This thesis addresses two planning problems motivated by the operations of PSOD air transportation: scheduled maintenance planning, and base location and fleet allocation. In the first part of the thesis, we study tactical planning for scheduled maintenance which determines the daily maintenance capacities for two operating conditions: a growth phase and the steady state. We model tactical maintenance capacity planning during the growth phase as an integer program and develop an optimization-based local search to solve the problem. Tactical planning of steady state maintenance capacity concerns a special case for which we determine the optimal and the long run capacities with a pseudo-polynomial time algorithm. In the second part of the thesis, we address operational planning for scheduled maintenance which is concerned with assigning itineraries to jets and determining the specific jets to be scheduled for maintenance on a daily basis given a certain maintenance capacity. We present a solution methodology that employs a look-ahead approach to consider the impact of our current decisions on the future and decomposes the problem exploiting the differences between jets with respect to the proximity to their next maintenance. We further develop an integrated framework in order to capture the interaction between operational level maintenance decisions and flight scheduling. In the third and final part of the thesis, we present the tactical level base location and fleet allocation problem. As PSOD air transportation experiences changes in travel demand and fleet size, decisions regarding where to open new bases and how to allocate the number of jets among the bases are made. We first present a solution approach in which high level information about flight scheduling is used in a traditional facility location problem. We next develop a model that works directly with transportation requests and integrates a simplified version of flight scheduling with the base location and fleet allocation decisions in order to capture more detail.

We are constantly struggling to understand how nature works, trying to identify recurrent events and looking for analogies and relations between objects or individuals. Knowing patterns of behavior is powerful and fundamental for survival of any species. In this thesis, datasets of diverse systems related to transportation, economics, sexual and social contacts, are characterized by using the formalisms of time series and network theory. Part of the results consists on the collection and analyzes of original network data, the rest focuses on the simulation of dynamical processes on these networks and to study how they are affected by the particular structures. The majority of the thesis is about temporal networks, i.e. networks whose structure changes in time. The new temporal dimension reveals structural dynamical properties that help to understand the feedback mechanisms responsible to make the network structure to adapt and to understand the emergence and inhibition of diverse phenomena in dynamic systems, as epidemics in sexual and contact networks. / Vi är ständigt kämpar för att förstå hur naturen fungerar, försöker identifier återkommande evenemang och söker analogier och relationer mellan objekt eller individer. Veta beteendemönster är kraftfull och grundläggande för överlevnad av arter. I denna avhandling, dataset av olika system i samband med transporter är ekonomi, sexuella och sociala kontakter, som kännetecknas av att använda formalismer av tidsserier och nätverk teori. En del av resultatet utgörs av insamling och analys av ursprungliga nätdata, fokuserar resten på simulering av dynamiska processer i dessa nätverk och att studera hur de påverkas av de särskilda strukturer. Huvuddelen av avhandlingen handlar om tidsmässiga nät, i.e. nät vars struktur förändringar i tid. Den nya tidsdimensionen avslöjar strukturella dynamiska egenskaper som hjälper till att förstå den feedback mekanismer som ansvarar för att göra nätverksstruktur att anpassa sig och förstå uppkomsten och hämning av olika företeelser i dynamiska system, epidemier i sexuella och kontaktnät. / Constantemente nos esforçamos para entender como a natureza funciona, tentando identificar eventos recorrentes e procurando por analogias e relações entre objetos ou indivíduos. Conhecer padrões de comportamento é algo poderoso e fundamental para a sobrevivência de qualquer espécie. Nesta tese, dados de sistemas diversos, relacionados a transporte, economia, contatos sexuais e sociais, são caracterizados usando o formalismo de séries temporais e teoria de redes. Uma parte dos resultados consiste na coleta e análise de dados de redes originais, a outra parte concentra-se na simulação de processos dinâmicos nessas redes e no estudo de como esses processos são afetados por determinadas estruturas. A maior parte da tese é sobre redes temporais, ou seja, redes cuja estrutura varia no tempo. A nova dimensão temporal revela propriedades estruturais dinâmicas que contribuem para o entendimento dos mecanismos de resposta responsáveis pela adaptação da rede, e para o entendimento da emergência e inibição de fenômenos diversos em sistemas dinâmicos, como epidemias em redes sexuais e de contato pessoal.

Cette thèse se compose de trois articles empiriques appliquant à divers sujets des techniques d'économétrie sur données de panel. L'article principal étudie l'évolution de la transmission des prix des trois principales céréales (blé, maïs, riz) des marchés internationaux vers les producteurs domestiques pour 52 pays sur la période 1970-2013, et cherche à identifier les principaux facteurs expliquant l'hétérogénéité des pass-through. Le second article mesure l'élasticité du trafic aérien au produit intérieur brut dans le monde et met en évidence la grande stabilité de la relation tant dans le temps que d'une région à l'autre. Enfin, le troisième article modélise le mécanisme de fixation du taux de rendement servi par les assureurs français à leurs clients sur les produits d'assurance-vie. / This dissertation is composed of three empirical articles resorting to econometric methods in panel data analysis to address various research questions. The main article investigates the evolution of the level of price transmission for the three major cereals (wheat, maize and rice) from the international commodity markets down to the local producers for 52 countries between 1970 and 2013 while attempting to identify the main drivers of the heterogeneity in pass-through. The second article measures the elasticity of air-traffic to GDP around the world and demonstrates that the relationship is very stable across régions and through time. Eventually, the third article models the mechanisms through which French life-insurers set the rate of return they pay annually to their policyholders.

Holiday air travel behaviors are nowadays a significant issue in relation to climate change and sustainable tourism. Indeed, transportation, and especially air transportation, have a significant role in climate change. Hence, it is important that the tourism industry includes the transportation sector when developing solutions for sustainable tourism. As students are the future main target group of this industry, it is important to understand the reasons behind their choices. Until now, travel behaviors have been explained using single and specific theories, which did not include many factors explaining holiday air travel decisions. In this study, this concern is addressed by combining two theories in relation to behavior formation - the theory of planned behavior and the value-belief-norm theory - in order to understand all motivations and barriers behind students’ holiday air travel behaviors. The analysis of the findings shows that many internal and external factors affect students decisions in regards to flying during holidays, including values, beliefs, social and personal norms, as well as accessibility, country of origin, price, time, distance, and social influence. However, the analysis of the results also demonstrates two gaps between attitudes and behaviors within the student community, which link to the cognitive dissonance theory: an awareness-attitude behavior gap and a contextual gap. The paper argues that while the theory of planned behavior and the value-belief-norm theory can be used simultaneously in order to analyze decisions regarding holiday air transportation, they are not sufficient as these two gaps emerged. The study concludes suggesting destination developers and national governments to take into account the present factors behind students’ decisions in order to develop sustainable destinations.

Memento Mori, Latin for “remember thy death,” implores us to be mindful that death is both inevitable and inescapable. What of the records created during the process of dying and about death? Based upon wide-ranging archival research into primary documents, this thesis explores the rich sources of both official, public records, and personal, private ones, relating to mortality on the small-town Canadian frontier before 1950. The community of Red Lake, Ontario, which was established on the frontier as the result of the Red Lake gold rush of 1926, is the subject of a case study. Rather than merely cataloguing sources, this thesis illustrates that by adapting aspects from such archival appraisal methodologies as macroappraisal and documentation strategy, one is able to make available to researchers a wider range of sources relevant to the themes of dying and death. Specifically, by employing a documentation strategy methodology to identify and illuminate the records of human activities surrounding the functions of dying and death, archivists can offer to researchers the opportunity to locate relevant records wherever they may physically be. Since this is an Archival Studies thesis, it does not provide an historical analysis of dying and death, but is an archival study of the types of records related to the theme of mortality on the Canadian frontier: how those records were created, their character, and their capture and preservation in a small community. This thesis is organized into three chapters and a conclusion. Chapter One explores some relevant trends in the secondary literature of three fields: archival appraisal and description, small town or local development on the frontier, and dying and death as human activities. Chapter Two sets the context in which the thesis analyzes mortality on the frontier by outlining the relevant history of the Red Lake District of Northwestern Ontario and its pioneers. The focus is especially on the gold-mining boom years from the mid-1920s until shortly after the Second World War. The heart of the thesis, Chapter Three, is a case study of the various records creators, human activities, and resultant records related to mortality. It is organized according to three phases or functional categories surrounding dying, death, and memorialization. The conclusion summarizes the usefulness of the case study, in light of the literature review in Chapter One. It also suggests areas of further research, including aspects not covered herein, of the records of dying and death on the Canadian frontier. The documentation strategy, adapted from the original methods employed by archivists Helen Samuels and Richard Cox, was found to work best when deployed as a research and descriptive tool for exploring and documenting the records of mortality, more so than its original purpose as an acquisition tool. The strategy has wide-ranging usefulness discovering and then describing a “virtual” documentation universe relating to record-generating human functions and activities. / February 2008

Air traffic flow management is a critical component of air transport operations because at some point in time, often very frequently, one of more of the critical resources in the air transportation network has significantly reduced capacity, resulting in congestion and delay for airlines and other entities and individuals who use the network. Typically, these “bottlenecks” are noticed at a given airport or terminal area, but they also occur in en route airspace. The two-stage combinatorial optimization framework for air traffic flow management under constrained capacity that is presented in this thesis, represents a important step towards the full consideration of the combinatorial nature of air traffic flow management decision that is often ignored or dealt with via priority-based schemes. It also illustrates the similarities between two traffic flow management problems that heretofore were considered to be quite distinct. The runway systems at major airports are highly constrained resources. From the perspective of arrivals, unnecessary delays and emissions may occur during peak periods when one or more runways at an airport are in great demand while other runways at the same airport are operating under their capacity. The primary cause of this imbalance in runway utilization is that the traffic flow into and out of the terminal areas is asymmetric (as a result of airline scheduling practices), and arrivals are typically assigned to the runway nearest the fix through which they enter the terminal areas. From the perspective of departures, delays and emissions occur because arrivals take precedence over departures with regard to the utilization of runways (despite the absence of binding safety constraints), and because arrival trajectories often include level segments that ensure “procedural separation” from arriving traffic while planes are not allowed to climb unrestricted along the most direct path to their destination. Similar to the runway systems, the terminal radar approach control facilities (TRACON) boundary fixes are also constrained resources of the terminal airspace. Because some arrival traffic from different airports merges at an arrival fix, a queue for the terminal areas generally starts to form at the arrival fix, which are caused by delays due to heavy arriving traffic streams. The arrivals must then absorb these delays by path stretching and adjusting their speed, resulting in unplanned fuel consumption. However, these delays are often not distributed evenly. As a result, some arrival fixes experience severe delays while, similar to the runway systems, the other arrival fixes might experience no delays at all. The goal of this thesis is to develop a combined optimization approach for terminal airspace flow management that assigns a TRACON boundary fix and a runway to each flight while minimizing the required fuel burn and emissions. The approach lessens the severity of terminal capacity shortage caused by and imbalance of traffic demand by shunting flights from current positions to alternate runways. This is done by considering every possible path combination. To attempt to solve the congestion of the terminal airspace at both runways and arrival fixes, this research focuses on two sequential optimizations. The fix assignments are dealt with by considering, simultaneously, the capacity constraints of fixes and runways as well as the fuel consumption and emissions of each flight. The research also develops runway assignments with runway scheduling such that the total emissions produced in the terminal area and on the airport surface are minimized. The two-stage sequential framework is also extended to en route airspace. When en route airspace loses its capacity for any reason, e.g. severe weather condition, air traffic controllers and flight operators plan flight schedules together based on the given capacity limit, thereby maximizing en route throughput and minimizing flight operators' costs. However, the current methods have limitations due to the lacks of consideration of the combinatorial nature of air traffic flow management decision. One of the initial attempts to overcome these limitations is the Collaborative Trajectory Options Program (CTOP), which will be initiated soon by the Federal Aviation Administration (FAA). The developed two-stage combinatorial optimization framework fits this CTOP perfectly from the flight operator's perspective. The first stage is used to find an optimal slot allocation for flights under satisfying the ration by schedule (RBS) algorithm of the FAA. To solve the formulated first stage problem efficiently, two different solution methodologies, a heuristic algorithm and a modified branch and bound algorithm, are presented. Then, flights are assigned to the resulting optimized slots in the second stage so as to minimize the flight operator's costs.

Memento Mori, Latin for “remember thy death,” implores us to be mindful that death is both inevitable and inescapable. What of the records created during the process of dying and about death? Based upon wide-ranging archival research into primary documents, this thesis explores the rich sources of both official, public records, and personal, private ones, relating to mortality on the small-town Canadian frontier before 1950. The community of Red Lake, Ontario, which was established on the frontier as the result of the Red Lake gold rush of 1926, is the subject of a case study. Rather than merely cataloguing sources, this thesis illustrates that by adapting aspects from such archival appraisal methodologies as macroappraisal and documentation strategy, one is able to make available to researchers a wider range of sources relevant to the themes of dying and death. Specifically, by employing a documentation strategy methodology to identify and illuminate the records of human activities surrounding the functions of dying and death, archivists can offer to researchers the opportunity to locate relevant records wherever they may physically be. Since this is an Archival Studies thesis, it does not provide an historical analysis of dying and death, but is an archival study of the types of records related to the theme of mortality on the Canadian frontier: how those records were created, their character, and their capture and preservation in a small community. This thesis is organized into three chapters and a conclusion. Chapter One explores some relevant trends in the secondary literature of three fields: archival appraisal and description, small town or local development on the frontier, and dying and death as human activities. Chapter Two sets the context in which the thesis analyzes mortality on the frontier by outlining the relevant history of the Red Lake District of Northwestern Ontario and its pioneers. The focus is especially on the gold-mining boom years from the mid-1920s until shortly after the Second World War. The heart of the thesis, Chapter Three, is a case study of the various records creators, human activities, and resultant records related to mortality. It is organized according to three phases or functional categories surrounding dying, death, and memorialization. The conclusion summarizes the usefulness of the case study, in light of the literature review in Chapter One. It also suggests areas of further research, including aspects not covered herein, of the records of dying and death on the Canadian frontier. The documentation strategy, adapted from the original methods employed by archivists Helen Samuels and Richard Cox, was found to work best when deployed as a research and descriptive tool for exploring and documenting the records of mortality, more so than its original purpose as an acquisition tool. The strategy has wide-ranging usefulness discovering and then describing a “virtual” documentation universe relating to record-generating human functions and activities.

Memento Mori, Latin for “remember thy death,” implores us to be mindful that death is both inevitable and inescapable. What of the records created during the process of dying and about death? Based upon wide-ranging archival research into primary documents, this thesis explores the rich sources of both official, public records, and personal, private ones, relating to mortality on the small-town Canadian frontier before 1950. The community of Red Lake, Ontario, which was established on the frontier as the result of the Red Lake gold rush of 1926, is the subject of a case study. Rather than merely cataloguing sources, this thesis illustrates that by adapting aspects from such archival appraisal methodologies as macroappraisal and documentation strategy, one is able to make available to researchers a wider range of sources relevant to the themes of dying and death. Specifically, by employing a documentation strategy methodology to identify and illuminate the records of human activities surrounding the functions of dying and death, archivists can offer to researchers the opportunity to locate relevant records wherever they may physically be. Since this is an Archival Studies thesis, it does not provide an historical analysis of dying and death, but is an archival study of the types of records related to the theme of mortality on the Canadian frontier: how those records were created, their character, and their capture and preservation in a small community. This thesis is organized into three chapters and a conclusion. Chapter One explores some relevant trends in the secondary literature of three fields: archival appraisal and description, small town or local development on the frontier, and dying and death as human activities. Chapter Two sets the context in which the thesis analyzes mortality on the frontier by outlining the relevant history of the Red Lake District of Northwestern Ontario and its pioneers. The focus is especially on the gold-mining boom years from the mid-1920s until shortly after the Second World War. The heart of the thesis, Chapter Three, is a case study of the various records creators, human activities, and resultant records related to mortality. It is organized according to three phases or functional categories surrounding dying, death, and memorialization. The conclusion summarizes the usefulness of the case study, in light of the literature review in Chapter One. It also suggests areas of further research, including aspects not covered herein, of the records of dying and death on the Canadian frontier. The documentation strategy, adapted from the original methods employed by archivists Helen Samuels and Richard Cox, was found to work best when deployed as a research and descriptive tool for exploring and documenting the records of mortality, more so than its original purpose as an acquisition tool. The strategy has wide-ranging usefulness discovering and then describing a “virtual” documentation universe relating to record-generating human functions and activities.

The convergence of various technological and operational advancements has reinstated the interest in On-Demand Air Service (ODAS) as a viable mode of transportation. ODAS enables an end-user to be transported in an aircraft between their desired origin and destination at their preferred time without advance notice. Industry, academia, and the government organizations are collaborating to create technology solutions suited for large-scale implementation of this mode of transportation. Market studies suggest reducing vehicle operating cost per passenger as one of the biggest enablers of this market. To enable ODAS, an ODAS operator controls a fleet of aircraft that are deployed across a set of nodes (e.g., airports, vertiports) to satisfy end-user transportation requests. There is a gap in the literature for a tractable and online methodology that can enable ride-sharing in the on-demand operations while maintaining a publicly acceptable level of service (such as with low waiting time). The need for an approach that not only supports a dynamic-stochastic formulation but can also handle uncertainty with unknowable properties, drives me towards the field of Reinforcement Learning (RL). In this work, a novel two-layer hierarchical RL framework is proposed that can distribute a fleet of aircraft across a nodal network as well as perform real-time scheduling for an ODAS operator. The top layer of the framework - the Fleet Distributor - is modeled as a Partially Observable Markov Decision Process whereas the lower layer - the Trip Request Manager - is modeled as a Semi-Markov Decision Process. This framework is successfully demonstrated and assessed through various studies for a hypothetical ODAS operator in the Chicago region. This approach provides a new way of solving fleet distribution and scheduling problems in aviation. It also bridges the gap between the state-of-the-art RL advancements and node-based transportation network problems. Moreover, this work provides a non-proprietary approach to reasonably model ODAS operations that can be leveraged by researchers and policy makers.