego aptitude among male Japanese cutting-edge science researchers. The Brief Job Stress Questionnaire and the Tokyo University Ego-gram New Version II were distributed to all workers at two Japanese academic institutions. Qualitative overload and adult ego aptitude, representing rationalism, were higher in male researchers than in the Japanese male general sample. In addition, adapted child aptitude, representing obedience, was lower in male researchers. Lack of supervisor support was positively associated with qualitative overload, and nurturing parent ego aptitude was negatively associated with it. Male researchers had higher levels of qualitative overload. Increasing supervisor support is essential in decreasing this qualitative overload. Furthermore, enhancement of nurturing parent ego aptitude (i.e., careful consideration for others) is also important for qualitative overload management.

Assessing muscular oxygenation during incremental exercise using near-infrared spectroscopy: comparison of three different methods.

PubMed

Agbangla, N F; Audiffren, M; Albinet, C T

2017-12-20

Using continuous-wave near-infrared spectroscopy (NIRS), this study compared three different methods, namely the slope method (SM), the amplitude method (AM), and the area under the curve (AUC) method to determine the variations of intramuscular oxygenation level as a function of workload. Ten right-handed subjects (22+/-4 years) performed one isometric contraction at each of three different workloads (30 %, 50 % and 90 % of maximal voluntary strength) during a period of twenty seconds. Changes in oxyhemoglobin (delta[HbO(2)]) and deoxyhemoglobin (delta[HHb]) concentrations in the superficial flexor of fingers were recorded using continuous-wave NIRS. The results showed a strong consistency between the three methods, with standardized Cronbach alphas of 0.87 for delta[HHb] and 0.95 for delta[HbO(2)]. No significant differences between the three methods were observed concerning delta[HHb] as a function of workload. However, only the SM showed sufficient sensitivity to detect a significant decrease in delta[HbO(2)] between 30 % and 50 % of workload (p<0.01). Among these three methods, the SM appeared to be the only method that was well adapted and sensitive enough to determine slight changes in delta[HbO(2)]. Theoretical and methodological implications of these results are discussed.

Smartphone form factors: Effects of width and bottom bezel on touch performance, workload, and physical demand.

PubMed

Lee, Seul Chan; Cha, Min Chul; Hwangbo, Hwan; Mo, Sookhee; Ji, Yong Gu

2018-02-01

This study aimed at investigating the effect of two smartphone form factors (width and bottom bezel) on touch behaviors with one-handed interaction. User experiments on tapping tasks were conducted for four widths (67, 70, 72, and 74 mm) and five bottom bezel levels (2.5, 5, 7.5, 10, and 12.5 mm). Task performance, electromyography, and subjective workload data were collected to examine the touch behavior. The success rate and task completion time were collected as task performance measures. The NASA-TLX method was used to observe the subjective workload. The electromyogram signals of two thumb muscles, namely the first dorsal interosseous and abductor pollicis brevis, were observed. The task performances deteriorated with increasing width level. The subjective workload and electromyography data showed similar patterns with the task performances. The task performances of the bottom bezel devices were analyzed by using three different evaluation criteria. The results from these criteria indicated that tasks became increasingly difficult as the bottom bezel level decreased. The results of this study provide insights into the optimal range of smartphone form factors for one-handed interaction, which could contribute to the design of new smartphones. Copyright © 2017. Published by Elsevier Ltd.

Interval training based on ventilatory anaerobic threshold improves aerobic functional capacity and metabolic profile: a randomized controlled trial in coronary artery disease patients.

PubMed

Tamburús, Nayara Y; Kunz, Vandeni C; Salviati, Mariana R; Castello Simões, Viviane; Catai, Aparecida M; Da Silva, Ester

2016-02-01

Exercise training has been an essential component of cardiac rehabilitation. However, it is not known if interval training (IT) based on the ventilatory anaerobic threshold (VAT) could be effective in improving aerobic functional capacity and metabolic profile in patients without or with coronary artery disease (CAD). To investigate the effects of an IT program, based-intensity between 70-110% of workload reached at the VAT, on the aerobic functional capacity and metabolic profile of patients with and without CAD. Randomized controlled trial. Outpatients from a cardiac rehabilitation. A sample was composed of 32 patients with CAD (CAD group) and 32 patients without CAD (noCAD group) that were randomized into a trained or control groups. Submaximal cardiopulmonary exercise test on the cycle ergometer and blood samples were realized at baseline and post 16 weeks of IT program. The cardiorespiratory variables were obtained at the VAT level. Trained groups (CAD-T, N.=15; noCAD-T, N.=15) underwent a supervised three-week session IT program (30-40 minutes each exercise session, at the intensity workloads equivalent to %VAT [70-110%]) for 16 weeks. After 16 weeks of IT program, there were a significant increase of VO(2VAT) and workload in the trained groups (P<0.05), while in the control groups VO(2VAT) and heart rate decreased (P<0.05). Body mass and body index mass decreased in trained groups (P<0.05), and low-density lipoprotein increased only in noCAD group after 16 weeks (P<0.05). The magnitude of the improvement in VO(2VAT) was related to VO(2VAT) (r=-0.57, P<0.05) and workload (r=-0.52, P<0.05) at baseline. The IT program prescribed with intensities based on VAT improved the aerobic functional capacity and decreased body mass and body index mass loss in patients with and without CAD. IT program based on VAT provides new possibilities for cardiac rehabilitation in relation to individualized exercise prescription of the interval training.

Fitness characteristics of a suburban special weapons and tactics team.

PubMed

Pryor, Riana R; Colburn, Deanna; Crill, Matthew T; Hostler, David P; Suyama, J

2012-03-01

Special Weapons and Tactics (SWAT) operators are specialized law enforcement officers who traditionally perform their duties with higher anticipated workloads because of additional body armor, weapons, and equipment used for enhanced operations and protection. This elevated workload increases the need for SWAT operators to improve or maintain their physical fitness to consistently perform routine operations. Typical tasks require trunk rotation, overhead upper extremity use, upper and lower body strength use, and long waiting periods followed by explosive movements while wearing additional equipment. Eleven male SWAT operators from 1 SWAT team performed flexibility, strength, power, and aerobic capacity tests and a variety of job-related tasks. Data were compared with age- and gender-based normative data. Fitness testing revealed that officers ranked high on tests of muscular strength (leg strength, 90th percentile; bench press, 85th percentile); however, body composition (55th percentile), core body strength, and flexibility ranked lower. Furthermore, aerobic capacity and muscular power had a wide range of scores and were also not ideal to support maximal performance during routine operations. These data can assist exercise specialists choose fitness programs specifically for job-related tasks of SWAT operators when creating fitness programs. Fitness programming for law enforcement should focus on improving aerobic fitness, flexibility, core strength, and muscular power while maintaining muscular strength to meet the needs of these specialized officers.

Strategic behavior, workload, and performance in task scheduling

NASA Technical Reports Server (NTRS)

Moray, Neville; Dessouky, Mohamed I.; Kijowski, Brian A.; Adapathya, Ravi

1991-01-01

Scheduling theory is proposed as a normative model for strategic behavior when operators are confronted by several tasks, all of which should be completed within a fixed time span, and when they are free to choose the order in which the tasks should be done. Three experiments are described to investigate the effect of knowing the correct scheduling rule on the efficiency of performance, subjective workload, and choice of strategy under different conditions of time pressure. The most potent effects are from time pressure. The reasons for the weak effect of knowing the rules are discussed, and implications for strategic behavior, displays, and decision aids are indicated.

Effect of task load and task load increment on performance and workload

NASA Technical Reports Server (NTRS)

Hancock, P. A.; Williams, G.

1993-01-01

The goal of adaptive automated task allocation is the 'seamless' transfer of work demand between human and machine. Clearly, at the present time, we are far from this objective. One of the barriers to achieving effortless human-machine symbiosis is an inadequate understanding of the way in which operators themselves seek to reallocate demand among their own personal 'resources.' The paper addresses this through an examination of workload response, which scales an individual's reaction to common levels of experienced external demand. The results indicate the primary driver of performance is the absolute level of task demand over the increment in that demand.

Maximizing time from the constraining European Working Time Directive (EWTD): The Heidelberg New Working Time Model.

PubMed

Schimmack, Simon; Hinz, Ulf; Wagner, Andreas; Schmidt, Thomas; Strothmann, Hendrik; Büchler, Markus W; Schmitz-Winnenthal, Hubertus

2014-01-01

The introduction of the European Working Time Directive (EWTD) has greatly reduced training hours of surgical residents, which translates into 30% less surgical and clinical experience. Such a dramatic drop in attendance has serious implications such compromised quality of medical care. As the surgical department of the University of Heidelberg, our goal was to establish a model that was compliant with the EWTD while avoiding reduction in quality of patient care and surgical training. We first performed workload analyses and performance statistics for all working areas of our department (operation theater, emergency room, specialized consultations, surgical wards and on-call duties) using personal interviews, time cards, medical documentation software as well as data of the financial- and personnel-controlling sector of our administration. Using that information, we specifically designed an EWTD-compatible work model and implemented it. Surgical wards and operating rooms (ORs) were not compliant with the EWTD. Between 5 pm and 8 pm, three ORs were still operating two-thirds of the time. By creating an extended work shift (7:30 am-7:30 pm), we effectively reduced the workload to less than 49% from 4 pm and 8 am, allowing the combination of an eight-hour working day with a 16-hour on call duty; thus, maximizing surgical resident training and ensuring patient continuity of care while maintaining EDTW guidelines. A precise workload analysis is the key to success. The Heidelberg New Working Time Model provides a legal model, which, by avoiding rotating work shifts, assures quality of patient care and surgical training.

Budget Cuts: Financial Aid Offices Face Budget Cuts and Increasing Workload. Quick Scan Survey Results

ERIC Educational Resources Information Center

National Association of Student Financial Aid Administrators (NJ1), 2010

2010-01-01

The majority of college financial aid offices have seen cuts to their operating budgets this year compared to the 2007-08 academic year when the recession began, according to the National Association of Student Financial Aid Administrator's latest QuickScan Survey. Sixty-two percent of financial aid offices reported operating budget cuts this year…

Evaluating Aircrew and Maintainer Warfighter Performance in Aeronautical Systems using Mission-Oriented Measures of Effectiveness

DTIC Science & Technology

2001-02-01

ECM Electronic Countermeasures EEG Electroencephalograph EKG Electrocardiogram EPA Extended Planning Annex EPF Equipment Performance Factor...related physiological measures Changes in the brain/neural system caused by workload. Rehmann, 1995, p. 12 M 8.2.16 Electroencephalograph ( EEG ...architecture TMD Operational Objectives: Destroy Theater Missiles ( TM ) and their infrastructure as far forward as possible (Attack Operations

Construct and face validity of the American College of Surgeons/Association of Program Directors in Surgery laparoscopic troubleshooting team training exercise.

PubMed

Arain, Nabeel A; Hogg, Deborah C; Gala, Rajiv B; Bhoja, Ravi; Tesfay, Seifu T; Webb, Erin M; Scott, Daniel J

2012-01-01

Our aim was to develop an objective scoring system and evaluate construct and face validity for a laparoscopic troubleshooting team training exercise. Surgery and gynecology novices (n = 14) and experts (n = 10) participated. Assessments included the following: time-out, scenario decision making (SDM) score (based on essential treatments rendered and completion time), operating room communication assessment (investigator developed), line operations safety audits (teamwork), and National Aeronautics and Space Administration-Task Load Index (workload). Significant differences were detected for SDM scores for scenarios 1 (192 vs 278; P = .01) and 3 (129 vs 225; P = .004), operating room communication assessment (67 vs 91; P = .002), and line operations safety audits (58 vs 87; P = .001), but not for time-out (46 vs 51) or scenario 2 SDM score (301 vs 322). Workload was similar for both groups and face validity (8.8 on a 10-point scale) was strongly supported. Objective decision-making scoring for 2 of 3 scenarios and communication and teamwork ratings showed construct validity. Face validity and participant feedback were excellent. Copyright © 2012 Elsevier Inc. All rights reserved.

Design considerations to improve cognitive ergonomic issues of unmanned vehicle interfaces utilizing video game controllers.

PubMed

Oppold, P; Rupp, M; Mouloua, M; Hancock, P A; Martin, J

2012-01-01

Unmanned (UAVs, UCAVs, and UGVs) systems still have major human factors and ergonomic challenges related to the effective design of their control interface systems, crucial to their efficient operation, maintenance, and safety. Unmanned system interfaces with a human centered approach promote intuitive interfaces that are easier to learn, and reduce human errors and other cognitive ergonomic issues with interface design. Automation has shifted workload from physical to cognitive, thus control interfaces for unmanned systems need to reduce mental workload on the operators and facilitate the interaction between vehicle and operator. Two-handed video game controllers provide wide usability within the overall population, prior exposure for new operators, and a variety of interface complexity levels to match the complexity level of the task and reduce cognitive load. This paper categorizes and provides taxonomy for 121 haptic interfaces from the entertainment industry that can be utilized as control interfaces for unmanned systems. Five categories of controllers were based on the complexity of the buttons, control pads, joysticks, and switches on the controller. This allows the selection of the level of complexity needed for a specific task without creating an entirely new design or utilizing an overly complex design.

Cognitive demands and the relationship between age and workload in apron control.

PubMed

Müller, Andreas; Petru, Raluca; Angerer, Peter

2011-01-01

Apron controllers (ACs) determine the taxiways for aircraft entering the apron area until they reach their parking positions and vice versa. The aims of this study were to identify age-sensitive job requirements of apron control (Study 1), and to investigate the relationship between age of ACs and their workload (Study 2). Study 1: There were 14 experienced ACs who assessed the job requirements of apron control with the Fleishman-Job Analyses Survey. Additionally, during one shift, the number of parallel processed traffic data sets (indicating memory-load) and the number of delivered radio messages (indicating processing speed requirements) were assessed. Study 2: There were 30 ACs (age: 23-51 yr) who volunteered for trials during late shifts at an international airport. ACs assessed their subjective workload (NASA-Task Load Index) at four times during the shift and carried out an attention test (d2) before and after the shift. Moreover, their heart rate was assessed during the shift and in a reference period. Study 1: Results indicate that apron control requires especially high levels of memory-load and processing speed. Study 2: Hierarchical regression analyses revealed a u-shaped relationship between age and subjective workload (beta = 0.59) as well as heart rate (beta = 0.33). Up to the age of about 35-37 yr, workload and heart rate decreased with age, but afterwards the relationship became positive. There was no association between chronological age and attention performance. There is a need for age adequate job design in apron control that should especially aim at the reduction of memory-load and processing speed.

Entropy, instrument scan and pilot workload

NASA Technical Reports Server (NTRS)

Tole, J. R.; Stephens, A. T.; Vivaudou, M.; Harris, R. L., Jr.; Ephrath, A. R.

1982-01-01

Correlation and information theory which analyze the relationships between mental loading and visual scanpath of aircraft pilots are described. The relationship between skill, performance, mental workload, and visual scanning behavior are investigated. The experimental method required pilots to maintain a general aviation flight simulator on a straight and level, constant sensitivity, Instrument Landing System (ILS) course with a low level of turbulence. An additional periodic verbal task whose difficulty increased with frequency was used to increment the subject's mental workload. The subject's looppoint on the instrument panel during each ten minute run was computed via a TV oculometer and stored. Several pilots ranging in skill from novices to test pilots took part in the experiment. Analysis of the periodicity of the subject's instrument scan was accomplished by means of correlation techniques. For skilled pilots, the autocorrelation of instrument/dwell times sequences showed the same periodicity as the verbal task. The ability to multiplex simultaneous tasks increases with skill. Thus autocorrelation provides a way of evaluating the operator's skill level.

Pilot performance in zero-visibility precision approach. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Ephrath, A. R.

1975-01-01

The pilot's short-term decisions regarding performance assessment and failure monitoring is examined. The performance of airline pilots who flew simulated zero-visibility landing approaches is reported. Results indicate that the pilot's mode of participation in the control task has a strong effect on his workload, the induced workload being lowest when the pilot acts as a monitor during a coupled approach and highest when the pilot is an active element in the control loop. A marked increase in workload at altitudes below 500 ft. is documented at all participation modes; this increase is inversely related to distance-to-go. The participation mode is shown to have a dominant effect on failure-detection performance, with a failure in a monitored (coupled) axis being detected faster than a comparable failure in a manually-controlled axis. Touchdown performance is also documented. It is concluded that the conventional instrument panel and its associated displays are inadequate for zero-visibility operations in the final phases of the landing approach.

Predicting physiological capacity of human load carriage - a review.

PubMed

Drain, Jace; Billing, Daniel; Neesham-Smith, Daniel; Aisbett, Brad

2016-01-01

This review article aims to evaluate a proposed maximum acceptable work duration model for load carriage tasks. It is contended that this concept has particular relevance to physically demanding occupations such as military and firefighting. Personnel in these occupations are often required to perform very physically demanding tasks, over varying time periods, often involving load carriage. Previous research has investigated concepts related to physiological workload limits in occupational settings (e.g. industrial). Evidence suggests however, that existing (unloaded) workload guidelines are not appropriate for load carriage tasks. The utility of this model warrants further work to enable prediction of load carriage durations across a range of functional workloads for physically demanding occupations. If the maximum duration for which personnel can physiologically sustain a load carriage task could be accurately predicted, commanders and supervisors could better plan for and manage tasks to ensure operational imperatives were met whilst minimising health risks for their workers. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Analysis of the workload imposed on the workers of the imprint and cutting/welding sectors of a flexible packaging manufacturer.

PubMed

de M Guimarães, L B; Pessa, S L R; Biguelini, C

2012-01-01

This article presents a study on the evaluation of the workload imposed to workers of two sectors of a flexible packaging manufacturer that operates in three shifts. The workers are allocated in one of the shifts (morning, evening and night shifts) without evaluation of their chronotype and/or social needs. The Imprint sector has a more dynamic work, which is done only by man due to the effort demanded by handling loads. The work in the Cutting/Welding sector is static, done mainly by women. The results showed that the overall workload was the same in the Imprint and Cutting/Welding sectors, because physical effort for load handling is higher in the former but the latter involves high static load. The levels of urinary catecholamines and salivary cortisol were consistent with the workers biological clock showing that none of the workers changed his/her biological cycle to accommodate to the time of the shift schedule.

Visual scanning behavior and pilot workload

NASA Technical Reports Server (NTRS)

Tole, J. R.; Stephens, A. T.; Vivaudou, M.; Ephrath, A. R.; Young, L. R.

1983-01-01

Sophisticated man machine interaction often requires the human operator to perform a stereotyped scan of various instruments in order to monitor and/or control a system. For situations in which this type of stereotyped behavior exists, such as certain phases of instrument flight, scan pattern was shown to be altered by the imposition of simultaneous verbal tasks. A study designed to examine the relationship between pilot visual scan of instruments and mental workload is described. It was found that a verbal loading task of varying difficulty causes pilots to stare at the primary instrument as the difficulty increases and to shed looks at instruments of less importance. The verbal loading task also affected the rank ordering of scanning sequences. By examining the behavior of pilots with widely varying skill levels, it was suggested that these effects occur most strongly at lower skill levels and are less apparent at high skill levels. A graphical interpretation of the hypothetical relationship between skill, workload, and performance is introduced and modelling results are presented to support this interpretation.

Flight Experiment Investigation of General Aviation Self-Separation and Sequencing Tasks

NASA Technical Reports Server (NTRS)

Murdoch, Jennifer L.; Ramiscal, Ermin R.; McNabb, Jennifer L.; Bussink, Frank J. L.

2005-01-01

A new flight operations concept called Small Aircraft Transportation System (SATS) Higher Volume Operations (HVO) was developed to increase capacity during Instrument Meteorological Conditions (IMC) at non-towered, non-radar airports by enabling concurrent operations of multiple aircraft. One aspect of this concept involves having pilots safely self-separate from other aircraft during approaches into these airports using appropriate SATS HVO procedures. A flight experiment was conducted to determine if instrument-rated general aviation (GA) pilots could self-separate and sequence their ownship aircraft, while following a simulated aircraft, into a non-towered, non-radar airport during simulated IMC. Six GA pilots' workload levels and abilities to perform self-separation and sequencing procedures while flying a global positioning system (GPS) instrument approach procedure were examined. The results showed that the evaluation pilots maintained at least the minimum specified separation between their ownship aircraft and simulated traffic and maintained their assigned landing sequence 100-percent of the time. Neither flight path deviations nor subjective workload assessments were negatively impacted by the additional tasks of self-separating and sequencing during these instrument approaches.

Multidimensional Environmental Data Resource Brokering on Computational Grids and Scientific Clouds

NASA Astrophysics Data System (ADS)

Montella, Raffaele; Giunta, Giulio; Laccetti, Giuliano

Grid computing has widely evolved over the past years, and its capabilities have found their way even into business products and are no longer relegated to scientific applications. Today, grid computing technology is not restricted to a set of specific grid open source or industrial products, but rather it is comprised of a set of capabilities virtually within any kind of software to create shared and highly collaborative production environments. These environments are focused on computational (workload) capabilities and the integration of information (data) into those computational capabilities. An active grid computing application field is the fully virtualization of scientific instruments in order to increase their availability and decrease operational and maintaining costs. Computational and information grids allow to manage real-world objects in a service-oriented way using industrial world-spread standards.

Incremental Cost Study.

ERIC Educational Resources Information Center

Shymoniak, Leonard; McIntyre, Chuck

Administrative and empirical factors affecting the relationship between changing workloads and concomitant budget adjustments are examined in this analysis of the funding structure by which state aid to each California community college is adjusted for increases or decreases in average daily attendance (ADA). The report first describes current…

Operative and consultative proportions of neurosurgical disease worldwide: estimation from the surgeon perspective.

PubMed

Dewan, Michael C; Rattani, Abbas; Baticulon, Ronnie E; Faruque, Serena; Johnson, Walter D; Dempsey, Robert J; Haglund, Michael M; Alkire, Blake C; Park, Kee B; Warf, Benjamin C; Shrime, Mark G

2018-05-11

OBJECTIVE The global magnitude of neurosurgical disease is unknown. The authors sought to estimate the surgical and consultative proportion of diseases commonly encountered by neurosurgeons, as well as surgeon case volume and perceived workload. METHODS An electronic survey was sent to 193 neurosurgeons previously identified via a global surgeon mapping initiative. The survey consisted of three sections aimed at quantifying surgical incidence of neurological disease, consultation incidence, and surgeon demographic data. Surgeons were asked to estimate the proportion of 11 neurological disorders that, in an ideal world, would indicate either neurosurgical operation or neurosurgical consultation. Respondent surgeons indicated their confidence level in each estimate. Demographic and surgical practice characteristics-including case volume and perceived workload-were also captured. RESULTS Eighty-five neurosurgeons from 57 countries, representing all WHO regions and World Bank income levels, completed the survey. Neurological conditions estimated to warrant neurosurgical consultation with the highest frequency were brain tumors (96%), spinal tumors (95%), hydrocephalus (94%), and neural tube defects (92%), whereas stroke (54%), central nervous system infection (58%), and epilepsy (40%) carried the lowest frequency. Similarly, surgery was deemed necessary for an average of 88% cases of hydrocephalus, 82% of spinal tumors and neural tube defects, and 78% of brain tumors. Degenerative spine disease (42%), stroke (31%), and epilepsy (24%) were found to warrant surgical intervention less frequently. Confidence levels were consistently high among respondents (lower quartile > 70/100 for 90% of questions), and estimates did not vary significantly across WHO regions or among income levels. Surgeons reported performing a mean of 245 cases annually (median 190). On a 100-point scale indicating a surgeon's perceived workload (0-not busy, 100-overworked), respondents selected a mean workload of 75 (median 79). CONCLUSIONS With a high level of confidence and strong concordance, neurosurgeons estimated that the vast majority of patients with central nervous system tumors, hydrocephalus, or neural tube defects mandate neurosurgical involvement. A significant proportion of other common neurological diseases, such as traumatic brain and spinal injury, vascular anomalies, and degenerative spine disease, demand the attention of a neurosurgeon-whether via operative intervention or expert counsel. These estimates facilitate measurement of the expected annual volume of neurosurgical disease globally.

Impact of 3D vision on mental workload and laparoscopic performance in inexperienced subjects.

PubMed

Gómez-Gómez, E; Carrasco-Valiente, J; Valero-Rosa, J; Campos-Hernández, J P; Anglada-Curado, F J; Carazo-Carazo, J L; Font-Ugalde, P; Requena-Tapia, M J

2015-05-01

To assess the effect of vision in three dimensions (3D) versus two dimensions (2D) on mental workload and laparoscopic performance during simulation-based training. A prospective, randomized crossover study on inexperienced students in operative laparoscopy was conducted. Forty-six candidates executed five standardized exercises on a pelvitrainer with both vision systems (3D and 2D). Laparoscopy performance was assessed using the total time (in seconds) and the number of failed attempts. For workload assessment, the validated NASA-TLX questionnaire was administered. 3D vision improves the performance reducing the time (3D = 1006.08 ± 315.94 vs. 2D = 1309.17 ± 300.28; P < .001) and the total number of failed attempts (3D = .84 ± 1.26 vs. 2D = 1.86 ± 1.60; P < .001). For each exercise, 3D vision also shows better performance times: "transfer objects" (P = .001), "single knot" (P < .001), "clip and cut" (P < .05), and "needle guidance" (P < .001). Besides, according to the NASA-TLX results, less mental workload is experienced with the use of 3D (P < .001). However, 3D vision was associated with greater visual impairment (P < .01) and headaches (P < .05). The incorporation of 3D systems in laparoscopic training programs would facilitate the acquisition of laparoscopic skills, because they reduce mental workload and improve the performance on inexperienced surgeons. However, some undesirable effects such as visual discomfort or headache are identified initially. Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Validation of the NASA-TLX Score in Ongoing Assessment of Mental Workload During a Laparoscopic Learning Curve in Bariatric Surgery.

PubMed

Ruiz-Rabelo, Juan Francisco; Navarro-Rodriguez, Elena; Di-Stasi, Leandro Luigi; Diaz-Jimenez, Nelida; Cabrera-Bermon, Juan; Diaz-Iglesias, Carlos; Gomez-Alvarez, Manuel; Briceño-Delgado, Javier

2015-12-01

Fatigue and mental workload are directly associated with high-complexity tasks. In general, difficult tasks produce a higher mental workload, leaving little opportunity to deal with new/unexpected events and increasing the likelihood of performance errors. The laparoscopic Roux-en-Y gastric bypass (LRYGB) learning curve is considered to be one of the most difficult to complete in laparoscopic surgery. We wished to validate the National Aeronautics and Space Administration Task Load Index (NASA-TLX) in LRYGB and identify factors that could provoke a higher mental workload for surgeons during the learning curve. A single surgeon was enrolled to undertake 70 consecutive LRYGB procedures with two internal surgeons mentoring the first 35 cases. Patients were consecutive and ranked from case 35 to case 105 according to the date of the surgical procedure ("case rank"). Self-ratings of satisfaction, performance, and fatigue were measured at the end of surgery using a validated NASA-TLX questionnaire. The procedure was recorded for later viewing by two external evaluators. General data for patients and surgical variables were collected prospectively. A moderate correlation between the NASA-TLX score, BMI, operative time, and volumes of blood drainage was observed. There was no correlation between the NASA-TLX score and duration of hospital stay or time of drain removal. BMI ≥50 kg/m(2), male sex, inexperienced first assistant, and type 2 diabetes mellitus were identified as independent predictive factors of a higher NASA-TLX score. The NASA-TLX is a valid tool to gauge mental workload in LRYGB.

Three-dimensional virtual navigation versus conventional image guidance: A randomized controlled trial.

PubMed

Dixon, Benjamin J; Chan, Harley; Daly, Michael J; Qiu, Jimmy; Vescan, Allan; Witterick, Ian J; Irish, Jonathan C

2016-07-01

Providing image guidance in a 3-dimensional (3D) format, visually more in keeping with the operative field, could potentially reduce workload and lead to faster and more accurate navigation. We wished to assess a 3D virtual-view surgical navigation prototype in comparison to a traditional 2D system. Thirty-seven otolaryngology surgeons and trainees completed a randomized crossover navigation exercise on a cadaver model. Each subject identified three sinonasal landmarks with 3D virtual (3DV) image guidance and three landmarks with conventional cross-sectional computed tomography (CT) image guidance. Subjects were randomized with regard to which side and display type was tested initially. Accuracy, task completion time, and task workload were recorded. Display type did not influence accuracy (P > 0.2) or efficiency (P > 0.3) for any of the six landmarks investigated. Pooled landmark data revealed a trend of improved accuracy in the 3DV group by 0.44 millimeters (95% confidence interval [0.00-0.88]). High-volume surgeons were significantly faster (P < 0.01) and had reduced workload scores in all domains (P < 0.01), but they were no more accurate (P > 0.28). Real-time 3D image guidance did not influence accuracy, efficiency, or task workload when compared to conventional triplanar image guidance. The subtle pooled accuracy advantage for the 3DV view is unlikely to be of clinical significance. Experience level was strongly correlated to task completion time and workload but did not influence accuracy. N/A. Laryngoscope, 126:1510-1515, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

78 FR 74118 - Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-10

... operational management of DoD personnel security investigation (PSI) workload projections, and for monitoring... the instructions for submitting comments. Mail: Federal Docket Management System Office, 4800 Mark... submissions. The Office of Personnel Management (OPM) has responsibility for conducting PSIs and the...

The effects of total laboratory automation on the management of a clinical chemistry laboratory. Retrospective analysis of 36 years.

PubMed

Sarkozi, Laszlo; Simson, Elkin; Ramanathan, Lakshmi

2003-03-01

Thirty-six years of data and history of laboratory practice at our institution has enabled us to follow the effects of analytical automation, then recently pre-analytical and post-analytical automation on productivity, cost reduction and enhanced quality of service. In 1998, we began the operation of a pre- and post-analytical automation system (robotics), together with an advanced laboratory information system to process specimens prior to analysis, deliver them to various automated analytical instruments, specimen outlet racks and finally to refrigerated stockyards. By the end of 3 years of continuous operation, we compared the chemistry part of the system with the prior 33 years and quantitated the financial impact of the various stages of automation. Between 1965 and 2000, the Consumer Price Index increased by a factor of 5.5 in the United States. During the same 36 years, at our institution's Chemistry Department the productivity (indicated as the number of reported test results/employee/year) increased from 10,600 to 104,558 (9.3-fold). When expressed in constant 1965 dollars, the total cost per test decreased from 0.79 dollars to 0.15 dollars. Turnaround time for availability of results on patient units decreased to the extent that Stat specimens requiring a turnaround time of <1 h do not need to be separately prepared or prioritized on the system. Our experience shows that the introduction of a robotics system for perianalytical automation has brought a large improvement in productivity together with decreased operational cost. It enabled us to significantly increase our workload together with a reduction of personnel. In addition, stats are handled easily and there are benefits such as safer working conditions and improved sample identification, which are difficult to quantify at this stage.

Modeling Operator Performance in Low Task Load Supervisory Domains

DTIC Science & Technology

2011-06-01

PDF Probability Distribution Function SAFE System for Aircrew Fatigue Evaluation SAFTE Sleep , Activity, Fatigue, and Task Effectiveness SCT...attentional capacity due to high mental workload. In low task load settings, fatigue is mainly caused by lack of sleep and boredom experienced by...performance decrements. Also, psychological fatigue is strongly correlated with lack of sleep . Not surprisingly, operators of the morning shift reported the

Defense Medical Human Resources System-internet (DMHRSi): A Case Study on Compliance and Accuracy

DTIC Science & Technology

2009-06-02

including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations ...military, contractor operated facilities. The hospital also houses the second oldest Family Practice Residency in the Army (DeWitt, 2008). The...collection and analysis of financial, workload, and personnel data within the organization. The MHS utilizes information managemen * systems like the

Quiet Clean Short-haul Experimental Engine (QCSEE) under-the-wing engine digital control system design report

NASA Technical Reports Server (NTRS)

1978-01-01

A digital electronic control was combined with conventional hydromechanical components to operate the four controlled variables on the under-the-wing engine: fuel flow, fan blade pitch, fan exhaust area, and core compressor stator angles. The engine and control combination offers improvements in noise, pollution, thrust response, operational monitoring, and pilot workload relative to current engines.

Visual performance modeling in the human operator simulator

NASA Technical Reports Server (NTRS)

Strieb, M. I.

1979-01-01

A brief description of the history of the development of the human operator simulator (HOS) model is presented. Features of the HOS micromodels that impact on the obtainment of visual performance data are discussed along with preliminary details on a HOS pilot model designed to predict the results of visual performance workload data obtained through oculometer studies on pilots in real and simulated approaches and landings.

The Effects of 12 Hours of Low-Grade Hypoxia at 10,000 ft at Night in Special Operations Forces Aircraft Operations on Cognition, Night Vision, Goggle Vision and Subjective Symptoms

DTIC Science & Technology

2007-06-28

SUBJECTS 7 DURATION 7 DESCRIPTION OF EXPERIMENT 7 COGNITIVE PERFORMANCE BATTERY 8 WORK LOAD 10 VISUAL...Once During the Experimental Session vi LIST OF...shared performance on several sub tasks under experimenter manipulated workload conditions such as monitoring of dials and displays with dynamic

Ergonomic task reduction prevents bone osteopenia in a rat model of upper extremity overuse

PubMed Central

BARBE, Mary F.; JAIN, Nisha X.; MASSICOTTE, Vicky S.; POPOFF, Steven N.; BARR-GILLESPIE, Ann E.

2015-01-01

We evaluated the effectiveness of ergonomic workload reduction of switching rats from a high repetition high force (HRHF) lever pulling task to a reduced force and reach rate task for preventing task-induced osteopenic changes in distal forelimb bones. Distal radius and ulna trabecular structure was examined in young adult rats performing one of three handle-pulling tasks for 12 wk: 1) HRHF, 2) low repetition low force (LRLF); or 3) HRHF for 4 wk and than LRLF thereafter (HRHF-to-LRLF). Results were compared to age-matched controls rats. Distal forelimb bones of 12-wk HRHF rats showed increased trabecular resorption and decreased volume, as control rats. HRHF-to-LRLF rats had similar trabecular bone quality as control rats; and decreased bone resorption (decreased trabecular bone volume and serum CTX1), increased bone formation (increased mineral apposition, bone formation rate, and serum osteocalcin), and decreased osteoclasts and inflammatory cytokines, than HRHF rats. Thus, an ergonomic intervention of HRHF-to-LRLF prevented loss of trabecular bone volume occurring with prolonged performance of a repetitive upper extremity task. These findings support the idea of reduced workload as an effective approach to management of work-related musculoskeletal disorders, and begin to define reach rate and load level boundaries for such interventions. PMID:25739896

Nursing workload in the acute-care setting: A concept analysis of nursing workload.

PubMed

Swiger, Pauline A; Vance, David E; Patrician, Patricia A

2016-01-01

A pressing need in the field of nursing is the identification of optimal staffing levels to ensure patient safety. Effective staffing requires comprehensive measurement of nursing workload to determine staffing needs. Issues surrounding nursing workload are complex, and the volume of workload is growing; however, many workload systems do not consider the numerous workload factors that impact nursing today. The purpose of this concept analysis was to better understand and define nursing workload as it relates to the acute-care setting. Rogers' evolutionary method was used for this literature-based concept analysis. Nursing workload is influenced by more than patient care. The proposed definition of nursing workload may help leaders identify workload that is unnoticed and unmeasured. These findings could help leaders consider and identify workload that is unnecessary, redundant, or more appropriate for assignment to other members of the health care team. Published by Elsevier Inc.

Automation of P-3 Simulations to Improve Operator Workload

DTIC Science & Technology

2012-09-01

Training GBE Group Behavior Engine GCC Geocentric Coordinates GCS Global Coordinate System GUI Graphical User Interface xiv HLA High...sonobuoys are in a different cell. Therefore, the sonobuoy positions in JSAF must be converted to geocentric coordinates (GCC) before applying the

14 CFR 25.1523 - Minimum flight crew.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum flight crew. 25.1523 Section 25.1523 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... sufficient for safe operation, considering— (a) The workload on individual crewmembers; (b) The accessibility...

14 CFR 29.1523 - Minimum flight crew.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Minimum flight crew. 29.1523 Section 29.1523 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... sufficient for safe operation, considering— (a) The workload on individual crewmembers; (b) The accessibility...

14 CFR 29.1523 - Minimum flight crew.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum flight crew. 29.1523 Section 29.1523 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... sufficient for safe operation, considering— (a) The workload on individual crewmembers; (b) The accessibility...

14 CFR 25.1523 - Minimum flight crew.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Minimum flight crew. 25.1523 Section 25.1523 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... sufficient for safe operation, considering— (a) The workload on individual crewmembers; (b) The accessibility...

14 CFR 27.1523 - Minimum flight crew.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Minimum flight crew. 27.1523 Section 27.1523 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... safe operation, considering— (a) The workload on individual crewmembers; (b) The accessibility and ease...

14 CFR 27.1523 - Minimum flight crew.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum flight crew. 27.1523 Section 27.1523 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... safe operation, considering— (a) The workload on individual crewmembers; (b) The accessibility and ease...

77 FR 8823 - Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-15

... and responsibility for central operational management of DoD PSI workload projections, and monitoring... instructions for submitting comments. Mail: Federal Docket Management System Office, 4800 Mark Center Drive... actual PSI submissions. The Office of Personnel Management (OPM) has responsibility to conduct PSIs and...

Research funding expectations as a function of faculty teaching/administrative workload.

PubMed

Surratt, Christopher K; Kamal, Khalid M; Wildfong, Peter L D

2011-06-01

Persistent faculty shortages at US pharmacy schools make faculty recruitment and retention a perennial priority. The literature indicates that a key retention issue is whether the faculty member's scholarship is compromised because of a heavy teaching or service workload. Assess US pharmacy faculty perceptions concerning their views of appropriate expectations of research grant support given their teaching/administrative workloads. Data and opinions were collected using a multiple-choice, cross-sectional survey instrument (SurveyMonkey®; Menlo Park, CA), e-mailed to 1047 faculty members, randomly selected from all Accreditation Council of Pharmacy Education (ACPE)-accredited US pharmacy schools. Statistical analyses were performed using SPSS® (Chicago, IL) for Windows, Version 17.0. Of the researcher respondents, a majority felt that the amount of teaching expected was too much to be a competitive researcher. Teaching commitment was found more likely to increase than decrease after achieving tenure. Reported new faculty start-up funding was well below that typically found at nonpharmacy research schools. This information is anticipated to help pharmacy faculty members gauge their workload and productivity relative to a national peer group, and to help pharmacy schools improve in faculty recruitment and retention. The survey findings may assist pharmacy schools in clarifying reasonable teaching and funding expectations for pre- and post-tenure faculty, which in turn may help attract more pharmaceutical scientists to academic pharmacy positions. Copyright © 2011 Elsevier Inc. All rights reserved.

Self-determination, control, and reactions to changes in workload: a work simulation.

PubMed

Parker, Stacey L; Jimmieson, Nerina L; Amiot, Catherine E

2013-04-01

The objective of this experimental study is to capture the dynamic temporal processes that occur in changing work settings and to test how work control and individuals' motivational predispositions interact to predict reactions to these changes. To this aim, we examine the moderating effects of global self-determined and non-self-determined motivation, at different levels of work control, on participants' adaptation and stress reactivity to changes in workload during four trials of an inbox activity. Workload was increased or decreased at Trial 3, and adaptation to this change was examined via fluctuations in anxiety, coping, motivation, and performance. In support of the hypotheses, results revealed that, for non-self-determined individuals, low work control was stress-buffering and high work control was stress-exacerbating when predicting anxiety and intrinsic motivation. In contrast, for self-determined individuals, high work control facilitated the adaptive use of planning coping in response to a change in workload. Overall, this pattern of results demonstrates that, while high work control was anxiety-provoking and demotivating for non-self-determined individuals, self-determined individuals used high work control to implement an adaptive antecedent-focused emotion regulation strategy (i.e., planning coping) to meet situational demands. Other interactive effects of global motivation emerged on anxiety, active coping, and task performance. These results and their practical implications are discussed.

Physical and mental workload in single-incision laparoscopic surgery and conventional laparoscopy.

PubMed

Koca, Dilek; Yıldız, Sedat; Soyupek, Feray; Günyeli, İlker; Erdemoglu, Ebru; Soyupek, Sedat; Erdemoglu, Evrim

2015-06-01

The aim of the present study is to evaluate mental workload and fatigue in fingers, hand, arm, shoulder in single-incision laparoscopic surgery (SILS) and multiport laparoscopy. Volunteers performed chosen tasks by standard laparoscopy and SILS. Time to complete tasks and finger and hand strength were evaluated. Lateral, tripod, and pulp pinch strengths were measured. Hand dexterity was determined by pegboard. Electromyography recordings were taken from biceps and deltoid muscles of both extremities. The main outcome measurement was median frequency (MF) slope. NASA-TLX was used for mental workload. Time to complete laparoscopic tasks were longer in the SILS group (P < .05). Decrease of strength in fingers and hand were similar in SILS and standard laparoscopy. Pegboard time was increased in both hands after SILS (P < .05). MF slope of biceps muscle and deltoid muscle in SILS was far away from the reference slope. MF slope of biceps muscle and deltoid muscle in standard laparoscopy was close to reference slope, indicating there was more fatigue in biceps and deltoid muscles of both upper extremities in SILS group. NASA-TLX score was 73 ± 13.3 and 42 ± 19.5 in SILS and multiport laparoscopy, respectively (P < .01). Mental demand, physical demand, temporal demand, performance, effort, and frustration were, respectively, scored 10.7 ± 3.8, 11.7 ± 3.5, 12.2 ± 2.7, 11 ± 3, 13.6 ± 2.7, and 13.5 ± 2.8 in SILS and 6.3 ± 3.1, 6.6 ± 3.3, 7.3 ± 3.3, 7.1 ± 4.1, 7.9 ± 3.9, and 6.6 ± 3.8 in standard laparoscopy (P < .01). SILS is mentally and physically demanding, particularly on arms and shoulders. Fatigue of big muscles, effort, and frustration were major challenges of SILS. Ergonomic intervention of instruments are needed to decrease mental and physical workload. © The Author(s) 2014.

Initial development of a metric to describe the level of safety associated with piloting an aircraft with synthetic vision systems (SVS) displays

NASA Astrophysics Data System (ADS)

Bartolone, Anthony P.; Glaab, Louis J.; Hughes, Monica F.; Parrish, Russell V.

2005-05-01

Synthetic Vision Systems (SVS) displays provide pilots with a continuous view of terrain combined with integrated guidance symbology in an effort to increase situation awareness (SA) and decrease workload during operations in Instrument Meteorological Conditions (IMC). It is hypothesized that SVS displays can replicate the safety and operational flexibility of flight in Visual Meteorological Conditions (VMC), regardless of actual out-the-window (OTW) visibility or time of day. Throughout the course of recent SVS research, significant progress has been made towards evolving SVS displays as well as demonstrating their ability to increase SA compared to conventional avionics in a variety of conditions. While a substantial amount of data has been accumulated demonstrating the capabilities of SVS displays, the ability of SVS to replicate the safety and operational flexibility of VMC flight performance in all visibility conditions is unknown to any specific degree. The previous piloted simulations and flight tests have shown better SA and path precision is achievable with SVS displays without causing an increase in workload, however none of the previous SVS research attempted to fully capture the significance of SVS displays in terms of their contribution to safety or operational benefits. In order to more fully quantify the relationship of flight operations in IMC with SVS displays to conventional operations conducted in VMC, a fundamental comparison to current day general aviation (GA) flight instruments was warranted. Such a comparison could begin to establish the extent to which SVS display concepts are capable of maintaining an "equivalent level of safety" with the round dials they could one day replace, for both current and future operations. Such a comparison was the focus of the SVS-ES experiment conducted under the Aviation Safety and Security Program's (AvSSP) GA Element of the SVS Project at NASA Langley Research Center in Hampton, Virginia. A combination of subjective and objective data measures were used in this preliminary research to quantify the relationship between selected components of safety that are associated with flying an approach. Four information display methods ranging from a "round dials" baseline through a fully integrated SVS package that includes terrain, pathway based guidance, and a strategic navigation display, were investigated in this high fidelity simulation experiment. In addition, a broad spectrum of pilots, representative of the GA population, were employed for testing in an attempt to enable greater application of the results and determine if "equivalent levels of safety" are achievable through the incorporation of SVS technology regardless of a pilot's flight experience.

A comparison of policies on nurse faculty workload in the United States.

PubMed

Ellis, Peggy A

2013-01-01

This article describes nurse faculty workload policies from across the nation in order to assess current practice. There is a well-documented shortage of nursing faculty leading to an increase in workload demands. Increases in faculty workload results in difficulties with work-life balance and dissatisfaction threatening to make nursing education less attractive to young faculty. In order to begin an examination of faculty workload in nursing, existing workloads must be known. Faculty workload data were solicited from nursing programs nationwide and analyzed to determine the current workloads. The most common faculty teaching workload reported overall for nursing is 12 credit hours per semester; however, some variations exist. Consideration should be given to the multiple components of the faculty workload. Research is needed to address the most effective and efficient workload allocation for nursing faculty.

Use of Thermoregulatory Models to Enhance Space Shuttle and Space Station operations and Review of Human Thermoregulatory Control

NASA Technical Reports Server (NTRS)

Pisacane, V. L.; Kuznetz, L. H.; Logan, J. S.; Clark, J. B.; Wissler, E. H.

2007-01-01

Thermoregulation in the space environment is critical for survival, especially in off- nominal operations. In such cases, mathematical models of thermoregulation are frequently employed to evaluate safety-of-flight issues in various human mission scenarious. In this study, the 225-node Wissler model and the 41-Node Metabolic Man model are employed to evaluate the effects of such a scenario. Metabolic loads on astronauts wearing the advanced crew escape suit (ACES) and liquid cooled ventilation garment (LCVG) are imposed on astronauts exposed to elevated cabin temperatures resulting from a systems failure. The study indicates that the performance of the ACES/LCVG cooling system is marginal. Increases in workload and or cabin temperature above nominal will increase rectal temperature, stored heat load, heart rate, and sweating, which could lead to deficits in the performance of cognitive and motor tasks. This is of concern as the ACES/LCVG is employed during Shuttle decent when the likelihood of a safe landing may be compromised. The study indicates that the most effective mitigation strategy would be to decrease the LCVG inlet temperature.

Job satisfaction and stressors for working in out-of-hours care - a pilot study with general practitioners in a rural area of Germany.

PubMed

Leutgeb, R; Frankenhauser-Mannuß, J; Scheuer, M; Szecsenyi, J; Goetz, Katja

2018-06-22

Challenging work environment, high workload, and increasing physician shortages characterize current rural general practice in Germany and in most European Countries. These factors extend into Out-Of-Hours Care (OOHC). However, little research about potential stressors for general practitioners (GPs) in OOHC settings is available. This pilot study aimed to evaluate workload, different elements of job satisfaction and stressors for GPs in OOHC and to analyze whether these aspects are associated with overall job satisfaction. Cross-sectional survey with a sample of 320 GPs who are working in OOHC was used to measure workload in OOHC, job satisfaction (using the Warr-Cook-Wall scale) and stressors with the effort-reward imbalance questionnaire. In order to assess associations between workload, job satisfaction and stressors at work we performed descriptive analyses as well as multivariable regression analyses. The response rate was 40.9%. Over 80% agreed that OOHC was perceived as a stressor and 79% agreed that less OOHC improved job satisfaction. Only 42% of our sample were satisfied with their overall job satisfaction. The regression analysis showed that the modification of current OOHC organization was significantly associated with overall job satisfaction. Our results suggest that OOHC in the current form is a relevant stressor in daily work of rural GPs in Germany and one of the reasons for a decreasing overall job satisfaction. Strategic changes such as the implementation of structural reforms e.g. reducing frequency of OOHC duties for each GP and improving continuing professional development options related to OOHC are needed to address current workload challenges experienced by GPs providing OOHC in Germany.

Maximizing time from the constraining European Working Time Directive (EWTD): The Heidelberg New Working Time Model

PubMed Central

2014-01-01

Background The introduction of the European Working Time Directive (EWTD) has greatly reduced training hours of surgical residents, which translates into 30% less surgical and clinical experience. Such a dramatic drop in attendance has serious implications such compromised quality of medical care. As the surgical department of the University of Heidelberg, our goal was to establish a model that was compliant with the EWTD while avoiding reduction in quality of patient care and surgical training. Methods We first performed workload analyses and performance statistics for all working areas of our department (operation theater, emergency room, specialized consultations, surgical wards and on-call duties) using personal interviews, time cards, medical documentation software as well as data of the financial- and personnel-controlling sector of our administration. Using that information, we specifically designed an EWTD-compatible work model and implemented it. Results Surgical wards and operating rooms (ORs) were not compliant with the EWTD. Between 5 pm and 8 pm, three ORs were still operating two-thirds of the time. By creating an extended work shift (7:30 am-7:30 pm), we effectively reduced the workload to less than 49% from 4 pm and 8 am, allowing the combination of an eight-hour working day with a 16-hour on call duty; thus, maximizing surgical resident training and ensuring patient continuity of care while maintaining EDTW guidelines. Conclusion A precise workload analysis is the key to success. The Heidelberg New Working Time Model provides a legal model, which, by avoiding rotating work shifts, assures quality of patient care and surgical training. PMID:25984433

Evaluation Metrics for the Paragon XP/S-15

NASA Technical Reports Server (NTRS)

Traversat, Bernard; McNab, David; Nitzberg, Bill; Fineberg, Sam; Blaylock, Bruce T. (Technical Monitor)

1993-01-01

On February 17th 1993, the Numerical Aerodynamic Simulation (NAS) facility located at the NASA Ames Research Center installed a 224 node Intel Paragon XP/S-15 system. After its installation, the Paragon was found to be in a very immature state and was unable to support a NAS users' workload, composed of a wide range of development and production activities. As a first step towards addressing this problem, we implemented a set of metrics to objectively monitor the system as operating system and hardware upgrades were installed. The metrics were designed to measure four aspects of the system that we consider essential to support our workload: availability, utilization, functionality, and performance. This report presents the metrics collected from February 1993 to August 1993. Since its installation, the Paragon availability has improved from a low of 15% uptime to a high of 80%, while its utilization has remained low. Functionality and performance have improved from merely running one of the NAS Parallel Benchmarks to running all of them faster (between 1 and 2 times) than on the iPSC/860. In spite of the progress accomplished, fundamental limitations of the Paragon operating system are restricting the Paragon from supporting the NAS workload. The maximum operating system message passing (NORMA IPC) bandwidth was measured at 11 Mbytes/s, well below the peak hardware bandwidth (175 Mbytes/s), limiting overall virtual memory and Unix services (i.e. Disk and HiPPI I/O) performance. The high NX application message passing latency (184 microns), three times than on the iPSC/860, was found to significantly degrade performance of applications relying on small message sizes. The amount of memory available for an application was found to be approximately 10 Mbytes per node, indicating that the OS is taking more space than anticipated (6 Mbytes per node).

Job satisfaction, income, workload, workplace, and demographics of Japanese radiologists in the 2008 survey.

PubMed

Sone, Miyuki; Mizunuma, Kimiyoshi; Nakajima, Yasuo; Yasunaga, Hideo; Ohtomo, Kuni

2013-05-01

This study aimed to verify radiologists' demographics and job satisfaction in Japan and analyze factors affecting job satisfaction. A self-administered questionnaire was mailed to 7,491 eligible radiologists between April and June 2008. The questionnaire consisted of items concerning participants' demographics and job satisfaction. A multivariate regression analysis was conducted to analyze the impact of practice environments on radiologists' overall job satisfaction. There were 3,986 (53 %) valid responses. In 2008, 67.7 % of radiologists reported being extremely or somewhat satisfied with their job. With regard to changes in job satisfaction over the previous 5 years, 45.8 % felt much increased or somewhat increased satisfaction, whereas 18.8 % felt somewhat decreased or much decreased. The significant factors associated with overall job satisfaction were annual income (p < 0.01) and working at larger hospitals (500 or more beds) (p < 0.01). Older age (p < 0.01) and night duty (p < 0.01) was significantly related to dissatisfaction. The main reasons for increasing job satisfaction over 5 years were interest and lifestyle, whereas the strongest reason for decreasing job satisfaction was workload. This survey revealed Japanese radiologists had a high level of job satisfaction.

Effects of Nitrate Supplementation on Cardiovascular and Autonomic Reactivity in African-American Females

PubMed Central

Bond, Vernon; Curry, Bryan H.; Adams, R. George; Asadi, M. Sadegh; Stancil, Kimani A.; Millis, Richard M.; Haddad, Georges E.

2014-01-01

Previous studies have shown that beetroot juice (BJ) decreases systolic blood pressure (SBP) and oxygen demand. This study tests the hypothesis that a beetroot juice (BJ) treatment increases heart rate variability (HRV) measured by the average standard deviation of normal-normal electrocardiogram RR intervals (SDNN) and the low frequency (LF), mainly sympathetic, fast Fourier transform spectral index of HRV. The subjects were 13 healthy young adult African-American females. Placebo control orange juice (OJ) and BJ treatments were given on separate days. Blood nitric oxide [NO], SBP and RR intervals were measured at rest and at constant workloads set to 40% and 80% of the predetermined VO2peak. Two hours after ingestion the BJ treatment increased [NO] and decreased SBP. BJ also increased SDNN at rest and at the 40% VO2peak workload, without significant effects on LF. SDNN was significantly greater after the BJ than after the OJ treatment, across the two physical activity conditions and SDNN was (negatively) correlated with SBP. These results suggest that BJ decreases SBP and increases HRV at rest and during aerobic exercise. Similar results in subjects with prehypertension or hypertension could translate to a dietary nitrate treatment for hypertension. PMID:25401100

Nursing and Health Care Reform: Implications for Curriculum Development.

ERIC Educational Resources Information Center

Bowen, Mary; Lyons, Kevin J.; Young, Barbara E.

2000-01-01

A survey of registered nurses who graduated in 1986 (n=50) and 1991 (n-58) revealed these opinions: insurance companies increasingly control patient care; workload and paperwork have increased; and there are fewer jobs and less job security. A significant number reported decreased job satisfaction. (SK)

The Art of Instituting and Maintaining Learners' Motivation

ERIC Educational Resources Information Center

Tran, Thu H.

2013-01-01

Whereas teachers' responsibilities with accountability, class sizes and workload increase, their benefits, income and job security seem to decrease. Motivating and keeping classroom teachers motivated to successfully and happily perform their instructional duties can be challenging. One feasible approach to motivating teachers is offering…

Subsistence Agriculture versus Cash Cropping: The Social Repercussions.

ERIC Educational Resources Information Center

Rennie, Sandra Joy

1991-01-01

The introduction of cash cropping in the Solomon Islands and Tonga has had negative effects on women, leading to deterioration in their status, decreased leisure time, fewer opportunities to earn cash, increased birth rate (to help with the increased workload), and more sharply defined sex roles. (SV)

Beyond NextGen: AutoMax Overview and Update

NASA Technical Reports Server (NTRS)

Kopardekar, Parimal; Alexandrov, Natalia

2013-01-01

Main Message: National and Global Needs - Develop scalable airspace operations management system to accommodate increased mobility needs, emerging airspace uses, mix, future demand. Be affordable and economically viable. Sense of Urgency. Saturation (delays), emerging airspace uses, proactive development. Autonomy is Needed for Airspace Operations to Meet Future Needs. Costs, time critical decisions, mobility, scalability, limits of cognitive workload. AutoMax to Accommodate National and Global Needs. Auto: Automation, autonomy, autonomicity for airspace operations. Max: Maximizing performance of the National Airspace System. Interesting Challenges and Path Forward.

Optical cross-talk and visual comfort of a stereoscopic display used in a real-time application

NASA Astrophysics Data System (ADS)

Pala, S.; Stevens, R.; Surman, P.

2007-02-01

Many 3D systems work by presenting to the observer stereoscopic pairs of images that are combined to give the impression of a 3D image. Discomfort experienced when viewing for extended periods may be due to several factors, including the presence of optical crosstalk between the stereo image channels. In this paper we use two video cameras and two LCD panels viewed via a Helmholtz arrangement of mirrors, to display a stereoscopic image inherently free of crosstalk. Simple depth discrimination tasks are performed whilst viewing the 3D image and controlled amounts of image crosstalk are introduced by electronically mixing the video signals. Error monitoring and skin conductance are used as measures of workload as well as traditional subjective questionnaires. We report qualitative measurements of user workload under a variety of viewing conditions. This pilot study revealed a decrease in task performance and increased workload as crosstalk was increased. The observations will assist in the design of further trials planned to be conducted in a medical environment.

Evaluation of three ergonomic measures on productivity, physical work demands, and workload in gypsum bricklayers.

PubMed

van der Molen, Henk F; Kuijer, P Paul F M; Formanoy, Margriet; Bron, Lennart; Hoozemans, Marco J M; Visser, Bart; Frings-Dresen, Monique H W

2010-06-01

This study evaluated the effects of a combination of three ergonomic measures designed to reduce the risk of low back complaints among gypsum bricklayers. The measures focused on optimizing working height and reducing carrying distances. A within-subjects (N = 10) controlled field study was used to compare the effects of working with the ergonomic measures with those of working with conventional working methods at the worksite during the course of a full working day. Productivity, work demands, and workload were assessed. No effects were found on productivity, total work time, duration of tasks, duration of carrying, or energetic or biomechanical workload. However, the duration and frequency of working between knee and hip height during a working day increased by 25% and 15%, respectively, due to the ergonomic measures. During the finishing task, the duration and frequency of working below knee level decreased significantly by 4 min and 71 times, respectively. The limited impact of the ergonomic measures argues for additional measures to reduce the risk of low back complaints. 2010 Wiley-Liss, Inc.

Mitigating clogging and arrest in confined self-propelled systems

NASA Astrophysics Data System (ADS)

Savoie, William; Aguilar, Jeffrey; Monaenkova, Daria; Linevich, Vadim; Goldman, Daniel

Ensembles of self-propelling elements, like colloidal surfers, bacterial biofilms, and robot swarms can spontaneously form density heterogeneities. To understand how to prevent potentially catastrophic clogs in task-oriented active matter systems (like soil excavating robots), we present a robophysical study of excavation of granular media in a confined environment. We probe the efficacy of two social strategies observed in our studies of fire ants (S. invicta). The first behavior (denoted as unequal workload) prescribes to each excavator a different probability to enter the digging area. The second behavior (denoted as reversal\\x9D), is characterized by a probability to forfeit excavation when progress is sufficiently obstructed. For equal workload distribution and no reversal behavior, clogs at the digging site prevent excavation for sufficient numbers of robots. Measurements of aggregation relaxation times reveal how the strategies mitigate clogs. The unequal workload behavior reduces the tunnel density, decreasing the probability of clog formation. Reversal behavior, while allowing clogs to form, reduces aggregation relaxation time. We posit that application of social behaviors can be useful for swarm robot systems where global control and organization may not be possible.

Using an integrated information system to reduce interruptions and the number of non-relevant contacts in the inpatient pharmacy at tertiary hospital.

PubMed

Binobaid, Saleh; Almeziny, Mohammed; Fan, Ip-Shing

2017-07-01

Patient care is provided by a multidisciplinary team of healthcare professionals intended for high-quality and safe patient care. Accordingly, the team must work synergistically and communicate efficiently. In many hospitals, nursing and pharmacy communication relies mainly on telephone calls. In fact, numerous studies have reported telephone calls as a source of interruption for both pharmacy and nursing operations; therefore, the workload increases and the chance of errors raises. This report describes the implementation of an integrated information system that possibly can reduce telephone calls through providing real-time tracking capabilities and sorting prescriptions urgency, thus significantly improving traceability of all prescriptions inside pharmacy. The research design is based on a quasi-experiment using pre-post testing using the continuous improvement approach. The improvement project is performed using a six-step method. A survey was conducted in Prince Sultan Military Medical City (PSMMC) to measure the volume and types of telephone calls before and after implementation to evaluate the impact of the new system. Beforehand of the system implementation, during the two-week measurement period, all pharmacies received 4466 calls and the majority were follow-up calls. Subsequently of the integrated system rollout, there was a significant reduction ( p  > 0.001) in the volume of telephone calls to 2630 calls; besides, the calls nature turned out to be more professional inquiries ( p  > 0.001). As a result, avoidable interruptions and workload were decreased.

Ambulance helicopter contribution to search and rescue in North Norway.

PubMed

Glomseth, Ragnar; Gulbrandsen, Fritz I; Fredriksen, Knut

2016-09-13

Search and rescue (SAR) operations constitute a significant proportion of Norwegian ambulance helicopter missions, and they may limit the service's capacity for medical operations. We compared the relative contribution of the different helicopter resources using a common definition of SAR-operation in order to investigate how the SAR workload had changed over the last years. We searched the mission databases at the relevant SAR and helicopter emergency medical service (HEMS) bases and the Joint Rescue Coordination Centre (North) for helicopter-supported SAR operations within the potential operation area of the Tromsø HEMS base in 2000-2010. We defined SAR operations as missions over land or sea within 10 nautical miles from the coast with an initial search phase, missions with use of rescue hoist or static rope, and avalanche operations. There were 769 requests in 639 different SAR operations, and 600 missions were completed. The number increased during the study period, from 46 in 2000 to 77 in 2010. The Tromsø HEMS contributed with the highest number of missions and experienced the largest increase, from 10 % of the operations in 2000 to 50 % in 2010. Simple terrain and sea operations dominated, and avalanches accounted for as many as 12 % of all missions. The helicopter crews used static rope or rescue hoist in 141 operations. We have described all helicopter supported SAR operations in our area by combining databases. The Tromsø HEMS service had taken over one half of the missions by 2010. Increased availability for SAR work is one potential explanation. The number of SAR missions increased during 2000-2010, and the Tromsø HEMS experienced the greatest increase in workload.

Use of Traffic Intent Information by Autonomous Aircraft in Constrained Operations

NASA Technical Reports Server (NTRS)

Wing, David J.; Barmore, Bryan E.; Krishnamurthy, Karthik

2002-01-01

This paper presents findings of a research study designed to provide insight into the issue of intent information exchange in constrained en-route air-traffic operations and its effect on pilot decision-making and flight performance. The piloted simulation was conducted in the Air Traffic Operations Laboratory at the NASA Langley Research Center. Two operational modes for autonomous flight management were compared under conditions of low and high operational complexity (traffic and airspace hazard density). The tactical mode was characterized primarily by the use of traffic state data for conflict detection and resolution and a manual approach to meeting operational constraints. The strategic mode involved the combined use of traffic state and intent information, provided the pilot an additional level of alerting, and allowed an automated approach to meeting operational constraints. Operational constraints applied in the experiment included separation assurance, schedule adherence, airspace hazard avoidance, flight efficiency, and passenger comfort. The strategic operational mode was found to be effective in reducing unnecessary maneuvering in conflict situations where the intruder's intended maneuvers would resolve the conflict. Conditions of high operational complexity and vertical maneuvering resulted in increased proliferation of conflicts, but both operational modes exhibited characteristics of stability based on observed conflict proliferation rates of less than 30 percent. Scenario case studies illustrated the need for maneuver flight restrictions to prevent the creation of new conflicts through maneuvering and the need for an improved user interface design that appropriately focuses the pilot's attention on conflict prevention information. Pilot real-time assessment of maximum workload indicated minimal sensitivity to operational complexity, providing further evidence that pilot workload is not the limiting factor for feasibility of an en-route distributed traffic management system, even under highly constrained conditions.

Physicians' and nurses' perceptions of patient safety risks in the emergency department.

PubMed

Källberg, Ann-Sofie; Ehrenberg, Anna; Florin, Jan; Östergren, Jan; Göransson, Katarina E

2017-07-01

The emergency department has been described as a high-risk area for errors. It is also known that working conditions such as a high workload and shortage off staff in the healthcare field are common factors that negatively affect patient safety. A limited amount of research has been conducted with regard to patient safety in Swedish emergency departments. Additionally, there is a lack of knowledge about clinicians' perceptions of patient safety risks. Therefore, the purpose of this study was to describe emergency department clinicians' experiences with regard to patient safety risks. Semi-structured interviews were conducted with 10 physicians and 10 registered nurses from two emergency departments. Interviews were analysed by inductive content analysis. The experiences reflect the complexities involved in the daily operation of a professional practice, and the perception of risks due to a high workload, lack of control, communication and organizational failures. The results reflect a complex system in which high workload was perceived as a risk for patient safety and that, in a combination with other risks, was thought to further jeopardize patient safety. Emergency department staff should be involved in the development of patient safety procedures in order to increase knowledge regarding risk factors as well as identify strategies which can facilitate the maintenance of patient safety during periods in which the workload is high. Copyright © 2017 Elsevier Ltd. All rights reserved.

Workload and Stress in New Zealand Universities.

ERIC Educational Resources Information Center

Boyd, Sally; Wylie, Cathy

This study examined the workloads of academic, general, support, library, and technical staff of New Zealand universities. It focused on current levels of workload, changes in workload levels and content, connections between workload and stress, and staff attitudes towards the effects of workload changes and educational reforms on the quality of…

Driving performance analysis of the ACAS FOT data and recommendations for a driving workload manager.

DOT National Transportation Integrated Search

2006-12-01

This report contains analyses of driving performance data from the Advanced Collision Avoidance System (ACAS) Field Operational Test (FOT), with data from nearly 100 drivers and over 100,000 miles of driving. The analyses compared normal and distract...

14 CFR Appendix D to Part 25 - Appendix D to Part 25

Code of Federal Regulations, 2014 CFR

2014-01-01

..., electronic controls, pressurization system controls, and engine controls. (2) The accessibility and... considered: (1) Flight path control. (2) Collision avoidance. (3) Navigation. (4) Communications. (5) Operation and monitoring of aircraft engines and systems. (6) Command decisions. (b) Workload factors. The...

14 CFR Appendix D to Part 25 - Appendix D to Part 25

Code of Federal Regulations, 2010 CFR

2010-01-01

..., electronic controls, pressurization system controls, and engine controls. (2) The accessibility and... considered: (1) Flight path control. (2) Collision avoidance. (3) Navigation. (4) Communications. (5) Operation and monitoring of aircraft engines and systems. (6) Command decisions. (b) Workload factors. The...

14 CFR Appendix D to Part 25 - Appendix D to Part 25

Code of Federal Regulations, 2011 CFR

2011-01-01

..., electronic controls, pressurization system controls, and engine controls. (2) The accessibility and... considered: (1) Flight path control. (2) Collision avoidance. (3) Navigation. (4) Communications. (5) Operation and monitoring of aircraft engines and systems. (6) Command decisions. (b) Workload factors. The...

14 CFR Appendix D to Part 25 - Appendix D to Part 25

Code of Federal Regulations, 2012 CFR

2012-01-01

..., electronic controls, pressurization system controls, and engine controls. (2) The accessibility and... considered: (1) Flight path control. (2) Collision avoidance. (3) Navigation. (4) Communications. (5) Operation and monitoring of aircraft engines and systems. (6) Command decisions. (b) Workload factors. The...

ATD-1 ATM Technology Demonstration-1 and Integrated Scheduling

NASA Technical Reports Server (NTRS)

Quon, Leighton

2014-01-01

Enabling efficient arrivals for the NextGen Air Traffic Management System and developing a set of integrated decision support tools to reduce the high cognitive workload so that controllers are able to simultaneously achieve safe, efficient, and expedient operations at high traffic demand levels.

Flight crew fatigue III: North Sea helicopter air transport operations.

PubMed

Gander, P H; Barnes, R M; Gregory, K B; Graeber, R C; Connell, L J; Rosekind, M R

1998-09-01

We studied 32 helicopter pilots before, during, and after 4-5 d trips from Aberdeen, Scotland, to service North Sea oil rigs. On duty days, subjects awoke 1.5 h earlier than pretrip or posttrip, after having slept nearly an hour less. Subjective fatigue was greater posttrip than pretrip. By the end of trip days, fatigue was greater and mood more negative than by the end of pretrip days. During trips, daily caffeine consumption increased 42%, reports of headache doubled, reports of back pain increased 12-fold, and reports of burning eyes quadrupled. In the cockpits studied, thermal discomfort and high vibration levels were common. Subjective workload during preflight, taxi, climb, and cruise was related to the crewmembers' ratings of the quality of the aircraft systems. During descent and approach, workload was affected by weather at the landing site. During landing, it was influenced by the quality of the landing site and air traffic control. Beginning duty later, and greater attention to aircraft comfort and maintenance, should reduce fatigue in these operations.

Learning from Accident and Error: Avoiding the Hazards of Workload, Stress, and Routine Interruptions in the Emergency Department

PubMed Central

Morrison, J. Bradley; Rudolph, Jenny W.

2012-01-01

This article presents a model of how a build-up of interruptions can shift the dynamics of the emergency department (ED) from an adaptive, self-regulating system into a fragile, crisis-prone one. Drawing on case studies of organizational disasters and insights from the theory of high-reliability organizations, the authors use computer simulations to show how the accumulation of small interruptions could have disproportionately large effects in the ED. In the face of a mounting workload created by interruptions, EDs, like other organizational systems, have tipping points, thresholds beyond which a vicious cycle can lead rather quickly to the collapse of normal operating routines and in the extreme to a crisis of organizational paralysis. The authors discuss some possible implications for emergency medicine, emphasizing the potential threat from routine, non-novel demands on EDs and raising the concern that EDs are operating closer to the precipitous edge of crisis as ED crowding exacerbates the problem. PMID:22168187

A Study to Determine the Best Approach for Conducting a Formal Ambulatory Surgery Program at William Beaumont Army Medical Center, El Paso, Texas

DTIC Science & Technology

1982-05-01

and sex of the patient, but also scheduled time of surgery. It is not advisable to mix pre-operative and post-operative patients in the same area...Texas 79920 Haim4-=IC 18 January 1982 SUDJECT: pwequet for Surgical Workload Data 6. 1 certainly app-eciate your valuablOe sevice . 2 Incl HNRM C

Aircraft Engine-Monitoring System And Display

NASA Technical Reports Server (NTRS)

Abbott, Terence S.; Person, Lee H., Jr.

1992-01-01

Proposed Engine Health Monitoring System and Display (EHMSD) provides enhanced means for pilot to control and monitor performances of engines. Processes raw sensor data into information meaningful to pilot. Provides graphical information about performance capabilities, current performance, and operational conditions in components or subsystems of engines. Provides means to control engine thrust directly and innovative means to monitor performance of engine system rapidly and reliably. Features reduce pilot workload and increase operational safety.

EMS helicopter incidents reported to the NASA Aviation Safety Reporting System

NASA Technical Reports Server (NTRS)

Connell, Linda J.; Reynard, William D.

1993-01-01

The objectives of this evaluation were to: Identify the types of safety-related incidents reported to the Aviation Safety Reporting System (ASRS) in Emergency Medical Service (EMS) helicopter operations; Describe the operational conditions surrounding these incidents, such as weather, airspace, flight phase, time of day; and Assess the contribution to these incidents of selected human factors considerations, such as communication, distraction, time pressure, workload, and flight/duty impact.

Investigating the Usefulness of Soldier Aids for Autonomous Unmanned Ground Vehicles, Part 2

DTIC Science & Technology

2015-03-01

distribution is unlimited. 13. SUPPLEMENTARY NOTES DCS Corporation, Alexandria, VA 14. ABSTRACT In the past, robot operation has been a high-cognitive...increase performance and reduce perceived workload. The aids were overlays displaying what an autonomous robot perceived in the environment and the...subsequent course of action planned by the robot . Eight active-duty, US Army Soldiers completed 16 scenario missions using an operator interface

Fatigue in Military Operational Environments: An Annotated Bibliography

DTIC Science & Technology

2007-07-01

Office Soldier, SFAE-SDR, 5901 Putnam Road, Bldg. 328, Ft. Belvoir, VA 22060-5422. Reproduction of all or part of this report is authorized...During the operation there was an extensive use of hypnotics (temazepam) by air crews. The workload was depending on aircraft type and mission...countermeasures. Various components of the U.S. military have authorized the use of specific compounds for this purpose. Hypnotics such as temazepam

Helicopter Handling Qualities

NASA Technical Reports Server (NTRS)

1982-01-01

Helicopters are used by the military and civilian communities for a variety of tasks and must be capable of operating in poor weather conditions and at night. Accompanying extended helicopter operations is a significant increase in pilot workload and a need for better handling qualities. An overview of the status and problems in the development and specification of helicopter handling-qualities criteria is presented. Topics for future research efforts by government and industry are highlighted.

Staffing benchmarks for histology laboratories.

PubMed

Buesa, René J

2010-06-01

This article summarizes annual workloads for staff positions and work flow productivity (WFP) values from 247 human pathology, 31 veterinary, and 35 forensic histology laboratories (histolabs). There are single summaries for veterinary and forensic histolabs, but the data from human pathology are divided into 2 groups because of statistically significant differences between those from Spain and 6 Hispano American countries (SpHA) and the rest from the United States and 17 other countries. The differences reflect the way the work is organized, but the histotechnicians and histotechnologists (histotechs) from SpHA have the same task productivity levels as those from any other country (Buesa RJ. Productivity standards for histology laboratories. [YADPA 50,552]). The information is also segregated by groups of histolabs with increasing workloads; this aspect also showed statistical differences. The information from human pathology histolabs other than those from SpHA were used to calculate staffing annual benchmarks for pathologists (from 3700 to 6500 cases depending on the histolab annual workload), pathology assistants (20,000 cases), staff histotechs (9900 blocks), cutting histotechs (15,000 blocks), histotechs doing special procedures (9500 slides if done manually or 15,000 slides with autostainers), dieners (100 autopsies), laboratory aides and transcriptionists (15,000 cases each), and secretaries (20,000 cases). There are also recommendations about workload limits for supervisory staff (lead techs and supervisors) and when neither is required. Each benchmark was related with the productivity of the different tasks they include (Buesa RJ. Productivity standards for histology laboratories. [YADPA 50,552]) to calculate the hours per year required to complete them. The relationship between workload and benchmarks allows the director of pathology to determine the staff needed for the efficient operation of the histolab.

The influence of anaesthetists' experience on workload, performance and visual attention during simulated critical incidents.

PubMed

Schulz, Christian M; Schneider, Erich; Kohlbecher, Stefan; Hapfelmeier, Alexander; Heuser, Fabian; Wagner, Klaus J; Kochs, Eberhard F; Schneider, Gerhard

2014-10-01

Development of accurate Situation Awareness (SA) depends on experience and may be impaired during excessive workload. In order to gain adequate SA for decision making and performance, anaesthetists need to distribute visual attention effectively. Therefore, we hypothesized that in more experienced anaesthetists performance is better and increase of physiological workload is less during critical incidents. Additionally, we investigated the relation between physiological workload indicators and distribution of visual attention. In fifteen anaesthetists, the increase of pupil size and heart rate was assessed in course of a simulated critical incident. Simulator log files were used for performance assessment. An eye-tracking device (EyeSeeCam) provided data about the anaesthetists' distribution of visual attention. Performance was assessed as time until definitive treatment. T tests and multivariate generalized linear models (MANOVA) were used for retrospective statistical analysis. Mean pupil diameter increase was 8.1% (SD ± 4.3) in the less experienced and 15.8% (±10.4) in the more experienced subjects (p = 0.191). Mean heart rate increase was 10.2% (±6.7) and 10.5% (±8.3, p = 0.956), respectively. Performance did not depend on experience. Pupil diameter and heart rate increases were associated with a shift of visual attention from monitoring towards manual tasks (not significant). For the first time, the following four variables were assessed simultaneously: physiological workload indicators, performance, experience, and distribution of visual attention between "monitoring" and "manual" tasks. However, we were unable to detect significant interactions between these variables. This experimental model could prove valuable in the investigation of gaining and maintaining SA in the operation theatre.

Charlotte - EDC Evaluation and Demonstration (CEED) Human-in-the-Loop Results Briefing to ATD-2 FAA Partners

NASA Technical Reports Server (NTRS)

Chevalley, Eric

2016-01-01

The Charlotte EDC Evaluation and Demonstration (CEED) was the first Human-In-The-Loop experiment under the Air Traffic Management Technology Demonstration-2 (ATD-2) project. The purpose of the study was fourfold: 1) to establish a simulation environment (Charlotte) for airspace operations for ATD-2 technology, 2) to simulate current-day departures and arrival operations, 3) to assess the impact of current Traffic Management Initiatives (TMI) on Charlotte (CLT) departure flows and en route operations in Washington (ZDC) and Atlanta Centers (ZTL), and 4) to assess the impact of departure takeoff time compliance on airspace operations. The experimental design compared 3 TMIs and 2 compliance levels. Fourteen FAA retired controllers participated in the simulation. In addition, two Traffic Management Coordinators from ZTL and ZDC managed traffic flows. Surface and airborne delays, control efficiency, throughput, realism, workload, and acceptability were assessed and will be compared across the experimental conditions. Participants rated the simulation as very realistic. Results indicate that different TMIs have different impacts on surface and airspace delay. Departure compliance indicates partial benefits to sector complexity and controller workload. This simulation will provide an initial assessment of the tactical scheduling problems that the ATD-2 technology will address in the near term.

CRAB3: Establishing a new generation of services for distributed analysis at CMS

NASA Astrophysics Data System (ADS)

Cinquilli, M.; Spiga, D.; Grandi, C.; Hernàndez, J. M.; Konstantinov, P.; Mascheroni, M.; Riahi, H.; Vaandering, E.

2012-12-01

In CMS Computing the highest priorities for analysis tools are the improvement of the end users’ ability to produce and publish reliable samples and analysis results as well as a transition to a sustainable development and operations model. To achieve these goals CMS decided to incorporate analysis processing into the same framework as data and simulation processing. This strategy foresees that all workload tools (TierO, Tier1, production, analysis) share a common core with long term maintainability as well as the standardization of the operator interfaces. The re-engineered analysis workload manager, called CRAB3, makes use of newer technologies, such as RESTFul based web services and NoSQL Databases, aiming to increase the scalability and reliability of the system. As opposed to CRAB2, in CRAB3 all work is centrally injected and managed in a global queue. A pool of agents, which can be geographically distributed, consumes work from the central services serving the user tasks. The new architecture of CRAB substantially changes the deployment model and operations activities. In this paper we present the implementation of CRAB3, emphasizing how the new architecture improves the workflow automation and simplifies maintainability. In particular, we will highlight the impact of the new design on daily operations.

[Cost analysis of home care with activity-based costing (ABC)].

PubMed

Lee, Su-Jeong

2004-10-01

This study was carried out to substantiate the application process of activity-based costing on the current cost of hospital home care (HHC) service. The study materials were documents, 120 client charts, health insurance demand bills, salary of 215 HHC nurses, operating expense, 6 HHC agencies, and 31 HHC nurses. The research was carried out by analyzing the HHC activities and then collecting labor and operating expenses. For resource drivers, HHC activity performance time and workload were studied. For activity drivers, the number of HHC activity performances and the activity number of visits were studied. The HHC activities were classified into 70 activities. In resource, the labor cost was 245 won per minute, operating cost was 9,570 won per visit and traffic expense was an average of 12,750 won. In resource drivers, education and training had the longest time of 67 minutes. Average length of performance for activities was 13.7 minutes. The workload was applied as a relative value. The average cost of HHC was 62,741 won and the cost ranged from 55,560 won to 74,016 won. The fixed base rate for a visit in the current HHC medical fee should be increased. Exclusion from the current fee structure or flexible operation of traveling expenses should be reviewed.

Maximum Movement Workloads and High-Intensity Workload Demands by Position in NCAA Division I Collegiate Football.

PubMed

Sanders, Gabriel J; Roll, Brad; Peacock, Corey A; Kollock, Roger O

2018-05-02

Sanders, GJ, Roll, B, Peacock, CA, and Kollock, RO. Maximum movement workloads and high-intensity workload demands by position in NCAA division I collegiate football. J Strength Cond Res XX(X): 000-000, 2018-The purpose of the study was to quantify the average and maximum (i.e., peak) movement workloads, and the percent of those workloads performed at high intensity by NCAA division I football athletes during competitive games. Using global positioning system devices (Catapult Sports), low, moderate, and high and total multidirectional movement workloads were quantified by each position. Strategically achieving maximal workloads may improve both conditioning and rehabilitation protocols for athletes as they prepare for competition or return to play after an injury. A total of 40 football athletes were included in the analysis. For the data to be included, athletes were required to participate in ≥75% of the offensive or defensive snaps for any given game. There was a total of 286 data downloads from 13 different games for 8 different football positions. Data were calculated and compared by offensive and defensive position to establish the mean, SD, and maximum workloads during competitive games. The percent high-intensity workload profile was established to assess the total number and percent of high-intensity movement workloads by position. The profile was calculated by dividing a position's maximal high-intensity movement workload by the total (e.g., sum of maximal low, moderate, and high-intensity movements) movement workload. One-way analysis of variances revealed that there was a main effect of football position for total movement workloads and the percent of workloads performed at high intensities (p ≤ 0.025 for all). Maximal high-intensity workloads were 1.6-4.3 times greater than average high-intensity workloads, and the percent of total workloads performed at high intensities varied greatly by position. Strategically training for and using maximal movement workloads can help ensure that athletes are achieving workloads that are similar to the greatest demands of a competitive game.

DESIGN AND EVALUATION OF INDIVIDUAL ELEMENTS OF THE INTERFACE FOR AN AGRICULTURAL MACHINE.

PubMed

Rakhra, Aadesh K; Mann, Danny D

2018-01-29

If a user-centered approach is not used to design information displays, the quantity and quality of information presented to the user may not match the needs of the user, or it may exceed the capability of the human operator for processing and using that information. The result may be an excessive mental workload and reduced situation awareness of the operator, which can negatively affect the machine performance and operational outcomes. The increasing use of technology in agricultural machines may expose the human operator to excessive and undesirable information if the operator's information needs and information processing capabilities are ignored. In this study, a user-centered approach was used to design specific interface elements for an agricultural air seeder. Designs of the interface elements were evaluated in a laboratory environment by developing high-fidelity prototypes. Evaluations of the user interface elements yielded significant improvement in situation awareness (up to 11%; overall mean difference = 5.0 (4.8%), 95% CI (6.4728, 3.5939), p 0.0001). Mental workload was reduced by up to 19.7% (overall mean difference = -5.2 (-7.9%), n = 30, a = 0.05). Study participants rated the overall performance of the newly designed user-centered interface elements higher in comparison to the previous designs (overall mean difference = 27.3 (189.8%), 99% CI (35.150, 19.384), p 0.0001. Copyright© by the American Society of Agricultural Engineers.

A Method to Increase Drivers' Trust in Collision Warning Systems Based on Reliability Information of Sensor

NASA Astrophysics Data System (ADS)

Tsutsumi, Shigeyoshi; Wada, Takahiro; Akita, Tokihiko; Doi, Shun'ichi

Driver's workload tends to be increased during driving under complicated traffic environments like a lane change. In such cases, rear collision warning is effective for reduction of cognitive workload. On the other hand, it is pointed out that false alarm or missing alarm caused by sensor errors leads to decrease of driver' s trust in the warning system and it can result in low efficiency of the system. Suppose that reliability information of the sensor is provided in real-time. In this paper, we propose a new warning method to increase driver' s trust in the system even with low sensor reliability utilizing the sensor reliability information. The effectiveness of the warning methods is shown by driving simulator experiments.

Automation design and crew coordination

NASA Technical Reports Server (NTRS)

Segal, Leon D.

1993-01-01

Advances in technology have greatly impacted the appearance of the modern aircraft cockpit. Where once one would see rows upon rows. The introduction of automation has greatly altered the demands on the pilots and the dynamics of aircrew task performance. While engineers and designers continue to implement the latest technological innovations in the cockpit - claiming higher reliability and decreased workload - a large percentage of aircraft accidents are still attributed to human error. Rather than being the main instigators of accidents, operators tend to be the inheritors of system defects created by poor design, incorrect installation, faulty maintenance and bad management decisions. This paper looks at some of the variables that need to be considered if we are to eliminate at least one of these inheritances - poor design. Specifically, this paper describes the first part of a comprehensive study aimed at identifying the effects of automation on crew coordination.

A Human-in-the Loop Exploration of the Dynamic Airspace Configuration Concept

NASA Technical Reports Server (NTRS)

Homola, Jeffrey; Lee, Paul U.; Prevot, Thomas; Lee, Hwasoo; Kessell, Angela; Brasil, Connie; Smith, Nancy

2010-01-01

An exploratory human-in-the-loop study was conducted to better understand the impact of Dynamic Airspace Configuration (DAC) on air traffic controllers. To do so, a range of three progressively more aggressive algorithmic approaches to sectorizations were chosen. Sectorizations from these algorithms were used to test and quantify the range of impact on the controller and traffic. Results show that traffic count was more equitably distributed between the four test sectors and duration of counts over MAP were progressively lower as the magnitude of boundary change increased. However, taskload and workload were also shown to increase with the increase in aggressiveness and acceptability of the boundary changes decreased. Overall, simulated operations of the DAC concept did not appear to compromise safety. Feedback from the participants highlighted the importance of limiting some aspects of boundary changes such as amount of volume gained or lost and the extent of change relative to the initial airspace design.

The Relative Merits of PBL (Problem-Based Learning) in University Education

ERIC Educational Resources Information Center

Benson, Steve

2012-01-01

In Australia, academic workloads are increasing, and university funding is decreasing. Academics and university managers are engaging in risk adverse behavior and tending to focus on customer satisfaction and student retention, potentially at the expense of academic standards. Conventional approaches to pedagogy minimize adverse student feedback,…

Bioinstrumentation for evaluation of workload in payload specialists: results of ASSESS II

NASA Astrophysics Data System (ADS)

Wegmann, Hans M.; Herrmann, Reinhold; Winget, Charles M.

1980-11-01

ASSESS II‡Acronym for Airborne Science/Spacelab Experiments System Simulation. was a cooperative NASA-ESA project which consisted of a detailed simulation of Spacelab operations using the NASA Ames Research Center CV-990 aircraft laboratory. The Medical Experiment reported on in this paper was part of the complex payload consisting of 11 different experiments. Its general purpose was to develop a technology, possibly flown on board of Spacelab, and enabling the assessment of workload through evaluating changes of circadian rhythmicity, sleep disturbances and episodical or cumulative stress. As parameters the following variables were measured: Rectal temperature, ECG, sleep-EEG and -EOG, the urinary excretion of hormones and electrolytes. The results revealed evidence that a Spacelab environment, as simulated in ASSESS II, will lead to internal dissociation of circadian rhythms, to sleep disturbances and to highly stressful working conditions. Altogether these effects will impose considerable workload upon Payload Specialists. It is suggested that an intensive pre-mission system simulation will reduce these impairments to a reasonable degree. The bioinstrumentation applied in this experiment proved to be a practical and reliable tool in assessing the objectives of the study.

Workload measurement in a communication application operated through a P300-based brain-computer interface

NASA Astrophysics Data System (ADS)

Riccio, A.; Leotta, F.; Bianchi, L.; Aloise, F.; Zickler, C.; Hoogerwerf, E.-J.; Kübler, A.; Mattia, D.; Cincotti, F.

2011-04-01

Advancing the brain-computer interface (BCI) towards practical applications in technology-based assistive solutions for people with disabilities requires coping with problems of accessibility and usability to increase user acceptance and satisfaction. The main objective of this study was to introduce a usability-oriented approach in the assessment of BCI technology development by focusing on evaluation of the user's subjective workload and satisfaction. The secondary aim was to compare two applications for a P300-based BCI. Eight healthy subjects were asked to use an assistive technology solution which integrates the P300-based BCI with commercially available software under two conditions—visual stimuli needed to evoke the P300 response were either overlaid onto the application's graphical user interface or presented on a separate screen. The two conditions were compared for effectiveness (level of performance), efficiency (subjective workload measured by means of NASA-TXL) and satisfaction of the user. Although no significant difference in usability could be detected between the two conditions, the methodology proved to be an effective tool to highlight weaknesses in the technical solution.

Automated Air Traffic Control Operations with Weather and Time-Constraints: A First Look at (Simulated) Far-Term Control Room Operations

NASA Technical Reports Server (NTRS)

Prevot, Thomas; Homola, Jeffrey R.; Martin, Lynne H.; Mercer, Joey S.; Cabrall, Christopher C.

2011-01-01

In this paper we discuss results from a recent high fidelity simulation of air traffic control operations with automated separation assurance in the presence of weather and time-constraints. We report findings from a human-in-the-loop study conducted in the Airspace Operations Laboratory (AOL) at the NASA Ames Research Center. During four afternoons in early 2010, fifteen active and recently retired air traffic controllers and supervisors controlled high levels of traffic in a highly automated environment during three-hour long scenarios, For each scenario, twelve air traffic controllers operated eight sector positions in two air traffic control areas and were supervised by three front line managers, Controllers worked one-hour shifts, were relieved by other controllers, took a 3D-minute break, and worked another one-hour shift. On average, twice today's traffic density was simulated with more than 2200 aircraft per traffic scenario. The scenarios were designed to create peaks and valleys in traffic density, growing and decaying convective weather areas, and expose controllers to heavy and light metering conditions. This design enabled an initial look at a broad spectrum of workload, challenge, boredom, and fatigue in an otherwise uncharted territory of future operations. In this paper we report human/system integration aspects, safety and efficiency results as well as airspace throughput, workload, and operational acceptability. We conclude that, with further refinements. air traffic control operations with ground-based automated separation assurance can be an effective and acceptable means to routinely provide very high traffic throughput in the en route airspace.

INITIATORS AND TRIGGERING CONDITIONS FOR ADAPTIVE AUTOMATION IN ADVANCED SMALL MODULAR REACTORS

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

Katya L Le Blanc; Johanna h Oxstrand

It is anticipated that Advanced Small Modular Reactors (AdvSMRs) will employ high degrees of automation. High levels of automation can enhance system performance, but often at the cost of reduced human performance. Automation can lead to human out-of the loop issues, unbalanced workload, complacency, and other problems if it is not designed properly. Researchers have proposed adaptive automation (defined as dynamic or flexible allocation of functions) as a way to get the benefits of higher levels of automation without the human performance costs. Adaptive automation has the potential to balance operator workload and enhance operator situation awareness by allocating functionsmore » to the operators in a way that is sensitive to overall workload and capabilities at the time of operation. However, there still a number of questions regarding how to effectively design adaptive automation to achieve that potential. One of those questions is related to how to initiate (or trigger) a shift in automation in order to provide maximal sensitivity to operator needs without introducing undesirable consequences (such as unpredictable mode changes). Several triggering mechanisms for shifts in adaptive automation have been proposed including: operator initiated, critical events, performance-based, physiological measurement, model-based, and hybrid methods. As part of a larger project to develop design guidance for human-automation collaboration in AdvSMRs, researchers at Idaho National Laboratory have investigated the effectiveness and applicability of each of these triggering mechanisms in the context of AdvSMR. Researchers reviewed the empirical literature on adaptive automation and assessed each triggering mechanism based on the human-system performance consequences of employing that mechanism. Researchers also assessed the practicality and feasibility of using the mechanism in the context of an AdvSMR control room. Results indicate that there are tradeoffs associated with each mechanism, but that some are more applicable to the AdvSMR domain. The two mechanisms that consistently improve performance in laboratory studies are operator initiated adaptive automation based on hierarchical task delegation and the Electroencephalogram(EEG) –based measure of engagement. Current EEG methods are intrusive and require intensive analysis; therefore it is not recommended for an AdvSMR control rooms at this time. Researchers also discuss limitations in the existing empirical literature and make recommendations for further research.« less

77 FR 329 - Flightcrew Member Duty and Rest Requirements

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-04

... length of duty day, starting time, workload, and other factors shown by recent research, scientific... the universality of factors that lead to fatigue in most individuals and regulates these factors to... between domestic, supplemental and flag passenger operations because the factors leading to fatigue are...

78 FR 9865 - Air Carrier Contract Maintenance Requirements; Extension of Comment Period

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-12

..., RACCA believes the proposed rulemaking would result in significant unintended consequences, including greater operator cost and manpower requirements than those estimated in the NPRM, loss of efficiency, unbudgeted loss of aircraft availability, and a substantial additional workload for the FAA that would result...

Spikes in acute workload are associated with increased injury risk in elite cricket fast bowlers.

PubMed

Hulin, Billy T; Gabbett, Tim J; Blanch, Peter; Chapman, Paul; Bailey, David; Orchard, John W

2014-04-01

To determine if the comparison of acute and chronic workload is associated with increased injury risk in elite cricket fast bowlers. Data were collected from 28 fast bowlers who completed a total of 43 individual seasons over a 6-year period. Workloads were estimated by summarising the total number of balls bowled per week (external workload), and by multiplying the session rating of perceived exertion by the session duration (internal workload). One-week data (acute workload), together with 4-week rolling average data (chronic workload), were calculated for external and internal workloads. The size of the acute workload in relation to the chronic workload provided either a negative or positive training-stress balance. A negative training-stress balance was associated with an increased risk of injury in the week after exposure, for internal workload (relative risk (RR)=2.2 (CI 1.91 to 2.53), p=0.009), and external workload (RR=2.1 (CI 1.81 to 2.44), p=0.01). Fast bowlers with an internal workload training-stress balance of greater than 200% had a RR of injury of 4.5 (CI 3.43 to 5.90, p=0.009) compared with those with a training-stress balance between 50% and 99%. Fast bowlers with an external workload training-stress balance of more than 200% had a RR of injury of 3.3 (CI 1.50 to 7.25, p=0.033) in comparison to fast bowlers with an external workload training-stress balance between 50% and 99%. These findings demonstrate that large increases in acute workload are associated with increased injury risk in elite cricket fast bowlers.

Terminal Area Procedures for Paired Runways

NASA Technical Reports Server (NTRS)

Lozito, Sandra; Verma, Savita Arora

2011-01-01

Parallel runway operations have been found to increase capacity within the National Airspace but poor visibility conditions reduce the use of these operations. The NextGen and SESAR Programs have identified the capacity benefits from increased use of closely-space parallel runway. Previous research examined the concepts and procedures related to parallel runways however, there has been no investigation of the procedures associated with the strategic and tactical pairing of aircraft for these operations. This simulation study developed and examined the pilot and controller procedures and information requirements for creating aircraft pairs for parallel runway operations. The goal was to achieve aircraft pairing with a temporal separation of 15s (+/- 10s error) at a coupling point that was about 12 nmi from the runway threshold. Two variables were explored for the pilot participants: two levels of flight deck automation (current-day flight deck automation and auto speed control future automation) as well as two flight deck displays that assisted in pilot conformance monitoring. The controllers were also provided with automation to help create and maintain aircraft pairs. Results show the operations in this study were acceptable and safe. Subjective workload, when using the pairing procedures and tools, was generally low for both controllers and pilots, and situation awareness was typically moderate to high. Pilot workload was influenced by display type and automation condition. Further research on pairing and off-nominal conditions is required however, this investigation identified promising findings about the feasibility of closely-spaced parallel runway operations.

Evaluation of occupational physical load during 6-month international crisis management operation.

PubMed

Pihlainen, Kai; Santtila, Matti; Vasankari, Tommi; Häkkinen, Keijo; Kyröläinen, Heikki

2018-01-07

Generally, operational military duties are associated with a variety of stressors, such as prolonged physical activity (PA). However, limited information is available on the occupational workload or changes in PA during international military operations. Thus, the aim of the study was to investigate the changes in body composition, stress biomarkers, PA, and heart rate (HR) responses of 79 male soldiers during a 6-month international crisis management operation. Measurements were conducted 3 times in South-Lebanon during the operation. Body composition was assessed by the bioelectrical impedance method. Blood samples were analyzed for serum testosterone, sex-hormone binding globulin (SHBG), cortisol and insulin-like growth factor. Saliva sampling was used for analyzing stress biomarkers, cortisol and α-amylase. Heart rate and physical activity were monitored by a recordable belt and tri-axial accelerometer, respectively. Increases in muscle mass (39.2±4.1 vs. 39.5±4.2 kg, p < 0.05) and testosterone (15.9±4.6 vs. 17.2±4 nmol/l, p < 0.01), and reductions in PA variables (e.g., daily step count 9472±2547 vs. 8321±2720, p < 0.05) were observed during the first half (i.e., PRE-MID) of the study. The increase in muscle mass remained significant during the latter half (PRE-POST, 39.2±4.1 vs. 39.6±4.4 kg, p < 0.05), but also fat mass increased (MID-POST, 10.6±4.6 vs. 11.0±4.7 kg, p < 0.05) while SHBG (MID-POST, 31.8±12.1 vs. 26.6±13.2 nmol/l, p < 0.01) and cortisol (MID-POST, 445±116 vs. 400±123 nmol/l, p < 0.05) decreased. With the exception of increased concentration of salivary α-amylase (PRE-POST, 36.5±33.7 vs. 55.1±39.7 U/ml), the acute stress biomarkers and HR responses remained unchanged. Furthermore, the low quantity of PA, low HR values and subjective ratings of exertion refer to rather light physical workload. Due to the operatively calm nature of the working environment, the present soldiers did not express any significant signs of physical overload during the study period. Int J Occup Med Environ Health 2018;31(2):185-197. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Visual scanning behavior and pilot workload

NASA Technical Reports Server (NTRS)

Harris, R. L., Sr.; Tole, J. R.; Stephens, A. T.; Ephrath, A. R.

1982-01-01

This paper describes an experimental paradigm and a set of results which demonstrate a relationship between the level of performance on a skilled man-machine control task, the skill of the operator, the level of mental difficulty induced by an additional task imposed on the basic control task, and visual scanning performance. During a constant, simulated piloting task, visual scanning of instruments was found to vary with the difficulty of a verbal mental loading task. The average dwell time of each fixation on the pilot's primary instrument increased with the estimated skill level of the pilots, with novices being affected by the loading task much more than experts. The results suggest that visual scanning of instruments in a controlled task may be an indicator of both workload and skill.

Heavy vehicle driver workload assessment. Task 4, review of workload and related research

DOT National Transportation Integrated Search

This report reviews literature on workload measures and related research. It depicts the preliminary development of a theoretical basis for relating driving workload to highway safety and a selective review of driver performance evaluation, workload ...

Handbook for Operating the OWLKNEST Technology

DTIC Science & Technology

1992-06-01

D . A. (Ed.). (1988). Expert systems [Special issue]. Human Factors, 30(4), 377-443. Byers, J . C., Hill, S. G., Zaklad, A. L., & Christ, R. E. (1989...Sons. Harmon, P., & King, D . (1985). Expert systems: Artificial intelligence in business. New York, NY: John Wiley & Sons. Hill, S. G., Byers, J . C...Plamondon, B. D ., Linton, P. M., Wierwille, W. W., Zaklad, A. L., Bittner, A. C., Jr., & Wherry, R. J ., Jr. (1989). Operator workload: Comprehensive

A covert attention P300-based brain-computer interface: Geospell.

PubMed

Aloise, Fabio; Aricò, Pietro; Schettini, Francesca; Riccio, Angela; Salinari, Serenella; Mattia, Donatella; Babiloni, Fabio; Cincotti, Febo

2012-01-01

The Farwell and Donchin P300 speller interface is one of the most widely used brain-computer interface (BCI) paradigms for writing text. Recent studies have shown that the recognition accuracy of the P300 speller decreases significantly when eye movement is impaired. This report introduces the GeoSpell interface (Geometric Speller), which implements a stimulation framework for a P300-based BCI that has been optimised for operation in covert visual attention. We compared the Geospell with the P300 speller interface under overt attention conditions with regard to effectiveness, efficiency and user satisfaction. Ten healthy subjects participated in the study. The performance of the GeoSpell interface in covert attention was comparable with that of the P300 speller in overt attention. As expected, the effectiveness of the spelling decreased with the new interface in covert attention. The NASA task load index (TLX) for workload assessment did not differ significantly between the two modalities. This study introduces and evaluates a gaze-independent, P300-based brain-computer interface, the efficacy and user satisfaction of which were comparable with those off the classical P300 speller. Despite a decrease in effectiveness due to the use of covert attention, the performance of the GeoSpell far exceeded the threshold of accuracy with regard to effective spelling.

Effective Connectivity Analysis of the Brain Network in Drivers during Actual Driving Using Near-Infrared Spectroscopy

PubMed Central

Liu, Zhian; Zhang, Ming; Xu, Gongcheng; Huo, Congcong; Tan, Qitao; Li, Zengyong; Yuan, Quan

2017-01-01

Driving a vehicle is a complex activity that requires high-level brain functions. This study aimed to assess the change in effective connectivity (EC) between the prefrontal cortex (PFC), motor-related areas (MA) and vision-related areas (VA) in the brain network among the resting, simple-driving and car-following states. Twelve young male right-handed adults were recruited to participate in an actual driving experiment. The brain delta [HbO2] signals were continuously recorded using functional near infrared spectroscopy (fNIRS) instruments. The conditional Granger causality (GC) analysis, which is a data-driven method that can explore the causal interactions among different brain areas, was performed to evaluate the EC. The results demonstrated that the hemodynamic activity level of the brain increased with an increase in the cognitive workload. The connection strength among PFC, MA and VA increased from the resting state to the simple-driving state, whereas the connection strength relatively decreased during the car-following task. The PFC in EC appeared as the causal target, while the MA and VA appeared as the causal sources. However, l-MA turned into causal targets with the subtask of car-following. These findings indicate that the hemodynamic activity level of the cerebral cortex increases linearly with increasing cognitive workload. The EC of the brain network can be strengthened by a cognitive workload, but also can be weakened by a superfluous cognitive workload such as driving with subtasks. PMID:29163083

Reconsidering the conceptualization of nursing workload: literature review.

PubMed

Morris, Roisin; MacNeela, Padraig; Scott, Anne; Treacy, Pearl; Hyde, Abbey

2007-03-01

This paper reports a literature review that aimed to analyse the way in which nursing intensity and patient dependency have been considered to be conceptually similar to nursing workload, and to propose a model to show how these concepts actually differ in both theoretical and practical terms. The literature on nursing workload considers the concepts of patient 'dependency' and nursing 'intensity' in the realm of nursing workload. These concepts differ by definition but are used to measure the same phenomenon, i.e. nursing workload. The literature search was undertaken in 2004 using electronic databases, reference lists and other available literature. Papers were sourced from the Medline, Psychlit, CINAHL and Cochrane databases and through the general search engine Google. The keywords focussed on nursing workload, nursing intensity and patient dependency. Nursing work and workload concepts and labels are defined and measured in different and often contradictory ways. It is vitally important to understand these differences when using such conceptualizations to measure nursing workload. A preliminary model is put forward to clarify the relationships between nursing workload concepts. In presenting a preliminary model of nursing workload, it is hoped that nursing workload might be better understood so that it becomes more visible and recognizable. Increasing the visibility of nursing workload should have a positive impact on nursing workload management and on the provision of patient care.

Cardiorespiratory fitness, cardiovascular workload and risk factors among cleaners; a cluster randomized worksite intervention.

PubMed

Korshøj, Mette; Krustrup, Peter; Jørgensen, Marie Birk; Prescott, Eva; Hansen, Åse Marie; Kristiansen, Jesper; Skotte, Jørgen Henrik; Mortensen, Ole Steen; Søgaard, Karen; Holtermann, Andreas

2012-08-13

Prevalence of cardiovascular risk factors is unevenly distributed among occupational groups. The working environment, as well as lifestyle and socioeconomic status contribute to the disparity and variation in prevalence of these risk factors. High physical work demands have been shown to increase the risk for cardiovascular disease and mortality, contrary to leisure time physical activity. High physical work demands in combination with a low cardiorespiratory fitness infer a high relative workload and an excessive risk for cardiovascular mortality. Therefore, the aim of this study is to examine whether a worksite aerobic exercise intervention will reduce the relative workload and cardiovascular risk factors by an increased cardiorespiratory fitness. A cluster-randomized controlled trial is performed to evaluate the effect of the worksite aerobic exercise intervention on cardiorespiratory fitness and cardiovascular risk factors among cleaners. Cleaners are eligible if they are employed ≥ 20 hours/week, at one of the enrolled companies. In the randomization, strata are formed according to the manager the participant reports to. The clusters will be balanced on the following criteria: Geographical work location, gender, age and seniority. Cleaners are randomized to either I) a reference group, receiving lectures concerning healthy living, or II) an intervention group, performing worksite aerobic exercise "60 min per week". Data collection will be conducted at baseline, four months and 12 months after baseline, at the worksite during working hours. The data collection will consist of a questionnaire-based interview, physiological testing of health and capacity-related measures, and objective diurnal measures of heart rate, physical activity and blood pressure. Primary outcome is cardiorespiratory fitness. Information is lacking about whether an improved cardiorespiratory fitness will affect the cardiovascular health, and additionally decrease the objectively measured relative workload, in a population with high physical work demands. Previous intervention studies have lacked robust objective measurements of the relative workload and physical work demands. This study will monitor the relative workload and general physical activity before, during after the intervention, and contribute to the understanding of the previously observed opposing effects on cardiovascular health and mortality from occupational and leisure time physical activity. The study is registered as ISRCTN86682076.

Task Engagement, Cerebral Blood Flow Velocity, and Diagnostic Monitoring for Sustained Attention

ERIC Educational Resources Information Center

Matthews, Gerald; Warm, Joel S.; Reinerman-Jones, Lauren E.; Langheim, Lisa K.; Washburn, David A.; Tripp, Lloyd

2010-01-01

Loss of vigilance may lead to impaired performance in various applied settings including military operations, transportation, and industrial inspection. Individuals differ considerably in sustained attention, but individual differences in vigilance have proven to be hard to predict. The dependence of vigilance on workload factors is consistent…

76 FR 62074 - Proposed Revision of Performance Standards for State Medicaid Fraud Control Units

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-06

... volume of case referrals and workload for each location. Performance Standard 3--Policies and Procedures A Unit establishes written policies and procedures for its operations and ensures that staff are familiar with, and adhere to, policies and procedures. In meeting this standard, the following performance...

Space Station Human Factors Research Review. Volume 4: Inhouse Advanced Development and Research

NASA Technical Reports Server (NTRS)

Tanner, Trieve (Editor); Clearwater, Yvonne A. (Editor); Cohen, Marc M. (Editor)

1988-01-01

A variety of human factors studies related to space station design are presented. Subjects include proximity operations and window design, spatial perceptual issues regarding displays, image management, workload research, spatial cognition, virtual interface, fault diagnosis in orbital refueling, and error tolerance and procedure aids.

Classification Systems for Individual Differences in Multiple-task Performance and Subjective Estimates of Workload

NASA Technical Reports Server (NTRS)

Damos, D. L.

1984-01-01

Human factors practitioners often are concerned with mental workload in multiple-task situations. Investigations of these situations have demonstrated repeatedly that individuals differ in their subjective estimates of workload. These differences may be attributed in part to individual differences in definitions of workload. However, after allowing for differences in the definition of workload, there are still unexplained individual differences in workload ratings. The relation between individual differences in multiple-task performance, subjective estimates of workload, information processing abilities, and the Type A personality trait were examined.

Operational requirements for flight control and navigation systems for short haul transport aircraft

NASA Technical Reports Server (NTRS)

Morrison, J. A.

1978-01-01

To provide a background for evaluating advanced STOL systems concepts, a number of short haul and STOL airline operations in the United States and one operation in Canada were studied. A study of flight director operational procedures for an advanced STOL research airplane, the Augmented Wing Jet STOL Research Airplane, was conducted using the STOLAND simulation facility located at the Ames Changes to the advanced digital flight control system (STOLAND) installed in the Augmentor Wing Airplane are proposed to improve the mode sequencing to simplify pilot procedures and reduce pilot workload.

Feasibility of negative pressure wound therapy during intercontinental aeromedical evacuation of combat casualties.

PubMed

Fang, Raymond; Dorlac, Warren C; Flaherty, Stephen F; Tuman, Caroline; Cain, Steven M; Popey, Tracy L C; Villard, Douglas R; Aydelotte, Jayson D; Dunne, James R; Anderson, Adam M; Powell, Elisha T

2010-07-01

The objective of this study was to assess the feasibility of utilizing negative pressure wound therapy (NPWT) for the treatment of wartime soft-tissue wounds during intercontinental aeromedical evacuation. Attempts to use NPWT during early phases of overseas contingency operations resulted in occasional vacuum system failures and potentially contributed to wound complications. These anecdotal episodes led to a perception that NPWT during aeromedical evacuation carried a high risk of wound complications and limited its use. As a result, NPWT was not frequently applied in the management of soft-tissue wounds before US casualty arrival in the continental United States (CONUS) for wounds sustained in the combat theaters. Concurrently, early NPWT on the traumatic wounds of host nation casualties not requiring aeromedical evacuation seemed to provide many benefits typically associated with the therapy such as decreased infection rates, earlier wound closure, and improved pain management. On a daily basis, study investigators reviewed the trauma in-patient census at Landstuhl Regional Medical Center, Germany, to identify patient candidates with soft-tissue extremity or torso wounds that required packing. Patient demographics, injuries, and previous wound treatments were recorded. Surgeons inspected wounds in the operating room and applied a NPWT dressing if deemed appropriate. NPWT was continued throughout the remainder of the patient's hospitalization and also during aeromedical evacuation to CONUS. A study investigator escorted the patient during aeromedical evacuation to educate the flight crews, to record the impact on crew workload, and to troubleshoot the system if necessary. Thirty enrolled patients with 41 separate wounds flew from Germany to CONUS with a portable NPWT system (VAC Freedom System; Kinetic Concepts Incorporated, San Antonio, TX). All 30 patients arrived at the destination facilities with intact and functional systems. No significant in-flight complications were identified, impact on flight crew workload was negligible, and subjective feedback from both flight crews and patients was uniformly positive. For 29 patients, the NPWT dressing was replaced (frequently with serial exchanges) during initial surgical treatment in CONUS; the 30th patient underwent delayed primary closure of his right forearm fasciotomy. Receiving care teams reported no complications attributable to NPWT during aeromedical evacuation. NPWT is feasible during intercontinental aeromedical evacuation of combat casualties without an increase in wound complications or a significant impact on air crew workload. Further studies are indicated to evaluate the efficacy of NPWT in combat wounds compared with other wound care techniques.

Exploring factors that have caused a decrease in surgical manpower in Taiwan.

PubMed

Chen, Yi-Cheng; Shih, Chung-Liang; Wu, Chih-Hsiung; Chiu, Chiung-Hsuan

2014-10-01

The decreasing availability of surgical physicians is a concern in most countries. In the past decade, total physician manpower in Taiwan increased by 12%, but the number of surgical physicians decreased by 11%. Medical students are not inclined to choose surgery as a career--this study examines the factors involved in students' career choices. This study was conducted from January 2011 to April 2011. In total, 401 interns successfully completed questionnaires; this population makes up 34% of all interns in Taiwan. The structural questionnaire was designed to investigate factors affecting specialty decisions, with additional open-ended questions to investigate students' preferences in career specialty. Based on the research findings, the 3 most relevant factors in decreasing order of priority are personal interest, career-oriented lifestyle, and specialty characteristics (including workload and stress). For students likely to become surgical physicians, concerns about the work environment include the balance between work and family, wages that are incompatible with the workload, and the shortage of manpower on duty. Addressing the following concerns would increase medical students' likelihood of choosing a career in surgery: the need for a facilitator to help mitigate medical disputes and legal problems, decreased work hours, and decreased on-call duty hours. This study shows both motivating and discouraging factors affecting whether medical students choose surgery as a career. The purpose of this study is to strengthen the incentives for medical students to choose surgery as a career and to minimize the influence of factors that negatively affect such a choice. © The Author(s) 2014.

Use of computer-assisted drug therapy outside the operating room.

PubMed

Singh, Preet Mohinder; Borle, Anuradha; Goudra, Basavana G

2016-08-01

The number of procedures performed in the out-of-operating room setting under sedation has increased many fold in recent years. Sedation techniques aim to achieve rapid patient turnover through the use of short-acting drugs with minimal residual side-effects (mainly propofol and opioids). Even for common procedures, the practice of sedation delivery varies widely among providers. Computer-based sedation models have the potential to assist sedation providers and offer a more consistent and safer sedation experience for patients. Target-controlled infusions using propofol and other short-acting opioids for sedation have shown promising results in terms of increasing patient safety and allowing for more rapid wake-up times. Target-controlled infusion systems with real-time patient monitoring can titrate drug doses automatically to maintain optimal depth of sedation. The best recent example of this is the propofol-based Sedasys sedation system. Sedasys redefined individualized sedation by the addition of an automated clinical parameter that monitors depth of sedation. However, because of poor adoption and cost issues, it has been recently withdrawn by the manufacturer. Present automated drug delivery systems can assist in the provision of sedation for out-of-operating room procedures but cannot substitute for anesthesia providers. Use of the available technology has the potential to improve patient outcomes, decrease provider workload, and have a long-term economic impact on anesthesia care delivery outside of the operating room.

Flight Crew Workload Evaluation Based on the Workload Function Distribution Method.

PubMed

Zheng, Yiyuan; Lu, Yanyu; Jie, Yuwen; Fu, Shan

2017-05-01

The minimum flight crew on the flight deck should be established according to the workload for individual crewmembers. Typical workload measures consist of three types: subjective rating scale, task performance, and psychophysiological measures. However, all these measures have their own limitations. To reflect flight crew workload more specifically and comprehensively within the flight environment, and more directly comply with airworthiness regulations, the Workload Function Distribution Method, which combined the basic six workload functions, was proposed. The analysis was based on the different conditions of workload function numbers. Each condition was analyzed from two aspects, which were overall proportion and effective proportion. Three types of approach tasks were used in this study and the NASA-TLX scale was implemented for comparison. Neither the one-function condition nor the two-function condition had the same results with NASA-TLX. However, both the three-function and the four- to six- function conditions were identical with NASA-TLX. Further, the significant differences were different on four to six conditions. The overall proportion was insignificant, while the effective proportions were significant. The results show that the conditions with one function and two functions seemed to have no influence on workload, while executing three functions and four to six functions had an impact on workload. Besides, effective proportions of workload functions were more precisely compared with the overall proportions to indicate workload, especially in the conditions with multiple functions.Zheng Y, Lu Y, Jie Y, Fu S. Flight crew workload evaluation based on the workload function distribution method. Aerosp Med Hum Perform. 2017; 88(5):481-486.

Supporting Academic Workloads in Online Learning

ERIC Educational Resources Information Center

Haggerty, Carmel E.

2015-01-01

Academic workloads in online learning are influenced by many variables, the complexity of which makes it difficult to measure academic workloads in isolation. While researching issues associated with academic workloads, professional development stood out as having a substantive impact on academic workloads. Many academics in applied health degrees…

A physical workload index to evaluate a safe resident handling program for nursing home personnel.

PubMed

Kurowski, Alicia; Buchholz, Bryan; Punnett, Laura

2014-06-01

The aim of this study was to obtain a comprehensive analysis of the physical workload of clinical staff in long-term care facilities, before and after a safe resident handling program (SRHP). Ergonomic exposures of health care workers include manual handling of patients and many non-neutral postures. A comprehensive assessment requires the integration of loads from these varied exposures into a single metric. The Postures, Activities, Tools, and Handling observational protocol, customized for health care, was used for direct observations of ergonomic exposures in clinical jobs at 12 nursing homes before the SRHP and 3, 12, 24, and 36 months afterward. Average compressive forces on the spine were estimated for observed combinations of body postures and manual handling and then weighted by frequencies of observed time for the combination. These values were summed to obtain a biomechanical index for nursing assistants and nurses across observation periods. The physical workload index (PWI) was much higher for nursing assistants than for nurses and decreased more after 3 years (-24% versus -2.5%). Specifically during resident handling, the PWI for nursing assistants decreased by 41% of baseline value. Spinal loading was higher for nursing assistants than for nurses in long-term care centers. Both job groups experienced reductions in physical loading from the SRHP, especially the nursing assistants and especially while resident handling. The PWI facilitates a comprehensive investigation of physical loading from both manual handling and non-neutral postures. It can be used in any work setting to identify high-risk tasks and determine whether reductions in one exposure are offset by increases in another.

Timeliness in the German surveillance system for infectious diseases: Amendment of the infection protection act in 2013 decreased local reporting time to 1 day

PubMed Central

Diercke, Michaela; Salmon, Maëlle; Czogiel, Irina; Schumacher, Dirk; Claus, Hermann; Gilsdorf, Andreas

2017-01-01

Time needed to report surveillance data within the public health service delays public health actions. The amendment to the infection protection act (IfSG) from 29 March 2013 requires local and state public health agencies to report surveillance data within one working day instead of one week. We analysed factors associated with reporting time and evaluated the IfSG amendment. Local reporting time is the time between date of notification and date of export to the state public health agency and state reporting time is time between date of arrival at the state public health agency and the date of export. We selected cases reported between 28 March 2012 and 28 March 2014. We calculated the median local and state reporting time, stratified by potentially influential factors, computed a negative binominal regression model and assessed quality and workload parameters. Before the IfSG amendment the median local reporting time was 4 days and 1 day afterwards. The state reporting time was 0 days before and after. Influential factors are the individual local public health agency, the notified disease, the notification software and the day of the week. Data quality and workload parameters did not change. The IfSG amendment has decreased local reporting time, no relevant loss of data quality or identifiable workload-increase could be detected. State reporting time is negligible. We recommend efforts to harmonise practices of local public health agencies including the exclusive use of software with fully compatible interfaces. PMID:29088243

Anxiety is associated with diminished exercise performance and quality of life in severe emphysema: a cross-sectional study.

PubMed

Giardino, Nicholas D; Curtis, Jeffrey L; Andrei, Adin-Cristian; Fan, Vincent S; Benditt, Joshua O; Lyubkin, Mark; Naunheim, Keith; Criner, Gerard; Make, Barry; Wise, Robert A; Murray, Susan K; Fishman, Alfred P; Sciurba, Frank C; Liberzon, Israel; Martinez, Fernando J

2010-03-09

Anxiety in patients with chronic obstructive pulmonary disease (COPD) is associated with self-reported disability. The purpose of this study is to determine whether there is an association between anxiety and functional measures, quality of life and dyspnea. Data from 1828 patients with moderate to severe emphysema enrolled in the National Emphysema Treatment Trial (NETT), collected prior to rehabilitation and randomization, were used in linear regression models to test the association between anxiety symptoms, measured by the Spielberger State Trait Anxiety Inventory (STAI) and: (a) six-minute walk distance test (6 MWD), (b) cycle ergometry peak workload, (c) St. Georges Respiratory Questionnaire (SRGQ), and (d) UCSD Shortness of Breath Questionnaire (SOBQ), after controlling for potential confounders including age, gender, FEV1 (% predicted), DLCO (% predicted), and the Beck Depression Inventory (BDI). Anxiety was significantly associated with worse functional capacity [6 MWD (B = -0.944, p < .001), ergometry peak workload (B = -.087, p = .04)], quality of life (B = .172, p < .001) and shortness of breath (B = .180, p < .001). Regression coefficients show that a 10 point increase in anxiety score is associated with a mean decrease in 6 MWD of 9 meters, a 1 Watt decrease in peak exercise workload, and an increase of almost 2 points on both the SGRQ and SOBQ. In clinically stable patients with moderate to severe emphysema, anxiety is associated with worse exercise performance, quality of life and shortness of breath, after accounting for the influence of demographic and physiologic factors known to affect these outcomes. ClinicalTrials.gov NCT00000606.

Associations between Emotional Exhaustion, Social Capital, Workload, and Latitude in Decision-Making among Professionals Working with People with Disabilities

ERIC Educational Resources Information Center

Kowalski, Christoph; Driller, Elke; Ernstmann, Nicole; Alich, Saskia; Karbach, Ute; Ommen, Oliver; Schulz-Nieswandt, Frank; Pfaff, Holger

2010-01-01

Background: Many people working in human services in Western countries suffer from burnout, characterized by emotional exhaustion, depersonalization, and decreased personal performance. Prevention of emotional exhaustion (the first phase of burnout) constitutes a great challenge because emotional exhaustion may cause increasing turnover rates in…

Analysis of adaptive algorithms for an integrated communication network

NASA Technical Reports Server (NTRS)

Reed, Daniel A.; Barr, Matthew; Chong-Kwon, Kim

1985-01-01

Techniques were examined that trade communication bandwidth for decreased transmission delays. When the network is lightly used, these schemes attempt to use additional network resources to decrease communication delays. As the network utilization rises, the schemes degrade gracefully, still providing service but with minimal use of the network. Because the schemes use a combination of circuit and packet switching, they should respond to variations in the types and amounts of network traffic. Also, a combination of circuit and packet switching to support the widely varying traffic demands imposed on an integrated network was investigated. The packet switched component is best suited to bursty traffic where some delays in delivery are acceptable. The circuit switched component is reserved for traffic that must meet real time constraints. Selected packet routing algorithms that might be used in an integrated network were simulated. An integrated traffic places widely varying workload demands on a network. Adaptive algorithms were identified, ones that respond to both the transient and evolutionary changes that arise in integrated networks. A new algorithm was developed, hybrid weighted routing, that adapts to workload changes.

Study on workloads of human care worker with the introduction of IT system - the characteristics of work loads by observational research and the suggestions for KAIZEN.

PubMed

Mizuno, Yuki; Yoshikawa, Toru; Matsuda, Fumiko; Takeuchi, Yuriko; Motegi, Nobuyuki; Ikegami, Thor; Sakai, Kazuhiro

2012-01-01

The purpose of this study was to clarify the characteristic of workloads on human care worker with the introduction of IT system, and suggested the support measures for KAIZEN in Japan. The investigation method is workflow line and hearing with a focus on work observation. The objects were 8 human care workers of the acute hospital that introduced an electronic system. By the introduction of the electronic chart, the nurse station sojourn time decreased, sickroom sojourn time increased, and time about direct nursing care to a patient increased. In addition, access to patient information became easy, and the offer of the health care service based on correct information came to be possible in real time. By The point of workflow line, it was effect that moving lengths decreased in order to install the electronic chart in patients' rooms. Though, it was a problem that it hasn't formed where to place the instruments such as sphygmomanometer, clinical thermometer and others.

Balancing nurses' workload in hospital wards: study protocol of developing a method to manage workload.

PubMed

van den Oetelaar, W F J M; van Stel, H F; van Rhenen, W; Stellato, R K; Grolman, W

2016-11-10

Hospitals pursue different goals at the same time: excellent service to their patients, good quality care, operational excellence, retaining employees. This requires a good balance between patient needs and nursing staff. One way to ensure a proper fit between patient needs and nursing staff is to work with a workload management method. In our view, a nursing workload management method needs to have the following characteristics: easy to interpret; limited additional registration; applicable to different types of hospital wards; supported by nurses; covers all activities of nurses and suitable for prospective planning of nursing staff. At present, no such method is available. The research follows several steps to come to a workload management method for staff nurses. First, a list of patient characteristics relevant to care time will be composed by performing a Delphi study among staff nurses. Next, a time study of nurses' activities will be carried out. The 2 can be combined to estimate care time per patient group and estimate the time nurses spend on non-patient-related activities. These 2 estimates can be combined and compared with available nursing resources: this gives an estimate of nurses' workload. The research will take place in an academic hospital in the Netherlands. 6 surgical wards will be included, capacity 15-30 beds. The study protocol was submitted to the Medical Ethical Review Board of the University Medical Center (UMC) Utrecht and received a positive advice, protocol number 14-165/C. This method will be developed in close cooperation with staff nurses and ward management. The strong involvement of the end users will contribute to a broader support of the results. The method we will develop may also be useful for planning purposes; this is a strong advantage compared with existing methods, which tend to focus on retrospective analysis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

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.

Into the Wild: Neuroergonomic Differentiation of Hand-Held and Augmented Reality Wearable Displays during Outdoor Navigation with Functional Near Infrared Spectroscopy.

PubMed

McKendrick, Ryan; Parasuraman, Raja; Murtza, Rabia; Formwalt, Alice; Baccus, Wendy; Paczynski, Martin; Ayaz, Hasan

2016-01-01

Highly mobile computing devices promise to improve quality of life, productivity, and performance. Increased situation awareness and reduced mental workload are two potential means by which this can be accomplished. However, it is difficult to measure these concepts in the "wild". We employed ultra-portable battery operated and wireless functional near infrared spectroscopy (fNIRS) to non-invasively measure hemodynamic changes in the brain's Prefrontal cortex (PFC). Measurements were taken during navigation of a college campus with either a hand-held display, or an Augmented reality wearable display (ARWD). Hemodynamic measures were also paired with secondary tasks of visual perception and auditory working memory to provide behavioral assessment of situation awareness and mental workload. Navigating with an augmented reality wearable display produced the least workload during the auditory working memory task, and a trend for improved situation awareness in our measures of prefrontal hemodynamics. The hemodynamics associated with errors were also different between the two devices. Errors with an augmented reality wearable display were associated with increased prefrontal activity and the opposite was observed for the hand-held display. This suggests that the cognitive mechanisms underlying errors between the two devices differ. These findings show fNIRS is a valuable tool for assessing new technology in ecologically valid settings and that ARWDs offer benefits with regards to mental workload while navigating, and potentially superior situation awareness with improved display design.

Into the Wild: Neuroergonomic Differentiation of Hand-Held and Augmented Reality Wearable Displays during Outdoor Navigation with Functional Near Infrared Spectroscopy

PubMed Central

McKendrick, Ryan; Parasuraman, Raja; Murtza, Rabia; Formwalt, Alice; Baccus, Wendy; Paczynski, Martin; Ayaz, Hasan

2016-01-01

Highly mobile computing devices promise to improve quality of life, productivity, and performance. Increased situation awareness and reduced mental workload are two potential means by which this can be accomplished. However, it is difficult to measure these concepts in the “wild”. We employed ultra-portable battery operated and wireless functional near infrared spectroscopy (fNIRS) to non-invasively measure hemodynamic changes in the brain’s Prefrontal cortex (PFC). Measurements were taken during navigation of a college campus with either a hand-held display, or an Augmented reality wearable display (ARWD). Hemodynamic measures were also paired with secondary tasks of visual perception and auditory working memory to provide behavioral assessment of situation awareness and mental workload. Navigating with an augmented reality wearable display produced the least workload during the auditory working memory task, and a trend for improved situation awareness in our measures of prefrontal hemodynamics. The hemodynamics associated with errors were also different between the two devices. Errors with an augmented reality wearable display were associated with increased prefrontal activity and the opposite was observed for the hand-held display. This suggests that the cognitive mechanisms underlying errors between the two devices differ. These findings show fNIRS is a valuable tool for assessing new technology in ecologically valid settings and that ARWDs offer benefits with regards to mental workload while navigating, and potentially superior situation awareness with improved display design. PMID:27242480

Assessing Cognitive Distraction in the Automobile.

PubMed

Strayer, David L; Turrill, Jonna; Cooper, Joel M; Coleman, James R; Medeiros-Ward, Nathan; Biondi, Francesco

2015-12-01

The objective was to establish a systematic framework for measuring and understanding cognitive distraction in the automobile. Driver distraction from secondary in-vehicle activities is increasingly recognized as a significant source of injuries and fatalities on the roadway. Across three studies, participants completed eight in-vehicle tasks commonly performed by the driver of an automobile. Primary, secondary, subjective, and physiological measures were collected and integrated into a cognitive distraction scale. In-vehicle activities, such as listening to the radio or an audio book, were associated with a low level of cognitive workload; the conversation activities of talking to a passenger in the vehicle or conversing with a friend on a handheld or hands-free cell phone were associated with a moderate level of cognitive workload; and using a speech-to-text interfaced e-mail system involved a high level of cognitive workload. The research established that there are significant impairments to driving that stem from the diversion of attention from the task of operating a motor vehicle and that the impairments to driving are directly related to the cognitive workload of these in-vehicle activities. Moreover, the adoption of voice-based systems in the vehicle may have unintended consequences that adversely affect traffic safety. These findings can be used to help inform scientifically based policies on driver distraction, particularly as they relate to cognitive distraction stemming from the diversion of attention to other concurrent activities in the vehicle. © 2015, Human Factors and Ergonomics Society.

Pilot Workload and Speech Analysis: A Preliminary Investigation

NASA Technical Reports Server (NTRS)

Bittner, Rachel M.; Begault, Durand R.; Christopher, Bonny R.

2013-01-01

Prior research has questioned the effectiveness of speech analysis to measure the stress, workload, truthfulness, or emotional state of a talker. The question remains regarding the utility of speech analysis for restricted vocabularies such as those used in aviation communications. A part-task experiment was conducted in which participants performed Air Traffic Control read-backs in different workload environments. Participant's subjective workload and the speech qualities of fundamental frequency (F0) and articulation rate were evaluated. A significant increase in subjective workload rating was found for high workload segments. F0 was found to be significantly higher during high workload while articulation rates were found to be significantly slower. No correlation was found to exist between subjective workload and F0 or articulation rate.

A human factors engineering conceptual framework of nursing workload and patient safety in intensive care units.

PubMed

Carayon, Pascale; Gürses, Ayşe P

2005-10-01

In this paper, we review the literature on nursing workload in intensive care units (ICUs) and its impact on patient safety and quality of working life of nurses. We then propose a conceptual framework of ICU nursing workload that defines causes, consequences and outcomes of workload. We identified four levels of nursing workload (ICU/unit level, job level, patient level, and situation level), and discuss measures associated with each of the four levels. A micro-level approach to ICU nursing workload at the situation level is proposed and recommended in order to reduce workload and mitigate its negative impact. Performance obstacles are conceptualized as causes of ICU nursing workload at the situation level.

The Workload Curve: Subjective Mental Workload.

PubMed

Estes, Steven

2015-11-01

In this paper I begin looking for evidence of a subjective workload curve. Results from subjective mental workload assessments are often interpreted linearly. However, I hypothesized that ratings of subjective mental workload increase nonlinearly with unitary increases in working memory load. Two studies were conducted. In the first, the participant provided ratings of the mental difficulty of a series of digit span recall tasks. In the second study, participants provided ratings of mental difficulty associated with recall of visual patterns. The results of the second study were then examined using a mathematical model of working memory. An S curve, predicted a priori, was found in the results of both the digit span and visual pattern studies. A mathematical model showed a tight fit between workload ratings and levels of working memory activation. This effort provides good initial evidence for the existence of a workload curve. The results support further study in applied settings and other facets of workload (e.g., temporal workload). Measures of subjective workload are used across a wide variety of domains and applications. These results bear on their interpretation, particularly as they relate to workload thresholds. © 2015, Human Factors and Ergonomics Society.

Personality Traits Moderate the Effect of Workload Sources on Perceived Workload in Flying Column Police Officers

PubMed Central

Chiorri, Carlo; Garbarino, Sergio; Bracco, Fabrizio; Magnavita, Nicola

2015-01-01

Previous research has suggested that personality traits of the Five Factor Model play a role in worker's response to workload. The aim of this study was to investigate the association of personality traits of first responders with their perceived workload in real-life tasks. A flying column of 269 police officers completed a measure of subjective workload (NASA-Task Load Index) after intervention tasks in a major public event. Officers' scores on a measure of Five Factor Model personality traits were obtained from archival data. Linear Mixed Modeling was used to test the direct and interaction effects of personality traits on workload scores once controlling for background variables, task type and workload source (mental, temporal and physical demand of the task, perceived effort, dissatisfaction for the performance and frustration due to the task). All personality traits except extraversion significantly interacted at least with one workload source. Perceived workload in flying column police officers appears to be the result of their personality characteristics interacting with the workload source. The implications of these results for the development of support measures aimed at reducing the impact of workload in this category of workers are discussed. PMID:26640456

Neural mechanisms to predict subjective level of fatigue in the future: a magnetoencephalography study

PubMed Central

Ishii, Akira; Tanaka, Masaaki; Watanabe, Yasuyoshi

2016-01-01

Fatigue is a major contributor to workplace accidents, morbidity, and mortality. To prevent the disruption of homeostasis and to concurrently accomplish an assigned workload, it is essential to control the level of workload based on the subjective estimation of the level of fatigue that will be experienced in the near future. In this study, we aimed to clarify the neural mechanisms related to predicting subjective levels of fatigue that would be experienced 60 min later, using magnetoencephalography. Sixteen healthy male volunteers participated in this study. In relation to the prediction, a decrease of alpha band power in the right Brodmann’s area (BA) 40 and BA 9 at 1200 to 1350 ms and that in the right BA 9 at 1350 to 1500 ms, and a decrease of gamma band power in the right BA 10 at 1500 to 1650 ms were observed. In addition, the decreased level of alpha band power in BA 9 at 1200 to 1350 ms was positively associated with the daily level of fatigue. These findings may help increase our understanding of the neural mechanisms activated to indicate the need to take a rest based on the prediction of the subjective fatigue in the future. PMID:27112115

Collective workload organization in confined excavation of granular media

NASA Astrophysics Data System (ADS)

Monaenkova, Daria; Linevich, Vadim; Goodisman, Michael A.; Goldman, Daniel I.

2015-03-01

Many social insects collectively construct large nests in complex substrates; such structures are often composed of narrow tunnels. The benefits of collective construction, including reduced construction costs per worker come with challenges of navigation in crowded, confined spaces. Here we study the workforce organization of groups of S. invicta fire ants creating tunnels in wet granular media. We monitor the activity levels of marked (painted) workers-defined as a number of tunnel visits over 12 hours- during initiation of tunnels. The activity levels are described by a Lorenz curve with a Gini coefficient of ~ 0 . 7 indicating that a majority of the excavation is performed by a minority of workers. We hypothesize that this workload distribution is beneficial for excavation in crowded conditions, and use a 2D cellular automata (CA) model to reproduce behaviors of the excavating ants. CA simulations reveal that tunnel construction rates decrease in groups of equally active animals compared to groups with the natural workload distribution. We use predictions of the CA model to organize collective excavation of granular material by teams of digging robots, and use the robots to test hypotheses of crowded excavation in the physical world. We acknowledge support of National Science Foundation, Physics of Living Systems division.

Task errors by emergency physicians are associated with interruptions, multitasking, fatigue and working memory capacity: a prospective, direct observation study.

PubMed

Westbrook, Johanna I; Raban, Magdalena Z; Walter, Scott R; Douglas, Heather

2018-01-09

Interruptions and multitasking have been demonstrated in experimental studies to reduce individuals' task performance. These behaviours are frequently used by clinicians in high-workload, dynamic clinical environments, yet their effects have rarely been studied. To assess the relative contributions of interruptions and multitasking by emergency physicians to prescribing errors. 36 emergency physicians were shadowed over 120 hours. All tasks, interruptions and instances of multitasking were recorded. Physicians' working memory capacity (WMC) and preference for multitasking were assessed using the Operation Span Task (OSPAN) and Inventory of Polychronic Values. Following observation, physicians were asked about their sleep in the previous 24 hours. Prescribing errors were used as a measure of task performance. We performed multivariate analysis of prescribing error rates to determine associations with interruptions and multitasking, also considering physician seniority, age, psychometric measures, workload and sleep. Physicians experienced 7.9 interruptions/hour. 28 clinicians were observed prescribing 239 medication orders which contained 208 prescribing errors. While prescribing, clinicians were interrupted 9.4 times/hour. Error rates increased significantly if physicians were interrupted (rate ratio (RR) 2.82; 95% CI 1.23 to 6.49) or multitasked (RR 1.86; 95% CI 1.35 to 2.56) while prescribing. Having below-average sleep showed a >15-fold increase in clinical error rate (RR 16.44; 95% CI 4.84 to 55.81). WMC was protective against errors; for every 10-point increase on the 75-point OSPAN, a 19% decrease in prescribing errors was observed. There was no effect of polychronicity, workload, physician gender or above-average sleep on error rates. Interruptions, multitasking and poor sleep were associated with significantly increased rates of prescribing errors among emergency physicians. WMC mitigated the negative influence of these factors to an extent. These results confirm experimental findings in other fields and raise questions about the acceptability of the high rates of multitasking and interruption in clinical environments. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

[Distribution and main influential factors of mental workload of middle school teachers in Nanchang City].

PubMed

Xiao, Yuanmei; Li, Weijuan; Ren, Qingfeng; Ren, Xiaohui; Wang, Zhiming; Wang, Mianzhen; Lan, Yajia

2015-01-01

To investigate the distribution and main influential factors of mental workload of middle school teachers in Nanchang City. A total of 504 middle school teachers were sampled by random cluster sampling from middle schools in Nanchang City, and the mental workload level was assessed with National Aeronautics and Space Administration-Task Load Index (NASA-TLX) which was verified in reliability and validity. The mental workload scores of middle school teachers in Nanchang was approximately normal distribution. The mental workload level of middle school teachers aged 31 -35 years old was the highest. For those no more than 35 years old, there was positive correlation between mental workload and age (r = 0.146, P < 0.05). For those more than 35 years old, the levels of their mental workload had no statistically significant difference. There was a negative correlation between mental workload and educational level(r = -0.172, P < 0.05). The middle school teachers with lower educational level seemed to have a higher mental workload (P < 0.01). The longer a middle school teacher worked per day, the higher the mental workload was. Working hours per day was the most influential factor on mental workload in all influential factors (P < 0.001). Mental workload of middle school teachers was closely related to age, educational level and work hours per day. Working hours per day was the important risk factor of mental workload. Reducing working hours per day, especially reducing it to be no more than 8 hours per day, may be a significant and useful approach alleviating mental workload of middle school teachers in Nanchang City.

Physiological measures in participants with chronic fatigue syndrome, multiple sclerosis and healthy controls following repeated exercise: a pilot study.

PubMed

Hodges, L D; Nielsen, T; Baken, D

2017-08-07

To compare physiological responses of chronic fatigue syndrome (CFS/ME), multiple sclerosis (MS) and healthy controls (HC) following a 24-h repeated exercise test. Ten CFS, seven MS and 17 age- and gender-matched healthy controls (10, CFS HC; and seven, MS HC) were recruited. Each participant completed a maximal incremental cycle exercise test on day 1 and again 24 h later. Heart rate (HR), blood pressure (BP), rating of perceived exertion (RPE), oxygen consumption (V˙O2), carbon dioxide production and workload (WL) were recorded. Data analysis investigated these responses at anaerobic threshold (AT) and peak work rate (PWR). On day 2, both CFS and MS had significantly reduced max workload compared to HC. On day 2, significant differences were apparent in WL between CFS and CFS HC (93 ± 37 W, 132 ± 42 W, P<0·042). CFS workload decreased on day 2, alongside a decrease in HR but with an increase in V˙O2 (ml   kg   min -1 ). This was in comparison with an increase in WL, HR and V˙O2 for CFS HC. MS demonstrated a decreased WL compared to MS HC on both days of the study (D1 81 ± 30 W, 116 ±30 W; D2 84 ± 29 W, 118 ± 36 W); however, patients with MS were able to achieve a higher WL on day 2 alongside MS HC. These results suggest that exercise exhibits a different physiological response in MS and CFS/ME, demonstrating repeated cardiovascular exercise testing as a valid measure for differentiating between fatigue conditions. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Psychophysiological Correlates of Sexually and Non-Sexually Motivated Attention to Film Clips in a Workload Task

PubMed Central

Carvalho, Sandra; Leite, Jorge; Galdo-Álvarez, Santiago; Gonçalves, Óscar F.

2011-01-01

Some authors have speculated that the cognitive component (P3) of the Event-Related Potential (ERP) can function as a psychophysiological measure of sexual interest. The aim of this study was to determine if the P3 ERP component in a workload task can be used as a specific and objective measure of sexual motivation by comparing the neurophysiologic response to stimuli of motivational relevance with different levels of valence and arousal. A total of 30 healthy volunteers watched different films clips with erotic, horror, social-positive and social-negative content, while answering an auditory oddball paradigm. Erotic film clips resulted in larger interference when compared to both the social-positive and auditory alone conditions. Horror film clips resulted in the highest levels of interference with smaller P3 amplitudes than erotic and also than social-positive, social-negative and auditory alone condition. No gender differences were found. Both horror and erotic film clips significantly decreased heart rate (HR) when compared to both social-positive and social-negative films. The erotic film clips significantly increased the skin conductance level (SCL) compared to the social-negative films. The horror film clips significantly increased the SCL compared to both social-positive and social-negative films. Both the highly arousing erotic and non-erotic (horror) movies produced the largest decrease in the P3 amplitude, a decrease in the HR and an increase in the SCL. These data support the notion that this workload task is very sensitive to the attentional resources allocated to the film clip, although they do not act as a specific index of sexual interest. Therefore, the use of this methodology seems to be of questionable utility as a specific measure of sexual interest or as an objective measure of the severity of Hypoactive Sexual Desire Disorder. PMID:22216305

Psychophysiological correlates of sexually and non-sexually motivated attention to film clips in a workload task.

PubMed

Carvalho, Sandra; Leite, Jorge; Galdo-Álvarez, Santiago; Gonçalves, Oscar F

2011-01-01

Some authors have speculated that the cognitive component (P3) of the Event-Related Potential (ERP) can function as a psychophysiological measure of sexual interest. The aim of this study was to determine if the P3 ERP component in a workload task can be used as a specific and objective measure of sexual motivation by comparing the neurophysiologic response to stimuli of motivational relevance with different levels of valence and arousal. A total of 30 healthy volunteers watched different films clips with erotic, horror, social-positive and social-negative content, while answering an auditory oddball paradigm. Erotic film clips resulted in larger interference when compared to both the social-positive and auditory alone conditions. Horror film clips resulted in the highest levels of interference with smaller P3 amplitudes than erotic and also than social-positive, social-negative and auditory alone condition. No gender differences were found. Both horror and erotic film clips significantly decreased heart rate (HR) when compared to both social-positive and social-negative films. The erotic film clips significantly increased the skin conductance level (SCL) compared to the social-negative films. The horror film clips significantly increased the SCL compared to both social-positive and social-negative films. Both the highly arousing erotic and non-erotic (horror) movies produced the largest decrease in the P3 amplitude, a decrease in the HR and an increase in the SCL. These data support the notion that this workload task is very sensitive to the attentional resources allocated to the film clip, although they do not act as a specific index of sexual interest. Therefore, the use of this methodology seems to be of questionable utility as a specific measure of sexual interest or as an objective measure of the severity of Hypoactive Sexual Desire Disorder. © 2011 Carvalho et al.

Impact of Conflict Avoidance Responsibility Allocation on Pilot Workload in a Distributed Air Traffic Management System

NASA Technical Reports Server (NTRS)

Ligda, Sarah V.; Dao, Arik-Quang V.; Vu, Kim-Phuong; Strybel, Thomas Z.; Battiste, Vernol; Johnson, Walter W.

2010-01-01

Pilot workload was examined during simulated flights requiring flight deck-based merging and spacing while avoiding weather. Pilots used flight deck tools to avoid convective weather and space behind a lead aircraft during an arrival into Louisville International airport. Three conflict avoidance management concepts were studied: pilot, controller or automation primarily responsible. A modified Air Traffic Workload Input Technique (ATWIT) metric showed highest workload during the approach phase of flight and lowest during the en-route phase of flight (before deviating for weather). In general, the modified ATWIT was shown to be a valid and reliable workload measure, providing more detailed information than post-run subjective workload metrics. The trend across multiple workload metrics revealed lowest workload when pilots had both conflict alerting and responsibility of the three concepts, while all objective and subjective measures showed highest workload when pilots had no conflict alerting or responsibility. This suggests that pilot workload was not tied primarily to responsibility for resolving conflicts, but to gaining and/or maintaining situation awareness when conflict alerting is unavailable.

Data Elements for Workload Analysis of Armored Vehicle Crews

DTIC Science & Technology

1990-09-01

weapon status, terrain, enemy, etc.) and 2) managing the operation of the various mental processes through which the operator interacts with the...contrive, or plan a process or procedure for carrying out a tactical action. DICTATE - To speak aloud into a recorder. DIRECT - To manage the action of...To mark or note on a map or chart; to locate by means of coordinates. POSITION - To place oneself or others in a location or posture. PREPARE - To

Auditory display as feedback for a novel eye-tracking system for sterile operating room interaction.

PubMed

Black, David; Unger, Michael; Fischer, Nele; Kikinis, Ron; Hahn, Horst; Neumuth, Thomas; Glaser, Bernhard

2018-01-01

The growing number of technical systems in the operating room has increased attention on developing touchless interaction methods for sterile conditions. However, touchless interaction paradigms lack the tactile feedback found in common input devices such as mice and keyboards. We propose a novel touchless eye-tracking interaction system with auditory display as a feedback method for completing typical operating room tasks. Auditory display provides feedback concerning the selected input into the eye-tracking system as well as a confirmation of the system response. An eye-tracking system with a novel auditory display using both earcons and parameter-mapping sonification was developed to allow touchless interaction for six typical scrub nurse tasks. An evaluation with novice participants compared auditory display with visual display with respect to reaction time and a series of subjective measures. When using auditory display to substitute for the lost tactile feedback during eye-tracking interaction, participants exhibit reduced reaction time compared to using visual-only display. In addition, the auditory feedback led to lower subjective workload and higher usefulness and system acceptance ratings. Due to the absence of tactile feedback for eye-tracking and other touchless interaction methods, auditory display is shown to be a useful and necessary addition to new interaction concepts for the sterile operating room, reducing reaction times while improving subjective measures, including usefulness, user satisfaction, and cognitive workload.

Relationship between workload and mind-wandering in simulated driving

PubMed Central

2017-01-01

Mental workload and mind-wandering are highly related to driving safety. This study investigated the relationship between mental workload and mind-wandering while driving. Participants (N = 40) were asked to perform a car following task in driving simulator, and report whether they had experienced mind-wandering upon hearing a tone. After driving, participants reported their workload using the NASA-Task Load Index (TLX). Results revealed an interaction between workload and mind-wandering in two different perspectives. First, there was a negative correlation between workload and mind-wandering (r = -0.459, p < 0.01) for different individuals. Second, from temporal perspective workload and mind-wandering frequency increased significantly over task time and were positively correlated. Together, these findings contribute to understanding the roles of workload and mind-wandering in driving. PMID:28467513

Defining the subjective experience of workload

NASA Technical Reports Server (NTRS)

Hart, S. G.; Childress, M. E.; Bortolussi, M.

1981-01-01

Flight scenarios that represent different types and levels of pilot workload are needed in order to conduct research about, and develop measures of, pilot workload. In order to be useful, however, the workload associated with such scenarios and the component tasks must be determined independently. An initial study designed to provide such information was conducted by asking a panel of general aviation pilots to evaluate flight-related tasks for the overall, perceptual, physical, and cognitive workload they impose. These ratings will provide the nucleus for a data base of flight-related primary tasks that have been independently rated for workload to use in workload assessment research.

The workload analysis in welding workshop

NASA Astrophysics Data System (ADS)

Wahyuni, D.; Budiman, I.; Tryana Sembiring, M.; Sitorus, E.; Nasution, H.

2018-03-01

This research was conducted in welding workshop which produces doors, fences, canopies, etc., according to customer’s order. The symptoms of excessive workload were seen from the fact of employees complaint, requisition for additional employees, the lateness of completion time (there were 11 times of lateness from 28 orders, and 7 customers gave complaints). The top management of the workshop assumes that employees’ workload was still a tolerable limit. Therefore, it was required workload analysis to determine the number of employees required. The Workload was measured by using a physiological method and workload analysis. The result of this research can be utilized by the workshop for a better workload management.

Heart rate and performance during combat missions in a flight simulator.

PubMed

Lahtinen, Taija M M; Koskelo, Jukka P; Laitinen, Tomi; Leino, Tuomo K

2007-04-01

The psychological workload of flying has been shown to increase heart rate (HR) during flight simulator operation. The association between HR changes and flight performance remains unclear. There were 15 pilots who performed a combat flight mission in a Weapons Tactics Trainer simulator of an F-18 Hornet. An electrocardiogram (ECG) was recorded, and individual incremental heart rates (deltaHR) from the HR during rest were calculated for each flight phase and used in statistical analyses. The combat flight period was divided into 13 phases, which were evaluated on a scale of 1 to 5 by the flight instructor. HR increased during interceptions (from a mean resting level of 79.0 to mean value of 96.7 bpm in one of the interception flight phases) and decreased during the return to base and slightly increased during the ILS approach and landing. DeltaHR appeared to be similar among experienced and less experienced pilots. DeltaHR responses during the flight phases did not correlate with simulator flight performance scores. Overall simulator flight performance correlated statistically significantly (r = 0.50) with the F-18 Hornet flight experience. HR reflected the amount of cognitive load during the simulated flight. Hence, HR analysis can be used in the evaluation of the psychological workload of military simulator flight phases. However, more detailed flight performance evaluation methods are needed for this kind of complex flight simulation to replace the traditional but rough interval scales. Use of a visual analog scale by the flight instructors is suggested for simulator flight performance evaluation.

Benefits of Imperfect Conflict Resolution Advisory Aids for Future Air Traffic Control.

PubMed

Trapsilawati, Fitri; Wickens, Christopher D; Qu, Xingda; Chen, Chun-Hsien

2016-11-01

The aim of this study was to examine the human-automation interaction issues and the interacting factors in the context of conflict detection and resolution advisory (CRA) systems. The issues of imperfect automation in air traffic control (ATC) have been well documented in previous studies, particularly in conflict-alerting systems. The extent to which the prior findings can be applied to an integrated conflict detection and resolution system in future ATC remains unknown. Twenty-four participants were evenly divided into two groups corresponding to a medium- and a high-traffic density condition, respectively. In each traffic density condition, participants were instructed to perform simulated ATC tasks under four automation conditions, including reliable, unreliable with short time allowance to secondary conflict (TAS), unreliable with long TAS, and manual conditions. Dependent variables accounted for conflict resolution performance, workload, situation awareness, and trust in and dependence on the CRA aid, respectively. Imposing the CRA automation did increase performance and reduce workload as compared with manual performance. The CRA aid did not decrease situation awareness. The benefits of the CRA aid were manifest even when it was imperfectly reliable and were apparent across traffic loads. In the unreliable blocks, trust in the CRA aid was degraded but dependence was not influenced, yet the performance was not adversely affected. The use of CRA aid would benefit ATC operations across traffic densities. CRA aid offers benefits across traffic densities, regardless of its imperfection, as long as its reliability level is set above the threshold of assistance, suggesting its application for future ATC. © 2016, Human Factors and Ergonomics Society.