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In the UAV-based urban delivery setting, the battery capacity serves as one of the key factors affecting the delivery range of drones. For a typical multi-rotor unmanned aerial vehicle (UAV), the maximum effective working range of a lithium battery for a single flight leg is approximately 20 km. In practice, the lithium battery is replaced each time the UAV completes a delivery, even though the remaining power of the replaced lithium battery is still capable of supporting the following flight legs. Therefore, the one-order-one-swapping strategy significantly brings down the battery utilisation as well as the efficiency of the delivery system. In the present paper, the UAV-based delivery problem with battery swapping decision is considered, where multiple en route pickup and deliveries are allowed. To obtain optimal decisions in terms of flight route, time and location of each battery swapping, a branch-and-price-and-cut algorithm is introduced. First we formulate this problem as a mixed integer linear programming (MILP) model, and then decompose it into a master problem and a pricing sub-problem, where the master problem is considered as a set covering model, and the sub-problem as an elementary shortest path problem with resource constraints (ESPPRC). To speed up the process of column generation, efficient heuristics are also integrated to provide basic feasible solutions. In the pricing sub-problem, a combination of heuristic algorithm and dynamic programming is implemented to improve the computational efficiency. In the numerical experiments, the proposed algorithm is tested on various scales of UAV-based urban delivery instances, the performance of which is analysed and compared with the off-the-shelf commercial solver. [ABSTRACT FROM AUTHOR]

A NOtice To AirMen (NOTAM) contains important flight route related information. To search and filter them, NOTAMs are grouped into categories called QCodes. In this paper, we develop a tool to predict, with some explanations, a Qcode for a NOTAM. We present a way to extend the interpretable binary classification using column generation proposed in Dash, Gunluk, and Wei (2018) to a multiclass text classification method. We describe the techniques used to tackle the issues related to one-vs-rest classification, such as multiple outputs and class imbalances. Furthermore, we introduce some heuristics, including the use of a CP-SAT solver for the subproblems, to reduce the training time. Finally, we show that our approach compares favorably with state-of-the-art machine learning algorithms like Linear SVM and small neural networks while adding the needed interpretability component. [ABSTRACT FROM AUTHOR]

The overlap between edge computing and unmanned aerial systems enables Unmanned Aerial Vehicles (UAV) to quickly offload image processing tasks onto edge devices, avoiding the transmission of images over long distances. To improve the speed and efficiency of UAV image stitching in an edge computing environment, this paper proposes an adaptive UAV image parallel stitching algorithm in an edge computing environment. The algorithm incorporates both route-based parallel processing and inverted binary tree-based parallel processing, dividing the image stitching task into multiple processes and allocating them to different cores based on the CPU core count, number of flight routes, and number of images, thereby enhancing computational efficiency in edge scenarios. The experimental results indicate that, when the number of flight routes is greater than or equal to the number of CPUs, the adaptive algorithm will employ the more efficient route parallelism. Conversely, when the number of flight routes is less than the number of CPUs, the efficiency of inverted binary tree parallelism is higher. In the same experimental environment and dataset, the adaptive image stitching algorithm demonstrates an efficiency improvement of approximately 2–10 times compared to other algorithms, with no significant degradation in image quality. This demonstrates that in edge environments, the utilization of multi-threaded adaptive route and inverted binary tree-based parallel approaches can effectively harness the computing resources of edge devices, significantly improving the stitching speed of UAV images and providing technical support for rapid real-time monitoring by UAV. [ABSTRACT FROM AUTHOR]

This paper examines the impact of different public policies on air connectivity in remote regions. In particular, it estimates price and supply equations using route-level data for several countries around the world that have implemented route-based policies (public service obligations, traffic distribution rules), airline-based policies (state-owned airline) or passenger-based policies (discounts to residents). It is found that policies generally achieve affordable prices and high frequency levels in protected routes in comparison with unprotected routes. However, the implementation of these policies may also be associated with some costs. [ABSTRACT FROM AUTHOR]

Mainland China's involvement in African aviation is qualitatively and quantitatively different to participation by European, American and Persian Gulf countries. This paper contextualizes and outlines the Chinese emphasis on airport finance, design and construction on the continent; Chinese airline service is secondary (and Africa-dominated), and joint operational ventures are in their infancy. The prominence of one foreign country in airport provision in Africa, the recency of Chinese involvement, its pace, its price-tag, its conditionality, and minimal concurrent Chinese airline route building to and from Africa, fix the novelty and perhaps significance of Chinese involvement in African aviation. [ABSTRACT FROM AUTHOR]

In this paper, a game-theoretic framework is applied in order to model the competition scenario between high-speed rail (HSR) and airlines in the Indian context and assess the impact of speed and passengers' characteristics on the equilibrium of the game. The competition is modelled in terms of the fare and frequency offered by the operators to maximize their profits. The speed of HSR is taken as an additional strategic variable in the game with three levels of high speed: low, medium, high. A three-stage game is formulated with the entrant playing its speed strategy in the first stage followed by optimal fare and frequency selection by both the modes. Passengers are considered to be heterogeneous in nature by assuming a continuous distribution of the value of time. Numerical simulations indicate that the dominant strategy for airlines and HSR is based on accommodation and medium speed, respectively. [ABSTRACT FROM AUTHOR]

The factors accounting for the significant increase in new routes in the European air transport market in the period 2002–13 are examined. Data for 259 airports with more 250,000 annual passengers are used. The analysis reveals that low-cost airlines extended the benefits of air connectivity to regions with relatively low rates of gross domestic product per capita, increasing the geographical coverage of small or medium-sized airports. New routes are more likely when a tourist destination is an endpoint and are less likely in competitive environments. Finally, different opening patterns by low cost and network airlines are found. [ABSTRACT FROM AUTHOR]

We consider the problem of covering a set of shipments in a logistic distribution network with a fleet of aircraft. The aim is to cover as many shipments as possible, while also minimizing the number of aircraft utilized for that purpose. We develop an integer programming model and a branch and price solution algorithm for this problem. The proposed methodology utilizes a master problem that covers the maximum possible number of shipments using a given set of aircraft-routes, and a column generation subproblem that generates cost-effective aircraft-routes which are fed into the master problem. We describe the proposed methodology, illustrating how it can be modified in order to accommodate several problem extensions. We also investigate how its efficiency is affected by various key design parameters. We conclude with extensive experimental results demonstrating its computational performance. [ABSTRACT FROM PUBLISHER]