4,289 research outputs found

    Aerospace medicine and biology: A continuing bibliography with indexes, supplement 203

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    This bibliography lists 150 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1980

    Queueing Network Modeling of Human Performance and Mental Workload in Perceptual-Motor Tasks.

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    Integrated with the mathematical modeling approaches, this thesis uses Queuing Network-Model Human Processors (QN-MHP) as a simulation platform to quantify human performance and mental workload in four representative perceptual-motor tasks with both theoretical and practical importance: discrete perceptual-motor tasks (transcription typing and psychological refractory period) and continuous perceptual-motor tasks (visual-manual tracking and vehicle steering with secondary tasks). The properties of queuing networks (queuing/waiting in processing information, serial and parallel information processing capability, overall mathematical structure, and entity-based network arrangement) allow QN-MHP to quantify several important aspects of the perceptual-motor tasks and unify them into one cognitive architecture. In modeling the discrete perceptual-motor task in a single task situation (transcription typing), QN-MHP quantifies and unifies 32 transcription typing phenomena involving many aspects of human performance--interkey time, typing units and spans, typing errors, concurrent task performance, eye movements, and skill effects, providing an alternative way to model this basic and common activities in human-machine interaction. In quantifying the discrete perceptual-motor task in a dual-task situation (psychological refractory period), the queuing network model is able to account for various experimental findings in PRP including all of these major counterexamples of existing models with less or equal number of free parameters and no need to use task-specific lock/unlock assumptions, demonstrating its unique advantages in modeling discrete dual-task performance. In modeling the human performance and mental workload in the continuous perceptual-motor tasks (visual-manual tracking and vehicle steering), QN-MHP is used as a simulation platform and a set of equations is developed to establish the quantitative relationships between queuing networks (e.g., subnetwork s utilization and arrival rate) and P300 amplitude measured by ERP techniques and subjective mental workload measured by NASA-TLX, predicting and visualizing mental workload in real-time. Moreover, this thesis also applies QN-MHP into the design of an adaptive workload management system in vehicles and integrates QN-MHP with scheduling methods to devise multimodal in-vehicle systems. Further development of the cognitive architecture in theory and practice is also discussed.Ph.D.Industrial & Operations EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/55678/2/changxuw_1.pd

    Survey of Human Models for Verification of Human-Machine Systems

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    We survey the landscape of human operator modeling ranging from the early cognitive models developed in artificial intelligence to more recent formal task models developed for model-checking of human machine interactions. We review human performance modeling and human factors studies in the context of aviation, and models of how the pilot interacts with automation in the cockpit. The purpose of the survey is to assess the applicability of available state-of-the-art models of the human operators for the design, verification and validation of future safety-critical aviation systems that exhibit higher-level of autonomy, but still require human operators in the loop. These systems include the single-pilot aircraft and NextGen air traffic management. We discuss the gaps in existing models and propose future research to address them

    Queuing Network Modeling of Human Multitask Performance and its Application to Usability Testing of In-Vehicle Infotainment Systems.

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    Human performance of a primary continuous task (e.g., steering a vehicle) and a secondary discrete task (e.g., tuning radio stations) simultaneously is a common scenario in many domains. It is of great importance to have a good understanding of the mechanisms of human multitasking behavior in order to design the task environments and user interfaces (UIs) that facilitate human performance and minimize potential safety hazards. In this dissertation I investigated and modeled human multitask performance with a vehicle-steering task and several typical in-vehicle secondary tasks. Two experiments were conducted to investigate how various display designs and control modules affect the driver's eye glance behavior and performance. A computational model based on the cognitive architecture of Queuing Network-Model Human Processor (QN-MHP) was built to account for the experiment findings. In contrast to most existing studies that focus on visual search in single task situations, this dissertation employed experimental work that investigates visual search in multitask situations. A modeling mechanism for flexible task activation (rather than strict serial activations) was developed to allow the activation of a task component to be based on the completion status of other task components. A task switching scheme was built to model the time-sharing nature of multitasking. These extensions offer new theoretical insights into visual search in multitask situations and enable the model to simulate parallel processing both within one task and among multiple tasks. The validation results show that the model could account for the observed performance differences from the empirical data. Based on this model, a computer-aided engineering toolkit was developed that allows the UI designers to make quantitative prediction of the usability of design concepts and prototypes. Scientifically, the results of this dissertation research offer additional insights into the mechanisms of human multitask performance. From the engineering application and practical value perspective, the new modeling mechanism and the new toolkit have advantages over the traditional usability testing methods with human subjects by enabling the UI designers to explore a larger design space and address usability issues at the early design stages with lower cost both in time and manpower.PHDIndustrial and Operations EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113590/1/fredfeng_1.pd

    Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 182, July 1978

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    This bibliography lists 165 reports, articles, and other documents introduced into the NASA scientific and technical information system in June 1978

    Aerospace medicine and biology: A continuing bibliography with indexes (supplement 326)

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    This bibliography lists 108 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during July, 1989. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

    Nonlinear Dynamical Systems for Theory And Research In Ergonomics

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    Nonlinear dynamical systems (NDS) theory offers new constructs, methods and explanations for phenomena that have in turn produced new paradigms of thinking within several disciplines of the behavioural sciences. This article explores the recent developments of NDS as a paradigm in ergonomics. The exposition includes its basic axioms, the primary constructs from elementary dynamics and so-called complexity theory, an overview of its methods, and growing areas of application within ergonomics. The applications considered here include: psychophysics, iconic displays, control theory, cognitive workload and fatigue, occupational accidents, resilience of systems, team coordination and synchronisation in systems. Although these applications make use of different subsets of NDS constructs, several of them share the general principles of the complex adaptive system

    Queueing Network Modeling of Human Performance in Complex Cognitive Multi-task Scenarios.

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    As the complexity of human-machine systems grows rapidly, there is an increasing need for human factors theories and computational methods that can quantitatively model and simulate human performance and mental workload in complex multi-task scenarios. In response to this need, I have developed and evaluated an integrated cognitive architecture named QN-ACTR, which integrates two previously isolated but complementary cognitive architectures – Queueing Network (QN) and Adaptive Control of Thought-Rational (ACT-R). Combining their advantages and overcoming the limitations of each method, QN-ACTR possesses the benefits of modeling a wider range of tasks including multi-tasks with complex cognitive activities that existing methods have difficulty to model. These benefits have been evaluated and demonstrated by comparing model results with human results in the simulation of multi-task scenarios including skilled transcription typing and reading comprehension (human-computer interaction), medical decision making with concurrent tasks (healthcare), and driving with a secondary speech comprehension task (transportation), all of which contain important and practical human factors issues. QN-ACTR models produced performance and mental workload results similar to the human results. To support industrial applications of QN-ACTR, I have also developed the usability features of QN-ACTR to facilitate the use of this cognitive engineering tool by industrial and human factors engineers. Future research can apply QN-ACTR – which is a generic computational modeling theory and method – to other domains with important human factors issues.PHDIndustrial & Operations EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/102477/1/shicao_1.pd

    Pedestrian Dynamics: Modeling and Analyzing Cognitive Processes and Traffic Flows to Evaluate Facility Service Level

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    Walking is the oldest and foremost mode of transportation through history and the prevalence of walking has increased. Effective pedestrian model is crucial to evaluate pedestrian facility service level and to enhance pedestrian safety, performance, and satisfaction. The objectives of this study were to: (1) validate the efficacy of utilizing queueing network model, which predicts cognitive information processing time and task performance; (2) develop a generalized queueing network based cognitive information processing model that can be utilized and applied to construct pedestrian cognitive structure and estimate the reaction time with the first moment of service time distribution; (3) investigate pedestrian behavior through naturalistic and experimental observations to analyze the effects of environment settings and psychological factors in pedestrians; and (4) develop pedestrian level of service (LOS) metrics that are quick and practical to identify improvement points in pedestrian facility design. Two empirical and two analytical studies were conducted to address the research objectives. The first study investigated the efficacy of utilizing queueing network in modeling and predicting the cognitive information processing time. Motion capture system was utilized to collect detailed pedestrian movement. The predicted reaction time using queueing network was compared with the results from the empirical study to validate the performance of the model. No significant difference between model and empirical results was found with respect to mean reaction time. The second study endeavored to develop a generalized queueing network system so the task can be modeled with the approximated queueing network and its first moment of any service time distribution. There was no significant difference between empirical study results and the proposed model with respect to mean reaction time. Third study investigated methods to quantify pedestrian traffic behavior, and analyze physical and cognitive behavior from the real-world observation and field experiment. Footage from indoor and outdoor corridor was used to quantify pedestrian behavior. Effects of environmental setting and/or psychological factor on travel performance were tested. Finally, adhoc and tailor-made LOS metrics were presented for simple realistic service level assessments. The proposed methodologies were composed of space revision LOS, delay-based LOS, preferred walking speed-based LOS, and ‘blocking probability’

    Individual Differences in the Experience of Cognitive Workload

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    This study investigated the roles of four psychosocial variables – anxiety, conscientiousness, emotional intelligence, and Protestant work ethic – on subjective ratings of cognitive workload as measured by the Task Load Index (TLX) and the further connections between the four variables and TLX ratings of task performance. The four variables represented aspects of an underlying construct of elasticity versus rigidity in response to workload. Participants were 141 undergraduates who performed a vigilance task under different speeded conditions while working on a jigsaw puzzle for 90 minutes. Regression analysis showed that anxiety and emotional intelligence were the two variables most proximally related to TLX ratings. TLX ratings contributed to the prediction of performance on the puzzle, but not the vigilance task. Severity error bias was evident in some of the ratings. Although working in pairs improved performance, it also resulted in higher ratings of temporal demand and perceived performance pressure
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