MobilityGPT: Enhanced Human Mobility Modeling with a GPT model

Fuente: arXiv
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Auteurs principaux: Haydari, Ammar, Chen, Dongjie, Lai, Zhengfeng, Zhang, Michael, Chuah, Chen-Nee
Format: Preprint
Publié: 2024
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author Haydari, Ammar
Chen, Dongjie
Lai, Zhengfeng
Zhang, Michael
Chuah, Chen-Nee
author_facet Haydari, Ammar
Chen, Dongjie
Lai, Zhengfeng
Zhang, Michael
Chuah, Chen-Nee
contents Generative models have shown promising results in capturing human mobility characteristics and generating synthetic trajectories. However, it remains challenging to ensure that the generated geospatial mobility data is semantically realistic, including consistent location sequences, and reflects real-world characteristics, such as constraining on geospatial limits. We reformat human mobility modeling as an autoregressive generation task to address these issues, leveraging the Generative Pre-trained Transformer (GPT) architecture. To ensure its controllable generation to alleviate the above challenges, we propose a geospatially-aware generative model, MobilityGPT. We propose a gravity-based sampling method to train a transformer for semantic sequence similarity. Then, we constrained the training process via a road connectivity matrix that provides the connectivity of sequences in trajectory generation, thereby keeping generated trajectories in geospatial limits. Lastly, we proposed to construct a preference dataset for fine-tuning MobilityGPT via Reinforcement Learning from Trajectory Feedback (RLTF) mechanism, which minimizes the travel distance between training and the synthetically generated trajectories. Experiments on real-world datasets demonstrate MobilityGPT's superior performance over state-of-the-art methods in generating high-quality mobility trajectories that are closest to real data in terms of origin-destination similarity, trip length, travel radius, link, and gravity distributions. We release the source code and reference links to datasets at https://github.com/ammarhydr/MobilityGPT.
format Preprint
id arxiv_https___arxiv_org_abs_2402_03264
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle MobilityGPT: Enhanced Human Mobility Modeling with a GPT model
Haydari, Ammar
Chen, Dongjie
Lai, Zhengfeng
Zhang, Michael
Chuah, Chen-Nee
Machine Learning
Generative models have shown promising results in capturing human mobility characteristics and generating synthetic trajectories. However, it remains challenging to ensure that the generated geospatial mobility data is semantically realistic, including consistent location sequences, and reflects real-world characteristics, such as constraining on geospatial limits. We reformat human mobility modeling as an autoregressive generation task to address these issues, leveraging the Generative Pre-trained Transformer (GPT) architecture. To ensure its controllable generation to alleviate the above challenges, we propose a geospatially-aware generative model, MobilityGPT. We propose a gravity-based sampling method to train a transformer for semantic sequence similarity. Then, we constrained the training process via a road connectivity matrix that provides the connectivity of sequences in trajectory generation, thereby keeping generated trajectories in geospatial limits. Lastly, we proposed to construct a preference dataset for fine-tuning MobilityGPT via Reinforcement Learning from Trajectory Feedback (RLTF) mechanism, which minimizes the travel distance between training and the synthetically generated trajectories. Experiments on real-world datasets demonstrate MobilityGPT's superior performance over state-of-the-art methods in generating high-quality mobility trajectories that are closest to real data in terms of origin-destination similarity, trip length, travel radius, link, and gravity distributions. We release the source code and reference links to datasets at https://github.com/ammarhydr/MobilityGPT.
title MobilityGPT: Enhanced Human Mobility Modeling with a GPT model
topic Machine Learning
url https://arxiv.org/abs/2402.03264