5,243 research outputs found

    Proposal For A Market-Based Solution to Airport Delays

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    With the clamor rising over airport delays and with both the Congress and the Administration considering remedies, this paper advocates the use of market mechanisms, specifically slot auctions, to promote efficient usage of airport capacity, reduce airport delays, and, more generally, promote competition.

    Overview of Infrastructure Charging, part 4, IMPROVERAIL Project Deliverable 9, “Improved Data Background to Support Current and Future Infrastructure Charging Systems”

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    Improverail aims are to further support the establishment of railway infrastructure management in accordance with Directive 91/440, as well as the new railway infrastructure directives, by developing the necessary tools for modelling the management of railway infrastructure; by evaluating improved methods for capacity and resources management, which allow the improvement of the Life Cycle Costs (LCC) calculating methods, including elements related to vehicle - infrastructure interaction and external costs; and by improving data background in support of charging for use of railway infrastructure. To achieve these objectives, Improverail is organised along 8 workpackages, with specific objectives, responding to the requirements of the task 2.2.1/10 of the 2nd call made in the 5th RTD Framework Programme in December 1999.This part is the task 7.1 (Review of infrastructure charging systems) to the workpackage 7 (Analysis of the relation between infrastructure cost variation and diversity of infrastructure charging systems).Before explaining the economic characteristics of railway and his basic pricing principles, authors must specify the objectives of railways infrastructure charging.principle of pricing ; rail infrastructure charging ; public service obligation ; rail charging practice ; Europe ; Improverail

    Flight Delays in Spanish Airports

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    This paper analyses the duration of flight delays at Spanish airports. To do so, several hazard models are adopted to take into account the delays observed. The results show that the most important factors are certain airport characteristics and contextual characteristics. The policy implications are derived.hazard model; flights; Spanish airports; delays; duration.

    Efficiency analysis of a congested Brazilian airport applying slots optimization control: Congonhas Airport Case

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    The current slot allocation mechanism in Brazil, based on the International Air Transport Association (IATA) rules, and its supplementary local regulation The National Civil Aviation Agency (ANAC), displays a few issues and limitations (e.g. slot misuse, allocation inefficiencies). Such issues are particularly present in the case of busy airports that works near their maximum capacity for major parts of the day. This inefficiency problem is generated because of the complexity of slot allocation added to the limited decision support available for the Brazilian system. This study focuses on the implementation of an optimal slot model, based on IATA regulations with local adaptations from ANAC at Congonhas Airport (CGH/SBSP). Final results include the reallocated slots examined within airport capacity limits and declared capacity for flights GOL 1389 and GOL 1666. This optimal solution represents an improvement in the slot allocation efficiency of 35,22% and 67,83% for flights GOL 1389 for GOL 1666 respectively. The main limitation is that the model focuses only on the availability of slots and their optimization. No consideration is given to the airport capabilities such as gate availability, baggage handling capacity and aircraft size. This leads to a less systemic analysis of the whole system

    Fairness in Slot Allocation

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    The recent interpretations of fairness in slot allocation of flights are considered as the word equity and upon these interpretations for fairness, aviation agencies as airspace administrators along with stakeholders have been applying ground delay problem procedure with ration by schedule and compression algorithms as fair distribution of slots among them in reduced capacity airports. The drawback of these approaches is that the slots to be allocated to flights are all of the equal size or duration since the flights to be assigned to slots can not be differentiated. In fact, the absence of a scientific framework of fairness in air traffic management has led to the different contradictory interpretations for it. As proposed in this study, fairness is the minimum deviation from the planned outcome in terms of time, quantity and quality under the optimum share management rule for each stakeholder. To achieve fairness in slot allocation of the airport under reduced and normal capacity, a new allocation rule of ration by fairness is proposed in which the elements of time, quantity and quality are proposed to be the original time of departure or arrival, slot size or duration, and airspace safety and preflight checklist, respectively

    Coalition Formation and Combinatorial Auctions; Applications to Self-organization and Self-management in Utility Computing

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    In this paper we propose a two-stage protocol for resource management in a hierarchically organized cloud. The first stage exploits spatial locality for the formation of coalitions of supply agents; the second stage, a combinatorial auction, is based on a modified proxy-based clock algorithm and has two phases, a clock phase and a proxy phase. The clock phase supports price discovery; in the second phase a proxy conducts multiple rounds of a combinatorial auction for the package of services requested by each client. The protocol strikes a balance between low-cost services for cloud clients and a decent profit for the service providers. We also report the results of an empirical investigation of the combinatorial auction stage of the protocol.Comment: 14 page

    Applications of stochastic modeling in air traffic management:Methods, challenges and opportunities for solving air traffic problems under uncertainty

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    In this paper we provide a wide-ranging review of the literature on stochastic modeling applications within aviation, with a particular focus on problems involving demand and capacity management and the mitigation of air traffic congestion. From an operations research perspective, the main techniques of interest include analytical queueing theory, stochastic optimal control, robust optimization and stochastic integer programming. Applications of these techniques include the prediction of operational delays at airports, pre-tactical control of aircraft departure times, dynamic control and allocation of scarce airport resources and various others. We provide a critical review of recent developments in the literature and identify promising research opportunities for stochastic modelers within air traffic management

    Improving the predictability of take-off times with Machine Learning : a case study for the Maastricht upper area control centre area of responsibility

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    The uncertainty of the take-off time is a major contribution to the loss of trajectory predictability. At present, the Estimated Take-Off Time (ETOT) for each individual flight is extracted from the Enhanced Traffic Flow Management System (ETFMS) messages, which are sent each time there is an event triggering a recalculation of the flight data by the Network Man- ager Operations Centre. However, aircraft do not always take- off at the ETOTs reported by the ETFMS due to several factors, including congestion and bad weather conditions at the departure airport, reactionary delays and air traffic flow management slot improvements. This paper presents two machine learning models that take into account several of these factors to improve the take- off time prediction of individual flights one hour before their estimated off-block time. Predictions performed by the model trained on three years of historical flight and weather data show a reduction on the take-off time prediction error of about 30% as compared to the ETOTs reported by the ETFMS.Peer ReviewedPostprint (published version

    Resource-Constrained Airline Ground Operations: Optimizing Schedule Recovery under Uncertainty

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    Die zentrale europĂ€ische Verkehrsflusssteuerung (englisch: ATFM) und Luftverkehrsgesellschaften (englisch: Airlines) verwenden unterschiedliche Paradigmen fĂŒr die Priorisierung von FlĂŒgen. WĂ€hrend ATFM jeden Flug als individuelle Einheit betrachtet, um die KapazitĂ€tsauslastung aller Sektoren zu steuern, bewerten Airlines jeden Flug als Teilabschnitt eines Flugzeugumlaufes, eines Crew-Einsatzplanes bzw. einer Passagierroute. Infolgedessen sind ATFM-Zeitfenster fĂŒr FlĂŒge in KapazitĂ€tsengpĂ€ssen oft schlecht auf die RessourcenabhĂ€ngigkeiten innerhalb eines Airline-Netzwerks abgestimmt, sodass die Luftfahrzeug-Bodenabfertigung – als Verbindungselement bzw. Bruchstelle zwischen einzelnen FlĂŒgen im Netzwerk – als Hauptverursacher primĂ€rer und reaktionĂ€rer VerspĂ€tungen in Europa gilt. Diese Dissertation schließt die LĂŒcke zwischen beiden Paradigmen, indem sie ein integriertes Optimierungsmodell fĂŒr die Flugplanwiederherstellung entwickelt. Das Modell ermöglicht Airlines die Priorisierung zwischen FlĂŒgen, die von einem ATFM-KapazitĂ€tsengpass betroffen sind, und berĂŒcksichtigt dabei die begrenzte VerfĂŒgbarkeit von Abfertigungsressourcen am Flughafen. Weiterhin werden verschiedene Methoden untersucht, um die errechneten FlugprioritĂ€ten vertraulich innerhalb von kooperativen Lösungsverfahren mit externen Stakeholdern austauschen zu können. Das integrierte Optimierungsmodell ist eine Erweiterung des Resource-Constrained Project Scheduling Problems und integriert das Bodenprozessmanagement von Luftfahrzeugen mit bestehenden AnsĂ€tzen fĂŒr die Steuerung von FlugzeugumlĂ€ufen, Crew-EinsatzplĂ€nen und Passagierrouten. Das Modell soll der Verkehrsleitzentrale einer Airline als taktische EntscheidungsunterstĂŒtzung dienen und arbeitet dabei mit einer Vorlaufzeit von mehr als zwei Stunden bis zur nĂ€chsten planmĂ€ĂŸigen Verkehrsspitze. Systemimmanente Unsicherheiten ĂŒber Prozessabweichungen und mögliche zukĂŒnftige Störungen werden in der Optimierung in Form von stochastischen Prozesszeiten und mittels des neu-entwickelten Konzeptes stochastischer VerspĂ€tungskostenfunktionen berĂŒcksichtigt. Diese Funktionen schĂ€tzen die Kosten der VerspĂ€tungsausbreitung im Airline-Netzwerk flugspezifisch auf der Basis historischer Betriebsdaten ab, sodass knappe Abfertigungsressourcen am Drehkreuz der Airline den kritischsten FlugzeugumlĂ€ufen zugeordnet werden können. Das Modell wird innerhalb einer Fallstudie angewendet, um die taktischen Kosten einer Airline in Folge von verschiedenen Flugplanstörungen zu minimieren. Die Analyseergebnisse zeigen, dass die optimale Lösung sehr sensitiv in Bezug auf die Art, den Umfang und die IntensitĂ€t einer Störung reagiert und es folglich keine allgemeingĂŒltige optimale Flugplanwiederherstellung fĂŒr verschiedene Störungen gibt. Umso dringender wird der Einsatz eines flexiblen und effizienten Optimierungsverfahrens empfohlen, welches die komplexen RessourcenabhĂ€ngigkeiten innerhalb eines Airline-Netzwerks berĂŒcksichtigt und kontextspezifische Lösungen generiert. Um die Effizienz eines solchen Optimierungsverfahrens zu bestimmen, sollte das damit gewonnene Steuerungspotenzial im Vergleich zu aktuell genutzten Verfahren ĂŒber einen lĂ€ngeren Zeitraum untersucht werden. Aus den in dieser Dissertation analysierten Störungsszenarien kann geschlussfolgert werden, dass die flexible Standplatzvergabe, Passagier-Direkttransporte, beschleunigte Abfertigungsverfahren und die gezielte VerspĂ€tung von AbflĂŒgen sehr gute Steuerungsoptionen sind und wĂ€hrend 95 Prozent der Saison Anwendung finden könnten, um geringe bis mittlere VerspĂ€tungen von EinzelflĂŒgen effizient aufzulösen. Bei Störungen, die zu hohen VerspĂ€tungen im gesamten Airline-Netzwerk fĂŒhren, ist eine vollstĂ€ndige Integration aller in Betracht gezogenen Steuerungsoptionen erforderlich, um eine erhebliche Reduzierung der taktischen Kosten zu erreichen. Dabei ist insbesondere die Möglichkeit, Ankunfts- und Abflugzeitfenster zu tauschen, von hoher Bedeutung fĂŒr eine Airline, um die ihr zugewiesenen ATFM-VerspĂ€tungen auf die FlugzeugumlĂ€ufe zu verteilen, welche die geringsten EinschrĂ€nkungen im weiteren Tagesverlauf aufweisen. Die BerĂŒcksichtigung von Unsicherheiten im nachgelagerten Airline-Netzwerk zeigt, dass eine Optimierung auf Basis deterministischer VerspĂ€tungskosten die taktischen Kosten fĂŒr eine Airline ĂŒberschĂ€tzen kann. Die optimale Flugplanwiederherstellung auf Basis stochastischer VerspĂ€tungskosten unterscheidet sich deutlich von der deterministischen Lösung und fĂŒhrt zu weniger Passagierumbuchungen am Drehkreuz. DarĂŒber hinaus ist das vorgeschlagene Modell in der Lage, FlugprioritĂ€ten und Airline-interne Kostenwerte fĂŒr ein zugewiesenes ATFM-Zeitfenster zu bestimmen. Die errechneten FlugprioritĂ€ten können dabei vertraulich in Form von optimalen VerspĂ€tungszeitfenstern pro Flug an das ATFM ĂŒbermittelt werden, wĂ€hrend die Definition von internen Kostenwerten fĂŒr ATFM-Zeitfenster die Entwicklung von kĂŒnftigen Handelsmechanismen zwischen Airlines unterstĂŒtzen kann.:1 Introduction 2 Status Quo on Airline Operations Management 3 Schedule Recovery Optimization Approach with Constrained Resources 4 Implementation and Application 5 Case Study Analysis 6 ConclusionsAir Traffic Flow Management (ATFM) and airlines use different paradigms for the prioritisation of flights. While ATFM regards each flight as individual entity when it controls sector capacity utilization, airlines evaluate each flight as part of an aircraft rotation, crew pairing and passenger itinerary. As a result, ATFM slot regulations during capacity constraints are poorly coordinated with the resource interdependencies within an airline network, such that the aircraft turnaround -- as the connecting element or breaking point between individual flights in an airline schedule -- is the major contributor to primary and reactionary delays in Europe. This dissertation bridges the gap between both paradigms by developing an integrated schedule recovery model that enables airlines to define their optimal flight priorities for schedule disturbances arising from ATFM capacity constraints. These priorities consider constrained airport resources and different methods are studied how to communicate them confidentially to external stakeholders for the usage in collaborative solutions, such as the assignment of reserve resources or ATFM slot swapping. The integrated schedule recovery model is an extension of the Resource-Constrained Project Scheduling Problem and integrates aircraft turnaround operations with existing approaches for aircraft, crew and passenger recovery. The model is supposed to provide tactical decision support for airline operations controllers at look-ahead times of more than two hours prior to a scheduled hub bank. System-inherent uncertainties about process deviations and potential future disruptions are incorporated into the optimization via stochastic turnaround process times and the novel concept of stochastic delay cost functions. These functions estimate the costs of delay propagation and derive flight-specific downstream recovery capacities from historical operations data, such that scarce resources at the hub airport can be allocated to the most critical turnarounds. The model is applied to the case study of a network carrier that aims at minimizing its tactical costs from several disturbance scenarios. The case study analysis reveals that optimal recovery solutions are very sensitive to the type, scope and intensity of a disturbance, such that there is neither a general optimal solution for different types of disturbance nor for disturbances of the same kind. Thus, airlines require a flexible and efficient optimization method, which considers the complex interdependencies among their constrained resources and generates context-specific solutions. To determine the efficiency of such an optimization method, its achieved network resilience should be studied in comparison to current procedures over longer periods of operation. For the sample of analysed scenarios in this dissertation, it can be concluded that stand reallocation, ramp direct services, quick-turnaround procedures and flight retiming are very efficient recovery options when only a few flights obtain low and medium delays, i.e., 95% of the season. For disturbances which induce high delay into the entire airline network, a full integration of all considered recovery options is required to achieve a substantial reduction of tactical costs. Thereby, especially arrival and departure slot swapping are valuable options for the airline to redistribute its assigned ATFM delays onto those aircraft that have the least critical constraints in their downstream rotations. The consideration of uncertainties in the downstream airline network reveals that an optimization based on deterministic delay costs may overestimate the tactical costs for the airline. Optimal recovery solutions based on stochastic delay costs differ significantly from the deterministic approach and are observed to result in less passenger rebooking at the hub airport. Furthermore, the proposed schedule recovery model is able to define flight priorities and internal slot values for the airline. Results show that the priorities can be communicated confidentially to ATFM by using the concept of 'Flight Delay Margins', while slot values may support future inter-airline slot trading mechanisms.:1 Introduction 2 Status Quo on Airline Operations Management 3 Schedule Recovery Optimization Approach with Constrained Resources 4 Implementation and Application 5 Case Study Analysis 6 Conclusion

    Modeling Airline Frequency Competition for Airport Congestion Mitigation

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    Demand often exceeds capacity at congested airports. Airline frequency competition is partially responsible for the growing demand for airport resources. We propose a game-theoretic model for airline frequency competition under slot constraints. The model is solved to obtain a Nash equilibrium using a successive optimizations approach, wherein individual optimizations are performed using a dynamic programming-based technique. The model predictions are validated against actual frequency data, with the results indicating a close fit to reality. We use the model to evaluate different strategic slot allocation schemes from the perspectives of the airlines and the passengers. The most significant result of this research shows that a small reduction in the total number of allocated slots translates into a substantial reduction in flight and passenger delays and also a considerable improvement in airlines' profits
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