A multitude of wireless technologies are used by air traffic communication systems during different flight phases. From a conceptual perspective, all of them are insecure as security was never part of their design and the evolution of wireless security in aviation did not keep up with the state of the art. Recent contributions from academic and hacking communities have exploited this inherent vulnerability and demonstrated attacks on some of these technologies. However, these inputs revealed that a large discrepancy between the security perspective and the point of view of the aviation community exists. In this thesis, we aim to bridge this gap and combine wireless security knowledge with the perspective of aviation professionals to improve the safety of air traffic communication networks. To achieve this, we develop a comprehensive new threat model and analyse potential vulnerabilities, attacks, and countermeasures. Since not all of the required aviation knowledge is codified in academic publications, we examine the relevant aviation standards and also survey 242 international aviation experts. Besides extracting their domain knowledge, we analyse the awareness of the aviation community concerning the security of their wireless systems and collect expert opinions on the potential impact of concrete attack scenarios using insecure technologies. Based on our analysis, we propose countermeasures to secure air traffic communication that work transparently alongside existing technologies. We discuss, implement, and evaluate three different approaches based on physical and data link layer information obtained from live aircraft. We show that our countermeasures are able to defend against the injection of false data into air traffic control systems and can significantly and immediately improve the security of air traffic communication networks under the existing real-world constraints. Finally, we analyse the privacy consequences of open air traffic control protocols. We examine sensitive aircraft movements to detect large-scale events in the real world and illustrate the futility of current attempts to maintain privacy for aircraft owners.

La recherche d’aide est une stratégie qui peut améliorer l’apprentissage et la réussite scolaire. Malgré ce constat, la littérature montre que les étudiants ou élèves décident fréquemment de ne pas rechercher de l’aide. Par ailleurs, dans le domaine de l’aéronautique, peu d’études ont été consacrées à la formation des contrôleurs aériens, qui jouent un rôle central dans le système de régulation du trafic aérien. Étant donné que la performance humaine est classiquement considérée comme un facteur qui contribue à la majorité des incidents et accidents aériens, l’enjeu de ces formations est majeur. L’objectif de cette thèse est double: au plan général, comprendre pourquoi les étudiants décident de ne pas rechercher de l’aide alors que la tâche à réaliser n’est pas à leur portée. Cela relève-t-il d’une décision rationnelle? Quels sont les coûts impliqués? Au plan particulier, vérifier si ce problème existe aussi dans l’environnement d’apprentissage des contrôleurs aériens et si les mêmes conclusions concernant la décision de rechercher ou non de l’aide peuvent être tirées. En ayant pour base un modèle rationnel de prise de décision, dans lequel la décision est une fonction des coûts, de la probabilité et des bénéfices, quatre expériences ont été menées: trois dont les participants étaient des étudiants universitaires et une avec les élèves contrôleurs aériens. Les résultats montrent que les étudiants hésitent à demander de l’aide quand elle est objectivement coûteuse; que le temps consommé en l’utilisant n’est pas considéré comme un coût; et que les étudiants sont prêts à demander de l’aide même quand elle n’est pas assurément utile. En outre, il y a un coût social impliqué dans la décision de rechercher de l’aide: la présence d’un expert baisse les taux de recherche d’aide, notamment quand la tâche est considérée comme facile. Les données de la quatrième expérience suggèrent que le coût social n’impacte pas la décision des élèves contrôleurs d’utiliser les aides. / Learners who encounter difficulties can improve learning and achievement by seeking help. However, literature shows that students frequently decide to not seek help. In aeronautics domain, few studies were dedicated to the training of air traffic controllers, who play an important role in the air traffic regulation system. Given that the human performance is traditionally considered a factor that contributes to the majority of incidents and accidents in aviation, the challenge of their training is greater. This thesis has two goals: generally, understand why students decide not to seek help while the task they have to realize is beyond their reach. Is this a rational decision? What are the costs involved? Specifically, to verify if this issue also exists in the context of air traffic controller training and if we find the same conclusions about help-seeking decision. Based on a rational decision model, where the decision is a function of costs, expectancies and benefits, four experiences were conducted: three of them in a general context, having university students as participants, and an experience with air traffic controllers’ students. Results show that students hesitate to seek help when it is objectively costly; the time consumed to seek help is not considered as a cost; and that students are ready to seek help even when its utility is not assured. Besides, there is a social cost implicated in the decision to seek help: the presence of an expert reduces the levels of help-seeking, particularly when the task is considered easy. The results of the fourth study suggest that the social cost adversely do not have an effect in the decision of air traffic controller students of using all help tools, but the difficulty of the exercise may affect the decision of seeking some kinds of help.

Emerging connected and autonomous vehicle technologies (CAV) provide an opportunity to improve highway capacity and reduce adverse impacts of stop-and-go traffic. To realize the potential benefits of CAV technologies, this study provides insightful methodological and managerial tools in microscopic and macroscopic traffic scales. In the macroscopic scale, this dissertation proposes an analytical method to formulate highway capacity for a mixed traffic environment where a portion of vehicles are CAVs and the remaining are human-driven vehicles (HVs). The proposed analytical mixed traffic highway capacity model is based on a Markov chain representation of spatial distribution of heterogeneous and stochastic headways. This model captures not only the full spectrum of CAV market penetration rates but also all possible values of CAV platooning intensities that largely affect the spatial distribution of different headway types. Numerical experiments verify that this analytical model accurately quantifies the corresponding mixed traffic capacity at various settings. This analytical model allows for examination of the impact of different CAV technology scenarios on mixed traffic capacity. We identify sufficient and necessary conditions for the mixed traffic capacity to increase (or decrease) with CAV market penetration rate and platooning intensity. These theoretical results caution scholars not to take CAVs as a sure means of increasing highway capacity for granted but rather to quantitatively analyze the actual headway settings before drawing any qualitative conclusion. In the microscopic scale, this study develops innovative control strategies to smooth highway traffic using CAV technologies. First, it formulates a simplified traffic smoothing model for guiding movements of CAVs on a general one-lane highway segment. The proposed simplified model is able to control the overall smoothness of a platoon of CAVs and approximately optimize traffic performance in terms of fuel efficiency and driving comfort. The elegant theoretical properties for the general objective function and the associated constraints provides an efficient analytical algorithm for solving this problem to the exact optimum. Numerical examples reveal that this exact algorithm has an efficient computational performance and a satisfactory solution quality. This trajectory-based traffic smoothing concept is then extended to develop a joint trajectory and signal optimization problem. This problem simultaneously solves the optimal CAV trajectory function shape and the signal timing plan to minimize travel time delay and fuel consumption. The proposed algorithm simplifies the vehicle trajectory and fuel consumption functions that leads to an efficient optimization model that provides exact solutions. Numerical experiments reveal that this algorithm is applicable to any signalized crossing points including intersections and work-zones. Further, the model is tested with various traffic conditions and roadway geometries. These control approaches are then extended to a mixed traffic environment with HVs, connected vehicles (CVs), and CAVs by proposing a CAV-based speed harmonization algorithm. This algorithm develops an innovative traffic prediction model to estimate the real-time status of downstream traffic using traffic sensor data and information provided by CVs and CAVs. With this prediction, the algorithm controls the upstream CAVs so that they smoothly hedge against the backward deceleration waves and gradually merge into the downstream traffic with a reasonable speed. This model addresses the full spectrum of CV and CAV market penetration rates and various traffic conditions. Numerical experiments are performed to assess the algorithm performance with different traffic conditions and CV and CAV market penetration rates. The results show significant improvements in damping traffic oscillations and reducing fuel consumption.

It is becoming widely recognised that shiftwork has significant implications for the health, safety and quality of life of shiftworkers. To date, little research has been carried out on how individuals cope with the problems caused by shiftwork and how effective coping strategies maintain their health and well-being. It has been proposed, by Monk (1994), that there are a number of aspects of a shiftworker's life which are important in determining the ability of an individual to cope with shiftwork. These factors are an individual's circadian rhythms, sleep patterns, and social and domestic situation. Further literature also suggests that workplace factors and coping style are an important part of tolerating shiftwork. The primary aim of the present study was to determine which factors are important in predicting the physical and mental well-being of Air Traffic Services staff working on shifts. It was hypothesised that individuals who are evening types, have few social, domestic, sleep, and work place difficulties will be physically and mentally healthy. In addition, it was hypothesised that the use of engagement strategies in dealing with shiftwork related problems will relate to better physical and mental health. To test the hypotheses, 183 Air Traffic Services staff from Melbourne centre, Australia were surveyed by questionnaire. The results of the regressions showed that physical health was predicted by variables from each of the five areas considered; circadian typology, the social and domestic situation, work place factors, sleep patterns and coping style. Mental well-being was best predicted by a single domestic variable, which is the extent to which shiftwork caused domestic problems and the two coping variables of engagement and disengagement. The results support the suggestion that in order for an individual to be able to tolerate shiftwork they must have strategies in place to help them deal with the effect of shiftwork variables on a range of factors in their lives. An additional aim of the present study was to determine the reliability of a questionnaire for use with Air Traffic Services staff. This was due to a lack of suitable questionnaires for use in this occupational context. Overall the items in the questionnaire were found to have acceptable reliability, although the collection of sleep data by subjective reporting is not recommended.

Non-controlled airports are literally that - uncontrolled. Safe separation is achieved by pilot vigilance. The consensus of reports on incidences at noncontrolled airports generally conclude that pilots cannot rely entirely on vision to avoid collision and attempts should be made to obtain all available traffic information to enable a directed traffic search. Ideally, a system is required which has the ability to provide advice to all parties to ensure separation minima is maintained. Provision of a such a system would remove a measure of pressure from the pilot to allow that person to devote their attention to their prime responsibility of flying the aircraft. To this end, research on use of intelligent remote advisory systems for non-controlled airports was undertaken with emphasis on those systems which could minimize human resources and associated recurring costs, to provide a measure of repeatability and to provide an acceptable level of safety. A rule based system was developed and evaluated. The evaluation showed that use of a rule based system as the basis of an intelligent remote air traffic control system for non-controlled airports is a viable proposition. In test scenarios, collision hazards were identified and evasion tactics generated. For a full operational system, the application of the rules and definition of the aircraft circuit area may need refining; however, the results are certainly encouraging.

The aim of the present research was to examine the impact of mental workload on conflict resolution decision making in air traffic control (ATC). While previous studies have examined the effect of workload on performance (Averty, 2004; Kopardekar & Magyrits, 2002) and conflict detection (Mogford, 1997; Seamster, Redding, Cannon, Ryder & Purcell, 1993), limited research examines the effect of workload on conflict resolution decisions. The aim of the first study was to gain an initial understanding of how controllers manage their airspace. Results demonstrated that controllers scan repetitively, in a clockwise and top-bottom pattern; group aircraft with similar characteristics and use at least five lateral and eight vertical conflict resolution heuristics. Study two examined the effect of conflict type on conflict resolution under different levels of workload. Under moderate workload controllers used a mix of solutions, while under high workload, solutions became more conservative. Study three examined the effect of other contextual factors on conflict resolution. Results again suggested conflict type affects conflict resolution decisions and also that other contextual parameters, such as aircraft performance may play a role in solution preferences. Study four examined the effect of workload on conflict resolution using a realistic ATC task. Workload not only impacted on controllers’ performance scores, but interacted with conflict type to determine whether an efficient solution was preferred over a less efficient solution. This research identifies some of the heuristics experts use when competing priorities are present and provides an understanding of how conflict type, contextual factors and workload affect decisions. Findings contribute to the naturalistic decision making (NDM) literature by demonstrating how the situation can influence decision making.

<p>As air traffic is forecasted to increase, air traffic control software subsequently needs to be more sophisticated. To efficiently push development forward, testing is important in order to determine usability. The tests need to be adapted to fit a particular purpose and carried out with methods that preserve the validity of the results. </p><p>This thesis describes an implementation project carried out at the EUROCONTROL Experimental Centre, Bretigny-sur-Orge, France. The purpose of the project is to create an application that enables a user to create datasets of air traffic to be used for these tests. The application allows for manual work or bulk imports from external data sources. Furthermore it compiles scenarios as output datasets intended for prototype air traffic control software developed at Linköping University. </p><p>The application design rationale and development process is described. Some time is spent on demonstrating the flexibility of the application and how its usage fits in a bigger picture.</p>

<p>Now a day, one of the most attractive research topics in the area of Intelligent Traffic Control is </p><p>Inter-vehicle communication (V2V communication). In V2V communication, a vehicle can </p><p>communicate to its neighbouring vehicles even in the absence of a central Base Station. The </p><p>concept of this direct communication is to send vehicle safety messages one-to-one or one-to- </p><p>many vehicles via wireless connection. Such messages are usually short in length and have very </p><p>short lifetime in which they must reach the destination. The Inter-vehicle communication system </p><p>is an ad-hoc network with high mobility and changing number of nodes, where mobile nodes </p><p>dynamically create temporary sensor networks and transferring messages from one network to </p><p>others by using multiple hops due to limitation of short range. </p><p> </p><p>The goal of the project is to investigate some basic research questions in order to organize such </p><p>sensor networks and at the same time highlight the appropriate routing protocol that support </p><p>mobile ad hoc networks in an efficient and reliable manner. </p><p> </p><p>In our investigation, we have answered the technical issues in order to construct a V2V </p><p>communication system. We have also studied some mobile ad hoc network routing protocols in </p><p>detail and then selected the DSR (Dynamic Source Routing) for our V2V communication and </p><p>then simulated it according to our system requirements. We are quite satisfied by the result of </p><p>DSR, but at the same time much more work is required to come up with an absolute application </p><p>for the end user.</p>

R.B. Adler, S.J. Fricker. / "August 13, 1951." / Bibliography: p. 50. / Air Navigation Development Board of the Department of Commerce Contract No. Cca-28152.

The current project is an examination of the effectiveness of decision-support graphics in a simulated real-world task, and of the role those graphics should play in training. It is also an attempt to apply a theoretical account of memory performance-transfer-appropriate processing-to naturalistic decision making. The task in question is a low-fidelity air traffic control simulation. In some conditions, that task includes decision-support graphics designed to explicitly represent elements of the task that normally must be mentally represented-namely, trajectory and relative altitude. The assumption is that those graphics will encourage a type of processing different from that used in their absence. If so, then according to the theory of transfer-appropriate processing (TAP), the best performance should occur in conditions in which the graphics are present either during both training and testing, or else not at all. For other conditions, the inconsistent presence or absence of the graphics should lead to mismatches in the type of processing used during training and testing, thus hurting performance. A sample of 205 undergraduate students were randomly assigned to four experimental and two control groups. The results showed that the support graphics provided immediate performance benefits, regardless of their presence during training. However, presenting them during training had an apparent overshadowing effect, in that removing them during testing significantly hurt performance. Finally, although no support was found for TAP, some support was found for the similar but more general theory of identical elements.