Forward operators are subjected to both physical and mental workload in their work and a way to reduce mental workload and increase productivity is to automating the crane movement. To enable study the impact of automation you need methods to estimate the forwarder operators mental workload in conventional crane work and with semi automation. This study evaluated the psychophysiological parameters; trapezius muscle activity, heart rate, heart rate variability, respiratory rate, skin conductance and finger temperature. To ensure the validity and methodology reliability one need to perform more extensive studies. As for future studies this work propose additional studies of forward operator mental workload in the simulator environment regarding heart rate, heart rate variability and respiration. / Skogsmaskinförarens arbete innebär en hög belastning såväl fysiskt som mentalt. Dels för att det innefattar moment av statiskt och repetitvt arbete och dels för att en stor mängd information bearbetas och många beslut fattas på kort tid. Mental belastning är ett begrepp för olika former av belastning som påverkar människans förmåga att bearbeta information. Det finns ingen enskild faktor som kan utgöra ett mått på mental belastning. Såväl prestation som subjektiva bedömningar och psykofysiologiska mätmetoder används för att mäta mental belastning. Exempel på psykofysiologiska mätmetoder är muskelaktivitet, hjärtfrekvens, hjärtfrekvensvariabilitet, andningsfrekvens, hudkonduktans och fingertemperatur. Ett sätt att försöka minska belastningen för skotarföraren är att automatisera vissa moment i kranens arbete. Syftet med examensarbetet var att utvärdera psykofysiologiska mätmetoder lämpliga för att beöma skillnaden i mental belastning hos skotarförare vid arbete med konventionellt- och delautomatiserat kranarbete i simulatormiljö. Resultatet visar på en potential hos analyserna hjärtfrekvens, hjärtfrekvensvariabilitet och andning för fortsatta studier. Muskelaktiviteten i form av trapezius-EMG och hudkonduktans var analyser behäftade med höga brusnivåer och artefakter i studien. Arbetet ger även en bild av komplexiteten i studier där teknik och människa interagerar. Den tekniska kapaciteten på skogsmaskiner är idag så avancerad att maskinföraren bedöms vara den begränsande faktorn för prestationen. För att öka produktiviteten i skogsbruket är det av stor vikt att den tekniska utvecklingen samspelar med interaktionen mellan människa och maskin för att främja ett hållbart skogsbruk för såväl maskinförare som för skog och miljö.

This diploma thesis deals with impact of stress on performance of military pilots of supersonic aircrafts. The theoretical part is based on definition of the term stress, his relating theories, the strategies of coping with stress and possible methods of objectivization of mental workload. This part also provides an overview of stress occuring during flight activity and specifics of the job of military pilot. The research is based on theoretical models and previous researches and the aim is to analyze the hypothesis about the dependence of stress on performance of the military pilot.This correlation was empirically verified by experimental study conducted in tactical flight simulator designed for a training on supersonic airplanes. The mental workload was investigated by physiological data and psychological questionnaires. The results are showing the most stressful and most difficult situations that appeared during tactical combat mission. There was a significant correlation between personality, resting heart rate and the effectivity of the performance. Key words: Stress, Military pilots, Performance, Mental workload, Heart rate

Background: Concern has been raised that the workload of community pharmacists (CPs) is linked to the occurrence of dispensing errors (DEs). One aspect of workload that has not yet been measured in this setting, but has been linked to errors in other industries, is mental workload (MWL). Aims: (1) Measure the relationship between MWL and DEs during a routine pharmacy task, the final accuracy check, which research suggests is critical to DE prevention. (2) Quantify the role that expertise plays in this relationship. (3) Explore CPs and pharmacy students’ experiences of MWL and DEs. Methods: A mixed methods approach was taken and three studies were conducted. In study one, CPs (n=104) and students (n=93) checked dispensed items for DEs. Participants took part in one of four conditions (distraction, no distraction, dual-task or single-task) and their DE detection and MWL was measured. Study two was a diary study of CPs’ (n=40) MWL during a day in their “real-life” practice. Study three presented an interpretative phenomenological analysis of CPs’ (n=14) and students’ (n=15) experiences of MWL and DEs. Main findings: Study one found that high MWL was related to reduced DE detection, but only for students, confirming the important role of expertise. Distractions did not affect DE detection but was linked to increased MWL. Study 2 highlighted specific times of the day when CPs’ MWL was exceptionally high. Study 3 found several factors which increased MWL, including the lack of control CP’s had over their workload, difficulties communicating with prescribers and targets. Conclusions: MWL has been found to be a useful tool for measuring the impact of workload on pharmacy safety. The findings are linked to current work design and human factors theory and suggestions are made for how CPs’ work could be redesigned to reduce their MWL and improve safety.

This research compares methods for measuring pilot mental workload (MWL) from the electrocardiogram (ECG) signal. ECG-based metrics have been used extensively in MWL research. Heart rate (HR) and heart-rate variability (HRV) exhibit changes in response to varying levels of task demand. Classical methods for HRV analysis examine the ECG signal in the linear time and frequency domains. More contemporary research has advanced the notion that nonlinear elements contribute to cardiac control and ECG signal generation, spawning development of analytical techniques borrowed from the domain of nonlinear dynamics (NLD). Applications of nonlinear HRV analysis are substantial in clinical diagnosis settings; however, such applications are less frequent in MWL research, especially in the aviation domain. Specifically, the relative utility of linear and non-linear HRV analysis methods has not been fully assessed in pilot MWL research. This thesis contributes to aforementioned research gap by comparing a non-linear HRV method, utilizing transition probability variances (TPV), to classical time and frequency domain methods, focusing the analysis on sensitivity and diagnosticity. ECG data is harvested from a recent study characterizing spatial disorientation (SDO) risk amongst three candidate off-boresight (OBS) helmet-mounted display (HMD) symbologies in a tactically relevant live-flight task. A comparative analysis of methods on this dataset and supplemental workload analysis for the HMD study are presented. Results indicate the TPV method may exhibit higher sensitivity and diagnosticity than classical methods. However, limitations of this analysis warrant further investigation into this question.

<p>The goal of this thesis has been to study the behaviour of the closed loop driver-vehicle-environment in simulation and to find parameters of the synthetic vehicle model, which minimise certain optimisation criteria. A method of optimising parameters using genetic algorithms has been implemented and has proven to work well. Two different driving strategies have been tried in the optimisation of an ISO lane-change maneouvre. The first approach has simulated a beginner driver and his or her behaviour. The second approach simulates an experienced driver and also the possibility of driver adaption to different vehicle types. The implemented driver model has shown to be sufficient to describe the driver's behaviour during lateral maneouvres. A parameter set which minimises the lateral acceleration response on steering wheel angle has proven to be the optimum. This includes a small steering wheel ratio, and a small but positive under steer gradient. The driver has demonstrated the ability to adapt to different vehicles, and therefore different parameter sets, describing the driver, should be used for different problems.</p>

Experienced and novice simulator pilots are subject to some of the constraints of a real flight (or a full flight simulator) situation in a PC based flight simulation. In this thesis, the effects of expertise, working memory capacity, inhibition and divided attention on situation awareness (SA) in simulated flight task environments are investigated. The cognitive aspects underlying the process of situation awareness are explored by analyzing the compound effects of above listed factors. Online and Offline SA measurements obtained from a simulated flight task are used with flight hours standing for expertise and scores of Automated Operation Span Task, Stroop and Coskun&ouml / z visual attention tasks as measurements for working memory capacity, inhibition and divided attention respectively. Regression analyses reveal that expected relationships of simulator pilots&rsquo / SA with expertise and inhibition capacity are supported. On the other hand, expected relationships of SA with working memory and divided attention capacities are not revealed. This situation probably results from unsystematic differences in simulator pilots&rsquo / practices. In addition to the main experiment, simulator pilots&rsquo / levels of neural activity at their dorsolateral prefrontal cortex are also measured during their behavioral performance. The relationships among neural correlates of mental workload induced by the simulated flight are investigated by the functional near-infrared (fNIR) spectroscopy optical brain imaging technology. Theorized mental workload distinction in the scenario of the simulated flight task is successfully observed in both perceived workload declarations and oxygenation measurements by fNIR.

Ytters är skälen till undersökningarna i denna avhandling ekonomiska. Att flyga moderna krisgsflygplan är dyrt. Kan effektiv träning bedrivas intermittent i stället för kontinuerligt? Kan billigare skolflygplan vara ett komplement till krigsflygplan i systemutbildningen? En studie av intermittent flygning på jaktflygplan gjordes i två etapper, först i simulator - del I i avhandlingen - och sedan i luften - del II i avhandlingen. En del av en attackstudie med kompletteringsflygning i skolflygplan är del III.  Studierna hade en experiment-kontrollgrupps-design. I jaktstudien jämfördes avgångna flygförare med aktiv personal. I attackstudien jämfördes aktiva förare vid en experimentdivision med likaledes aktiva förare vid en kontrolldivision. Prestationsvärdering är av avgörande betydelse i undersökningarna. Parallellt med flygförarnas prestation har även deras arbetsbelastning mätts både i simulator och i luften, liksom deras ansträngning, motivation och sinnesstämning. Prognosen från simulator till luften angående förarnas kapacitet och operativa användbarhet kunde förbättras, när hänsyn togs även till andra variabler än prestation. Modeller av flygförares funktion och prestation under flygning kunde konstrueras med utgångspunkt från den utmaning, d v s risk och svårighet, som upplevdes före flygning.

The goal of this thesis has been to study the behaviour of the closed loop driver-vehicle-environment in simulation and to find parameters of the synthetic vehicle model, which minimise certain optimisation criteria. A method of optimising parameters using genetic algorithms has been implemented and has proven to work well. Two different driving strategies have been tried in the optimisation of an ISO lane-change maneouvre. The first approach has simulated a beginner driver and his or her behaviour. The second approach simulates an experienced driver and also the possibility of driver adaption to different vehicle types. The implemented driver model has shown to be sufficient to describe the driver's behaviour during lateral maneouvres. A parameter set which minimises the lateral acceleration response on steering wheel angle has proven to be the optimum. This includes a small steering wheel ratio, and a small but positive under steer gradient. The driver has demonstrated the ability to adapt to different vehicles, and therefore different parameter sets, describing the driver, should be used for different problems.

Les variables neurovégétatives permettent d’évaluer l’état fonctionnel de l’individu, et représentent un intérêt pour mieux comprendre le comportement du conducteur, facteur déterminant de la sécurité routière. Ce travail est centré sur l’évaluation de la charge mentale du conducteur automobile par l’analyse de l’activité électrodermale. L’objectif est d’extraire les meilleurs indicateurs du signal électrodermal pour différencier la charge mentale induite par des situations de conduite réelle. L’analyse d’une trentaine d’indicateurs phasiques a permis de différencier des situations de conduite nominale, comparables en termes d’exigence comportementale mais différentes au niveau cognitif. Après traitement approprié du signal, en particulier en appliquant des transformations log, l’amplitude des réponses électrodermales est apparue comme un des indices les plus discriminants. Toutefois, les différences de charge mentale induites par les situations de conduite n’ont pas exactement correspondu à celles qui avaient été supposées. Une explication alternative mettant en avant des processus d’anticipation est proposée. Trois indicateurs toniques, dont deux sont nouveaux, ont ensuite été testés dans une expérience de double tâche, où une activité secondaire distractive était effectuée simultanément à la conduite. L’un s’est révélé inadapté au profil des signaux, mais les deux autres ont permis d’établir une hiérarchisation partielle de la surcharge induite. Particulièrement sensible à l’aspect cognitif de la distraction, l’évaluation psychophysiologique de la charge mentale par l’activité électrodermale apparaît complémentaire de l’analyse de la performance de conduite. / As an assessment tool for individual’s functional state, autonomic indices can help improving our knowledge of drivers’ behaviour, which is a central road safety causal factor. This work is focused on driver’s mental workload assessment, relying on electrodermal activity analysis. This is an attempt to highlight the most reliable electrodermal indices with the aim to distinguish accurately mental workload elicited by actual driving situations. The analysis of about thirty phasic indices, led to differentiate nominal driving situations. These were selected on the basis of comparable behavioural requirements, but of differences cognitive processes. After appropriate signal processing, (using log transformations in particular), electrodermal responses amplitude has the most potential to distinguish among experimental conditions. However, some of the differences about mental workload were not exactly those which were previously expected. An alternative interpretation of results highlighting anticipation processes is thus proposed. Tonic variations were then studied in a dual task experiment, including two new indices. The distractive power of several secondary tasks, performed while driving, was to be evaluated using these indices. One of the indices was unrelated to signals’ profile. Conversely, the two others gave a clear distinction of potential distraction elicited selectively by each secondary task. Mental workload was thus showed as being evaluated accurately using electrodermal activity analysis. Using objective physiological data and defining new electrodermal indices brought more reliability in the field of mental workload. Thus, electrodermal activity is a good candidate to complete data usually brought by tests or questionnaires.

Les situations de collaboration à distance dans l’industrie induisent de nouvelles contraintes pour les opérateurs. Dans le contexte de l’utilisation d’environnements virtuels collaboratifs immersifs, nous avons mis en place une série d’études portant sur la compréhension mutuelle, et plus particulièrement au partage d’information de nature spatiale. Les résultats de la première étude ont permis de mettre en évidence l’influence du rôle des participants, guides ou manipulateurs, sur les énoncés spatialisés. Les énoncés étaient centrés préférentiellement sur l’action du manipulateur, suggérant la recherche d’un moindre effort collaboratif. Les résultats de deux études sur la production d’énoncés spatialisés ont permis d’identifier que l’exigence mentale pour la production d’énoncés est modulée notamment par la position de la cible à décrire par rapport au destinataire. En effet, selon la position de la cible, le locuteur doit opérer ou non des transformations mentales coûteuses pour prendre la perspective du destinataire. Cet effort peut être amoindri en présence d’indices visuels distaux. La dernière étude, portant sur la compréhension d’énoncés spatialisés, a permis de mettre en évidence que les énoncés centrés sur le destinataire sont les plus simples à comprendre pour une tâche de nature égocentrée. Certains énoncés exocentrés induisent également une moindre exigence mentale, mais uniquement selon certaines conditions. Les résultats sont discutés selon le principe du moindre effort collaboratif et la théorie des cadres de référence. Ce travail a permis de proposer des pistes de développement pour faciliter la collaboration à distance dans les environnements virtuels. / Remote collaborative situations in industry involve new constraints for workers. In the context of using immersive virtual environments to collaborate, we set up a series of experiments focusing on the mutual comprehension, and more specifically on the process of sharing spatial information. Results of the first experiment showed the influence of one collaborator’s role on spatial statements. Guides and manipulators both used statements preferentially centered on manipulator’s action, which supports the least collaborative effort principle. Results of two experiments about spatial statements production allowed to point out that mental workload is modulated by the target position relative to the addressee. According to the target location, the speaker must operate or not cognitively costly mental transformations to take the addressee perspective. However this workload could be lowered by means of visual cues. The last experiment focused on the understanding of spatial statements. It showed that statements centered on the addressee are the easiest to understand when the task is also centered on the addressee. Some exocentered statements could also induce a lower mental workload but only in some conditions. Results are discussed in relation to the least collaborative effort principle and the spatial frames of reference theory. This work opens new leads to facilitate remote collaboration through virtual environments.