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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Exploring the Effects of Language on Angry Drivers' Situation Awareness, Driving Performance, and Subjective Perception

Muhundan, Sushmethaa 28 April 2021 (has links)
Research shows that anger has a negative impact on cognition due to the rumination effect and in the context of driving, anger negatively impacts situation awareness, driving performance, and road safety. In-vehicle agents are capable of mitigating the effects of anger and subsequent effects on driving behavior. Language is another important aspect that influences information processing and human behavior during social interactions. This thesis aims to explore the effects of the language of in-vehicle agents on angry drivers' situation awareness, driving performance, and subjective perception. The three conditions explored are the native language agent condition (Hindi or Chinese), secondary language agent condition (English), and no agent condition. Results indicate that driving performance is better in the case of the native language agent condition when compared to the no agent condition. Higher levels of situational awareness were affected by the agent condition, favoring the native language condition over the secondary language condition. The participants preferred native language agents over the other conditions and the perceived workload was higher in the no-agent condition than the native agent condition. Drivers also expressed the need to control the state of the in-vehicle agent. The study results have practical design implications and the results are expected to help foster future work in this domain. / Master of Science / People are deeply influenced by emotions. Anger while driving is shown to negatively impact people's perception and understanding of what is going on in the driving context and prediction about what will happen. As a result, this influences driving performance and road safety. Intelligent agents (such as Siri or Alexa) built into vehicles can help regulate the emotions of the drivers and can positively impact driving performance. Language is another important aspect that influences human behavior during social interactions. The current thesis aims to leverage the positive impacts of in-vehicle agents and language to design in-vehicle agent interactions capable of mitigating the negative effects of anger to ensure better driving performance and increased situation awareness. The three conditions explored are the native language agent condition (Hindi or Chinese), secondary language agent condition (English), and no agent condition. The effects on angry drivers' situation awareness, driving performance, and subjective perception are studied. Results indicate that the driving performance is better in the case of the native language agent condition when compared to the no agent condition. Participants preferred native language agents over the other conditions. People's understanding and prediction capability in the driving context was better in the native agent condition over the other conditions. The study results have practical design implications in designing in-vehicle agent interfaces and the results are expected to help foster future work.
82

Evaluation of an Auditory Localization Training System for Use in Portable Configurations: Variables, Metrics, and Protocol

Cave, Kara Meghan 22 January 2020 (has links)
Hearing protection can mitigate the harmful effects of noise, but for Service Members these devices can also obscure auditory situation awareness cues. Tactical Communication and Protective Systems (TCAPS) can restore critical cues through electronic circuitry with varying effects on localization. Evidenced by past research, sound localization accuracy can improve with training. The investigator hypothesized that training with a broadband stimulus and reducing the number of presentations would result in training transfer. Additionally, training transfer would occur with implementation of more user-engaged training strategies. The purpose of the experiments described in this study was to develop an optimized auditory azimuth-training protocol for use in a field-validated portable training system sensitive to differences among different TCAPS. A series of indoor experiments aimed to shorten and optimize a pre-existing auditory localization training protocol. Sixty-four normal-hearing participants underwent localization training. The goal of training optimization included the following objectives: 1) evaluate the effects of reducing stimulus presentations; 2) evaluate the effects of training with a broadband stimulus (but testing on untrained military-relevant stimuli); and 3) evaluate performance differences according to training strategies. Twenty-four (12 trained and 12 untrained) normal-hearing listeners participated in the field-validation experiment. The experiment evaluated localization training transfer from the indoor portable system to live-fire blanks in field. While training conducted on the portable system was predicted to transfer to the field, differences emerged between an in-the-ear and over-the-ear TCAPS. Three of four untrained stimuli showed evidence of training transfer. Shortening the training protocol also resulted in training transfer, but manipulating training strategies did not. A comparison of changes in localization scores from the indoor pretest to the field posttest demonstrated significant differences among listening conditions. Training improved accuracy and response time for the open ear and one of two TCAPS. Posttest differences between the two TCAPS were not statistically significant. Despite training, localization with TCAPS never matched the open ear. The portable apparatus employed in this study offers a means to evaluate the effects of TCAPS on localization. Equipped with a known effect on localization, TCAPS users can render informed decisions on the benefits or risk associated with certain devices. / Doctor of Philosophy / Hearing protection can mitigate the harmful effects of noise, but for Service Members these devices can obscure auditory situation awareness cues. Certain powered hearing protection can restore critical cues through electronic circuitry with varying effects on localization. Evidenced by past research, sound localization accuracy can improve with training. The investigator hypothesized that training with a broadband stimulus and reducing the number of presentations would result in auditory learning. Additionally, implementing more user-engaged training strategies would demonstrate more auditory learning. The purpose of the experiments described in this study was to develop an optimized auditory azimuth-training protocol for use in a field-validated training system sensitive to differences among active hearing protection. A series of indoor experiments aimed to shorten and optimize a pre-existing auditory localization training protocol. Sixty-four normal-hearing participants underwent localization training. The goal of training optimization included the following objectives: 1) evaluate the effects of reducing stimulus presentations; 2) evaluate the effects of training with a broadband stimulus (but testing on untrained military-relevant stimuli); and 3) evaluate performance differences in localization performance according to training strategies. In the field-validation study, 12 trained and 12 untrained normal-hearing listeners participated. The experiment evaluated localization learning from the indoor portable training system to live-fire blanks in a field. Training conducted on the portable system was predicted to transfer to the field, but differences would emerge between an in-the-ear and an over-the-ear TCAPS. Three of four untrained stimuli showed evidence of localization learning. Shortening the protocol also resulted in localization learning, but manipulating training strategies did not. A comparison of changes in localization scores from the indoor pretest to the field posttest demonstrated significant differences among listening conditions. Training improved performance for the open ear and one of two active hearing protectors. Posttest differences between the two devices were not significant. Despite training, performance with hearing protection never equaled the open ear. The portable apparatus employed in this study offers a means to evaluate the effects of hearing protection on localization. Knowing the effects of hearing protection on localization apprises users of the benefits and/or risk associated with the use of certain devices.
83

The Attention of Train Drivers : An experimental study of differences in attention between Automatic Train Control and European Railway Traffic Management System (ERTMS)

Bernheim, Lisa January 2022 (has links)
A European project is gradually replacing the current train control systems to a mutual control system called as the European Railway Traffic Management System (ERTMS). I Sweden they have implemented the new train control system on a few train-lines in the northern part of Sweden. There has been reported problems from train drivers that have used the new control system, the problems consist of both negative affects on train performance and railroad capacity. This study is part of a larger project conducted by The Swedish National Road and Transport Research Institute, with an aim to investigate how the attention is affected in the new train control system compared to the Automatic Train Control (ATC) system. Data collection through eye-tracking have shown significant results in the distribution of visual glances inside and outside the cabin of the train. Drivers tend to distribute more and longer glances inside the train with the ERTMS. Drivers also tend to miss information presented on the track, such as signs informing when to make a sound before an unattended level crossing. These results suggest that ERTMS could have a negative impact on the drivers situation awareness and also could have a negative affect on the drivers attention that impacts the ability to notice what is happening outside the cabin. / I dagsläget utförs ett projekt i Europa med syfte att ersätta nuvarande tågskyddssystem till ett gemensamt signalsystem kallat ERTMS (European Railway Traffic Management System). Detta nya system har implementerats på ett fåtal tåg-linjer i norra delen av Sverige. Olika problem har rapporterats från tågförare som använt det nya signalsystemet. Dessa problem innefattar negativ påverkan på prestation och järnvägens kapacitet. Denna studie är en del av ett större projekt hos Statens väg- och transportforskningsinstitut med ett syfte att studera hur uppmärksamhet påverkas i det nya tågskyddssystemet ERTMS jämfört med det nuvarande systemet ATC (Automatic Train Control). Data som samlades in via eye-tracking har visat signifikanta resultat i fördelning av visuella blickar inne i och utanför tågets kabin. Förare tenderar att fördela mer och även längre blickar inuti tågets kabin med ERTMS. Dessutom tenderar förare att missa information som presenteras ute på spåret, detta kan exempelvis vara information som påvisar att tuta innan ett obevakat övergångsställe. Dessa resultat föreslår att ERTMS kan ha en negativ påverkan på förares uppmärksamhet vilket kan påverka förarens förmåga att bli varse om vad som händer utanför kabinen, på spåret.
84

Situation awareness amongst emergency care practitioners

Abd Hamid, Harris Shah January 2011 (has links)
The increase and changes in the demand for emergency care require pro-active responses from the designers and implementers of the emergency care system. The role of Emergency Care Practitioner (ECP) was introduced in England to improve the delivery of emergency care in the community. The role was evaluated using cost-benefit approach and compared with other existing emergency care roles. An analysis of the cognitive elements (situation awareness (SA) and naturalistic decision making (NDM)) of the ECP job was proposed considering the mental efforts involved. While the cost-benefit approach can justify further spending on developing the role, a cognitive approach can provide the evidence in ensuring the role is developed to fulfil its purpose. A series of studies were carried out to describe SA and NDM amongst ECPs in an ambulance service in England. A study examined decision-making process using Critical Decision Method interviews which revealed the main processes in making decision and how information was used to develop SA. Based on the findings, the subsequent studies focus on the non-clinical factors that influence SA and decision making. Data from a scoping study were used to develop a socio-technical systems framework based on existing models and frameworks. The framework was then used to guide further exploration of SA and NDM. Emergency calls that were assigned to ECPs over a period of 8 months were analysed. The analysis revealed system-related influences on the deployment of ECPs. Interviews with the ECPs enabled the identification of influences on their decision-making with respect to patient care. Goal-directed task analysis was used to identify the decision points and information requirements of the ECPs. The findings and the framework were then evaluated via a set of studies based on an ethnographic approach. Participant observations with 13 ECPs were carried out. Field notes provided further insight into the characteristics of jobs assigned to the ECPs. It was possible to map the actual information used by the ECP to their information needs. The sources of the information were classified according to system levels. A questionnaire based on factors influencing decision-making was tested with actual cases. It was found that the items in the questionnaire could reliably measure factors that influence decision-making. Overall, the studies identify factors that have direct and indirect influences on the ECP job. A coherent model for the whole emergency care systems can be developed to build safety into the care delivery process. Further development of the ECP role need to consider the support for cognitive tasks in light of the findings reported in this thesis.
85

Le rôle des comportements informationnels dans la prise de conscience de la situation : usage dans le serious game 3D Virtual Operating Room / The role of human information behaviors in the situation awarness : use for the serious game 3D Virtual Operating Room

Devreux, Gilles 18 December 2015 (has links)
L’objectif de cette thèse de doctorat est d’étudier les mécanismes en jeu dans les comportements informationnels lors de la prise de conscience de la situation afin d’en dégager des leviers permettant d’orienter ces comportements. Ces travaux s’inscrivent dans le cadre du développement du Serious Game 3DVOR, dispositif dédié à la gestion des risques au bloc opératoire. Dans un premier temps, nous avons filmé puis analysé 6 situations d’opération chirurgicale sans complication et avons observé les comportements informationnels des opérateurs du bloc lors d’une simulation numérique d’un cas complexe de chirurgie. Enfin nous avons élaboré un scénario permettant d’interagir avec des partenaires virtuels afin d’observer l’impact de leurs actions sur les stratégies informationnelles d’un apprenant. Nous avons analysé les données recueillies au regard de la littérature sur la conscience de la situation, particulièrement le modèle d’Endsley (1995). Nos résultats montrent que les comportements informationnels varient selon l’expertise des opérateurs et l’ambiguïté de la situation. Les experts adaptent leurs stratégies lorsque la situation ne leur est pas familière et varient leurs sources d’informations pour mettre à jour leur représentation de la situation. Enfin, nous avons montré que l’engagement de partenaires, même virtuels, modifient les stratégies de traitement de l’information des apprenants face à un dispositif de formation numérique. / This doctoral thesis aims at investigating the mechanisms playing a role in both human information behavior and situation awareness in order to develop pedagogical levers that could guide those behaviors. The work we present is part of an industrial project for the development of a serious game named 3DVOR, this game is targeting the risk management education within the operating room. First, we filmed 6 surgical operations that did not present any complications, then we created a simulation of a complex case of surgery to observe the informational behaviors of each member of the surgical team. Last, we elaborated a scenario allowing a learner to interact with virtual partners in order to observe the impact of their actions on the learners’ informational strategies. We analyzed the data in view of the literature on situation awareness and the Endsley’s model. Our results show that the information behaviors vary according to the expertise of the operators and the ambiguity of the situation. Experts adapt their strategies when the situation does not seem familiar and vary their sources of information to update their mental representation of the current situation. Finally, we showed that the engagement, even of virtual partners, modify the learners’ strategies of information processing while using a digital learning software.
86

Buzz or Beep? How Mode of Alert Influences Driver Takeover Following Automation Failure

January 2018 (has links)
abstract: Highly automated vehicles require drivers to remain aware enough to takeover during critical events. Driver distraction is a key factor that prevents drivers from reacting adequately, and thus there is need for an alert to help drivers regain situational awareness and be able to act quickly and successfully should a critical event arise. This study examines two aspects of alerts that could help facilitate driver takeover: mode (auditory and tactile) and direction (towards and away). Auditory alerts appear to be somewhat more effective than tactile alerts, though both modes produce significantly faster reaction times than no alert. Alerts moving towards the driver also appear to be more effective than alerts moving away from the driver. Future research should examine how multimodal alerts differ from single mode, and see if higher fidelity alerts influence takeover times. / Dissertation/Thesis / Masters Thesis Human Systems Engineering 2018
87

MEASURING SITUATION AWARENESS IN MIXED REALITY SIMULATIONS

Forsman, Viking January 2019 (has links)
Off-highway vehicle, such as excavators and forklifts, are heavy machines that are capable of causing harm to humans or damage property. Therefore, it is necessary to be able to develop interfaces for these kind of vehicles that can aid the operator to maintain a high level of situational awareness. How the interface affects the operators’ situational awareness is consequently an important metric to measure when evaluating the interface. Mixed reality simulators can be used to both develop and evaluate such interfaces in an immersive and safe environment. In this thesis we investigated how to measure situational awareness in a mixed-reality off-highway vehicle simulation scenario, without having to pause the scenario, by cross-referencing logs from the virtual environment and logs from the users' gaze position. Our method for investigating this research question was to perform a literature study and a user test. Each participant in the user test filled out a SART post-simulation questionnaire which we then compared with our measurement system.
88

Team Performance : exploring team situation awareness, mental models, and team processes in breathing apparatus rescues / Prestation i team : studie av situationsmedvetenhet, mentala modeller och processer inom team vid rökdykning

Fogel, Annelie January 2004 (has links)
<p>The current study aimed at investigating the concepts of team situation awareness, mental models, and team processes in relation to performance in the complex, dynamic environment of breathing apparatus rescues. Data was collected during exercises at Ågesta training center through questionnaires and after action reviews. 28 firemen and 5 instructors participated in the exercises. Also, a stimulated recall interview was conducted with 2 of the firemen that had participated in one of the exercises. The different data collection methods all indicated that well-developed mental models or a high degree of pre-task knowledge affected performance in a positive way. Moreover, a multiple regression analysis showed that both pre-task knowledge and team processes significantly can predict performance. The results of the analysis of team situation awareness in relation to performance were fairly ambiguous. Therefore, further research is needed to establish the relation between these concepts in the domain at matter.</p>
89

Traveler Centric Trip Planning: A situation-Aware System

Amar, Haitham January 2012 (has links)
Trip planning is a well cited problem for which various solutions have been reported in the literature. This problem has been typically addressed, to a large extent, as a shortest distance path planning problem. In some scenarios, the concept of shortest path is extended to reflect temporal objectives and/or constraints. This work takes an alternative perspective to the trip planning problem in the sense it being situation aware. Thus, allowing multitudes of traveler centric objectives and constraints, as well as aspects of the environment as they pertain to the trip and the traveler. The work in this thesis introduces TSADA (Traveler Situation Awareness and Decision Aid) system. TSADA is designed as a modular system that combines linguistic situation assessment with user-centric decision-making. The trip planning problem is modeled as a graph G. The objective is to find a route with the minimum cost. Both hard and soft objective/attributes are incorporated. Soft objective/attributes such as safety, speed and driving comfortability are described using a linguistic framework and processed using hierarchical fuzzy inference engine. A user centric situation assessment is used to compute feasible routes and map them into route recommendation scheme: recommended, marginally recommended, and not recommended. In this work, we introduce traveler's doctrines concept. This concept is proposed to make the process of situation assessment user centric by being driven by the doctrine that synthesizes the user's specific demands. Hard attributes/objectives, such as the time window and trip monitory allowances, are included in the process of determining the final decision about the trip. We present the underline mathematical formulation for this system and explain the working of the proposed system to achieve optimal performance. Results are introduced to show how the system performs under a wide range of scenarios. The thesis is concluded with a discussion on findings and recommendations for future work.
90

Explanation Methods for Bayesian Networks

Helldin, Tove January 2009 (has links)
<p> </p><p>The international maritime industry is growing fast due to an increasing number of transportations over sea. In pace with this development, the maritime surveillance capacity must be expanded as well, in order to be able to handle the increasing numbers of hazardous cargo transports, attacks, piracy etc. In order to detect such events, anomaly detection methods and techniques can be used. Moreover, since surveillance systems process huge amounts of sensor data, anomaly detection techniques can be used to filter out or highlight interesting objects or situations to an operator. Making decisions upon large amounts of sensor data can be a challenging and demanding activity for the operator, not only due to the quantity of the data, but factors such as time pressure, high stress and uncertain information further aggravate the task. Bayesian networks can be used in order to detect anomalies in data and have, in contrast to many other opaque machine learning techniques, some important advantages. One of these advantages is the fact that it is possible for a user to understand and interpret the model, due to its graphical nature.</p><p>This thesis aims to investigate how the output from a Bayesian network can be explained to a user by first reviewing and presenting which methods exist and second, by making experiments. The experiments aim to investigate if two explanation methods can be used in order to give an explanation to the inferences made by a Bayesian network in order to support the operator’s situation awareness and decision making process when deployed in an anomaly detection problem in the maritime domain.</p><p> </p>

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