In this dissertation, I present three theoretical results with real-world applications related to scheduling and distributionally-robust games, important fields in discrete optimization, and computer science. The first chapter provides simple, technology-free interventions to manage elevator queues in high-rise buildings when passenger demand far exceeds the capacity of the elevator system. The problem was motivated by the need to manage passengers safely in light of reduced elevator capacities during the COVID-19 pandemic. We use mathematical modeling, epidemiological expertise, and simulation to design and evaluate our algorithmic solutions. The key idea is to explicitly or implicitly group passengers that are going to the same floor into the same elevator as much as possible, substantiated theoretically using a technique from queuing theory known as stability analysis. This chapter is joint work with Charles Branas, Adam Elmachtoub, Clifford Stein, and Yeqing Zhou, directly in collaboration with the New York City Mayor’s Office of the Chief Technology Officer and the Department of Citywide Administrative Services. The second chapter proposes new algorithms for recomputing passenger itineraries for airlines during major disruptions when carefully planned schedules are thrown into disarray. An airline network is a massive temporal graph, often with tight regulatory and operational constraints. When disruptions propagate through an airline network, the objective is to \textit{recover} within a given time frame from a disruption, meaning we replan schedules affected by the disruption such that the new schedules have to match the originally planned schedules after the time frame. We aim to solve the large-scale airline recovery problem with quick, user-independent, consistent, and near-optimal algorithms. We provide new algorithms to solve the passenger recovery problem, given recovered flight and crew solutions. We build a preprocessing step and construct an Integer Program as well as a network-based approach based on solving multiple-label shortest path problems. Experiments show the tractability of our proposed algorithms on airline data sets with heavy flight disruptions. This chapter is joint work with Clifford Stein, stemming from an internship and collaboration with the Machine Learning team (Artificial Intelligence organization) of GE Global Research, Niskayuna, New York. The third chapter is about computing distributionally-robust strategies for a popular game theory model called Stackelberg games, where one player, called the leader, is able to commit to a strategy first, assuming the other player(s), called follower(s) would best respond to the strategy. In many of the real-world applications of Stackelberg games, parameters such as payoffs of the follower(s) are not known with certainty. Distributionally-robust optimization allows a distribution over possible model parameters, where this distribution comes from a set of possible distributions. The goal for the leader is to maximize their expected utility with respect to the worst-case distribution from the set. We initiate the study of distributionally-robust models for Stackelberg games, show that a distributionally-robust Stackelberg equilibrium always exists across a wide array of uncertainty models, and provide tractable algorithms for some general settings with experimental results. This chapter is joint work with Christian Kroer.

Flight planning is a large part of the air traffic operations that are presently being conducted. Airlines strive to achieve the cheapest and most cost effective routes for their flights, resulting in aircraft sometimes flying longer routes in order to avoid expensive airspaces with high unit rates. This issue has been an ongoing obstacle for the Swedish air navigation provider, LFV, as some airlines tend to fly over the Baltic Sea, through the Baltic countries, instead of the shorter route through Swedish airspace. These protracted routes result in extra kilometers being flown yearly,consuming extra fuel, as well as imply a revenue loss to LFV and Sweden. The conclusions of this study is that the airspace dodging behavior generate a revenue loss to LFV, totaling approximately €5 032 354 million per year. Should these flights fly the shortest route between their origin and destination, the before mentioned sum would mean an increase in LFV’s reported revenue from air traffic control services by 2%. Airspace dodging also results in roughly 380 408 superfluous kilometers being flown and 1 874 486 liters of additional fuel being consumed every year.

Long Walk in Flight School is a document intended to complement a body of artwork that includes photographs, giclee prints, animation, and a twenty two page book of images. The main focus of the text is to discuss two types of exchange; my energy with tools in exchange for an object or event, which is then exchanged in the imagination of the audience for something else, a hybrid thing. These exchanges are part of the performance or presentation of the work. Beginning with a brief description of intent at the start of graduate school, it traces my development as an artist over a two year period, highlighting shifts in my thinking and activity during that time. Finally, it describes my thesis artwork as a set of potential narratives that are conceptually related but visually diverse.

I Nyköping utövar försvaret telekrigsövning för målflyg vilket Saab i Arboga är en del av. Telekrig är ett “digitalt krig” där syftet är att störa ut elektrisk utrustning, exempelvis störa ut radarfunktionen så att en eventuell fiende inte ska dyka upp på densamma.  Syftet med uppgiften var att tillförse målflygen med ett kommunikationssätt som underlättade kommunikationen vid en övning. Detta kommunikationssätt måste vara hemligt då man aldrig kan veta vem som lyssnar på informationen som skickas. Komradion behövde en ersättare som både var snabb, säker och enkel att använda. Kommunikationen skulle komma att ske via transpondrar som är installerade i samtliga övningsflygplan Nyköping tillhandahåller. Dessa transpondrar skickar och tar emot den vanliga AISinformationen vilket bland annat beskriver riktning och bäring för planet.  Del ett av uppgiften gick ut på att undersöka dessa transpondrar för att se om det fanns möjlighet att skicka egendefinierade meddelanden. Denna uppgift löstes genom att koppla upp två datorer till transpondrarna och pratade med dem via IP.  I del två av uppgiften ingick det att ta fram funktioner, ramverk och stödprogram för meddelandekommunikation. Genom att ta fram en programvara som grundades på lösningen i del ett så kan vi ta emot och sända ut meddelanden på radionätet vilket effektiviserar kommunikationen vid telekrigsövningar där flertalet enheter deltagar. Vi tog fram ett programvara som agerade hjälpprocess till programvaran i del ett. Programvaran genererar hemliga kodord till varje textkommando så att endast ett kodord behöver transmitteras över nätet, där kodordet matchas mot en textstäng på mottagande sida.  I sista delen av uppgiften, som vi skulle göra om tid fanns, skulle vi göra en applikation som gjorde detsamma som programvaran i del två gjorde fast på en surfplatta. Detta löste vi genom att innan vi började på del två använda ett tillägg som tillät oss att köra programvaran på både dator och surfplatta.

Les effets de la foudre sur les lignes d'assemblage des avions peuvent s'avérer catastrophiques. L'un des phénomènes redoutés est l'étincelage au niveau d'une fixation bien souvent associé à un défaut sur les résistances de contact. Au vu des contraintes normatives, du manque de connaissance de cette problématique multi-physiques et de l'incapacité structurelle à avoir une approche uniquement expérimentale, les avionneurs se sont notamment tournés vers la modélisation. Dans ce manuscrit, on s'intéresse particulièrement à la modélisation des lignes d'assemblage pour le dimensionnement de la contrainte locale sur celles-ci. La méthode des différences finies dans le domaine temporel (FDTD), couramment utilisée pour la problématique foudre en aéronautique, nous sert de méthode de résolution. De multiples modèles de fixations allant de modèles simplifiés, représentant par exemple la fixation par un fil résistif, à des modèles plus complexes, représentant l'ensemble des résistances de contact, sont développés et validés. Par ailleurs, pour répondre aux incertitudes associées aux résistances de contact des fixations, des modèles statistiques sont appliqués aux paramètres résistifs des modèles de fixation. Ces mêmes modèles statistiques découlent de l'étude d'une base de données issue d’une campagne de mesures menée par Dassault Aviation sur un ensemble d’éprouvettes tests. A l'aide de ces modèles, la contrainte sur les fixations d'un caisson représentant un réservoir de carburant d'un avion est étudiée de manière stochastique. / The lightning effects on the fastening assemblies of an airplane may be critical. One of the most critical phenomenon is the sparking effect around the fasteners. This effect is usually associated to the contact resistances. Due to the standards, the lack of knowledge about this multiphysics issue and the inability to follow only an experimental approach, the aircraft manufacturers have chosen a modelling way. In this manuscript, we model the fastening assemblies in order to understand the local constraint on these assemblies. The finite difference time domain (FDTD) method mostly used for the lightning issue in the aircraft industry is chosen as the solving method. Several fastener models are developed and validated. We present simplified models, as the resistive wire model for instance, up to complex one with all the contact resistance of the fastener. Furthermore, due to the large uncertainties from one fastener to the other one in the same family, the fastener models are supplemented with statistical models. Thanks to a data base measurement created from several measurement campaigns made by Dassault Aviation, distribution laws are established to characterize the lightning injection effects or the state after lightning injection on the fasteners. Using this statistical models, a stochastic study is presented in order to evaluate the uncertainties in a fuel tank modelling.

The Traffic alert and Collision Avoidance System (TCAS) is an aircraft collision avoidance system designed to prevent mid-air collisions. During an advisory, danger is imminent, and TCAS is assumed to have better, more up-to-date information than the ground operated air traffic control (ATC) facility. Following a TCAS RA is generally the safe course of action during an advisory. However, pilot compliance with RAs is surprisingly low. Results from a TCAS monitoring study show pilots are not complying with many TCAS advisories. As revealed by pilot-submitted Aviation Safety Reporting System (ASRS) reports, this noncompliance could be attributed, in part, to pilot confusion to TCAS operation as well as misunderstandings of the appropriate response to a TCAS issued advisory. This thesis details the development and evaluation of a TCAS training program intended to improve pilots' understanding of TCAS use for collision avoidance in a range of traffic situations. The training program integrated Demonstration Based and Event Based Training techniques. Its efficacy was analyzed in an integrated ATC-cockpit simulator study in which eighteen commercial airline pilots were asked to complete the TCAS training program and afterwards experienced twelve experimental traffic events. The trained pilots' performance was compared to the performance of 16 baseline pilots who did not receive the modified training. Overall, the training program did have a significant impact on the pilots' behavior and response to TCAS advisories. The measure Time Pilots First Achieved Compliance decreased with the trained pilots, as did the measure Autopilot Disconnect Time After RA Initiation. Trained pilots exhibited less aggressive performance in response to a TCAS RA (including a decrease in the measures Altitude Deviation Over Duration Of RA, Average Vertical Rate Difference, Maximum Vertical Rate Difference, and Maximum Vertical Rate). The measure Percent Compliance did not significantly vary between trained and baseline pilots, although trained pilots had a more consistent response in the traffic event with conflicting ATC guidance. Finally, on the post-experiment questionnaires, pilots commented on their increase in understanding of TCAS as well as an increase in their trust in the advisory system. Results of this research inform TCAS training objectives provided by the FAA as well as the design of TCAS training. Additionally, conclusions extend more broadly to improved training techniques for other similar complex, time-critical situations.

An urban operation of unmanned aerial vehicles (UAVs) demands a high level of autonomy for tasks presented in a cluttered environment. While fixed-wing UAVs are well suited for long-endurance missions at a high altitude, enabling them to navigate inside an urban area brings another level of challenges. Their inability to hover and low agility in motion cause more difficulties on finding a feasible path to move safely in a compact region, and the limited payload allows only low-grade sensors for state estimation and control. We address the problem of achieving vision-based autonomous navigation for a small fixed-wing in an urban area with contributions to the following several key topics. Firstly, for robust attitude estimation during dynamic maneuvering, we take advantage of the line regularity in an urban scene, which features vertical and horizontal edges of man-made structures. The sensor fusion with gravity-related line segments and gyroscopes in a Kalman filter can provide driftless and realtime attitude for ight stabilization. Secondly, as a prerequisite to sensor fusion, we present a convenient self-calibration scheme based on the factorization method. Natural references such as gravity, vertical edges, and distant scene points, available in urban fields, are sufficient to find intrinsic and extrinsic parameters of inertial and vision sensors. Lastly, to generate a dynamically feasible motion plan, we propose a discrete planning method that encodes a path into interconnections of finite trim states, which allow a significant dimension reduction of a search space and result in naturally implementable paths integrated with ight controllers. The most probable path to reach a target is computed by the Markov Decision Process with motion uncertainty due to wind, and a minimum target observation time is imposed on the final motion plan to consider a camera's limited field-of-view. In this thesis, the effectiveness of our vision-based navigation system is demonstrated by what we call an "air slalom" task in which the UAV must autonomously search and localize multiple gates, and pass through them sequentially. Experiment results with a 1m wing-span airplane show essential navigation capabilities demanded in urban operations such as maneuvering passageways between buildings.

Cette thèse s’inscrit dans le cadre d’un projet industriel multi-partenaires ayant pour objectif le développement d’un robot mobile collaboratif (un cobot), autonome dans ses mouvements au sol, capable de réaliser l’inspection visuelle d’un aéronef, à la fois en phase de petite ou grande maintenance dans un hangar ou en phase de pré-vol sur le tarmac d’un aéroport. Le cobot est équipé de capteurs lui permettant d’effectuer ses tâches de navigation autonome, mais également d’un ensemble de capteurs optiques constituant la tête d’inspection : une caméra orientable Pan-Tilt-Zoom et un scanner 3D qui délivrent respectivement des données sous forme d’images 2D et de nuages de points 3D. L’objectif de la thèse est de développer des algorithmes d’analyse d’images 2D et de nuages de points 3D, afin d’établir un diagnostic sur l’état de l’avion et son aptitude à voler. Nous avons développé des algorithmes pour vérifier certains éléments de l’appareil, tels que valves, portes, capteurs, pneus ou moteurs, et également pour détecter et caractériser des dommages 3D sur le fuselage (impacts, rayures, etc.). Nous avons exploité dans nos algorithmes les connaissances a priori disponibles, en particulier le modèle 3D CAO de l’avion (un AIRBUS A320 dans le cadre de nos essais). Durant ces travaux de la thèse, nous avons pu répondre à deux besoins (parfois antagonistes) : développer des algorithmes d’inspection rapides et robustes, mais également répondre aux exigences spécifiques d’un projet industriel qui visait à développer un prototype opérationnel. Nous nous sommes attachés à développer des algorithmes les plus génériques possibles, de manière à ce qu’ils puissent être utilisés pour d’autres types d’inspection, tels que l’inspection de bâtiments ou de navires par exemple. Nous avons aussi contribué au développement du prototype (robot mobile équipé de capteurs) en développant le module de contrôle des capteurs d’inspection et en intégrant nos codes sur le robot avec les autres modules développés par les partenaires. Le prototype a fait l’objet de nombreux essais en hangar de maintenance ou sur tarmac. / This thesis makes part of an industry oriented multi-partners project aimed at developing a mobile collaborative robot (a cobot), autonomous in its movements on the ground, capable of performing visual inspection of an aircraft during short or long maintenance procedures in the hangar or in the pre-flight phase on the tarmac. The cobot is equipped with sensors for realizing its navigation tasks as well as with a set of optical sensors which constitute the inspection head: an orientable Pan-Tilt-Zoom visible light camera and a three-dimensional scanner, delivering data in the format of two-dimensional images and three-dimensional point clouds, respectively. The goal of the thesis is to propose original approaches for processing 2D images and 3D clouds, with intention to make a decision with respect to the flight readiness of the airplane. We developed algorithms for verification of the aircraft items such as vents, doors, sensors, tires or engine as well as for detection and characterization of three-dimensional damages on the fuselage. We integrated a-priori knowledge on the airplane structure, notably numerical three-dimensional CAD model of the Airbus-A320. We argue that with investing effort to develop robust enough algorithms and with the help of existing optical sensors to acquire suitable data, we can come up with non-invasive, accurate, and time-efficient system for automatic airplane exterior inspection. The thesis work was placed in between two main requirements: develop inspection algorithms which could be as general as possible and also meet the specific requirements of an industry oriented project. Often, these two goals do not go along and the balance had to be made. On one side, we were aiming to design and assess the approaches that can be employed on other large structures, for ex. buildings, ships. On the other hand, writing source code for controlling sensors as well as integrating our whole developed source code with other modules on the real-time robotic system, were necessary in order to demonstrate the feasibility of our robotic prototype.

[pt] A imobilidade na postura sentada reclinada e as limitações no espaço da poltrona de viagens aéreas longas, somadas aos efeitos da pressão do peso do corpo sobre os tecidos levam o passageiro a uma acomodação na busca de conforto. Os constrangimentos músculo-esqueléticos conseqüentes podem provocar dores e desconforto nos usuários. Para estudar as causas dos constrangimentos foram vistos os dados sobre a postura humana, com ênfase na região sacro-lombar, assim como indicações de ergonomistas sobre cadeiras e as prioridades da aviação comercial. Os métodos usados na observação foram a revisão bibliográfica em autores de ergonomia, anatomia, cinesiologia. A assessoria de informante qualificado em interiores de aviões juntou-se à consulta a revistas especializadas na área da aviação comercial. Os resultados obtidos através da análise dos dados do questionário (n=115) confirmam o desconforto sentido pelos passageiros de viagens aéreas longas em regiões como pescoço (64,3 por cento), lombo-sacra (48,7 por cento) e pés (59,1 por cento). Inadequações como a largura do assento (58,3 por cento), o espaço para as pernas (50,4 por cento), o apoio do pescoço (47,8 por cento), e o apoio lombar (37,4 por cento) foram apontadas por estes usuários. As conclusões confirmam a hipótese O espaço limitado das poltronas aéreas e as conseqüentes posições assumidas pelos passageiros durante viagens aéreas longas acarretam constrangimentos posturais músculo-esqueléticos, e trazem como conseqüência desconforto e dores no pescoço, região lombar e pés, dormência e dores irradiadas nos usuários. As recomendações foram em relação à ergonomia da postura sentada para o apoio lombar, assento e posições de membros inferiores. Desdobramentos sugeridos foram a observação de passageiros durante a viagem, estudos sobre o sistema circulatório dos membros inferiores, constrangimentos posturais na região cervical e posterior da pelve. / [en] The lack of mobility in reclined sitting posture, the space limitations in seats in long distance flights along with the relief of pressure lead the passenger to scoop his hip forwards or to twist it. Consequent muscular and skeletal postural constraints may cause discomfort and pain on users. Searching for the reasons of constraints, human posture studies, ergonomics recommendations on chairs and aicraft priorities were seen. The study methods employed were a literature review on Ergonomics, Anatomies and Kinesiologists, aircraft interiors qualified informant and aircraft interiors specialized revues. A questionnaire was submitted to long flight passengers to search for body discomfort and inadequacies on seats. Data analysis (n=115) showed discomfort on neck region (63,3 percent), feet (59,1 percent) and low back (48,7 percent). Inadequacies on seats design such as width (58,3 percent), room for legs (50,4 percent), neck support (47,8 percent) and lumbar support (37,4 percent) were pointed by passengers. The hypothesis Lack of room in aircraft seats and the positions assumed during long distance flights cause postural constraints that lead to discomfort and pain on neck, low back and feet, numbness and irradiation on users was confirmed. Recommendations on lumbar support possibilities, height of seat and lower limbs positions were made. Suggestions like further observation of flying passengers, circulatory system and postural constraints on cervical and pelvic region were proposed.

A primeira opção de viagem por avião se dá por meio dos voos oferecidos pela aviação comercial. Nos últimos anos, o crescimento do número de passageiros no Brasil superou o crescimento do número de aeronaves disponíveis para voos comerciais, gerando efeitos inconvenientes aos usuários desse segmento de transporte. De outro lado, a aviação executiva surge como opção para diminuir estes inconvenientes. Este segmento oferece vantagens como a diminuição dos tempos de embarque e desembarque e o acesso a um maior número de destinos, resultando numa melhor utilização do tempo dos executivos das empresas. O objetivo deste trabalho foi estudar o mercado de jatos executivos no Brasil quanto à sua caracterização e a relação entre o índice do valor da frota e o PIB brasileiro entre os anos 2000 e 2013.Como método, foram estudados os aspectos qualitativos e quantitativos referentes a este mercado, utilizando-se de pesquisa a fontes primárias e entrevistas com profissionais atuantes nesse mercado. Foi realizado um estudo quantitativo para estudar uma relação entre o índice do valor da frota de jatos executivos e o índice da variação do PIB brasileiro. Conclui-se que os empresários são os maiores usuários dos jatos executivos, e adquirem este tipo de produto para se locomoverem a um número maior de regiões do território nacional com a finalidade de ampliar seus negócios. O crescimento da frota foi impulsionado por jatos leves, categoria que apresentou uma maior aceitação pelos clientes brasileiros. O estudo econométrico revelou que há correlação positiva entre o valor da frota de jatos executivos com o PIB brasileiro. / The first option to travel by airplane is through commercial aviation. In the last few years, the growth in the number of passengers in Brazil has overcome the number of available airplanes for commercial flights, resulting in inconvenient effects to users of this segment of transport. On the other hand, business aviation arises as an option to diminish their convenient. This transports segment offers some advantages, as the reduction of boarding and landing times and the access to a larger number of destinations, resulting in a better use of the time of companies executives. To study the characteristics of the Brazilian market of executive jets, the objective of this research was to study the business jets market in Brazil regarding its characterization and the relation between the fleet value index and the Brazilian GDP between the years 2000 and 2013. In the method, qualitative and quantitative aspects were studied related to the business jets markets in Brazil, using primary sources research and interviews with professionals actuating in this market. A quantitative test was conducted to study a possible relation between the variation of business jets fleet in operation in Brazil and the variation of Brazilian gross domestic product. Conclusions showed that businesspersons are the main users of business jets, and they acquire this type of product to be able to access more regions in the national territory with the aim to spread their business. Light jets drove the fleet growth, category that showed the best acceptance by Brazilian customers. The econometric study revealed that there is a positive correlation between the jet fleet values with Brazilian GDP.