Flight planning, a pivotal challenge in the airline industry, strives to achieve economic and flexible scheduling of airplanes to serve designated flight itineraries. As the demand for air transportation soars, traditional planning methods can be inefficient in managing large-scale flights. Thus, we introduce Swift, a data-driven system tailored to enhance the scalability and effectiveness of flight planning. Swift primarily employs the bipartite graph model to derive optimal and economic flight plans for airlines. Our method not only minimizes the number of required planes but also ensures a balanced workload across these planes. Furthermore, Swift offers the capability of dynamic updates to flight plans in response to unexpected incidents at airports, such as bad weather conditions. Besides, Swift incorporates other functionalities like predicting future flight demand and monitoring real-time flight trajectories. Conference participants can interact with this system and explore our flight planning solution in real-world scenarios.

Spatiotemporal applications such as taxi order dispatching and warehouse task scheduling depend critically on the algorithms for operational efficiency. However, the inherent dynamic nature of these applications presents challenges in algorithm design. The growth of mobility services has facilitated the collection of extensive spatiotemporal data, which in turn prompted algorithm designers to use data-driven methods. Reinforcement learning (RL), recognized for its strong performance and suitability for spatiotemporal contexts, has garnered considerable research interest. Despite their potential, RL algorithms necessitate the use of a simulator for both training and validation purposes. However, no specific simulation system has been developed for spatiotemporal algorithm design. This vacancy hinders the progress of spatiotemporal algorithm designers. In this demo, we build a system called Data-driven Spatiotemporal Simulator (DSS), hoping to bring convenience for spatiotemporal algorithm designers. DSS is adept at handling problems related to taxi order dispatching and warehouse task scheduling and possesses the versatility to be expanded for other user-defined scenarios. The system includes visualization modules that offer insightful panels, alongside developer tools designed to streamline the development process. This enables designers to efficiently craft, evaluate, and refine their algorithms, potentially accelerating innovation in spatiotemporal application development.

Shared mobility leverages under-utilized vehicles to offer on-demand transport services by sharing vehicles among users. It strives to match supply with demand via a series of data-intensive operations such as supply prediction and task assignment. However, its full potential is often compromised in practice as most shared mobility platforms operate in isolation, leading to sub-optimal resource utilization. In this demonstration, we advocate a federated approach to shared mobility, which enhances its effectiveness by enabling optimizations across platforms while retaining their autonomy. We develop privacy-preserving operators and incentive mechanisms dedicated to supply prediction and task assignment in shared mobility and implement generic interfaces that support diverse prediction and assignment algorithms. We showcase the shared mobility system with real-world ride-hailing applications.

Federated Trajectory Matching (FTM) is gaining increasing importance in big trajectory data analytics, supporting diverse applications such as public health, law enforcement, and emergency response. FTM retrieves trajectories that match with a query trajectory from a large-scale trajectory database, while safeguarding the privacy of trajectories in both the query and the database. A naive solution to FTM is to process the query through Secure Multi-party Computation (SMC) across the entire database, which is inherently secure yet inevitably slow due to the massive secure operations. A promising acceleration strategy is to filter irrelevant trajectories from the database based on the query, thus reducing the SMC operations. However, a key challenge is how to publish the query in a way that both preserves privacy and enables efficient trajectory filtering. In this paper, we design${\sf GIST}$, a novel framework for efficient Federated Trajectory Matching.${\sf GIST}$is grounded in Geo-Indistinguishability, a privacy criterion dedicated to locations. It employs a new privacy mechanism for the query that facilitates efficient trajectory filtering. We theoretically prove the privacy guarantee of the mechanism and the accuracy of the filtering strategy of${\sf GIST}$. Extensive evaluations on five real datasets show that${\sf GIST}$is significantly faster and incurs up to 2 orders of magnitude lower communication cost than the state-of-the-arts.

Skyline is a primitive operation in multi-objective decision applications and there is a growing demand to support such operations over a data federation, where the entire dataset is separately held by multiple data providers (a.k.a., silos). Data federations notably increase the amount of data available for data-intensive applications such as commercial recommendation and location based services. Yet they also challenge the conventional implementation of skyline queries because the raw data cannot be shared within the federation and the secure computation cross silos can be two or three orders of magnitude slower than plaintext computation. These constraints render existing solutions inefficient on data federation. In this work, we propose a novel local dominance based framework for efficient skyline queries over a vertical data federation. We decompose the skyline query into plaintext local dominance computations and secure result aggregations, which can perform as many computations in plaintext as possible without compromising security. We further propose a dedicate private set intersection based algorithm to accelerate the query processing. Extensive evaluations on both synthetic and real-world datasets show that compared with general-purpose secure multi-party computation techniques, our solutions reduce the time cost by up to 35.4× and communication cost by two orders of magnitude respectively.

kNN is a fundamental query in various location based services such as POI recommendation and ride planning. There is an increasing demand to scale such services by querying over a data federation, where the entire dataset is distributedly held by multiple data providers (a.k.a., silos), and each silo keeps its data partition private. However, it is challenging to provide secure kNN queries over a large-scale data federation. Prior secure kNN queries can be are highly inefficient if performed cross silos because they involve excessive secure distance operations, which can be two or three orders of magnitude slower than the corresponding plaintext operations. In this work, we propose a novel threshold based framework for efficient kNN queries over a spatial data federation. The key idea is to rewrite excessive secure distance computations as light-weight secure operations. We further propose an adaptive threshold algorithm to reduce the secure communication rounds and accelerate the query processing. Extensive evaluations on both synthetic and real-world datasets show that compared with the state-of-the-art secure kNN querying methods, our solutions reduce the time cost by up to 104.1 times and communication cost by three orders of magnitude.