In the past, the study of Emergency Vehicle (EV) signal preemption has been mostly done using field studies. None of the simulation models that are currently commercially available have the capability to model the presence of EVs and simulate the traffic dynamics of the vehicles surrounding them. This study presents a macroscopic traffic model for examining the effect of signal preemption for EVs on traffic control measures, roadway capacity, and delays incurred to the vehicles on the side streets. The model is based on the cell transmission model, which is consistent with the hydrodynamic theory of traffic flow. A special component, in the form of a moving bottleneck that handles the traffic dynamics associated with the presence of EVs, was developed in the model. Several test scenarios were constructed to demonstrate the capabilities of the model for studying the impact of signal preemption on an arterial with multiple intersections under various traffic demand levels and varying frequencies of the arrival of EVs. Performance measures, such as average vehicle delay, maximum delay, and standard deviation of delay to traffic on all approaches, were obtained. An additional advantage of the model, apart from the capability to model EVs, is that the state-space equations used in the model can be easily incorporated into a mathematical programming problem. By coupling with a desired objective function, the model can be solved analytically. Optimal solutions can be generated to obtain insights into the development of traffic control strategies in the presence of EVs. / Master of Science

The use of graphical processing units (GPUs) for autonomous robots has grown recently due to their efficiency and suitability for data intensive computation. However, the current embedded GPU platforms may lack sufficient real-time capabilities for safety-critical autonomous systems. The GPU driver provides little to no control over the execution of the computational kernels and does not allow multiple kernels to execute concurrently for integrated GPUs. With the development of modern embedded platforms with integrated GPU, many embedded applications are accelerated using GPU. These applications are very computationally intensive, and they often have different criticality levels. In this thesis, we provide a software-based approach to schedule the real-world robotics application with two different scheduling policies: Fixed Priority FIFO Scheduling and Earliest Deadline First Scheduling. We implement several commonly used applications in autonomous mobile robots, such as Path Planning, Object Detection, and Depth Estimation, and improve the response time of these applications. We test our framework on NVIDIA AGX Xavier, which provides high computing power and supports eight different power modes. We measure the response times of all three applications with and without the scheduler on the NVIDIA AGX Xavier platform on different power modes, to evaluate the effectiveness of the scheduler. / Master of Science / Autonomous mobile robots for general human services have increased significantly due to ever-growing technology. The common applications of these robots include delivery services, search and rescue, hotel services, and so on. This thesis focuses on implementing the computational tasks performed by these robots as well as designing the task scheduler, to improve the overall performance of these tasks. The embedded hardware is resource-constrained with limited memory, power, and operating frequency. The use of a graphical processing unit (GPU) for executing the tasks to speed up the operation has increased with the development of the GPU programming framework. We propose a software-based GPU scheduler to execute the functions on GPU and get the best possible performance from the embedded hardware.

In this dissertation, I propose a reductive account of causation. This account may be stated as follows: Causation: c is a cause of e within a possibility horizon ℓ if a) c is process-connected to e, and b) e security-depends on c within ℓ. More precisely, my suggestion is that there are two kinds of causal relata: instantaneous events (defined in Chapter 4) and possibility horizons (defined in Chapter 5). Causation is a ternary relation between two actual instantaneous events - the cause c and the effect e - and a possibility horizon ℓ. I argue that causation has a dual nature: on the one hand, a cause must be connected to its effect via a genuine process; on the other hand, a cause must make a difference to its effect. The first condition - namely, the condition of process-connection (defined in Chapter 6) - captures the sense in which a cause must be connected to its effect via a genuine process. This condition allows my account to separate causation from mere correlation, distinguish genuine causes from preempted backups, and capture how a cause must be at the right level of detail relative to its effect (Chapter 7). The second condition - namely, the condition of security-dependence (defined in Chapter 8) - captures the sense in which a cause must make a difference to its effect. This condition allows my account to yield intuitively correct verdicts on the counterexamples to the transitivity and intrinsicness of causation, resolve the problem of profligate omissions, accommodate structurally isomorphic but causally different cases, and handle contrastive causal claims (Chapter 9 and 10). Finally, my proposed account of causation logically entails restricted versions of three important principles of causal reasoning concerning the sufficiency of counterfactual dependence for causation, and the transitivity and intrinsicness of causation (Chapter 11).

Transit Signal Priority (TSP) is an operational strategy that can speed the movement of in-service transit vehicles (typically bus, light rail, or streetcar) through traffic signals. By reducing control delay at signalized intersections, TSP can improve schedule adherence and travel time efficiency while minimizing impacts to normal traffic operations. These benefits improve the quality of service thereby making it more attractive to choice riders. A TSP system can also allow for fewer buses on the same due to travel time reductions and increased reliability, thus reducing transit operating costs. Much of the previous research on TSP has focused on signal control strategies and bus stop placement with little of it analyzing the effectiveness of the system using actual data. This study aims to evaluate the effectiveness of the system using a bus route corridor in Portland, Oregon through real-time Automatic Vehicle Locator data. Key measures that TSP is promoted to improve are evaluated, including travel time, schedule adherence and variability. The TSP system on data was collected for two weeks and is compared to an adjacent two weeks of bus data with the TSP system turned off such that there is no skewing of data due to changes in traffic volumes or transit ridership. This research has shown, that on certain corridors there may be little to no benefit towards TSP implementation and may possibly provide some disbenefit. The direct comparison for TSP on and off scenarios completed for this research yielded no significant differences in reduction in travel time or schedule adherence performance. An additional interesting result was that the standard deviation of the results did not have any specific tendencies with the TSP on or off. Based on these findings, recommendations are made to increase the effectiveness of the system.

Dedicated short-range communication (DSRC) systems, a form of vehicle-to-everything (V2X) systems, were placed on Utah Department of Transportation (UDOT) snowplows to request signal preemption. The study took place along five state routes in the Salt Lake City metropolitan area. Snowplows and intersections were equipped with the technology to communicate and process requests for signal preemption. Signal performance and vehicle performance analysis were performed to understand the impacts that snowplows requesting signal preemption had. Signal performance analysis was done to determine how snowplows with V2X systems using DSRC affected signals. Vehicle performance analysis was done to see if plowing and traffic efficiency and performance were improved, as well as evaluating safety implications of signal preemption. To perform the signal performance analysis, V2X data were collected to understand how often signal preemption was requested by snowplows, how often it was granted by signal controllers, and how long preemption requests affected signal controller timing. Snowplows requested preemption over 50 percent of the time they approached a signalized intersection. Of messages that requested signal preemption, over 80 percent were granted. On average, signal controllers are affected by preemption processing for less than 5 minutes. This shows that the system works as designed, is used often, and does not have adverse effects on signal controller. Data for vehicle performance analysis included analysis of snowplow speed data, general travel speed data, and crash data. These were collected to analyze the effects of snowplows requesting signal preemption on vehicle performance. The analysis showed that snowplow speeds are not changed due to the signal preemption system, but the number of times snowplows stopped was reduced. General travel speeds on equipped routes were more consistently closer to the speed limits than not equipped routes. Crash data showed a greater negative decrease on equipped routes than on not equipped routes. These findings showed minimal changes or impacts to vehicle performance, but anecdotal evidence from snowplow drivers indicates benefits from the system overall. There were various limitations in the analysis. Data granularity differed among datasets, making comparison between the different datasets difficult without reducing data integrity. Some datasets did not have much data, making statistical significance unclear. With these data limitations, conclusions were drawn, but do not fully describe all the potential benefits and impacts of snowplows with V2X systems that use DSRC to request signal preemption. Additional research is needed to better understand the impacts that snowplows requesting signal preemption has on different maintenance metrics, such as fuel usage and time spent plowing. It is also recommended that data used is explored for ways to improve the granularity.

Enabling vehicles to preempt the normal operation of traffic signals has the potential to improve the safety and efficiency of both the requesting vehicle and all of the other vehicles. Little is known about which strategy is the most effective to exit from preemption control and transition back to the traffic signals normal timing plan. Common among these traffic signal transition strategies is the method of either increasing or decreasing the cycle length of the signal timing plan, as the process followed to return to the coordination point of the effected signal timing plan, to coordinate its operation with adjacent traffic signals. This research evaluates commonly available transition strategies: best way, long, short, and hold strategies. The major contribution of this research is enhancing the methodology to evaluate the impacts of using these alternative transition strategies. Part of this methodology consists of the "software-in-the-loop" simulation tool which replicates the stochastic characteristics of traffic flow under different traffic volume levels. This tool combines the software from a traffic signal controller (Gardner NextPhase Suitcase Tester, version 1.4B) with a microscopic traffic simulation model (CORSIM, TSIS 5.2 beta version). The research concludes that a statistically significant interaction exists between traffic volume levels and traffic signal transition strategies. This interaction eliminates the ability to determine the isolated effects of either the transition strategies on average travel delay and average travel time, or the effects of changes in traffic volume levels on average travel delay and average travel time. Conclusions, however, could be drawn on the performance of different transition strategies for specific traffic volume levels. As a result, selecting the most effective transition strategy needs to be based on the traffic volume levels and conditions specific to each traffic signal or series of coordinated traffic signals. The research also concludes that for the base traffic volume and a 40% increase in traffic volume, the most effective transition strategies are the best way, long or hold alternatives. The best way was the most effective transition strategy for a 20% increase in traffic volume. The least effective strategy is the short transition strategy for both the base and 40% increase in traffic volume, and the long and short for a 20% increase in traffic volume. Further research needs to be conducted to assess the performance of different transition strategies in returning to coordinated operation under higher levels of traffic volume (e.g., approaching or exceeding congested flow regime), with varying cycle lengths, with different signal timing plans, and when different roadway geometric configurations (e.g., turn lanes, length of turn lanes, number of lanes, spacing between intersections) are present. / Ph. D.

Much of the first generation literature on counter terrorist financing made sweeping generalisations and observations regarding these interventions based on relatively limited case study data. Given that the UK approach to counter terrorism clearly attests to the symbiosis between terrorism and money, this thesis evaluates the contemporary relevance of Cicero's aphorism that “the sinews of war are infinite money.” Drawing on a series of discussions and formal interviews with CTF practitioners into several of the most recent high profile terror attacks in the United Kingdom, it confirms a notable shift in terrorist financing methodology in recent years and underscores the trend towards increasing operational independence and financial autonomy. It thus considers the continuing centrality of money in the terrorism equation and has been framed specifically to examine the financing challenges posed by domestic terror cells in the UK, given the trend towards low cost terrorism with its emphasis on self sufficiency and the emergence of more discreet and ‘criminally sterile' funding methodologies. This thesis is primarily concerned with reviewing the efficacy of the UK counter terrorism-financing (CTF) model as perceived by practitioners, both in policy terms and in the context of operational outcomes. The increasing emphasis on new funding methodologies and the ensuing lack of visibility and opportunities for interdiction at the conspiracy phase of terrorist plots, further highlights the operational challenges posed for practitioners in confronting these ‘new' threats. As such, this research encourages several new perspectives, including a review of UK corporate knowledge on previous CTF interventions and consideration of military ‘threat finance' practice to deliver greater operational impact. In particular, it advocates a new focus on micro CTF interventions to address changes in the ‘economy of terror'. Finally, this thesis strongly attests to the continued relevance of finance or more specifically, the 'financial footprint' to inform and provide intelligence insight for counter terrorism responses generally. In doing so, it also considers the impact on privacy from increasingly intrusive financial and digital data collection and the trade-offs that inevitably emerge when liberty and security collide.

The 2002 National Security Strategy of the US (NSS 2002) appeared to have presented a momentous approach to self-defense. To many, the doctrine of preemptive selfdefense seemed to challenge the legal and political foundations of the post-World War II international order. Some saw in the US stated reliance on preemption a direct threat to the international system embodied in the UN Charter. The prima facie case that the US position was novel and even dangerous appeared persuasive. This thesis attempts to assess the exceptionality of NSS 2002 in its formulation and implications. This question of exceptionality is broadly divided into two sections. The first section deals with internal exceptionality, in terms of means (the deliberation and drafting processes) and ends (the US defense posture). The second section deals with external exceptionality in the broader terms of possible consequences outside the US. Section One begins by establishing the grounds for looking into the formulation of NSS 2002, and provides the background for that Strategy's mandated precursors. After exploring how National Security Strategy documents are conceived and framed, Section One discusses the Strategy as it was published, and examines a sampling of contemporaneous reactions to its publication. Section Two concentrates on the second part of the research question, and utilizes a thematic approach - in terms of the use of force, the international security environment, and international law. Possible consequences of the proposed US response to contemporary security challenges are considered in these three key areas.

There is a lively academic debate concerning US foreign policy in the post-Cold War era and especially after the terrorist attacks of 11 September 2001. Neoconservatism has become a cause celebre in the literature of international relations with a variety of scholars disagreeing as to its supposed impact on Washington's world affairs approach and the Bush administration's decision to remove Saddam Hussein, from power manu militari. This thesis is an analysis of the way this political ideology was interpreted in the European elite media. It will be demonstrated how a significant section of key opinion-forming newspapers of Britain, France, Germany and Italy framed neoconservatism during the administration of Bill Clinton and partly that of George W. Bush. There will be an exploration of whether and how newspapers vary in their coverage. The thesis will outline that the influence of the neoconservatives in US foreign policy can be disputed and will suggest that their ideas can be hardly considered as revolutionary ones. It will then focus on the media coverage and will show that the prominence devoted to neoconservatism by the accessed print sources is a relatively recent phenomenon. The findings indicate that the newspapers differed in their representation of the political ideology only in the period before 9/11 when they mainly discussed it in the context of domestic affairs. By contrast, after the terrorist atrocities and especially since 2003 they linked neoconservatism to US foreign policy and largely focused on it - as opposed to competing international relations theories -, representing it in a remarkably similar way. With the exception of The Times, which followed a comparatively balanced approach, they constructed it as a driving force behind George W. Bush's international politics approach and the war on Iraq. The media emphasis on neoconservatism will be attributed to different factors - such the scapegoat theory - which maybe influenced the journalistic work. The general consensus as to their understanding of neoconservatism and its supposed impact will not support the claim of a European public sphere but will be considered as a positive step towards its possible creation.

Droit de propriété et liberté contractuelle fondent le droit pour tout propriétaire de choisir la personne à laquelle il souhaite, le cas échéant, vendre son bien. Il est pourtant des hypothèses où le législateur a accordé d’autorité à certaines personnes un droit de préemption qui leur permet d’être préférées à d’autres lors de la conclusion du contrat de vente. Cela étant, le droit de préemption demeure une institution mal connue et discutée. En effet, le législateur a institué de très nombreux droits de préemption en fonction de ses ambitions politiques, en dotant chacun d’eux d’un régime juridique spécifique. Le fait qu’il ne se soit guère préoccupé de conférer une quelconque cohérence à cet ensemble génère de nombreux conflits entre droits de préemption ou entre un droit de préemption et une autre institution juridique. Par ailleurs, l’intérêt général qui justifie le droit de préemption et exige que le domaine de celui-ci soit cantonné au strict nécessaire ainsi que l’octroi de garanties aux personnes concernées, ne dissuade pas le législateur de renforcer constamment l’emprise de cette institution. Ces données, qui illustrent les finalités du droit de préemption, influencent nécessairement la notion. Elles conduisent en effet à considérer que la prestation attendue du vendeur, à savoir proposer par priorité l’acquisition de son bien au bénéficiaire, constitue l’essence du droit de préemption. Le régime et l’effectivité de tous les droits de préemption reposent sur cette prestation. Il est alors possible de suggérer une nouvelle définition du droit de préemption et d’établir sa nature juridique à partir du droit des biens. Deux critères de délimitation du droit de préemption peuvent également être proposés, le premier reposant sur sa source légale, le second résultant de la détermination du moment de son intervention, ce qui n’est pas sans conséquence pratique. / Property right (jus proprietatis) and contractual freedom establish the right for every owner to choose the person to whom he may wish to sell his property. There are nevertheless hypotheses where the legislator granted to some persons, by his own authority, a right of pre-emption which allows them to be preferred to others when concluding the sale contract. Right of preemption remains, however, a badly known and controversial institution, as the legislator established a very great quantity of rights of preemption, according to his political ambitions, and endowed each of these rights of a specific legal regime. The fact that he hardly worried to confer on them any coherence generates many conflicts between rights of preemption, or between a right of preemption and another legal institution. Besides, general interest, which justifies right of preemption and requires that its domain be limited to strict minimum as well as the guarantees granted to the concerned persons, does not dissuade the legislator to strengthen constantly the influence of this institution. These data, which illustrate the purposes of right of preemption, do inevitably influence its notion : indeed, they lead to consider that the service expected from the seller, which is to propose by priority the acquisition of his property to the beneficiary, is constituting the basis of right of preemption. The regime and the effectiveness of all the rights of preemption are based upon that service. It becomes then possible to suggest a new definition of right of preemption and to establish its legal nature from property right. Two criteria of delimitation of right of preemption can be also proposed, the first one resting on its legal source, the second resulting from the determination of the moment of its intervention, which is not without practical consequence.