The Experts below are selected from a list of 626031 Experts worldwide ranked by ideXlab platform
Max Mulder - One of the best experts on this subject based on the ideXlab platform.
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Interactions of Outside Visual Cues and Motion Cueing Settings in Yaw Tracking
AIAA Modeling and Simulation Technologies Conference, 2016Co-Authors: H.p.m. Peterse, Daan M. Pool, Marinus M Van Paassen, Max MulderAbstract:Knowledge of how human operators’ tracking Behavior is affected by simulator motion cueing settings is of great value for flight simulator design and fidelity evaluations. Previous studies have revealed strong effects of degraded motion cueing quality on human operator Control Behavior in compensatory tracking, but the presented visual cues in such studies are often not consistent with what operators perceive in more realistic settings, as they typically do not include the visual cues provided by the out-of-the-window view from their vehicle. This paper aims to investigate the effects of the interaction of such outside visual cues and of motion cueing settings on human operator Behavior. Thereto, an experiment in a flight simulator was conducted in which participants performed a yaw-axis target-following disturbance-rejection tracking task. The presence of an outside visual scene and simulator motion feedback quality were varied independently. In the experiment, motion cues were either absent or presented with varying attenuation induced by changing the break frequency of a first-order high-pass yaw motion filter. The results indicate a strong effect of outside visual cues on human operator Control Behavior in the absence of motion feedback, which is comparable to the measured effect of motion feedback. Overall, human operator Control Behavior was found to be less affected by varying motion cueing settings when the outside visual cues were available in parallel.
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Influences of Simulator Motion System Characteristics on Pilot Control Behavior
Journal of Guidance Control and Dynamics, 2013Co-Authors: Frank M. Nieuwenhuizen, Max Mulder, M.m. Van Paassen, Heinrich H. BülthoffAbstract:Low-cost motion systems have been proposed for certain training tasks that would otherwise be performed on high-performance full-flight simulators. These systems usually have lower bandwidth and lower smoothness. The influence of these characteristics on pilot perception and Control Behavior is unknown and needs to be investigated. In this paper, this is done by simulating a model of a simulator with limited capabilities on a high-end simulator. The platform limitations, which consist of a platform filter, time delay, and noise characteristics, can then be removed one by one, and their effect on Control Behavior is studied in isolation. An experiment was conducted to identify pilot perception and Control Behavior in a closed-loop Control task. The time delay and noise characteristics of the simulators did not have an effect. However, it was found that the bandwidth of the motion system had a significant effect on performance and Control Behavior. Results indicate that the motion cues were barely used at a...
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Cross-platform Validation for a Model of a Low-cost Stewart Platform
Journal of Modeling Simulation Identification and Control, 2013Co-Authors: Frank M. Nieuwenhuizen, Max Mulder, M.m. Van Paassen, Olaf Stroosma, Heinrich H. BülthoffAbstract:Low-cost motion systems have been proposed for certain training tasks that would otherwise be performed on high-performance full flight simulators. These systems have shorter stroke actuators, lower bandwidth, and higher motion noise. The influence of these characteristics on pilot perception and Control Behavior is unknown, and needs to be investigated. A possible approach to this would be to simulate a platform with limited capabilities with a high-end platform, and then remove the platform limitations one by one. The effects of these platform limitations on pilot Behavior can then be investigated in isolation. In this paper, a model of a low-cost simulator was validated for simulation on a high-performance simulator. A dynamic model of the MPI Stewart platform was analyzed and compared with measurements of the baseline simulator response. Measurements for validation of the implementation of the model on the SIMONA Research Simulator showed that the dynamics of the MPI Stewart platform could be represented well in terms of dynamic range, time delay, and noise characteristics. The implementation of the model of the MPI Stewart platform will be used in experiments on the effects of these characteristics on pilot Control Behavior.
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Effects of Heave Washout Filtering on Motion Fidelity and Pilot Control Behavior for a Large Commercial Airliner
AIAA Modeling and Simulation Technologies Conference, 2011Co-Authors: A.t. Van Wieringen, Daan M. Pool, Marinus M Van Paassen, Max MulderAbstract:Due to the significant translational heave motion at the pilot station associated with changes in aircraft pitch attitude, themotion cueing for aircraft pitchmaneuvering typically requires significant heave washout filtering. Previous studies that attempted to motivate choices in the motion cueing strategy for pitch maneuvering based on measurements of pilot Behavior. For the small conventional aircraft considered in these studies, the results indicated that, despite the fact that pilots were found to adapt their Control strategy to changes in heave cueing, the pitch rotation had a dominant influence on pilot Behavior during pitch tracking. For large commercial airliners, a relevant application of this research as a lot of commercial pilot training occurs on moving-base simulators, the location of the pilot station is significantly further from the center of aircraft pitch rotation, yielding more pronounced heave motion cues during changes in pitch attitude. This difference, in addition to typically slower pitch dynamics that require more lead equalization, implies the best choice in motion cueing for large aircraft may be significantly different from what would be optimal for smaller aircraft. In this paper, an experiment is described in which pilot Behavior is measured in a pitch attitude disturbance-rejection task with a Controlled element and motion cueing conditions that are representative for a Boeing 747 aircraft. Different third-order heave washout filter settings were considered, in addition to a variation in the presence of 1-to-1 rotational pitch motion. Significant effects of the applied variation in pitch and heave motion cueing are observed, even though the effect of heave motion feedback is indeed found to be comparatively more important for larger aircraft. Furthermore, a heave motion filter that combined a low gain with low filter phase distortion was found to yield the least effect on pilot Behavior, while for heave motion filters with a relatively high gain and high break frequency significantly larger contributions of motion feedback to pilot Behavior were observed.
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effects of displayed error scaling in compensatory roll axis tracking tasks
AIAA Modeling and Simulation Technologies Conference Toronto Canada 2-5 August 2010; AIAA 2010-8091, 2010Co-Authors: S W Breur, D M Pool, Marinus M Van Paassen, Max MulderAbstract:This paper describes an investigation into the effects of displayed error scaling on manual Control Behavior during compensatory roll-axis tracking. Previous experiments have indicated that for compensatory displays that, similar to an artificial horizon, present the roll tracking errors in rotational form, the deviations for typical quasi-random forcing function signals are comparatively small and difficult to perceive. This was found to lead to degraded tracking performance and lower crossover frequencies than would be expected. To investigate this, a roll-axis tracking experiment has been performed in which the scaling of the presented tracking errors was varied from 0.5 to 5 times the true tracking error. In addition, both double integrator dynamics and typical conventional roll dynamics of a small jet aircraft were considered in a mixed experimental design. The main hypothesis for this experiment was that increased scaling of the presented roll-axis tracking error would result in improved tracking performance and correlation of manual Control inputs with the target forcing function signal. In addition, these effects were hypothesized to be more pronounced for the more difficult double integrator dynamics. For both Controlled elements, both tracking performance and linearity of pilot Control were indeed found to increase with increasing display gain, leveling of for the highest considered display gains. Further analysis of manual Control Behavior using McRuer et al.’s Precision Model revealed marked changes in the adopted Control strategy due to changes in displayed error scaling, which were found to be highly similar for both Controlled elements.
Ingrid H. M. Steenhuis - One of the best experts on this subject based on the ideXlab platform.
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portion size latest developments and interventions
The European health psychologist, 2017Co-Authors: Ingrid H. M. Steenhuis, Maartje P. PoelmanAbstract:Background: Portion sizes have increased over the past decades. This contributes to an increased energy intake and consequently an increased prevalence of overweight and obesity. The aim of this overview is to provide an overview of 1) underlying mechanisms of the effect of portion size on energy intake, 2) external factors explaining the portion size effect and 3) interventions and measurements aimed at food portion size. Methods: A literature overview of recent findings (last 5 years) is provided. Findings: Previous studies have shown that portion sizes have increased in recent decades. Many experimental studies have been conducted to unravel the mechanisms underlying the portion-size effect on food intake (e.g. the appropriateness mechanism, the ‘unit bias’ mechanism, the ‘previous experience/expectation’ mechanism, the ‘visual cue’ mechanism and the ‘bite size’ mechanism).In addition, external factors have been found to drive food portion selection and consumption (e.g. value for money, mindless eating, levels of awareness, estimation bias. Research on several interventions (ranging from ‘providing information’ to ‘eliminating choice’) have been conducted, but remain scarce, especially intervention studies in which portion size is a key focus in weight loss. Moreover, only three new instruments with respect to portion Control Behavior have been developed. Discussion: There is considerable evidence for the portion-size effect on energy intake. However, the work on interventions targeting portion size and measurements for portion Control Behavior are limited. Moreover, from the literature it is not yet clear what type of interventions work best, for whom and in what context.
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portionControl home results of a randomized Controlled trial evaluating the effect of a multi component portion size intervention on portion Control Behavior and body mass index
Annals of Behavioral Medicine, 2015Co-Authors: Maartje P. Poelman, Elizabeth Velema, Michiel R De Boer, J C Seidell, Ingrid H. M. SteenhuisAbstract:Background Food portion sizes influence energy intake. Purpose The purpose of this paper is to determine effectiveness of the “PortionControl@HOME” intervention on body mass index and portion Control Behavior. Methods A randomized Controlled trial among 278 overweight and obese participants was conducted. PortionControl@HOME aimed to increase: portion size awareness, portion Control Behavior, portion Control cooking skills, and to create a home environment favoring portion Control. Results Intention-to-treat multi-level regression analysis indicated statistically significant effects of the intervention on portion Control Behavior at 3, 6, and 12 months follow-up. The effect on body mass index was significant only at 3 months follow-up and when outliers (n=3) were excluded (B=−0.45; 95%CI=−0.88to −0.04). The interventioneffect on body mass index was mediated by portion Control Behavior. Conclusions The intervention improves portion Control Behavior, which in turn influence body mass index. Once the intervention ceased, sustained effects on body mass index were no longer evident. (Current-Controlled-Trials ISRCT N12363482).
Huang Chaohui - One of the best experts on this subject based on the ideXlab platform.
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relationship between unhealthy weight Control Behavior and health risk Behavior in medical freshmen and sophomores
Chinese Journal of Public Health, 2010Co-Authors: Huang ChaohuiAbstract:Objective To analyze the cooccurrence of unhealthy weight-Control Behavior and other health-risk Behavior in undergraduates.Methods A total of 3 777 freshmen and sophomores from a medical university in Hefei city were selected as participants.The information on 7 kinds of unhealthy weight-Control Behaviors as well as multiple health-risk Behaviors were collected.Results Totally 3 718 participants completed the questionnaire.The prevalence of unhealthy weight-Control Behavior was 9.8%(6.9% in boys and 12.5% in girls).Compared with the boys with unhealthy weight Control Behaviors,the girls had higher prevalences of overexcercise(5.0% vs 3.2%),without eating rice in a day(3.4% vs 1.5%),and drinking weight loss tea(2.1% vs 1.1%).Prevalences of binge eating,current smoking,current alcohol drinking,current heavy alcohol drinking,current drunk,and internet addiction tendency in students with unhealthy weight-Control Behaviors were higher than the prevalences in those without unhealthy weight-Control Behavior(P0.05).More cooccurences of other health-risk Behaviors were reported in students with unhealthy weight-Control Behaviors(P0.05).Conclusion There is a cooccurence of unhealthy weight-Control Behaviors and other health-risk Behaviors.
Maartje P. Poelman - One of the best experts on this subject based on the ideXlab platform.
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portion size latest developments and interventions
The European health psychologist, 2017Co-Authors: Ingrid H. M. Steenhuis, Maartje P. PoelmanAbstract:Background: Portion sizes have increased over the past decades. This contributes to an increased energy intake and consequently an increased prevalence of overweight and obesity. The aim of this overview is to provide an overview of 1) underlying mechanisms of the effect of portion size on energy intake, 2) external factors explaining the portion size effect and 3) interventions and measurements aimed at food portion size. Methods: A literature overview of recent findings (last 5 years) is provided. Findings: Previous studies have shown that portion sizes have increased in recent decades. Many experimental studies have been conducted to unravel the mechanisms underlying the portion-size effect on food intake (e.g. the appropriateness mechanism, the ‘unit bias’ mechanism, the ‘previous experience/expectation’ mechanism, the ‘visual cue’ mechanism and the ‘bite size’ mechanism).In addition, external factors have been found to drive food portion selection and consumption (e.g. value for money, mindless eating, levels of awareness, estimation bias. Research on several interventions (ranging from ‘providing information’ to ‘eliminating choice’) have been conducted, but remain scarce, especially intervention studies in which portion size is a key focus in weight loss. Moreover, only three new instruments with respect to portion Control Behavior have been developed. Discussion: There is considerable evidence for the portion-size effect on energy intake. However, the work on interventions targeting portion size and measurements for portion Control Behavior are limited. Moreover, from the literature it is not yet clear what type of interventions work best, for whom and in what context.
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portionControl home results of a randomized Controlled trial evaluating the effect of a multi component portion size intervention on portion Control Behavior and body mass index
Annals of Behavioral Medicine, 2015Co-Authors: Maartje P. Poelman, Elizabeth Velema, Michiel R De Boer, J C Seidell, Ingrid H. M. SteenhuisAbstract:Background Food portion sizes influence energy intake. Purpose The purpose of this paper is to determine effectiveness of the “PortionControl@HOME” intervention on body mass index and portion Control Behavior. Methods A randomized Controlled trial among 278 overweight and obese participants was conducted. PortionControl@HOME aimed to increase: portion size awareness, portion Control Behavior, portion Control cooking skills, and to create a home environment favoring portion Control. Results Intention-to-treat multi-level regression analysis indicated statistically significant effects of the intervention on portion Control Behavior at 3, 6, and 12 months follow-up. The effect on body mass index was significant only at 3 months follow-up and when outliers (n=3) were excluded (B=−0.45; 95%CI=−0.88to −0.04). The interventioneffect on body mass index was mediated by portion Control Behavior. Conclusions The intervention improves portion Control Behavior, which in turn influence body mass index. Once the intervention ceased, sustained effects on body mass index were no longer evident. (Current-Controlled-Trials ISRCT N12363482).
D M Pool - One of the best experts on this subject based on the ideXlab platform.
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identification of the feedforward component in manual Control with predictable target signals
IEEE Transactions on Systems Man and Cybernetics, 2013Co-Authors: Frank M Drop, D M Pool, H. J. Damveld, Marinus M Van Paassen, M MulderAbstract:In the manual Control of a dynamic system, the human Controller (HC) often follows a visible and predictable reference path. Compared with a purely feedback Control strategy, performance can be improved by making use of this knowledge of the reference. The operator could effectively introduce feedforward Control in conjunction with a feedback path to compensate for errors, as hypothesized in literature. However, feedforward Behavior has never been identified from experimental data, nor have the hypothesized models been validated. This paper investigates human Control Behavior in pursuit tracking of a predictable reference signal while being perturbed by a quasi-random multisine disturbance signal. An experiment was done in which the relative strength of the target and disturbance signals were systematically varied. The anticipated changes in Control Behavior were studied by means of an ARX model analysis and by fitting three parametric HC models: two different feedback models and a combined feedforward and feedback model. The ARX analysis shows that the experiment participants employed Control action on both the error and the target signal. The Control action on the target was similar to the inverse of the system dynamics. Model fits show that this Behavior can be modeled best by the combined feedforward and feedback model.
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effects of displayed error scaling in compensatory roll axis tracking tasks
AIAA Modeling and Simulation Technologies Conference Toronto Canada 2-5 August 2010; AIAA 2010-8091, 2010Co-Authors: S W Breur, D M Pool, Marinus M Van Paassen, Max MulderAbstract:This paper describes an investigation into the effects of displayed error scaling on manual Control Behavior during compensatory roll-axis tracking. Previous experiments have indicated that for compensatory displays that, similar to an artificial horizon, present the roll tracking errors in rotational form, the deviations for typical quasi-random forcing function signals are comparatively small and difficult to perceive. This was found to lead to degraded tracking performance and lower crossover frequencies than would be expected. To investigate this, a roll-axis tracking experiment has been performed in which the scaling of the presented tracking errors was varied from 0.5 to 5 times the true tracking error. In addition, both double integrator dynamics and typical conventional roll dynamics of a small jet aircraft were considered in a mixed experimental design. The main hypothesis for this experiment was that increased scaling of the presented roll-axis tracking error would result in improved tracking performance and correlation of manual Control inputs with the target forcing function signal. In addition, these effects were hypothesized to be more pronounced for the more difficult double integrator dynamics. For both Controlled elements, both tracking performance and linearity of pilot Control were indeed found to increase with increasing display gain, leveling of for the highest considered display gains. Further analysis of manual Control Behavior using McRuer et al.’s Precision Model revealed marked changes in the adopted Control strategy due to changes in displayed error scaling, which were found to be highly similar for both Controlled elements.
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pilot equalization in manual Control of aircraft dynamics
Systems Man and Cybernetics, 2009Co-Authors: D M Pool, M.m. Van Paassen, H. J. Damveld, P. M. T. Zaal, M MulderAbstract:In continuous manual Control tasks, pilots adapt their Control strategy to the dynamics of the Controlled element to yield adequate performance of the combined pilot-vehicle system. For a Controlled element representing the linearized pitch dynamics of a small jet aircraft, the pilot models described in literature were found to lack the required freedom in the pilot equalization term to accurately model the adopted pilot compensation. An additional lead term in the pilot equalization transfer function was found to significantly increase the accuracy in modeling manual Control Behavior of aircraft pitch dynamics.
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effects of peripheral visual and physical motion cues in roll axis tracking tasks
Journal of Guidance Control and Dynamics, 2008Co-Authors: D M Pool, Max Mulder, Marinus M Van Paassen, J C Van Der VaartAbstract:In this paper, the effects of peripheral visual and physical motion cues on manual Control of second-order roll dynamics are investigated. In particular, the differences between the use of these cues in compensatory target-following and disturbance-rejection tasks are considered. Tracking performance, Control activity, and measures of Control Behavior are determined from recent measurements and compared with results from an earlier experiment. Most previously reported effects of peripheral visual and physical motion cues in target following and disturbance rejection are confirmed. A comparison of tasks with varying levels of difficulty is found to reveal reduced effectiveness of peripheral visual and physical motion cues in the less difficult target-following tasks only. Observed differences in measured Control Behavior for target following and disturbance rejection are related to effective strategies for reducing tracking errors introduced by the forcing-function signals in both tasks.